International Nuclear Information System (INIS)
Conn, R.W.
1984-05-01
Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6MW of auxiliary neutral beam heating. Experiments have also been done with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a region may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this Z-mode of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described
International Nuclear Information System (INIS)
Conn, R.W.; California Univ., Los Angeles
1984-01-01
Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scrape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this 'Z-mode' of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described. (orig.)
International Nuclear Information System (INIS)
Sonnenberg, K.; Deksnis, E.; Shaw, R.; Reiter, D.
1988-01-01
JET plans to install two pump limiter modules which can be used for belt-limiter, inner-wall and X-point discharges and, also, for 1-2s as the main limiter. A design is presented which is compatible with two diagnostic systems, and which allows partial removal of the pump limiter to provide access for remote-handling operations. The high heat-flux components are initially cooled during a pulse. Heat is removed between discharges by radiation and pressure contacts to a water-cooled support structure. The pumping edge will be made of annealed pyrolytic graphite. Exhaust efficiency has been estimated, for a 1-d edge model, using a Monte-Carlo calculation of neutral gas transport. When the pump limiter is operated together with other wall components we expect an efficiency of ≅ 5% (2.5 x 10 21 part/s). As a main limiter the efficiency increases to about 10%. (author)
Effect of pump limiter throat on pumping efficiency
International Nuclear Information System (INIS)
Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.
1988-01-01
The necessary control of plasma edge density has led to the development of pump limiters to achieve this task. On Tore Supra, where a large part of the program is devoted to plasma edge studies, two types of such density control apparatus have been implemented, a set of pump limiters and the pumps associated to the ergodic divertor (magnetically assisted pump limiters). Generally two different kinds of pump limiters can be used, those with a throat which drives the plasma from the open edge plasma (SOL) to the neutralizer plate, and those without or with a very short throat. We are interested here in this aspect of the pump limiter concept, i.e. on the throat effect on neutral density build-up in the vicinity of the pumping plates (and hence on pumping efficieny). The underlying idea of this throat effect can be readily understood; indeed while the neutral capture in pump limiters without throats is only a ballistic effect, on expects the plasma to improve the efficiency of pump-limiters via plasma-neutral-sidewall interactions in the throat. This problem has been studied both numerically and analytically. The paper is divided as follows. In section 2, we describe the basic features of pump-limiters which are modelized by the numerical code Cezanne. Section 3 is devoted to the throat length effect considering in particular the neutral density profile in the throat and the neutral density buil-up as a function of the throat lenght. In section 4, we show that the plugging effect occurs for reasonnable values of throat lengths. An analytical value of the plugging length is discussed and compared to the values obtained numerically
ALT-I pump limiter experiments
International Nuclear Information System (INIS)
Goebel, D.M.; Conn, R.W.; Campbell, G.A.
1987-09-01
Results from the ALT-I pump limiter experiments in TEXTOR are presented. ALT-I has demonstrated control of the plasma density in a high recycling tokamak by pumping up to 15% of the core efflux. The closed pump limiter designs with restricted entrance geometries to reduce the backflow of neutral gas to the plasma remove over 50% of the ion flux incident on the collection slot. Up to 80% of the entrance ion flux is removed when the edge electron temperature is less than 10 eV and plasma-neutral gas interactions are minimized inside the limiter. Results from a 3-D Monte Carlo neutral gas transport code agree closely with these experimental results. The compound curvature of the head is found to distribute the heat over the surface as predicted in the original designs. Impurity removal experiments demonstrate that significant helium exhaust can be achieved with a pump limiter. During ohmic heating in TEXTOR, the energy and particle confinement times are proportional to the line averaged core density. With ICRH auxiliary heating, tau/sub E/ follow L-mode scaling independent of particle removal by the pump limiter. Pump limiter operation does not directly modify the SOL plasma density and electron temperature, but controls the core plasma density by changing the global recycling at the boundary. The global particle confinement, the particle flux to the limiter, and the edge electron temperature follow the changes in the core density and auxiliary heating power. 25 refs
Pump limiter studies in Tore Supra
International Nuclear Information System (INIS)
Chatelier, M.; Bonnel, P.; Bruneau, J.L.; Gil, C.; Grisolia, C.; Loarer, T.; Martin, G.; Pegourie, B.; Rodriguez, L.
1991-01-01
The aim of the Tore Supra pump limiter program is to study particle exhaust with a pump limiter system in long-pulse discharges with continuous pellet fueling and strong auxiliary heating. The pump limiter system consists of six vertical modules, located at the bottom of the machine, and one horizontal module at the outer midplane. The instrumentation of the limiter included pressure gauges, a residual gas analyser Langmuir probes, a spectrometer and water calorimeters. Initial results in low-density discharges, with the outboard limiter only, showed a modest effect on the plasma density, while large exhaust fluxes were measured in the pump limiter, without any external fueling
Pump limiter experiment in the TFR tokamak
International Nuclear Information System (INIS)
Anon.
1987-01-01
Pump limiter experiments are carried out in the TFR Tokamak. The first TFR pump limiter is located in the outer part of the torus, its double-throat head is made of graphite tiles, the neutralizer plates are made of stainless steel, and it is pumped by a 3500 l s -1 titanium sublimation pump. The first attempts showed that the exhaust efficiency ε of this pump limiter was low (1.5% of the total plasma particle efflux). To improve on these results, a new limiter head with a single longer throat has been built. The particles were better trapped and the pumping achieved an important decrease of the recycling coefficient. Geometric features and also the highly non linear regime of pressure in the pump limiter as a function of the density at the entrance slot could explain the increase by a factor 3.5 of the exhaust efficiency (ε = 5%). Ion temperatures of the order of a few eV have been deduced from Doppler broadening measurements at the neutralizer plate of the pump limiter. (orig.)
Tokamak advanced pump limiter experiments and analysis
International Nuclear Information System (INIS)
Conn, R.W.
1983-06-01
Experiments with pump limiter modules on several operating tokamaks establish such limiters as efficient collectors of particles and has demonstrated the importance of ballistic scattering as predicted theoretically. Plasma interaction with recycling neutral gas appears to become important as the plasma density increases and the effective ionization mean free path within the module decreases. In limiters with particle collection but without active internal pumping, the neutral gas pressure is found to vary nonlinearly with the edge plasma density at the highest densities studies. Both experiments and theory indicate that the energy spectrum of gas atoms in the pump ducting is non-thermal, consistent with the results of Monte Carlo neutral atom transport calculations. The distribution of plasma power over the front surface of such modules has been measured and appears to be consistent with the predictions of simple theory. Initial results from the latest experiment on the ISX-B tokamak with an actively pumped limiter module demonstrates that the core plasma density can be controlled with a pump limiter and that the scrape-off layer plasma can partially screen the core plasma from gas injection. The results from module pump limiter experiments and from the theory and design analysis of advanced pump limiters for reactors are used to suggest the major features of a definitive, axisymmetric, toroidal belt pump limiter experiment
FED pumped limiter configuration issues
International Nuclear Information System (INIS)
Haines, J.R.; Fuller, G.M.
1983-01-01
Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge
FED pumped limiter configuration issues
International Nuclear Information System (INIS)
Haines, J.R.; Fuller, G.M.
1983-01-01
Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge
TFCX pumped limiter and vacuum pumping system design and analysis
International Nuclear Information System (INIS)
Haines, J.R.
1985-04-01
Impurity control system design and performance studies were performed in support of the Tokamak Fusion Core Experiment (TFCX) pre-conceptual design. Efforts concentrated on pumped limiter and vacuum pumping system design configuration, thermal/mechanical and erosion lifetime performance of the limiter protective surface, and helium ash removal performance. The reference limiter design forms a continuous toroidal belt at the bottom of the device and features a flat surface with a single leading edge. The vacuum pumping system features large vacuum ducts (diameter approximately 1 m) and high-speed, compound cryopumps. Analysis results indicate that the limiter/vacuum pumping system design provides adequate helium ash removal. Erosion, primarily by disruption-induced vaporization and/or melting, limits the protective surface lifetime to about one calendar year or only about 60 full-power hours of operation. In addition to evaluating impurity control system performance for nominal TFCX conditions, these studies attempt to focus on the key plasma physics and engineering design issues that should be addressed in future research and development programs
International Nuclear Information System (INIS)
Alessandrini, C.; Ciotti, M.; Mattei, A. De; Maddaluno, G.; Mazzitelli, G.
1989-01-01
The control of the refuelling and recycling of the plasma is crucial in providing enhanced performances in tokamaks and steady-state operation in future reactors. In this paper, we report details of the design and analysis for the pump limiter to be incorporated into the FTU tokamak. The FTU, presently under commissioning, is a compact high field (B=8T), medium high density, circular cross section machine with small accesses. The dimensions of the equatorial port (width 8 cm) would reduce the length of the entrance throat to a few centimeters, which is unacceptable for efficient particle trapping. We have, therefore, designed a rotating blade of the pump limiter head that, in the working position, extends in the toroidal direction inside the vacuum chamber. (author) 8 refs., 4 figs
Particle removal with pump limiters in ISX-B
International Nuclear Information System (INIS)
Mioduszewski, P.; Emerson, L.C.; Simpkins, J.E.
1983-01-01
First pump limiter experiments were performed on ISX-B. Two pump limiter modules were installed in the top and bottom of one toroidal sector of the tokamak. The modules consist of inertia cooled, TiC coated graphite heads and Zr-Al getter pumps each with a pumping speed of 1000 to 2000 l/s. The objective of the initial experiments was the demonstration of plasma particle control with pump limiters. The first set of experiments were performed in ohmic discharges (OH) in which the effect of the pump limiters on the plasma density was clearly demonstrated. In discharges characterized by: I/sub p/ = 110 kA, B/sub T/ = 15 kG, anti n/sub e/ = 1 - 5 x 10 13 cm -3 and t = 0.3 s the pressure rise in the pump limiters was typically 2 mTorr with the pumps off and 0.7 mTorr after activating the pumps. When the pumps were activated, the line-average plasma density decreased by up to a factor 2 at identical gas flow rates. The second set of measurements were performed in neutral beam heated discharges (NBI) with injected powers between 0.6 MW and 1.0 MW. Due to a cooling problem on one of the Zr-Al pumps the NBI experiments were carried out with one limiter only. The maximum pressure observed in NBI-discharges was 5 mTorr without activating the pumps, i.e., approximately twice as high as in OH-discharges. The exhaust efficiency, which is defined as the removed particle flux over the total particle flux in the scrape-off layer is estimated to be 5%
Modular pump limiter systems for large tokamaks
International Nuclear Information System (INIS)
Uckan, T.; Klepper, C.C.; Mioduszewski, P.K.; McGrath, R.T.
1987-09-01
Long-pulse (>10-s) operation of large tokamaks with high-power (>10-MW) heating and extensive external fueling will require correspondingly efficient particle exhaust for density control. A pump limiter can provide the needed exhaust capability by removing a small percentage of the particles, which would otherwise be recycled. Single pump limiter modules have been operated successfully on ISX-B, PDX, TEXTOR, and PLT. An axisymmetric pump limiter is now being installed and will be studied in TEXTOR. A third type of pump limiter is a system that consists of several modules and exhibits performance different from that of a single module. To take advantage of the flexibility of a modular pump limiter system in a high-power, long-pulse device, the power load must be distributed among a number of modules. Because each added module changes the performance of all the others, a set of design criteria must be defined for the overall limiter system. The design parameters for the modules are then determined from the system requirements for particle and power removal. Design criteria and parameters are presented, and the impact on module design of the state of the art in engineering technology is discussed. The relationship between modules are considered from the standpoint of flux coverage and shadowing effects. The results are applied to the Tore Supra tokamak. A preliminary conceptual design for the Tore Supra pump limiter system is discussed, and the design parameters of the limiter modules are presented. 21 refs., 12 figs
Results from the DITE pump-limiter experiment
International Nuclear Information System (INIS)
Johnson, P.C.; Fielding, S.J.; Matthews, G.F.; Pitts, R.; Pritchard, J.; Vayakis, G.
1989-01-01
Experiments have been carried out on the DITE tokamak with a large poloidal pump limiter of a relatively simple design. A particle exhaust into the pump limiter of 6% of the total particle flux leaving the plasma has been achieved. (orig.)
Thermal fracture and pump limit of Nd: glass
International Nuclear Information System (INIS)
Wang Mingzhe; Ma Wen; Tan Jichun; Zhang Yongliang; Li Mingzhong; Jing Feng
2011-01-01
Based on published fracture experiments and 3D transient finite-element analyses, and taking the first principal stress as the criterion and the Griffith crack theory to determine the critical fracture stress, a Weibull statistical model is established to predict the fracture possibility of Nd: glass with certain pump parameters. Other issues which limit the pump power are also presented. The results show that the fracture limit of laser medium depends on the optical polishing technology. For a short pulse and high energy Nd: glass laser, taking America's polishing technology in the 1990s as reference,the pump saturation limits the pump power to 18 kW/cm 2 when the repetition rate is lower than 1 Hz, while the thermal fracture limits the pump power when the repetition rate is higher than 10 Hz. (authors)
Vacuum physics analysis of HT-7 superconducting tokamak pump limiter
International Nuclear Information System (INIS)
Hu Jiansheng; Li Chengfu; He Yexi
1998-10-01
The pump limiter is analysed with HT-7 superconducting tokamak parameter and the pump limiter construction. The particle exhaust of the pump limiter can be to achieve about 7.7%. So the pump limiter can be applied in the HT-7 device and will make good affection in plasma discharge
First pump limiter experiments in Tore Supra
International Nuclear Information System (INIS)
Chatelier, M.; Bruneau, J.L.; Chappuis, P.; Gil, C.; Guilhem, D.; Lipa, M.; Rodriguez, L.; Vallet, J.C.; Van Houtte, D.; Watkins, J.G.
1989-01-01
The thermal load and the particle pumping effects on the outboard pump limiters (OPL), in Tore Supra are analyzed. The investigations are performed for the plasma either in contact with the OPL/ONPL (outboard non pumped limiters) alone or with the OPL and the vertical limiters together. Calorimetric measurements provide estimates of the time-integrated balance of the energy flow at the plasma edge. Radiated and charge exchange energy losses are deduced from the inner vessel calorimetry (R=242cm, a=94cm). Conductive/convective losses on the OPL and vertical (top and bottom) limiters are independently measured, as well as the integrated energy flow on the ergodic divertors. The calorimetric results, the bolometric measurements of the radiated power and the Ohmic power estimates, are indicated. The central line density from interferometric measurement for the two successive shots, with the ONPL and with the OPL, are given
International Nuclear Information System (INIS)
Schultz, J.H.
1981-01-01
The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure
International Nuclear Information System (INIS)
Schultz, J.H.
1981-01-01
The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topologies are suggested which allow high erosion without limiter failure
Scrape-off profiles and effects of limiter pumping in Tore Supra
International Nuclear Information System (INIS)
Budny, R.
1986-11-01
A one dimensional plasma scrape-off model was used to simulate Tore Supra discharges which are limited by various combinations of the pumped and inner limiters. Scrape-off profiles of the electron density and temperature, ion temperature, and neutral density are given. For each case, various fractions of the ion flux to the neutralizers were assumed to be pumped. Modifications of the scrap-off profiles caused by pumping are predicted. Pumping efficiencies are calculated including the effects of flux amplification caused by recycling. The pumping efficiency is estimated to be 8% for low-power discharges formed on the outer pumped limiter, 7.5% for intermediate-power discharges formed on the seven-module pumped-limiter system, and 5% for full-power discharges formed on both the inner limiter and the pumped-limiter system. The maximum particle removal rate is estimated to be 150 Tl/s
Particle exhaust studies in Tore Supra with a pump limiter
International Nuclear Information System (INIS)
Klepper, C.C.; Haste, G.R.; Horton, L.D.; Mioduszewski, P.K.; Uckan, T.; Bonnel, P.; Bruneau, J.L.; Chatelier, M.; Gil, C.; Grisolia, C.; Loarer, T.; Martin, G.; Pegourie, B.; Rodriguez, L.; Watkins, J.G.
1990-01-01
The aim of the Tore Supra pump limiter program is to study particle exhaust with a pump limiter system in long-pulse discharges with continuous pellet fueling and strong auxiliary heating. The pump limiter system consists of six vertical modules, located at the bottom of the machine, and one horizontal module at the outer midplane. The results presented here were obtained with the horizontal module only. This module was equipped with two titanium pumps with a total pumping speed of 100000 L/s. The instrumentation of the limiter included pressure gauges, a residual gas analyzer, Langmuir probes, a spectrometer viewing the neutralizer plate for H α and impurity measurements, and water calorimeters. All diagnostics have been commissioned and are operational. Initial results were obtained in low-density discharges, with no gas puffing during the shot. While only a modest effect on the plasma density was observed, large exhaust fluxes were measured in the pump limiter. The most likely source of this gas was outgassing of the graphite walls. Straightforward particle balance between the plasma efflux and the pump limiter exhaust, as applied in previous pump limiter experiments, did not apply. The core plasma and the edge plasma seemed to be largely decoupled and a multi-layer model is being developed to explain the experimental results. (orig.)
First pump limiter experiments in TORE SUPRA
International Nuclear Information System (INIS)
Chatelier, M.; Klepper, C.C.; Bruneau, J.L.; Chappuis, P.; Gil, C.; Guilhem, D.; Lipa, M.; Rodriguez, L.; Vallet, J.C.; Van Houtte, D.; Watkins, J.G.
1989-01-01
The operation of TORE SUPRA at full power (25MW, 30s) has led to the design of a full set of actively pumped carbon limiters to remove at least 8MW and to partially control the particle balance. An interim version is now installed, composed of 5 vertical and one horizontal outboard (OPL) pump limiters, semi-inertially water cooled. The latter is a result of a collaboration between the US DOE and the Association EUR-CEA, it is fully instrumented and therefore can serve as a reference for the final design. Ohmic discharges (1.85T, 740kA, 8.5s) in helium have been used to test the thermal load on and the particle exhaust efficiency of the OPL. In these experiments the plasma is formed on the inner wall (R = 232 cm, a = 76 cm) and subsequently displaced (6 cm) outward, early on the current plateau, to lean on the OPL (R = 238 cm, a = 75 cm). In addition to the limiters above, a non-pumped outboard (ONLP) limiter of identical shape to the OPL served to produce similar discharges for better comparison and determination of particle control. A comparison is made hereafter of the thermal load and particle pumping effects on the OPL when the plasma is in contact either with the OPL/ONPL alone or with the OPL and the vertical limiters together. 3 refs., 1 fig., 2 tabs
The preliminary studies of HL-1 plasma with pump limiter
International Nuclear Information System (INIS)
Ran, L.B.; Li, G.D.; Sum, S.Q.
1991-01-01
Reduction of the impurity and control of the density are very important task in the present tokamak research. Some experiments showed that the pump limiter is effective to improve impurity and density control. A small-scale pump limiter has been installed on HL-1 tokamak in 1990 and the experiment has been carried out firstly with hydrogen ohmic discharge. In this paper we would present the improvements of the plasma properties as the pump limiter was main limiter and the movable limiter was auxiliary limiter. (author) 3 refs., 8 figs
Detailed Balance Limit of Efficiency of Broadband-Pumped Lasers.
Nechayev, Sergey; Rotschild, Carmel
2017-09-13
Broadband light sources are a wide class of pumping schemes for lasers including LEDs, sunlight and flash lamps. Recently, efficient coupling of broadband light to high-quality micro-cavities has been demonstrated for on-chip applications and low-threshold solar-pumped lasers via cascade energy transfer. However, the conversion of incoherent to coherent light comes with an inherent price of reduced efficiency, which has yet to be assessed. In this paper, we derive the detailed balance limit of efficiency of broadband-pumped lasers and discuss how it is affected by the need to maintain a threshold population inversion and thermodynamically dictated minimal Stokes' shift. We show that lasers' slope efficiency is analogous to the nominal efficiency of solar cells, limited by thermalisation losses and additional unavoidable Stokes' shift. The lasers' power efficiency is analogous to the detailed balance limit of efficiency of solar cells, affected by the cavity mirrors and impedance matching factor, respectively. As an example we analyze the specific case of solar-pumped sensitized Nd 3+ :YAG-like lasers and define the conditions to reach their thermodynamic limit of efficiency. Our work establishes an upper theoretical limit for the efficiency of broadband-pumped lasers. Our general, yet flexible model also provides a way to incorporate other optical and thermodynamic losses and, hence, to estimate the efficiency of non-ideal broadband-pumped lasers.
The Advanced Limiter Test-I (ALT-I) variable-geometry pump limiter module
International Nuclear Information System (INIS)
Pontau, A.E.; Malinowski, M.E.; Ver Berkmoes, A.A.; Guthrie, S.E.; Watson, R.D.; Goebel, D.M.; Campbell, G.A.
1984-01-01
The ALT-I variable geometry module has been designed to address many of the issues not previously settled by earlier experiments. The goal is to study the basic processes involved in pump limiter operation as well as demonstrate its utility and effect on the plasma. The flexibility and extensive instrumentation of ALT-I will offer a unique opportunity to parameterize operation and facilitate the engineering design of future pump limiters. (orig.)
Designs for a TFTR full-power pumped limiter
International Nuclear Information System (INIS)
Budny, R.
1986-10-01
A pumped-limiter system which would provide increased particle control and enhance the performance of full-power discharges is being considered for TFTR. The system consists of two toroidal belts located near the Zirconium-Aluminium (ZrAl) getter panels. The limiter blades would be made of carbon/carbon composite in order to have a very thin profile, allowing a large fraction of the scrape-off flux to be pumped. Simulations of the plasma scrape-off and neutral transport indicate that the limiter pumping should reduce the recycling coefficient by 10 to 25%. Simulations of central plasma processes indicate that the lowered recycling could increase Q/sub fusion/ by more than 100%. This paper discusses the designs and the performance predictions for the system
Role of the pump limiter throat-ergodic divertor effect on edge plasma
International Nuclear Information System (INIS)
Grosman, A.; Samain, A.; Ghendrih, P.; Capes, H.; Morera, J.P.
1988-01-01
A large part of the Tore Supra programme is devoted to plasma edge studies. Two types of such density control apparatus have been implemented, a set of pumps limiters and the ergodic divertor. The goal of the present paper is to investigate the effect of the pump limiter throat on pumping efficiency. We present also the possibilities of the ergodic divertor device to facilitate plasma pumping and power exhaust
An analytical model for neutral and charged particles in closed pump limiter
International Nuclear Information System (INIS)
Tokar, M.Z.
1990-01-01
In number of modern tokamaks pump limiters are used for control of the edge plasma parameters. In thermonuclear reactor projects pump limiters are considered as a possible alternative or additional for divertor configuration of magnetic field method for unburnt fuel, helium ash and other impurity exhaust. From the point of view of limiter operation efficiency the dependence of neutral particle pressure P g in pumping system on the plasma parameters in the scrape-off layer (SOL) is of importance since an increase of P g will permit to decrease needed pump rate and facilitate solution of reactor technological problems. In connection with this the experimentally observed mode of closed pump limiter operation with strong neutral compression is of great interest. In such a mode P g sharply grows up when the SOL plasma density n s exceeds some critial level. (author) 6 refs., 2 figs
Effect of the self-pumped limiter concept on the tritium fuel cycle
International Nuclear Information System (INIS)
Finn, P.A.; Sze, D.K.; Hassanein, A.
1988-01-01
The self-pumped limiter concept was the impurity control system for the reactor in the Tokamak Power Systems Study (TPSS). The use of a self-pumped limiter had a major impact on the design of the tritium systems of the TPSS fusion reactor. The self-pumped limiter functions by depositing the helium ash under a layer of metal (vanadium). The majority of the hydrogen species are recycled at the plasma edge; a small fraction permeates to the blanket/coolant which was lithium in TPSS. Use of the self-pumped limiter results in the elimination of the plasma processing system. Thus, the blanket tritium processing system becomes the major tritium system. The main advantages achieved for the tritium systems with a self-pumped limiter are a reduction in the capital cost of tritium processing equipment as well as a reduction in building space, a reduced tritium inventory for processing and for reserve storage, an increase in the inherent safety of the fusion plant and an improvement in economics for a fusion world economy
Pumped-limiter study for Alcator DCT
International Nuclear Information System (INIS)
Brooks, J.N.; Mattas, R.F.; Cha, Y.S.; Hassanein, A.M.; Majumdar, S.
1983-06-01
A study was performed for a pumped-limiter design for the proposed Alcator DCT device. The study focused on reactor-relevant issues. The main issues examined were configuration, surface erosion, thermal hydraulics, and the choice of structural and surface materials. A bottom, flat limiter, with a copper-alloy substrate, seems to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon is recommended as a surface material if acceptable redeposition properties can be demonstrated
Pumped-limiter study for Alcator DCT
Energy Technology Data Exchange (ETDEWEB)
Brooks, J.N.; Mattas, R.F.; Cha, Y.S.; Hassanein, A.M.; Majumdar, S.
1983-06-01
A study was performed for a pumped-limiter design for the proposed Alcator DCT device. The study focused on reactor-relevant issues. The main issues examined were configuration, surface erosion, thermal hydraulics, and the choice of structural and surface materials. A bottom, flat limiter, with a copper-alloy substrate, seems to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon is recommended as a surface material if acceptable redeposition properties can be demonstrated.
ALT-I pump limiter results on TEXTOR
International Nuclear Information System (INIS)
Dippel, K.H.; Finken, K.H.; Guthrie, S.E.; Malinowski, M.E.; Pontau, A.E.; Campbell, G.A.; Goebel, D.M.; Conn, R.W.
1985-01-01
The ALT-I pump limiter is used to control hydrogen fluxes from the TEXTOR tokamak. The performance of two different modules, the open fixed geometry (FG) and the closed variable geometry (VG) is discussed. In unpumped scoop limiter operation, the pressure in the ALT-I chamber increases to 3x10 -4 torr(FG) and 2x10 -3 torr(VG). With pumping, the fraction of particles incident on the neutralizer plate that is removed is 25-50%(FG) and 50-80%(VG). These removed particles are estimated to be 2-4(8)%(FG) and 6-13%(VG) of the total plasma outflux (Nsub(e)/tausub(p)). The collection of helium from the plasma using the FG module is approximately half as effective as hydrogen collection. The higher particle removal efficiency for the VG module is attributed to lower neutral backstreaming. (author)
Plasma influence on throat conductance of the TEXTOR pump limiter ALT-I
International Nuclear Information System (INIS)
Hardtke, A.; Finken, K.H.; Reiter, D.; Dippel, K.H.; Goebel, D.M.; McGrath, R.T.; Sagara, A.
1989-01-01
On the TEXTOR pump limiter ALT-I conductance measurements for the backstreaming of gas from the pump limiter vessel through the pump limiter entrance have been performed. In these experiments neutral gas has been injected into the pump limiter plenum during a short pulse. The influence of the instreaming plasma results in a reduction of the conductance of the outstreaming gas. For helium the conductance is reduced to about 40% of the molecular conductance when a plasma flux of 0.8 A/cm 2 (T e =T i =11 eV) is streaming into the pump limiter throat. The reduction of the conductance for backstreaming hydrogen and deuterium under the same plasma conditions is smaller; about 70% of the molecular conductance is obtained. This reduction can be explained by an increased recycling of ions which have been produced in the throat back to the neutralizer plate. The experimental results can be reproduced by Monte Carlo neutral transport code calculations if the recycling coefficient is about 0.85 for hydrogen and deuterium and about 0.95 for helium ions. Processes causing these high recycling coefficients are discussed and their influence is estimated. (orig.)
A vented pump limiter for the reversed field pinch RFX
International Nuclear Information System (INIS)
Sonato, P.
