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Sample records for bed retorting process

  1. Cyclone oil shale retorting concept. [Use it all retorting process

    Energy Technology Data Exchange (ETDEWEB)

    Harak, A.E.; Little, W.E.; Faulders, C.R.

    1984-04-01

    A new concept for above-ground retorting of oil shale was disclosed by A.E. Harak in US Patent No. 4,340,463, dated July 20, 1982, and assigned to the US Department of Energy. This patent titled System for Utilizing Oil Shale Fines, describes a process wherein oil shale fines of one-half inch diameter and less are pyrolyzed in an entrained-flow reactor using hot gas from a cyclone combustor. Spent shale and supplemental fuel are burned at slagging conditions in this combustor. Because of fines utilization, the designation Use It All Retorting Process (UIARP) has been adopted. A preliminary process engineering design of the UIARP, analytical tests on six samples of raw oil shale, and a preliminary technical and economic evaluation of the process were performed. The results of these investigations are summarized in this report. The patent description is included. It was concluded that such changes as deleting air preheating in the slag quench and replacing the condenser with a quench-oil scrubber are recognized as being essential. The addition of an entrained flow raw shale preheater ahead of the cyclone retort is probably required, but final acceptance is felt to be contingent on some verification that adequate reaction time cannot be obtained with only the cyclone, or possibly some other twin-cyclone configuration. Sufficient raw shale preheating could probably be done more simply in another manner, perhaps in a screw conveyor shale transporting system. Results of the technical and economic evaluations of Jacobs Engineering indicate that further investigation of the UIARP is definitely worthwhile. The projected capital and operating costs are competitive with costs of other processes as long as electric power generation and sales are part of the processing facility.

  2. Fluidized-bed retorting of Colorado oil shale: Topical report. [None

    Energy Technology Data Exchange (ETDEWEB)

    Albulescu, P.; Mazzella, G.

    1987-06-01

    In support of the research program in converting oil shale into useful forms of energy, the US Department of Energy is developing systems models of oil shale processing plants. These models will be used to project the most attractive combination of process alternatives and identify future direction for R and D efforts. With the objective of providing technical and economic input for such systems models, Foster Wheeler was contracted to develop conceptual designs and cost estimates for commercial scale processing plants to produce syncrude from oil shales via various routes. This topical report summarizes the conceptual design of an integrated oil shale processing plant based on fluidized bed retorting of Colorado oil shale. The plant has a nominal capacity of 50,000 barrels per operating day of syncrude product, derived from oil shale feed having a Fischer Assay of 30 gallons per ton. The scope of the plant encompasses a grassroots facility which receives run of the mine oil shale, delivers product oil to storage, and disposes of the processed spent shale. In addition to oil shale feed, the battery limits input includes raw water, electric power, and natural gas to support plant operations. Design of the individual processing units was based on non-confidential information derived from published literature sources and supplemented by input from selected process licensors. The integrated plant design is described in terms of the individual process units and plant support systems. The estimated total plant investment is similarly detailed by plant section and an estimate of the annual operating requirements and costs is provided. In addition, the process design assumptions and uncertainties are documented and recommendations for process alternatives, which could improve the overall plant economics, are discussed.

  3. Investigation of the geokinetics horizontal in situ oil shale retorting process. Quarterly report, April, May, June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.L.

    1980-08-01

    The Retort No. 18 burn was terminated on May 11, 1980. A total of 5547 barrels of shale oil or 46 percent of in-place resource was recovered from the retort. The EPA-DOE/LETC post-burn core sampling program is underway on Retort No. 16. Eleven core holes (of 18 planned) have been completed to date. Preliminary results indicate excellent core recovery has been achieved. Recovery of 702 ft of core was accomplished. The Prevention of Significant Deterioration (PSD) permit application was submitted to the EPA regional office in Denver for review by EPA and Utah air quality officials. The application for an Underground Injection Control (UIC) permit to authorize GKI to inject retort wastewater into the Mesa Verde Formation is being processed by the State of Utah. A hearing before the Board of Oil, Gas and Mining is scheduled in Salt Lake City, Utah, for July 22, 1980. Re-entry drilling on Retort No. 24 is progressing and placement of surface equipment is underway. Retort No. 25 blasthole drilling was completed and blast preparations are ongoing. Retort No. 25 will be blasted on July 18, 1980. The retort will be similar to Retort No. 24, with improvements in blasthole loading and detonation. US Patent No. 4,205,610 was assigned to GKI for a shale oil recovery process. Rocky Mountain Energy Company (RME) is evaluating oil shale holdings in Wyoming for application of the GKI process there.

  4. Investigation of the geokinetics horizontal in situ oil shale retorting process. Quarterly report, October, November, December 1983

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, K.B.

    1984-03-01

    Retort No. 27 was ignited on August 11, 1983 and by December 31 had completed 139 days of operation and produced 11,420 barrels of oil. Retort No. 28 was ignited on October 18, 1983 and on December 31 had completed 74 days of operation and produced 5,285 barrels of oil. The off-gas processing plants for the two retorts was completed and put through a shakedown run. Concentration levels of H/sub 2/S and NH/sub 3/ in the retort off gas did not warrant plant operation in the fourth quarter. Environmental studies are reported.

  5. Energy and process substitution in the frozen-food industry: geothermal energy and the retortable pouch

    Energy Technology Data Exchange (ETDEWEB)

    Stern, M.W.; Hanemann, W.M.; Eckhouse, K.

    1981-12-01

    An assessment is made of the possibilities of using geothermal energy and an aseptic retortable pouch in the food processing industry. The focus of the study is on the production of frozen broccoli in the Imperial Valley, California. Background information on the current status of the frozen food industry, the nature of geothermal energy as a potential substitute for conventional fossil fuels, and the engineering details of the retortable pouch process are covered. The analytical methodology by which the energy and process substitution were evaluated is described. A four-way comparison of the economics of the frozen product versus the pouched product and conventional fossil fuels versus geothermal energy was performed. A sensitivity analysis for the energy substitution was made and results are given. Results are summarized. (MCW)

  6. Optimization of processing conditions for the sterilization of retorted short-rib patties using the response surface methodology.

    Science.gov (United States)

    Choi, Su-Hee; Cheigh, Chan-Ick; Chung, Myong-Soo

    2013-05-01

    The aim of this study was to determine the optimum sterilization conditions for short-rib patties in retort trays by considering microbiological safety, nutritive value, sensory characteristics, and textural properties. In total, 27 sterilization conditions with various temperatures, times, and processing methods were tested using a 3(3) factorial design. The response surface methodology (RSM) and contour analysis were applied to find the optimum sterilization conditions for the patties. Quality attributes were significantly affected by the sterilization temperature, time, and processing method. From RSM and contour analysis, the final optimum sterilization condition of the patties that simultaneously satisfied all specifications was determined to be 119.4°C for 18.55min using a water-cascading rotary mode. The findings of the present study suggest that using optimized sterilization conditions will improve the microbial safety, sensory attributes, and nutritional retention for retorted short-rib patties.

  7. Oil shale project: run summary for small retort Run S-11

    Energy Technology Data Exchange (ETDEWEB)

    Sandholtz, W.A.; Ackerman, F.J.; Bierman, A.; Kaehler, M.; Raley, J.; Laswell, B.H.; Tripp, L.J. (eds.)

    1978-06-01

    Results are reported on retort run S-11 conducted to observe the effects of combustion retorting with undiluted air at relatively rapid burn (retorting) rates and to provide a base case for retorting small uniform shale (Anvil Points master batch -2.5 +- 1.3 cm) with undiluted air. It was found that a 0.6 m/sup 3//m/sup 2//minute superficial gas velocity gave an average rate of propagation of the combustion peak of about 2.7 m/day and an average maximum temperature on the centerline of the rubble bed of 1003/sup 0/C. Oil yield was 93 percent of Fischer assay. For small uniform shale particles (-2.5 + 1.3 cm) it is concluded that only small losses in yield (92 percent vs 96 percent in Run S-10) result from high retorting rates. Maximum temperature considerations preclude going to higher rates with undiluted air. Without diluent, a larger air flux would give excessive bed temperatures causing rock melting and potential closure to gas flow. In experimental retorts, another problem of excessive temperatures is potential damage to metal walls and in-situ sensors. No advantage is seen to using recycled off-gas as a combustion gas diluent. Inert diluents (e.g. nitrogen or steam) may be necessary for process control, but the fuel values in the off-gas should best be used for energy recovery rather than burned in the retort during recycle. Another consideration from model calculations is that the use of recycle gas containing fuel components retards the retorting rate and so is undesirable. No further recycle experiments are planned as the results of this run proved satisfactory.

  8. Environmental research plan for the Geokinetics Inc. investigation of the horizontal in situ oil shale retorting process

    Energy Technology Data Exchange (ETDEWEB)

    Spradlin, H.K.L.; Hutchinson, D.L.; Mankowski, S.G.

    1979-11-30

    The development of a horizontal in-situ retorting process may have significant impacts upon valuable environmental resources. A research program has been developed to identify, assess, and minimize the adverse environmental impacts which may result. The goals are to: describe the environment as it existed prior to disturbance; determine the nature and extent of the changes; develop and implement measures to minimize the adverse impacts; develop and implement reclamation procedures which will return the affected land to its original level; and coordinate measures to protect the health and safety of persons and animals which may be affected by the activities. Specific research areas are outlined. These include atmospheric, hydrologic, terrestrial ecology, and social/economic research. (DMC)

  9. Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters.

    Science.gov (United States)

    Han, Xiangxin; Jiang, Xiumin; Cui, Zhigang; Liu, Jianguo; Yan, Junwei

    2010-03-15

    Shale char, formed in retort furnaces of oil shale, is classified as a dangerous waste containing several toxic compounds. In order to retort oil shale to produce shale oil as well as treat shale char efficiently and in an environmentally friendly way, a novel kind of comprehensive utilization system was developed to use oil shale for shale oil production, electricity generation (shale char fired) and the extensive application of oil shale ash. For exploring the combustion properties of shale char further, in this paper organic matters within shale chars obtained under different retorting conditions were extracted and identified using a gas chromatography-mass spectrometry (GC-MS) method. Subsequently, the effects of retorting factors, including retorting temperature, residence time, particle size and heating rate, were analyzed in detail. As a result, a retorting condition with a retorting temperature of 460-490 degrees C, residence time of circulating fluidized bed technology with fractional combustion.

  10. Oil shale mining cost analysis. Volume I. Surface retorting process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Resnick, B.S.; English, L.M.; Metz, R.D.; Lewis, A.G.

    1981-01-01

    An Oil Shale Mining Economic Model (OSMEM) was developed and executed for mining scenarios representative of commercially feasible mining operations. Mining systems were evaluated for candidate sites in the Piceance Creek Basin. Mining methods selected included: (1) room-and-pillar; (2) chamber-and-pillar, with spent shale backfilling; (3) sublevel stopping; and (4) sublevel stopping, with spent shale backfilling. Mines were designed to extract oil shale resources to support a 50,000 barrels-per-day surface processing facility. Costs developed for each mining scenario included all capital and operating expenses associated with the underground mining methods. Parametric and sensitivity analyses were performed to determine the sensitivity of mining cost to changes in capital cost, operating cost, return on investment, and cost escalation.

  11. Minimum bed parameters for in situ processing of oil shale. Third quarterly report, April 1-June 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Tyner, C. E.

    1980-11-01

    Oil shale retort runs 028 (16% void) and 029 (7% void), composed of competent shale blocks plus shale rubble, were completed. Retort 028, processed with air at a flux of 0.017 kg/sub air//m/sup 2/ /sub shale/.second, had peak temperatures of 700/sup 0/C, a retorting rate of 1.1 m/day, and a yield of 82% FA. Retort 029, processed with air at a flux of 0.027 kg/sub air//m/sup 2//sub shale/.second, had peak temperatures of 750/sup 0/C, a retorting rate of 1.6 m/day, and a yield of 75% FA. Comparisons of retort model calculations with experimental data from previous retort run 027 (16% void, air flux of .029 kg/sub air//m/sup 2//sub shale/.second were good; observed experimental yield was 95% FA, calculated yield, 92.8%; experimental retorting rates varied from 9.5 to 8.9 cm/h, calculated rates from 10.3 to 10.0 cm/h; observed local heating rates ranged from 29 to 14/sup 0/C/h, calculated heating rates from 20 to 16/sup 0/C/h; and observed peak temperatures ranged from 815 to 825/sup 0/C, calculated from 820 to 825/sup 0/C.

  12. 牛蒡花生软罐头的加工工艺%Study on Processing Technology of Arctium lappa L.and Peanut Retort Pouch

    Institute of Scientific and Technical Information of China (English)

    曹雪慧; 王奔

    2011-01-01

    Using Arctium lappa L. and peanut as materials, the processing technology of retort pouch is studied.The results show that the better color protective condition is immersing Arctium lappa L. in 0.5% of citrate, 1.5% of salt, and 0.2% of CaCl2. The optimal formula is consisted of 1.5% of sucrose, 0.2% of monosodium glutamate,3% of salt, and 1.2% of yellow wine based on the orthogonal test. The Arctium lappa L and peanut retort pouch with rich nutrition and unique taste can be achieved after being sterilized 10′-30′- 10′/121℃ and cooling at reverse -pressure at 0.12MPa.%以牛蒡和花生为原料,对软罐头生产的工艺进行研究,结果表明:采用柠檬酸0.5%、食盐1.5%、CaCl20.2%的复合护色剂对牛蒡有较好护色效果,通过正交试验得出最佳的汤汁配比为白砂糖1.5%,味精0.2%,食盐3%,黄酒1.2%,经10′-30′-10′/121℃,反压0.12 MPa杀菌处理后,可生产出营养丰富,口感独特的牛蒡花生软罐头.

  13. Oil shale project run summary for small retort Run S-10

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, F.J.; Sandholtz, W.A.; Raley, J.H.; Laswell, B.H. (eds.)

    1978-06-01

    A combustion run using sidewall heaters to control heat loss and computer control to set heater power were conducted to study the effectiveness of the heater control system, compare results with a one-dimensional retort model when radial heat loss is not significant, and determine effects of recycling off-gas to the retort (by comparison with future runs). It is concluded that adequate simulation of in-situ processing in laboratory retorts requires control of heat losses. (JRD)

  14. Fluidized-bed reactors processes and operating conditions

    CERN Document Server

    Yates, John G

    2016-01-01

    The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.

  15. Modelling the bed characteristics in fluidised-beds for top-spray coating processes

    Institute of Scientific and Technical Information of China (English)

    Mike Vanderroost; Frederik Ronsse; Koen Dewettinck; Jan G.Pieters

    2012-01-01

    A particle sub-model describing the bed characteristics of a bubbling fluidised bed is presented.Atomisation air,applied at high pressures via a nozzle positioned above the bed for s pray formation,is incorporated in the model since its presence has a profound influence on the bed characteristics,though the spray itself is not yet considered.A particle sub-model is developed using well-known empirical relations for particle drag force,bubble growth and velocity and particle distribution above the fluidised-bed surface.Simple but effective assumptions and abstractions were made concerning bubble distribution,particle ejection at the bed surface and the behaviour of atomisation air flow upon impacting the surface of a bubbling fluidised bed.The model was shown to be capable of predicting the fluidised bed characteristics in terms of bed heights,voidage distributions and solids volume fractions with good accuracy in less than 5 min of calculation time on a regular desktop PC.It is therefore suitable for incorporation into general process control models aimed at dynamic control for process efficiency and product quality in top-spray fluidised bed coating processes.

  16. Measurement of powder bed density in powder bed fusion additive manufacturing processes

    Science.gov (United States)

    Jacob, G.; Donmez, A.; Slotwinski, J.; Moylan, S.

    2016-11-01

    Many factors influence the performance of additive manufacturing (AM) processes, resulting in a high degree of variation in process outcomes. Therefore, quantifying these factors and their correlations to process outcomes are important challenges to overcome to enable widespread adoption of emerging AM technologies. In the powder bed fusion AM process, the density of the powder layers in the powder bed is a key influencing factor. This paper introduces a method to determine the powder bed density (PBD) during the powder bed fusion (PBF) process. A complete uncertainty analysis associated with the measurement method was also described. The resulting expanded measurement uncertainty, U PBD (k  =  2), was determined as 0.004 g · cm-3. It was shown that this expanded measurement uncertainty is about three orders of magnitude smaller than the typical powder bed density. This method enables establishing correlations between the changes in PBD and the direction of motion of the powder recoating arm.

  17. 油页岩干馏工艺积碳特性正交分析%Oil Shale Retorting Process Characteristic Orthogonal Carbon Analysis

    Institute of Scientific and Technical Information of China (English)

    柏静儒; 许伟; 潘朔; 张本熙

    2015-01-01

    To evaluate coking behavior of oil shale full cycle carbonization process,we established the experi-mental table independently. Determining that propylene is the main matrix coking among various of organic ga-ses of retorting gas of oil shale based on self-building experiment table and gas chromatography. I selected pro-pylene as carbon source to analysis the phenomenon of coking in different cases ( reaction time/wall tempera-ture/gas flow rate) . Coke amount increased with the longer reaction time and higher wall temperature ( under 800 ℃) ,Coke amount continuous increased with the increasing of gas flow rate until the gas flow rate reached 30 mL·min-1 meeting a sudden decrease. According to the result of experiments,the influence degree of co-king behavior by different cases is as follows:reaction time> gas flow rate > wall temperature.%通过自建实验台模拟瓦斯全循环油页岩干馏工艺并进行积碳实验,利用气相色谱仪对积碳反应前后瓦斯气组分性质进行分析。使用丙烯为碳源气,观察不同工况下(反应时间、壁面温度、气体流量)的积碳现象。结果表明:瓦斯气中主要积碳母体为烯烃,含量最高为丙烯。积碳量随反应时间和壁面温度(800℃以下)的增加而增加,随气体流量的增加而变化,流量达到30 mL·min-1后积碳量开始减少。各工况对积碳现象的影响程度依次是反应时间>气体流量>壁面温度。

  18. Heat transfer simulation and retort program adjustment for thermal processing of wheat based Haleem in semi-rigid aluminum containers.

    Science.gov (United States)

    Vatankhah, Hamed; Zamindar, Nafiseh; Shahedi Baghekhandan, Mohammad

    2015-10-01

    A mixed computational strategy was used to simulate and optimize the thermal processing of Haleem, an ancient eastern food, in semi-rigid aluminum containers. Average temperature values of the experiments showed no significant difference (α = 0.05) in contrast to the predicted temperatures at the same positions. According to the model, the slowest heating zone was located in geometrical center of the container. The container geometrical center F0 was estimated to be 23.8 min. A 19 min processing time interval decrease in holding time of the treatment was estimated to optimize the heating operation since the preferred F0 of some starch or meat based fluid foods is about 4.8-7.5 min.

  19. Physicochemical interaction and its influence on deep bed filtration process

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-long; MENG Jun; LI GUI-ping; LUAN Zhao-kun; TANG Hong-xiao

    2004-01-01

    The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. Thephysicochemical interaction forces between the filter media and suspended particles and their influence on deep bedfiltration process were also studied theoretically. Through the comparison of the hydraulic and physicochemicalforces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the micro-flocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and theexperimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoreticalprediction was reasonably consistent with the experimental results under different conditions, which indicated that theregulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of thephysicochemical interactions. Further theoretical and experimental research should be carried out to investigate theinteraction mechanism and its application in the deep bed filtration and other cases.

  20. Rapid Retort Processing of Eggs

    Science.gov (United States)

    2006-12-04

    heat sensitive than ovoalbumin but less susceptible to heat denaturation. Di- and trivalent ions are bound firmly by conalbumin ( Stadelmann , 1977...tyrosine ( Stadelmann , 1977). Lysozyme. Lysozyme is an enzyme of the albumen, which has a lytic action of bacterial cell walls. It contains 129...white heated at 63 C per 10 min this enzyme is inactivated ( Stadelmann , 1977) Ovomucin. It is a glycoprotein that contributes to the gel-like structure

  1. Evaluation of oil shale from Eastern Canada by retorting and by concentration of a kerogen-rich fraction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.W.; Abbott, D.

    1981-12-16

    An apparatus was developed for testing the retorting behaviour of oil shales under pressures up to 500 psi hydrogen and 700/sup 0/C. Equipment was also constructed and brought into service for the determination of oil yields by the Fischer assay method. Six samples of Albert shale of varying oil content (<10 to 40-50 gals/ton) were tested by the Fischer method and by hydrogen retorting to determine yields of liquid distillate under different conditions of retorting. The Fischer assays gave oil yields of 2.9 to 47.5 gals/ton which corresponded to carbon conversion of 50.5 to 87.8 per cent. The hydrogen retorting tests at 700/sup 0/C and 500/sup 0/C gave carbon conversion rates of 53 to 87 per cent which are comparable to that for the Fischer retorting. Retorting at 500/sup 0/C gave oil yields similar to the Fischer assay but at 700/sup 0/C oil yields were reduced, 4 to 30 gals/ton, although gas yields increased. In the retorting tests performed, the use of hydrogen at 500 psi did not increase yields. More work is needed to understand the retorting behaviour of New Brunswick and other Canadian oil shales. Retorting tests for resource assessment purposes are also needed. These should be coupled to determining the rate of carbon conversion and hence the effectiveness of the retorting technique. Petrographic, chemical and thermogravimetric analyses of the oil shales were undertaken to characterize the materials for retorting tests. The second part of the project involved producing a kerogen concentrate by standard beneficiation methods, spherical agglomeration, gravity methods and by flotation. Only gravity separation showed promise of being a viable industrial process. Fine grinding and gravity separation gave high concetrations up to 70 gals/ton but yields were low. 11 figs., 13 tabs.

  2. Acoustic monitoring of a fluidized bed coating process

    DEFF Research Database (Denmark)

    Naelapaa, Kaisa; Veski, Peep; Pedersen, Joan G.;

    2007-01-01

      The aim of the study was to investigate the potential of acoustic monitoring of a production scale fluidized bed coating process. The correlation between sensor signals and the estimated amount of film applied and percentage release, respectively, were investigated in coating potassium chloride...

  3. COMPUTATIONALLY INTELLIGENT MODELLING AND CONTROL OF FLUIDIZED BED COMBUSTION PROCESS

    Directory of Open Access Journals (Sweden)

    Ivan T Ćirić

    2011-01-01

    Full Text Available In this paper modelling and control approaches for fluidized bed combustion process have been considered, that are based on the use of computational intelligence. Proposed adaptive neuro-fuzzy-genetic modelling and intelligent control strategies provide for efficient combining of available expert knowledge with experimental data. Firstly, based on the qualitative information on the desulphurization process, models of the SO2 emission in fluidized bed combustion have been developed, which provides for economical and efficient reduction of SO2 in FBC by estimation of optimal process parameters and by design of intelligent control systems based on defined emission models. Also, efficient fuzzy nonlinear FBC process modelling strategy by combining several linearized combustion models has been presented. Finally, fuzzy and conventional process control systems for fuel flow and primary air flow regulation based on developed models and optimized by genetic algorithms have also been developed. Obtained results indicate that computationally intelligent approach can be successfully applied for modelling and control of complex fluidized bed combustion process.

  4. 油页岩干馏厂污水处理工艺的设计%Design and Application of Wastewater Treatment Process in Oil Shale Retorting Plant

    Institute of Scientific and Technical Information of China (English)

    上官中华; 李魏山; 王铮

    2013-01-01

    Oil shale retort wastewater is characterized by high concentrations of organic compounds, ammonia nitrogen and oils, many types of pollutants and refractory degradation. This type of wastewater was designed to be pretreated separately, and the stripper was used to reduce ammonia nitrogen to below 200 mg/L and oil to below 20 mg/L. The treated wastewater was mixed with domestic sewage for biochemical treatment. The final effluent quality met the first class criteria specified in the Integrated Wastewater Discharge Standard ( GB 8978 - 1996).%针对某污水处理站油页岩干馏废水中有机物浓度高、氨氮高、含油量高、污染物种类多、难降解的特性,设计对该部分生产废水单独做预处理,使动植物油降到20 mg/L以下,然后采用氨吹脱塔去除氨氮,使出水氨氮降到200 mg/L以下,而后再与生活污水混合后进行生化处理,出水水质达到《污水综合排放标准》(GB 8978-1996)的一级标准,其经验值得推广借鉴.

  5. Evaluation of physical-chemical and biological treatment of shale oil retort water

    Energy Technology Data Exchange (ETDEWEB)

    Mercer, B.W.; Mason, M.J.; Spencer, R.R.; Wong, A.L.; Wakamiya, W.

    1982-09-01

    Bench scale studies were conducted to evaluate conventional physical-chemical and biological treatment processes for removal of pollutants from retort water produced by in situ shale oil recovery methods. Prior to undertaking these studies, very little information had been reported on treatment of retort water. A treatment process train patterned after that generally used throughout the petroleum refining industry was envisioned for application to retort water. The treatment train would consist of processes for removing suspended matter, ammonia, biodegradable organics, and nonbiodegradable or refractory organics. The treatment processes evaluated include anaerobic digestion and activated sludge for removal of biodegradable organics and other oxidizable substances; activated carbon adsorption for removal of nonbiodegradable organics; steam stripping for ammonia removal; and chemical coagulation, sedimentation and filtration for removal of suspended matter. Preliminary cost estimates are provided.

  6. Water Usage for In-Situ Oil Shale Retorting – A Systems Dynamics Model

    Energy Technology Data Exchange (ETDEWEB)

    Earl D. Mattson; Larry Hull; Kara Cafferty

    2012-12-01

    A system dynamic model was construction to evaluate the water balance for in-situ oil shale conversion. The model is based on a systems dynamics approach and uses the Powersim Studio 9™ software package. Three phases of an insitu retort were consider; a construction phase primarily accounts for water needed for drilling and water produced during dewatering, an operation phase includes the production of water from the retorting process, and a remediation phase water to remove heat and solutes from the subsurface as well as return the ground surface to its natural state. Throughout these three phases, the water is consumed and produced. Consumption is account for through the drill process, dust control, returning the ground water to its initial level and make up water losses during the remedial flushing of the retort zone. Production of water is through the dewatering of the retort zone, and during chemical pyrolysis reaction of the kerogen conversion. The major water consumption was during the remediation of the insitu retorting zone.

  7. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O' Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  8. Application of ultrasonic backscattering for level measurement and process monitoring of expanded-bed adsorption columns.

    Science.gov (United States)

    Thelen, T V; Mairal, A P; Thorsen, C S; Ramirez, W F

    1997-01-01

    Expanded-bed adsorption is a newly commercialized technique for the purification of proteins from cellular debris in downstream processing. An expanded bed presents the possibility of protein recovery in a single step, eliminating the often costly clarification processing steps such as ultrafiltration, centrifugation, and precipitation. A major obstacle to the successful commercialization of this technology is the inability to accurately monitor and control the bed height in these systems. Fluctuations in the feedstock viscosity are common during normal operation and tend to make the operation and control of expanded beds for biological applications complex and difficult. We develop a level measurement technique based upon ultrasonics. It is shown that this technique has great promise for bed-height measurement in expanded-bed adsorption systems. Furthermore, the bed-height measurement can be used in feedback control strategies for bed-height regulation. The proposed ultrasonic sensor is also capable of monitoring for plugging and bubbling in the column.

  9. Innovations in wastewater treatment: the moving bed biofilm process.

    Science.gov (United States)

    Odegaard, Hallvard

    2006-01-01

    This paper describes the moving bed biofilm reactor (MBBR) and presents applications of wastewater treatment processes in which this reactor is used. The MBBR processes have been extensively used for BOD/COD-removal, as well as for nitrification and denitrification in municipal and industrial wastewater treatment. This paper focuses on the municipal applications. The most frequent process combinations are presented and discussed. Basic design data obtained through research, as well as data from practical operation of various plants, are presented. It is demonstrated that the MBBR may be used in an extremely compact high-rate process (treatment. Most European plants require P-removal and performance data from plants combining MBBR and chemical precipitation is presented. Likewise, data from plants in Italy and Switzerland that are implementing nitrification in addition to secondary treatment are presented. The results from three Norwegian plants that are using the so-called combined denitrification MBBR process are discussed. Nitrification rates as high as 1.2 g NH4-N/m2 d at complete nitrification were demonstrated in practical operation at low temperatures (11 degrees C), while denitrification rates were as high as 3.5g NO3-Nequiv./m2.d. Depending on the extent of pretreatment, the total HRT of the MBBR for N-removal will be in the range of 3 to 5 h.

  10. Moving bed biofilm reactor technology: process applications, design, and performance.

    Science.gov (United States)

    McQuarrie, James P; Boltz, Joshua P

    2011-06-01

    The moving bed biofilm reactor (MBBR) can operate as a 2- (anoxic) or 3-(aerobic) phase system with buoyant free-moving plastic biofilm carriers. These systems can be used for municipal and industrial wastewater treatment, aquaculture, potable water denitrification, and, in roughing, secondary, tertiary, and sidestream applications. The system includes a submerged biofilm reactor and liquid-solids separation unit. The MBBR process benefits include the following: (1) capacity to meet treatment objectives similar to activated sludge systems with respect to carbon-oxidation and nitrogen removal, but requires a smaller tank volume than a clarifier-coupled activated sludge system; (2) biomass retention is clarifier-independent and solids loading to the liquid-solids separation unit is reduced significantly when compared with activated sludge systems; (3) the MBBR is a continuous-flow process that does not require a special operational cycle for biofilm thickness, L(F), control (e.g., biologically active filter backwashing); and (4) liquid-solids separation can be achieved with a variety of processes, including conventional and compact high-rate processes. Information related to system design is fragmented and poorly documented. This paper seeks to address this issue by summarizing state-of-the art MBBR design procedures and providing the reader with an overview of some commercially available systems and their components.

  11. Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Joe Enneking

    2011-05-01

    Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absoption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

  12. Documentation of INL’s In Situ Oil Shale Retorting Water Usage System Dynamics Model

    Energy Technology Data Exchange (ETDEWEB)

    Earl D Mattson; Larry Hull

    2012-12-01

    A system dynamic model was construction to evaluate the water balance for in-situ oil shale conversion. The model is based on a systems dynamics approach and uses the Powersim Studio 9™ software package. Three phases of an in situ retort were consider; a construction phase primarily accounts for water needed for drilling and water produced during dewatering, an operation phase includes the production of water from the retorting process, and a remediation phase water to remove heat and solutes from the subsurface as well as return the ground surface to its natural state. Throughout these three phases, the water is consumed and produced. Consumption is account for through the drill process, dust control, returning the ground water to its initial level and make up water losses during the remedial flushing of the retort zone. Production of water is through the dewatering of the retort zone, and during chemical pyrolysis reaction of the kerogen conversion. The document discusses each of the three phases used in the model.

  13. Numerical Simulation of Physical and Chemical Processes in Fluidized Bed

    Science.gov (United States)

    Baturin, D. A.; Gil, A. V.

    2015-10-01

    The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out for the bottom of the combustion chamber with the varying heights of volume filling. The results contours of particulate matter concentration and of velocities, as well as a graphical representation of changes in the concentration of particles on the bed height are shown. Simulation performed in Eulerian - Eulerian representation on a 2D model.

  14. Fluidized-bed bioreactor process for the microbial solubiliztion of coal

    Science.gov (United States)

    Scott, Charles D.; Strandberg, Gerald W.

    1989-01-01

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

  15. Biofluid process: fluidised-bed gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, A. [ATEKO a.s., Hradec Kralove (Czech Republic)

    1996-12-31

    Fluidised-bed gasification of biomass was developed by ATEKO by using long-term experience from coal gasification. An experimental unit was built and a number of tests, first with sawdust gasification, were carried out. A gas combustion engine combined with a power generator was installed and operated in power production. (orig.)

  16. Fluid Bed Technology: Overview and Parameters for Process Selection

    OpenAIRE

    Saurabh Srivastava; Garima Mishra

    2010-01-01

    Formulation development is the most emerging and upcoming face of pharmaceutical technology in the current era. It is contemporarily capturing the market leaps and bounds with recent trends and developments with its innovative techniques. The day-to-day advancements in the research have provided an edge to this brilliant branch of pharmaceutical sector for not only uplifting the pharmacy profession but also to conquer the diseased state for nurturing the health and humanity. The fluid-bed tec...

  17. Double Retort System for Materials Compatibility Testing

    Energy Technology Data Exchange (ETDEWEB)

    V. Munne; EV Carelli

    2006-02-23

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contamination has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented.

  18. Development of second-generation pressurized fluidized bed combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Wolowodiuk, W.; Robertson, A. [Foster Wheeler Development Corp., Livingston, NJ (United States); Bonk, D. [Dept. of Energy, Morgantown, WV (United States)

    1995-12-01

    Under the sponsorship of the United States Department of Energy, Foster Wheeler Development Corporation, and its team members, Westinghouse, Gilbert/Commonwealth, and the Institute of Gas Technology are developing second-generation pressurized fluidized bed combustion technology capable of achieving net plant efficiency in excess of 45 percent based on the higher heating value of the coal. A three-phase program entails design and costing of a 500 MWe power plant and identification of developments needed to commercialize this technology (Phase 1), testing of individual components (Phase 2), and finally testing these components in an integrated mode (Phase 3). This paper briefly describes the results of the first two phases as well as the progress on the third phase. Since other projects which use the same technology are in construction or in negotiation stages-namely, the Power System Development Facility and the Four Rivers Energy Modernization Projects-brief descriptions of these are also included.

  19. Addition of cattle manure to sheep bedding allows vermicomposting process and improves vermicompost quality.

    Science.gov (United States)

    Cestonaro, Taiana; Costa, Mônica Sarolli Silva de Mendonça; Costa, Luiz Antonio de Mendonça; Pereira, Dercio Ceri; Rozatti, Marcos A T; Martins, Marcos F Leal

    2017-02-04

    Animal waste is usually a good substrate for vermicomposting. However, numerous animal husbandry systems use bedding that consists primarily of lignocellulosic substrates, which hinders earthworm and microorganism's development and thus, the entire bioconversion process. One possible solution is to mix the used bedding with other waste materials that are more amenable to earthworm ingestion and can provide better conditions for earthworm population growth. Here, we have aimed to examine the effectiveness of such procedure by mixing rice-husk-based sheep bedding with cattle manure in different proportions (0%, 25%, 50%, 75% and 100%). We have carried out vermicomposting experiments in benchtop vermireactors inoculated with 0.88kg of dry matter (sheep bedding+cattle manure). Data used in the Principal Component Analysis were the multiple vermicomposting variables (i.e., EC; pH; HA/FA and C/N ratios; P, K, cellulose, and hemicellulose content). The effect of the treatment on earthworm count was analyzed with ANOVA. We have observed that the addition of at least 25% of cattle manure to sheep bedding allows vermicomposting process but it is necessary 148days to obtain a stabilized vermicompost. However, increasing the proportion of cattle manure to sheep bedding, the vermicomposting time decreases proportionally to 94days. We concluded that vermicomposting can be considered a bioprocess to stabilize rice husk after being used as sheep bedding.

  20. Hot gas stripping of ammonia and carbon dioxide from simulated and actual in situ retort waters

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.L.

    1979-01-01

    This study proved that ammonia and carbon dioxide could be removed from retort water by hot gas stripping and that overall transfer rates were slower than for physical desorption alone. The ammonia in solution complexed with the carbonate species with the result that the CO/sub 2/ transfer rates were linked to the relatively slower desorption of NH/sub 3/ from solution. Ionic reactions in the liquid phase limited the quantity of free NH/sub 3/ and CO/sub 2/, thus decreasing the driving forces for mass transfer. The retort water exhibited foaming tendencies that affected the interfacial area which should be taken into account if a stripping tower is considered on a larger scale. Transfer unit heights were calculated for the process conditions studied and correlated such that scaleup to increased capacities is possible.

  1. [Structure and fluidization of an internally circulating fluidized bed for FGD process].

    Science.gov (United States)

    Yang, Liuchun; Yang, Wenqi; Tong, Zhiquan

    2003-09-01

    A new internally circulating fluidized bed for FGD process was developed, and different types of top and bottom structures were employed in the experiment to find out the best fluidized bed structure. Fluidizing status, the axial distribution of solid hold-up and the fluid mechanics under cold conditions were investigated. The results indicate that the unit can realize internally circulating of a large number of solid particles which presents an core-annulus structure when the velocity of fluidizing gas was at the range of 2.5 to 5 m/s, and that the solid density in the bed is higher than that in traditional equal diameter fluidized bed, which provide the equipment with potential for application in FGD process.

  2. Mechanistic modelling of fluidized bed drying processes of wet porous granules

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; De Beer, Thomas; Gernaey, Krist;

    2011-01-01

    Fluidized bed dryers are frequently used in industrial applications and also in the pharmaceutical industry. The general incentives to develop mechanistic models for pharmaceutical processes are listed, and our vision on how this can particularly be done for fluidized bed drying processes of wet...... will reside in a certain interval. Population Balance Model (ling) (PBM) offers a tool to describe the distribution of particle properties which can be of interest for the application. PBM formulation and solution methods are therefore reviewed. In a fluidized bed, the granules show a fluidization pattern...... Eddy Simulation (LES). Another important aspect of CFD is the choice between the Eulerian–Lagrangian and the Eulerian–Eulerian approach. Finally, the PBM and CFD frameworks can be integrated, to describe the evolution of the moisture content of granules during fluidized bed drying....

  3. Fluidized-bed combustion process evaluation and program support. Quarterly report, January-March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, I.; Podolski, W.F.; Swift, W.M.; Henry, R.F.; Hanway, J.E.; Griggs, K.E.; Herzenberg, C.; Helt, J.E.; Carls, E.L.

    1980-12-01

    Argonne National Laboratory is undertaking several tasks primarily in support of the pressurized fluidized-bed combustion project management team at Morgantown Energy Technology Center. Work is under way to provide fluidized-bed combustion process evaluation and program support to METC, determination of the state of the art of instrumentation for FBC applications, evaluation of the performance capability of cyclones for hot-gas cleaning in PFBC systems, and an initial assessment of methods for the measurement of sodium sulfate dew point.

  4. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    OpenAIRE

    Slyusarskiy Konstantin V.; Korotkikh Alexander G.; Sorokin Ivan V.

    2017-01-01

    Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The o...

  5. Morphology of retorted oil shale particles

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.C.; Mahajan, O.P.

    The formation of two distinct coked particle morphotypes, namely exfoliated and peripheral, during oil shale retorting and their implications toward the coking mechanism are discussed. Rapid heating causes swelling, exfoliation, and formation of a matrix of veinlets and cracks; these changes lead to uniform coking within the particle body. In contrast, slow heating produces the peripheral morphotype with a low coke density at the center and a high coke density at the periphery. The difference in the coking morphology of the two particle types has been explained on the basis of kerogen pyrolysis kinetics. Of the two morphotypes, peripheral coke makes the particles stronger and more resistant to size attrition. In addition to the formation of coke in the particle body of the two morphotypes, coke is also formed on the outer surface of both the particle types. It has been concluded that more coke is produced from the secondary decomposition reactions than directly from the kerogen itself. 25 references, 8 figures.

  6. Gasification process of refuse derived fuel in circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, S.; Kinoshita, Y.; Lee, C.W.; Itaya, Y.; Mori, S. [Nagoya Univ., Nagoya (Japan). Dept. of Chemical Engineering

    2002-07-01

    This paper presents a fuel gas production system involving gasification of refuse-derived fuel (RDF) in a circulating fluidized bed (CFB). Although RDF is considered to be a viable source of energy, combustion of RDF has not spread widely because of a lack of conventional incinerators, erosion due to hydrogen chloride, and emissions of dioxin. This paper presents the results of an experimental study of the pyrolysis behaviour of 3 kinds of RDF and the particle motion in a cold model CFB. The objective was to clarify operating parameters for optimum control. It was shown that an increase in combustion temperature improves the yield of the combustible gas components and the energy recycling efficiency from the RDF. The highest heating value of pyrolysis gas was obtained at 873 to 973 degrees K. The gas flow rate in the pneumatic valve of the CFB was an important control factor for the circulation flux and solids holdup in the riser. High holdups were observed when minute silica sand particles were used in the CFB. 15 refs., 1 tab., 8 figs.

  7. Bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.

    2013-01-01

    to describe the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. In this work both models consider the incoming solid fuel as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is treated as a 0D system, but the thermo......Because of the complexity to describe and solve thermo-chemical processes occurring in a fuel bed in grate-fired boiler, it is often necessary to simplify the process and use modeling techniques based on overall mass, energy and species conservation. A comparison between two numerical models......-chemical processes are divided in two successive sections: drying and conversion (which includes pyrolysis, gasification and combustion). The second model is an empirical 1D approach. The two models need input data such as composition, temperature and feeding rate of biomass and primary air. Temperature, species...

  8. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    Energy Technology Data Exchange (ETDEWEB)

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899 (United States)

    2014-02-18

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  9. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    Science.gov (United States)

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John

    2014-02-01

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  10. Development of a trickle bed reactor of electro-Fenton process for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yangming [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Hong, E-mail: liuhong@cigit.ac.cn [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Shen, Zhemin, E-mail: zmshen@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Wenhua [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-10-15

    Highlights: • An electrochemical trickle bed reactor was composed of C-PTFE-coated graphite chips. • The trickle bed reactor had a high H{sub 2}O{sub 2} production rate in a dilute electrolyte. • An azo dye was effectively decomposed by the electro-Fenton process in the reactor. -- Abstract: To avoid electrolyte leakage and gas bubbles in the electro-Fenton (E-Fenton) reactors using a gas diffusion cathode, we developed a trickle bed cathode by coating a layer composed of carbon black and polytetrafluoroethylene (C-PTFE) onto graphite chips instead of carbon cloth. The trickle bed cathode was optimized by single-factor and orthogonal experiments, in which carbon black, PTFE, and a surfactant were considered as the determinant of the performance of graphite chips. In the reactor assembled by the trickle bed cathode, H{sub 2}O{sub 2} was generated with a current of 0.3 A and a current efficiency of 60%. This performance was attributed to the fine distribution of electrolyte and air, as well as the effective oxygen transfer from the gas phase to the electrolyte–cathode interface. In terms of H{sub 2}O{sub 2} generation and current efficiency, the developed trickle bed reactor had a performance comparable to that of the conventional E-Fenton reactor using a gas diffusion cathode. Further, 123 mg L{sup −1} of reactive brilliant red X-3B in aqueous solution was decomposed in the optimized trickle bed reactor as E-Fenton reactor. The decolorization ratio reached 97% within 20 min, and the mineralization reached 87% within 3 h.

  11. Processes and parameters involved in modeling radionuclide transport from bedded salt repositories. Final report. Technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Evenson, D.E.; Prickett, T.A.; Showalter, P.A.

    1979-07-01

    The parameters necessary to model radionuclide transport in salt beds are identified and described. A proposed plan for disposal of the radioactive wastes generated by nuclear power plants is to store waste canisters in repository sites contained in stable salt formations approximately 600 meters below the ground surface. Among the principal radioactive wastes contained in these canisters will be radioactive isotopes of neptunium, americium, uranium, and plutonium along with many highly radioactive fission products. A concern with this form of waste disposal is the possibility of ground-water flow occurring in the salt beds and endangering water supplies and the public health. Specifically, the research investigated the processes involved in the movement of radioactive wastes from the repository site by groundwater flow. Since the radioactive waste canisters also generate heat, temperature is an important factor. Among the processes affecting movement of radioactive wastes from a repository site in a salt bed are thermal conduction, groundwater movement, ion exchange, radioactive decay, dissolution and precipitation of salt, dispersion and diffusion, adsorption, and thermomigration. In addition, structural changes in the salt beds as a result of temperature changes are important. Based upon the half-lives of the radioactive wastes, he period of concern is on the order of a million years. As a result, major geologic phenomena that could affect both the salt bed and groundwater flow in the salt beds was considered. These phenomena include items such as volcanism, faulting, erosion, glaciation, and the impact of meteorites. CDM reviewed all of the critical processes involved in regional groundwater movement of radioactive wastes and identified and described the parameters that must be included to mathematically model their behavior. In addition, CDM briefly reviewed available echniques to measure these parameters.

  12. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2008-01-01

    Full Text Available In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.8 g NOx-N kg VSS-1 h-1. The results of the average effluent soluble COD concentration from each reactor showed that denitrification process in the second anoxic reactor consumed most of the biodegradable organic matter. As seen from the results, denitrification rate has increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed a good correlation to the anaerobic phosphate release rate. Moreover, phosphate removal rate showed a strong correlation to the phosphate loading rate in the aerobic reactor. In optimum conditions, the average SCOD, total nitrogen and phosphorus removal efficiencies were 96.9, 84.6 and 95.8%, respectively. This study showed that the moving bed biofilm process could be used as an ideal and efficient option for the total nutrient removal from municipal wastewater.

  13. Optimum process design of packed bed type thermal storage systems and other applications

    Energy Technology Data Exchange (ETDEWEB)

    Bindra, Hitesh; Bueno, Pablo

    2016-10-25

    Methods and systems for optimizing the process of heat and/or mass transfer operations in packed beds and embodiments of applications of the methods are disclosed herein below. In one instance, the method results in the profile of the quantity representative of the heat and/or mass transfer operation having a propagating substantially sharp front.

  14. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    Directory of Open Access Journals (Sweden)

    Slyusarskiy Konstantin V.

    2017-01-01

    Full Text Available Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The optimal fuel residence time and gasifyer specific productivity were defined. The prevail reactions in oxidizing and reduction zones together with its height were defined.

  15. Vistula River bed erosion processes and their influence on Warsaw’s flood safety

    OpenAIRE

    Magnuszewski, A.; Moran, S

    2015-01-01

    Large cities have historically been well protected against floods as a function of their importance to society. In Warsaw, Poland, located on a narrow passage of the Vistula River valley, urban flood disasters were not unusual. Beginning at the end of the 19th century, the construction of river embankment and training works caused the narrowing of the flood passage path in the downtown reach of the river. The process of bed erosion lowered the elevation of the river bed by 205 cm over the 20t...

  16. Engineering bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.

    2014-01-01

    A comparison between two numerical models describing the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. Both models consider the incoming biomass as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed...... of the syngas predicted by the two models is equal to about 7%. The application to different types of biomass shows that the difference in the predictions increases as the carbon content grows. The phenomenological model, in fact, generally considers higher conversion rates of this element to volatiles...

  17. Powder Bed Layer Characteristics: The Overseen First-Order Process Input

    Science.gov (United States)

    Mindt, H. W.; Megahed, M.; Lavery, N. P.; Holmes, M. A.; Brown, S. G. R.

    2016-08-01

    Powder Bed Additive Manufacturing offers unique advantages in terms of manufacturing cost, lot size, and product complexity compared to traditional processes such as casting, where a minimum lot size is mandatory to achieve economic competitiveness. Many studies—both experimental and numerical—are dedicated to the analysis of how process parameters such as heat source power, scan speed, and scan strategy affect the final material properties. Apart from the general urge to increase the build rate using thicker powder layers, the coating process and how the powder is distributed on the processing table has received very little attention to date. This paper focuses on the first step of every powder bed build process: Coating the process table. A numerical study is performed to investigate how powder is transferred from the source to the processing table. A solid coating blade is modeled to spread commercial Ti-6Al-4V powder. The resulting powder layer is analyzed statistically to determine the packing density and its variation across the processing table. The results are compared with literature reports using the so-called "rain" models. A parameter study is performed to identify the influence of process table displacement and wiper velocity on the powder distribution. The achieved packing density and how that affects subsequent heat source interaction with the powder bed is also investigated numerically.

  18. Chemical Processes Related to Combustion in Fluidised Bed

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Lindqvist, Oliver [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

    2002-12-01

    with evaluation of other biomass ash particles and, as an extension, the speciation of Cu and Zn will be studied as well. Ash fractions from combustion of MSW in a BFB boiler have been investigated regarding composition and leaching properties, i.e. environmental impact risks. The release of salts from the cyclone ash fraction can be minimised by the application of a simple washing process, thus securing that the leaching of soluble substances stays within the regulative limits. The MSW ash - water systems contain some interesting chemical issues, such as the interactions between Cr(VI) and reducing substances like Al-metal. The understanding of such chemical processes is important since it gives a possibility to predict effects of a change in ash composition. An even more detailed understanding of interactions between a solution containing ions and particle surfaces can be gained by theoretical modelling. In this project (and with additional unding from Aangpannefoereningens Forskningsstiftelse) a theoretical description of ion-ion interactions and the solid-liquid-interface has been developed. Some related issues are also included in this report. The publication of a paper on the reactions of ammonia in the presence of a calcining limestone surface is one of them. A review paper on the influence of combustion conditions on the properties of fly ash and its applicability as a cement replacement in concrete is another. The licentiate thesis describing the sampling and measurement of Cd in flue gas is also included since it was finalised during the present period. A co-operation project involving the Geology Dept. at Goeteborg Univ. and our group is briefly discussed. This project concerns the utilisation of granules produced from wood ash and dolomite as nutrient source for forest soil. Finally, the plans for our flue gas simulator facility are discussed.

  19. Study of instrumentation needs for process control and safety in coal fluidized-bed combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Herzenberg, C.L.; Griggs, K.E.; Henry, R.F.; Podolski, W.F.

    1981-02-01

    A study was conducted to evaluate the current state of the art of instrumentation for planned and operating fluidized-bed combustion systems. This study is intended to identify instrumentation needs and serve as a data base for projects to develop this instrumentation. A considerable number of needs for measurements for which presently available instrumentation is not suitable were reported by respondents. The identified deficiencies are presented with the associated physical parameter ranges for FBC processes. New techniques and instrumentation under development, as well as some available alternative instruments, are discussed briefly. Also, newly instituted mechanisms for technical information exchange on instrumentation for fossil energy applications are identified. Development of instruments to meet the identified measurement deficiencies is recommended in order to ensure the feasibility of automatic control of large-scale fluidized-bed combustion systems, and to advance the state of the art of fluidized-bed combustion technology.

  20. ENERGY AND MASS TRANSPORT PROCESSES IN THE GRANULAR BED OF AN INDIRECTLY HEATED ROTARY KILN

    Institute of Scientific and Technical Information of China (English)

    Wolfgang Klose; Arndt-Peter Schinkel

    2004-01-01

    The transport mechanisms of momentum, mass, species, and energy are investigated in detail for the rotary kiln process. The residence time prediction of the granular bed is well improved by considering different flow patterns in the drum. Introducing a mixed flow pattem of the basic slipping and slumping behaviour has the most important effect on the improvement of the residence time prediction. The granular bed is assumed to behave as a Bingham fluid in the active layer of the bed. The transport mechanisms of momentum, species, and energy are modelled on the basis of this assumption and using the kinetic gas theory. Additionally, a mathematical transformation is presented to save computational time. The model results of the temperature field are in very good agreement with experimental data.

  1. Bio-oil production from palm fronds by fast pyrolysis process in fluidized bed reactor

    Science.gov (United States)

    Rinaldi, Nino; Simanungkalit, Sabar P.; Kiky Corneliasari, S.

    2017-01-01

    Fast pyrolysis process of palm fronds has been conducted in the fluidized bed reactor to yield bio-oil product (pyrolysis oil). The process employed sea sand as the heat transfer medium. The objective of this study is to design of the fluidized bed rector, to conduct fast pyrolysis process to product bio-oil from palm fronds, and to characterize the feed and bio-oil product. The fast pyrolysis process was conducted continuously with the feeding rate around 500 g/hr. It was found that the biomass conversion is about 35.5% to yield bio-oil, however this conversion is still minor. It is suggested due to the heating system inside the reactor was not enough to decompose the palm fronds as a feedstock. Moreover, the acids compounds ware mostly observed on the bio-oil product.

  2. Comparison of low shear, high shear, and fluid bed granulation during low dose tablet process development.

    Science.gov (United States)

    Hausman, Debra S

    2004-03-01

    Three processing methods were compared to develop a low dose (0.1%) immediate release tablet. Similar formulations were used to evaluate low shear, high shear, and fluid bed granulation methods. For each granulation process, the drug was dissolved or suspended in the granulating fluid and sprayed into the granulator. Both water and methanol were evaluated as granulating fluids. The low shear granulation was performed in a Patterson-Kelley V-Blender with I-bar. The high shear granulation was performed in a GRAL (top entry impeller) and a Diosna (bottom mounted impeller). Fluid bed granulation was also performed using top-spray. Acceptable content uniformity was obtained using each technology. The type of granulator and granulating solvent affected the granulation particle size distributions and bulk/tap densities. However, the addition of extragranular microcrystalline cellulose minimized the effect of variable granulation properties and allowed similar tablets to be produced from each granulation process.

  3. Monitoring granulation rate processes using three PAT tools in a pilot-scale fluidized bed.

    Science.gov (United States)

    Tok, Ai Tee; Goh, Xueping; Ng, Wai Kiong; Tan, Reginald B H

    2008-01-01

    The purpose of this research was to analyze and compare the responses of three Process Analytical Technology (PAT) techniques applied simultaneously to monitor a pilot-scale fluidized bed granulation process. Real-time measurements using focused beam reflectance measurement (Lasentec FBRM) and near-infra red spectroscopy (Bruker NIR) were taken by inserting in-line probes into the fluidized bed. Non-intrusive acoustic emission measurements (Physical Acoustic AE) were performed by attaching piezoelectric sensors on the external wall of the fluidized bed. Powder samples were collected at regular intervals during the granulation process and characterized offline using laser diffraction, scanning electron microscopy, stereo-optical microscopy and loss on drying method. PAT data comprising chord length distribution and chord count (from FBRM), absorption spectra (from NIR) and average signal levels and counts (from AE) were compared with the particle properties measured using offline samples. All three PAT techniques were able to detect the three granulation regimes or rate processes (wetting and nucleation, consolidation and growth, breakage) to varying degrees of sensitivity. Being dependent on optical signals, the sensitivities of the FBRM and NIR techniques were susceptible to fouling on probe windows. The AE technique was sensitive to background fluidizing air flows and external interferences. The sensitivity, strengths and weaknesses of the PAT techniques examined may facilitate the selection of suitable PAT tools for process development and scale-up studies.

  4. Process intensification by direct product sequestration from batch fermentations: application of a fluidised bed, multi-bed external loop contactor

    Science.gov (United States)

    Hamilton; Morton; Young; Lyddiatt

    1999-08-01

    A critical comparison has been made of the relative efficacy of the primary purification of an extracellular acid protease produced by the yeast Yarrowia lipolytica. The performance of conventional, discrete sequences of fermentation, broth clarification and fixed bed, anion exchange chromatography has been compared with fluidised bed adsorption directly interfaced with post-term fermentation broth and fluidised bed adsorption directly integrated with productive fermentations (so-called direct product sequestration; DPS). Advantages of the latter, in terms of the improved yield and molecular quality of the protease end product are discussed in terms of the design, assembly and operation of component parts of DPS devices and their generic application to other extracellular bioproducts of microbial fermentations. Copyright 1999 John Wiley & Sons, Inc.

  5. The application of moving bed biofilm reactor to denitrification process after trickling filters.

    Science.gov (United States)

    Kopec, Lukasz; Drewnowski, Jakub; Kopec, Adam

    2016-12-01

    The paper presents research of a prototype moving bed biofilm reactor (MBBR). The device was used for the post-denitrification process and was installed at the end of a technological system consisting of a septic tank and two trickling filters. The concentrations of suspended biomass and biomass attached on the EvU Perl moving bed surface were determined. The impact of the external organic carbon concentration on the denitrification rate and efficiency of total nitrogen removal was also examined. The study showed that the greater part of the biomass was in the suspended form and only 6% of the total biomass was attached to the surface of the moving bed. Abrasion forces between carriers of the moving bed caused the fast stripping of attached microorganisms and formation of flocs. Thanks to immobilization of a small amount of biomass, the MBBR was less prone to leaching of the biomass and the occurrence of scum and swelling sludge. It was revealed that the maximum rate of denitrification was an average of 0.73 gN-NO(3)/gDM·d (DM: dry matter), and was achieved when the reactor was maintained in external organic carbon concentration exceeding 300 mgO2/dm(3) chemical oxygen demand. The reactor proved to be an effective device enabling the increase of total nitrogen removal from 53.5% to 86.0%.

  6. [Analysis of novel style biological fluidized bed A/O combined process in dyeing wastewater treatment].

    Science.gov (United States)

    Wei, Chao-Hai; Huang, Hui-Jing; Ren, Yuan; Wu, Chao-Fei; Wu, Hai-Zhen; Lu, Bin

    2011-04-01

    A novel biological fluidized bed was designed and developed to deal with high-concentration refractory organic industrial wastewater. From 12 successful projects, three cases of dyeing wastewater treatment projects with the scale of 1200, 2000 and 13000 m3/d respectively were selected to analyze the principle of treating refractory organic wastewater with fluidized bed technology and discuss the superiority of self-developed biological fluidized bed from the aspects of technical and economic feasibility. In the three cases, when the hydraulic retention time (HRT) of biological system were 23, 34 and 21. 8 h, and the volume loading of influents (COD) were 1.75, 4.75 and 2.97 kg/(m3 x d), the corresponding COD removal were 97.3%, 98.1% and 95.8%. Furthermore the operating costs of projects were 0.91, 1.17 and 0.88 yuan per ton of water respectively. The index of effluent all met the 1st grade of Guangdong Province wastewater discharge standard. Results showed that the biological fluidized bed had characteristics of shorter retention time, greater oxygen utilization rate, faster conversion rate of organic pollutants and less sludge production, which made it overcome the shortcomings of traditional methods in printing and dyeing wastewater treatment. Considering the development of technology and the combination of ecological security and recycling resources, a low-carbon wastewater treatment process was proposed.

  7. In line NIR quantification of film thickness on pharmaceutical pellets during a fluid bed coating process.

    Science.gov (United States)

    Lee, Min-Jeong; Seo, Da-Young; Lee, Hea-Eun; Wang, In-Chun; Kim, Woo-Sik; Jeong, Myung-Yung; Choi, Guang J

    2011-01-17

    Along with the risk-based approach, process analytical technology (PAT) has emerged as one of the key elements to fully implement QbD (quality-by-design). Near-infrared (NIR) spectroscopy has been extensively applied as an in-line/on-line analytical tool in biomedical and chemical industries. In this study, the film thickness on pharmaceutical pellets was examined for quantification using in-line NIR spectroscopy during a fluid-bed coating process. A precise monitoring of coating thickness and its prediction with a suitable control strategy is crucial to the quality assurance of solid dosage forms including dissolution characteristics. Pellets of a test formulation were manufactured and coated in a fluid-bed by spraying a hydroxypropyl methylcellulose (HPMC) coating solution. NIR spectra were acquired via a fiber-optic probe during the coating process, followed by multivariate analysis utilizing partial least squares (PLS) calibration models. The actual coating thickness of pellets was measured by two separate methods, confocal laser scanning microscopy (CLSM) and laser diffraction particle size analysis (LD-PSA). Both characterization methods gave superb correlation results, and all determination coefficient (R(2)) values exceeded 0.995. In addition, a prediction coating experiment for 70min demonstrated that the end-point can be accurately designated via NIR in-line monitoring with appropriate calibration models. In conclusion, our approach combining in-line NIR monitoring with CLSM and LD-PSA can be applied as an effective PAT tool for fluid-bed pellet coating processes.

