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Sample records for centrifugal contactors

  1. Characteristics of centrifugal rapid contactor, (3)

    International Nuclear Information System (INIS)

    Organic solvent yields the degradation product as a result of irradiation, in the extraction process of spent fuel reprocessing. The development of a centrifugal rapid contactor is required for the reduction of the solvent degradation by shortening the contact time. The effects of fine solid particles were investigated with a SGN-Robatel LX-208N contactor, following the uranium extraction and re-extraction performance tests. It was found as the experimental result that the considerable quantity of solids accumulated in the rotor of the centrifugal contactor. As for this experimental apparatus, the flow diagram for the centrifugal rapid contactor and auxiliary apparatuses is shown, which are the same system used for the uranium extraction and re-extraction tests. The schematic diagram, the typical stage construction and fluid transfer path of the LX-208 contactor are illustrated. The main specifications of the LX-208 contactor are as follows: the internal diameter of a rotating bowl 200 mm, the material SUS 316, the number of stages 8, and the total hold-up volume of the contactor 1.8 l. Most tests were carried out with aqueous feed only, because white Alundum is easily deposited in the rotor, and the particle concentration in effluent stream becomes undetectable when organic and aqueous feeds are supplied simultaneously. As the experimental results, the correlation of Alundum concentration in effluent and running time, the effect of rotor speed on effluent stream concentration, the particle size distribution curves for No. 6000 and No. 8000 white Alundum, the effect of flow rate on effluent stream concentration and the effect of flow rate on particle size distribution for both No. 6000 and No. 8000 white Alundum are presented. (Nakai, Y.)

  2. A vibration model for centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.A.; Wasserman, M.O.; Wygmans, D.G.

    1992-11-01

    Using the transfer matrix method, we created the Excel worksheet ``Beam`` for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k{sub B}) of a motor after measuring the k{sub B} value for three different motors. The k{sub B} value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.

  3. Recent advances in centrifugal contactors design

    International Nuclear Information System (INIS)

    Advances in thedesign of the Argonne centrifugal contactor for solvent extaction are being realized as these contactors are built, tested, and used to implement the TRUEX process for the cleanup of nuclear waste liquids. These advances include (1) using off-the-shelf, face-mounted motors, (2) modifying the contractor so that relatively volatile solvents can be used, (3) adding a high-level liquid detector that can be used to alert the plant operator of process upsets, (4) providing secondary feed ports, (5) optimizing support frame design, (6) maintaining a linear design with external interstage lines so the stages can be allocated as needed for extraction, scrub, strip, and solvent cleanup operations, and (7) developing features that facilitate contractor operation in remote facilities. 11 refs., 8 figs

  4. Fluidic Analysis in an Annular Centrifugal Contactor for Fuel Reprocessing

    International Nuclear Information System (INIS)

    An annular centrifugal contactor (ACC) is a promising device for fuel reprocessing process, because it offers several advantages—a smaller size, a smaller holdup volume, and a higher separation performance—over conventional contactors such as a mixer-settler and a pulse column. Fluid dynamics and dispersion in an ACC, which has a combined mixer/centrifuge structure, are closely related to its separation performance and capacity, and this information is useful in improving equipment design. In this paper, experimental and computational fluid dynamics (CFD) studies were conducted to analyze fluidic and dispersion behavior in ACCs. Multiphase mixing (water/TBP-dodecane/air) in the annular zone was observed by Particle Imaging Velocimetry, and the change in the fluidic and dispersion behavior was ascertained under several operational conditions. The results of the CFD studies, which considered multiphase turbulent flow in the annular and rotor interior zones, were in a good agreement with the experimental data. (author)

  5. Centrifugal contactor operations for UREX process flowsheet. An update

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-08-01

    The uranium extraction (UREX) process separates uranium, technetium, and a fraction of the iodine from the other components of the irradiated fuel in nitric acid solution. In May 2012, the time, material, and footprint requirements for treatment of 260 L batches of a solution containing 130 g-U/L were evaluated for two commercial annular centrifugal contactors from CINC Industries. These calculated values were based on the expected volume and concentration of fuel arising from treatment of a single target solution vessel (TSV). The general conclusions of that report were that a CINC V-2 contactor would occupy a footprint of 3.2 m 2 (0.25 m x 15 m) if each stage required twice the nominal footprint of an individual stage, and approximately 1,131 minutes or nearly 19 hours is required to process all of the feed solution. A CINC V-5 would require approximately 9.9 m 2 (0.4 m x 25 m) of floor space but would require only 182 minutes or ~ 3 hours to process the spent target solution. Subsequent comparison with the Modular Caustic Side Solvent Extraction Unit (MCU) at Savannah River Site (SRS) in October 2013 suggested that a more compact arrangement is feasible, and the linear dimension for the CINC V-5 may be reduced to about 8 m; a comparable reduction for the CINC V-2 yields a length of 5 m. That report also described an intermediate-scale (10 cm) contactor design developed by Argonne in the early 1980s that would better align with the SHINE operations as they stood in May 2012. In this report, we revisit the previous evaluation of contactor operations after discussions with CINC Industries and analysis of the SHINE process flow diagrams for the cleanup of the TSV, which were not available at the time of the first assessment.

  6. Liquid–Liquid Mixing Studies in Annular Centrifugal Contactors Comparing Stationary Mixing Vane Options

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, Kent E.

    2015-11-10

    Comparative studies of multiphase operation of annular centrifugal contactors showing the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported with selected measurements in a lab-scale 5 cm contactor and 12.5 cm engineering-scale unit. Fewer straight vanes give greater mixingzone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

  7. Synthesis and refining of sunflower biodiesel in a cascade of continuous centrifugal contactor separators

    NARCIS (Netherlands)

    Bin Abu Ghazali, Yusuf; van Ulden, Wouter; van de Bovenkamp, Hendrik; Teddy, T; Picchioni, Francesco; Manurung, Robert; Heeres, Hero J.

    2015-01-01

    The synthesis of fatty acid methyl esters (FAME) from sunflower oil and methanol was studied in a continuous centrifugal contactor separator (CCCS) using sodium methoxide as the catalyst. The effect of relevant process variables like oil and methanol flow rate, rotational speed and catalyst concentr

  8. Novel highly integrated biodiesel production technology in a centrifugal contactor separator device

    NARCIS (Netherlands)

    Kraai, G. N.; Schuur, B.; van Zwol, F.; van de Bovenkamp, H. H.; Heeres, H. J.

    2009-01-01

    The base catalyzed production of biodiesel (FAME) from sunflower oil and methanol in a continuous centrifugal contactor separator (CCS) with integrated reaction and phase separation was studied. The effect of catalyst loading (sodium methoxide), temperature, rotational frequency and flow rates of th

  9. Biodiesel synthesis from Jatropha curcas L. oil and ethanol in a continuous centrifugal contactor separator

    NARCIS (Netherlands)

    Abduh, Muhammad Yusuf; van Ulden, Wouter; Kalpoe, Vijay; van de Bovenkamp, Hendrik H.; Manurung, Robert; Heeres, Hero J.

    2013-01-01

    The synthesis of fatty acid ethyl esters (FAEE) from Jatropha curcas L. oil was studied in a batch reactor and a continuous centrifugal contactor separator (CCCS) using sodium ethoxide as the catalyst. The effect of relevant process variables like rotational speed, temperature, catalyst concentratio

  10. Hydraulic Performance and Mass Transfer Efficiency of Engineering Scale Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    David Meikrantz; Troy Garn; Nick Mann; Jack Law; Terry Todd

    2007-09-01

    Annular centrifugal contactors (ACCs) are being evaluated for process-scale solvent extraction operations in support of Advanced Fuel Cycle Initiative (AFCI) separations goals. Process-scale annular centrifugal contactors have the potential for high stage efficiency if properly employed and optimized for the application. Hydraulic performance issues related to flow instability and classical flooding are likely unimportant, especially for units with high throughputs. However, annular mixing increases rapidly with increasing rotor diameter while maintaining a fixed g force at the rotor wall. In addition, for engineering/process-scale contactors, elevated rotor speeds and/or throughput rates, can lead to organic phase foaming at the rotor discharge collector area. Foam buildup in the upper rotor head area can aspirate additional vapor from the contactor housing resulting in a complete loss of separation equilibrium. Variable speed drives are thus desirable to optimize and balance the operating parameters to help ensure acceptable performance. Proper venting of larger contactors is required to balance pressures across individual stages and prevent vapor lock due to foam aspiration.

  11. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    International Nuclear Information System (INIS)

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup

  12. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, K.E. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-07-01

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.

  13. Evaluation of Argonne 9-cm and 10-cm Annular Centrifugal Contactors for SHINE Solution Processing

    International Nuclear Information System (INIS)

    Work is in progress to evaluate the SHINE Medical Technologies process for producing Mo-99 for medical use from the fission of dissolved low-enriched uranium (LEU). This report addresses the use of Argonne annular centrifugal contactors for periodic treatment of the process solution. In a letter report from FY 2013, Pereira and Vandegrift compared the throughput and physical footprint for the two contactor options available from CINC Industries: the V-02 and V-05, which have rotor diameters of 5 cm and 12.7 cm, respectively. They suggested that an intermediately sized Goldilocks contactor might provide a better balance between throughput and footprint to meet the processing needs for the uranium extraction (UREX) processing of the SHINE solution to remove undesired fission products. Included with the submission of this letter report are the assembly drawings for two Argonne-design contactors that are in this intermediate range 9-cm and 10-cm rotors, respectively. The 9-cm contactor (drawing number CE-D6973A, stamped February 15, 1978) was designed as a single-stage unit and built and tested in the late 1970s along with other size units, both smaller and larger. In subsequent years, a significant effort to developed annular centrifugal contactors was undertaken to support work at Hanford implementing the transuranic extraction (TRUEX) process. These contactors had a 10-cm rotor diameter and were fully designed as multistage units with four stages per assembly (drawing number CMT-E1104, stamped March 14, 1990). From a technology readiness perspective, these 10-cm units are much farther ahead in the design progression and, therefore, would require significantly less re-working to make them ready for UREX deployment. Additionally, the overall maximum throughput of ~12 L/min is similar to that of the 9-cm unit (10 L/min), and the former could be efficiently operated over much of the same range of throughput. As a result, only the 10-cm units are considered here, though

  14. Evaluation of Argonne 9-cm and 10-cm Annular Centrifugal Contactors for SHINE Solution Processing

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, Kent E. [Argonne National Lab. (ANL), Argonne, IL (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-02-01

    Work is in progress to evaluate the SHINE Medical Technologies process for producing Mo-99 for medical use from the fission of dissolved low-enriched uranium (LEU). This report addresses the use of Argonne annular centrifugal contactors for periodic treatment of the process solution. In a letter report from FY 2013, Pereira and Vandegrift compared the throughput and physical footprint for the two contactor options available from CINC Industries: the V-02 and V-05, which have rotor diameters of 5 cm and 12.7 cm, respectively. They suggested that an intermediately sized “Goldilocks” contactor might provide a better balance between throughput and footprint to meet the processing needs for the uranium extraction (UREX) processing of the SHINE solution to remove undesired fission products. Included with the submission of this letter report are the assembly drawings for two Argonne-design contactors that are in this intermediate range—9-cm and 10-cm rotors, respectively. The 9-cm contactor (drawing number CE-D6973A, stamped February 15, 1978) was designed as a single-stage unit and built and tested in the late 1970s along with other size units, both smaller and larger. In subsequent years, a significant effort to developed annular centrifugal contactors was undertaken to support work at Hanford implementing the transuranic extraction (TRUEX) process. These contactors had a 10-cm rotor diameter and were fully designed as multistage units with four stages per assembly (drawing number CMT-E1104, stamped March 14, 1990). From a technology readiness perspective, these 10-cm units are much farther ahead in the design progression and, therefore, would require significantly less re-working to make them ready for UREX deployment. Additionally, the overall maximum throughput of ~12 L/min is similar to that of the 9-cm unit (10 L/min), and the former could be efficiently operated over much of the same range of throughput. As a result, only the 10-cm units are considered here

  15. Towards an optimized flow-sheet for a SANEX demonstration process using centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, D. [European Commission, Joint Research Center, Karlsruhe (Germany). Inst. for Transuranium Elements; Chalmers Univ. of Technology, Gothenburg (Sweden). Nuclear Chemistry, Dept. of Chemical and Biological Engineering; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D. [European Commission, Joint Research Center, Karlsruhe (Germany). Inst. for Transuranium Elements; Modolo, G. [Forschungszentrum Juelich GmbH (Germany). Inst. for Energy Research, Safety Research and Reactor Technology; Sorel, C. [Commissariat a l' Energie Atomique Valrho (CEA), DRCP/SCPS, Bagnols-sur-Ceze (France)

    2009-07-01

    The design of an efficient process flow-sheet requires accurate extraction data for the experimental set-up used. Often this data is provided as equilibrium data. Due to the small hold-up volume compared to the flow rate in centrifugal contactors the time for extraction is often too short to reach equilibrium D-ratios. In this work single stage kinetics experiments have been carried out to investigate the D-ratio dependence of the flow rate and to compare this with equilibrium batch experiments for a SANEX system based on CyMe{sub 4}-BTBP. The first centrifuge experiment was run with spiked solutions while in the second a genuine actinide/lanthanide fraction from a TODGA process was used. Three different flow rates were tested with each set-up. The results show that even with low flow rates, only around 9% of the equilibrium D-ratio (Am) was reached for the extraction in the spiked test and around 16% in the hot test (the difference is due to the size of the centrifuges). In the hot test the lanthanide scrubbing was inefficient whereas in the stripping both the actinides and the lanthanides showed good results. Based on these results improvements of the suggested flow-sheet is discussed. (orig.)

  16. Centrifugal contactor modified for end stage operation in a multistage system

    Science.gov (United States)

    Jubin, Robert T.

    1990-01-01

    A cascade formed of a plurality of centrifugal contactors useful for countercurrent solvent extraction processes such as utilizable for the reprocessing of nuclear reactor fuels is modified to permit operation in the event one or both end stages of the cascade become inoperative. Weir assemblies are connected to each of the two end stages by suitable conduits for separating liquids discharged from an inoperative end stage based upon the weight of the liquid phases uses in the solvent extraction process. The weir assembly at one end stage is constructed to separate and discharge the heaviest liquid phase while the weir assembly at the other end stage is constructed to separate and discharge the lightest liquid phase. These weir assemblies function to keep the liquid discharge from an inoperative end stages on the same weight phase a would occur from an operating end stage.

  17. Mass Transfer Testing of a 12.5-cm Rotor Centrifugal Contactor

    International Nuclear Information System (INIS)

    TRUEX mass transfer tests were performed using a single stage commercially available 12.5 cm centrifugal contactor and stable cerium (Ce) and europium (Eu). Test conditions included throughputs ranging from 2.5 to 15 Lpm and rotor speeds of 1750 and 2250 rpm. Ce and Eu extraction forward distribution coefficients ranged from 13 to 19. The first and second stage strip back distributions were 0.5 to 1.4 and .002 to .004, respectively, throughout the dynamic test conditions studied. Visual carryover of aqueous entrainment in all organic phase samples was estimated at < 0.1 % and organic carryover into all aqueous phase samples was about ten times less. Mass transfer efficiencies of = 98 % for both Ce and Eu in the extraction section were obtained over the entire range of test conditions. The first strip stage mass transfer efficiencies ranged from 75 to 93% trending higher with increasing throughput. Second stage mass transfer was greater than 99% in all cases. Increasing the rotor speed from 1750 to 2250 rpm had no significant effect on efficiency for all throughputs tested

  18. Mass Transfer Testing of a 12.5-cm Rotor Centrifugal Contactor

    Energy Technology Data Exchange (ETDEWEB)

    D. H. Meikrantz; T. G. Garn; J. D. Law; N. R. Mann; T. A. Todd

    2008-09-01

    TRUEX mass transfer tests were performed using a single stage commercially available 12.5 cm centrifugal contactor and stable cerium (Ce) and europium (Eu). Test conditions included throughputs ranging from 2.5 to 15 Lpm and rotor speeds of 1750 and 2250 rpm. Ce and Eu extraction forward distribution coefficients ranged from 13 to 19. The first and second stage strip back distributions were 0.5 to 1.4 and .002 to .004, respectively, throughout the dynamic test conditions studied. Visual carryover of aqueous entrainment in all organic phase samples was estimated at < 0.1 % and organic carryover into all aqueous phase samples was about ten times less. Mass transfer efficiencies of = 98 % for both Ce and Eu in the extraction section were obtained over the entire range of test conditions. The first strip stage mass transfer efficiencies ranged from 75 to 93% trending higher with increasing throughput. Second stage mass transfer was greater than 99% in all cases. Increasing the rotor speed from 1750 to 2250 rpm had no significant effect on efficiency for all throughputs tested.

  19. Centrifugal contactor with liquid mixing and flow control vanes and method of mixing liquids of different phases

    Science.gov (United States)

    Jubin, Robert T.; Randolph, John D.

    1991-01-01

    The invention is directed to a centrifugal contactor for solvent extraction systems. The centrifugal contactor is provided with an annular vertically oriented mixing chamber between the rotor housing and the rotor for mixing process liquids such as the aqueous and organic phases of the solvent extraction process used for nuclear fuel reprocessing. A set of stationary helically disposed vanes carried by the housing is in the lower region of the mixing chamber at a location below the process-liquid inlets for the purpose of urging the liquids in an upward direction toward the inlets and enhancing the mixing of the liquids and mass transfer between the liquids. The upper region of the mixing vessel above the inlets for the process liquids is also provided with a set helically disposed vanes carried by the housing for urging the process liquids in a downward direction when the liquid flow rates through the inlets are relatively high and the liquids contact the vane set in the upper region. The use of these opposing vane sets in the mixing zone maintains the liquid in the mixing zone at suitable levels.

  20. Experimental and modelling studies on continuous synthesis and refining of biodiesel in a dedicated bench scale unit using centrifugal contactor separator technology

    NARCIS (Netherlands)

    Abduh, Muhammad Yusuf; Martinez, Alberto Fernandez; Kloekhorst, Arjan; Manurung, Robert; Heeres, Hero J.

    2016-01-01

    Continuous synthesis and refining of biodiesel (FAME) using a laboratory scale bench scale unit was explored. The unit consists of three major parts: (i) a continuous centrifugal contactor separator (CCCS) to perform the reaction between sunflower oil and methanol; (ii) a washing unit for the crude

  1. Experimental Measurements of Drop Size Distributions in 30 mm Diameter Annular Centrifugal Contactor with 30% TBP-Nitric Acid Biphasic System

    Directory of Open Access Journals (Sweden)

    Shekhar Kumar

    2013-01-01

    Full Text Available For design and development of liquid-liquid extraction systems, it is essential to have an accurate estimation of hydrodynamic and mass transfer characteristics of the employed contactor. In the present study, experimental evaluations consisted primarily of determining the maximum solution throughput that could be processed without cross-phase contamination at a given rotor speed, O/A flow ratio, and organic-aqueous solution pair in a 30 mm bowl diameter centrifugal contactor. In addition, analysis included experimental drop size determinations as well as holdup determination. The experimental drop size distributions are expected to be helpful for modeling work.

  2. Fractional reactive extraction for symmetrical separation of 4-nitro-D,L-phenylalanine in centrifugal contactor separators: experiments and modeling.

    Science.gov (United States)

    Tang, Kewen; Wen, Ping; Zhang, Panliang; Huang, Yan

    2015-01-01

    The enantioselective liquid-liquid extraction of 4-nitro-D,L-phenylalanine (D,L-Nphy) using PdCl2 {(s)-BINAP} as extractant in dichloroethane was studied experimentally in a countercurrent cascade of 10 centrifugal contactor separators (CCSs) at 5°C, involving flow ratio, extractant concentration, and Cl(-) concentration. The steady-state enantiomeric excess (ee) in both stream exits was 90.86% at a 93.29% yield. The predicted value was modeled using an equilibrium stage approach. The correlation between model and experiment was satisfactory. The model was applied to optimize the production of both enantiomers in >97% ee and >99% ee. 14 stages and 16 stages are required for 97% ee and 99% ee for both enantiomers, respectively.

  3. Application of annular centrifugal contactors in the hot test of the improved total partitioning process for high level liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Wuhua, E-mail: dwh203@mail.tsinghua.edu.cn; Chen, Jing; Wang, Jianchen; Wang, Shuwei; Feng, Xiaogui; Wang, Xinghai; Li, Shaowei; Xu, Chao

    2014-08-15

    Highlights: • An improved total partitioning process for high level liquid waste was developed. • Genuine high level liquid waste was used in the hot test. • 72-Stage 10-mm-dia annular centrifugal contactors were used in the hot test. • The decontamination factors of actinides, Sr and Cs were very high. • The stripping efficiencies of actinides, Sr and Cs were very high. - Abstract: High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, {sup 90}Sr, {sup 137}Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P and T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a CECE (calixcrown ether cesium extraction) process for the removal of Cs, has been developed to treat Chinese HLLW. A 160-hour hot test of the improved total partitioning process was carried out using 72-stage 10-mm-dia annular centrifugal contactors (ACCs) and genuine HLLW. The hot test results showed that the average DFs of total α activity, Sr and Cs were 3.57 × 10{sup 3}, 2.25 × 10{sup 4} and 1.68 × 10{sup 4} after the hot test reached equilibrium, respectively. During the hot test, 72-stage 10-mm-dia ACCs worked stable, continuously with no stage failing or interruption of the operation.

  4. Evaluation of an alkaline-side solvent extraction process for cesium removal from SRS tank waste using laboratory-scale centrifugal contactors

    International Nuclear Information System (INIS)

    An alkaline-side solvent extraction process for cesium removal from Savannah River Site (SRS) tank waste was evaluated experimentally using a laboratory-scale centrifugal contactor. Single-stage and multistage tests were conducted with this contactor to determine hydraulic performance, stage efficiency, and general operability of the process flowsheet. The results and conclusions of these tests are reported along with those from various supporting tests. Also discussed is the ability to scale-up from laboratory- to plant-scale operation when centrifugal contractors are used to carry out the solvent extraction process. While some problems were encountered, a promising solution for each problem has been identified. Overall, this alkaline-side cesium extraction process appears to be an excellent candidate for removing cesium from SRS tank waste

  5. Demonstration of a SANEX Process in Centrifugal Contactors using the CyMe{sub 4}-BTBP Molecule on a Genuine Fuel Solution

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, D.; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D. [European Commiss, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, (Germany); Foreman, M.R.S. [Univ Reading, Dept Chem, Reading RG6 6AD, Berks, (United Kingdom); Geist, A. [Forschungszentrum Karlsruhe, Inst Nukl Entsorgung, D-76021 Karlsruhe, (Germany); Modolo, G. [Forschungszentrum Julich, Inst Energy Res Safety Res and Reactor Technol, D-52425 Julich, (Germany); Sorel, C. [Commissariat Energie Atom Valrho, CEA, DRCP SCPS, F-30207 Bagnols Sur Ceze, (France)

    2009-07-01

    Efficient recovery of minor actinides from a genuine spent fuel solution has been successfully demonstrated by the CyMe{sub 4}-BTBP/DMDOHEMA extractant mixture dissolved in octanol. The continuous countercurrent process, in which actinides(III) were separated from lanthanides(III), was carried out in laboratory centrifugal contactors using an optimized flow-sheet involving a total of 16 stages. The process was divided into 9 stages for extraction from a 2 M nitric acid feed solution, 3 stages for lanthanide scrubbing, and 4 stages for actinide back-extraction. Excellent feed decontamination factors for Am (7000) and Cm (1000) were obtained and the recoveries of these elements were higher than 99.9%. More than 99.9% of the lanthanides were directed to the raffinate except Gd for which 0.32% was recovered in the product. (authors)

  6. Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

    Science.gov (United States)

    Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

    2016-03-01

    Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%.

  7. Centrifugal pyrocontactor

    Science.gov (United States)

    Chow, Lorac S.; Leonard, Ralph A.

    1993-01-01

    A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

  8. Integrated AMP-PAN, TRUEX, and SREX Flowsheet Test to Remove Cesium, Surrogate Actinide Elements, and Strontium from INEEL Tank Waste Using Sorbent Columns and Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, Ronald Scott; Law, Jack Douglas; Todd, Terry Allen; Wood, D. J.; Garn, Troy Gerry; Wade, Earlen Lawrence

    2000-02-01

    Three unit operations for the removal of selected fission products, actinides, and RCRA metals (mercury and lead) have been successfully integrated and tested for extended run times with simulated INEEL acidic tank waste. The unit operations were ion exchange for Cs removal, followed by TRUEX solvent extraction for Eu (actinide surrogate), Hg, and Re (Tc surrogate) removal, and subsequent SREX solvent extraction for Sr and Pb removal. Approximately 45 L of simulated INTEC tank waste was first processed through three ion exchange columns in series for selective Cs removal. The columns were packed with a composite ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) sorbent. The experimental breakthrough data were in excellent agreement with modeling predictions based on data obtained with much smaller columns. The third column (220 cm3) was used for polishing and Cs removal after breakthrough of the up-stream columns. The Cs removal was >99.83% in the ion exchange system without interference from other species. Most of the effluent from the ion exchange (IX) system was immediately processed through a TRUEX solvent extraction flowsheet to remove europium (americium surrogate), mercury and rhenium (technetium surrogate) from the simulated waste. The TRUEX flowsheet test was performed utilizing 23 stages of 3.3-cm centrifugal contactors. Greater than 99.999% of the Eu, 96.3% of the Hg, and 56% of the Re were extracted from the simulated feed and recovered in the strip and wash streams. Over the course of the test, there was no detectable build-up of any components in the TRUEX solvent. The raffinate from the TRUEX test was stored and subsequently processed several weeks later through a SREX solvent extraction flowsheet to remove strontium, lead, and Re (Tc surrogate) from the simulated waste. The SREX flowsheet test was performed using the same centrifugal contactors used in the TRUEX test after reconfiguration and the addition of three stages. Approximately 99.9% of

  9. Membrane contactor applications

    NARCIS (Netherlands)

    Klaassen, R.; Feron, P.H.M.; Jansen, A.

    2008-01-01

    In a membrane contactor the membrane separation is completely integrated with an extraction or absorption operation in order to exploit the benefits of both technologies fully. Membrane contactor applications that have been developed can be found in both water and gas treatment. Several recently dev

  10. Identification And Characterization Of The Solids Found In Extraction Contactor SEP-401 In June 2012

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F.; Fink, S. D.

    2012-12-10

    The Modular Caustic-Side Solvent Extraction Unit (MCU) recently conducted an outage that included maintenance on the centrifugal contactors. Operations personnel observed solids or deposits in two contactors and attempted to collect samples for analyses by Savannah River National Laboratory (SRNL). The residues found in Extraction Contactor SEP-401 are a mixture of amorphous silica, aluminosilicate, titanium, and debris from low alloy steel. The solids contain low concentrations of plutonium and strontium. These isotopes are associated with the titanium that came from the monosodium titanate (MST) added in the Actinide Removal Process (ARP) most likely as leached Ti from the MST that precipitated subsequently in MCU. An attempt was also made to obtain samples from the contents of Wash Contactor SEP-702. However, sampling provide ineffective.

  11. CFD Simulation of Annular Centrifugal Extractors

    OpenAIRE

    Vedantam, S.; Wardle, K. E.; Tamhane, T. V.; Ranade, V. V.; Joshi, J. B.

    2012-01-01

    Annular centrifugal extractors (ACE), also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of cent...

  12. FLUID CONTACTOR APPARATUS

    Science.gov (United States)

    Spence, R.; Streeton, R.J.W.

    1956-04-17

    The fluid contactor apparatus comprises a cylindrical column mounted co- axially and adapted to rotate within a cylindrical vessel, for the purpose of extracting a solute from am aqueous solution by means of an organic solvent. The column is particularly designed to control the vortex pattern so as to reduce the height of the vortices while, at the same time, the width of the annular radius in the radial direction between the vessel and column is less than half the radius of the column. A plurality of thin annular fins are spaced apart along the rotor approximately twice the radial dimension of the column such that two contrarotating substantially circular vortices are contained within each pair of fins as the column is rotated.

  13. Contactor/filter improvements

    Science.gov (United States)

    Stelman, David

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  14. Electric vehicle drive train with contactor protection

    Science.gov (United States)

    Konrad, Charles E.; Benson, Ralph A.

    1994-01-01

    A drive train for an electric vehicle includes a traction battery, a power drive circuit, a main contactor for connecting and disconnecting the traction battery and the power drive circuit, a voltage detector across contacts of the main contactor, and a controller for controlling the main contactor to prevent movement of its contacts to the closed position when the voltage across the contacts exceeds a predetermined threshold, to thereby protect the contacts of the contactor. The power drive circuit includes an electric traction motor and a DC-to-AC inverter with a capacitive input filter. The controller also inhibits the power drive circuit from driving the motor and thereby discharging the input capacitor if the contacts are inadvertently opened during motoring. A precharging contactor is controlled to charge the input filter capacitor prior to closing the main contactor to further protect the contacts of the main contactor.

  15. ENGINEERING BULLETIN: ROTATING BIOLOGICAL CONTACTORS

    Science.gov (United States)

    Rotating biological contactors employ aerobic fixed-film treatment to degrade either organic and/or nitrogenous (ammonia-nitrogen) constituents present in aqueous waste streams. ixed-film systems provide a surface to which the biomass can adhere. Treatment is achieved as the wast...

  16. Effects of solvent-extraction contactor selection on flowsheet and facility design

    International Nuclear Information System (INIS)

    The notion is developed that the selection of a solvent extraction contactor is part of a more general development of principles and philosophy guiding the overall plant design. Specifically, the requirements and constraints placed on the plant by the solvent extraction system must be consistent with those imposed by the other operations, which generally are more expensive and more complicated. Were a conservative philosophy employed throughout the plant, the choice of pulsed columns seem correct. Were the plant intended to employ modern techniques and state-of-the-art technology, particularly in remote maintenance and process control, the selection of centrifugal contactors seems appropriate. The process improvements attainable from employing more stages in a more tightly controlled solvent extraction system seem marginal at present when applied to conventional flowsheets, although the cost-benefit may be attractive in a modern plant. The potential for improvement through major flowsheet modification can not presently be assessed quantitatively

  17. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  18. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  19. Study on reliability technology of contactor relay

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-jin; ZHAO Jing-ying; WANG Hai-tao; YANG Chen-guang; SUN Shun-li

    2007-01-01

    In this paper, the reliability of contactor relay is studied. There are three main parts about reliability test and analysis. First, in order to analyze reliability level of contact relay, the failure ratio ranks are established as index base on the product level. Second, the reliability test method is put forward. The sample plan of reliability compliance test is gained from reliability sample theory. The failure criterion is ensured according to the failure modes of contactor relay. Third, after reliability test experiment, the analysis of failure physics is made and the failure reason is found.

  20. Micro contactor based on isotachophoretic sample transport.

    Science.gov (United States)

    Goet, Gabriele; Baier, Tobias; Hardt, Steffen

    2009-12-21

    It is demonstrated how isotachophoresis (ITP) in a microfluidic device may be utilized to bring two small sample volumes into contact in a well-controlled manner. The ITP contactor serves a similar purpose as micromixers that are designed to mix two species rapidly in a microfluidic channel. In contrast to many micromixers, the ITP contactor does not require complex channel architectures and allows a sample processing in the spirit of "digital microfluidics", i.e. the samples always remain in a compact volume. It is shown that the ITP zone transport through microchannels proceeds in a reproducible and predictable manner, and that the sample trajectories follow simple relationships obtained from Ohm's law. Firstly, the micro contactor can be used to synchronize two ITP zones having reached a channel at different points in time. Secondly, fulfilling its actual purpose it is capable of bringing two samples in molecular contact via an interpenetration of ITP zones. It is demonstrated that the contacting time is proportional to the ITP zone extension. This opens up the possibility of using that type of device as a special type of micromixer with "mixing times" significantly below one second and an option to regulate the duration of contact through specific parameters such as the sample volume. Finally, it is shown how the micro contactor can be utilized to conduct a hybridization reaction between two ITP zones containing complementary DNA strands.

  1. Thermal Simulation of AC Electromagnetic Contactor

    Institute of Scientific and Technical Information of China (English)

    NIUChun-ping; CHENDe-gui; ZHANGJing-shu; LIXing-wen

    2005-01-01

    Transient magnetic circuit method is adopted to calculate the power loss in winding and shading coil. Based on the analysis of heat transfer process in AC contactor, a thermal model is proposed and the temperature field distribution is simulated with 3-D FEM of ANSYS.Comparison of simulation results with measurements shows that the proposed method is effective.

  2. Characterization of fouling of membrane contactors

    DEFF Research Database (Denmark)

    Ciurkot, Kaludia; Zarebska, Agata; Christensen, Knud Villy

    2013-01-01

    In this study liquid-liquid membrane contactors have been tested for ammonia removal from model manure solution and undigested pig manure. The aim of this work is to compare the efficiency of ammonia removal by different hydrophobic membranes including the material’s influence on mass transfer...

  3. Continuous fluidized-bed contactor with recycle of sorbent

    Science.gov (United States)

    Scott, Charles D.; Petersen, James N.; Davison, Brian H.

    1996-01-01

    A continuous fluidized-bed contactor containing sorbent particles is used to remove solutes from liquid solvents. As the sorbent particles, for example gel beads, sorb the solute, for example metal ion species, the sorbent particles tend to decrease in diameter. These smaller loaded sorbent particles rise to the top of the contactor, as larger sorbent particles remain at the bottom of the contactor as a result of normal hydraulic forces. The smaller loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. Alternatively, the loaded sorbent particles may also slightly increase in diameter, or exhibit no change in diameter but an increase in density. As a result of normal hydraulic forces the larger loaded sorbent particles fall to the bottom of the contactor. The larger loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor.

  4. Rotating biological contactors: the Canadian experience

    Energy Technology Data Exchange (ETDEWEB)

    Cuenca, Manuel A. [Ryerson Polytechnical Univ., Toronto, ON (Canada). Chemical Engineering Dept.; Smith, Tom [CMS Rotordisk Inc., Concord, ON (Canada); Vianna, Arlinda C. [Servico Nacional de Aprendizagem Industrial (SENAI), Salvador, BA (Brazil)

    1993-12-31

    In fifteen years, Rotating Biological Contactors (RBC) have become one of the most attractive technologies for secondary wastewater treatment. The present work is a review of the evolution of RBC technology in the last twenty years. In addition, the status of the technology in Canada is described, emphasizing industrial facilities and landfill leachate treatment. An enumeration of the most relevant development areas is included. (author). 34 refs., 3 figs., 7 tabs.

  5. Denitrification in anoxic rotating biological contactors

    OpenAIRE

    Teixeira, P; Oliveira, Rosário; Mota, M.

    2009-01-01

    Rotating Biological Contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency, as well as easy scalability. It is well known that the performance of this type of reactors is controlled by a high number of design parameters. In thi...

  6. Desorption of trihalomethanes in gas liquid contactors

    International Nuclear Information System (INIS)

    Updated studies show that gastric cancer is related with the existence of trihalomethanes (THMs) in the drinking water. The trihalomethanes are sub products from the degradation of humic acids and your reaction with chlorine and bromine used like decontaminates. The desorption process is used to eliminate the THMs with air in contact with the water. The experimental design was used in three contactors. The contactors selected were: the bubbling's column, the packed column and the shaken tank without screen. There were selected three variable: initial concentration of THMs, the residence time and the turbulence degree (measured with the Reynolds number). The concentrations were made with a gas chromatograph. The objective of this project is to do a comparison with the gas liquid contactors more used in the industrial level to determinate which ones are the best in the desorption process. The conclusion of the experimental design is that the tank is the equipment with the best capacity to eliminate THMs. Too it includes other techniques to eliminate THMs of the water and your treatment

  7. Hollow fiber membrane contactor as a gas–liquid model contactor

    NARCIS (Netherlands)

    Dindore, V.Y.; Brilman, D.W.F.; Versteeg, G.F.

    2005-01-01

    Microporous hollow fiber gas–liquid membrane contactors have a fixed and well-defined gas–liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  8. Hollow fiber membrane contactor as a gas-liquid model contactor

    NARCIS (Netherlands)

    Dindore, V. Y.; Brilman, D. W. F.; Versteeg, G. F.

    2005-01-01

    Microporous hollow fiber gas-liquid membrane contactors have a fixed and well-defined gas-liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  9. CFD Simulation of Annular Centrifugal Extractors

    Directory of Open Access Journals (Sweden)

    S. Vedantam

    2012-01-01

    Full Text Available Annular centrifugal extractors (ACE, also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of centrifugal field. For the development of rational and reliable design procedures, it is important to understand the flow patterns in the mixer and settler zones. Computational Fluid Dynamics (CFD has played a major role in the constant evolution and improvements of this device. During the past thirty years, a large number of investigators have undertaken CFD simulations. All these publications have been carefully and critically analyzed and a coherent picture of the present status has been presented in this review paper. Initially, review of the single phase studies in the annular region has been presented, followed by the separator region. In continuation, the two-phase CFD simulations involving liquid-liquid and gas-liquid flow in the annular as well as separator regions have been reviewed. Suggestions have been made for the future work for bridging the existing knowledge gaps. In particular, emphasis has been given to the application of CFD simulations for the design of this equipment.

  10. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  11. Uranium recovery from assorted laboratory organic waste solutions using centrifugal contractors

    International Nuclear Information System (INIS)

    Countercurrent extraction runs, carried out in our laboratory for the evaluation studies of N,N-dihexyloctanamide (DHOA) as an alternative of tributyl phosphate (TBP) for spent fuel reprocessing, have led to generation of large volumes of organic wastes containing varying amounts of uranium. It was desirable to recover uranium from such waste solutions prior to the disposal of organic waste solutions. Even though, batch stripping can be used for this purpose, it may take several days to achieve the desired goal. In this context, the centrifugal contactors appear attractive due to high liquid through-put, which may simplify the uranium recovery process. Uranium recovery studies from assorted organic waste solutions were therefore carried out using centrifugal contactors

  12. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  13. Low cost membrane contactors based on hollow fibres

    Directory of Open Access Journals (Sweden)

    Raudensky Miroslav

    2012-04-01

    Full Text Available Membrane contactors are used to solve different chemical engineering tasks (e.g. water saturation with gases. Such elements are traditionally used for bubble less oxidation of blood. However, their industrial applications are rather limited by their high investment costs. This is probably the main reason why membrane contactors are not used so widely, e.g. classical absorbers, etc. If potted bundles of hollow fibres are available, then it is a relatively simple task to design an ad hoc membrane contactor. However, it must be emphasised that to achieve the highest mass transfer efficiency requires a rather time-consuming tuning of each ad hoc designed contactor. To check the differences by water evaporation were aligned two modes, the water inside the hollow fibre membrane and fan air outside, next with the water outsides and flowing pressure air inside the membrane.

  14. Centrifugal reciprocating compressor

    Science.gov (United States)

    High, W. H.

    1980-01-01

    Efficient compressor uses centrifugal force to compress gas. System incorporates two coupled dc motors, each driving separate centrifugal reciprocating-compressor assembly. Motors are synchronized to accelerate and decelerate alternately.

  15. Enrichment: centrifuge process

    International Nuclear Information System (INIS)

    This short course is divided into three sections devoted respectively to the physics of the process, some practical problems raised by the design of a centrifuge and the present situation of centrifugation in the World. 31 figs., 18 refs

  16. Centrifuge modeling of monopiles

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    2010-01-01

    To gain a larger knowledge of the monopile foundation concept, centrifuge modeling is used by the geotechnical group at DTU. The centrifuge operated at DTU is a beam centrifuge and was built in 1976. In the recent years it has been upgraded with onboard data acquisition and control systems....... The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 85 in experiments which equals a soil volume in prototype scale of a diameter of 40 meters and a depth of 40 meters. This paper describes centrifuge modeling theory, the centrifuge setup at DTU and as an example show results...... from centrifuge tests performed on large diameter piles installed in dry sand....

  17. Performance comparison of suspended bed and batch contactor chromatography.

    Science.gov (United States)

    Quiñones-García, I; Rayner, I; Levison, P R; Dickson, N; Purdom, G

    2001-01-26

    In some applications, the purification and recovery of biomolecules is performed via a cascade of batch adsorption and desorption stages using agitated contactors and related filtration devices. Suspended bed chromatography is a recent process-scale innovation that is applicable to these separations. This hybrid technique exploits the benefits of combining batch adsorption in an agitated contactor with elution in an enclosed column system. To some extent, the process is similar to batch contactor chromatography but can be fully contained and significantly quicker. The process has two steps; first the fluid containing the sample is mixed with the adsorbent in a stirred tank. Second, the slurry suspension is transferred directly into a specialized column, such as an IsoPak column. The media with the adsorbed product is formed as a packed bed, whilst the suspension liquid is passed out of the column. The product is then eluted from the packed bed utilizing standard column-chromatography techniques. The performance of the suspended bed and the agitated contactor operations are demonstrated both by full-scale experimental results and process simulations. The purification of ovalbumin from a hen-egg white feedstock by anion-exchange chromatography was used as a case study in order to prove the concept. With the availability of both pump-packed systems and shear-resistant media, suspended bed chromatography is a better alternative for a range of applications than the traditional batch separations using agitated contactors. PMID:11218119

  18. Development of novel contactor for nuclear solvent extraction

    International Nuclear Information System (INIS)

    For current designs of radiochemical plants, solvent-extraction contactors with no periodic maintenance like pulse column are the first choice. In addition, as costs of specialty solvents for nuclear extraction are quite high, there is a demand for operation at extreme phase ratios. Recently a novel mixer-settler was visualized and developed for this kind of service. The mixer of the novel contactor is based on rotated helical tubes and does not involve any mechanical moving part. Mass-transfer runs were carried out with aqueous nitric acid and 30% TBP solvent at A/O of 0.25-200 (in extraction) and A/O of 0.25-10 (in back-extraction mode). The developed contactor exhibited nearly 100% efficiency for all the cases. (authors)

  19. Rotating Biological Contactors (RBC's). Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Zickefoose, Charles S.

    This student manual provides the textual material for a unit on rotating biological contactors (RBC's). Topic areas considered include: (1) flow patterns of water through RBC installations; (2) basic concepts (shaft and stage); (3) characteristics of biomass; (4) mechanical features (bearings, mechanical drive systems, and air drive systems); (5)…

  20. STRINGFELLOW LEACHATE TREATMENT WITH RBC (ROTATING BIOLOGICAL CONTACTOR)

    Science.gov (United States)

    A study was conducted with a rotating biological contactor (RBC) for treatment of leachate from the Stringfellow hazardous waste site in Riverside County, California. The leachate was transported from California to Cincinnati, where a pilot sized RBC was installed at the U.S. EPA...

  1. Carbon Dioxide Absorption in a Membrane Contactor with Color Change

    Science.gov (United States)

    Pantaleao, Ines; Portugal, Ana F.; Mendes, Adelio; Gabriel, Joaquim

    2010-01-01

    A pedagogical experiment is described to examine the physical absorption of gases, in this case carbon dioxide, in a hollow fiber membrane contactor (HFMC) where the absorption concentration profile can be followed by a color change. The HFMC is used to teach important concepts and can be used in interesting applications for students, such as…

  2. Centrifugal pump handbook

    CERN Document Server

    Pumps, Sulzer

    2010-01-01

    This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

  3. DESIGN INFORMATION REPORT: CENTRIFUGES

    Science.gov (United States)

    In the 1960s, manufacturers began to design centrifuges specifically for wastewater sludge applications. In addition, sludge thickening and dewatering processes were improved with the introduction of polyelectrolytes for chemical sludge conditioning. The report contains a brief d...

  4. Electrolytically aided denitrification on a rotating biological contactor.

    Science.gov (United States)

    Rodziewicz, Joanna; Filipkowska, Urszula; Dziadkiewicz, Ewa

    2011-01-01

    The study was conducted at a bench scale on a rotating biological contactor under both conventional conditions (without the flow of electric current) and with the passage of an electric current having the following densities: 0.2 A m(-2), 0.8 A m(-)2 and 1.5 A m(-2). Stainless-steel discs covered with an immobilized biofilm served as a cathode, whereas an electrode made of stainless steel immersed in the wastewater of the flow tank of the contactor served as an anode. Experiments were carried out on municipal wastewater containing nitrogen in the organic and ammonium forms. The highest efficiency of nitrogen removal was observed with the passage of electric current at the density of 0.2 A m(-2). The efficiency of the denitrification process was over 64% and the nitrification efficiency was 93.4%.

  5. Treatment of Antibiotic Pharmaceutical Wastewater Using a Rotating Biological Contactor

    OpenAIRE

    Rongjun Su; Guangshan Zhang; Peng Wang; Shixiong Li; Ryan M. Ravenelle; JOHN C. CRITTENDEN

    2015-01-01

    Rotating biological contactors (RBC) are effective for treating wastewater, while they are rarely reported to be used for treating antibiotic pharmaceutical wastewater (APW). The current study investigates treatment of APW using an RBC. The effects of influent concentration, number of stages, and temperature on the remediation of APW were studied. The results indicated, even at low ambient temperature, 45% COD and 40% NH4+-N removal efficiencies. Moreover, the BOD5 removal efficiency was 85%....

  6. Membrane contactor assisted extraction/reaction process employing ionic liquids

    Science.gov (United States)

    Lin, Yupo J.; Snyder, Seth W.

    2012-02-07

    The present invention relates to a functionalized membrane contactor extraction/reaction system and method for extracting target species from multi-phase solutions utilizing ionic liquids. One preferred embodiment of the invented method and system relates to an extraction/reaction system wherein the ionic liquid extraction solutions act as both extraction solutions and reaction mediums, and allow simultaneous separation/reactions not possible with prior art technology.

  7. A Computer Model for Teaching the Dynamic Behavior of AC Contactors

    Science.gov (United States)

    Ruiz, J.-R. R.; Espinosa, A. G.; Romeral, L.

    2010-01-01

    Ac-powered contactors are extensively used in industry in applications such as automatic electrical devices, motor starters, and heaters. In this work, a practical session that allows students to model and simulate the dynamic behavior of ac-powered electromechanical contactors is presented. Simulation is carried out using a rigorous parametric…

  8. CO2 absorption at elevated pressures using a hollow fiber membrane contactor

    NARCIS (Netherlands)

    Dindore, V.Y.; Brilman, D.W.F.; Feron, P.H.M.; Versteeg, G.F.

    2004-01-01

    Recently, hollow fiber membrane gas–liquid contactor-based processes have gained an increasing attention. Compared to conventional processes, these processes have numerous advantages. The membrane contactors provide a very high interfacial area per unit volume, independent regulation of gas and liqu

  9. Geotechnical centrifuge under construction

    Science.gov (United States)

    Richman, Barbara T.