1998-01-01
The reversed field pinch (RFP) plasma performance, as in the Tokamak, is strongly correlated with the edge neutral particle control. The drawbacks of the conventional magnetic divertors and throat limiters on the RFP plasma have slackened the application of an active particle control system in existing devices. An advanced solution, based on the idea of the 'vented pump limiter' experimented on Tore Supra, has been conceived for RFX. This type of pump limiter is very attractive for a RFP. In this paper, the design of a 'vented limiter' prototype for RFX is presented. Up to six modules of this limiter can be installed at the equatorial plane of RFX, allowing a particle exhaust efficiency comparable with a divertor or a throat limiter working in a Tokamak. Finally, the optimization of this concept for the next step RFP device is presented. (orig.)
Plugging regime in the pump limiter throat
International Nuclear Information System (INIS)
Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.
1988-08-01
The plugging regime -with no outstreaming neutral flux- is studied for a closed configuration pump limiter (throat). We derive the plugging length and the neutral density build-up at the neutralizer plate. The analytical expressions are supported by numerical evidence. We find an improved efficiency related to the throat effect mainly due to neutral-sidewall interactions
International Nuclear Information System (INIS)
Hitoki, Shigehisa; Sugihara, Masayoshi; Saito, Seiji; Fujisawa, Noboru
1985-01-01
A detailed calculation of the behavior of fuel and He particles in tokamak reactor with pumped-limiter is performed by one-dimensional tokamak transport code. Energy of neutral particles flowing back from limiter chamber is calculated by two-dimensional Monte Carlo neutral code. Feasibility of He ash exhaust and heat removal by the pumped-limiter are analyzed. Following features of the pumped-limiter are clarified: (1) Electron temperature decays rapidly in radial direction in scrape-off layer, while density profile is broader than that of temperature. (2) Helium accumulation in main plasma can be kept at desired level by rather short limiter and moderate pumping system. (3) Minimum amount of tritium pumped out little depends on limiter length. (4) Although high temperature plasma in scrape-off layer could be realized by large pumping and ideal pellet injection, it is not sufficiently high to reduce the erosion of the limiter surface and the leading edge. In conclusion, He ash exhaust may be possible by the pumped-limiter, while the heat load and erosion will be so high that the pumped-limiter may not be applicable unless the boundary plasma is cooled by radiation or by some other means. (author)
Edge plasma control: Particle channeling in Tore Supra pump limiter and ergodic divertor
International Nuclear Information System (INIS)
Ghendrih, P.; Samain, A.; Grosman, A.; Capes, H.; Morera, J.P.
1989-01-01
Improved pumping efficiency can be achieved on Tore Supra by channeling process for particles, i.e. channeling of neutrals in the throat of pump limiters and channeling of plasma towards neutralizer plates in the ergodic divertor. The plugging length for the pump limiter throat is computed and numerical evidence of plasma flux channeling between the conductor bars of the ergodic divertor is presented. The effect of the Tore Supra ergodic divertor on edge plasma state and edge plasma transport is discussed. (orig.)
Reduction of recycling by pumping at the PDX limiter
International Nuclear Information System (INIS)
Cecchi, J.L.; Knize, R.J.; Dylla, H.F.; Fonck, R.J.; Owens, D.K.; Sredniawski, J.J.
1983-02-01
We have installed two arrays of Zr-Al getters adjacent to the PDX limiter to affect the pumping of neutrals formed in this region. The projected area of the getters is approximately 0.4% of the plasma area, and the measured H 2 pumping speed is 16,000 l/sec. During ohmic discharges, the getters reduced the electron density decay time from 340 to 180 msec. This result, combined with H/sub α'/ data indicates that the recycling coefficient decreases by 10% or more
Reduction of recycling by pumping at the PDX limiter
Energy Technology Data Exchange (ETDEWEB)
Cecchi, J.L.; Knize, R.J.; Dylla, H.F.; Fonck, R.J.; Owens, D.K. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Sredniawski, J.J. (Grumman Aerospace Corp., Bethpage, NY (USA))
We have installed two arrays of Zr-Al getters adjacent to the PDX limiter to effect the pumping of neutrals formed in this region. The projected area of the getters is approximately 0.4% of the plasma area, and the measured H/sub 2/ pumping speed is 16000 l/s. During ohmic discharges, the getters reduced the electron density decay time from 340 to 180 ms. This result, combined with Hsub(..cap alpha..), data indicates that the recycling coefficient decreases by 10% or more.
Tritium system for a tokamak reactor with a self-pumped limiter
International Nuclear Information System (INIS)
Hassanein, A.M.; Sze, D.K.
1986-01-01
Benefits of the self-pumping system are the elimination of vacuum ducts, pumps, and penetration shielding (except for a very small startup system), and the reduction of tritium recycle and refueling. In addition, a self-pumped system may perform better and last longer than alternative systems such as a pumped limiter. The reference case here is a self-cooled lithium/vanadium blanket with a first wall/limiter. This concept combines the functions of first wall and limiter into a single first-wall structure. The wall is shaped in accordance with the outermost plasma flux surface. Trapping material is added to the plasma scrape-off or edge region where it is transported to the wall. The entire wall area is used for helium trapping. The tritium inventory, tritium permeation rate, and plasma protium concentration for the vanadium wall as a function of the number of years of operation are calculated. The tritium inventory is acceptable, the protium concentration in the plasma is acceptably small, and the tritium permeation rate is moderate. At the start of operation, it is equal to about five times the tritium burnup rate. This tritium will enter the coolant and the cost of the blanket tritium recovery system will be higher
Power deposition to the pump limiters in Tore-Supra with ohmic plasmas
International Nuclear Information System (INIS)
Guilhem, D.; Chatelier, M.; Chappuis Fleury, I.; Klepper, C.
1990-01-01
The modification of power scrape-off-length, λq, and power deposition are studied both with the horizontal limiter alone and with the full set of 7 pump limiters for 1MW ohmic plasmas in TORE-SUPRA. By making spatially resolved infrared surface temperature measurements during the plasma discharge, the magnitude and distribution of the energy flux can be derived. For comparison, the surface temperature of the horizontal pump limiter is calculated with a finite element code using a 3D description of the field lines, an exponential scrape-off-layer, and the pump limiter geometry. From comparison of the infrared images of the limiter we derived that the λq for power deposition was slightly less than 9 mm (±1mm) which is in agreement with the predicted design value of 10 mm. For an 8 seconds discharge, the maximum surface temperature on the horizontal limiter is 450 0 C. Inserting the 7 limiters does not modify λq (which becomes 10 mm). The power is shared by all the limiters and the maximum surface temperature on the horizontal limiter decreased to 320 0 C. These λq values have been independently measured by the integrated energy deposition on the horizontal limiter and other internal structures 5 cm into the scrape-off layer. These values agree with the infrared measurements in the two cases
Pump-beam-instability limits to Raman-gain-doublet ''fast-light'' pulse propagation
International Nuclear Information System (INIS)
Stenner, Michael D.; Gauthier, Daniel J.
2003-01-01
We investigate the behavior of a system for generating ''fast-light'' pulses in which a bichromatic Raman pumping beam is used to generate optical gain at two frequencies and a region of anomalous dispersion between them. It is expected that increasing the gain will increase the pulse advancement. However, as the gain increases, the pumping field becomes increasingly distorted, effectively limiting the pulse advancement. We observe as much as 12% of the input pump power converted to orthogonal polarization, broadening of the initially bichromatic pump field (25 MHz initial frequency separation) to more than 2.5 GHz, and a temporal collapse of the pump beam into an erratic train of sub-500-ps pulses. The instability is attributed to the combined effects of the cross modulation instability and stimulated Raman scattering. Extreme distortion of an injected pulse that should (absent the instability) experience an advancement of 21% of its width is observed. We conclude that the fast-light pulse advancement is limited to just a few percent of the pulse width using this pulse advancement technique. The limitation imposed by the instability is important because careful study of the information velocity in fast-light pulses requires that pulse advancement be large enough to distinguish the velocities of different pulse features. Possible methods for achieving pulse advancement by avoiding the distortion caused by the instability are discussed
Effects of ionizing scrape-off layers on local recycling in Tore Supra pump limiter experiments
International Nuclear Information System (INIS)
Chatelier, M.; Loarer, T.
1992-01-01
A series of ohmic discharges with active pumping in the Tore Supra outboard pump limiter has been analyzed with the DEGAS neutrals transport code and an analytic scrape-off layer (SOL) plasma model. Pumping speed and plenum pressure measurements indicated 5-10 torr.L/s throughput with only modest effects on density. A model is developed in which large exhaust fluxes, with little attendant effect on core plasma density, are explained in terms of SOL ionization of recycled and wall-desorbed neutrals. Particle balance with active pumping and constant line density requires that the wall return flux exceed the incident flux by approximately the pump throughput in the absence of external fueling. The radial profile of the H + source rate from ionization and dissociation of wall-desorbed molecules is seen to peak very near the radial position of the limiter throat. Consequently, a strong recycling vortex is created in the region of the limiter, with the ion flux amplified by factors of 2 at the outer limiter surfaces and > 3 within the limiter throat. The calculations indicate that less than 30% of the pump throughput is due to first-generation ions from the core efflux, with the balance from local recycling in the strongly ionizing SOL
Effect of the self-pumped limiter concept on the tritium fuel cycle
International Nuclear Information System (INIS)
Finn, P.A.; Sze, D.K.; Hassanein, A.
1988-01-01
The self-pumped limiter concept for impurity control of the plasma of a fusion reactor has a major impact on the design of the tritium systems. To achieve a sustained burn, conventional limiters and divertors remove large quantities of unburnt tritium and deuterium from the plasma which must be then recycled using a plasma processing system. The self-pumped limiter which does not remove the hydrogen species, does not require any plasma processing equipment. The blanket system and the coolant processing systems acquire greater importance with the use of this unconventional impurity control system. 3 refs., 2 figs
Effects of ionizing scrape-off layers on local recycling in Tore Supra pump limiter experiments
International Nuclear Information System (INIS)
Owen, L.W.; Hogan, J.T.; Klepper, C.C.; Mioduszewski, P.K.; Uckan, T.; Chatelier, M.; Loarer, T.
1992-01-01
A series of ohmic discharges with active pumping in the Tore Supra outboard pump limiter has been analyzed with the DEGAS neutrals transport code and an analysis scrape-off layer (SOL) plasma model. Pumping speed and plenum pressure measurements indicated 5--10 torr-L/s throughput with only modest effects on density (dN core /dt + source rate from ionization and dissociation of wall-desorbed molecules is seen to peak very near the radial position of the limiter throat. Consequently, a strong recycling vortex is created in the region of the limiter, with the ion flux amplified by factors of ∼2 at the outer limiter surfaces and >3 within the limiter throat. The calculations indicate that less than 30% of the pump throughput is due to first-generation ions from the core efflux, with the balance from local recycling in the strongly ionizing scrape-off layer
Conceptual design of a high heat flux toroidal pumped limiter for Tore Supra
International Nuclear Information System (INIS)
Doceul, L.; Schlosser, J.; Chappuis, Ph.; Chatelier, M.; Cocat, J.P.; Deck, C.; Faisse, F.; Grosman, A.; Mitteau, R.; Tonon, G.
1994-01-01
In the frame of the Tore-Supra upgrade, where it is planned to inject up to 25 MW during a time up to 1000 s, a complete toroidal pumped limiter covered of CFC (Carbon Fiber Composite) tiles is being designed. The design is based on the important experience gained from the operation on Tore Supra of actively cooled plasma facing components and pumped limiters. This toroidal limiter covers 7.5 m 2 of the bottom part of the inner vessel and is composed of 576 elementary components. Each element is built from dispersion strengthened copper (DSCu) protected by brazed CFC flat tiles and cooled by pressurised water at 150 deg C. This limiter is designed to sustain 15 MW of convective power. (author) 7 refs.; 5 figs., 3 tabs
Low plasma edge temperatures for the self-pumped limiter
International Nuclear Information System (INIS)
Terry, W.K.; Brooks, J.N.
1985-03-01
Transport code calculations have been performed to study the operation of an INTOR-like tokamak plasma from which helium is removed by a self-pumped limiter, which traps helium, but not hydrogen, in its surface layers. To prevent saturation by helium, the surface is renewed by continuous injection of the surface material (vanadium in this study) into the scrape-off layer. The presence of the injected vanadium leads to plasma temperatures well below 50 eV in the scrape-off layer, with supplementary rf heating. Operation in this edge temperature regime is essential for the use of medium- and high-Z limiter coatings
Solar-based groundwater pumping for irrigation: Sustainability, policies, and limitations
International Nuclear Information System (INIS)
Closas, Alvar; Rap, Edwin
2017-01-01
The increasing demand for solar-powered irrigation systems in agriculture has spurred a race for projects as it potentially offers a cost-effective and sustainable energy solution to off-grid farmers while helping food production and sustaining livelihoods. As a result, countries such as Morocco and Yemen have been promoting this technology for farmers and national plans with variable finance and subsidy schemes like in India have been put forward. By focusing on the application of solar photovoltaic (PV) pumping systems in groundwater-fed agriculture, this paper highlights the need to further study the impacts, opportunities and limitations of this technology within the Water-Energy-Food (WEF) nexus. It shows how most policies and projects promoting solar-based groundwater pumping for irrigation through subsidies and other incentives overlook the real financial and economic costs of this solution as well as the availability of water resources and the potential negative impacts on the environment caused by groundwater over-abstraction. There is a need to monitor groundwater abstraction, targeting subsidies and improving the knowledge and monitoring of resource use. Failing to address these issues could lead to further groundwater depletion, which could threaten the sustainability of this technology and dependent livelihoods in the future. - Highlights: • Solar pumping projects require assessing environmental and financial sustainability. • Subsidies for solar pumping need to be tied to groundwater pumping regulations. • Solar irrigation projects need to consider groundwater availability and depletion. • Data and monitoring are needed to improve water resource impact assessments.
Numerical modelling of pump limiter biasing on TEXTOR-94 and Tore Supra
International Nuclear Information System (INIS)
Gerhauser, H.; Claassen, H.A.; Mank, G.; Zagorski, R.; Loarer, T.; Gunn, J.; Boucher, C.
2002-01-01
The two-dimensional multifluid code TECXY has been used to model the biasing (with respect to the first wall) of the toroidal belt limiter ALT-II on the tokamak TEXTOR-94 and of the new toroidal pump limiter being installed on Tore Supra tokamak in the framework of the CIEL project. It is well known that the edge flow pattern can be influenced by the poloidal electric drifts from imposing radial electric fields. The modelling with TECXY introduces imprinted bias currents in the scrape-off layer (SOL) for the case of negative (limiter) biasing, and imprinted bias potentials for the case of positive biasing. This allowed us to simulate sufficiently well the experimental I-V characteristics for either biasing of ALT-II and also reproduced the essential features and trends of the observed plasma profiles in the SOL of TEXTOR-94. For negative biasing a moderate improvement of the pumping exhaust efficiency can be achieved in the case of TEXTOR. For Tore Supra, however, only a negligible improvement of the limiter performance with biasing can be predicted, which is explained by the relatively weak drift flows in Tore Supra. (author)
Langmuir probe measurements in the TEXTOR tokamak during ALT-I pump limiter experiments
International Nuclear Information System (INIS)
Goebel, D.M.; Campbell, G.A.; Conn, R.W.; Leung, W.K.; Dippel, K.H.; Finken, K.H.; Thomas, G.J.; Pontau, A.E.
1986-04-01
Langmuir probes have been used to characterize the edge plasma of the TEXTOR tokamak and measure the parameters of the plasma incident on the ALT-I pump limiter during ohmic and ICRH heating. Probes mounted directly on the ALT limiter, and a scanning probe located 90 0 toroidally from the limiter, provide data for the evaluation of pump limiter performance and its effect on the edge plasma. The edge plasma is characterized by density and flux e-folding lengths of about 1.8cm when ALT is the main limiter. These scrape-off lengths do not vary significantly as ALT is moved between the normal 42-46cm minor radii, but increase to over 2.2cm when ALT is inserted to 40cm. The flux to probes at a fixed position in the limiter shadow varies by less than 25% for core density changes of a factor of five. This suggests that the global particle confinement time tau/sub p/, scales as the core density. Estimates from the probes indicate that tau/sub p/ is on the order of the energy confinement time, tau/sub E/. The edge electron temperature, T/sub e/, typically decreases by a factor of two when the core density is raised from 1 to 4 x 10 13 cm -3 . The T/sub e/ profile is essentially flat in the limiter shadow, with values of 10-25 eV depending on the core plasma density and ICRH power. ICRH heating increases the electron temperature and flux in proportion to the coupled power. With ALT as the primary limiter and no direct shadowing, the ion side receives 2 to 3 times the flux of the electron side during both ohmic and ICRH heating. The edge plasma is not directly modified by pump limiter operation, but changes with the core plasma density as particle removal lowers the recycling of neutrals in the boundary
Pumping mechanisms in sputter-ion pumps low pressure operation
International Nuclear Information System (INIS)
Welch, K.M.
1991-01-01
It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 is pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump
Pumping mechanisms in sputter-ion pumps low pressure operation
International Nuclear Information System (INIS)
Welch, K.M.
1991-01-01
It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump. 13 refs., 5 figs., 1 tab
Near shot-noise limited time-resolved circular dichroism pump-probe spectrometer
Stadnytskyi, Valentyn; Orf, Gregory S.; Blankenship, Robert E.; Savikhin, Sergei
2018-03-01
We describe an optical near shot-noise limited time-resolved circular dichroism (TRCD) pump-probe spectrometer capable of reliably measuring circular dichroism signals in the order of μdeg with nanosecond time resolution. Such sensitivity is achieved through a modification of existing TRCD designs and introduction of a new data processing protocol that eliminates approximations that have caused substantial nonlinearities in past measurements and allows the measurement of absorption and circular dichroism transients simultaneously with a single pump pulse. The exceptional signal-to-noise ratio of the described setup makes the TRCD technique applicable to a large range of non-biological and biological systems. The spectrometer was used to record, for the first time, weak TRCD kinetics associated with the triplet state energy transfer in the photosynthetic Fenna-Matthews-Olson antenna pigment-protein complex.
Adsorption pump for helium pumping out
International Nuclear Information System (INIS)
Donde, A.L.; Semenenko, Yu.E.
1981-01-01
Adsorption pump with adsorbent cooling by liquid helium is described. Shuttered shield protecting adsorbent against radiation is cooled with evaporating helium passing along the coil positioned on the shield. The pump is also equipped with primed cylindrical shield, cooled with liquid nitrogen. The nitrogen shield has in the lower part the shuttered shield, on the pump casing there is a valve used for pump pre-burning, and valves for connection to recipient as well. Pumping- out rates are presented at different pressures and temperatures of adsorbent. The pumping-out rate according to air at absorbent cooling with liquid nitrogen constituted 5x10 -4 Pa-3000 l/s, at 2x10 -2 Pa-630 l/s. During the absorbent cooling with liquid hydrogen the pumping-out rate according to air was at 4x10 -4 Pa-580 l/s, at 2x10 -3 Pa-680 l/s, according to hydrogen - at 8x10 -5 Pa-2500 l/s, at 5x10 -3 Pa-4200 l/s. During adsorbent cooling with liquid helium the rate of pumping-out according to hydrogen at 3x10 5 Pa-2400% l/s, at 6x10 3 Pa-1200 l/s, and according to helium at 3.5x10 -5 Pa-2800 l/s, at 4x10 -3 Pa-1150 l/s. The limit vacuum is equal to 1x10 -7 Pa. The volume of the vessel with liquid helium is equal to 3.5 l. Helium consumption is 80 cm 3 /h. Consumption of liquid nitrogen from the shield is 400 cm 3 /h. The limit pressure in the pump is obtained after forevacuum pumping-out (adsorbent regeneration) at 300 K temperature. The pump is made of copper. The pump height together with primed tubes is 800 mm diameter-380 mm [ru
International Nuclear Information System (INIS)
Nygren, R.; Koski, J.; Lutz, T.; McGrath; Miller, J.; Watkins, J.; Guilhem, D.; Chappuis, P.; Cordier, J.; Loarer, T.
1995-01-01
Tore Supra's Phase III outboard pump limiter (OPL) is a modular actively-cooled mid-plane limiter, designed for heat and particle removal during long pulse operation. During its initial operation in 1993, the OPL successfully removed about 1 MW of power during ohmicly heated shots of up to 10 s duration and reached (steady state) thermal equilibrium. The particle pumping of the Phase III OPL was found to be about 50% greater than the Phase II OPL which had a radial distance between the last closed flux surface and the entrance of the pumping throat of 3.5 cm compared with only 2.5 cm for the Phase III OPL. This paper gives examples of power distribution over the limiter from IR measurements of surface temperature and from extensively calorimetry (34 thermocouples and 10 flow meters) and compares the distributions with values predicted by a 3D model (HF3D) with a detailed magnetic configuration (e.g., includes field ripple). ((orig.))
Rotary piston blood pumps: past developments and future potential of a unique pump type.
Wappenschmidt, Johannes; Autschbach, Rüdiger; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Margreiter, Raimund; Klima, Günter; Goetzenich, Andreas
2016-08-01
The design of implantable blood pumps is either based on displacement pumps with membranes or rotary pumps. Both pump types have limitations to meet the clinical requirements. Rotary piston blood pumps have the potential to overcome these limitations and to merge the benefits. Compared to membrane pumps, they are smaller and with no need for wear-affected membranes and valves. Compared to rotary pumps, the blood flow is pulsatile instead of a non-physiological continuous flow. Furthermore, the risk of flow-induced blood damage and platelet activation may be reduced due to low shear stress to the blood. The past developments of rotary piston blood pumps are summarized and the main problem for long-term application is identified: insufficient seals. A new approach with seal-less drives is proposed and current research on a simplified rotary piston design is presented. Expert commentary: The development of blood pumps focuses mainly on the improvement of rotary pumps. However, medical complications indicate that inherent limitations of this pump type remain and restrict the next substantial step forward in the therapy of heart failure patients. Thus, research on different pump types is reasonable. If the development of reliable drives and bearings succeeds, rotary piston blood pumps become a promising alternative.
Design considerations of modular pump limiters for large tokamaks
International Nuclear Information System (INIS)
Uckan, T.; Klepper, C.C.; Mioduszewski, P.K.
1987-11-01
Long-pulse (>10-s) and high-power (>10-MW) operation of large tokamaks requires multiple limiter modules for particle and heat removal, and the power load must be distributed among a number of modules. Because each added module changes the performance of all the others, a set of design criteria must be defined for the overall limiter system. The relationship between individual modules must also be considered from the standpoint of flux coverage and shadowing effects. This paper addresses these issues and provides design guidelines. Parameters of the individual modules are then determined from the system requirements for particle and power removal. Long-pulse operation of large tokamaks requires that the limiter modules be equipped with active cooling. At the leading edge of a module, the cooling channel determines the thickness of the limiter blade (or head). A model has been developed for estimating the system exhaust efficiency in terms of the parameters of the leading edge (i.e., its thickness and the design heat flux) in terms of given device parameters and the power load that must be removed. The impact on module design of state-of-the-art engineering technology for high heat removal is discussed. The choice of locations for the modules is also investigated, and the effects of shadowing between modules on particle and power removal are examined. The results are applied to the Tore Supra tokamak. Conceptual design parameters of the modular pump limiter system are given. 10 refs., 5 figs
Particle exhaust of helium plasmas with actively cooled outboard pump limiter on Tore Supra
International Nuclear Information System (INIS)
Uckan, T.; Mioduszewski, P.K.; Loarer, T.; Chatelier, M.; Guilhem, D.; Lutz, T.; Nygren, R.E.; Mahdavi, M.A.
1995-08-01
The superconducting tokamak Tore Supra was designed for long-pulse (30-s) high input power operation. Here observations on the particle-handling characteristics of the actively cooled modular outboard pump limiter (OPL) are presented for helium discharges. The important experimental result was that a modest pumping speed (1 m 3 /s) of the OPL turbomolecular pump (TMP) provided background helium exhaust. This result came about due to a well-conditioned vessel wall with helium discharges that caused no wall outgasing. The particle accountability in these helium discharges was excellent, and the well-conditioned wall did not play a significant role in the particle balance. The helium density control, 25% density drop with OPL exhaust efficiency of ∼1%, was possible with TMP although this may not be the case with reactive gases such as deuterium. The observed quadratic increase of the OPL neutral pressure with helium density was consistent with an improvement of the particle control with increasing plasma density
International Nuclear Information System (INIS)
Stacey, W. M.
2001-01-01
Several series of model problem calculations have been performed to investigate the predicted effect of pumping, divertor configuration and fueling on the maximum achievable density in diverted tokamaks. Density limitations due to thermal instabilities (confinement degradation and multifaceted axisymmetric radiation from the edge) and to divertor choking are considered. For gas fueling the maximum achievable density is relatively insensitive to pumping (on or off), to the divertor configuration (open or closed), or to the location of the gas injection, although the gas fueling rate required to achieve this maximum achievable density is quite sensitive to these choices. Thermal instabilities are predicted to limit the density at lower values than divertor choking. Higher-density limits are predicted for pellet injection than for gas fueling
Comparison between a pumped-limiter and a divertor for the next step machines
International Nuclear Information System (INIS)
Harrison, F.F.A.
1985-01-01
The paper presents a simple description of the physics issues which influence the conceptual design of a pumped-limiter and single-null poloidal divertor in a next step, long burn tokamak of NET/INTOR scale. Predicted performance of the limiter and divertor are compared in regard to localised recycling, sputtering of the plasma collection surfaces, penetration of sputtered impurities into the fusion plasma, surface power loading and exhaust of helium ash. It is concluded that the performance of the divertor is superior and that it can be predicted with a reasonable degree of confidence. The viability of the limiter remains in doubt but the concept cannot be rejected at the present time
The ground fault detection system for the Tore Supra toroidal pump limiter
International Nuclear Information System (INIS)
Zunino, K.; Cara, P.; Fejoz, P.; Hourtoule, J.; Loarer, T.; Pomaro, N.; Santagiustina, A.; Spuig, P.; Villecroze, F.
2003-01-01
The toroidal pump limiter (TPL) of Tore Supra is electrically insulated from the vacuum-vessel, to allow its polarization at a voltage of up to 1 kV. In order to monitor continuously the integrity of the TPL electrical insulation, an electronic diagnostic system called TPL ground fault detection system (GFDS) has been developed. The paper will report on the design and the operation experience of the GFD system and on the evolution of the TPL grounding
Dhanjal, S.; Hoogland, S.; Roberts, J.S.; Hayward, R.A.; Clarkson, W.A.; Tropper, Anne
2000-01-01
We describe a diode-bar-pumped vertical-external-cavity surface-emitting semiconductor laser, which in quasi-cw operation emitted a peak power of >1 W at 1020 nm in a circular, near diffraction-limited beam.
Study of Hydrogen Pumping through Condensed Argon in Cryogenic pump
International Nuclear Information System (INIS)
Jadeja, K A; Bhatt, S B
2012-01-01
In ultra high vacuum (UHV) range, hydrogen is a dominant residual gas in vacuum chamber. Hydrogen, being light gas, pumping of hydrogen in this vacuum range is limited with widely used UHV pumps, viz. turbo molecular pump and cryogenic pump. Pre condensed argon layers in cryogenic pump create porous structure on the surface of the pump, which traps hydrogen gas at a temperature less than 20° K. Additional argon gas injection in the cryogenic pump, at lowest temperature, generates multiple layers of condensed argon as a porous frost with 10 to 100 A° diameters pores, which increase the pumping capacity of hydrogen gas. This pumping mechanism of hydrogen is more effective, to pump more hydrogen gas in UHV range applicable in accelerator, space simulation etc. and where hydrogen is used as fuel gas like tokamak. For this experiment, the cryogenic pump with a closed loop refrigerator using helium gas is used to produce the minimum cryogenic temperature as ∼ 14° K. In this paper, effect of cryosorption of hydrogen is presented with different levels of argon gas and hydrogen gas in cryogenic pump chamber.