  8. Inversion of Bedding and Parasequence Types Preserved in Shelfal Mudstone Strata to Significant Marine Processes

    Science.gov (United States)

    Bohacs, K.; Lazar, R.; Demko, T.

    2012-12-01

    Mudstone strata contain an almost bewildering variety of physical, chemical, and biogenic attributes at the lamina to bed scale (mm - dm). Our observations of more than 7 km of Paleozoic to Pliocene mudstone revealed patterns in this variety of such macroscopic attributes as lithofacies, bedding, sedimentary structures, and stratal stacking patterns at the bedset to parasequence scale (cm - m). We quantified characteristics of each association and linked them to sets of depositional processes. Most shelfal mudstone strata appear to have accumulated in one of three end-member facies association successions (FASs) that can be related to physiographic settings and depositional regimes through characteristic modes of sediment transport and accumulation, as well as variations in benthic-energy and oxygen levels. FAS-1 comprises 1- to 10-meter-thick coarsening/thickening-upward stratal units, defined by lithologic indices: percent sandstone/siltstone/grainstone (Ss/Zs/Gs), maximum grain size, thickness of individual Ss/Zs/Gs bedsets. These FASs also have increasing total-organic-carbon content (TOC) and planktonic material in basal bedsets, overlain by an interval with an upward decrease in TOC and planktonic microfossil abundance along with an upward increase in skeletal phosphate, palynomorph content, and bioturbation. FAS-2 comprise 1- to 14-meter-thick coarsening/thickening-upward stratal units, defined by similar lithologic indices and changes as FAS-1; FAS-2 also has an upward decrease in content of TOC and planktonic microfossils, skeletal phosphate, and ichnofossil abundance and diversity. Very basal bedsets tend to have relatively low concentrations of planktonic material. Also distinctive are the common occurrence of palynodebris throughout (in post-Silurian rocks), with thin lags of macrofossils and skeletal phosphate in basal portions, Bouma B-C bedsets, and soft-sediment deformation with minimal, horizontal burrows in its middle portions, and scours, graded

  9. Industrial demonstration plant for the gasification of herb residue by fluidized bed two-stage process.

    Science.gov (United States)

    Zeng, Xi; Shao, Ruyi; Wang, Fang; Dong, Pengwei; Yu, Jian; Xu, Guangwen

    2016-04-01

    A fluidized bed two-stage gasification process, consisting of a fluidized-bed (FB) pyrolyzer and a transport fluidized bed (TFB) gasifier, has been proposed to gasify biomass for fuel gas production with low tar content. On the basis of our previous fundamental study, an autothermal two-stage gasifier has been designed and built for gasify a kind of Chinese herb residue with a treating capacity of 600 kg/h. The testing data in the operational stable stage of the industrial demonstration plant showed that when keeping the reaction temperatures of pyrolyzer and gasifier respectively at about 700 °C and 850 °C, the heating value of fuel gas can reach 1200 kcal/Nm(3), and the tar content in the produced fuel gas was about 0.4 g/Nm(3). The results from this pilot industrial demonstration plant fully verified the feasibility and technical features of the proposed FB two-stage gasification process.

  10. Materials problems in fluidized-bed combustion systems: effect of process variables on in-bed corrosion. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Minchener, A.J.; Rogers, E.A.; LaNauze, R.D.

    1980-08-01

    The influence of operating conditions in a coal fired fluidized bed combustor on the rate of fireside corrosion of air cooled heat exchanger tubes, with metal temperatures in the range 540/sup 0/C to 900/sup 0/C, has been investigated. Four 250 hour tests were carried out on a 0.3 m square atmospheric pressure fluidized bed combustor operating with a fluidizing velocity of 0.9 ms/sup -1/, 10 to 20% excess air and bed temperatures of 850/sup 0/C and 900/sup 0/C. The feed coal was Illinois No. 6 which was used both with and without the addition of limestones to suppress the emission of sulfur oxides. A test without the addition of limestone showed very little corrosive attack of any metal components. Tests with the addition of limestone showed a range of corrosive attack. In general, where different alloy types were exposed at the same metal temperature, the iron based austenitic steels showed a better corrosion resistance than the nickel based alloys. This result strongly supports the model for the corrosion which has been developed as a result of the earlier investigations. This model postulates that local regions of low oxygen activity exist in the system, and, in the presence of calcium sulfate, these result in the generation of high local sulfur activities. The combination of low oxygen and high sulfur activities leads to sulfidation of sensitive alloys.

  11. Rhythmic bedding in prodeltaic deposits of the ancient Colorado River: Exploring genetic processes

    Science.gov (United States)

    Waresak, Sandra; Nalin, Ronald; Lucarelli, Andrea

    2016-04-01

    Prodeltaic deposits represent a valuable archive for the characterization of deltaic depositional systems, offering a distal, minimally reworked record of dominant processes active at the fluvial-marine interface. The Fish Creek Basin (CA, US) preserves a ~ 3-km thick, lower Pliocene, progradational deltaic succession formed when the ancestral Colorado River infiltrated a marine rift basin (the early Gulf of California). The unit in this succession interpreted as prodeltaic, corresponding to the upper Mud Hills Member of the Deguynos Formation, consists of ~ 300 m of muddy siltstones. A striking attribute of parts of this unit is the presence of rhythmic bedding, with consistently alternating silt- to fine sand-dominated and clay-dominated beds forming couplets with an average thickness of 12 cm. By performing a detailed sedimentological analysis of the rhythmites and investigating periodicities in bed thickness, our study aimed at reconstructing the mode of deposition of this enigmatic prodeltaic succession. We measured at high stratigraphic resolution 265 consecutive couplets, for a total thickness of 33 m. Individual beds have good lateral persistence of at least tens of meters and gradational to sharp, flat contacts. Observed sedimentary structures are concentrated on the coarser portion of the couplets and mostly consist of parallel and wavy lamination, with subordinate ripple cross-lamination and localized internal scours. Bioturbation appears low in intensity or absent. Most notably, grain size analysis performed with laser diffraction techniques on several couplets shows a consistent pattern of inverse grading transitioning to normal grading. The cumulative evidence of these sedimentological features indicates that deposition of the rhythmites was accomplished via hyperpycnal flows, each couplet most likely representing an individual event in a setting characterized by high overall depositional rates. We performed time series analysis on bed thickness of

  12. A Spouted Bed Reactor Monitoring System for Particulate Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    D. S. Wendt; R. L. Bewley; W. E. Windes

    2007-06-01

    Conversion and coating of particle nuclear fuel is performed in spouted (fluidized) bed reactors. The reactor must be capable of operating at temperatures up to 2000°C in inert, flammable, and coating gas environments. The spouted bed reactor geometry is defined by a graphite retort with a 2.5 inch inside diameter, conical section with a 60° included angle, and a 4 mm gas inlet orifice diameter through which particles are removed from the reactor at the completion of each run. The particles may range from 200 µm to 2 mm in diameter. Maintaining optimal gas flow rates slightly above the minimum spouting velocity throughout the duration of each run is complicated by the variation of particle size and density as conversion and/or coating reactions proceed in addition to gas composition and temperature variations. In order to achieve uniform particle coating, prevent agglomeration of the particle bed, and monitor the reaction progress, a spouted bed monitoring system was developed. The monitoring system includes a high-sensitivity, low-response time differential pressure transducer paired with a signal processing, data acquisition, and process control unit which allows for real-time monitoring and control of the spouted bed reactor. The pressure transducer is mounted upstream of the spouted bed reactor gas inlet. The gas flow into the reactor induces motion of the particles in the bed and prevents the particles from draining from the reactor due to gravitational forces. Pressure fluctuations in the gas inlet stream are generated as the particles in the bed interact with the entering gas stream. The pressure fluctuations are produced by bulk movement of the bed, generation and movement of gas bubbles through the bed, and the individual motion of particles and particle subsets in the bed. The pressure fluctuations propagate upstream to the pressure transducer where they can be monitored. Pressure fluctuation, mean differential pressure, gas flow rate, reactor

  13. Application of quality by design concepts in the development of fluidized bed granulation and tableting processes.

    Science.gov (United States)

    Djuris, Jelena; Medarevic, Djordje; Krstic, Marko; Djuric, Zorica; Ibric, Svetlana

    2013-06-01

    This study illustrates the application of experimental design and multivariate data analysis in defining design space for granulation and tableting processes. According to the quality by design concepts, critical quality attributes (CQAs) of granules and tablets, as well as critical parameters of granulation and tableting processes, were identified and evaluated. Acetaminophen was used as the model drug, and one of the study aims was to investigate the possibility of the development of immediate- or extended-release acetaminophen tablets. Granulation experiments were performed in the fluid bed processor using polyethylene oxide polymer as a binder in the direct granulation method. Tablets were compressed in the laboratory excenter tablet press. The first set of experiments was organized according to Plackett-Burman design, followed by the full factorial experimental design. Principal component analysis and partial least squares regression were applied as the multivariate analysis techniques. By using these different methods, CQAs and process parameters were identified and quantified. Furthermore, an in-line method was developed to monitor the temperature during the fluidized bed granulation process, to foresee possible defects in granules CQAs. Various control strategies that are based on the process understanding and assure desired quality attributes of the product are proposed.

  14. Study on mixing and segregation behaviors in particulate fluidized bed system for mineral processing

    Institute of Scientific and Technical Information of China (English)

    Sahu S.N.; Sahu A.K.; Biswal S.K

    2015-01-01

    In order to identify the mixing and segregation behaviors in a mineral processing operation, present study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite (4800 kg/m3) and quartz (2600 kg/m3) at different size fractions in the range of average size 87 ? 10?6 m to 400 ? 10?6 m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass (50%) at a particular height of fluidized bed, referred as ‘locus point’ of mixing. Study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is enhanced. Further, the present study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.

  15. Chemical looping combustion in a rotating bed reactor--finding optimal process conditions for prototype reactor.

    Science.gov (United States)

    Håkonsen, Silje Fosse; Blom, Richard

    2011-11-15

    A lab-scale rotating bed reactor for chemical looping combustion has been designed, constructed, and tested using a CuO/Al(2)O(3) oxygen carrier and methane as fuel. Process parameters such as bed rotating frequency, gas flows, and reactor temperature have been varied to find optimal performance of the prototype reactor. Around 90% CH(4) conversion and >90% CO(2) capture efficiency based on converted methane have been obtained. Stable operation has been accomplished over several hours, and also--stable operation can be regained after intentionally running into unstable conditions. Relatively high gas velocities are used to avoid fully reduced oxygen carrier in part of the bed. Potential CO(2) purity obtained is in the range 30 to 65%--mostly due to air slippage from the air sector--which seems to be the major drawback of the prototype reactor design. Considering the prototype nature of the first version of the rotating reactor setup, it is believed that significant improvements can be made to further avoid gas mixing in future modified and up-scaled reactor versions.

  16. High efficiency pollutant removal with the Moving-Bed Copper Oxide Process

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Hoffman, J.S.; Yeh, J.T. [Dept. of Energy, Pittsburgh, PA (United States). Pittsburgh Energy Technology Center; Resnik, K.P.; Vore, P.A. [Gilbert Commonwealth, Inc., Pittsburgh, PA (United States)

    1995-12-31

    Dry, regenerable flue gas cleanup techniques that use a sorbent can have various advantages, such as simultaneous removal of pollutants, production of a salable by-product, and low costs when compared to commercially available scrubbing technology. Due to the temperature of reaction, the placement of the process into an advanced power system could actually increase the thermal efficiency of the plant. One such technique, the Moving-Bed Copper Oxide Process, is capable of simultaneously removing sulfur oxides and nitric oxides within the reactor system. A parametric study of the process was conducted on a life-cycle test system. All process steps, including absorption and regeneration, were integrated into this life-cycle test system so that continuous, long-term operation of the total process cold be experimentally evaluated. The effects of absorption temperature, sorbent and gas residence times, and inlet SO{sub 2} and NO{sub x} concentration on removal efficiencies and overall operational performance are discussed.

  17. Investigation of the moving-bed copper oxide process for flue gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Hoffman, J.S.; Yeh, J.T. [Dept. of Energy, Pittsburgh, PA (United States). Pittsburgh Energy Technology Center; Resnik, K.P.; Vore, P.A. [Parsons Power Group, Inc., Pittsburgh, PA (United States)

    1996-12-31

    The Moving-Bed Copper Oxide Process is a dry, regenerable sorbent technique that uses supported copper oxide sorbent to simultaneously remove SO{sub 2} and NO{sub x} emissions from flue gas generated by coal combustion. The process can be integrated into the design of advanced power systems, such as the Low-Emission Boiler System (LEBS) or the High-Performance Power System (HIPPS). This flue gas cleanup technique is currently being evaluated in a life-cycle test system (LCTS) with a moving-bed flue gas contactor at DOE`s Pittsburgh Energy Technology Center. An experimental data base being established will be used to verify reported technical and economic advantages, optimize process conditions, provide scaleup information, and validate absorber and regenerator mathematical models. In this communication, the results from several process parametric test series with the LCTS are discussed. The effects of various absorber and regenerator parameters on sorbent performance (e.g., SO{sub 2} removal) were investigated. Sorbent spheres of 1/8-in diameter were used as compared to 1/16-in sized sorbent of a previous study. Also discussed are modifications to the absorber to improve the operability of the LCTS when fly ash is present during coal combustion.

  18. Applicability of fluidized bed reactor in recalcitrant compound degradation through advanced oxidation processes: a review.

    Science.gov (United States)

    Tisa, Farhana; Abdul Raman, Abdul Aziz; Wan Daud, Wan Mohd Ashri

    2014-12-15

    Treatment of industrial waste water (e.g. textile waste water, phenol waste water, pharmaceutical etc) faces limitation in conventional treatment procedures. Advanced oxidation processes (AOPs) do not suffer from the limits of conventional treatment processes and consequently degrade toxic pollutants more efficiently. Complexity is faced in eradicating the restrictions of AOPs such as sludge formation, toxic intermediates formation and high requirement for oxidants. Increased mass-transfer in AOPs is an alternate solution to this problem. AOPs combined with Fluidized bed reactor (FBR) can be a potential choice compared to fixed bed or moving bed reactor, as AOP catalysts life-span last for only maximum of 5-10 cycles. Hence, FBR-AOPs require lesser operational and maintenance cost by reducing material resources. The time required for AOP can be minimized using FBR and also treatable working volume can be increased. FBR-AOP can process from 1 to 10 L of volume which is 10 times more than simple batch reaction. The mass transfer is higher thus the reaction time is lesser. For having increased mass transfer sludge production can be successfully avoided. The review study suggests that, optimum particle size, catalyst to reactor volume ratio, catalyst diameter and liquid or gas velocity is required for efficient FBR-AOP systems. However, FBR-AOPs are still under lab-scale investigation and for industrial application cost study is needed. Cost of FBR-AOPs highly depends on energy density needed and the mechanism of degradation of the pollutant. The cost of waste water treatment containing azo dyes was found to be US$ 50 to US$ 500 per 1000 gallons where, the cost for treating phenol water was US$ 50 to US$ 800 per 1000 gallons. The analysis for FBR-AOP costs has been found to depend on the targeted pollutant, degradation mechanism (zero order, 1st order and 2nd order) and energy consumptions by the AOPs.

  19. Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Granular activated carbon (GAC) anaerobic fluidized-bed reactor was applied to treating phenols wastewater. When influent phenol concentration was 1000 mg/L, volume loadings of phenol and CODCr were 0.39 kg/(m3*d) and 0.98 kg/(m3*d), their removal rates were 99.9% and 96.4% respectively. From analyzing above results, the main mechanisms of the process are that through fluidizing GAC, its adsorption is combined with biodegradation, both activities are brought into full play, and phenol in wastewater is effectively decomposed. Meanwhile problems concerning gas-liquid separation and medium plugging are well solved.

  20. Process development and modeling of fluidized-bed reactor with coimmobilized biocatalyst for fuel ethanol production

    Science.gov (United States)

    Sun, May Yongmei

    This research focuses on two steps of commercial fuel ethanol production processes: the hydrolysis starch process and the fermentation process. The goal of this research is to evaluate the performance of co-immobilized biocatalysts in a fluidized bed reactor with emphasis on economic and engineering aspects and to develop a predictive mathematical model for this system. The productivity of an FBR is higher than productivity of a traditional batch reactor or CSTR. Fluidized beds offer great advantages over packed beds for immobilized cells when small particles are used or when the reactant feed contains suspended solids. Plugging problems, excessive pressure drops (and thus attrition), or crushing risks may be avoided. No mechanical stirring is required as mixing occurs due to the natural turbulence in the fluidized process. Both enzyme and microorganism are immobilized in one catalyst bead which is called co-immobilization. Inside this biocatalyst matrix, starch is hydrolyzed by the enzyme glucoamylase to form glucose and then converted to ethanol and carbon dioxide by microorganisms. Two biocatalysts were evaluated: (1) co-immobilized yeast strain Saccharomyces cerevisiae and glucoamylase. (2) co-immobilized Zymomonas mobilis and glucoamylase. A co-immobilized biocatalyst accomplishes the simultaneous saccharification and fermentation (SSF process). When compared to a two-step process involving separate saccharification and fermentation stages, the SSF process has productivity values twice that given by the pre-saccharified process when the time required for pre-saccharification (15--25 h) was taken into account. The SSF process should also save capital cost. The information about productivity, fermentation yield, concentration profiles along the bed, ethanol inhibition, et al., was obtained from the experimental data. For the yeast system, experimental results showed that: no apparent decrease of productivity occurred after two and half months, the productivity

  1. Development of regenerable sorbents for the Copper Oxide Bed Regenerable Absorber (COBRA) process

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B. [Inst. of Gas Technology, Des Plaines, IL (United States); Carty, R.H. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1999-07-01

    In the clean air act amendments (CAAA) of 1990, legislation was introduced requiring electric utilities to adopt available technology for removal of pollutant gases (mainly SO{sub 2} and NO{sub x}) and particulates from coal combustion flue gases so that the increased use of coal is done in an environmentally acceptable manner. The copper oxide process has been selected as one of the most promising emerging technologies for SO{sub 2} and NO{sub x} removal from flue gases in the Combustion 2000 program of the U.S. Department of Energy. In particular, the development of the Copper Oxide Bed Regenerable Absorber (COBRA) process, which is based on moving-bed cross-flow reactor design for the combined removal of SO{sub 2}, NO{sub x}, and particulates, has been pursued in conjunction with the use of Illinois coal. This ongoing study has been directed towards the evaluation of the ALCOA copper oxide sorbent currently being utilized in the demonstration of the COBRA process, to identify areas of improvement, and to develop and implement a strategy for preparing improved sorbents. The targeted areas of sorbent improvement include higher reactivity, higher theoretical sulfur capacity, lower regeneration temperature, and better attrition resistance. In this paper, the results obtained to-date from tests carried out for the evaluation of the commercial sorbent for SO2 removal from simulated flue gases, its regenerability, and its effectiveness with repeated use are presented and discussed. (orig.)

  2. Performance analysis of RDF gasification in a two stage fluidized bed-plasma process.

    Science.gov (United States)

    Materazzi, M; Lettieri, P; Taylor, R; Chapman, C

    2016-01-01

    The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.

  3. Ignition technique for an in situ oil shale retort

    Science.gov (United States)

    Cha, Chang Y.

    1983-01-01

    A generally flat combustion zone is formed across the entire horizontal cross-section of a fragmented permeable mass of formation particles formed in an in situ oil shale retort. The flat combustion zone is formed by either sequentially igniting regions of the surface of the fragmented permeable mass at successively lower elevations or by igniting the entire surface of the fragmented permeable mass and controlling the rate of advance of various portions of the combustion zone.

  4. Modified graphical autocatalytic set model of combustion process in circulating fluidized bed boiler

    Science.gov (United States)

    Yusof, Nurul Syazwani; Bakar, Sumarni Abu; Ismail, Razidah

    2014-07-01

    Circulating Fluidized Bed Boiler (CFB) is a device for generating steam by burning fossil fuels in a furnace operating under a special hydrodynamic condition. Autocatalytic Set has provided a graphical model of chemical reactions that occurred during combustion process in CFB. Eight important chemical substances known as species were represented as nodes and catalytic relationships between nodes are represented by the edges in the graph. In this paper, the model is extended and modified by considering other relevant chemical reactions that also exist during the process. Catalytic relationship among the species in the model is discussed. The result reveals that the modified model is able to gives more explanation of the relationship among the species during the process at initial time t.

  5. Numerical investigation of solid mixing in a fluidized bed coating process

    Science.gov (United States)

    Kenche, Venkatakrishna; Feng, Yuqing; Ying, Danyang; Solnordal, Chris; Lim, Seng; Witt, Peter J.

    2013-06-01

    Fluidized beds are widely used in many process industries including the food and pharmaceutical sectors. Despite being an intensive research area, there are no design rules or correlations that can be used to quantitatively predict the solid mixing in a specific system for a given set of operating conditions. This paper presents a numerical study of the gas and solid dynamics in a laboratory scale fluidized bed coating process used for food and pharmaceutical industries. An Eulerian-Eulerian model (EEM) with kinetic theory of granular flow is selected as the modeling technique, with the commercial computational fluid dynamics (CFD) software package ANSYS/Fluent being the numerical platform. The flow structure is investigated in terms of the spatial distribution of gas and solid flow. The solid mixing has been evaluated under different operating conditions. It was found that the solid mixing rate in the horizontal direction is similar to that in the vertical direction under the current design and operating conditions. It takes about 5 s to achieve good mixing.

  6. FUZZY INFERENCE SYSTEM MODELING FOR BED ACTIVE CARBON RE-GENERATION PROCESS (CO2 GAS FACTORY CASE

    Directory of Open Access Journals (Sweden)

    S. Febriana

    2005-01-01

    Full Text Available Bed active carbon is one of the most important materials that had great impact in determining level of impurities in production of CO2 gas. In this particular factory case, there is unavailability of standard duration time of heating and cooling and steam flow rate for the re-generation process of bed active carbon. The paper discusses the fuzzy inference system for modeling of re-generation process of bed active carbon to find the optimum setting parameter. The fuzzy inference system was build using real historical daily processing data. After validation process, surface plot analysis was performed to find the optimum setting. The result of re-generation parameter setting is 9-10 hours of heating process, 4.66-5.32 hours of cooling process, and 1500-2500 kg/hr of steam flow rate.

  7. Modeling of spatial lag in bed-load transport processes and its effect on dune morphology

    NARCIS (Netherlands)

    Duin, van O.J.M.; Hulscher, S.J.M.H.; Ribberink, J.S.; Dohmen-Janssen, C.M.

    2016-01-01

    In the present study, two bed-load transport models are introduced in an existing idealized dune model. These allow for the modeling of the spatial lag between the sediment transport rate and bed shear stress along dune surfaces. This lag is an important factor in determining transitions between bed

  8. Process defects and in situ monitoring methods in metal powder bed fusion: a review

    Science.gov (United States)

    Grasso, Marco; Colosimo, Bianca Maria

    2017-04-01

    Despite continuous technological enhancements of metal Additive Manufacturing (AM) systems, the lack of process repeatability and stability still represents a barrier for the industrial breakthrough. The most relevant metal AM applications currently involve industrial sectors (e.g. aerospace and bio-medical) where defects avoidance is fundamental. Because of this, there is the need to develop novel in situ monitoring tools able to keep under control the stability of the process on a layer-by-layer basis, and to detect the onset of defects as soon as possible. On the one hand, AM systems must be equipped with in situ sensing devices able to measure relevant quantities during the process, a.k.a. process signatures. On the other hand, in-process data analytics and statistical monitoring techniques are required to detect and localize the defects in an automated way. This paper reviews the literature and the commercial tools for in situ monitoring of powder bed fusion (PBF) processes. It explores the different categories of defects and their main causes, the most relevant process signatures and the in situ sensing approaches proposed so far. Particular attention is devoted to the development of automated defect detection rules and the study of process control strategies, which represent two critical fields for the development of future smart PBF systems.

  9. Two—Dimensional Mathematical Model and Numerical Simulation Describing the Melting Process of Cylindrical Basalt Bed

    Institute of Scientific and Technical Information of China (English)

    YanQuanying; ShangDeku; 等

    1999-01-01

    A two-dimensional mathematical model was built to describe the melting process of cylindrical basalt particle bed in a crucible.The melting processes with respect to the factors of thermal boundary conditions and particle sizes of basalt were simulated by using the numerical method (FDM).The governing equations were discretized in tridiagonal matrix form and were solved by using the tridiagonal matrix algorithm (TDMA) as well as the alternative direction implicit(ADI) solver.The temperature distribution,the moving law of the two dimensional phase-change boundaries the thermal current distribution were given through the numerical simulation.The results provided a theoretical basis for deciding heating procedure,for evaluating power import and controlling furnace temperature and for predicting basalt melting states etc.In the experiment,an electrical furnace was designed based on the computations.It has been proved that the simulation results are reasonably coincident with the experimental data.

  10. COLLISION PROCESS DETAILS CONTROL THE HYDRODYNAMICS AND HEAT TRANSFER IN FLUIDIZED BED REACTORS

    Institute of Scientific and Technical Information of China (English)

    Masayuki; Horio

    2005-01-01

    In the '90s DEM simulation research was successful in exploring its potential in the simulation of fluidization phenomenaand in its application to the design of fluidized-bed processes. Nevertheless, not much progress has been made regardingthe realistic treatment of collision processes that are critical in determining macroscopic mode of fluidization. All throughthe second half of the '90s, the author investigated/demonstrated the issue by introducing different surface interactionscaused by formation of liquid and/or solid bridges, van der Waals force and the existence of surface roughness. In the firstpart of the presentation these are to be summarized and the tasks remaining are discussed. In the second part, are pre-sented the results from a newly developed force-deformation meter to demonstrate the significance of the surfaceroughness and its elasto-plastic characteristics.

  11. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25-1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  12. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300°C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200–230ºC and 270–280ºC. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25–1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  13. Tensiomygraphic Measurement of Atrophy Related Processes During Bed Rest and Recovery

    Science.gov (United States)

    Simunic, B. ostjan; Degens, Hans; Rittweger, Jorn; Narici, Marcco; Pisot, Venceslav; Mekjavic, Igor B.; Pisot, Rado

    2013-02-01

    Tensiomyographic (TMG) parameters were recently proposed for a non-invasive estimation of MHC distribution in human vastus lateralis muscle. However, TMG potential is even higher, offers additional insight into the skeletal muscle physiology, especially in the field of atrophy and hypertrophy. The purpose of this study is in developing time dynamics of TMG-measured contraction time (Tc) and maximal response amplitude (Dm), together with muscle belly thickness, measure thoroughly during 35-day bed rest and followed in 30-day recovery (N = 10 males; age 24.3 ± 2.6 years). Measurements were performed in two postural muscles (vastus medialis and lateralis) and one non-postural muscle (biceps femoris). During bed rest period we found different dynamics of muscle thickness decrease and Dm increase. Tc was unchanged in postural muscles, but in non-postural muscle increased significantly and stayed as such even at the end of recovery. We could conclude that TMG related parameters are more sensitive in measuring muscle atrophic and hypertrophic processes than biomedical imaging technique. However, a mechanism that regulates Dm still needs to be identified.

  14. Preparative chromatography with supercritical fluids. Comparison of simulated moving bed and batch processes.

    Science.gov (United States)

    Peper, Stephanie; Johannsen, Monika; Brunner, Gerd

    2007-12-28

    Preparative chromatography is a key technology for the separation of fine chemicals in production scale. Most of the published studies are carried out using liquid solvents as mobile phase. However, the used organic solvents can often be replaced by supercritical fluids. A reduction or renouncement of organic solvents does not only correspond to the trend of the so-called green chemistry--a sustainable, environmentally friendly production of chemical products. But a changeover to chromatography with supercritical fluids can also be reasonable under economic criteria. In this contribution a comparison between the Batch-supercritical fluid chromatography (Batch-SFC) process and the simulated moving bed (SMB)-SFC process is presented. Because of the minor importance of solvent consumption and solvent recovery in SFC, the separation systems were optimized primarily in terms of their specific productivity. For three of the four investigated model systems, the specific productivity of the SMB process is significantly higher than the productivity of the Batch process. Due to the fact, that the process with the higher specific productivity is not inevitably the more economical process, supplementary the costs of the process were considered. Therefore the comparison of the two processes was done from an economic point of view considering the minimum product price that has to be realized to fulfill the defined economic aim. It was found that although the optimized specific productivities of the SMB process were significantly higher than the productivities of the Batch process, the Batch process is the more profitable process for the investigated production rate range between 0.4 and 5t/a.

  15. Acid mine drainage potential of raw, retorted, and combusted Eastern oil shale: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, P.J.; Yelton, J.L.; Reddy, K.J.

    1987-09-01

    In order to manage the oxidation of pyritic materials effectively, it is necessary to understand the chemistry of both the waste and its disposal environment. The objective of this two-year study was to characterize the acid production of Eastern oil shale waste products as a function of process conditions, waste properties, and disposal practice. Two Eastern oil shales were selected, a high pyrite shale (unweathered 4.6% pyrite) and a low pyrite shale (weathered 1.5% pyrite). Each shale was retorted and combusted to produce waste products representative of potential mining and energy conversion processes. By using the standard EPA leaching tests (TCLP), each waste was characterized by determining (1) mineralogy, (2) trace element residency, and (3) acid-base account. Characterizing the acid producing potential of each waste and potential trace element hazards was completed with laboratory weathering studies. 32 refs., 21 figs., 12 tabs.

  16. Optimization and scale-up of a fluid bed tangential spray rotogranulation process.

    Science.gov (United States)

    Bouffard, J; Dumont, H; Bertrand, F; Legros, R

    2007-04-20

    The production of pellets in the pharmaceutical industry generally involves multi-step processing: (1) mixing, (2) wet granulation, (3) spheronization and (4) drying. While extrusion-spheronization processes have been popular because of their simplicity, fluid-bed rotogranulation (FBRG) is now being considered as an alternative, since it offers the advantages of combining the different steps into one processing unit, thus reducing processing time and material handling. This work aimed at the development of a FBRG process for the production of pellets in a 4.5-l Glatt GCPG1 tangential spray rotoprocessor and its optimization using factorial design. The factors considered were: (1) rotor disc velocity, (2) gap air pressure, (3) air flow rate, (4) binder spray rate and (5) atomization pressure. The pellets were characterized for their physical properties by measuring size distribution, roundness and flow properties. The results indicated that: pellet mean particle size is negatively affected by air flow rate and rotor plate speed, while binder spray rate has a positive effect on size; pellet flow properties are enhanced by operating with increased air flow rate and worsened with increased binder spray rate. Multiple regression analysis enabled the identification of an optimal operating window for production of acceptable pellets. Scale-up of these operating conditions was tested in a 30-l Glatt GPCG15 FBRG.

  17. A new process control strategy for aqueous film coating of pellets in fluidised bed

    DEFF Research Database (Denmark)

    Larsen, C.C.; Sonnergaard, Jørn; Bertelsen, Pernille Scholdan;

    2003-01-01

    The parameters with effect on maximum spray rate and maximum relative outlet air humidity when coating pellets in a fluidised bed were investigated. The tested variables include type of water based modified release film coating (Eudragit® NE 30D, Eudragit® RS 30D, Aquacoat ECD®) coating principle...... (top spray, bottom spray), inlet air humidity and type of pellets (sugar spheres, microcrystalline cellulose pellets). The maximum spray rate was not influenced by the coating principles. The highest spray rate was obtained for the film polymer with the lowest tackiness which is assumed......-process calculation of degree of utilisation of the potential evaporation energy (DUE) of the outlet air and the relative outlet air humidity (RH). The spray rate is maximised using set points of DUE and RH as control parameters. The product temperature is controlled simultaneously by regulating the inlet air...

  18. Development of a fluid bed granulation process control strategy based on real-time process and product measurements.

    Science.gov (United States)

    Burggraeve, Anneleen; Silva, Ana F T; Van den Kerkhof, Tom; Hellings, Mario; Vervaet, Chris; Remon, Jean Paul; Vander Heyden, Yvan; De Beer, Thomas

    2012-10-15

    This article describes the results of three case studies conducted consecutively, in order to develop a process control strategy for a top-spray fluid bed granulation process. The use of several real-time particle size (i.e., spatial filter velocimetry and focused beam reflectance measurement) and moisture (i.e., near infrared (NIR) and Lighthouse near infrared spectroscopy) analyzers was examined. A feed-forward process control method was developed, where in-line collected granulation information during the process spraying phase was used to determine the optimum drying temperature of the consecutive drying phase. Via real-time monitoring of process (i.e., spraying temperature and spray rate) and product (i.e., granule size distribution and moisture) parameters during the spraying period, the batch bulk density was predicted at the end of the spraying cycle, using a PLS model. When this predicted bulk density was not meeting the desired value, the developed control method allowed the calculation of an adjusted drying temperature leading to the desired batch bulk density at the end of the granulation process. Besides the development of the feed-forward control strategy, a quantitative PLS model for in-line moisture content prediction of the granulated end product was built using the NIR data.

  19. Development of improved sorbents for the moving-bed copper oxide process

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B.; Carty, R.H.; Cengiz, P.A.; Khalili, N.R.

    1999-07-01

    In the Clean Air Act Amendments (CAAA) of 1990, legislation was introduced requiring electric utilities to adopt available technology for removal of pollutant gases (mainly SO{sub 2} and NO{sub x}) and particulates from coal combustion flue gases so that the increased use of coal is done in an environmentally acceptable manner. The threat from the damaging effects of gaseous pollutants is more of a concern in the state of Illinois where over 90% of the high-sulfur coal mined is consumed by electric utilities that are based on pulverized coal combustion, but only a very small fraction is currently equipped with Flue Gas Desulfurization (FGD) processes. The copper oxide process has been selected as one of the most promising emerging technologies for SO{sub 2} and NO{sub x} removal from flue gases in the Combustion 2000 program of the US Department of Energy. In particular, the development of the Copper Oxide Bed Regenerable Absorber (COBRA) process, which is based on moving-bed cross-flow reactor design for the combined removal of SO{sub 2}, NO{sub x} and particulates, has been pursued in conjunction with the use of Illinois coal. Given the strict limits on SO{sub 2} emissions (1.2 lbs of SO{sub 2} per million Btu by the year 2000), the high sulfur content of Illinois coal, and the growing concern with the disposal of solid residues from conventional FGD processes, the pursuit of the COBRA technology to meet CAAA emission standards represents a strategic choice for the Illinois coal research and development program. This Study has been directed towards the evaluation of the commodity copper oxide sorbent currently being utilized in the demonstration of the COBRA process, to identify areas of improvement, and to develop and implement a strategy for preparing improved sorbents. In this paper, the results obtained to-date from tests carried out for the evaluation of the commercial sorbent for SO{sub 2} removal, its regenerability, and its effectiveness with repeated use

  20. Development of retort porch bovine runnet%牛百叶软罐头的研制

    Institute of Scientific and Technical Information of China (English)

    吴红棉; 董萍; 洪鹏志

    2001-01-01

    以牛百叶为原料,以PET/AL/PP复合蒸煮袋作包装材料,经原料处理、预煮、油炸、浸汤、真空封口、杀菌等工序,制得牛百叶软罐头。研究了各工序中的最佳工艺条件及不同的复合材料包装袋对制品质量的影响。%A PET/AL/PP packed retort porch bovine runnet was d eveloped bypretreatment,precooking,frying,soaking,vacuum packaging and steriliz ation. The effects of processing parameters and packaging materials on the quali ty of the product were studied.

  1. Evaluation of Selected Chemical Processes for Production of Low-cost Silicon, Phase 3. [using a fluidized bed reactor

    Science.gov (United States)

    Blocher, J. M., Jr.; Browning, M. F.

    1979-01-01

    The construction and operation of an experimental process system development unit (EPSDU) for the production of granular semiconductor grade silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles is presented. The construction of the process development unit (PDU) is reported. The PDU consists of four critical units of the EPSDU: the fluidized bed reactor, the reactor by product condenser, the zinc vaporizer, and the electrolytic cell. An experimental wetted wall condenser and its operation are described. Procedures are established for safe handling of SiCl4 leaks and spills from the EPSDU and PDU.

  2. Research on the pyrolysis of hardwood in an entrained bed process development unit

    Energy Technology Data Exchange (ETDEWEB)

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O' Neil, D.J. (Georgia Inst. of Tech., Atlanta, GA (United States). Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  3. Nitrogen cycling processes and microbial community composition in bed sediments in the Yukon River at Pilot Station

    Science.gov (United States)

    Repert, Deborah A.; Underwood, Jennifer C.; Smith, Richard L.; Song, Bongkeun

    2014-01-01

    Information on the contribution of nitrogen (N)-cycling processes in bed sediments to river nutrient fluxes in large northern latitude river systems is limited. This study examined the relationship between N-cycling processes in bed sediments and N speciation and loading in the Yukon River near its mouth at the Bering Sea. We conducted laboratory bioassays to measure N-cycling processes in sediment samples collected over distinct water cycle seasons. In conjunction, the microbial community composition in the bed sediments using genes involved in N-cycling (narG, napA, nosZ, and amoA) and 16S rRNA gene pyrosequences was examined. Temporal variation was observed in net N mineralization, nitrate uptake, and denitrification rate potentials and correlated strongly with sediment carbon (C) and extractable N content and microbial community composition rather than with river water nutrient concentrations. The C content of the bed sediment was notably impacted by the spring flood, ranging from 1.1% in the midst of an ice-jam to 0.1% immediately after ice-out, suggesting a buildup of organic material (OM) prior to scouring of the bed sediments during ice break up. The dominant members of the microbial community that explained differences in N-processing rates belonged to the genera Crenothrix,Flavobacterium, and the family of Comamonadaceae. Our results suggest that biogeochemical processing rates in the bed sediments appear to be more coupled to hydrology, nutrient availability in the sediments, and microbial community composition rather than river nutrient concentrations at Pilot Station.

  4. Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    GUAN Bao-hong

    2005-01-01

    Terylene artificial silk printing and dyeing wastewater(TPD wastewater), containing averaged 710 mg/L terephthalic acid(TA) as the main carbon source and the character pollutant, was subjected to expanded granular sludge bed(EGSB) process. The stability of theEGSB process was firstly conducted by laboratory experiment. TA ionization was the predominated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to neutralize the volatile fatty acids(VFA)generated from substrate degradation and provided strong base for anaerobic system to resist the pH decrease below 6.5. VFA and UFA caused almost no inhibition on the anaerobic process and biogas production except that pH was below 6.35 and VFA was at its maximum value. Along with the granulating of the activated sludge, the efficiency of organic removal and production rate of biogas increased gradually and became more stable. After start-up, the efficiency of COD removal increased to 57%-64%, pH stabilized in a range of 7.99-8.04, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted in neglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment.

  5. Morphodynamic river processes and techniques for assessment of channel evolution in Alpine gravel bed rivers

    Science.gov (United States)

    Formann, E.; Habersack, H. M.; Schober, St.

    2007-10-01

    Over the past 10 years many restoration projects have been undertaken in Austria, and river engineering measures such as spur dykes and longitudinal bank protection, which imposed fixed lateral boundaries on rivers, have been removed. The EU-Life Project "Auenverbund Obere Drau" has resulted in extensive restoration on the River Drau, aimed to improve the ecological integrity of the river ecosystem, to arrest riverbed degradation, and to ensure flood protection. An essential part of the restoration design involved the consideration of self-forming river processes, which led to new demands being imposed on river management. This paper illustrates how model complexity is adapted to the solution and evaluation of different aspects of river restoration problems in a specific case. Point-scale monitoring data were up-scaled to the whole investigation area by means of digital elevation models, and a scaling approach to the choice of model complexity was applied. Simple regime analysis methods and 1-D models are applicable to the evaluation of long-term and reach-scale restoration aims, and to the prediction of kilometre-scale processes (e.g. mean river bed aggradation or degradation, flood protection). 2-D models gave good results for the evaluation of hydraulic changes (e.g. transverse flow velocities, shear stresses, discharges at diffluences) for different morphological units at the local scale (100 m-10 m), and imposed an intermediate demand on calibration data and topographic survey. The study shows that complex 3-D numerical models combined with high resolution digital elevation models are necessary for detailed analysis of processes (1 m-0.01 m), but not for the evaluation of the restoration aims on the River Drau. In conclusion, model choice (complexity) will depend on both lower limits (determined by the complexity of processes to be analysed) and upper limits (field data quality and process understanding for numerical models).

  6. Source characterization studies at the Paraho semiworks oil shale retort. [Redistribution of trace and major elements

    Energy Technology Data Exchange (ETDEWEB)

    Fruchter, J.S.; Wilkerson, C.L.; Evans, J.C.; Sanders, R.W.; Abel, K.W.

    1979-05-01

    In order to determine the redistribution of trace and major elements and species during aboveground oil shale retorting, a comprehensive program was carried out for the sampling and analysis of feedstock, products, effluents, and ambient particulates from the Paraho Semiworks Retort. Samples were obtained during two periods in 1977 when the retort was operating in the direct mode. The data were used to construct mass balances for 31 trace and major elements in various effluents, including the offgas. The computed mass balances indicated that approx. 1% or greater fractions of the As, Co, Hg, N, Ni, S, and Se were released during retorting and redistributed to the product oil, retort water, or product offgas. The fraction released for these seven elements ranged from approx. 1% for Co and Ni to 50 to 60% for Hg and N. Approximately 20% of the S and 5% each of the As and Se were released. Ambient aerosols were found to be elevated near the retorting facility and associated crushing and retorted shale disposal sites. Approximately 50% of these particles were in the respirable range (< 5 ..mu..m). The elevated dust loadings are presented very local, as indicated by relatively low aerosol loadings at background sites 100 to 200 m away. State-of-the-art dust control measures were not employed. 15 figures, 19 tables.

  7. Leaching Behavior of Circulating Fluidised Bed MSWI Air Pollution Control Residue in Washing Process

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-09-01

    Full Text Available In this study, air pollution control (APC residue is conducted with water washing process to reduce its chloride content. A novel electrical conductivily (EC measurement method is proposed to monitor the dynamic change of chloride concentrations in leachate as well as the chloride content of the residue. The method equally applies to various washing processes with different washing time, liquid/solid ratio and washing frequency. The results show that washing effectively extracts chloride salts from APC residues, including those from circulating fluidized bed (CFB municipal solid waste incineration (MSWI. The most appropriate liquid/solid ratio and washing time in the first washing are found to be around 4 L water per kg of APC residue and 30 min, respectively, and washing twice is required to obtain maximum dissolution. The pH value is the major controlling factor of the heavy metals speciation in leachate, while chloride concentration also affects the speciation of Cd. Water washing causes no perceptible transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs from the APC residue to leachate. The chloride concentration is strongly related with electrical conductivity (EC, as well as with the concentrations of calcium, sodium and potassium of washing water. Their regression analyses specify that soluble chloride salts and EC could act as an indirect indicator to monitor the change of chloride concentration and remaining chloride content, thus, contributing to the selection of the optimal washing conditions.

  8. Multiple sensor detection of process phenomena in laser powder bed fusion

    Science.gov (United States)

    Lane, Brandon; Whitenton, Eric; Moylan, Shawn

    2016-05-01

    Laser powder bed fusion (LPBF) is an additive manufacturing (AM) process in which a high power laser melts metal powder layers into complex, three-dimensional shapes. LPBF parts are known to exhibit relatively high residual stresses, anisotropic microstructure, and a variety of defects. To mitigate these issues, in-situ measurements of the melt-pool phenomena may illustrate relationships between part quality and process signatures. However, phenomena such as spatter, plume formation, laser modulation, and melt-pool oscillations may require data acquisition rates exceeding 10 kHz. This hinders use of relatively data-intensive, streaming imaging sensors in a real-time monitoring and feedback control system. Single-point sensors such as photodiodes provide the temporal bandwidth to capture process signatures, while providing little spatial information. This paper presents results from experiments conducted on a commercial LPBF machine which incorporated synchronized, in-situ acquisition of a thermal camera, high-speed visible camera, photodiode, and laser modulation signal during fabrication of a nickel alloy 625 AM part with an overhang geometry. Data from the thermal camera provides temperature information, the visible camera provides observation of spatter, and the photodiode signal provides high temporal bandwidth relative brightness stemming from the melt pool region. In addition, joint-time frequency analysis (JTFA) was performed on the photodiode signal. JTFA results indicate what digital filtering and signal processing are required to highlight particular signatures. Image fusion of the synchronized data obtained over multiple build layers allows visual comparison between the photodiode signal and relating phenomena observed in the imaging detectors.

  9. Study of the process of working layered-heterogeneous beds with injection of cold and hot water

    Energy Technology Data Exchange (ETDEWEB)

    Teslyuk, Ye.V.; Borisov, Yu.P.; Rozenberg, M.D.; Yshakov, V.V.

    1983-01-01

    A technique was developed for engineering calculations of the nonisothermic process of oil displacement by water from a layered-heterogeneous bed when it is injected into linear cutting rows for fields with paraffin and viscous oil. Results are presented of calculations as applied to the Uzen field conditions.

  10. The influence of the moisture content of microcrystalline cellulose on the coating process in a fluidized bed

    Directory of Open Access Journals (Sweden)

    Silva O. S.

    2004-01-01

    Full Text Available The objective of this work was to study the coating of microcrystalline cellulose with a polymeric suspension in a fluidized bed. The coating operation was carried out using a fluidized bed with top spraying by a double-fluid nozzle. The fluidized bed consists of a cylindrical column made of plexiglass with a height of 0.6 m and an inner diameter of 0.14 m. The polymeric coating suspension was formulated using Eudragit® as the basic component. As the quality of the coating product is greatly affected by the spraying characteristics, the influence of the flow rate of the coating suspension and the moisture content of the particles on the agglomeration index and efficiency of the process of coating microcrystalline cellulose was analyzed.

  11. Fixed bed pyrolysis of the rapeseed cake

    Energy Technology Data Exchange (ETDEWEB)

    Sensoz, S.; Yorgun, S.; Angin, D.; Culcuoglu, E.; Ozcimen, D.; Karaosmanoglu, F.

    2001-12-15

    The fixed bed atmospheric pressure pyrolysis and nitrogen swept pyrolysis of the rapeseed cake obtained from cold extraction press have been investigated. Experiments were performed in the Heinze retort at a 7{sup o}C min{sup -1} heating rate, with a 500{sup o}C final temperature varying sweep gas velocity (50, 100, 150, 200, 250, 300 cm{sup 3} min{sup -1}) under nitrogen atmosphere. Liquid, gas, and char yields were determined, pyrolysis conversion was calculated, and liquid, char, and gas products were presented as an environmentally friendly fuel candidate. (author)

  12. Reverse osmosis concentrate treatment by chemical oxidation and moving bed biofilm processes.

    Science.gov (United States)

    Vendramel, S M R; Justo, A; González, O; Sans, C; Esplugas, S

    2013-01-01

    In the present work, four oxidation techniques were investigated (O3, O3/UV, H2O2/O3, O3/H2O2/UV) to pre-treat reverse osmosis (RO) concentrate before treatment in a moving-bed biofilm reactor (MBBR) system. Without previous oxidation, the MBBR was able to remove a small fraction of the chemical oxygen demand (COD) (5-20%) and dissolved organic carbon (DOC) (2-15%). When the concentrate was previously submitted to oxidation, DOC removal efficiencies in the MBBR increased to 40-55%. All the tested oxidation techniques improved concentrate biodegradability. The concentrate treated by the combined process (oxidation and MBBR) presented residual DOC and COD in the ranges of 6-12 and 25-41 mg L(-1), respectively. Nitrification of the RO concentrate, pre-treated by oxidation, was observed in the MBBR. Ammonium removal was comprised between 54 and 79%. The results indicate that the MBBR was effective for the treatment of the RO concentrate, previously submitted to oxidation, generating water with an improved quality.

  13. 9 CFR 318.306 - Processing and production records.

    Science.gov (United States)

    2010-01-01

    ....306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Canning and Canned Products § 318.306 Processing and production records. At least the following processing... the first can enters and the time the last can exits the retort. The retort or reel speed shall...

  14. The Study of Gas-Dynamic Processes in the Current Boiler Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Baturin Dmitry A.

    2015-01-01

    Full Text Available The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out for the bottom of the combustion chamber with the varying heights of volume filling. The results of the concentration of particulate matter and fields of speeding, as well as a graphical representation of changes in the concentration of particles on the bed height. Simulation performed in Euler - Euler representation on a 2D model.

  15. The Study of Dynamic Processes in the Boiler Furnace with Circulating Fluidized Bed

    OpenAIRE

    Gil A. V.; Baturin D. A.

    2016-01-01

    The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out on all volume of the combustion chamber. The results contours of particulate matter concentration and of velocities, as well as a graphical representation of changes in the concentration of particles on the bed height are shown. Simulation performed in Eulerian - Eulerian and Lagrange representation on a 3D model.

  16. The Study of Dynamic Processes in the Boiler Furnace with Circulating Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Gil A. V.

    2016-01-01

    Full Text Available The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out on all volume of the combustion chamber. The results contours of particulate matter concentration and of velocities, as well as a graphical representation of changes in the concentration of particles on the bed height are shown. Simulation performed in Eulerian - Eulerian and Lagrange representation on a 3D model.

  17. [Performance and substrate inhibition kinetics model of nitritation process in inverse turbulent bed reactor].

    Science.gov (United States)

    Jin, Ren-Cun; Yang, Guang-Feng; Ma, Chun; Zheng, Ping

    2011-01-01

    The performance of a nitritation inverse turbulent bed (ITB) reactor was tested and the substrate inhibition kinetics characteristics of the reactor were analyzed. The results showed that a rapid reactor startup could be realized within 20 d with a strategy that combined the biofilm attachment method named "precoating carrier treatment" and "rapid suspending sludge discharge", with the feeding strategy named "low strength, high load". When operated at a hydraulic retention time of 3 h and influent NH4(+) -N of 700 mg x L(-1), corresponding to a nitrogen loading rate of 5.60 kg x (m3 x d)(-1), a maximum NH4(+) -N removal rate of 4.25 kg x (m3 x d)(-1) was observed. The maximum NO2(-) -N production rate was as high as 3.70 kg x (m3 x d)(-1). Four inhibition kinetic models (Haldane, Edwards, Aiba and Luong) were analyzed through non-linear regression to represent the inhibitions caused by substrate of nitritation process and the parameters of models were gained, which were r(max) of 1.84 kg x (m3 x d)(-1), K(IH) of 97.4 mg x L(-1) and K(m) of 0.188 mg x L(-1) for Haldane model, and r(max) of 1.83 kg x (m3 x d)(-1) and K(IA) of 114 mg x L(-1) for Aiba model. It was proposed that Haldane and Aiba models well fitted the process data harvested in the ITB reactor.

  18. Bubbling bed catalytic hydropyrolysis process utilizing larger catalyst particles and smaller biomass particles featuring an anti-slugging reactor

    Science.gov (United States)

    Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

    2014-09-23

    This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

  19. Bubbling bed catalytic hydropyrolysis process utilizinig larger catalyst particles and small biomass particles featuring an anti-slugging reactor

    Energy Technology Data Exchange (ETDEWEB)

    Marker, Terry L.; Felix, Larry G.; Linck, Martin B.; Roberts, Michael J.

    2016-12-06

    This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

  20. Development of a trickle bed reactor of electro-Fenton process for wastewater treatment.

    Science.gov (United States)

    Lei, Yangming; Liu, Hong; Shen, Zhemin; Wang, Wenhua

    2013-10-15

    To avoid electrolyte leakage and gas bubbles in the electro-Fenton (E-Fenton) reactors using a gas diffusion cathode, we developed a trickle bed cathode by coating a layer composed of carbon black and polytetrafluoroethylene (C-PTFE) onto graphite chips instead of carbon cloth. The trickle bed cathode was optimized by single-factor and orthogonal experiments, in which carbon black, PTFE, and a surfactant were considered as the determinant of the performance of graphite chips. In the reactor assembled by the trickle bed cathode, H2O2 was generated with a current of 0.3A and a current efficiency of 60%. This performance was attributed to the fine distribution of electrolyte and air, as well as the effective oxygen transfer from the gas phase to the electrolyte-cathode interface. In terms of H2O2 generation and current efficiency, the developed trickle bed reactor had a performance comparable to that of the conventional E-Fenton reactor using a gas diffusion cathode. Further, 123 mg L(-1) of reactive brilliant red X-3B in aqueous solution was decomposed in the optimized trickle bed reactor as E-Fenton reactor. The decolorization ratio reached 97% within 20 min, and the mineralization reached 87% within 3h.

  1. Experiment research on grain drying process in the heat pump assisted fluidized beds

    Institute of Scientific and Technical Information of China (English)

    Jing Yang; Li Wang; Fi Xiang; Lige Tong; Hua Su

    2004-01-01

    A heat pump assisted fluidized bed grain drying experimental system was developed. Based on this system, a serial of experiments was performed under four kinds of air cycle conditions. According to the experimental analysis, an appropriate drying medium-air cycle for the heat pump assisted fluidized bed drying equipment was decided, which is different from the commonly used heat pump assisted drying system. The experimental results concerning the drying operation performance of the new system show that the averaged coefficient of performance (COP) can reach more than 2.5. The economical evaluation was performed and the powefficiency and great application potentiality in future market.

  2. An Economic and Ecologic Comparison of the Nuclear Stimulation of Natural Gas Fields with Retorting of Oil Shale

    Science.gov (United States)

    1975-06-06

    a completely different system of retorting. Unlike the gas-combustion retorts, the TOSCO II is a rotary type retort that uses hot ceramic balls to... kilns and smelters are designed to do the nonvolatile solid such as iron, copper, or lime. This is the mining technique envisioned in most shale...burned. Such heating also con- verts -ome of the other minerals to their oxide forms and the resulting ash has be»n described as a low grade of cement

  3. Nitrogen removal in micro-polluted surface water by the combined process of bio-filter and ecological gravel bed.

    Science.gov (United States)

    Sheng-Bing, He; Jian-Wen, Gao; Xue-Chu, Chen; Ding-Li, Dai

    2013-01-01

    Nitrogen removal in micro-polluted surface water by the combined process of a bio-filter and an ecological gravel bed was studied. Sodium acetate was added into micro-polluted surface water as carbon source and the nitrogen removal under different C/N ratio, hydraulic load and temperature were investigated. The results showed that the variations in C/N ratio, hydraulic load and temperature have significant influence on nitrogen removal in bio-filter. It was found that the denitrification rate was above 90% when C/N ratio reached 10; also, the denitrification was inhibited at low water temperature (2-10 °C); at the condition of water temperature above 20 °C, C/N ratio 10, hydraulic load 8 m(3)/(m(2) h), the combined process obtained the nitrogen removal of more than 90%, and the residual organics could be removed in ecological gravel bed.

  4. Simultaneous dioxin and mercury collection in a filter bed reactor; Process concepts and test results. Simultane Dioxin- und Quecksilberabscheidung im Filterschichtreaktor; Verfahrenskonzepte und Versuchsergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Weirich, W. (Deutsche Babcock Anlagen GmbH, Oberhausen (Germany)); Glinka, U. (Deutsche Babcock Anlagen GmbH, Oberhausen (Germany)); Ruther, G. (Deutsche Babcock Anlagen GmbH, Oberhausen (Germany))

    1993-03-01

    In the process chain dealt with in this paper, which uses a combined SCR reactor and filter bed reactor where the most far-reaching catalytic destruction of NO[sub x] and dioxins is obtained, the filter bed reactor was operated as a pilot plant using an inexpensive additive with multiple recycling. (orig.)

  5. Heat and Mass Transfer in Process of Fluidized-Bed Spray Granulation%流化床喷雾造粒过程的传热传质

    Institute of Scientific and Technical Information of China (English)

    于才渊; 齐涛; 王喜忠

    2004-01-01

    This article presents a mathematical model of heat and mass transfer for the process of fluidized-bed spray granulation, which can be applied in the analysis of bed temperature profile, temperature and humidity of outlet gas and moisture content of particles. Effects of operation parameters on the batch granulation are investigated. The theoretical calculation agrees reasonably well with the experimental data.

  6. Two-dimensional coupled mathematical modeling of fluvial processes with intense sediment transport and rapid bed evolution

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Alluvial rivers may experience intense sediment transport and rapid bed evolution under a high flow regime,for which traditional decoupled mathematical river mod-els based on simplified conservation equations are not applicable. A two-dimen-sional coupled mathematical model is presented,which is generally applicable to the fluvial processes with either intense or weak sediment transport. The governing equations of the model comprise the complete shallow water hydrodynamic equa-tions closed with Manning roughness for boundary resistance and empirical rela-tionships for sediment exchange with the erodible bed. The second-order Total-Variation-Diminishing version of the Weighted-Average-Flux method,along with the HLLC approximate Riemann Solver,is adapted to solve the governing equations,which can properly resolve shock waves and contact discontinuities. The model is applied to the pilot study of the flooding due to a sudden outburst of a real glacial-lake.

  7. Two-dimensional coupled mathematical modeling of fluvial processes with intense sediment transport and rapid bed evolution

    Institute of Scientific and Technical Information of China (English)

    YUE ZhiYuan; CAO ZhiXian; LI Xin; CHE Tao

    2008-01-01

    Alluvial rivers may experience intense sediment transport and rapid bed evolution under a high flow regime, for which traditional decoupled mathematical river mod-els based on simplified conservation equations are not applicable. A two-dimen-sional coupled mathematical model is presented, which is generally applicable to the fluvial processes with either intense or weak sediment transport. The governing equations of the model comprise the complete shallow water hydrodynamic equa-tions closed with Manning roughness for boundary resistance and empirical rela-tionships for sediment exchange with the erodible bed. The second-order Total-Variation-Diminishing version of the Weighted-Average-Flux method, along with the HLLC approximate Riemann Solver, is adapted to solve the governing equations, which can properly resolve shock waves and contact discontinuities. The model is applied to the pilot study of the flooding due to a sudden outburst of a real glacial-lake.

  8. Experimental analysis and evaluation of the mass transfer process in a trickle-bed reactor

    Directory of Open Access Journals (Sweden)

    Silva J.D.

    2003-01-01

    Full Text Available A transient experimental analysis of a three-phase descendent-cocurrent trickle-bed H2O/CH4-Ar/g -Al2O3 system was made using the stimulus-response technique, with the gas phase as a reference. Methane was used as a tracer and injected into the argon feed and the concentration vs time profiles were obtained at the entrance and exit of the bed, which were maintained at 298K and 1.013 10(5 Pa. A mathematical model for the tracer was developed to estimate the axial dispersion overall gas-liquid mass transfer and liquid-solid mass transfer coefficients. Experimental and theoretical results were compared and shown to be in good agreement. The model was validated by two additional experiments, and the values of the coefficients obtained above were confirmed.