    Modifications are underway at the National Aeronautics and Space Administration (NASA) Ames Research Center in California to transform a centrifuge used in the Apollo space program to the largest geotechnical centrifuge in the free world. The centrifuge, to be finished in August and opened next January, following check out and tuning, will enable geoscientists to model stratigraphic features down to 275 m below the earth's surface. Scientists will be able to model processes that are coupled with body force loading, including earthquake response of earth structures and soil structure interaction; rubbled-bed behavior during in situ coal gasification or in oil shale in situ retorts; behavior of frozen soil; frost heave; behavior of offshore structures; wave-seabed interactions; explosive cratering; and blast-induced liquefaction.The centrifuge will have a load capacity of 900-g-tons (short); that is, it will be able to carry a net soil load of 3 short tons to a centripetal acceleration of 300 times the acceleration caused by gravity. Modified for a total cost of $2.4 million, the centrifuge will have an arm with a 7.6-m radius and a swinging platform or bucket at its end that will be able to carry a payload container measuring 2.1×2.1 m. An additional future input of $500,000 would enable the purchase of a larger bucket that could accommodate a load of up to 20 tons, according to Charles Babendreier, program director for geotechnical engineering at the National Science Foundation. Additional cooling for the motor would also be required. The centrifuge has the capability of accelerating the 20-ton load to 100 g.

  10. Perceived radial translation during centrifugation

    NARCIS (Netherlands)

    Bos, J.E.; Correia Grácio, B.J.

    2015-01-01

    BACKGROUND: Linear acceleration generally gives rise to translation perception. Centripetal acceleration during centrifugation, however, has never been reported giving rise to a radial, inward translation perception. OBJECTIVE: To study whether centrifugation can induce a radial translation percepti

  11. Central centrifugal cicatricial alopecia

    OpenAIRE

    Collin Blattner; Dennis C Polley; Frank Ferritto; Elston, Dirk M

    2013-01-01

    Central centrifugal cicatricial alopecia is a common cause of progressive permanent apical alopecia. This unique form of alopecia includes entities previously know as “hot comb alopecia,” “follicular degeneration syndrome,” “pseudopelade” in African Americans and “central elliptical pseudopelade” in Caucasians. The etiology appears to be multifactorial and the condition occurs in all races.

  12. Centrifugal atomisation of alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li Huiping [School of Mechanical and Materials Engineering, Univ. of Surrey, Guilford (United Kingdom); Dept. of Inorganic Materials, East China Univ. of Science and Technology, Shanghai, SH (China); Tsakiropoulos, P. [School of Mechanical and Materials Engineering, Univ. of Surrey, Guilford (United Kingdom); Johnson, T. [Tetronics Ltd., Faringdon, Oxfordshire (United Kingdom)

    2001-07-01

    Centrifugal atomisation using a rotating disk is described and compared to REP and PREP. Results of calculations of models describing the interaction of a melt with a rotating disk, the formation of thin film on the disk and the break up of the thin film and its atomisation at the edge of the disk are compared with experimental results. (orig.)

  13. Centrifugal analyzer development

    International Nuclear Information System (INIS)

    The development of the centrifuge fast analyzer (CFA) is reviewed. The development of a miniature CFA with computer data analysis is reported and applications for automated diagnostic chemical and hematological assays are discussed. A portable CFA system with microprocessor was adapted for field assays of air and water samples for environmental pollutants, including ammonia, nitrates, nitrites, phosphates, sulfates, and silica. 83 references

  14. Effect of Organic Loading on Rotating Biological Contactor Efficiency

    Directory of Open Access Journals (Sweden)

    Kossay K. Al-Ahmady

    2005-12-01

    Full Text Available Organic loading (weight per unit time per volume is useful for the design of rotating biological contactors (RBC and for comparison with the other processes such as activated sludge or oxidation ponds. The present study puts emphasis on the significance of this control or design parameter because it allows direct comparison of the RBC system's performance when operated under various circumstances and with different kinds of wastewater. The results of the paper proved that, the COD removal in rotating biological contactor systems is a function of the organic loading rate. However, each of the wastewater concentration and flow rate are also influence on the system efficiency but theirs impact can be combined by the effect of organic loading. The majority of COD removal (40-85 % of the total removal depending on the organic loading applied occurs in the first stages of the system. There is a strong correlation between the organic loading and the concentration of the suspended solids in the rotating biological contactor basin. At higher loadings higher concentrations noted. At a loading of about, (24 g/m2.d suspended solids were 225, 125, 35, and 25 mg/L in the first, second, third and, the fourth stage respectively. To achieve an effluent quality of (BOD < 25 mg/L, COD < 60 mg/L, the system must be operated on organic loadings of about (22 gBOD/m2.d and 65 gCOD/m2.d respectively. For nitrification process, the system must be designed to operate at organic loading of about (10 g/m2.d or less and, the reactor or basin volume should be designed to achieve a hydraulic loading of about (40 L/m2.d or less.

  15. Rotating biological contactors for wastewater treatment - A review

    OpenAIRE

    Hassard, Francis; Biddle, Jeremy R.; Cartmell, Elise; Jefferson, Bruce; Tyrrel, Sean F.; Stephenson, Tom

    2014-01-01

    Rotating biological contactors (RBCs) for wastewater treatment began in the 1970s. Removal of organic matter has been targeted within organic loading rates of up to 120 g m−2 d−1 with an optimum at around 15 g m−2 d−1 for combined BOD and ammonia removal. Full nitrification is achievable under appropriate process conditions with oxidation rates of up to 6 g m−2 d−1 reported for municipal wastewater. The RBC process has been adapted for denitrification with reported removal rates of up to 14 g...

  16. Performance characteristics of cross-flow membrane contactors for liquid desiccant systems

    International Nuclear Information System (INIS)

    Highlights: • Different types of flat plate membrane contactors developed to eliminate carryover in liquid desiccant systems. • Two-dimensional steady-state model developed to predict performance of contactors. • The simulated results are found to be in good agreement with experimental findings. • Performance of the contactors depends significantly on the membrane characteristics. • Parametric analysis carried out to select best operating ranges of design parameters. - Abstract: Membrane based indirect contact liquid desiccant dehumidification technology subsides the serious concern of liquid desiccant droplet carryover observed in conventional direct contact liquid desiccant systems. In the membrane contactor the air and liquid desiccant streams flow in alternate channels in cross-flow arrangement, separated by micro-porous semi-permeable hydrophobic membranes. Only water vapor can pass through the membranes but liquid desiccant cannot permeate. A two-dimensional steady-state mathematical model for semipermeable membrane based indirect contactors as dehumidifiers for liquid desiccant dehumidification applications has been developed. The model can predict the air and desiccant parameters inside the dehumidifier and the outlet parameters for a given input parameters. Five different membrane contactors have been fabricated and series of experiments have been conducted to validate the mathematical model. Aqueous solution of lithium chloride has been used as desiccant. The maximum deviations between experimental and predicted values are within ±10% for outlet specific humidity and outlet enthalpy of air, ±15% deviation in dehumidification effectiveness and ±20% deviation in enthalpy effectiveness. The distributions of major parameters viz. temperature, humidity, concentration, etc., within the contactor have been presented. Parametric analysis has been carried out to study the effects of membrane characteristics, contactor design, fluid flow rates, ambient

  17. Centrifugal unbalance detection system

    Science.gov (United States)

    Cordaro, Joseph V.; Reeves, George; Mets, Michael

    2002-01-01

    A system consisting of an accelerometer sensor attached to a centrifuge enclosure for sensing vibrations and outputting a signal in the form of a sine wave with an amplitude and frequency that is passed through a pre-amp to convert it to a voltage signal, a low pass filter for removing extraneous noise, an A/D converter and a processor and algorithm for operating on the signal, whereby the algorithm interprets the amplitude and frequency associated with the signal and once an amplitude threshold has been exceeded the algorithm begins to count cycles during a predetermined time period and if a given number of complete cycles exceeds the frequency threshold during the predetermined time period, the system shuts down the centrifuge.

  18. Centrifugally decoupling touchdown bearings

    Science.gov (United States)

    Post, Richard F

    2014-06-24

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  19. Performance in Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    K. Sato

    1999-01-01

    Full Text Available A 3-D unsteady thin-layer Navier-Stokes code has been used to calculate the flow through a centrifugal compressor stage. The validation of the code for steady flows in centrifugal compressors was conducted for the Krain’s impeller with a vaneless diffuser as a test case and the numerical results were compared with the experimental results. The predicted flow field and performance agreed well with the experimental data. An unsteady stage solution was then conducted with this impeller followed by a generic low-solidity vaned-diffuser to examine the unsteady effects on the impeller performance. The computational results showed a stabilising effect of the blade row interaction.

  20. Indicators for technological, environmental and economic sustainability of ozone contactors.

    Science.gov (United States)

    Zhang, Jie; Tejada-Martinez, Andres E; Lei, Hongxia; Zhang, Qiong

    2016-09-15

    Various studies have attempted to improve disinfection efficiency as a way to improve the sustainability of ozone disinfection which is a critical unit process for water treatment. Baffling factor, CT10, and log-inactivation are commonly used indicators for quantifying disinfection credits. However the applicability of these indicators and the relationship between these indicators have not been investigated in depth. This study simulated flow, tracer transport, and chemical species transport in a full-scale ozone contactor operated by the City of Tampa Water Department and six other modified designs using computational fluid dynamics (CFD). Through analysis of the simulation results, we found that baffling factor and CT10 are not optimal indicators of disinfection performance. We also found that the relationship between effluent CT obtained from CT transport simulation and baffling factor depends on the location of ozone release. In addition, we analyzed the environmental and economic impacts of ozone contactor designs and upgrades and developed a composite indicator to quantify the sustainability in technological, environmental and economic dimensions. PMID:27322565

  1. A new method for liposome preparation using a membrane contactor.

    Science.gov (United States)

    Jaafar-Maalej, Chiraz; Charcosset, Catherine; Fessi, Hatem

    2011-09-01

    In this article, we present a novel, scalable liposomal preparation technique suitable for the entrapment of pharmaceutical agents into liposomes. This new method is based on the ethanol-injection technique and uses a membrane contactor module, specifically designed for colloidal system preparation. In order to investigate the process, the influence of key parameters on liposome characteristics was studied. It has been established that vesicle-size distribution decreased with a decrease of the organic-phase pressure, an increase of the aqueous-phase flow rate, and a decrease of the phospholipid concentration. Additionally, special attention was paid on reproducibility and long-term stability of lipid vesicles, confirming the robustness of the membrane contactor-based technique. On the other hand, drug-loaded liposomes were prepared and filled with two hydrophobic drug models. High entrapment-efficiency values were successfully achieved for indomethacin (63%) and beclomethasone dipropionate (98%). Transmission electron microscopy images revealed nanometric quasispherical-shaped multilamellar vesicles (size ranging from 50 to 160 nm).

  2. Indicators for technological, environmental and economic sustainability of ozone contactors.

    Science.gov (United States)

    Zhang, Jie; Tejada-Martinez, Andres E; Lei, Hongxia; Zhang, Qiong

    2016-09-15

    Various studies have attempted to improve disinfection efficiency as a way to improve the sustainability of ozone disinfection which is a critical unit process for water treatment. Baffling factor, CT10, and log-inactivation are commonly used indicators for quantifying disinfection credits. However the applicability of these indicators and the relationship between these indicators have not been investigated in depth. This study simulated flow, tracer transport, and chemical species transport in a full-scale ozone contactor operated by the City of Tampa Water Department and six other modified designs using computational fluid dynamics (CFD). Through analysis of the simulation results, we found that baffling factor and CT10 are not optimal indicators of disinfection performance. We also found that the relationship between effluent CT obtained from CT transport simulation and baffling factor depends on the location of ozone release. In addition, we analyzed the environmental and economic impacts of ozone contactor designs and upgrades and developed a composite indicator to quantify the sustainability in technological, environmental and economic dimensions.

  3. Gas Centrifuges and Nuclear Proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Albright, David

    2004-09-15

    Gas centrifuges have been an ideal enrichment method for a wide variety of countries. Many countries have built gas centrifuges to make enriched uranium for peaceful nuclear purposes. Other countries have secretly sought centrifuges to make highly enriched uranium for nuclear weapons. In more recent times, several countries have secretly sought or built gas centrifuges in regions of tension. The main countries that have been of interest in the last two decades have been Pakistan, Iraq, Iran, and North Korea. Currently, most attention is focused on Iran, Pakistan, and North Korea. These states did not have the indigenous abilities to make gas centrifuges, focusing instead on illicit and questionable foreign procurement. The presentation covered the following main sections: Spread of centrifuges through illicit procurement; Role of export controls in stopping proliferation; Increasing the transparency of gas centrifuge programs in non-nuclear weapon states; and, Verified dismantlement of gas centrifuge programs. Gas centrifuges are important providers of low enriched uranium for civil nuclear power reactors. They also pose special nuclear proliferation risks. We all have special responsibilities to prevent the spread of gas centrifuges into regions of tension and to mitigate the consequences of their spread into the Middle East, South Asia, and North Asia.

  4. Tests of a Higgins contactor for the engineering-scale resin loading of uranium

    International Nuclear Information System (INIS)

    The loading of uranium on weak-acid ion exchange resin is a basic step in the production of fuel particles for high-temperature gas-cooled reactors (HTGRs). In the work reported here, an engineering-scale continuous resin loader (2-in.-ID Higgins contactor) was tested with existing engineering-scale process equipment. The Higgins contactor was first successfully used to convert Na+-form resin to the H+-form; then it was evaluated as a uranium loader. Results show that the 2-in.-ID Higgins contactor can easily load 25 kg of uranium per day, indicating that a 4-in.-ID contactor could load 100 kg/day. Process control was achieved by monitoring and controlling the density, pH, and inventory volume of the uranium feed solution. This control scheme is amenable to remote operation

  5. Simulation Study of AC Contactor Dynamic Contacts Contact Pressure Based on ADAMS

    Directory of Open Access Journals (Sweden)

    Gu Yungao

    2015-01-01

    Full Text Available A multi-body dynamics simulation model of CJ20-25 AC contactor was established with Pro/E(Pro/Engineerin this paper. A coupling simulation with machine, electric, magnetic on the contactor has been achieved in this model. Dynamic parameters which were called use the secondary development technology of ADAMS. The dynamic contact pressure signal of an AC contactor was obtained with ADAMS’s own simultaneous solution such as electromagnetic suction, kinematics and dynamics equations. The simulation results and actual measurement of contactor contact pressure signals are very similar. However, the complexity of the measured contacts vibration is greater than the simulation results because the actual working condition is more complex. This result provides a theoretical foundation to the dynamic contacts contact pressure test.

  6. OZONE CONTACTOR FLOW VISUALIZATION AND CHARACTERIZATION USING 3-DIMENSIONAL LASER INDUCED FLUORESCENCE

    Science.gov (United States)

    Hydrodynamics of ozone contactors have a crucial impact on efficient inactivation of pathogens such as Cryptosporidium as well as control of disinfection byproducts such as bromate. Improper mixing behaviors including short-circuiting, internal recirculation and presence...

  7. Applying Closing Phase-Angle Control Technique in Bounce Reduction of AC Permanent Magnet Contactor

    Directory of Open Access Journals (Sweden)

    Chieh-Tsung Chi

    2009-01-01

    Full Text Available A new low-cost electronic control circuit actuator is proposed for minimizing the bouncing times of an AC permanent magnet (PM contactor after two contacts closing. The proposed new actuator overcomes the bouncing problem of an uncontrollable restrictions imposed by previously conventional AC electromagnetic (EM contactor based on the minimization of kinetic energy prior to two contacts impact. By choosing the closing phase angle of coil voltage on purpose, the bouncing problems of the movable contact during the closing process are then overcome. The using life of contacts is then prolonged and their operating reliability is improved as well. In order to validate the feasibility and effectiveness of the proposed method here, several simulation and experimental procedures were performed on a prototype of AC PM contactor in the laboratory. Testing results actually showed that bouncing problem of contactor's contacts during the closing process was to be controlled by using the proposed technology.

  8. REVIEW OF CURRENT RBC (ROTATING BIOLOGICAL CONTACTOR) PERFORMANCE AND DESIGN PROCEDURES

    Science.gov (United States)

    The rapid emergence of rotating biological contactor (RBC) technology as an alternative secondary wastewater treatment process has increased the need to review their performance history to provide information to the design engineer. This study, to review and compare current desig...

  9. Centrifugal-reciprocating compressor

    Science.gov (United States)

    Higa, W. H. (Inventor)

    1984-01-01

    A centrifugal compressor is described which includes at least one pair of cylinders arranged in coaxial alignment and supported for angular displacement about a common axis of rotation normally disecting a common longitudinal axis of symmetry for the cylinders. The cylinders are characterized by ported closures located at the mutually remote ends thereof through which the cylinders are charged and discharged, and a pair of piston heads seated within the cylinders and supported for floating displacement in compressive strokes in response to unidirectional angular displacement imparted to the cylinders.

  10. Centrifugal bucket hoist

    OpenAIRE

    Kotačka, Petr

    2014-01-01

    This bachelor thesis deals with an engineering design of a centrifugal bucket elevator with transport height 6.5 metres and transport performance 40 000 kilograms per hour. The thesis focuses especially on a functional calculation of the elevator thanks to which a gear motor, band and bucket are chosen. This is followed by an analysis of a constructional solution with a strength check of a drive shaft and parallel keys as well as a calculation of a service life of bearings. Technical document...

  11. Treatment of Antibiotic Pharmaceutical Wastewater Using a Rotating Biological Contactor

    Directory of Open Access Journals (Sweden)

    Rongjun Su

    2015-01-01

    Full Text Available Rotating biological contactors (RBC are effective for treating wastewater, while they are rarely reported to be used for treating antibiotic pharmaceutical wastewater (APW. The current study investigates treatment of APW using an RBC. The effects of influent concentration, number of stages, and temperature on the remediation of APW were studied. The results indicated, even at low ambient temperature, 45% COD and 40% NH4+-N removal efficiencies. Moreover, the BOD5 removal efficiency was 85%. Microscopic observations illustrated that there were various active microorganisms displayed in the biofilms and their distribution changed from stage to stage. Compared with activated sludge, the biofilms in this study have higher content of dry matter and are easier to dehydrate and settle. Compared with current commercial incineration processes or advanced oxidation processes, RBC can greatly reduce the treatment cost. This research shows RBC is effective for such an inherently biorecalcitrant wastewater even at low ambient temperature.

  12. DENITRIFICATION PROCESS ENHANCING IN FOUR-STAGES ROTATING BIOLOGICAL CONTACTOR

    Directory of Open Access Journals (Sweden)

    Artur Mielcarek

    2016-06-01

    Full Text Available The aim of the study was to determine the degree of an organic substrate consumption in the denitrification process involving a biofilm in four-stages laboratory scale rotating biological contactor (RBC. The discs submergence was 40% of their diameter. Acetic acid, used as external carbon source, was fed to the fourth stage of RBC. Consumption of substrate was observed for 2 and 24 hours. For a shorter period there was the removal of 37.9 ± 1.8 mg N·m-2, while using 499,9 ± 33.2 mg O2·m-2 of organic compounds. The prolongation of the experiment duration guaranteed higher efficiency of denitrification. The ratio of organic substrate used to the amount of nitrogen removed was 13: 1 and 21: 1 for 2 and 24 hours respectively.

  13. LOW-PRESSURE MEMBRANE CONTACTORS FOR CARBON DIOXIDE CAPTURE

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Richard; Kniep, Jay; Hao, Pingjiao; Chan, Chi Cheng; Nguyen, Vincent; Huang, Ivy; Amo, Karl; Freeman, Brice; Fulton, Don; Ly, Jennifer; Lipscomb, Glenn; Lou, Yuecun; Gogar, Ravikumar

    2014-09-30

    This final technical progress report describes work conducted by Membrane Technology and Research, Inc. (MTR) for the Department of Energy (DOE NETL) on development of low-pressure membrane contactors for carbon dioxide (CO2) capture from power plant flue gas (award number DE-FE0007553). The work was conducted from October 1, 2011 through September 30, 2014. The overall goal of this three-year project was to build and operate a prototype 500 m2 low-pressure sweep membrane module specifically designed to separate CO2 from coal-fired power plant flue gas. MTR was assisted in this project by a research group at the University of Toledo, which contributed to the computational fluid dynamics (CFD) analysis of module design and process simulation. This report details the work conducted to develop a new type of membrane contactor specifically designed for the high-gas-flow, low-pressure, countercurrent sweep operation required for affordable membrane-based CO2 capture at coal power plants. Work for this project included module development and testing, design and assembly of a large membrane module test unit at MTR, CFD comparative analysis of cross-flow, countercurrent, and novel partial-countercurrent sweep membrane module designs, CFD analysis of membrane spacers, design and fabrication of a 500 m2 membrane module skid for field tests, a detailed performance and cost analysis of the MTR CO2 capture process with low-pressure sweep modules, and a process design analysis of a membrane-hybrid separation process for CO2 removal from coal-fired flue gas. Key results for each major task are discussed in the report.

  14. Centrifugal shot blast system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997.

  15. Centrifugal shot blast system

    International Nuclear Information System (INIS)

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997

  16. Centrifugal microfluidics for biomedical applications.

    Science.gov (United States)

    Gorkin, Robert; Park, Jiwoon; Siegrist, Jonathan; Amasia, Mary; Lee, Beom Seok; Park, Jong-Myeon; Kim, Jintae; Kim, Hanshin; Madou, Marc; Cho, Yoon-Kyoung

    2010-07-21

    The centrifugal microfluidic platform has been a focus of academic and industrial research efforts for almost 40 years. Primarily targeting biomedical applications, a range of assays have been adapted on the system; however, the platform has found limited commercial success as a research or clinical tool. Nonetheless, new developments in centrifugal microfluidic technologies have the potential to establish wide-spread utilization of the platform. This paper presents an in-depth review of the centrifugal microfluidic platform, while highlighting recent progress in the field and outlining the potential for future applications. An overview of centrifugal microfluidic technologies is presented, including descriptions of advantages of the platform as a microfluidic handling system and the principles behind centrifugal fluidic manipulation. The paper also discusses a history of significant centrifugal microfluidic platform developments with an explanation of the evolution of the platform as it pertains to academia and industry. Lastly, we review the few centrifugal microfluidic-based sample-to-answer analysis systems shown to date and examine the challenges to be tackled before the centrifugal platform can be more broadly accepted as a new diagnostic platform. In particular, fully integrated, easy to operate, inexpensive and accurate microfluidic tools in the area of in vitro nucleic acid diagnostics are discussed.

  17. Unshrouded Centrifugal Turbopump Impeller

    Science.gov (United States)

    Prueger, George; Williams, Morgan; Chen, Wei; Paris, John; Stewart, Eric; Williams, Robert

    1999-01-01

    The ratio of rocket engine thrust to weight is a limiting constraint in placing more payload into orbit at a low cost. A key component of an engine's overall weight is the turbopump weight, Reducing the turbopump weight can result in significant engine weight reduction and hence, increased delivered payload. There are two main types of pumps: centrifugal and axial pumps. These types of pumps can be further sub-divided into those with shrouds and those without shrouds (unshrouded pumps). Centrifugal pumps can achieve the same pump discharge pressure as an axial pump and it requires fewer pump stages and lower pump weight than an axial pump. Also, with unshrouded centrifugal pumps (impeller), the number of stages and weight can be further reduced. However. there are several issues with regard to using an unshrouded impeller: 1) there is a pump performance penalty due to the front open face recirculation flow; 2) there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face; and, 3) since test data is very linu'ted for this configuration, there is uncertainty in the magnitude and phase of the rotordynamics forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the design's hydrodynamic performance, axial thrust, and rotordynamics performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design. In particular, the paper will discuss the design of three unshrouded impellers - one with 5 full and 5 partial blades (5+5). one with 6+6 blades and one with 8+8 blades. One of these designs will be selected for actual fabrication and flow test. Computational fluid dynamics (CFD) is used to help design and optimize the unshrouded impeller. The relative pump performance penalty is assessed by comparing the CFD results of the unshrouded impeller with the equivalent shrouded impeller for a

  18. Pre-Combustion Carbon Capture by a Nanoporous, Superhydrophobic Membrane Contactor Process

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Howard; Zhou, S James; Ding, Yong; Bikson, Ben

    2012-03-31

    This report summarizes progress made during Phase I and Phase II of the project: "Pre-Combustion Carbon Capture by a Nanoporous, Superhydrophobic Membrane Contactor Process," under contract DE-FE-0000646. The objective of this project is to develop a practical and cost effective technology for CO{sub 2} separation and capture for pre-combustion coal-based gasification plants using a membrane contactor/solvent absorption process. The goals of this technology development project are to separate and capture at least 90% of the CO{sub 2} from Integrated Gasification Combined Cycle (IGCC) power plants with less than 10% increase in the cost of energy services. Unlike conventional gas separation membranes, the membrane contactor is a novel gas separation process based on the gas/liquid membrane concept. The membrane contactor is an advanced mass transfer device that operates with liquid on one side of the membrane and gas on the other. The membrane contactor can operate with pressures that are almost the same on both sides of the membrane, whereas the gas separation membranes use the differential pressure across the membrane as driving force for separation. The driving force for separation for the membrane contactor process is the chemical potential difference of CO{sub 2} in the gas phase and in the absorption liquid. This process is thus easily tailored to suit the needs for pre-combustion separation and capture of CO{sub 2}. Gas Technology Institute (GTI) and PoroGen Corporation (PGC) have developed a novel hollow fiber membrane technology that is based on chemically and thermally resistant commercial engineered polymer poly(ether ether ketone) or PEEK. The PEEK membrane material used in the membrane contactor during this technology development program is a high temperature engineered plastic that is virtually non-destructible under the operating conditions encountered in typical gas absorption applications. It can withstand contact with most of the common treating

  19. [Galileo and centrifugal force].

    Science.gov (United States)

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century.

  20. [Galileo and centrifugal force].

    Science.gov (United States)

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century. PMID:25029818

  1. Membrane contactor assisted water extraction system for separating hydrogen peroxide from a working solution, and method thereof

    Science.gov (United States)

    Snyder, Seth W.; Lin, Yupo J.; Hestekin' Jamie A.; Henry, Michael P.; Pujado, Peter; Oroskar, Anil; Kulprathipanja, Santi; Randhava, Sarabjit

    2010-09-21

    The present invention relates to a membrane contactor assisted extraction system and method for extracting a single phase species from multi-phase working solutions. More specifically one preferred embodiment of the invention relates to a method and system for membrane contactor assisted water (MCAWE) extraction of hydrogen peroxide (H.sub.2O.sub.2) from a working solution.

  2. Evaluating hydraulic and disinfection efficiencies of a full-scale ozone contactor using a RANS-based modeling framework.

    Science.gov (United States)

    Zhang, Jie; Tejada-Martínez, Andrés E; Zhang, Qiong; Lei, Hongxia

    2014-04-01

    The capability of predicting hydraulic and disinfection efficiencies of ozone disinfection contactors is essential for evaluating existing contactors and improving future designs. Previous attempts based on ideal and non-ideal models for the hydraulics and simplified mechanisms for chemical reaction modeling have resulted in low accuracy and are restricted to contactors with simple geometries. This manuscript develops a modeling framework for the ozonation process by combining computational fluid dynamics (CFD) with a kinetics-based reaction modeling for the first time. This computational framework has been applied to the full-scale ozone contactor operated by the City of Tampa Water Department. Flow fields, residence time distribution, ozone concentration distribution, and concentration-contact time (CT) distribution within the contactor have been predicted via the computational framework. The predictions of ozone and bromate concentrations at sample points agree well with physical experimental data measured in the contactor. The predicted CT values at the contactor outlet demonstrate that the disinfection performance of the ozone contactor operated by the City of Tampa Water Department is sufficient to meet regulation requirements. The impact of seasonal flow rate change on disinfection performance is found to be significant and deserves attention during the management and operation of a water treatment plant.

  3. Microwave assisted centrifuge and related methods

    Science.gov (United States)

    Meikrantz, David H [Idaho Falls, ID

    2010-08-17

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  4. Uranium enrichment by gas centrifuge

    International Nuclear Information System (INIS)

    After recalling the physical principles and the techniques of centrifuge enrichment the report describes the centrifuge enrichment programmes of the various countries concerned and compares this technology with other enrichment technologies like gaseous diffusion, laser, aerodynamic devices and chemical processes. The centrifuge enrichment process is said to be able to replace with advantage the existing enrichment facilities in the short and medium term. Future prospects of the process are also described, like recycled uranium enrichment and economic improvements; research and development needs to achieve the economic prospects are also indicated. Finally the report takes note of the positive aspect of centrifuge enrichment as far as safeguards and nuclear safety are concerned. 27 figs, 113 refs

  5. Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Duignan, M. R.; Williams, M. R.; Peters, T. B.; Poirier, M. R.; Fondeur, F. F.

    2013-07-31

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the “first stage” D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet

  6. Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent

    International Nuclear Information System (INIS)

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7 dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the ''first stage'' D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet

  7. Gas centrifugal separator

    International Nuclear Information System (INIS)

    Object: To enhance separating performance by jointly using separating action of impulse wave without increasing peripheral speed of a gas centrifugal separator and lengthening a cylindrical portion thereof. Structure: A mixed gas is introduced into a rotating cylinder from a mixed gas pipe and is separated into gas rich in light component and gas decreased in light component, these gases being taken outside the rotating cylinder through a product opening and a fixed waste pipe, respectively. A fixed product recycling pipe is disposed between an upper end plate and an upper buffer plate of the rotating cylinder the recycling pipe having an opening formed at the leading end so as to oppose to the rotating mixed gas, and the gas introduced from the opening is re-introduced into the central portion of the rotating cylinder for recirculation. A waste pipe is disposed between a lower end plate and a lower buffer plate of the rotating cylinder, and the gas not introduced into the opening of the waste pipe is circulated within the rotating cylinder. (Kamimura, M.)

  8. Preliminary Study of Greywater Treatment through Rotating Biological Contactor

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmed Pathan

    2011-07-01

    Full Text Available The characteristics of the greywater vary from country to country and it depends upon the cultural and social behavior of the respective country. There was a considerable need to characterize and recycle the greywater. In this regard greywater was separated from the black water and analyzed for various physiochemical parameters. Among various greywater recycling treatment technologies, RBC (Rotating Biological Contactor is more effective treatment technique in reducing COD (Chemical Oxygen Demand and organic matters from the greywater. But this technology was not applied and tested in Pakistan. There was extensive need to investigate the RBC technology for greywater recycling at small scale before applying at mass scale. To treat the greywater, a single-stage RBC simulator was designed and developed at laboratory scale. An electric motor equipped with gear box to control the rotations of the disks was mounted on the tank. The simulator was run at the rate of 1.7 rpm. The disc area of the RBC was immersed about 40% in the greywater. Water samples were collected at each HRT (Hydraulic Retention Time and analyzed for the parameters such as pH, conductivity, TDS (Total Dissolved Solids, salinity, BOD5 (Biochemical Oxygen Demand, COD and suspended solids by using standard methods. The results are encouraging with percentage removal of BOD5 and COD being 53 and 60% respectively.

  9. Effect of Sedimentation on Treated Greywater Through Rotating Biological Contactor

    Directory of Open Access Journals (Sweden)

    Ashfaque Ahmed Pathan

    2016-06-01

    Full Text Available The aim of this paper was to study the effect of sedimentation on effluent of a pilot scale Rotating Biological Contactor (RBC. The treated greywater was given three hours sedimentation period and samples were analyzed to observe the effect of sedimentations under variousflow rates. Greywater was separated from the black water and collected in the collection tank and then it was pumped to an overhead tank. This tank supplied a regulated continuous flow of greywater into the RBC chamber at the required flow rate ranging between 0.28 to 1.89 l/min. A pilot scale RBC simulator was developed and placed outside a hall of residence at National Center of Excellence in Analytical Chemistry, Sindh University, Jamshoro. The simulator was operated at the rotational speed of discs of 1.7 rpm. The disks were uneven and textured so as to encourage growth of bacteria on them. These discs were immersed about 40 percent in the greywater.The simulator produced effluent of significant quality and was found efficient in removal of BOD5, COD and TSS as 85%, 68% and 95% respectively.

  10. A turbulent bed contactor: energetic efficiency for particle collection

    Directory of Open Access Journals (Sweden)

    M. L. Gimenes

    2007-03-01

    Full Text Available Particle collection experiments were conducted in a fluidizing irrigated bed to evaluate the performance of mobile packings: 38 x 50 mm plain oblate spheroids 38 mm ID plain spheres and alternative perforated spheres with a 38 mm ID and 10% and 25% free areas were used as fluidizing media in a 0.264 m diameter and 1.20 m high turbulent bed contactor (TBC. Particle collection experiments were carried out above the minimum fluidization velocity, using as particulate test powder polysized alumina (size 1.5 to 5.5 mm. Experimental results demonstrated that the perforated spheres performed better in collecting particles than the other packings tested. The efficiency of particle collection was analysed based on energy consumption in the TBC, using the energetic efficiency concept. It was verified that not much more energy was consumed per unit of gas flow in fluidized beds of perforated packings than in those of conventional plain sphere packings, since the perforated spheres were more energetically efficient for particle collection than plain spheres and oblate spheroid packings.

  11. Modified rotating biological contactor for removal of dichloromethane vapours.

    Science.gov (United States)

    Ravi, R; Philip, Ligy; Swaminathan, T

    2015-01-01

    Bioreactors are used for the treatment of waste gas and odour that has gained much acceptance in the recent years to treat volatile organic compounds (VOCs). The different types of bioreactors (biofilter, biotrickling filter and bioscrubber) have been used for waste gas treatment. Each of these reactors has some advantages and some limitations. Though biodegradation is the main process for the removal of the pollutants, the mechanisms of removal and the microbial communities may differ among these bioreactors. Consequently, their performance or removal efficiency may also be different. Clogging of reactor and pressure drop are the main problems. In this study attempts are made to use the principle of rotating biological contactor (RBC) used for wastewater treatment for the removal of VOC. To overcome the above problem the RBC is modified which is suitable for the treatment of VOC (dichloromethane, DCM). DCM is harmful to human health and hazardous to the atmospheric environment. Modified RBC had no clogging problems and no pressure drop. So, it can handle the pollutant load for a longer period of time. A maximum elimination capacity of 25.7 g/m3 h has been achieved in this study for the DCM inlet load of 58 g/m3 h. The average biofilm thickness is 1 mm. The transient behaviour of the modified RBC treating DCM was investigated. The modified RBC is able to handle shutdown, restart and shock loading operations.

  12. Life Cycle Tests on a Hollow Cathode Based Plasma Contactor

    Science.gov (United States)

    Vaughn, Jason A.; Schneider, Todd A.; Munafo, Paul (Technical Monitor)

    2001-01-01

    The propulsive Small Expendable Deployer System (ProSEDS) mission is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta II unmanned expendable booster with a mission duration of 12 days. A 5-km conductive tether is attached to the Delta II second stage and collects current from the low Earth orbit (LEO) plasma, and a Hollow Cathode Plasma Contactor (HCPC) emits the collected electrons from the Delta II, completing the electrical circuit to the ambient plasma. The HCPC for the ProSEDS mission have made it necessary to turn off the HCPC once a minute throughout the entire mission. Because of the unusual operating requirements by the ProSEDS mission, an engineering development unit of the HCPC was built to demonstrate the HCPC design would start reliably for the life of the ProSEDS mission. During the life test the engineering unit cycled for over 10,000 on/off cycles without missing a single start, and during that same test the HCPC unit demonstrated the capability to emit 0 to 5 A electron emission current. The performance of the HCPC unit during this life test will be discussed.

  13. Apparatus for supporting contactors used in extracting nuclear materials from liquids

    Science.gov (United States)

    Leonard, Ralph A.; Frank, Robert C.

    1991-01-01

    Apparatus is provided for supporting one or more contactor stages used to remove radioactive materials from aqueous solutions. The contactor stages include a housing having an internal rotor, a motor secured to the top of the housing for rotating the rotor, and a drain in the bottom of the housing. The support apparatus includes two or more vertical members each secured to a ground support that is horizontal and perpendicular to the frame member, and a horizontally disposed frame member. The frame member may be any suitable shape, but is preferably a rectangular tube having substantially flat, spaced top and bottom surfaces separated by substantially vertical side surfaces. The top and bottom surfaces each have an opening through which the contactor housing is secured so that the motor is above the frame and the drain is below the frame during use.

  14. Application of PTFE membrane for ammonia removal in a membrane contactor.

    Science.gov (United States)

    Ahn, Y T; Hwang, Y H; Shin, H S

    2011-01-01

    The feasibility of a membrane contactor system for ammonia removal was studied. The mass transfer coefficient was used to quantitatively compare the effect of various operation conditions on ammonia removal efficiency. Effective removal of ammonia was possible with a Polytetrafluoroethylene (PTFE) membrane contactor system at all tested conditions. Among the various operation parameters, contact time and solution pH showed significant effect on the ammonia removal mechanism. The overall ammonia removal rate was not affected by influent suspended solution concentration unlike other pressure driven membrane filtration processes. Also the osmotic distillation phenomena which deteriorate the mass transfer efficiency can be minimized by preheating of influent wastewater. A membrane contactor system can be a possible alternative to treat high strength nitrogen wastewater by optimizing operation conditions such as stripping solution flow rate, influent wastewater temperature, and influent pH.

  15. Modeling and Hardware-in-the-loop Simulations of Contactor Dynamics : Mechanics, Electromagnetics and Software

    OpenAIRE

    Tjerngren, Jon

    2014-01-01

    This master thesis’s subject is to model an ABB contactor’s dynamics and to develop a hardware-in-the-loop simulation environment. The hardware-in-the-loop method utilizes computer models that are simulated in a real-time simulator. The real-time simulator is connected to hardware components. A contactor is an electrically controlled mechanical switching device and it is used in circuits where large currents can occur. In this thesis, the contactor is divided into three separate subsystems an...

  16. Hyperbolically Shaped Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Romuald Puzyrewski; Pawel Flaszy(n)ski

    2003-01-01

    Starting from the classical centrifugal compressor, cone shaped in meridional cross section, two modifications are considered on the basis of results from 2D and 3D flow models. The first modification is the change of the meridional cross section to hyperbolically shaped channel. The second modification, proposed on the basis of 2D axisymmetric solution, concerns the shape of blading. On the strength of this solution the blades are formed as 3D shaped blades, coinciding with the recent tendency in 3D designs. Two aims were considered for the change of meridional compressor shape. The first was to remove the separation zone which appears as the flow tums from axial to radial direction. The second aim is to uniformize the flow at exit of impeller. These two goals were considered within the frame of 2D axisymmetric model. Replacing the cone shaped compressor by a hyperbolically shaped one, the separation at the corner was removed. The disc and shroud shape of the compressor was chosen in the way which satisfies the condition of most uniform flow at the compressor exit. The uniformity of exit flow from the rotor can be considered as the factor which influences the performance of the diffuser following the rotor. In the 2D model a family of stream surfaces of S1 type is given in order to find S2 surfaces which may be identified with the midblade surfaces of compressor blading. A computation of 3D type has been performed in order to establish the relations between 2D and 3D models in the calculation of flow parameters. In the presented example the 2D model appears as the inverse model which leads to 3D shape of blading whereas the 3D model has been used for the direct solution. In the presented example the confrontation of two models, 2D and 3D, leads to a better understanding of the application of these models to the design procedure.

  17. Centrifugation. A theoretical study of oxygen enrichment by centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Kierkegaard, P.; Raetz, E.

    1998-12-01

    In the present paper we first investigate what happens if we fill a cylinder with air, close it and rotate it. The results show that no matter which peripheral speed is used, it is not possible by means of the radial separation effect alone, to enrich the oxygen concentration from the previous 21% to more then 23.3%, which is of no practical value. In case of a too low enrichment in one centrifuge, the wanted material from this centrifuge can be used as an input for a second centrifuge and so on, in this way forming a cascade of centrifuges. Oxygen will be enriched in each step, until the desired concentration is reached. Cascading was the technology in the very beginning by enrichment plants for uraniumhexaflouride, used for atomic weapons and nuclear power plants. In this study we try to avoid cascading by aiming for higher separation factors. Therefore, we next investigate the possibilities of using a countercurrent centrifuge where in principle the enriched gas is subjected to several centrifugation in the same centrifuge. The calculations show, that in this way it is possible to produce nearly a 100% pure oxygen (polluted with some heavier molecules like argon) in one machine. Our third step was to calculate the amount of oxygen produced per hour. Using a countercurrent centrifuge of the Zippe type, 100 cm high and 20 cm in diameter, it is or will be possible in the near future to produce 17 g enriched air per hour enriched to 50% oxygen. That corresponds to processing 1 m{sup 3} atmospherical air in the period of approximately 24 hours. This is not very impressive. Our fourth step was to estimate the amount of power used for producing this amount of oxygen. A rough, but complicated, estimate shows that the power consumption at the production level will be about the double of the consumption used today. The overall conclusion is, that centrifugation as a production method for oxygen (or nitrogen) will not be competitive with the currently used method in the

  18. FOULING CHARACTERIZATION OF MEMBRANE CONTACTORS USED FOR THE RECOVERY AND CONCENTRATION OF AMMONIA FROM UNDIGESTED PIG SLURRY

    DEFF Research Database (Denmark)

    Zarebska, Agata; Norddahl, Birgir; Christensen, Knud Villy

    2012-01-01

    The main obstacle impeding implementation of membrane contactors for the recovery and concentration of ammonia from swine manure is the phenomena of membrane fouling. Fouling is defined as the accumulation of suspended or dissolved substances on the membrane surface and/or within its pores. Due...... a week of running the contactor without cleaning. This indicates that fouling could be a severe problem. The intensity of fouling can be reduced by feed pretreatment and by optimizing the operating conditions of the membrane contactor. This will also facilitate removal of ammonia....

  19. 新型交流接触器的应用%Application of New Type of AC Contactor

    Institute of Scientific and Technical Information of China (English)

    刘冬英; 李克芹

    2009-01-01

    简要介绍了TJ40(CJ45)系列新型交流接触器,详细阐述了两种派生产品的用途、结构、特点和应用,即机械联锁可逆交流接触器和切换电容器交流接触器.%The TJ40(CJ45)series new of AC contactors were introduced briefly.The use,structure,trait and application of the two derived contactor products,viz.mechanical interlock reversible AC contactor and smtching capacitor AC eontactor,were expounded.

  20. Treatment of anaerobically pre-treated domestic sewage by a rotating biological contactor

    NARCIS (Netherlands)

    Tawfik, A.; Klapwijk, A.; el-Gohary, F.; Lettinga, G.

    2002-01-01

    The performance of a rotating biological contactor (RBC) for the post-treatment of the effluent of an up-flow anaerobic sludge blanket (UASB) was the subject of this study. Different hydraulic and organic loading rates have been investigated. The removal efficiencies of CODtotal, CODsuspended, CODco

  1. Surface-Roughness-Based Virtual Textiles: Evaluation Using a Multi-Contactor Display.

    Science.gov (United States)

    Philpott, Matthew; Summers, Ian R

    2015-01-01

    Virtual textiles, generated in response to exploratory movements, are presented to the fingertip via a 24-contactor vibrotactile array. Software models are based on surface-roughness profiles from real textiles. Results suggest that distinguishable "textile-like" surfaces are produced, but these lack the necessary accuracy for reliable matching to real textiles.

  2. Validation of a simple method for predicting the disinfection performance in a flow-through contactor.

    Science.gov (United States)

    Pfeiffer, Valentin; Barbeau, Benoit

    2014-02-01

    Despite its shortcomings, the T10 method introduced by the United States Environmental Protection Agency (USEPA) in 1989 is currently the method most frequently used in North America to calculate disinfection performance. Other methods (e.g., the Integrated Disinfection Design Framework, IDDF) have been advanced as replacements, and more recently, the USEPA suggested the Extended T10 and Extended CSTR (Continuous Stirred-Tank Reactor) methods to improve the inactivation calculations within ozone contactors. To develop a method that fully considers the hydraulic behavior of the contactor, two models (Plug Flow with Dispersion and N-CSTR) were successfully fitted with five tracer tests results derived from four Water Treatment Plants and a pilot-scale contactor. A new method based on the N-CSTR model was defined as the Partially Segregated (Pseg) method. The predictions from all the methods mentioned were compared under conditions of poor and good hydraulic performance, low and high disinfectant decay, and different levels of inactivation. These methods were also compared with experimental results from a chlorine pilot-scale contactor used for Escherichia coli inactivation. The T10 and Extended T10 methods led to large over- and under-estimations. The Segregated Flow Analysis (used in the IDDF) also considerably overestimated the inactivation under high disinfectant decay. Only the Extended CSTR and Pseg methods produced realistic and conservative predictions in all cases. Finally, a simple implementation procedure of the Pseg method was suggested for calculation of disinfection performance.

  3. Using 3D LIF to Investigate and Improve Performance of a Multichamber Ozone Contactor

    Science.gov (United States)

    Three-dimensional laser-induced fluorescence (3DLIF) was applied to visualize and quantitatively analyze hydrodynamics and mixing in a multi-chamber ozone contactor, the most widely used design for water disinfection. The results suggested that the mixing was characterized by ext...

  4. Modelling of cross-flow membrane contactors : Physical mass transfer processes

    NARCIS (Netherlands)

    Dindore, V. Y.; Brilman, D. W. F.; Versteeg, G. F.

    2005-01-01

    Traditionally, hollow fiber membrane contactors used for gas-liquid contacting were designed in a shell and tube configuration with shell-side fluid flowing parallel to the fiber-side fluid, either in co-current or counter-current pattern. The primary limitations of these so-called 'parallel flow' c

  5. Membrane–solvent selection for CO2 removal using membrane gas–liquid contactors

    NARCIS (Netherlands)

    Dindore, V.Y.; Brilman, D.W.F.; Geuzebroek, F.H.; Versteeg, G.F.

    2004-01-01

    Membrane gas–liquid contactors can provide very high interfacial area per unit volume, independent regulation of gas and liquid flows and are insensitive to module orientation, which make them very attractive in comparison with conventional equipments for offshore application. However, the membrane

  6. Axial liquid mixing in a gas-liquid Multi-Stage Agitated Contactor (MAC)

    NARCIS (Netherlands)

    Breman, B.B; Beenackers, A.A C M; Bouma, M.J; VanderWerf, M.H.

    1996-01-01

    Data on interstage liquid mixing are reported for a gas-liquid Multi-stage Agitated Contactor (MAC). A dynamic method using heat as a tracer was applied for water, n-octane and monoethylene glycol as liquids both with and without the presence of a dispersed gas phase (air). In all cases, the axial m

  7. Extraction of uranium from in-situ leach solutions using the NIMCIX ion exchange contactor

    International Nuclear Information System (INIS)

    The NIMCIX ion exchange column is a multi-stage fluidized bed contactor to permit a counter-current flow of solution and resin in order to maximize extraction efficiency. Batch or continuous elution methods with fully automated or manual control systems may be selected for different process solution conditions. 8 refs

  8. Biofilm growth of Chlorella sorokiniana in a rotating biological contactor based photobioreactor

    NARCIS (Netherlands)

    Blanken, W.M.; Janssen, M.G.J.; Cuaresma, M.; Libor, Z.; Bhaiji, T.; Wijffels, R.H.