Cleff, C.; Gross, P.; Fallnich, C.; Offerhaus, Herman L.; Herek, Jennifer Lynn; Kruse, K.; Beeker, W.P.; Lee, Christopher James; Boller, Klaus J.
2013-01-01
We present a theoretical investigation of stimulated emission pumping to achieve sub-diffraction-limited spatial resolution in coherent anti-Stokes Raman scattering (CARS) microscopy. A pair of control light fields is used to prepopulate the Raman state involved in the CARS process prior to the CARS
International Nuclear Information System (INIS)
Mioduszewski, P.K.; Edmonds, P.H.; Sheffield, J.
1982-01-01
Continuous removal of heat and particles becomes a vital necessity in future steady-state fusion devices. The pump limiter seems to be an attractive concept to combine these two tasks. On ISX, various schemes of pump limiters are being explored with the final goal to furnish the ISX--C device with a pump limiter to handle heat removal and particle control in steady state. The emphasis of the present paper is on pump limiters based on ballistic particle collection. If this concept turns out to be successful in supplying sufficient pumping efficiency, it may be possible to design pump limiters without a leading edge. Analytical calculations of the particle collection efficiency are given for various limiter configurations. Pumping efficiencies of approximately 4--10%, depending on the specific configuration, seem to be feasible and should be sufficient for steady-state operation. Initial experimental results on pump limiter studies in ISX--B confirm the calculated collection efficiencies. By measuring the ion saturation current to the limiter blade and the pressure buildup simultaneously, we found a correlation between the incident particle flux and the pressure rise that agrees well with a simple model
Observation of advanced particle removal rates in pump limiter simulation experiments
International Nuclear Information System (INIS)
Goebel, D.M.; Conn, R.W.
1984-05-01
The performance of particle removal schemes for density and impurity control in tokamaks and mirror machines depends strongly on the plasma parameters and local recycling near the plasma neutralizier plates and gas pumping ducts. The relationship between plasma density, electron temperature, ion energy and gas flow and particle removal rate through a pumping duct located near a plasma neutralizer plate has been experimentally investigated in the steady state plasma device PISCES. Results indicate that initially the particle removal by pumps at the end of the duct is proportional to the plasma flux to the plate. A nonlinear increase in the pumping rate occurs when the ionization mean free path for neutrals from the plate becomes less than the plasma radius. The transition from a transparent to an opaque plasma due to local ionization of the neutrals produced at the neutralizer plate greatly enhances the particle removal rate by recycling of the neutral gas as it flows away from the neutralizer plate or out of the pumping ducts. Parameters were varied to determine the importance of ballistic scattering of higher energy ions from the plate, but no effects were found in these experiments
DEFF Research Database (Denmark)
Ommen, Torben Schmidt; Jensen, Jonas Kjær; Markussen, Wiebke Brix
2014-01-01
A large amount of operational and economic constraints limit the applicability of heat pumps operated with natural working fluids. The limitations are highly dependent on the integration of heat source and sink streams. An evaluation of feasible operating conditions is carried out considering...... the constraints of available refrigeration equipment and a requirement of a positive Net Present Value of the investment. The considered sink outlet temperature range is from 40 °C to 140 °C, but for the heat pumps considered in this paper, the upper limit is 100 °C. Five heat pumps are studied. For each set...... of heat sink and source temperatures the optimal solution is determined. At low sink temperature glide R717 heat pumps show best performance, while at higher sink glide transcritical R744 may become important. In a second paper, the results of the VCHP are compared to a similar study considering...
Runaway electron damage to the Tore Supra Phase III outboard pump limiter
International Nuclear Information System (INIS)
Nygren, R.; Lutz, T.; Walsh, D.; Martin, G.; Chatelier, M.; Loarer, T.; Guilhem, D.
1996-01-01
Operation of the Phase III outboard pump limiter (OPL) in Tore Supra in 1994 was terminated prematurely when runaway electrons during the current decay following a disruption pierced leading edge tube on the electron side and caused a water leak. The location, about 20 mm outside the last closed flux surface during normal operation, and the infrared (IR) images of the limiter indicate that the runaways moved in large outward steps, i.e. tens of millimeters, in one toroidal revolution. For plasma (runaway) currents in the range of 155 to 250 kA, the drift orbits open to the outside. Basic trajectory computations suggest that such motion is possible under the conditions present for this experiment. Activation measurements made on sections of the tube to indicate the area of local damage are presented here. An understanding of this event may provide important guidance regarding the potential damage from runaways in future tokamaks
Pumping station design for a pumped-storage wind-hydro power plant
International Nuclear Information System (INIS)
Anagnostopoulos, John S.; Papantonis, Dimitris E.
2007-01-01
This work presents a numerical study of the optimum sizing and design of a pumping station unit in a hybrid wind-hydro plant. The standard design that consists of a number of identical pumps operating in parallel is examined in comparison with two other configurations, using one variable-speed pump or an additional set of smaller jockey pumps. The aim is to reduce the amount of the wind generated energy that cannot be transformed to hydraulic energy due to power operation limits of the pumps and the resulting step-wise operation of the pumping station. The plant operation for a period of one year is simulated by a comprehensive evaluation algorithm, which also performs a detailed economic analysis of the plant using dynamic evaluation methods. A preliminary study of the entire plant sizing is carried out at first using an optimization tool based on evolutionary algorithms. The performance of the three examined pumping station units is then computed and analyzed in a comparative study. The results reveal that the use of a variable-speed pump constitutes the most effective and profitable solution, and its superiority is more pronounced for less dispersed wind power potential
International Nuclear Information System (INIS)
Dorodnov, A.M.; Minajchev, V.E.; Miroshkin, S.I.
1980-01-01
The action of an electric-arc high-vacuum pump intended for evacuating the volumes in which the operation processes are followed by a high gas evolution is considered. The operation of the pump is based on the principle of controlling the getter feed according to the gas load and effect of plasma sorbtion pumping. The pump performances are given. The starting pressure is about 5 Pa, the limiting residual pressure is about 5x10 -6 Pa, the pumping out rate of nitrogen in the pressure range 5x10 -5 -5x10 -3 Pa accounts for about 4000 l/s, the power consumption comes to 6 kW. Analyzing the results of the test operation of the pump, it has been concluded that its principal advantages are the high starting pressure, controlled getter feed rate and possibility of pumping out the gases which are usually pumped out with difficulty. The operation reliability of the pump is defined mainly by reliable operation of the ignition system of the vacuum arc [ru
Spatially resolved charge exchange flux calculations on the Toroidal Pumped Limiter of Tore Supra
International Nuclear Information System (INIS)
Marandet, Y.; Tsitrone, E.; Boerner, P.; Reiter, D.; Beaute, A.; Delchambre, E.; Escarguel, A.; Brezinsek, S.; Genesio, P.; Gunn, J.; Monier-Garbet, P.; Mitteau, R.; Pegourie, B.
2009-01-01
A spatially resolved calculation of the charge exchange particle and energy fluxes on the Toroidal Pumped Limiter (TPL) of Tore Supra is presented, as a first step towards a better understanding and modelling of carbon erosion, migration, as well as deuterium codeposition and bulk diffusion of deuterium in Tore Supra. The results are obtained with the EIRENE code run in a 3D geometry. Physical and chemical erosion maps on the TPL are calculated, and the contribution of neutrals to erosion, especially in the self-shadowed area, is calculated.
Scrape-off model and pumped-limiter design for reversed-field pinches (RFP)
International Nuclear Information System (INIS)
Embrechts, M.J.; Bathke, C.G.; Krakowski, R.A.
1983-01-01
In order to develop a better understanding of the plasma/first-wall interaction in an RFP configuration, the models being developed to describe edgeplasma and scrapeoff regions for the tokamak have been adopted. Specifically, a scrapeoff model similar to the one developed and used for the tokamak FED design is used to model the parameter range where pumped limiters may be applied to the compact RFP. The one-dimensional, steady-state heat and particle equations are solved in the scrapeoff layer for an RFP geometry, assuming equal electron and ion temperature and density, convective transport along field lines, and Bohm-like diffusion. All charge-exchange and radiation effects are assumed to take place in the region between plasma and scrapeoff layer, and only a specific fraction of the total plasma energy will enter the scrapeoff layer in the form of conduction and convection. A simplified recycling model based on an effective recycling coefficient is used. For a given particle and energy flux entering the scrapeoff and for specified relationships between the particle flux and the energy flux near the first wall, the temperature and density profiles in the scrapeoff layer region are determined. The shape of the limiter surface is determined iteratively for a specified number of poloidal limiters by specifying a constant (design) heat flux for the limiter surfaces
Neutral pumping rates for a next step tokamak ignition device
International Nuclear Information System (INIS)
Galambos, J.D.; Peng, Y.K.M.; Heifetz, D.
1985-01-01
Neutral pumping rates are calculated for pump-limiter and divertor options of a next step tokamak ignition device using a method that accounts for the coupled effects of neutral transport and plasma transport. For both pump limiters and divertors the plasma flow into the channel surrounding the neutralizer plate is greatly reduced by the neutral recycling. The fraction of this flow that is pumped can be large (>50%) but in general is dependent on the particular geometry and plasma conditions. It is estimated that pumping speeds greater than or approximately 10 5 L/s are adequate for the exhaust requirements in the pump-limiter and the divertor cases
Tritium system for a tokamak reactor with a self-pumped limiter
International Nuclear Information System (INIS)
Hassanein, A.M.; Sze, D.K.
1986-01-01
The self-pumping concept was proposed as a means of simplifying the impurity control system in a fusion reactor. The idea is to remove helium in-situ by trapping in freshly deposited metal surface layers of a limiter or divertor. Trapping material is added to the plasma scrape-off or edge region where it is transported to the wall. Some of the key issues for this concept are the tritium inventory in the trapping material and the permeation of protium and recycling of tritium. These quantities are shown to be acceptable for the reference design. The tritium issues for a helium-cooled solid breeder reactor design with vanadium alloy as a structural material are also examined. Models are presented for tritium permeation and inventory calculation for structure materials with the effect of a thin layer of coating material
Pump failure leads to alternative vertical pump condition monitoring technique
International Nuclear Information System (INIS)
DeVilliers, Adriaan; Glandon, Kevin
2011-01-01
Condition monitoring and detecting early signs of potential failure mechanisms present particular problems in vertical pumps. Most often, the majority of the pump assembly is not readily accessible for visual or audible inspection or conventional vibration monitoring techniques using accelerometers and/or proximity sensors. The root cause failure analysis of a 2-stage vertical centrifugal service-water pump at a nuclear power generating facility in the USA is presented, highlighting this long standing challenge in condition monitoring of vertical pumps. This paper will summarize the major findings of the root cause analysis (RCA), highlight the limitations of traditional monitoring techniques, and present an expanded application of motor current monitoring as a means to gain insight into the mechanical performance and condition of a pump. The 'real-world' example of failure, monitoring and correlation of the monitoring technique to a detailed pump disassembly inspection is also presented. This paper will explain some of the reasons behind well known design principles requiring natural frequency separation from known forcing frequencies, as well as explore an unexpected submerged brittle fracture failure mechanism, and how such issues may be avoided. (author)
Parallel operation of primary sodium pumps in FBTR
International Nuclear Information System (INIS)
Athmalingam, S.; Ellappan, T.R.; Vaidyanathan, G.; Chetal, S.C.; Bhoje, S.B.
1994-01-01
Sodium pumps used in the primary main circuit of Fast Breeder Test Reactor (FBTR) are centrifugal pumps. These pumps have a free level of sodium with a cover gas above it to simplify the pump seal arrangement. The sodium level in the pumps will vary based on the flow. The minimum level is governed by consideration of gas entrainment and net positive suction head (NPSH) to the pump while the maximum level is limited by sodium entering the pump tank gas line. There is a special feature in these pumps in that a small portion of the pump outlet sodium flow is led back into the suction chamber to maintain level and avoid gas entrainment. A control valve in this line helps in controlling the level at the desired value. With parallel operation of two sodium pumps a study was conducted to find the regions of safe operation of the two pumps. The purpose of this paper is to give the various design features and methodology of the analysis to arrive at the limiting condition of operation for the different operating states of the two pumps and the effect of pump speed variations on the fluctuations in sodium flows. (author). 6 figs
International Nuclear Information System (INIS)
Matusz, J.M.
1991-01-01
This patent describes a service apparatus for one or more inverted canned motor pumps installed above a floor and beneath a steam generator in a nuclear or fossil power plant with limited access space and limited access time at least in the case of nuclear power plants, each of the canned motor pumps having a pump casing and a depending motor having a flange secured to a pump casing flange by tensioned studs with tightened nuts. It comprises a maintenance cart having a height greater than the height of the motor beneath the motor flange and further having a generally U-shaped frame means with an open vertical side that permits the cart to be moved horizontally such that the cart frame means can be moved under the pump casing to surround the depending motor; actuator means supported by the cart frame means and having translating arm means engageable with support means on the motor; means for operating the translating arm means to support, raise and lower the motor; means supported by the frame means to support the motor flange prior to raising the motor to its installed position and after the motor has been released from its installed position and lowered to the cart; work platform means provided on the cart frame means at an elevation beneath the motor flange elevation; and roller means provided on the bottom of the cart frame means to facilitate horizontal cart movement along the floor
High brightness diode-pumped organic solid-state laser
Energy Technology Data Exchange (ETDEWEB)
Zhao, Zhuang; Mhibik, Oussama; Nafa, Malik; Chénais, Sébastien; Forget, Sébastien, E-mail: sebastien.forget@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, Laboratoire de Physique des Lasers, F-93430, Villetaneuse (France); CNRS, UMR 7538, LPL, F-93430, Villetaneuse (France)
2015-02-02
High-power, diffraction-limited organic solid-state laser operation has been achieved in a vertical external cavity surface-emitting organic laser (VECSOL), pumped by a low-cost compact blue laser diode. The diode-pumped VECSOLs were demonstrated with various dyes in a polymer matrix, leading to laser emissions from 540 nm to 660 nm. Optimization of both the pump pulse duration and output coupling leads to a pump slope efficiency of 11% for a DCM based VECSOLs. We report output pulse energy up to 280 nJ with 100 ns long pump pulses, leading to a peak power of 3.5 W in a circularly symmetric, diffraction-limited beam.
International Nuclear Information System (INIS)
Chavez, R.; Johnson, F.T.; Ekeroth, D.E.; Matusz, J.M.
1994-01-01
Elongated coolant pump motors suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an upright elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator on rollers and out through the auxiliary equipment hatch. The cart includes a top V-shaped collar for supporting the motor, and a further lower support cradle operative when the cart is horizontal. Jacks support the motor during unbolting from the pump casing and lower it onto the cart. (Author)
Vacuum pumping for controlled thermonuclear reactors
International Nuclear Information System (INIS)
Watson, J.S.; Fisher, P.W.
1976-01-01
Thermonuclear reactors impose unique vacuum pumping problems involving very high pumping speeds, handling of hazardous materials (tritium), extreme cleanliness requirements, and quantitative recovery of pumped materials. Two principal pumping systems are required for a fusion reactor, a main vacuum system for evacuating the torus and a vacuum system for removing unaccelerated deuterium from neutral beam injectors. The first system must pump hydrogen isotopes and helium while the neutral beam system can operate by pumping only hydrogen isotopes (perhaps only deuterium). The most promising pumping techniques for both systems appear to be cryopumps, but different cryopumping techniques can be considered for each system. The main vacuum system will have to include cryosorption pumps cooled to 4.2 0 K to pump helium, but the unburned deuterium-tritium and other impurities could be pumped with cryocondensation panels (4.2 0 K) or cryosorption panels at higher temperatures. Since pumping speeds will be limited by conductance through the ducts and thermal shields, the pumping performance for both systems will be similar, and other factors such as refrigeration costs are likely to determine the choice. The vacuum pumping system for neutral beam injectors probably will not need to pump helium, and either condensation or higher temperature sorption pumps can be used
Bizarro, João P S; Rodrigues, Paulo
2012-11-01
For work-producing heat engines, or work-consuming refrigerators and heat pumps, the percentage decrease caused by friction in their efficiencies, or coefficients of performance (COP's), is approximately given by the ratio W(fric)/W between the work spent against friction forces and the work performed by, or delivered to, the working fluid. This universal scaling, which applies in the limit of small friction (W(fric)/W heat-engine efficiencies), allows a simple and quick estimate of the impact that friction losses can have on the FOM's of thermal engines and plants, or of the level of those losses from the observed and predicted FOM's. In the case of refrigerators and heat pumps, if W(fric)/W heat engines), the COP percentage decrease due to friction approaches asymptotically (W(fric)/W)/(1+W(fric)/W) instead of W(fric)/W. Estimates for the level of frictional losses using the Carnot (or, for heat engines and power plants only, the Curzon-Ahlborn) predictions and observed FOM's of real power plants, heat engines, refrigerators, and heat pumps show that they usually operate in domains where these behaviors are valid.
International Nuclear Information System (INIS)
Guer, M.; Guiton, P.
Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads
Nuclear power plant safety related pump issues
Energy Technology Data Exchange (ETDEWEB)
Colaccino, J.
1996-12-01
This paper summarizes of a number of pump issues raised since the Third NRC/ASME Symposium on Valve and Pump Testing in 1994. General issues discussed include revision of NRC Inspection Procedure 73756, issuance of NRC Information Notice 95-08 on ultrasonic flow meter uncertainties, relief requests for tests that are determined by the licensee to be impractical, and items in the ASME OM-1995 Code, Subsection ISTB, for pumps. The paper also discusses current pump vibration issues encountered in relief requests and plant inspections - which include smooth running pumps, absolute vibration limits, and vertical centrifugal pump vibration measurement requirements. Two pump scope issues involving boiling water reactor waterlog and reactor core isolation cooling pumps are also discussed. Where appropriate, NRC guidance is discussed.
Nuclear power plant safety related pump issues
International Nuclear Information System (INIS)
Colaccino, J.
1996-01-01
This paper summarizes of a number of pump issues raised since the Third NRC/ASME Symposium on Valve and Pump Testing in 1994. General issues discussed include revision of NRC Inspection Procedure 73756, issuance of NRC Information Notice 95-08 on ultrasonic flow meter uncertainties, relief requests for tests that are determined by the licensee to be impractical, and items in the ASME OM-1995 Code, Subsection ISTB, for pumps. The paper also discusses current pump vibration issues encountered in relief requests and plant inspections - which include smooth running pumps, absolute vibration limits, and vertical centrifugal pump vibration measurement requirements. Two pump scope issues involving boiling water reactor waterlog and reactor core isolation cooling pumps are also discussed. Where appropriate, NRC guidance is discussed
Motor Pump Revolution in Ethiopia: Promises at a Crossroads
Directory of Open Access Journals (Sweden)
Mengistu Dessalegn
2015-06-01
Full Text Available In sub-Saharan Africa, motor pump irrigation is at an earlier stage than in Asia but is growing rapidly in many countries. The focus of both policy and research in Africa to date has been on facilitating supply chains to make pumps available at a reasonable price. In Africa, pump irrigation is mainly based on two sources: shallow groundwater aquifers and small streams and rivers. Both usually have limited and variable yields. We present a case study from Ethiopia where pump irrigation based on small rivers and streams is expanding rapidly, and draw parallels to experiences in Asia and other African countries. We show that while farmers understand the social nature of community-managed irrigation, they share with policymakers a narrow understanding of pump irrigation as being primarily 'technical'. They perceive pumps as liberating them from the 'social' limitations of traditional communal irrigation. However, the rapid expansion of pump irrigation is leading to increasing competition and conflict over the limited water resource. We analyse the wider implications for Africa of this blindness to the social dimension of pump irrigation and offer suggestions on future policy and applied research to address the problem before it becomes a widespread crisis.
Pumps and pump facilities. 2. ed.
International Nuclear Information System (INIS)
Bohl, W.; Bauerfeind, H.; Gutmann, G.; Leuschner, G.; Matthias, H.B.; Mengele, R.; Neumaier, R.; Vetter, G.; Wagner, W.
1981-01-01
This book deals with the common fundamental aspects of liquid pumps and gives an exemplary choice of the most important kinds of pumps. The scientific matter is dealt with by means of practical mathematical examples among other ways of presenting the matter. Survey of contents: Division on main operational data of pumps - pipe characteristics - pump characteristics - suction behaviour of the pumps - projecting and operation of rotary pumps - boiler feed pumps - reactor feed pumps - oscillating positive-displacement pumps - eccentric spiral pumps. (orig./GL) [de
The effect of pump cavitation on the design of the primary pumps for C.F.R
International Nuclear Information System (INIS)
Worster, R.C.
1976-01-01
In the design appraisal of the sodium pumps for the primary circuit of the proposed 1300 MW(e) CFR it has been recognised that cavitation, its effects and its control, is the outstanding hydraulic design problem. Careful consideration of this problem and of the possible effects of pump cavitation on the performance of other reactor systems has led to the conclusion that it is more prudent at present to specify pumps with zero cavitation at normal full speed operating conditions. Under abnormal operation it may be necessary to reduce the pumps' speed to prevent cavitation in the pumps or associated equipment. The principal reasons for this decision were uncertainties concerning the possibility of erosion due to limited cavitation in sodium and the possibility of pump cavitation noise interfering with acoustic detection of malfunctioning of reactor components or of boiling in the reactor core
International Nuclear Information System (INIS)
Greene, R.H.; Casada, D.A.; Ayers, C.W.
1995-08-01
This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented
Energy Technology Data Exchange (ETDEWEB)
Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others
1995-08-01
This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.
Double-shell tank annulus pumping alternative evaluation
International Nuclear Information System (INIS)
RIESENWEBER, S.D.
1999-01-01
This engineering evaluation compares five alternative schemes for maintaining emergency annulus pumping equipment in a reliable condition. The five schemes are: (1) continue status quo; (2) periodic pump removal and run-in; (3) periodic in-place limited maintenance; (4) uninstalled ready spares; and (5) expanded mission of Single-Shell Tank Emergency Pumping Trailer. Each alternative is described, the pros and cons identified, and rough order of magnitude life-cycle costs computed. The alternatives are compared using weighted evaluation criteria. The evaluation concludes that staging adjustable length submersible pumps in the Single-Shell Tank Emergency Pumping Trailer has the best cost-benefit characteristics
High power diode pumped solid state lasers
International Nuclear Information System (INIS)
Solarz, R.; Albrecht, G.; Beach, R.; Comaskey, B.
1992-01-01
Although operational for over twenty years, diode pumped solid state lasers have, for most of their existence, been limited to individual diodes pumping a tiny volume of active medium in an end pumped configuration. More recent years have witnessed the appearance of diode bars, packing around 100 diodes in a 1 cm bar which have enabled end and side pumped small solid state lasers at the few Watt level of output. This paper describes the subsequent development of how proper cooling and stacking of bars enables the fabrication of multi kill average power diode pump arrays with irradiances of 1 kw/cm peak and 250 W/cm 2 average pump power. Since typical conversion efficiencies from the diode light to the pumped laser output light are of order 30% or more, kW average power diode pumped solid state lasers now are possible
Trusov, K K
1994-02-20
A new experimental setup of a Rhodamine 6G dye laser with a transverse-discharge flash-lamp-pumping system is presented. It differs from a previous setup [Sov. J. Quantum Electron. 16, 468-471 (1989)] in that it has a larger laser beam aperture (32 mm) and higher pumping energy (1 kJ), which made it possible to test the scalability and reach near diffraction-limited laser beam divergence of 3 × 10(-5) rad FWHM at beam energy 1.4 J. The effect of spectral dispersion in the active medium and of other optical elements on the beam divergence is also discussed.
50V All-PMOS Charge Pumps Using Low-Voltage Capacitors
Emira, Ahmed
2012-10-06
In this work, two high-voltage charge pumps are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the charge pump, high density capacitors have been utilized. Nonetheless, these high density capacitors suffer from low breakdown voltage which is not compatible with the targeted high voltage application. To circumvent the breakdown limitation, a special clocking scheme is used to limit the maximum voltage across any pumping capacitor. The two charge pump circuits were fabricated in a 0:6m CMOS technology with poly0-poly1 capacitors. The output voltage of the two charge pumps reached 42:8V and 51V while the voltage across any capacitor did not exceed the value of the input voltage. Compared to other designs reported in the literature, the proposed charge pump provides the highest output voltage which makes it more suitable for tuning MEMS devices.
50V All-PMOS Charge Pumps Using Low-Voltage Capacitors
Emira, Ahmed; AbdelGhany, M.; Elsayed, M.; Elshurafa, Amro M.; Sedky, S.; Salama, Khaled N.
2012-01-01
In this work, two high-voltage charge pumps are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the charge pump, high density capacitors have been utilized. Nonetheless, these high density capacitors suffer from low breakdown voltage which is not compatible with the targeted high voltage application. To circumvent the breakdown limitation, a special clocking scheme is used to limit the maximum voltage across any pumping capacitor. The two charge pump circuits were fabricated in a 0:6m CMOS technology with poly0-poly1 capacitors. The output voltage of the two charge pumps reached 42:8V and 51V while the voltage across any capacitor did not exceed the value of the input voltage. Compared to other designs reported in the literature, the proposed charge pump provides the highest output voltage which makes it more suitable for tuning MEMS devices.
Cladding For Transversely-Pumped Laser Rod
Byer, Robert L.; Fan, Tso Yee
1989-01-01
Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.
Pumping behavior of sputter ion pumps
International Nuclear Information System (INIS)
Chou, T.S.; McCafferty, D.
The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed
Walking beam pumping unit system efficiency measurements
International Nuclear Information System (INIS)
Kilgore, J.J.; Tripp, H.A.; Hunt, C.L. Jr.
1991-01-01
The cost of electricity used by walking beam pumping units is a major expense in producing crude oil. However, only very limited information is available on the efficiency of beam pumping systems and less is known about the efficiency of the various components of the pumping units. This paper presents and discusses measurements that have been made on wells at several Shell locations and on a specially designed walking beam pump test stand at Lufkin Industries. These measurements were made in order to determine the overall system efficiency and efficiency of individual components. The results of this work show that the overall beam pumping system efficiency is normally between 48 and 58 percent. This is primarily dependent on the motor size, motor type, gearbox size, system's age, production, pump size, tubing size, and rod sizes
Gas Fride Heat Pumps : The Present and Future
Kurosawa, Shigekichi; Ogura, Masao
In japan techniques for saving energy is an important goal since energy resources such as oil and nuclear power are limited. Recently gas fired absorption heat pumps and gas engine driven heat pumps have been installed in facilifies such as hotels, swimming pools and offices. In this article recent techniques, applications and future aspects for gas fired heat pumps are explained.
Engineering: Liquid metal pumped at a record temperature
Lambrinou, Konstantina
2017-10-01
Although liquid metals are effective fluids for heat transfer, pumping them at high temperatures is limited by their corrosiveness to solid metals. A clever pump design addresses this challenge using only ceramics. See Article p.199
Heat pumps in district heating networks
DEFF Research Database (Denmark)
Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian
constraints limit the power plants. Efficient heat pumps can be used to decouple the constraints of electricity and heat production, while maintaining the high energy efficiency needed to match the politically agreed carbon emission goals. The requirements in terms of COP, location, capacity and economy...... and strategic planning in the energy sector. The paper presents a case study of optimal implementation of heat pumps in the present energy system of the Copenhagen area. By introduction of the correct capacity of heat pumps, a 1,6 % reduction in fuel consumption for electricity and heat production can...
Considerations for reference pump curves
International Nuclear Information System (INIS)
Stockton, N.B.
1992-01-01
This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point
International Nuclear Information System (INIS)
Butterfield, J.M.