  9. Standard Guide for Dosimetry In Radiation Processing of Fluidized Beds and Fluid Streams

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This guide describes several dosimetry systems and methods suitable for the documentation of the irradiation of product transported as fluid or in a fluidized bed. 1.2 The sources of penetrating ionizing radiation included in this guide are electron beams, X-rays (bremsstrahlung) and gamma rays. 1.3 Absorbed doses from 10 to 100,000 gray are considered, including applications such as disinfestation, disinfection, bioburden reduction, sterilization, crosslinking and graft modification of products, particularly powders and aggregates. 1.4 This guide does not purport to address the safety concerns, if any, associated with the use of fluidized beds and streams incorporating sources of ionizing radiation. It is the responsibility of the user of this guide to establish appropriate safety and health practices and to determine compliance with regulatory limitations prior to use.

  10. Review on Biomass Torrefaction Process and Product Properties and Design of Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shankar Tumuluru; Christopher T. Wright; Shahab Sokhansanj

    2011-08-01

    A Review on Torrefaction Process and Design of Moving Bed Torrefaction System for Biomass Processing Jaya Shankar Tumuluru1, Shahab Sokhansanj2 and Christopher T. Wright1 Idaho National Laboratory Biofuels and Renewable Energy Technologies Department Idaho Falls, Idaho 83415 Oak Ridge National Laboratory Bioenergy Resource and Engineering Systems Group Oak Ridge, TN 37831 Abstract Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, which produces a final product that will have a lower mass but a higher heating value. There is a lack of literature on the design aspects of torrefaction reactor and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed torrefier for different capacities ranging from 25-1000 kg/hr, designing the heat loads and gas flow rates, and

  11. Functionalization of polymers using an atmospheric plasma jet in a fluidized bed reactor and the impact on SLM-processes

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, M., E-mail: karl-ernst.wirth@fau.de; Schmitt, A., E-mail: karl-ernst.wirth@fau.de; Schmidt, J., E-mail: karl-ernst.wirth@fau.de; Peukert, W., E-mail: karl-ernst.wirth@fau.de; Wirth, K-E, E-mail: karl-ernst.wirth@fau.de [Institute of Particle Technology, University of Erlangen-Nuremberg (Germany)

    2014-05-15

    In order to improve thermoplastics (e.g. Polyamide, Polypropylene and Polyethylene) for Selective Laser Beam Melting (SLM) processes a new approach to functionalize temperature sensitive polymer powders in a large scale is investigated. This is achieved by combining an atmospheric pressure plasma jet and a fluidized bed reactor. Using pressurized air as the plasma gas, radicals like OH* are created. The functionalization leads to an increase of the hydrophilicity of the treated polymer powder without changing the bulk properties. Using the polymers in a SLM process to build single layers of melted material leads to an improvement of the melted layers.

  12. Modern processes controlling the sea bed sediment formation in Barents Sea

    Science.gov (United States)

    Balanyuk, I.; Dmitrievsky, A.; Shapovalov, S.; Chaikina, O.; Akivis, T.

    2009-04-01

    The Barents Sea is one of the key regions for understanding of the postglacial history of the climate and circulation of the World Ocean. There are the limits of warm North Atlantic waters penetration to the Arctic and a zone of interaction between Atlantic and Arctic waters. The Barents Se's limits are the deep Norwegian Sea in the West, the Spitsbergen Island and the Franz Josef Land and the deep Nansen trough in the North, the Novaya Zemlya archipelago in the East and the North shore of Europe in the South. An analysis of Eurasian-Arctic continental margin shows correspondence between the rift systems of the shelf with those of the ocean. This relation can be observed in the central Arctic region. All the rift systems underlying the sediment basin are expressed in the sea bed relief as spacious and extensive graben valleys burnished by lobes. Two transverse trenches cross both shelf and continental slope, namely the Medvezhinsky trench between Norway and Spitsbergen in the West and the Franz Victoria trench between Spitsbergen and the Franz Josef Land in the North. The Barents and the Kara Seas are connected by the Kara Gate Strait and wide transverse trough of Saint Anna in the North-West. The recent assessment of the eolian solid sediment supply to the Barents Sea is about 0.904 tons. The Barents Sea as a whole should be considered as "starving" in terms of its feeding with solid sediment matter. Observations show the considerable part of the sea bottom to be free of Holocene sediment cover. The more ancient Quaternary units or bedrock can be seen at the bottom surface. This phenomenon is the most typical for arches of relatively shallow elevations. Thick accumulations of new sediments are connected with fjords. The amount of sea ice delivered from the Barents Sea to the Arctic Ocean is 35 km3 a year. This value should be added by iceberg delivery from the North island of Novaya Zemlya, the Franz Josef Land, the Spitsbergen Island and North Norway but most of

  13. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    Energy Technology Data Exchange (ETDEWEB)

    None

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  14. Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schrodt, J.T.

    1981-02-01

    Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

  15. Functionalization of polymer powders for SLS-processes using an atmospheric plasma jet in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, Marius; Schmitt, Adeliene; Schmidt, Jochen; Peukert, Wolfgang; Wirth, Karl-Ernst [Institute of Particle Technology, Friedrich-Alexander-University Erlangen-Nuremberg (Germany)

    2015-05-22

    Recently additive manufacturing processes such as selective laser sintering (SLS) of polymers have gained more importance for industrial applications [1]. Tailor-made modification of polymers is essential in order to make these processes more efficient and to cover the industrial demands. The so far used polymer materials show weak performance regarding the mechanical stability of processed parts. To overcome this limitation, a new route to functionalize the surface of commercially available polymer particles (PA12; PE-HD; PP) using an atmospheric plasma jet in combination with a fluidized bed reactor has been investigated. Consequently, an improvement of adhesion and wettability [2] of the polymer surface without restraining the bulk properties of the powder is achieved. The atmospheric plasma jet process can provide reactive species at moderate temperatures which are suitable for polymer material. The functionalization of the polymer powders improves the quality of the devices build in a SLS-process.

  16. Analysis of the laser powder bed fusion additive manufacturing process through experimental measurement and finite element modeling

    Science.gov (United States)

    Dunbar, Alexander Jay

    The objective in this work is to provide rigourous experimental measurements to aid in the development of laser powder bed fusion (LPBF) additive manufacturing (AM). A specialized enclosed instrumented measurement system is designed to provide in situ experimental measurements of temperature and distortion. Experiments include comparisons of process parameters, materials and LPBF machines. In situ measurements of distortion and temperature made throughout the build process highlight inter-layer distortion effects previously undocumented for laser powder bed fusion. Results from these experiments are also be implemented in the development and validation of finite element models of the powder bed build process. Experimental analysis is extended from small-scale to larger part-scale builds where experimental post-build measurements are used in analysis of distortion profiles. Experimental results provided from this study are utilized in the validation of a finite element model capable of simulating production scale parts. The validated finite element model is then implemented in the analysis of the part to provide information regarding the distortion evolution process. A combination of experimental measurements and simulation results are used to identify the mechanism that results in the measured distortion profile for this geometry. Optimization of support structure primarily focuses on the minimization of material use and scan time, but no information regarding failure criteria for support structure is available. Tensile test samples of LPBF built support structure are designed, built, and tested to provide measurements of mechanical properties of the support structure. Experimental tests show that LPBF built support structure has only 30-40% of the ultimate tensile strength of solid material built in the same machine. Experimental measurement of LPBF built support structure provides clear failure criteria to be utilized in the future design and implementation of

  17. Soy protein recovery in a solvent-free process using continuous liquid-solid circulating fluidized bed ion exchanger.

    Science.gov (United States)

    Prince, Andrew; Bassi, Amarjeet S; Haas, Christine; Zhu, Jesse X; Dawe, Jennifer

    2012-01-01

    Soy protein concentrates and soy protein isolates act as ingredients in bakery, meat and dairy products, baby formulas, starting materials for spun textured vegetable products, and other nutritional supplements. In this study, the effectiveness of a liquid-solid circulating fluidized bed (LSCFB) ion exchanger is demonstrated for the recovery of soluble soy proteins from full fat and defatted soy flour. Under steady-state operating conditions, about 50% of the proteins could be recovered from the feed streams entering the ion exchanger. The LSCFB was shown to be a promising system for the recovery of soy protein from both defatted and full fat soy flour solutions. As the ion exchange process captures dissolved proteins, the system may offer a less damaging form of processing compared with the acid precipitation process where soy protein aggregates form and functionality is affected. In addition, the LSCFB allows simultaneous adsorption and desorption of the proteins allowing for a continuous operation. No prefiltration of feed containing suspended particles is required as well, because fluidization is used in place of packed bed technology to improve on current ion exchange processes.

  18. Conceptual approach for an in-line quality control system in Additive Manufacturing Powder Bed Fusion processes

    Directory of Open Access Journals (Sweden)

    Fulga Simina

    2017-01-01

    Full Text Available Additive Manufacturing is one of the genuine hopes for the forth industrial revolution since digital data is controlling the whole layered production process. At the same time the geometric freedom and tool-free production assures a high degree of individualisation. But to be the driving force behind a new industrial revolution, a qualification of additive manufacturing processes is necessary so that the resulting products meet the required quality and safety standards in the different fields of application such as in handling technology or medical technology. This paper will discuss a conceptual approach for the development of an in-line quality control system in Additive Manufacturing Powder Bed Fusion processes using the example of the Selective Laser Sintering process.

  19. Gamma 60Co-irradiation of organic matter in the Phosphoria Retort Shale

    Science.gov (United States)

    Lewan, M. D.; Ulmishek, G. F.; Harrison, W.; Schreiner, F.

    1991-04-01

    Irradiation experiments were conducted on a thermally immature rock sample of the Phosphoria Retort Shale and its isolated kerogen. A 60Co-source for gamma radiation was employed at dosages ranging from 81 to 885 Mrads, which are attainable by Paleozoic and Precambrian black shales with syngenetic uranium enrichments. Kerogen elemental, isotopic, and pyrolysate compositions are not affected at these dosages, but the bitumens extracted from the irradiated rock are affected. The major effects are reductions in the amounts of bitumen, acyclic isoprenoids, and high-molecular weight acyclic carboxylic acids. Natural differences in the amounts of bitumen and acyclic isoprenoid due to regional and stratigraphie variations in organic source input and depositional conditions make the radiation-induced reductions in these parameters difficult to use as indicators of natural radiation damage in black shales. However, the preferential reduction in the high-molecular weight acyclic carboxylic acids, which are ubiquitous in the living precursory organic matter, is diagnostic of experimental γ-irradiation but may not be diagnostic of natural irradiation. The overall process associated with radiation damage is polymerization by cross-linking through a free radical mechanism. As a result, irradiation of organic matter in black shales is more likely to retard rather than enhance petroleum generation.

  20. Observation and simulation of heterogeneous 2D water and solute flow processes in ditch beds for subsequent catchment modelling

    Science.gov (United States)

    Dages, Cecile; Samouelian, Anatja; Lanoix, Marthe; Dollinger, Jeanne; Chakkour, Sara; Chovelon, Gabrielle; Trabelsi, Khouloud; Voltz, Marc

    2015-04-01

    Ditches are involved in the transfer of pesticide to surface and groundwaters (e.g. Louchart et al., 2001). Soil horizons underlying ditch beds may present specific soil characteristics compared to neighbouring field soils due to erosion/deposition processes, to the specific biological activities (rooting dynamic and animal habitat) in the ditches (e.g. Vaughan et al., 2008) and to management practices (burning, dredging, mowing,...). Moreover, in contrast to percolation processes in field soils that can be assumed to be mainly 1D vertical, those occurring in the ditch beds are by essence 2D or even 3D. Nevertheless, due to a lake of knowledge, these specific aspects of transfer within ditch beds are generally omitted for hydrological simulation at the catchment scale (Mottes et al., 2014). Accordingly, the aims of this study were i) to characterize subsurface solute transfer through ditch beds and ii) to determine equivalent hydraulic parameters of the ditch beds for use in catchment scale hydrological simulations. A complementary aim was to evaluate the error in predictions performed when percolation in ditches is assumed to be similar to that in the neighbouring field soil. First, bromide transfer experiments were performed on undisturbed soil column (15 cm long with a 15 cm inner-diameter), horizontally and vertically sampled within each soil horizon underlying a ditch bed and within the neighboring field. Columns were sampled at the Roujan catchment (Hérault, France), which belongs to the long term Mediterranean hydrological observatory OMERE (Voltz and Albergel, 2002). Second, for each column, a set of parameters was determined by inverse optimization with mobile-immobile or dual permeability models, with CXTFIT (Toride et al., 1999) or with HYDRUS (Simunek et al., 1998). Third, infiltration and percolation in the ditch was simulated by a 2D flow domain approach considering the 2D variation in hydraulic properties of the cross section of a ditch bed. Last

  1. Development of RM-1 type coated electrode for reducing retorts in magnesium refining

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the working condition of high temperature oxidation and sulphidation corrosion of the ZG35Cr24Ni7SiN heat-resisting stainless steel used for reducing retort in magnesium refining, and the practical situation which the weld metal between the body and cover of reducing retort must possess resisting high temperature oxidation and corrosion, a kind of RM-1 type coated electrode for reducing retorts in magnesium refining with special alloying system and excellent usability has been developed. The RM-1 coated electrode is made of H0Cr21Ni10 wire core and is alloyed chromium and nickel simultaneously through coating material and wire core and some rare-earth oxides are added in coating material. The electrode has been verified to be satisfied the operation requirements of practical production.

  2. Method for forming an in situ oil shale retort with horizontal free faces

    Science.gov (United States)

    Ricketts, Thomas E.; Fernandes, Robert J.

    1983-01-01

    A method for forming a fragmented permeable mass of formation particles in an in situ oil shale retort is provided. A horizontally extending void is excavated in unfragmented formation containing oil shale and a zone of unfragmented formation is left adjacent the void. An array of explosive charges is formed in the zone of unfragmented formation. The array of explosive charges comprises rows of central explosive charges surrounded by a band of outer explosive charges which are adjacent side boundaries of the retort being formed. The powder factor of each outer explosive charge is made about equal to the powder factor of each central explosive charge. The explosive charges are detonated for explosively expanding the zone of unfragmented formation toward the void for forming the fragmented permeable mass of formation particles having a reasonably uniformly distributed void fraction in the in situ oil shale retort.

  3. Knife grid size reduction to pre-process packed beds of high- and low-moisture switchgrass.

    Science.gov (United States)

    Igathinathane, C; Womac, A R; Sokhansanj, S; Narayan, S

    2008-05-01

    A linear knife grid device was developed for first-stage size reduction of high- and low-moisture switchgrass (Panicum virgatum L.), a tough, fibrous perennial grass being considered as a feedstock for bioenergy. The size reduction is by a shearing action accomplished by forcing a thick packed bed of biomass against a grid of sharp knives. The system is used commercially for slicing forages for drying or feed mixing. No performance data or engineering equations are available in published literature to optimize the machine and the process for biomass size reductions. Tests of a linear knife grid with switchgrass quantified the combined effect of shearing stresses, packed bed consolidation, and frictional resistance to flow through a knife grid. A universal test machine (UTM) measured load-displacement of switchgrass at two moisture contents: 51%, and 9% wet basis; three knife grid spacings: 25.4, 50.8, and 101.6mm; and three packed bed depths: 50.8, 101.6, and 152.4mm. Results showed that peak load, ultimate shear stress, and cutting energy values varied inversely with knife grid spacing and directly with packed bed depth (except ultimate shear stress). Mean ultimate shear stresses of high- and low-moisture switchgrass were 0.68+/-0.24, and 0.41+/-0.21 MPa, mass-based cutting energy values were 4.50+/-4.43, and 3.64+/-3.31 MJ/dry Mg, and cutting energy based on new surface area, calculated from packed-circle theory, were 4.12+/-2.06, and 2.53+/-0.45 kJ/m2, respectively. The differences between high- and low-moisture switchgrass were significant (P<0.05), such that high-moisture switchgrass required increased shear stress and cutting energy. Reduced knife grid spacing and increased packed bed depths required increased cutting energy. Overall, knife grid cutting energy was much less than energy values published for rotary equipment. A minimum knife grid spacing of 25.4mm appears to be a practical lower limit, considering the high ram force that would be needed for

  4. Mercury isotope fractionation during ore retorting in the Almadén mining district, Spain

    Science.gov (United States)

    Gray, John E.; Pribil, Michael J.; Higueras, Pablo L.

    2013-01-01

    Almadén, Spain, is the world's largest mercury (Hg) mining district, which has produced over 250,000 metric tons of Hg representing about 30% of the historical Hg produced worldwide. The objective of this study was to measure Hg isotopic compositions of cinnabar ore, mine waste calcine (retorted ore), elemental Hg (Hg0(L)), and elemental Hg gas (Hg0(g)), to evaluate potential Hg isotopic fractionation. Almadén cinnabar ore δ202Hg varied from − 0.92 to 0.15‰ (mean of − 0.56‰, σ = 0.35‰, n = 7), whereas calcine was isotopically heavier and δ202Hg ranged from − 0.03‰ to 1.01‰ (mean of 0.43‰, σ = 0.44‰, n = 8). The average δ202Hg enrichment of 0.99‰ between cinnabar ore and calcines generated during ore retorting indicated Hg isotopic mass dependent fractionation (MDF). Mass independent fractionation (MIF) was not observed in any of the samples in this study. Laboratory retorting experiments of cinnabar also were carried out to evaluate Hg isotopic fractionation of products generated during retorting such as calcine, Hg0(L), and Hg0(g). Calcine and Hg0(L) generated during these retorting experiments showed an enrichment in δ202Hg of as much as 1.90‰ and 0.67‰, respectively, compared to the original cinnabar ore. The δ202Hg for Hg0(g) generated during the retorting experiments was as much as 1.16‰ isotopically lighter compared to cinnabar, thus, when cinnabar ore was roasted, the resultant calcines formed were isotopically heavier, whereas the Hg0(g) generated was isotopically lighter in Hg isotopes.

  5. Study on Optimal Strategy of Grade Transition in Industral Fluidized Bed Gas-Phase Polyethylene Production Process

    Institute of Scientific and Technical Information of China (English)

    王靖岱; 阳永荣; 等

    2003-01-01

    A model of grade transition is presented for a commercialized fluidized bed gas-phase polyethylene production process.The quantity of off-specification product and the time of grade transition can be minimized by the optimization of operating variables,such as polymerization temperature,the ratio of hydrogen to ethylene,the ratio of co-monomer to ethylene,feed rate of catalyst,and bed level.A new performance index,the ratio of melt flow(MFR),is included in the objective function,for restraining the sharp adjustment of operation variables and narrowing the distribution of molecular weight of the resion.It is recommended that catalyst feed rate and bed level are decreased in order to reduce the grade transition time and the quantity of off-specification product.This optimization problem is solved by an algorithm of sequential quadratic programming (SQP) in MATLAB. There is considerable difference between the forward transition and reverse transition of grade with regard to the operating variables due to the non-linearity of the system.The grade transition model is extended to a high space time yield(STY)Process with the so-called condensed model operation.In the end,an optimization strategy for multi-product transition is proposed with two-level optimization of the objective function J(x,u) on the the basis of the optimal grade transition model.A sequential transition of six commercial polyethylene grades in illustrated for an optimal multi-product operation.

  6. A highly efficient polyampholyte hydrogel sorbent based fixed-bed process for heavy metal removal in actual industrial effluent.

    Science.gov (United States)

    Zhou, Guiyin; Luo, Jinming; Liu, Chengbin; Chu, Lin; Ma, Jianhong; Tang, Yanhong; Zeng, Zebing; Luo, Shenglian

    2016-02-01

    High sorption capacity, high sorption rate, and fast separation and regeneration for qualified sorbents used in removing heavy metals from wastewater are urgently needed. In this study, a polyampholyte hydrogel was well designed and prepared via a simple radical polymerization procedure. Due to the remarkable mechanical strength, the three-dimensional polyampholyte hydrogel could be fast separated, easily regenerated and highly reused. The sorption capacities were as high as 216.1 mg/g for Pb(II) and 153.8 mg/g for Cd(II) owing to the existence of the large number of active groups. The adsorption could be conducted in a wide pH range of 3-6 and the equilibrium fast reached in 30 min due to its excellent water penetration for highly accessible to metal ions. The fixed-bed column sorption results indicated that the polyampholyte hydrogel was particularly effective in removing Pb(II) and Cd(II) from actual industrial effluent to meet the regulatory requirements. The treatment volumes of actual smelting effluent using one fixed bed column were as high as 684 bed volumes (BV) (7736 mL) for Pb(II) and 200 BV (2262 mL) for Cd(II). Furthermore, the treatment volumes of actual smelting effluent using tandem three columns reached 924 BV (31,351 mL) for Pb(II) and 250 BV (8483 mL) for Cd(II), producing only 4 BV (136 mL) eluent. Compared with the traditional high density slurry (HDS) process with large amount of sludge, the proposed process would be expected to produce only a small amount of sludge. When the treatment volume was controlled below 209.3 BV (7103 mL), all metal ions in the actual industrial effluent could be effectively removed (hydrogel sorbents for the removal of heavy metal ions from practical wastewater.

  7. Explosion limits analysis of oil shale retorting under areobic condition%油页岩含氧干馏工艺流程爆炸极限分析

    Institute of Scientific and Technical Information of China (English)

    周洁琼; 张福群; 刘云义

    2012-01-01

    The main industrial utilization of oil shale is to produce shale oil through a retorting process. In order to lower the carrier gas temperature so as to save energy consumption and achieve better industrial application potential , moderate amount of oxygen was added to the carrier gas in the oil shale retorting process. And the potential security problems owing to combustible mixtures might occur. These tests focused on how gaseous products of thermal decomposition of oil shale changed depending on pyrolysis temperature. Explosion limits under different temperature and inert gas condition combining with theoretical study on explosion limits were analyzed and calculated. The results showed that H2, CH4 are the main combustible gas of the retorting process and the process caused no explosion hazards because of the concentration of flammable gas did not within the limits of explosion danger zone in the whole heating process. It was suggested to prevent explosive occurrence of that process by controlling oxygen flow. The results can give a reference to quantitative understanding gas release law in process of oil shale retorting under areobic condition and antiexplosion treatment.%根据干馏工艺流程配入适量氧气,可以降低载热气体需要预热的温度,以实现低能耗、易于工业生产的特点,设计了一套新型的有氧干馏工艺流程.有氧干馏工艺因其过程中存在可燃性混合物,有发生爆炸事故的可能性,通过实验对所收集的不同温度下的干馏气体的成分与含量进行了分析,结合爆炸极限理论,对该有氧干馏工艺流程的不同温度、不同惰性气体含量条件下可燃气体爆炸极限进行了分析计算.结果表明,可燃气体的浓度在整个反应升温过程中始终没有进入爆炸危险区域,说明该实验装置不具备爆炸危险性;对干馏工艺流程中氧气的输入量的控制,可以防止该工艺流程的火灾爆炸的发生.

  8. An analysis of process heat recovery in a gas-solid shallow fluidized bed

    Directory of Open Access Journals (Sweden)

    A. A. B. Pécora

    2006-12-01

    Full Text Available This work presents an experimental study of a continuous gas-solid fluidized bed with an immersed horizontal tube. Silica sand (254mm diameter was used as solid particles and air was used for fluidization in a 900mm long and 150mm wide heat exchanger. Measurements were made under steady state conditions for a solid particle mass flow rate from 14 to 95kg.h-1 and a number of baffles from 0 to 8. Results showed that the heat transfer coefficient increases with the solid particle mass flow rate and with the number of baffles, suggesting that these are important factors to be considered in the design of such equipment. An empirical correlation for the heat transfer coefficient is proposed as a function of solid particle and gas mass flow rate, number of baffles and gas velocity.

  9. Processing RoxAnn sonar data to improve its categorization of lake bed surficial sediments

    Science.gov (United States)

    Cholwek, Gary; Bonde, John; Li, Xing; Richards, Carl; Yin, Karen

    2000-01-01

    To categorize spawning and nursery habitat for lake trout in Minnesota's near shore waters of Lake Superior, data was collected with a single beam echo sounder coupled with a RoxAnn bottom classification sensor. Test areas representative of different bottom surficial substrates were sampled. The collected data consisted of acoustic signals which showed both depth and substrate type. The location of the signals was tagged in real-time with a DGPS. All data was imported into a GIS database. To better interpret the output signal from the RoxAnn, several pattern classifiers were developed by multivariate statistical method. From the data a detailed and accurate map of lake bed bathymetry and surficial substrate types was produced. This map will be of great value to fishery and other natural resource managers.

  10. Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment.

    Science.gov (United States)

    Shin, D H; Shin, W S; Kim, Y H; Han, Myung Ho; Choi, S J

    2006-01-01

    A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2. ln the MBBR process, 85% of COD and 70% of color (influent COD = 807.5 mg/L and color = 3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT = 44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

  11. Role of spent shale in oil shale processing and the management of environmental residues. Final technical report, January 1979-May 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hines, A.L.

    1980-08-15

    The adsorption of hydrogen sulfide on retorted oil shale was studied at 10, 25, and 60/sup 0/C using a packed bed method. Equilibrium isotherms were calculated from the adsorption data and were modeled by the Langmuir, Freundlich, and Polanyi equations. The isosteric heat of adsorption was calculated at three adsorbent loadings and was found to increase with increased loading. A calculated heat of adsorption less than the heat of condensation indicated that the adsorption was primarily due to Van der Waals' forces. Adsorption capacities were also found as a function of oil shale retorting temperature with the maximum uptake occurring on shale that was retorted at 750/sup 0/C.

  12. Processes for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil, and apparatuses for treating biomass-derived pyrolysis oil

    Science.gov (United States)

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-11-24

    Processes and apparatuses for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil are provided herein. An exemplary process for washing a spent ion exchange bed employed in purification of biomass-derived pyrolysis oil includes the step of providing a ion-depleted pyrolysis oil stream having an original oxygen content. The ion-depleted pyrolysis oil stream is partially hydrotreated to reduce the oxygen content thereof, thereby producing a partially hydrotreated pyrolysis oil stream having a residual oxygen content that is less than the original oxygen content. At least a portion of the partially hydrotreated pyrolysis oil stream is passed through the spent ion exchange bed. Water is passed through the spent ion exchange bed after passing at least the portion of the partially hydrotreated pyrolysis oil stream therethrough.

  13. Early processing variations in selective attention to the color and direction of moving stimuli during 30 days head-down bed rest

    Science.gov (United States)

    Wang, Lin-Jie; He, Si-Yang; Niu, Dong-Bin; Guo, Jian-Ping; Xu, Yun-Long; Wang, De-Sheng; Cao, Yi; Zhao, Qi; Tan, Cheng; Li, Zhi-Li; Tang, Guo-Hua; Li, Yin-Hui; Bai, Yan-Qiang

    2013-11-01

    , but no variations were detected in the no response and direction selective response tasks. It is suggested that the negative shift in color selective response task on the 3rd day of bed rest are a result of fluid redistribution. And feature selection was more affected than motion selection in the head down bed rest. The variations in cognitive processing speed observed for the combined color-direction selective response task are suggested to reflect the interaction between top-down mechanisms and hierarchical physiological characteristics during 30 days head-down bed rest.

  14. Effects of organic wastes on water quality from processing of oil shale from the Green River Formation, Colorado, Utah, and Wyoming

    Science.gov (United States)

    Leenheer, J.A.; Noyes, T.I.

    1986-01-01

    A series of investigations were conducted during a 6-year research project to determine the nature and effects of organic wastes from processing of Green River Formation oil shale on water quality. Fifty percent of the organic compounds in two retort wastewaters were identified as various aromatic amines, mono- and dicarboxylic acids phenols, amides, alcohols, ketones, nitriles, and hydroxypyridines. Spent shales with carbonaceous coatings were found to have good sorbent properties for organic constituents of retort wastewaters. However, soils sampled adjacent to an in situ retort had only fair sorbent properties for organic constituents or retort wastewater, and application of retort wastewater caused disruption of soil structure characteristics and extracted soil organic matter constituents. Microbiological degradation of organic solutes in retort wastewaters was found to occur preferentially in hydrocarbons and fatty acid groups of compounds. Aromatic amines did not degrade and they inhibited bacterial growth where their concentrations were significant. Ammonia, aromatic amines, and thiocyanate persisted in groundwater contaminated by in situ oil shale retorting, but thiosulfate was quantitatively degraded one year after the burn. Thiocyanate was found to be the best conservative tracer for retort water discharged into groundwater. Natural organic solutes, isolated from groundwater in contact with Green River Formation oil shale and from the White River near Rangely, Colorado, were readily distinguished from organic constituents in retort wastewaters by molecular weight and chemical characteristic differences. (USGS)

  15. Metabolic and microbial community dynamics during the hydrolytic and acidogenic fermentation in a leach-bed process

    Energy Technology Data Exchange (ETDEWEB)

    Straeuber, Heike; Kleinsteuber, Sabine [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy; UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Environmental Microbiology; Schroeder, Martina [UFZ - Helmholtz Centre for Environmental Research, Leipzig (Germany). Dept. of Bioenergy

    2012-12-15

    Biogas production from lignocellulosic feedstock not competing with food production can contribute to a sustainable bioenergy system. The hydrolysis is the rate-limiting step in the anaerobic digestion of solid substrates such as straw. Hence, a detailed understanding of the metabolic processes during the steps of hydrolysis and acidogenesis is required to improve process control strategies. The fermentation products formed during the acidogenic fermentation of maize silage as a model substrate in a leach-bed process were determined by gas and liquid chromatography. The bacterial community dynamics was monitored by terminal restriction fragment length polymorphism analysis. The community profiles were correlated with the process data using multivariate statistics. The batch process comprised three metabolic phases characterized by different fermentation products. The bacterial community dynamics correlated with the production of the respective metabolites. In phase 1, lactic and acetic acid fermentations dominated. Accordingly, bacteria of the genera Lactobacillus and Acetobacter were detected. In phase 2, the metabolic pathways shifted to butyric acid fermentation, accompanied by the production of hydrogen and carbon dioxide and a dominance of the genus Clostridium. In phase 3, phylotypes affiliated with Ruminococcaceae and Lachnospiraceae prevailed, accompanied by the formation of caproic and acetic acids, and a high gas production rate. A clostridial butyric type of fermentation was predominant in the acidogenic fermentation of maize silage, whereas propionic-type fermentation was marginal. As the metabolite composition resulting from acidogenesis affects the subsequent methanogenic performance, process control should focus on hydrolysis/acidogenesis when solid substrates are digested. (orig.)

  16. A Review of Techniques for the Process Intensification of Fluidized Bed Reactors%流化床反应器过程强化技术

    Institute of Scientific and Technical Information of China (English)

    张维

    2009-01-01

    Fluidized beds enable good solids mixing, high rates of heat and mass transfer, and large throughputs, but there remain issues related to fluidization quality and scale-up. In this work I review modification techniques for fluidized beds from the perspective of the principles of process intensification (PI), that is, effective bubbling sup-pression and elutriation control. These techniques are further refined into (Ⅰ) design factors, e.g. modifying the bed configuration, or the application of internal and external forces, and (2) operational factors, including altering the particle properties (e.g. size, density, surface area) and fluidizing gas properties (e.g. density, viscosity, or velocity). As far as two proposed PI principles are concerned, our review suggests that it ought to be possible to gain improve-ments of between 2 and 4 times over conventional fluidized bed designs by the application of these techniques.

  17. Effect of Process and Post-Process Conditions on the Mechanical Properties of an A357 Alloy Produced via Laser Powder Bed Fusion

    Directory of Open Access Journals (Sweden)

    Alberta Aversa

    2017-02-01

    Full Text Available A357 samples were realized by laser powder bed fusion (LPBF on building platforms heated up to different temperatures. The effect of the preheating temperature and of the post processing heat treatment on the microstructure and the mechanical properties of the samples was studied. It was demonstrated that building platform heating can act as an in situ ageing heat treatment following the fast cooling that arises during laser scanning. A 17% higher ultimate tensile strength was achieved by the selection of the optimum building platform temperature. Moreover, the possibility to further increase the mechanical properties by means of a direct ageing heat treatment was investigated.

  18. Comparison of electron beam and laser beam powder bed fusion additive manufacturing process for high temperature turbine component materials

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ryan, Daniel [Solar Turbines, Inc., San Diego, CA (United States)

    2016-04-01

    The evolving 3D printer technology is now at the point where some turbine components could be additive manufactured (AM) for both development and production purposes. However, this will require a significant evaluation program to qualify the process and components to meet current design and quality standards. The goal of the project was to begin characterization of the microstructure and mechanical properties of Nickel Alloy X (Ni-22Cr-18Fe-9Mo) test bars fabricated by powder bed fusion (PBF) AM processes that use either an electron beam (EB) or laser beam (LB) power source. The AM materials produced with the EB and LB processes displayed significant differences in microstructure and resultant mechanical properties. Accordingly, during the design analysis of AM turbine components, the specific mechanical behavior of the material produced with the selected AM process should be considered. Comparison of the mechanical properties of both the EB and LB materials to those of conventionally processed Nickel Alloy X materials indicates the subject AM materials are viable alternatives for manufacture of some turbine components.

  19. Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

    Directory of Open Access Journals (Sweden)

    Anna Zaghi

    2016-12-01

    Full Text Available A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-transfer process from the carbamoyl anion of the N,N-dimethylformamide (DMF solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel columns have been fabricated and operated to accomplish the chemoselective synthesis of aroylated α-hydroxy ketones and 2-benzoyl-1,4-diones (benzoin- and Stetter-like products, respectively with a good level of efficiency and with a long-term stability of the packing material (up to five days.

  20. Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

    Science.gov (United States)

    Zaghi, Anna; Ragno, Daniele; Di Carmine, Graziano; De Risi, Carmela; Bortolini, Olga; Giovannini, Pier Paolo; Fantin, Giancarlo

    2016-01-01

    A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-transfer process from the carbamoyl anion of the N,N-dimethylformamide (DMF) solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP) as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel columns) have been fabricated and operated to accomplish the chemoselective synthesis of aroylated α-hydroxy ketones and 2-benzoyl-1,4-diones (benzoin- and Stetter-like products, respectively) with a good level of efficiency and with a long-term stability of the packing material (up to five days). PMID:28144342

  1. Size distribution of agglomerates of milk powder in wet granulation process in a vibro-fluidized bed

    Directory of Open Access Journals (Sweden)

    M. Banjac

    2009-09-01

    Full Text Available Results of experiments on the influence of technological parameters (intensity of vibration, granulation of the liquid feed, temperature of fluidization agent on the change of size distribution, as well as mass mean diameter of the milk powder particles subjected to the wet granulation process (agglomeration in a vibro-fluidized bed granulator are shown in this paper. Using water as a granulation liquid and air as a fluidization agent, it was found that mass mean diameter increases with increase of water feed, intensity of vibration, and decrease of air temperature. Increasing the intensity of vibration and decreasing the air temperature, primarily induces the increase of the dimensions of the initial nuclei. This can be explained on the basis of different influences that these changes (velocity of particle motion, intensity of particle collision, drying rate have on the coalescence of particles with smaller and/or bigger dimensions.

  2. Coal gasification by indirect heating in a single moving bed reactor: Process development & simulation

    Directory of Open Access Journals (Sweden)

    Junaid Akhlas

    2015-10-01

    Full Text Available In this work, the development and simulation of a new coal gasification process with indirect heat supply is performed. In this way, the need of pure oxygen production as in a conventional gasification process is avoided. The feasibility and energetic self-sufficiency of the proposed processes are addressed. To avoid the need of Air Separation Unit, the heat required by gasification reactions is supplied by the combustion flue gases, and transferred to the reacting mixture through a bayonet heat exchanger installed inside the gasifier. Two alternatives for the flue gas generation have been investigated and compared. The proposed processes are modeled using chemical kinetics validated on experimental gasification data by means of a standard process simulator (Aspen PlusTM, integrated with a spreadsheet for the modeling of a special type of heat exchanger. Simulation results are presented and discussed for proposed integrated process schemes. It is shown that they do not need external energy supply and ensure overall efficiencies comparable to conventional processes while producing syngas with lower content of carbon dioxide.

  3. Thermochemical process for seasonal storage of solar energy: characterization and modeling of a high-density reactive bed

    OpenAIRE

    Michel, Benoit; Mazet, Nathalie; Mauran, Sylvain; Stitou, Driss; Jing XU

    2012-01-01

    International audience; This paper focuses on the characterization and modeling of a solid/gas thermochemical reaction between a porous reactive bed and moist air flowing through it. The aim is the optimization of both energy density and permeability of the reactive bed, in order to realize a high density thermochemical system for seasonal thermal storage for house heating application. Several samples with different implementation parameters (density, binder, diffuser, porous bed texture) hav...

  4. An Investigation into the Relationship of Fluidization Velocity to the Optimal Economic Design of a Fluidized-Bed Drying Process.

    Science.gov (United States)

    1982-12-01

    is described by many investigators. Zenz and Othmer (Ia), Leva (11), Kunii and Levenspiel (8), Coulson and Richardson (3), Lewis and Bower- man (13...with the fluid stream. The fluid bed reactor has a broad usage in chemical engineering industry (8). However, the complex nature of this fluid bed makes...interest in the Icombustion of solid material in a fluidized-bed reactor . The lack of fundamental design knowledge at that time was pro- hibiting

  5. A compact process for treating oilfield wastewater by combining hydrolysis acidification, moving bed biofilm, ozonation and biologically activated carbon techniques.

    Science.gov (United States)

    Zheng, Tao

    2016-01-01

    A lab-scale hybrid system integrating a hybrid hydrolysis acidification (HA) reactor, a moving bed biofilm reactor (MBBR) and an ozonation-biologically activated carbon (O3-BAC) unit was used in the treatment of heavy oil wastewater with high chemical oxygen demand (COD) and low biodegradability. The effects of hydraulic retention time and ozonation time were investigated. The results show that under the optimal conditions, the effluent concentrations of COD, oil and ammonia were 48, 1.3 and 3.5 mg/L, respectively, corresponding to total removal efficiencies of 95.8%, 98.9% and 94.4%, respectively. The effluent could meet the grade I as required by the national discharge standard of China. The HA process remarkably improved the biodegradability of the wastewater, while the MBBR process played an important role in degrading COD. The ozonation process further enhanced the biodegradability of the MBBR effluent, and finally, deep treatment was completed in the BAC reactor. This work demonstrates that the hybrid HA/MBBR/O3-BAC system has the potential to be used for the treatment of high-strength oilfield wastewater.

  6. Treatment of oil sands process-affected water using moving bed biofilm reactors: With and without ozone pretreatment.

    Science.gov (United States)

    Shi, Yijing; Huang, Chunkai; Rocha, Ketley Costa; El-Din, Mohamed Gamal; Liu, Yang

    2015-09-01

    Two moving bed biofilm reactors (MBBRs) were operated to treat raw (untreated) and 30 mg/L ozone-treated oil sands process-affected water (OSPW). After 210 days, the MBBR process showed 18.3% of acid-extractable fraction (AEF) and 34.8% of naphthenic acids (NAs) removal, while the ozonation combined MBBR process showed higher removal of AEF (41.0%) and NAs (78.8%). Biodegradation of raw and ozone treated OSPW showed similar performance. UPLC/HRMS analysis showed a highest NAs removal efficiency with a carbon number of 14 and a -Z number of 4. Confocal laser scanning microscopy (CLSM) showed thicker biofilms in the raw OSPW MBBR (97 ± 5 μm) than in the ozonated OSPW MBBR (71 ± 12 μm). Quantitative polymerase chain reaction (q-PCR) results showed higher abundance of gene copies of total bacteria and nitrogen removal relevant bacteria in the ozonated OSPW MBBR, but no significant difference was found. MiSeq sequencing showed Proteobacteria, Nitrospirae, and Acidobacteria were dominant.

  7. Organizational learning as a test-bed for business process reengineering

    DEFF Research Database (Denmark)

    Larsen, Michael Holm; Leinsdorff, Torben

    1998-01-01

    The fact that a company's learning ability may prevent strategic drift and the fact that many companies are undertaking BPR (business process reengineering) projects leads us to ask whether all these BPR activities promote organizational learning. Within this framework, we studied the extent...... to which BPR promotes organizational learning by focusing on the project group and the steering committee. This paper is based partly on a theoretical study of the significant characteristics of BPR and of organizational learning and partly on a field study carried out in cooperation with the business unit...... of Enzyme Business, Novo Nordisk A/S. The result of the analysis is that a correlation between BPR and organizational learning has been established, i.e. the BPR elements: customer focus, process orientation, high level of ambition, clean sheet principle, performance measuring, the business system diamond...

  8. 12 Bootis: a test bed for extra-mixing processes in stars

    CERN Document Server

    Miglio, A; Maceroni, C; Miglio, Andrea; Montalban, Josefina; Maceroni, Carla

    2007-01-01

    12 Bootis is a spectroscopic binary whose visual orbit has been resolved by interferometry. Though the physical parameters of the system have been determined with an excellent precision, the theoretical modelling of the components is still uncertain. We study the capability of solar-like oscillations to distinguish between calibrated models of the system obtained by including in the stellar modelling different mixing processes. We consider different scenarios for the chemical transport processes: classical overshooting, microscopic diffusion and turbulent mixing. For each of them we calibrate the stellar models of 12 Boo A and B by fitting the available observational constraints by means of a Levenberg-Marquardt minimization algorithm, and finally, we analyze the asteroseismic properties of different calibrated models. Several solutions with 12 Boo A in (or close to) post-main sequence and 12 Boo B on main sequence are found by assuming a thickness of the overshooting layer between 0.06 and 0.23 the pressure ...

  9. Validation of a model for process development and scale-up of packed-bed solid-state bioreactors

    NARCIS (Netherlands)

    Weber, F.J.; Oostra, J.; Tramper, J.; Rinzema, A.

    2002-01-01

    We have validated our previously described model for scale-up of packed-bed solid-state fermenters (Weber et al., 1999) with experiments in an adiabatic 15-dm3 packed-bed reactor, using the fungi Coniothyrium minitans and Aspergillus oryzae. Effects of temperature on respiration, growth, and sporula

  10. Cretaceous black shale and the oceanic red beds:Process and mechanisms of oceanic anoxic events and oxic environment

    Institute of Scientific and Technical Information of China (English)

    Zhenguo ZHANG; Nianqiao FANG; Lianfeng GAO; Baoling GUI; Muhua CUI

    2008-01-01

    The Cretaceous is an important period in which many geological events occurred,especially the OAEs (oceanic anoxic events) which are characterized by black shale,and the oxic process characterized by CORBs (Cretaceous oceanic red beds).In this paper,the causative mechanism behind the formation of black shale and the oceanic red beds are described in detail.This may explain how the oceanic environment changed from anoxic to oxic in the Cretaceous period.It is suggested that these two different events happened because of the same cause.On the one hand,the large-scale magma activities in Cretaceous caused the concentration of CO2,the release of the inner energy of the earth,superficial change in the ocean-land,and finally,the increase of atmospheric temperature.These changes implied the same tendency as the oceanic water temperature show,and caused the decrease in O2 concentration in the Cretaceous ocean,and finally resulted in the occurrence of the OAEs.On the other hand,violent and frequent volcanic eruptions in the Cretaceous produced plenty of Fe-enriched lava on the seafloor.When the seawater reacted with the lava,the element Fe became dissolved in seawater.Iron,which could help phytoplankton grow rapidly,is a micronutrient essential to the synthesis of enzymes required for photosynthesis in the oceanic environment.Phytoplankton,which grows in much of the oceans around the world,can consume carbon dioxide in the air and the ocean.Meanwhile,an equal quantity of oxygen can be produced by the phytoplankton during its growth.Finally,the oxic environment characterized by red sediment rich in Fe3+appeared.The anoxic and oxic conditions in the Cretaceous ocean were caused by volcanic activities,but they stemmed from different causative mechanisms.The former was based on physical and chemical processes,while the latter involved more complicated bio-oceanic-geochemical processes.

  11. Novel dry-desulfurization process using Ca(OH)2/fly ash sorbent in a circulating fluidized bed.

    Science.gov (United States)

    Matsushima, Norihiko; Li, Yan; Nishioka, Masateru; Sadakata, Masayoshi; Qi, Haiying; Xu, Xuchang

    2004-12-15

    A dry-desulfurization process using Ca(OH)2/fly ash sorbent and a circulating fluidized bed (CFB) was developed. Its aim was to achieve high SO2 removal efficiency without humidification and production of CaSO4 as the main byproduct. The CaSO4 produced could be used to treat alkalized soil. An 83% SO2 removal rate was demonstrated, and a byproduct with a high CaSO4 content was produced through baghouse ash. These results indicated that this process could remove SO2 in flue gas with a high efficiency under dry conditions and simultaneously produce soil amendment. It was shown that NO and NO2 enhanced the SO2 removal rate markedly and that NO2 increased the amount of CaSO4 in the final product more than NO. These results confirmed that the significant effects of NO and NO2 on the SO2 removal rate were due to chain reactions that occurred under favorable conditions. The amount of baghouse ash produced increased as the reaction progressed, indicating that discharge of unreacted Ca(OH)2 from the reactor was suppressed. Hence, unreacted Ca(OH)2 had a long residence time in the CFB, resulting in a high SO2 removal rate. It was also found that 350 degrees C is the optimum reaction temperature for dry desulfurization in the range tested (320-380 degrees C).

  12. Real-Time Signal Processing for Multiantenna Systems: Algorithms, Optimization, and Implementation on an Experimental Test-Bed

    Directory of Open Access Journals (Sweden)

    Haustein Thomas

    2006-01-01

    Full Text Available A recently realized concept of a reconfigurable hardware test-bed suitable for real-time mobile communication with multiple antennas is presented in this paper. We discuss the reasons and prerequisites for real-time capable MIMO transmission systems which may allow channel adaptive transmission to increase link stability and data throughput. We describe a concept of an efficient implementation of MIMO signal processing using FPGAs and DSPs. We focus on some basic linear and nonlinear MIMO detection and precoding algorithms and their optimization for a DSP target, and a few principal steps for computational performance enhancement are outlined. An experimental verification of several real-time MIMO transmission schemes at high data rates in a typical office scenario is presented and results on the achieved BER and throughput performance are given. The different transmission schemes used either channel state information at both sides of the link or at one side only (transmitter or receiver. Spectral efficiencies of more than 20 bits/s/Hz and a throughput of more than 150 Mbps were shown with a single-carrier transmission. The experimental results clearly show the feasibility of real-time high data rate MIMO techniques with state-of-the-art hardware and that more sophisticated baseband signal processing will be an essential part of future communication systems. A discussion on implementation challenges towards future wireless communication systems supporting higher data rates (1 Gbps and beyond or high mobility concludes the paper.

  13. The innovative moving bed biofilm reactor/solids contact reaeration process for secondary treatment of municipal wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Rusten, B.; McCoy, M.; Proctor, R.; Siljudalen, J.G.

    1998-07-01

    The innovative moving bed biofilm reactor/solids contact reaeration (MBBR/SCR) process has been chosen for a new wastewater treatment plant serving a population of 200,000 at Moa Point, Wellington, New Zealand. Because the MBBR/SCR combination was new, a pilot-scale demonstration project was made part of the contract. Thorough pilot tests using a wide range of organic loads under both steady and transient-flow conditions demonstrated that the MBBR/SCR process produced the required effluent quality at loads higher than used in the original design. At 3 days mean cell residence time (MCRT) in the SCR stage, a final effluent with a 5-day biochemical oxygen demand (BOD{sub 5}) of less than 10 mg/L was achieved at an organic load on the MBBR of 15 g BOD{sub 5}/m{sup 2}{center_dot}d (5.0 kg BOD{sub 5}/m{sup 3}{center_dot}d). With the same MCRT, a final effluent of less than 15 mg BOD{sub 5}/L was achieved at an organic load on the MBBR of 20 g BOD{sub 5}/m{sup 2}{center_dot}d (6.7 kg BOD{sub 5}/m{sup 3}{center_dot}d). Dynamic loading tests demonstrated that a good-quality effluent was produced with a diurnal peak-hour load on the MBBR of more than 40 g BOD{sub 5}/m{sup 2}{center_dot}d (13.3 kg BOD{sub 5}/m{sup 3}{center_dot}d). The MBBR/SCR process was more compact and significantly cheaper than a conventional trickling filter/solids contact or activated-sludge process at the Moa Point site.

  14. Effect of algae on flocculation of suspended bed sediments in a large shallow lake. Consequences for ecology and sediment transport processes

    NARCIS (Netherlands)

    de Lucas Pardo, MiguelAngel; Sarpe, Dirk; Winterwerp, JohanChristian

    2015-01-01

    Lake Markermeer, a large shallow lake in The Netherlands, suffers from turbidity and ecology problems. As part of a study aiming to mitigate these problems, we study flocculation processes in the lake; in particular, the possible mutual flocculation between algae and re-suspended bed sediments. We s

  15. Pollution of bed sediments and its changing process of Nansihu Lake

    Institute of Scientific and Technical Information of China (English)

    ZHANGZulu; SUNJuan; WANGLin; ShenJi

    2004-01-01

    In order to research the changing process of the pollution from the formation of Nansihu Lake, this study determined the isotope age and depositional rate and analyzed the organic geo-chemical quotas and heavy metal quotas of two sedimentary profiles of Weishan and Dushan lakes. Research results showed that from the formation of Nansihu Lake, the change of the pollution could be divided into four phrases. At the early phrase of the formation, the organic matters of the lake mainly derived from the exotic matters and had a close relation to the effect on the water and sands from the Huanghe (Yellow) River. At the middle and late phrases of the development, the endogenous matters of the lake became the main and stable source of the organic matters. The overflow of the Huanghe River, the excavation of the Grand Canal and the cut of trees caused the changes of the historic pollution. In recent 20 years, the modem industrial pollution from the organic matters and heavy metals has an increasingly heavy tendency.

  16. THE SCALE-UP OF LARGE PRESSURIZED FLUIDIZED BEDS FOR ADVANCED COAL-FIRED POWER PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Leon R. Glicksman; Michael Louge; Hesham F. Younis; Richard Tan; Mathew Hyre; Mark Torpey

    2003-11-24

    This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor an agency thereof, nor any of the their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, A combined-cycle High Performance Power System (HIPPS) capable of overall cycle efficiencies approaching 50% has been proposed and designed by Foster Wheeler Development Corporation (FWDC). A pyrolyzer in the first stage of the HIPPS process converts a coal feedstock into fuel gas and char at an elevated pressure of 1.4 Map. (206 psia) and elevated temperature of 930 C (1700 F). The generated char serves as the feedstock for a Pulverized Coal (PC) boiler operating at atmospheric pressure, and the fuel gas is directly fired in a gas turbine. The hydrodynamic behavior of the pyrolyzer strongly influences the quality of both the fuel gas and the generated char, the energy split between the gas turbine and the steam turbine, and hence the overall efficiency of the system. By utilizing a simplified set of scaling parameters (Glicksman et al.,1993), a 4/7th labscale cold model of the pyrolyzer operating at ambient temperature and pressure was constructed and tested. The scaling parameters matched include solid to gas density ratio, Froude number, length to diameter ratio; dimensionless superficial gas velocity and solid recycle rate, particle sphericity and particle size distribution (PSD).

  17. Application of Distributed Temperature Sensing for coupled mapping of sedimentation processes and spatio-temporal variability of groundwater discharge in soft-bedded streams

    DEFF Research Database (Denmark)

    Sebök, Éva; Calvache, Carlos Duque; Engesgaard, Peter Knudegaard;

    2015-01-01

    -induced temperature anomalies resemble the signal of groundwater discharge while scouring will cause the cable to float in the water column and measure stream water temperatures. DTS applied in a looped layout with nine fibre optic cable rows in a 70 × 5 m section of a soft-bedded stream made it possible to detect......The delineation of groundwater discharge areas based on Distributed Temperature Sensing (DTS) data of the streambed can be difficult in soft-bedded streams where sedimentation and scouring processes constantly change the position of the fibre optic cable relative to the streambed. Deposition...... on the simultaneous interpretation of streambed temperature and elevation data, a method is proposed to delineate potential high-groundwater discharge areas and identify deposition-induced temperature anomalies in soft-bedded streams. Potential high-discharge sites were detected using as metrics the daily minimum...

  18. Field enhancements of packed-bed performance for low-concentration acidic and basic-waste gases from semiconductor manufacturing process.

    Science.gov (United States)

    Chein, Hung Min; Aggarwal, Shankar Gopala; Wu, Hsin Hsien; Chen, Tzu Ming; Huang, Chun-Chao

    2005-05-01

    Low-concentration acidic and basic-waste gas pollutants contribute significantly in the total emission of a facility. Previous results show that the control of high volumetric flow rate (approximately 500 m3/min), low-concentration acidic (< 1 ppm by vol) and basic (< 3 ppm by vol) gases from semiconductor process vent, by conventional wet scrubbing technique is a challenging task. This work was targeted to enhance the performance of packed beds for high-volumetric flow rate, low-concentration acidic (HF, HCl), and basic (NH3)-waste gases from the semiconductor manufacturing process. The methodology used to meet the goal was the application of fine-water mist over the inlet stream before entering to the packed bed and use of the surfactant with mist/packed-bed liquid in low concentration. An experimental study was carried out in two acid-packed beds to optimize the operating conditions, such as pH of the liquid, circulating liquid flow rate, blow-down cycle, and so forth. The relationship among liquid pH, liquid ionic concentration, and the removal efficiency of the packed bed for the pollutants has been discussed considering chemical equilibrium, two-film theory, and Henry's law. For the potential utilization of scrubbing water, the dependency of the efficiency on blow-down cycle was studied, and a mechanism is suggested. The proposed water-mist surfactant system was installed in two acid-packed beds, and performance of the packed beds was compared. The background efficiencies of the acid-packed beds for HF, HCl, and NH3 were found max to be (n = 11) 53, 40, and 27%, whereas after installation of the system, they increased significantly and became 76 +/- 13% (n = 10), 76 +/- 8% (n = 7), and 78 +/- 7% (n = 7), respectively, for inlet concentrations of HF and HCl < 1 ppm and NH3 < 14 ppm. The mechanism by which the surfactants operate to enhance the removal in scrubbing process is suggested considering the hydrodynamic effect and the interfacial effect with the

  19. Deammonification process start-up after enrichment of anammox microorganisms from reject water in a moving-bed biofilm reactor.

    Science.gov (United States)

    Zekker, Ivar; Rikmann, Ergo; Tenno, Toomas; Kroon, Kristel; Vabamäe, Priit; Salo, Erik; Loorits, Liis; Rubin, Sergio S C dC; Vlaeminck, Siegfried E; Tenno, Taavo

    2013-01-01

    Deammonification via intermittent aeration in biofilm process for the treatment of sewage sludge digester supernatant (reject water) was started up using two opposite strategies. Two moving-bed biofilm reactors were operated for 2.5 years at 26 (+/- 0.5 degree C with spiked influent(and hence free ammonia (FA)) addition. In the first start-up strategy, an enrichment of anammox biomass was first established, followed by the development of nitrifying biomass in the system (R1). In contrast, the second strategy aimed at the enrichment of anammox organisms into a nitrifying biofilm (R2). The first strategy was most successful, reaching higher maximum total nitrogen (TN) removal rates over a shorter start-up period. For both reactors, increasing FA spiking frequency and increasing effluent concentrations of the anammox intermediate hydrazine correlated to decreasing aerobic nitrate production (nitritation). The bacterial consortium of aerobic and anaerobic ammonium oxidizing bacteria in the bioreactor was determined via denaturing gel gradient electrophoresis, polymerase chain reaction and pyrosequencing. In addition to a shorter start-up with a better TN removal rate, nitrite oxidizing bacteria (Nitrospira) were outcompeted by spiked ammonium feeding from R1.

  20. Inorganic nitrogen transformations in the bed of the Shingobee River, Minnesota: Integrating hydrologic and biological processes using sediment perfusion cores

    Science.gov (United States)

    Sheibley, R.W.; Duff, J.H.; Jackman, A.P.; Triska, F.J.

    2003-01-01

    Inorganic N transformations were examined in streambed sediments from the Shingobee River using sediment perfusion cores. The experimental design simulated groundwater-stream water mixing within sediment cores, which provided a well-defined one-dimensional representation of in situ hydrologic conditions. Two distinct hydrologic and chemical settings were preserved in the sediment cores: the lowermost sediments, perfused with groundwater, remained anaerobic during the incubations, whereas the uppermost sediments, perfused with oxic water pumped from the overlying water column, simulated stream water penetration into the bed. The maintenance of oxic and anoxic zones formed a biologically active aerobic-anaerobic interface. Ammonium (NH4+) dissolved in groundwater was transported conservatively through the lower core zone but was removed as it mixed with aerated recycle water. Concurrently, a small quantity of nitrate (NO3-) equaling ???25% of the NH4+ loss was produced in the upper sediments. The NH4+ and NO3- profiles in the uppermost sediments resulted from coupled nitrification-denitrification, because assimilation and sorption were negligible. We hypothesize that anaerobic microsites within the aerated upper sediments supported denitrification. Rates of nitrification and denitrification in the perfusion cores ranged 42-209 and 53-160 mg N m-2 day-1, respectively. The use of modified perfusion cores permitted the identification and quantification of N transformations and verified process control by surface water exchange into the shallow hyporheic zone of the Shingobee River.

  1. Simulation assessment of continuous simulating moving bed chromatography process with partial feed and new strategy with partial feed

    Directory of Open Access Journals (Sweden)

    H. Khan

    2009-09-01

    Full Text Available Partial Feed simulating moving bed (SMB has proved to be more efficient in binary separation performance (purity, recovery, productivity because of its two additional degrees of freedom, namely feed length and feed time, as compared to classical SMB process. The binary separation of dextran T6 and fructose with linear isotherm is modeled with Aspen Chromatography simulator in a four zone SMB with one column per zone for both normal-feed and Partial Feed. Increase in number of feed length and feed time in the cycle plays a very important role in the separation performance with Partial Feed. In addition, the effect of mode of operation (early or late introduction of increase in number of feed length in the cycle on product purity and recovery is also investigated. Furthermore, the binary separation system is designed with the safety margin method and the optimum operating parameters for simulation are calculated with triangle theory. Finally, a new strategy with Partial Feed is developed, showing improved separation performance relative to the basic four-zone SMB with regard to extract stream purity and recovery. The results of the proposed study can served as a useful summary of Partial Feed operation.

  2. Withdrawal of gases and liquids from an in situ oil shale retort

    Science.gov (United States)

    Siegel, Martin M.

    1982-01-01

    An in situ oil shale retort is formed within a subterranean formation containing oil shale. The retort contains a fragmented permeable mass of formation particles containing oil shale. A production level drift extends below the fragmented mass, leaving a lower sill pillar of unfragmented formation between the production level drift and the fragmented mass. During retorting operations, liquid and gaseous products are recovered from a lower portion of the fragmented mass. A liquid outlet line extends from a lower portion of the fragmented mass through the lower sill pillar for conducting liquid products to a sump in the production level drift. Gaseous products are withdrawn from the fragmented mass through a plurality of gas outlet lines distributed across a horizontal cross-section of a lower portion of the fragmented mass. The gas outlet lines extend from the fragmented mass through the lower sill pillar and into the production level drift. The gas outlet lines are connected to a gas withdrawal manifold in the production level drift, and gaseous products are withdrawn from the manifold separately from withdrawal of liquid products from the sump in the production level drift.