    2014-01-01

    Microalgae biofilms could be used as a production platform for microalgae biomass. In this study, a photobioreactor design based on a rotating biological contactor (RBC) was used as a production platform for microalgae biomass cultivated in biofilm. In the photobioreactor, referred to as Algadisk, m

  9. Amine-based solvents regeneration in gas-liquid membrane contactor based on asymmetric PVTMS

    NARCIS (Netherlands)

    Volkov, A.V.; Tsarkov, S.E.; Goetheer, E.L.V.; Volkov, V.V.

    2015-01-01

    Asymmetric flat-sheet membranes made of poly(vinyltrimethylsilane) (PVTMS) were studied for the regeneration of amine-based absorption solvents in a membrane gas-liquid contactor at 100°C. It was shown that PVTMS membrane possesses good mechanical and chemical stability in contact with 4 M monoethan

  10. Centrifugation and the Manhattan Project

    Science.gov (United States)

    Reed, Cameron

    2009-05-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  11. Mass Transfer And Hydraulic Testing Of The V-05 And V-10 Contactors With The Next Generation Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Duignan, M. R.; Williams, M. R.; Peters, T. B.; Poirier, M. R.; Fondeur, F. F.

    2013-07-31

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent. To support this integration of NGS into the MCU facilities, Savannah River Remediation (SRR) requested that Savannah River National Laboratory (SRNL) perform testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing differs from prior testing by utilizing a blend of BOBCalixC6 based solvent and the NGS with the full (0.05 M) concentration of the MaxCalix as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. Stage efficiency and mass distribution ratios were determined by measuring Cs concentration in the aqueous and organic phases during single contactor testing. The nominal cesium distribution ratio, D(Cs) measured for extraction ranged from 37-60. The data showed greater than 96% stage efficiency for extraction. No significant differences were noted for operations at 4, 8 or 12 gpm aqueous salt simulant feed flow rates. The first scrub test (contact with weak caustic solution) yielded average scrub D(Cs) values of 3.3 to 5.2 and the second scrub test produced an average value of 1.8 to 2.3. For stripping behavior, the “first stage” D Cs) values ranged from 0.04 to 0.08. The efficiency of the low flow (0.27 gpm aqueous) was calculated to be 82.7%. The Spreadsheet

  12. Empirical Design Considerations for Industrial Centrifugal Compressors

    OpenAIRE

    Cheng Xu; Amano, Ryoichi S.

    2012-01-01

    Computational Fluid Dynamics (CFD) has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still ...

  13. Performance of a Centrifugal Slurry Pump

    OpenAIRE

    Hawas Yahya Bajawi; Basharat Salim; Ziyadh Suhibani

    2014-01-01

    The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pu...

  14. Continuous-Flow Centrifugal Separator

    Science.gov (United States)

    Waldron, Robert D.

    1988-01-01

    Apparatus combines principles of centrifugal and cyclone separators to control movement of solid or liquid particles suspended in flowing gas. Spinning disk contains radial channels, width varys as function of distance from center. Gas flows from outer ring around disk toward center. Particles in gas collected at periphery, center or both.

  15. Centrifugal pumps for rocket engines

    Science.gov (United States)

    Campbell, W. E.; Farquhar, J.

    1974-01-01

    The use of centrifugal pumps for rocket engines is described in terms of general requirements of operational and planned systems. Hydrodynamic and mechanical design considerations and techniques and test procedures are summarized. Some of the pump development experiences, in terms of both problems and solutions, are highlighted.

  16. Laser and gas centrifuge enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, Olli [Senior Fellow, Belfer Center for Science and International Affairs, Harvard Kennedy School, Cambridge, Massachusetts (United States)

    2014-05-09

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  17. Laser and gas centrifuge enrichment

    Science.gov (United States)

    Heinonen, Olli

    2014-05-01

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  18. Centrifugal separator devices, systems and related methods

    Science.gov (United States)

    Meikrantz, David H.; Law, Jack D.; Garn, Troy G.; Todd, Terry A.; Macaluso, Lawrence L.

    2012-03-20

    Centrifugal separator devices, systems and related methods are described. More particularly, fluid transfer connections for a centrifugal separator system having support assemblies with a movable member coupled to a connection tube and coupled to a fixed member, such that the movable member is constrained to movement along a fixed path relative to the fixed member are described. Also, centrifugal separator systems including such fluid transfer connections are described. Additionally, methods of installing, removing and/or replacing centrifugal separators from centrifugal separator systems are described.

  19. Design of a centrifugal blood pump: Heart Turcica Centrifugal.

    Science.gov (United States)

    Demir, Onur; Biyikli, Emre; Lazoglu, Ismail; Kucukaksu, Suha

    2011-07-01

    A prototype of a new implantable centrifugal blood pump system named Heart Turcica Centrifugal (HTC) was developed as a left ventricular assist device (LVAD) for the treatment of end-stage cardiac failure. In the development of HTC, effects of blade height and volute tongue profiles on the hydraulic and hemolytic performances of the pump were investigated. As a result, the prototype was manufactured using the best blade height and volute tongue profiles. Performance of the prototype model was experimentally evaluated in a closed-loop flow system using water as the medium. The hydraulic performance requirement of an LVAD (5 L/min flow rate against a pressure difference of 100 mm Hg) was attained at 2800 rpm rotational speed.

  20. Simulation studies of ammonia removal from water in a membrane contactor under liquid-liquid extraction mode.

    Science.gov (United States)

    Mandowara, Amish; Bhattacharya, Prashant K

    2011-01-01

    Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH(3) in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors.

  1. Simulation studies of ammonia removal from water in a membrane contactor under liquid-liquid extraction mode.

    Science.gov (United States)

    Mandowara, Amish; Bhattacharya, Prashant K

    2011-01-01

    Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH(3) in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors. PMID:20843596

  2. Centrifuge pellet injector for JET

    International Nuclear Information System (INIS)

    An engineering design of a centrifuge pellet injector for JET is reported as part of the Phase I contract number JE 2/9016. A rather detailed design is presented for the mechanical and electronic features. Stress calculations, dynamic behaviour and life estimates are considered. The interfaces to the JET vacuum system and CODAS are discussed. Proposals for the pellet diagnostics (velocity, mass and shape) are presented. (orig.)

  3. Centrifugal pumps and allied machinery

    CERN Document Server

    Anderson, HH

    1994-01-01

    This book will be of vital interest to all engineers and designers concerned with centrifugal pumps and turbines. Including statistical information derived from 20000 pumps and 700 turbines with capacities of 5gpm to 5000000gpm, this book offers the widest range and scope of information currently available. Statistical analyses suggest practical methods of increasing pump performance and provide valuable data for new design aspects.

  4. EFFECT OF ORGANIC LOADING RATES FOR TREATING GREY WATER IN ROTATING BIOLOGICAL CONTACTORS

    Directory of Open Access Journals (Sweden)

    S. Syed Enayathali

    2012-05-01

    Full Text Available The laboratory model of two-stage Rotating Biological Contactor (RBC which was used in the present study is a modified one, with a rovision to vary the speed of rotating blades. Grey wastewater was used to study the performance of the modified rotating biological contactor. The reactor had four rotating blades in each stage, having the size of 300 mm x100 mm x 10 mm, attached perpendicular to the shaft. The experiment was conducted for different influent COD loads and different speeds of rotating blades. Among the different speedsof rotational blades in treating grey water, the rotational speed of 3 rpm was found to yield better percent removal of COD at 95.07% as maximum, where as against the rotational speeds of 4.5 and 6 rpm, the treatment efficiency is 95.04% and 94.96% respectively

  5. An air-liquid contactor for large-scale capture of CO2 from air.

    Science.gov (United States)

    Holmes, Geoffrey; Keith, David W

    2012-09-13

    We present a conceptually simple method for optimizing the design of a gas-liquid contactor for capture of carbon dioxide from ambient air, or 'air capture'. We apply the method to a slab geometry contactor that uses components, design and fabrication methods derived from cooling towers. We use mass transfer data appropriate for capture using a strong NaOH solution, combined with engineering and cost data derived from engineering studies performed by Carbon Engineering Ltd, and find that the total costs for air contacting alone-no regeneration-can be of the order of $60 per tonne CO(2). We analyse the reasons why our cost estimate diverges from that of other recent reports and conclude that the divergence arises from fundamental design choices rather than from differences in costing methodology. Finally, we review the technology risks and conclude that they can be readily addressed by prototype testing.

  6. Method of reliability tolerance design based on EDA technology and its application on DC hybrid contactor

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-juan; SHA You-tao; ZHANG Hui; ZHAI Guo-fu

    2007-01-01

    Tolerance design, including tolerance analysis and distribution, is an important part of the electronic system's reliability design. The traditional design needs to construct mathematic model of material circuit, which involves large amount of workload and lacks of practicability. This paper discusses the basic theory of electronic system's reliability tolerance design and presents a new design method based on EDA (Electronic Design Automatic) software. This method has been validated through the application research on reliability tolerance design of the DC hybrid contactor's control circuit.

  7. Liposome and niosome preparation using a membrane contactor for scale-up.

    Science.gov (United States)

    Pham, Thi Thuy; Jaafar-Maalej, Chiraz; Charcosset, Catherine; Fessi, Hatem

    2012-06-01

    The scaling-up ability of liposome and niosome production, from laboratory scale using a syringe-pump device to a pilot scale using the membrane contactor module, was investigated. For this aim, an ethanol injection-based method was applied for liposome and niosome preparation. The syringe-pump device was used for laboratory scale batches production (30 ml for liposomes, 20 ml for niosomes) then a pilot scale (750 ml for liposomes, 1000 ml for niosomes) were obtained using the SPG membrane contactor. Resulted nanovesicles were characterized in terms of mean vesicles size, polydispersity index (PdI) and zeta potential. The drug encapsulation efficiency (E.E.%) was evaluated using two drug-models: caffeine and spironolactone, a hydrophilic and a lipophilic molecule, respectively. As results, nanovectors mean size using the syringe-pump device was comprised between 82 nm and 95 nm for liposomes and between 83 nm and 127 nm for niosomes. The optimal E.E. of caffeine within niosomes, was found around 9.7% whereas the spironolactone E.E. reached 95.6% which may be attributed to its lipophilic properties. For liposomes these values were about 9.7% and 86.4%, respectively. It can be clearly seen that the spironolactone E.E. was slightly higher within niosomes than liposomes. Optimized formulations, which offered smaller size and higher E.E., were selected for pilot scale production using the SPG membrane. It has been found that vesicles characteristics (size and E.E.%) were reproducible using the membrane contactor module. Thus, the current study demonstrated the usefulness of the membrane contactor as a device for scaling-up both liposome and niosome preparations with small mean sizes.

  8. Mechanical evolution of the rotating biological contactor into the 21st century.

    OpenAIRE

    Mba, David

    2003-01-01

    This paper presents a review on the evolution of the mechanical design of rotating biological contactors (RBCs) within the UK. The findings documented have been taken from the biggest mechanical survey on RBCs ever undertaken worldwide and focuses on 300 operational units. The paper looks at the main components of the RBC and discusses the evolution of each member. Mechanical deficiencies associated with each design are briefly presented, giving an insight into reasons for i...

  9. Triple-bore hollow fiber membrane contactor for liquid desiccant based air dehumidification

    KAUST Repository

    Bettahalli, N.M. Srivatsa

    2016-04-26

    Dehumidification is responsible for a large part of the energy consumption in cooling systems in high humidity environments worldwide. Improving efficiency is therefore essential. Liquid desiccants offer a promising solution for dehumidification, as desired levels of humidity removal could be easily regulated. The use of membrane contactors in combination with liquid desiccant is attractive for dehumidification because they prevent direct contact between the humid air and the desiccant, removing both the potential for desiccant carryover to the air and the potential for contamination of the liquid desiccant by dust and other airborne materials, as well as minimizing corrosion. However, the expected additional mass transport barrier of the membrane surface can lower the expected desiccation rate per unit of desiccant surface area. In this context, hollow fiber membranes present an attractive option for membrane liquid desiccant contactors because of their high surface area per unit volume. We demonstrate in this work the performance of polyvinylidene fluoride (PVDF) based triple-bore hollow fiber membranes as liquid desiccant contactors, which are permeable to water vapor but impermeable to liquid water, for dehumidification of hot and humid air.

  10. Extraction and quantification of SO2 content in wines using a hollow fiber contactor.

    Science.gov (United States)

    Plaza, Andrea; Romero, Julio; Silva, Wladimir; Morales, Elizabeth; Torres, Alejandra; Aguirre, María J

    2014-10-01

    Sulfites [Formula: see text] or sulfur dioxide (SO2) is a preservative widely used in fruits and fruit-derived products. This study aims to propose a membrane contactor process for the selective removal and recovery of SO2 from wines in order to obtain its reliable quantification. Currently, the aspiration and Ripper methods offer a difficult quantification of the sulfite content in red wines because they involve evaporation steps of diluted compounds and a colorimetric assay, respectively. Therefore, an inexpensive and accurate methodology is not currently available for continuous monitoring of SO2 in the liquids food industry. Red wine initially acidified at pH Contactor, which separates the acidified red wine in the shell side and a diluted aqueous sodium hydroxide solution as receiving solution into the lumenside in countercurrent. Sulfite and bisulfite in the acidified red wine become molecular SO2, which is evaporated through the membrane pores filled with gas. Thus, SO2 is trapped in a colorless solution and the membrane contactor controls its transfer, decreasing experimental error induced in classical methods. Experimental results using model solutions with known concentration values of [Formula: see text] show an average extraction percentage of 98.91 after 4 min. On the other hand, two types of Chilean Cabernet Sauvignon wines were analyzed with the same system to quantify the content of free and total sulfites. Results show a good agreement between these methods and the proposed technique, which shows a lower experimental variability.

  11. THC1系列交流接触器%THC1 Series AC Contactor

    Institute of Scientific and Technical Information of China (English)

    夏芳娟; 曾萍; 陈红; 陈晓军

    2009-01-01

    介绍了THC1系列交流接触器.从技术参数、结构特点、创新点及材料方面介绍了该接触器的主要特征.新产品采用热塑件以利环保,采用塑料卡扣拼装和端子罩盖便于装配,将原有限的空间分割出若十小室,互不干扰,保证了工作时期的可靠绝缘及安全.%The THC1 AC contactor was introduced.The main traits of this contactor,such as technology,structure point,innovation points and material,were introduced.Thermal plastic was adopted to protect environ-ment.Plastic block buckle and terminal cover were adopted to assemble conveniently.Primary finite space was di-vided into several small cells so that they didn't interfere each other,with ensuring reliable insulation and safety when contactor works.

  12. Centrifuge facilities at Technical University of Denmark

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane; Krogsbøll, Anette Susanne; Hededal, Ole

    2008-01-01

    The geotechnical group at the Danish Technical University (DTU) operates a geotechnical beam centrifuge. The centrifuge was build in 1976 and has been upgraded through the years, latest with onboard data and control systems. The centrifuge concept involves an increased gravity field in which...... the physical model is placed and tested. The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 75-85 in the tests which equals a soil volume in prototype scale of ø40m and a depth of 36 m. The centrifuge facilities at DTU have through the years been used for testing various...... geotechnical issues, such as suction anchors, tension piles in clay, active earth pressures on sheet piles and group effects for lateral loaded piles. The paper describes physical modelling in general, the centrifuge, present setups and shows samples of obtained results....

  13. Empirical Design Considerations for Industrial Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2012-01-01

    Full Text Available Computational Fluid Dynamics (CFD has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still very important. The impeller is the key part of the centrifugal stage. Designing a highly efficiency impeller with a wide operation range can ensure overall stage design success. This paper provides some empirical information for designing industrial centrifugal compressors with a focus on the impeller. A ported shroud compressor basic design guideline is also discussed for improving the compressor range.

  14. Effect of Centrifugation on Sesame Paste Temperature

    Directory of Open Access Journals (Sweden)

    Ahmad Kouchakzadeh

    2012-01-01

    Full Text Available The sesame seeds were mechanically cold pressed at temperature below 45 then centrifuged. No chemicals were used. The temperature during centrifugation of sesame paste was recorded. Temperatures in less than one hour operation has elevated to 148, 273 and 315 in 1200, 1800 and 2400 G-force centrifugal acceleration, respectively. since the centrifugal accelerations during the process cut at 1200, 1800 and 2400 G-force at about 35, 20 and 10 minutes, respectively. The maximum allowable temperatures raised to about 100 . Linear and quadratics regression model were fitted to data.

  15. Centrifugal separators and related devices and methods

    Science.gov (United States)

    Meikrantz, David H.; Law, Jack D.; Garn, Troy G.; Macaluso, Lawrence L.; Todd, Terry A.

    2012-03-06

    Centrifugal separators and related methods and devices are described. More particularly, centrifugal separators comprising a first fluid supply fitting configured to deliver fluid into a longitudinal fluid passage of a rotor shaft and a second fluid supply fitting sized and configured to sealingly couple with the first fluid supply fitting are described. Also, centrifugal separator systems comprising a manifold having a drain fitting and a cleaning fluid supply fitting are described, wherein the manifold is coupled to a movable member of a support assembly. Additionally, methods of cleaning centrifugal separators are described.

  16. Cavitation Effects in Centrifugal Pumps- A Review

    Directory of Open Access Journals (Sweden)

    Maxime Binama

    2016-05-01

    Full Text Available Cavitation is one of the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump flow behaviors and physical characteristics. Centrifugal pumps’ most low pressure zones are the first cavitation victims, where cavitation manifests itself in form of pitting on the pump internal solid walls, accompanied by noise and vibration, all leading to the pump hydraulic performance degradation. In the present article, a general description of centrifugal pump performance and related parameters is presented. Based on the literature survey, some light were shed on fundamental cavitation features; where different aspects relating to cavitation in centrifugal pumps were briefly discussed

  17. Virgin Coconut Oil Production by Centrifugation Method

    Directory of Open Access Journals (Sweden)

    Y.C.Wong

    2014-03-01

    Full Text Available The virgin coconut oil (VCO production by centrifugation method was studied. The production of VCO was studied by using various centrifugation speed, temperature and time intervals. The results showed that the yield of VCO was 13.53% at 12000rpm, at 120 minutes. The highest yield of VCO was 13.80% at centrifugation temperature of 40oC. The concentration of lauric acid present in the samples with variables of centrifugation temperatures, speed, and time intervals were 0.4543µg, 6.2367µg, and 6.4894µg respectively.

  18. CFD simulation of centrifugal cells washers.

    Science.gov (United States)

    Kellet, Beth E; Binbing, Han; Dandy, David S; Wickramasinghe, S Ranil

    2004-01-01

    The feasibility of using computational fluid dynamics to guide the design of better centrifuges for processing shed blood is explored here. The velocity field and the rate of protein removal from the shed blood have been studied. The results indicate that computational fluid dynamics could help screen preliminary centrifuge bowl designs thus reducing the number of initial experimental tests required when developing new centrifuge bowls. Though the focus of this work is on washing shed blood the methods developed here are applicable to the design of centrifuge bowls for other blood processing applications. PMID:15133962

  19. Centrifugal quantum states of neutrons

    Science.gov (United States)

    Nesvizhevsky, V. V.; Petukhov, A. K.; Protasov, K. V.; Voronin, A. Yu.

    2008-09-01

    We propose a method for observation of the quasistationary states of neutrons localized near a curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi potential. This phenomenon is an example of an exactly solvable “quantum bouncer” problem that can be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop a formalism that describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.

  20. PUMA - a new mathematical model for the rapid calculation of steady-state concentration profiles in mixer-settler extraction, partitioning, and stripping contactors using the Purex process

    International Nuclear Information System (INIS)

    The mathematical basis for a computer code PUMA (Plutonium-Uranium-Matrix-Algorithm) is described. The code simulates steady-state concentration profiles of solvent extraction contactors used in the Purex process, directly without first generating the transient behavior. The computational times are reduced, with no loss of accuracy, by about tenfold over those required by codes that generate the steady-state profiles via transient state conditions. Previously developed codes that simulate the steady-state conditions directly are not applicable to partitioning contactors, whereas PUMA is applicable to all contactors in the Purex process. Since most difficulties are encountered with partitioning contactors when simulating steady-state profiles via transient state conditions, it is with these contactors that the greatest saving in computer times is achieved

  1. Centrifuge modelling of offshore monopile foundation

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Hededal, Ole

    2010-01-01

    centrifuge tests on a laterally loaded monopile in dry sand. The prototype dimension of the piles was modelled to a diameter of 1 meter and penetration depth on 6 meter. The test series were designed in order to investigate the scaling laws in the centrifuge both for monotonic and cyclic loading...

  2. Centrifugal innervation of the mammalian olfactory bulb.

    Science.gov (United States)

    Matsutani, Shinji; Yamamoto, Noboru

    2008-12-01

    Although it has been known for decades that the mammalian olfactory bulb receives a substantial number of centrifugal inputs from other regions of the brain, relatively few data have been available on the function of the centrifugal olfactory system. Knowing the role of the centrifugal projection and how it works is of critical importance to fully understanding olfaction. The centrifugal fibers can be classified into two groups, a group that release neuromodulators, such as noradrenaline, serotonin, or acetylcholine, and a group originating in the olfactory cortex. Accumulating evidence suggests that centrifugal neuromodulatory inputs are associated with acquisition of odor memory. Because the distribution of the terminals on these fibers is diffuse and widespread, the neuromodulatory inputs must affect diverse subsets of bulbar neurons at the same time. In contrast, knowledge of the role of centrifugal fibers from the olfactory cortical areas is limited. Judging from recent morphological evidence, these fibers may modify the activity of neurons located in sparse and discrete loci in the olfactory bulb. Given the modular organization of the olfactory bulb, centrifugal fibers from the olfactory cortex may help coordinate the activities of restricted subsets of neurons belonging to distinct functional modules in an odor-specific manner. Because the olfactory cortex receives inputs from limbic and neocortical areas in addition to inputs from the bulb, the centrifugal inputs from the cortex can modulate odor processing in the bulb in response to non-olfactory as well as olfactory cues.

  3. Detection methods for centrifugal microfluidic platforms

    DEFF Research Database (Denmark)

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-01-01

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation...... for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles....

  4. High frequency dynamics in centrifugal compressors

    NARCIS (Netherlands)

    Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

    2008-01-01

    Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a n

  5. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  6. Control system modeling of a centrifuge

    International Nuclear Information System (INIS)

    Improved control of a centrifuge can be achieved by using a mathematical model. This model is a linear, time-invariant, second order model which relates the input to the output of the centrifuge. After the Z-transform of the model was taken, a digital computer program was written to implement the model. The model parameters were optimized through correlation of the theoretical output as compared with the actual output of the centrifuge. As a result, a model was developed that simulated the centrifuge. Traditionally, a desired centrifuge output was produced by an input which was determined by trial and error. However, using the model with the desired output curve, the necessary input can be calculated with the digital computer program

  7. DETERMINATION OF LIQUID FILM THICKNESS FOLLOWING DRAINING OF CONTACTORS, VESSELS, AND PIPES IN THE MCU PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M; Fernando Fondeur, F; Samuel Fink, S

    2006-06-06

    The Department of Energy (DOE) identified the caustic side solvent extraction (CSSX) process as the preferred technology to remove cesium from radioactive waste solutions at the Savannah River Site (SRS). As a result, Washington Savannah River Company (WSRC) began designing and building a Modular CSSX Unit (MCU) in the SRS tank farm to process liquid waste for an interim period until the Salt Waste Processing Facility (SWPF) begins operations. Both the solvent and the strip effluent streams could contain high concentrations of cesium which must be removed from the contactors, process tanks, and piping prior to performing contactor maintenance. When these vessels are drained, thin films or drops will remain on the equipment walls. Following draining, the vessels will be flushed with water and drained to remove the flush water. The draining reduces the cesium concentration in the vessels by reducing the volume of cesium-containing material. The flushing, and subsequent draining, reduces the cesium in the vessels by diluting the cesium that remains in the film or drops on the vessel walls. MCU personnel requested that Savannah River National Laboratory (SRNL) researchers conduct a literature search to identify models to calculate the thickness of the liquid films remaining in the contactors, process tanks, and piping following draining of salt solution, solvent, and strip solution. The conclusions from this work are: (1) The predicted film thickness of the strip effluent is 0.010 mm on vertical walls, 0.57 mm on horizontal walls and 0.081 mm in horizontal pipes. (2) The predicted film thickness of the salt solution is 0.015 mm on vertical walls, 0.74 mm on horizontal walls, and 0.106 mm in horizontal pipes. (3) The predicted film thickness of the solvent is 0.022 mm on vertical walls, 0.91 mm on horizontal walls, and 0.13 mm in horizontal pipes. (4) The calculated film volume following draining is: (a) Salt solution receipt tank--1.6 gallons; (b) Salt solution feed

  8. Design of centrifugal impeller blades

    Science.gov (United States)

    Betz, A; Flugge-Lotz, I

    1939-01-01

    This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated. For the computation of flow for a finite number of blades, the approximation method as developed by Munk, Prandtl and Birnbaum, or Glauert is found suitable. The essential idea of this method is to replace the wing by a vortex sheet and compute the flow as the field of these vortices. The shape of the blades is then obtained from the condition that the flow must be along the surface of the blade.

  9. Centrifugal membrane filtration - Task 9

    International Nuclear Information System (INIS)

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-microm TiO2/Al2O3 membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance

  10. Centrifugal membrane filtration -- Task 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  11. Regeneration of Alkanolamine Solutions in Membrane Contactor Based on Novel Polynorbornene

    Directory of Open Access Journals (Sweden)

    Shutova A.A.

    2014-11-01

    Full Text Available For the first time, a novel highly permeable glassy polymer, addition poly[bis(trimethylsilyltricyclononene] (PBTMST, was proposed for its use in a gas-liquid membrane contactor for the regeneration of CO2 absorption liquids (desorption of CO2. This membrane material possesses a good chemical stability and high barrier properties for a number of alkanolmines (30 wt% solutions of MEA, DEA, MDEA, AMP, DEAE or AEAE under typical regeneration conditions (T = 100°C. Studies on gas transport properties of PBTMST (100°C and 1-40 bar show that permeability coefficients of oxygen, nitrogen and carbon dioxide initially tend to decrease, and then level off after first 6-8 hours of operation. This behavior can be explained by partial relaxation of the free-volume structure of PBTMST, no chemical degradation of polymer material at high temperature was confirmed by IR analysis. At the same time, this membrane material preserves high gas permeability coefficients which are higher than those of conventional materials used in the membrane contactors. Gas-liquid membrane contactor based on dense PBTMST membrane shows a good, stable performance; particularly, CO2 loading in diethanolamine solution (30 wt% can be reduced for 0.05-0.34 mole/mole by single pass through the membrane desorber at 100°C and elevated pressure. It seems that desorption rate here is mainly controlled by liquid phase because decreasing of membrane thickness by 50% (from 31 to 21 μm leads to improvement of DEA regeneration only by 1.5-8.5%.

  12. Denitrification in an anoxic rotating biological contactor under two carbon/nitrogen ratios

    OpenAIRE

    Cortez, Susana; Teixeira, P; Oliveira, Rosário; Mota, M.

    2008-01-01

    The aim of the present work was to compare the performance of an anoxic bench-scale rotating biological contactor (RBC), in terms of the denitrification process, applied to treat synthetic wastewater under two carbon/nitrogen (C/N) molar ratios (1.5 and 3). The average removal efficiency in terms of nitrogen-nitrate was of about 90.4% at a C/N=1.5 lowering to 73.7% at a C/N=3. Considering carbon-acetate removal an overall efficiency of 82.0% and 63.6% was attained at a C/N rati...

  13. Centrifuge workers study. Phase II, completion report

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  14. Centrifuge workers study. Phase II, completion report

    International Nuclear Information System (INIS)

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom

  15. Fault Detection and Isolation in Centrifugal Pumps

    DEFF Research Database (Denmark)

    Kallesøe, Carsten

    Centrifugal pumps are used in a variety of different applications, such as water supply, wastewater, and different industrial applications. Some pump installations are crucial for the applications to work. Failures can lead to substantial economic losses and can influence the life of many people...... is placed. The topic of this work is Fault Detection and Identification in centrifugal pumps. Different approaches are developed with special focus on robustness. Robustness with respect to disturbances, unknown parts of the system, and parameter variations are considered. All developed algorithms...... are tested on an industrial test setup, showing the usability of the algorithms on a real centrifugal pump....

  16. Gas dynamics in strong centrifugal fields

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, S.V.; Kislov, V.A.; Tronin, I.V. [National research nuclear university “MEPhI”, Kashirskoje shosse, 31,115409, Moscow (Russian Federation)

    2015-03-10

    Dynamics of waves generated by scopes in gas centrifuges (GC) for isotope separation is considered. The centrifugal acceleration in the GC reaches values of the order of 106g. The centrifugal and Coriolis forces modify essentially the conventional sound waves. Three families of the waves with different polarisation and dispersion exist in these conditions. Dynamics of the flow in the model GC Iguasu is investigated numerically. Comparison of the results of the numerical modelling of the wave dynamics with the analytical predictions is performed. New phenomena of the resonances in the GC is found. The resonances occur for the waves polarized along the rotational axis having the smallest dumping due to the viscosity.

  17. Modeling of Centrifugal Force Field and the Effect on Filling and Solidification in Centrifugal Casting

    Science.gov (United States)

    Sheng, Wenbin; Ma, Chunxue; Gu, Wanli

    2011-06-01

    Based on the steady flow in a tube, a mathematical model has been established for the consideration of centrifuging force field by combining the equations of continuity, conservation of momentum and general energy. Effects of centrifugal field on the filling and solidification are modeled by two accessional terms: centrifugal force and Chorios force. In addition, the transfer of heat by convection is considered to achieve a coupling calculation of velocity field and temperature field. The solution of pressure item is avoided by introducing the stream function ψ(x,y) and the eddy function ξ(x,y). Corresponding difference formats for the simultaneous equations of centrifugal filling, the accessional terms and the solidifying latent heat have been established by the finite difference technique. Furthermore, the centrifugal filling and solidification processes in a horizontal tube are summarized to interpret the mechanism by which internal defects are formed in centrifugal castings.

  18. Counteracting ammonia inhibition in anaerobic digestion by removal with a hollow fiber membrane contactor.

    Science.gov (United States)

    Lauterböck, B; Ortner, M; Haider, R; Fuchs, W

    2012-10-01

    The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal. In the second reactor, a hollow fiber membrane contactor module was used for continuous ammonia removal. The hollow fiber membranes were directly submerged into the digestate of the anaerobic reactor. Sulfuric acid was circulated in the lumen as an adsorbent solution. Using this set up, the NH₄⁺-N concentration in the membrane reactor was significantly reduced. Moreover the extraction of ammonia lowered the pH by 0.2 units. In combination that led to a lowering of the free NH₃-N concentration by about 70%. Ammonia inhibition in the reference reactor was observed when the concentration exceeded 6 g/L NH₄⁺-N or 1-1.2 g/L NH₃-N. In contrast, in the membrane reactor the volatile fatty acid concentration, an indicator for process stability, was much lower and a higher gas yield and better degradation was observed. The chosen approach offers an appealing technology to remove ammonia directly from media having high concentrations of solids and it can help to improve process efficiency in anaerobic digestion of ammonia rich substrates.

  19. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

    Institute of Scientific and Technical Information of China (English)

    SHAO Jiahui; FANG Xuliang; HE Yiliang; JIN Qiang

    2008-01-01

    Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.

  20. A study of the operational effectiveness of a disk-rotor contactor in a deasphalting installation

    Energy Technology Data Exchange (ETDEWEB)

    Kvetkov, B.A.; Anisimkov, Yu.P.; Boreysha, T.Yu.; Bronfin, I.B.; Chernyshov, S.D.; Golygin, M.I.; Mikita, V.P.; Shkolnikov, V.M.; Veselovskaya, L.F.

    1980-01-01

    Results are cited of many years of operation and study of an industrial rotary disk contactor (RDK) in the process of deasphalting of Western Siberian oils. The evaluation of the operational effectiveness of the rotary disk contactor was conducted from the output of the deparaffinated oil with a viscosity index (IV) of 90. The asphalt processed had a conditional viscosity at 80 degrees C of 22 to 28 seconds, a boil away at 500 degrees C of 15 to 20 percent, a potential content of oils with a viscosity index of 90 of 30 percent. The operational effectiveness of the apparatus was studied with the following parameters: diameter of the rotary disks of 1.8 and 1.5 meters; rotor rotation speed of 0.8; 16 and 24 revolutions per minute; a raw material productivity of 22 to 34 cubic meters per hour; a top temperature of 80 to 85 degrees C; a temperature gradient of 25 to 27 degrees and a propane to raw material ratio of 3.3 to 4.5 total.

  1. Determination of economically justified parameters of synchronous disconnection at low-voltage circuit switching via a synchronous vacuum contactor

    Directory of Open Access Journals (Sweden)

    A.V. Verkhola

    2014-04-01

    Full Text Available Dependence of a single switching procedure cost upon the contact opening delay time and delay-time spread is derived for a low-voltage synchronous vacuum contactor. For different cost levels, boundaries of permissible values of delay-time and delay-time spread are specified.

  2. Talking about the Maintenance of AC Contactor%浅谈交流接触器的维修

    Institute of Scientific and Technical Information of China (English)

    王如军

    2011-01-01

    AC eleOromagnetic contactor as an automatic switch in the control of electrical equipment companies have been widely used. But for various reasons often lead to the emergence of various AC contactor failure or damage. Therefore, there must be targeted to take various measures to do a goodjob AC contactor failure prevention, maintenance and processing, to protect AC contactor to work.%交流接触器作为一种电磁式自动开关在企业电气设备的控制中得到了广泛的应用。但由于各种原因经常导致交流接触器出现各种故障甚至损坏。因此,必须有针对性地采取各种措施,认真做好交流接触器故障的预防、维护和处理工作,保障交流接触器正常工作。

  3. INACTIVATION OF CRYPTOSPORIDIUM OOCYSTS IN A PILOT-SCALE OZONE BUBBLE-DIFFUSER CONTACTOR - II: MODEL VALIDATION AND APPLICATION

    Science.gov (United States)

    The ADR model developed in Part I of this study was successfully validated with experimenta data obtained for the inactivation of C. parvum and C. muris oocysts with a pilot-scale ozone-bubble diffuser contactor operated with treated Ohio River water. Kinetic parameters, required...

  4. FLOW REGIMES, GAS HOLD-UP AND AXIAL GAS MIXING IN THE GAS-LIQUID MULTISTAGE AGITATED CONTACTOR

    NARCIS (Netherlands)

    BREMAN, BB; BEENACKERS, AACM; BOUMA, MJ

    1995-01-01

    Experimental data are reported on Row regimes, gas hold-up and axial gas mixing of a gas-liquid Multi-stage Agitated Contactor (MAC), consisting of nine compartments [height, H, over diameter, D = 1; D = 0.09 m) separated by horizontal baffles with an opening of 0.04 m and with one centrally positio

  5. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    International Nuclear Information System (INIS)

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: ► Novel reactor using membranes for ozone distributor, reaction contactor and water separator. ► Designed to achieve an order of magnitude enhancement over traditional reactor. ► Al2O3 and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. ► High surface area coating prevents polarization and improves membrane separation and life.

  6. Molecular structure and centrifugal distortion in methylthioethyne

    NARCIS (Netherlands)

    Engelsen, D. den

    1969-01-01

    The investigation of the microwave spectra of five isotopic species of methylthioethyne, HCCSCH3 enabled a fairly reliable calculation to be made of bond lengths and angles. The centrifugal distortion parameters are related to molecular vibrations.

  7. Geotechnical Centrifuge Studies of Unsaturated Transport

    Science.gov (United States)

    Smith, R. W.; Mattson, E. D.; Palmer, C. D.

    2007-12-01

    Improved understanding of contaminant migration in heterogeneous, variably saturated porous media is required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose-zone barriers to contaminant migrations. A geotechnical centrifuge provides an experimental approach to explore vadose zone transport over a wide range of relevant conditions in time frames not possible for conventional bench-top experiments. Our research to date resulted in the design, construction, and testing of in-flight experimental apparatus allowing the replication of traditional bench top unsaturated transport experiments using the 2-meter radius geotechnical centrifuge capabilities at the Idaho National Laboratory. Additionally we conducted a series of unsaturated 1-dimenstional column experiments using conservative tracers to evaluate the effects of increased centrifugal acceleration on derived transport properties and assessing the scaling relationships for these properties. Our experimental results indicated that breakthrough times for a conservative tracer decreased significantly and systematically as a function of increased centrifugal acceleration. Differences between these experimental results and estimates based on predictive scaling rules are due to slight moisture content differences between experiments at different centrifugal accelerations. In contrast, dispersion coefficients varied systemically with centrifugal acceleration in accordance with predictive scaling rules. The results we obtained in this study indicate that the centrifuge technique is a viable experimental method for the study of subsurface processes where gravitational acceleration is important. The geotechnical centrifuge allows experiments to be completed more quickly than tests conducted at 1-gravity and can be used to experimentally address important scaling issues, and permits experiments under a range of conditions that

  8. Towards Centrifugal Compressor Stages Virtual Testing

    OpenAIRE

    Guidotti, Emanuele

    2014-01-01

    Flow features inside centrifugal compressor stages are very complicated to simulate with numerical tools due to the highly complex geometry and varying gas conditions all across the machine. For this reason, a big effort is currently being made to increase the fidelity of the numerical models during the design and validation phases. Computational Fluid Dynamics (CFD) plays an increasing role in the assessment of the performance prediction of centrifugal compressor stages. Historically, CFD wa...

  9. Meridional Considerations of the Centrifugal Compressor Development

    OpenAIRE

    Xu, C.; Amano, R. S.

    2012-01-01

    Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some ...

  10. Finite element analysis of centrifugal impellers

    OpenAIRE

    Sham Sunder, K.

    1981-01-01

    A three-dimensional method of stress analysis using finite element techniques is presented for determining the stress distribution in centrifugal impellers. It can treat all of the three types of loading possible in an inpeller, viz centrifugal, thermal and fluid. The method has no known limitations with regards to the geometric factors such as asymnetry of disk, blade curvature, presence of a cover disk or shroud, single or double sided impeller etc. A comparison of r...

  11. CFD Analysis of Centrifugal Pump: A Review

    OpenAIRE

    Narayan P. Jaiswal

    2014-01-01

    The main objective of this work is to understand role of the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of centrifugal pump. Computational Fluid Dynamics (CFD) is the present day state-of-art technique for fluid flow analysis. The critical review of CFD analysis of CFD analysis of centrifugal pump along with future scope for further improvement is presented in this paper. Different solver like ANSYS-CFX, FLUENT etc can be used for ...

  12. Return Vane Installed in Multistage Centrifugal Pump

    OpenAIRE

    Miyano, Masafumi; Kanemoto, Toshiaki; Kawashima, Daisuke; Wada, Akihiro; Hara, Takashi; Sakoda, Kazuyuki

    2008-01-01

    To optimize the stationary components in the multistage centrifugal pump, the effects of the return vane profile on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the inlet flow conditions for the next stage impeller. The return vane, whose trailing edge is set at the outer wall position of the annular channel downstream of the vane and which discharges the swirl-less flow, gives better pump performances. By equipping such return vane w...

  13. Enrichment technology. Dependable vendor of gas centrifuges

    International Nuclear Information System (INIS)

    Enrichment Technology is an innovative, high-tech company that develops, manufactures and installs gas centrifuges for enriching uranium. In addition, Enrichment Technology designs enrichment plants that use gas centrifuge technology. This technology offers the most efficient and cost-effective method for enriching uranium yet: high-performance, safe technology that dominates the market with a global share of 45 percent. A determining factor in Enrichment Technology's success is its mission: supplying its customers with safe, reliable technology. Production of the centrifuges requires versatile know-how and collaboration between different departments as well as interdisciplinary teams at the various sites. More than 2000 operators at 8 sites in 5 countries contribute their individual knowledge and personal skills in order to produce this exceptional technology. The head office is in Beaconsfield near London and the operational headquarters are in Almelo in the Netherlands. There are other sites in Germany (Juelich und Gronau), Great Britain (Capenhurst) as well as project sites in the USA and France. Capenhurst is where experienced engineers design new enrichment plants and organise their construction. Centrifuge components are manufactured in Almelo and Juelich, while the pipework needed to connect up the centrifuges is produced at the site in Gronau. In Juelich, highly qualified scientists in interdisciplinary teams are continuously researching ways of improving the current centrifuges. Communication between specialists in the fields of chemistry, physics and engineering forms the basis for the company's success and the key to extending this leading position in the global enrichment market. (orig.)

  14. Separation of uranium isotopes by gas centrifugation

    International Nuclear Information System (INIS)

    The uranium isotope enrichment is studied by means of the countercurrent gas centrifuge driven by thermal convection. A description is given of (a) the transfer and purification of the uranium hexafluoride used as process gas in the present investigation; (b) the countercurrent centrifuge ZG3; (c) the system designed for the introduction and extraction of the process gas from the centrifuge; (d) the measurement of the process gas flow rate through the centrifuge; (e) the determination of the uranium isotopic abundance by mass spectrometry; (f) the operation and mechanical behavior of the centrifuge and (g) the isotope separation experiments, performed, respectively, at total reflux and with production of enriched material. The results from the separation experiments at total reflux are discussed in terms of the enrichment factor variation with the magnitude and flow profile of the countercurrent given by the temperature difference between the rotor covers. As far as the separation experiments with production are concerned, the discussion of their results is presented through the variation of the enrichment factor as a function of the flow rate, the observed asymmetry of the process and the calculated separative power of the centrifuge. (Author)

  15. Clinical experience with the Sarns centrifugal pump.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Demmy, T L; Boley, T M; Schmaltz, R A; Goss, C F; Wagner-Mann, C C

    1993-07-01

    Since October 1986, we have had experience with 96 Sarns centrifugal pumps in 72 patients (pts). Heparinless left atrial to femoral artery or aorta bypass was used in 14 pts undergoing surgery on the thoracic aorta with 13 survivors (93%). No paraplegia or device-related complications were observed. In 57 patients, the Sarns centrifugal pump was used as a univentricular (27 pts) or biventricular (30 pts) cardiac assist device for postcardiotomy cardiogenic shock. In these patients, cardiac assist duration ranged from 2 to 434 h with a hospital survival rate of 29% in those requiring left ventricular assist and 13% in those requiring biventricular assist. Although complications were ubiquitous in this mortally ill patient population, in 5,235 pump-hours, no pump thrombosis was observed. Hospital survivors followed for 4 months to 6 years have enjoyed an improved functional class. We conclude that the Sarns centrifugal pump is an effective cardiac assist device when used to salvage patients otherwise unweanable from cardiopulmonary bypass. Partial left ventricular bypass using a centrifugal pump has become our procedure of choice for unloading the left ventricle and for maintenance of distal aortic perfusion pressure when performing surgery on the thoracic aorta. This clinical experience with the Sarns centrifugal pump appears to be similar to that reported with other centrifugal assist devices.

  16. Current-voltage characteristics of a cathodic plasma contactor with discharge chamber for application in electrodynamic tether propulsion

    Science.gov (United States)

    Xie, Kan; Martinez, Rafael A.; Williams, John D.

    2014-04-01

    This paper focuses on the net electron-emission current as a function of bias voltage of a plasma source that is being used as the cathodic element in a bare electrodynamic tether system. An analysis is made that enables an understanding of the basic issues determining the current-voltage (C-V) behaviour. This is important for the efficiency of the electrodynamic tether and for low impedance performance without relying on the properties of space plasma for varying orbital altitudes, inclinations, day-night cycles or the position of the plasma contactor relative to the wake of the spacecraft. The cathodic plasma contactor considered has a cylindrical discharge chamber (10 cm in diameter and ˜11 cm in length) and is driven by a hollow cathode. Experiments and a 1D spherical model are both used to study the contactor's C-V curves. The experiments demonstrate how the cathodic contactor would emit electrons into space for anode voltages in the range of 25-40 V, discharge currents in the range of 1-2.5 A, and low xenon gas flows of 2-4 sccm. Plasma properties are measured and compared with (3 A) and without net electron emission. A study of the dependence of relevant parameters found that the C-V behaviour strongly depends on electron temperature, initial ion energy and ion emission current at the contactor exit. However, it depended only weakly on ambient plasma density. The error in the developed model compared with the experimental C-V curves is within 5% at low electron-emission currents (0-2 A). The external ionization processes and high ion production rate caused by the discharge chamber, which dominate the C-V behaviour at electron-emission currents over 2 A, are further highlighted and discussed.

  17. Design and evaluation of hydraulic baffled-channel PAC contactor for taste and odor removal from drinking water supplies.

    Science.gov (United States)

    Kim, Young-Il; Bae, Byung-Uk

    2007-05-01

    Based on the concept of hydraulic flocculator, a baffled-channel powdered activated carbon (PAC) contactor, placed before the rapid-mixing basin, was designed and evaluated for removal of taste and odor (T&O) in drinking water. PAC adsorption kinetic tests for raw water samples were conducted for selection of design parameters related to contact time and degree of mixing. Within the tested range of velocity gradient (G) from 18 to 83s(-1), mixing had a relatively minor effect on the adsorption kinetics of the PAC. The hydrodynamic characteristics of the pilot-scale horizontally and vertically baffled-channel PAC contactor were investigated by tracer tests. It was found that the plug flow fractions of vertically baffled-channel PAC contactor (vBPC) were higher than those of the horizontally baffled-channel PAC contactor (hBPC) for the same bend width or bend height. However, the hBPC seems to be more appropriate than the vBPC in terms of construction and maintenance. The geosmin and MIB removal rate increased with the number of baffles, PAC dose and contact time increased regardless of bend width in the pilot-scale hBPC. The pair of full-scale hBPCs at Pohang water treatment plant, having a design capacity of 6.5x10(4)m(3)/d with 20min of hydraulic retention time with a safety factor of 2, was designed based on lab- and pilot-scale experimental results. Under a velocity gradient of 20s(-1), the number of baffles to be installed was calculated to be 20 with a space of about 2m between each baffle, resulting in a hydraulic head loss through the contactor of about 0.056m. The successful application of hBPC for T&O removal from drinking water supplies should provide momentum for developing more effective treatment methods.

  18. Numerical and experimental investigation of the centrifugal stage axial compressor centrifugal stationary GTE

    OpenAIRE

    Шаровский, Михаил Антонович; Усатенко, Елена Александровна; Шелковский, Михаил Юрьевич; Зубрицкая, Инна Аркадьевна

    2012-01-01

    About increase in efficiency of a centrifugal step of the compressor in low-dimensional GTD with the osetsentrobezhny compressor. Use of the “closed” driving wheel as basic possibility of receiving a highly effective centrifugal step. The gazodinamichesky aspect of its design and manufacturing is considered.