1981-01-01
A system is considered where a number of pumps operate in parallel. Normally, all pumps operate, driven by main motors fed from the grid. Each pump has a pony motor fed from an individual battery supply. Each pony motor is normally running, but not engaged to the pump shaft. On demand, e.g. failure of grid supplies, each pony motor is designed to clutch-in automatically when the pump speed falls to a specified value. The probability of all the pony motors failing to clutch-in on demand must be demonstrated with 95% confidence to be less than 10 -8 per demand. This assessment considers how the required reliability of pony motor drives might be demonstrated in practice and the implications on choice of the number of pumps at the design stage. The assessment recognises that not only must the system prove to be extremely reliable, but that demonstration that reliability is adequate must be done during plant commissioning, with practical limits on the amount of testing performed. It is concluded that a minimum of eight pony motors should be provided, eight pumps each with one pony motor (preferred) or five pumps each with two independent pony motors. A minimum of two diverse pony motor systems should be provided. (author)
Axisymmetric pumping scheme for the thermal barrier in a tandem mirror
International Nuclear Information System (INIS)
Li, X.Z.
1985-09-01
An axisymmetric pumping scheme is proposed to pump the particles that trap in a thermal barrier without invoking the neutral beam or geodesic curvature. In this scheme a magnetic scraper is moved uni-directionally on the barrier peak to push the barely trapped particles into the central cell. We utilize a potential jump that forms at the peak field for sufficiently strong pumping. The non-collisional catching effect has to be limited by setting an upper limit on the scraping frequency of the magnetic bump. On the other hand, the dynamic stability of the pumping scheme sets a lower limit on the scraping frequency. Using the variational method, we are able to estimate the window between these two limits, which seems feasible for the Tara reactor parameter set. A primary calculation shows that the magnetic bump, ΔB/B is about 10 -4 and the scraping frequency, nu/sub sc/, is about 10 +5 sec -1 , which are similar to the parameters required for those for drift pumping
Jet pumps hydrdynamics for application on BWRS
International Nuclear Information System (INIS)
Girardi, G.; Pitimada, D.
1979-01-01
An analysis of single-phase jet-pump hydrodynamics is carried out by this paper with special regard to the applications on cooling water recirculation in the boiling water reactors (BWR). Firstly, in order to asses on efficiency of jet pumps, several theories regarding the hydrodynamic of these machines are also investigated. The results of the above theories are critically analysed and compared regarding to water-jet-pump design, to operational performance curves and to section limits. Some general criteria in jet-pump design are introduced and values of geometric and kinematic parameters are suggested together with losses coefficients which are all concerned with the ''high ratio'' type jet pump of this typical application. Finally, the experimental test program following the sim of this research is briefly described
Latest development of safeguard pumps for nuclear power stations
International Nuclear Information System (INIS)
Schill, J.; Fekadu, J.
1979-01-01
Performance testing of Residual Heat Removal (RHR) pumps and High Pressure Safety Injection (HPSI) pumps is described. RHR pump is characterised by a combination of an impeller, diffuser and has an annular pressure retaining casted casing. This casing enables a 100% radiographic examination and its geometrical pattern facilitates the use of an axi-symmetric shell model for the computer analysis. Similar considerations govern the choice of the pressure casing of the HPSI pumps. These pumps are meant for nuclear facilities and have to meet certain limiting factors which are mentioned. (M.G.B.)
End-pumped Nd:YVO4 laser with reduced thermal lensing via the use of a ring-shaped pump beam.
Lin, Di; Andrew Clarkson, W
2017-08-01
A simple approach for alleviating thermal lensing in end-pumped solid-state lasers using a pump beam with a ring-shaped intensity distribution to decrease the radial temperature gradient is described. This scheme has been implemented in a diode-end-pumped Nd:YVO 4 laser yielding 14 W of TEM 00 output at 1.064 μm with a corresponding slope efficiency of 53% and a beam propagation factor (M 2 ) of 1.08 limited by available pump power. By comparison, the same laser design with a conventional quasi-top-hat pump beam profile of approximately equal radial extent yielded only 9 W of output before the power rolled over due to thermal lensing. Further investigation with the aid of a probe beam revealed that the thermal lens power was ∼30% smaller for the ring-shaped pump beam compared to the quasi-top-hat beam. The implications for further power scaling in end-pumped laser configurations are considered.
Main coolant pump testing at Ontario Hydro
International Nuclear Information System (INIS)
Hartlen, R.
1991-01-01
This article describes Ontario Hydro Research Division's experience with a computerized data acquisition and analysis system for monitoring mechanical vibration in reactor coolant pumps. The topics covered include bench-marking of the computer system and the coolant pumps, signatures of normal and malfunctioning pumps, analysis of data collected by the monitoring system, simulation of faults, and concerns that have been expressed about data interpretation, sensor types and locations, alarm/shutdown limits and confirmation of nondestructive examination testing. This presentation consists of overheads only
Hybrid pump for Pazflor deepwater development
Energy Technology Data Exchange (ETDEWEB)
Bibet, Pierre-Jean
2010-07-01
Subsea Processing gives engineers permanent technical challenges due to the comprehensive specifications which often stretch the proven limits of technology. It is particularly true for pumps that have to boost a multiphase effluent, because they must, often at the same time, be tolerant to free gas, able to handle very viscous, generate a high ?P, and be efficient. The Pazflor project decided to base the development on full utilization of subsea pumps. This paper presents the state of the art of the pumps that are designed to be installed on the sea floor. It further describes why existing technology could not match the technical requirements for the Pazflor project. It finally presents the pump specifically developed for this world first full field's development application, the so called 'Hybrid Pump', with the description of the associated qualification program and results. (Author)
Vadiei, Nina; Shuman, Carrie A; Murthy, Manasa S; Daley, Mitchell J
2017-08-01
There is a lack of data evaluating the impact of hard limit implementation into intelligent infusion pump technology (IIPT). The purpose of this study was to determine if incorporation of vasopressor upper hard limits (UHL) into IIPT increases efficacy of alerts by preventing pump programming errors. Retrospective review from five hospitals within a single healthcare network between April 1, 2013 and May 31, 2014. A total of 65,680 vasopressor data entries were evaluated; 19,377 prior to hard limit implementation and 46,303 after hard limit implementation. The primary outcome was the percent of effective alerts. The secondary outcome was the proportional dose increase from the soft limit provided. A reduction in alert rate occurred after incorporation of hard limits to the IIPT drug library (pre-UHL 4.7% vs. post-UHL 4.0%) with a subsequent increase in the number of errors prevented as represented by a higher effective alert rate (pre-UHL 23.0% vs. post-UHL 37.3%; p < 0.001). The proportional dose increase was significantly reduced (pre-UHL 188% ± 380%] vs. post-UHL 95% ± 128%; p < 0.001). Incorporation of UHLs into IIPT in a multi-site health system with varying intensive care unit and emergency department acuity increases alert effectiveness, reduces dosing errors, and reduces the magnitude of dosing errors that reach the patient.
Vacuum pumping by the halo plasma
International Nuclear Information System (INIS)
Barr, W.L.
1985-01-01
An estimate is made of the effective vacuum pumping speed of the halo plasma in a tandem mirror fusion reactor, and it is shown that, if the electron temperature and line density are great enough, the halo can be a very good vacuum pump. One can probably obtain the required density by recycling the ions at the halo dumps. An array of small venting ports in the dump plates allows local variation of the recycle fraction and local removal of the gas at a conveniently high pressure. This vented-port concept could introduce more flexibility in the design of pumped limiters for tokamaks
International Nuclear Information System (INIS)
Ehrenberg, J.; Harbour, P.J.
1991-01-01
The enhanced wall pumping phenomenon in JET is observed for hydrogen or deuterium plasmas which are moved from the outer (larger major radius) limiter position either to the inner wall or to the top/bottom wall of the vacuum vessel. This phenomenon is analysed by employing a particle recycling model which combines plasma particle transport with particle re-emission from and retention within material surfaces. The model calculates the important experimentally observable quantities, such as particle fluxes, global particle confinement time, plasma density and density profile. Good qualitative agreement is found and, within the uncertainties, the agreement is quantitative if the wall pumping is assumed to be caused by two simultaneously occurring effects: (1) Neutral particle screening at the inner wall and the top/bottom wall is larger than that at the outer limiter because of different magnetic topologies at different poloidal positions; and (2) although most of the particles (≥ 90%) impacting on the wall can be promptly re-emitted, a small fraction (≤ 10%) of them must be retained in the wall for a period of time which is similar to or larger than the global plasma particle confinement time. However, the wall particle retention time need not be different from that of the outer limiter, i.e. pumping can occur when there is no difference between the material properties of the limiter and those of the wall. (author). 45 refs, 18 figs
Operating states of PFBR-primary sodium pump
International Nuclear Information System (INIS)
Sreedharan, K.V.; Rao, A.S.L.K.; Raju, C.; Kale, R.D.
1994-01-01
The proposed 500 MWe Prototype Fast Breeder Reactor (PFBR), the design of which is in progress at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam will be equipped with four centrifugal sodium pumps each in its primary and secondary circuits. This paper discusses the various operating states of the primary pumps viz. (i) normal steady state (ii) transient state operation. The paper also discusses the safe limits on the pump operating speed and a few design basis incidents. (author). 1 ref., 2 figs., 3 tabs
International Nuclear Information System (INIS)
Georges, J.-L.; Veyret, J.-F.
1973-01-01
Description is given of a thermo-pump for electrically conductive liquid fluids, e.g. for a liquid metal such as sodium. This pump is characterized in that the piping for the circulation of the conductive liquid is constituted by a plurality of conduits defined by two co-axial cylinders and two walls parallel to their axis. Each conduit limited outside by a magnet, inside by a mild-iron tube, and laterally by two materials forming a thermocouple. The electric current generated by that thermo-couple and the magnetic flux generated by the magnets both loop the loop through an outer cylindrical nickel shell. This can be applied to sodium circulation loops for testing nuclear fuel elements [fr
Room temperature diode-pumped Yb:CaYAlO4 laser with near quantum limit slope efficiency
International Nuclear Information System (INIS)
Tan, W D; Tang, D Y; Zhang, J; Xu, C W; Cong, Z H; Xu, X D; Li, D Z; Xu, J
2011-01-01
The room temperature continuous wave (CW) laser performance of a compact Yb:CaYAlO 4 (Yb:CYA) laser with near quantum limit slope efficiency is demonstrated. Pumped with a CW diode operating at 979 nm, the laser emitted a maximum CW output power of 2.3 W at 1050 nm. The corresponding slope efficiency was found to be 92% while the optical to optical conversion efficiency was 70%. The laser can also be continuously tuned from 1008 nm to 1063 nm using an intra-cavity SF 10 prism. The round trip cavity losses of Yb:CYA was 0.6% while the loss coefficient of the crystal was 0.01 cm -1
Carbon source from the toroidal pumped limiter during long discharge operation in Tore Supra
International Nuclear Information System (INIS)
Dufour, E.; Brosset, C.; Lowry, C.; Bucalossi, J.; Chappuis, P.; Corre, Y.; Desgranges, C.; Guirlet, R.; Gunn, J.; Loarer, T.; Mitteau, R.; Monier-Garbet, P.; Pegourie, B.; Reichle, R.; Thomas, P.; Tsitrone, E.; Hogan, J.; Roubin, P.; Martin, C.; Arnas, C.
2005-01-01
A better understanding of deuterium retention mechanisms requires the knowledge of carbon sources in Tore-Supra. The main source of carbon in the vacuum vessel during long discharges is the toroidal pumped limiter (TPL). This work is devoted to the experimental characterisation of the carbon source from the TPL surface during long discharges using a visible spectroscopy diagnostic. Moreover, we present an attempt to perform a carbon balance over a typical campaign and we discuss it with regards to the deuterium in-vessel inventory deduced from particle balance and the deuterium content of the deposited layers. The study shows that only a third of the estimated deuterium trapped in the vessel is trapped in the carbon deposits. Thus, in the present state of our knowledge and characterisation of the permanent retention, one has to search for mechanisms other than co-deposition to explain the deuterium retention in Tore Supra. (A.C.)
Estimation of free-hydrocarbon recovery from dual-pump systems
International Nuclear Information System (INIS)
Charbeneau, R.J.
1995-01-01
Free-product hydrocarbon which floats on the water table may be recovered using single-pump and dual-pump systems. The factors that affect the long-term free-product recovery using dual-pump systems include the free-product thickness as measured in monitoring wells, the ground-water pumping rate, hydrocarbon density and viscosity, and the soil permeability. This paper presents a simple model for prediction of free-product recovery using dual-pump systems. The model predicts the long-term rather than short-term recovery rates, and lends itself to spreadsheet calculations on microcomputers. A particularly simple form arises for cases where the drawdown is small. An application for estimating recovery from a dual-pump system is presented, and limitations of the model are summarized
Concrete volute pumps: technology review and improvement
Prunières, R.; Longatte, F.; Catelan, F. X.; Philippot, J. M.
2012-11-01
When pumps need to deliver large water flow rates (typically more than 5 m3.s-1), concrete volute pumps (CVP) offer an interesting alternative to standard vertical wet-pit pumps. One of the major advantages of CVP is its simplicity in terms of design, manufacturability and maintainability. In addition, CVP geometrical arrangement allows to reach high performances in terms of hydraulic and mechanical behaviour. These advantages can be specifically appreciated when such pumps are used in the energy field for Power Plants which need high flow rate and reliability, and can lead to important financial savings over the Plant lifetime compared to vertical wet-pit pumps. Finally, as CVP was for a long time limited to total head rise lower than 30 mWC, it was established through CFD analysis that the addition of guide vanes between the impeller and the volute allows to achieve higher head rise without risk.
Magnetic shielding of a limiter
International Nuclear Information System (INIS)
Brevnov, N.N.; Stepanov, S.B.; Khimchenko, L.N.; Matthews, G.F.; Goodal, D.H.J.
1991-01-01
Localization of plasma interaction with material surfaces in a separate chamber, from where the escape of impurities is hardly realized, i.e. application of magnetic divertors or pump limiters, is the main technique for reduction of the impurity content in a plasma. In this case, the production of a divertor configuration requires a considerable power consumption and results in a less effective utilization of the magnetic field volume. Utilization of a pump limiter, for example the ICL-type, under tokamak-reactor conditions would result in the extremely high and forbidden local heat loadings onto the limiter surface. Moreover, the magnetically-shielded pump limiter (MSL) was proposed to combine positive properties of the divertor and the pump limiter. The idea of magnetic shielding is to locate the winding with current inside the limiter head so that the field lines of the resultant magnetic field do not intercept the limiter surface. In this case the plasma flows around the limiter leading edges and penetrates into the space under the limiter. The shielding magnetic field can be directed either counter the toroidal field or counter the poloidal one of a tokamak, dependent on the concrete diagram of the device. Such a limiter has a number of advantages: -opportunity to control over the particle and impurity recycling without practical influence upon the plasma column geometry, - perturbation of a plasma column magnetic configuration from the side of such a limiter is less than that from the side of the divertor coils. The main deficiency is the necessity to locate active windings inside the discharge chamber. (author) 5 refs., 3 figs
Comparison of rechargeable versus battery-operated insulin pumps: temperature fluctuations.
Vereshchetin, Paul; McCann, Thomas W; Ojha, Navdeep; Venugopalan, Ramakrishna; Levy, Brian L
2016-01-01
The role of continuous subcutaneous insulin infusion (insulin pumps) has become increasingly important in diabetes management, and many different types of these systems are currently available. This exploratory study focused on the reported heating issues that lithium-ion battery-powered pumps may have during charging compared with battery-operated pumps. It was found that pump temperature increased by 6.4°C during a long charging cycle of a lithiumion battery-operated pump under ambient temperatures. In an environmental-chamber kept at 35°C, the pump temperature increased by 4.4°C, which indicates that the pump temperature was above that of the recommended safety limit for insulin storage of 37°C. When designing new pumps, and when using currently available rechargeable pumps in warmer climates, the implications of these temperature increases should be taken into consideration. Future studies should also further examine insulin quality after charging.
Mathematical modelling of flow in disc friction LVAD pump
Medvedev, A. E.; Fomin, V. M.; Prikhodko, Yu. M.; Cherniavskiy, A. M.; Fomichev, V. P.; Fomichev, A. V.; Chekhov, V. P.; Ruzmatov, T. M.
2017-10-01
The need for blood circulation support systems in the treatment of chronic heart failure is constantly increasing as 20% of patients on the waiting list die every year. Despite the great need for mechanical heart support systems the use of available systems is limited by the high cost. Therefore, further research in the field of circulatory support systems is appropriate taking into account medical and technical requirements. One of the new research areas is viscous friction disk pumps for transporting liquids based on the Tesla pump principle. The experimental model of LVAD disk pump is developed. Analytical dependencies are obtained to optimize the hydraulic parameters of the pump. On their basis, the experimental model of LVAD disk pump was designed and created. The results of analytical and experimental studies of such a pump are presented.
Method and apparatus for protection of pump systems
International Nuclear Information System (INIS)
Youngborg, L.H.
1987-01-01
This patent describes a nuclear power plant having a fluid-filler reactor vessel with a vapor outflow line for removing vapor from the reactor vessel, and liquid inflow means for injecting liquid to the reactor vessel. The inflow means includes an inflow line, a centrifugal pump disposed along the inflow line having an inlet and an outlet, an induction motor to drive the pump, flow control means along the inflow line between the pump and the reactor vessel from the pump. A means is included for generating a first control signal in response to liquid level in the reactor vessel and net vapor outflow versus liquid inflow with respect to the reactor vessel, the first control signal generating means being effective to generate a first signal to open and a second signal to close the flow control means to maintain liquid level in the vessel within predetermined limits. A pump and pump motor protection apparatus is described comprising: means for measuring the pressure of the liquid in the inlet of the pump; means for measuring the temperature of the liquid in the inlet of the pump; means for determining a required subcooling for the pump at the instantaneous temperature of the liquid in the inlet of the pump; and means for determining the enthalpy of the liquid in the inlet of the pump from the pressure and temperature of the liquid
Book of presentations of the International Workshop on High Temperature Heat Pumps
DEFF Research Database (Denmark)
Modern society moves towards an electrifed energy system based on wind, solarand other renewable sources. Utilizing these sources effciently by heat pumps ishighly attractive and a significant potential for improving the energy system byextensive adaptation of heat pumping technology in all fields...... exists. However, challenges are present for heat pump technology. In particular for high temperature applications like industrial processes and to some extent district heating, heat pumps are not yet commercially available. In some countries the expansion already occurs, but other places the development...... is much more limited. Some obstacles relate to regulations and boundary conditions which may not be favorablefor heat pumps and electrification. But, the level of the technology willprobably also improve with regards to temperature limits, efficiency, capacity, and economy, and hence inherently become...
Radiance limits of ceramic phosphors under high excitation fluxes
Lenef, Alan; Kelso, John; Zheng, Yi; Tchoul, Maxim
2013-09-01
Ceramic phosphors, excited by high radiance pump sources, offer considerable potential for high radiance conversion. Interestingly, thermodynamic arguments suggest that the radiance of the luminescent spot can even exceed that of the incoming light source. In practice, however, thermal quenching and (non-thermal) optical saturation limit the maximum attainable radiance of the luminescent source. We present experimental data for Ce:YAG and Ce:GdYAG ceramics in which these limits have been investigated. High excitation fluxes are achieved using laser pumping. Optical pumping intensities exceeding 100W/mm2 have been shown to produce only modest efficiency depreciation at low overall pump powers because of the short Ce3+ lifetime, although additional limitations exist. When pump powers are higher, heat-transfer bottlenecks within the ceramic and heat-sink interfaces limit maximum pump intensities. We find that surface temperatures of these laser-pumped ceramics can reach well over 150°C, causing thermal-quenching losses. We also find that in some cases, the loss of quantum efficiency with increasing temperature can cause a thermal run-away effect, resulting in a rapid loss in converted light, possibly over-heating the sample or surrounding structures. While one can still obtain radiances on the order of many W/mm2/sr, temperature quenching effects ultimately limit converted light radiance. Finally, we use the diffusion-approximation radiation transport models and rate equation models to simulate some of these nonlinear optical pumping and heating effects in high-scattering ceramics.
Modulation above Pump Beam Energy in Photoreflectance
Directory of Open Access Journals (Sweden)
D. Fuertes Marrón
2017-01-01
Full Text Available Photoreflectance is used for the characterisation of semiconductor samples, usually by sweeping the monochromatized probe beam within the energy range comprised between the highest value set up by the pump beam and the lowest absorption threshold of the sample. There is, however, no fundamental upper limit for the probe beam other than the limited spectral content of the source and the responsivity of the detector. As long as the modulation mechanism behind photoreflectance does affect the complete electronic structure of the material under study, sweeping the probe beam towards higher energies from that of the pump source is equally effective in order to probe high-energy critical points. This fact, up to now largely overseen, is shown experimentally in this work. E1 and E0 + Δ0 critical points of bulk GaAs are unambiguously resolved using pump light of lower energy. This type of upstream modulation may widen further applications of the technique.
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
Multistage quantum absorption heat pumps.
Correa, Luis A
2014-04-01
It is well known that heat pumps, while being all limited by the same basic thermodynamic laws, may find realization on systems as "small" and "quantum" as a three-level maser. In order to quantitatively assess how the performance of these devices scales with their size, we design generalized N-dimensional ideal heat pumps by merging N-2 elementary three-level stages. We set them to operate in the absorption chiller mode between given hot and cold baths and study their maximum achievable cooling power and the corresponding efficiency as a function of N. While the efficiency at maximum power is roughly size-independent, the power itself slightly increases with the dimension, quickly saturating to a constant. Thus, interestingly, scaling up autonomous quantum heat pumps does not render a significant enhancement beyond the optimal double-stage configuration.
LMFBR with booster pump in pumping loop
International Nuclear Information System (INIS)
Rubinstein, H.J.
1975-01-01
A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation
Toothed gear pumps for special applications; Zahnradpumpen fuer Sonderanwendungen
Energy Technology Data Exchange (ETDEWEB)
Kremer, H. [WITTE PUMPS und TECHNOLOGY GmbH, Uetersen (Germany)
2007-07-01
Gear pumps are utilized in a big variety of industrial processes. This essay discusses the typical applications gear pumps are used for. Based on the general function of gear pumps the technical features of these different pump types are pointed out. The process parameters have been more or less the same for the last decades. Nowadays a higher demand regarding pressures and temperatures, sometimes even a combination of both, can be observed. This development is the challenge to go for special constructions and new materials. The range of applications is extended step by step, always aware of the fact, that these gear pumps are often operating at their specific limits. Finally some examples right from the plant give an overview over this development. (orig.)
Assessing braze quality in the actively cooled Tore Supra phase III outboard pump limiter
International Nuclear Information System (INIS)
Hygren, R.; Lutz, T.; Miller, J.
1994-01-01
This paper discusses the assessment of quality of brazing of pyrolytic graphite (PG) armor brazed to copper tubes in Tore Supra's Phase III Outboard Pump Limiter (OPL). The limiter head is a bank of 14 water-cooled copper tubes with several hundred brazed PG tiles. Braze quality was first assessed through pre-service qualification testing of individual copper/tiles assemblies. The quality of brazes was evaluated using (non-destructive) transient heating (open-quotes hot waterclose quotes) tests performed in the high temperature, high pressure flow loop at Sandia's Plasma Materials Test Facility. The surface temperatures of tiles were monitored with an infra-red (IR) camera as water at 120 degrees C water at about 2.07 MPa (300 psi) passed through a tube assembly initially at 30 degrees C. For tiles with braze voids or cracks, the surface temperatures lagged behind those of adjacent well bonded tiles. Temperature lags were correlated with flaw sizes observed during repairs using a detailed 2-D heat transfer analyses. open-quotes Badclose quotes tiles, i.e., temperature lags of 10-20 degrees C depending upon tile's size, were easy to detect and, when removed, revealed braze voids of roughly 50% of the joint area. 11 of the 14 tubes were rebrazed after bad tiles were detected and removed. Three tubes were re-brazed twice
Efficient Ho:YLF laser pumped by a Tm:fiber laser
CSIR Research Space (South Africa)
Koen, W
2013-10-01
Full Text Available A thulium fiber laser pumped Ho:YLF laser delivering 45.1 W in a near diffraction limited beam when pumped with 84.7 W is demonstrated. The optical-to-optical efficiency of 53 % compares favorably with similar Ho:YAG lasers....
The pumping of hydrogen and helium by sputter-ion pumps
International Nuclear Information System (INIS)
Welch, K.M.; Pate, D.J.; Todd, R.J.
1992-01-01
The pumping of hydrogen in diode and triode sputter-ion pumps is discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium or titanium alloy anodes is also shown to measurably impact on the speed of these pumps at.very low pressures. This stems from the fact that hydrogen is x10 6 more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Lastly, quantitative data are given for the He speeds and capacities of both noble and conventional diode and triode pumps. The effectiveness of various pump regeneration procedures, subsequent to the pumping of He, is reported.These included bakeout and N 2 glow discharge cleaning. The comparative desorption of He with the subsequent pumping of N 2 is reported on. The N 2 speed of these pumps was used as the benchmark for defining the size of the pumps vs. their respective He speeds
International Nuclear Information System (INIS)
Le Frere, J.P.
1984-01-01
Pumps used to pump liquid metals depend on the liquid metal and on the type of application concerned. One deals more particularly with electromagnetic pumps, the main pumps used with mechanical pumps. To pump sodium in the nuclear field, these two types of pumps are used; the pumps of different circuits of Super Phenix are presented and described [fr
Feasibility study on the type of KALIMER coolant circulation pump
International Nuclear Information System (INIS)
Nam, H. Y.; Kim, Y. K.; Lee, Y. B.; Hwang, J. S.; Choi, S. K.
1997-07-01
The characteristics of mechanical pump and electromagnetic (EM) pump for liquid sodium coolant in a liquid metal reactor are compared and analysed as a design concept of KALIMER coolant pumps. The type of coolant circulation pump affects the selection of reactor type, economics, and reliability of reactor. Though the mechanical pump has much application experience and give satisfaction to the reliability of developed reactor type, the possibility of development is limited and its large weight and volume have a negative effect on the design of the economical liquid metal reactor. The large scale electromagnetic pump has not been verified yet, but it is expected to be demonstrated in time. Because the size of EM pump is small relative to the mechanical pump, the compact reactor design is possible. Therefore the selection of EM pump can be one of the methods to improve the economics. Since the shape of EM pump can be varied according to the arrangement of electromagnet coils, a new or unique reactor type can be developed easily in the process of KALIMER development. In the view point of economic LMR development, it is desirable to adopt the electromagnetic pump. (author). 50 refs., 11 tabs., 24 figs
Investigation of pump and pump switch failures in rainwater harvesting systems
Moglia, Magnus; Gan, Kein; Delbridge, Nathan; Sharma, Ashok K.; Tjandraatmadja, Grace
2016-07-01
Rainwater harvesting is an important technology in cities that can contribute to a number of functions, such as sustainable water management in the face of demand growth and drought as well as the detention of rainwater to increase flood protection and reduce damage to waterways. The objective of this article is to investigate the integrity of residential rainwater harvesting systems, drawing on the results of the field inspection of 417 rainwater systems across Melbourne that was combined with a survey of householders' situation, maintenance behaviour and attitudes. Specifically, the study moves beyond the assumption that rainwater systems are always operational and functional and draws on the collected data to explore the various reasons and rates of failure associated with pumps and pump switches, leaving for later further exploration of the failure in other components such as the collection area, gutters, tank, and overflows. To the best of the authors' knowledge, there is no data like this in academic literature or in the water sector. Straightforward Bayesian Network models were constructed in order to analyse the factors contributing to various types of failures, including system age, type of use, the reason for installation, installer, and maintenance behaviour. Results show that a number of issues commonly exist, such as failure of pumps (5% of systems), automatic pump switches that mediate between the tank and reticulated water (9% of systems), and systems with inadequate setups (i.e. no pump) limiting their use. In conclusion, there appears to be a lack of enforcement or quality controls in both installation practices by sometimes unskilled contractors and lack of ongoing maintenance checks. Mechanisms for quality control and asset management are required, but difficult to promote or enforce. Further work is needed into how privately owned assets that have public benefits could be better managed.