  3. Color removal from textile dyebath effluents in a zeolite fixed bed reactor: determination of optimum process conditions using Taguchi method.

    Science.gov (United States)

    Engin, Ahmet Baki; Ozdemir, Ozgür; Turan, Mustafa; Turan, Abdullah Z

    2008-11-30

    Taguchi method was applied as an experimental design to determine optimum conditions for color removal from textile dyebath house effluents in a zeolite fixed bed reactor. After the parameters were determined to treat real textile wastewater, adsorption experiments were carried out. The breakthrough curves for adsorption studies were constructed under different conditions by plotting the normalized effluent color intensity (C/C(0)) versus time (min) or bed volumes (BV). The chosen experimental parameters and their ranges are: HTAB concentration (C(htab)), 1-7.5 gL(-1); HTAB feeding flowrate (Q(htab)), 0.015-0.075 L min(-1); textile wastewater flowrate (Q(dye)), 0.025-0.050 L min(-1) and zeolite bed height (H(bed)), 25-50 cm, respectively. Mixed orthogonal array L(16) (4(2)x2(2)) for experimental plan and the larger the better response category were selected to determine the optimum conditions. The optimum conditions were found to be as follows: HTAB concentration (C(htab))=1g L(-1), HTAB feeding flowrate (Q(htab))=0.015 L min(-1), textile wastewater flowrate (Q(dye))=0.025 L min(-1) and bed height (H(bed))=50 cm. Under these conditions, the treated wastewater volume reached a maximum while the bed volumes (BV) were about 217. While HTAB concentration, gL(-1) (A); zeolite bed height, cm (D) and wastewater flowrate, L min(-1) (C) were found to be significant parameters, respectively, whereas, HTAB flowrate, L min(-1) (B) was found to be an insignificant parameter.

  4. Color removal from textile dyebath effluents in a zeolite fixed bed reactor: Determination of optimum process conditions using Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Engin, Ahmet Baki [Sakarya University, Industrial Engineering Department, 54040 Sakarya (Turkey); Ozdemir, Ozguer [Istanbul Technical University, Environmental Engineering Department, 34469 Istanbul (Turkey); Turan, Mustafa [Istanbul Technical University, Environmental Engineering Department, 34469 Istanbul (Turkey)], E-mail: mturan@ins.itu.edu.tr; Turan, Abdullah Z. [Istanbul Technical University, Chemical and Metallurgical Engineering Department, 34469 Istanbul (Turkey)

    2008-11-30

    Taguchi method was applied as an experimental design to determine optimum conditions for color removal from textile dyebath house effluents in a zeolite fixed bed reactor. After the parameters were determined to treat real textile wastewater, adsorption experiments were carried out. The breakthrough curves for adsorption studies were constructed under different conditions by plotting the normalized effluent color intensity (C/C{sub 0}) versus time (min) or bed volumes (BV). The chosen experimental parameters and their ranges are: HTAB concentration (C{sub htab}), 1-7.5 g L{sup -1}; HTAB feeding flowrate (Q{sub htab}), 0.015-0.075 L min{sup -1}; textile wastewater flowrate (Q{sub dye}), 0.025-0.050 L min{sup -1} and zeolite bed height (H{sub bed}), 25-50 cm, respectively. Mixed orthogonal array L{sub 16} (4{sup 2} x 2{sup 2}) for experimental plan and the larger the better response category were selected to determine the optimum conditions. The optimum conditions were found to be as follows: HTAB concentration (C{sub htab}) = 1 g L{sup -1}, HTAB feeding flowrate (Q{sub htab}) = 0.015 L min{sup -1}, textile wastewater flowrate (Q{sub dye}) = 0.025 L min{sup -1} and bed height (H{sub bed}) = 50 cm. Under these conditions, the treated wastewater volume reached a maximum while the bed volumes (BV) were about 217. While HTAB concentration, g L{sup -1} (A); zeolite bed height, cm (D) and wastewater flowrate, L min{sup -1} (C) were found to be significant parameters, respectively, whereas, HTAB flowrate, L min{sup -1} (B) was found to be an insignificant parameter.

  5. Effect of organic loading rate on a wastewater treatment process combining moving bed biofilm and membrane reactors.

    Science.gov (United States)

    Melin, E; Leiknes, T; Helness, H; Rasmussen, V; Odegaard, H

    2005-01-01

    The effect of moving bed biofilm reactor (MBBR) loading rate on membrane fouling rate was studied in two parallel units combining MBBR and membrane reactor. Hollow fiber membranes with molecular weight cut-off of 30 kD were used. The HRTs of the MBBRs varied from 45 min to 4 h and the COD loading rates ranged from 4.1 to 26.6 g COD m(-2) d(-1). The trans-membrane pressure (TMP) was very sensitive to fluxes for the used membranes and the experiments were carried out at relatively low fluxes (3.3-5.6 l m(-2) h(-1)). Beside the test with the highest flux, there were no consistent differences in fouling rate between the low- and high-rate reactors. Also, the removal efficiencies were quite similar in both systems. The average COD removal efficiencies in the total process were 87% at 3-4 h HRT and 83% at 0.75-1 h HRT. At high loading rates, there was a shift in particle size distribution towards smaller particles in the MBBR effluents. However, 79-81% of the COD was in particles that were separated by membranes, explaining the relatively small differences in the removal efficiencies at different loading rates. The COD fractionation also indicated that the choice of membrane pore size within the range of 30 kD to 0.1 microm has very small effect on the COD removal in the MBBR/membrane process, especially with low-rate MBBRs.

  6. 内加热移动床生物质炭化中试设备监控系统开发%Monitoring and control system development for pilot-scale moving bed biomass carbonization equipment with internal heating

    Institute of Scientific and Technical Information of China (English)

    丛宏斌; 赵立欣; 孟海波; 姚宗路

    2015-01-01

    Biochar is a pyrolysis solid product of biological organic material (biomass) in anoxic and anaerobic conditions, It can be widely used in carbon emission reduction, water purification, adsorption of heavy metals and soil improvement, etc., so it can partly provide solutions for the focus issues of global concern, such as climate warming, environmental pollution and soil degradation. The production and application of biochar have aroused wide attention of researchers both at home and abroad. According to the continuity of production process, two types of biomass carbonization techniques have been developed in China, which are respectively fixed bed carbonization technique and moving bed carbonization technique. The fixed bed carbonization techniques can be divided into kiln carbonization technique and retort carbonization. Accordingly, the kiln carbonization technique commonly adopts spontaneous combustion heating method, its corresponding equipments have the features of simple structure and low-cost, so this technique has been used widely in China. The retort carbonization technique adopts external heating method, so its corresponding device has more complicated structure than the kiln carbonization technique, this technique can commonly realize the poly-generation of biochar and other byproducts. The moving bed carbonization technique is upgraded from the fixed bed carbonization technique, and according to flowing the direction of material, this technique can be divided into transverse flow moving bed carbonization technique and vertical flow moving bed carbonization technique. Continuous producing is the remarkable feature of the moving bed biomass carbonization technique, and it has higher automation level and lower labor intensity, compared with the fixed bed carbonization technique. The moving bed carbonization technique represents developing direction of China’s biomass carbonization technique. Aimed at the problems of low productivity, high energy

  7. Eroded riverbank assessing in a gravel bed reach of the Piave River by processing LiDAR and TLS data

    Science.gov (United States)

    Moretto, Johnny; Rainato, Riccardo; Rigon, Emanuel; Aristide Lenzi, Mario

    2015-04-01

    represents a valuable support for river topography description, river management, ecology and restoration purposes. Keywords: Fluvial processes; gravel bed river; riverbank erosion; LiDAR data; TLS data; vegetation filtering; erosion-deposition analysis.

  8. Improved and more environmentally friendly charcoal production system using a low-cost retort-kiln (Eco-charcoal)

    Energy Technology Data Exchange (ETDEWEB)

    Adam, J.C. [Adam and Partner, Bahnhofstrasse 13, 82467 Garmisch (Germany)

    2009-08-15

    Research into a low-cost retort-kiln, used to produce charcoal from sustainably managed forests in a more environmentally friendly way (Eco-Charcoal), has been completed and pilot units have been built in India and East Africa. The unit is called ICPS (Improved Charcoal Production System). Importantly, it has a much higher efficiency rating than traditional earth-mound kilns, which have until now been the main means of domestic charcoal production in developing nations. The efficiency of traditional charcoal production methods is about 10%-22% (calculated on using oven-dry wood with 0% water content) while the efficiency of the ICPS is approximately 30%-42%. As compared with traditional carbonisation processes, the ICPS reduces emissions to the atmosphere by up to 75%. The ICPS works in two different phases. During the first phase the ICPS works like a traditional kiln; however, waste wood is burned in a separate fire box to dry the wood. During the second phase of operation the harmful volatiles are burned in a hot 'fire chamber' meaning all resulting emissions are cleaner, minus these already reduced volatiles. The heat gained by flaring the wood gazes, is used and recycled to accelerate the carbonisation process. Unlike traditional methods the ICPS can complete a carbonisation cycle within 12 h. (author)

  9. Carbonisation of bagasse in a fixed bed reactor: influence of process variables on char yield and characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Katyal, S.; Thambimuthu, K.; Valix, M. [University of Sydney (Australia). Dept. of Chemical Engineering

    2003-04-01

    Carbonisation experiments on samples of sugar cane bagasse were conducted in a static fixed bed reactor to determine the effect of process variables such as temperature, heating rate, inert sweep gas flow rate and particle size on the yield and composition of solid product char. Experiments were performed to the final temperatures of 250-700{sup o}C with heating rates from 5 to 30{sup o}C/min with nitrogen sweep gas flow rate of 350 cc/min. Additional tests were aimed at studying the effect of different flow rates of nitrogen sweep gas from 0 to 700 cc/min during carbonization and different particle size fractions of bagasse. The results showed that as the carbonisation temperature was increased, the yield of char decreased. The reduction in yield was rapid up to a final temperature of 500{sup o}C and was slower thereafter. The yield of char was relatively insensitive to the changes in heating rate and particle size. Increasing the sweep gas flow rate to 350 cc/min reduced the yield of char. It appears the presence of inert sweep gas reduced secondary reactions which promoted char formation. The proximate analysis of the char suggests that fixed carbon and ash content increased with temperature. The char obtained at temperatures higher than 500{sup o}C have high carbon content and is suitable as renewable fuel and for other applications. The carbonization of bagasse has the potential to produce environmental friendly fuels and can assist in reducing deforestation for the production of charcoal. (Author)

  10. PRODUCTION OF MEDIUM-CHAIN ACYLGLYCEROLS BY LIPASE ESTERIFICATION IN PACKED BED REACTOR: PROCESS OPTIMIZATION BY RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    ZANARIAH MOHD DOM

    2014-06-01

    Full Text Available Medium-chain acylglycerols (or glycerides are formed of mono-, di- and triacylglycerol classes. In this study, an alternative method to produce MCA from esterifying palm oil fatty acid distillate (PFAD with the presence of oil palm mesocarp lipase (OPML which is a plant-sourced lipase and PFAD is also cheap by-product is developed in a packed bed reactor. The production of medium-chain acylglycerols (MCA by lipase-catalysed esterification of palm oil fatty acid distillate with glycerol are optimize in order to determine the factors that have significant effects on the reaction condition and high yield of MCA. Response surface methodology (RSM was applied to optimize the reaction conditions. The reaction conditions, namely, the reaction time (30-240 min, enzyme load (0.5-1.5 kg, silica gel load (0.2-1.0 kg, and solvent amount (200-600 vol/wt. Reaction time, enzyme loading and solvent amount strongly effect MCA synthesis (p0.05 influence on MCA yield. Best-fitting models were successfully established for MCA yield (R 2 =0.9133. The optimum MCA yield were 75% from the predicted value and 75.4% from the experimental data for 6 kg enzyme loading, a reaction time of 135min and a solvent amount of 350 vol/wt at 65ºC reaction temperature. Verification of experimental results under optimized reaction conditions were conducted, and the results agreed well with the predicted range. Esterification products (mono-, di- and triacylglycerol from the PBR were identified using Thin Layer Chromatography method. The chromatograms showed the successful fractionation of esterified products in this alternative method of process esterification.

  11. Remediation of acid mine drainage at the friendship hill national historic site with a pulsed limestone bed process

    Science.gov (United States)

    Sibrell, P.L.; Watten, B.; Boone, T.; ,

    2003-01-01

    A new process utilizing pulsed fluidized limestone beds was tested for the remediation of acid mine drainage at the Friendship Hill National Historic Site, in southwestern Pennsylvania. A 230 liter-per-minute treatment system was constructed and operated over a fourteen-month period from June 2000 through September 2001. Over this period of time, 50,000 metric tons of limestone were used to treat 50 million liters of water. The influent water pH was 2.5 and acidity was 1000 mg/L as CaCO3. Despite the high potential for armoring at the site, effluent pH during normal plant operation ranged from 5.7 to 7.8 and averaged 6.8. As a result of the high influent acidity, sufficient CO2 was generated and recycled to provide a net alkaline discharge with about 50 mg/L as CaCO3 alkalinity. Additions of commercial CO2 increased effluent alkalinity to as high as 300 mg/L, and could be a useful process management tool for transient high flows or acidities. Metal removal rates were 95% for aluminum (60 mg/L in influent), 50 to 90% for iron (Fe), depending on the ratio of ferrous to ferric iron, which varied seasonally (200 mg/L in influent), and iron and Mn removal was incomplete because of the high pH required for precipitation of these species. Iron removal could be improved by increased aeration following neutralization, and Mn removal could be effected by a post treatment passive settling/oxidation pond. Metal hydroxide sludges were settled in settling tanks, and then hauled from the site for aesthetic purposes. Over 450 metric tons of sludge were removed from the water over the life of the project. The dried sludge was tested by the Toxicity Characteristics Leaching Protocol (TCLP) and was found to be non-hazardous. Treatment costs were $43,000 per year and $1.08 per m 3, but could be decreased to $22,000 and $0.51 per m3 by decreasing labor use and by onsite sludge handling. These results confirm the utility of the new process in treatment of acid impaired waters that were

  12. Gully erosion processes impacted by vegetation on gully beds based on an in situ scouring experiment in a Dry-hot Valley of Southwest China

    Science.gov (United States)

    Dong, Yifan; Xiong, Donghong; Su, Zhengan

    2015-04-01

    Vegetation can protect soil from water erosion. Some previous researches on the subjects of vegetation and gully erosion were mainly focused on the topography changes cause by vegetation and the conservation effects and techniques. While the mechanics of vegetation effects on the hydraulic processes of gully bed to influence the erosion processes were still not very clear. In this study, an in situ scouring experiment was conducted 11 times assuming a consistent flow condition (7 times with a flow discharge of 83.3L/min and 4 times with a flow discharge of 166.7 L/min on five gully head plots with gully bed lengths of 20 m, which were constructed with similar initial topography (height of the headcuts were 0.5m, the slope of gully beds were from 18.2% to 19.1%) and same soil type (Dry red soil which classified as Rhodoxeralfs in USDA Soil Taxonomy ). Five vegetation condition levels were set on gully bed (the same vegetation density and different lengths of the vegetation sites as 0 m, 4m, 8m, 12m and 16m). Each scouring last 1h and the flow rate, flow depth and flow width were recorded every 10 minutes, after each scouring the topography changes were measured by RTK GPS. The total gully bed erosion volume (TEV) exhibited a significant exponentially decreasing relationship with increasing length of the vegetation sites (VL) due to the similar relationship between the VL and the runoff erosion capacity. The hydrodynamic parameters in the vegetation sites were clearly lower than those in bare sites and caused the average TEV of the vegetation sites to be approximately 3.3 times lower than that of the bare gully bed. However, the vegetation protection efficiency did not increase as the length of the vegetation sites increased. The hydrodynamics of the bare site sections showed a good relationship with TEV, while in the vegetation sites, the relationship was quite weak, indicating that hydraulics conditions were not the main factors influencing gully bed erosion in the

  13. Biosorption of cadmium(II) ions by citrus peels in a packed bed column: effect of process parameters and comparison of different breakthrough curve models

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Abhijit; Schiewer, Silke [Department of Civil and Environmental Engineering, University of Alaska Fairbanks, Fairbanks, AK (United States)

    2011-09-15

    The efficiency of low cost citrus peels as biosorbents for removal of cadmium ions from aqueous solution was investigated in a fixed bed column, a process that could be applied to treat industrial wastewaters similar to commonly used ion exchange columns. Effluent concentration versus time profiles (i.e., breakthrough curves) were experimentally determined in a laboratory-scale packed bed column for varying operational parameters such as flow rate (2, 9, and 15.5 mL/min), influent cadmium concentration (5, 10, and 15 mg/L), and bed height (24, 48, and 72 cm) at pH 5.5. Column operation was most efficient for empty bed contact times of at least 10 min, which were apparently necessary for mass transfer. While the sorption capacity was largely unaffected by operational variables, the Thomas (Th) rate constant increased with the flow rate, and slightly decreased with increasing column length. Three widely used semi-mechanistic models (Th, Bohart-Adams, and Yoon-Nelson) were shown to be equivalent and the generalized model was compared with a two-parameter empirical model (dose-response). The latter was found to be able to better simulate the breakthrough curve in the region of breakthrough and saturation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Understanding and predicting bed humidity in fluidized bed granulation.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John; Winstead, Denita

    2008-04-01

    Bed humidity is a critical parameter that needs to be controlled in a fluidized bed granulation to ensure reliability. To predict and control the bed humidity during the fluidized bed granulation process, a simple model based on the mass conservation of moisture was developed. The moisture mass balance model quantitatively simulates the effects of spray rate, binder solution concentration, airflow rate, inlet air temperature, and dew point on the bed humidity. The model was validated by a series of granulations performed in different scale granulators including Glatt GPCG-1, GPCG-15, and GPCG-60. Good agreement was observed between the theoretical prediction and the measured loss on drying (LOD). The model developed in the current work enables us to choose the appropriate parameters for the fluidized bed granulation and can be used as a valuable tool in process scaling-up.

  15. On suitability of novel fluidised bed technique for separation of metallic powders during commercial powder metallurgical processing

    NARCIS (Netherlands)

    Ritherdon, J; Dechsiri, C; Jones, AR; Hoffmann, AC; Wright, IG

    2005-01-01

    Experiments have been performed to test the efficiency with which a novel fluidised bed technique could separate different metallic powders in terms of size and density. The overall aim was to assess the potential of this technique for the commercial separation of defective powder fractions from mec

  16. An Integrated Process of a Two-Stage Fixed Bed Syngas Production and F-T Synthesis for GTL in Remote Gas Field

    Institute of Scientific and Technical Information of China (English)

    代小平; 余长春; 等

    2003-01-01

    A novel process for catalytic oxidation of methane to synthesis gas (syngas),which consists of two consecutive fixed-bed reactors with air introduced into the reactors,integrated Fischer-Tropsch synthesis,was investigated.At the Same time,a catalytic combustion technology has been investigated for utilizing the F-T offgas to generate heat or powr energy.The results show that the two-stage fixed reactor process keep away from explosion of CH4/O2.The integrated process is fitted to produce diesel oil and lubricating oil in remote gas field.

  17. Extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Cader SA

    2012-10-01

    Full Text Available Samária Ali Cader,1 Rodrigo Gomes de Souza Vale,1 Victor Emmanuel Zamora,2 Claudia Henrique Costa,2 Estélio Henrique Martin Dantas11Laboratory of Human Kinetics Bioscience, Federal University of Rio de Janeiro State, 2Pedro Ernesto University Hospital, School of Medicine, State University of Rio de Janeiro, Rio de Janeiro, BrazilBackground: The purpose of this study was to evaluate the extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training (IMT and identify predictors of successful weaning.Methods: Twenty-eight elderly intubated patients in an intensive care unit were randomly assigned to an experimental group (n = 14 that received conventional physiotherapy plus IMT with a Threshold IMT® device or to a control group (n = 14 that received only conventional physiotherapy. The experimental protocol for muscle training consisted of an initial load of 30% maximum inspiratory pressure, which was increased by 10% daily. The training was administered for 5 minutes, twice daily, 7 days a week, with supplemental oxygen from the beginning of weaning until extubation. Successful extubation was defined by the ventilation time measurement with noninvasive positive pressure. A vacuum manometer was used for measurement of maximum inspiratory pressure, and the patients' Tobin index values were measured using a ventilometer.Results: The maximum inspiratory pressure increased significantly (by 7 cm H2O, 95% confidence interval [CI] 4–10, and the Tobin index decreased significantly (by 16 breaths/min/L, 95% CI −26 to 6 in the experimental group compared with the control group. The Chi-squared distribution did not indicate a significant difference in weaning success between the groups (Χ2 = 1.47; P = 0.20. However, a comparison of noninvasive positive pressure time dependence indicated a significantly lower value for the experimental group (P = 0.0001; 95% CI 13.08–18.06. The receiver

  18. Continuous processing of recombinant proteins: Integration of inclusion body solubilization and refolding using simulated moving bed size exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2013-12-06

    An integrated process which combines continuous inclusion body dissolution with NaOH and continuous matrix-assisted refolding based on closed-loop simulated moving bed size exclusion chromatography was designed and experimentally evaluated at laboratory scale. Inclusion bodies from N(pro) fusion pep6His and N(pro) fusion MCP1 from high cell density fermentation were continuously dissolved with NaOH, filtered and mixed with concentrated refolding buffer prior to refolding by size exclusion chromatography (SEC). This process enabled an isocratic operation of the simulated moving bed (SMB) system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling by concentrating the raffinate using tangential flow filtration. With this continuous refolding process, we increased the refolding and cleavage yield of both model proteins by 10% compared to batch dilution refolding. Furthermore, more than 99% of the refolding buffer of the raffinate could be recycled which reduced the buffer consumption significantly. Based on the actual refolding data, we compared throughput, productivity, and buffer consumption between two batch dilution refolding processes - one using urea for IB dissolution, the other one using NaOH for IB dissolution - and our continuous refolding process. The higher complexity of the continuous refolding process was rewarded with higher throughput and productivity as well as significantly lower buffer consumption compared to the batch dilution refolding processes.

  19. Pressurized fluidized-bed hydroretorting of eastern oil shales. Volume 2, Task 3, Testing of process improvement concepts: Final report, September 1987--May 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This final report, Volume 2, on ``Process Improvement Concepts`` presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). Results of work on electroseparation of shale oil and fines conducted by IIT is included in this report, as well as work conducted by IGT to evaluate the restricted pipe discharge system. The work was conducted as part of the overall program on ``Pressurized Fluidized-Bed Hydroretorting of Eastern Oil Shales.``

  20. A Systematic Approach of Employing Quality by Design Principles: Risk Assessment and Design of Experiments to Demonstrate Process Understanding and Identify the Critical Process Parameters for Coating of the Ethylcellulose Pseudolatex Dispersion Using Non-Conventional Fluid Bed Process.

    Science.gov (United States)

    Kothari, Bhaveshkumar H; Fahmy, Raafat; Claycamp, H Gregg; Moore, Christine M V; Chatterjee, Sharmista; Hoag, Stephen W

    2016-07-14

    The goal of this study was to utilize risk assessment techniques and statistical design of experiments (DoE) to gain process understanding and to identify critical process parameters for the manufacture of controlled release multiparticulate beads using a novel disk-jet fluid bed technology. The material attributes and process parameters were systematically assessed using the Ishikawa fish bone diagram and failure mode and effect analysis (FMEA) risk assessment methods. The high risk attributes identified by the FMEA analysis were further explored using resolution V fractional factorial design. To gain an understanding of the processing parameters, a resolution V fractional factorial study was conducted. Using knowledge gained from the resolution V study, a resolution IV fractional factorial study was conducted; the purpose of this IV study was to identify the critical process parameters (CPP) that impact the critical quality attributes and understand the influence of these parameters on film formation. For both studies, the microclimate, atomization pressure, inlet air volume, product temperature (during spraying and curing), curing time, and percent solids in the coating solutions were studied. The responses evaluated were percent agglomeration, percent fines, percent yield, bead aspect ratio, median particle size diameter (d50), assay, and drug release rate. Pyrobuttons® were used to record real-time temperature and humidity changes in the fluid bed. The risk assessment methods and process analytical tools helped to understand the novel disk-jet technology and to systematically develop models of the coating process parameters like process efficiency and the extent of curing during the coating process.

  1. Effect of combination processing on the microbial, chemical and sensory quality of ready-to-eat (RTE) vegetable pulav

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R., E-mail: kumardfrl@gmail.com [Defence Food Research Laboratory, Mysore, Karnataka 570011 (India); George, Johnsy; Rajamanickam, R.; Nataraju, S.; Sabhapathy, S.N.; Bawa, A.S. [Defence Food Research Laboratory, Mysore, Karnataka 570011 (India)

    2011-12-15

    Effect of irradiation in combination with retort processing on the shelf life and safety aspects of an ethnic Indian food product like vegetable pulav was investigated. Gamma irradiation of RTE vegetable pulav was carried out at different dosage rates with {sup 60}Co followed by retort processing. The combination processed samples were analysed for microbiological, chemical and sensory characteristics. Microbiological analysis indicated that irradiation in combination with retort processing has significantly reduced the microbial loads whereas the chemical and sensory analysis proved that this combination processing is effective in retaining the properties even after storage for one year at ambient conditions. The results also indicated that a minimum irradiation dosage at 4.0 kGy along with retort processing at an F{sub 0} value of 2.0 is needed to achieve the desired shelf life with improved organoleptic qualities. - Highlights: > A combination processing involving gamma irradiation and retort processing. > Combination processing reduced microbial loads. > Minimum dose of 4.0 kGy together with retort processing at F{sub 0}-2.0 is required to achieve commercial sterility.

  2. Combining microwave resonance technology to multivariate data analysis as a novel PAT tool to improve process understanding in fluid bed granulation.

    Science.gov (United States)

    Lourenço, Vera; Herdling, Thorsten; Reich, Gabriele; Menezes, José C; Lochmann, Dirk

    2011-08-01

    A set of 192 fluid bed granulation batches at industrial scale were in-line monitored using microwave resonance technology (MRT) to determine moisture, temperature and density of the granules. Multivariate data analysis techniques such as multiway partial least squares (PLS), multiway principal component analysis (PCA) and multivariate batch control charts were applied onto collected batch data sets. The combination of all these techniques, along with off-line particle size measurements, led to significantly increased process understanding. A seasonality effect could be put into evidence that impacted further processing through its influence on the final granule size. Moreover, it was demonstrated by means of a PLS that a relation between the particle size and the MRT measurements can be quantitatively defined, highlighting a potential ability of the MRT sensor to predict information about the final granule size. This study has contributed to improve a fluid bed granulation process, and the process knowledge obtained shows that the product quality can be built in process design, following Quality by Design (QbD) and Process Analytical Technology (PAT) principles.

  3. Comparison of three different wastewater sludge and their respective drying processes: Solar, thermal and reed beds - Impact on organic matter characteristics.

    Science.gov (United States)

    Collard, Marie; Teychené, Benoit; Lemée, Laurent

    2016-06-09

    Drying process aims at minimising the volume of wastewater sludge (WWS) before disposal, however it can impact sludge characteristics. Due to its high content in organic matter (OM) and lipids, sludge are mainly valorised by land farming but can also be considered as a feedstock for biodiesel production. As sludge composition is a major parameter for the choice of disposal techniques, the objective of this study was to determine the influence of the drying process. To reach this goal, three sludges obtained from solar, reed beds and thermal drying processes were investigated at the global and molecular scales. Before the drying step the sludges presented similar physico-chemical (OM content, elemental analysis, pH, infrared spectra) characteristics and lipid contents. A strong influence of the drying process on lipids and humic-like substances contents was observed through OM fractionation. Thermochemolysis-GCMS of raw sludge and lipids revealed similar molecular content mainly constituted with steroids and fatty acids. Molecular changes were noticeable for thermal drying through differences in branched to linear fatty acids ratio. Finally the thermal drying induced a weakening of OM whereas the solar drying led to a complexification. These findings show that smooth drying processes such as solar or reed-beds are preferable for amendment production whereas thermal process leads to pellets with a high lipid content which could be considered for fuel production.

  4. Wet scrubbing for control of particular emissions from oil shale retorting

    Energy Technology Data Exchange (ETDEWEB)

    Rinaldi, G.M.; Thurnau, R.C.; Lotwala, J.T.

    1981-01-01

    A mobile pilot-scale venturi scrubber was tested for control of particulate emissions from the Laramie Energy Techonolgy Center's 136-mg (150-ton)-capacity oil shale retort. The entire retort off-gas flow of 15.4 m/sup 3//min (545 ft/sup 3//min), discharged from a heat exchanger at a temperature of 58 /degree/C and saturated with water, was scrubbed at liquid-to-gas ratios of l.5 to 2.4 L/m/sup 3/. Sampling and analysis of the scrubber inlet and outlet gases were conducted to determine particulate removal. Outlet particulate concentrations were consistently reduced to 35 mg/m/sup 3/, even through inlet loadings varied from 125 to 387 mg/m/sup 3/ and 50 weight percent of the particles were less than four micrometers in diameter. Particulate control efficiencies up to 94 percent were achieved, although no correlation to liquid-to-gas ratio was observed. Simultaneous control of ammonia emissions, at efficiencies up to 75 percent, was also observed. 5 refs.

  5. Sterilization of Staple Foods in Retort Pouch%软包装主食罐头杀菌工艺研究

    Institute of Scientific and Technical Information of China (English)

    郑志强; 刘嘉喜; 王越鹏

    2012-01-01

    对软包装主食罐头的杀菌工艺进行研究,分析在不同杀菌温度和时间条件下食品中心温度及F值的变化,确定最佳杀菌方式为双峰高温杀菌,杀菌参数为80℃、5min,110℃、5min,121℃、12min,125℃、(30+30)s,峰底113℃,该杀菌工艺能够有效降低软包装主食罐头的杀菌强度,杀菌后的产品大大降低了因高温产生的后熟蒸馏味,大幅延长了保质期,最终产品品质显著提高。%This study was undertaken to investigate the sterilization of retort pouches containing staple foods.Variations in central temperature and F value were analyzed under various conditions of sterilization temperature and time.The optimal sterilization process was double peak high temperature sterilization at 80 ℃ for 5 min,110 ℃ for 5 min,121 ℃ for 12 min and 125 ℃ for 30 s + 30 s with a peak base temperature of 113 ℃.Under these conditions,the sterilization intensity of retort pouches was attenuated effectively.Moreover,the distillation odor caused by high-temperature sterilization was reduced greatly,and the shelf life was markedly extended.As a result,the quality of staple foods could be obviously improved.

  6. Post Retort, Pre Hydro-treat Upgrading of Shale Oil

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John

    2012-09-30

    Various oil feedstocks, including oil from oil shale, bitumen from tar sands, heavy oil, and refin- ery streams were reacted with the alkali metals lithium or sodium in the presence of hydrogen or methane at elevated temperature and pressure in a reactor. The products were liquids with sub- stantially reduced metals, sulfur and nitrogen content. The API gravity typically increased. Sodi- um was found to be more effective than lithium in effectiveness. The solids formed when sodium was utilized contained sodium sulfide which could be regenerated electrochemically back to so- dium and a sulfur product using a "Nasicon", sodium ion conducting membrane. In addition, the process was found to be effective reducing total acid number (TAN) to zero, dramatically reduc- ing the asphaltene content and vacuum residual fraction in the product liquid. The process has promise as a means of eliminating sulfur oxide and carbon monoxide emissions. The process al- so opens the possibility of eliminating the coking process from upgrading schemes and upgrad- ing without using hydrogen.

  7. Production of specifically structured lipids by enzymatic interesterification in a pilot enzyme bed reactor: process optimization by response surface methodology

    DEFF Research Database (Denmark)

    Xu, Xuebing; Mu, Huiling; Høy, Carl-Erik;

    1999-01-01

    Pilot production of specifically structured lipids by Lipozyme IM-catalyzed interesterification was carried out in a continuous enzyme bed reactor without the use of solvent. Medium chain triacylglycerols and oleic acid were used as model substrates. Response surface methodology was applied...... and the production of mono-incorporated and di-incorporated structured lipids with multiple regression and backward elimination. The coefficient of determination (R2) for the incorporation was 0.93, and that for the di-incorporated products was 0.94. The optimal conditions were flow rate, 2 ml/min; temperature, 65...

  8. An Optical Receiver Post-Processing System for the Integrated Radio and Optical Communications Software Defined Radio Test Bed

    Science.gov (United States)

    Nappier, Jennifer M.; Tokars, Roger P.; Wroblewski, Adam C.

    2016-01-01

    The Integrated Radio and Optical Communications (iROC) project at the National Aeronautics and Space Administration's (NASA) Glenn Research Center is investigating the feasibility of a hybrid radio frequency (RF) and optical communication system for future deep space missions. As a part of this investigation, a test bed for a radio frequency (RF) and optical software defined radio (SDR) has been built. Receivers and modems for the NASA deep space optical waveform are not commercially available so a custom ground optical receiver system has been built. This paper documents the ground optical receiver, which is used in order to test the RF and optical SDR in a free space optical communications link.

  9. Laboratory Testing of a Fluidized-Bed Dry-Scrubbing Process for the Removal of Acidic Gases from a Simulated Incinerator Flue Gas

    Science.gov (United States)

    1989-04-01

    Vertical Pneu- matic Transport Reactor ," Ind. Eng. Chem. Process Des. Dev., 23(3), 539-45 (1984). 3. R. Graf and J. D. Riley, "Dry/Semi-Dry Flue Cas...Kuni and Levenspiel ) W0 Gildart clo,,itiat ion" Group ItI l rotI ed r desc r i bed in ASTM St arda rd C 110-87. 22 REFERENCES 1. W. M. Bradshaw...Cement; Lime; Gyp- sum, American Society for Testing and Materials, Philadelphia, Pennsylvania, 1988. 3. D. Kuni and 0. Levenspiel , Fluidization

  10. Laboratory Testing of a Fluidized Bed Dry Scrubbing Process for Removal of Sulfur Dioxide and Phosphorous Pentoxide from an Inert Carrier Gas.

    Science.gov (United States)

    1988-03-01

    from vent gas streams in a bench-scale packed bed reactor using quicklime at 135 to 3000C. 4 A 99% HF removal rate was reported at calcium utiliza...Fan et al., "Limestone/Dolomite Sulfation in a Vertical Pneu- matic Transport Reactor ," Ind. Eng. Chem. Process Des. Dev., 23(3), 539-45, 1984. 6. G. A...Vol. II, June 1986. 7. D. Kunni and 0. Levenspiel , Fluidization Engineering, Robert E. % Krieger Publishing Company, Inc., Huntington, N.Y., 1977. 8. R

  11. Test bed for real-time image acquisition and processing systems based on FlexRIO, CameraLink, and EPICS

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, E., E-mail: eduardo.barrera@upm.es [Grupo de Investigación en Instrumentación y Acústica Aplicada, Universidad Politécnica de Madrid (UPM) (Spain); Ruiz, M.; Sanz, D. [Grupo de Investigación en Instrumentación y Acústica Aplicada, Universidad Politécnica de Madrid (UPM) (Spain); Vega, J.; Castro, R. [Asociación EURATOM/CIEMAT para Fusión, Madrid (Spain); Juárez, E.; Salvador, R. [Centro de Investigación en Tecnologías Software y Sistemas Multimedia para la Sostenibilidad, Universidad Politécnica de Madrid (UPM) (Spain)

    2014-05-15

    Highlights: • The test bed allows for the validation of real-time image processing techniques. • Offers FPGA (FlexRIO) image processing that does not require CPU intervention. • Is fully compatible with the architecture of the ITER Fast Controllers. • Provides flexibility and easy integration in distributed experiments based on EPICS. - Abstract: Image diagnostics are becoming standard ones in nuclear fusion. At present, images are typically analyzed off-line. However, real-time processing is occasionally required (for instance, hot-spot detection or pattern recognition tasks), which will be the objective for the next generation of fusion devices. In this paper, a test bed for image generation, acquisition, and real-time processing is presented. The proposed solution is built using a Camera Link simulator, a Camera Link frame-grabber, a PXIe chassis, and offers software interface with EPICS. The Camera Link simulator (PCIe card PCIe8 DVa C-Link from Engineering Design Team) generates simulated image data (for example, from video-movies stored in fusion databases) using a Camera Link interface to mimic the frame sequences produced with diagnostic cameras. The Camera Link frame-grabber (FlexRIO Solution from National Instruments) includes a field programmable gate array (FPGA) for image acquisition using a Camera Link interface; the FPGA allows for the codification of ad-hoc image processing algorithms using LabVIEW/FPGA software. The frame grabber is integrated in a PXIe chassis with system architecture similar to that of the ITER Fast Controllers, and the frame grabber provides a software interface with EPICS to program all of its functionalities, capture the images, and perform the required image processing. The use of these four elements allows for the implementation of a test bed system that permits the development and validation of real-time image processing techniques in an architecture that is fully compatible with that of the ITER Fast Controllers

  12. Comparison of the Acceptability of Various Oil Shale Processes

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, A K; McConaghy, J R

    2006-03-11

    While oil shale has the potential to provide a substantial fraction of our nation's liquid fuels for many decades, cost and environmental acceptability are significant issues to be addressed. Lawrence Livermore National Laboratory (LLNL) examined a variety of oil shale processes between the mid 1960s and the mid 1990s, starting with retorting of rubble chimneys created from nuclear explosions [1] and ending with in-situ retorting of deep, large volumes of oil shale [2]. In between, it examined modified-in-situ combustion retorting of rubble blocks created by conventional mining and blasting [3,4], in-situ retorting by radio-frequency energy [5], aboveground combustion retorting [6], and aboveground processing by hot-solids recycle (HRS) [7,8]. This paper reviews various types of processes in both generic and specific forms and outlines some of the tradeoffs for large-scale development activities. Particular attention is given to hot-recycled-solids processes that maximize yield and minimize oil shale residence time during processing and true in-situ processes that generate oil over several years that is more similar to natural petroleum.

  13. Expanded bed adsorption as a primary recovery step for the isolation of the insulin precursor MI3 process development and scale up.

    Science.gov (United States)

    Brixius, Peter; Mollerup, Inger; Jensen, Ole Elvang; Halfar, Markus; Thömmes, Jörg; Kula, Maria-Regina

    2006-01-05

    Expanded bed adsorption (EBA) was evaluated for the isolation of the human insulin precursor MI3, expressed and secreted by the yeast Saccharomyces cerevisiae. The isoelectric point of the insulin precursor (pH 5.3) makes cation exchange a prime candidate for direct adsorption. In order to find a suitable window of operation for the process the adsorption equilibrium was analysed in a wide range of operating conditions (pH and conductivity) and for three different stationary phases. The same array of operating conditions was examined with regard to stable fluidisation of the adsorbents in S. cerevisiae suspensions. Interactions of the yeast with the fluidised stationary phase were investigated by a pulse response technique and the hydrodynamics of the fluidised bed under process conditions by residence time distribution analysis. The case study demonstrates that by parallel examination of product binding and fluidisation quality a window of operation can be found. Analysis of the binding kinetics by breakthrough experiments and modelling led to the definition of a set of operating conditions, which yield a compromise between optimal use of the equilibrium capacity provided by the adsorbent and high throughput required for an industrial separation. After initial experiments on the bench scale the protocol was transferred successfully to pilot scale demonstrating the design of a reliable operation.

  14. Fluidization quality analyzer for fluidized beds

    Science.gov (United States)

    Daw, C. Stuart; Hawk, James A.

    1995-01-01

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence.

  15. Pilot study of the moving-bed copper oxide process for SO{sub 2} and NO{sub x} control

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, J.S.; Yeh, J.T.; Pennline, H.W. [Department of Energy, Pittsburgh, PA (United States); Resnik, K.P. [Parsons Power Group, Inc., Pittsburgh, PA (United States)

    1997-07-01

    The Moving-Bed Copper Oxide Process is a dry, regenerable sorbent technique that uses supported copper oxide sorbent to simultaneously remove SO{sub 2} and NO{sub x} emissions from flue gas generated by coal combustion. This process can meet the goals of a Department of Energy (DOE) initiative to develop flue gas control technologies to remove 99% and 95% of SO{sub 2} and NO{sub x}, respectively, at a low cost for emission control. The process can be integrated into the design of advanced power systems, such as the Low-Emission Boiler System (LEBS) or the High-Performance Power System (HIPPS). This flue gas cleanup technique is currently being evaluated in a life-cycle tea system (LCTS) with a moving-bed flue gas contractor at DOE`s Federal Energy Technology Center. An experimental data base being established will be used to verify reported technical and economic advantages, optimize process conditions, provide scaleup information, and validate absorber and regenerator mathematical models. The chemistry of the process is relatively straightforward. In the absorption step, SO{sub 2} in the flue gas reacts with copper oxide, supported on small spheres of alumina, to form copper sulfate. Ammonia is injected into the flue gas before the absorption reactor and a selective catalytic reduction-type reaction occurs that reduces the nitric oxides in the flue gas. In the regeneration step, the copper sulfate is reduced in a regenerator with a reducing agent, such as natural gas, producing a concentrated stream of SO{sub 2}. Another advantage of the process is that the lower pressure drop across the moving-bed configuration as compared to other designs reduces power consumption and thus influences the overall economic costs. LCTS results are discussed from several proms parametric test series (MBCuO-11 through MBCuO-14). The effects of various absorber and regenerator parameters on sorbent performance (e.g., SO{sub 2} and NO{sub x} removal) were investigated.

  16. Linking River Management-Induced Perturbations of Hydrologic and Sediment Regimes to Geomorphic Processes Along a Highly-Dynamic Gravel-Bed River: Snake River, WY.

    Science.gov (United States)

    Leonard, C.; Legleiter, C. J.

    2015-12-01

    Encroachment of human development onto river floodplains creates a need to stabilize rivers and provide flood protection. Structural interventions, such as levees, often perturb hydrologic and sediment regimes and thus can initiate morphological responses. An understanding of how human activities affect river morphodynamics and trigger channel change is needed to anticipate future river responses and facilitate effective restoration. This study examines approximately 66 km of the Snake River, WY, USA, and links sediment transport processes to channel form and behavior by developing a morphological sediment budget that spans both a natural, unconfined reach and a reach confined by artificial levees. Sediment transport rates are inferred from the morphological sediment budget and a bed mobility study is used to estimate entrainment thresholds that allow us to link the hydrological regime during the sediment budget period to the observed channel changes. Results indicate that lateral constriction by levees triggers a positive feedback mechanism by incising the bed, focusing flow energy, thus increasing transport capacity, and leading to armoring of the bed. In other systems, armoring promotes widening of the channel but in this case levees prevent widening and the channel instead migrates across the braidplain rapidly, producing further erosion of bars and vegetated islands that is expressed as negative net volumetric changes and increased sediment transport rates. Furthermore, decreased slopes and reduced discharges due to dam regulation in the upstream unconfined reach cause gravel sheets to stall on bars and in other areas of storage, creating a spatial discontinuity in sediment conveyance downstream, and thus contributing to the sediment deficit within the leveed reach.

  17. An Innovated Tower-fluidized Bed Prilling Process%喷洒造粒过程的分析和革新

    Institute of Scientific and Technical Information of China (English)

    伍沅; 包传平; 周玉新

    2007-01-01

    Cooling-solidification of sprayed droplets is one of major methods for prilling of melt.Traditionally, this is carried out in an empty tower, and the equipment requirement for producing larger particles is very high, resulting in not only significant cost increasing but also difficulties in transporting melt etc.Based on analysis and simulation, a new prilling process is developed for the melt prilling, which combines a tower with a fluidized bed so that the height of equipment is greatly decreased, and it exhibits satisfactory performance in industrial application.Mathematical model for tower prilling, its simulated results, the structure of the equipment for the innovated prilling process and its application are addressed.

  18. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    Science.gov (United States)

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process.

  19. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: enhanced removal of aromatic amines.

    Science.gov (United States)

    Koupaie, E Hosseini; Moghaddam, M R Alavi; Hashemi, S H

    2011-11-15

    The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  20. Creation of Pd/Al2O3 Catalyst by a Spray Process for Fixed Bed Reactors and Its Effective Removal of Aqueous Bromate

    Science.gov (United States)

    Gao, Yu; Sun, Wuzhu; Yang, Weiyi; Li, Qi

    2017-02-01

    Palladium nanoparticles were grown on sub-millimeter activated Al2O3 particle support by spraying H2PdCl4 solution evenly onto the support, followed with a thermal reduction under H2 atmosphere. Compared with its counterpart created by the conventional impregnation method, the Pd/Al2O3 catalyst created by the spray process could enrich the existence of active Pd nanoparticles on the surface of the catalyst support and increase their degree of dispersion, resulting in a much higher activity in the catalytic reduction of bromate in water. The effect of Al2O3 support particle size on the bromate removal rate was also investigated, which demonstrated that smaller support particle size could have higher activity in the catalytic reduction of bromate in water because of its larger exposed surface. This Pd/Al2O3 catalyst could be easily used in the fixed bed reactor due to its large support size and demonstrated excellent stability in the catalytic reduction of bromate in mineral water. This Pd/Al2O3 catalyst also exhibited a good catalytic reduction performance on azo dyes as demonstrated by its effective catalytic hydrogenation of methyl orange. Thus, catalysts prepared by the spray method developed in this work could have the potential to be used in fixed bed reactors for various water treatment practices.

  1. Biomass gasification and in-bed contaminants removal: performance of iron enriched olivine and bauxite in a process of steam/O2 gasification.

    Science.gov (United States)

    Barisano, D; Freda, C; Nanna, F; Fanelli, E; Villone, A

    2012-08-01

    A modified Olivine, enriched in iron content (10% Fe/Olivine), and a natural bauxite, were tested in the in-bed reduction of tar and alkali halides (NaCl and KCl) released in a process of biomass steam/O(2) gasification. The tests were carried out at an ICBFB bench scale reactor under the operating conditions of: 855-890 °C, atmospheric pressure, 0.5 steam/biomass and 0.33 ER ratios. From the use of the two materials, a reduction in the contaminant contents of the fuel gas produced was found. For the alkali halides, a decrease up to 70%(wt) was observed for the potassium concentration, while for sodium, the reduction was found to be quite poor. For the organic content, compared to unmodified Olivine, the chromatographically determined total tar quantity showed a removal efficiency of 38%(wt). Moreover, regarding the particulate content a rough doubling in the fuel gas revealed a certain brittleness of the new bed material.

  2. Bed rest during pregnancy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000581.htm Bed rest during pregnancy To use the sharing features on ... your daily activities. Why Do I Need Bed Rest? Bed rest used to be recommended routinely for ...

  3. Method for establishing a combustion zone in an in situ oil shale retort having a pocket at the top

    Science.gov (United States)

    Cha, Chang Y.

    1980-01-01

    An in situ oil shale retort having a top boundary of unfragmented formation and containing a fragmented permeable mass has a pocket at the top, that is, an open space between a portion of the top of the fragmented mass and the top boundary of unfragmented formation. To establish a combustion zone across the fragmented mass, a combustion zone is established in a portion of the fragmented mass which is proximate to the top boundary. A retort inlet mixture comprising oxygen is introduced to the fragmented mass to propagate the combustion zone across an upper portion of the fragmented mass. Simultaneously, cool fluid is introduced to the pocket to prevent overheating and thermal sloughing of formation from the top boundary into the pocket.

  4. Laser powder-bed fusion additive manufacturing: Effects of main physical processes on dynamical melt flow and pore formation from mesoscopic powder simulation

    CERN Document Server

    Khairallah, Saad A; Rubenchik, Alexander

    2015-01-01

    There is a need in laser powder-bed fusion of metals to produce high quality parts without pores by better understanding the complex interplay of process parameters. This study considers the main physical phenomena involved in laser powder interactions using a high fidelity three-dimensional mesoscopic simulation model of 316L stainless steel powder. The model emphasizes the importance of the recoil pressure and the Marangoni effect in generating strong dynamical melt flow and the role of radiative and evaporative cooling at capping the maximum surface temperature. The melt track is divided into an indentation, transition and tail end regions, each being the stage of specific physical effects. Pore formation mechanisms are observed at the edge of a scan track, at the melt pool bottom center during collapse of the indentation, and at the end of the melt track during laser power ramp down. Remedies to these undesirable pores are discussed.

  5. Performance of on-site pilot static granular bed reactor (SGBR) for treating dairy processing wastewater and chemical oxygen demand balance modeling under different operational conditions.

    Science.gov (United States)

    Oh, Jin Hwan; Park, Jaeyoung; Ellis, Timothy G

    2015-02-01

    The performance and operational stability of a pilot-scale static granular bed reactor (SGBR) for the treatment of dairy processing wastewater were investigated under a wide range of organic and hydraulic loading rates and temperature conditions. The SGBR achieved average chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS)-removal efficiencies higher than 90% even at high loading rates up to 7.3 kg COD/m(3)/day, with an hydraulic retention time (HRT) of 9 h, and at low temperatures of 11 °C. The average methane yield of 0.26 L CH4/g COD(removed) was possibly affected by a high fraction of particulate COD and operation at low temperatures. The COD mass balance indicated that soluble COD was responsible for most of the methane production. The reactor showed the capacity of the methanogens to maintain their activity and withstand organic and hydraulic shock loads.

  6. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Koupaie, E., E-mail: ehssan.hosseini.k@gmail.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Hashemi, S.H., E-mail: h_hashemi@sbu.ac.ir [Environmental Science Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2011-11-15

    Highlights: {yields} Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. {yields} More than 65% of the dye total metabolites was completely mineralized. {yields} Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. {yields} Inhibition of biofilm growth was increased with increasing the initial dye concentration. {yields} Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  7. Characteristics of high-sulfate wastewater treatment by two-phase anaerobic digestion process with Jet-loop anaerobic fluidized bed

    Institute of Scientific and Technical Information of China (English)

    WEI Chao-hai; WANG Wen-xiang; DENG Zhi-yi; WU Chao-fei

    2007-01-01

    A new anaerobic reactor,Jet-loop anaerobic fluidized bed(JLAFB),was designed for treating high-sulfate wastewater.The treatment characteristics,including the effect of influent COD/SO42- ratio and alkalinity and sulfide inhibition in reactors,were discussed for a JLAFB and a general anaerobic fluidized bed(AFB)reactor used as sulfate-reducing phase and methane-producing phase,respectively,in two-phase anaerobic digestion process.The formation of granules in the two reactors was also examined.The results indicated that COD and sulfate removal had different demand of influent COD/S042- ratios.When total COD removal Was up to 85%,the ratio was only required up to 1.2,whereas,total sulfate removal up to 95%required it exceeding 3.0.The alkalinity in the two reactors increased linearly with the growth of influent alkalinity.Moreover,the change of influent alkalinity had no significant effect on pH and volatile fatty acids(VFA)in the two reactors.Influent alkalinity kept at 400-500 mg/t,could meet the requirement of the treating process.The JLAFB reactor had great advantage in avoiding sulfide and free-H2S accumulation and toxicity inhibition on microorganisms.When sulfate loading rate was up to 8.1 kg/(m3·d),the sulfide and free-H2S concentrations in JLAFB reactor were 58.6 and 49.7 mg/L,respectively.Furthermore,the granules,with offwhite color,ellipse shape and diameters of 1.0-3.0 mm,could be developed in JLAFB reactor.In granules,different groups of bacteria were distributed in different layers,and some inorganic metal compounds such as Fe,Ca,Mg etc.were found.

  8. Pressurized fluidized-bed hydroretorting of eastern oil shales. Volume 4, Task 5, Operation of PFH on beneficiated shale, Task 6, Environmental data and mitigation analyses and Task 7, Sample procurement, preparation, and characterization: Final report, September 1987--May 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The objective of Task 5 (Operation of Pressurized Fluidized-Bed Hydro-Retorting (PFH) on Beneficiated Shale) was to modify the PFH process to facilitate its use for fine-sized, beneficiated Eastern shales. This task was divided into 3 subtasks: Non-Reactive Testing, Reactive Testing, and Data Analysis and Correlations. The potential environment impacts of PFH processing of oil shale must be assessed throughout the development program to ensure that the appropriate technologies are in place to mitigate any adverse effects. The overall objectives of Task 6 (Environmental Data and Mitigation Analyses) were to obtain environmental data relating to PFH and shale beneficiation and to analyze the potential environmental impacts of the integrated PFH process. The task was divided into the following four subtasks. Characterization of Processed Shales (IGT), 6.2. Water Availability and Treatment Studies, 6.3. Heavy Metals Removal and 6.4. PFH Systems Analysis. The objective of Task 7 (Sample Procurement, Preparation, and Characterization) was to procure, prepare, and characterize raw and beneficiated bulk samples of Eastern oil shale for all of the experimental tasks in the program. Accomplishments for these tasks are presented.

  9. Design of a fixed-bed ion-exchange process for the treatment of rinse waters generated in the galvanization process using Laminaria hyperborea as natural cation exchanger.

    Science.gov (United States)

    Mazur, Luciana P; Pozdniakova, Tatiana A; Mayer, Diego A; Boaventura, Rui A R; Vilar, Vítor J P

    2016-03-01

    In this study, the removal of zinc from galvanization wastewaters was performed in a fixed bed column packed with brown macro-algae Laminaria hyperborea, acting as a natural cation exchanger (resin). The rinse wastewater presents a zinc concentration between 9 and 22 mg/L, a high concentration of light metals (mainly Na and Ca), a high conductivity (0.5-1.5 mS/cm) and a low organic content (DOC = 7-15 mg C/L). The zinc speciation diagram showed that approximately 80% of zinc is in the form of Zn(2+) and ≅20% as ZnSO4, considering the effluent matrix. From all operational conditions tested for zinc uptake (17 treatment of 2.4 m(3)/day of galvanization wastewater, resulting in an estimated reactants cost of 2.44 €/m(3).

  10. Novel Magnetically Fluidized Bed Reactor Development for the Looping Process: Coal to Hydrogen Production R&D

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Renwei; Hahn, David; Klausner, James; Petrasch, Jorg; Mehdizadeh, Ayyoub; Allen, Kyle; Rahmatian, Nima; Stehle, Richard; Bobek, Mike; Al-Raqom, Fotouh; Greek, Ben; Li, Like; Chen, Chen; Singh, Abhishek; Takagi, Midori; Barde, Amey; Nili, Saman

    2013-09-30

    The coal to hydrogen project utilizes the iron/iron oxide looping process to produce high purity hydrogen. The input energy for the process is provided by syngas coming from gasification process of coal. The reaction pathways for this process have been studied and favorable conditions for energy efficient operation have been identified. The Magnetically Stabilized Porous Structure (MSPS) is invented. It is fabricated from iron and silica particles and its repeatable high performance has been demonstrated through many experiments under various conditions in thermogravimetric analyzer, a lab-scale reactor, and a large scale reactor. The chemical reaction kinetics for both oxidation and reduction steps has been investigated thoroughly inside MSPS as well as on the surface of very smooth iron rod. Hydrogen, CO, and syngas have been tested individually as the reducing agent in reduction step and their performance is compared. Syngas is found to be the most pragmatic reducing agent for the two-step water splitting process. The transport properties of MSPS including porosity, permeability, and effective thermal conductivity are determined based on high resolution 3D CT x-ray images obtained at Argonne National Laboratory and pore-level simulations using a lattice Boltzmann Equation (LBE)-based mesoscopic model developed during this investigation. The results of those measurements and simulations provide necessary inputs to the development of a reliable volume-averaging-based continuum model that is used to simulate the dynamics of the redox process in MSPS. Extensive efforts have been devoted to simulate the redox process in MSPS by developing a continuum model consist of various modules for conductive and radiative heat transfer, fluid flow, species transport, and reaction kinetics. Both the Lagrangian and Eulerian approaches for species transport of chemically reacting flow in porous media have been investigated and verified numerically. Both approaches lead to correct

  11. Impact of ozonation pre-treatment of oil sands process-affected water on the operational performance of a GAC-fluidized bed biofilm reactor.

    Science.gov (United States)

    Islam, Md Shahinoor; Dong, Tao; McPhedran, Kerry N; Sheng, Zhiya; Zhang, Yanyan; Liu, Yang; Gamal El-Din, Mohamed

    2014-11-01

    Treatment of oil sands process-affected water (OSPW) using biodegradation has the potential to be an environmentally sound approach for tailings water reclamation. This process is both economical and efficient, however, the recalcitrance of some OSPW constituents, such as naphthenic acids (NAs), require the pre-treatment of raw OSPW to improve its biodegradability. This study evaluated the treatment of OSPW using ozonation followed by fluidized bed biofilm reactor (FBBR) using granular activated carbon (GAC). Different organic and hydraulic loading rates were applied to investigate the performance of the bioreactor over 120 days. It was shown that ozonation improved the adsorption capacity of GAC for OSPW and improved biodegradation by reducing NAs cyclicity. Bioreactor treatment efficiencies were dependent on the organic loading rate (OLR), and to a lesser degree, the hydraulic loading rate (HLR). The combined ozonation, GAC adsorption, and biodegradation process removed 62 % of chemical oxygen demand (COD), 88 % of acid-extractable fraction (AEF) and 99.9 % of NAs under optimized operational conditions. Compared with a planktonic bacterial community in raw and ozonated OSPW, more diverse microbial communities were found in biofilms colonized on the surface of GAC after 120 days, with various carbon degraders found in the bioreactor including Burkholderia multivorans, Polaromonas jejuensis and Roseomonas sp.

  12. Bio-Remediation of Acid Mine Drainage in the Sarcheshmeh Porphyry Copper Mine by Fungi: Batch and Fixed Bed Process

    Directory of Open Access Journals (Sweden)

    Hanieh Soleimanifar

    2012-12-01

    Full Text Available Acid mine drainage (AMD containing high concentrations of iron and sulphate, low pH and variableconcentrations of heavy metals leads to many environmental problems. The concentrations of Cu and Mnare high in the AMD of the Sarcheshmeh porphyry copper mine, Kerman province, south of Iran. In thisstudy, the bio-remediation of Cu and Mn ions from acid mine drainage was investigated using two nativefungi called Aspergillus niger and Phanerochaete chrysosporium which were extracted from the soil andsediment samples of the Shour River at the Sarcheshmeh mine. The live fungi was first harvested andthen killed by boiling in 0.5 N NaOH solution. The biomass was finally dried at 60 C for 24 h andpowdered. The optimum biosorption parameters including pH, temperature, the amount of biosorbent andcontact time were determined in a batch system. The optimum pH varied between 5 and 6. It was foundthat the biosorption process increased with an increase in temperature and the amount of biosorbent.Biosorption data were attempted by Langmuir and Freundlich isotherm models and showed a good match.Kinetic studies were also carried out in the present study. The results show that the second-order kineticsmodel fits well the experimental data. The biosorption experiments were further investigated with acontinuous system to compare the biosorption capacities of two systems. The results show thatbiosorption process using a continuous system increases efficiency up to 99%. A desorption process waseventually performed in order to recover Copper and Manganese ions. This process was successful andfungi could be used again.