  19. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  20. A Review of Biomedical Centrifugal Microfluidic Platforms

    Directory of Open Access Journals (Sweden)

    Minghui Tang

    2016-02-01

    Full Text Available Centrifugal microfluidic or lab-on-a-disc platforms have many advantages over other microfluidic systems. These advantages include a minimal amount of instrumentation, the efficient removal of any disturbing bubbles or residual volumes, and inherently available density-based sample transportation and separation. Centrifugal microfluidic devices applied to biomedical analysis and point-of-care diagnostics have been extensively promoted recently. This paper presents an up-to-date overview of these devices. The development of biomedical centrifugal microfluidic platforms essentially covers two categories: (i unit operations that perform specific functionalities, and (ii systems that aim to address certain biomedical applications. With the aim to provide a comprehensive representation of current development in this field, this review summarizes progress in both categories. The advanced unit operations implemented for biological processing include mixing, valving, switching, metering and sequential loading. Depending on the type of sample to be used in the system, biomedical applications are classified into four groups: nucleic acid analysis, blood analysis, immunoassays, and other biomedical applications. Our overview of advanced unit operations also includes the basic concepts and mechanisms involved in centrifugal microfluidics, while on the other hand an outline on reported applications clarifies how an assembly of unit operations enables efficient implementation of various types of complex assays. Lastly, challenges and potential for future development of biomedical centrifugal microfluidic devices are discussed.

  1. Bacterial Cellulose Production by Gluconacetobacter sp. RKY5 in a Rotary Biofilm Contactor

    Science.gov (United States)

    Kim, Yong-Jun; Kim, Jin-Nam; Wee, Young-Jung; Park, Don-Hee; Ryu, Hwa-Won

    A rotary biofilm contactor (RBC) inoculated with Gluconacetobacter sp. RKY5 was used as a bioreactor for improved bacterial cellulose production. The optimal number of disk for bacterial cellulose production was found to be eight, at which bacterial cellulose and cell concentrations were 5.52 and 4.98 g/L. When the aeration rate was maintained at 1.25 vvm, bacterial cellulose and cell concentrations were maximized (5.67 and 5.25 g/L, respectively). The optimal rotation speed of impeller in RBC was 15 rpm. When the culture pH in RBC was not controlled during fermentation, the maximal amount of bacterial cellulose (5.53 g/L) and cells (4.91 g/L) was obtained. Under the optimized culture conditions, bacterial cellulose and cell concentrations in RBC reached to 6.17 and 5.58 g/L, respectively.

  2. Bioaugmentation for treating transient 4-fluorocinnamic acid shock loads in a rotating biological contactor.

    Science.gov (United States)

    Amorim, Catarina L; Duque, Anouk F; Afonso, Carlos M M; Castro, Paula M L

    2013-09-01

    A rotating biological contactor (RBC) was used to treat shock loadings of 4-fluorocinnamic acid (4-FCA). Intermittent 4-FCA shocks of 35 mg L(-1) were applied (ca. 3 months) with only limited mineralization occurring and accumulation of 4-fluorobenzoate (4-FBA) as an intermediate. After bioaugmentation with a degrading bacterium the RBC was able to deal with 4-FCA intermittent loading of 80 mg L(-1) however, a gradual decline in RBC performance occurred, leading to 4-FBA accumulation. The degrading strain was recovered from the biofilm during 2 months but intermittent feeding may have led to diminishing strain numbers. Distinct bacterial communities in the 1st and the 5th and 10th stages of the RBC were revealed by denaturating gradient gel electrophoresis. Several isolates retrieved from the RBC transformed 4-FCA into 4-FBA but only two strains mineralized the compound. Bioaugmentation allowed removal of the fluorinated compound however intermittent feeding may have compromised the bioreactor efficiency.

  3. Recovery of volatile fatty acids via membrane contactor using flat membranes: experimental and theoretical analysis.

    Science.gov (United States)

    Tugtas, Adile Evren

    2014-07-01

    Volatile fatty acid (VFA) separation from synthetic VFA solutions and leachate was investigated via the use of a membrane contactor. NaOH was used as a stripping solution to provide constant concentration gradient of VFAs in both sides of a membrane. Mass flux (12.23 g/m(2)h) and selectivity (1.599) observed for acetic acid were significantly higher than those reported in the literature and were observed at feed pH of 3.0, flow rate of 31.5 ± 0.9 mL/min, and stripping solution concentration of 1.0 N. This study revealed that the flow rate, stripping solution strength, and feed pH affect the mass transfer of VFAs through the PTFE membrane. Acetic and propionic acid separation performances observed in the present study provided a cost effective and environmental alternative due to elimination of the use of extractants.

  4. Numerical Simulation and Analysis of CO2 Removal in a Polypropylene Hollow Fiber Membrane Contactor

    Directory of Open Access Journals (Sweden)

    Zhien Zhang

    2014-01-01

    Full Text Available This present study shows a comprehensive 2D numerical model for removal of CO2 in a polypropylene (PP hollow fiber membrane contactor (HFMC using the computational fluid dynamics (CFD method. Monoethanolamine (MEA solution was used as the liquid absorbent in a nonwetting mode. The simulation results represented that higher liquid velocity and concentration and lower gas velocity and concentration led to higher percent of CO2 removal. The most proper parameters for CO2 removal were less than 1 mol m−3 gas concentration and 0.2 m s−1 gas flow rate, and for MEA the values were above 8 mol m−3 concentration and approximately 1 m s−1 liquid velocity. Furthermore, the model was validated with the experiment results. Therefore, the modeling results provided references to the selection of absorbents and operation parameters in the experimental study and pilot-scale applications.

  5. The use of the fungus Dichomitus squalens for degradation in rotating biological contactor conditions.

    Science.gov (United States)

    Novotný, Ceněk; Trošt, Nina; Šlušla, Martin; Svobodová, Kateřina; Mikesková, Hana; Válková, Hana; Malachová, Kateřina; Pavko, Aleksander

    2012-06-01

    Biodegradation potential of Dichomitus squalens in biofilm cultures and rotating biological contactor (RBC) was investigated. The fungus formed thick biofilms on inert and lignocellulosic supports and exhibited stable activities of laccase and manganese peroxidase to reach 40-62 and 25-32% decolorization of anthraquinone Remazol Brilliant Blue R and heterocyclic phthalocyanine dyes, respectively. The decolorization ceased when glucose concentration dropped to 1 mmol l(-1). In RBC reactor, respective decolorizations of Remazol Brilliant Blue R and heterocyclic Methylene Blue and Azure B dyes (50 mg l(-1)) attained 99%, 93%, and 59% within 7, 40 and 200 h. The fungus exhibited tolerance to coliform and non-coliform bacteria on rich organic media, the inhibition occurred only on media containing tryptone and NaCl. The degradation efficiency in RBC reactor, capability to decolorize a wide range of dye structures and tolerance to bacterial stress make D. squalens an organism applicable to remediation of textile wastewaters.

  6. Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

    2006-11-15

    This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

  7. Stability study and lyophilization of vitamin E-loaded nanocapsules prepared by membrane contactor.

    Science.gov (United States)

    Khayata, N; Abdelwahed, W; Chehna, M F; Charcosset, C; Fessi, H

    2012-12-15

    In this research, we studied the accelerated stability of vitamin E-loaded nanocapsules (NCs) prepared by the nanoprecipitation method. Vitamin E-loaded NCs were optimized firstly at the laboratory scale and then scaled up using the membrane contactor technique. The optimum conditions of the membrane contactor preparation (pilot scale) produced vitamin E-loaded NCs with an average size of 253 nm, polydispersity index 0.19 and a zeta potential -16 mV. The average size, polydispersity index and zeta potential values were 185 nm, 0.12 and -15 mV, respectively for the NCs prepared at laboratory scale. No significant changes were noticed in these values after 3 and 6 months of storage at high temperature (40±2 °C) and relative humidity (75±5%) in spite of vitamin E sensitivity to light, heat and oxygen. The entrapment efficiency of NCs prepared at pilot scale was 97% at the beginning of the stability study, and became (95%, 59%) after 3 and 6 months of storage, respectively. These values at lab-scale were (98%, 96%, and 89%) at time zero and after 3 and 6 months of storage, respectively. This confirms the ability of vitamin E encapsulation to preserve its stability, which is one major goal of our work. Lyophilization of the optimized formula at lab-scale was also performed. Four types of cryoprotectants were tested (poly(vinyl pyrrolidone), sucrose, mannitol, and glucose). Freeze-dried NCs prepared with sucrose were found acceptable. The other lyophilized NCs obtained at different conditions presented large aggregates.

  8. Centrifugal compressor design for electrically assisted boost

    Science.gov (United States)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

    2013-12-01

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  9. Analysis of Secondary Flows in Centrifugal Impellers

    Directory of Open Access Journals (Sweden)

    Brun Klaus

    2005-01-01

    Full Text Available Secondary flows are undesirable in centrifugal compressors as they are a direct cause for flow (head losses, create nonuniform meridional flow profiles, potentially induce flow separation/stall, and contribute to impeller flow slip; that is, secondary flows negatively affect the compressor performance. A model based on the vorticity equation for a rotating system was developed to determine the streamwise vorticity from the normal and binormal vorticity components (which are known from the meridional flow profile. Using the streamwise vorticity results and the small shear-large disturbance flow method, the onset, direction, and magnitude of circulatory secondary flows in a shrouded centrifugal impeller can be predicted. This model is also used to estimate head losses due to secondary flows in a centrifugal flow impeller. The described method can be employed early in the design process to develop impeller flow shapes that intrinsically reduce secondary flows rather than using disruptive elements such as splitter vanes to accomplish this task.

  10. Centrifugal compressor design for electrically assisted boost

    International Nuclear Information System (INIS)

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically

  11. Comparison of extraction and stripping behavior of uranium in centrifugal contactors using tributyl phosphate (TBP) and N,N-dihexyl octanamide (DHOA) as extractants

    International Nuclear Information System (INIS)

    Uranium analysis in organic and aqueous phases was carried out by Davis Grey titration. The extraction and stripping behaviour of the the two solvents under the conditions used in this study are compared. As expected, uranium extraction increased with increased feed acidity for both the extractants. Stripping studies of uranium from loaded were carried out using distilled water. The stripping of uranium decreased with increased feed acidity (employed during extraction cycle). This behavior was explained in terms of acid reflux during the stripping cycle. These studies suggested that uranium extraction ability of DHOA at 3-4 M HNO3 as feed acidity, is comparable to that of TBP. However, stripping behavior is better than that of TBP. These observations were in conformity with the batch as well as counter-current mixer settler runs

  12. Demonstration of Caustic-Side Solvent Extraction with Optimized Solvent in the 2-cm Centrifugal Contactor Apparatus Using Dissolved Salt Cake from Tank 37H

    Energy Technology Data Exchange (ETDEWEB)

    Norato, M.A.

    2002-10-21

    A solvent extraction process for removal of cesium from alkaline solutions has been developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant (BOBCalix) dissolved in an inert hydrocarbon matrix (Isopar(R) L). An alkylphenoxy alcohol modifier added to the solvent enhances the extraction power of the calixarene and prevents the formation of a third phase. An additional additive, trioctylamine (TOA), improves stripping performance and mitigates the effects of any surfactants present in the feed stream. The solvent extraction process was successfully demonstrated with actual SRS HLW supernate during testing performed at SRTC in FY-2001. However, the solvent system has recently been optimized to enhance extractant solubility in the diluent and increase suppressor concentration. The results of the optimized solvent performance in tests using the same SRS composite waste supernate as was used FY-20 01 are described in another report.

  13. Demonstration of Caustic-Side Solvent Extraction with Optimized Solvent in the 2-cm Centrifugal Contactor Apparatus Using Dissolved Salt Cake from Tank 37H

    Energy Technology Data Exchange (ETDEWEB)

    Norato, M.A.

    2003-01-06

    Researchers successfully demonstrated the chemistry of the Caustic-Side Solvent Extraction (CSSX) flow sheet with optimized solvent. This represents the third such process demonstration using actual Savannah River Site (SRS) high level waste (HLW). The present test differed from previous studies in the use of radioactive waste derived from Tank 37H dissolved salt cake, as opposed to supernate solutions used in previous demonstrations.

  14. Wave-Driven Rotation In Centrifugal Mirrors

    International Nuclear Information System (INIS)

    Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

  15. Detection methods for centrifugal microfluidic platforms.

    Science.gov (United States)

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-02-15

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation, have been developed and allow automation and integration of complex assay protocols in lab-on-a-disc systems. Besides liquid handling, the detection strategy for reading out the assay is crucial for developing a fully integrated system. In this review, we focus on biosensors and readout methods for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles.

  16. The effect of surfactants on the ozonation of o-cresol in aqueous solutions in a rotating packed contactor.

    Science.gov (United States)

    Ku, Young; Ji, Yan-Shiun; Chen, Hua-Wei; Chou, Yiang-Chen; Chang, Ching-Yuan

    2010-02-01

    Steady-state dissolved ozone concentrations were maintained relatively constant for experiments on ozone dissolution conducted in the presence of various amounts of sodium dodecyl sulphate (SDS) and Triton X-100 (TX-100), an anionic surfactant and a nonionic surfactant, respectively. Ozonation in a rotating packed contactor has been shown to be feasible for achieving nearly complete decomposition of o-cresol within about 10 minutes of reaction time for most experiments conducted. The temporal decomposition behaviour of o-cresol in aqueous solution by ozonation was described by a two-step pseudo-first-order reaction kinetics. Even though the presence of SDS and TX-100 slightly affected the decomposition rate constant of o-cresol by ozonation in the rotating packed contactor, the mineralization of total organic carbon was apparently reduced with the addition of SDS and TX-100.

  17. Centrifugal Sieve for Size-Segregation/ Beneficiation of Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilizing centrifugal force as the primary body-force, combined with both shearing flow and vibratory motion the proposed centrifugal-sieve separators can provide...

  18. Low-ammonia niche of ammonia-oxidizing archaea in rotating biological contactors of a municipal wastewater treatment plant

    OpenAIRE

    Sauder, L.A.; Peterse, F.; Schouten, S; Neufeld, J. D.

    2012-01-01

    The first step of nitrification is catalysed by both ammonia-oxidizing bacteria (AOB) and archaea (AOA), but physicochemical controls on the relative abundance and function of these two groups are not yet fully understood, especially in freshwater environments. This study investigated ammonia-oxidizing populations in nitrifying rotating biological contactors (RBCs) from a municipal wastewater treatment plant. Individual RBC stages are arranged in series, with nitrification at each stage creat...

  19. Design Optimization of Centrifugal Pump Using Radial Basis Function Metamodels

    OpenAIRE

    Yu Zhang; Jinglai Wu; Yunqing Zhang; Liping Chen

    2014-01-01

    Optimization design of centrifugal pump is a typical multiobjective optimization (MOO) problem. This paper presents an MOO design of centrifugal pump with five decision variables and three objective functions, and a set of centrifugal pumps with various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for centrifugal pump such as head, efficiency, and required net positive suction head (NPSHr) are investigated, and the results indicate that th...

  20. Effect of polymer concentration on the structure and performance of PEI hollow fiber membrane contactor for CO2 stripping.

    Science.gov (United States)

    Naim, R; Ismail, A F

    2013-04-15

    A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13-16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of liquid entry pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10(-2)mol/m(2)s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.

  1. Gauge design for electrical contactor parts%电工触头零件的检具设计

    Institute of Scientific and Technical Information of China (English)

    赵延岭

    2015-01-01

    概述了电工触头检具的概念、种类、使用要求、设计原则和结构.介绍了检具材料选择、认证验收标准和维护等.分析了检具功能部件设计及原则 ,通过 TeSys接触器触头检具设计 ,举例说明了如何设计检测直观准确、高效可靠的电工触头检具 ,利用设定的检具系统重复性和再现性数据统计表格来快速判断检具是否合格.结果表明 ,在电工触头批量生产中使用检具测量是一种准确、快捷和高效的方法.%In this paper the conceptions ,types ,requirements ,design principles and structure of electrical contactor gauge were introduced ;material selection ,acceptance criteria and maintenance were illustrated ;the design principles of gauge features was analyzed .Taking TeSys contactor gauge design as an example ,it was explained how to design intuitive ;accu-rate ,efficient and reliable electrical contact gauge .The results showed that the use of the gauge measurements in electrical contactor production is an accurate ,fast and efficient way .

  2. Differential white cell count by centrifugal microfluidics.

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  3. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    Science.gov (United States)

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  4. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    Science.gov (United States)

    Vanderslice, Nicholas; Oberto, Richard; Marrero, Thomas R.

    2012-01-01

    The purpose of this paper is to describe a Centrifugal Pump Experiment that provided an experiential learning experience to chemical engineering undergraduates at the University of Missouri in the spring of 2010 in the Unit Operations Laboratory course. Lab equipment was used by senior students with computer-based data and control technology. In…

  5. Performance of a Centrifugal Slurry Pump

    Directory of Open Access Journals (Sweden)

    Hawas Yahya Bajawi

    2014-02-01

    Full Text Available The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pump was also tested with clean water. The performance of pump has been reported as variations of head, power and efficiency at various flow rates along with the system characteristics of the pump. The results reveal that the pump performance is grossly affected by the type of slurry, its concentration and size. Besides this the variation in speed also affects the performance as is observed in pumps with water. The maximum decrease in the head, with respect to clear water, at the operating point was found to be 47% for aggregate for size 20 mm, 15% concentration and 2600 rpm. The maximum decrement in efficiency at operating point for aggregate was found to be 47% for 4 mm size, 15% concentration and at 2200 rpm. The power increment requirement for aggregate was 9% for 4 mm size, 15% concentration and 2600 rpm.

  6. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, Frank; Heemels, W.P.M.H.; Jager, de Bram; Stoorvogel, Anton A.

    2002-01-01

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to stabiliz

  7. Flow Pattern Characterization for a Centrifugal Impeller

    Science.gov (United States)

    Benavides, Efrén M.

    2014-08-01

    This paper proposes a model for characterizing the flow pattern of a centrifugal impeller attending to the severity of the reverse flow. The model assumes 1) a definition of an escaping particle as the one that flows in every operational point from the trailing edge towards the leading edge of the impeller blades, and 2) a characterization of flow where an operational point is said to have a theoretical flow pattern if it is not possible to establish a fully-reversed escaping particle on it. Therefore, the first part of the article is focused on defining an escaping particle for a centrifugal compressor. The model locates over the map of a centrifugal impeller the line that splits the map in two regions: the region on the right hand side, where a theoretical flow pattern can exist, and the region on the left, where a theoretical flow pattern cannot exist. Therefore, the locus of this line marks a frontier where the expected performance of the impeller cannot be sustained as high as expected. The second part of the article uses a high-performance commercial centrifugal impeller wheel for contrasting the model. A qualitative characterization of the surge line, conclusions and discussions are presented.

  8. 14 CFR 35.35 - Centrifugal load tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Centrifugal load tests. 35.35 Section 35.35... STANDARDS: PROPELLERS Tests and Inspections § 35.35 Centrifugal load tests. The applicant must demonstrate... to twice the maximum centrifugal load to which the propeller would be subjected during operation...

  9. Bacterial Cell Surface Damage Due to Centrifugal Compaction

    NARCIS (Netherlands)

    Peterson, Brandon W.; Sharma, Prashant K.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Centrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we pr

  10. Life Testing of the Hollow Cathode Plasma Contactor for the ProSEDS Mission

    Science.gov (United States)

    Vaughn, Jason A.; Schneider, Todd A.; Finckenor, Miria M.; Munafo, Paul M. (Technical Monitor)

    2001-01-01

    The Propulsive Small Expendable Deployer System (ProSEDS) mission is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta 11 unmanned expendable booster. A 5-km conductive tether is attached to the Delta 11 second stage and collects current from the low Earth orbit (LEO) plasma. A hollow cathode plasma contactor emits the collected electrons from the Delta II, completing the electrical circuit with the ambient plasma. The current flowing through the tether generates thrust based on the Lorentz Force Law. The thrust will be generated opposite to the velocity vector, slowing down the spacecraft and causing it to de-orbit in approximately 14 days compared to the normal 6 months. A 10-km non-conductive tether is between the conductive tether and an endmass containing several scientific instruments. The ProSEDS mission lifetime was set at I day because most of the primary objectives can be met in that time. The extended ProSEDS mission will be for as many days as possible, until the Delta 11 second stage burns up or the tether is severed by a micrometeoroid or space debris particle. The Hollow Cathode Plasma Contactor (HCPC) unit has been designed for a 12-day mission. Because of the science requirements to measure the background ambient plasma, the HCPC must operate on a duty cycle. Later in the ProSEDS mission, the HCPC is operated in a manner to allow charging of the secondary battery. Due to the unusual operating requirements by the ProSEDS mission, a development unit of the HCPC was built for thorough testing. This developmental unit was tested for a simulated ProSEDS mission, with measurements of the ability to start and stop during the duty cycle. These tests also provided valuable data for the ProSEDS software requirements. Qualification tests of the HCPC flight hardware are also discussed.

  11. Meridional Considerations of the Centrifugal Compressor Development

    Directory of Open Access Journals (Sweden)

    C. Xu

    2012-01-01

    Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

  12. High stability design for new centrifugal compressor

    Science.gov (United States)

    Kanki, H.; Katayama, K.; Morii, S.; Mouri, Y.; Umemura, S.; Ozawa, U.; Oda, T.

    1989-01-01

    It is essential that high-performance centrifugal compressors be free of subsynchronous vibrations. A new high-performance centrifugal compressor has been developed by applying the latest rotordynamics knowledge and design techniques: (1) To improve the system damping, a specially designed oil film seal was developed. This seal attained a damping ratio three times that of the conventional design. The oil film seal contains a special damper ring in the seal cartridge. (2) To reduce the destabilizing effect of the labyrinth seal, a special swirl canceler (anti-swirl nozzle) was applied to the balance piston seal. (3) To confirm the system damping margin, the dynamic simulation rotor model test and the full load test applied the vibration exciting test in actual load conditions.

  13. Vibration analysis of large centrifugal pump rotors

    Science.gov (United States)

    Y Zhao, W.; Ge, J. G.; Ma, D.; Li, C. M.; Bao, S. B.

    2013-12-01

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance.

  14. Vibration analysis of large centrifugal pump rotors

    International Nuclear Information System (INIS)

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance

  15. Condensing Heat Recovery of Centrifugal Chiller

    Institute of Scientific and Technical Information of China (English)

    GONG Guang-cai; JIAO Jun-jun; WANG Li-ping; ZENG Wei

    2009-01-01

    To a kind of centrifugal water chiUer with R22 and about 1745 kW of cooling capacity.a heat exchanger was added between the outlet of compressor and original condenser to get part of or all the condensing heat.Condensing heat can be recovered by compound condensing method,which adopts air-cooling model+wa-ter-cooling model or water-cooling model+water-cooling model at the condensing side of the system.By exergy analysis and experiment research on compound condensing heat recovery of centrifugal chiller,the results are ob-tained that the capability of the whole system increases,the energy efficiency ratio (EER) becomes 3.2~5.0 from 2.2~3.4, which implies the EER increases about 1.0~1.5,the exergy efficiency increases about 10%,and the chiller runs more stably after reformation.

  16. Characterization of biofilm of a rotating biological contactor treating synthetic wastewater.

    Science.gov (United States)

    Singh, V; Mittal, A K

    2012-01-01

    A four-stage rotating biological contactor (RBC) was designed and operated to treat synthetic wastewater containing 1,000 mg/l chemical oxygen demand (COD) and 112 mg/l NH(4)(+)-N. A mixed culture bacterial biofilm was developed consisting of a heterotrophic bacterium Paracoccus pantotrophus, nitrifiers and other heterotrophs. Applying the peculiar characteristics of P. pantotrophus of simultaneous heterotrophic nitrification and aerobic denitrification, high simultaneous removal of carbon and nitrogen could be achieved in the fully aerobic RBC. The microbial community structure of the RBC biofilm was categorized based on the nitrate reduction, biochemical reactions, gram staining and morphology. The presence of P. pantotrophus within the RBC biofilm was confirmed with an array of biochemical tests. Isolates from the four stages of RBC were grouped into complete denitrifiers, incomplete denitrifiers and non-denitrifiers. This categorization showed a higher relative abundance of P. pantotrophus in the first stage as compared with subsequent stages, in which other nitrifiers and heterotrophs were significantly present. High total nitrogen removal of upto 68% was in conformity with observations made using microbial categorization and biochemical tests. The high relative abundance of P. pantotrophus in the biofilm revealed that it could successfully compete with other heterotrophs and autotrophic nitrifiers in mixed bacterial biomass. PMID:22699350

  17. Surface Charging Controlling of the Chinese Space Station with Hollow Cathode Plasma Contactor

    Science.gov (United States)

    Jiang, Kai; Wang, Xianrong; Qin, Xiaogang; Yang, Shengsheng; Yang, Wei; Zhao, Chengxuan; Chen, Yifeng; Shi, Liang; Tang, Daotan; Xie, Kan

    2016-07-01

    A highly charged manned spacecraft threatens the life of an astronaut and extravehicular activity, which can be effectively reduced by controlling the spacecraft surface charging. In this article, the controlling of surface charging on Chinese Space Station (CSS) is investigated, and a method to reduce the negative potential to the CSS is the emission electron with a hollow cathode plasma contactor. The analysis is obtained that the high voltage (HV) solar array of the CSS collecting electron current can reach 4.5 A, which can be eliminated by emitting an adequate electron current on the CSS. The theoretical analysis and experimental results are addressed, when the minimum xenon flow rate of the hollow cathode is 4.0 sccm, the emission electron current can neutralize the collected electron current, which ensures that the potential of the CSS can be controlled in a range of less than 21 V, satisfied with safety voltage. The results can provide a significant reference value to define a flow rate to the potential controlling programme for CSS.

  18. Continuous treatment of coloured industry wastewater using immobilized Phanerochaete chrysosporium in a rotating biological contactor reactor.

    Science.gov (United States)

    Pakshirajan, Kannan; Kheria, Sumeet

    2012-06-30

    Coloured industry wastewaters often contain dyes and other toxic ingredients, and, therefore, pose serious threat to the receiving environment. Among the available methods the eco-friendly biological method has gained maximum attention due to its many advantages over the traditional methods. In the present study, continuous biological treatment of coloured wastewater from a textile dyeing industry was investigated using the white rot fungus Phanerochaete chrysosporium in a rotating biological contactor (RBC) reactor. The raw wastewater was diluted with an equal volume of either distilled water or media containing glucose at varying concentrations to study its effect on the decolourization process. Results revealed that the wastewater could be decolourized to an extent of more than 64% when diluted with media containing glucose; and, a maximum decolourization efficiency of 83% was obtained with 10 g/l glucose concentration. COD removal efficiencies were also found to be consistent with the decolourization efficiencies of the wastewaters. Further, the results were correlated with the enzyme activities of manganese peroxidase (MnP) and lignin peroxidase (LiP) by the fungus, which were found to play some significant role in decolourization of the wastewater. Results of replacing the costly carbon source glucose in the decolourization media with the more cheap molasses, however, revealed very high COD removal efficiency, but low decolourization efficiency of the industry wastewater.

  19. A portable membrane contactor sampler for analysis of noble gases in groundwater.

    Science.gov (United States)

    Matsumoto, Takuya; Han, Liang-Feng; Jaklitsch, Manfred; Aggarwal, Pradeep K

    2013-01-01

    To enable a wider use of dissolved noble gas concentrations and isotope ratios in groundwater studies, we have developed an efficient and portable sampling device using a commercially available membrane contactor. The device separates dissolved gases from a stream of water and collects them in a small copper tube (6 mm in diameter and 100 mm in length with two pinch-off clamps) for noble gas analysis by mass spectrometry. We have examined the performance of the sampler using a tank of homogeneous water prepared in the laboratory and by field testing. We find that our sampling device can extract heavier noble gases (Ar, Kr, and Xe) more efficiently than the lighter ones (He and Ne). An extraction time of about 60 min at a flow rate of 3 L/min is sufficient for all noble gases extracted in the sampler to attain equilibrium with the dissolved phase. The extracted gas sample did not indicate fractionation of helium ((3) He/(4) He) isotopes or other noble gas isotopes. Field performance of the sampling device was tested using a groundwater well in Vienna and results were in excellent agreement with those obtained from the conventional copper tube sampling method.

  20. Macroscale and microscale analysis of Anammox in anaerobic rotating biological contactor

    Institute of Scientific and Technical Information of China (English)

    Yongtao Lv; Lei Wang; Xudong Wang; Yongzhe Yang; Zhiying Wang; Jie Li

    2011-01-01

    Inoculated with conventional anaerobic activated sludge,the Anammox process was successfully developed in an anaerobic rotating biological contactor (AnRBC) fed with a low ratio of C/N synthetic wastewater.Operated in a single point feed mode,the AnRBC removed 92.1% (n =126) of the influent N at the highest surface load of 12 g/(m2.day).The biomass increased by 25% and 17.1 g/(m2.day) of maximum N removal surface load was achieved by elevating flow rate with another feed point.Fluorescence in situ hybridization and polymerase chain reaction analysis indicated that the Anammox genus Candidatus Kuenenia stuttgartiensis dominated the community.Both Anammox and denitrifying activity were detected in biofilm by the application of microelectrodes.In the outer layer of the biofilm (0-2500 μm),nitrite and ammonium consumed simultaneously in a ratio of 1.12/1,revealing the occurrence of Anammox.In the inner layer (> 2500 μm),a decrease of nitrate was caused by denitrification in the absence of nitrite and ammonium.

  1. Bacterial community dynamics in a rotating biological contactor treating 2-fluorophenol-containing wastewater.

    Science.gov (United States)

    Duque, Anouk F; Bessa, Vânia S; Castro, Paula M L

    2014-01-01

    One of the main factors affecting the performance of rotating biological contactors (RBC) is the biofilm characteristics. Therefore, a deep understanding of the microbial population dynamics and structure of the biofilm is mandatory if optimization of organic matter and nutrients removal is targeted. This study focused on the effects of organic shock loads of 2-fluorophenol (2-FP) on the microbial diversity present in an RBC biofilm. The RBC was seeded with activated sludge from a conventional wastewater treatment plant and was operated during 496 days. During the first 126 days, the RBC was subjected to intermittent 2-FP shocks of 25 mg l(-1) and no degradation occurred. Therefore, the reactor was subsequently augmented with a 2-FP-degrading strain (FP1). Afterwards, the RBC had a stable performance when subjected to 2-FP shocks up to 50 mg l(-1) and to a starvation period, as indicated by removal of the compound. Denaturing gradient gel electrophoresis (DGGE) revealed large shifts in microbial communities present in the first and fifth stages, although no clear relation between the sample collection time and spatial factor was found. Phylogenetic affiliation of some predominant members was assessed by direct sequencing of correspondent DGGE bands. Affiliations to α-, β- and δ-Proteobacteria were found. Several bacterial strains isolated from the reactor showed capacity for 2-FP degradation. Strain FP1 was successfully recovered from the biofilm by plating and by DGGE, reinforcing that bioaugmentation was successfully achieved.

  2. Degradation of phenolics, nitrogen-heterocyclics and polynuclear aromatic hydrocarbons in a rotating biological contactor.

    Science.gov (United States)

    Jeswani, Hansa; Mukherji, Suparna

    2012-05-01

    The degradation of phenolics, heterocyclics and polynuclear aromatic hydrocarbons (PAHs) in a synthetic biomass gasifier wastewater with average COD of 1388 mg/L was studied in a three stage rotating biological contactor (RBC) using the pyrene degrader, Exiguobacterium aurantiacum and activated sludge consortia (1:3 v/v). As the organic loading rate (OLR) was varied from 3.3 to 14 g/m(2)/d, the COD removal ranged from 63.3% to 92.6%. Complete removal of all the constituents was observed at the lowest OLR of 3.3g/m(2)/d. At 24h hydraulic retention time (HRT) and OLR of 6.6g/m(2)/d complete removal of pyridine, quinoline and benzene and 85-96% removal of phenol, naphthalene, phenanthrene, fluoranthene and pyrene was observed. E. aurantiacum was found to be the dominant bacteria in the biofilm. Clark's model provided good fits to data for all the three stages of the RBC.

  3. Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

    Institute of Scientific and Technical Information of China (English)

    SLADE Paul G.; LI Wang-pei; MAYO Stephen; SMITH R.Kirkland; TAYLOR Erik D.

    2007-01-01

    The use of vacuum interrupters (VIs) as the current interruption component for switches, circuit breakers, reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950's. This electrical product has developed a dominating position for switching and protecting distribution circuits. VIs are even being introduced into switching products operating at transmission voltages. Among the reasons for the VI's popularity are its compactness, its range of application, its low cost, its superb electrical and mechanical life and its ease of application. Its major advantage is its well-established reliability. In this paper we show how this reliability has been achieved by design, by mechanical life testing and by electrical performance testing. We introduce the "sealed for life" concept for the VI's integrity. We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years. We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity. Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.

  4. Energy-efficient treatment of organic wastewater streams using a rotatable bioelectrochemical contactor (RBEC).

    Science.gov (United States)

    Cheng, Ka Yu; Ho, Goen; Cord-Ruwisch, Ralf

    2012-12-01

    A membraneless bioelectrochemical system - rotatable bio-electrochemical contactor (RBEC) consists of an array of rotatable electrode disks was developed to convert the chemical energy from wastewater organics (acetate) directly into electricity. Each rotatable electrode disk had an upper-air exposing and a lower-water submerging halves. Intermittent rotation (180°) enabled each halve to alternately serve as anode and cathode. Removal of chemical oxygen demand (COD) was increased by 15% (from 0.79 to 0.91 kg COD m(-3) d(-1)) by allowing electron flow from the lower to the upper disk halves. Coupling with a potentiostat could alleviate cathodic limitation and increased COD removal to 1.32 kg COD m(-3) day(-1) (HRT 5h). About 40% of the COD removed was via current, indicating that the biofilm could use the lower half disk as electron acceptor. The RBEC removed COD more energy-efficiently than conventional activated sludge processes as active aeration is not required (0.47 vs. 0.7-2.0 kW h kg COD(-1)).

  5. Rotating biological contactor reactor with biofilm promoting mats for treatment of benzene and xylene containing wastewater.

    Science.gov (United States)

    Sarayu, K; Sandhya, S

    2012-12-01

    A novel rotating biological contactor (RBC) bioreactor immobilized with microorganisms was designed to remove volatile organic compounds (VOC), such as benzene and xylene from emissions, and its performance was investigated. Gas-phase VOCs stripped by air injection were 98 % removed in the RBC when the superficial air flow rate was 375 ml/h (1,193 and 1,226 mg/l of benzene and xylene, respectively). The maximum removal rate was observed to be 1,007 and 1,872 mg/m(3)/day for benzene and xylene, respectively. The concentration profile of benzene and xylene along the RBC was dependent on the air flow rate and the degree of microbial adaptation. Air flow rate and residence time were found to be the most important operational parameters for the RBC reactor. By manipulating these operational parameters, the removal efficiency and capacity of the bioreactor could be enhanced. The kinetic constant K (s) demonstrated a linear relationship that indicated the maximum removal of benzene and xylene in RBC reactor. The phylogenic profile shows the presence of bacterium like Pseudomonas sp., Bacillus sp., and Enterococcus sp., which belonged to the phylum Firmicutes, and Proteobacteria that were responsible for the 98 % organic removal in the RBC.

  6. Performance of an in-situ rotating biological contactor in a recirculating aquaculture system.

    Science.gov (United States)

    Marin, P; Donoso-Bravo, A; Campos, J L; Ruiz-Filippi, G; Chamy, R

    2011-01-01

    The start-up and activation of a nitrifying rotating biological contactor (RBC) and its performance inside a culture tank of rainbow trout were studied. First, in a lab-scale operation, the system was fed with a synthetic medium containing a high ammonia concentration (567 mg NH(4)(+)-N L(-1)) and operated at a high hydraulic retention time (HRT) (6.5 days) to minimize the wash-out of the biomass and promote the biofilm formation. Then, both inlet ammonia concentration and HRT were decreased in order to obtain operational conditions similar to those of the culture tank. During this period, the RBC was able to treat an ammonia loading rate (ALR) of 0.64 g N-NH(4)(+) L(-1) d(-1) with a removal efficiency within 70-100%. Pilot-scale experiments were carried out in culture tanks of rainbow trout. The operation of a recirculating system with the RBC unit was compared with a recirculating system without biological treatment and with a flow-through system. The use of this in-situ nitrifying unit allowed working at a recirculation ratio of 90% without negative effects on either growth or the condition factor of fishes. Up to 70% of ammonia generated was removed and a removal rate of 1.41 g NH(4)(+)-N m(-2) d(-1) was reached. PMID:22156125

  7. Experimental design and statistical analysis in Rotating Disc Contactor (RDC) column

    Science.gov (United States)

    Ismail, Wan Nurul Aiffah; Zakaria, Siti Aisyah; Noor, Nor Fashihah Mohd; Ariffin, Wan Nor Munirah

    2015-12-01

    The purpose of this paper is to examine the performance of the liquid-liquid extraction in Rotating Disc Contactor (RDC) Column that being used in industries. In this study, the performance of small diameter column RDC using the chemical system involving cumene/isobutryric asid/water are analyzed by the method of design of the experiments (DOE) and also Multiple Linear Regression (MLR). The DOE method are used to estimated the effect of four independent. Otherwise, by using Multiple Linear Regression (MLR) is to justify the relationship between the input variables and output variables and also to determine which variable are more influence for both output variable. The input variables for both method include rotor speed (Nr); ratio of flow (Fd); concentration of continuous inlet (Ccin); concentration of dispersed inlet (Cdin); interaction between Nr with Fd; interaction between Nr with Ccin; interaction Nr with Cdin. Meanwhile the output variables are concentration of continuous outlet (Ccout) and concentration of dispersed outlet (Cdout) on RDC column performance. By using this two method, we have two linear model represent two output of Ccout and Cdout for MLR. Lastly, the researcher want to determine which input variable that give more influence to output variable by using this two method. Based on the result, we obtained that rotor speed (Nr) more influence to dependent variable, Ccout and concentration of continuous inlet (Ccin) more influence to dependent variable, Cdout according the two method that was used.

  8. Innovative use of membrane contactor as condenser for heat recovery in carbon capture.

    Science.gov (United States)

    Yan, Shuiping; Zhao, Shuaifei; Wardhaugh, Leigh; Feron, Paul H M

    2015-02-17

    The gas-liquid membrane contactor generally used as a nonselective gas absorption enhancement device is innovatively proposed as a condenser for heat recovery in liquid-absorbent-based carbon capture. The membrane condenser is used as a heat exchanger to recover the latent heat of the exiting vapor from the desorber, and it can help achieve significant energy savings when proper membranes with high heat-transfer coefficients are used. Theoretical thermodynamic analysis of mass and heat transfer in the membrane condensation system shows that heat recovery increases dramatically as inlet gas temperature rises and outlet gas temperature falls. The optimal split mass flow rate is determined by the inlet gas temperature and the overall heat-transfer coefficient in the condensation system. The required membrane area is also strongly dependent on the overall heat-transfer coefficient, particularly at higher inlet gas temperatures. Mass transfer across the membrane has an insignificant effect on heat transfer and heat recovery, suggesting that membrane wetting may not be an issue when a membrane condenser is used for heat recovery. Our analysis provides important insights into the energy recovery performance of the membrane condensation system as well as selection of operational parameters, such as split mass flow rate and membrane area, thickness, and thermal conductivity.

  9. Dispersion-free solvent extraction of Cr(VI) from acidic solutions using hollow fiber contactor.

    Science.gov (United States)

    Alguacil, Francisco J; Alonso, Manuel; Lopez, Félix A; Lopez-Delgado, Aurora; Padilla, Isabel

    2009-10-15

    The use of dispersión-free solvent extraction, through microporous hydrophobic membrane has been investigated. The hollow fiber contactor, with surface area of 1.4 m2 was used to extract Cr(VI) (0.005-0.12 g/L from aqueous sulphuric acidic media (pH 2.5-4.2 +/- 0.05). Several parameters such as extractant concentration, feed acidity and metal concentration in the initial aqueous solution were investigated. Results revealed that 15% v/v Cyanex 923 in Exxsol D-100 as organic phase and feed in the 2.5 pH range, gave optimum extraction (exceeding 95%) of Cr(VI) and it was possible to strip using 10 g/L hydrazine sulfate (also with recoveries exceeding 95%). In this step, Cr(VI) is immediately reduced to the less hazardous Cr(III) state. Results also showed that under the various experimental conditions, chromium(VI) extraction was rate-controlled by the interfacial reaction on the membrane surface. Typical overall mass transfer coefficients values are 4.2 x 10(-5) and 3.6 x 10(-6) cm/s for extraction and stripping operations, respectively.

  10. Centrifuge modeling of soil atmosphere interaction

    OpenAIRE

    CAICEDO, B; TRISTANCHO, J; THOREL, Luc

    2010-01-01

    Atmosphere process of infiltration or evaporation affect the behavior of geotechnical structures located near the soil surface. This paper focuses on the drying process of soils due to evaporation. The scaling laws are analyzed and afterwards the results on applying two cycles of heating and cooling on a soil mass are presented. Based on these results, conclusions about the feasibility of reproducing evaporation on centrifuge models are recommended.

  11. Centrifugal shot blasting. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    1999-07-01

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

  12. Aerodynamic instabilities in transonic centrifugal compressor

    OpenAIRE

    Buffaz, Nicolas; Trébinjac, Isabelle

    2014-01-01

    International audience This paper presents the analysis of the instabilities inception in a transonic centrifugal com-pressor for different rotation speeds. The analysis was conducted from experimental results obtained with unsteady pressure sensors implanted in the inducer, vaneless diffuser and vaned diffuser. Beyond the stability limit the compressor enters into a deep surge without any precursor, whatever the speed. The surge process is initiated in the vaned diffuser by a massive boun...

  13. Submarine landslide flows simulation through centrifuge modelling

    OpenAIRE

    Gue, Chang Shin

    2012-01-01

    Landslides occur both onshore and offshore. However, little attention has been given to offshore landslides (submarine landslides). Submarine landslides have significant impacts and consequences on offshore and coastal facilities. The unique characteristics of submarine landslides include large mass movements and long travel distances at very gentle slopes. This thesis is concerned with developing centrifuge scaling laws for submarine landslide flows through the study of modell...

  14. Development of centrifuge modelling in geotechnics

    OpenAIRE

    J. Garnier

    2006-01-01

    In order to satisfy similitude conditions, physical modelling in the field of geotechnics requires major facilities, such as shaking tables, calibration chambers and centrifuges. The rapid expansion of centifuge modelling since the beginning of the 1980's can be explained by technological developments in computing, electronics and mechanics as well by enhanced knowledge in the areas of scaling laws, thanks to recent research work on both the properties of reconstituted soils and similitude co...

  15. Centrifugal shot blasting. Innovative technology summary report

    International Nuclear Information System (INIS)

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer

  16. Potential flow through centrifugal pumps and turbines

    Science.gov (United States)

    Sorensen, E

    1941-01-01

    The methods of conformal transformation up to the present have been applied to the potential flows in the rotation of solid bodies only to a limited extent. This report deals with aspects of centrifugal pumps and turbines such as: the complex potential for rotation, potential for the flow due to the blade rotation, velocities at the blade tip, comparison with "infinite number of blades," and a variable number of blades.

  17. CENTRIFUGAL VIBRATION TEST OF RC PILE FOUNDATION

    Science.gov (United States)

    Higuchi, Shunichi; Tsutsumiuchi, Takahiro; Otsuka, Rinna; Ito, Koji; Ejiri, Joji

    It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

  18. Stable isotope enrichment using a plasma centrifuge

    Science.gov (United States)

    Krishnan, Mahadevan; Bures, Brian; Madden, Robert

    2012-10-01

    A primary goal of the Department of Energy's Isotope Development and Production for Research and Applications Program (Isotope Program) within the Office of Nuclear Physics (NP) is to produce isotopes that are in short supply in the U.S. and of which there exists no or insufficient domestic commercial production capability. A vacuum arc plasma centrifuge is a rigid rotor column of metal plasma in which centrifugal forces re-distribute ions radially according to their mass/charge ratio. Early work demonstrated rotation at 2 million rpm and separation of various stable isotopes. The spinning plasma column had a Gaussian flux profile, peaked on the rigid rotor axis. This work adopts a more efficient approach, with the plasma created as a hollow column, wherein the flux is concentrated at larger radii where the centrifugal action is highest. By tailoring the vacuum arc discharge geometry, the rotation rate can also be increased to ˜10 million rpm. Data from Cu, Al and other metal plasmas will be presented and discussed in light of enriched stable isotopes needed for research and medicine.

  19. Centrifugal compressor design choices for chillers

    Energy Technology Data Exchange (ETDEWEB)

    Brasz, J.J. [United Technologies Carrier, New York, NY (United States)

    1999-07-01

    The use of centrifugal compressors in the air conditioning and refrigeration industry is currently limited to large water cooled chillers varying in size from about 0.5 to 6 MW cooling capacity. These systems are primarily used for comfort or process cooling applications. All systems try to chill relatively large amounts of indoor or process water by a few degrees Celsius in a refrigerant evaporator. The heat removed from the chilled water is released together with the heat of compression in a refrigerant condenser to cooling tower water, from where it is discharged to the atmosphere. Different centrifugal compressor design concepts are used by the various chiller manufacturers: single-stage versus multi-stage, vaneless versus vaned diffuser, hermetic versus open-drive motors, shrouded versus open impellers, fixed versus variable diffuser geometry, low- versus high-pressure refrigerant. This variability seems strange for a mature industry like the air conditioning and refrigeration industry. This paper will show that the reason for this variability is the product compromise between the various conflicting system requirements with respect to size, cost, efficiency and refrigerant choice. The different system applications of the chillers (e.g. comfort cooling in a equatorial region versus process cooling in a moderate climate zone) play another major role in selecting an optimal centrifugal compression concept. Some general recommendations will be given for applications where a clear choice can be made. (Author)

  20. Compact, Automated Centrifugal Slide-Staining System

    Science.gov (United States)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2004-01-01

    The Directional Acceleration Vector-Driven Displacement of Fluids (DAVD-DOF) system, under development at the time of reporting the information for this article, would be a relatively compact, automated, centrifugally actuated system for staining blood smears and other microbiological samples on glass microscope slides in either a microgravitational or a normal Earth gravitational environment. The DAVD-DOF concept is a successor to the centrifuge-operated slide stainer (COSS) concept, which was reported in Slide-Staining System for Microgravity or Gravity (MSC-22949), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 64. The COSS includes reservoirs and a staining chamber that contains a microscope slide to which a biological sample is affixed. The staining chamber is sequentially filled with and drained of staining and related liquids from the reservoirs by use of a weighted plunger to force liquid from one reservoir to another at a constant level of hypergravity maintained in a standard swing-bucket centrifuge. In the DAVD-DOF system, a staining chamber containing a sample would also be sequentially filled and emptied, but with important differences. Instead of a simple microscope slide, one would use a special microscope slide on which would be fabricated a network of very small reservoirs and narrow channels connected to a staining chamber (see figure). Unlike in the COSS, displacement of liquid would be effected by use of the weight of the liquid itself, rather than the weight of a plunger.