The Tore Supra toroidal pump limiter: experience feedback of HHF elements series manufacture
Energy Technology Data Exchange (ETDEWEB)
Cordier, J.J.; Bayetti, P.; Chappuis, P.; Durocher, A.; Escourbiac, F.; Grosman, A.; Lipa, M.; Mitteau, R.; Schlosser, J.; Van Houtte, D
2003-07-01
Since 1992, reliable High Heat Flux PFCs based on copper alloy heat sink structures and a CFC armour, have been developed. The final result is an actively cooled high heat flux element that is capable of removing up to 10 MW.m{sup -2} in stationary operating conditions. About 600 of these high performance individual components have then been manufactured and assembled in order to equip a Toroidal Pump Limiter (TPL). The final deliveries was successfully achieved end of 2001. The paper deals with the experience feedback built-up along the four years duration of the TPL components manufacture. We will show where issues were encountered, how solutions were found to achieve the fabrication of components and will highlight what are the main technical lessons to be learned: acceptance criteria, choice of materials, margins of processes. Finally a proposal of an alternative optimised design is presented, fruit of the experience gained from this up to now, unique series manufacture of actively cooled plasma facing HHF components. We believe that such experience will certainly be of use to ITER as well as to Wendelstein 7-X as far as PFC is concerned. (authors)
DEFF Research Database (Denmark)
Ommen, Torben Schmidt; Jensen, Jonas Kjær; Markussen, Wiebke Brix
2015-01-01
A large amount of operational and economic constraints limit the applicability of heat pumps operated with natural working fluids. The limitations are highly dependent on the integration of heat source and sink streams. An evaluation of feasible operating conditions was carried out considering......, the transcritical R744 expands the working domain for low sink outlet temperatures....
Continuously pumping and reactivating gas pump
International Nuclear Information System (INIS)
Batzer, T.H.; Call, W.R.
1984-01-01
Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped
Continuously pumping and reactivating gas pump
Batzer, Thomas H.; Call, Wayne R.
1984-01-01
Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.
Particles pumping in Tore Supra
International Nuclear Information System (INIS)
Bonnel, P.; Chappuis, P.; Lipa, M.
1989-01-01
TORE SUPRA and its peripheral equipments are provided with routine clean high vacuum by turbomolecular pumping. During plasma discharges large quantity of very hot gases activating at plasma edge and plasma density in scrape off layer has to be controlled before they strike violently solid wall provoking increase in impurities content and make density up to disruptive level. A Magnetic Ergodic Divertor made of six winding structures - MED - six Vertical Pumped Limiters - VPL - and one Horizontal Pumped Limiter - HPL - are set in the vacuum chamber in order to cope with plasma-wall interactions and neutral gas recycling. Each apparatus is equipped at front side with thermal shield respectively made of polycristallin and pyrolitic graphite bolted on stainless steel support for MED and HPL whereas for VPL it is made of CFC Aerolor 05 brazed on hardened copper. The total heat removal capacity of these plasma facing components is 12 MW. Design of particles collection openings and ducts conductance allow 10% of capture efficiency, that means for TORE SUPRA a flux of 3 x 10 21 particles/second has to be sorbed by water cooled titanium getter pumps, settled at rear side. All those facilities were put into plasma operation at the beginning of 1989 for a short time. Preliminary observations go along with theoretical predictions, that actions in scrappe-off layer may provoke effects in bulk plasma. Very first results drawn out, show that particle collection and heat removal were effective by MED, VPL and HPL and that plasma behaviour was not disturbed by their presence and actions but instead tendency to improvement was observed
A "place n play" modular pump for portable microfluidic applications.
Li, Gang; Luo, Yahui; Chen, Qiang; Liao, Lingying; Zhao, Jianlong
2012-03-01
This paper presents an easy-to-use, power-free, and modular pump for portable microfluidic applications. The pump module is a degassed particle desorption polydimethylsiloxane (PDMS) slab with an integrated mesh-shaped chamber, which can be attached on the outlet port of microfluidic device to absorb the air in the microfluidic system and then to create a negative pressure for driving fluid. Different from the existing monolithic degassed PDMS pumps that are generally restricted to limited pumping capacity and are only compatible with PDMS-based microfluidic devices, this pump can offer various possible configures of pumping power by varying the geometries of the pump or by combining different pump modules and can also be employed in any material microfluidic devices. The key advantage of this pump is that its operation only requires the user to place the degassed PDMS slab on the outlet ports of microfluidic devices. To help design pumps with a suitable pumping performance, the effect of pump module geometry on its pumping capacity is also investigated. The results indicate that the performance of the degassed PDMS pump is strongly dependent on the surface area of the pump chamber, the exposure area and the volume of the PDMS pump slab. In addition, the initial volume of air in the closed microfluidic system and the cross-linking degree of PDMS also affect the performance of the degassed PDMS pump. Finally, we demonstrated the utility of this modular pumping method by applying it to a glass-based microfluidic device and a PDMS-based protein crystallization microfluidic device.
Assessing braze quality in the actively cooled Tore Supra Phase III outboard pump limiter
International Nuclear Information System (INIS)
Nygren, R.E.; Lutz, T.L.; Miller, J.D.; McGrath, R.; Dale, G.
1994-01-01
The quality of brazing of pyrolytic graphite armor brazed to copper tubes in Tore Supra's Phase III Outboard Pump Limiter was assessed through pre-service qualification testing of individual copper/tile assemblies. The evaluation used non-destructive, hot water transient heating tests performed in the high-temperature, high-pressure flow loop at Sandia's Plasma Materials Test Facility. Surface temperatures of tiles were monitored with an infrared camera as water at 120 degrees C at about 2.07 MPa (300 psi) passed through a tube assembly initially at 30 degrees C. For tiles with braze voids or cracks, the surface temperatures tagged behind those of adjacent well-bonded tiles. Temperature tags were correlated with flaw sizes observed during repairs based upon a detailed 2-D heat transfer analyses. open-quotes Badclose quotes tiles, i.e., temperature tags of 10-20 degrees C depending upon tile's size, were easy to detect and, when removed, revealed braze voids of roughly 50% of the joint area. Eleven of the 14 tubes were rebrazed after bad tiles were detected and removed. Three tubes were rebrazed twice
Signal-to-pump back action and self-oscillation in double-pump Josephson parametric amplifier
International Nuclear Information System (INIS)
Kamal, Archana; Marblestone, Adam; Devoret, Michel
2009-01-01
We present the theory of a Josephson parametric amplifier employing two-pump sources. Our calculations are based on input-output theory, and can easily be generalized to any coupled system involving parametric interactions. We analyze the operation of the device, taking into account the feedback introduced by the reaction of the signal and noise on the pump power, and in this framework, compute the response functions of interest--signal and idler gains, internal gain of the amplifier, and self-oscillation signal amplitude. To account for this back action between signal and pump, we adopt a mean-field approach and self-consistently explore the boundary between amplification and self-oscillation. The coincidence of bifurcation and self-oscillation thresholds reveals that the origin of coherent emission of the amplifier lies in the multiwave mixing of the noise components. Incorporation of the back action leads the system to exhibit hysteresis, dependent on parameters such as temperature and detuning from resonance. Our analysis also shows that the resonance condition itself changes in the presence of back action and this can be understood in terms of the change in plasma frequency of the junction. The potential of the double-pump amplifier for quantum-limited measurements and as a squeezer is also discussed.
International Nuclear Information System (INIS)
Ralph, J. E.; Marsh, K. A.; Pak, A. E.; Lu, W.; Clayton, C. E.; Fang, F.; Joshi, C.; Tsung, F. S.; Mori, W. B.
2009-01-01
A study of self-guiding of ultra short, relativistically intense laser pulses is presented. Here, the laser pulse length is on the order of the nonlinear plasma wavelength and the normalized vector potential is greater than one. Self-guiding of ultrashort laser pulses over tens of Rayliegh lengths is possible when driving a highly nonlinear wake. In this case, self-guiding is limited by nonlinear pump depletion. Erosion of the pulse due to diffraction at the head of the laser pulse is minimized for spot sizes close to the blow-out radius. This is due to the slowing of the group velocity of the photons at the head of the laser pulse. Using an approximately 10 TW Ti:Sapphire laser with a pulse length of approximately 50 fs, experimental results are presented showing self-guiding over lengths exceeding 30 Rayliegh lengths in various length Helium gas jets. Fully explicit 3D PIC simulations supporting the experimental results are also presented.
Wan, You-peng; Yin, Kui-hao; Peng, Sheng-hua
2015-06-01
Taking a pumped storage reservoir located in southern China as the research object, the paper established a three-dimensional hydrodynamic and eutrophication model of the reservoir employing EFDC (environmental fluid dynamics code) model, calibrated and verified the model using long-term hydraulic and water quality data. Based on the model results, the effects of nitrogen and phosphorus concentrations on the algae growth were analyzed, and the response of algae to nitrogen and phosphorus concentration and quantity of pumping water was also calculated. The results showed that the nitrogen and phosphorus concentrations had little limit on algae growth rate in the reservoir. In the nutrients reduction scenarios, reducing phosphorus would gain greater algae biomass reduction than reducing nitrogen. When reducing 60 percent of nitrogen, the algae biomass did not decrease, while 12.4 percent of algae biomass reduction could be gained with the same reduction ratio of phosphorus. When the reduction ratio went to 90 percent, the algae biomass decreased by 17.9 percent and 35.1 percent for nitrogen and phosphorus reduction, respectively. In the pumping water quantity regulation scenarios, the algae biomass decreased with the increasing pumping water quantity when the pumping water quantity was greater than 20 percent of the current value; when it was less than 20 percent, the algae biomass increased with the increasing pumping water quantity. The algae biomass decreased by 25.7 percent when the pumping water quantity was doubled, and increased by 38.8 percent when it decreased to 20 percent. The study could play an important role in supporting eutrophication controlling in water source area.
1-kilowatt CW all-fiber laser oscillator pumped with wavelength-beam-combined diode stacks.
Xiao, Y; Brunet, F; Kanskar, M; Faucher, M; Wetter, A; Holehouse, N
2012-01-30
We have demonstrated a monolithic cladding-pumped ytterbium-doped single all-fiber laser oscillator generating 1 kW of CW signal power at 1080 nm with 71% slope efficiency and near diffraction-limited beam quality. Fiber components were highly integrated on "spliceless" passive fibers to promote laser efficiency and alleviate non-linear effects. The laser was pumped through a 7:1 pump combiner with seven 200-W 91x nm fiber-pigtailed wavelength-beam-combined diode-stack modules. The signal power of such a single all-fiber laser oscillator showed no evidence of roll-over, and the highest output was limited only by available pump power.
International Nuclear Information System (INIS)
Sibuet, R
2008-01-01
For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R and D/industries, merits over conventional pumps and future growth scope will be discussed
Off-Pump Versus On-Pump Coronary Artery Bypass Grafting
DEFF Research Database (Denmark)
Møller, Christian H; Steinbrüchel, Daniel A
2014-01-01
Coronary artery bypass grafting (CABG) remains the preferred treatment in patients with complex coronary artery disease. However, whether the procedure should be performed with or without the use of cardiopulmonary bypass, referred to as off-pump and on-pump CABG, is still up for debate....... Intuitively, avoidance of cardiopulmonary bypass seems beneficial as the systemic inflammatory response from extracorporeal circulation is omitted, but no single randomized trial has been able to prove off-pump CABG superior to on-pump CABG as regards the hard outcomes death, stroke or myocardial infarction....... In contrast, off-pump CABG is technically more challenging and may be associated with increased risk of incomplete revascularization. The purpose of the review is to summarize the current literature comparing outcomes of off-pump versus on-pump coronary artery bypass surgery....
Thermoeconomic comparison of industrial heat pumps
DEFF Research Database (Denmark)
Ommen, Torben Schmidt; Markussen, Christen Malte; Reinholdt, L.
2011-01-01
Four natural working fluids in various heat pump cycles are expected to cover the heating range between 50oC and 150°C. The different thermodynamic cycles are the Condensing Vapour, Transcritical and Compression/Absorption. As the considered technologies have significant differences in application......, limitations and design, a generic comparison is used. To establish the optimal individual temperature range of operation, a thermoeconomic evaluation is performed, with heat price as the decision parameter. Each individual heat pump is favourable in specific temperature intervals, which will vary according...... to the temperature lift between sink and source. At temperature lifts below 30°C the entire temperature range is covered. Exceeding this temperature lift, the range of sink temperatures is not completely covered above 125°C. Three of the heat pumps prove very cost competitive when compared to heating with natural...
Investigation into the pumping characteristics of ITER cryopumps
International Nuclear Information System (INIS)
Day, C.; Mack, A.
1998-01-01
Within the framework of the European fusion technology programme, a cryopump system for ITER is being developed. It is based on combined sorption and condensation of gases at SK-surfaces, which are coated with activated charcoal. For verification of the design conditions an experimental programme has been launched. The tested cryopanels followed a quilted design, which is currently being discussed for its use in ITER. According to the composition range of the ITER exhaust gas in the various operation modes foreseen, pure gases (protium, deuterium, helium and neon) and gas mixtures (pseudobinaries of a D 2 -based mixture and one noble gas out of helium, neon or argon) were investigated. Quantitative measurements of pumping speed and equilibrium pressures at zero flow conditions were performed as a function of gas load; relative pumping probabilities were also derived. It is revealed that protium is pumped by sorption whereas neon is pumped by sublimation and deuterium is subjected to both mechanisms. The results demonstrate that the required pump ultimate pressure can be achieved. It is further shown that for the gases investigated the pumping characteristics will not be a limiting factor; the ITER requirements are well achieved. The saturation capacity will not be reached, except if pure helium is pumped. (orig.)
Von Cube, Hans Ludwig; Goodall, E G A
2013-01-01
Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno
Pennell, William E.
1982-01-01
The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.
International Nuclear Information System (INIS)
Pennell, W.E.
1982-01-01
The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair
Study of a new hydraulic pumping unit based on the offshore platform
Yu, Yanqun; Chang, Zongyu; Qi, Yaoguang; Xue, Xin; Zhao, Jiannan
2017-01-01
This article introduces a new technology about a rod pumping in the offshore platform according to the demand of offshore heavy oil thermal recovery and the production of stripper well, analyzes the research status of hydraulic pumping unit at home and abroad, and designs a new kind of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure to resolve the problem of space limitation. The article also describes the whole structure and the working principle of...
Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski
2013-01-01
Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o
Long-term safety issues associated with mixer pump operation
International Nuclear Information System (INIS)
Kubic, W.L. Jr.
1994-01-01
In this report, we examine several long-term issues: the effect of pump operation on future gas release events (GREs), uncontrolled chemical reactions, chronic toxic gas releases, foaming, and erosion and corrosion. Heat load in excess of the design limit, uncontrolled chemical reactions, chronic toxic gas releases, foaming, and erosion and corrosion have been shown not to be safety concerns. The effect of pump operation on future GREs could not be quantified. The problem with evaluating the long-term effects of pump operation on GREs is a lack of knowledge and uncertainty. In particular, the phenomena governing gas retention, particle size distribution, and settling are not well understood, nor are the interactions among these factors understood. There is a possibility that changes in these factors could increase the size of future GREs. Bounding estimates of the potential increase in size of GREs are not possible because of a lack of engineering data. Proper management of the hazards can reduce, but not eliminate, the possibility of undesirable changes. Maintaining temperature within the historical limits can reduce the possibility of undesirable changes. A monitoring program to detect changes in the gas composition and crust thickness will help detect slowly occurring changes. Because pump operation has be shown to eliminate GREs, continued pump operation can eliminate the hazards associated with future GREs
ATES/heat pump simulations performed with ATESSS code
Vail, L. W.
1989-01-01
Modifications to the Aquifer Thermal Energy Storage System Simulator (ATESSS) allow simulation of aquifer thermal energy storage (ATES)/heat pump systems. The heat pump algorithm requires a coefficient of performance (COP) relationship of the form: COP = COP sub base + alpha (T sub ref minus T sub base). Initial applications of the modified ATES code to synthetic building load data for two sizes of buildings in two U.S. cities showed insignificant performance advantage of a series ATES heat pump system over a conventional groundwater heat pump system. The addition of algorithms for a cooling tower and solar array improved performance slightly. Small values of alpha in the COP relationship are the principal reason for the limited improvement in system performance. Future studies at Pacific Northwest Laboratory (PNL) are planned to investigate methods to increase system performance using alternative system configurations and operations scenarios.
In situ performance curves measurements of large pumps
International Nuclear Information System (INIS)
Anton, A
2010-01-01
The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.
In situ performance curves measurements of large pumps
Anton, A.
2010-08-01
The complex energetic system on the river Lotru in Romania comprises of a series of lakes and pumping stations and a major hydroelectric power plant: Lotru-Ciunget. All the efforts have been oriented towards the maintenance of the Pelton turbines and very little attention has been directed to the pumps. In the system, there are three large pumping stations and only in the last 5 years, the pump performances have become a concern. The performances where determined using portable ultrasonic flow meters, a Yates meter, precision manometers and appropriate electrical equipment for power measurement (Power Analiser - NORMA D4000 LEM). The measurements are not supposed to interfere with the normal operation so only a limited number of tests could be performed. Based on those tests, portions of the test curves have been measured and represented in specific diagrams.
Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump
Li, Tao; Zhang, Weiming; Jiang, Ming; Li, Zhengyang
2013-01-01
A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...
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
FIX-II/2032, BWR Pump Trip Experiment 2032, Simulation Mass Flow and Power Transients
International Nuclear Information System (INIS)
1988-01-01
1 - Description of test facility: In the FIX-II pump trip experiments, mass flow and power transients were simulated subsequent to a total loss of power to the recirculation pumps in an internal pump boiling water reactor. The aim was to determine the initial power limit to give dryout in the fuel bundle for the specified transient. In addition, the peak cladding temperature was measured and the rewetting was studied. 2 - Description of test: Pump trip experiment 2032 was a part of test group 2, i.e. the mass flow transient was to simulate the pump coast down with a pump inertia of 11.3 kg.m -2 . The initial power in the 36-rod bundle was 4.44 MW which gave dryout after 1.4 s from the start of the flow transient. A maximum rod cladding temperature of 457 degrees C was measured. Rewetting was obtained after 7.6 s. 3 - Experimental limitations or shortcomings: No ECCS injection systems
Management of insulin pump therapy in children with type 1 diabetes.
Abdullah, Nadeem; Pesterfield, Claire; Elleri, Daniela; Dunger, David B
2014-12-01
Insulin pump therapy is a current treatment option for children and adolescents with type 1 diabetes. Insulin pumps can provide a greater flexibility in insulin administration and meal planning, as compared with multiple insulin injections, and they may be particularly suitable for the paediatric age group. Many young people with diabetes have integrated insulin pumps into their daily practice. The use of insulin pumps can also be supplemented by the information retrieved from continuous glucose monitoring in the sensor-augmented pump therapy, which may improve glycaemic control. In this review, we describe the principles of pump therapy and summarise features of commercially available insulin pumps, with focus on practical management and the advantages and disadvantages of this technology. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
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Pumping characteristics of sputter ion pump (SIP) and titanium sublimation pump (TSP) combination
International Nuclear Information System (INIS)
Ratnakala, K.C.; Patel, R.J.; Bhavsar, S.T.; Pandiyar, M.L.; Ramamurthi, S.S.
1995-01-01
For achieving hydrocarbon free, clean ultra high vacuum, SIP-TSP combination is one of the ideal choice for pumping. For the SRS facility in Centre for Advanced Technology (CAT), we are utilising this combination, enmass. For this purpose, two modules of these combination set-ups are assembled, one with the TSP as an integral part of SIP and the other, with TSP as a separate pump mounted on the top of SIP. The pump bodies were vacuum degassed at 700 degC at 10 -5 mbar for 3 hrs. An ultimate vacuum of 3 x 10 -11 mbar was achieved, after a bake-out at 250 degC for 4 hrs, followed by continuous SIP pumping for 48 hrs, with two TSP flashing at approximately 10 hrs interval. The pump-down patterns as well as the pressure-rise patterns are studied. (author). 2 refs., 5 figs
Detailed characterization of CW- and pulsed-pump four-wave mixing in highly nonlinear fibers
DEFF Research Database (Denmark)
Lillieholm, Mads; Galili, Michael; Grüner-Nielsen, L.
2016-01-01
We present a quantitative comparison of continuouswave- (CW) and pulsed-pump four-wave mixing (FWM) in commercially available highly nonlinear fibers (HNLFs), and suggest properties for which the CW and pulsed FWM bandwidths are limited in practice. The CWand pulsed-pump parametric gain is charac......We present a quantitative comparison of continuouswave- (CW) and pulsed-pump four-wave mixing (FWM) in commercially available highly nonlinear fibers (HNLFs), and suggest properties for which the CW and pulsed FWM bandwidths are limited in practice. The CWand pulsed-pump parametric gain...... bandwidth. However, an inverse scaling of the TOD with the dispersion fluctuations, leads to different CW-optimized fibers, which depend only on the even dispersion-orders....
Using Composite Materials in a Cryogenic Pump
Batton, William D.; Dillard, James E.; Rottmund, Matthew E.; Tupper, Michael L.; Mallick, Kaushik; Francis, William H.
2008-01-01
Several modifications have been made to the design and operation of an extended-shaft cryogenic pump to increase the efficiency of pumping. In general, the efficiency of pumping a cryogenic fluid is limited by thermal losses which is itself caused by pump inefficiency and leakage of heat through the pump structure. A typical cryogenic pump includes a drive shaft and two main concentric static components (an outer pressure containment tube and an intermediate static support tube) made from stainless steel. The modifications made include replacement of the stainless-steel drive shaft and the concentric static stainless-steel components with components made of a glass/epoxy composite. The leakage of heat is thus reduced because the thermal conductivity of the composite is an order of magnitude below that of stainless steel. Taking advantage of the margin afforded by the decrease in thermal conductivity, the drive shaft could be shortened to increase its effective stiffness, thereby increasing the rotordynamic critical speeds, thereby further making it possible to operate the pump at a higher speed to increase pumping efficiency. During the modification effort, an analysis revealed that substitution of the shorter glass/epoxy shaft for the longer stainless-steel shaft was not, by itself, sufficient to satisfy the rotordynamic requirements at the desired increased speed. Hence, it became necessary to increase the stiffness of the composite shaft. This stiffening was accomplished by means of a carbon-fiber-composite overwrap along most of the length of the shaft. Concomitantly with the modifications described thus far, it was necessary to provide for joining the composite-material components with metallic components required by different aspects of the pump design. An adhesive material formulated specially to bond the composite and metal components was chosen as a means to satisfy these requirements.
Optical--microwave pumping of alkali atoms and population capture
International Nuclear Information System (INIS)
Aleksandrov, E.B.; Vershovskii, A.K.
1985-01-01
The steady-state distribution of the populations of the hyperfine sublevels of the ground state of alkali atoms is calculated for the case in which the atoms are subjected to a spectrally selective optical pumping on 2 S 1 /sub // 2 -- 2 P/sub 1/2,3/2/ transitions and a simultaneous pumping by microwave fields which are at resonance with transitions in the hyperfine structure of the ground state, F = 2, M/sub F/ = +- 2, +- 1bold-arrow-left-rightF = 1, M/sub F/ = +- 1. The addition of the microwave pumping is shown to substantially increase the population difference for the O--O transition in the hyperfine structure. During selective optical pumping of the F = 1 level, the population inversion which can be achieved for the O--O transition is limited by the effect of population capture. This capture can be eliminated by using incoherent microwave fields. The quality factor of the O--O resonance is calculated as a function of the parameters of the pump. The outlook for the use of composite pumping in frequency-stabilization systems is discussed
Seven-laser diode end-pumped Nd
International Nuclear Information System (INIS)
Berger, J.; Welch, D.F.; Streifer, W.; Scifres, D.R.; Smith, J.J.; Hoffman, H.J.; Peisley, D.; Radecki, D.
1988-01-01
End pumping of solid-state lasers by single semiconductor laser diode arrays (LDAs) is efficient, but the maximum pump power is limited by the source brightness and matching the TEM/sub 00/ Nd:YAG cavity mode. To increase the output power from a solid-state Nd:YAG laser, one option is to employ a multiplicity of LDA to provide more pump power than is available from a single source. The authors report herein a 660-mW cw TEM/sub 00/ Nd:YAG laser, end-pumped by seven LDA, with bundled optical fibers coupling the light from each diode to the Nd:YAG rod end. The maximum electrical-to-optical conversion efficiency attained was 4.7% at 560-mW Nd:YAG output power. The LDAs (SDL-2430-C, 100 μm wide) were mounted on separate thermoelectric coolers to tune emission wavelength to the Nd:YAG absorption bands. The diodes were operated at their rated output power (50,000 h mean time to failure). The 110/125-μm diam 0.37-N.A. fibers were butt coupled to the lasers and glued together into a hexagonal close pack. The authors have obtained the highest average power demonstrated to date in the TEM/sub 00/ mode from a Nd:YAG laser, reliably end-pumped by multiple laser diodes with good efficiency
Asymmetric Functional Conversion of Eubacterial Light-driven Ion Pumps*
Inoue, Keiichi; Nomura, Yurika; Kandori, Hideki
2016-01-01
In addition to the well-known light-driven outward proton pumps, novel ion-pumping rhodopsins functioning as outward Na+ and inward Cl− pumps have been recently found in eubacteria. They convert light energy into transmembrane electrochemical potential difference, similar to the prototypical archaeal H+ pump bacteriorhodopsin (BR) and Cl− pump halorhodopsin (HR). The H+, Na+, and Cl− pumps possess the conserved respective DTE, NDQ, and NTQ motifs in the helix C, which likely serve as their functional determinants. To verify this hypothesis, we attempted functional interconversion between selected pumps from each category by mutagenesis. Introduction of the proton-pumping motif resulted in successful Na+ → H+ functional conversion. Introduction of the respective characteristic motifs with several additional mutations leads to successful Na+ → Cl− and Cl− → H+ functional conversions, whereas remaining conversions (H+ → Na+, H+ → Cl−, Cl− → Na+) were unsuccessful when mutagenesis of 4–6 residues was used. Phylogenetic analysis suggests that a H+ pump is the common ancestor of all of these rhodopsins, from which Cl− pumps emerged followed by Na+ pumps. We propose that successful functional conversions of these ion pumps are achieved exclusively when mutagenesis reverses the evolutionary amino acid sequence changes. Dependence of the observed functional conversions on the direction of evolution strongly suggests that the essential structural mechanism of an ancestral function is retained even after the gain of a new function during natural evolution, which can be evoked by a few mutations. By contrast, the gain of a new function needs accumulation of multiple mutations, which may not be easily reproduced by limited mutagenesis in vitro. PMID:26929409
International Nuclear Information System (INIS)
Chavez, R.V.; Ekeroth, D.E.; Johnson, F.T.; Matusz, J.M.
1994-01-01
Elongated coolant pumps suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator and out through the auxiliary equipment hatch. 14 figures
Backward pumping kilowatt Yb3+-doped double-clad fiber laser
Han, Z. H.; Lin, X. C.; Hou, W.; Yu, H. J.; Zhou, S. Z.; Li, J. M.