  13. Design, fabrication, operation and Aspen simulation of oil shale pyrolysis and biomass gasification process using a moving bed downdraft reactor

    Science.gov (United States)

    Golpour, Hassan

    Energy is the major facilitator of the modern life. Every developed and developing economy requires access to advanced sources of energy to support its growth and prosperity. Declining worldwide crude oil reserves and increasing energy needs has focused attention on developing existing unconventional fossil fuels like oil shale and renewable resources such as biomass. Sustainable, renewable and reliable resources of domestically produced biomass comparing to wind and solar energy is a sensible motivation to establish a small-scale power plant using biomass as feed to supply electricity demand and heat for rural development. The work in Paper I focuses on the possibility of water pollution from spent oil shale which should be studied before any significant commercial production is attempted. In Paper II, the proposed Aspen models for oil shale pyrolysis is to identify the key process parameters for the reactor and optimize the rate of production of syncrude from oil shale. The work in Paper III focuses on (1) Design and operation of a vertical downdraft reactor, (2) Establishing an optimum operating methodology and parameters to maximize syngas production through process testing. Finally in Paper IV, a proposed Aspen model for biomass gasification simulates a real biomass gasification system discussed in Paper III.

  14. Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs.

    Science.gov (United States)

    Sing, Swee Leong; An, Jia; Yeong, Wai Yee; Wiria, Florencia Edith

    2016-03-01

    Additive manufacturing (AM), also commonly known as 3D printing, allows the direct fabrication of functional parts with complex shapes from digital models. In this review, the current progress of two AM processes suitable for metallic orthopaedic implant applications, namely selective laser melting (SLM) and electron beam melting (EBM) are presented. Several critical design factors such as the need for data acquisition for patient-specific design, design dependent porosity for osteo-inductive implants, surface topology of the implants and design for reduction of stress-shielding in implants are discussed. Additive manufactured biomaterials such as 316L stainless steel, titanium-6aluminium-4vanadium (Ti6Al4V) and cobalt-chromium (CoCr) are highlighted. Limitations and future potential of such technologies are also explored.

  15. Moving-Bed Process for Residue Hydrotreating Procédé à lit mobile pour l'hydrotraitement des résidus

    Directory of Open Access Journals (Sweden)

    Euzen J. P.

    2006-11-01

    Full Text Available A lot of chemical, petrochemical or refining processes require contact between three phases : a liquid feed, a gaseous reactant and a solid catalyst. Frequently, the catalyst activity is reduced by poisoning of active sites or coke deposits. This is especially the case with the processes used in heavy residual oils hydrotreating. As the catalyst life is reduced, the substitution or regeneration of the inactive catalyst is frequently necessary. Various solutions, such, as fixed beds used with swing reactors, fluidized beds, or moving beds with down flow of the catalyst and co-current or counter-current of the feed, can be proposed to perform this task with a minimum of time and production losses. A theoretical comparison between the performances of the various technologies has been made by means of a detailed simulation of the behaviour of each of these catalytic beds over a long period. Of course, in the models, some assumptions are necessary, like the ideal fluid and solids flows. Nevertheless, the problem remains complex because hydrodynamic, kinetic, catalyst deactivation, or thermal effects occur simultaneously, within the particules and/or in the bed as a whole. Various pilot plant data are of course used in order to build the kinetic part of the models. This comparison shows a marked advantage for the moving bed with counter-current flow between feed and catalyst owing to the systematic optimum use of the catalyst potential. Consequently, a series of experiments was made on various sized cold mockups designed to simulate counter-current movind beds. These experiments were necessary to demonstrate the feasability of the process, to specify the relations among gas and liquid superficial velocities, particles and fluids properties, and hydrodynamic regimes, and to develop the scale-up rules. The main goal is to secure a uniform distribution of the two fluids through out the whole bed of catalyst, and at the same time a regular progression of

  16. Continuous processing of recombinant proteins: integration of refolding and purification using simulated moving bed size-exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2014-04-11

    Continuous processing of recombinant proteins was accomplished by combining continuous matrix-assisted refolding and purification by tandem simulated moving bed (SMB) size-exclusion chromatography (SEC). Recombinant proteins, N(pro) fusion proteins from inclusion bodies were dissolved with NaOH and refolded in the SMB system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling of the refolding buffer of the raffinate by tangential flow filtration. For further purification of the refolded proteins, a second SMB operation also based on SEC was added. The whole system could be operated isocratically with refolding buffer as the desorbent buffer, and buffer recycling could also be applied in the purification step. Thus, a significant reduction in buffer consumption was achieved. The system was evaluated with two proteins, the N(pro) fusion pep6His and N(pro) fusion MCP-1. Refolding solution, which contained residual N(pro) fusion peptide, the cleaved autoprotease N(pro), and the cleaved target peptide was used as feed solution. Full separation of the cleaved target peptide from residual proteins was achieved at a purity and recovery in the raffinate and extract, respectively, of approximately 100%. In addition, more than 99% of the refolding buffer of the raffinate was recycled. A comparison of throughput, productivity, and buffer consumption of the integrated continuous process with two batch processes demonstrated that up to 60-fold higher throughput, up to 180-fold higher productivity, and at least 28-fold lower buffer consumption can be obtained by the integrated continuous process, which compensates for the higher complexity.

  17. Optimization of the pyrolysis process of empty fruit bunch (EFB) in a fixed-bed reactor through a central composite design (CCD)

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Alina Rahayu; Hamzah, Zainab; Daud, Mohamed Zulkali Mohamed [School of Bioprocess Engineering, Jejawi Complex of Academics (3), UniMAP, 02600 Arau Perlis (Malaysia)

    2014-07-10

    The production of crude palm oil from the processing of palm fresh fruit bunches in the palm oil mills in Malaysia hs resulted in a huge quantity of empty fruit bunch (EFB) accumulated. The EFB was used as a feedstock in the pyrolysis process using a fixed-bed reactor in the present study. The optimization of process parameters such as pyrolysis temperature (factor A), biomass particle size (factor B) and holding time (factor C) were investigated through Central Composite Design (CCD) using Stat-Ease Design Expert software version 7 with bio-oil yield considered as the response. Twenty experimental runs were conducted. The results were completely analyzed by Analysis of Variance (ANOVA). The model was statistically significant. All factors studied were significant with p-values < 0.05. The pyrolysis temperature (factor A) was considered as the most significant parameter because its F-value of 116.29 was the highest. The value of R{sup 2} was 0.9564 which indicated that the selected factors and its levels showed high correlation to the production of bio-oil from EFB pyrolysis process. A quadratic model equation was developed and employed to predict the highest theoretical bio-oil yield. The maximum bio-oil yield of 46.2 % was achieved at pyrolysis temperature of 442.15 °C using the EFB particle size of 866 μm which corresponded to the EFB particle size in the range of 710–1000 μm and holding time of 483 seconds.

  18. Optimization of the pyrolysis process of empty fruit bunch (EFB) in a fixed-bed reactor through a central composite design (CCD)

    Science.gov (United States)

    Mohamed, Alina Rahayu; Hamzah, Zainab; Daud, Mohamed Zulkali Mohamed

    2014-07-01

    The production of crude palm oil from the processing of palm fresh fruit bunches in the palm oil mills in Malaysia hs resulted in a huge quantity of empty fruit bunch (EFB) accumulated. The EFB was used as a feedstock in the pyrolysis process using a fixed-bed reactor in the present study. The optimization of process parameters such as pyrolysis temperature (factor A), biomass particle size (factor B) and holding time (factor C) were investigated through Central Composite Design (CCD) using Stat-Ease Design Expert software version 7 with bio-oil yield considered as the response. Twenty experimental runs were conducted. The results were completely analyzed by Analysis of Variance (ANOVA). The model was statistically significant. All factors studied were significant with p-values < 0.05. The pyrolysis temperature (factor A) was considered as the most significant parameter because its F-value of 116.29 was the highest. The value of R2 was 0.9564 which indicated that the selected factors and its levels showed high correlation to the production of bio-oil from EFB pyrolysis process. A quadratic model equation was developed and employed to predict the highest theoretical bio-oil yield. The maximum bio-oil yield of 46.2 % was achieved at pyrolysis temperature of 442.15 °C using the EFB particle size of 866 μm which corresponded to the EFB particle size in the range of 710-1000 μm and holding time of 483 seconds.

  19. N2O emissions from a one stage partial nitrification/anammox process in moving bed biofilm reactors.

    Science.gov (United States)

    Yang, Jingjing; Trela, Jozef; Plaza, Elzbieta; Tjus, Kåre

    2013-01-01

    Nitrous oxide (N2O) emissions from wastewater treatment are getting increased attention because their global warming potential is around 300 times that of carbon dioxide. The aim of the study was to measure nitrous oxide emissions from one stage partial nitrification/anammox (Anaerobic Ammonium Oxidation) reactors, where nitrogen is removed in a biological way. The first part of the experimental study was focused on the measurements of nitrous oxide emissions from two pilot scale reactors in the long term; one reactor with intermittent aeration at 25 °C and the other reactor with continuous aeration at 22-23 °C. The second part of the experiment was done to evaluate the influence of different nitrogen loads and aeration strategies, described by the ratio between the non-aerated and aerated phase and the dissolved oxygen concentrations, on nitrous oxide emissions from the process. The study showed that 0.4-2% of the nitrogen load was converted into nitrous oxide from two reactors. With higher nitrogen load, the amount of nitrous oxide emission was also higher. A larger fraction of nitrous oxide was emitted to the gas phase while less was emitted with the liquid effluent. It was also found that nitrous oxide emissions were similar under intermittent and continuous aeration.

  20. Use of processed resistivity borehole imaging to assess the insoluble content of the massively bedded Preesall Halite NW England

    Science.gov (United States)

    Kingdon, Andrew; Evans, David J.

    2013-04-01

    subject to a filtering process to develop a detailed understanding of the halite sequence's insoluble content. The results were then calibrated, post-normalisation, by new laboratory determinations of the insoluble content of laterally equivalent samples of core from the nearby Arm Hill #1 borehole. The FMI logs provide a greater degree of resolution when compared to conventional geophysical logs. With the statistical analysis provided by this process, it further enhances the correlation between the logs and core and ultimately, the assessment of insoluble content. Despite the obvious increase in resolution, precise statistical quantification of the success of the borehole imaging technique is somewhat obfuscated by the absence of both FMI logs and continuous core in a single borehole. The acquisition parameters for these images are at the limits for the tools and therefore more noisy than those acquired in other lithologies or logging environments. The optimum acquisition parameters (in particular gain settings and logging speed), the nature of the filtering required to quantify the insoluble content and the effects of image noise on those calculations are discussed.

  1. The self-regulation process and its mechanism of channels’ bed changes in the Changjiang (Yangtze) Estuary in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaohe; LI Jiufa; ZHU Wenwu; CHENG Heqin; CHEN Wei

    2015-01-01

    Recent bathymetric changes in the Changjiang Estuary under the influence of artificial regulation engineerings and basin reservoirs have been analyzed based on the maritime charts since 1997 and recent fieldworks. The results indicate a slight erosion of the channels in the upper and middle estuary, continuing deposition and seaward move of the mouth bar crest and intensifying erosion at the nearshore seabed. It is noteworthy that the morphological evolution caused by intensive human activities dominates over the changes from nature process. First, the riverbes are eroded overall in the South Branch (SB), the South Channel (SC) and the upper and middle reaches of the North Channel (NC). The nearshore seabed outside the river mouth is being eroded slightly, which is attributed to the declining sediment supply from the Changjiang Basin due to the construction of the Three Gorges Dam upstream. The sediment above the seabed is very active and coarsened, meanwhile, sand waves are becoming more distinct. Second, a deposition occurs in the North Brach (NB), the mouth of the NC, the mouth bars of the North Passage (NP) and the South Passage (SP) and especially the main channel of the NP, where it shows a massive siltation after the deep waterway project. The reasons for the recent changes are not only the dynamic structure in estuarine mouth bars, but also the supply of sediment resuspension in a local and offshore area. Meanwhile, the severe erosion and siltation in some reaches is related to the construction of estuarine engineerings. It is indicated that the Changjiang Estuary is gradually self-adjusted and adapting to the varying natural factors and intensive human activities. The study on the mechanism of self-regulation of the recent bathymetric changes in the Changjiang Estuary has important and practical significance.

  2. Development and Testing of the Advanced CHP System Utilizing the Off-Gas from the Innovative Green Coke Calcining Process in Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Chudnovsky, Yaroslav; Kozlov, Aleksandr

    2013-08-15

    Green petroleum coke (GPC) is an oil refining byproduct that can be used directly as a solid fuel or as a feedstock for the production of calcined petroleum coke. GPC contains a high amount of volatiles and sulfur. During the calcination process, the GPC is heated to remove the volatiles and sulfur to produce purified calcined coke, which is used in the production of graphite, electrodes, metal carburizers, and other carbon products. Currently, more than 80% of calcined coke is produced in rotary kilns or rotary hearth furnaces. These technologies provide partial heat utilization of the calcined coke to increase efficiency of the calcination process, but they also share some operating disadvantages. However, coke calcination in an electrothermal fluidized bed (EFB) opens up a number of potential benefits for the production enhancement, while reducing the capital and operating costs. The increased usage of heavy crude oil in recent years has resulted in higher sulfur content in green coke produced by oil refinery process, which requires a significant increase in the calcinations temperature and in residence time. The calorific value of the process off-gas is quite substantial and can be effectively utilized as an “opportunity fuel” for combined heat and power (CHP) production to complement the energy demand. Heat recovered from the product cooling can also contribute to the overall economics of the calcination process. Preliminary estimates indicated the decrease in energy consumption by 35-50% as well as a proportional decrease in greenhouse gas emissions. As such, the efficiency improvement of the coke calcinations systems is attracting close attention of the researchers and engineers throughout the world. The developed technology is intended to accomplish the following objectives: - Reduce the energy and carbon intensity of the calcined coke production process. - Increase utilization of opportunity fuels such as industrial waste off-gas from the novel

  3. Innovative Bed Load Measurement System for Large Alpine Gravel-Bed Rivers

    Science.gov (United States)

    Seitz, H.; Habersack, H. M.

    2009-04-01

    The aim of the work is to figure out the bed load transport processes using direct and surrogate measurement methods for the free flowing reach of the Drau River and its most important tributary Isel River, both large Alpine gravel-bed rivers, situated in the south western part of Austria. There are some techniques for bed load measurements in natural streams; we used collecting moving particles and indirectly determining transport intensity at the study sites. Former measurements in the study reach were performed also using mobile bed load samplers and fixed bed load samplers. Individually they all are adequate bed load measurement instruments - used in combination they are complementing one another, whereas each applied separately leads to specific deficits. The investigation payed special attention on results out of the geophone installations, whereas steel plate vibrations (the plates are mounted on top of concrete structures even with the river bed surface) caused by bed load particles with a diameter larger than about 20 mm are inducing a signal into the geophones. The signal above a defined threshold voltage than is recorded in a computer system as the sum of impacts during one minute intervals. The spatio-temporal distribution of the transported bed load material, its amount and the transport processes itself could be figured out for the first time out of continuous data collection since 2006 for large alpine gravel-bed rivers. Before building up the gauging stations there were no continuous recordings of bed load transport processes in large alpine rivers over their entire cross section, hence the investigation promises a better process understanding and the possibility to determine bed load transport rates and a rough approximation of the grain size distributions of the transported bed load material under different flow conditions. A relation between detected geophone records, the flow discharge and direct bed load sampling methods (Large Helley Smith

  4. 加压固定床粗煤气再转化工艺研究%Research on reconversion process of pressurized fixed-bed raw coal gas

    Institute of Scientific and Technical Information of China (English)

    张庆九; 王光龙

    2011-01-01

    Combining the technical characteristics of pressurized fixed-bed gasification process and hydrocarbon conversion process,put forward the reconversion process of pressurized fixed-bed raw coal gas through theoretical analysis. The coal gas water separation,phenolic ammonia recovery,flue gas burner,conversion scrubber,devices in low-temperature methanol washing system and naphtha separation system and so on have been abandoned thanks to the new technology. This technology reduces the fixed asset investment by 4. 69 billion yuan annually (while the present technical process costs 11.725 billion annually) ,saves raw coal by 0. 9684 million to 1. 1818 million tons annually,approximate to 129 million yuan when the price of lignite is 120 yuan per ton,saves DIPE by 2100 tons, lowers methonal consumption by 9600 tons and sodium hydroxide which mass fraction is 32% by 3600 tons; decreases the dusty gas water and oil gas water emission by 1585. 71 t/h while it uesd to pour sewage 1761. 9 t/h, lessens the land area taken by wastewater treatment plant over 17790 m2. It also improves the utilization rate of carbon dioxide and the recovery of sulfur. This reconversion process need less investment in equipments and engineering construction as well as low operating cost and environmentally friendly.%通过理论分析,综合加压固定床煤气化工艺和烃类转化工艺的技术特点,提出加压固定床粗煤气再转化工艺.加压固定床粗煤气再转化工艺取消了现有加压固定床煤气化工艺中煤气水分离、酚氨回收、废气焚烧、变换工艺洗涤塔、低温甲醇洗工艺萃取系统和石脑油分离系统等装置,降低固定资产投资46.9亿元(现用煤气化工艺化工固定资产投资117.25亿元);每年减少使用原料煤96.84万~118.18万t,约合1.29亿元(以褐煤120元/t计);取消使用二异丙基醚0.21万t/a、减少甲醇用量0.96万t/a和质量分数32%的NaOH用量0.36万t/a;取消含尘煤气

  5. Packed fluidized bed blanket for fusion reactor

    Science.gov (United States)

    Chi, John W. H.

    1984-01-01

    A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

  6. Classifying bed inclination using pressure images.

    Science.gov (United States)

    Baran Pouyan, M; Ostadabbas, S; Nourani, M; Pompeo, M

    2014-01-01

    Pressure ulcer is one of the most prevalent problems for bed-bound patients in hospitals and nursing homes. Pressure ulcers are painful for patients and costly for healthcare systems. Accurate in-bed posture analysis can significantly help in preventing pressure ulcers. Specifically, bed inclination (back angle) is a factor contributing to pressure ulcer development. In this paper, an efficient methodology is proposed to classify bed inclination. Our approach uses pressure values collected from a commercial pressure mat system. Then, by applying a number of image processing and machine learning techniques, the approximate degree of bed is estimated and classified. The proposed algorithm was tested on 15 subjects with various sizes and weights. The experimental results indicate that our method predicts bed inclination in three classes with 80.3% average accuracy.

  7. Introduction to Bed Bugs

    Science.gov (United States)

    The common bed bug (Cimex lectularius) is a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. EPA and other agencies all consider bed bugs a public health pest, but bed bugs are not known to transmit disease.

  8. Heavy metal removal from produced water using retorted shale; Remocao de metais pesados em aguas produzidas utilizando xisto retortado

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Patricia M.; Melo, Marcos A.F.; Melo, Dulce M.A.; Silva Junior, Carlos N.; Assuncao, Ary L.C. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Anjos, Marcelino J. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2004-07-01

    The Production of oil and gas is usually accompanied by the production of large volume of water that can have significant environmental effects if not properly treated. In this work, the use of retort shale was investigated as adsorbent agent to remove heavy metals in produced water. Batch adsorption studies in synthetic solution were performed for several metal ions. The efficiency removal was controlled by solution pH, adsorbent dosage, and initial ion concentration and agitation times. Two simple kinetic models were used, pseudo-first- and second-order, were tested to investigate the adsorption mechanisms. The equilibrium data fitted well with Langmuir and Freundlich models. The produced water samples were treated by retorted shale under optimum adsorption conditions. Synchrotron radiation total reflection X-ray fluorescence was used to analyze the elements present in produced water samples from oil field in Rio Grande do Norte, Brazil. The removal was found to be approximately 20-50% for Co, Ni, Sr and above 80% for Cr, Ba, Hg and Pb. (author)

  9. Development on iron-based moving bed chemical looping process%铁基移动床化学链技术进展

    Institute of Scientific and Technical Information of China (English)

    许迪恺; Tong Andrew; 曾亮; 罗四维; 范良士

    2014-01-01

    在日益增长的能源需求与日益严峻的全球气候变化带来的双重压力下,清洁、高效且经济的能源利用方法显得尤为重要。将化学链概念用于传统化石能源的转化是一种前景广阔的新技术。化学链燃烧利用载氧体间接转化含碳燃料,同时实现二氧化碳的捕集。俄亥俄州立大学研发了采用铁基载氧体和移动床反应器的化学链技术,可实现天然气、煤、生物质等多种燃料向电力、氢、液体燃料等产品的零排放转化。目前,合成气化学链(syngas chemical looping, SCL)和煤直接化学链(coal direct chemical looping, CDCL)技术两套25 kWth级小试装置已成功运行总计超过850 h,一套250 kWth级的高压SCL装置即将投入示范运行。%Driven by increasing demands for energy and concerns for climate change, more attention are paid to the development of clean, efficient, and economical technologies for energy conversion, among which chemical looping is considered as a promising alternative for fossil fuel conversion. Chemical looping processes enable highly efficient in situ CO2 capture in oxidation of carbonaceous fuels by making use of solid oxygen carriers. The Ohio State University (OSU) has developed a unique chemical looping technology utilizing iron-based oxygen carrier and moving bed reactors. Thermodynamic analysis shows that counter-current moving bed reactor can maximize oxygen carrier conversion while fully converting fuels, enabling high purity H2 production by iron-steam reaction. OSU chemical looping is highly flexible for converting a variety of gaseous and solid fuels to electricity, H2, and chemicals with CO2 captured. To date, the syngas chemical looping (SCL) technology and the coal direct chemical looping technology has been successfully operated for more than 850 h in total on two 25 kWth sub-pilot units. A 250 kWth high pressure SCL pilot unit is constructed at National Carbon Capture Center

  10. MICU clean bedding and clothing management process optimization and practice%产科重症监护病房被服清洗管理流程的优化与实践

    Institute of Scientific and Technical Information of China (English)

    高兰凤; 丁玉琴; 卢凌香; 徐洁

    2015-01-01

    目的::探讨优化流程在产科重症监护病房(MICU)污被服清洗管理中的作用。方法:确立以降低 MICU 污被服清洗管理缺陷发生率为改善主题,通过优化流程,运用质量管理工具对污被服清洗管理中存在问题进行改进,并将改进前后对比。结果:优化流程后,MICU 污被服清洗管理缺陷率由38%下降到11% 。结论:MICU 被服清洗管理流程的优化,不仅有效降低了我院 MICU 污被服清洗管理的缺陷,还提高了护士主动参与管理的能力和科室间的协作能力,提高了护士的工作效率。%Objective:To study the optimization of the process to reduce obstetric intensive care unit (MICU) clean bedding and clothing management role. Methods:To establish " reduce the incidence of MICU dirty clean bedding and clothing management shortcomings" for the improvement theme,through the optimization process,use quality management tools to improve the problems of pollution clean bedding and clothing management,and compared before and after improvement. Results:After the optimization process,MICU corrupt clean bedding and clothing management defect rate from 38% to 11% . Conclusion:The MICU clean bedding and clothing management process optimization,not only effectively reduce the hospital MICU clean bedding and clothing manage-ment defect,but also improve the nurses ability of management and cooperation ability,improve the work efficiency of nurses.

  11. Effect of heating style on gasification process of pilot scale bubble fluidized bed%升温方式对中试鼓泡流化床气化过程的影响

    Institute of Scientific and Technical Information of China (English)

    李晓伟; 刘建坤; 王贵路; 李明鹤; 郑磊; 叶仁文; 张大雷

    2015-01-01

    In order to study the heat process characteristics of pilot scale bubbing fluidized bed, by using the self heating pilot scale bubbling fluidized bed reactor of 50 kg/h in capacity, with sawdust as raw material, the experimental study on air gasification were conducted. At present, the externally heating for the fluidized bed startup was widely used in bench scale experiment. It had the advantages of rapidly raising of temperature, accurate control, etc., but the equipment was complex and difficult for maintenance, and was higher energy cost, especially, the externally heating was quite different with that for practical utilization. It is not helpful for find out the reaction characteristics so that the guiding for practical utilization was weakened. For solving the problem, using the pilot scale fluidized bed reactor as experimental device which is self heated, continuously fed and operated, air gasification experiment study on 3 temperature raising modes were conducted. Three temperature raising modes, which were sawdust combustion heating, sawdust/charcoal mixture combustion heating and charcoal combustion heating, were adopted respectively. The influence of different temperature raising ways on gasification temperature, tar content, the minimum fluidization velocity and gas quality in the process of gasification has been studied. The results showed that the heating effect of charcoal combustion was more ideal, and its heat value of charcoal was up to 32 MJ/kg, thus the heat released was much larger than that of sawdust. It provided more heat for bed heating process. In the preheating process, the warming up process was faster in the first hour, along with the increase of bed height, the heat storage in the bed material was also increased, and the heating rate was steady. It took 2.5 h for the gasification reactor to reach the reaction temperature. Due to the complexity for adding bed material and charcoal in the reactor, the optimization on the feeding device

  12. Fluidised-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Kudjoi, A.; Hippinen, I.; Heinolainen, A.; Suominen, M.; Lu Yong [Helsinki Univ. of Technology (Finland). Lab of Energy Economics and Power Plant Engineering

    1996-12-01

    Partial gasification processes have been presented as possibilities for future power production. In the processes, the solid materials removed from a gasifier (i.e. fly ash and bed material) contain unburnt fuel and the fuel conversion is increased by burning this gasification residue either in an atmospheric or a pressurised fluidised-bed. In this project, which is a part of European JOULE 2 EXTENSION research programme, the main research objectives are the behaviour of calcium and sulphur compounds in solids and the emissions of sulphur dioxide and nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurised fluidised-bed combustion of gasification residues. (author)

  13. Flue gas desulfurization by rotating beds

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, N.; Keyvani, M.; Coskundeniz, A.

    1992-01-01

    The operating and mass transfer characteristics of rotating foam metal beds were studied to determine the potential for flue gas desulfurization. This is a final technical report on the work supported by DOE [number sign]FG22-87-PC79924. The report is divided into two sections, Part 1 deals primarily with the operating characteristics of rotating beds, and Part 2 covers the mass transfer characteristics of S0[sub 2] absorption in water-lime slurries. Rotating foam metal beds are in essence packed towers operated in high gravitational fields. The foam metal bed is in the form of a cylindrical donut, or torus, and is rotated to produced the high centrifugal forces. The liquid phase enters the bed at the inner surface of the torus and is pulled by the field through the bed. Gas flows countercurrent to the liquid. The bed packing can have a very large specific surface areas and not flood. Possible benefits include much smaller height of a transfer unit resulting in smaller equipment and supporting structures, reduced solvent inventory, faster response with improved process control, reduced pressure drop, and shorter startup and shut-down times. This work is concerned broadly with the operating characteristics of rotating beds, the objectives being to (1) determine the pressure drop through the rotating bed; (2) determine the power required to operate the beds, (3) investigate the residence time distribution of the liquid phase in the beds; and (4) determine the mass transfer coefficients of S0[sub 2] absorption. Three packings of differing specific surface areas were studied, with areas ranging from 656 to 2952 m[sub 2]/m[sub 3]. Liquid flow rates to 36 kg/s*m[sub 2], gas flow rate to 2.2 kg/s*m[sub 2], and gravitational fields to 300 g were covered in this study.

  14. 含氧煤层气流量变化对液化工艺影响的模拟研究%Simulation Study on Influence of Flow Change of Oxygen-contained Coal-bed Methane upon Liquefaction Process

    Institute of Scientific and Technical Information of China (English)

    朱菁; 王长元; 张武; 任小坤

    2014-01-01

    In this paper, simulation calculation wad carried out on the liquefaction process of coal-bed methane by using HYSYS software and analysis was made on influence of the flow change of coal-bed methane upon the energy consumption of liquefaction and the recovery rate of methane. The results showed that the change range of the total liquefaction energy consumption was identical with that of coal-bed methane flow, of which the change range of the nitrogen compression energy consumption was greater than that of coal-bed methane flow and that of the MRC compression energy consumption was smaller than that of coal-bed methane;the flow change increased the liquefaction energy consumption of unit LNG product, but the flow decrease did not affect the recovery rate of coal-bed methane, and only the flow increase may reduce its recovery rate. In actual operation, it’ s better to make the cooling system having 5% margin so as to ensure the security and stability of the liquefaction process.%利用HYSYS软件对煤层气液化工艺进行模拟计算,分析了煤层气流量变化对液化能耗和CH4回收率的影响,结果表明:总液化能耗变化幅度与煤层气流量变化幅度一致,其中氮气压缩功耗变化幅度大于流量变化幅度,混合冷剂压缩功耗变化幅度小于流量变化幅度;煤层气流量变化会使LNG单位产品液化能耗增加,但流量减小不影响CH4回收率,只有流量增加会降低CH4回收率。在实际运行时,应使制冷系统提供的冷量留有5%的余量,以确保工艺过程的安全与稳定。

  15. Synchrotron-Based X-ray Microtomography Characterization of the Effect of Processing Variables on Porosity Formation in Laser Power-Bed Additive Manufacturing of Ti-6Al-4V

    Science.gov (United States)

    Cunningham, Ross; Narra, Sneha P.; Montgomery, Colt; Beuth, Jack; Rollett, A. D.

    2017-03-01

    The porosity observed in additively manufactured (AM) parts is a potential concern for components intended to undergo high-cycle fatigue without post-processing to remove such defects. The morphology of pores can help identify their cause: irregularly shaped lack of fusion or key-holing pores can usually be linked to incorrect processing parameters, while spherical pores suggest trapped gas. Synchrotron-based x-ray microtomography was performed on laser powder-bed AM Ti-6Al-4V samples over a range of processing conditions to investigate the effects of processing parameters on porosity. The process mapping technique was used to control melt pool size. Tomography was also performed on the powder to measure porosity within the powder that may transfer to the parts. As observed previously in experiments with electron beam powder-bed fabrication, significant variations in porosity were found as a function of the processing parameters. A clear connection between processing parameters and resulting porosity formation mechanism was observed in that inadequate melt pool overlap resulted in lack-of-fusion pores whereas excess power density produced keyhole pores.

  16. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  17. A method of moments for analyzing and predicting the outlet curve for an adsorption process. I. Idealized model for fixed bed adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Blasinski, H.; Krauze, S.M.

    1985-01-01

    An idealized model based on equilibrium and kinetic principles is proposed for fixed-bed adsorption. Seven initial moments of the step response are given in a form which allows their use in the prediction of the outlet response curves. The results of 9 series of tests representing 38 outlet response curves were used to verify the model and the predictive method; good agreement was observed.

  18. Development of pressurised fluidised bed combustion technique for coal-fired gas/steam processes; Entwicklung der Druckwirbelschicht-Feuerungstechnik fuer kohlegefeuerte Gas-Dampfprozesse

    Energy Technology Data Exchange (ETDEWEB)

    Pitt, R.; Steven, H.

    1992-12-31

    The investigations for the development of the pressurized fluidized bed technique have shown that it is possible, in principle, to keep within the emission limits with the steady state pressurised fluidised bed combustion, even at low part load. However, the construction expense is considerable and the type of coal and grain size must comply relatively exactly with the design values. Not every fuel is suitable for fluidised bed combustion regarding emission. The most important parameter for emission is the temperature profile for this component, which should be as even as possible at a high temperature level. A sufficient dwell time of the gas and the particles is decisive for CO emission, where a minimum reaction time is required for both phases. (orig.) [Deutsch] Die Untersuchungen zur Entwicklung der Druckwirbelschichttechnik haben gezeigt, dass es prinzipiell moeglich ist, mit der stationaeren druckaufgeladenen Wirbelschichtfeuerung die Emissionsgrenzwerte auch bei geringer Teillast einzuhalten, allerdings ist der bauliche Aufwand erheblich und auch die Kohleart und Koernung muessen relativ genau den Auslegungswerten entsprechen. Auch hinsichtlich der Emissionen ist nicht jeder Brennstoff fuer die Wirbelschichtfeuerung geeignet. Wichtigster Einflusspartner auf die Emission ist auch bei dieser Komponente das Temperaturprofil, das moeglichst gleichmaessig auf hohem Temperaturniveau liegen sollte. Ausreichende Verweilzeit des Gases und der Partikel sind fuer die CO-Emission entscheidend, wobei fuer beide Phasen eine Mindestreaktionszeit erforderlich ist. (orig.)

  19. Paraho environmental data. Part I. Process characterization. Par II. Air quality. Part III. Water quality

    Energy Technology Data Exchange (ETDEWEB)

    Heistand, R.N.; Atwood, R.A.; Richardson, K.L.

    1980-06-01

    From 1973 to 1978, Development Engineering, Inc. (DEI), a subsidiary of Paraho Development Corporation, demostrated the Paraho technology for surface oil shale retorting at Anvil Points, Colorado. A considerable amount of environmentally-related research was also conducted. This body of data represents the most comprehensive environmental data base relating to surface retorting that is currently available. In order to make this information available, the DOE Office of Environment has undertaken to compile, assemble, and publish this environmental data. The compilation has been prepared by DEI. This report includes the process characterization, air quality, and water quality categories.

  20. Fluidized bed calciner apparatus

    Science.gov (United States)

    Owen, Thomas J.; Klem, Jr., Michael J.; Cash, Robert J.

    1988-01-01

    An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

  1. Application of CaO-Based Bed Material for Dual Fluidized Bed Steam Biomass Gasification

    Science.gov (United States)

    Koppatz, S.; Pfeifer, C.; Kreuzeder, A.; Soukup, G.; Hofbauer, H.

    Gasification of biomass is a suitable option for decentralized energy supply based on renewable sources in the range of up to 50 MW fuel input. The paper presents the dual fluidized bed (DFB) steam gasification process, which is applied to generate high quality and nitrogen-free product gas. Essential part of the DFB process is the bed material used in the fluidized reactors, which has significant impact on the product gas quality. By the use of catalytically active bed materials the performance of the overall process is increased, since the bed material favors reactions of the steam gasification. In particular, tar reforming reactions are favored. Within the paper, the pilot plant based on the DFB process with 100kW fuel input at Vienna University of Technology, Austria is presented. Actual investigations with focus on CaO-based bed materials (limestone) as well as with natural olivine as bed material were carried out at the pilot plant. The application of CaO-based bed material shows mainly decreased tar content in the product gas in contrast to experiments with olivine as bed material. The paper presents the results of steam gasification experiments with limestone and olivine, whereby the product gas composition as well as the tar content and the tar composition are outlined.

  2. 9 CFR 318.305 - Equipment and procedures for heat processing systems.

    Science.gov (United States)

    2010-01-01

    ... processing systems. 318.305 Section 318.305 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PREPARATION OF PRODUCTS Canning and Canned Products § 318.305 Equipment and procedures for heat processing... opposite the steam inlet. All bleeders shall be arranged so that the retort operator can observe that...

  3. Updated Performance Evaluation of the ISS Water Processor Multifiltration Beds

    Science.gov (United States)

    Bowman, Elizabeth M.; Carter, Layne; Carpenter, Joyce; Orozco, Nicole; Weir, Natalee; Wilson, Mark

    2014-01-01

    The ISS Water Processor Assembly (WPA) produces potable water from a waste stream containing humidity condensate and urine distillate. The primary treatment process is achieved in the Multifiltration Beds, which include adsorbent media and ion exchange resin for the removal of dissolved organic and inorganic contaminants. Two Multifiltration Beds (MF Beds) were replaced on ISS in July 2010 after initial indication of inorganic breakthrough of the first bed and an increasing Total Organic Carbon (TOC) trend in the product water. The first bed was sampled and analyzed Sept 2011 through March 2012. The second MF Bed was sampled and analyzed June 2012 through August 2012. The water resident in the both beds was analyzed for various parameters to evaluate adsorbent loading, performance of the ion exchange resin, microbial activity, and generation of leachates from the ion exchange resin. Portions of the adsorbent media and ion exchange resin were sampled and subsequently desorbed to identify the primary contaminants removed at various points in the bed in addition to microbial analysis. Analysis of the second bed will be compared to results from the first bed to provide a comprehensive overview of how the Multifiltration Beds function on orbit. New data from the second bed supplements the analysis of the first bed (previously reported) and gives a more complete picture of breakthrough compounds, resin breakdown products, microbial activity, and difficult to remove compounds. The results of these investigations and implications to the operation of the WPA on ISS are documented in this paper.

  4. Experimental evaluation of the effect of a modified port-location mode on the performance of a three-zone simulated moving-bed process for the separation of valine and isoleucine.

    Science.gov (United States)

    Park, Chanhun; Nam, Hee-Geun; Kim, Pung-Ho; Mun, Sungyong

    2014-06-01

    The removal of isoleucine from valine has been a key issue in the stage of valine crystallization, which is the final step in the valine production process in industry. To address this issue, a three-zone simulated moving-bed (SMB) process for the separation of valine and isoleucine has been developed previously. However, the previous process, which was based on a classical port-location mode, had some limitations in throughput and valine product concentration. In this study, a three-zone SMB process based on a modified port-location mode was applied to the separation of valine and isoleucine for the purpose of making a marked improvement in throughput and valine product concentration. Computer simulations and a lab-scale process experiment showed that the modified three-zone SMB for valine separation led to >65% higher throughput and >160% higher valine concentration compared to the previous three-zone SMB for the same separation.

  5. Numerical investigation of flow and heat transfer in a novel configuration multi-tubular fixed bed reactor for propylene to acrolein process

    Science.gov (United States)

    Jiang, Bin; Hao, Li; Zhang, Luhong; Sun, Yongli; Xiao, Xiaoming

    2015-01-01

    In the present contribution, a numerical study of fluid flow and heat transfer performance in a pilot-scale multi-tubular fixed bed reactor for propylene to acrolein oxidation reaction is presented using computational fluid dynamics (CFD) method. Firstly, a two-dimensional CFD model is developed to simulate flow behaviors, catalytic oxidation reaction, heat and mass transfer adopting porous medium model on tube side to achieve the temperature distribution and investigate the effect of operation parameters on hot spot temperature. Secondly, based on the conclusions of tube-side, a novel configuration multi-tubular fixed-bed reactor comprising 790 tubes design with disk-and-doughnut baffles is proposed by comparing with segmental baffles reactor and their performance of fluid flow and heat transfer is analyzed to ensure the uniformity condition using molten salt as heat carrier medium on shell-side by three-dimensional CFD method. The results reveal that comprehensive performance of the reactor with disk-and-doughnut baffles is better than that of with segmental baffles. Finally, the effects of operating conditions to control the hot spots are investigated. The results show that the flow velocity range about 0.65 m/s is applicable and the co-current cooling system flow direction is better than counter-current flow to control the hottest temperature.

  6. Bed Bugs FAQs

    Science.gov (United States)

    ... Bed bugs have been found in five-star hotels and resorts and their presence is not determined ... sleep. These areas include apartments, shelters, rooming houses, hotels, cruise ships, buses, trains, and dorm rooms. They ...

  7. Tapered bed bioreactor

    Science.gov (United States)

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

  8. Effect of Gas/Water Ratio on the Performance of Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactors for Biological Nutrients Removal from Domestic Wastewater by Fully Nitrification-Denitrification Processes

    Directory of Open Access Journals (Sweden)

    Husham T. Ibrahim

    2014-04-01

    Full Text Available In this research the continuously up-flow pilot scale Moving Bed Biofilm Reactor (MBBR which was consists of combined cylindrical anoxic/aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 under fully nitrification-denitrification process were used to treated 4 m34+-N, TN and TP, respectively, while the average Dissolved Oxygen concentration (DO in aerobic and anoxic MBBRs were 4.49 and 0.16 mg/L, respectively.

  9. Plan and justification for a Proof-of-Concept oil shale facility. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The technology being evaluated is the Modified In-Situ (MIS) retorting process for raw shale oil production, combined with a Circulating Fluidized Bed Combustor (CFBC), for the recovery of energy from the mined shale. (VC)

  10. Plan and justification for a Proof-of-Concept oil shale facility

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The technology being evaluated is the Modified In-Situ (MIS) retorting process for raw shale oil production, combined with a Circulating Fluidized Bed Combustor (CFBC), for the recovery of energy from the mined shale. (VC)

  11. 9 CFR 381.305 - Equipment and procedures for heat processing systems.

    Science.gov (United States)

    2010-01-01

    ... processing systems. 381.305 Section 381.305 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Canning and Canned... shall be arranged so that the retort operator can observe that they are functioning properly. In...

  12. Modelagem do processo de desidratação de lodo anaeróbio em leitos de secagem simulados Anaerobic sludge dewatering process modeling in simulated drying beds

    Directory of Open Access Journals (Sweden)

    Sérgio R. A. Soares

    2001-05-01

    Full Text Available O emprego de leitos de secagem para a desidratação de lodo de descarte de reatores UASB, constitui excelente alternativa, face a sua simplicidade operacional e aos reduzidos custos de implantação. Este trabalho apresenta uma análise dos fenômenos que influenciam o processo de desidratação de lodo anaeróbio, a partir de simulação de leitos de secagem. Neste sentido, são feitas considerações sobre as características e o comportamento do lodo durante cada fase da secagem. Sugere-se também, um modelo matemático para representar o processo de secagem, obtido a partir dos dados experimentais.The employment of drying beds is an excellent option for dewatering of UASB reactor discarded sludge, because of their simple operation and low construction costs. This paper presents an anaerobic sludge dewatering process analysis of the most influential phenomenon based on drying beds simulation. Therefore, some considerations were made about sludge characteristics and behavior during each dewatering stage. A mathematical model for dewatering process representation obtained from experimental data is also suggested.

  13. Gasificación con aire en lecho fluidizado de los residuos sólidos del proceso industrial de la naranja//Air gasification in fluidized bed of solid residue the orange industrial process

    Directory of Open Access Journals (Sweden)

    Leonardo Aguiar-Trujillo

    2012-12-01

    Full Text Available La industria procesadora de la naranja genera elevados volúmenes de residuos sólidos. Este residuo se ha utilizado en la alimentación animal y en procesos bioquímicos; pero no se ha aprovechado a través de la gasificación. El objetivo del trabajo fue determinar el aporte energético por medio del proceso de gasificación, realizándose estudios de los residuos sólidos de naranja, utilizando aire en reactor de lecho fluidizado burbujeante (variando la temperatura de gasificación, relación estequiométrica y altura del lecho. En el proceso se utilizó un diseño de experimento factorial completo de 2k, valorando la influencia de las variables independientes y sus interacciones en las respuestas, con un grado de significación del 95 %. Se obtuvieron los parámetros para efectuar el proceso de gasificación de los residuos sólidos de naranja, obteniendo un gas de bajo poder calórico, próximo a 5046 kJ/m3N, demostrando sus cualidades para su aprovechamiento energético.Palabras claves: gasificación con aire, lecho fluidizado, residuo de naranja._______________________________________________________________________________AbstractThe orange industrial process generates high volumes of solid residue. This residue has been used as complement in the animal feeding and biochemical processes; but it has not taken advantage through of the gasification process. The objective of the work was to determine the energy contribution by means ofthe gasification process, were carried out studies of the orange solid residue, using air in reactor of bubbling fluidized bed (varying the gasification temperature, air ratio and bed height. In the process a design of complete factorial experiment of 2k, was used, valuing the influence of the independent variables and its interactions in the answers, using a confidence level of 95 %. Were obtained the parameters to make the process of gasification of the orange solid residue, obtaining a gas of lower heating

  14. Modelling and simulation of a circulating fluidized-bed steam generator as an aid for process analysis and automation. Modellierung und Simulation eines ZWS-Dampferzeugers als Hilfsmittel zur Prozessanalyse und -automatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Karbach, A.; Peters, R.; Schaub, G. (Lurgi GmbH, Frankfurt am Main (Germany, F.R.))

    1990-04-01

    This book deals with the development and application of mathematical model for the simulation of a steam generator with fluidized-bed combustion (coal combustion in the circulating fluidized-bed combustion). (orig./EF).

  15. Staged fluidized-bed combustion and filter system

    Science.gov (United States)

    Mei, Joseph S.; Halow, John S.

    1994-01-01

    A staged fluidized-bed combustion and filter system for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste.

  16. Particle transport in fluidized beds : experiments and stochastic models

    NARCIS (Netherlands)

    Dechsiri, Chutima

    2004-01-01

    Fluidization is a process in which solids are caused to behave like fluid by blowing gas or liquid upwards through the solid-filled reactor. The behavior of a bed of particles within the reactor during the process is very complex and difficult to predict. To make sure that a fluidized bed reactor is

  17. Adaptation to the KMT Fixed Biomass on Moving Bed process in the waste water treatment plant in Tafalla and Olite, Navarra, Spain; Adaptacion al proceso KMT de Biomasa Fija sobre Lecho Movil en la EDAR de Tafalla y Olite

    Energy Technology Data Exchange (ETDEWEB)

    Cortacans, J. A.; Rodrigo, J. C.; Garcia Gamuza, J.

    2001-07-01

    This article describes the remodeling carried out on the Tafalla and Olite waste water treatment plant in 2000to enable it to cope with a larger flow and load without having to construct new treatment lines. This was made possible by adapting the existing conventional active sludge process to the KMT Fixed Biomass on Moving Bed process. The article also shows how the final two-stage design was verified by means of pilot plant trials. These experiments tested the technical viability of installing a first high-load reactor prior to the existing primary decantation as a way of dealing with the seasonal effluents from the wine-cellars in the region and of obtaining partial nitrification in the last biological tank of the second stage during the rest of the year. (Author) 7 refs.

  18. Bed bug deterrence

    Directory of Open Access Journals (Sweden)

    Haynes Kenneth F

    2010-09-01

    Full Text Available Abstract A recent study in BMC Biology has determined that the immature stage of the bed bug (the nymph signals its reproductive status to adult males using pheromones and thus avoids the trauma associated with copulation in this species. The success of this nymphal strategy of deterrence is instructive. Against the background of increasing problems with bed bugs, this research raises the question whether pheromones might be used to control them. See research article http://www.biomedcentral.com/1741-7007/8/121

  19. in Spouted Bed

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2013-01-01

    Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

  20. Virtual Test Bed

    Science.gov (United States)

    2016-06-07

    SEP 1999 2. REPORT TYPE 3. DATES COVERED 00-00-1999 to 00-00-1999 4. TITLE AND SUBTITLE Virtual Test Bed 5a. CONTRACT NUMBER 5b. GRANT...Virtual Test Bed Donald T. Resio U.S. Army Engineer Research and Development Center Coastal and Hydraulics Laboratory Vicksburg, MS 39180-6199 Phone...into three parts: 1) assembly of field and laboratory data sets for testing ; 2) set-up of a benchmark system; and 3) exercising the benchmark system

  1. Treatment of ammonia by catalytic wet oxidation process over platinum-rhodium bimetallic catalyst in a trickle-bed reactor: effect of pH.

    Science.gov (United States)

    Hung, Chang-Mao; Lin, Wei-Bang; Ho, Ching-Lin; Shen, Yun-Hwei; Hsia, Shao-Yi

    2010-08-01

    This work adopted aqueous solutions of ammonia for use in catalytic liquid-phase reduction in a trickle-bed reactor with a platinum-rhodium bimetallic catalyst, prepared by the co-precipitation of chloroplatinic acid (H2PtCl6) and rhodium nitrate [Rh(NO3)3]. The experimental results demonstrated that a minimal amount of ammonia was removed from the solution by wet oxidation in the absence of any catalyst, while approximately 97.0% of the ammonia was removed by wet oxidation over the platinum-rhodium bimetallic catalyst at 230 degrees C with an oxygen partial pressure of 2.0 MPa. The oxidation of ammonia has been studied as a function of pH, and the main reaction products were determined. A synergistic effect is manifest in the platinum-rhodium bimetallic structure, in which the material has the greatest capacity to reduce ammonia. The reaction pathway linked the oxidizing ammonia to nitric oxide, nitrogen, and water.

  2. Effect of process temperature on morphology of CNTs grown in a vertically fluidized bed reactor with Fe{sub 2}O{sub 3}/Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shukrullah, Shazia, E-mail: zshukrullah@gmail.com; Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Shaharun, Maizatul Shima, E-mail: maizats@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    Carbon nanotubes (CNTs) are one of the most researched materials due to their exceptional mechanical and electrical properties. Among the various techniques, catalytic chemical vapor deposition in a fluidized bed reactor is the most promising technique for bulk production of CNTs. To meet the demand of good quality along with the bulk production of CNTs, the effect of reaction temperature on the micro structures, morphology, diameter, quality and quantity of CNTs was investigated in these studies. CNTs were synthesized at process temperature ranging from 700-850°C by catalytic decomposition of C{sub 2}H{sub 4} on Fe{sub 2}O{sub 3}/Al{sub 2}O{sub 3} catalyst a vertical fluidized bed reactor. The microstructures of the grown CNTs at different reaction temperatures were investigated by using scanning electron microscope. The results of this study depicted a positive correlation between the average diameter of CNTs and reaction temperature. Narrow diameters (35∼40 nm) of CNTs with fewer defects were found at the low and mild temperatures, in particular 800°C. At this temperature, a dynamic equilibrium between the rate of C{sub 2}H{sub 4} decomposition and CNTs quantity was found due to maximum carbon diffusion over catalyst. The CNTs produced with Fe{sub 2}O{sub 3}/Al{sub 2}O{sub 3} catalyst wer e also exhibiting high quality with relatively small mean outer diameter and fewer surface defects.

  3. Surviving Bed Rest

    Science.gov (United States)

    ... your pregnancy — and your bed rest start a family tree that you can share with your child someday firm up your baby-name choices; use books and websites for ideas organize photo albums read anything — ... people (friends and family) whom you know will probably give gifts build ...

  4. MULTISTAGE FLUIDIZED BED REACTOR

    Science.gov (United States)

    Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.

    1959-11-01

    A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

  5. Fluidized bed combustion chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kullendorff, A.; Wikner, J.

    1985-03-25

    The chamber is confined in a pressure vessel. The lower part of the chamber has tilted parallel gutters up to the height of the fluidized bed. The slope of the gutter walls is 5 degrees-15 degrees and the top area of the gutters is 1.3 to 3 times larger than their bottom.

  6. Effect of bed particles to combustion of gases in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R.; Wallen, V.; Etelaeaho, R.; Correia, S. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1997-10-01

    The objective of this project was to obtain experimental data on effects of sand particles to the combustion of gases. The effect of the surface area of the particles was tested using different sized particles. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 42 mm surrounded by an electric heater. The test rig was built in the Laboratory of Energy and Process Engineering at Tampere University of Technology. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies were conducted with both fresh bed particles and used bed particles. These measurements indicate that carbon monoxide significantly reacts with oxygen in the particulate or emulsion phase of a fluidized bed, if the residence time is long enough. The reaction rate depends mainly on temperature, air coefficient, residence time and particle size of the solids. It seems that the combustion enhances if the average particle size increases. Whether this is caused by increased free path length or reduced specific surface area of the bed is yet unknown. The first might be more probable cause because the majority of reactions often took place in the freeboard right above the bed. It was clear that the bed hindered proper combustion in several cases. (orig.)

  7. Perspectives for Fluidized Bed Nuclear Reactor Technology using Rotating Fluidized Beds in a Static Geometry

    Science.gov (United States)

    Broqueville, Axel De; Wilde, Juray De

    The new concept of a rotating fluidized bed in a static geometry opens perspectives for fluidized bed nuclear reactor technology and is experimentally and numerically investigated. With conventional fluidized bed technology, the maximum attainable power is rather limited and maximum at a certain fluidization gas flow rate. Using a rotating fluidized bed in a static geometry, the fluidization gas drives both the centrifugal force and the counteracting radial gas-solid drag force in a similar way. This allows operating the reactor at any chosen sufficiently high solids loading over a much wider fluidization gas flow rate range and in particular at much higher fluidization gas flow rates than with conventional fluidized bed reactor technology, offering increased flexibility with respect to cooling via the fluidization gas. Furthermore, the centrifugal force can be a multiple of earth gravity, allowing radial gas-solid slip velocities much higher than in conventional fluidized beds. The latter result in gas-solid heat transfer coefficients one or multiple orders of magnitude higher than in conventional fluidized beds. The combination of dense operation and high fluidization gas flow rates allows process intensification and a more compact reactor design.

  8. Biomass ash - bed material interactions leading to agglomeration in fluidised bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Visser, H.J.M.; Hofmans, H.; Huijnen, R.; Kastelein, R.; Kiel, J.H.A. [ECN Biomass, Petten (Netherlands)

    2000-07-01

    The present study has been aimed at improving the fundamental understanding of mechanisms underlying agglomeration and defluidisation in fluidised bed combustion and gasification of biomass and waste. To this purpose dedicated lab-scale static heating and fluidisation experiments have been conducted with carefully selected and prepared ashes and bed materials, viz. straw ash/sand and willow ash/sand mixtures, mullite subjected to straw gasification and artificially coated mullite. The main conclusion is that ash/bed material interaction processes are very important and often determine the bed agglomeration and defluidisation tendency. In the static heating experiments with both ash/sand mixtures, partial melting-segregation of ash components and dissolution/reaction with the bed material are processes that determine the melt composition. This melt composition and behaviour can deviate considerably form expectations based on ash-only data. Artificially coated bed materials prove to be very useful for systematic studies on the influence of coating composition and thickness on agglomeration tendency. For the coated mullite samples, different stages in the defluidisation process are identified and the influence of coating properties (thickness, composition, morphology) and operating parameters is elucidated. The behaviour of the mullite appears to be dominated by a remnant glass phase. On the one hand, this glass phase accounts for an alkali-getter capability, while on the other hand it is mainly responsible for agglomeration at temperatures {>=} 800C. 3 refs.

  9. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  10. Bathing a patient in bed

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000427.htm Bathing a patient in bed To use the sharing features on this page, please enable JavaScript. Some patients cannot safely leave their beds to bathe. For ...

  11. IMPROVEMENT OF PURGE METHOD OF SEED BED WATERREMOVAL IN UNIPOL POLYETHYLENE PROCESS%Unipol聚乙烯工艺中种子床置换方法的改进

    Institute of Scientific and Technical Information of China (English)

    栗文革

    2001-01-01

    This article introduced the original purge method of seed bed water-rem oval in Unipol polyethylene process,discussed the improved purge method and comp ared the effects of these two methods,suggested to use the improved purge method in practical operating procedures.%介绍了Unipol聚乙烯工艺中种子床脱水置换的常规方法,讨论了改进的置换方法,并对2种方法的效果进行了比较,建议在实际操作过程中采用改进的置换方法。

  12. RESEARCH ON DENSITY STABILITY OF AIR DENSE MEDIUM FLUIDIZED BED

    Institute of Scientific and Technical Information of China (English)

    骆振福; 陈清如

    1994-01-01

    In this papcr on thc basis of studying the distribution of fine coal in the dense medium fluidized bed, the optimal size range of fine coal, which constitutes a fluidized bed together with the dense medium, has been found. In the separating process the fine coal will continuously accumulate in fluidized bed, thus inevitably reducing the density of the bed. In order to keep bed density stable, the authors adopted such measures as split-flow of used medium and complement of fresh dense medium. The experiment results in both lab and pilot systems of the air-dense medium fluidized bed show that these measures are effective and satisfactory. Then authors also have established some relative dynamic mathematical models for it.

  13. Fluctuations and time scales for bed-load sediment motion over a smooth bed

    Institute of Scientific and Technical Information of China (English)

    Francesco Ballio n; Alessio Radice

    2015-01-01

    Results are presented for experiments of bed-load sediment transport over a plane, smooth bed. The smooth-bed configuration, though not adequate for mimicking natural streams, enables the effects of bed roughness to be filtered out, thus, highlighting the role of flow turbulence for particle dynamics. Sediments were individually tracked along their paths, measuring position and velocity of the individual grains. A number of analyses were then applied to the data: probability density function, auto-correla-tion, and spectra of the grain velocity. Several Lagrangian time scales of particle motion were obtained and compared to available data for the turbulent flow field to determine a phenomenological inter-pretation of the process.

  14. Geomechanics of bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Serata, S.; Milnor, S.W.

    1979-06-08

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained.

  15. Hydrodynamics of multi-phase packed bed micro-reactors

    NARCIS (Netherlands)

    Márquez Luzardo, N.M.

    2010-01-01

    Why to use packed bed micro-reactors for catalyst testing? Miniaturized packed bed reactors have a large surface-to-volume ratio at the reactor and particle level that favors the heat- and mass-transfer processes at all scales (intra-particle, inter-phase and inter-particle or reactor level). If the

  16. Numerical modeling of straw combustion in a fixed bed

    DEFF Research Database (Denmark)

    Zhou, Haosheng; Jensen, Anker; Glarborg, Peter

    2005-01-01

    . The straw combustion processes include moisture evaporation, straw pyrolysis, gas combustion, and char combustion. The model provides detailed information of the structure of the ignition flame front. Simulated gas species concentrations at the bed surface, ignition flame front rate, and bed temperature...

  17. Separation of proteins by simulated moving bed chromatography

    NARCIS (Netherlands)

    Houwing, J.

    2003-01-01

    This thesis describes the use of simulated moving bed (SMB) chromatography for separation of proteins. The underlying aim is the increase of the efficiency of process chromatography in terms of a reduction of the sorbent and buffer consumption in comparison to fixed bed chromatography. Both size exc

  18. Modelling of Devolatilization in Fluidized Bed Combustion

    DEFF Research Database (Denmark)

    Stenseng, Mette; Lin, Weigang; Johnsson, Jan Erik

    1997-01-01

    A mathematical model is developed to describe the devolatilization process in a circulating fluidized bed combustor. The model is a combination of two submodels: single particle devolatilization and fluid dynamics. The single particle model includes the influence of both chemical kinetics and hea...

  19. Agglomeration in fluidized beds: detection and counteraction

    NARCIS (Netherlands)

    Bartels. M.

    2008-01-01

    Fluidized beds comprise a quantity of solid particles that is suspended by an upward flowing gas. They are used for a variety of processes in the chemical industry, such as catalytic reactions, drying, coating and energy conversion. A major problem in industrial practice is the occurrence of unwante

  20. Control of fluidized bed tea drying

    NARCIS (Netherlands)

    Temple, S.J.