  1. EM Task 9 - Centrifugal Membrane Filtration

    International Nuclear Information System (INIS)

    This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

  2. Shallow water model for horizontal centrifugal casting

    Science.gov (United States)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  3. CFD Analysis of Centrifugal Pump: A Review

    Directory of Open Access Journals (Sweden)

    Narayan P. Jaiswal

    2014-05-01

    Full Text Available The main objective of this work is to understand role of the computational fluid dynamics (CFD technique in analyzing and predicting the performance of centrifugal pump. Computational Fluid Dynamics (CFD is the present day state-of-art technique for fluid flow analysis. The critical review of CFD analysis of CFD analysis of centrifugal pump along with future scope for further improvement is presented in this paper. Different solver like ANSYS-CFX, FLUENT etc can be used for simulations. Shear stress transport model has been found appropriate as turbulence model. Study of pressure contours, velocity contours, flow streamlines etc can be studied by CFD techniques. Unsteady Reynolds Averaged Navier Stokes (URANS equations are solved by solver to get flow simulation results inside centrifugal pump. CFD results has to be validated with testing results or with performance characteristics curves. Performance prediction at design and off-design conditions, parametric study, cavitation analysis, diffuser pump analysis, performance of pump running in turbine mode etc. are possible with CFD simulation techniques.

  4. 交流接触器的常见故障及处理方法%Common failures and processing method of AC contactor

    Institute of Scientific and Technical Information of China (English)

    吕俊霞

    2012-01-01

      AC contactor is the most common application of a kind of electrical appliances in power system. The AC contactor common faults, the fault cause and the specific methods removing the faults are analyzed, including contactor inadequate suction, coil overheat or burn out, interphase short circuit and abnormal arcing etc..%  交流接触器是电力系统应用最普遍的一种电器。分析了交流接触器的常见故障、产生故障的原因及排除故障的具体方法,主要涉及接触器吸力不足、线圈过热或烧坏、相间短路、灭弧装置不正常灭弧等。

  5. Based on prole ac contactor automatic assembly system research%基于Pro/E的交流接触器自动装配系统研究

    Institute of Scientific and Technical Information of China (English)

    王军浩; 杨丽华; 厉鹏

    2014-01-01

    Parts for ac contactor with proltoolklt application interface is provided for the secondary development of pro/engineer, the realization of ac contactor automatic assembly parts.Through automatic assembly can improve the design efficiency. shorten product development cycle.%针对交流接触器常用零件,利用Pro/TOOLKIT应用程序接口对Pro/ENGINEER进行二次开发,实现交流接触器零部件的自动装配。通过自动装配可以提高设计效率,缩短产品开发周期。

  6. Research on Environmental Adaptation Experiments for Contactors%接触器高原环境适应性试验研究

    Institute of Scientific and Technical Information of China (English)

    田华

    2015-01-01

    To enhance the capability and reliability of contactors in specific high altitude environment, this paper assesses the environmental adaptation experiments for contactors.%为了增强接触器在高原环境条件下的适应性能,提高接触器在高原特殊环境条件下的可靠性水平,特此提出对接触器应通过的环境适应性试验提出了考核评价。

  7. Preparation of Bovine Serum Albumin (BSA) nanoparticles by desolvation using a membrane contactor: a new tool for large scale production.

    Science.gov (United States)

    Yedomon, B; Fessi, H; Charcosset, C

    2013-11-01

    Albumin nanoparticles are attractive drug delivery systems as they can be prepared under soft conditions and incorporate several kinds of molecules. The aim of this study was to upscale the desolvation process for preparing Bovine Serum Albumin (BSA) nanoparticles using a membrane contactor. At a first step, the BSA nanoparticles were prepared at small scale using a syringe pump. BSA nanoparticles of 139 nm in size, with a polydispersity index of 0.046, were obtained at the optimal conditions: pH 8.2, 100 mg mL(-1) BSA albumin solution (2 mL), and 1 mL min(-1) flow rate of ethanol addition (8 mL). The upscaling with a membrane contactor was achieved by permeating ethanol through the pores of a Shirasu Porous Glass (SPG Technology Co., Japan) membrane and circulating the aqueous phase tangentially to the membrane surface. By increasing the pressure of the ethanol from 1 to 2.7 bars, a progressive decrease in nanoparticle size was obtained with a high nanoparticles yield (around 94-96%). In addition, the flow rate of the circulating phase did not affect the BSA nanoparticle characteristics. At the optimal conditions (pH 8.2, 100 mg mL(-1) BSA albumin solution, pressure of ethanol 2.7 bars, flow rate of the circulating phase 30.7 mL s(-1)), the BSA nanoparticles showed similar characteristics to those obtained with the syringe pump. Large batches of BSA nanoparticles were prepared up to 10 g BSA. The BSA nanoparticles were stable at least during 2 months at 4 °C, and their characteristics were reproducible. It was then concluded that the membrane contactor technique could be a suitable method for the preparation of albumin nanoparticles at large scale with properties similar to that obtained at small scale.

  8. Studies of efficiency in a perforated rotating disc contactor using a polymer-polymer aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    L. A. Sarubbo

    2005-09-01

    Full Text Available The mass transfer process in a perforated rotating disc contactor (PRDC using a polymer-polymer aqueous two-phase system was investigated. The results show that the efficiency did not show a regular trend with the increase of the dispersed phase velocity and increased with the rotation velocity. The separation efficiency was higher for three rotating discs than for four discs. The increase in tie-line length decreased the efficiency. The separation efficiency reached high values, about 96% under conditions studied in this work.

  9. Hydrodynamic study of fine metallic powders in an original spouted bed contactor in view of chemical vapor deposition treatments

    OpenAIRE

    Caussat, Brigitte; Juarez, Fernando L.; Vahlas, Constantin

    2006-01-01

    An original gas–solid contactor was developed so as to treat by chemical vapor deposition, fine (mean diameter 23 μm) and dense (bulk density 7700 kg/m3) NiCoCrAlYTa powders with large size distribution. In order to avoid the presence of a distributor in the reactive zone, a spouted bed configuration was selected, consisting in a glass cylindrical column associated through a 60° cone to an inlet tube, connected at its bottom to a grid so as to support the powders at rest. A hydrodynamic study...

  10. Comparative non-dispersive solvent extraction of uranium and thorium using a hollow fiber contactor containing TBP/DHOA

    International Nuclear Information System (INIS)

    Non-dispersive solvent extraction of Uranium and Thorium was carried out from nitric acid medium using hollow fiber contactor containing TBP and DHOA as the carrier extractants. The effect of flow rate was studied while carrying out the extraction studies in counter current mode using 10 g/L solutions of the metal ions in 3 M HNO3 and 50 mL/minute was found to be most suitable for better separation efficiency. Stripping studies were also carried out using deionized water as the strippant for both the metal ions. (author)

  11. ELECTRO-HYDRAULIC SERVO SYSTEM IN THE CENTRIFUGE FIELD

    Institute of Scientific and Technical Information of China (English)

    Dong Longlei; Yan Guirong; Li Ronglin

    2004-01-01

    The mechanical characteristics of the electro-hydraulic servo system in the centrifuge field are analyzed.The hydraulic pressure law in the centrifuge field indicates the existence of the centrifuge hydraulic pressure.The mechanical characteristics of the slide-valve and the dual nozzle flapper valve are studied,and it is found that the centrifuge field can not only increase the driving force or moment of the function units,but also decrease the stability of the components.Finally by applying Gauss minimum constraint principle,the dynamic model of the electro-hydraulic vibrator in the centrifuge field is established,and the mechanical restriction of the system is also presented.The study will be helpful for the realization of the combined vibration and centrifuge test system.

  12. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    OpenAIRE

    Hongkun Li; Xuefeng Zhang; Xiaowen Zhang; Shuhua Yang; Fujian Xu

    2014-01-01

    Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP) sensor installed in vicinity to the crack area is used to d...

  13. Numerical Investigations on the Transient Performance of a Centrifugal Pump

    OpenAIRE

    Asim, Taimoor; Mishra, Rakesh

    2015-01-01

    Centrifugal pumps are an integral part of plants used in process industries. The flow structure within a centrifugal pump is very complex due to the interaction between the rotating impeller and the geometric features around it. In the present study, numerical investigations on a centrifugal pump have been carried out using a Computational Fluid Dynamics (CFD) based solver. This study employs finite volume technique in order to analyse the influence of variations in the rotational speed of th...

  14. Latex Micro-balloon Pumping in Centrifugal Microfluidic Platforms

    OpenAIRE

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Wadi harun, Sulaiman; Madou, Marc

    2014-01-01

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-stepped processes on a single microfluidics disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a...

  15. pH-sensitive micelles for targeted drug delivery prepared using a novel membrane contactor method.

    Science.gov (United States)

    Laouini, Abdallah; Koutroumanis, Konstantinos P; Charcosset, Catherine; Georgiadou, Stella; Fessi, Hatem; Holdich, Richard G; Vladisavljević, Goran T

    2013-09-25

    A novel membrane contactor method was used to produce size-controlled poly(ethylene glycol)-b-polycaprolactone (PEG-PCL) copolymer micelles composed of diblock copolymers with different average molecular weights, Mn (9200 or 10,400 Da) and hydrophilic fractions, f (0.67 or 0.59). By injecting 570 L m(-2) h(-1) of the organic phase (a 1 mg mL(-1) solution of PEG-PCL in tetrahydrofuran) through a microengineered nickel membrane with a hexagonal pore array and 200 μm pore spacing into deionized water agitated at 700 rpm, the micelle size linearly increased from 92 nm for a 5-μm pore size to 165 nm for a 40-μm pore size. The micelle size was finely tuned by the agitation rate, transmembrane flux and aqueous to organic phase ratio. An encapsulation efficiency of 89% and a drug loading of ~75% (w/w) were achieved when a hydrophobic drug (vitamin E) was entrapped within the micelles, as determined by ultracentrifugation method. The drug-loaded micelles had a mean size of 146 ± 7 nm, a polydispersity index of 0.09 ± 0.01, and a ζ potential of -19.5 ± 0.2 mV. When drug-loaded micelles where stored for 50 h, a pH sensitive drug release was achieved and a maximum amount of vitamin E (23%) was released at the pH of 1.9. When a pH-sensitive hydrazone bond was incorporated between PEG and PCL blocks, no significant change in micelle size was observed at the same micellization conditions.

  16. Ammonia removal in the carbon contactor of a hybrid membrane process.

    Science.gov (United States)

    Stoquart, Céline; Servais, Pierre; Barbeau, Benoit

    2014-12-15

    The hybrid membrane process (HMP) coupling powdered activated carbon (PAC) and low-pressure membrane filtration is emerging as a promising new option to remove dissolved contaminants from drinking water. Yet, defining optimal HMP operating conditions has not been confirmed. In this study, ammonia removal occurring in the PAC contactor of an HMP was simulated at lab-scale. Kinetics were monitored using three PAC concentrations (1-5-10 g L(-1)), three PAC ages (0-10-60 days), two temperatures (7-22 °C), in ambient influent condition (100 μg N-NH4 L(-1)) as well as with a simulated peak pollution scenario (1000 μg N-NH4L(-1)). The following conclusions were drawn: i) Using a colonized PAC in the HMP is essential to reach complete ammonia removal, ii) an older PAC offers a higher resilience to temperature decrease as well as lower operating costs; ii) PAC concentration inside the HMP reactor is not a key operating parameter as under the conditions tested, PAC colonization was not limited by the available surface; iii) ammonia flux limited biomass growth and iv) hydraulic retention time was a critical parameter. In the case of a peak pollution, the process was most probably phosphate-limited but a mixed adsorption/nitrification still allowed reaching a 50% ammonia removal. Finally, a kinetic model based on these experiments is proposed to predict ammonia removal occurring in the PAC reactor of the HMP. The model determines the relative importance of the adsorption and biological oxidation of ammonia on colonized PAC, and demonstrates the combined role of nitrification and residual adsorption capacity of colonized PAC.

  17. Biofilm growth of Chlorella sorokiniana in a rotating biological contactor based photobioreactor.

    Science.gov (United States)

    Blanken, W; Janssen, M; Cuaresma, M; Libor, Z; Bhaiji, T; Wijffels, R H

    2014-12-01

    Microalgae biofilms could be used as a production platform for microalgae biomass. In this study, a photobioreactor design based on a rotating biological contactor (RBC) was used as a production platform for microalgae biomass cultivated in biofilm. In the photobioreactor, referred to as Algadisk, microalgae grow in biofilm on vertical rotating disks partially submerged in a growth medium. The objective is to evaluate the potential of the Algadisk photobioreactor with respect to the effects of disk roughness, disk rotation speed and CO2 concentration. These objectives where evaluated in relationship to productivity, photosynthetic efficiency, and long-term cultivation stability in a lab-scale Algadisk system. Although the lab-scale Algadisk system is used, operation parameters evaluated are relevant for scale-up. Chlorella Sorokiniana was used as model microalgae. In the lab-scale Algadisk reactor, productivity of 20.1 ± 0.7 g per m(2) disk surface per day and a biomass yield on light of 0.9 ± 0.04 g dry weight biomass per mol photons were obtained. Different disk rotation speeds did demonstrate minimal effects on biofilm growth and on the diffusion of substrate into the biofilm. CO2 limitation, however, drastically reduced productivity to 2-4 g per m(2) disk surface per day. Productivity could be maintained over a period of 21 weeks without re-inoculation of the Algadisk. Productivity decreased under extreme conditions such as pH 9-10, temperature above 40°C, and with low CO2 concentrations. Maximal productivity, however, was promptly recovered when optimal cultivation conditions were reinstated. These results exhibit an apparent opportunity to employ the Algadisk photobioreactor at large scale for microalgae biomass production if diffusion does not limit the CO2 supply.

  18. Biosorption of heavy metals in a photo-rotating biological contactor--a batch process study.

    Science.gov (United States)

    Orandi, Sanaz; Lewis, David M

    2013-06-01

    Metal removal potential of indigenous mining microorganisms from acid mine drainage (AMD) has been well recognised in situ at mine sites. However, their removal capacity requires to be investigated for AMD treatment. In the reported study, the capacity of an indigenous AMD microbial consortium dominated with Klebsormidium sp., immobilised in a photo-rotating biological contactor (PRBC), was investigated for removing various elements from a multi-ion synthetic AMD. The synthetic AMD was composed of major (Cu, Mn, Mg, Zn, Ca, Na, Ni) and trace elements (Fe, Al, Cr, Co, Se, Ag, Mo) at initial concentrations of 2 to 100 mg/L and 0.005 to 1 mg/L, respectively. The PRBC was operated for two 7-day batch periods under pH conditions of 3 and 5. The maximum removal was observed after 3 and 6 days at pH 3 and 5, respectively. Daily water analysis data demonstrated the ability of the algal-microbial biofilm to remove an overall average of 25-40 % of the major elements at pH 3 in the order of Na > Cu > Ca > Mg > Mn > Ni > Zn, whereas a higher removal (35-50 %) was observed at pH 5 in the order of Cu > Mn > Mg > Ca > Ni > Zn > Na. The removal efficiency of the system for trace elements varied extensively between 3 and 80 % at the both pH conditions. The batch data results demonstrated the ability for indigenous AMD algal-microbial biofilm for removing a variety of elements from AMD in a PRBC. The work presents the potential for further development and scale-up to use PBRC inoculated with AMD microorganisms at mine sites for first or secondary AMD treatment.

  19. Ammonia removal in the carbon contactor of a hybrid membrane process.

    Science.gov (United States)

    Stoquart, Céline; Servais, Pierre; Barbeau, Benoit

    2014-12-15

    The hybrid membrane process (HMP) coupling powdered activated carbon (PAC) and low-pressure membrane filtration is emerging as a promising new option to remove dissolved contaminants from drinking water. Yet, defining optimal HMP operating conditions has not been confirmed. In this study, ammonia removal occurring in the PAC contactor of an HMP was simulated at lab-scale. Kinetics were monitored using three PAC concentrations (1-5-10 g L(-1)), three PAC ages (0-10-60 days), two temperatures (7-22 °C), in ambient influent condition (100 μg N-NH4 L(-1)) as well as with a simulated peak pollution scenario (1000 μg N-NH4L(-1)). The following conclusions were drawn: i) Using a colonized PAC in the HMP is essential to reach complete ammonia removal, ii) an older PAC offers a higher resilience to temperature decrease as well as lower operating costs; ii) PAC concentration inside the HMP reactor is not a key operating parameter as under the conditions tested, PAC colonization was not limited by the available surface; iii) ammonia flux limited biomass growth and iv) hydraulic retention time was a critical parameter. In the case of a peak pollution, the process was most probably phosphate-limited but a mixed adsorption/nitrification still allowed reaching a 50% ammonia removal. Finally, a kinetic model based on these experiments is proposed to predict ammonia removal occurring in the PAC reactor of the HMP. The model determines the relative importance of the adsorption and biological oxidation of ammonia on colonized PAC, and demonstrates the combined role of nitrification and residual adsorption capacity of colonized PAC. PMID:25459222

  20. Separative power of an optimised concurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  1. [Design and optimization of a centrifugal pump for CPCR].

    Science.gov (United States)

    Pei, J; Tan, X; Chen, K; Li, X

    2000-06-01

    Requirements for an optimal centrifugal pump, the vital component in the equipment for cardiopulmonary cerebral resuscitation(CPCR), have been presented. The performance of the Sarns centrifugal pump (Sarns, Inc./3M, Ann arbor, MI, U.S.A) was tested. The preliminarily optimized model for CPCR was designed according to the requirements of CPCR and to the comparison and analysis of several clinically available centrifugal pumps. The preliminary tests using the centrifugal pump made in our laboratory(Type CPCR-I) have confirmed the design and the optimization.

  2. Effects of centrifugation on gonadal and adrenocortical steroids in rats

    Science.gov (United States)

    Kakihana, R.; Butte, J. C.

    1980-01-01

    Many endocrine systems are sensitive to external changes in the environment. Both the pituitary adrenal and pituitary gonadal systems are affected by stress including centrifugation stress. The effect of centrifugation on the pituitary gonadal and pituitary adrenocortical systems was examined by measuring the gonadal and adrenal steroids in the plasma and brain following different duration and intensity of centrifugation stress in rats. Two studies were completed and the results are presented. The second study was carried out to describe the developmental changes of brain, plasma and testicular testosterone and dihydrotestosterone in Sprague Dawley rats so that the effect of centrifugation stress on the pituitary gonadal syatem could be better evaluated in future studies.

  3. Computer simulation for centrifugal mold filling of precision titanium castings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Computer simulation codes were developed based on a proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings (CASM-3D for Windows). Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings under a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section precision castings.

  4. EM Task 9 - Centrifugal membrane filtration

    International Nuclear Information System (INIS)

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc)

  5. Rotational spectroscopy with an optical centrifuge

    CERN Document Server

    Korobenko, Aleksey; Hepburn, John W; Milner, Valery

    2013-01-01

    We demonstrate a new spectroscopic method for studying electronic transitions in molecules with extremely broad range of angular momentum. We employ an optical centrifuge to create narrow rotational wave packets in the ground electronic state of $^{16}$O$_2$. Using the technique of resonance-enhanced multi-photon ionization, we record the spectrum of multiple ro-vibrational transitions between $X^3\\Sigma_{g}^{-}$ and $C^3\\Pi_{g}$ electronic manifolds of oxygen. Direct control of rotational excitation, extending to rotational quantum numbers as high as $N\\gtrsim 120$, enables us to interpret the complex structure of rotational spectra of $C^3\\Pi_{g}$ beyond thermally accessible levels.

  6. Gas centrifuge bibliography 1980-1982

    International Nuclear Information System (INIS)

    A bibliography, with abstract, is presented of the gas centrifuge literature published from 1980 to 1982 inclusive. It supplements PG Information Series 25 (CA), BNFL Information Series 15 (CA) and BNFL Information Series 23 (CA), which covered the periods 1895 to 1970, 1970 to 1974, and 1975 to 1979 respectively. After bibliographies and books and pamphlets, the main list is arranged chronologically under the headings, Reports, Journal articles, and Conference papers. Items omitted from the earlier bibliographies or received too late for inclusion in this, have been listed separately. There are author, report number and subject indexes. (U.K.)

  7. DESIGN PARAMETERS OF CENTRIFUGAL COMPRESSOR INDUCER

    Directory of Open Access Journals (Sweden)

    Saim KOÇAK

    1998-03-01

    Full Text Available Design characteristics of centrifugal compressor impellers working with compressible fluids are analyzed, and the design parameters of inducer are defined. The effects of incidence, deviation and deflection angles, relative eddy, rotating stall and Mach number are investigated. The relation between minimum relative Mach number of inducer and flow angle is investigated and it is observed that the minimum Mach number occurs for flow angle values between -680 and -520 . In the design, the effect of a 100 difference in flow angle is found to be less than 1 % on minimum relative Mach number.

  8. Rotordynamic Forces on Centrifugal Pump Impellers

    OpenAIRE

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A.J

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with rad...

  9. THERMODYNAMIC DESIGN OF CENTRIFUGAL COMPRESSOR FOR TURBOCHARGER

    OpenAIRE

    Sonawane Shubham*, Sondkar Pratik, Qasim Siddiqui, Phirke Indraneel, Prof. R. P. Kakde

    2016-01-01

    The purpose of a turbocharger is to increase the power output of an engine by supplying compressed air to the engine intake manifold so that fuel can be burnt efficiently. In this work, thermodynamic design of a high pressure ratio centrifugal compressor, for 75 kW class engines, was carried out. A pressure ratio of 2.8 was considered with a compressor rotational speed of 60,000 RPM. The compressor was designed for vane less diffuser. The impeller designs were obtained using ci...

  10. Design and Prototyping of Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei Mizuki; Gaku Minorikawa; Toshiyuki Hirano; Yuichiro Asaga; Naoki Yamaguchi; Yutaka Ohta; Eisuke Outa

    2003-01-01

    In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

  11. Impeller blade design method for centrifugal compressors

    Science.gov (United States)

    Jansen, W.; Kirschner, A. M.

    1974-01-01

    The design of a centrifugal impeller with blades that are aerodynamically efficient, easy to manufacture, and mechanically sound is discussed. The blade design method described here satisfies the first two criteria and with a judicious choice of certain variables will also satisfy stress considerations. The blade shape is generated by specifying surface velocity distributions and consists of straight-line elements that connect points at hub and shroud. The method may be used to design radially elemented and backward-swept blades. The background, a brief account of the theory, and a sample design are described.

  12. Theory and experiments on centrifuge cratering

    Science.gov (United States)

    Schmidt, R. M.; Holsapple, K. A.

    1980-01-01

    Centrifuge experimental techniques provide possibilities for laboratory simulation of ground motion and cratering effects due to explosive loadings. The results of a similarity analysis for the thermomechanical response of a continuum show that increased gravity is a necessary condition for subscale testing when identical materials for both model and prototype are being used. The general similarity requirements for this type of subscale testing are examined both theoretically and experimentally. The similarity analysis is used to derive the necessary and sufficient requirements due to the general balance and jump equations and gives relations among all the scale factors for size, density, stress, body forces, internal energy, heat supply, heat conduction, heat of detonation, and time. Additional constraints due to specific choices of material constitutive equations are evaluated separately. The class of constitutive equations that add no further requirements is identified. For this class of materials, direct simulation of large-scale cratering events at small scale on the centrifuge is possible and independent of the actual constitutive equations. For a rate-independent soil it is shown that a small experiment at gravity g and energy E is similar to a large event at 1 G but with energy equal to g3E. Consequently, experiments at 500 G with 8 grams of explosives can be used to simulate a kiloton in the field. A series of centrifuge experiments was performed to validate the derived similarity requirements and to determine the practicality of applying the technique to dry granular soils having little or no cohesion. Ten shots using Ottawa sand at various gravities confirmed reproducibility of results in the centrifuge environment, provided information on particle size effects, and demonstrated the applicability of the derived similitude requirements. These experiments used 0.5-4 grams of pentaerythritol-tetranitrate (PETN) and 1.7 grams of lead-azide explosives. They

  13. Experimental study on the separation of CO{sub 2} from flue gas using hollow fiber membrane contactors without wetting

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shui-ping; Fang, Meng-Xiang; Zhang, Wei-Feng; Luo, Zhong-Yang; Cen, Ke-Fa [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Wang, Shu-Yuan; Xu, Zhi-Kang [Institute of Polymer Science, Zhejiang University, Hangzhou 310027 (China)

    2007-05-15

    Experiments on CO{sub 2} removal from flue gas using polypropylene (PP) hollow fiber membrane contactors were conducted in this study. Absorbents including aqueous potassium glycinate (PG) solution, aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) were used to absorb CO{sub 2} in the experiments. Based on the wetting experimental results, aqueous PG solution can offer a higher surface tension than water, aqueous MEA and MDEA solutions. Aqueous PG solution has a lower potential of membrane wetting after a continuously steady operation for 40 h to maintain CO{sub 2} removal efficiency of about 90%. Under moderate operating conditions, effects of the temperature, flow rate, and concentration of absorbents, and the flow rate of flue gas as well as the volumetric concentration of carbon dioxide in the flue gas on the mass transfer rate of CO{sub 2} were studied on a pilot-scale test facility. Unlike conventional absorbents, the mass transfer decreases with an increasing liquid temperature when using aqueous PG solution. Results show that CO{sub 2} removal efficiency was above 90% and the mass transfer rate was above 2.0 mol/(m{sup 2} h) using the PG aqueous solution. It indicates that the hollow fiber membrane contactor has a great potential in the area of CO{sub 2} separation from flue gas when absorbent's concentration and liquid-gas pressure difference are designed elaborately. (author)

  14. Preparation of Calcium Carbonate Nanoparticles with a Continuous Gas-liquid Membrane Contactor:Particles Morphology and Membrane Fouling

    Institute of Scientific and Technical Information of China (English)

    JIA Zhiqian; CHANG Qing; QIN Jin; MAMAT Aynur

    2013-01-01

    Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor.The effects of Ca(OH)2 concentration,CO2 pressure and liquid flow velocity on the particles morphology,pressure drop and membrane fouling were studied.With rising Ca(OH)2 concentrations,the average size of the particles increased.The effects of Ca(OH)2 concentration and CO2 pressure on particles were not apparent under the experimental conditions.When the Ca(OH)2 concentration and liquid flow velocity were high,or the CO2 pressure was low,the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage,whereas the fouling was slight at exit.The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials.The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.

  15. Hollow fiber membrane contactors for post-combustion CO2 capture: a scale-up study from laboratory to pilot plant

    NARCIS (Netherlands)

    Chabanon, E.; Kimball, E.; Favre, E.; Lorain, O.; Goetheer, E.L.V.; Ferre, D.; Gomez, A.; Broutin, P.

    2013-01-01

    Membrane contactors have been proposed for decades as a way to achieve intensified mass transfer processes. Post-combustion CO2 capture by absorption into a chemical solvent is one of the currently most intensively investigated topics in this area. Numerous studies have already been reported, unfort

  16. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    Science.gov (United States)

    Delcourt, Dominique; Seki, K.; Terada, N.; Moore, Thomas E.

    2012-01-01

    We investigate the transport of ions in the low-altitude magnetosphere magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of the E B drift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low-energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low-energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, the E B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.

  17. Postcardiotomy centrifugal assist: a single surgeon's experience.

    Science.gov (United States)

    Curtis, Jack J; McKenney-Knox, Charlotte A; Wagner-Mann, Colette C

    2002-11-01

    Because of the infrequent application of cardiac assist devices for postcardiotomy heart failure, most published reports include the results of learning curves from multiple surgeons. Between October 1986 and June 2001, a single surgeon used 35 Sarns Centrifugal Pumps as ventricular assist devices in 21 patients with severe hemodynamic compromise after open heart surgery (0.88% incidence). Patients' ages ranged from 39 to 77 (mean, 59.6 years). Three patients required right ventricular assist devices, 4 left ventricular assist devices, and 14 had biventricular assist devices. For all, the indication for application was inability to wean from cardiopulmonary bypass despite multiple inotropes and intraaortic balloon pumping. All were expected to be intraoperative deaths without further mechanical assistance. Patients were assisted from 2 to 434 h (median, 48 h). Fifteen patients (71.4%) were weaned from device(s), and 11 patients (52.4%) were hospital survivors. Actuarial survival in those dismissed from the hospital was 78% at 5 years and 39% at 10 years. Patients facing certain demise after cardiac surgery can be salvaged with temporary centrifugal mechanical assist. Results are competitive with that achieved with more sophisticated devices. Hospital survivors enjoy reasonable longevity.

  18. PARTICLE DISTRIBUTION IN CENTRIFUGAL ACCELERATING FIELDS

    Institute of Scientific and Technical Information of China (English)

    Yu Sirong; Zhang Xinping; He Zhenming; Liu Yaohui

    2003-01-01

    Based on continuum theory and moving law of particles, a model is presented to obtain gradient distribution of particles in centrifugal accelerating field, by which the particle distribution in gradient composite material can be predicted. The simulation shows with increases in rotating time, four regions gradually appear from the internal periphery to the external one, they are free region, transition region, steady region and surface reinforced region,and the latest three regions are defined as a rich region. Finally, the steady region disappears, and the rich region only includes transition region and surface reinforced region. The influences of centrifugal acceleration coefficient G,primary volume fraction (0,pouring temperature (p and density difference between the particle and the metal matrix on particles gradient distribution are studied in detail. The results of the theoretical analysis agree with experiment ones. Both of analysis and experiment results indicate that with the increase in G and (p, the particle distribution becomes more centralized and the consistence of particle in the surface periphery becomes larger.

  19. Some aversive characteristics of centrifugally generated gravity.

    Science.gov (United States)

    Altman, F.

    1973-01-01

    The effective weight of rats was manipulated by centrifugation. Two effective weight levels were obtained. In three escape avoidance conditions a lever press produced a change from a base level of 2.1 g to a response level of 1.1 g. In a punishment condition a response produced a change from a 1.1 g level to a 2.1 g level and in an extinction condition responses had no effect on the 2.1 g effective weight level present. All changes took 30 sec and were maintained for an additional 10 sec before a return to base level was initiated. When responses occurred closer together than the 40 sec, they delayed the return to base level by 40 sec. This 40 sec interval is referred to as response-contingent-time. The response rate and amount of response-contingent-time served as the data. The results confirmed previous data that centrifugation is aversive. The results are interpreted as indicating that the aversiveness is attributable to the increase in effective weight, and that rats can discriminate the different angular velocity-radius of rotation combinations used.

  20. Virtual Prototyping Technology of AC Contactor%交流接触器虚拟样机设计技术

    Institute of Scientific and Technical Information of China (English)

    何晓燕; 许志红

    2016-01-01

    采用虚拟样机技术,建立全面反映交流接触器动态特性的三维虚拟样机模型,模型包含完整触头系统、铁心系统及连接部件,从而考虑结构特点对其运动特性的影响。引入Ansys/LS-DYNA 动力学分析软件,采用基于连续介质力学的有限元法考虑机构之间的非线性接触、碰撞问题及弹性材料的形变作用,计算接触器动作过程中的触头弹跳情况。通过三维可视化界面得到触头、铁心等运动部件位移、速度随时间变化情况,对接触器动态特性进行直观地分析。通过交流接触器虚拟样机模型的仿真,从机械动力学角度,分析触头系统闭合速度和触头弹簧初压力、金属簧片物理特性及触头表面摩擦系数对触头弹跳的影响。交流接触器的三维虚拟样机设计对其结构优化设计具有良好的理论依据和实用价值。%With virtual prototyping technology, this paper establishes the 3D virtual prototyping model of AC contactor including the whole contact system, core system and connecting parts. It reflects the real dynamic characteristics of AC contactor affected by the structure. Based on the finite method of continuum mechanics, the nonlinear contact, collision problem and elastic material deformation have been taken into account in the dynamic analysis software Ansys/LS-DYNA. Contact bounce in the process of contactor action is simulated. Moreover, by 3D visualization window, the displacement and velocity of movable contact and core changing over time are obtained and the dynamic characteristics of contactor are analyzed visually. In addition, the influence of closure speed, pre force of spring, properties of reed and friction coefficient of contact on contact bounce has been analyzed from the view of mechanical dynamics. The 3D virtual prototype design of AC contactor provides theoretical basis for its structure optimization design and has high practical value.

  1. Performance Characteristics ofAC Contactor During Voltage Sag%晃电故障下交流接触器的工作特性分析

    Institute of Scientific and Technical Information of China (English)

    林抒毅; 许志红

    2011-01-01

    电磁式交流接触器是一种应用广泛的低压电器产品,当晃电故障发生时,交流接触器可能因为不稳定电压而频繁接通或分断,对系统造成很大的影响。论文以CJ20.63A交流接触器为研究对象,建立考虑触头运动情况的电磁机构吸合过程、吸持阶段以及释放过程的磁路动态计算方程,并通过实验验证了模型的正确性。针对不同的合闸相角和工作状态进行仿真,分析了发生晃电故障时电压下降幅度、晃电故障持续时间、晃电故障发生时刻及电压相角变化对接触器工作特性的影响。结果表明,吸合阶段的晃电影响与吸合时问有直接关系,吸合以后的晃电故障影响存在临界%Electromagnetic contactor is a kind of widely used electric product. When the voltage drops suddenly, the contactor will be open or closed frequently, and the circuit will be influenced seriously. Based on the research of CJ20-63A contactor dynamic equations were established during closing, cIosed and opening processes; the movement process of the moving contact and the bounce of the contacts were considered at the meantime. The experimental data shows the model is correct. Simulations were carried out with respect to different working states and various closing phase angles. Influences of the range, duration and occurrence time of voltage drop, and the variation of voltage phases on performance characteristics of contactors were analyzed; the result indicates that the influences of voltage sag on the contactor are related to the closing time directly in the closing process; and a critical time value should be considered after the contactor is closed. This research provides the basic for the further study on the intelligent AC contactor with anti-voltage sag.

  2. V5 AND V10 CONTACTOR TESTING WITH THE NEXT GENERATION (CSSX) SOLVENT FOR THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Restivo, M.; Peters, T.; Pierce, R.; Fondeur, F.; Steeper, T.; Williams, M.; Giddings, B.; Hickman, B.; Fink, S.

    2012-01-17

    program to test the full size strip (V5) and extraction (V10) centrifugal contactors and the associated strip and extraction effluent coalescers to determine the hydraulic and mass transfer characteristics with the NGS. The test program evaluated the amount of organic carryover and the droplet size of the carryover phases using several analytical methods. Provisions were also made to enable an evaluation of coalescer performance. Stage efficiency and mass distribution ratios were determined using Cs mass transfer measurements. Using 20 millimolar (mM) extractant (instead of 50 mM), the nominal D(Cs) measured was 16.0-17.5. The data indicate that equilibrium is achieved rapidly and maintained throughout sampling. The data showed good stage efficiency for extraction (Tests 1A-1D), ranging from 98.2% for Test 1A to 90.5% for Test 1D. No statistically-significant differences were noted for operations at 12 gpm aqueous flow when compared with either 4 gpm or 8 gpm of aqueous flow. The stage efficiencies equal or exceed those previously measured using the baseline CSSX solvent system. The nominal target for scrub Cs distribution values are {approx}1.0-2.5. The first scrub test yielded an average scrub value of 1.21 and the second scrub test produced an average value of 0.78. Both values are considered acceptable. Stage efficiency was not calculated for the scrub tests. For stripping behavior, six tests were completed in a manner to represent the first strip stage. For three tests at the baseline flow ratios (O:A of 3.75:1) but at different total flow rates, the D(Cs) values were all similar at {approx}0.052. Similar behavior was observed for two tests performed at an O:A ratio of 7:1 instead of 3.75:1. The data for the baseline strip tests exhibited acceptable stage efficiency, ranging from 82.0% for low flow to 89-90% for medium and high flow. The difference in efficiency may be attributable to the low volume in the contactor housing at lower flow rates. The concentrations of

  3. V5 AND V10 CONTACTOR TESTING WITH THE NEXT GENERATION (CSSX) SOLVENT FOR THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Restivo, M.; Peters, T.; Pierce, R.; Fondeur, F.; Steeper, T.; Williams, M.; Giddings, B.; Hickman, B.; Fink, S.

    2012-01-17

    program to test the full size strip (V5) and extraction (V10) centrifugal contactors and the associated strip and extraction effluent coalescers to determine the hydraulic and mass transfer characteristics with the NGS. The test program evaluated the amount of organic carryover and the droplet size of the carryover phases using several analytical methods. Provisions were also made to enable an evaluation of coalescer performance. Stage efficiency and mass distribution ratios were determined using Cs mass transfer measurements. Using 20 millimolar (mM) extractant (instead of 50 mM), the nominal D(Cs) measured was 16.0-17.5. The data indicate that equilibrium is achieved rapidly and maintained throughout sampling. The data showed good stage efficiency for extraction (Tests 1A-1D), ranging from 98.2% for Test 1A to 90.5% for Test 1D. No statistically-significant differences were noted for operations at 12 gpm aqueous flow when compared with either 4 gpm or 8 gpm of aqueous flow. The stage efficiencies equal or exceed those previously measured using the baseline CSSX solvent system. The nominal target for scrub Cs distribution values are {approx}1.0-2.5. The first scrub test yielded an average scrub value of 1.21 and the second scrub test produced an average value of 0.78. Both values are considered acceptable. Stage efficiency was not calculated for the scrub tests. For stripping behavior, six tests were completed in a manner to represent the first strip stage. For three tests at the baseline flow ratios (O:A of 3.75:1) but at different total flow rates, the D(Cs) values were all similar at {approx}0.052. Similar behavior was observed for two tests performed at an O:A ratio of 7:1 instead of 3.75:1. The data for the baseline strip tests exhibited acceptable stage efficiency, ranging from 82.0% for low flow to 89-90% for medium and high flow. The difference in efficiency may be attributable to the low volume in the contactor housing at lower flow rates. The concentrations of

  4. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    Science.gov (United States)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2014-01-01

    The report "High Efficiency Centrifugal Compressor for Rotorcraft Applications" documents the work conducted at UTRC under the NRA Contract NNC08CB03C, with cost share 2/3 NASA, and 1/3 UTRC, that has been extended to 4.5 years. The purpose of this effort was to identify key technical barriers to advancing the state-of-the-art of small centrifugal compressor stages; to delineate the measurements required to provide insight into the flow physics of the technical barriers; to design, fabricate, install, and test a state-of-the-art research compressor that is representative of the rear stage of an axial-centrifugal aero-engine; and to acquire detailed aerodynamic performance and research quality data to clarify flow physics and to establish detailed data sets for future application. The design activity centered on meeting the goal set outlined in the NASA solicitation-the design target was to increase efficiency at higher work factor, while also reducing the maximum diameter of the stage. To fit within the existing Small Engine Components Test Facility at NASA Glenn Research Center (GRC) and to facilitate component re-use, certain key design parameters were fixed by UTRC, including impeller tip diameter, impeller rotational speed, and impeller inlet hub and shroud radii. This report describes the design effort of the High Efficiency Centrifugal Compressor stage (HECC) and delineation of measurements, fabrication of the compressor, and the initial tests that were performed. A new High-Efficiency Centrifugal Compressor stage with a very challenging reduction in radius ratio was successfully designed, fabricated and installed at GRC. The testing was successful, with no mechanical problems and the running clearances were achieved without impeller rubs. Overall, measured pressure ratio of 4.68, work factor of 0.81, and at design exit corrected flow rate of 3 lbm/s met the target requirements. Polytropic efficiency of 85.5 percent and stall margin of 7.5 percent were

  5. Separative power of an optimised concurrent gas centrifuge

    CERN Document Server

    Bogovalov, S V

    2015-01-01

    The problem of separation of uranium isotopes in a concurrent gas centrifuge is solved analytically. Separative power of the optimized concurrent gas centrifuges equals to $\\delta U=12.7(V/700~{\\rm m/s})^2 (300 ~{\\rm K}/T)L, ~{\\rm kg ~SWU/yr}$, where $L$ and $V$ are the length and linear velocity of the rotor of the gas centrifuge, $T$ is the temperature. This formula well agrees with an empirical separative power of counter current gas centrifuges. The optimal value of the separative power is not unique on the plane $(p_w,v_z)$, where $p_w$ is pressure at the wall of the rotor and $v_z$ is axial velocity of the gas. This value is constant on a line defined by the equation $p_wv_z=constant$. Equations defining the mass flux and the electric power necessary to support the rotation of the gas centrifuge are obtained.

  6. Centrifugal acceleration of plasma in pulsar magnetosphere

    Indian Academy of Sciences (India)

    R T Gangadhara; V Krishna

    2003-12-01

    We present a relativistic model for the centrifugal acceleration of plasma bunches and the coherent radio emission in pulsar magnetosphere. We find that rotation broadens the width of leading component compared to the width of trailing component. We explain this difference in the component widths using the nested cone emission geometry. We estimate the effect of pulsar spin on the Stokes parameters, and find that the inclination between the rotation and magnetic axes can introduce an asymmetry in the circular polarization of the conal components. We analyse the single pulse polarization data of PSR B0329+54 at 606 MHz, and find that in its conal components, one sense of circular polarization dominates in the leading component while the other sense dominates in the trailing component. Our simulation shows that changing the sign of the impact parameter changes the sense of circular polarization as well as the swing of polarization angle.

  7. [Hemodynamic analysis of a centrifugal blood pump].

    Science.gov (United States)

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels.

  8. Stability of centrifugal pump characteristic curve

    OpenAIRE

    Chmatil, Ľuboš

    2011-01-01

    Předložená diplomová práce obsahuje teoretický rozbor charakteristik odstředíveho čerpadla, podmínky stability Y(Q) charakteristiky, výpočet charakteristiky ßč(ns), úpravy vedúce k stabilizaci spirálního telesa a oběžného kola, návrh spirály, obežného kola a následný výpočet v programe Fluent. This master's thesis includes theoretical analysis of characteristics of a centrifugal pump, conditions of stability of Y(Q) characteristic, calculation of characteristics ßč(ns), modifications leadi...

  9. Rotordynamic forces on centrifugal pump impellers

    Science.gov (United States)

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A. J.

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with radically increased shroud clearance, a two-dimensional impeller, and an impeller with an inducer, the impeller of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine). In each case, a destabilizing force was observed over a region of positive whirl.

  10. [Hemodynamic analysis of a centrifugal blood pump].

    Science.gov (United States)

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels. PMID:26027287

  11. Potential commercial applications of centrifuge technology

    International Nuclear Information System (INIS)

    As part of an effort to prevent the loss of and maximize the use of unique developments of the centrifuge program, this document identifies and briefly describes unclassified technologies potentially available for transfer. In addition, this document presents a preliminary plan for action needed to carry out the transfer activity. Continuing efforts will provide additional descriptions of technologies which have applications that are not as apparent or as obvious as those presented here. Declassification of some of the program information, now classified as restricted data, would permit the descriptions of additional technologies which have significant commercial potential. The following are major areas of technology where transfer opportunities exist: biomedical; separation; motors and control systems; materials; vacuum; dynamics and balancing; and diagnostics and instrumentation

  12. A Novel Fabrication Method for Functionally Graded Materials under Centrifugal Force: The Centrifugal Mixed-Powder Method

    Directory of Open Access Journals (Sweden)

    Eri Miura-Fujiwara

    2009-12-01

    Full Text Available One of the fabrication methods for functionally graded materials (FGMs is a centrifugal solid-particle method, which is an application of the centrifugal casting technique. However, it is the difficult to fabricate FGMs containing nano-particles by the centrifugal solid-particle method. Recently, we proposed a novel fabrication method, which we have named the centrifugal mixed-powder method, by which we can obtain FGMs containing nano-particles. Using this processing method, Cu-based FGMs containing SiC particles and Al-based FGMs containing TiO2 nano-particles on their surfaces have been fabricated. In this article, the microstructure and mechanical property of Cu/SiC and Al/TiO2 FGMs, fabricated by the centrifugal mixed-powder method are reviewed.

  13. Multiphase flow modeling in centrifugal partition chromatography.

    Science.gov (United States)

    Adelmann, S; Schwienheer, C; Schembecker, G

    2011-09-01

    The separation efficiency in Centrifugal Partition Chromatography (CPC) depends on selection of a suitable biphasic solvent system (distribution ratio, selectivity factor, sample solubility) and is influenced by hydrodynamics in the chambers. Especially the stationary phase retention, the interfacial area for mass transfer and the flow pattern (backmixing) are important parameters. Their relationship with physical properties, operating parameters and chamber geometry is not completely understood and predictions are hardly possible. Experimental flow visualization is expensive and two-dimensional only. Therefore we simulated the flow pattern using a volume-of-fluid (VOF) method, which was implemented in OpenFOAM®. For the three-dimensional simulation of a rotating FCPC®-chamber, gravitational centrifugal and Coriolis forces were added to the conservation equation. For experimental validation the flow pattern of different solvent systems was visualized with an optical measurement system. The amount of mobile phase in a chamber was calculated from gray scale values of videos recorded by an image processing routine in ImageJ®. To visualize the flow of the stationary phase polyethylene particles were used to perform a qualitative particle image velocimetry (PIV) analysis. We found a good agreement between flow patterns and velocity profiles of experiments and simulations. By using the model we found that increasing the chamber depth leads to higher specific interfacial area. Additionally a circular flow in the stationary phase was identified that lowers the interfacial area because it pushes the jet of mobile phase to the chamber wall. The Coriolis force alone gives the impulse for this behavior. As a result the model is easier to handle than experiments and allows 3D prediction of hydrodynamics in the chamber. Additionally it can be used for optimizing geometry and operating parameters for given physical properties of solvent systems. PMID:21324465

  14. Analysis of centrifugal convection in rotating pipes

    Science.gov (United States)

    Shtern, Vladimir; Zimin, Valery; Hussain, Fazle

    2001-08-01

    New exact solutions, obtained for centrifugal convection of a compressible fluid in pipes and annular pipes, explain axially elongated counterflow and energy separation—poorly understood phenomena occurring in vortex devices, e.g., hydrocyclones and Ranque tubes. Centrifugal acceleration (which can be up to 106 times gravity in practical vortex tubes), combined with an axial gradient of temperature (even small), induces an intense flow from the cold end to the hot end along the pipe wall and a backflow near the axis. To account for large density variations in vortex devices, we use the axial temperature gradient as a small parameter instead of the Boussinesq approximation. For weak pipe rotation, the swirl is of solid-body type and solutions are compact: vz/vza=1-4y2+3y4 and (T-Tw)/(Ta-Tw)=(1-y2)3; where y=r/rw, the subscripts w and a denote values of axial velocity vz, temperature T, and radial distance r, at the wall and on the axis. The axial gradient of pressure, being proportional to 3y2-1, has opposite directions near the wall, y=1, and near the axis, y=0; this explains the counterflow. With increasing pipe rotation, the flow starts to converge to the axis. This causes important new effects: (i) the density and swirl velocity maxima occur away from the wall (vortex core formation), (ii) the temperature near the axis becomes lower than near the wall (the Ranque effect), (iii) the axial gradient of temperature drops from the wall to the axis, and (iv) the total axial heat flux (Nu) reaches its maximum Numax≈4000 and then decreases as swirl increases. These features can be exploited for the development of a micro-heat-exchanger, e.g., for cooling computer chips.