2011-09-01
A ytterbium-doped double-clad fiber laser generating up to 1026 W of continuous-wave output power at 1085 nm with a slope efficiency of 74% by single-ended backward pumping configuration is reported. The core diameter was 20 μm with a low numerical aperture of 0.06, and a good beam quality (BPP < 1.8 mm mrad) is achieved without special mode selection methods. No undesirable roll-over was observed in output power with increasing pump power, and the maximum output power was limited by the available pump power. The instability of maximum output power was better than ±0.6%. Different pumping configurations were also compared in experiment, which shows good agreements with theoretical analyses.
Comparison of different wavelength pump sources for Tm subnanosecond amplifier
Cserteg, Andras; Guillemet, Sébastien; Hernandez, Yves; Giannone, Domenico
2012-06-01
We report here a comparison of different pumping wavelengths for short pulse Thulium fibre amplifiers. We compare the results in terms of efficiency and required fibre length. As we operate the laser in the sub-nanosecond regime, the fibre length is a critical parameter regarding non linear effects. With 793 nm clad-pumping, a 4 m long active fibre was necessary, leading to strong spectral deformation through Self Phase Modulation (SPM). Core-pumping scheme was then more in-depth investigated with several wavelengths tested. Good results with Erbium and Raman shifted pumping sources were obtained, with very short fibre length, aiming to reach a few micro-joules per pulse without (or with limited) SPM.
Vapor pumps and gas-driven machines
International Nuclear Information System (INIS)
Guillet, R.
1991-01-01
The vapor pump, patented in 1979 by Gaz de France, is an additional mass and heat exchanger which uses the combustion air of fuel-burning machines as an additional cold source. This cold source is preheated and, above all, humidified before reaching the burner, by means of the residual sensible and latent heat in the combustion products of the fuel-burning process. This final exchanger thus makes it possible, in many cases, to recover all the gross calorific value of natural gas, even when the combustion products leave the process at a wet temperature greater than 60 0 C, the maximum dew point of the products of normal combustion. Another significant advantage of the vapor pump being worth highlighting is the selective recycling of water vapor by the vapor pump which reduces the adiabatic combustion temperature and the oxygen concentration in the combustion air, two factors which lead to considerable reductions in nitrogen oxides formation, hence limiting atmospheric pollution. Alongside a wide range of configurations which make advantageous use of the vapor pump in association with gas-driven machines and processes, including gas turbines, a number of boiler plant installations are also presented [fr
Design of a Mechanical NaK Pump for Fission Space Power
Mireles, Omar R.; Bradley, David E.; Godfroy, Thomas
2011-01-01
Alkali liquid metal cooled fission reactor concepts are under development for spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid, which has specific pumping requirements. Traditionally, electromagnetic linear induction pumps have been used to provide the required flow and pressure head conditions for NaK systems but they can be limited in performance, efficiency, and number of available vendors. The objective of the project was to develop a mechanical NaK centrifugal pump that takes advantages of technology advances not available in previous liquid metal mechanical pump designs. This paper details the design, build, and performance test of a mechanical NaK pump developed at NASA Marshall Space Flight Center. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.
High heat flux testing impact on the Tore Supra toroidal pumped limiter achievement
International Nuclear Information System (INIS)
Schlosser, J.; Escourbiac, F.; Cordier, J.J.; Mitteau, R.; Durocher, A.; Grosman, A.
2003-01-01
The toroidal pumped limiter of Tore Supra is made of 576 elementary high heat flux (HHF) cooled plasma-facing components (PFCs) and designed to sustain 10 MW/m 2 in steady state. One of the main technical difficulties is to ensure a high quality of the bond between the carbon fiber composite armor tile and the water-cooled heat sink due to the high thermal stresses that develop at the bond during operation. Consequently, a HHF facility able to reproduce in service operation of PFCs is required all along the development and manufacturing route. In Europe, the FE200 facility (electron beam, 200 kW, France) operating since 1991, was extensively used for such a development. A first testing campaign in 1995 was devoted to the qualification of this bond: AMC technology from Plansee GmbH was selected. Afterwards, a second campaign on scale-one elements (1996) allowed an optimization of the element design and series production to be launched. During the mass production, a non-destructive control process - cheaper and faster than HHF testing - based on infrared characterization was routinely operated on 100% of the manufactured elements. Strong variability of the bond quality was observed and a repair process allowing the replacement of deficient tiles was developed. In 2000 and 2001, 2 campaigns of HHF testing were launched to correlate the non-destructive measurements and to optimize and validate the repair process. This was done, in two steps, with success. This yielded moreover interesting information for qualifying both tests across each other and also to analyze the fatigue evolution of the bond. The qualification and the achievement of the Tore Supra limiter has greatly been made possible by such HHF tests, which appears as essential before and during PFC manufacturing. (authors)
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...
Can wall and limiter erosion be eliminated in fusion reactors
International Nuclear Information System (INIS)
Norem, J.H.
1981-10-01
A pump limiter system is described which is compatible with in-situ recoating of the limiter surface. The recoating could be done during normal tokamak operation. We have shown how this system is compatible with most of the constraints of fusion reactor operation and might provide a significant advantage over magnetic diverter and some other pump limiter geometries
Pumping characteristics of roots blower pumps for light element gases
International Nuclear Information System (INIS)
Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Jun-ichi; Ohbayashi, Tetsuro
2002-07-01
The pumping speed and compression ratio of the two-stage roots blower pumping system were measured for light element gases (H 2 , D 2 and He) and for N 2 , in order to assess validity of the ITER torus roughing system as an ITER R and D task (T234). The pumping system of an Edwards EH1200 (nominal pumping speed of 1200 m 3 /s), two EH250s (ibid. 250 m 3 /s) and a backing pump (ibid. 100 m 3 /s) in series connection was tested under PNEUROP standards. The maximum pumping speeds of the two-stage system for D 2 and N 2 were 1200 and 1300 m 3 /h, respectively at 60 Hz, which satisfied the nominal pumping speed. These experimental data support the design validity of the ITER torus roughing system. (author)
Thornton, J.D.
1959-03-24
A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.
Quantitative assessment of haemolysis secondary to modern infusion pumps.
Poder, T G; Boileau, J-C; Lafrenière, R; Thibault, L; Carrier, N; de Grandmont, M-J; Beauregard, P
2017-04-01
Although most studies have shown that little haemolysis is induced by infusion pumps, there are some notable exceptions. Only limited data are available on the actual infusion pumps that are most used in hospitals in Quebec and elsewhere, namely, the Infusomat ® Space (peristaltic), Plum A+™ (piston) and Colleague ® CXE (shuttle) pumps. Haemolysis and potassium levels were compared before and after the use of the three different infusion pumps. Using 135 units of packed red blood cells (RBCs) aged from 10 to 28 days, 27 measurements were taken for each pump at various flow rates (30, 60, 150, 300 and 450 ml/h) and were compared with measurements taken before using the pumps. The range of flow rates was chosen to cover those of paediatric and adult transfusions. The shuttle- and piston-type pumps resulted in low haemolysis levels. The peristaltic-type pump produced significantly more haemolysis, which worsened at low flow rates, but the absolute value of haemolysis remained within the range recommended by the regulatory agencies in North America and Europe. Approximately two-thirds of the haemolysis produced by the peristaltic-type pump seemed to be secondary to the use of an antisiphon valve (ASV) on the transfusion line recommended by the manufacturer. Potassium levels did not increase with the use of the pumps. Modern infusion pumps widely used in hospitals in Quebec and elsewhere produce non-threatening levels of haemolysis during the transfusion of packed RBCs aged from 10 to 28 days. ASVs appear to induce additional haemolysis, and we do not recommend using them for blood transfusion. © 2017 International Society of Blood Transfusion.
Pump characteristics and applications
Volk, Michael
2013-01-01
Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae
DEFF Research Database (Denmark)
2011-01-01
The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... relative to the rod element so as to allow for a fluid flow in the tube through the first valve member, along the rod element, and through the second valve member. The tube comprises an at least partly flexible tube portion between the valve members such that a repeated deformation of the flexible tube...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...
Pumping behavior of sputtering ion pump
Energy Technology Data Exchange (ETDEWEB)
Chou, T.S.; Bittner, J.; Schuchman, J.
1991-12-31
To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.
Pumping behavior of sputtering ion pump
Energy Technology Data Exchange (ETDEWEB)
Chou, T.S.; Bittner, J.; Schuchman, J.
1991-01-01
To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.
Donoho, II, Michael R.; Elliott; Christopher M.
2010-03-23
A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.
Assessing the energy efficiency of pumps and pump units background and methodology
Bernd Stoffel, em Dr-Ing
2015-01-01
Assessing the Energy Efficiency of Pumps and Pump Units, developed in cooperation with Europump, is the first book available providing the background, methodology, and assessment tools for understanding and calculating energy efficiency for pumps and extended products (pumps+motors+drives). Responding to new EU requirements for pump efficiency, and US DOE exploratory work in setting pump energy efficiency guidelines, this book provides explanation, derivation, and illustration of PA and EPA methods for assessing energy efficiency. It surveys legislation related to pump energy eff
Enteral feeding pumps: efficacy, safety, and patient acceptability
Directory of Open Access Journals (Sweden)
White H
2014-08-01
Full Text Available Helen White, Linsey King Nutrition and Dietetic Group, School of Health and Wellbeing, Faculty Health and Social Science, Leeds Metropolitan University, Leeds, United Kingdom Abstract: Enteral feeding is a long established practice across pediatric and adult populations, to enhance nutritional intake and prevent malnutrition. Despite recognition of the importance of nutrition within the modern health agenda, evaluation of the efficacy of how such feeds are delivered is more limited. The accuracy, safety, and consistency with which enteral feed pump systems dispense nutritional formulae are important determinants of their use and acceptability. Enteral feed pump safety has received increased interest in recent years as enteral pumps are used across hospital and home settings. Four areas of enteral feed pump safety have emerged: the consistent and accurate delivery of formula; the minimization of errors associated with tube misconnection; the impact of continuous feed delivery itself (via an enteral feed pump; and the chemical composition of the casing used in enteral feed pump manufacture. The daily use of pumps in delivery of enteral feeds in a home setting predominantly falls to the hands of parents and caregivers. Their understanding of the use and function of their pump is necessary to ensure appropriate, safe, and accurate delivery of enteral nutrition; their experience with this is important in informing clinicians and manufacturers of the emerging needs and requirements of this diverse patient population. The review highlights current practice and areas of concern and establishes our current knowledge in this field. Keywords: nutrition, perceptions, experience
International Nuclear Information System (INIS)
Chikazawa, Yoshitaka; Kisohara, Naoyuki; Hishida, Masahiko; Fujii, Tadashi; Konomura, Mamoru; Ara, Kuniaki; Hori, Toru; Uchida, Akihito; Nishiguchi, Youhei; Nibe, Nobuaki
2006-07-01
In the feasibility study on commercialized fast breeder cycle system, a medium scale sodium cooled reactor with 750 MW electricity has been designed. In this study, EMPs are applied to the secondary sodium main pump. The EMPs type is selected to be an annular linear induction pump (ALIP) type with double stators which is used in the 160 m 3 /min EMP demonstration test. The inner structure and electromagnetic features are decided reviewing the 160 m 3 /min EMP. Two dimensional electromagnetic fluid analyses by EAGLE code show that Rms (magnetic Reynolds number times slip) is evaluated to be 1.08 which is less than the stability limit 1.4 confirmed by the 160 m 3 /min EMP test, and the instability of the pump head is evaluated to be 3% of the normal operating pump head. Since the EMP stators are cooled by contacting coolant sodium duct, reliability of the inner structures are confirmed by temperature distribution and stator-duct contact pressure analyses. Besides, a power supply system, maintenance and repair feature and R and D plan of EMP are reported. (author)
Development of a standardized, citywide process for managing smart-pump drug libraries.
Walroth, Todd A; Smallwood, Shannon; Arthur, Karen; Vance, Betsy; Washington, Alana; Staublin, Therese; Haslar, Tammy; Reddan, Jennifer G; Fuller, James
2018-06-15
Development and implementation of an interprofessional consensus-driven process for review and optimization of smart-pump drug libraries and dosing limits are described. The Indianapolis Coalition for Patient Safety (ICPS), which represents 6 Indianapolis-area health systems, identified an opportunity to reduce clinically insignificant alerts that smart infusion pumps present to end users. Through a consensus-driven process, ICPS aimed to identify best practices to implement at individual hospitals in order to establish specific action items for smart-pump drug library optimization. A work group of pharmacists, nurses, and industrial engineers met to evaluate variability within and lack of scrutiny of smart-pump drug libraries. The work group used Lean Six Sigma methodologies to generate a list of key needs and barriers to be addressed in process standardization. The group reviewed targets for smart-pump drug library optimization, including dosing limits, types of alerts reviewed, policies, and safety best practices. The work group also analyzed existing processes at each site to develop a final consensus statement outlining a model process for reviewing alerts and managing smart-pump data. Analysis of the total number of alerts per device across ICPS-affiliated health systems over a 4-year period indicated a 50% decrease (from 7.2 to 3.6 alerts per device per month) after implementation of the model by ICPS member organizations. Through implementation of a standardized, consensus-driven process for smart-pump drug library optimization, ICPS member health systems reduced clinically insignificant smart-pump alerts. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Reza Fatahialkouhi
2018-03-01
Full Text Available The ram pump is a device which pumps a portion of input discharge to the pumping system in a significant height by using renewable energy of water hammer. The complexities of flow hydraulic on one hand and on the other hand the use of simplifying assumptions in ram pumps have caused errors in submitted analytical models for analyzing running cycle of these pumps. In this study it has been tried to modify the governing analytical model on hydraulic performance of these pumps in pumping stage. In this study by creating a logical division, the cycle of the ram pump was divided into three stages of acceleration, pumping and recoil and the governing equations on each stage of cycling are presented by using method of characteristics. Since the closing of impulse valve is nonlinear, velocity loss in pumping stage is considered nonlinearly. Also the governing equations in pumping stage were modified by considering disc elasticity of impulse valve and changing volume of the pump body when the water hammer phenomenon is occurred. In order to evaluate results and determine empirical factors of the proposed analytical model, a physical model of the ram pump is made with internal diameter of 51 mm. Results of this study are divided into several parts. In the first part, loss coefficients of the impulse valve were measured experimentally and empirical equations of drag coefficient and friction coefficient of the impulse valve were submitted by using nonlinear regression. In the second part, results were evaluated by using experimental data taken from this study. Evaluation of statistical error functions showed that the proposed model has good accuracy for predicting experimental observations. In the third part, in order to validate the results in pumping stage, the analytical models of Lansford and Dugan (1941 and Tacke (1988 were used and the error functions resulted from prediction of experimental observations were investigated through analytical models of
Bulk-edge correspondence in topological transport and pumping
Imura, Ken-Ichiro; Yoshimura, Yukinori; Fukui, Takahiro; Hatsugai, Yasuhiro
2018-03-01
The bulk-edge correspondence (BEC) refers to a one-to-one relation between the bulk and edge properties ubiquitous in topologically nontrivial systems. Depending on the setup, BEC manifests in different forms and govern the spectral and transport properties of topological insulators and semimetals. Although the topological pump is theoretically old, BEC in the pump has been established just recently [1] motivated by the state-of-the-art experiments using cold atoms [2, 3]. The center of mass (CM) of a system with boundaries shows a sequence of quantized jumps in the adiabatic limit associated with the edge states. Despite that the bulk is adiabatic, the edge is inevitably non-adiabatic in the experimental setup or in any numerical simulations. Still the pumped charge is quantized and carried by the bulk. Its quantization is guaranteed by a compensation between the bulk and edges. We show that in the presence of disorder the pumped charge continues to be quantized despite the appearance of non-quantized jumps.
Benefits and risks of using smart pumps to reduce medication error rates: a systematic review.
Ohashi, Kumiko; Dalleur, Olivia; Dykes, Patricia C; Bates, David W
2014-12-01
Smart infusion pumps have been introduced to prevent medication errors and have been widely adopted nationally in the USA, though they are not always used in Europe or other regions. Despite widespread usage of smart pumps, intravenous medication errors have not been fully eliminated. Through a systematic review of recent studies and reports regarding smart pump implementation and use, we aimed to identify the impact of smart pumps on error reduction and on the complex process of medication administration, and strategies to maximize the benefits of smart pumps. The medical literature related to the effects of smart pumps for improving patient safety was searched in PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) (2000-2014) and relevant papers were selected by two researchers. After the literature search, 231 papers were identified and the full texts of 138 articles were assessed for eligibility. Of these, 22 were included after removal of papers that did not meet the inclusion criteria. We assessed both the benefits and negative effects of smart pumps from these studies. One of the benefits of using smart pumps was intercepting errors such as the wrong rate, wrong dose, and pump setting errors. Other benefits include reduction of adverse drug event rates, practice improvements, and cost effectiveness. Meanwhile, the current issues or negative effects related to using smart pumps were lower compliance rates of using smart pumps, the overriding of soft alerts, non-intercepted errors, or the possibility of using the wrong drug library. The literature suggests that smart pumps reduce but do not eliminate programming errors. Although the hard limits of a drug library play a main role in intercepting medication errors, soft limits were still not as effective as hard limits because of high override rates. Compliance in using smart pumps is key towards effectively preventing errors. Opportunities for improvement include upgrading drug
Alternative method of inservice hydraulic testing of difficult to test pumps
International Nuclear Information System (INIS)
Stockton, N.B.; Shangari, S.
1994-01-01
The pump test codes require that system resistance be varied until the independent variable (either the pump flow rate or differential pressure) equals its reference value. Variance from this fixed reference value is not specifically allowed. However, the design of many systems makes it impractical to set the independent variable to an exact value. Over a limited range of pump operation about the fixed reference value, linear interpolation between two points of pump operation can be used to accurately determine degradation at the reference value without repeating reference test conditions. This paper presents an overview of possible alternatives for hydraulic testing of pumps and a detailed discussion of the linear interpolation method. The approximation error associated with linear interpolation is analyzed. Methods to quantify and minimize approximation error are presented
Recovery of light nonaqueous-phase liquids without groundwater pumping
International Nuclear Information System (INIS)
Markley, D.E.; Prince-Larsen, N.
1995-01-01
This paper outlines recovery of light nonaqueous-phase liquids (LNAPL) encountered in the subsurface at a remote natural gas facility. Remediation of LNAPL in the subsurface usually begins with dual pumping of LNAPL and groundwater. However, regulations required that only LNAPL be recovered. Methods were sought for recovering LNAPL from groundwater without pumping groundwater to the surface. Alternative methods of LNAPL recovery, using a variety of skimming pumps, included: LNAPL recovery from large-diameter wells; LNAPL recovery from trenches; LNAPL recovery from small-diameter wells; and vacuum-enhanced recovery of LNAPL while skimming with a belt skimmer. Based on the goals of the site owner and the costs associated with each alternative examined, the recommended method for recovering LNAPL without groundwater pumping was recovery of LNAPL while skimming with a belt skimmer. This paper discusses both the advantages and limitations of this technique
Performance Analysis Of Single-Pumped And Dual-Pumped Parametric Optical Amplifier
Directory of Open Access Journals (Sweden)
Sandar Myint
2015-06-01
Full Text Available Abstract In this study we present a performance analysis of single-pumped and dual- pumped parametric optical amplifier and present the analysis of gain flatness in dual- pumped Fiber Optical Parametric Amplifier FOPA based on four-wave mixing FWM. Result shows that changing the signal power and pump power give the various gains in FOPA. It is also found out that the parametric gain increase with increase in pump power and decrease in signal power. .Moreover in this paper the phase matching condition in FWM plays a vital role in predicting the gain profile of the FOPAbecause the parametric gain is maximum when the total phase mismatch is zero.In this paper single-pumped parametric amplification over a 50nm gain bandwidth is demonstrated using 500 nm highly nonlinear fiber HNLF and signal achieves about 31dB gain. For dual-pumped parametric amplification signal achieves 26.5dB gains over a 50nm gain bandwidth. Therefore dual-pumped parametric amplifier can provide relatively flat gain over a much wider bandwidth than the single-pumped FOPA.
Residual heat removal pump and low pressure safety injection pump retrofit program
International Nuclear Information System (INIS)
Dudiak, J.G.; McKenna, J.M.
1992-01-01
Residual Heat Removal (RHR) and low pressure safety injection (LPSI) pumps installed in pressurized water-to-reactor power plants are used to provide low-head safety injection in the event of loss of coolant in the reactor coolant system. Because these pumps are subjected to rather severe temperature and pressure transients, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. Typically the pump impeller is mounted on an extended motor shaft (close-coupled configuration) and a mechanical seal is employed at the pump end of the shaft. Traditionally RHR and LPSI pumps have been a significant maintenance item for many utilities. Periodic mechanical seal of motor bearing replacement often is considered routine maintenance. The closed-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. This paper introduces a design modification developed to convert the close-coupled RHR and LPSI pumps to a coupled configuration
Engineering design of cryocondensation pumps for the DIII-D Radiative Divertor Program
International Nuclear Information System (INIS)
Bozek, A.S.; Baxi, C.B.; Del Bene, J.V.; Laughon, G.J.; Reis, E.E.; Shatoff, H.D.; Smith, J.P.
1995-01-01
A new double-null, slotted divertor configuration will be installed for the DIII-D Radiative Divertor Program at General Atomics in late 1996. Four cryocondensation pumps, three new and one existing, will be part of this new divertor. The purpose of the pumps is to provide plasma density control and to limit the impurities entering the plasma core by providing pumping at each divertor strike point. The three new pumps are based on the design of the existing pump, installed in 1992 as part of the Advanced Divertor Program. The pump continues to operate successfully. The new pumps require geometry modifications to the original design. Therefore, extensive modal and dynamic analyses were performed to determine the behavior of these pumps and their helium and nitrogen feed lines during disruption events. Thermal and fluid analyses were also performed to characterize the helium two-phase flow regime in the pumps and their feedlines. A flow testing program was completed to test the change in geometry of the pump feed lines with respect to helium flow stability. The results were compared to the helium thermal and fluid analyses to verify predicted flow regimes and flow stability
Quality-improvement analytics for intravenous infusion pumps.
Skledar, Susan J; Niccolai, Cynthia S; Schilling, Dennis; Costello, Susan; Mininni, Nicolette; Ervin, Kelly; Urban, Alana
2013-04-15
The implementation of a smart-pump continuous quality-improvement (CQI) program across a large health system is described, with an emphasis on key metrics for outcomes analyses and program refinement. Three years ago, the University of Pittsburgh Medical Center health system launched a CQI initiative to help ensure the safe use of 6000 smart pumps in its 14 inpatient facilities. A centralized team led by pharmacists is responsible for the retrieval and interpretation of smart-pump data, which is continuously transmitted to a main server. CQI findings are regularly posted on the health system's interdisciplinary intranet. Monitored metrics include rates of compliance with preprogrammed infusion limits, the top 20 drugs involved in alerts, drugs associated with alert-override rates of ≥90%, numbers of alerts by infusion type, nurse responses to alerts, and alert rate per drug library update. Based on the collected CQI data and site-specific requests, four systemwide updates of the smart-pump drug library were performed during the first 18 months of the program, reducing "nuisance alerts" by about 10% per update cycle and enabling targeted interventions to reduce rapid-infusion errors, other adverse drug events (ADEs), and pump-programming workarounds. Over one 12-month period, bedside alerts prompted nurses to reprogram or cancel continuous infusions an average of 400 times per month, potentially averting i.v. medication ADEs. A smart-pump CQI program is an effective tool for enhancing the safety of i.v. medication administration. The ongoing refinement of the drug library through the development and implementation of key interventions promotes the growth and sustainability of the smart-pump initiative systemwide.
Low-Cost Touchscreen Driven Programmable Dual Syringe Pump for Life Science Applications
Liu, Jamin; Garcia, Valentina; Derisi, Joseph
2018-01-01
Syringe pumps are powerful tools able to automate routine laboratory practices that otherwise consume large amounts of manual labor time. Commercially available syringe pumps are expensive, difficult to customize, and often preset for a narrow range of operations. Here, we show how to build a programmable dual syringe pump (PDSP) that overcomes these limitations. The PDSP is driven by a Raspberry Pi paired with a stepper motor controller to allow maximal customization via Python scripting. Th...
Pump Application as Hydraulic Turbine – Pump as Turbine (PaT)
Rusovs, D
2009-01-01
The paper considers pump operation as hydraulic turbine with purpose to produce mechanical power from liquid flow. The Francis hydraulic turbine was selected for comparison with centrifugal pump in reverse operation. Turbine and centrifugal pump velocity triangles were considered with purpose to evaluate PaT efficiency. Shape of impeller blades for turbine and pumps was analysed. Specific speed calculation is carried out with purpose to obtain similarity in pump and turbine description. For ...
Topological magnetoelectric pump in three dimensions
Fukui, Takahiro; Fujiwara, Takanori
2017-11-01
We study the topological pump for a lattice fermion model mainly in three spatial dimensions. We first calculate the U(1) current density for the Dirac model defined in continuous space-time to review the known results as well as to introduce some technical details convenient for the calculations of the lattice model. We next investigate the U(1) current density for a lattice fermion model, a variant of the Wilson-Dirac model. The model we introduce is defined on a lattice in space but in continuous time, which is suited for the study of the topological pump. For such a model, we derive the conserved U(1) current density and calculate it directly for the (1 +1 )-dimensional system as well as (3 +1 )-dimensional system in the limit of the small lattice constant. We find that the current includes a nontrivial lattice effect characterized by the Chern number, and therefore the pumped particle number is quantized by the topological reason. Finally, we study the topological temporal pump in 3 +1 dimensions by numerical calculations. We discuss the relationship between the second Chern number and the first Chern number, the bulk-edge correspondence, and the generalized Streda formula which enables us to compute the second Chern number using the spectral asymmetry.
Macmichael, DBA
1988-01-01
A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.
Fluid structure interaction in piston diaphragm pumps
van Rijswick, R.J.A.
2017-01-01
Piston diaphragm pumps are used world-wide to transport abrasive and/or aggressive slurries against high discharge pressures in the mining, mineral processing and power industries. Limitation of excessive deformation of the diaphragm is of utmost importance for eliminating fatigue failures of the
Reactor coolant purification system circulation pumps (CUW pumps)
International Nuclear Information System (INIS)
Tsutsui, Toshiaki
1979-01-01
Coolant purification equipments for BWRs have been improved, and the high pressure purifying system has become the main type. The quantity of purifying treatment also changed to 2% of the flow rate of reactor feed water. As for the circulation pumps, canned motor pumps are adopted recently, and the improvements of reliability and safety are attempted. The impurities carried in by reactor feed water and the corrosion products generated in reactors and auxiliary equipments are activated by neutron irradiation or affect heat transfer adversely, adhering to fuel claddings are core structures. Therefore, a part of reactor coolant is led to the purification equipments, and returned to reactors after the impurities are eliminated perfectly. At the time of starting and stopping reactors, excess reactor water and the contaminated water from reactors are transferred to main condenser hot wells or waste treatment systems. Thus the prescribed water quality is maintained. The operational modes of and the requirements for the CUW pumps, the construction and the features of the canned motor type CUW pumps are explained. Recently, a pump operated for 11 months without any maintenance has been disassembled and inspected, but the wear of bearings has not been observed, and the high reliability of the pump has been proved. (Kako, I.)
Work plan, AP-102 mixer pump removal and pump replacement
International Nuclear Information System (INIS)
Jimenez, R.F.