    2000-01-01

    Tea is a product made from the leaf of the tea bush by several processes, including drying. The drying stage is the most energy intensive, and has tight performance criteria. This project investigated the options for the control of a fluidized bed tea dryer. The work included establishing some of th

  1. 生物滤池/生态砾石床处理含氮微污染地表水%Nitrogen Removal from Micro-polluted Surface Water by Combined Process of Biofilter and Ecological Gravel Bed

    Institute of Scientific and Technical Information of China (English)

    高建文; 何圣兵; 陈雪初; 戴鼎立; 孔海南

    2012-01-01

    Nitrogen removed from micro-polluted surface water with low carbon and high NO3 - N by the combined process of biofilter and ecological gravel bed was studied. The influence of C/N ratio, water temperature and hydraulic loading on nitrogen removal efficiency was investigated using sodium acetate as carbon source. The results show that C/N ratio has significant influence on nitrogen removal efficiency , and the denitrification rate of more than 90% can be achieved when C/N ratio is 10. The denitri-fication efficiency of the reactor is inhibited at low water temperature of 2 to 10 t , and the denitrification rate is recovered to about 60% at 13 to 17 qC. The removal rate of NO3~ - N can reach more than 90% at water temperature of more than 20 t, hydraulic loading of 8 mV(m2 ? H) , HRT of 15 min in biofilter and 30 min in ecological gravel bed. The remaining carbon source in the effluent from biofilter can be removed in ecological gravel bed, thus ensuring the water quality safety.%采用生物滤池/生态砾石床组合工艺进行了微污染地表水(含低碳、高NO3- -N浓度)的脱氮研究,通过投加乙酸钠为碳源考察了C/N值、温度、水力负荷对反应器脱氮效能的影响.结果表明,C/N值对反应器的脱氮效能影响较大,在C/N值为10时可以取得较高的反硝化效率(>90%).在低温下(2~10℃)反应器的反硝化效能受到严重抑制;在13~17℃条件下,反硝化效率恢复到60%左右;当水温>20℃时,在水力负荷为8 m3/(m2·h)的条件下(此时生物滤池和生态砾石床的水力停留时间分别为15、30 min),对NO3- -N的去除率能够达到90%以上.生态砾石床能够将生物滤池出水中残余的碳源去除,保证了出水的水质安全.

  2. Grain Exchange Probabilities Within a Gravel Bed

    Science.gov (United States)

    Haschenburger, J.

    2008-12-01

    Sediment transfers in gravel-bed rivers involve the vertical exchange of sediments during floods. These exchanges regulate the virtual velocity of sediment and bed material texture. This study describes general tendencies in the vertical exchange of gravels within the substrate that result from multiple floods. Empirical observations come from Carnation Creek, a small gravel-bed river with large woody debris located on the west coast of Vancouver Island, British Columbia. Frequent floods and the relatively limited armor layer facilitate streambed activity and relatively high bedload transport rates, typically under partial sediment transport conditions. Over 2000 magnetically tagged stones, ranging in size from 16 to 180 mm, were deployed on the bed surface between 1991 and 1992. These tracers have been recovered 10 times over 12 flood seasons to quantify their vertical position in the streambed. For analysis, the bed is divided into layers based on armor layer thickness. Once tracers are well mixed within the streambed, grains in the surface layer are most likely to be mixed into the subsurface, while subsurface grains are most likely to persist within the subsurface. Fractional exchange probabilities approach size independence when the most active depth of the substrate is considered. Overall these results highlight vertical mixing as an important process in the dispersion of gravels.

  3. Combined biological fluidized bed-advanced catalytic oxidation process used for pharmacy wastewater treatment%生物流化床—高级催化氧化工艺处理制药废水

    Institute of Scientific and Technical Information of China (English)

    杜家绪; 买文宁; 王敏; 唐启

    2016-01-01

    采用生物流化床—高级催化氧化工艺处理制药废水,介绍了制药废水处理工程的工艺流程、工艺设计、调试方法、处理效果和工程效益.运行结果表明,该系统处理效果好且运行稳定,出水水质满足《混装制剂类制药工业水污染物排放标准》(GB 21908—2008)表2标准.%The combined biological fluidized bed-advanced catalytic oxidation process has been designed for the treatment of pharmacy wastewater. The process flow,process design,debugging methods,treatment effect and engi-neering benefit of the pharmacy wastewater treatment project are introduced. The running results show that the treat-ment effect of the system is good,it runs steadily,and the effluent quality meets the requirements specified in Tab. 2 of the Discharge Standards of Water Pollutants for Pharmaceutical Industry Mixing/Compounding and Formulati on Category(GB 21908—2008).

  4. K Basin Sludge Conditioning Process Testing Project Results from Test 4, ''Acid Digestion of Mixed-Bed Ion Exchange Resin''

    Energy Technology Data Exchange (ETDEWEB)

    Pool, K.H.; Delegard, C.H.; Schmidt, A.J.; Thornton, B.M.; Silvers, K.L.

    1999-04-02

    Approximately 73 m{sup 3} of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). The Hanford Spent Nuclear Fuel (HSNF) project has conducted a number of evaluations to examine technology and processing alternatives to pretreat K Basin sludge to meet storage and disposal requirements. From these evaluations, chemical pretreatment has been selected to address criticality issues, reactivity, and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Chemical pretreatment, referred to as the K Basin sludge conditioning process, includes nitric acid dissolution of the sludge (with removal of acid insoluble solids), neutrons absorber addition, neutralization, and reprecipitation. Laboratory testing is being conducted by the Pacific Northwest National Laboratory (PNNL) to provide data necessary to develop the sludge conditioning process.

  5. Modeling on Flash Flood Disaster Induced by Bed Load

    Institute of Scientific and Technical Information of China (English)

    CAO Shuyou; LIU Xingnian; HUANG Er; YANG Keiun

    2008-01-01

    Flash floods result from a complex interaction among hydro-meteorological, hydrologi-cal, and hydraulic processes across various spatial and temporal scales. Sichuan Province suffers flash floods frequently owing to mountain weather and topography. A flash flood and gravel bed load transport are two key relative problems in mountain river engineering. Bed materials are often encountered in alternate scouring and deposition in mountain fluvial processes during a flash flood.In this circumstance, CRS-1 bed load numerical model jointly with scale physical model is em-ployed to predict water level and gravel bed scour and deposition for design of flood control dykes and flash flood disaster mitigation. A case study on the mechanism of a flash flood disaster in-duced by bed load transport for a hydropower station in Sichuan Province is conducted. Finally,suggestions to protect the hydropower station are proposed.

  6. Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Michael; Henderson, Ann

    2012-04-01

    The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in

  7. EFFECT OF VERTICAL BAFFLES ON PARTICLE MIXING AND DRYING IN FLUIDIZED BEDS OF GROUP D PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Chung Lim Law; Siti Masrinda Tasirin; Wan Ramli Wan Daud; Derek Geldart

    2003-01-01

    This study reports the effect of vertical baffles on the group D powder mixing and drying characteristics in a batch fluidized bed dryer. Results obtained in this study showed that operating the fluidized bed dryer with vertical baffles gave better particle mixing. This is due to the fact that the vertical baffles acted to limit the growth of small bubbles into large bubbles and the small bubbles caused more vigorous mixing in the bed of particles before finally erupting at the bed surface. Thus, insertion of vertical baffles is a useful way to process group D particles in a fluidized bed, especially when the fluidized bed is large.

  8. Bed Rest Muscular Atrophy

    Science.gov (United States)

    Greenleaf, John E.

    2000-01-01

    A major debilitating response from prolonged bed rest (BR) is muscle atrophy, defined as a "decrease in size of a part of tissue after full development has been attained: a wasting away of tissue as from disuse, old age, injury or disease". Part of the complicated mechanism for the dizziness, increased body instability, and exaggerated gait in patients who arise immediately after BR may be a result of not only foot pain, but also of muscular atrophy and associated reduction in lower limb strength. Also, there seems to be a close association between muscle atrophy and bone atrophy. A discussion of many facets of the total BR homeostatic syndrome has been published. The old adage that use determines form which promotes function of bone (Wolff's law) also applies to those people exposed to prolonged BR (without exercise training) in whom muscle atrophy is a consistent finding. An extreme case involved a 16-year-old boy who was ordered to bed by his mother in 1932: after 50 years in bed he had "a lily-white frame with limbs as thin as the legs of a ladder-back chair". These findings emphasize the close relationship between muscle atrophy and bone atrophy. In addition to loss of muscle mass during deconditioning, there is a significant loss of muscle strength and a decrease in protein synthesis. Because the decreases in force (strength) are proportionately greater than those in fiber size or muscle cross-sectional area, other contributory factors must be involved; muscle fiber dehydration may be important.

  9. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  10. Racing for the Bed

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    No one knows when the people ofMacheng City began to employthe marriage custom of racingfor the bed, once a custom unique to theTujia ethnic minority. It is said that at the end of awedding, bride and bridegroom enter thebridal chamber together and race for thebed. The one who is the first to sit on thebed will be the master of the new familyIt sounds unreasonable, but quite anumber of people believe in it.Therefore, on the wedding night, manybrides and bridegrooms try their best to

  11. Biparticle fluidized bed reactor

    Science.gov (United States)

    Scott, C.D.

    1993-12-14

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

  12. In Situ Erosion Flume (ISEF): determination of bed-shear stress and erosion of a kaolinite bed

    Science.gov (United States)

    Houwing, Erik-Jan; van Rijn, Leo C.

    1998-06-01

    The strength of a cohesive sediment bed is difficult to determine and must be found experimentally from laboratory tests or through in situ field tests. A new in situ erosion instrument, the In situ Erosion Flume (ISEF), has been developed which is a circulating flow system in the vertical plane. The erosion process of sediment particles of the bed in the test section of the ISEF is related to the prevailing bed-shear stress induced by a unidirectional current. The bed-shear stress can be determined from the measured velocity profile in the test section assuming a logarithmic distribution in a vertical direction. The bed-shear stress equation has been calibrated under various conditions characterised by initiation of motion of sand and gravel particles at a flat bed where the bed-shear stresses mobilising the particles are known from the Shields curve. Three reproducibility tests were carried out under laboratory conditions. The bed consisted of kaolinite and was formed by sedimentation in still fresh water. The results of the three tests showed similar values. The erosion of a kaolinite sediment bed is more precisely determined under laboratory conditions by means of the ISEF. The results are compared with data from the literature. The ISEF is a relatively simple instrument for the determination of the strength of (cohesive) sediment beds. The results based on the ISEF measurements represent the minimum shear stress exerted at initiation of erosion of the bed, which will lead to the maximum shear strength of the top layer of the (cohesive) sediment bed.

  13. A continuous production process for silica aerogel powders based on sodium silicate by fluidized bed drying of wet-gel slurry

    Science.gov (United States)

    Bhagat, Sharad D.; Park, Kyung-Tae; Kim, Yong-Ha; Kim, Jong-Soon; Han, Jong-Hun

    2008-09-01

    The present study described a continuous process for the production of hydrophobic silica aerogel powders based on an inexpensive precursor such as sodium silicate. Fluidization technique was employed for the drying of wet-gel slurry at an ambient pressure. The fluidization column was fed with the silylated wet-gel slurry in a continuous mode and the fluidization was carried out at 220 °C. The aerogel powder collected in Trap-I was fluidized twice at room temperature in order to separate the lighter aerogel particles from the first trap. The tapping density of the aerogel powder decreased from 0.09 to 0.05 g/cm 3 for Trap-II, however, the microstructure did not differ significantly. Using this process, hydrophobic silica aerogel powders exhibiting tapping density as low as 0.05 g/cm 3, high specific surface area of 783 m 2/g and cumulative pore volume of 1.79 cm 3/g have been obtained. The aerogels were characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), BET specific surface area, N 2 physisorption isotherms, pore size distribution and particle size analyses. The results have been compared with aerogel powders obtained by ambient pressure drying of the wet-gel slurry in a furnace.

  14. A continuous production process for silica aerogel powders based on sodium silicate by fluidized bed drying of wet-gel slurry

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, Sh.D.; Park, K.T.; Kim, Y.H. [Pukyong National Univ., Faculty of Chemical Engineering, Powder Technology Lab., Busan (Korea, Republic of); Kim, J.S. [NGETECH Inc., Nam-Gu, Busan (Korea, Republic of); Han, J.H. [Korea Electronics Technology Institute, Seongnam, Gyeonggi-do (Korea, Republic of)

    2008-09-15

    The present study described a continuous process for the production of hydrophobic silica aerogel powders based on an inexpensive precursor such as sodium silicate. Fluidization technique was employed for the drying of wet-gel slurry at an ambient pressure. The fluidization column was fed with the silylated wet-gel slurry in a continuous mode and the fluidization was carried out at 220 C. The aerogel powder collected in Trap-I was fluidized twice at room temperature in order to separate the lighter aerogel particles from the first trap. The tapping density of the aerogel powder decreased from 0.09 to 0.05 g/cm{sup 3} for Trap-II, however, the microstructure did not differ significantly. Using this process, hydrophobic silica aerogel powders exhibiting tapping density as low as 0.05 g/cm{sup 3}, high specific surface area of 783 m{sup 2}/g and cumulative pore volume of 1.79 cm{sup 3}/g have been obtained. The aerogels were characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), BET specific surface area, N{sub 2} physi-sorption isotherms, pore size distribution and particle size analyses. The results have been compared with aerogel powders obtained by ambient pressure drying of the wet-gel slurry in a furnace. (authors)

  15. Calculation and optimization of the copper (II sulphate monohydrate from copper (II sulphate pentahydrate production process in a fluidized bed dryer

    Directory of Open Access Journals (Sweden)

    Kaluđerović-Radoičić Tatjana

    2015-01-01

    Full Text Available In this paper the process of the copper (II sulphate monohydrate from copper (II sulphate pentahydrate (also known as a Blue vitriol or Bluestone production was analyzed. Copper (II sulphate pentahydrate is one of the most important copper salts which has been known since the ancient Egyptians. In the nineteenth century its application as a fungicide was discovered which provoked wide industrial production. Molecule of the copper (II sulphate pentahydrate is a crystalohydrate with five water molecules linked by chemical bonds to a molecule of the copper (II sulphate. Copper (II sulphate exists as a series of compounds that differ in their degree of hydratation. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4•5H2O, the most commonly encountered salt, is bright blue. In order to obtain copper (II sulphate monohydrate from copper (II sulphate pentahydrate four water molecules need to be removed. To determine the optimum temperature and time required for the removal of four water molecules from a molecule of pentahydrate in this work thermogravimetric (TGA analysis was performed. Thermogravimetric (TGA analysis - dehydration of copper (II sulphate pentahydrate is done using simultaneous TG-DSC thermal analyzer DTG-Q600 SDT from TA Instruments. Analyzes was carried out for two type of samples, the sample containing particles of the average diameter equal to 0.17 mm and the particles of the average diameter 0.5 mm. In addition, fluidization and drying curve was determined using a semi-industrial fluidization column. On top, the industrial fluidization column aimed to produce 300 tones per month of copper (II sulphate monohydrate was designed. Material and energy calculations were performed using software packages Simprosys 3.0 and SuperPro Designer 5.1. Simprosys 3.0 is a software package designed for the modeling and simulation of a drying process as well as for 20 different unit operations. Super

  16. Circulating fluidized bed biological reactor for nutrients removal

    Institute of Scientific and Technical Information of China (English)

    Yubo CUI; Hongbo LIU; Chunxue BAI

    2008-01-01

    A new biological nitrogen removal process, which is named herein "The circulating fluidized bed bio-reactor (CFBBR)", was developed for simultaneous removal of nitrogen and organic matter. This process was composed of an anaerobic bed (Riser), aerobic bed (Downer) and connecting device. Influent and nitrified liquid from the aerobic bed enters the anaerobic bed from the bottom of the anaerobic bed, completing the removal of nitrogen and organic matter. The system performance under the conditions of different inflow loadings and nitrified liquid recirculation rates ranging from 200% to 600% was examined. From a technical and economic point of view, the optimum nitrified liquid recirculation rate was 400%. With a shortest total retention time of 2.5 h (0.8 h in the anaerobic bed and 1.5 h in the aerobic bed) and a nitrified liquid recir-culation rate of 400% based on the intluent flow rate, the average removal efficiencies of total nitrogen (TN) and sol-uble chemical oxygen demand (SCOD) were found to be 88% and 95%, respectively. The average effluent concentra-tions of TN and SCOD were 3.5 mg/L and 16 mg/L, respectively. The volatile suspended solid (VSS) concentra-tion, nitrification rate and denitrification rate in the system were less than 1.0 g/L, 0.026-0.1 g NH4+-N/g VSS.d, and 0.016-0.074 g NOx--N/g VSS.d, respectively.

  17. Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors

    DEFF Research Database (Denmark)

    Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

    2011-01-01

    In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4/g......VS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380mL-CH4/gVS-added at the organic loading rate of 3.2gCOD/(L-reactor.d). In a UASB reactor, higher organic loading rate of 5.1gCOD/(L-reactor.d) could be tolerated, however, it resulted in a lower methane yield of 240m...

  18. New Developments in Spinning Fluidised Bed Incineration Technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    At the present time, the sewage treatment plants in the UK produce about 25 million tons of sewage sludge each year at a concentration of 4% solids. New regulations forbid sea dumping and in the near future new incinerators will be required to dispose of about 5 million tons per year. Bubbling fluidised bed incinerators are widely used to burn sewage sludge at a typical consumption rate of about 0.02kg(dry)·s-1·m2, and it follows that over 300 conventional fluidised bed incinerators of 3m diameter could be required to cope with the increased demand.At Sheffield University Waste Incineration Centre (SUWIC) research work is being carried out to develop a novel spinning fluidised bed incinerator. The key factor to note is that when air flows up through a bed of near mono-sized particles, it fluidises when the pressure drop across the bed is equal to the weight of the bed. Normally, the weight of the bed is determined by gravity. However, if the bed is contained by a cylindrical air distributor 'plate' that is rotating rapidly about its axis, then the effective weight of the bed can be increased dramatically. The airflow passing through the bed can be increased proportionally to the "g" level produced by the rotation and it follows that the process has been intensified. In exploratory tests with a spinning fluidised bed we have achieved combustion intensities with coal combustion as high as 100MW/m3. A problem with burning coal is that it was difficult to remove the heat and rotating water seals had to be used to transfer cooling water into the bed. In the case of sewage and other sludges, this problem does not exist since the flue gases can remove the small amount of heat released. The rotating fluidised bed sludge incinerator is a novel device, which is very compact. It is able to solve the turndown problem encountered with conventional fluidised beds by simply changing the rotation speed. Bearing in mind that a centrifugal sludge de-watering unit is already used

  19. 西南红层地区泥化夹层演化过程中的微观特征研究%The Research of the Microscopic Characteristics of the Argillation Intercalations’ Evolution Process in Southwest Red Bed Area

    Institute of Scientific and Technical Information of China (English)

    易靖松; 孙金辉; 鲜杰良

    2016-01-01

    The red bed area in southwest of China often occurs many geological disasters, and causes serious casualties and property losses. The argillation intercalations were widely distributed in southwest red bed region, it was the worst of the engineering characteristics, structural planes in rock mass slope and was the key to red layer in southwest slope geological hazard control factors, along with all kinds of engineering geological problems. Based on many different period time sampling different intensity of hydration of clay layer, after the indoor experimental re-search and analysis, the mineral composition, chemical elements and microstructure change rule of the evolution process were obtained from argillaceous rock to argillation intercalations in southweast area. According to test results of experiment, the evolution process is divided into three stages:ion exchange adsorption stage, minerals dissolved stage, mineral production phase stage.%西南红层地区地质灾害频发,通常造成严重的人员伤亡和财产损失。泥化夹层在西南红层地区分布广泛,是斜坡岩体中工程特性最差的结构面,也是控制西南红层地区斜坡地质灾害的关键因素,常常引发各种工程地质问题。通过对不同期次不同水化作用强度的泥化夹层取样,进行室内试验研究分析,获取了西南红层地区泥质岩层~泥化夹层演化过程中矿物成分、化学元素和微观结构变化规律。根据试验结果将演化过程划分为三个阶段:离子交换吸附阶段、矿物溶解阶段、软化崩解阶段。

  20. HW粗煤泥流化床分选试验研究与工艺优化%Experimental study and process optimization on separation of coarse slime using HW fluidized bed

    Institute of Scientific and Technical Information of China (English)

    张祖军

    2014-01-01

    This paper introduces principle and characters of HW fluidized bed sorting ma-chine for coarse slime��The HW fluidized bed separation experimental study of coarse slime with the diameter 2~0��074 mm in Baizhuagn Coal preparation plant has been conducted��The effects between velocity of water and slime with different diameter on the separation have been re-searched��The results showed that the technological process in Baizhuagn Coal preparation plant was optimized and HW sorting machine has been used for recover coarse slime with the diameter from 0��2~2 mm��The probable deviation of separation can be 0��08~0��1 1��After the technologi-cal process has been optimized,under the same ash of clean coal condition,clean coal yield could increase 4��09%.%介绍了HW粗煤泥流化床分选机的分选原理及特点,并对白庄煤矿选煤厂2~0��074 mm的粗煤泥进行HW流化床分选相关试验,探究了上升水流速对不同粒级煤泥的分选效果的影响.试验结果表明,针对白庄煤矿选煤厂的生产情况进行工艺优化,最终决定采用 HW粗煤泥分选机回收2~0��2 mm粒级粗煤泥,分选可能偏差达到0��08~0��11.经过改造后,选煤厂在保持精煤灰分不变的情况下,综合精煤产率提高了4��09%.

  1. Experiment study on process parameters of coal-bed gas separation by vacuum pressure swing adsorption%真空变压吸附分离含氧煤层气的工艺参数实验研究

    Institute of Scientific and Technical Information of China (English)

    刘应书; 杨雄; 李永玲; 张传钊; 孟宇; 杨海军

    2011-01-01

    Oxygen-containing coal-bed gas recovery using vacuum pressure swing adsorption processes is investigated expenmentally, the optimization experiment on process parameters and the structure of adsorption tower is camed out. The results show that the methane concentration in effluent gas and adsorption gas increases with the increase of adsorption time within a certain time, but the oxygen concentration in effluent gas decreases appreciably. Purge step decreases the methane and oxygen concentration of the effluent gas, but the methane concentration of desorption gas decreases with the increase of purge time. When the length-to-diameter ratio from 3.7 increased to 13. 3 with the adsorhent weight constant , the methane concentration in product increases by 2. 1 % , and the concentration of methane in effluent gas decreases by 1%. The results could provide reference for the industrial application in low concentration oxygen-containing coal-bed gas enrichment.%针对真空变压吸附富集低浓度含氧煤层气,对工艺参数和吸附塔结构进行了优化试验研究.实验结果标明,在一定的时间范围内,随着吸附时间的延长,解吸气和排放气中甲烷体积分数逐渐增大,而排放气中的氧气体积分数则小幅度降低;反吹步骤可以降低排放气中甲烷和氧气的体积分数,但反吹步骤也会降低解吸气中甲烷的体积分数;保持吸附剂不变,吸附塔高径比由3.7增大到13.3,解吸气中甲烷体积分数增大了2.1%,排放气中甲烷体积分数降低了1%.可以为低浓度含氧煤层气富集的实际应用提供参考.

  2. 南四湖底泥污染及其变化过程%Pollution of bed sediments and its changing process of Nansihu Lake

    Institute of Scientific and Technical Information of China (English)

    张祖陆; 孙娟; 王琳

    2004-01-01

    In order to research the changing process of the pollution from the formation of Nansihu Lake, this study determined the isotope age and depositional rate and analyzed the organic geo-chemical quotas and heavy metal quotas of two sedimentary profiles of Weishan and Dushan lakes. Research results showed that from the formation of Nansihu Lake, the change of the pollution could be divided into four phrases. At the early phrase of the formation, the organic matters of the lake mainly derived from the exotic matters and had a close relation to the effect on the water and sands from the Huanghe (Yellow) River. At the middle and late phrases of the development, the endogenous matters of the lake became the main and stable source of the organic matters. The overflow of the Huanghe River, the excavation of the Grand Canal and the cut of trees caused the changes of the historic pollution. In recent 20 years, the modern industrial pollution from the organic matters and heavy metals has an increasingly heavy tendency.

  3. Characteristics of charcoal fines obtained by rapid pyrolysis process of elephant grass in fluidized bed in different operation conditions; Caracteristicas dos finos de carvao vegetal obtido pelo processo de pirolise rapida de capim elefante em leito fluidizado em diferentes condicoes de operacao

    Energy Technology Data Exchange (ETDEWEB)

    Mesa Perez, Juan Miguel; Cortez, Luis Augusto Barbosa [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Agricola; Gomez, Edgardo Olivares; Rocha, Jose Dilcio [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico

    2004-07-01

    This paper presents a study about the effect of excess air and the inert fixed bed height upon the characteristics of fine charcoal particles and the main reactor parameters. The pyrolysis process is considered as a method to concentrate carbon in fine charcoal particles and a method to reduce oxygen content in the biomass.The study concludes that the operation point which gives the highest percentage if carbon fine charcoal particles and reduces the most the oxygen in biomass corresponds to a fixed bed height of 207 mm and excess air of 8%. (author)

  4. Flue gas desulfurization by rotating beds. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, N.; Keyvani, M.; Coskundeniz, A.

    1992-12-01

    The operating and mass transfer characteristics of rotating foam metal beds were studied to determine the potential for flue gas desulfurization. This is a final technical report on the work supported by DOE {number_sign}FG22-87-PC79924. The report is divided into two sections, Part 1 deals primarily with the operating characteristics of rotating beds, and Part 2 covers the mass transfer characteristics of S0{sub 2} absorption in water-lime slurries. Rotating foam metal beds are in essence packed towers operated in high gravitational fields. The foam metal bed is in the form of a cylindrical donut, or torus, and is rotated to produced the high centrifugal forces. The liquid phase enters the bed at the inner surface of the torus and is pulled by the field through the bed. Gas flows countercurrent to the liquid. The bed packing can have a very large specific surface areas and not flood. Possible benefits include much smaller height of a transfer unit resulting in smaller equipment and supporting structures, reduced solvent inventory, faster response with improved process control, reduced pressure drop, and shorter startup and shut-down times. This work is concerned broadly with the operating characteristics of rotating beds, the objectives being to (1) determine the pressure drop through the rotating bed; (2) determine the power required to operate the beds, (3) investigate the residence time distribution of the liquid phase in the beds; and (4) determine the mass transfer coefficients of S0{sub 2} absorption. Three packings of differing specific surface areas were studied, with areas ranging from 656 to 2952 m{sub 2}/m{sub 3}. Liquid flow rates to 36 kg/s*m{sub 2}, gas flow rate to 2.2 kg/s*m{sub 2}, and gravitational fields to 300 g were covered in this study.

  5. Variability of bed drag on cohesive beds under wave action

    Science.gov (United States)

    Safak, Ilgar

    2016-01-01

    Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law), a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10  m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold) with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  6. Variability of Bed Drag on Cohesive Beds under Wave Action

    Directory of Open Access Journals (Sweden)

    Ilgar Safak

    2016-04-01

    Full Text Available Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law, a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 - 4 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  7. Stabilizing effect of plasma discharge on bubbling fluidized granular bed

    Science.gov (United States)

    Hu, Mao-Bin; Dang, Sai-Chao; Ma, Qiang; Xia, Wei-Dong

    2015-07-01

    Fluidized beds have been widely used for processing granular materials. In this paper, we study the effect of plasma on the fluidization behavior of a bubbling fluidized bed with an atmospheric pressure plasma discharger. Experiment results show that the bubbling fluidized bed is stabilized with the discharge of plasma. When the discharge current reaches a minimum stabilization current Cms, air bubbles in the bed will disappear and the surface fluctuation is completely suppressed. A simplified model is proposed to consider the effect of electric Coulomb force generated by the plasma. It is found that the Coulomb force will propel the particles to move towards the void area, so that the bubbling fluidized bed is stabilized with a high enough plasma discharge. Project supported by the National Natural Science Foundation of China (Grant Nos. 11035005 and 11034010).

  8. NUMERICAL SIMULATION OF BED DEFORMATION IN DIKE BURST

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The key point in the numerical simulation of breach growth and bed deformation process in a dike burst is the accurate computation of flow and sediment transport. A numerical model for horizontal 2-D non-uniform sediment was developed to simulate the bed deformation process in the dike burst. The first-order scheme was used in computation. Several simulated results were worked out to demonstrate the applicability of the numerical model.

  9. Eficiência do processo de recobrimento de sementes de brócolos recobertas com polímero em leito de jorro Coating process efficiency for polymer coated broccoli seeds in spouted bed

    Directory of Open Access Journals (Sweden)

    Celina de Almeida

    2008-06-01

    Full Text Available Neste trabalho, sementes de brócolos foram recobertas em leito de jorro cone-cilíndrico, com suspensão aquosa de hidroxietilcelulose, visando a aprimorar a técnica do recobrimento de sementes, utilizando o processo fluidodinâmico. Foram investigados os efeitos das variáveis operacionais temperatura do ar de jorro, pressão de ar de atomização e vazão de suspensão de recobrimento, na eficiência do processo e na germinação das sementes. Os resultados revelaram que houve influência das variáveis operacionais na eficiência do processo e na germinação. Verificou-se, também, que as sementes recobertas apresentaram de 2 a 10% de umidade a menos que as sementes não-recobertas, quando em ambiente com temperatura controlada e saturado de vapor de água em determinado período.Broccoli seeds were coated in a conical-cylindrical spouted bed with an aqueous suspension of hydroxy ethyl cellulose aiming to improve the seeds coating technique using a fluid-dynamic process. An experimental design was applied to investigate the effects of the operating variables: gas temperature, atomizing air pressure and suspension flow rate on the germination of the seeds and on the process efficiency. Results indicated that the operating variables affect both the coating process efficiency and the germination ability. However, the analysis didn’t identify differences between the germination potential of coated and uncoated seeds. Coated seeds absorbed up to 10 percent less moisture than the uncoated ones, when the environment temperature and humidity were controlled over a period of time.

  10. Fluidized bed gasification of industrial solid recovered fuels.

    Science.gov (United States)

    Arena, Umberto; Di Gregorio, Fabrizio

    2016-04-01

    The study evaluates the technical feasibility of the fluidized bed gasification of three solid recovered fuels (SRFs), obtained as co-products of a recycling process. The SRFs were pelletized and fed to a pilot scale bubbling fluidized bed reactor, operated in gasification and co-gasification mode. The tests were carried out under conditions of thermal and chemical steady state, with a bed of olivine particles and at different values of equivalence ratio. The results provide a complete syngas characterization, in terms of its heating value and composition (including tars, particulates, and acid/basic pollutants) and of the chemical and physical characterization of bed material and entrained fines collected at the cyclone outlet. The feasibility of the fluidized bed gasification process of the different SRFs was evaluated with the support of a material and substance flow analysis, and a feedstock energy analysis. The results confirm the flexibility of fluidized bed reactor, which makes it one of the preferable technologies for the gasification of different kind of wastes, even in co-gasification mode. The fluidized bed gasification process of the tested SRFs appears technically feasible, yielding a syngas of valuable quality for energy applications in an appropriate plant configuration.

  11. Elution test in the separation process of zirconium and hafnium with D296 resin in the ion exchange fixed bed%D296树脂分离锆、铪洗脱的效果

    Institute of Scientific and Technical Information of China (English)

    黎志万; 刘锦洪; 刘小龙

    2016-01-01

    This paper introduces the study of elution test in the separation process of zirconium and hafnium with D296 resin in the ion exchange fixed bed.The temperature of the adsorption and elution tests was between 2 and 5 degrees Celsius.Elution tests was carried out in a saturated adsorption ion exchange column,an ion exchange column with exchange region,and an ion exchange column with exchange region and no adsorption region.The results showed that the status of the ion exchange column and the acidity of the eluting agent had a significant effect on the separation effect.When the ion exchange column had exchange region,with the any acidity of sulphuric acid elution,hafnium would be eluted first,but the high acidity of eluent was more favorable for the separation of zirconium and hafnium.When the ion exchange column was saturated adsorption state,with low acidity and high acidity of eluent,zirconium and hafnium could not get effective separation.Experiments proved that, the single fixed bed has low separation efficiency of zirconium and hafnium.In order to achieve separation of zirconium and hafnium,need to design the continuous moving bed separation.%介绍了在离子交换固定床上用D296强碱性阴离子交换树脂分离锆、铪的洗脱实验研究。吸附与洗脱实验的温度均控制在2~5℃,洗脱实验在饱和吸附的离子交换柱、过漏的离子交换柱、未过漏的离子交换柱中进行。研究结果表明:离子交换柱吸附状态以及洗脱剂酸度对分离效果有显著的影响。当离子交换柱存在交换区时,用任何酸度的硫酸作为洗脱剂,铪均被先洗脱出来,但高酸度的洗脱剂对分离锆、铪更有利;当离子交换柱为饱和状态时,低酸度和高酸度的洗脱剂洗脱,锆、铪不能得到分离。实验证明了单一的固定床分离锆、铪的效率低,要成功实现锆、铪的分离,需采用连续分离的离子交换移动床。

  12. Fixed-bed pyrolysis and hydropyrolysis of sunflower bagasse: product yields and compositions

    Energy Technology Data Exchange (ETDEWEB)

    Putun, A.E.; Kockar, O.M.; Yorgun, S.; Gercel, H.F.; Andresen, J.; Snape, C.E.; Putun, E. [Anadolu University, Eskisehir (Turkey). Dept. of Chemistry

    1996-01-01

    Pyrolysis and hydropyrolysis experiments at different temperatures, heating rates and pressures have been conducted on a sample of sunflower pressed bagasse to investigate the effect of particle size, sweep gas velocity, and hydrogen pressure on the product yields and characteristics. In contrast to coal and oil shales, char and oil yields from sunflower pressed bagasse were found to be largely independent of particle size and sweep gas velocity in a Heinze retort with the oil yield of {approx} 40% w/w being the same as that from a well-swept fixed-bed reactor in which a much smaller sample size was used. The use of high hydrogen pressure ({gt} 50 bar) increased the oil yields by up to {approx} 10% w/w but these increases are much greater when expressed on a carbon basis due to the reduced oxygen contents of the oils. Even at low pressure, it has been estimated that {approx} 40% of the carbon aromatized during pyrolysis. 25 refs., 12 figs., 5 tabs.

  13. Description of emission control using fluidized-bed, heat-exchange technology

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Grogan, P.J.

    1980-06-01

    Environmental effects of fluidized-bed, waste-heat recovery technology are identified. The report focuses on a particular configuration of fluidized-bed, heat-exchange technology for a hypothetical industrial application. The application is a lead smelter where a fluidized-bed, waste-heat boiler (FBWHB) is used to control environmental pollutants and to produce steam for process use. Basic thermodynamic and kinetic information for the major sulfur dioxide (SO/sub 2/) and NO/sub x/ removal processes is presented and their application to fluidized-bed, waste heat recovery technology is discussed. Particulate control in fluidized-bed heat exchangers is also discussed.

  14. Internal Combustion Engines as Fluidized Bed Reactors

    Science.gov (United States)

    Lavich, Zoe; Taie, Zachary; Menon, Shyam; Beckwith, Walter; Daly, Shane; Halliday, Devin; Hagen, Christopher

    2016-11-01

    Using an internal combustion engine as a chemical reactor could provide high throughput, high chemical conversion efficiency, and reactant/product handling benefits. For processes requiring a solid catalyst, the ability to develop a fluidized bed within the engine cylinder would allow efficient processing of large volumes of fluid. This work examines the fluidization behavior of particles in a cylinder of an internal combustion engine at various engine speeds. For 40 micron silica gel particles in a modified Megatech Mark III transparent combustion engine, calculations indicate that a maximum engine speed of about 60.8 RPM would result in fluidization. At higher speeds, the fluidization behavior is expected to deteriorate. Experiments gave qualitative confirmation of the analytical predictions, as a speed of 48 RPM resulted in fluidized behavior, while a speed of 171 RPM did not. The investigation shows that under certain conditions a fluidized bed can be obtained within an engine cylinder. Corresponding Author.

  15. Closed Process of Shale Oil Recovery from Circulating Washing Water by Hydrocyclones

    Directory of Open Access Journals (Sweden)

    Yuan Huang

    2016-12-01

    Full Text Available The conventional oil recovery system in the Fushun oil shale retorting plant has a low oil recovery rate. A large quantity of fresh water is used in the system, thereby consuming a considerable amount of water and energy, as well as polluting the environment. This study aims to develop a closed process of shale oil recovery from the circulating washing water for the Fushun oil shale retorting plant. The process would increase oil yield and result in clean production. In this process, oil/water hydrocyclone groups were applied to decrease the oil content in circulating water and to simultaneously increase oil yield. The oil sludge was removed by the solid/liquid hydrocyclone groups effectively, thereby proving the smooth operation of the devices and pipes. As a result, the oil recovery rate has increased by 5.3 %, which corresponds to 230 tonnes a month.

  16. Bed-To-Wall Heat Transfer in a Supercritical Circulating Fluidised Bed Boiler

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2014-06-01

    Full Text Available The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.

  17. In-bed sulphur capture during pressurized fluidized-bed hydroretorting of Eastern oil shales

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Rue, D.M.; Lau, F.S. (Institute of Gas Technology, Chicago, IL (USA))

    1991-11-01

    The Institute of Gas Technology is developing a pressurized fluidized-bed hydroretorting (PFH) process for the production of oil from Eastern oil shales. The sulphur present in the Eastern oil shales is converted to H{sub 2}S during hydroretorting. A solid sorbent (limestone or siderite) may be added to the PFH reactor with the oil shale to achieve in-bed desulphurization. The effects of operating conditions on the effectiveness of in-bed sulphur capture with limestone and siderite have been investigated. Reactivities of a limestone and a siderite towards H{sub 2}S were determined in experiments conducted in an ambient pressure thermogravimetric analyser. These tests were conducted in the temperature range of 480-565{degree}C using solid sorbents with an average particle diameter of 0.018 cm ({minus}60{plus}100 mesh). The results of thermogravimetric analysis tests indicate that both limestone and siderite should be capable of capturing a significant fraction of H{sub 2}S removal with in-bed sorbents. The results of these tests confirm that a significant fraction of H{sub 2}S produced in the PFH reactor can be removed with in-bed sorbents. 10 refs., 8 figs., 6 tabs.

  18. A Primer on Wound Bed Preparation

    OpenAIRE

    Gokoo, Chuck

    2009-01-01

    Successful wound closure and healing are a major concern for today's clinician. Determining if the wound will progress or not relies on a comprehensive assessment, recognition of wound characteristics that will promote or impede the healing process and preparing the wound bed such that pathological features are removed allowing the healing cascade to occur. When complications are no longer a roadblock the wound will achieve a stable microenvironment and progress through the normal repairative...

  19. Biological denitrification in a fluidized bed.

    Science.gov (United States)

    Narjari, N K; Khilar, K C; Mahajan, S P

    1984-12-01

    A fluidized bed biofilm reactor using sand as the carrier particle was employed to study the effects of superficial velocity on the removal of nitrates as well as on the growth of the biofilm. Velocity was found to affect significantly both nitrate removal and biofilm growth. An analysis based on heterogenous catalysis was used to describe the denitrification process. There is good agreement between analysis and experimental measurements for startup and steady-state operating conditions.

  20. Particle Dynamics and Gravel-Bed Adjustments

    Science.gov (United States)

    1993-05-01

    detecteur des movement des sediments fins. Societe hydrotechnique de France. Transport Hydraulique et Decantation des Materiaux Solides. pp3 9 p. 38...Kirkby, MJ. (Eds.) Channel Ndork Hydrology. Wiley. Chichester. pp 129-173. 67. Lapointe, M.F. (1992) Burst-like sediment suspension events in a sand bed...alluvial sand suspension by eddy correlation. Earth Surface Processes & Landforms, 11, (in press). 69. Soulsby, R.L. (1983) The bottom boundary layer of

  1. New Dimensions of Moving Bed Biofilm Carriers

    OpenAIRE

    Piculell, Maria

    2016-01-01

    The moving bed biofilm reactor (MBBR) is a biological wastewater treatment process in which microorganisms grow as biofilms on suspended carriers. Conventionally, MBBRs are mainly designed and optimized based on the carrier surface area, neglecting the dynamic relationship between carrier design, reactor operation and biofilm characteristics, such as biofilm thickness and the composition of the microbial community. The purpose of this research project was to learn more about the roles of the ...

  2. Single-stage fluidized-bed gasification

    Science.gov (United States)

    Lau, F. S.; Rue, D. M.; Weil, S. A.; Punwani, D. V.

    1982-04-01

    The single-stage fluidized-bed gasification process, in addition to being a simple system, maximizes gas production and allows the economic exploitation of small peat deposits. The objective of this gasification project is to conduct experiments in order to obtain data for designing a single-stage fluidized-bed gasifier, and to evaluate the economics of converting peat to synthesis gas and to SNG by this process. An existing high-temperature and high-pressure process development unit (PDU) was modified to permit the direct feeding of peat to the fluidized bed. Peat flows by gravity from the feed hopper through a 6-inch line to the screw-feeder conveyor. From there, it is fed to the bottom tee section of the reactor and transported into the gasification zone. Oxygen and steam are fed through a distributing ring into the reactor. Gasification reactions occur in the annulus formed by the reactor tube and a central standpipe. Peat ash is discharged from the reactor by overflowing into the standpipe and is collected in a solids receiver.

  3. Kinetics of Reduction Reaction in Micro-Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    LINYin-he; GUOZhan—cheng; TANGHui—qing; REN Shan; LIJing—wei

    2012-01-01

    Micro-fluidized bed reactor is a new research method for the reduction of iron ore fines. The reactor is op- erated as a differential reactor to ensure a constant gas concentration and temperature within the reactor volume. In order to understand the dynamic process of the reduction reaction in micro-fluidized bed, a series of kinetic experi- ments were designed. In the micro fluidized bed, the use of shrinking core model describes the dynamic behavior of reduction of iron ore. And the apparent activation energy is calculated in the range of 700--850 ~C while the initial atmosphere is 100% content of CO.

  4. Simulation and Design of Shale Flashing Retorting Recovery Oil and Gas%油页岩闪速干馏油气回收工艺设计及模拟

    Institute of Scientific and Technical Information of China (English)

    张原源; 曹祖宾; 韩冬云

    2016-01-01

    According to the process characteristics of flashing retorting process,a set of suitable for high temperature oil washing oil vapor recovery technology was designed,combined with pilot plant field data,using plus Aspen software for process simulation.Shale oil was separated to heavy oil,heavy diesel oil,light oil fraction and gasoline fraction by the oil washing method.The process produced steam as by-product and it had the advantages of high recovery rate,low oil loss,low energy consumption,and could effectively avoided environmental pollution.Using this process,the rate of gas recovery could be greatly enhanced:crude oil washing tower could recycle 39.7% of the oil steam,heavy diesel oil washing tower could recycle 60.3% of the oil steam.Compared with the traditional process,it could improve the recovery rate of 10%-20%.%针对闪速干馏工艺特点,设计了一套适合高温油洗法回收油气工艺,并结合中试装置现场数据,运用Aspen Plus 软件进行了工艺模拟.油洗工艺可将页岩油粗分为重油、重柴油馏分、轻油馏分、汽油馏分.该工艺副产水蒸气,具有油损失小、能耗低、可减轻环境污染等特点,采用该回收工艺,可大幅度提升干馏油气的回收率,重油洗涤塔可回收 39.7%的油蒸气,重柴油洗涤塔可回收 60.3%的油蒸气,与传统工艺相比回收率可提高 10%~20%.

  5. Flow boiling heat transfer in circulating fluidized bed

    Institute of Scientific and Technical Information of China (English)

    Xiaoguang REN; Jiangdong ZHENG; Sefiane KHELLII; Arumemi-Ikhide MICHAEL

    2009-01-01

    In order to enhance heat transfer and mitigate contamination in the boiling processes, a new type of vapor-liquid-solid (3-phase) circulating fluidized bed boil-ing system has been designed, combining a circulating fluidized bed with boiling heat transfer. Experimental results show an enhancement of the boiling curve. Flow visualization studies concerning flow hydrodynamics within the riser column are also conducted whose results are presented and discussed.

  6. Granulation in Miniaturised Fluid Bed Using Electrostatic Atomisation

    OpenAIRE

    Kivikero, Niina

    2010-01-01

    The development of a new drug is extremely expensive and the development process is very slow, up to 15 years. Especially the early formulation development phase is a challenge for the pharmaceutical industry, as the amount of a new active pharmaceutical ingredient may only be a few grams. A small amount of drug should be used to produce as much data as rapidly possible. In this thesis, a small scale fluid bed device (Multipart Microscale Fluid bed powder Processor, MMFP) with electrosta...

  7. Bed mixing dryer for high moisture content fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hulkkonen, S.; Heinonen, O. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    Bed mixing dryer is a new type of fuel drying technology for fluidized bed combustion. The idea is to extract hot bed material from the fluidized bed and use it as a heat source for drying the fuel. Drying occurs at steam atmosphere which makes it possible to recover the latent heat of evaporation to process. This improves the thermal efficiency of the power plant process considerably, especially in combined heat and power applications. Imatran Voima Oy (IVO) has developed the Bed Mixing Dryer technology since early 1990s. The first pilot plant was built in 1994 to IVO`s Kuusamo peat and wood fired power plant. The capacity of the plant is 6 MW{sub e} and 20 MW of district heat. In Kuusamo the dryer is connected to a bubbling fluidized bed. Since it`s commissioning the dryer has been used successfully for about 3000 hours during the heating season in wintertime. The second application of the technology will be a demonstration project in Oerebro (S). IVO Power Engineering Ltd will supply in 1997 a dryer to Oerebro Energi`s peat, wood and coal fired CHP plant equipped with circulating fluidized bed boiler. The fuel to be dried is sawdust with fuel input of about 60 MW. In Kuusamo the dryer produces 3 MW of additional district heat and in Oerebro 6 MW. The fuels in Kuusamo are peat, saw dust and bark. In addition to the municipal heat production this type of drying technology has its benefits in pulp and paper industry processes. Disposal of paper mill sludges is becoming more difficult and costly which has resulted in need of alternative treatment. Drying of the sludge before combustion in a boiler for power production is an attractive option. At the moment IVO is carrying out several studies to apply the Bed Mixing Dryer in pulp and paper industry processes. Economy of drying the sludge looks promising

  8. Separation of proteins by simulated moving bed chromatography

    OpenAIRE

    Houwing, J.

    2003-01-01

    This thesis describes the use of simulated moving bed (SMB) chromatography for separation of proteins. The underlying aim is the increase of the efficiency of process chromatography in terms of a reduction of the sorbent and buffer consumption in comparison to fixed bed chromatography. Both size exclusion and ion exchange separations of synthetic mixtures of proteins are considered. The main topics covered are the selection of the liquid to sorbent flow rate ratios, mass transfer effects and ...

  9. Security analysis and measures for the liquefaction process of oxygen-bearing coal-bed methane%含氧煤层气液化流程安全性分析与措施

    Institute of Scientific and Technical Information of China (English)

    邓骥; 诸林; 肖娅; 赵启龙

    2014-01-01

    There is a risk of explosion during purifying the coal-bed methane coming from un-derground drainage ,for the reason that the gas contains oxygen .In this paper ,the results of simulation with HYSYS and the flammability limit theory were combined together to analyze the security of whole process .The results showed that the explosion hazard concentrated at the end of the condensation and on the top of rectification tower .The measure to reduce the compressor outlet pressure or raise the final condensation temperature was proposed .What′s more ,the secu-rity measure was proposed to control the methane content of rectification tower gas above the up-per limit of the explosion strictly ,and then the inerting gas with nitrogen contacts with liquid ni-trogen upstream for further recovery of CH4 .The results indicate that when the value of nitrogen injection ratio is greater than 0 .6 (mole ratio ) ,there is no danger of explosion in liquefaction process ,and both methane yield and process safety are improved greatly in this way .%矿下抽采的煤层气由于混有空气而在液化中存在爆炸危险。通过将HYSYS对常规液化分离流程的模拟结果与爆炸极限理论相结合进行分析计算得出:爆炸危险主要集中在冷凝终了处和精馏塔顶部。进而提出降低压缩机出口压力或提高最终冷凝温度;严格控制精馏塔塔顶气相C H4含量在爆炸上限之上,塔顶气用N2惰化后再与液氮逆流接触以进一步回收C H4。计算表明,当N2注入比达0.6(摩尔比),气相CH4含量曲线将绕过临界点进入安全区。采取措施后CH4有较高收率且液化流程安全性得以提高。

  10. Association Rules Mining Based on SVM and Its Application in Simulated Moving Bed PX Adsorption Process%基于支持向量基的关联规则挖掘及其在模拟移动床PX吸附分离过程中的应用

    Institute of Scientific and Technical Information of China (English)

    张英; 苏宏业; 褚健

    2005-01-01

    In this paper, a novel data mining method is introduced to solve the multi-objective optimization problems of process industry. A hyperrectangle association rule mining (HARM) algorithm based on support vector machines (SVMs) is proposed. Hyperrectangles rules are constructed on the base of prototypes and support vectors (SVs) under some heuristic limitations. The proposed algorithm is applied to a simulated moving bed (SMB) paraxylene (PX) adsorption process. The relationships between the key process variables and some objective variables such as purity, recovery rate of PX are obtained. Using existing domain knowledge about PX adsorption process, most of the obtained association rules can be explained.

  11. Performance Evaluation of the ISS Water Processor Multifiltration Beds

    Science.gov (United States)

    Bowman, Elizabeth M.; Carter, Layne; Wilson, Mark; Cole, Harold; Orozco, Nicole; Snowdon, Doug

    2012-01-01

    The ISS Water Processor Assembly (WPA) produces potable water from a waste stream containing humidity condensate and urine distillate. The primary treatment process is achieved in the Multifiltration Bed, which includes adsorbent media and ion exchange resin for the removal of dissolved organic and inorganic contaminants. The first Multifiltration Bed was replaced on ISS in July 2010 after initial indication of inorganic breakthrough. This bed was returned to ground in July 2011 for an engineering investigation. The water resident in the bed was analyzed for various parameters to evaluate adsorbent loading, performance of the ion exchange resin, microbial activity, and generation of leachates from the ion exchange resin. Portions of the adsorbent media and ion exchange resin were sampled and subsequently desorbed to identify the primary contaminants removed at various points in the bed. In addition, an unused Multifiltration Bed was evaluated after two years in storage to assess the generation of leachates during storage. This assessment was performed to evaluate the possibility that these leachates are impacting performance of the Catalytic Reactor located downstream of the Multifiltration Bed. The results of these investigations and implications to the operation of the WPA on ISS are documented in this paper.

  12. How to Find Bed Bugs

    Science.gov (United States)

    ... strap of old box spring covering that is housing adults, skin castings, feces, and eggs. (Photo courtesy ... Bed bugs can survive and remain active at temperatures as low as 7°C (46°F), but they die ...

  13. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  14. Bed Bugs: The Australian Response

    Directory of Open Access Journals (Sweden)

    Richard C. Russell

    2011-04-01

    Full Text Available Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coordinated efforts of several organizations. The key components of the strategy included the introduction of a pest management standard ‘A Code of Practice for the Control of Bed Bug Infestations in Australia’ that defines and promotes ‘best practice’ in bed bug eradication, the development of a policy and procedural guide for accommodation providers, education of stakeholders in best management practices, and research. These strategies continue to evolve with developments that lead to improvements in ‘best practice’ while bed bugs remain problematic in Australia.

  15. Getting Rid of Bed Bugs

    Science.gov (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Bed Bugs Share Facebook Twitter ... integrated pest management. Preparing for control is very important whether you are considering hiring a professional or ...

  16. Top Ten Bed Bug Tips

    Science.gov (United States)

    ... temperatures are necessary for successful heat treatment. Black plastic bags in the sun might work to kill bed ... Place the used bag in a tightly sealed plastic bag and in an outside garbage bin. 10. Turn ...

  17. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  18. 含氧煤层气液化流程爆炸极限分析%Analysis of flammability limits for liquefaction process of oxygen-bearing coal-bed methane

    Institute of Scientific and Technical Information of China (English)

    李秋英; 王莉; 巨永林

    2011-01-01

    大部分含氧煤层气由于技术限制没有被合理利用,而是直接放空,不仅浪费资源.而且污染大气环境.针对某一典型煤层气气源条件和组分特点,设计了一种新型的液化精馏工艺流程,结合HYSYS软件模拟计算结果以及爆炸极限理论,对该液化精馏工艺流程的爆炸极限进行了分析计算,结果表明煤层气中甲烷浓度在压缩、液化以及节流过程中都高于爆炸上限,操作过程安全性比较高.但在精馏塔顶部甲烷浓度开始低于爆炸上限而导致精馏过程存在安全隐患.首先对原料气进行初步脱氧,然后再通过调整精馏塔塔底采出量来控制塔顶杂质气体中甲烷含量,使得其在整个液化及精馏流程中始终高于爆炸上限.分析结果表明,采取安全措施后整个流程都不存在爆炸危险性,甲烷回收率和产品纯度都较高,而且整个流程能耗也比较低.模拟结果显示,所设计的液化及精馏流程对不同气源具有较好的适用性,分析计算结果为含氧煤层气的杂质分离、操作过程的爆炸极限分析以及安全措施的采取提供了一定的参考.%Most of oxygen-bearing coal-bed methane (CBM) has not been utilized due to the limit in technique for production. The discharged gas leads to not only the waste of resources but also environmental pollution. In this study, a liquefaction process is proposed and designed for the typical CBM. HYSYS software is adopted to simulate the process. The flammability limits are analyzed and calculated based on the flammability limit theory and the simulated results of HYSYS. The results indicate that no flammable hazards exist in the processes of compression, liquefaction and throttling but they may appear at the top of the distillation tower. A method, in which oxygen is first removed from the feed gas with the control of the bottom flowrate (flowrate of the liquid product at column bottom), is adopted to ensure that the methane

  19. Bedømmelsens kompleksitet

    Directory of Open Access Journals (Sweden)

    Elsa Schmidt

    2006-03-01

    Full Text Available I artiklen sammenholdes hverdagens bedømmelser af mennesker med de bedømmelser, der sker ved eksaminer. Der er forskelle på grund af det retlige grundlag, men også ligheder. Konkrete erfaringer med klage- og ankesager gennem 8 år fra faget psykologi på landsplan opsummeres. Nogle få praktiske løsninger beskrives.

  20. Multiscale Modeling of Powder Bed-Based Additive Manufacturing

    Science.gov (United States)

    Markl, Matthias; Körner, Carolin

    2016-07-01

    Powder bed fusion processes are additive manufacturing technologies that are expected to induce the third industrial revolution. Components are built up layer by layer in a powder bed by selectively melting confined areas, according to sliced 3D model data. This technique allows for manufacturing of highly complex geometries hardly machinable with conventional technologies. However, the underlying physical phenomena are sparsely understood and difficult to observe during processing. Therefore, an intensive and expensive trial-and-error principle is applied to produce components with the desired dimensional accuracy, material characteristics, and mechanical properties. This review presents numerical modeling approaches on multiple length scales and timescales to describe different aspects of powder bed fusion processes. In combination with tailored experiments, the numerical results enlarge the process understanding of the underlying physical mechanisms and support the development of suitable process strategies and component topologies.

  1. Dual Fluidized Bed Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-30

    The dual fluidized bed reactor is a recirculating system in which one half of the unit operates as a steam pyrolysis device for biomass. The pyrolysis occurs by introducing biomass and steam to a hot fluidized bed of inert material such as coarse sand. Syngas is produced during the pyrolysis and exits the top of the reactor with the steam. A crossover arm, fed by gravity, moves sand and char from the pyrolyzer to the second fluidized bed. This sand bed uses blown air to combust the char. The exit stream from this side of the reactor is carbon dioxide, water and ash. There is a second gravity fed crossover arm to return sand to the pyrolysis side. The recirculating action of the sand and the char is the key to the operation of the dual fluidized bed reactor. The objective of the project was to design and construct a dual fluidized bed prototype reactor from literature information and in discussion with established experts in the field. That would be appropriate in scale and operation to measure the relative performance of the gasification of biomass and low ranked coals to produce a high quality synthesis gas with no dilution from nitrogen or combustion products.

  2. 49 CFR 236.336 - Locking bed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking bed. 236.336 Section 236.336 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Instructions § 236.336 Locking bed. The various parts of the locking bed, locking bed supports, and tappet...

  3. Bed form dynamics in distorted lightweight scale models

    Science.gov (United States)

    Aberle, Jochen; Henning, Martin; Ettmer, Bernd

    2016-04-01

    The adequate prediction of flow and sediment transport over bed forms presents a major obstacle for the solution of sedimentation problems in alluvial channels because bed forms affect hydraulic resistance, sediment transport, and channel morphodynamics. Moreover, bed forms can affect hydraulic habitat for biota, may introduce severe restrictions to navigation, and present a major problem for engineering structures such as water intakes and groynes. The main body of knowledge on the geometry and dynamics of bed forms such as dunes originates from laboratory and field investigations focusing on bed forms in sand bed rivers. Such investigations enable insight into the physics of the transport processes, but do not allow for the long term simulation of morphodynamic development as required to assess, for example, the effects of climate change on river morphology. On the other hand, this can be achieved through studies with distorted lightweight scale models allowing for the modification of the time scale. However, our understanding of how well bed form geometry and dynamics, and hence sediment transport mechanics, are reproduced in such models is limited. Within this contribution we explore this issue using data from investigations carried out at the Federal Waterways and Research Institute in Karlsruhe, Germany in a distorted lightweight scale model of the river Oder. The model had a vertical scale of 1:40 and a horizontal scale of 1:100, the bed material consisted of polystyrene particles, and the resulting dune geometry and dynamics were measured with a high spatial and temporal resolution using photogrammetric methods. Parameters describing both the directly measured and up-scaled dune geometry were determined using the random field approach. These parameters (e.g., standard deviation, skewness, kurtosis) will be compared to prototype observations as well as to results from the literature. Similarly, parameters describing the lightweight bed form dynamics, which

  4. SIMULATION OF PARTICLE COATING IN THE SUPERCRITICAL FLUIDIZED BED

    Institute of Scientific and Technical Information of China (English)

    Carsten; Vogt; Ernst-Ulrich; Hartge; Joachim; Werther; Gerd; Brunner

    2005-01-01

    Fluidized bed technology using supercritical carbon dioxide both as a fluidizing gas and as a solvent for the coating material makes possible the production of thin, uniform and solvent-free coatings. But operation at low fluidizing velocities, which is favorable to facilitate gas cleaning under the high pressure conditions, may lead to uneven distribution of the coating in the fluidized bed and to unstable operation due to agglomeration. Therefore a model has been developed which describes local fluid dynamics within the high pressure fluidized bed. Based on this model, the coating process is described and the distribution of the coating inside the fluidized bed is calculated. Furthermore a submodel for the calculation of local concentrations of liquid paraffin has been set up, which may be used as a basis for the prediction of agglomeration and thus stability of operation.