  15. A straight path centrifugal blood pump concept in the Capiox centrifugal pump.

    Science.gov (United States)

    Kijima, T; Oshiyama, H; Horiuchi, K; Nogawa, A; Hamasaki, H; Amano, N; Nojiri, C; Fukasawa, H; Akutsu, T

    1993-07-01

    This article describes comparative studies of a newly developed "straight path" centrifugal pump (Capiox centrifugal pump) targeted for open-heart surgery and circulatory support. A unique straight path design of the rotor was very effective in reducing the pump's rotational speed and prime volume. This pump was evaluated for hydraulics, hemolysis, depriming characteristics, cavitation, and heat generation. Two commercially available centrifugal pumps, the Biomedicus cone-type pump and the Sarns 3M impeller-type pump, were used as controls. The new pump required the lowest pump speed to produce the same flow rates under the same pressure loads and demonstrated the lowest hemolysis and the lowest temperature rise with the outlet clamped. The air volume required to deprime the new pump was one-third to one-half that for the other pumps, and no sign of cavitation was observed even if a small amount of air was introduced to the pump inlet under a negative pressure of 200 mm Hg.

  16. Tropic responses of Phycomyces sporangiophores to gravitational and centrifugal stimuli.

    Science.gov (United States)

    DENNISON, D S

    1961-09-01

    A low-speed centrifuge was used to study the tropic responses of Phycomyces sporangiophores in darkness to the stimulus of combined gravitational and centrifugal forces. If this stimulus is constant the response is a relatively slow tropic reaction, which persists for up to 12 hours. The response is accelerated by increasing the magnitude of the gravitational-centrifugal force. A wholly different tropic response, the transient response, is elicited by an abrupt change in the gravitational-centrifugal stimulus. The transient response has a duration of only about 6 min. but is characterized by a high bending speed (about 5 degrees /min.). An analysis of the distribution of the transient response along the growing zone shows that the active phase of the response has a distribution similar to that of the light sensitivity for the light-growth and phototropic responses. Experiments in which sporangiophores are centrifuged in an inert dense fluid indicate that the sensory mechanism of the transient response is closely related to the physical deformation of the growing zone caused by the action of the gravitational-centrifugal force on the sporangiophore as a whole. However, the response to a steady gravitational-centrifugal force is most likely not connected with this deformation, but is probably triggered by the shifting of regions or particles of differing density relative to one another inside the cell. PMID:13721903

  17. Purification of Sardinella sp., Oil: Centrifugation and Bentonite Adsorbent

    Directory of Open Access Journals (Sweden)

    S.H. Suseno

    2014-01-01

    Full Text Available Centrifugation and purification using adsorbents is one example of a fish oil refining techniques applied to reduce impurities of fish oil. The study aimed to determine the sardine oil quality before treatment, to determine yield of fish oil after centrifugation treatment and to determine the influence of centrifugation speed and bentonite concentration on sardine oil quality. Factorial design with two factors was used in this study. Level of free fatty acid and peroxide value before purification was 35.53% and 170 mEq/kg. Yield of fish oil after centrifugation treatment has been ranged from 17.42±3.56 to 76.33±0.21%. The best treatment which could reduce the peroxide value and total oxidation was a treatment with centrifugation speed at 6500 rpm and bentonite concentration at 3%. Peroxide value and total oxidation of its treatment was 25.00±0.00 and 51.43±0.01 mEq/kg. The lowest value of p-anisidine was 1.29±0.05 mEq/kg and its value could be found in a treatment with centrifugation speed at 4500 rpm and bentonite concentration at 5%. The level of free fatty acid after purification process was ranged from 27.35 to 34.69%. Oil clarity tended to increase with the increase of centrifugation speed and adsorbent concentration.

  18. Performance analysis of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Wada, T.; Shinohara, H.

    2013-12-01

    Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter blades. Further, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

  19. Control of nitratation in an oxygen-limited autotrophic nitrification/denitrification rotating biological contactor through disc immersion level variation.

    Science.gov (United States)

    Courtens, Emilie N P; Boon, Nico; De Clippeleir, Haydée; Berckmoes, Karla; Mosquera, Mariela; Seuntjens, Dries; Vlaeminck, Siegfried E

    2014-03-01

    With oxygen supply playing a crucial role in an oxygen-limited autotrophic nitrification/denitrification (OLAND) rotating biological contactor (RBC), its controlling factors were investigated in this study. Disc rotation speeds (1.8 and 3.6rpm) showed no influence on the process performance of a lab-scale RBC, although abiotic experiments showed a significant effect on the oxygenation capacity. Estimations of the biological oxygen uptake rate revealed that 85-89% of the oxygen was absorbed by the microorganisms during the air exposure of the discs. Indeed, increasing the disc immersion (50 to 75-80%) could significantly suppress undesired nitratation, on the short and long term. The presented results demonstrated that nitratation could be controlled by the immersion level and revealed that oxygen control in an OLAND RBC should be predominantly based on the atmospheric exposure percentage of the discs.

  20. Preparation of vitamin E loaded nanocapsules by the nanoprecipitation method: from laboratory scale to large scale using a membrane contactor.

    Science.gov (United States)

    Khayata, N; Abdelwahed, W; Chehna, M F; Charcosset, C; Fessi, H

    2012-02-28

    Vitamin E or α-tocopherol is widely used as a strong antioxidant in many medical and cosmetic applications, but is rapidly degraded, because of its light, heat and oxygen sensitivity. In this study, we applied the nanoprecipitation method to prepare vitamin E-loaded nanocapsules, at laboratory-scale and pilot-scale. We scaled-up the preparation of nanocapsule with the membrane contactor technique. The effect of several formulation variables on the vitamin E-loaded nanocapsules properties (mean diameter, zeta potential, and drug entrapment efficiency) was investigated. The optimized formulation at laboratory-scale and pilot-scale lead to the preparation of vitamin E-loaded nanocapsules with mean diameter of 165 and 172 nm, respectively, and a high encapsulation efficiency (98% and 97%, respectively).

  1. Hydrodynamic and absorption studies of carbon dioxide absorption in aqueous amide solutions using a bubble column contactor

    Directory of Open Access Journals (Sweden)

    A. Blanco

    2013-12-01

    Full Text Available The present work analyses the carbon dioxide absorption process in aqueous n-alkylpyrrolidones solutions, from the point of view of hydrodynamic studies as well as mass transfer, using a bubble column contactor. An analysis of the influence of solute concentration and gas flow-rate is complemented by the study of the effect caused by the alkyl group on the hydrodynamics and mass transfer. The presence of this kind of substance produces a decrease in mass transfer rate, but on the basis of interfacial area and mass transfer coefficient values, ethyl-2-pyrrolidine (EP shows suitable characteristics to replace methyl-2-pyrrolidine (MP in gas separation processes due to its lower safety problems.

  2. Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation

    KAUST Repository

    Akbulut, Ozge

    2012-08-08

    This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge. © 2012 American Chemical Society.

  3. Operating Characteristics Test System for AC/DC Contactor%交直流接触器动作特性测试系统

    Institute of Scientific and Technical Information of China (English)

    林文贵; 许志红

    2014-01-01

    The operating characteristics test system of AC/DC contactor was introduced.It achieves phase selection in the closing and opening course of contactor.Keyence laser displacement sensor is used to achieve the test of displacement of contact and iron core changing over time.Moreover,the sound signal making in the closing course of contactor by electret microphone is captured.The voltage,current of coil and main circuit with three-phase contacts are obtained.All signals mentioned above transmitting to PC based on data-acquisition,the system achieves data processing,automatically measuring and saving.The test system provides technical support for contactor studying and simulation,control strategy verifying of AC/DC contactor.It is of theoretical and practical significance in the design and development of AC/DC contactor.%介绍了一套交/直流接触器动作特性测试系统。系统实现了对交流接触器的选相分/合闸控制,采用激光位移传感器实现触头与铁心动态位移测试,驻极体传声器采集接触器闭合过程声音信号,霍尔传感器采集线圈回路和三相触头回路电压电流信号;同时使用数据采集卡将信号采集到上位机,完成数据的处理分析、自动测量、数据存储等功能。系统为交直流接触器的仿真研究、控制方案等提供技术支持,对提高接触器的设计与开发水平具有理论和实际意义。

  4. Continuous measuring method for static magnetic force of contactors%一种接触器静态吸力连续测量的方法

    Institute of Scientific and Technical Information of China (English)

    黄文锋; 朱翔鸥

    2012-01-01

    The dynamic process of AC contactor involves the coupling of electromagnetic conversion and mechanical movement, while the magnitude of the electromagnetic force is the function of both exciting current and the moving core displacement. However,there are some limitations in numerical calculation and simulation method. The results can not reflect the real process of the dynamics of the contactors. In order to understand the dynamic response of AC contactor precisely.it isimpossible to measure the electromagnetic force based on different currents and displacements. A method to achieve continuous measurement of the static magnetic force of contactors using force sensor is proposed, which can measure the electromagnetic force based on different currents and displacements. This method is used to measure the electromagnetic force of CJ20-100 contactor. The results are compared to simulation result, which shows that the methods is accurate. The measurement method provides an important reference value to study the dynamic characteristics of the electromagnetic contactors.%交流接触器动态过程涉及电磁转换和机械运动的耦合,其电磁吸力的大小同时是励磁电流和动铁芯位移的函数.目前广泛采用的数值计算与模拟仿真方法存在一定的局限性,其计算仿真结果难以反映真实的运动过程.为了准确掌握交流接触器的动态响应过程,需要对不同电流、不同位移时的电磁吸力进行测量.开发一种基于拉力传感器静态电磁吸力测量的方法,可以对不同电流或者不同位移时的电磁吸力进行连续测量.采用该测量方法对CJ20-100型接触器进行了实验研究,将测量结果与模拟仿真结果相比较,验证了该测量方法的准确性.该测量方法为电磁机构动态特性测量方法的研究提供了重要的参考价值.

  5. Technology of Zero-Current Breaking of Intelligent AC Contactor%智能交流接触器零电流分断技术

    Institute of Scientific and Technical Information of China (English)

    鲍光海; 张培铭

    2012-01-01

    Zero-current breaking technology is an important content in the research of intelligent AC contactor, In this paper, the optimization calculation aimed to breaking quickly of the electromagnetic mechanism of the intelligent AC contactor is conducted, by using the ANSYS electromagnetic software and the artificial fish swarm optimization algorithm based on genetic algorithm. This method not only ensures the reliable contact process of the intelligent AC contactor, but also realizes a quick release of the executive mechanism, thus greatly reduces the influence to the stability and accuracy of the three-phase contactors, especially the first opening phase when zero-current breaking, which improves the reliability of zero-current breaking and increases the technology research level of the intelligent AC contactor. A prototype is made based on the results of the optimization designation. The testing results show that the breaking time of the intelligent AC contactor is shortened greatly, and the stability of the breaking time is improved significantly too, so the reliability of the zero-current breaking increases significantly.%零电流分断技术是交流接触器智能化研究的重要内容。本文采用Ansys电磁场软件和基于遗传算法的人工鱼群优化算法对智能交流接触器电磁动作机构进行以快速分断为目标的优化计算,不仅保证智能交流接触器可靠与优化的接通过程,而且实现了动作机构快速释放,从而大幅度减小机构分散性对三相触头特别是首开相触头零电流分断准确性与稳定性影响,提高零电流分断的可靠性,从而提高了交流接触器智能化技术的研究水平。根据优化设计结果加工了样机,对样机测试与试验的结果表明,智能交流接触器的分断时间大幅缩短,三相触头分断时间稳定性也得到明显改善,因此零电流分断的可靠性显著提高。

  6. International Space Station (ISS) Plasma Contactor Unit (PCU) Utilization Plan Assessment Update

    Science.gov (United States)

    Hernandez-Pellerano, Amri; Iannello, Christopher J.; Garrett, Henry B.; Ging, Andrew T.; Katz, Ira; Keith, R. Lloyd; Minow, Joseph I.; Willis, Emily M.; Schneider, Todd A.; Whittlesey, Edward J.; Wollack, Edward J.; Wright, Kenneth H.

    2014-01-01

    The International Space Station (ISS) vehicle undergoes spacecraft charging as it interacts with Earth's ionosphere and magnetic field. The interaction can result in a large potential difference developing between the ISS metal chassis and the local ionosphere plasma environment. If an astronaut conducting extravehicular activities (EVA) is exposed to the potential difference, then a possible electrical shock hazard arises. The control of this hazard was addressed by a number of documents within the ISS Program (ISSP) including Catastrophic Safety Hazard for Astronauts on EVA (ISS-EVA-312-4A_revE). The safety hazard identified the risk for an astronaut to experience an electrical shock in the event an arc was generated on an extravehicular mobility unit (EMU) surface. A catastrophic safety hazard, by the ISS requirements, necessitates mitigation by a two-fault tolerant system of hazard controls. Traditionally, the plasma contactor units (PCUs) on the ISS have been used to limit the charging and serve as a "ground strap" between the ISS structure and the surrounding ionospheric plasma. In 2009, a previous NASA Engineering and Safety Center (NESC) team evaluated the PCU utilization plan (NESC Request #07-054-E) with the objective to assess whether leaving PCUs off during non-EVA time periods presented risk to the ISS through assembly completion. For this study, in situ measurements of ISS charging, covering the installation of three of the four photovoltaic arrays, and laboratory testing results provided key data to underpin the assessment. The conclusion stated, "there appears to be no significant risk of damage to critical equipment nor excessive ISS thermal coating damage as a result of eliminating PCU operations during non- EVA times." In 2013, the ISSP was presented with recommendations from Boeing Space Environments for the "Conditional" Marginalization of Plasma Hazard. These recommendations include a plan that would keep the PCUs off during EVAs when the

  7. Confusion around the tidal force and the centrifugal force

    CERN Document Server

    Matsuda, Takuya; Boffin, Henri M J

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  8. Experimental study on cavitation in centrifugal pump impellers

    International Nuclear Information System (INIS)

    Investigations concerning cavitation in centrifugal impellers were carried out in a closed circuit. The value of net positive suction head (NPSH) at different head drops and at breakdown were used to verify the affinity laws

  9. MULTIOBJECT OPTIMIZATION OF A CENTRIFUGAL IMPELLER USING EVOLUTIONARY ALGORITHMS

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Liu Lijun; Feng Zhenping

    2004-01-01

    Application of the multiobjective evolutionary algorithms to the aerodynamic optimization design of a centrifugal impeller is presented. The aerodynamic performance of a centrifugal impeller is evaluated by using the three-dimensional Navier-Stokes solutions. The typical centrifugal impeller is redesigned for maximization of the pressure rise and blade load and minimization of the rotational total pressure loss at the given flow conditions. The B閦ier curves are used to parameterize the three-dimensional impeller blade shape. The present method obtains many reasonable Pareto optimal designs that outperform the original centrifugal impeller. Detailed observation of the certain Pareto optimal design demonstrates the feasibility of the present multiobjective optimization method tool for turbomachinery design.

  10. TECHNOLOGY EVALUATION REPORT: RETECH'S PLASMA CENTRIFUGAL FURNACE - VOLUME I

    Science.gov (United States)

    A demonstration of the Retech, Inc. Plasma Centrifugal Furnace (PCF) was conducted under the Superfund Innovative Technology Evaluation (SITE) Program at the Department of Energy's (DOE's) Component Development and Integration Facility in Butte, Montana. The furnace uses heat gen...

  11. Centrifuging Step-Screw Conveyor for Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A variety of ISRU operations will utilize lunar regolith as feedstock. The proposed centrifuging step-screw conveyor concept will provide a well controlled robust,...

  12. Fluent-based numerical simulation of flow centrifugal fan

    Institute of Scientific and Technical Information of China (English)

    LI Xian-zhang

    2011-01-01

    Testing centrifugal fan flow field by physical laboratory is difficult because the testing system is complex and the workload is heavy, and the results observed by naked-eye deviates far from the actual value. To address this problem, the computational fluid dynamics software FLUENT was applied to establish three-dimensional model of the centrifugal fan. The numeral model was verified by comparing simulation data to experimental data. The pressure centrifugal fan and the speed changes in distribution in centrifugal fan was simulated by computational fluid dynamics software FLUENT. The simulation results show that the gas flow velocity in the impeller increases with impeller radius increase. Static pressure gradually increases when gas from the fan access is imported through fan impeller leaving fans.

  13. Investigation on complete characteristics and hydraulic transient of centrifugal pump

    International Nuclear Information System (INIS)

    An improved method was developed to obtain the complete characteristic of centrifugal pump. The conversion formula of complete characteristics is established based on the normal performance curve. An example was presented to illuminate the new method, and the complete characteristic curves of 14SA-10 centrifugal pump were obtained by the new method. The hydraulic transient of the centrifugal pump failure and start-up was simulated by method of characteristics (MOC), which quote the complete characteristics data. The results show that the inversion method is available to obtain the complete pump characteristic curves provided the normal performance curve. For hydraulic transient simulation, more accurate numerical result can be obtained, if the new model is adopted to convert the experimental normal performance curve to complete characteristics curve of centrifugal pump

  14. Measurement of ground shock in explosive centrifuge model tests

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has begun a project to simulate the formation and collapse of underground cavities produced by nuclear explosions using chemical explosions at much smaller scale on a large geotechnical centrifuge. Use of a centrifuge for this project presents instrumentation challenges which are not encountered in tests at similar scale off of the centrifuge. Electromagnetic velocity measuring methods which have been very successfully applied to such models at 1 g would be very difficult, if not impossible, to implement at 100 g. We are investigating the feasibility of other techniques for monitoring the ground shock in small-scale tests including accelerometers, stress gauges, dynamic strain meters and small, mutual-inductance particle velocity gauges. Initial results indicate that some of these techniques can be adapted for centrifuge applications. 17 references, 4 figures

  15. Central centrifugal cicatricial alopecia: challenges and solutions.

    Science.gov (United States)

    Herskovitz, Ingrid; Miteva, Mariya

    2016-01-01

    Central centrifugal cicatricial alopecia (CCCA) is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression. PMID:27574457

  16. Failure analysis of a polymer centrifugal impeller

    Directory of Open Access Journals (Sweden)

    Nikhil K. Kar

    2015-10-01

    Full Text Available A failure analysis investigation was performed on a fractured polymer impeller used in a respiratory blower. Light microscopy, scanning electron microscopy and finite element analysis techniques were utilized to characterize the mode(s of failure and fracture surfaces. A radial split down the impeller center was observed with symmetric fracture faces about the impeller bore. Fractographic analysis revealed brittle fracture features including Wallner lines, mirror, mist and hackle features stemming from the impeller bore, emanating radially outward. Crazed fibrils and faint fatigue striations suggest that intermittent load cycling led to initiation, and rapid propagation of multiple crack fronts originating along the impeller lip. Finite element analysis revealed a flexural condition induces localized stresses along the impeller lip. Significant wear features were also observed within the impeller bore, which may have contributed to premature failure of the impeller. The brittle fracture morphology and defects within the impeller bore suggest that premature failure occurred because of multiple interacting factors including: intermittently high centrifugal velocities, imbalance bore and shaft conditions, defects within the bore caused by machining, and stress concentrations along the circumference of the impeller lip.

  17. Investigation of Flow in a Centrifugal Pump

    Science.gov (United States)

    Fischer, Karl

    1946-01-01

    The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages. The relative velocity on the pressure side of the vane, which for passages completely filled with active flow would differ little from zero even at comparatively lower than normal delivery volume, is increased, so that no rapid reverse flow occurs on the pressure side of the vane even for smaller delivery volume. It was established, further, that the flow ceases to be stationary for very small quantities of water. The inflow to the impeller can be regarded as radial for the operating range an question. The velocity triangles at the exit are subjected to a significant alteration in shape ae a result of the increased peripheral velocity, which may be of particular importance in the determination of the guide vane entrance angle.

  18. Central centrifugal cicatricial alopecia: challenges and solutions.

    Science.gov (United States)

    Herskovitz, Ingrid; Miteva, Mariya

    2016-01-01

    Central centrifugal cicatricial alopecia (CCCA) is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression.

  19. Central centrifugal cicatricial alopecia: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Herskovitz I

    2016-08-01

    Full Text Available Ingrid Herskovitz, Mariya Miteva Department of Dermatology and Cutaneous Surgery, University of Miami L Miller School of Medicine, Miami, FL, USA Abstract: Central centrifugal cicatricial alopecia (CCCA is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression. Keywords: hair loss, alopecia, dermatoscopy, dermoscopy, trichoscopy, black scalp, African American, scarring alopecia

  20. Centrifugal Liquid/Gas Separator With Phase Detectors

    Science.gov (United States)

    Schneider, Steven J.

    1994-01-01

    Centrifugal liquid/gas separator that includes phase (liquid or gas) detectors helps ensure exclusiveness of each phase at its assigned outlet. Acoustic sensors in centrifugal liquid/gas separator measure speeds of sound in nominally pure liquid and nominally pure gas at liquid and gas outlets respectively. When speed of sound is that of pure liquid or gas, valve opens to let liquid or gas flow out.

  1. CALCULATION AND IMPROVEMENT OF DYNAMIC CHARACTERISTICS OF CENTRIFUGE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The modeling of the rotor-support system of a typical centrifuge is discussed. The impedance matching method, cooperating with Riccati transfer matrix method and modal analysis method are adopted to calculate its dynamic characteristics. The influences of the main parts to the critical speeds are analyzed. Based on the analysis, a critical speed in the operating speed range is tuned successfully, and thus the dynamic characteristics of the centrifuge are much improved.

  2. Design Method for Channel Diffusers of Centrifugal Compressors

    OpenAIRE

    Mykola Kalinkevych; Andriy Skoryk

    2013-01-01

    The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical si...

  3. Design and Characterization of a Centrifugal Compressor Surge Test Rig

    OpenAIRE

    Kin Tien Lim; Se Young Yoon; Christopher P. Goyne; Zongli Lin; Allaire, Paul E.

    2011-01-01

    A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characte...

  4. Non Adiabatic Centrifugal Compressor Gas Dynamic Performance Definition

    OpenAIRE

    Soldatova, Kristina

    2014-01-01

    Most centrifugal compressors operate in conditions with negligible heat transfer (adiabatic compression). Their plant tests conditions are similar or close to adiabatic conditions. Test regulations establish measures to diminish influence of a heat transfer “compressor body – atmospheric air” to an exit temperature. Therefore a temperature rise in a compressor is used to calculate a work input coefficient and efficiency. Unlike it high pressure centrifugal compressors of gas turbines and supe...

  5. Centrifugal microfluidic platforms: advanced unit operations and applications.

    Science.gov (United States)

    Strohmeier, O; Keller, M; Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N

    2015-10-01

    Centrifugal microfluidics has evolved into a mature technology. Several major diagnostic companies either have products on the market or are currently evaluating centrifugal microfluidics for product development. The fields of application are widespread and include clinical chemistry, immunodiagnostics and protein analysis, cell handling, molecular diagnostics, as well as food, water, and soil analysis. Nevertheless, new fluidic functions and applications that expand the possibilities of centrifugal microfluidics are being introduced at a high pace. In this review, we first present an up-to-date comprehensive overview of centrifugal microfluidic unit operations. Then, we introduce the term "process chain" to review how these unit operations can be combined for the automation of laboratory workflows. Such aggregation of basic functionalities enables efficient fluidic design at a higher level of integration. Furthermore, we analyze how novel, ground-breaking unit operations may foster the integration of more complex applications. Among these are the storage of pneumatic energy to realize complex switching sequences or to pump liquids radially inward, as well as the complete pre-storage and release of reagents. In this context, centrifugal microfluidics provides major advantages over other microfluidic actuation principles: the pulse-free inertial liquid propulsion provided by centrifugal microfluidics allows for closed fluidic systems that are free of any interfaces to external pumps. Processed volumes are easily scalable from nanoliters to milliliters. Volume forces can be adjusted by rotation and thus, even for very small volumes, surface forces may easily be overcome in the centrifugal gravity field which enables the efficient separation of nanoliter volumes from channels, chambers or sensor matrixes as well as the removal of any disturbing bubbles. In summary, centrifugal microfluidics takes advantage of a comprehensive set of fluidic unit operations such as

  6. Numerical Calculation on Cavitation Pressure Pulsation in Centrifugal Pump

    OpenAIRE

    Weidong Shi; Chuan Wang; Wei Wang; Bing Pei

    2014-01-01

    In order to study the internal flow in centrifugal pump when cavitation occurs, numerical calculation of the unsteady flow field in the WP7 automobile centrifugal pump is conducted based on the Navier-Stokes equations with the RNG k-ε turbulence model and Zwart-Gerber-Belamri cavitation model. The distributions of bubble volume fraction and pressure pulsation laws in the pump are analyzed when cavitation occurs. The conclusions are as follows: the bubble volume fraction is larger on the sucti...

  7. Research on the Release Characteristics of Marine DC Contactor%船用直流接触器脱扣特性的研究

    Institute of Scientific and Technical Information of China (English)

    陆干文; 韩露; 彭格; 袁征; 王永鑫

    2009-01-01

    论述了直流接触器脱扣原理,分析了影响直流接触器正确脱扣的主要因素,以三维有限元分析为基础,采用ANSYS软件仿真分析,提出一种减小铁心剩磁吸力的方法,保证船用接触器断电后可靠释放,提高了船用直流接触器的可靠性.%The principle of the release characteristics on marine DC eontaetor was surveyed and the main fac-tors which impact DC contactor correct release were analyzed.Based on 3D finite element method,by ANSYS soft-ware,a way to reduce residual flux force was introduced to ensure the DC eontactor release correctly.The reliability of marine DC contactor was impmved.

  8. Discussion on Usage of Contactor in Distribution Circuit of Frequency Converter%变频器配电回路中接触器的用法探讨

    Institute of Scientific and Technical Information of China (English)

    王婧; 黄岩; 刘学忠; 张风友

    2015-01-01

    针对目前在变频器配电回路设计中,对接触器用法存在的一些争议进行分析讨论,包括在输入侧和输出侧使用接触器的原因,以及操作中需要注意的问题等,并结合实际案例进行分析,给出解决该问题的一般性原则。%Analysis and discussion have been made for some disputes about the usage of contactor in current design for distribution circuit of frequency converter, including the reason for using contactor at input side and output side and considerations during operation; actual cases are analyzed and general principles for solving such problem are offered.

  9. 船用真空接触器合闸速度研究%Research on Marine Vacuum Contactor Closing Speed

    Institute of Scientific and Technical Information of China (English)

    余晓松

    2015-01-01

    结合现有船用真空接触器样机,在分析船用真空接触器合闸机理的基础上,对影响船用真空接触器性能关键的合闸速度进行了理论分析和设计校核。通过试验验证,表明合闸速度满足设计要求。%Combined with the existing marine vacuum contactor prototype and based on analysis of the closing operations mechanism of marine vacuum contactor,this paper did some theoretical research and design proof on the closing speed of affecting the marine vacuum contactor’s characteristics and verified by experiment that the closing speed can meet the design requirements.

  10. 交流接触器自动检测系统设计%Design of Automatic Detecting System of AC Contactor

    Institute of Scientific and Technical Information of China (English)

    李林; 强秀华; 邹斌

    2012-01-01

    针对交流接触器传统检测方法存在的缺点,设计了交流接触器自动检测系统.首先,对检测流程和设计要求做了说明;然后,给出了数据采集程序和PLC程序流程图.结果表明,该系统运行可靠,检测精度高,达到了规定的设计目标.%Focused on the defects of the traditional method of detecting for AC contactor, the paper designed the auto-matic detecting system of AC contactor. Firstly detecting process and design requirements were introduced, secondly the software flowchart of data acquisition program and PLC program were given. The results showed that this automatic detec-ting runs reliably and has high accuracy, it achieves the required goals and designed requirements.

  11. 转换型接触器/继电器应用中的误区%Some Misunderstandings on Transfer Contactor and Relay Application

    Institute of Scientific and Technical Information of China (English)

    崔子南; 朱黔; 杨英奕; 夏瑞

    2014-01-01

    通过三个具有代表性的案例,介绍了单刀双掷或双刀双掷转换型接触器/继电器在电气控制电路中存在的隐患。分析了隐患产生的原因,并就如何正确使用转换型接触器/继电器提出了建议。%Three representative cases were presented in this article.Hidden troubles in the electric control circuit of single pole double throw or double pole double throw transfer contactor and relay were presented.Suggestions on how to use single pole double throw or double pole double throw transfer contactor and relay correctly were proposed.

  12. Centrifugal potential energy : an astounding renewable energy concept

    Energy Technology Data Exchange (ETDEWEB)

    Oduniyi, I.A. [Aled Conglomerate Nigeria Ltd., Lagos (Nigeria)

    2010-07-01

    A new energy concept known as centrifugal potential energy was discussed. This new energy concept is capable of increasing the pressure, temperature and enthalpy of a fluid, without having to apply work or heat transfer to the fluid. It occurs through a change in the centrifugal potential energy of the flowing fluid in a rotating frame of reference or a centrifugal force field, where work is performed internally by the centrifugal weight of the fluid. This energy concept has resulted in new energy equations, such as the Rotational Frame Bernoulli's Equation for liquids and the Rotational Frame Steady-Flow Energy Equation for gases. Applications of these equations have been incorporated into the design of centrifugal field pumps and compressors. Rather than compressing a fluid with a physical load transfer, these devices can compress a fluid via the effect of centrifugal force applied to the object. A large amount of energy is therefore produced when this high pressure compressed working fluid expands in a turbine. When water is used as the working fluid, it could reach renewable energy densities in the range of 25-100 kJ/kg of water. When atmospheric air is used, it could reach energy densities in the range of 500-1,500 kJ/kg of air.

  13. 膜接触器在环境治理中的应用研究进展%Novel Membrane Contactors and Their Application in Environmental Protection

    Institute of Scientific and Technical Information of China (English)

    李娜; 盛新江; 马青兰; 张国亮; 王家德

    2011-01-01

    In a novel membrane contactor, separation is efficiently integrated with conventional chemical separation technology, which achieves gas/liquid or liquid/liquid mass transfer without dispersion of one phase with another. After the first successful industrial installations, different kinds of membrane contactors have found important applications in environmental protection such as aromatics recovery from a process water, selective removal of heavy metals from an industrial process and recovery of ammonia, CO2 and H2S from an off gas stream. Principle of several typical membrane contactors were introduced, including membrane distillation, membrane adsorption, membrane extraction and membrane structured packing. Characteristics of material used in typical membrane contactors were also discussed.%膜接触器是将膜分离和传统化工单元操作有机结合而成的一种新型高效分离器,可不通过两相的直接接触而实现相间传质.继21世纪初首个工业化实例成功以来,在废水中芳香族化合物脱除、重金属选择吸收、废气中氨、CO2、H2S去除等多个领域的环境治理中,膜接触器技术的研究与应用日益重要.在此基础上,文章对膜蒸馏、膜吸收、膜萃取和膜填料替代等膜接触器技术的作用机理进行了比较,重点阐述了其在环境治理中的应用和发展状况,并对典型接触器中膜材料的性能和特点进行了分析.

  14. 一种高可靠性辅助触头设计与验证%Design and Verification of the Auxiliary Contactor with High Reliability

    Institute of Scientific and Technical Information of China (English)

    陈伟刚

    2015-01-01

    Against the current status of the poor reliability of the auxiliary contactors in low voltage electric appliances, the auxiliary contactor with double contacts that can laterally sliding is designed. The structure of double contacts can effectively reduce the beam current resistance, and the lateral sliding friction can effectively eliminate the dirt and oxide layers on surface of the contacts to reduce the membrane resistance. In addition, the simulation analysis for different types of the contact bridges is carried out, thus better structure of the contact bridge is obtained. The test results verify that the high reliable auxiliary contactor can effectively enhance the making capacity for small load, this provides certain reference to the design and optimization of the auxiliary contactors in low voltage electric appliances.%针对低压电器辅助触头可靠性差的现状,设计了一种双触点可横向滑动的辅助触头。其双触点结构可以有效降低束流电阻;横向滑动产生的滑动摩擦可以有效去除触点表面脏物和氧化层,降低触头接触的膜电阻。此外,对不同形式的触桥进行了仿真分析,获得了较优化的触桥结构。实测结果验证了高可靠性辅助触头可以有效提高小负载接通能力,从而为低压电器中辅助触头组的设计和优化提供相应参考。

  15. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    International Nuclear Information System (INIS)

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport

  16. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.D.

    1994-08-04

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport.

  17. Toward gas-phase controlled mass transfer in micro-porous membrane contactors for recovery and concentration of dissolved methane in the gas phase

    OpenAIRE

    McLeod, Andrew J.; Jefferson, Bruce; McAdam, Ewan

    2016-01-01

    A micro-porous hollow fibre membrane contactor (HFMC) operated in sweep-gas mode has been studied to enable the recovery of dissolved methane from water in concentrated form. At high sweep-gas flow rates, up to 97% dissolved methane removal efficiency is achievable which is sufficient to achieve carbon neutrality (around 88%). An increase in methane composition of the recovered sweep-gas was achievable through two primary mechanisms: (i) an increase in liquid velocity which improved dissolved...

  18. Hollow Fiber Membrane Contactors for Post-Combustion CO2 Capture: A Scale-Up Study from Laboratory to Pilot Plant

    Directory of Open Access Journals (Sweden)

    Chabanon E.

    2014-11-01

    Full Text Available Membrane contactors have been proposed for decades as a way to achieve intensified mass transfer processes. Post-combustion CO2 capture by absorption into a chemical solvent is one of the currently most intensively investigated topics in this area. Numerous studies have already been reported, unfortunately almost systematically on small, laboratory scale, modules. Given the level of flue gas flow rates which have to be treated for carbon capture applications, a consistent scale-up methodology is obviously needed for a rigorous engineering design. In this study, the possibilities and limitations of scale-up strategies for membrane contactors have been explored and will be discussed. Experiments (CO2 absorption from a gas mixture in a 30%wt MEA aqueous solution have been performed both on mini-modules and at pilot scale (10 m2 membrane contactor module based on PTFE hollow fibers. The results have been modelled utilizing a resistance in series approach. The only adjustable parameter is in fitting the simulations to experimental data is the membrane mass transfer coefficient (km, which logically plays a key role. The difficulties and uncertainties associated with scaleup computations from lab scale to pilot scale modules, with a particular emphasis on the km value, are presented and critically discussed.

  19. Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

    Directory of Open Access Journals (Sweden)

    Hayder Mohammed Issa

    2016-01-01

    Full Text Available Multiple or dual impellers are widely implemented in stirred contactors used in various biological processes like fermentation, water treatment, and pharmaceutical production. The spacing between impellers is considered as a crucial factor in designing of these types of contactors resulting in variation of oxygen mass transfer, mixing time, or power consumption for such biological system. A study of three parts was conducted to characterize the effect of the spacing between impellers on the most important parameters that related to biological contactor performance: oxygen mass transfer coefficient kla from the gas phase (air to the liquid phase (water, mixing time, and power consumption for different operating rotational speeds (1.67–3.33 rps and for three different spacing positions. The used impellers system in the study is a dual impeller system which consists of an inverted and bladed rotated cone (IBRC and a pitched-blade up-flow propeller (PBPU. The experimental results showed that the shorter spacing (the lower PBPU in a higher position is more convenient, as the achieved oxygen mass transfer coefficient has showed an improvement in its values with lower mixing time and with a slight alteration in power consumption.

  20. 对接触器干扰单片机系统的抑制%Inhibition of Contactor Interferences to Monolithic Microcomputer System

    Institute of Scientific and Technical Information of China (English)

    王昊; 那文鹏; 姚丽萍

    2001-01-01

    On the occasions of monolithic microcomputer and contactors are packed in one case, electromagnetic interferences, yielded by contactor coils as they are switched on or off, and spark interferences, generated by the pushbutton swi tches that control contactor coils as they are switched on or off, all make mono lith ic microcomputer application system work improperly. The article introduces inh ibiting methods such as phase splitting, TVP, resistive and capacitive absorbing , time delay and coupling removing.%当单片机与接触器装在同一箱体时,接触器线圈在通、断电时产生的电磁干扰 ,控制接触器线圈通电、断电的按钮开关在通、断电时产生的火花干扰,均使单片机应用系统不能正常工作。本文介绍了分相、TVP、阻容吸收、延时、去耦等抑制方法。

  1. 新型智能混合式交流接触器%A New Type of Hybrid Semiconductor Intelligent AC Contactor

    Institute of Scientific and Technical Information of China (English)

    张培铭; 陈从华; 郑昕

    2001-01-01

    介绍了一种新型的混合式智能交流接触器,其仅用2个单向晶闸管就实现了接触器的少弧或无弧运行,且大大降低成本,减少体积。该接触器实现了全过程的动态优化控制,达到了节能、节材、无噪声、高操作频率、高电寿命,且可与主控计算机进行双向通信。%A new-type hybrid semiconductor intelligent AC contactor was developed. In the contacts of this kind of contactor with two SCRs only will there be no arcing or just small arcing when they are broken. The cost and volume are reduced greatly. This contactor realizes the optimal control in dynamic process and brings the benefits of energy and materials saving, no noise, high operating frequency and high electrical endurance. And it can also be communicated with the central master computer.

  2. Novel Water Treatment Processes Based on Hybrid Membrane-Ozonation Systems: A Novel Ceramic Membrane Contactor for Bubbleless Ozonation of Emerging Micropollutants

    Directory of Open Access Journals (Sweden)

    Stylianos K. Stylianou

    2015-01-01

    Full Text Available The aim of this study is the presentation of novel water treatment systems based on ozonation combined with ceramic membranes for the treatment of refractory organic compounds found in natural water sources such as groundwater. This includes, firstly, a short review of possible membrane based hybrid processes for water treatment from various sources. Several practical and theoretical aspects for the application of hybrid membrane-ozonation systems are discussed, along with theoretical background regarding the transformation of target organic pollutants by ozone. Next, a novel ceramic membrane contactor, bringing into contact the gas phase (ozone and water phase without the creation of bubbles (bubbleless ozonation, is presented. Experimental data showing the membrane contactor efficiency for oxidation of atrazine, endosulfan, and methyl tert-butyl ether (MTBE are shown and discussed. Almost complete endosulfan degradation was achieved with the use of the ceramic contactor, whereas atrazine degradation higher than 50% could not be achieved even after 60 min of reaction time. Single ozonation of water containing MTBE could not result in a significant MTBE degradation. MTBE mineralization by O3/H2O2 combination increased at higher pH values and O3/H2O2 molar ratio of 0.2 reaching a maximum of around 65%.

  3. A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge

    Science.gov (United States)

    Hoang, Tony; Patel, Dhruv S.; Halvorsen, Ken

    2016-08-01

    The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis.

  4. A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge.

    Science.gov (United States)

    Hoang, Tony; Patel, Dhruv S; Halvorsen, Ken

    2016-08-01

    The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis. PMID:27587129

  5. Parametric representation of centrifugal pump homologous curves

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo A.; Mattos, Joao R.L. de, E-mail: velosom@cdtn.br, E-mail: jrmattos@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  6. Contactor Energy Requirements for Capturing CO2 From ambient air using NaOH determined in a pilot-scale prototype system

    Science.gov (United States)

    Stolaroff, J. K.; Keith, D.; Lowry, G.

    2005-12-01

    Systems for capturing CO2 from ambient air for sequestration have recently been proposed (e.g. Dubey et al., 2002; Zeman and Lackner, 2004; Keith et al., 2004). Capture from ambient air has a number of structural advantages over capture from point sources; in particular it makes possible future emissions scenarios with negative net CO2 emissions. The systems suggested use either a Ca(OH)2 or NaOH solution to capture CO2 and then regenerate the solution in a chemical loop. The energy requirements of such a system, however, have been hotly disputed (Herzog, 2003). The energy requirements and effectiveness of the chemical regeneration are well established as they are practiced on a large scale in the industrial kraft process used in pulp and paper production, but the energy and land use requirements of a contactor for this system are uncertain as this component of the system is not implemented industrially. In this research, we address the most controversial component of the system, the contactor, which extracts CO2 from air into solution. A prototype contactor with a spray tower design is constructed (1m by 6m), and CO2 absorption by a NaOH solution spray (5 l/min) is measured. The CO2 absorption efficiency and energy requirements per unit CO2 absorbed are calculated. The energy requirements of the contactor are found to be on the order of 10-40 kJ/mol-CO2, which is small compared to the energy of combustion of fossil fuels, and compared with the energy required for the regeneration steps. Thus, a NaOH-based spray tower design can serve as an energy-efficient contactor for capturing CO2 from ambient air. Dubey, M. K., Ziock, H., Rueff, G., Elliott, S., and Smith, W. S. (2002). ``Extraction of carbon dioxide from the atmosphere through engineered chemical sinkage''. ACS -- Division of Fuel Chemistry Reprints, 47(1):81--84. Herzog, H. (2003). Assessing the feasibility of capturing co2 from the air. Technical report, MIT Laboratory for Energy and the Environment. Keith

  7. Analysis and design of digital control for AC contactors%交流接触器数字化控制的分析与设计

    Institute of Scientific and Technical Information of China (English)

    罗海海; 许志红

    2015-01-01

    Digital control is put forward into AC contactors with dsPIC .Coil supply circuit is modified from BUCK whose current can be closed -loop in real -time by digital PI or on/off.The dynamic attraction and counterforce of contactor fit well in making to reduce the bounce or collision of contact and core , so the lifetime of AC contactors prolonged .Cutting off the PWM , keeping coil current in a low to save energy and undo noise after making stable .In breaking , the negative-voltage is adopted to enhance the break speed .Entire process of contactors are simulated by PROTEUS to guide the design of intelligent module and the analysis of control scheme .It also verified by experiments , which show that the digital control is flexibility and universality to improve the performance of AC contactors .%提出了以dsPIC为控制核心的交流接触器数字化控制技术。对BUCK电路进行改造作为线圈供电主回路,分别利用数字PI和流限开/关,实现了线圈电流的闭环控制,使得吸合过程的吸反力合理配合,减小触头和铁芯的弹跳与碰撞,提高电寿命。可靠吸合后,切断PWM斩波信号,转入直流低压运行,能耗小、无噪声。分断时,采用负压控制,线圈能量被快速吸收,提高了接触器的分断速度。通过PROTEUS软件对吸合、吸持和分断过程进行仿真,有助于智能控制模块的设计及控制方案的分析。相关试验结果表明,数字化控制技术改善了交流接触器各项性能指标,具有较好灵活性、通用性。

  8. [The analytical setting of rotary speed of centrifuge rotor and centrifugation time in chemical, biochemical and microbiological practice].

    Science.gov (United States)

    Zolotarev, K V

    2012-08-01

    The researchers happen to face with suspensions in their chemical, biochemical and microbiological practice. The suspensions are the disperse systems with solid dispersed phase and liquid dispersion medium and with dispersed phase particle size > 100 nm (10-7 m). Quite often the necessity occurs to separate solid particles from liquid. To use for this purpose the precipitation in gravitation field can make the process to progress too long. In this respect an effective mode is the precipitation in the field of centrifugal forces--the centrifugation. The rotary speed of centrifuge rotor and centrifugation time can be set analytically using regularities of general dynamics and hydrodynamics. To this effect, should be written and transformed the equation of First and Second Newton Laws for suspension particle being in the field of centrifugal forces and forces of resistance of liquid and vessel wall. The force of liquid resistance depends on particle motion condition in liquid. To determine the regimen the Archimedes and Reynolds numerical dimensionless criteria are to be applied. The article demonstrates the results of these transformations as analytical inverse ratio dependence of centrifugation time from rotary speed. The calculation of series of "rate-time" data permits to choose the optimal data pair on the assumption of centrifuge capacity and practical reasonability. The results of calculations are validated by actual experimental data hence the physical mathematical apparatus can be considered as effective one. The setting progress depends both from parameter (Reynolds criterion) and data series calculation. So, the most convenient way to apply this operation is the programming approach. The article proposes to use the program Microsoft Excel and VBA programming language for this purpose. The possibility to download the file from Internet to use it for fast solution is proposed. PMID:23097986

  9. A fuzzy controlled three-phase centrifuge for waste separation

    International Nuclear Information System (INIS)

    The three-phase centrifuge technology discussed in this paper was developed by Neal Miller, president of Centech, Inc. The three-phase centrifuge is an excellent device for cleaning up oil field and refinery wastes which are typically composed of hydrocarbons, water, and solids. The technology is unique. It turns the waste into salable oil, reusable water, and landfill-able solids. No secondary waste is produced. The problem is that only the inventor can set up and run the equipment well enough to provide an optimal cleanup. Demand for this device has far exceeded a one man operation. There is now a need for several centrifuges to be operated at different locations at the same time. This has produced a demand for an intelligent control system, one that could replace a highly skilled operator, or at least supplement the skills of a less experienced operator. The control problem is ideally suited to fuzzy logic, since the centrifuge is a highly complicated machine operated entirely by the skill and experience of the operator. A fuzzy control system was designed for and used with the centrifuge

  10. Comparative analysis of discrete exosome fractions obtained by differential centrifugation

    DEFF Research Database (Denmark)

    Jeppesen, Dennis Kjølhede; Hvam, Michael L; Primdahl-Bengtson, Bjarke;

    2014-01-01

    BACKGROUND: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugat......BACKGROUND: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete...... ultracentrifugation speeds on the purification from different cell types, however, is limited. METHODS: We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder...... of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration...