1994-01-01
The objective of this work plan is to plan the steps and estimate the costs required to remove the failed AP-102 mixer pump, and to plan and estimate the cost of the necessary design and specification work required to order a new, but modified, mixer pump including the pump and pump pit energy absorbing design. The main hardware required for the removal of the mixer is as follows: a flexible receiver and blast shield; a metal container for the pulled mixer pump; and a trailer and strongback to haul and manipulate the container. Additionally: a gamma scanning device will be needed to detect the radioactivity emanating from the mixer as it is pulled from the tank; a water spray system will be required to remove tank waste from the surface of the mixer as it is pulled from the AP-102 tank; and a lifting yoke to lift the mixer from the pump pit (the SY-101 Mixer Lifting Yoke will be used). A ''green house'' will have to be erected over the AP-102 pump pit and an experienced Hoisting and Rigging crew must be assembled and trained in mixer pump removal methods before the actual removal is undertaken
Small machinery for pumping and compressing helium near 40K
International Nuclear Information System (INIS)
Swift, W.L.; Sixsmith, H.
1984-01-01
There is a significant need for small, reliable pumps and compressors suitable for circulating helium at temperatures near 4 0 K. Most pumps or compressors which have been developed to data for these applications are designed for relatively limited use. They are generally used in laboratory environments where life requirements for the experiments may be relatively short, being of the order of several hundred hours. In recent years, several applications have been identified where pumps or compressors (at liquid helium temperatures) must have high reliability if they are to be used successfully. These applications include liquid helium circulation systems through superconducting magnets and transmission lines, and cold compression applications where the compressor is used as a vacuum pump to lower the temperature of a liquid helium bath. This paper discusses the technical considerations which must be taken into account in the design and development of machinery to meet these needs. The design of a centrifugal machine which can act as a helium pump or compressor is presented
Adiabatic pumping solutions in global AdS
Energy Technology Data Exchange (ETDEWEB)
Carracedo, Pablo [Meteo-Galicia,Santiago de Compostela E-15782 (Spain); Mas, Javier; Musso, Daniele; Serantes, Alexandre [Departamento de Física de Partículas, Universidade de Santiago de Compostela,Santiago de Compostela E-15782 (Spain); Instituto Galego de Física de Altas Enerxías (IGFAE),Santiago de Compostela E-15782 (Spain)
2017-05-26
We construct a family of very simple stationary solutions to gravity coupled to a massless scalar field in global AdS. They involve a constantly rising source for the scalar field at the boundary and thereby we name them pumping solutions. We construct them numerically in D=4. They are regular and, generically, have negative mass. We perform a study of linear and nonlinear stability and find both stable and unstable branches. In the latter case, solutions belonging to different sub-branches can either decay to black holes or to limiting cycles. This observation motivates the search for non-stationary exactly time-periodic solutions which we actually construct. We clarify the role of pumping solutions in the context of quasistatic adiabatic quenches. In D=3 the pumping solutions can be related to other previously known solutions, like magnetic or translationally-breaking backgrounds. From this we derive an analytic expression.
The outline design of FEB-E particle exhaust and pumping system
International Nuclear Information System (INIS)
Zhu Yukun; Huang Jinhua; Feng Kaiming; Deng Peizhi; Li Yiqiang
1999-01-01
The particle exhaust of Fusion Experimental Breeder FEB-E is carried out with divertor. The FEB-E divertor consists of 48 wedge shaped cassette modules connected with primary pumping system and cooling system. The FEB-E pumping system consists of two major subsystems, the torus rough pumping system and the torus high vacuum pumping system. The torus high vacuum pumping system consists of a series of internal cryopumps located in most of the lower ports (up to 20) and additional turbomolecular pumps located outside of the bio-shield. These cryopumps are capable of providing a nominal gross pumping speed of 576 m 3 ·s -1 , regulated with inlet valves for throttle control of the exhaust particle flow in the case of high neutral pressure (>1 Pa) in the divertor. However, limited conductance through the divertor pumping slot and through the clearance between the underside of the divertor and the vacuum vessel results in the effective net pumping speed of 160 m 3 ·s -1 in the divertor private region. This pumping speed implies that a neutral pressure operation range of 0.5 - 1.0 Pa is required in the divertor private region to achieve an exhausting throughput range of 80 - 160 Pa·m 3 ·s -1 . The regeneration of cryopump is activated at the end of the 1000 s of the breeder burning
Directory of Open Access Journals (Sweden)
Nyers Jozsef
2017-01-01
Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.
Continuous quality improvement using intelligent infusion pump data analysis.
Breland, Burnis D
2010-09-01
The use of continuous quality-improvement (CQI) processes in the implementation of intelligent infusion pumps in a community teaching hospital is described. After the decision was made to implement intelligent i.v. infusion pumps in a 413-bed, community teaching hospital, drug libraries for use in the safety software had to be created. Before drug libraries could be created, it was necessary to determine the epidemiology of medication use in various clinical care areas. Standardization of medication administration was performed through the CQI process, using practical knowledge of clinicians at the bedside and evidence-based drug safety parameters in the scientific literature. Post-implementation, CQI allowed refinement of clinically important safety limits while minimizing inappropriate, meaningless soft limit alerts on a few select agents. Assigning individual clinical care areas (CCAs) to individual patient care units facilitated customization of drug libraries and identification of specific CCA compliance concerns. Between June 2007 and June 2008, there were seven library updates. These involved drug additions and deletions, customization of individual CCAs, and alterations of limits. Overall compliance with safety software use rose over time, from 33% in November 2006 to over 98% in December 2009. Many potentially clinically significant dosing errors were intercepted by the safety software, prompting edits by end users. Only 4-6% of soft limit alerts resulted in edits. Compliance rates for use of infusion pump safety software varied among CCAs over time. Education, auditing, and refinement of drug libraries led to improved compliance in most CCAs.
Electromagnetic pump technology
International Nuclear Information System (INIS)
Prabhakar, R.
1994-01-01
Fast Breeder Reactors have an important role to play in our nuclear power programme. Liquid metal sodium is used as the coolant for removing fission heat generated in fast reactors and a distinctive physical property of sodium is its high electrical conductivity. This enables application of electromagnetic (EM) pumps, working on same principle as electric motors, for pumping liquid sodium. Due to its lower efficiency as compared to centrifugal pumps, use of EM pumps has been restricted to reactor auxiliary circuits and experimental facilities. As part of our efforts to manufacture fast reactor components indigenously, work on the development of two types of EM pumps namely flat linear induction pump (FLIP) and annular linear induction pump (ALIP) has been undertaken. Design procedures based on an equivalent circuit approach have been established and results from testing a 5.6 x 10E-3 Cum/s (20 Cum/h) FLIP in a sodium loop were used to validate the procedure. (author). 7 refs., 6 figs
DEFF Research Database (Denmark)
Sitsel, Oleg; Dach, Ingrid; Hoffmann, Robert Daniel
2012-01-01
The name PUMPKIN may suggest a research centre focused on American Halloween traditions or the investigation of the growth of vegetables – however this would be misleading. Researchers at PUMPKIN, short for Centre for Membrane Pumps in Cells and Disease, are in fact interested in a large family o......’. Here we illustrate that the pumping of ions means nothing less than the pumping of life....
Jones, Jack A.
2004-01-01
The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.
Acceptance test report: Field test of mixer pump for 241-AN-107 caustic addition project
International Nuclear Information System (INIS)
Leshikar, G.A.
1997-01-01
The field acceptance test of a 75 HP mixer pump (Hazleton serial number N-20801) installed in Tank 241-AN-107 was conducted from October 1995 thru February 1996. The objectives defined in the acceptance test were successfully met, with two exceptions recorded. The acceptance test encompassed field verification of mixer pump turntable rotation set-up and operation, verification that the pump instrumentation functions within established limits, facilitation of baseline data collection from the mixer pump mounted ultrasonic instrumentation, verification of mixer pump water flush system operation and validation of a procedure for its operation, and several brief test runs (bump) of the mixer pump
Pumping of methane by an ionization assisted Zr/Al getter pump
International Nuclear Information System (INIS)
Shen, G.L.
1987-01-01
The pumping of methane by an ionization assisted Zr/Al getter pump has been investigated. This pump consists of 12 pieces of ring getters. A spiral shape W filament is located within the ring getters. A bias voltage is applied across the filament and the getter itself. The experiments have shown that (1) when the bias voltage is turned off, the pumping speed of the getter pump for methane increases exponentially with the filament temperature; (2) when the filament temperature is held constant, its pumping speed varies directly with the ionization electron current; (3) when the filament temperature is 2063 0 C and the electron current is 57 mA, the pumping speed of the Zr/Al getter pump is 475 ml/s, and the specific speed is 16.8 ml/s cm 2 ; and (4) an activation energy and critical temperature measured for methane molecules decomposition are, respectively, 47.4 kcal/mol and about 1700 0 C. Analysis of the results indicates that methane is pumped by an ionization assisted Zr/Al getter pump not because of the adsorption and the diffusion of methane molecules directly, but because methane molecules are decomposed as C and H 2 through a catalysis of the hot W filament, carbon is adsorbed on the surface of the W filament, and is diffused into the interior of the W lattice. H 2 is immediately absorbed by the Zr/Al getters. Besides, electron impact with CH 4 would result in the additional decomposition and ionization, then the effect of electron bombardment enhances methane pumping by the Zr/Al getters
Experiences in design up-gradation of mechanical seal cooling scheme of Dhruva PHT pumps
International Nuclear Information System (INIS)
Balakrishnan, K.T.P.
2002-01-01
Full text: Dhruva is a natural uranium fuelled high flux research reactor. Heavy water is used as coolant, moderator and reflector. Heat from the heavy water coolant is removed in heat exchangers by demineralised water. The heavy water coolant is re-circulated between the reactor core and the heat exchangers in three separate loops by three main coolant pumps (MCPs). The MCPs are high capacity centrifugal pumps and are rated for continuous service. The mechanical seal of the pump prevents leakage of the process fluid, which is heavy water, through the pump shaft. Continuous operation of the pump results in the heating up of the seal and necessitates sustained cooling. An integral cooling provision is made by tapping a 15 NB line from the discharge volute of the pump and feeding the process fluid itself as coolant to the seal. A non-indicating type flow-sensing device monitors flow through this line. Limiting values of flow are set and annunciated by a pair of magnetic reed type relays. This cooling line was a built in feature of the pumps as supplied by the manufacturer. This arrangement had the following inherent limitations: 1. There was no on line indication of the coolant flow. 2. The reed type magnetic relays initiated pump trips by spurious actuation, resulting in the interruption of reactor operation. Servicing a faulty flow switch involved lengthy procedures and necessitated draining, filling and venting of the pump. This entailed extended plant outages. Close proximity of these flow switches to a highly radioactive piping element imposed severe restrictions on the planned maintenance activity on them. Efforts were made to provide a suitable alternate cooling and flow measurement scheme to overcome the above-mentioned limitations. After evaluating the relative merits and demerits of several schemes, a turbine type flow sensor, on a modified cooling line was selected as the most suitable alternative. The alternate seal-cooling scheme was implemented for all
Experiences in design up-gradation of mechanical seal cooling scheme of Dhruva PHT pumps
International Nuclear Information System (INIS)
Balakrishnan, K.T.P.; Bharathan, R.
2002-01-01
Full text: Dhruva is a natural uranium fuelled high flux research reactor. Heavy water is used as coolant, moderator and reflector. Heat from the heavy water coolant is removed in heat exchangers by demineralised water. The heavy water coolant is re-circulated between the reactor core and the heat exchangers in three separate loops by three main coolant pumps (MCPs). The MCPs are high capacity centrifugal pumps and are rated for continuous service. The mechanical seal of the pump prevents leakage of the process fluid, which is heavy water, through the pump shaft. Continuous operation of the pump results in the heating up of the seal and necessitates sustained cooling. An integral cooling provision is made by tapping a 15 NB line from the discharge volute of the pump and feeding the process fluid itself as coolant to the seal. A non-indicating type flow-sensing device monitors flow through this line. Limiting values of flow are set and annunciated by a pair of magnetic reed type relays. This cooling line was a built in feature of the pumps as supplied by the manufacturer. This arrangement had the following inherent limitations : 1. There was no on line indication of the coolant flow. 2. The reed type magnetic relays initiated pump trips by spurious actuation, resulting in the interruption of reactor operation. Servicing a faulty flow switch involved lengthy procedures and necessitated draining, filling and venting of the pump. This entailed extended plant outages. Close proximity of these flow switches to a highly radioactive piping element imposed severe restrictions on the planned maintenance activity on them. Efforts were made to provide a suitable alternate cooling and flow measurement scheme to overcome the above-mentioned limitations. After evaluating the relative merits and demerits of several schemes, a turbine type flow sensor, on a modified cooling line was selected as the most suitable alternative. The alternate seal-cooling scheme was implemented for all
Cavitation performance improvement of high specific speed mixed-flow pump
International Nuclear Information System (INIS)
Chen, T; Sun, Y B; Wu, D Z; Wang, L Q
2012-01-01
Cavitation performance improvement of large hydraulic machinery such as pump and turbine has been a hot topic for decades. During the design process of the pumps, in order to minimize size, weight and cost centrifugal and mixed-flow pump impellers are required to operate at the highest possible rotational speed. The rotational speed is limited by the phenomenon of cavitation. The hydraulic model of high-speed mixed-flow pump with large flow rate and high pumping head, which was designed based on the traditional method, always involves poor cavitation performance. In this paper, on the basis of the same hydraulic design parameters, two hydraulic models of high-speed mixed-flow pump were designed by using different methods, in order to investigate the cavitation and hydraulic performance of the two models, the method of computational fluid dynamics (CFD) was adopted for internal flow simulation of the high specific speed mixed-flow pump. Based on the results of numerical simulation, the influences of impeller parameters and three-dimensional configuration on pressure distribution of the blades' suction surfaces were analyzed. The numerical simulation results shows a better pressure distribution and lower pressure drop around the leading edge of the improved model. The research results could provide references to the design and optimization of the anti-cavitation blade.
... of pump is best? You can buy or rent a breast pump from lactation consultants, hospitals, retail ... place to do it. Many companies offer their employees pumping and nursing areas. If yours doesn't, ...
Development and evaluation of cryosorption pump and cryotrapping pump for CTR applications
International Nuclear Information System (INIS)
Kuribayashi, S.; Ota, H.; Sato, H.
1986-01-01
In order to obtain the engineering data to design compound cryopump for CTR, the authors tested the cryosorption pump and cryotrapping pump. The cryosorption panel was consisted of coconut charcoal metallically bonded to 4.2K cryopanel by brazing. The initial pumping speed of helium of cryosorption pump was found to be ≅2.2 iota/scm/sup 2/. The speed dropped off with loading (about 8 Torr iota/cm/sup 2/) to 1.5 iota/scm/sup 2/. The initial helium pumping speed of the 4.2K cryotrapping pump by argon spray was found to be ≅6 iota/scm/sup 2/. The speed, however, dropped off with loading (≅0.3 Torr iota/cm/sup 2/) to less than 5%. These results indicate that the cryosorption pump by coconut charcoal is superior to the cryotrapping pump, because the capacity of the former is larger than the latter
Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers
Hwang, In H.; Lee, Ja H.
1991-01-01
The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.
Energy Technology Data Exchange (ETDEWEB)
Weis, M.P.; Lawler, D.M.
1994-08-01
This report revisits and consolidates two analyses previously performed for the installation of the Hydrogen Mitigation Pump (HMT) pump. The first report determines, as a function of the crane-imposed dome load, the point to which the crane can encroach into the exclusion zone without exceeding the 50-ton limit. The second performs a load evaluation for the crane and the components in the load path (crane lift accessories and pump). In doing so, it determines the weakest component in the load path and the effect of this component on the allowable encroachment distance. Furthermore, the second report sets operational limits on the allowable load decrease (unload) during installation in the event the pump sticks in the riser. The analysis presented here expands on the latter subject by setting an operational limit on the amount of allowable load increase (overload) during pump removal in the event the pump sticks in the riser.
Design aspects of commercial open-loop heat pump systems
Energy Technology Data Exchange (ETDEWEB)
Rafferty, Kevin
2000-01-01
Open loop (or groundwater heat pump systems are the oldest of the ground-source systems. Common design variations include direct (groundwater used directly in the heat pump units), indirect (building loop isolated with a plate heat exchanger), and standing column (water produced and returned to the same well). Direct systems are typically limited to the smallest applications. Standing column systems are employed in hard rock geology sites where it is not possible to produce sufficient water for a conventional system. Due to its greater potential application, this paper reviews key design aspects of the indirect approach. The general design procedure is reviewed, identification of optimum groundwater flow, heat exchanger selection guidelines, well pump control, disposal options, well spacing, piping connections and related issues.
Design Aspects of Commerical Open-Loop Heat Pump Systems
Energy Technology Data Exchange (ETDEWEB)
Rafferty, Kevin
2001-03-01
Open loop (or groundwater heat pump systems are the oldest of the ground-source systems. Common design variations include direct (groundwater used directly in the heat pump units), indirect (building loop isolated with a plate heat exchanger), and standing column (water produced and returned to the same well). Direct systems are typically limited to the smallest applications. Standing column systems are employed in hard rock geology sites where it is not possible to produce sufficient water for a conventional system. Due to its greater potential application, this paper reviews key design aspects of the indirect approach. The general design procedure is reviewed, identification of optimum groundwater flow, heat exchanger selection guidelines, well pump control, disposal options, well spacing, piping connections and related issues.
Feedback control of primary circulation pump of PIUS-Type reactor
International Nuclear Information System (INIS)
Fujii, Mikiya; Anoda, Yoshinari; Murata, Hideo; Yonomoto, Taisuke; Kukita, Yutaka; Tasaka, Kanji.
1991-05-01
In operating the PIUS-Type reactor, it is required to keep stationary density interfaces between the primary loop hot water and the poison tank cold, borated water by maintaining pressure balance between the primary-loop and the poison-tank. The authors have developed a primary circulation pump speed control system and tested it in small-scale experiments. This control system regulates the pump speed based on measurements of the density lock differential pressure which is proportional to the elevation of the interface in the density lock. This pump speed control facilitated the normal plant operation which included core power changes. However, the elevation of the density interface indicated oscillatory behavior when the pump speed was regulated as a linear function of the density lock differential pressure. The mechanism responsible for such oscillatory behavior was found to be manometric oscillations that could be eliminated by adding a damping term to compensate for the mechanical delay of the primary pump speed. The passive shutdown function of the reactor was retained by setting an upper limit to the pump speed. This was confirmed in a loss-of-feedwater abnormal transient test. (author)
International Nuclear Information System (INIS)
Zmood, R.; Cholewka, J.; Patak, C.; Feng, G.; Zhang, C.; Maleri, T.; Pinder, B.; McDonald, R.; Homrigh, J.
1991-01-01
Conventional pumps having external drive motors experience problems due to bearing noise. In addition failure of bearings and seals can lead to limited operational reliability and impaired integrity of these pumps. Pumps using DC brushless motors and magnetic bearings offer means of overcoming these problems. A design of a pump having a DC brushless motor and magnetic bearings with a potential for Naval applications in ships and submarines is discussed. In this paper attention is given to the selection of the magnetic bearings suitable for achieving active noise cancellation
BWR series pump recirculation system
International Nuclear Information System (INIS)
Dillmann, C.W.
1992-01-01
This patent describes a recirculation system for driving reactor coolant water contained in an annular downcomer defined between a boiling water reactor vessel and a reactor core spaced radially inwardly therefrom. It comprises a plurality of circumferentially spaced second pumps disposed in the downcomer, each including an inlet for receiving from the downcomer a portion of the coolant water as pump inlet flow, and an outlet for discharging the pump inlet flow pressurized in the second pump as pump outlet flow; and means for increasing pressure of the pump inlet flow at the pump inlet including a first pump disposed in series flow with the second pump for first receiving the pump inlet flow from the downcomer and discharging to the second pump inlet flow pressurized in the first pump
Early outcome of off-pump versus on-pump coronary revascularization
African Journals Online (AJOL)
Introduction: The use of coronary artery bypass surgery (CABG) with cardiopulmonary bypass (CPB) or without CPB technique (off-pump) can be associated with different mortality and morbidity and their outcomes remain uncertain. The goal of this study was to evaluate the early outcome of on-pump versus off-pump CABG.
Pumps in wearable ultrafiltration devices: pumps in wuf devices.
Armignacco, Paolo; Garzotto, Francesco; Bellini, Corrado; Neri, Mauro; Lorenzin, Anna; Sartori, Marco; Ronco, Claudio
2015-01-01
The wearable artificial kidney (WAK) is a device that is supposed to operate like a real kidney, which permits prolonged, frequent, and continuous dialysis treatments for patients with end-stage renal disease (ESRD). Its functioning is mainly related to its pumping system, as well as to its dialysate-generating and alarm/shutoff ones. A pump is defined as a device that moves fluids by mechanical action. In such a context, blood pumps pull blood from the access side of the dialysis catheter and return the blood at the same rate of flow. The main aim of this paper is to review the current literature on blood pumps, describing the way they have been functioning thus far and how they are being engineered, giving details about the most important parameters that define their quality, thus allowing the production of a radar comparative graph, and listing ideal pumps' features. © 2015 S. Karger AG, Basel.
TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps
International Nuclear Information System (INIS)
Sink, D.A.; Sniderman, M.
1976-06-01
The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented
Design of a Mechanical NaK Pump for Fission Space Power Systems
Mireles, Omar R.; Bradley, David; Godfroy, Thomas
2010-01-01
Alkali liquid metal cooled fission reactor concepts are under development for mid-range spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid. Traditionally, linear induction pumps have been used to provide the required flow and head conditions for liquid metal systems but can be limited in performance. This paper details the design, build, and check-out test of a mechanical NaK pump. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.
A cryocondensation pump for the DIII-D Advanced Divertor Program
International Nuclear Information System (INIS)
Smith, J.P.; Baxi, C.; Reis, E.; Sevier, L.
1992-03-01
A cryocondensation pump was designed for the baffle chamber of General Atomics DIII-D tokamak and will be installed in the fall of 1992. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long and located in the lower outer corner of the vacuum chamber of the machine. It consists of a 1 m 2 liquid helium-cooled surface surrounded by a liquid nitrogen-cooled shield to limit the heat load on the helium-cooled surface. The liquid nitrogen-cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. A thermal enhancement coating was applied to the nitrogen shell to lower the maximum temperature of the shell. The coating is non-continuous to keep the toroidal electrical resistance high. The whole pump is supported off the water-cooled vacuum vessel wall. Supports for the pump were designed to accommodate the thermal differences between the 4 K helium surface, the 77 K nitrogen shells, and the 300 K vacuum vessel supporting the pump and to provide a low heat leak structural support. Disruption loading on the pump was analyzed and a finite element structural analysis of the pump was completed. A testing program was completed to evaluate coating techniques to enhance heat transfer and emissivity of the various surfaces. Fabrication tests were performed to determine the best method of attaching the liquid nitrogen flow tubes to their shield surfaces and to determine the best alternative to fabricating the different shells of the pump. A prototype sector of the pump was built to verify fabrication and assembly techniques
Klockgether, J.; Kiessling, K. P.
1983-09-01
Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.
Damages on pumps and systems the handbook for the operation of centrifugal pumps
Merkle, Thomas
2014-01-01
Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems
Patel, Kamlesh D.
2007-11-20
A method for altering the surface properties of a particle bed. In application, the method pertains particularly to an electrokinetic pump configuration where nanoparticles are bonded to the surface of the stationary phase to alter the surface properties of the stationary phase including the surface area and/or the zeta potential and thus improve the efficiency and operating range of these pumps. By functionalizing the nanoparticles to change the zeta potential the electrokinetic pump is rendered capable of operating with working fluids having pH values that can range from 2-10 generally and acidic working fluids in particular. For applications in which the pump is intended to handle highly acidic solutions latex nanoparticles that are quaternary amine functionalized can be used.
Pumping behavior of ion pump elements at high and misaligned magnetic fields
Energy Technology Data Exchange (ETDEWEB)
Hseuh, H. C.; Jiang, W. S.; Mapes, M.
1994-11-01
The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae.
Pumping behavior of ion pump elements at high and misaligned magnetic fields
International Nuclear Information System (INIS)
Hseuh, H.C.; Jiang, W.S.; Mapes, M.
1994-01-01
The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae
International Nuclear Information System (INIS)
Pennell, W.E.
1981-01-01
A liquid metal pump comprising a shaft support structure which is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft carries an impeller and the support structure carries an impeller cage which is slidably disposed in a diffuser so as to allow complete removal of pump internals for inspection and repair. The diffuser is concentrically supported in the pump housing which also takes up all reaction forces generated by the discharge of the liquid metal from the diffuser, with floating seals arranged between impeller cage and the diffuser. The space between the diffuser and the pump housing permits the incoming liquid to essentially surround the diffuser. (author)
Diode-pumped glass laser (10 J X 10 HZ) development
International Nuclear Information System (INIS)
Tadashi Kanabe; Toshiyuki Kawashima; Masanobu Yamanaka; Masahiro Nakatsuka; Yasukazu Izawa; Takeshi Kanzaki; Hirofumi Kan; Sadao Nakai
2002-01-01
A high-energy, high beam quality, diode-pumped 1053-nm Nd:phosphate glass laser amplifier has been demonstrated in order to verify the conceptual design of HALNA (High Average-power Laser for Nuclear-fusion Application): a diode-pumped solid-state laser based on a water-cooled zig-zag slab optical geometry. This amplifier yielded 8.5 J output energy per pulse at 0.5 Hz in a 20 ns pulse of two times the diffraction limit beam quality with an optical-to-optical conversion efficiency of 10.9%. The experimental results revealed that the primary requirements for the IFE driver, such as diode-pumping, energy storage and extraction efficiencies, and beam quality have been fulfilled
[Proton pump inhibitors in gastro-oesophageal reflux disease: what is the further step?].
Simon, Mireille; Zerbib, Frank
2013-01-01
Optimisation of proton pump inhibitors use may improve reflux symptoms in 20-25% of the patients. Pathological gastro-oesophageal reflux should be documented in a patient with refractory reflux symptoms using upper endoscopy and/or pH testing. While on proton pump inhibitors twice daily, persistent symptoms are not related to gastro-oesophageal refluxdisease(GERD) in 50% of the patients. The new anti-reflux compounds have yet a limited efficacy and side effects that currently limit their development. Copyright © 2012. Published by Elsevier Masson SAS.
Pumping machinery theory and practice
Badr, Hassan M
2014-01-01
Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi
Fluid Dynamics in Rotary Piston Blood Pumps.
Wappenschmidt, Johannes; Sonntag, Simon J; Buesen, Martin; Gross-Hardt, Sascha; Kaufmann, Tim; Schmitz-Rode, Thomas; Autschbach, Ruediger; Goetzenich, Andreas
2017-03-01
Mechanical circulatory support can maintain a sufficient blood circulation if the native heart is failing. The first implantable devices were displacement pumps with membranes. They were able to provide a sufficient blood flow, yet, were limited because of size and low durability. Rotary pumps have resolved these technical drawbacks, enabled a growing number of mechanical circulatory support therapy and a safer application. However, clinical complications like gastrointestinal bleeding, aortic insufficiency, thromboembolic complications, and impaired renal function are observed with their application. This is traced back to their working principle with attenuated or non-pulsatile flow and high shear stress. Rotary piston pumps potentially merge the benefits of available pump types and seem to avoid their complications. However, a profound assessment and their development requires the knowledge of the flow characteristics. This study aimed at their investigation. A functional model was manufactured and investigated with particle image velocimetry. Furthermore, a fluid-structure interaction computational simulation was established to extend the laboratory capabilities. The numerical results precisely converged with the laboratory measurements. Thus, the in silico model enabled the investigation of relevant areas like gap flows that were hardly feasible with laboratory means. Moreover, an economic method for the investigation of design variations was established.