  5. Thermal degradation of PMMA in fluidised beds.

    Science.gov (United States)

    Smolders, K; Baeyens, J

    2004-01-01

    In recent years, the production and consumption of plastics have increased significantly and wastes are commonly incinerated or dumped in a landfill. Plastics pyrolysis, on the other hand, may provide an alternative means for disposal of plastic wastes with recovery of valuable gasoline-range hydrocarbons or the monomer. Pyrolysis of polymethyl methacrylate (PMMA) may result in very high recycling rates (90-98%) of the monomer methylmethacrylate (MMA) since the cracking of MMA to lighter molecules (CO2, CO and light hydrocarbons) is limited. The MMA-yield is mainly dependent on the residence time of the gas in the reactor and to a lesser extent on the operating temperature. The paper presents experimental work performed in a lead bath and in a fluidised bed. At low temperatures, the reaction is kinetically controlled, whereas at high temperatures, heat transfer restricts the overall reaction rate. It was demonstrated that the heat transfer in the fluid bed could be estimated by the equation of Kothari. A design procedure for a fluid bed PMMA-depolymerisation reactor is outlined and illustrated for a process of 1 tpd PMMA.

  6. Direct contact condensation in packed beds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Klausner, James F.; Mei, Renwei; Knight, Jessica [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2006-12-15

    A diffusion driven desalination process was recently described where a very effective direct contact condenser with a packed bed is used to condense water vapor out of an air/vapor mixture. A laboratory scale direct contact condenser has been fabricated as a twin tower structure with two stages, co-current and countercurrent. Experiments have been operated in each stage with respective saturated air inlet temperatures of 36, 40 and 43{sup o}C. The temperature and humidity data have been collected at the inlet and exit of the packed bed for different water to air mass flow ratios that vary between 0 and 2.5. A one-dimensional model based on conservation principles has been developed, which predicts the variation of temperature, humidity, and condensation rate through the condenser stages. Agreement between the model and experiments is very good. It is observed that the countercurrent flow stage condensation effectiveness is significantly higher than that for the co-current stage. The condensation heat and mass transfer rates were found to decrease when water blockages occur within the packed bed. Using high-speed digital cinematography, it was observed that this problem can occur at any operating condition, and is dependent on the packing surface wetting characteristics. This observation is used to explain the requirement for two different empirical constants, depending on packing diameter, suggested by Onda for the air side mass transfer coefficient correlation. (author)

  7. Reference repository design concept for bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.W.; Martin, R.W.

    1980-10-08

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

  8. 联合两段氧化制合成气/F-T合成的GTL工艺和催化剂%An Integrated Process of a Two-Stage Fixed Bed Syngas Production and F-T Synthesis for GTL in Remote Gas Field

    Institute of Scientific and Technical Information of China (English)

    代小平; 余长春; 李强; 张长斌; 江启滢; 沈师孔

    2003-01-01

    A novel process for catalytic oxidation of methane to synthesis gas (syngas), which consists of twoconsecutive fixed-bed reactors with air introduced into the reactors, integrated Fischer-Tropsch synthesis, was inves-tigated. At the same time, a catalytic combustion technology has been investigated for utilizing the F-T offgas togenerate heat or power energy. The results show that the two-stage fixed reactor process keep away from explosionof CH4/O2. The integrated process is fitted to produce diesel oil and lubricating oil in remote gas field.

  9. Study of fluidized-bed desulfurization with zinc ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Grindley, T

    1991-01-01

    Previous work established the technical feasibility of desulfurizing the hot product gases of coal gasification with fixed beds of a regenerable zinc ferrite sorbent. This process, intended for integration with coal gasifiers and gas turbines, has been tested and studied in considerable detail in a process development unit. Though possessing the advantages of high-sulfur absorption at low-sulfur breakthrough and the lack of sorbent attrition characteristic of a stationary bed, fixed beds also have inherent disadvantages: susceptibility to plugging by particles and a large diluent requirement during regeneration to control the reaction zone temperature. Therefore, METC conducted a scoping laboratory test program to determine the desulfurizing capability of fluid beds of zinc ferrite. Results from this program are presented. The results generally demonstrated that fluid beds of zinc ferrite have the potential to lower the H{sub 2}S level in hot gas from 10,000 to 10 ppmv. To achieve this at a high-sorbent sulfur loading would require two fluid-bed stages. Sorbent attrition appears to be acceptably low. Planned future activities include tests at high pressure with both simulated gas and in a gasifier sidestream.

  10. Single-step Purification of Molecular Chaperone GroEL by Expanded Bed Chromatography

    Institute of Scientific and Technical Information of China (English)

    佟晓冬; 杨征; 董晓燕; 孙彦

    2003-01-01

    Expanded bed adsorption (EBA) is an integrative downstream processing technique for the purification of biological substances directly from unclarified feedstock. In this study, molecular chaperone GroEL, an important protein folding helper both in vivo and in vitro, was purified by the single-step EBA technique from the unclarified homogenate of recombinant E. coli cells. Compared with packed bed adsorption, the EBA technique provided a single-step approach to yield an electrophoretic purity of GroEL. After the homogenate loading and column washing in the expanded bed mode, the GroEL protein was recovered by stepwise salt-gradient elution in packed-bed or expanded-bed modes, respectively. The expanded-bed elution mode was found as efficient as the packed-bed mode in the purification of GroEL from cell disruptate.

  11. Rapid ignition of fluidized bed boiler

    Science.gov (United States)

    Osborn, Liman D.

    1976-12-14

    A fluidized bed boiler is started up by directing into the static bed of inert and carbonaceous granules a downwardly angled burner so that the hot gases cause spouting. Air is introduced into the bed at a rate insufficient to fluidize the entire bed. Three regions are now formed in the bed, a region of lowest gas resistance, a fluidized region and a static region with a mobile region at the interface of the fluidized and static regions. Particles are transferred by the spouting action to form a conical heap with the carbonaceous granules concentrated at the top. The hot burner gases ignite the carbonaceous matter on the top of the bed which becomes distributed in the bed by the spouting action and bed movement. Thereafter the rate of air introduction is increased to fluidize the entire bed, the spouter/burner is shut off, and the entire fluidized bed is ignited.

  12. Soft-bed experiments beneath Engabreen, Norway: regelation infiltration, basal slip and bed deformation

    Science.gov (United States)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Moore, P. L.; Jackson, M.; Lappegard, G.; Kohler, J.

    To avoid some of the limitations of studying soft-bed processes through boreholes, a prism of simulated till (1.8 m × 1.6 m × 0.45 m) with extensive instrumentation was constructed in a trough blasted in the rock bed of Engabreen, a temperate glacier in Norway. Tunnels there provide access to the bed beneath 213 m of ice. Pore-water pressure was regulated in the prism by pumping water to it. During experiments lasting 7-12 days, the glacier regelated downward into the prism to depths of 50- 80 mm, accreting ice-infiltrated till at rates predicted by theory. During periods of sustained high pore water pressure (70-100% of overburden), ice commonly slipped over the prism, due to a water layer at the prism surface. Deformation of the prism was activated when this layer thinned to a sub-millimeter thickness. Shear strain in the till was pervasive and decreased with depth. A model of slip by ploughing of ice-infiltrated till across the prism surface accounts for the slip that occurred when effective pressure was sufficiently low or high. Slip at low effective pressures resulted from water-layer thickening that increased non-linearly with decreasing effective pressure. If sufficiently widespread, such slip over soft glacier beds, which involves no viscous deformation resistance, may instigate abrupt increases in glacier velocity.

  13. Occidental vertical modified in situ process for the recovery of oil from oil shale. Phase II. Quarterly progress report, September 1-November 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, William F.

    1979-12-01

    The major activities at OOSI's Logan Wash site during the quarter were: driving the access drifts towards the underground locations for Retorts 7 and 8; manway raise boring; constructing the change house; rubbling the first lift of Mini-Retort (MR)1; preparing the Mini-Retorts for tracer testing; coring of Retort 3E; and beginning the DOE instrumentation program.

  14. Study on preparation of the microencapsulated diet for larvae of Pseudosciaena crocea using fluidized bed coating process%流化床制备大黄鱼仔稚幼体微胶囊饲料的应用研究

    Institute of Scientific and Technical Information of China (English)

    谢中国; 王芙蓉; 牛化欣; 祝爱侠; 袁信华; 过世东

    2011-01-01

    The basal diet as core material was made into ball-shape granule and the diet microencapsulated with ethyl cellulose was prepared using fluidized bed coating process. Over 70% of the microencapsulated diet were between 150~840μm in size. The inclusion efficiency and lipid encapsulation efficiency of the microencapsulated diet was estimated to be 97.2% ± 1.7%, 63.2% ± 3.7% respectively. The nitrogen retention efficiency of the microencapsulated diet incubation in 35‰ NaCl solution for 20,40,60min was 3.6% ± 2.6% ,5.8% ± 3.5% ,53.7% ±4.2%, respectively. The surface superstructure of microencapsulated diet observed by scanning electron microscopy(SEM)was of regulation and uniformity,not conglutination. The larvae of Pseudosciaena crocea of 15d after hatching were fed with the microencapsulated diet for 25d as experimental group and the control was fed with frozen copepods. At the end of the experiment,the survival of the larvae in experimental group was significantly lower than that in the control group, however the body weight was greater than that in the control group.%将基础饲料先制成球丸,用流化床制备乙基纤维素包衣的微胶囊饲料.微胶囊饲料粒径为150~840μm的达70%.微胶囊饲料的包含率和脂类包埋率分别为97.2%±1.7%,63.2%±3.7%,在35.0%.的NaCl溶液中浸泡20,40,60min,氮保留率分别为73.6%±2.6%,65.8%±3.5%,53.7%±4.2%.扫描电镜(SEM)观察微胶囊饲料表面为均匀光滑一致的包衣膜,形状规则且无粘连现象.将微胶囊饲料饲喂15日龄大黄鱼25d作为实验组,对照组饲喂冷藏挠足类.实验结束时,实验组大黄鱼鱼苗的成活率虽显著低于对照组,但体重大于对照组.

  15. Numerical simulation of resin degassing unit in gas-phase fluidized bed polyethylene process and its application%气相法PE装置脱挥单元的数值模拟及应用

    Institute of Scientific and Technical Information of China (English)

    吴文清

    2014-01-01

    基于费克扩散定理、亨利定律、质量守恒定律等,结合气相法工艺聚乙烯(PE)装置脱挥单元中脱气仓的运行情况,建立了脱气仓的数学模型。运用该模型定量分析了N2流量、停留时间、压力等操作条件对脱气仓操作曲线和脱挥性能的影响,模拟分析了300kt/a气相法PE装置脱挥单元,确定了优选操作条件:操作点应同时位于出口处组分的质量分数与N2流量关系曲线的转折点,以及N2流量与停留时间关系曲线的转折点附近;N2流量与PE流量之比为0.010~0.040。%The resin degassing unit mathematical model of gas-phase fluidized bed polyethylene process was established based on Fick's diffusion law, Henry's law, mass conservation equation and so on. Then the model was applied to quantitatively analyzing the impact of the operating conditions such as nitrogen flow rate, residence time and pressure on the operation curve of purge bin and degassing performance curve, and simulation analysis of resin degassing unit in a 300 kt/a gas-phase polyethylene installations was performed to determine the preferred operating conditions. Specific conditions: operating point should be located at the turning point on outlet mass percentage of the components-nitrogen flow curve and at the turning point on nitrogen flow-residence time curve, and the flow ratio of nitrogen to polyethylene ranged from 0.010 to 0.040.

  16. Characterization of the pneumatic behavior of a novel spouted bed apparatus with two adjustable gas inlets

    NARCIS (Netherlands)

    Gryczka, O.; Heinrich, S.; Miteva, V.; Deen, N.G.; Kuipers, J.A.M.; Jacob, M.; Mörl, L.

    2008-01-01

    Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Within this work the fluid dynamics of a novel spouted bed plant with two adjustable gas inlets is investigated. By analysis of

  17. Grimethorpe experimental pressurized fluidized-bed combustor: in future energy concepts

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, D.B.

    1979-01-01

    The experimental pressurized fluidized bed combustor project at Grimethorpe, UK, is described. The design of the combustor, which is a pressure vessel containing a furnace, which contains the fluidized bed is discussed. Details of the process, the steam water circuit, the fuel system and method of feeding coal, ash removal during the process, the water treatment plant and plant control are given.

  18. Mechanism of film formation during granules capsulation in fluidized bed

    OpenAIRE

    Ostroha, Ruslan; Yukhymenko, Mykola

    2013-01-01

    It is proposed to perform granules capsulation process in the device of fluidized bed. Analysis of different approaches to mathematical description of granules growth kinetics was made. Equation of size determination of received granules in the device is proposed including granules growth rate and changes of density of granules distribution according to sizes in film forming process.

  19. Transients in a circulating fluidized bed boiler

    Science.gov (United States)

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-11-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  20. Computational fluid dynamic modeling of fluidized-bed polymerization reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rokkam, Ram [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

  1. Investigation of radiative heat transfer in fixed bed biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    T. Klason; X.S. Bai; M. Bahador; T.K. Nilsson; B. Sunden [Lund Institute of Technology, Lund (Sweden). Division of Fluid Mechanics

    2008-08-15

    This paper presents an investigation of the radiative heat transfer process in two fixed bed furnaces firing biomass fuels and the performance of several widely used models for calculation of radiative heat transfer in the free-room of fixed bed furnaces. The effective mean grey gas absorption coefficients are calculated using an optimised version of the exponential wide band model (EWBM) based on an optical mean beam length. Fly-ash and char particles are taken into account using Mie scattering. In the investigated updraft small-scale fixed bed furnace radiative transfer carries heat from the bed to the free-room, whereas in the cross-current bed large-scale industry furnace, radiative transfer brings heat from the hot zones in the free-room to the drying zone of the bed. Not all the investigated models can predict these heat transfer trends, and the sensitivity of results to model parameters is fairly different in the two furnaces. In the small-scale furnace, the gas absorption coefficient predicted by using different optical lengths has great impact on the predicted temperature field. In the large-scale furnaces, the predicted temperature field is less sensitive to the optical length. In both furnaces, with the same radiative properties, the low-computational-cost P1 model predicts a temperature field in the free-room similar to that by the more time consuming SLW model. In general, the radiative heat transfer rates to the fuel bed are not very sensitive to the radiative properties, but they are sensitive to the different radiative heat transfer models. For a realistic prediction of the radiative heat transfer rate to the fuel bed or to the walls, more computationally demanding models such as the FGG or SLW models should be used. 37 refs., 7 figs., 2 tabs.

  2. Food processing by high hydrostatic pressure.

    Science.gov (United States)

    Yamamoto, Kazutaka

    2017-04-01

    High hydrostatic pressure (HHP) process, as a nonthermal process, can be used to inactivate microbes while minimizing chemical reactions in food. In this regard, a HHP level of 100 MPa (986.9 atm/1019.7 kgf/cm(2)) and more is applied to food. Conventional thermal process damages food components relating color, flavor, and nutrition via enhanced chemical reactions. However, HHP process minimizes the damages and inactivates microbes toward processing high quality safe foods. The first commercial HHP-processed foods were launched in 1990 as fruit products such as jams, and then some other products have been commercialized: retort rice products (enhanced water impregnation), cooked hams and sausages (shelf life extension), soy sauce with minimized salt (short-time fermentation owing to enhanced enzymatic reactions), and beverages (shelf life extension). The characteristics of HHP food processing are reviewed from viewpoints of nonthermal process, history, research and development, physical and biochemical changes, and processing equipment.

  3. Dynamics of fine particles in liquid-solid fluidized beds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of the Local Equilibrium Model (LEM), fine particles with large Richardson-Zaki exponent n show, under certain conditions during bed expansion and collapse, different dynamic behavior from particles with small n. For an expansion process there may be a concentration discontinuity propagating upward from the distributor, and, on the contrary, for a collapse process there may be a progressively broadening and upward-propagating continuous transition zone instead of discontinuity. The predictions of the bed height variation and the discontinuity trace have been validated experimentally.

  4. Caracterização e uso de xisto para adsorção de chumbo (II em solução Characterization and use of retorted shale for adsorption of lead (II in solution

    Directory of Open Access Journals (Sweden)

    P. M. Pimentel

    2006-09-01

    Full Text Available Existe um grande interesse no uso de materiais de baixo custo para remoção de metais pesados em águas residuais. Novas técnicas de processamento e adsorventes incluindo argilas, resinas sintéticas, turfa e quitosana tem sido estudados objetivando substituir o carvão ativado. No presente trabalho, xisto retortado (XR, um rejeito sólido da transformação térmica do xisto oleígeno, foi caracterizado com o objetivo de utilizá-lo como adsorventes para remoção de metais pesados. O aproveitamento desse rejeito é de grande interesse, uma vez que o Brasil possui a segunda maior reserva mundial de xisto oleígeno. Os rejeitos foram caracterizados por diferentes técnicas de caracterização, incluindo tamanho de partícula, análise termogravimétrica, fluorescência de raios X, espectroscopia na região do infravermelho, difração de raios X, e microscopia eletrônica de varredura-EDS. As características dos pós foram adequadas para os experimentos de adsorção. Estudos de adsorção de Pb2+ pelo método de banho finito foram realizados. A remoção do Pb2+ foi superior a 85%.There has been a growing interest in the use of cost-effective materials to remove heavy metals from wastewater. New processing techniques and adsorbents including natural clays, synthetic resins, peat and chitosan have been studied aiming at replacing activated coal. In the present investigation, retorted shale, a solid residue of the thermal transformation of oil shale, was characterized with the objective of preparing heavy metals adsorbents. In addition to the direct environmental benefits from the technology to wastewater, Brazil has the second world reserve of oil shale. The fine residue was fully characterized by different techniques including particle size determination, thermogravimetric analyses, BET, FTIR, X-ray diffraction, and SEM/EDS. The characteristics of the powder were appropriate for adsorption. Batch adsorption studies in Pb2+ synthetic solution

  5. Fluidized-bed bioreactor system for the microbial solubilization of coal

    Science.gov (United States)

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

  6. Fixed-bed bioreactor system for the microbial solubilization of coal

    Science.gov (United States)

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fixed-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fixed-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the large scale production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fixed-bed bioreactor. 1 fig., 1 tab.

  7. Laboratory rearing of bed bugs

    Science.gov (United States)

    The resurgence of bed bugs Cimex lectularius L. in the United States and worldwide has resulted in an increase in research by university, government, and industry scientists directed at the biology and control of this blood-sucking pest. A need has subsequently arisen for producing sufficient biolog...

  8. Stratum energy of coal-bed gas reservoir and their control on the coal-bed gas reservoir formation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Stratum energy of coal-bed gas reservoir, including coal-radix flexibility energy, groundwater flexibility energy and gas flexibility energy (hereinafter "three energy"), depends on the energy homeostasis system, the core process of which is the effective transfer of energy and the geological selective process. Combining with the mechanics experimentations of coal samples, different flexibility energy has been analyzed and researched quantificationally, and a profound discussion to their controls on the coal-bed gas reservoir formation has been made. It is shown that when gas reservoir is surrounded by edge water and bottom water, the deposited energy in the early phase of forming gas reservoir is mostly coal-radix and gas flexibility energy, but the effect of groundwater flexibility energy increases while water-body increases. The deposited energy in the middle and later phase of forming gas reservoir is mostly gas flexibility energy, which is greater than 80% of all deposited energy. In the whole process, larger groundwater body exerts greater influences on gas accumulation. The paper indicated that higher stratum energy is more propitious to forming coal-bed gas reservoir. And higher coal-radix flexibility energy and gas flexibility energy are more propitious to higher yield of gas reservoirs, while higher groundwater flexibility energy is more propitious to stable yield of gas reservoirs. Therefore, the key to evaluating the coal-bed gas reservoir formation is the stratum energy of coal-bed gas reservoir.

  9. 基于Aspen Plus的低浓度含氧煤层气低温精馏的模拟研究%Simulation Study on Cryogenic Distillation Process of Low-concentration Oxygen-containing Coal-bed Methane Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    马代辉

    2016-01-01

    针对低浓度煤层气深冷液化工艺,使用化工流程模拟软件Aspen Plus,对低温精馏过程进行了模拟研究,发现当原料气入口流量为552 kmol/h,精馏塔压力为0.34 MPa时,塔底液态甲烷的纯度为99%。分析了抽采煤层气流量波动对低温精馏效果的影响,发现当煤层气流量降低时,塔顶氮氧尾气中的甲烷含量增加,并且处于爆炸界限内;随着煤层气流量增加,塔底甲烷的纯度和回收率均降低。%To aim at the cryogenic liquefaction technology of low-concentration coal-bed methane, simulation study was made on the cryogenic distillation process with Aspen Plus software. It was found from the study that when the inlet flow rate of the feed gas was 552 kmol/h and the pressure of the distillation column was 0. 34 MPa, the purity of the liquid methane at the column bottom was 99%. Analysis was carried out on the influence of the coal-bed methane flow rate fluctuations on the cryogenic distillation. When the flow rate of coal-bed methane decreased, the methane content in nitrogen oxide gases at the top of the column increased and was within the explosion limit;with the increase of the flow rate of coal-bed methane, the purity and recovery of the methane at the column bottom decreased.

  10. Biomass ash-bed material interactions leading to agglomeration in FBC

    DEFF Research Database (Denmark)

    Visser, H.J.M.; van Lith, Simone Cornelia; Kiel, J.H.A.

    2008-01-01

    In (bubbling) fluidized-bed combustion and gasification of biomass, several potential problems are associated with the inorganic components of the fuel. A major problem area is defluidization due to bed agglomeration. The most common found process leading to defluidization in commercial-scale ins......In (bubbling) fluidized-bed combustion and gasification of biomass, several potential problems are associated with the inorganic components of the fuel. A major problem area is defluidization due to bed agglomeration. The most common found process leading to defluidization in commercial...... describes a fundamental study on the mechanisms of defluidization. For the studied process of bed defluidization due to sintering of grain-coating layers, it was found that the onset of the process depends on (a) a critical coating thickness, (b) on the fluidization velocity when it is below approximately...... four times the minimum fluidization velocity, and (c) on the viscosity (stickiness) of the outside of the grains (coating)....

  11. Biofilm detachment mechanisms in a liquid-fluidized bed.

    Science.gov (United States)

    Chang, H T; Rittmann, B E; Amar, D; Heim, R; Ehlinger, O; Lesty, Y

    1991-08-20

    Bed fluidization offers the possibility of gaining the advantages of fixed-film biological processes without the disadvantage of pore clogging. However, the biofilm detachment rate, due to hydrodynamics and particle-to-particle attrition, is very poorly understood for fluidized-bed biofilm processes. In this work, a two-phase fluidized-bed biofilm was operated under a constant surface loading (0.09 mg total organic carbon/cm(2) day) and with a range of bed height (H), fluid velocities (U), and support-particle concentrations (C(p)). Direct measurements were made for the specific biofilm loss rate coefficient (b(s))and the total biofilm accumulation (X(f)L(f)). A hydrodynamic model allowed independent determination of the biofilm density (X(f)), biofilm thickness (L(f)), liquid shear stress (tau), and Reynolds number (Re). Multiple regression analysis of the results showed that increased particle-to-particle attrition, proportional to C(p) and increased turbulence, described by Re, caused the biofilms to be denser and thinner. The specific detachment rate coefficient (b(s)) increased as C(p) and Re increased. Almost all of the 6, values were larger than predicted by a previous model derived for smooth biofilms on a nonfluidized surface. Therefore, the turbulence and attrition of bed fluidization appear to be dominant detachment mechanisms.

  12. Moving Bed Gasification of Low Rank Alaska Coal

    Directory of Open Access Journals (Sweden)

    Mandar Kulkarni

    2012-01-01

    Full Text Available This paper presents process simulation of moving bed gasifier using low rank, subbituminous Usibelli coal from Alaska. All the processes occurring in a moving bed gasifier, drying, devolatilization, gasification, and combustion, are included in this model. The model, developed in Aspen Plus, is used to predict the effect of various operating parameters including pressure, oxygen to coal, and steam to coal ratio on the product gas composition. The results obtained from the simulation were compared with experimental data in the literature. The predicted composition of the product gas was in general agreement with the established results. Carbon conversion increased with increasing oxygen-coal ratio and decreased with increasing steam-coal ratio. Steam to coal ratio and oxygen to coal ratios impacted produced syngas composition, while pressure did not have a large impact on the product syngas composition. A nonslagging moving bed gasifier would have to be limited to an oxygen-coal ratio of 0.26 to operate below the ash softening temperature. Slagging moving bed gasifiers, not limited by operating temperature, could achieve carbon conversion efficiency of 99.5% at oxygen-coal ratio of 0.33. The model is useful for predicting performance of the Usibelli coal in a moving bed gasifier using different operating parameters.

  13. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    Energy Technology Data Exchange (ETDEWEB)

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas

  14. Fuel Gas Demonstration Plant Program. Volume I. Demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    The objective of this project is for Babcock Contractors Inc. (BCI) to provide process designs, and gasifier retort design for a fuel gas demonstration plant for Erie Mining Company at Hoyt Lake, Minnesota. The fuel gas produced will be used to supplement natural gas and fuel oil for iron ore pellet induration. The fuel gas demonstration plant will consist of five stirred, two-stage fixed-bed gasifier retorts capable of handling caking and non-caking coals, and provisions for the installation of a sixth retort. The process and unit design has been based on operation with caking coals; however, the retorts have been designed for easy conversion to handle non-caking coals. The demonstration unit has been designed to provide for expansion to a commercial plant (described in Commercial Plant Package) in an economical manner.

  15. 流化床透氧膜反应器用于天然气制氢的工艺模拟%Process simulation of fluidized-bed oxygen permeable membrane reactor for hydrogen production from natural gas

    Institute of Scientific and Technical Information of China (English)

    叶健文; 解东来; 杨振华; 曹志宇

    2012-01-01

    Hydrogen is an important chemical material. Fluidized-bed oxygen permeable membrane reactor is a novel technology for hydrogen production from natural gas. An Aspen model is built for this new reactor. The influences of reaction pressure, oxygen to carbon ratio ( Oc ) , steam to carbon ratio ( Sc ) on the reaction temperature and syngas composition are studied. Compared with the ordinary fluidized bed reactor, the fluidized bed oxygen permeable membrane reactor has a higher methane conversion, a hydrogen yield and a higher hydrogen concentration in the syngas, due to its in-situ oxygen separation from air.%氢气是一种重要的化工原料,流化床透氧膜反应器是一种新型的天然气制氢装置.建立了该新型装置的Aspen Plus(R)模型,并模拟了反应压力、氧碳比(Oc)、水碳比(Sc)对反应温度、合成气成分的影响,并与普通的流化床自热反应器进行了比较.结果表明,流化床透氧膜反应器由于分离了空气中的N2,反应可在高的氧气摩尔分数下进行,合成气中的H2摩尔分数大大提高,甲烷转化率较大,氢气产量也提高.

  16. [Historical analysis of the hospital bed].

    Science.gov (United States)

    Fajardo-Ortiz, Guillermo; Fajardo-Dolci, Germán

    2010-01-01

    Until now the bed has been the basic physical resource in hospitals. This type of furniture has served to study and treat patients, through out the centuries it has undergone changes in the materials they are made of dimensions, functionality, accessories, aesthetic, and design. The hospital bed history is not well known, there are thousands of documents about the evolution of hospitals, but not enough is known about hospital beds, a link between the past and the present. The medical, anthropological, technological, social, and economic dynamics and knowledge have produced a variety of beds in general and hospital beds in particular. From instinctive, rustic, poor and irregular "sites" that have differed in shape and size they had evolved into ergonomic equipment. The history of the hospital bed reflects the culture, techniques and human thinking. Current hospital beds include several types: for adults, for children, for labor, for intensive therapy, emergency purposes, census and non census beds etc.

  17. Chinese Bedding Technology Standard under Drafting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    National Home Textile Standardization Technology Committee(NHTSTC)set up its Bedding Branch Committee. This will promote the work of Chinese bedding technology standardization and a symbol that China step up to meet the

  18. Pulling a patient up in bed

    Science.gov (United States)

    Moving a patient in bed ... takes at least 2 people to safely move a patient up in bed. Friction from rubbing can ... A slide sheet is the best way to prevent friction. If you do not have one, you ...

  19. EMERGING TECHNOLOGY BULLETIN: SPOUTED BED REACTOR

    Science.gov (United States)

    The Spouted Bed Reactor (SBR) technology utilizes the unique attributes of the "spouting " fluidization regime, which can provide heat transfer rates comparable to traditional fluid beds, while providing robust circulation of highly heterogeneous solids, concurrent with very agg...

  20. STUCTURE OF PULSED BED

    Directory of Open Access Journals (Sweden)

    I. A. Bokun

    2014-01-01

    Full Text Available The structure of pulsed layer is proposed which can be suggested as a state of particulates that is blown by intermittent gas flow with speed which has the force to start material moving. Layer during one cycle is in a suspension, falling down and immobile state resulting in changes of particles arrangement as well as ways of gas flowing through layer. Moreover, it allows carrying out effective interphase heat exchange even adamant real granulation.The process of formation of impact flows is considered aw well as their influence on formation of air bubbles in pulsed layer. At startup of air blast the balance between the force of hydro-dynamic resistance is broken, on one side, and forces of gravity, particles inertia and their links with walls on the other side. The layer is transferred in the state of pulsed pseudo-fluidization, and presents gas-disperse mixture, inside of which impulse of pressure increasing is spreading to all sides as pressure waves (compression. These waves are the sources of impact flows’ formation, the force of which is two times more than during the stationary flow.The waves of pressure are divided into weak and strong ones depending on movement velocity within gas-disperse system. Weak waves are moving with a sound speed and strong ones in active phase of pulsed layer are moving over the speed of sound limit within gas-disperse system. The peculiarity of strong wave is that parameters of system (pressure, density and others are changing in discrete steps.The article describes the regime of layer’s falling down in the passive stage of cycle, which begins after finishing of gas impulse action. And suspension layer of moving up granular material is transferred in the state of falling resulting in change of the layer structure.

  1. Artificial neural network models for biomass gasification in fluidized bed gasifiers

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Hernández, J. Alfredo; Bruno, Joan Carles

    2013-01-01

    bed gasifier can be successfully predicted by applying neural networks. ANNs models use in the input layer the biomass composition and few operating parameters, two neurons in the hidden layer and the backpropagation algorithm. The results obtained by these ANNs show high agreement with published......Artificial neural networks (ANNs) have been applied for modeling biomass gasification process in fluidized bed reactors. Two architectures of ANNs models are presented; one for circulating fluidized bed gasifiers (CFB) and the other for bubbling fluidized bed gasifiers (BFB). Both models determine...

  2. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

  3. Bed Bug Education for School Maintenance

    Science.gov (United States)

    Henriksen, Missy

    2012-01-01

    Bed bugs are a growing problem, not only in homes and hotels, but also in schools and colleges. Facility administrators and staff need to understand the bed bug resurgence and develop best practices to deal with an infestation. In this article, the author offers tips for preventing and treating bed bugs in school and university settings.

  4. 21 CFR 868.5180 - Rocking bed.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rocking bed. 868.5180 Section 868.5180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5180 Rocking bed. (a) Identification. A rocking bed is a...

  5. Characteristics of fluidized-packed beds

    Science.gov (United States)

    Gabor, J. D.; Mecham, W. J.

    1968-01-01

    Study of fluidized-packed bed includes investigation of heat transfer, solids-gas mixing, and elutriation characteristics. A fluidized-packed bed is a system involving the fluidization of small particles in the voids of a packed bed of larger nonfluidized particles.

  6. Dynamics of Solid Bed Dehydration in a Niger Delta Natural Gas Liquids Plant

    Directory of Open Access Journals (Sweden)

    Akpabio, E.J

    2012-12-01

    Full Text Available This work focuses on the study of a natural gas liquid solid bed dehydration plant in the Niger delta. The dehydration system of the plant is made of a 3-bed cycling unit placed upstream the cryogenic section of the plant to prevent hydrate formation (desired dew point of -1010C. The system comprised three (3 solid desiccant beds, which are packed with molecular sieves and alumina balls. Each bed had a maximum design capacity of 300million standard cubic feet per day. The dehydrator beds are configured to operate under a timed cycle, such that two (2 beds are always online while the third bed is undergoing regeneration. During the dehydration (drying cycle, the amount of moisture adsorbed by the molecular sieves, at different cross section of the tower varied with time. At the initial stage of the drying cycle, most of the moisture was adsorbed by the molecular sieves at the top of the bed, since the flow direction was from top to bottom. Thus, as the gas flowed through the bed, the molecular sieves at the bottom only adsorbed traces of water, which were not adsorbed at the top. This enabled the attainment of the required dew point or maximum parts per million (ppm of water in the gas. Based on this, it was noted that the topmost layer of the molecular sieves got saturated first and with continuous flow of gas through the bed, the saturated layer of the molecular sieves moved gradually, with time to the bottom of the bed. This resulted in the formation of a saturation gradient across the height of the bed. Critical examination of the dehydration, regeneration and cooling processes of the beds revealed that for effective and optimum results, dehydration was done for approximately 1200mins, regeneration 410mins and cooling 150mins while De-pressurization and re-pressurization took 20mins.

  7. The role of grain-size ratio in the mobility of mixed granular beds

    Science.gov (United States)

    Staudt, Franziska; Mullarney, Julia C.; Pilditch, Conrad A.; Huhn, Katrin

    2017-02-01

    The main goal of the study was to understand the effects of grain-size distribution on the stability of beds in the sand-silt range, which is a critical subject for the understanding of geomorphological processes in aquatic environments. Although theoretical models can explain the mobilization of a mixed bed, there is a clear lack in knowledge regarding the stabilizing effect of non-cohesive fine material. To connect existing findings, we analysed bed stability in relation to grain-size distribution in laboratory experiments. Erosion experiments in an annular flume were conducted using beds of different size compositions of spherical glass beads, i.e. a) the grain-size ratio RD = D50,coarse/D50,fine (the relative size of coarse and fine grains; D50 = 39-367 μm) and b) the amount of fines. Several glass-bead combinations with unimodal and bimodal grain-size distributions (RD = 3.9, 5.8, and 9.4) and varying fine fractions (10-40% dry weight) were subjected to increasing flow speeds (0.01-0.19 m s-1). Using acoustic Doppler velocimetry (ADV) and optical backscatter, the flow profile in the vicinity of the bed surface, the changes in bed morphology, and the suspended sediment concentration (SSC) were measured. A new method was developed to evaluate the bed-level changes detected by the ADV as a proxy for the bed mobility. We found different modes of bed mobility depending on the grain-size ratio. For low grain-size ratios, an increase in the fine fraction (to 40%) led to increased bed-level changes during the experiment and the mobilization of the mixed bed at the highest flow speed. For high ratios an increase in fine fraction (to 40%) led to a decrease of bed-level changes and the beds remained stable, i.e. no bed forms developed even at the highest flow speed. Therefore, increasing the amount of fine particles can lead to different modes of behaviour depending on the grain-size ratio. For a bimodal sediment bed with spherical grains under unidirectional flow

  8. Model-free adaptive control of supercritical circulating fluidized-bed boilers

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L

    2014-12-16

    A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  9. Host-Seeking Behavior in the Bed Bug, Cimex lectularius

    Directory of Open Access Journals (Sweden)

    Vernard R. Lewis

    2011-03-01

    Full Text Available The reemergence of the bed bug, Cimex lectularius Linnaeus, has recently spawned a frenzy of public, media, and academic attention. In response to the growing rate of infestation, considerable work has been focused on identifying the various host cues utilized by the bed bug in search of a meal. Most of these behavioral studies examine movement within a confined environment, such as a Petri dish. This has prevented a more complete understanding of the insect’s host-seeking process. This work describes a novel method for studying host-seeking behavior, using various movement parameters, in a time-lapse photography system. With the use of human breath as an attractant, we qualitatively and quantitatively assessed how bed bugs navigate their environment between its harborage and the host. Levels of behavioral activity varied dramatically between bed bugs in the presence and absence of host odor. Bed bugs demonstrated not simply activation, but attraction to the chemical components of breath. Localized, stop-start host-seeking behavior or alternating periods of movement and pause were observed among bed bugs placed in the environment void of human breath, while those exposed to human breath demonstrated long range, stop-start host-seeking behavior. A more comprehensive understanding of bed bug host-seeking can lead to the development of traps and monitors that account for unique subtleties in their behavior. The time-lapse photography system uses a large, artificial environment and could also be employed to study other aspects of the insect’s behavioral patterns.

  10. Batch top-spray fluid bed coating: Scale-up insight using dynamic heat- and mass-transfer modelling

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, P.; Jensen, Anker Degn

    2009-01-01

    A mathematical model was developed for batch top-spray fluid bed coating processes based on Ronsse et al. [2007a.b. Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part I-model development and validation. journal of Food Engineering 78......, 296-307; Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part II-model and process analysis. journal of Food Engineering 78, 308-322]. The model is based on one-dimensional discretisation of the fluid bed into a number of well-mixed control...

  11. Review of acute cancer beds.

    LENUS (Irish Health Repository)

    Evans, D S

    2012-01-01

    A review of admissions to cancer services at University Hospital Galway (UHG) was undertaken to assess the appropriateness of hospital usage. All cancer specialty patients admitted from 26-28 May 2009 were reviewed (n = 82). Chi square tests, Exact tests, and One-way ANOVA were utilised to analyse key issues emerging from the data. Fifty (61%) were classified as emergencies. Twenty three (67%) occupied a designated cancer bed with 24 (30%) in outlying non-oncology wards. The mean length of stay was 29.3 days. Possible alternatives to admission were identified for 15 (19%) patients. There was no evidence of discharge planning for 50 (60%) admissions. There is considerable potential to make more appropriate utilisation of UHG for cancer patients, particularly in terms of reducing bed days and length of stay and the proportion of emergency cancer admissions, and further developing integrated systems of discharge planning.

  12. Gasification of lignocellulosic biomass in fluidized beds for renewable energy development: A review

    Energy Technology Data Exchange (ETDEWEB)

    Alauddin, Zainal Alimuddin Bin Zainal; Lahijani, Pooya [School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Mohammadi, Maedeh; Mohamed, Abdul Rahman [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-12-15

    A literature review on gasification of lignocellulosic biomass in various types of fluidized bed gasifiers is presented. The effect of several process parameters such as catalytic bed material, bed temperature and gasifying agent on the performance of the gasifier and quality of the producer gas is discussed. Based on the priorities of researchers, the optimum values of various desired outputs in the gasification process including improved producer gas composition, enhanced LHV, less tar and char content, high gas yield and enhanced carbon conversion and cold gas efficiency have been reported. The characteristics and performance of different fluidized bed gasifiers were assessed and the obtained results from the literature have been extensively reviewed. Survey of literature revealed that several industrial biomass gasification plants using fluidized beds are currently conducting in various countries. However, more research and development of technology should be devoted to this field to enhance the economical feasibility of this process for future exploitations. (author)

  13. Performance of a magnetically stabilized bed reactor with immobilized yeast cells.

    Science.gov (United States)

    Ivanova, V; Hristov, J; Dobreva, E; al-Hassan, Z; Penchev, I

    1996-05-01

    This paper is focused on the possibility to apply the magnetic stabilization technique in bioprocessing. The feasibility of a continuous ethanol fermentation process with immobilized Saccharomyces cerevisiae cells in a magnetically stabilized bed (MSB) was demonstrated. The fermentation processes were carried out in an external magnetic field, transverse to the fluid flow. The flexibility to change the bed expansion owing to the independent change of the fluid flow and the field intensity (the "magnetization FIRST" mode) permitted the creation of fixed beds with different particle arrangements, which affected the bed porosity, the effective fluid-particle contact area, and the mass transfer processes on the particle-fluid interface. As a result, higher ethanol concentration, ethanol production, and glucose uptake rates than in conventional packed bed reactor were reached.

  14. Study on an Integrated Sintered Metal Screen Moving Granular Bed Filter

    Institute of Scientific and Technical Information of China (English)

    吴晋沪; 王洋

    2004-01-01

    A new gas clean-up process called "integrated sintered metal screen moving granular bed" (ISMSMGB) for the integrated gasification combined cycle (IGCC) and pressured fluidized bed combustion (PFBC) was developed on the basis of a sintered metal candle filter and a cross-flow moving granular bed filter. This is a combination of the surface and deep bed filtering processes. A set of facilities was established and a series of cold model tests were carried out. The dust removal efficiency and the pressure drop of the filter were measured and analyzed. The results show that this process features the advantages of the moving bed for high capacity as well as high inlet dust load and the surface filter for high efficiency. Meanwhile, the granules moving downward cleans the cake on the screen surface, so that the system is operated at steady state.

  15. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  16. Empirical closures for particulate debris bed spreading induced by gas–liquid flow

    Energy Technology Data Exchange (ETDEWEB)

    Basso, S., E-mail: simoneb@kth.se; Konovalenko, A.; Kudinov, P.

    2016-02-15

    Highlights: • Experimental study of the debris bed self-leveling phenomenon. • A scaling approach and a non-dimensional model to describe particle flow rate are proposed. • The model is validated against experiments with particles of different properties and at different gas injection conditions. - Abstract: Efficient removal of decay heat from the nuclear reactor core debris is paramount for termination of severe accident progression. One of the strategies is based on melt fragmentation, quenching and cooling in a deep pool of water under the reactor vessel. Geometrical configuration of the debris bed is among the important factors which determine possibility of removing the decay heat from the debris bed by natural circulation of the coolant. For instance, a tall mound-shape debris bed can be non-coolable, while the same debris can be coolable if spread uniformly. Decay heat generates a significant amount of thermal energy which goes to production of steam inside the debris bed. Two-phase flow escaping through the top layer of the bed becomes a source of mechanical energy which can move the particulate debris along the slope of the bed. The motion of the debris will lead to flattening of the bed. Such process is often called “self-leveling” phenomenon. Spreading of the debris bed by the self-leveling process can take significant time, depending on the initial debris bed configuration and other parameters. There is a competition between the time scales for reaching (i) a coolable configuration of the bed, and (ii) onset of dryout and re-melting of the debris. In the previous work we have demonstrated that the rate of particulate debris spreading is determined by local gas velocity and local slope angle of the bed. In this work we develop a scaling approach and a closure for prediction of debris spreading rate based on generalization of available experimental data. We demonstrate that introduced scaling criteria are universal for particles of different

  17. The expression of the jigging bed porosity and its realizing of the computer detection system

    Institute of Scientific and Technical Information of China (English)

    DU Chang-long; LIN Ming-xing; YUAN Hui

    2001-01-01

    This peper proposes the expression of the jigging bed porosity based on the jumping height of the jigging bed and water wave. This kind of expression can help to realize the jigging process automation and intelligence. The computer detection system is also developed.

  18. Discrete element study of granulation in a spout-fluidized bed

    NARCIS (Netherlands)

    Link, J.M.; Godlieb, W.; Deen, N.G.; Kuipers, J.A.M.

    2007-01-01

    In this work a discrete element model (DEM) is presented for the description of the gas–liquid–solid flow in a spout-fluidized bed including all relevant phenomena for the study of granulation. The model is demonstrated for the case of a granulation process in a flat spout-fluidized bed, containing

  19. Fluidized beds as turbulence promoters in the concentration of food liquids by reverse osmosis

    NARCIS (Netherlands)

    Boer, de R.; Zomerman, J.J.; Hiddink, J.; Aufderheyde, J.; Swaay, van W.P.M.; Smolders, C.A.

    1980-01-01

    Fluidized beds offer a potential improvement of reverse osmosis processes for food liquids, less fouling of the membrane, and reduced energy consumption. Our experiments were concerned with tubular systems in which fluidized beds of glass, steel, and lead beads were used. Glass beads appeared to be

  20. Novel Simulated moving bed technologies

    Energy Technology Data Exchange (ETDEWEB)

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  1. Novel Simulated moving bed technologies

    Energy Technology Data Exchange (ETDEWEB)

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  2. Making decisive decisions on simulating moving bed designs

    NARCIS (Netherlands)

    Bussmann, P.; Boon, F.; Vroon, R.

    2012-01-01

    The working of an simulating moving bed (SMB) is still poorly understood. Although the SMB is used in food, petrochemical, and pharmaceutical industries, the operation is suboptimal and more widely applicable. Determining the design (CAPEX) and operating parameters (OPEX) of SMB processes remains a

  3. Mercury mine drainage and processes that control its environmental impact

    Science.gov (United States)

    Rytuba, J.J.

    2000-01-01

    Mine drainage from mercury mines in the California Coast Range mercury mineral belt is an environmental concern because of its acidity and high sulfate, mercury, and methylmercury concentrations. Two types of mercury deposits are present in the mineral belt, silica-carbonate and hot-spring type. Mine drainage is associated with both deposit types but more commonly with the silica-carbonate type because of the extensive underground workings present at these mines. Mercury ores consisting primarily of cinnabar were processed in rotary furnaces and retorts and elemental mercury recovered from condensing systems. During the roasting process mercury phases more soluble than cinnabar are formed and concentrated in the mine tailings, commonly termed calcines. Differences in mineralogy and trace metal geochemistry between the two deposit types are reflected in mine drainage composition. Silica-carbonate type deposits have higher iron sulfide content than hot- spring type deposits and mine drainage from these deposits may have extreme acidity and very high concentrations of iron and sulfate. Mercury and methylmercury concentrations in mine drainage are relatively low at the point of discharge from mine workings. The concentration of both mercury species increases significantly in mine drainage that flows through and reacts with calcines. The soluble mercury phases in the calcines are dissolved and sulfate is added such that methylation of mercury by sulfate reducing bacteria is enhanced in calcines that are saturated with mine drainage. Where mercury mine drainage enters and first mixes with stream water, the addition of high concentrations of mercury and sulfate generates a favorable environment for methylation of mercury. Mixing of oxygenated stream water with mine drainage causes oxidation of dissolved iron(II) and precipitation of iron oxyhydroxide that accumulates in the streambed. Both mercury and methylmercury are strongly adsorbed onto iron oxyhydroxide over the p

  4. Production of succinic acid in basket and mobile bed bioreactors-Comparative analysis of substrate mass transfer aspects☆

    Institute of Scientific and Technical Information of China (English)

    Anca-Irina Galaction; Dan Cacaval; Ramona-Mihaela Matran; Alexandra Tucaliuc

    2016-01-01

    The glucose mass transfer in the biosynthesis of succinic acid with immobilized Actinobacil us succinogenes cel s has been comparatively analyzed for a bioreactor with mobile bed vs. a stationary basket bioreactor. The process has been considered to occur under substrate and product inhibitory effects. The results indicated that the biore-actor with mobile bed is more efficient for biocatalyst particles with a diameter over 3 mm, while the basket bio-reactor is more efficient for smal er biocatalyst particles and basket bed thickness below 5 mm. The performances of both configurations of immobilized A. succinogenes cell beds were found to be superior to the column packed bed bioreactor.

  5. Fluidized-Bed Waste-Heat Recovery System development. Semiannual report, 1 August 1981-31 January 1982

    Energy Technology Data Exchange (ETDEWEB)

    Cole, W. E.; DeSaro, R.; Joshi, C.

    1982-02-01

    The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is designed to preheat this combustion air using the heat available in dirty flue gas streams. In this system, a recirculating medium is heated by the flue gas in a fluidized bed. The hot medium is then removed from the bed and placed in a second fluidized bed where it is fluidized by the combustion air. Through this process, the combustion air is heated. The cooled medium is then returned to the first bed. Initial development of this concept is for the aluminum smelting industry.

  6. Agglomeration-Free Distributor for Fluidized Beds

    Science.gov (United States)

    Ouyang, F.; Sinica, A.; Levenspiel, O.

    1986-01-01

    New gas distributor for fluidized beds prevents hot particles from reacting on it and forming hard crust. In reduction of iron ore in fluidized bed, ore particles do not sinter on distributor and perhaps clog it or otherwise interfere with gas flow. Distributor also relatively cool. In fluidized-bed production of silicon, inflowing silane does not decompose until within bed of hot silicon particles and deposits on them. Plates of spiral distributor arranged to direct incoming gas into spiral flow. Turbulence in flow reduces frequency of contact between fluidized-bed particles and distributor.

  7. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  8. [Comparative pathology of the microcirculatory bed].

    Science.gov (United States)

    Strukov, A I; Vorob'eva, A A

    1976-11-01

    This paper presents an analysis of publications, mostly by Soviet authores, on clinical studies and morphological examinations of the microcirculatory bed in different pathology. It is concluded that the microcirculatory bed should be regarded as an integral system responding to the pathological effects by a local and general reaction of its structural components and by changing the rheological properties of blood. Two types of changes develop in the microcirculatory system -- sterotyped ones, typical for extreme states (various kinds of shock, hypertensive crisis, stress situations), and those specific for certain diseases (diabetes melitus, essential hypertension, athersclerosis, collagenoses, etc.). In all the above diseases the pathological process affects the functional structures of microcirculation that undergo a rearrangement in accordance with the requirements of the body. In the initial period of the disease this re-arrangement is of a compensatory nature and passes ahead of the clinical manifestations. A comparison of the pictutrs obtained by biomicroscopy of the bulbconjunctiva of the eye and of other mucosae with film preparations of the serosae demonstrates their complete similarity. Therefore, the method of biomicroscopy of the eyeball and of the mucosae as a method reflecting the state of microcirculation in the body as a whole should become an integral part of the clinical examination of patients.

  9. Computational and Experimental Study of Spherocylinder Particles in Fluidized Beds

    Science.gov (United States)

    Mahajan, Vinay; Kuipers, Hans; Padding, Johan; Multiphase Reactors Group, TU Eindhoven Team

    2016-11-01

    Non-spherical particle flows are often encountered in fluidized process equipment. A coupled computational fluid dynamics (CFD) and discrete element method(DEM) approach has been extensively applied in recent years to study these flows at the particle scale. However, most of these studies focus on spherical particles while in reality, the constituent particles are seldom spherical. Particle shape can significantly affect the hydrodynamical response in fluidized beds. The drag force acting on a non-spherical particle can vary considerably with particle shape, orientation of the particle, Reynolds number and packing fraction. In this work, a CFD-DEM approach has been extended to model a lab scale quasi-2D fluidized bed of spherocylinder (rod-like) particles. These particles can be classified as Geldart D particles and have an aspect ratio of 4. Numerical results for the pressure drop, bed height and solid circulation patterns are compared with results from a complementary laboratory experiment. We also present results on particle orientations close to the confining walls, which provides interesting insight regarding the particle alignment. Thus the capability of the CFD-DEM approach to efficiently account for global bed dynamics in fluidized bed of rod-like particle is demonstrated. This research work is funded by ERC Grant.

  10. Investigation on Agropellet Combustion in the Fluidized Bed

    Science.gov (United States)

    Isemin, R. L.; Konayahin, V. V.; Kuzmin, S. N.; Zorin, A. T.; Mikhalev, A. V.

    Agricultural wastes (straw, sunflower or millet husk, etc.) are difficult to use as fuel because of low bulk density and relatively big ash content with a low melting point. It is possible to produce agropellets of agricultural wastes which are suggested to combust in a fluidized bed of pellets alone, their char particles and ash. The characteristics of the process of fluidization of agropellets are investigated at room temperature. The experiments on agropellet combustion in a fluidized bed are carried out in an experimental set-up. The results of the experiments have shown that in such a bed the pellets produced of straw and millet husk combust with the same rate as those of wood though the latter contain 8.76 - 19.4 times less ash. The duration of combustion of the same portion of straw pellets in a fluidized bed is 3.74 - 7.01 times less than the duration of combustion of cut straw in a fixed bed. Besides, the movement of agropellets prevents agglomeration and slagging of a boiler furnace.

  11. Gravity Drainage of Activated Sludge on Reed Beds

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian;

    Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows...... that the compressibility has a high influence on the drainage process especially during the start-up phases where the volumetric load on the sludge bed is critical. The load has to be low in order to ensure that the drainage properties of the bed are not destroyed. The data also shows that transport of activated sludge...

  12. Combustion in fluidized bed reactors; Verbrennung in Wirbelschichtreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Thome-Kozmiensky, Karl J. [vivis CONSULT GmbH, Nietwerder (Germany)

    2013-03-01

    Since the first application for the coal gasification, the fluidized bed technology has passed an impressive development. Nowadays, the fluidized bed technology is utilized at chemical processes, drying and cooling, gasification, combustion and purification of exhaust gas. In the firing technology, the fluidized technology initially has been proved in the combustion of very high ash coal and sewage sludge. Recently, the fluidized bed technology also is applied in the drying of sewage sludge, combustion of domestic waste - as in Japan and Sweden - as well as in the gasification and combustion of substitute fuels, biomass - wood pellets, wood chips, straw, cocoa shells and so forth - and residues from the paper manufacturing - such as in Germany and Austria. Under this aspect, the author of the contribution under consideration reports on the combustion of sewage sludge, substitute fuels and biomass.

  13. ELECTROSTATIC PHENOMENA IN GAS-SOLIDS FLUIDIZED BEDS

    Institute of Scientific and Technical Information of China (English)

    Hsiaotao T. Bi

    2005-01-01

    Electrostatic charges are generated by particle-wall, particle-particle and particle-gas contacts in gas-solids transport lines and fluidized bed reactors. High particle charge densities can lead to particle agglomeration,particle segregation, fouling of reactor walls and internals, leading to undesirable by-product and premature shut-down of processing equipment. In this paper, the charge generation, dissipation and segregation mechanisms are examined based on literature data and recent experimental findings in our laboratory. The particle-wall contact charging is found to be the dominant charge generation mechanism for gas-solids pneumatic transport lines, while bipolar charging due to intimate particle-particle contact is believed to be the dominant charge generation mechanism in gas fluidized beds. Such a bipolar charging mechanism is also supported by the segregation patterns of charged particles in fluidized beds in which highly charged particles tend to concentrate in the bubble wake and drift region behind rising bubbles.

  14. Equilibrium bed-concentration of nonuniform sediment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Knowledge of the equilibrium bed-concentration is vital to mathematical modeling of the river-bed deformation associated with suspended load but previous investigations only dealt with the reference concentration of uniform sediment because of difficulties in observation of the bed-concentration. This work is a first attempt to develop a theoretical formula for the equilibrium bed-concentration of any fraction of nonuniform sediment defined at the bed-surface. The formula is based on a stochastic-mechanistic model for the exchange of nonuniform sediment near the bed, and described as a function of incipient motion probability, non-ceasing probability, pick-up probability, and the ratio of the average single-step continuous motion time to static time. Comparison of bed-concentration calculated from the proposed formula with the measured data showed satisfactory agreement, indicating the present formula can be used for solving the differential equation governing the motion of suspended load.

  15. Process Intensification of VOC Removal from High Viscous Media by Rotating Packed Bed%旋转填充床内高黏介质脱除有机挥发组分过程强化

    Institute of Scientific and Technical Information of China (English)

    李沃源; 毋伟; 邹海魁; 初广文; 邵磊; 陈建峰

    2009-01-01

    The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotating packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer solution with acetone as the volatile compound. The influence of the rotating speed of RPB, liquid viscosity, liquid flow rate, vacuum degree, and initial acetone content in the liquid on acetone removal efficiency was investigated. The experimental results indicated that the removal efficiency increased with increasing rotating speed and initial acetone content in the viscous liquid and decreased with increasing liquid viscosity and flow rate. It was also observed that acetone removal efficiency increased with an increasing vacuum degree and reached 58% at a vacuum degree of 0.1 MPa. By the comparison with a flash tank devolatilizer, it was found that acetone removal efficiency in RPB increased by about 67%.

  16. Feasibility study - Lowered bed temperature in Fluidised Bed boilers for waste; Foerstudie - Saenkt baeddtemperatur i FB-pannor foer avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik

    2009-01-15

    Waste incineration generally serves two purposes; 1) dispose of waste and 2) generation of heat and power. In the process of power production from waste fuels, the steam temperatures in super heaters are generally limited by the severe fouling and corrosion that occurs at elevated material temperatures, caused by high concentrations of alkali metals and chloride in the flue gas and fly ash. The overall aim of a continuation of present project is to determine if a reduced temperature of the bed zone in a fluidized bed waste incinerator reduces the amount of alkali chlorides in the flue gas. If so, a reduced bed temperature might enable increased steam temperature in super heaters, or, at unchanged steam temperature, improve the lifespan of the super heaters. The results from the project are of interest for plant owners wishing to improve performance of existing plants. The results may also be used to modify the design of future plants by boiler manufacturers. The aim of present pre-study was to determine how far the bed temperature can be reduced in a waste fired fluidized bed boiler in Boraas while maintaining a stable operation with sufficient combustion temperature in the freeboard to fulfil the directives of waste incineration. A continuation of the project will be based on the results from present study. The work is based on experiments at the test boiler. During the present study, no other measurements were performed apart from some sampling of bed material and ashes at different modes of operation. The experiments show that it is possible to alter the air and recycled flue gas in such a manner that the bed temperature is reduced from about 870 deg C to 700 deg C at 100% load and normal fuel mixture, while fulfilling the directive of 850 deg C at 2 seconds. Within normal variations of the fuel properties, however, the bed temperature increases to somewhat above 700 deg C if the fuel turns dry, while it falls below 650 deg C when the fuel turns wet. With

  17. The Kaldnes Moving Bed biofilm technology for treatment of industrial wastewater; Tecnologia Kaldnes Moving Bed biofilm (KMT) para la depuracion de aguas residuales industriales

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, V.; Garcia Carrion, M.; Farre Solsona, C.

    2004-07-01

    The Kaldnes Moving bed biofilm technology is a biofilm process which is very suitable for treatment of industrial wastewaters. Biofilm processes have several acknowledged advantages compared to suspended biomass processes, e. g. resistance to toxicity and load variations. Traditionally biofilm processes have been known to clog at high loads and hence have not been suited for industrial effluents: however, the Kaldnes Moving Bed biofilm process has overcome this problem. This article describes how the process has been used as pre-treatment up front of activated sludge at a dairy in USA, and as sole treatment at pharmaceutical industry in Sweden. (Author)

  18. Use of optical probes to characterize bubble behavior in gas-solid fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Mainland, M.E.; Welty, J.R. (Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering)

    1995-02-01

    Optical probes are used to study gas-solid fluidized-bed hydrodynamics. The probes each consisting of a light source and photodetector separated by a gap are suitable for use at combustion-level temperatures. The methodology to process the signal for calculation of bubble properties such as bubble frequency, local bubble residence time, bubble velocity, pierced length, bubble size, and visible bubble flow is presented. The signal processing technique is independent of bed operating conditions. The probe signal processing methodology is validated by comparing calculated bubble properties based on the probe signal with properties observed on videotapes of a 2-D bed.

  19. Entrainment, motion, and deposition of coarse particles transported by water over a sloping mobile bed

    Science.gov (United States)

    Heyman, J.; Bohorquez, P.; Ancey, C.