  11. Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Schmaltz, R; Boley, T M; Nawarawong, W; Landreneau, R J

    1992-09-01

    The reported clinical use of the Sarns centrifugal pump (Sarns, Inc./3M, Ann Arbor, Mich.) as a cardiac assist device for postcardiotomy ventricular failure is limited. During a 25-month period ending November 1988, we used 40 Sarns centrifugal pumps as univentricular or biventricular cardiac assist devices in 27 patients who could not be weaned from cardiopulmonary bypass despite maximal pharmacologic and intraaortic balloon support. Eighteen men and nine women with a mean age of 60.4 years (28 to 83) required assistance. Left ventricular assist alone was used in 12 patients, right ventricular assist in 2, and biventricular assist in 13. The duration of assist ranged from 2 to 434 hours (median 45). Centrifugal assist was successful in weaning 100% of the patients. Ten of 27 patients (37%) improved hemodynamically, allowing removal of the device(s), and 5 of 27 (18.5%) survived hospitalization. Survival of patients requiring left ventricular assist only was 33.3% (4/12). Complications were common and included renal failure, hemorrhage, coagulopathy, ventricular arrhythmias, sepsis, cerebrovascular accident, and wound infection. During 3560 centrifugal pump hours, no pump thrombosis was observed. The Sarns centrifugal pump is an effective assist device when used to salvage patients who otherwise cannot be weaned from cardiopulmonary bypass. Statistical analysis of preoperative patient characteristics, operative risk factors, and postoperative complications failed to predict which patients would be weaned from cardiac assist or which would survive.

  12. Centrifuge modelling - migration of radionuclides from engineered trenches

    International Nuclear Information System (INIS)

    This report provides an overview of some centrifuge small-scale physical model tests and 1g experimental and theoretical work relating to the sub-surface migration of a model pollutant (sodium chloride) from a notional prototype surface landfill of width 25 metres and depth 3 metres cut into a 20 metre deep layer of nominally uniform soil overlying a more permeable base layer. An introduction is given to the application of geotechnical centrifuge modelling techniques to pollutant migration studies. Experiments performed at 1/100th scale using the Cambridge 10 metre diameter Geotechnical Beam Centrifuge simulating transport through silt over prototype time periods of around 35 years, are summarised. Comparisons of data with calculations using early versions of the POLLUTE and MIGRATE computer codes are presented. An experiment at 1/400th scale using the new Cambridge Geotechnical Drum Centrifuge, involving transport through clay over a prototype time period of around 1000 years, is described. Potential future uses of centrifuge modelling techniques to simulate long-term migration through more complex hydrological environments are also discussed. (author)

  13. Fault diagnosis of monoblock centrifugal pump using SVM

    Directory of Open Access Journals (Sweden)

    V. Muralidharan

    2014-09-01

    Full Text Available Monoblock centrifugal pumps are employed in variety of critical engineering applications. Continuous monitoring of such machine component becomes essential in order to reduce the unnecessary break downs. At the outset, vibration based approaches are widely used to carry out the condition monitoring tasks. Particularly fuzzy logic, support vector machine (SVM and artificial neural networks were employed for continuous monitoring and fault diagnosis. In the present study, the application of SVM algorithm in the field of fault diagnosis and condition monitoring is discussed. The continuous wavelet transforms were calculated for different families and at different levels. The computed transformation coefficients form the feature set for the classification of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different continuous wavelet families at different levels were calculated and compared to find the best wavelet for the fault diagnosis of the monoblock centrifugal pump.

  14. Oscillatory Counter-Centrifugation: Effects of History and Lift Forces

    Science.gov (United States)

    Nadim, Ali

    2014-11-01

    This work is co-authored with my doctoral student Shujing Xu and is dedicated to the memory of my doctoral advisor Howard Brenner who enjoyed thought experiments related to rotating systems. Oscillatory Counter-Centrifugation refers to our theoretical discovery that within a liquid-filled container that rotates in an oscillatory manner about a fixed axis as a rigid body, a suspended particle can be made to migrate on average in the direction opposite to that of ordinary centrifugation. That is, a heavy (or light) particle can move toward (or away from) the rotation axis, when the frequency of oscillations is high enough. In this work we analyze the effects of the Basset history force and the Saffman lift force on particle trajectories and find that the counter-centrifugation phenomenon persists even when these forces are active.

  15. Investigation of Surge Behavior in a Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei MIZUKI; Yuichiro ASAGA; Yushi ONO; Hoshio TSUJITA

    2006-01-01

    This paper reports the experimental and theoretical study of the surge occurred in prototyping an ultra micro centrifugal compressor. As the first step, the 10 times size model of an ultra micro centrifugal compressor having the 40 mm outer diameter was designed and manufactured. The detailed experimental investigations for the transient behavior of surge with several different values of B parameter were carried out. The experimental results during the surge were compared with those obtained by the non-linear lumped parameter theory in order to validate the effectiveness of the theoretical surge model for the micro centrifugal compressor. As a result, the quite different behavior of the surge appeared for the different values of B both in the experiment and in the analysis.

  16. Space Station Centrifuge: A Requirement for Life Science Research

    Science.gov (United States)

    Smith, Arthur H.; Fuller, Charles A.; Johnson, Catherine C.; Winget, Charles M.

    1992-01-01

    A centrifuge with the largest diameter that can be accommodated on Space Station Freedom is required to conduct life science research in the microgravity environment of space. (This was one of the findings of a group of life scientists convened at the University of California, Davis, by Ames Research Center.) The centrifuge will be used as a research tool to understand how gravity affects biological processes; to provide an on-orbit one-g control; and to assess the efficacy of using artificial gravity to counteract the deleterious biological effect of space flight. The rationale for the recommendation and examples of using ground-based centrifugation for animal and plant acceleration studies are presented. Included are four appendixes and an extensive bibliography of hypergravity studies.

  17. Centrifuge Techniques and Apparatus for Transport Experiments in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Earl D. Mattson; Carl D. Paler; Robert W. Smith; Markus Flury

    2010-06-01

    This paper describes experimental approaches and apparatus that we have developed to study solute and colloid transport in porous media using Idaho National Laboratory's 2-m radius centrifuge. The ex-perimental techniques include water flux scaling with applied acceleration at the top of the column and sub-atmospheric pressure control at the column base, automation of data collection, and remote experimental con-trol over the internet. These apparatus include a constant displacement piston pump, a custom designed liquid fraction collector based on switching valve technology, and modified moisture monitoring equipment. Suc-cessful development of these experimental techniques and equipment is illustrated through application to transport of a conservative tracer through unsaturated sand column, with centrifugal acceleration up to 40 gs. Development of such experimental equipment that can withstand high accelerations enhances the centrifuge technique to conduct highly controlled unsaturated solute/colloid transport experiments and allows in-flight liquid sample collection of the effluent.

  18. Parametric performance evaluation of a hydraulic centrifugal pump

    Science.gov (United States)

    Heo, M. W.; Y Kim, K.; Ma, S. B.; Yoo, I. S.; Choi, W. C.; Kim, J. H.; Choi, Y. S.

    2014-03-01

    Parametric study of a hydraulic centrifugal pump with backward curved blades has been performed numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model was used for analysis of turbulence. The finite volume method and an unstructured grid system were used for the numerical solution. The optimal grid system in the computational domain was selected through a grid dependency test. Tested parameters were related to the geometry of the impeller and volute: seven variables defining the hub and shroud contours and the blades angle of impeller, and two variables defining the inlet width and expansion angle of volute. The effects of these parameters on the hydrodynamic performance of the centrifugal pump have been investigated. It was found that the centrifugal water pump with the twisted blades has the enhancing efficiency compared to the straight blades pump.

  19. Design Optimization of a Centrifugal Fan with Splitter Blades

    Science.gov (United States)

    Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

    2015-05-01

    Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

  20. Design Method for Single-Blade Centrifugal Pump Impeller

    Science.gov (United States)

    Nishi, Yasuyuki; Fujiwara, Ryota; Fukutomi, Junichiro

    The sewage pumps are demanded a high pump efficiency and a performance in passing foreign bodies. Therefore, the impeller used by these usages requires the large passed particle size (minimum particle size in the pump). However, because conventional design method of pump impeller results in small impeller exit width, it is difficult to be applied to the design of single-blade centrifugal pump impeller which is used as a sewage pump. This paper proposes a design method for single-blade centrifugal pump impeller. As a result, the head curve of the impeller designed by the proposed design method satisfied design specifications, and pump efficiency was over 62% more than conventional single-blade centrifugal pump impeller. By comparing design values with CFD analysis values, the suction velocity ratio of the design parameter agreed well with each other, but the relative velocity ratio did not agree due to the influence of the backflow of the impeller entrance.

  1. Centrifugally activated bearing for high-speed rotating machinery

    Science.gov (United States)

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  2. Biodegradation and detoxification potential of rotating biological contactor (RBC) with Irpex lacteus for remediation of dye-containing wastewater.

    Science.gov (United States)

    Malachova, Katerina; Rybkova, Zuzana; Sezimova, Hana; Cerven, Jiri; Novotny, Cenek

    2013-12-01

    Use of fungal organisms in rotating biological contactors (RBC) for bioremediation of liquid industrial wastes has so far been limited in spite of their significant biodegradation potential. The purpose was to investigate the power of RBC using Irpex lacteus for decolorization and detoxification of industrial dyes and dyeing textile liquors. Recalcitrant dye Methylene Blue (150 mg L(-1)) was decolorized within 70 days, its mutagenicity removed, and the biological toxicity decreased more than 10-fold. I. lacteus biofilm in the RBC completely decolorized within 26 and 47 days dyeing liquors containing disperse or reactive dyes adjusted to pH4.5 and 5-fold diluted with the growth medium, respectively. Their respective biological toxicity values were reduced 10- to 10(4)-fold in dependence of the test used. A battery of toxicity tests comprising Vibrio fisheri, Lemna minor and Sinapis alba was efficient to monitor the toxicity of textile dyes and wastewaters. Strong decolorization and detoxification power of RBC using I. lacteus biofilms was demonstrated.

  3. Shifts in the microbial community, nitrifiers and denitrifiers in the biofilm in a full-scale rotating biological contactor.

    Science.gov (United States)

    Peng, Xingxing; Guo, Feng; Ju, Feng; Zhang, Tong

    2014-07-15

    The objective of this study was to investigate the microbial community shifts, especially nitrifiers and denitrifiers, in the biofilm of two rotating biological contactor (RBC) trains with different running times along the plug flowpath. The microbial consortia were profiled using multiple approaches, including 454 high-throughput sequencing of the V3-V4 region of 16S rRNA gene, clone libraries, and quantitative polymerase chain reaction (qPCR). The results demonstrated that (1) the overall microbial community at different locations had distinct patterns, that is, there were similar microbial communities at the beginnings of the two RBC trains and completely different populations at the ends of the two RBC trains; (2) nitrifiers, including ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB, Nitrosomonas) and nitrite-oxidizing bacteria (NOB, Nitrospira), increased in relative abundance in the biofilm along the flowpath, whereas denitrifiers (Rhodanobacter, Paracoccus, Thauera, and Azoarcus) markedly decreased; (3) the AOA were subdominant to the AOB in all sampled sections; and (4) strong ecological associations were shown among different bacteria. Overall, the results of this study provided more comprehensive information regarding the biofilm community composition and assemblies in full-scale RBCs.

  4. Effect of Flow Rate and Disc Area Increment on the Efficiency of Rotating Biological Contactor for Treating Greywater

    Directory of Open Access Journals (Sweden)

    Ashfaq Ahmed Pathan

    2015-04-01

    Full Text Available The performance of greywater treatment through RBC (Rotating Biological Contactor is related to many factors including rotational speed of disc, surface area of the media, thickness of biological film; quality and flow rate of influent. The plastic media provides surface for biological slime. The slime is rotated alternatively into the settled wastewater and then into atmosphere to provide aerobic conditions for the microorganisms. In this study the performance of RBC is investigated at different flow rates and disk areas of media by introducing additional discs on the shaft of RBC. Initially efficiency of the RBC was observed on six flow rates at the disc area of 9.78m2. Furthermore optimized three flow rates were used to augment the disk area. The efficiency of RBC system was improved significantly at disk area of 11.76m2 and flow rate of 20 L/h. Under these conditions the removal of BOD5 (Biochemical Oxygen Demand COD (Chemical Oxygen Demand and TSS (Total Suspended Solid was observed 83, 57 and 90% respectively

  5. Effect of flow rate and disc area increment on the efficiency of rotating biological contactor for treating greywater

    International Nuclear Information System (INIS)

    The performance of greywater treatment through RBC (Rotating Biological Contactor) is related to many factors including rotational speed of disc, surface area of the media, thickness of biological film; quality and flow rate of influent. The plastic media provides surface for biological slime. The slime is rotated alternatively into the settled wastewater and then into atmosphere to provide aerobic conditions for the microorganisms. In this study the performance of RBC is investigated at different flow rates and disk areas of media by introducing additional discs on the shaft of RBC. Initially efficiency of the RBC was observed on six flow rates at the disc area of 9.78m/sup 2/. Furthermore optimized three flow rates were used to augment the disk area. The efficiency of RBC system was improved significantly at disk area of 11.76m/sup 2/ and flow rate of 20 L/h. Under these conditions the removal of BOD5 (Biochemical Oxygen Demand) COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) was observed 83, 57 and 90% respectively. (author)

  6. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  7. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    Science.gov (United States)

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system.

  8. Centrifuge modelling of a laterally cyclic loaded pile

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Leth, Caspar Thrane; Hededal, Ole

    2010-01-01

    A total number of 9 static and 6 cyclic centrifuge tests on laterally loaded piles in very dense, dry sand was erformed. The prototype dimensions of the piles were 1 meter in diameter and penetration depths varying from 6 to 10 meters. The static tests were used to investigate the initial subgrade...... reaction modulus and as a reference for cyclic tests. For the cyclic tests the accumulation of deflections and the change in secant stiffness of the soil from repetitive loading were investigated. From all the tests carried out accumulations of deflections were seen. rom the centrifuge tests it was seen...

  9. Aspiration spiral-flow type centrifugal flotation machine

    Institute of Scientific and Technical Information of China (English)

    陈文义

    2002-01-01

    Aspiration spiral flow type centrifugal flotation machine takes full advantage of centrifugal force field and gravitational field, and strengthens flotation of coal slurry. As a new-type flotation machine of high efficiency, its key component is bubble generator. Which completes the process of ore pulp inflation and liberalization. The design, parameters and working principle of bubble generator provide the design of the same device in similar equipment with reference. The result of industrial operation shows that this machine is of such features as small occupational area, greater concentration ratio, high processing capacity, high efficiency and lower investment etc.

  10. Design Method for Channel Diffusers of Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Mykola Kalinkevych

    2013-01-01

    Full Text Available The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical simulation of the diffusers was implemented by means of CFD software. Obtained gas dynamic characteristics of the designed diffuser were compared to the base vaned diffuser of the compressor stage.

  11. Open-cycle centrifugal vapor-compression heat pump

    Science.gov (United States)

    Burgmeier, L. R.; Horner, J. E.

    1987-11-01

    The objectives of the program were: (1) to develop an open cycle, high lift, centrifugal steam compressor system that can be efficiently retrofitted to existing multi-effect and high temperature differential evaporators while maintaining the cost benefits of a single stage centrifugal compressor, and (2) to demonstrate the energy saving cost benefits of driving the compressor with a natural gas fueled gas turbine engine. The turbine exhaust was to be used for final drying of the product that was evaporated. The installation of the system is described along with the test activities through May 1987.

  12. On the characteristics of centrifugal-reciprocating machines. [cryogenic coolers

    Science.gov (United States)

    Higa, W. H.

    1980-01-01

    A method of compressing helium gas for cryogenic coolers is presented which uses centrifugal force to reduce the forces on the connecting rod and crankshaft in the usual reciprocating compressor. This is achieved by rotating the piston-cylinder assembly at a speed sufficient for the centrifugal force on the piston to overcome the compressional force due to the working fluid. The rotating assembly is dynamically braked in order to recharge the working space with fluid. The intake stroke consists of decelerating the rotating piston-cylinder assembly and the exhaust stroke consists of accelerating the assembly.

  13. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    OpenAIRE

    Bingbing Hu; Bing Li

    2015-01-01

    Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR) method to diagnose crack fault in cent...

  14. The effect of gas fraction on centrifugal pump

    Science.gov (United States)

    Zhu, Z. T.; Wang, Y.; Zhao, L. F.; Ning, C.; Xie, S. F.; Liu, Z. C.

    2015-01-01

    In order to study the multiphase flow field in M125 centrifugal pump, three-dimensional modeling was used for internal flow through three-dimensional software Pro/E. Then based on SST turbulence model combining with Rayleigh-Plesset cavitation model, and structured grid to simulate the hydraulic characteristics of volute and impeller within different gas conditions. The velocity, pressure and gas volume fraction distributions of the interior flow field of volute and impeller were obtained and analyzed, which revealed the effect of gas fractions on the flow characteristic of the centrifugal pump.

  15. Flow in a Low Specific Speed Centrifugal Pump Using PIV

    OpenAIRE

    Cui Dai; Liang Dong

    2013-01-01

    The interflow plays important roles in centrifugal pump design. In order to study the effect of rotation and z-axis on internal flow, two-dimensional particle image velocimetry (PIV) measurements have been performed to measure the steady velocity field on three planes in all impeller passages of a low specific-speed centrifugal pump. The results show that the relative velocity flows in blade passages are obviously different in terms of the positions of the blade relative to the tongue. The in...

  16. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    Science.gov (United States)

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system. PMID:26810802

  17. Apparatus and method for centrifugation and robotic manipulation of samples

    Science.gov (United States)

    Vellinger, John C. (Inventor); Ormsby, Rachel A. (Inventor); Kennedy, David J. (Inventor); Thomas, Nathan A. (Inventor); Shulthise, Leo A. (Inventor); Kurk, Michael A. (Inventor); Metz, George W. (Inventor)

    2007-01-01

    A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

  18. Mechanism of Gas Intrusion into Molten Metal during Horizontal Centrifugal Casting

    Institute of Scientific and Technical Information of China (English)

    NI Feng; ZHANG Xhan-ling; YANG Di-xin; BI Xiao-qin; ZHANG Yong-zhen

    2004-01-01

    A mechanism of gas intrusion into molten metal during horizontal centrifugal casting was introduced .Based upon this concept, a special pouring method was suggested ,which can effectively prevent the pinhole defects in horizontal centrifugal castings.

  19. Effects of centrifugation stress on pituitary-gonadal function in male rats

    Science.gov (United States)

    Gray, G. D.; Smith, E. R.; Damassa, D. A.; Davidson, J. M.

    1980-01-01

    The effects of centrifugation for various lengths of time on circulating levels of luteinizing hormone (LH) and testosterone in male rats were investigated. In a chronic 52-day experiment, centrifugation at 4.1 G significantly reduced LH and testosterone levels for the entire period. Centrifugation at 2.3 G had less effect inasmuch as LH levels were not significantly decreased and testosterone levels were significantly reduced only during the first few days of centrifugation. In more acute experiments, centrifugation at 4.1 G for 4 h resulted in reduced testosterone levels, whereas centrifugation for 15 min did not significantly alter the hormone levels. These results indicate that centrifugation can decrease circulating LH and testosterone levels if the gravitational force is of sufficient magnitude and is maintained for a period of hours. Chronic centrifugation may also inhibit the acute excitatory response of LH to handling and ether stress.

  20. Electromagnetic Transformation of DF4D Diesel Locomotive Electric Air Contactor%DF4D型内燃机车电空接触器电磁化改造

    Institute of Scientific and Technical Information of China (English)

    徐冬明; 朱琳; 欧阳爱莲

    2015-01-01

    Aiming at the problem of high failure rate and poor reliability of the electric air contactor of the DF4D die⁃sel locomotive,the improvement scheme of the electro pneumatic contactor is put forward in this paper.%本文针对DF4D型内燃机车主电路电空接触器故障率高、可靠性差等问题,提出电空接触器电磁化改进方案。

  1. Dynamic actuator for Soil-Structure Interaction physical modelling in centrifuge

    OpenAIRE

    CABRERA, Miguel; Caicedo, Bernardo; THOREL, Luc

    2014-01-01

    Dynamic interactions in centrifuge modelling are often induced with external or not controlled sources. This paper presents a method to study Soil-Structure Interaction in centrifuge, with the use of a dynamic actuator developed for centrifuge testing. The dynamic actuator is employed into the model giving the possibility to test the dynamic response of a wind turbine structure, without any additional supporting accessory. The centrifuge soil model was instrumented in order to measure the wav...

  2. Effect of inner structure of centrifugal separator on particle classification performance

    OpenAIRE

    Yamamoto, Tetsuya; Watanabe, Natsuko; Fukui, Kunihiro; Yoshida, Hideto

    2009-01-01

    This study investigated the effects of the inner structure of a centrifugal separator on particle classification performance. The typical inner structure of centrifugal separators is as follows: a blade, which consists of two orthogonal plates. is inserted into the centrifugal separator to create rigid fluid and particle rotations. The results of the present study demonstrate that centrifugal separator performance was significantly improved by attachment of a cylinder to the center of a conve...

  3. Thermal hydrodynamic analysis of a countercurrent gas centrifuge

    International Nuclear Information System (INIS)

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  4. Centrifuge modeling of LNAPL transport in partially saturated sand

    NARCIS (Netherlands)

    Esposito, G.; Allersma, H.G.B.; Selvadurai, A.P.S.

    1999-01-01

    Model tests were performed at the Geotechnical Centrifuge Facility of Delft University of Technology, The Netherlands, to examine the mechanics of light nonaqueous phase liquid (LNAPL) movement in a partially saturated porous granular medium. The experiment simulated a 2D spill of LNAPL in an unsatu

  5. Centrifugal impeller operating at a very low temperature

    International Nuclear Information System (INIS)

    Several compression stages working at very low temperatures (approximately= 4 K) and low pressures (approximately= 10 mb) have been calculated, assembled and tested. Good thermodynamic efficiencies (approximately= 0,55) and compression ratios (approximately= 3) are obtained. A compression stage is constituted by a centrifugal impeller surrounded by a static diffuser

  6. Centrifugal Model Tests on Railway Embankments of Expansive Soils

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Based on the centrifugal model tests on railway embankments of expansive soil in Nanning-Kunming railway,the author studied several embankments under different physical conditions. The stress and strain states and settlement of the embankments were analyzed, and the obtained results can be used as a reference to field construction.

  7. Centrifuge modelling of rigid piles in soft clay

    DEFF Research Database (Denmark)

    Klinkvort, R.T.; Poder, M.; Truong, P.;

    2016-01-01

    of this study is to employ centrifuge modelling in order to derive experimental p-y curves for rigid piles embedded in over-consolidated soft clay. A kaolin clay sample was prepared and pre-consolidated by applying a constant pressure at the soil surface, while different over-consolidation ratios were achieved...

  8. Model Based Fault Detection in a Centrifugal Pump Application

    DEFF Research Database (Denmark)

    Kallesøe, Carsten; Cocquempot, Vincent; Izadi-Zamanabadi, Roozbeh

    2006-01-01

    A model based approach for fault detection in a centrifugal pump, driven by an induction motor, is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, observer design and Analytical Redundancy Relation (ARR) design. Structural considerations...

  9. Liquid egg white pasteurization using a centrifugal UV irradiator

    Science.gov (United States)

    Studies are lacking on UV nonthermal pasteurization of liquid egg white (LEW). The objective of this study was to inactivate Escherichia coli using a UV irradiator that centrifugally formed a thin film of LEW on the inside of a rotating cylinder. The LEW was inoculated with E. coli K12 to approximat...

  10. DEMONSTRATION BULLETIN: THE PLASMA CENTRIFUGAL FURNACE RETECH, INC.

    Science.gov (United States)

    The plasma centrifugal furnace is a thermal technology which uses the heat generated from a plasma torch to decontaminate metal and organic contaminated waste. This is accomplished by melting metal-bearing solids and, in the process, thermally destroying organic contaminants. The...

  11. Pasteurization of grapefruit juice using a centrifugal ultraviolet light irradiator

    Science.gov (United States)

    The pharmaceutical industry uses UV irradiators to inactivate viruses in liquids without heat. The penetration depth of UV in some liquids, such as serum plasma, can be short. To overcome this, very thin films may be produced by centrifugal force, small diameter tubing, or other means. Many liquid f...

  12. Centrifugally driven microfluidic disc for detection of chromosomal translocations

    DEFF Research Database (Denmark)

    Brøgger, Anna Line; Kwasny, Dorota; Bosco, Filippo G.;

    2012-01-01

    and prognosis of patients. In this work we demonstrate a novel, centrifugally-driven microfluidic system for controlled manipulation of oligonucleotides and subsequent detection of chromosomal translocations. The device is fabricated in the form of a disc with capillary burst microvalves employed to control...

  13. Latex micro-balloon pumping in centrifugal microfluidic platforms.

    Science.gov (United States)

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Madou, Marc

    2014-03-01

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-step processes on a single microfluidic disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a latex membrane is introduced. It operates at low rotational speeds and pumps a larger volume of liquid towards the centre of the disc. Two different micro-balloon pumping mechanisms have been designed to study the pump performance at a range of rotational frequencies from 0 to 1500 rpm. The behaviour of the micro-balloon pump on the centrifugal microfluidic platforms has been theoretically analysed and compared with the experimental data. The experimental data show that the developed pumping method dramatically decreases the required rotational speed to pump liquid compared to the previously developed pneumatic pumping methods. It also shows that within a range of rotational speed, a desirable volume of liquid can be stored and pumped by adjusting the size of the micro-balloon.

  14. Pasteurization of Grapefruit Juice using a Centrifugal Ultraviolet Light Device

    Science.gov (United States)

    The pharmaceutical industry uses UV devices to nonthermally inactivate viruses in liquids. To overcome the low penetration depth of UV in some liquids, such as serum plasma, thin films are formed by centrifugal force. Liquid foods also have low UV penetration depths. Studies are lacking on nontherma...

  15. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    Directory of Open Access Journals (Sweden)

    Hongkun Li

    2014-01-01

    Full Text Available Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP sensor installed in vicinity to the crack area is used to determine blade crack according to blade vibration transfer process analysis. As it cannot show the blade crack information clearly, signal analysis and empirical mode decomposition (EMD are investigated for feature extraction and early warning. Firstly, signal filter is carried on PP signal around blade passing frequency (BPF based on working process analysis. Then, envelope analysis is carried on to filter the BPF. In the end, EMD is carried on to determine the characteristic frequency (CF for blade crack. Dynamic strain sensor is installed on the blade to determine the crack CF. Simulation and experimental investigation are carried on to verify the effectiveness of this method. The results show that this method can be helpful for blade crack classification for centrifugal compressors.

  16. Centrifugal pumping of gas-liquid mixtures: a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Estevam, Valdir [PETROBRAS, Rio de Janeiro, RJ (Brazil); Franca, Fernando A. [Universidade Estadual de Campinas, SP (Brazil); Alhanati, Francisco J.S. [C-Fer Technologies, Edmonton, Alberta (Canada)

    2004-07-01

    Centrifugal pumps are known to show a 'surging' behavior at certain conditions of free gas and liquid flow rate at the intake. In the 'surging region' on a pump characteristic curve, the head generated is significantly lower than if the pump were handling a gas-liquid homogeneous mixture. The surging happens, as one shows in this paper, due to the existence of a gas pocket, referred as 'elongated bubble', at the pump impeller inlet region. Therefore, to be able to predict the performance of centrifugal pumps under two-phase conditions, one has to disclose and model the mechanisms that set existence of the elongated bubble at the impeller inlet, besides calculating its length inside the impeller. This paper reports on the results of experimental and mechanistic modelling work conducted with the objective of better predicting the gas-liquid performance of centrifugal pumps under all range of conditions, including those characterized by 'surging'. The focus was on small diameter centrifugal pumps used to produce oil wells. A mechanistic two-fluid model devised to calculate the head generated by the pump was developed. The predictions of the model show good agreement with data collected for this study, and with data recently collected by other research organizations. (author)

  17. The cavitation behavior with short length blades in centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Quangnha; Lee, Chang Jin [Konkuk University, Seoul (Korea, Republic of)

    2010-10-15

    A CFD code with 2-D cascade model was developed to predict the cavitation behavior around the impeller blades of impeller in a centrifugal pump. The governing equations are the two-phase Reynolds Averaged Navier-Stokes equations in a homogeneous form in which both liquid and vapor phases are treated as incompressible fluid. To close the model, a standard k-{epsilon} turbulence model is introduced. And the mass transfer rates between liquid and vapor phases are implemented as well. The validations are carried out by comparing with reference data in impeller of a centrifugal pump impeller. The cavitation characteristics of current centrifugal pumps is tested at an on design point (V=8 m/s) and two off-design points (V=20 m/s and V=30 m/s), respectively. The criteria of cavitation and flow instability around blades are presented. The results show that the current centrifugal pump can safely operate without cavitation at on-design point. Also, the simulation shows cavitation develops inhomogeneously among the blades at off-design points. Moreover, the effects of additional blades in the impeller are studied as well. From the numerical results, it is expected that a half-length blade is the optimum configuration as additional blades in cavitation point of view

  18. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    Directory of Open Access Journals (Sweden)

    Bingbing Hu

    2015-01-01

    Full Text Available Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR method to diagnose crack fault in centrifugal fan. The ASR method, which can utilize the optimization ability of the grid search method and adaptively realize the optimal stochastic resonance system matching input signals, may weaken the noise and highlight weak characteristic and thus can diagnose the fault accurately. A centrifugal fan test rig is established and experiments with three cases of blades are conducted. In comparison with the ensemble empirical mode decomposition (EEMD analysis and the traditional Fourier transform method, the experiment verified the effectiveness of the current method in blade crack detection.

  19. Prediction of performance of centrifugal pumps during starts under pressure

    Science.gov (United States)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  20. Measurements of the rotordynamic shroud forces for centrifugal pumps

    Science.gov (United States)

    Guinzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1990-01-01

    An experiment was designed to measure the rotordynamic shroud forces on a centrifugal pump impeller. The measurements were done for various whirl/impeller speed ratios and for different flow rates. A destabilizing tangential force was measured for small positive whirl ratios and this force decreased with increasing flow rate.

  1. Cyber meets nuclear - Stuxnet and the cyberattacks on Iranian centrifuges

    International Nuclear Information System (INIS)

    In 2010 the computer worm Stuxnet attacked the information hardware of the Iranian uranium enrichment program. Stuxnet spread by USB flash drives and attacked SCADA software installed on Windows systems via several zero-day exploits. SCADA configures programmable logic controllers which control in the case of the Iranian centrifuge cascades frequency converter drives to choose the frequency of centrifuge motors. Thus the attackers were able to either change the rotation frequency of the rotor and thereby the separative power of the centrifuge or even destroy the fast spinning centrifuges by stopping and restarting them. The designers of Stuxnet must have had intimate knowledge of the facility design as e.g. the cascade connection scheme was programmed into Stuxnet. Based on this information some calculations of the Iranian cascade regarding the potential to produce highly enriched uranium will be presented using cascade simulation tools. The use of such highly sophisticated computer attacks to sabotage a nuclear program shed a new light on the debate about cyber attacks and the use of information technology for kinetic attacks in general. The talk will address problems the weaponization of information technology poses for international security and will highlight some more recent developments.

  2. Synthesis and Analytical Centrifugation of Magnetic Model Colloids

    NARCIS (Netherlands)

    Luigjes, B.

    2012-01-01

    This thesis is a study of the preparation and thermodynamic properties of magnetic colloids. First, two types of magnetic model colloids are investigated: composite colloids and single-domain nanoparticles. Thermodynamics of magnetic colloids is studied using analytical centrifugation, including a s

  3. Simulation of computational fluid dynamics in ozone contactor%臭氧接触池的计算流体力学模拟

    Institute of Scientific and Technical Information of China (English)

    王静; 邓保庆; 陆丽; 李勋栋

    2012-01-01

    The hydraulic characteristic of ozone contactor has a great impact on the disinfection effect of microorganism. Computational fluid dynamics ( CFD) technique was used to simulate the flow field of a single - column ozone contactor. The Eulerian multiphase model and the standard k - e turbulent model were used in the simulation. The results show that ozone distribution is relatively uniform in the single -column contactor. In general, there does not exist the phenomenon of "dead zone" , which helps to guarantee high disinfection efficiency. However, gas bubble was found to accumulate underneath the outlet trough. The results offer a sample for optimizing the ozonation system.%臭氧接触池的水力特性直接影响着微生物消毒效果.利用计算流体力学(CFD)技术,采用欧拉多相流模型和标准k-ε湍流模型对单管臭氧接触池内的流场进行数值模拟.结果表明:单管式臭氧接触池内臭氧分布比较均匀,基本上没有“死区”现象的产生,可以保证较高的消毒效率,但是气体气泡大量聚集在接触池出口槽下方.模拟结果对单管式臭氧接触池的优化有一定的借鉴作用.

  4. Integrated Control and Simulation of AC Contactor%交流接触器集成控制与仿真

    Institute of Scientific and Technical Information of China (English)

    庄杰榕; 许志红

    2014-01-01

    将集成控制技术引入交流接触器的控制中,以智能功率芯片为核心,集成跨周期调制电路和功率开关管,以132 kHz的高频工作模式,对交流接触器进行闭环控制。使用Multisim和LabView软件,建立智能控制下的接触器闭环机电一体化仿真系统。通过仿真系统分析瞬态特性,合理设计控制模块的工作模式,从底层分析高频工作方式引起电子器件产生的噪声及抑制措施,达到对电磁机构动作特性的良好控制,试验验证了集成方案的可行性。%This paper introduced integrated control technology to intelligent contactor control.The smart power IC built in internal power MOSFET and PSM circuit is the core of the control module.The control module works in the high frequency of 132 kHz to control the AC contactor with closed-loop.And using the software of Multisim and LabVIEW,the mechatronics simulation system of AC contactor with intelligent control was built.By means of the simulation system,this paper analyzed the working principle of control circuit and audio-frequency noise of electron device.The experiments were performed to verify the control module.

  5. Machine Tool Used AC Contactor Reliability Evaluation Method%机床用交流接触器可靠性评估方法

    Institute of Scientific and Technical Information of China (English)

    陆宾; 陆俭国

    2014-01-01

    Introduction was made to AC contactor reliability study development situations both at home and abroad. This paper described the reliability test method of machine tool used AC contactor mechanical operation and the evaluation method, pointing out that the product failure distribution type is Weibull distribution when AC contactor turning on/off the rating electrical load, failure rate is not constant, it is not suitable to adopt failure rate value as reliability index, but to adopt reliability measurement test, and the corresponding methods were given.%介绍了国内外开展交流接触器可靠性研究概况,阐述了机床用交流接触器机械操作可靠性试验方法与评估方法。指出交流接触器通断实际电气负载时产品失效分布类型为威布尔分布,失效率不是常数,不宜采用失效率大小作为交流接触器通断实际电气负载时的可靠性指标,而应采用可靠性测定试验,并给出了交流接触器通断实际电气负载时可靠性试验方法与提供可靠性数据的评估方法。

  6. The plasma properties and electron emission characteristics of near-zero differential resistance of hollow cathode-based plasma contactors with a discharge chamber

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kan, E-mail: xiekan@bit.edu.cn [School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 (China); Farnell, Casey C.; Williams, John D. [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80524 (United States)

    2014-08-15

    The formation of electron emission-bias voltage (I-V) characteristics of near-zero differential resistance in the cathodic plasma contactor for bare electrodynamic tether applications, based on a hollow cathode embedded in a ring-cusp ionization stage, is studied. The existence of such an I-V regime is important to achieve low impedance performance without being affected by the space plasma properties for a cathodic plasma contactor. Experimental data on the plasma structure and properties downstream from the ionization stage are presented as functions of the xenon flow rate and the electron emission current. The electrons were emitted from the cathode to the cylindrical vacuum chamber wall (r = 0.9 m) under ≈10{sup −5 }Torr of vacuum pressure. The ring-cusp configuration selected for the plasma contactor created a 125-Gauss axial field near the cathode orifice, along with a large-volume 50-Gauss magnitude pocket in the stage. A baseline ion energy cost of ≈300 eV/ion was measured in the ionization stage when no electrons were emitted to the vacuum chamber wall. In addition, the anode fall growth limited the maximum propellant unitization to below ≈75% in the discharge loss curves for this ion stage. Detailed measurements on the plasma properties were carried out for the no-electron emission and 3 A emission conditions. The experimental data are compared with 1-D models, and the effectiveness of the model is discussed. The four key issues that played important roles in the process of building the near-zero different resistance I-V regime are: a significant amount of ionization by the emission electrons, a decrease in the number of reflected electrons in the plume, the electron-temperature increment, and low initial ion energy at the source outlet.

  7. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  8. Enhancement of invasiveness of Yersinia enterocolitica and Escherichia coli in HEp-2 cells by centrifugation.

    OpenAIRE

    Vesikari, T; Bromirska, J; Mäki, M

    1982-01-01

    Centrifugation enhanced the infectivity of invasive Escherichia coli and Yersinia enterocolitica for HEp-2 cells. Noninvasive bacteria were not endocytosed after centrifugation. The centrifugation procedure may increase the sensitivity of testing for bacterial invasiveness in cell culture without causing false-positive results.

  9. Comparative analysis of discrete exosome fractions obtained by differential centrifugation

    Directory of Open Access Journals (Sweden)

    Dennis K. Jeppesen

    2014-11-01

    Full Text Available Background: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugation speeds on the purification from different cell types, however, is limited. Methods: We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder carcinoma FL3 cells. The fractions were evaluated by nanoparticle tracking analysis (NTA, total protein quantification and immunoblotting for CD81, TSG101, syntenin, VDAC1 and calreticulin. Results: NTA revealed the lowest background particle count in Dulbecco's Modified Eagle's Medium media devoid of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration and composition of the obtained fractions. In addition, HEK293 and FL3 vesicles displayed marked differences in sedimentation characteristics. Exosomes were pelleted already at 33,000×g, a g-force which also removed most contaminating microsomes. Optimal vesicle-to-protein yield was obtained at 67,000×g for HEK293 cells but 100,000×g for FL3 cells. Relative expression of exosomal markers (TSG101, CD81, syntenin suggested presence of exosome subpopulations with variable sedimentation characteristics. Conclusions: Specific g-force/k factor usage during differential centrifugation greatly influences the purity and yield of exosomes. The vesicle sedimentation profile differed between the 2 cell lines.

  10. The effects of a realistic hollow cathode plasma contactor model on the simulation of bare electrodynamic tether systems

    Science.gov (United States)

    Blash, Derek M.

    The region known as Low-Earth Orbit (LEO) has become populated with artificial satellites and space debris since humanities initial venture into the region. This has turned LEO into a hazardous region. Since LEO is very valuable to many different countries, there has been a push to prevent further buildup and talk of even deorbiting spent satellites and debris already in LEO. One of the more attractive concepts available for deorbiting debris and spent satellites is a Bare Electrodynamic Tether (BET). A BET is a propellantless propulsion technique in which two objects are joined together by a thin conducting material. When these tethered objects are placed in LEO, the tether sweeps across the magnetic field lines of the Earth and induces an electromotive force (emf) along the tether. Current from the space plasma is collected on the bare tether under the action of the induced emf, and this current interacts with the Earth's magnetic field to create a drag force that can be used to deorbit spent satellites and space debris. A Plasma Contactor (PC) is used to close the electrical circuit between the BET and the ionospheric plasma. The PC requires a voltage and, depending on the device, a gas flow to emit electrons through a plasma bridge to the ionospheric plasma. The PC also can require a plasma discharge electrode and a heater to condition the PC for operation. These parameters as well as the PC performance are required to build an accurate simulation of a PC and, therefore, a BET deorbiting system. This thesis focuses on the development, validation, and implementation of a simulation tool to model the effects of a realistic hollow cathode PC system model on a BET deorbit system.

  11. Mass transfer studies in miniature Rotating Disc Contactor (RDC) with 30% TBP/nitric acid biphasic system

    International Nuclear Information System (INIS)

    The rotating disc contactor is the widely used liquid-liquid extraction equipment for its high throughput and efficiency. In this work mass transfer performance of the miniature RDC column for the 30% TBP/nitric acid biphasic system was studied in terms of the operating variables such as rotor speed and flow rate of the aqueous and organic phase. The RDC column used in the experiments was shown. The column shell is made up of thick glass having diameter of 10.5 cm and height 100 cm. The rotor diameter is 5.3 cm and stator opening diameter is 6.3 cm. Totally 25 number of rotor discs were welded in the rotating shaft. This shaft was aligned in such a way that each rotor was placed in the centre of the compartment formed in between the two stator rings. The experiments were carried out to study the effect of rotor speed and superficial velocity of the dispersed and continuous phase on mass transfer efficiency. The organic solvent was made as the continuous phase and O/A ratio was set as 4 in both the continuous to dispersed phase(c-d) and dispersed to continuous phase (d-c) mass transfer experiments. The Number of Transfer Units (NTU) was estimated based on the solvent phase. The graphical representation of NTU was shown. The NTU value was observed as 4 and 3 respectively for extraction and stripping at the combined through put of 60 L/h and the rotor speed of 1000 rpm. This corresponds to the Height of Transfer Unit (HTU) value of 15 cm and 20 cm respectively for d-c and c-d mass transfer. The estimated overall mass transfer coefficient was increasing with rotor speed and superficial velocity of the liquid phases. The overall mass transfer coefficient also increases with increase in hold up

  12. Environmental and centrifugal factors influencing the visco-elastic properties of oral biofilms in vitro.

    Science.gov (United States)

    Peterson, Brandon W; Busscher, Henk J; Sharma, Prashant K; van der Mei, Henny C

    2012-01-01

    Centrifugal compaction causes changes in the surface properties of bacterial cells. It has been shown previously that the surface properties of planktonic cells change with increasing centrifugal compaction. This study aimed to analyze the influences of centrifugal compaction and environmental conditions on the visco-elastic properties of oral biofilms. Biofilms were grown out of a layer of initially adhering streptococci, actinomyces or a combination of these. Different uni-axial deformations were induced on the biofilms and the load relaxations were measured over time. Linear-Regression-Analysis demonstrated that both the centrifugation coefficient for streptococci and induced deformation influenced the percentage relaxation. Centrifugal compaction significantly influenced relaxation only upon compression of the outermost 20% of the biofilm (p centrifugal compaction of initially adhering, centrifuged bacteria extend to the visco-elastic properties of biofilms, indicating that the initial bacterial layer influences the structure of the entire biofilm.

  13. Analysis and Treatment of Causes for Common Faults of AC Contactor%交流接触器常见故障原因分析及处理

    Institute of Scientific and Technical Information of China (English)

    马英力

    2011-01-01

    AC Contactor ia the most common used apparatus in electric drive and automatic control system.As an actuator, it can frequently and automatically control the starting, running and stopping of the motors, or even the connecting and breaking of the power lines in far distance.This paper mainly expounds the causes for common faults of AC Contactor and its treatment.%交流接触器是电力拖动和自动控制系统中应用最普遍的一种电器.它作为执行元件,可以远距离频繁地自动控制电动机的启动、运转和停止,以及电力线路的接通与分断.本文对交流接触器常见故障产生的原因及采取的相应处理方法进行了阐述.

  14. 200A三相交流接触器的无火花控制%The sparkless control of 200A 3-phase AC contactors

    Institute of Scientific and Technical Information of China (English)

    党方义; 苟亚仙; 李锐

    2001-01-01

    AC contactors are widely used in various industrial fields.However,any conventional applications show that their contacts need frequent maintenance as they are so often burnt,thus even causing peripheral equipment to be damaged,which would have serious effects on the normal operation of the industrial production.The sparkless AC contactors described in this paper can solve such a difficult problem successfully by using the by-pass techniqure of short-time current,so that they can keep operating with no need of maintenance.%交流接触器广泛用于各种工业领域。然而,传统用法中接触器的触点经常被烧损,需要频繁维护,使用寿命短,有时甚至造成周边设备损坏,严重影响工业生产的正常运作。本文中的无火花交流接触器应用短时间电流傍路技术成功地解决了这一难题,可做到免维护使用。

  15. 大容量交流接触器灭弧性能的试验研究%Experimental Research of Arc Extinction Performance of Big-Capacity AC Contactor

    Institute of Scientific and Technical Information of China (English)

    史亚闻; 曾萍; 葛顺锋

    2015-01-01

    This paper researched the effects of arc extinction performance of big-capacity AC contactors which are caused by the different structure of arc chamber according to the method of test waveform image and high speed photography.The research results show that the placement of guiding-arc flake,the shape of leading-arc flake and distance between leading-arc flake and arc splitters are crirical to enhancing arc extinction performance of AC contactors.In addition,this method of research can shorten the developing period of AC contactor and reduce the cost of contactors'R&D.%通过试验波形图和高速摄影的方法研究了不同灭弧室结构对大容量交流接触器灭弧性能的影响。研究结果表明,导弧片的布置和引弧片的形状以及灭弧栅片与引弧片之间的位置关系都会对交流接触器的灭弧性能起到至关重要的作用。同时该试验方法能够缩短交流接触器的研发周期,降低研发成本。

  16. The Control Technology of Self-correction for Intelligent AC Contactors%智能交流接触器自校正控制技术

    Institute of Scientific and Technical Information of China (English)

    汤龙飞; 许志红

    2015-01-01

    将电力电子传统的电压控制模式及Buck电路经改造应用于交流接触器的智能控制中,实现了智能交流接触器的闭环控制。在此基础上,提出了加入主触头状态捕捉电路的自校正控制方案,分析自校正控制的工作原理,采用电流扫描方式实现自校正控制,使智能交流接触器具有起动过程自校正功能,减少了智能交流接触器起动过程中的触头弹跳。通过对自校正参数的记忆,精确复现起动电流,减少了智能交流接触器在线运行的触头弹跳。该控制方案对接触器本体的结构参数依赖较低,对输入电压波动不敏感,可以自动调整吸力特性,不需要对接触器进行复杂的建模仿真即可完成相对优化的过程控制,提高智能交流接触器的电寿命,结合相关实验验证了方案的有效性。%This paper applied the voltage control mode and the transformed buck circuit into the intelligent control of the ac contactor and realized closed-loop control. On this basis, a self-correction control scheme with the state capture circuit of main contacts has been proposed. This paper analyzed the principle of the self-correction control and realized it by current scanning. The control scheme can reduce the bounces of the ac contactor in making process with the offline self-correction. Through memory the offline self-correction parameters, the control module can recurrence the making coil current accurately. This control scheme relies less on the structure parameters of the ac contactor and is not sensitive to the input voltage fluctuation. The intelligent ac contactor can adjust the attractive force automatically and enhance the electrical life of the ac contactor. The complex modeling and simulation is not necessary during the optimal control. The experimental results verify the validity of the control scheme.

  17. Co-simulation and Digital Control Technology of the Intelligent AC Contactor%智能交流接触器一体化仿真及数字控制技术

    Institute of Scientific and Technical Information of China (English)

    许志红; 汤龙飞

    2015-01-01

    A brand-new simulation method for the intelligent AC contactor was proposed. The simulation method integrated the SPICE simulation of the control module with the dynamic simulation of the contactor and realized the closed-loop point-by-point co-simulation between the intelligent control module and the AC contactor. The underlying hardware circuit of the intelligent AC contactor can be designed in Multisim. And the dynamic model of AC contactor can be designed in LabVIEW. In addition, a two-way data channel has been built between Multisim and LabVIEW. Both of the softwares perform the nonlinear time-domain simulation simultaneously and independently, and exchange data at the end of each simulation time step so as to realize the co-simulation. The co-simulation system can find a reasonable control scheme for the intelligent AC contactor. At the same time, the digital control technology has been introduced and a current closed-loop control module for AC contactor was designed. The co-simulation and the digital control have been verified effectively.%该文提出了一种新的智能交流接触器仿真方法,将SPICE电路仿真与接触器动态仿真完全集成,实现了智能控制模块与接触器本体一体化的逐点闭环仿真系统.在Multisim 电路仿真软件中进行智能控制模块的底层硬件电路设计,在LabVIEW中构建接触器的动态仿真程序,同时构建Multisim和LabVIEW之间的双向数据通道,两个独立的仿真程序同时进行非线性时域仿真,然后在每一个仿真步长结束时交换数据,进行一体化仿真.通过一体化仿真确定合理的接触器运动过程控制方案,同时引入数字变流技术,开发了智能交流接触器电流闭环数字控制模块,并进行相关实验,验证了一体化仿真及数字控制的有效性.

  18. Analysis of cantilever NEMS in centrifugal-fluidic systems

    Science.gov (United States)

    Mohsen-Nia, Mohsen; Abadian, Fateme; Abadian, Naeime; Dehkordi, Keivan Mosaiebi; Keivani, Maryam; Abadyan, Mohamadreza

    2016-07-01

    Electromechanical nanocantilevers are promising for using as sensors/detectors in centrifugal-fluidic systems. For this application, the presence of angular speed and electrolyte environment should be considered in the theoretical analysis. Herein, the pull-in instability of the nanocantilever incorporating the effects of angular velocity and liquid media is investigated using a size-dependent continuum theory. Using d’Alembert principle, the angular speed is transformed into an equivalent centrifugal force. The electrochemical and dispersion forces are incorporated considering the corrections due to the presence of electrolyte media. Two different approaches, i.e., the Rayleigh-Ritz method (RRM) and proposing a lumped parameter model (LPM), were applied to analyze the system. The models are validated with the results presented in literature. Impacts of the angular velocity, electrolyte media, dispersion forces, and size effect on the instability characteristics of the nanocantilever are discussed.

  19. Considerations in designing a centrifugal atomiser for metal powder production

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.Y. [Department of Engineering, The University of Liverpool, Liverpool L69 3GH (United Kingdom)]. E-mail: y.y.zhao@livepool.ac.uk

    2006-07-01

    In centrifugal atomisation for metal powder production, the key to the control of the particle sizes is the design of the atomiser. This paper studies the main issues concerned in designing a centrifugal atomiser and provides guidance on the selection of an electric motor, radius of atomiser, slope angle of atomiser wall and flow rate of cooling water. In the selection of the atomiser radius, the power and material constraints as well as the hydraulic jump radius need to be considered. A cup atomiser with a slope angle of 60-70{sup o} would result in small spray droplets and thus a fine powder. The water cooling system needs to be assessed by examining the heat flow in the solid metal layer and in the atomiser.

  20. Concept for a short arm human centrifuge onbord ISS.

    Science.gov (United States)

    Kuebler, Ulrich; Grinberg, Anna; Kern, Peter

    Astrium is presently performing for ESA a definition study about the accommodation of a short arm human centrfiuge into a spacecraft. A scientific workshop has been part of the study with the goal to define from various research fields (e.g. cardiovascular, gravitational biology, neuroscience, bone/muscle) requirements for such an artificial gravity system on ISS. As a second step the requirements were consolidated to a set of common specfications for the developemnt of a centrifuge system serving as integrated countermeasure for longterm exposure to g. The presentation will focus on the scientific requirements and the respective translation into technical requirement, finally leading to a centrifuge concept, including accommodation possi-bilities onbord ISS.

  1. Centrifuge modeling of PGD response of buried pipe

    Institute of Scientific and Technical Information of China (English)

    Michael O'Rourke; Vikram Gadicherla; Tarek Abdoun

    2005-01-01

    A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented.The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experiment split-box are described: The split-box contains the model pipeline and surrounding soil and is manufactured such that half can be offset, in flight, simulating PGD. In addition, governing similitude relations which allow one to determine the physical characteristics,(diameter, wall thickness and material modulus of elasticity) of the model pipeline are presented. Finally, recorded strains induced in two buried pipes with prototype diameters of 0.63 m and 0.95 m (24 and 36 inch) subject to 0.6 and 2.0 meters (2and 6 feet) of full scale fault offsets and presented and compared to corresponding FE results.

  2. Stage-efficiency of centrifugal extractor used in nuclear industry

    Institute of Scientific and Technical Information of China (English)

    吴秋林; 景山; 王兴海; 宋崇立

    2003-01-01

    The stage-efficiency of a single-stage prototype (d70) centrifugal extractor and the cascade is tested by HNO3-Nd3+ and 30%TRPO-kerosene system. The experimental results of the single-stage centrifugal extractor show that the carryover of the two phases decreases with increasing ratio of the two flow rate and rotation rate and the stage efficiency increases with not only decreasing total flow rate but also increasing rotor speed. However, the experimental results of the cascade show that the average stage efficiency of the cascade increases with not only decreasing total flow rate but also increasing rotor speed in both three-stage mode and two-stage mode.

  3. Massively parallel single-molecule manipulation using centrifugal force

    CERN Document Server

    Halvorsen, Ken

    2009-01-01

    Precise manipulation of single molecules has already led to remarkable insights in physics, chemistry, biology and medicine. However, widespread adoption of single-molecule techniques has been impeded by equipment cost and the laborious nature of making measurements one molecule at a time. We have solved these issues with a new approach: massively parallel single-molecule force measurements using centrifugal force. This approach is realized in a novel instrument that we call the Centrifuge Force Microscope (CFM), in which objects in an orbiting sample are subjected to a calibration-free, macroscopically uniform force-field while their micro-to-nanoscopic motions are observed. We demonstrate high-throughput single-molecule force spectroscopy with this technique by performing thousands of rupture experiments in parallel, characterizing force-dependent unbinding kinetics of an antibody-antigen pair in minutes rather than days. Additionally, we verify the force accuracy of the instrument by measuring the well-est...

  4. Numerical investigation of suction vortices behavior in centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    An, Young Joon; Shin, Byeong Rog [Changwon National University, Changwon (Korea, Republic of)

    2011-03-15

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-{omega} Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed.

  5. Numerical investigation of suction vortices behavior in centrifugal pump

    International Nuclear Information System (INIS)

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-ω Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed

  6. Flow generation in a novel centrifugal diffuser test device

    Science.gov (United States)

    Vidos, P.

    1983-09-01

    Recognition of the need to develop optimum diffusers for advanced centrifugal compressors, resulted in the design and manufacture of a novel low-speed test facility for centrifugal diffuser testing. The CDTD was designed to allow the flow angle and wall boundary profiles into the test diffuser to be controlled by variable geometry in the flow generator. The present study reports on the design of the flow generator and the analysis of the internal flow using a NASA computer code (MERIDL). First test results are given and are compared with the results of a control volume analysis. The flow angle control technique was found to work effectively but to give somewhat smaller angles (by 4 deg) than were predicted. It was concluded that the information obtained would allow scaling of the device; however, an analysis code was needed which would accept the real physical boundary conditions.

  7. A centrifugal pump concept designed for multiple use in space

    Science.gov (United States)

    Wunderlich, E.; Wulz, H. G.

    A centrifugal pump concept was elaborated for a multiple application in future spacecrafts. Based on this concept a prototype of a small centrifugal pump was manufactured and comprehensively tested. The model pump has been approved in different test series with the fluids liquid ammonia and demineralized water. The design of the model pump was driven by strict requirements of COLUMBUS, namely long life, noiseless operation, minimum mass and low energy consumption. Because of its modular design and as a result of selected materials of multiple compatibility, this pump is suited for the delivery of various further fluids, such as freons, hydrocarbons, propellants (hydrazine) etc.. It is also capable of pumping corrosive or toxic fluids for laboratory processes in space. The wide speed range from about 1,00 to 20,000 rpm which corresponds to a flow from about 1 to 20 l/min, permits an energy saving adaption and flow control.

  8. Dynamical System Analysis of Unsteady Phenomena in Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    YasuyukiKomatsubara; ShimpeiMizuki

    1997-01-01

    Surge and rotating stall occurring in a centrifugal compressor system are investigated by using a phase portrait reconstruction method.From experimentally measured time series of data,the method clarified the cyclic behavior of surge.For rotating stall,there still remain problems in the phase portrait due to the chaotic behavior.However,the results obtained by the present method are able to provide new insights to the modelings for surge and rotating stall.Surge and roatting stall occurring in a centrifugal compressor system are investigated by using a phase portrait reconstruction method.From experimentally measured time series of data,the method clarified the cylcic behavior of surge.For rotating stall,there still remain problems in the phase portrait due to the chaotic behavior.However,the results obtained by the present method are able to provide new insights to the modelings for surge and rotating stall.

  9. Waste minimization and resource recovery using centrifugation and thermal desorption

    International Nuclear Information System (INIS)

    Separation and Recovery Systems, Inc. (SRS) provides on-site waste minimization and resource recovery using its state-of-the-art MX-1500 centrifuge and MX-2000 thermal desorber. The MX-1500 can process over 450 feed tons of material per day, resulting in centrifuged cake containing 20% to 60% by weight. The MX-2000 is a hollow-flite thermal processor indirectly heated by either steam or hot oil. SRS has dewatered and/or deoiled over 1,000,000 feed tons of material in the refining, chemical, and energy industries using the MX-1500. SRS estimates that over 300,000 barrels of reusable oil have been recovered from that material. Additionally, SRS has dried and/or detoxified over 150,000 wet tons of solids or soil to regulatory or customer-specified limits using the MX-2000

  10. Optimization of centrifugal pump cavitation performance based on CFD

    Science.gov (United States)

    Xie, S. F.; Wang, Y.; Liu, Z. C.; Zhu, Z. T.; Ning, C.; Zhao, L. F.

    2015-01-01

    In order to further improve the cavitation performance of a centrifugal pump, slots on impeller blade near inlet were studied and six groups of hydraulic model were designed. Base on cavitating flow feature inside a centrifugal pump, bubble growth and implosion are calculated from the Rayleigh-Plesset equation which describes the dynamic behavior of spherical bubble and RNG κ-epsilon model was employed to simulate and analyze the internal two-phase flow of the model pump under the same conditions. The simulation results show that slots on blade near inlet could improve the cavitation performance and cavitation performance improvement of the second group was more obvious. Under the same conditions, the pressure on the back of blade near inlet was higher than the pressure on the back of unmodified blade near inlet, and energy distribution in the flow channel between the two blades was more uniform with a small change of head.

  11. Centrifuge Modeling of Piles Subjected to Lateral Loads

    Science.gov (United States)

    Brant, Logan; Ling, Hoe I.

    There are many applications where piles are employed to absorb and deflect lateral impact loads. Structural elements of this type are used to protect infrastructure and are commonly found at marine sites. A series of model tests have been conducted using Columbia University's centrifuge facility to better understand the performance of piles subjected to these loading conditions. A device was designed to install and laterally load single model piles during centrifuge flight. This device uniquely contains two lateral loading systems, one which allows static testing and another appropriate for dynamic tests. This research examines the behavior of tubular steel piles embedded within dry or saturated soil and subjected to varied rates of lateral loading. This investigation provides insight on the contribution of lateral loading rates to the behavior of piles.

  12. Dynamic Actuator for Centrifuge Modeling of Soil-Structure Interaction

    OpenAIRE

    CABRERA, Miguel Angel; Caicedo, Bernardo; THOREL, Luc

    2012-01-01

    This paper presents a new dynamic actuator useful to study soil-structure interactions in a centrifuge. This new dynamic apparatus is based on an amplified piezoelectric actuator. Using this device it is possible to create vibrations in the soil sample of different frequencies and amplitudes. The dynamic actuator consists of a set of weights in a single degree of freedom system plus a piezoelectric actuator and a piezoelectric load cell, which measures the dynamic load. A description of the d...

  13. Centrifuge modeling of soil atmosphere interaction using climatic chamber

    OpenAIRE

    CAICEDO, B; TRISTANCHO, J; THOREL, Luc

    2010-01-01

    Soil-atmospheric interaction processes such as infiltration or evaporation can have a significant effect on the behavior of geotechnical structures located near the soil surface. This paper focuses on the drying process of soils due to evaporation. The scaling laws are analyzed and the results of the application of two cycles of heating and cooling on a soil mass are presented. Based on these results, conclusions about the feasibility of reproducing evaporation on centrifuge models are recomm...

  14. Centrifugal effects in a weakly ionized rotating gas

    International Nuclear Information System (INIS)

    The author deals with a weakly ionized gas rotating under the influence of the Lorentz force in a cylindrical vessel. This force occurs if an electrical current flows across a magnetic field. The investigation concerns the possibility to bring a neutral gas into rotation by a relatively small number of charged particles (ions and electrons) on which the Lorentz force is acting. Also the possibility to use the centrifugal force, due to the rotation of the gas, for mass separation, is discussed. (Auth.)

  15. Origins of hydrodynamic forces on centrifugal pump impellers

    OpenAIRE

    Adkins, Douglas R.; Brennen, Christopher E.

    1986-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and volute are experimentally and theoretically investigated. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of the flow in the volute. The disturbance at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force pe...

  16. Analyses of Hydrodynamic Radial Forces on Centrifugal Pump Impellers

    OpenAIRE

    Adkins, D. R.; Brennen, C. E.

    1988-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and a volute are experimentally and theoretically investigates. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of flow in the volute. Flow disturbances at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force...

  17. Computational and Experimental Study of an Industrial Centrifugal Compressor Volute

    Institute of Scientific and Technical Information of China (English)

    HarriPitkanen; HannuEsa; 等

    2000-01-01

    A centrifugal compressor with a vaneless diffuser was studied experimentally and numericallly.The main target of the study was to analyze the volute flow.Two different volute geometries was studied.The numerical solution was done by using a steady-state RANS code at both design and off-design conditions.Both calculated and measured pressure and velocity distributions are presented.

  18. Centrifugal stretching of 170Hf in the interacting boson model

    Directory of Open Access Journals (Sweden)

    Werner V.

    2014-03-01

    Full Text Available We present the results of a recent experiment to deduce lifetimes of members of the ground state rotational band of 170Hf, which show the effect of centrifugal stretching in this deformed isotope. Results are compared to the geometrical confined beta-soft(CBS rotor model, as well as to the interacting boson model (IBM. Two methods to correct for effects due to the finite valence space within the IBM are proposed.

  19. Purification of crime scene DNA extracts using centrifugal filter devices

    OpenAIRE

    Norén, Lina; Hedell, Ronny; Ansell, Ricky; Hedman, Johannes

    2013-01-01

    BACKGROUND: The success of forensic DNA analysis is limited by the size, quality and purity of biological evidence found at crime scenes. Sample impurities can inhibit PCR, resulting in partial or negative DNA profiles. Various DNA purification methods are applied to remove impurities, for example, employing centrifugal filter devices. However, irrespective of method, DNA purification leads to DNA loss. Here we evaluate the filter devices Amicon Ultra 30 K and Microsep 30 K with respect to re...

  20. A Review of Centrifugal Testing of Gasoline Contamination and Remediation

    OpenAIRE

    Jay N. Meegoda; Liming Hu

    2011-01-01

    Leaking underground storage tanks (USTs) containing gasoline represent a significant public health hazard. Virtually undetectable to the UST owner, gasoline leaks can contaminate groundwater supplies. In order to develop remediation plans one must know the extent of gasoline contamination. Centrifugal simulations showed that in silty and sandy soils gasoline moved due to the physical process of advection and was retained as a pool of free products above the water table. However, in clayey soi...

  1. Development and Design of a Centrifugal Compressor Volute

    OpenAIRE

    Cheng Xu; Michael Müller

    2005-01-01

    The volute is one of the key components of a centrifugal compressor. The design of the volute not only impacts the compressor efficiency but also influences the operating range. The detailed flow simulation presented here helps to better understand the volute flow mechanisms and provide design guidance in volute design to meet performance goals. In this study, the viscous Navier-Stokes equations are used to simulate the flow inside the vaneless diffuser and volute. The de...

  2. Dynamical system analysis of unstable flow phenomena in centrifugal blower

    Directory of Open Access Journals (Sweden)

    Garcia David

    2015-09-01

    Full Text Available Methods of dynamical system analysis were employed to analyze unsteady phenomena in a centrifugal blower. Pressure signals gathered at different control points were decomposed into their Principal Components (PCs by means of Singular Spectrum Analysis (SSA. Certain number of PCs was considered in the analysis based on their statistical correlation. Projection of the original signal onto its PCs allowed to draw the phase trajectory that clearly separated non-stable blower working conditions from its regular operation.

  3. Inverse Design of Centrifugal Compressor Stages Using a Meanline Approach

    OpenAIRE

    Yuri Biba; Peter Menegay

    2004-01-01

    This article discusses an approach for determining meanline geometric parameters of centrifugal compressor stages given specified performance requirements. This is commonly known as the inverse design approach. The opposite process, that of calculating performance parameters based on geometry input is usually called analysis, or direct calculation. An algorithm and computer code implementing the inverse approach is described. As an alternative to commercially available inverse design codes...

  4. A Novel Aerodynamic Design Method for Centrifugal Compressor Impeller

    OpenAIRE

    Mahdi Nili-Ahmadabadi; mohammad durali; Ali Hajilouy Benisi

    2014-01-01

    This paper describes a new quasi-3D design method for centrifugal compressor impeller. The method links up a novel inverse design algorithm, called Ball-Spine Algorithm (BSA), and a quasi-3D analysis. Euler equation is solved on the impeller meridional plane. The unknown boundaries (hub and shroud) of numerical domain are iteratively modified by BSA until a target pressure distribution in flow passage is reached. To validate the quasi-3D analysis code, existing compressor impeller is investig...

  5. Comparison of Two Diffusers in a Transonic Centrifugal Compressor

    OpenAIRE

    Koji Nakagawa; Hiroshi Hayami; Yuichi Keimi

    2003-01-01

    Flow mechanisms suppressing the flow separation in two diffusers, a low-solidity cascade diffuser and a vaned diffuser with additional small vanes near the inlet, were compared mainly by numerical simulation. As the superiority of the low-solidity cascade diffuser was expected, a series of experiments was conducted using a transonic centrifugal compressor with a maximum pressure ratio of 7. The performance of the compressor with the vaned diffuser was comparable to that of the low-solidity ca...

  6. Optimal Design of a Centrifugal Compressor Impeller Using Evolutionary Algorithms

    OpenAIRE

    Soo-Yong Cho; Kook-Young Ahn; Young-Duk Lee; Young-Cheol Kim

    2012-01-01

    An optimization study was conducted on a centrifugal compressor. Eight design variables were chosen from the control points for the Bezier curves which widely influenced the geometric variation; four design variables were selected to optimize the flow passage between the hub and the shroud, and other four design variables were used to improve the performance of the impeller blade. As an optimization algorithm, an artificial neural network (ANN) was adopted. Initially, the design of experiment...

  7. Centrifugal compressor flow instabilities at lowmass flow rate

    OpenAIRE

    Sundström, Elias

    2016-01-01

    Turbochargers play an important role in increasing the energetic efficiency andreducing emissions of modern power-train systems based on downsized recipro-cating internal combustion engines (ICE). The centrifugal compressor in tur-bochargers is limited at off-design operating conditions by the inception of flowinstabilities causing rotating stall and surge. They occur at reduced enginespeeds (low mass flow rates), i.e. typical operating conditions for a betterengine fuel economy, harming ICEs...

  8. Measurement and Calibration of Centrifugal Compressor Pressure Scanning Instrumentation

    OpenAIRE

    Rivas, Jose R; Lou, Fangyuan; Harrison, Herbert "Trey"; Key, Nicole

    2015-01-01

    The compressor is a key component of a jet engine necessary to compress air for the combustion process. Research to optimize compressor efficiency through the understanding of air flow behavior has led to increased efforts in creating modern compressor test facilities. In collaboration with Honeywell, the High Speed Compressor facility at Zucrow Laboratories has built a centrifugal compressor test cell with instrumentation to measure the temperatures and pressures of the air flow. This facili...

  9. Impeller Design of a Centrifugal Fan with Blade Optimization

    OpenAIRE

    Yu-Tai Lee; Vineet Ahuja; Ashvin Hosangadi; Michael E. Slipper; Lawrence P. Mulvihill; Roger Birkbeck; Coleman, Roderick M.

    2011-01-01

    A method is presented for redesigning a centrifugal impeller and its inlet duct. The double-discharge volute casing is a structural constraint and is maintained for its shape. The redesign effort was geared towards meeting the design volute exit pressure while reducing the power required to operate the fan. Given the high performance of the baseline impeller, the redesign adopted a high-fidelity CFD-based computational approach capable of accounting for all aerodynamic losses. The present eff...

  10. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    OpenAIRE

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J.; Anastasopoulos, Ioannis; GAZETAS, George

    2014-01-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces th...

  11. Fault Diagnosis in a Centrifugal Pump Using Active Magnetic Bearings

    OpenAIRE

    Nordmann Rainer; Aenis Martin

    2004-01-01

    The number of rotors running in active magnetic bearings (AMBs) has increased over the last few years. These systems offer a great variety of advantages compared to conventional systems. The aim of this article is to use the AMBs together with a developed built-in software for identification, fault detection, and diagnosis in a centrifugal pump. A single-stage pump representing the turbomachines is investigated. During full operation of the pump, the AMBs are used as actuators to generate def...

  12. Comparative hemolysis study of clinically available centrifugal pumps.

    Science.gov (United States)

    Naito, K; Suenaga, E; Cao, Z L; Suda, H; Ueno, T; Natsuaki, M; Itoh, T

    1996-06-01

    Centrifugal pumps have become important devices for cardiopulmonary bypass and circulatory assistance. Five types of centrifugal pumps are clinically available in Japan. To evaluate the blood trauma caused by centrifugal pumps, a comparative hemolysis study was performed under identical conditions. In vitro hemolysis test circuits were constructed to operate the BioMedicus BP-80 (Medtronic, BioMedicus), Sarns Delphin (Sarns/3M Healthcare), Isoflow (St. Jude Medical [SJM]), HPM-15 (Nikkiso), and Capiox CX-SP45 (Terumo). The hemolysis test loop consisted of two 1.5 m lengths of polyvinyl chloride tubing with a 3/8-inch internal diameter, a reservoir with a sampling port, and a pump head. All pumps were set to flow at 6 L/min against the total pressure head of 120 mm Hg. Experiments were conducted simultaneously for 6 h at room temperature (21 degrees C) with fresh bovine blood. Blood samples for plasma-free hemoglobin testing were taken, and the change in temperature at the pump outlet port was measured during the experiment. The mean pump rotational speeds were 1,570, 1,374, 1,438, 1,944, and 1,296 rpm, and the normalized indexes of hemolysis were 0.00070, 0.00745, 0.00096, 0.00066, 0.00090 g/100 L for the BP-80, Sarns, SJM, Nikkiso, and Terumo pumps, respectively. The change in temperature at the pump outlet port was the least for the Nikkiso pump (1.8 degrees C) and the most with the SJM pump (3.8 degrees C). This study showed that there is no relationship between the pump rotational speed (rpm) and the normalized index of hemolysis in 5 types of centrifugal pumps. The pump design and number of impellers could be more notable factors in blood damage.

  13. Effects of Different Blade Angle Distributions on Centrifugal Compressor Performance

    OpenAIRE

    Pekka Röyttä; Aki Grönman; Ahti Jaatinen; Teemu Turunen-Saaresti; Jari Backman

    2009-01-01

    A centrifugal compressor with three different shrouded 2D impellers is studied numerically. All impellers have the same dimensions, and they only differ in channel length and geometry. Noticeable differences in efficiency are observed. Two different turbulence models, Chien's k-ε and k-ω SST, are compared. For this case, k-ω SST was found more realistic. The hypothesis that pressure losses in a curved duct and in an impeller passage behave similarly is suggested and found inadequate.

  14. Numerical simulation of the countercurrent flow in a gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Cloutman, L.D.; Gentry, R.A.

    1983-03-01

    We present a finite difference method for the numerical simulation of the axisymmetric countercurrent flow in a gas centrifuge. A time-marching technique is used to relax an arbitrary initial condition to the desired steady-state solution. All boundary layers can be resolved, and nonlinear effects may be included. Numerical examples are presented. We conclude that this technique is capable of predicting accurately the performance of a wide variety of machines under all operating conditions of interest.

  15. Phase characterization in two centrifugally cast HK stainless steel tubes

    International Nuclear Information System (INIS)

    The petrochemical industry has been using 25% Cr - 20% Ni centrifugally cast stainless steel since the early 1960s in reformer and pyrolysis furnaces. This class of material has replaced the traditional superalloys showing similar creep behavior, with substantial reduction in costs. The use of the centrifugal casting technique for tube production has also contributed to better quality in these components. During the past two decades, several studies have been conducted concerning the improvement in the performance of this material at high temperatures. Some of them were related to failure analysis and life prediction, while others were related to the chemical composition balance and to new alloying procedures. As a consequence, a new generation of centrifugally cast steels has been developed in the form of niobium-modified HK and HP steels. The creep resistance of these alloys appears to be dependent on the composition, morphology, and distribution of carbides that form within them. The purpose of the study reported herein is to characterize the precipitation effects occurring during long- term service in two HK-type steels, one being of basic HK composition and the other a niobium-modified alloy

  16. Governing Principles of Alginate Microparticle Synthesis with Centrifugal Forces.

    Science.gov (United States)

    Eral, Huseyin Burak; Safai, Eric R; Keshavarz, Bavand; Kim, Jae Jung; Lee, Jisoek; Doyle, P S

    2016-07-19

    A controlled synthesis of polymeric particles is becoming increasingly important because of emerging applications ranging from medical diagnostics to self-assembly. Centrifugal synthesis of hydrogel microparticles is a promising method, combining rapid particle synthesis and the ease of manufacturing with readily available laboratory equipment. This method utilizes centrifugal forces to extrude an aqueous polymer solution, sodium alginate (NaALG) through a nozzle. The extruded solution forms droplets that quickly cross-link upon contact with aqueous calcium chloride (CaCl2) solution to form hydrogel particles. The size distribution of hydrogel particles is dictated by the pinch-off behavior of the extruded solution through a balance of inertial, viscous, and surface tension stresses. We identify the parameters dictating the particle size and provide a numerical correlation predicting the average particle size. Furthermore, we create a phase map identifying different pinch-off regimes (dripping without satellites, dripping with satellites, and jetting), explaining the corresponding particle size distributions, and present scaling arguments predicting the transition between regimes. By shedding light on the underlying physics, this study enables the rational design and operation of particle synthesis by centrifugal forces.

  17. Numerical Analysis and Centrifuge Modeling of Shallow Foundations

    Institute of Scientific and Technical Information of China (English)

    罗强; 栾茂田; 杨蕴明; 王忠涛; 赵守正

    2014-01-01

    The influence of non-coaxial constitutive model on predictions of dense sand behavior is investigated in this paper. The non-coaxial model with strain softening plasticity is applied into finite-element program ABAQUS, which is first used to predict the stress-strain behavior and the non-coaxial characteristic between the orientations of the principal stress and principal plastic strain rate in simple shear tests. The model is also used to predict load settlement responses and bearing capacity factors of shallow foundations. A series of centrifuge tests for shallow foundations on saturated dense sand are performed under drained conditions and the test results are compared with the corresponding numerical results. Various footing dimensions, depths of embedment, and footing shapes are considered in these tests. In view of the load settlement relationships, the stiffness of the load-displacement curves is significantly affected by the non-coaxial model compared with those predicted by the coaxial model, and a lower value of non-coaxial modulus gives a softer response. Considering the soil behavior at failure, the coaxial model predictions of bearing capacity factors are more advanced than those of centrifuge test results and the non-coaxial model results;besides, the non-coaxial model gives better predictions. The non-coaxial model predictions are closer to those of the centrifuge results when a proper non-coaxial plastic modulus is chosen.

  18. Flow measurements in a centrifugal diffusor test device

    Science.gov (United States)

    Vitting, T.

    1985-06-01

    This work sought to verify concepts used in the design of a large scale, low speed, radial cascade wind tunnel which was to be used to investigate flow phenomena in and the performance of vaned radial diffusors. A major contributor to centrifugal compressor efficiency is the performance of the vaned diffusor which closely follows the impeller of the compressor. The purpose of this diffusor is to efficiently convert most of the kinetic energy of the transonic flow entering the vane into pressure. The need for an experimental facility which could simulate adequately, at low cost and in a controlled way, the environment of the centrifugal compressor motivated the development of the Centrifugal Diffusor Test Device (CDTD). It was expected that the generation of a three dimensional flow would provide improved empirical data on annular cascade performance. This measurement program surveyed the axial and circumferential uniformity of the flow at the inlet of a transonic wedge-type blading mounted in the device. Evaluation of the results showed the flow uniformity to be unsatisfactory. Leakage and other small perturbations in the flow field in the swirl generator are believed to be amplified by the basic flow configuration of the device.

  19. Modelling of horizontal centrifugal casting of work roll

    Science.gov (United States)

    Xu, Zhian; Song, Nannan; Tol, Rob Val; Luan, Yikun; Li, Dianzhong

    2012-07-01

    A numerical model to simulate horizontal centrifugal roll castings is presented in this paper. In order to simulate the flow fluid and solidification of horizontal centrifugal roll casting correctly, the model uses a body fitted mesh technique to represent the geometry. This new method maps a plate layer mesh to a circular mesh. The smooth body fitted mesh method gives more accurate calculation results for cylindrical geometries. A velocity depending on the angular velocity and inner radius of the mould is set up as a velocity boundary condition. The fluid flow coupled with heat transfer and solidification in a rapidly rotating roll is simulated. A gravity free falling method is applied as a pouring condition. A moveable pouring system is also used in the simulations. High speed steel is used to produce the work roll. Two different gating positions and a moveable gating system are simulated in this paper. Results show that the position of pouring system has a significant influence on the temperature distribution. The temperature distribution at a fixed central pouring system is more favourable than the distribution from a side pouring system. A moving gating system method is a better way to obtain a uniform temperature field in centrifugal casting and offers an alternative for existing techniques.

  20. Governing Principles of Alginate Microparticle Synthesis with Centrifugal Forces.

    Science.gov (United States)

    Eral, Huseyin Burak; Safai, Eric R; Keshavarz, Bavand; Kim, Jae Jung; Lee, Jisoek; Doyle, P S

    2016-07-19

    A controlled synthesis of polymeric particles is becoming increasingly important because of emerging applications ranging from medical diagnostics to self-assembly. Centrifugal synthesis of hydrogel microparticles is a promising method, combining rapid particle synthesis and the ease of manufacturing with readily available laboratory equipment. This method utilizes centrifugal forces to extrude an aqueous polymer solution, sodium alginate (NaALG) through a nozzle. The extruded solution forms droplets that quickly cross-link upon contact with aqueous calcium chloride (CaCl2) solution to form hydrogel particles. The size distribution of hydrogel particles is dictated by the pinch-off behavior of the extruded solution through a balance of inertial, viscous, and surface tension stresses. We identify the parameters dictating the particle size and provide a numerical correlation predicting the average particle size. Furthermore, we create a phase map identifying different pinch-off regimes (dripping without satellites, dripping with satellites, and jetting), explaining the corresponding particle size distributions, and present scaling arguments predicting the transition between regimes. By shedding light on the underlying physics, this study enables the rational design and operation of particle synthesis by centrifugal forces. PMID:27311392

  1. Subchronic centrifugal mechanical assist in an unheparinized calf model.

    Science.gov (United States)

    Wagner-Mann, C; Curtis, J; Mann, F A; Turk, J; Demmy, T; Turpin, T

    1996-06-01

    The purpose of this study was to determine whether the major centrifugal pumps currently in use in the United States (Medtronic, BioMedicus BioPump and Carmeda-coated BioPump, Sarns 3M centrifugal pump, and St. Jude Medical Lifestream) could function as left mechanical assist devices in the subchronic (72 h) unheparinized calf model. Calves were instrumented for left atrial to aorta ex vivo assist, and the pump flow was set at 3.5 +/- 0.4 L/min. Two calves (Sarns 3M and St. Jude) survived 72 h of pumping without clinical complications. The other 2 calves died at 62 and 66 h (Medtronic BioPump and Carmeda-coated BioPump, respectively); both had pelvic limb paralysis. The seal of the Sarns 3M pump head ruptured after approximately 36 h of pumping and required replacement. On postmortem examination, pump-associated thromboembolic lesions were detected in 3 of the 4 calves in one or more of the following organs: kidneys, pancreas, abomasum, duodenum, ileum, spleen, and lumbar spinal cord. The calf with the Sarns 3M pump had no discernable lesions. Because of the clinical abnormalities and postmortem lesions in the unheparinized calf model, it was suggested that anticoagulation is necessary for conducting centrifugal mechanical assist studies in calves using presently available technology.

  2. 斜极面交流接触器动态特性与优化设计研究%Research for dynamic characteristics and optimization design in inclined surface AC contactors

    Institute of Scientific and Technical Information of China (English)

    鲍光海; 张培铭

    2011-01-01

    ANSYS software is used to simulate the dynamic characteristics of flat surface AC contactor and the dynamic characteristics is tested by high-speed cameras to verify the correctness of the simulation results. The magnetic force characteristics of inclined surface AC contactor in different angles are calculated and the static characteristics with the flat surface AC contactor are compared. Finally, artificial fish swarm optimization algorithm is used based on genetic algorithm to optimize the design of the dynamic characteristics of inclined surface AC contactor. The optimization results show that the coil and core volume of inclined surface decrease greatly than that of the flat surface, and its dynamic characteristics is better than flat surface AC contactor.%采用ANSYS有限元软件对平极面铁心的交流接触器动态特性进行仿真计算并通过高速摄像机进行了机构动态特性的非接触测试验证,证明仿真计算的正确性.在此基础上计算了斜极面铁心交流接触器在不同斜角度下的吸力特性,对平极面交流接触器与斜极面交流接触器静态特性进行比较分析.最后采用基于遗传算法的人工鱼群优化算法对斜极面交流接触器进行动态优化计算,优化结果表明,斜极面交流接触器线圈、铁心的体积比平极面有大幅度的减小,而且其动态特性比平极面交流接触器更好.

  3. Recovery of ascorbic oxidoreductase from crude extract with an aqueous two-phase system in a perforated rotating disc contactor

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Figueiredo Porto

    2004-09-01

    Full Text Available A continuous perforated rotating disc contactor was used to extract the enzyme ascorbic oxidoreductase (E.C.1.10.3.3 from crude extract of Curcubita maxima with an aqueous two-phase system of poly (ethylene glycol and phosphate salts. The effect of dispersed phase velocity on either protein mass transfer coefficients or separation efficiency at 1, 2 and 3 mL/min was studied. An increase of the mass transfer coefficients was observed with the dispersed phase velocity, while the separation efficiency showed a small decrease with the increase of this parameter. The experimental results obtained during continuous extraction showed that the ascorbic oxidoreductase activity was partitioned preferentially into the salt-rich phase in all conditions studied. The best recovery of enzyme activity was 236%, with a purification factor of 34 in flow rates of 1 mL/min for dispersed phase.Uma coluna de discos perfurados rotativos foi utilizada na extração da enzima ascorbato oxidorredutase (E.C.1.10.3.3, obtida do extrato bruto de Curcubita maxima, através da utilização do sistema bifásico aquoso Polietilenoglicol-sais de fosfato. Os efeitos da velocidade da fase dispersa nos coeficientes de transferência de massa e na eficiência de separação para valores de 1, 2 e 3 mL/min foram estudados. Observou-se um aumento da transferência de massa com a velocidade da fase dispersa, enquanto que a eficiência de separação demonstrou uma ligeira redução com o aumento deste parâmetro. Os resultados experimentais obtidos durante a extração contínua demonstraram que a atividade da ascorbato oxidorredutase se concentrou preferencialmente na fase rica em sal para todas as condições estudadas. A maior recuperação da atividade enzimática foi de 236%, com um fator de purificação de 34 para o valor de 1 mL/min para a fase dispersa.

  4. Influence of blade angle distribution along leading edge on cavitation performance of a centrifugal pump

    Science.gov (United States)

    Xu, Y.; Tan, L.; Cao, S. L.; Wang, Y. C.; Meng, G.; Qu, W. S.

    2015-01-01

    The influence of blade angle distribution along leading edge on cavitation performance of centrifugal pumps is analysed in the present paper. Three sets of blade angle distribution along leading edge for three blade inlet angles are chosen to design nine centrifugal pump impellers. The RNG k-epsilon turbulence model and the Zwart-Gerber-Belamri cavitation model are employed to simulate the cavitation flows in centrifugal pumps with different impellers and the same volute. The numerical results are compared with the experimental data, and the comparison proves that the numerical simulation can accurately predict the cavitation performance of centrifugal pumps. On the basis of the numerical simulations, the pump head variations with pump inlet pressure, and the flow details in centrifugal pump are revealed to demonstrate the influence of blade angle distribution along leading edge on cavitation performances of centrifugal pumps.

  5. Enriched surface acidity for surfactant-free suspensions of carboxylated carbon nanotubes purified by centrifugation

    Directory of Open Access Journals (Sweden)

    Elizabeth I. Braun

    2016-06-01

    Full Text Available It is well known that surfactant-suspended carbon nanotube (CNT samples can be purified by centrifugation to decrease agglomerates and increase individually-dispersed CNTs. However, centrifugation is not always part of protocols to prepare CNT samples used in biomedical applications. Herein, using carboxylated multi-walled CNTs (cMWCNTs suspended in water without a surfactant, we developed a Boehm titrimetric method for the analysis of centrifuged cMWCNT suspensions and used it to show that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ∼40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems.

  6. Differentiating Central Centrifugal Cicatricial Alopecia and Androgenetic Alopecia in African American Men: Report of Three Cases

    OpenAIRE

    Davis, Erica C.; Reid, Sophia D.; Callender, Valerie D.; Sperling, Leonard C.

    2012-01-01

    Central centrifugal cicatricial alopecia is a scarring alopecia that is predominantly seen in African American women, but occurs less frequently in men. The authors present three cases of African American men with biopsy-proven central centrifugal cicatricial alopecia and detail the clinical presentation, histological findings, and treatment regimens. Central centrifugal cicatricial alopecia should be considered in the differential diagnosis when evaluating male patients with vertex hair loss...

  7. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    OpenAIRE

    Xu, Daming; LI, XIN; Geving AN

    2004-01-01

    Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force fi...

  8. Topological analysis of the formation of Jet-Wake flow pattern in centrifugal impeller channel

    Institute of Scientific and Technical Information of China (English)

    ZHENG Qun; LIU Shun-long

    2004-01-01

    Topological analyses are carried out for the numerical results of internal flow field in centrifugal impeller. Topological rules of the singular point characteristics of the limiting streamline are derived and used to determine three dimensional separation patterns in centrifugal impeller and to verify the numerical results. The results reveal that the wake is saddle to nodal closed separation and the formation, its onset point and its developing process of Jet-Wake Flow pattern in centrifugal impeller are presented in this paper.

  9. The Dynamics of Stall and Surge Behavior in Axial-Centrifugal Compressors

    OpenAIRE

    Cousins, William T.

    1997-01-01

    The phenomena of stall and surge in axial-centrifugal compressors is investigated through high-response measurements of both the pressure field and the flowfield throughout the surge cycle. A unique high-response forward-facing and aft-facing probe provides flow information. Several axial-centrifugal compressors are examined, both in compressor rigs and engines. Extensive discussion is presented on the differences in axial and centrifugal rotors and their effect on the system response char...

  10. Increasing the Stable Operating Range of a Fixed-Geometry Variable-Speed Centrifugal Compressor

    OpenAIRE

    Brasz, Joost J.

    2014-01-01

    Centrifugal compressors used on water-cooled chillers require stable operation over a wide range of flows at greatly varying pressure ratios. These operational requirements are dictated by variations in cooling demand and ambient conditions. Variable-speed centrifugal compressors are known to maintain their peak efficiency at the varying operating conditions much better than fixed-speed compressors. Replacing a fixed-speed centrifugal compressor with a variable speed one can reduce the annual...

  11. A New Optimization Method for Centrifugal Compressors Based on 1D Calculations and Analyses

    OpenAIRE

    Pei-Yuan Li; Chu-Wei Gu; Yin Song

    2015-01-01

    This paper presents an optimization design method for centrifugal compressors based on one-dimensional calculations and analyses. It consists of two parts: (1) centrifugal compressor geometry optimization based on one-dimensional calculations and (2) matching optimization of the vaned diffuser with an impeller based on the required throat area. A low pressure stage centrifugal compressor in a MW level gas turbine is optimized by this method. One-dimensional calculation results show that D3/D...

  12. Quantification of platelets obtained by different centrifugation protocols in SHR rats

    Directory of Open Access Journals (Sweden)

    João Alberto Yazigi Junior

    2015-12-01

    Full Text Available ABSTRACT OBJECTIVE: To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × gand 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g+ 200 ×g; 200 × g+ 400 × g; 200 × g+ 800 × g; 400 ×g+ 400 × g; 400 × g+ 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample. RESULTS: We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × gfor 10 min + 400 ×gfor 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group. CONCLUSION: It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.

  13. A REVIEW PAPER ON DEVELOPMENT OF IMPELLER OF CENTRIFUGAL PUMP USING COMPUTATIONAL FLUID DYNAMICS

    OpenAIRE

    Mr. Nilesh Nemgonda Patil

    2015-01-01

    Nowadays, the centrifugal pumps became very popular because of recent development of high speed electric motors, steam turbines etc.Centrifugal pumps can be single-stage or may be multistage pumps. It depends upon the number of impellers used in the pump. Single stage pump consists of only one impeller while in multistage pumps the impellers are mounted in the series in pumps. These Centrifugal pumps can be analyzed by software code like Computational Fluid Dynamics (CFD).This CFD...

  14. WATER RETENTION VALUE MEASUREMENTS OF CELLULOSIC MATERIALS USING A CENTRIFUGE TECHNIQUE

    OpenAIRE

    Jinxin Wang; Qingzheng Cheng; Joseph McNeel; Peter Jacobson

    2010-01-01

    A centrifugal method has been modified and applied to the assessment of water retention value (WRV) in cellulosic materials. Microcrystalline cellulose (MCC), small particles/fibrils isolated from MCC using high-pressure homogenizer, and pulp fibers saturated in water were centrifuged at different speeds and times with filter paper and/or a membrane acting as the filter in the WRV measurement setup. As centrifugal speed, time, and filter pore-size increased, lower WRVs were obtained. Smaller ...

  15. Medical incidences during centrifuge training and F-16 flying in the Netherlands

    OpenAIRE

    Holewijn, M.

    1996-01-01

    A survey in the NAMC database containing the records of centrifuge runs of candidate and experienced pilots revealed that in 15.1% of the centrifuge training sessions, a run was stopped. The major reasons were motion sickness (31%), fatigue (28%), and arrhythmias (22%). During centrifuge training at the NAMC the prevalence of an episode of supra ventricular ectopies was 33%. In 21% of the runs a ventricular ectopie occurred. In-flight ECG monitoring revealed that arrhythmias occurred in 62% o...

  16. Adiabatic field-free alignment of asymmetric top molecules with an optical centrifuge

    CERN Document Server

    Korobenko, A

    2015-01-01

    We use an optical centrifuge to align asymmetric top $\\mathrm{SO_2}$ molecules by adiabatically spinning their most polarizable O-O axis. The effective centrifugal potential in the rotating frame confines sulfur atoms to the plane of the laser-induced rotation, leading to the planar molecular alignment which persists after the molecules are released from the centrifuge. Periodic appearance of the full three-dimensional alignment, typically observed only with linear and symmetric top molecules, is also detected. Together with strong in-plane centrifugal forces, which bend the molecules by up to 10 degrees, permanent field-free alignment offers new ways of controlling molecules with laser light.

  17. High Order Centrifugal Distortion Corrections to Energy Levels of Asymmetric Top Molecules

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-Yan; LIU Xiao-Yong; LIU Hong-Ping; GUO Yuan-Qing; HUANG Guang-Ming; LIN Jie-Li; GAO Hui

    2000-01-01

    High order centrifugal distortion terms have been derived and added to the effective Hamiltonian of asymmetric top molecules. Based on this Hamiltonian, a program in Fortran 77 has been developed for spectral analysis of asymmetric top molecules. The high order centrifugal distortion terms are found to be non-negligible even for the low-lying rotational transitions of molecules, such as Ha 18O, subjected to severe centrifugal distortion effect,and for the high-lying rotational transitions of molecules, such as 14N16O2 subjected to the moderate centrifugal distortion effect.

  18. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    Directory of Open Access Journals (Sweden)

    Daming XU

    2004-08-01

    Full Text Available Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section prcision castings.

  19. Preparation of drug-in-cyclodextrin-in-liposomes at a large scale using a membrane contactor: Application to trans-anethole.

    Science.gov (United States)

    Gharib, Riham; Greige-Gerges, Hélène; Jraij, Alia; Auezova, Lizette; Charcosset, Catherine

    2016-12-10

    The present study aimed to prepare liposomes loaded with cyclodextrin/drug inclusion complexes at a pilot scale based on the ethanol injection technique. Anethole (ANE), a major component of anise and fennel essential oils, was used as a model of a volatile and highly hydrophobic drug. Membrane contactor (600mL) and a pilot plant (3L) were used for liposome production. The liposome preparations obtained were characterized for size, polydispersity index, zeta potential, morphology, stability and ANE release rate. All experimental set-ups were shown to be appropriate for the preparation of small, multilamellar vesicles with narrow size distribution and good stability at 4°C. The drug release study showed that only a small amount of ANE was released from liposome formulations after 21days of storage at 4°C. The loading rate of ANE was higher when ethanol was evaporated directly on the pilot plant compared to a rotary evaporation.

  20. Large-scale preparation of clove essential oil and eugenol-loaded liposomes using a membrane contactor and a pilot plant.

    Science.gov (United States)

    Sebaaly, Carine; Greige-Gerges, Hélène; Agusti, Géraldine; Fessi, Hatem; Charcosset, Catherine

    2016-01-01

    Based on our previous study where optimal conditions were defined to encapsulate clove essential oil (CEO) into liposomes at laboratory scale, we scaled-up the preparation of CEO and eugenol (Eug)-loaded liposomes using a membrane contactor (600 mL) and a pilot plant (3 L) based on the principle of ethanol injection method, both equipped with a Shirasu Porous Glass membrane for injection of the organic phase into the aqueous phase. Homogenous, stable, nanometric-sized and multilamellar liposomes with high phospholipid, Eug loading rates and encapsulation efficiency of CEO components were obtained. Saturation of phospholipids and drug concentration in the organic phase may control the liposome stability. Liposomes loaded with other hydrophobic volatile compounds could be prepared at large scale using the ethanol injection method and a membrane for injection.