    2016-10-01

    In gravel bed rivers, bed load transport exhibits considerable variability in time and space. Recently, stochastic bed load transport theories have been developed to address the mechanisms and effects of bed load transport fluctuations. Stochastic models involve parameters such as particle diffusivity, entrainment, and deposition rates. The lack of hard information on how these parameters vary with flow conditions is a clear impediment to their application to real-world scenarios. In this paper, we determined the closure equations for the above parameters from laboratory experiments. We focused on shallow supercritical flow on a sloping mobile bed in straight channels, a setting that was representative of flow conditions in mountain rivers. Experiments were run at low sediment transport rates under steady nonuniform flow conditions (i.e., the water discharge was kept constant, but bed forms developed and migrated upstream, making flow nonuniform). Using image processing, we reconstructed particle paths to deduce the particle velocity and its probability distribution, particle diffusivity, and rates of deposition and entrainment. We found that on average, particle acceleration, velocity, and deposition rate were responsive to local flow conditions, whereas entrainment rate depended strongly on local bed activity. Particle diffusivity varied linearly with the depth-averaged flow velocity. The empirical probability distribution of particle velocity was well approximated by a Gaussian distribution when all particle positions were considered together. In contrast, the particles located in close vicinity to the bed had exponentially distributed velocities. Our experimental results provide closure equations for stochastic or deterministic bed load transport models.

  20. Thin bed responses and correction methods for cased hole density logging

    Institute of Scientific and Technical Information of China (English)

    Wu Wensheng; Zhang Yuling

    2008-01-01

    The study of the thin bed responses and correction methods in cased hole density logging can provide a theoretical basis for research to improve data processing methods. By using the Monte Carlo program MCNP, the change of detector count from thin beds with the vertical depth was calculated at different casing thicknesses. The calculation showed that with the low density thin bed moving upward,detector count first increased to a maximum then decreased. The responses of a thin bed with a high density were opposite to those of a thin bed with a low density. The change curve was symmetrical, and the maximums or minimums appeared at the midpoint between the detector and source. Besides, detector count increased with increasing thin bed thickness. At a specific thin bed thickness, further increase of thin bed thickness resulted in a slow increase of detector count then the count rate leveled off. In actual logging, the influence of adjacent formations on density log measurements can be ignored. Finally, based on numerical simulation correction methods for the dual influence of casing and thin beds are discussed.

  1. Evaluation of cage micro-environment of mice housed on various types of bedding materials

    Science.gov (United States)

    Smith, E.; Stockwell, J.D.; Schweitzer, I.; Langley, S.H.; Smith, A.L.

    2004-01-01

    A variety of environmental factors can affect the outcomes of studies using laboratory rodents. One such factor is bedding. Several new bedding materials and processing methods have been introduced to the market in recent years, but there are few reports of their performance. In the studies reported here, we have assessed the cage micro-environment (in-cage ammonia levels, temperature, and humidity) of mice housed on various kinds of bedding and their combinations. We also compared results for bedding supplied as Nestpaks versus loose bedding. We studied C57BL/6J mice (commonly used) and NOD/LtJ mice (heavy soilers) that were maintained, except in one study, in static duplex cages. In general, we observed little effect of bedding type on in-cage temperature or humidity; however, there was considerable variation in ammonia concentrations. The lowest ammonia concentrations occurred in cages housing mice on hardwood bedding or a mixture of corncob and alpha cellulose. In one experiment comparing the micro-environments of NOD/LtJ male mice housed on woodpulp fiber bedding in static versus ventilated caging, we showed a statistically significant decrease in ammonia concentrations in ventilated cages. Therefore, our data show that bedding type affects the micro-environment in static cages and that effects may differ for ventilated cages, which are being used in vivaria with increasing frequency.

  2. High temperature degradation by erosion-corrosion in bubbling fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Peggy Y.; MacAdam, S.; Niu, Y.; Stringer, J.

    2003-04-22

    Heat-exchanger tubes in fluidized bed combustors (FBCs) often suffer material loss due to combined corrosion and erosion. Most severe damage is believed to be caused by the impact of dense packets of bed material on the lower parts of the tubes. In order to understand this phenomenon, a unique laboratory test rig at Berkeley was designed to simulate the particle hammering interactions between in-bed particles and tubes in bubbling fluidized bed combustors. In this design, a rod shaped specimen is actuated a short distance within a partially fluidized bed. The downward specimen motion is controlled to produce similar frequencies, velocities and impact forces as those experienced by the impacting particle aggregates in practical systems. Room temperature studies have shown that the degradation mechanism is a three-body abrasion process. This paper describes the characteristics of this test rig, reviews results at elevated temperatures and compares them to field experience. At higher temperatures, deposits of the bed material on tube surfaces can act as a protective layer. The deposition depended strongly on the type of bed material, the degree of tube surface oxidation and the tube and bed temperatures. With HCl present in the bed, wastage was increased due to enhanced oxidation and reduced oxide scale adherence.

  3. The odorant receptor co-receptor from the bed bug, Cimex lectularius L.

    Science.gov (United States)

    Hansen, Immo A; Rodriguez, Stacy D; Drake, Lisa L; Price, David P; Blakely, Brittny N; Hammond, John I; Tsujimoto, Hitoshi; Monroy, Erika Y; Maio, William A; Romero, Alvaro

    2014-01-01

    Recently, the bed bug, Cimex lectularius L. has re-emerged as a serious and growing problem in many parts of the world. Presence of resistant bed bugs and the difficulty to eliminate them has renewed interest in alternative control tactics. Similar to other haematophagous arthropods, bed bugs rely on their olfactory system to detect semiochemicals in the environment. Previous studies have morphologically characterized olfactory organs of bed bugs' antenna and have physiologically evaluated the responses of olfactory receptor neurons (ORNs) to host-derived chemicals. To date, odorant binding proteins (OBPs) and odorant receptors (ORs) associated with these olfaction processes have not been studied in bed bugs. Chemoreception in insects requires formation of heteromeric complexes of ORs and a universal OR coreceptor (Orco). Orco is the constant chain of every odorant receptor in insects and is critical for insect olfaction but does not directly bind to odorants. Orco agonists and antagonists have been suggested as high-value targets for the development of novel insect repellents. In this study, we have performed RNAseq of bed bug sensory organs and identified several odorant receptors as well as Orco. We characterized Orco expression and investigated the effect of chemicals targeting Orco on bed bug behavior and reproduction. We have identified partial cDNAs of six C. lectularius OBPs and 16 ORs. Full length bed bug Orco was cloned and sequenced. Orco is widely expressed in different parts of the bed bug including OR neurons and spermatozoa. Treatment of bed bugs with the agonist VUAA1 changed bed bug pheromone-induced aggregation behavior and inactivated spermatozoa. We have described and characterized for the first time OBPs, ORs and Orco in bed bugs. Given the importance of these molecules in chemoreception of this insect they are interesting targets for the development of novel insect behavior modifiers.

  4. The odorant receptor co-receptor from the bed bug, Cimex lectularius L.

    Directory of Open Access Journals (Sweden)

    Immo A Hansen

    Full Text Available Recently, the bed bug, Cimex lectularius L. has re-emerged as a serious and growing problem in many parts of the world. Presence of resistant bed bugs and the difficulty to eliminate them has renewed interest in alternative control tactics. Similar to other haematophagous arthropods, bed bugs rely on their olfactory system to detect semiochemicals in the environment. Previous studies have morphologically characterized olfactory organs of bed bugs' antenna and have physiologically evaluated the responses of olfactory receptor neurons (ORNs to host-derived chemicals. To date, odorant binding proteins (OBPs and odorant receptors (ORs associated with these olfaction processes have not been studied in bed bugs. Chemoreception in insects requires formation of heteromeric complexes of ORs and a universal OR coreceptor (Orco. Orco is the constant chain of every odorant receptor in insects and is critical for insect olfaction but does not directly bind to odorants. Orco agonists and antagonists have been suggested as high-value targets for the development of novel insect repellents. In this study, we have performed RNAseq of bed bug sensory organs and identified several odorant receptors as well as Orco. We characterized Orco expression and investigated the effect of chemicals targeting Orco on bed bug behavior and reproduction. We have identified partial cDNAs of six C. lectularius OBPs and 16 ORs. Full length bed bug Orco was cloned and sequenced. Orco is widely expressed in different parts of the bed bug including OR neurons and spermatozoa. Treatment of bed bugs with the agonist VUAA1 changed bed bug pheromone-induced aggregation behavior and inactivated spermatozoa. We have described and characterized for the first time OBPs, ORs and Orco in bed bugs. Given the importance of these molecules in chemoreception of this insect they are interesting targets for the development of novel insect behavior modifiers.

  5. Design and simulation of a circulating fluidized bed to clean the products of biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Uchoa Neto, Moises; Carvalho, Yuri de Araujo [Dept. de Engenharia Mecanica. Faculdade de Tecnologia. Universidade de Brasilia, DF (Brazil); Oliveira, Taygoara Felamingo de; Barcelos, Manuel [Faculdade do Gama. Universidade de Brasilia, Gama, DF (Brazil)], e-mail: taygoara@unb.br

    2010-07-01

    The main goal of this work is to design a workbench circulating fluidized bed to study the cracking of tar in gases from the processes of biomass gasification. For this, a design methodology based on analytical results and empirical correlations for fluidized beds was employed. In parallel, a numerical code of open source technology (MFIX) for the solution of the transport equations of the multiphase flow in the column of a fluidized bed was used to give support to the choice of the design elements. The whole project of the workbench fluidized bed was completely developed, whose operation parameters such as bed geometry, gas velocity, circulating ratio and void fraction characterize a fast fluidization process. A preliminary mesh convergence study was executed with the numerical tool, that was validated comparing with analytical results. Among the most important results, the code computed the predicted value for the minimum fluidization. (author)

  6. 工业流化床乙烯共聚合生产过程中牌号切换的最优化研究%Study on Optimal Strategy of Grade Transition in Industrial Fluidized Bed Gas-Phase Polyethylene Production Process

    Institute of Scientific and Technical Information of China (English)

    王靖岱; 阳永荣

    2003-01-01

    A model of grade transition is presented for a commercialized fluidized bed gas-phase polyethyleneproduction process. The quantity of off-specification product and the time of grade transition can be minimizedby the optimization of operating variables, such as polymerization temperature, the ratio of hydrogen to ethylene,the ratio of co-monomer to ethylene, feed rate of catalyst, and bed level. A new performance index, the ratio ofmelt flow (MFR), is included in the objective function, for restraining the sharp adjustment of operation variablesand narrowing the distribution of molecular weight of the resin. It is recommended that catalyst feed rate andbed level are decreased in order to reduce the grade transition time and the quantity of off-specification product.This optimization problem is solved by an algorithm of sequential quadratic programming (SQP) in MATLAB.There is considerable difference between the forward transition and reverse transition of grade with regard to theoperating variables due to the non-linearity of the system. The grade transition model is extended to a high spacetime yield (STY) process with the so-called condensed model operation. In the end, an optimization strategy formulti-product transition is proposed with two-level optimization of the objective function J(x, u) on the basis ofthe optimal grade transition model. A sequential transition of six commercial polyethylene grades is illustrated foran optimal multi-product operation.

  7. The Berlin emissivity database (BED)

    Science.gov (United States)

    Maturilli, A.; Helbert, J.; Moroz, L.

    2008-03-01

    Remote-sensing infrared spectroscopy is the principal field of investigation for planetary surfaces composition. Past, present and future missions to the solar system bodies include in their payload, instruments measuring the emerging radiation in the infrared range. Apart from measuring the reflected radiance, more and more spacecrafts are equipped with instruments measuring directly the emitted radiation from the planetary surface. The emitted radiation is not only a function of the composition of the material but also of its texture and especially the grain size distribution. For the interpretation of the measured data an emissivity spectral library of planetary analogue materials in grain size fractions appropriate for planetary surfaces is needed. The Berlin emissivity database (BED) presented here is focused on relatively fine-grained size separates, providing thereby a realistic basis for the interpretation of thermal emission spectra of planetary regoliths. The BED is therefore complimentary to existing thermal emission libraries, like the ASU library for example. BED currently contains emissivity spectra of plagioclase and potassium feldspars, low Ca and high Ca pyroxenes, olivine, elemental sulfur, Martian analogue minerals and volcanic soils, and a lunar highland soil sample measured in the wavelength range from 7 to 22 μm as a function of particle size. For each sample we measured the spectra of four particle size separates ranging from <25 to 250 μm. The device we used is built at DLR (Berlin) and is coupled to a Fourier-transform infrared spectrometer Bruker IFS 88 purged with dry air and equipped with a nitrogen-cooled MCT detector. All spectra were acquired with a spectral resolution of 4 cm -1. We are currently working on upgrading our emissivity facility. A new spectrometer (Bruker VERTEX 80 V) and new detectors will allow us to measure the emissivity of samples in the wavelength range from 1 to 50 μm in a vacuum environment. This will be

  8. [Special beds. Pulmonary therapy system].

    Science.gov (United States)

    Calixto Rodríguez, Joaquín; Rodríguez Martínez, Xavier; Marín i Vivó, Gemma; Paunellas Albert, Josep

    2008-10-01

    To be bedridden reduces one's capacity to move and produces muscular debility that affects the respiratory system leading to a decreased effectiveness in expectoration, the ability to spit up sputum. The pulmonary therapy system integrated in a bed is the result of applying motorized elements to the articulation points of the bad in order to achieve safe positions at therapeutic angles, which improve the breathing-perfusion (blood flow) relationship. This system also makes it possible to apply vibration waves to the patient which favor the elimination of bronchial-pulmonary secretions, the rehabilitation of the bedridden patient and decrease the work load for nursing personnel.

  9. Designing a CR Test bed

    DEFF Research Database (Denmark)

    2014-01-01

    with their own set up, since the potential costs and efforts could not pay back in term of expected research results. Software Defined Radio solutions offer an easy way to communication researchers for the development of customized research test beds. While several hardware products are commercially available......, an overview on common research-oriented software products for SDR development, namely GNU Radio, Iris, and ASGARD, will be provided, including how to practically start the software development of simple applications. Finally, best practices and examples of all the software platforms will be provided, giving...

  10. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Haavisto, I. [Condens Oy, Haemeenlinna (Finland)

    1996-12-31

    Fixed bed biomass gasifiers are feasible in the effect range of 100 kW -10 MW. Co-current gasification is available only up to 1 MW for technical reasons. Counter-current gasifiers have been used in Finland and Sweden for 10 years in gasification heating plants, which are a combination of a gasifier and an oil boiler. The plants have proved to have a wide control range, flexible and uncomplicated unmanned operation and an excellent reliability. Counter-current gasifiers can be applied for new heating plants or for converting existing oil and natural gas boilers into using solid fuels. There is a new process development underway, aiming at motor use of the producer gas. The development work involves a new, more flexible cocurrent gasifier and a cleaning step for the counter-current producer gas. (orig.)

  11. Fluid bed solids heater. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L. C.

    1980-01-01

    A solids heater which operates at up to 2000 F was designed, fabricated, installed and operated through checkout at the Morgantown Energy Technology Center at Morgantown, West Virginia. The system, designated the 2000 F Fluid Bed Solids Heater (FBSH) uses a fluidized bed to heat limestone to 600 F and aluminium oxide or silicon carbide to 2000 F and discharges heated solids upon demand. The FBSH with added valve handling and pressurization equipment is known as the Valve Hot Solids Test Unit and is intended for use by the US Department of Energy for testing of valves for severe service applications in coal conversion and utilization processes. The FBSH as designed and supplied by Combustion Power Company includes process equipment, controls, the enclosing building and other associated equipment. In the 600 F range of operation it can circulate limestone through two valve test trains simultaneously on a continuous basis. Only one valve test train is used for 2000 F solids and operation in that range is also continuous. Limestone, crushed to minus 5/16 size, is heated, discharged, and recycled at a maximum average rate of 250 lb/min while aluminum oxide or silicon carbide, No. 8 grit, is circulated at rates up to 167 lb/min. The FBSH control system is designed for automatic operation, and capability is included for external computerized data acquisition and/or supervisory control. An operating and maintenance manual and as-built drawings have been submitted. This report describes the FBSH equipment, its design basis, and its operation. It has been prepared and submitted in fulfillment of Contract Number DIAC05-77ET10499.

  12. Crystallization process

    Science.gov (United States)

    Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey

    1986-01-01

    An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

  13. Multi-stage circulating fluidized bed syngas cooling

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Guan, Xiaofeng; Peng, WanWang

    2016-10-11

    A method and apparatus for cooling hot gas streams in the temperature range 800.degree. C. to 1600.degree. C. using multi-stage circulating fluid bed (CFB) coolers is disclosed. The invention relates to cooling the hot syngas from coal gasifiers in which the hot syngas entrains substances that foul, erode and corrode heat transfer surfaces upon contact in conventional coolers. The hot syngas is cooled by extracting and indirectly transferring heat to heat transfer surfaces with circulating inert solid particles in CFB syngas coolers. The CFB syngas coolers are staged to facilitate generation of steam at multiple conditions and hot boiler feed water that are necessary for power generation in an IGCC process. The multi-stage syngas cooler can include internally circulating fluid bed coolers, externally circulating fluid bed coolers and hybrid coolers that incorporate features of both internally and externally circulating fluid bed coolers. Higher process efficiencies can be realized as the invention can handle hot syngas from various types of gasifiers without the need for a less efficient precooling step.

  14. The WCSAR telerobotics test bed

    Science.gov (United States)

    Duffie, N.; Zik, J.; Teeter, R.; Crabb, T.

    1988-01-01

    Component technologies for use in telerobotic systems for space are being developed. As part of this effort, a test bed was established in which these technologies can be verified and integrated into telerobotic systems. The facility consists of two slave industrial robots, an articulated master arm controller, a cartesian coordinate master arm controller, and a variety of sensors, displays and stimulators for feedback to human operators. The controller of one of the slave robots remains in its commercial state, while the controller of the other robot has been replaced with a new controller that achieves high-performance in telerobotic operating modes. A dexterous slave hand which consists of two fingers and a thumb is being developed, along with a number of force-reflecting and non-force reflecting master hands, wrists and arms. A tactile sensing finger tip based on piezo-film technology has been developed, along with tactile stimulators and CAD-based displays for sensory feedback and sensory substitution. The telerobotics test bed and its component technologies are described, as well as the integration of these component technologies into telerobotic systems, and their performance in conjunction with human operators.

  15. Effects of Process Conditions on the Mechanical Behavior of Aluminium Wrought Alloy EN AW-2219 (AlCu6Mn Additively Manufactured by Laser Beam Melting in Powder Bed

    Directory of Open Access Journals (Sweden)

    Michael Cornelius Hermann Karg

    2017-01-01

    Full Text Available Additive manufacturing is especially suitable for complex-shaped 3D parts with integrated and optimized functionality realized by filigree geometries. Such designs benefit from low safety factors in mechanical layout. This demands ductile materials that reduce stress peaks by predictable plastic deformation instead of failure. Al–Cu wrought alloys are established materials meeting this requirement. Additionally, they provide high specific strengths. As the designation “Wrought Alloys” implies, they are intended for manufacturing by hot or cold working. When cast or welded, they are prone to solidification cracks. Al–Si fillers can alleviate this, but impair ductility. Being closely related to welding, Laser Beam Melting in Powder Bed (LBM of Al–Cu wrought alloys like EN AW-2219 can be considered challenging. In LBM of aluminium alloys, only easily-weldable Al–Si casting alloys have succeeded commercially today. This article discusses the influences of boundary conditions during LBM of EN AW-2219 on sample porosity and tensile test results, supported by metallographic microsections and fractography. Load direction was varied relative to LBM build-up direction. T6 heat treatment was applied to half of the samples. Pronounced anisotropy was observed. Remarkably, elongation at break of T6 specimens loaded along the build-up direction exceeded the values from literature for conventionally manufactured EN AW-2219 by a factor of two.

  16. Application of transfer functions to canned tuna fish thermal processing.

    Science.gov (United States)

    Ansorena, M R; del Valle, C; Salvadori, V O

    2010-02-01

    Design and optimization of thermal processing of foods need accurate dynamic models to ensure safe and high quality food products. Transfer functions had been demonstrated to be a useful tool to predict thermal histories, especially under variable operating conditions. This work presents the development and experimental validation of a dynamic model (discrete transfer function) for the thermal processing of tuna fish in steam retorts. Transfer function coefficients were obtained numerically, using commercial software of finite elements (COMSOL Multiphysics) to solve the heat transfer balance. Dependence of transfer function coefficients on the characteristic dimensions of cylindrical containers (diameter and height) and on the sampling interval is reported. A simple equation, with two empirical parameters that depends on the container dimensions, represented the behavior of transfer function coefficients with very high accuracy. Experimental runs with different size containers and different external conditions (constant and variable retort temperature) were carried out to validate the developed methodology. Performance of the thermal process simulation was tested for predicting internal product temperature of the cold point and lethality and very satisfactory results were found. The developed methodology can play an important role in reducing the computational effort while guaranteeing accuracy by simplifying the calculus involved in the solution of heat balances with variable external conditions and emerges as a potential approach to the implementation of new food control strategies leading not only to more efficient processes but also to product quality and safety.

  17. Fluidized bed spray granulation: analysis of heat and mass transfers and dynamic particle populations

    Directory of Open Access Journals (Sweden)

    S. Heinrich

    2005-06-01

    Full Text Available A model was developed taking into consideration the heat and mass transfer processes in liquid-sprayed fluidized beds. Such fluidized beds (FB are used for granulation, coating and agglomeration. Conclusions are drawn on the relevance of particle dispersion, spraying and drying to temperature and concentrations distributions. In extension, the model was coupled with a population balance model to describe the particle size distribution and the seeds formation for continuous external FBSG (fluidized bed spray granulation with non-classifying product discharge and a screening and milling unit in the seeds recycle. The effects of seeds formation on the stability of the process is discussed.

  18. ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

    2000-03-31

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000 F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost

  19. ADVANCED SORBENT DEVELOPMENT PROGRAM; DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    AYALA, R E; VENKATARAMANI, V S

    1998-09-30

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 °C (900-1000 °F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 °C (650 °F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 °C (650-1000 °F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a

  20. CERTS Microgrid Laboratory Test Bed

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joe; Lasseter, Robert; Schenkman, Ben; Stevens, John; Klapp, Dave; Volkommer, Harry; Linton, Ed; Hurtado, Hector; Roy, Jean

    2009-06-18

    The objective of the CERTS Microgrid Test Bed project was to enhance the ease of integrating energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of generating sources less than 100kW. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation, islanding the microgrid's load from a disturbance, thereby maintaining a higher level of service, without impacting the integrity of the utility's electrical power grid; 2) an approach to electrical protection within a limited source microgrid that does not depend on high fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications between sources. These techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations,and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers Standard 1547 and power quality requirements. The electrical protection system was able to distinguish between normal and faulted operation. The controls were found to be robust under all conditions, including difficult motor starts and high impedance faults. The results from these tests are expected to lead to additional testing of enhancements to the basic techniques at the test bed to improve the business case for microgrid technologies, as well to field

  1. C. elegans BED domain transcription factor BED-3 controls lineage-specific cell proliferation during organogenesis

    OpenAIRE

    Inoue, Takao; Sternberg, Paul W.

    2010-01-01

    The control of cell division is critical to organogenesis, but how this control is achieved is not fully understood. We found that mutations in bed-3, encoding a BED Zn-finger domain transcription factor, confer a phenotype where a specific set of cell divisions during vulval organogenesis is lost. Unlike general cell cycle regulators in Caenorhabditis elegans, the function of bed-3 is restricted to specific lineages. Transcriptional reporters suggest that bed-3 is expressed in a limited numb...

  2. Comprehensive Mathematical Model for Coal Combustion in a Circulating Fluidized Bed Combustor

    Institute of Scientific and Technical Information of China (English)

    金晓钟; 吕俊复; 杨海瑞; 刘青; 岳光溪; 冯俊凯

    2001-01-01

    Char combustion is on a special reducing condition in the dense bed of a circulating fluidized bedcombustor. Experimental findings were used to develop a comprehensive mathematical model to simulate thehydrodynamic and combustion processes in a circulating fluidized bed combustor. In the model, gas-solidinteraction was used to account for the mass transfer between the bubble phase and the emulsion phase in thedense bed, which contributes to the reducing atmosphere in the dense bed. A core-annular structure wasassumed in the dilute area rather than a one-dimensional model. The submodels were combined to build thecomprehensive model to analyze the combustion in a circulating fluidized bed combustor and the effect ofoperating parameters on the coal combustion. The model predictions agree well with experimental results.

  3. Non-intrusive measurement and hydrodynamics characterization of gas–solid fluidized beds: a review

    OpenAIRE

    Sun, Jingyuan; Yan, Yong

    2016-01-01

    Gas-solid fluidization is a well-established technique to suspend or transport particles and has been applied in a variety of industrial processes. Nevertheless, our knowledge of fluidization hydrodynamics is still limited for the design, scale-up and operation optimization of fluidized bed reactors. It is therefore essential to characterize the two-phase flow behaviours in gas-solid fluidized beds and monitor the fluidization processes for control and optimization. A range of non-intrusive t...

  4. Oil Sludge Treatment in Oil Shale Retorting Process%油母页岩干馏生产过程中的油泥处理

    Institute of Scientific and Technical Information of China (English)

    何红梅

    2009-01-01

    研究了在油母页岩干馏生产各个过程中的油泥的来源及其特点,利用废甲苯进行萃取、热碱水进行洗脱,处理回收页岩油.页岩油的回收率与碳酸钠的质量浓度、废甲苯的质量以及处理温度有关.把处理后的油泥渣与页岩粉尘、固硫剂等进行搅拌混合后压碇成型,经干燥后,进行低温干馏生产,从而实现油泥的资源化、无害化处理.

  5. A first classification scheme of flow-bed interaction for clay-laden density currents and soft substrates

    Science.gov (United States)

    Verhagen, Iris Thérèse Elise; Baas, Jaco Hugo; Jacinto, Ricardo Silva; McCaffrey, William Dale; Davies, Alan Geoffrey

    2013-04-01

    Many aquatic environments exhibit soft, muddy substrates, but this important property has largely been ignored in process-based models of Earth-surface flow. Novel laboratory experiments were carried out to shed light on the feedback processes that occur when particulate density currents (turbidity currents) move over a soft mud substrate. These experiments revealed multiple types of flow-bed interaction and large variations in bed deformation and bed erosion, which are interpreted to be related to the interplay between the shear forces of the current and the stabilising forces in the bed. Changes in this force balance were simulated by varying the clay concentrations in the flow and in the bed. Five different interaction types are described, and dimensional and non-dimensional phase diagrams for flow-bed interaction are presented.

  6. Fluidized bed coal combustion reactor

    Science.gov (United States)

    Moynihan, P. I.; Young, D. L. (Inventor)

    1981-01-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  7. CERTS Microgrid Laboratory Test Bed

    Energy Technology Data Exchange (ETDEWEB)

    ETO, J.; LASSETER, R.; SCHENKMAN, B.; STEVENS, J.; KLAPP, D.; VOLKOMMER, H.; LINTON, E.; HURTADO, H.; ROY, J.

    2010-06-08

    The objective of the CERTS Microgrid Test Bed project was to enhance the ease of integrating energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of generating sources less than 100kW. The techniques comprising the CERTS Microgrid concept are: 1 a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation, islanding the microgrid's load from a disturbance, thereby maintaining a higher level of service, without impacting the integrity of the utility's electrical power grid; 2 an approach to electrical protection within a limited source microgrid that does not depend on high fault currents; and 3 a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications between sources.

  8. Metabolic Resistance in Bed Bugs

    Directory of Open Access Journals (Sweden)

    Omprakash Mittapalli

    2011-03-01

    Full Text Available Blood-feeding insects have evolved resistance to various insecticides (organochlorines, pyrethroids, carbamates, etc. through gene mutations and increased metabolism. Bed bugs (Cimex lectularius are hematophagous ectoparasites that are poised to become one of the major pests in households throughout the United States. Currently, C. lectularius has attained a high global impact status due to its sudden and rampant resurgence. Resistance to pesticides is one factor implicated in this phenomenon. Although much emphasis has been placed on target sensitivity, little to no knowledge is available on the role of key metabolic players (e.g., cytochrome P450s and glutathione S-transferases towards pesticide resistance in C. lectularius. In this review, we discuss different modes of resistance (target sensitivity, penetration resistance, behavioral resistance, and metabolic resistance with more emphasis on metabolic resistance.

  9. Improving Operability of Lab-Scale Spouted Bed Using Global Stochastic Optimization

    Directory of Open Access Journals (Sweden)

    Dr.Ghanim.M. Alwan

    2015-01-01

    Full Text Available A spouted bed is a special case of fluidization. It is an effective means of contacting gas with coarse solid particles .Gas-solid spouted beds are either cylindrical bed with cone base or the whole bed is in a cone shape where the gas enters as a jet. The gas forms a spout region that carries the solids upward in a diluted phase that forms a fountain at the top of the bed where the solids fall down and move downward in the annular region. Performance of gas-solid spouted bed benefit from solids uniformity structure with lower pressure drop (PD.Dropping of PD across a spouted bed could reduce the dissipated pumping energy and improve stability and uniformity of solid particles. The objective of this work is to study and selecting best operating conditions that could minimize PD across the bed. Optimization technique is a powerful tool would guide the experimental work and reduce the risk and cost for design and operation Hence, PD is to be considered as objective function of the optimization process .Three selected decision variables are affecting objective function. These decision variables are gas velocity, particle density and particle diameter. Steady-state measurements were carried out in a narrow 3-inch (0.076 m ID cylindrical spouted bed made of Plexiglas that used 60° conical shape base. Radial concentration of particles (glass and steel beads at various bed heights under different flow patterns were measured using sophisticated optical probes. A superficial velocity of air ranging from 0.74 to 1.0 m/s .PD was measured across the bed by high accuracy pressure transducers. Stochastic Genetic Algorithm (GA has found suitable global search for the non-linear hybrid spouted bed. Optimum results could select the best operating conditions for high-performance and stable conditions. Uniformity and stability of solid particles in the bed would enhance hydrodynamic parameters, heat and mass transfer. Best Operability of the bed was observed with

  10. Pulsed atmospheric fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  11. The conundrum of coal bed thickness: a theory for stacked mire sequences

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, J.C.; Staub, J.R.; Moore, T.A. (Geological Survey of Wyoming, Laramie, WY (United States))

    1994-09-01

    Maximum thicknesses for modern peats have been documented only up to about 20 m, whereas coal beds can often be as much as 90 m thick. Since peat is expected to compact appreciably during burial, there appears to be no modern analogue for the processes which formed thick coal beds, and this seems to challenge the Law of Uniformitarianism. However, the conundrum of coal bed thickness can be resolved by identification of discontinuities in coal beds. Coal beds are generally treated as single entities, created by a continuous process of peat deposition. It is more likely, however, that most thick coal beds are composed of multiple paleo-peat bodies, stacked one upon another, rather than a single paleo-peat body. it is suggested that there are three types of bounding surfaces seen in modern peat bodies that can be used to distinguish individual paleo-peats in coal beds; these bounding surfaces can be recognized both in the field and microscopically. Each of these surfaces represents cessation, or at least extreme slowing, of peat deposition. The presence of these surfaces, and thus stacked mire sequences, in modern and ancient equivalents shows that processes in peat bodies have been similar through time and therefore do not challenge the Law of Uniformitarianism.

  12. A conceptual framework for shear flow-induced erosion of soft cohesive sediment beds

    Science.gov (United States)

    Winterwerp, J. C.; van Kesteren, W. G. M.; van Prooijen, B.; Jacobs, W.

    2012-10-01

    This paper proposes a conceptual framework for erosion of cohesive sediment beds. We focus on cohesive beds, distinguishing between floc erosion, surface erosion, and mass erosion. By (our) definition, surface erosion is a drained soil mechanical process, whereas mass erosion occurs under undrained conditions. The eroding shear stress is modeled through a probability density function. This yields a continuous description of floc erosion and surface erosion as a function of mean bed shear stress. Furthermore, we assume a distribution for the bed strength. The mean values of the bed strength are derived from soil mechanical theory, assuming that the surface erosion rate is limited by the swelling rate from the undrained shear strength in the bed to its drained value at its surface. The rate of erosion then relates to the undrained shear strength of the soil, and its consolidation (swelling) coefficient. The critical shear stress for erosion is slightly larger than the true cohesion of the bed, i.e., the drained strength, and follows a power law relation with the plasticity index. The conceptual framework proposed herein has been validated against a limited number of experimental data, and has a series of advantages above other methods of direct measuring erodibility, as it is inexpensive and can be used to attain space-covering information on the sediment bed. Moreover, the use of bulk soil mechanical parameters accounts implicitly for the effects of organic material, though the role of, e.g., macrophytobenthos mats and/or bioturbation is difficult to capture a priori.

  13. Method for using fast fluidized bed dry bottom coal gasification

    Science.gov (United States)

    Snell, George J.; Kydd, Paul H.

    1983-01-01

    Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

  14. Water softening by induced crystallization in fluidized bed.

    Science.gov (United States)

    Chen, Yuefang; Fan, Rong; An, Danfeng; Cheng, Yujie; Tan, Hazel

    2016-12-01

    Fluidized bed and induced crystallization technology were combined to design a new type of induced crystallization fluidized bed reactor. The added particulate matter served as crystal nucleus to induce crystallization so that the insoluble material, which was in a saturated state, could precipitate on its surface. In this study, by filling the fluidized bed with quartz sand and by adjusting water pH, precipitation of calcium carbonate was induced on the surface of quartz sand, and the removal of water hardness was achieved. With a reactor influent flow of 60L/hr, a fixed-bed height of 0.5m, pH value of 9.5, quartz sand nuclear diameter of 0.2-0.4mm, and a reflux ratio of 60%, the effluent concentration of calcium hardness was reduced to 60mg/L and 86.6% removal efficiency was achieved. The resulting effluent reached the quality standard set for circulating cooling water. Majority of the material on the surface of quartz sand was calculated to be calcium carbonate based on energy spectrum analysis and moisture content was around 15.994%. With the low moisture content, dewatering treatment is no longer required and this results to cost savings on total water treatment process.

  15. Packed bed heat storage: Continuum mechanics model and validation

    Science.gov (United States)

    Knödler, Philipp; Dreißigacker, Volker; Zunft, Stefan

    2016-05-01

    Thermal energy storage (TES) systems are key elements for various types of new power plant concepts. As possible cost-effective storage inventory option, packed beds of miscellaneous material come into consideration. However, high technical risks arise due to thermal expansion and shrinking of the packed bed's particles during cyclic thermal operation, possibly leading to material failure. Therefore, suitable tools for designing the heat storage system are mandatory. While particle discrete models offer detailed simulation results, the computing time for large scale applications is inefficient. In contrast, continuous models offer time-efficient simulation results but are in need of effective packed bed parameters. This work focuses on providing insight into some basic methods and tools on how to obtain such parameters and on how they are implemented into a continuum model. In this context, a particle discrete model as well as a test rig for carrying out uniaxial compression tests (UCT) is introduced. Performing of experimental validation tests indicate good agreement with simulated UCT results. In this process, effective parameters required for a continuous packed bed model were identified and used for continuum simulation. This approach is validated by comparing the simulated results with experimental data from another test rig. The presented method significantly simplifies subsequent design studies.

  16. Nonlinear dynamical characteristics of bed load motion

    Institute of Scientific and Technical Information of China (English)

    BAI; Yuchuan; XU; Haijue; XU; Dong

    2006-01-01

    Bed forms of various kinds that evolve naturally on the bottom of sandy coasts and rivers are a result of the kinematics of bed load transport. Based on the group motion of particles in the bed load within the bottom layer, a study on the nonlinear dynamics of bed load transport is presented in this paper. It is found that some development stages, such as the initiation, the equilibrium sediment transport, and the transition from a smooth bed to sand dunes, can be accounted for by different states in the nonlinear system of the bed load transport. It is verified by comparison with experimental data reported by Laboratoire Nationae D'Hydraulique, Chatou, France, that the evolution from a smooth bed to sand dunes is determined by mutation in the bed load transport. This paper presents results that may offer theoretical explanations to the experimental observations. It is also an attempt to apply the state-of-the-art nonlinear science to the classical sediment transport mechanics.

  17. Hipparions of the Laetolil Beds, Tanzania

    NARCIS (Netherlands)

    Hooijer, D.A.

    1979-01-01

    The Laetolil Beds in Tanzania, 20-30 miles south of Olduvai Gorge, have been extensively sampled by parties under the leadership of Mrs. Dr. Mary D. Leakey, who very kindly sent me Hipparion material collected in 1974, 1975, and 1976. In a restudy of proboscidean material from these beds described b

  18. Bed-levelling experiments with suspended load

    NARCIS (Netherlands)

    Talmon, A.M.; De Graaff, J.

    1991-01-01

    Bed-levelling experiments are conducted in a straight laboratory channel. The experiments involve a significant fraction of suspended sediment transport. The purpose of the experiments is to provide data for modelling of the direction of sediment transport on a transverse sloping alluvial river bed,

  19. International Standardization of Bed Rest Standard Measures

    Science.gov (United States)

    Cromwell, Ronita L.

    2010-01-01

    This slide presentation gives an overview of the standardization of bed rest measures. The International Countermeasures Working Group attempted to define and agree internationally on standard measurements for spaceflight based bed rest studies. The group identified the experts amongst several stakeholder agencys. It included information on exercise, muscle, neurological, psychological, bone and cardiovascular measures.

  20. Effective Thermal Conductivity of Adsorbent Packed Beds

    Science.gov (United States)

    Mori, Hideo; Hamamoto, Yoshinori; Yoshida, Suguru

    The effective thermal conductivity of adsorbent packed beds of granular zeolite 13X and granular silica gel A in the presence of stagnant steam or air was measured under different conditions of the adsorbent bed temperature, particle size and filler-gas pressure. The measured effective thermal conductivity showed to become smaller with decreasing particle size or decreasing pressure, but it was nearly independent of the bed temperature. When steam was the filler-gas, the rise in the thermal conductivity of the adsorbent particles due to steam adsorption led to the increase in the effective thermal conductivity of the bed, and this effect was not negligible at high steam pressure for the bed of large particle size. It was found that both the predictions of the effective thermal conductivity by the Hayashi et al.'s model and the Bauer-Schlünder model generally agreed well with the measurements, by considering the particle thermal conductivity rise due to steam adsorption. The thermal conductivity of a consolidated bed of granular zeolite 13X was also measured, and it was found to be much larger than that of the packed bed especially at lower pressure. The above prediction models underestimated the effective thermal conductivity of the consolidated bed.

  1. Gruppebaseret behandling af BED - et faseopdelt behandlingstilbud

    DEFF Research Database (Denmark)

    Laust, Jakob; Lau, Marianne Engelbrecht; Waaddegaard, Mette

    2015-01-01

    konsekvenser. BED blev i 2013 optaget i DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) som en selvstændig diagnose og BED forventes medtaget i den forestående revision af det internationale diagnose system, ICD-11. Sundhedsstyrelsen gav på denne baggrund satspuljemidler til erfaringsopsamling...

  2. Particle pressures in fluidized beds. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, C.S.; Rahman, K.; Jin, C.

    1996-09-01

    This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction), they impart to the bed. So rather than directly measure the particle pressure, the authors inferred the values of the elasticity from measurements of instability growth in liquid beds; the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined) and then working backwards to determine the unknown coefficients, including the elasticity.

  3. Particle Pressures in Fluidized Beds. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, C.S.; Rahman, K.; Jin, C.

    1996-09-01

    This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction): they impart to the bed. So rather than directly measure the particle pressure, we inferred the values of the elasticity from measurements of instability growth in liquid beds the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined)and then working backwards to determine the unknown coefficients, including the elasticity.

  4. Determination of true bed thickness using folded bed model and borehole data

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.S.; Velasquillo-Martinez, L.G.; Grajales-Nishimura, J.M.; Murillo-Muneton, G. [Inst. Mexicano del Petroleo, Mexico City (Mexico); Garcia-Hernandez, J. [Petroleos Mexicanos Exploracion y Produccion, Tamaulipas (Mexico); Nieto-Samaniego, A.F. [Nacional Autonoma de Mexico Univ., Veracruz (Mexico). Centro de Geociencias

    2007-11-15

    The actual thickness of a given formation perpendicular to the bedding plane is known as the true bed thickness. Petroleum engineers rely on information regarding true bed thickness, particularly in dipping beds and in deviated holes because reservoir volume and isochore maps depend on these properties and not on the measured thickness. True bed thickness can be estimated from information gathered from well logs such as the dipmeter and borehole images. However, when deviations and dips exceed 10 degrees, corrections are needed. In this paper, a folded bed model was proposed to calculate the true bed thickness in the subsurface utilizing well log data. The value of true bed thickness (t) was shown to depend on the angle and the direction of the dip of the measured formation, as well as the drift angle and azimuth of the borehole. A case study from the Cantarell oil field in the southern Gulf of Mexico, offshore Campeche, was used to test the folded bed method. The model was shown to yield more uniform spatial change of the values of t, compared to the monoclinal bed model that often overestimates the average value of t. The maximum relative deviation of t from the monoclinal bed model reached 22.3 per cent and the maximum absolute deviation of t reached 34.5 m. The key factors that influence the values of t were found to be the bed dip, the dip difference between the top and base of the bed and the deviated angle of the well. The folded bed model yielded fewer changed values of the true bed thickness. 10 refs., 2 tabs., 9 figs.

  5. Spatial and Temporal Patterns of Bed Mobility Revealed Through the Use of Hydrodynamic Modeling and Motion-Sensing Radio Tagged Particles in a Large Gravel-Bed River

    Science.gov (United States)

    May, C. L.; Smith Pryor, B.; Lisle, T. E.; Lang, M. M.

    2010-12-01

    Flow conditions that initiate bedload transport, and an understanding of the spatial and temporal variability in bed mobility, provide important insight into the dynamics of riverine habitat. However, quantifying these processes at the reach scale has been elusive, especially in large river systems. Our approach coupled hydrodynamic modeling and empirical measures of bed mobility based on traditional tracers and motion-sensing radio tagged particles to determine flow conditions at initial motion and the spatial extent of bed mobility in the Trinity River of northern California. High-resolution bathymetric surveying and grain size measurements were used as input for hydrodynamic modeling. A narrow band Acoustic Doppler Profiler positioned using a Real Time Kinematic global positioning system provided separate calibration and validation data during flood events. Model-predicted Shields stress identified spatially explicit zones of differential bed mobility and indicated that a potential zone of full mobility was limited to a central core that expanded with increasing flow strength. Model-predicted zones of full mobility were well validated by patches of traditional painted rock tracer particles. In addition to traditional tracers, motion-sensing radio tagged particles were used to identify the timing of initial motion. By simultaneously measuring discharge, and modeling bed forces at that discharge, shear stress at initial motion was calculated. These calculations revealed that initial motion of bed particles varied substantially between flood events. Temporal variability in the distribution of critical shear stress suggests that the sequence of flood events is an important determinant of bed strength and, thus, resistance to motion. The combined use of high-resolution instrumentation and flow modeling revealed important insight into the importance of bed conditioning by previous floods on bed mobility.

  6. Internal circulating fluidized bed incineration system and design algorithm.

    Science.gov (United States)

    Tian, W D; Wei, X L; Li, J; Sheng, H Z

    2001-04-01

    The internal circulating fluidized bed (ICFB) system is characterized with fast combustion, low emission, uniformity of bed temperature and controllability of combustion process. It is a kind of novel clean combustion system, especially for the low-grade fuels, such as municipal solid waste (MSW). The experimental systems of ICFB with and without combustion were designed and set up in this paper. A series of experiments were carried out for further understanding combustion process and characteristics of several design parameters for MSW. Based on the results, a design routine for the ICFB system was suggested for the calculation of energy balance, airflow rate, heat transfer rate, and geometry arrangement. A test system with ICFB combustor has been set up and the test results show that the design of the ICFB system is successful.

  7. Internal circulating fluidized bed system and design algorithm

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The internal circulating fluidized bed (ICFB) system ischaracterized with fast combustion, low emission, uniformity of bed temperature and controllability of combustion process. It is a kind of novel clean combustion system, especially for the low-grade fuels, such as municipal solid waste(MSW). The experimental systems of ICFB with and without combustion were designed and set up in this paper. A series of experiments were carried out for further understanding combustion process and characteristics of several design parameters for MSW. Based on the results, a design routine for the ICFB system was suggested for the calculation of energy balance, airflow rate, heat transfer rate, and geometry arrangement. A test system with ICFB combustor has been set up and the test results show that the design of the ICFB system issuccessful.

  8. Does Bedding Affect the Airway and Allergy?

    Directory of Open Access Journals (Sweden)

    J Crane

    2011-03-01

    Full Text Available Various cross-sectional and longitudinal studies have suggested that synthetic bedding is associated with asthma, allergic rhinitis and eczema while feather bedding seems to be protective. Synthetic bedding items have higher house dust mite allergen levels than feather bedding items. This is possibly the mechanism involved although fungal and bacterial proinflammatory compounds and volatile organic compounds may play a role. In this review we present and discuss the epidemiological evidence and suggest possible mechanisms. Primary intervention studies are required to show whether feather bedding is protective for the development of childhood asthma and allergic diseases while secondary intervention studies are required to potentially reduce symptoms and medication use in subjects with established disease.

  9. Incipient motion of gravel and coal beds

    Indian Academy of Sciences (India)

    Subhasish Dey; Uddaraju V Raju

    2002-10-01

    An experimental study on incipient motion of gravel and coal beds under unidirectional steady-uniform flow is presented. Experiments were carried out in a flume with various sizes of gravel and coal samples. The critical bed shear stresses for the experimental runs determined using side-wall correction show considerable disagreement with the standard curves. The characteristic parameters affecting the incipient motion of particles in rough-turbulent regime, identified based on physical reasoning and dimensional analysis, are the Shields parameter, particle Froude number, non-dimensional particle diameter and non-dimensional flow depth. Equations of critical bed shear stress for the initial movement of gravel and coal beds were obtained using experimental data. The method of application of critical bed shear stress equations is also mentioned.

  10. 四种石油污染土壤生物修复技术研究%Bioremediation on 4 Soils Contaminated by Petroleum Oils Using Prepared Bed Processes

    Institute of Scientific and Technical Information of China (English)

    张海荣; 李培军; 孙铁珩; 姜昌亮; 许华夏; 张春桂; 马学军; 姚德明

    2001-01-01

    In this investigation, the soils contaminated by crude oil fromLiaohe Oil Field were treated using prepared bed bioremediation technology. The results showed that degrading rate of TPHs were reached 38%—60% after 84 days treatment, when the concentrations of total petroleum hydrocarbons (TPHs) in soils were in a range of 25.8 g·kg-1 —77.2 g·kg-1. It was found that the composition of the oils greatly affected the degradation rate, having a degradation order of different oils as pollutants in soils with: thin oil > high condensed oil > thick oil > extremely thick oil. It has been indicated that the bioremediation of soil contaminated by oil is a practical technology.%在实验室小试和现场中试的基础上,采用预制床处理工艺对辽河油田4种不同类型石油污染土壤进行实用规模的生物处理技术研究。工程运行结果表明,当稀油、稠油、特稠油和高凝油污染土壤中石油烃总量(TPH)为25.8—77.2g.kg-1时,经过84d的运行,TPH去除率为38%—60%。TPH的降解速率除与微生物的生长环境有关外还与石油的理化性质密切相关。4种油污染土壤的降解速率依次为:稀油>高凝油>稠油>特稠油,TPH的组分对其降解速率有重要影响。本研究为大规模石油污染土壤异位生物修复提供了技术支持

  11. A Comparison of Cast-in-situ Bored Pile Construction Process in Pebble Bed%卵石层中钻孔灌注桩施工工艺比较

    Institute of Scientific and Technical Information of China (English)

    张波; 温玉启

    2013-01-01

      兰州市深安黄河大桥基础为钻孔灌注桩,地质条件以卵石层为主,桩端不入岩层。采用传统的冲击钻机成孔,施工效率低下,故较小桩径的钻孔桩采用旋挖钻机成孔,施工效率高,且无大功率用电需求。但旋挖钻机成孔后的孔壁相对不够稳定,施工阶段应遵循“三快”原则,即“快成孔、快下笼、快灌桩”,从而有效地控制成桩质量,尤其是沉渣厚度。通过2种钻机成桩后的检测及试验报告,以实际数值为依据,阐述了2种钻机在卵石层地质条件成孔的优缺点。%  The pile foundation of Lanzhou Shen’an Yellow River Bridge engineering is cast-in-situ bored pile with the engineering geological conditions of pebble layer in the main and the pile tip no entering the rock stratum. The work efficiency of drilling by the traditional percussive drilling machine will be low, while the work efficiency of rotary drilling machine will be higher when drilling the smaller diameter pile hole, and without large power electric. But the pile hole drilled by rotary drilling machine is instable. To control the construction quality, especially, the thickness of sediment, the principle of the Three Fast must be obeyed during the operation, that is, drilling the pile hole must be fast; placing the steel cage must be fast; pouring pile must be fast. According to the detection & test reports on the two drilling machines and the actual data, the advantages & disadvantages of the two drilling machines working in the pebble bed are discussed in detail.

  12. SEWAGE SLUDGE COMBUSTION IN A SPOUTED BED CASCADE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Mirko Barz

    2003-01-01

    @@ In modern society, sewage is disposed of in a two-step process: it is first made into granules and the sewage sludge granules are then burned in an appropriate combustor. The present paper describes a spouted bed cascade system for sewage sludge combustion developed at the Technical University of Berlin at the turn of the present century. Combustion results in the recovery of the combustible matters of the sewage in the form of thermal energy.

  13. Spectral methods applied to fluidized bed combustors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Christofides, N.J.; Junk, K.W.; Raines, T.S.; Thiede, T.D.

    1996-08-01

    The objective of this project was to develop methods for characterizing fuels and sorbents from time-series data obtained during transient operation of fluidized bed boilers. These methods aimed at determining time constants for devolatilization and char burnout using carbon dioxide (CO{sub 2}) profiles and from time constants for the calcination and sulfation processes using CO{sub 2} and sulfur dioxide (SO{sub 2}) profiles.

  14. Investigation of debris bed formation, spreading and coolability

    Energy Technology Data Exchange (ETDEWEB)

    Kudinov, P.; Konovalenko, A.; Grishchenko, D.; Yakush, S.; Basso, S.; Lubchenko, N.; Karbojian, A. [Royal Institute of Technology, KTH. Div. of Nuclear Power Safety, Stockholm (Sweden)

    2013-08-15

    The work is motivated by the severe accident management strategy adopted in Nordic type BWRs. It is assumed that core melt ejected from the vessel will fragment, quench and form a coolable debris bed in a deep water pool below the vessel. In this work we consider phenomena relevant to the debris bed formation and coolability. Several DEFOR-A (Debris Bed Formation - Agglomeration) tests have been carried out with new corium melt material and a melt releasing nozzle mockup. The influence of the melt material, melt superheat, jet free fall height on the (i) faction of agglomerated debris, (ii) particle size distribution, (iii) ablation/plugging of the nozzle mockup has been addressed. Results of the DECOSIM (Debris Coolability Simulator) code validation against available COOLOCE data are presented in the report. The dependence of DHF on system pressure from COOLOCE experiments can be reproduced quite accurately if either the effective particle diameter or debris bed porosity is increased. For a cylindrical debris bed, good agreement is achieved in DECOSIM simulations for the particle diameter 0.89 mm and porosity 0.4. The results obtained are consistent with MEWA simulation where larger particle diameters and porosities were found to be necessary to reproduce the experimental data on DHF. It is instructive to note that results of DHF prediction are in better agreement with POMECO-HT data obtained for the same particles. It is concluded that further clarification of the discrepancies between different experiments and model predictions. In total 13 exploratory tests were carried out in PDS (particulate debris spreading) facility to clarify potential influence of the COOLOCE (VTT) facility heaters and TCs on particle self-leveling process. Results of the preliminary analysis suggest that there is no significant influence of the pins on self-leveling, at least for the air superficial velocities ranging from 0.17 up to 0.52 m/s. Further confirmatory tests might be needed

  15. Novel designs of fluidized bed combustors for low pollutant emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.; Bleek, C.M. van den [Delft Univ. of Technology (Netherlands). Dept. of Chemical Engineering; Dam-Johansen, K. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

    1995-12-31

    It is known that NH{sub 3}, released during the devolatilization of fuel, is an important precursor for NO formation in fluidized bed combustors. On the other hand, NH{sub 3} may be used as a reducing agent in the thermal DeNO{sub x} process to reduce NO{sub x} emission levels. In this paper, a new concept of fluidized bed combustors is proposed based on the idea of in situ reduction of NO{sub x} by self-produced NH{sub 3} from fuel without lowering the sulfur capture level. This design is intended to separate the NH{sub 3} release process under reducing conditions from the char combustion process under oxidizing conditions; this self-released NH{sub 3}, together with some combustibles, is mixed with gaseous combustion products in the upper part of the combustor for a further reduction of the NO{sub x} formed during combustion. Furthermore, the combustion of the combustibles may cause the temperature to rise in this upper zone and thereby reduce the emission of N{sub 2}O. The applications of this design to bubbling and circulating fluidized bed combustors are described and the mechanisms of the main reactions involved discussed.

  16. DEGRADATION OF AROMATIC COMPOUNDS USING MOVING BED BIOFILM REACTORS

    Directory of Open Access Journals (Sweden)

    B. Ayati, H. Ganjidoust, M. Mir Fattah

    2007-04-01

    Full Text Available For biological treatment of water, there are many different biofilm systems in use. Examples of them are trickling filters, rotating biological contactors, fixed media submerged biofilters, granular media biofilters and fluidized bed reactors. They all have their advantages and disadvantages. Hence, the Moving Bed Biofilm Reactor process was developed in Norway in the late 1980s and early 1990s to adopt the best features of the activated sludge process as well as those of the biofilter processes, without including the worst. Two cylindrical moving bed biofilm reactors were used in this study working in upflow stream conditions. Experiments have been done in aerobic batch flow regime. Laboratory experiments were conducted at room temperature (23–28C and synthetic wastewater comprising a composition of phenol and hydroquinone in each reactor as the main organic constituents, plus balanced nutrients and alkalinity were used to feed the reactor. The ratio of influent to effluent COD was determined at different retention times. The results indicated that the removal efficiency of each selected compound is affected by the detention time. At low phenol and hydroquinone concentration (from 700 to 1000 mg/L maximum removal efficiency (over 80 % was obtained. By further increasing in COD loading rate up to 3000 mg/L, a decrease in COD removal rate was occurred. In the reactor containing pyrogallol in COD of 1500 mg/L, the removal rate decreased to 10 percent because of its toxicity for microorganisms.

  17. Bed-Deformation Experiments Beneath a Temperate Glacier

    Science.gov (United States)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    2002-12-01

    Fast flow of glaciers and genesis of glacial landforms are commonly attributed to shear deformation of subglacial sediment. Although models of this process abound, data gathered subglacially on the kinematics and mechanics of such deformation are difficult to interpret. Major difficulties stem from the necessity of either measuring deformation near glacier margins, where conditions may be abnormal, or at the bottoms of boreholes, where the scope of instrumentation is limited, drilling disturbs sediment, and local boundary conditions are poorly known. A different approach is possible at the Svartisen Subglacial Laboratory, where tunnels melted in the ice provide temporary human access to the bed of Engabreen, a temperate outlet glacier of the Svartisen Ice Cap in Norway. A trough (2 m x 1.5 m x 0.5 m deep) was blasted in the rock bed, where the glacier is 220 m thick and sliding at 0.1-0.2 m/d. During two spring field seasons, this trough was filled with 2.5 tons of simulated till. Instruments in the till recorded shear (tiltmeters), volume change, total normal stress, and pore-water pressure as ice moved across the till surface. Pore pressure was brought to near the total normal stress by feeding water to the base of the till with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. Results illustrate some fundamental aspects of bed deformation. Permanent shear deformation requires low effective normal stress and hence high pore-water pressure, owing to the frictional nature of till. Shear strain generally increases upward in the bed toward the glacier sole, consistent with previous measurements beneath thinner ice at glacier margins. At low effective normal stresses, ice sometimes decouples from underlying till. Overall, bed deformation accounts for 10-35 % of basal motion, although this range excludes shear in the uppermost 0.05 m of till where shear was not measured. Pump tests with durations ranging from seconds to hours highlight the need

  18. Bed shear stress estimation on an open intertidal flat using in situ measurements

    Science.gov (United States)

    Zhu, Q.; van Prooijen, B. C.; Wang, Z. B.; Ma, Y. X.; Yang, S. L.

    2016-12-01

    Accurate estimations for the bed shear stress are essential to predict the erosion and deposition processes in estuaries and coasts. This study used high-frequency in situ measurements of water depths and near-bed velocities to estimate bed shear stress on an open intertidal flat in the Yangtze Delta, China. To determine the current-induced bed shear stress (τc) the in situ near-bed velocities were first decomposed from the turbulent velocity into separate wave orbital velocities using two approaches: a moving average (MA) and energy spectrum analysis (ESA). τc was then calculated and evaluated using the log-profile (LP), turbulent kinetic energy (TKE), modified TKE (TKEw), Reynolds stress (RS), and inertial dissipation (ID) methods. Wave-induced bed shear stress (τw) was estimated using classic linear wave theory. The total bed shear stress (τcw) was determined based on the Grant-Madsen wave-current interaction model (WCI). The results demonstrate that when the ratio of significant wave height to water depth (Hs/h) is greater than 0.25, τcw is significantly overestimated because the vertical velocity fluctuations are contaminated by the surface waves generated by high winds. In addition, wind enhances the total bed shear stress as a result of the increases in both τw and τc generated by the greater wave height and reinforcing of vertical turbulence, respectively. From a comparison of these various methods, the TKEw method associated with ESA decomposition was found to be the best approach because: (1) this method generates the highest mean index of agreement; (2) it uses vertical velocities that are less affected by Doppler noise; and (3) it is less sensitive to the near-bed stratification structure and uncertainty in bed location and roughness.

  19. Intensification of interfacial mass, heat & momentum transfer in high-G fluidized beds in vortex chambers : experimental & theoretical study of potential applications

    OpenAIRE

    Eliaers, Philippe

    2014-01-01

    Vortex chambers can be used for the generation of rotating fluidized beds. High-G operation allows eliminating many of the limitations faced in conventional fluidized beds. In particular, interfacial transfer of mass, heat and momentum can be significantly intensified. This opens perspectives for increasing the efficiency of some existing fluidized bed processes, but also for developing novel processing routes. Two processes were studied in this context: 1. Biomass drying is frequently carrie...

  20. EXPERIMENTAL STUDY ON BED SCOUR IN A 90°CHANNEL BEND

    Institute of Scientific and Technical Information of China (English)

    Masoud GHODSIAN; S. Kamal MOUSAVI

    2006-01-01

    The special feature of bend flow leads to scouring of the bed and bank. Various parameters like flow depth, flow velocity or discharge, geometry of bend and characteristics of bed material may affect the scour process. Experiments were carried out to study the effect of some important parameters on bend scour under clear water condition. Experiments were conducted in a 0.6m wide and 0.7m high flume with 90 degree bend. The lateral variations of bed slope were studied. The maximum depth of scour was correlated to densimetric Froude number, relative bend radius and relative depth of flow.