A study of water pump efficiency for household water demand at Lubuklinggau
Emiliawati, Anna
2017-11-01
Water pump is a device to transport liquid from one place to another. This device is used in most of household in Indonesia. Small-scale water pump which is effective to lift more discharge is generally used. The ones that are most preferred are centrifugal types which having low absorbability. Pump performance is limited by pressure level in real electrical power whereas pump efficiency is influenced by head and discharge. The research aims to find out the efficiency of five distinct brands of home water pumps which are broadly distributed in market. Efficiency analysis take by laboratorium and financial analysis using NPV and BCR are done in order to obtained dicharge and pressure from each pump. At the end of the research, one out of 5 home water pump brands will be selected as the optimal working home water pump with low operational expense based on the utilizing age. The result of the research shows that the maximum efficiency value among various brands of water pump is diverse. Each value is arranged as follow from water pump A to E orderly: 12,9%, 13,5%, 12,8%, 14,8%, and 3,4%. From the calculation, water demand of South Lubuklinggau at stage 1 is 1117,7 l/s and stage 2 is 3495,2 l/s.. Moreover, the researcher conducts of investment, operation and maintenance cost with 25 years pump utilizing age towards 2 conditions (1) of maximum efficiency, i.e. pump A Rp16.563.971; pump B Rp12.163.798; pump C Rp11.809.513,2; pump D Rp11.473.928,3; pump E Rp12.648.708,3; (2) of max discharge, i.e. pump A Rp111.993.822,8; pump B Rp26.128.845,1; pump C Rp51.697.208,8; pump D Rp51.098.687,4; pump E Rp22.915.952,7;Financial analysis with interest rate 13% show a positive NPV(+) for all pump except pump A in max efficiency and a negative NPV (-) for all except pump B in max discharge. BCR value for max efficiency are pump A 0,8; pump B 1,6; pump C 1,7; pump D 1,7 and pump E 1,3. And for max discharge are pump A 0,2; pump B 1,1; pump C 0,7; pump D 0,7 and pump E 0,9. Result
Hydraulic optimization of 'S' characteristics of the pump-turbine for Xianju pumped storage plant
International Nuclear Information System (INIS)
Liu, W C; Zheng, J S; Cheng, J; Shi, Q H
2012-01-01
The pump-turbine with a rated power capacity of 375MW each at Xianju pumped storage plant is the most powerful one under construction in China. In order to avoid the instability near no-load conditions, the hydraulic design of the pump-turbine has been optimized to improving the 'S' characteristic in the development of the model pump-turbine. This paper presents the cause of 'S' characteristic of a pump-turbine by CFD simulation of the internal flow. Based on the CFD analysis, the hydraulic design optimization of the pump-turbine was carried out to eliminate the 'S' characteristics of the machine at Xianju pumped storage plant and a big step for removing the 'S' characteristic of a pump-turbine has been obtained. The model test results demonstrate that the pump-turbine designed for Xianju pumped storage plant can smoothly operate near no-load conditions without an addition of misaligned guide vanes.
Energy Technology Data Exchange (ETDEWEB)
Paulus, Thomas; Schullerer, Joachim; Oesterle, Manfred [KSB AG, Frankenthal (Germany)
2009-07-01
In many areas of industrial automation, centrifugal pumps and systems of centrifugal pumps are important actuators of a process und therefore a fundamental part of the entire plant. In contrary to the controlled valves, located behind the pump in the pipework system, the functions of the intelligent actuator pump or system of pumps are rarely used and noticed. With regard to the reduction of life cycle costs of the asset pump, pump integrated closed loop control of the fluid transport task has advantages over central closed loop control e.g. in a process control system. This article contains a survey of the intelligent actuator pump, its structure and functions with regard to the solution of the fluid transport task and according pump integrated closed loop control. (orig.)
Making effective use of rod pumping systems in coalbed methane applications
Energy Technology Data Exchange (ETDEWEB)
Crivello, A. [eProduction Solutions Inc., Kingwood, TX (United States)
2003-07-01
The advantages of optimizing coalbed methane (CBM) operations are increased production, reduced expenses, improved efficiency, and better inventory. The author discussed the CBM production cycle and the possible artificial lift options, including electric submersible pump (ESP), plunger lift, primary coolant pump (PCP), and reciprocating rod lift. The presentation focused on the rod lift, as it represents a low to moderate capital expenditure, has good system efficiency, an excellent fluid volume range, an excellent salvage value, excellent familiarity with equipment, and has readily available parts and service. The major disadvantage of the rod lift is that the fixed operating range does not adapt to changing reservoir characteristics. A comparison between the rod pump controller and the variable speed drive was presented. The well can be operated at or near the pumped off condition with variable speed drives with rod pumping intelligence. The author provided a closer examination of the variable frequency drive and the vector flux drive. The presentation also included a discussion of prime movers, drive and inclinometer, gearbox loading, rod load limiter, and dynamometer cards. Three case studies were presented: CSW1, CSW2, and CSW3. It was concluded that wells must be kept pumping, and that a Flux Vector Drive should be used along with an NEMA B motor and properly sized pumping unit and pump. tabs., figs.
High-vacuum pumping out of hydrogen isotopes by compressed and electrophysical pumps
International Nuclear Information System (INIS)
Bychkova, A.D.; Ershova, Z.V.; Saksaganskij, G.L.; Serebrennikov, D.V.
1982-01-01
To explain the selection of parameters of vacuum systems of projected thermonuclear devices, experiments are performed on the pumping-out of deuterium and tritium by high-vacuum pumps of different types. The values of the fast response of turbomolecular, diffusion vapour-mercury, magneto-discharge and titanium getter pumps in the operation pressure range are determined. The rate of sorption of hydrogen isotopes by non-spraying gas absorber of cial alloy depending on the amount of the gas absorbed and temperature, is measured. Gas current is determined by the pressure drop on the diagram of the known conductivity. Individual calibration of manometric converters for different gases using a mercury burette is performed preliminarily. The means of high-vacuum pumping-out that have been studied have the following values of fast response for tritium (relatively to protium): turbomolecular pump-0.95; evaporation getter pump-0.25; magneto-discharge pumps-0.65-0.9; cial alloy-0.1...0.5
Entropy, pricing and macroeconomics of pumped-storage systems
Karakatsanis, Georgios; Mamassis, Nikos; Koutsoyiannis, Demetris; Efstratiadis, Andreas
2014-05-01
We propose a pricing scheme for the enhancement of macroeconomic performance of pumped-storage systems, based on the statistical properties of both geophysical and economic variables. The main argument consists in the need of a context of economic values concerning the hub energy resource; defined as the resource that comprises the reference energy currency for all involved renewable energy sources (RES) and discounts all related uncertainty. In the case of pumped-storage systems the hub resource is the reservoir's water, as a benchmark for all connected intermittent RES. The uncertainty of all involved natural and economic processes is statistically quantifiable by entropy. It is the relation between the entropies of all involved RES that shapes the macroeconomic state of the integrated pumped-storage system. Consequently, there must be consideration on the entropy of wind, solar and precipitation patterns, as well as on the entropy of economic processes -such as demand preferences on either current energy use or storage for future availability. For pumped-storage macroeconomics, a price on the reservoir's capacity scarcity should also be imposed in order to shape a pricing field with upper and lower limits for the long-term stability of the pricing range and positive net energy benefits, which is the primary issue of the generalized deployment of pumped-storage technology. Keywords: Entropy, uncertainty, pricing, hub energy resource, RES, energy storage, capacity scarcity, macroeconomics
Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings
Energy Technology Data Exchange (ETDEWEB)
Hunt, A.; Easley, S.
2012-05-01
The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.
Energy Technology Data Exchange (ETDEWEB)
Wiernicki, M.V.
1987-05-05
This patent describes a wet motor gerotor fuel pump for pumping fuel from a fuel source to an internal combustion which consists of: gerotor pump means comprising an inner pump gear, an outer pump gear, and second tang means located on one of the inner and outer pump gears. The second tang means further extends in a second radial direction radially offset from the first radial direction and forms a driving connection with the first tang means such that the fuel pump pumps fuel from the fuel source into the narrow conduit inlet chamber, through the gerotor pump means past the electric motor means into the outlet housing means substantially along the flow axis to the internal combustion engine.
Diode-pumped laser with improved pumping system
Chang, Jim J.
2004-03-09
A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.
Happer, William; Walker, Thad
2010-01-01
Covering the most important knowledge on optical pumping of atoms, this ready reference is backed by numerous examples of modelling computation for optical pumped systems. The authors show for the first time that modern scientific computing software makes it practical to analyze the full, multilevel system of optically pumped atoms. To make the discussion less abstract, the authors have illustrated key points with sections of MATLAB codes. To make most effective use of contemporary mathematical software, it is especially useful to analyze optical pumping situations in the Liouville spa
DEFF Research Database (Denmark)
Bytzer, Peter; Jones, Roger; Vakil, Nimish
2012-01-01
The efficacy of proton-pump inhibitor (PPI) therapy often is assessed to determine whether patients' symptoms are acid-related and if patients have gastroesophageal reflux disease (GERD), although the accuracy of this approach is questionable. We evaluated the diagnostic performance of the PPI test...
Outcome of Cardiac Rehabilitation Following Off-Pump Versus On-Pump Coronary Bypass Surgery
Directory of Open Access Journals (Sweden)
Reza Arefizadeh
2017-05-01
CONCLUSIONS: Regarding QOL and psychological status, there were no differences in the CR outcome between those who underwent off-pump bypass surgery and those who underwent on-pump surgery; nevertheless, the off-pump technique was superior to the on-pump method on METs improvement following CR.
Measure Guideline. Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings
Energy Technology Data Exchange (ETDEWEB)
Hunt, A. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States); Easley, S. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States)
2012-05-01
This measure guideline evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provides a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.
Vapor-Compression Heat Pumps for Operation Aboard Spacecraft
Ruemmele, Warren; Ungar, Eugene; Cornwell, John
2006-01-01
Vapor-compression heat pumps (including both refrigerators and heat pumps) of a proposed type would be capable of operating in microgravity and would be safe to use in enclosed environments like those of spacecraft. The designs of these pumps would incorporate modifications of, and additions to, vapor-compression cycles of heat pumps now used in normal Earth gravitation, in order to ensure efficiency and reliability during all phases of operation, including startup, shutdown, nominal continuous operation, and peak operation. Features of such a design might include any or all of the following: (1) Configuring the compressor, condenser, evaporator, valves, capillary tubes (if any), and controls to function in microgravitation; (2) Selection of a working fluid that satisfies thermodynamic requirements and is safe to use in a closed crew compartment; (3) Incorporation of a solenoid valve and/or a check valve to prevent influx of liquid to the compressor upon startup (such influx could damage the compressor); (4) Use of a diode heat pipe between the cold volume and the evaporator to limit the influx of liquid to the compressor upon startup; and (5) Use of a heated block to vaporize any liquid that arrives at the compressor inlet.
International Nuclear Information System (INIS)
1999-01-01
The guide describes how the Finnish Radiation and Nuclear Safety Authority (STUK) controls pumps and their motors at nuclear power plants and other nuclear facilities. The scope of the control is determined by the Safety Class of the pump in question. The various phases of the control are: (1) review of construction plan, (2) control of manufacturing, and construction inspection, (3) commissioning inspection, and (4) control during operation. STUK controls Safety Class 1, 2 and 3 pumps at nuclear facilities as described in this guide. STUK inspects Class EYT (non-nuclear) pumps separately or in connection with the commissioning inspections of the systems. This guide gives the control procedure and related requirements primarily for centrifugal pumps. However, it is also applied to the control of piston pumps and other pump types not mentioned in this guide
Solar Pumped Lasers and Their Applications
Lee, Ja H.
1991-01-01
Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.
Advanced limiter test (ALT-I) in the TEXTOR tokamak - concept and experimental design
International Nuclear Information System (INIS)
Conn, R.W.; Grotz, S.P.; Prinja, A.K.
1983-01-01
The concept and experimental design of a pump-limiter for the TEXTOR tokamak is described. The module is constructed of stainless steel with a compound curvature head designed to limit the maximum heat flux to 300 W/cm 2 . The head is made of TiC-coated graphite containing a variable aperture slot to admit plasma to a deflector plate for ballistic pumping action. The assembly is actively pumped using Zr-Al getters with an estimated hydrogen pumping speed of 2x10 4 1/s. The aspect ratio of the pump duct and the length of the plasma channel are both variable to permit study of plasma plugging, ballistic scattering, and enhanced gas conduction effects. The module can be moved radially by 10 cm to permit its operation either as the primary or secondary limiter. Major diagnostics include Langmuir and solid state probes, bolometers, infrared thermography, thermocouples, ion gauges, manometers, and a gas mass analyzer. (author)
Full counting statistics of a charge pump in the Coulomb blockade regime
Andreev, A. V.; Mishchenko, E. G.
2001-12-01
We study full charge counting statistics (FCCS) of a charge pump based on a nearly open single electron transistor. The problem is mapped onto an exactly soluble problem of a nonequilibrium g=1/2 Luttinger liquid with an impurity. We obtain an analytic expression for the generating function of the transmitted charge for an arbitrary pumping strength. Although this model contains fractionally charged excitations only integer transmitted charges can be observed. In the weak pumping limit FCCS correspond to a Poissonian transmission of particles with charge e*=e/2 from which all events with odd numbers of transferred particles are excluded.
Survey of pumps for tritium gas
International Nuclear Information System (INIS)
Dowell, T.M.
1983-05-01
This report considers many different types of pumps for their possible use in pumping tritium gas in the low, intermediate and high vacuum ranges. No one type of pump is suitable for use over the wide range of pumping pressure required in a typical pumping system. The favoured components for such a system are: bellows pump (low vacuum); orbiting scroll pump (intermediate vacuum); magnetically suspended turbomolecular pump (high vacuum); cryopump (high vacuum). Other pumps which should be considered for possible future development are: mound modified vane pump; SRTI wobble pump; roots pump with canned motor. It is proposed that a study be made of a future tritium pumping system in a Canadian tritium facility, e.g. a tritium laboratory
Detection of cavitation inception by acoustic technique in centrifugal pumps for nuclear application
International Nuclear Information System (INIS)
Prakash, V.; Prabhakar, R.; Rao, A.S.L.K.; Kale, R.D.
1994-01-01
The primary centrifugal pumps in a pool type reactor like the proposed Prototype Fast Breeder Reactor (PFBR) are required to operate at low values of available net positive suction head due to the limited submergence available in the pool. Pump hydraulics are designed to ensure that there is no cavitation or only minimum cavitation in the pump impeller in order to minimise long term erosion damage. Rigorous cavitation tests are usually carried out during development and final testing phase and a promising cavitation detection technique lies in acoustic noise measurements on the pump. As part of PFBR pump development programme, cavitation noise measurements were initially carried out on an experimental sodium pump in a water rig to establish detection procedures. Recently cavitation noise measurements were carried out on a 1/3 scale model impeller of PFBR pump along with visual observation of impeller passages to establish a correlation between visual and acoustic technique. Accelerometer responding to structure borne noise seems to give the best result. (author). 4 refs., 6 figs
International Nuclear Information System (INIS)
Dohnal, M.; Rosel, J.; Skarka, V.
1988-01-01
The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig
Normetex Pump Alternatives Study
International Nuclear Information System (INIS)
Clark, Elliot A.
2013-01-01
A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying
High-energy high-efficiency Nd:YLF laser end-pump by 808 nm diode
Ma, Qinglei; Mo, Haiding; Zhao, Jay
2018-04-01
A model is developed to calculate the optimal pump position for end-pump configuration. The 808 nm wing pump is employed to spread the absorption inside the crystal. By the optimal laser cavity design, a high-energy high-efficiency Nd:YLF laser operating at 1053 nm is presented. In cw operation, a 13.6 W power is obtained with a slope efficiency of 51% with respect to 30 W incident pump power. The beam quality is near diffraction limited with M2 ∼ 1.02. In Q-switch operation, a pulse energy of 5 mJ is achieved with a peak power of 125 kW at 1 kHz repetition rate.
Performance of Wind Pump Prototype
African Journals Online (AJOL)
Mulu
Mekelle University, Mekelle, Ethiopia (*mul_at@yahoo.com). ABSTRACT. A wind ... balanced rotor power and reciprocating pump, hence did not consider the effect of pump size. ... Keywords: Wind pump, Windmill, Performance testing, Pump efficiency, Pump discharge, ... Unfortunately, in rural places, where the houses are.
Upgradation of design features of primary coolant pumps of Indian 220 MWe PHWR
International Nuclear Information System (INIS)
Sharma, S.S.; Mhetre, S.G.; Manna, M.M.
1994-01-01
Evolution in the design features of Primary Coolant Pump (PCP) had started in fifties for catering to stringent specification requirements of reactor coolant systems of larger capacity reactors of various kinds. Primary coolant pumps of PWR and PHWR are employed for circulating radioactive, pressurized hot water in a circuit consisting of reactor (heat source) and steam generator (heat sink). As primary coolant pump capacity decides the station capacity, larger capacity primary coolant pumps have been evolved. Since primary coolant pump pressure containing parts are part of Primary Heat Transport system envelope, the parts are designed, manufactured, inspected and tested in accordance with the applicable system guidelines. Flywheel is mounted on the motor shaft for increasing mass moment of inertia of pump motor rotor to meet the coast down requirements of reactor cooling system under Class-IV electrical power supply failure. Due to limited accessibility of the PCP (PCP installed in shut down accessible area), quick maintenance, condition monitoring, reliable shaft seal system/bearing system aspects have been of great concern to reactor owners and pump manufacturers. In this paper upgradation of design features of RAPS, MAPS and NAPS primary coolant pumps have been covered. (author). 4 figs., 1 tab
Development of model pump for establishing hydraulic design of primary sodium pumps in PFBR
International Nuclear Information System (INIS)
Chougule, R.J.; Sahasrabudhe, H.G.; Rao, A.S.L.K.; Balchander, K.; Kale, R.D.
1994-01-01
Indira Gandhi Centre for Atomic Research, Kalpakkam indicated requirement of indigenous development of primary sodium pump, handling liquid sodium as coolant in Fast Breeder Reactor. The primary sodium pump concept selected in its preliminary design is a vertical, single stage, with single suction impeller, suction facing downwards. The pump is having diffuser, discharge casing and discharge collector. The 1/3 rd size model pump is developed to establish the hydraulic performance of the prototype primary sodium pump. The main objectives were to verify the hydraulic design to operate on low net positive suction head available (NPSHA), no evidence of visible cavitation at available NPSHA, the pump should be designed with a diffuser etc. The model pump PSP 250/40 was designed and successfully developed by Research and Development Division of M/s Kirloskar Brothers Ltd., Kirloskarvadi. The performance testing using model pump was successfully carried out on a closed circuit test rig. The performance of a model pump at three different speeds 1900 rpm, 1456 rpm and 975 rpm was established. The values of hydraulic axial thrust with and without balancing holes on impeller at 1900 rpm was measured. Visual cavitation study at 1900 rpm was carried out to establish the NPSH at bubble free operation of the pump. The tested performance of the model pump is converted to the full scale prototype pump. The predicted performance of prototype pump at 700 rpm was found to be meeting fully with the expected duties. (author). 6 figs., 3 tabs
International Nuclear Information System (INIS)
Saikawa, Michiyuki; Koyama, Shigeru
2016-01-01
Highlights: • The ideal vapor compression cycle for tap water heating and its COP were defined. • It was verified theoretically that CO_2 achieves the highest COP for tap water heating. • The prototype of CO_2 heat pump water heater for residential use was developed. • Further COP improvement of CO_2 heat pump water heater was estimated. - Abstract: The ideal vapor compression cycle for tap water heating and its coefficient of performance (COP) have been studied theoretically at first. The ideal cycle is defined as the cycle whose high temperature heat source varies temperature with constant specific heat and other processes are same as the reverse Carnot cycle. The COP upper limit of single stage compression heat pump cycle for tap water heating with various refrigerants such as fluorocarbons and natural refrigerants was calculated. The refrigerant which achieves the highest COP for supplying hot water is CO_2. Next, the prototype of CO_2 heat pump water heater for residential use has been developed. Its outline and experimental results are described. Finally its further possibility of COP improvement has been studied. The COP considered a limit from a technical point of view was estimated about 6.0 at the Japanese shoulder season (spring and autumn) test condition of heating water from 17 °C to 65 °C at 16 °C heat source air temperature (dry bulb)/12 °C (wet bulb).
Speed control device for coolant recycling pump
International Nuclear Information System (INIS)
Kageyama, Takao.
1992-01-01
The present invention intends to increase a margin relative of the oscillations of neutron fluxes when the temperature of feedwater is lowered in a compulsory recycling type BWR reactor. That is, when the operation point represented by a reactor thermal power and a reactor core inlet flow rate is in a state approximate to an oscillation limit of the reactor power, the device of the present invention controls the recycling pump speed in the increasing direction depending on the lowering range of the feedwater temperature from a stationary state. With such a constitution, even if the reactor power is in the operation region near the oscillation limit in the BWR type reactor and a feedwater heating loss is caused, the speed of the coolant recycling pump is increased by 10% at the maximum depending on the extent of the reduction of the feedwater temperature, so that the oscillation of the reactor power can be prevented from lasting for a long period of time even if a reactivity external disturbance should occur in the reactor. (I.S.)
Computer simulations of the activity of RND efflux pumps.
Vargiu, Attilio Vittorio; Ramaswamy, Venkata Krishnan; Malloci, Giuliano; Malvacio, Ivana; Atzori, Alessio; Ruggerone, Paolo
2018-01-31
The putative mechanism by which bacterial RND-type multidrug efflux pumps recognize and transport their substrates is a complex and fascinating enigma of structural biology. How a single protein can recognize a huge number of unrelated compounds and transport them through one or just a few mechanisms is an amazing feature not yet completely unveiled. The appearance of cooperativity further complicates the understanding of structure-dynamics-activity relationships in these complex machineries. Experimental techniques may have limited access to the molecular determinants and to the energetics of key processes regulating the activity of these pumps. Computer simulations are a complementary approach that can help unveil these features and inspire new experiments. Here we review recent computational studies that addressed the various molecular processes regulating the activity of RND efflux pumps. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.
World Bank Group
2018-01-01
Solar photovoltaic water pumping (SWP) uses energy from solar photovoltaic (PV) panels to power an electric water pump. The entire process, from sunlight to stored energy, is elegant and simple. Over last seven years, the technology and price of solar pumping have evolved dramatically and hence the opportunities it presents. Solar pumping is most competitive in regions with high solar inso...
Electrokinetic pumps and actuators
International Nuclear Information System (INIS)
Phillip M. Paul
2000-01-01
Flow and ionic transport in porous media are central to electrokinetic pumping as well as to a host of other microfluidic devices. Electrokinetic pumping provides the ability to create high pressures (to over 10,000 psi) and high flow rates (over 1 mL/min) with a device having no moving parts and all liquid seals. The electrokinetic pump (EKP) is ideally suited for applications ranging from a high pressure integrated pump for chip-scale HPLC to a high flow rate integrated pump for forced liquid convection cooling of high-power electronics. Relations for flow rate and current fluxes in porous media are derived that provide a basis for analysis of complex microfluidic systems as well as for optimization of electrokinetic pumps
Electrokinetic pumps and actuators
Energy Technology Data Exchange (ETDEWEB)
Phillip M. Paul
2000-03-01
Flow and ionic transport in porous media are central to electrokinetic pumping as well as to a host of other microfluidic devices. Electrokinetic pumping provides the ability to create high pressures (to over 10,000 psi) and high flow rates (over 1 mL/min) with a device having no moving parts and all liquid seals. The electrokinetic pump (EKP) is ideally suited for applications ranging from a high pressure integrated pump for chip-scale HPLC to a high flow rate integrated pump for forced liquid convection cooling of high-power electronics. Relations for flow rate and current fluxes in porous media are derived that provide a basis for analysis of complex microfluidic systems as well as for optimization of electrokinetic pumps.
Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease
DEFF Research Database (Denmark)
Møller, Christian H; Penninga, Luit; Wetterslev, Jørn
2012-01-01
Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.......Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear....
Diode lasers optimized in brightness for fiber laser pumping
Kelemen, M.; Gilly, J.; Friedmann, P.; Hilzensauer, S.; Ogrodowski, L.; Kissel, H.; Biesenbach, J.
2018-02-01
In diode laser applications for fiber laser pumping and fiber-coupled direct diode laser systems high brightness becomes essential in the last years. Fiber coupled modules benefit from continuous improvements of high-power diode lasers on chip level regarding output power, efficiency and beam characteristics resulting in record highbrightness values and increased pump power. To gain high brightness not only output power must be increased, but also near field widths and far field angles have to be below a certain value for higher power levels because brightness is proportional to output power divided by beam quality. While fast axis far fields typically show a current independent behaviour, for broadarea lasers far-fields in the slow axis suffer from a strong current and temperature dependence, limiting the brightness and therefore their use in fibre coupled modules. These limitations can be overcome by carefully optimizing chip temperature, thermal lensing and lateral mode structure by epitaxial and lateral resonator designs and processing. We present our latest results for InGaAs/AlGaAs broad-area single emitters with resonator lengths of 4mm emitting at 976nm and illustrate the improvements in beam quality over the last years. By optimizing the diode laser design a record value of the brightness for broad-area lasers with 4mm resonator length of 126 MW/cm2sr has been demonstrated with a maximum wall-plug efficiency of more than 70%. From these design also pump modules based on 9 mini-bars consisting of 5 emitters each have been realized with 360W pump power.
Internal pump monitoring device
International Nuclear Information System (INIS)
Kurosaki, Toshikazu.
1996-01-01
In the present invention, a thermometer is disposed at the upper end of an internal pump casing of a coolant recycling system in a BWR type reactor to detect leakage of reactor water thereby ensuring the improvement of reliability of the internal pump. Namely, a thermometer is disposed, which can detect temperature elevation occurred when water in the internal pump leaked from a reactor pressure vessel passes through the gap between a stretch tube and an upper end of the pump casing. Signals from the thermometer are transmitted to a signal processing device by an instrumentation cable. The signal processing device generates an alarm when the temperature signal exceeds a predetermined value and announces that leakage of reactor water occurs in the internal pump. Since the present invention can detect the leakage of the reactor water in the pump casing in an early stage, it can contribute to the improvement of the safety and reliability of the internal pump. (I.S.)
Improvement of centrifugal pump performance through addition of splitter blades on impeller pump
Kurniawan, Krisna Eka; Santoso, Budi; Tjahjana, Dominicus Danardono Dwi Prija
2018-02-01
The workable way to improve pump performance is to redesign or modify the impellers of centrifugal pump. The purpose of impeller pump modification is to improve pump efficiency, reduce cross flow, reduce secondary incidence flows, and decrease backflow areas at impeller outlets. Number blades and splitter blades in the impeller are three. The outlet blade angle is 20°, and the rotating speed of impeller is 2400 rpm. The added splitter blades variations are 0.25, 0.375, and 0.5 of the original blade length. The splitter blade placements are on the outer side of the impeller. The addition of splitter blades on the outer side of the impeller with 0.5L increases the pump head until 22% and the pump has 38.66% hydraulic efficiency. The best efficiency point of water flow rate pump (Qbep) was 3.02 × 10-3 m3/s.
Achievement of new quantum limit by switching of pump frequency of squeezer
Koyano, Hidenori; Yoshida, Norihiro; Uyematsu, Tomohiko
In this paper, we have shown an realization method for the quantum state switch system which can provide the optical communication system beyond the SQL. The original idea of our proposed system is the frequency shift of pumping light of DPA by the application of the injection locking phenomena. This enables us to get the conditional unitary communication system. Furthermore an example of the design of our system has been given. As a result, we would like to emphasize that our system can be constructed by the current technology, because the new device is only squeezer and we can get the squeezer in near future.
International Nuclear Information System (INIS)
Kim, J.H.
1991-01-01
This paper reports that pumps play an important role in nuclear plant operation. For instance, reactor coolant pumps (RCPs) should provide adequate cooling for reactor core in both normal operation and transient or accident conditions. Pumps such as Low Pressure Safety Injection (LPSI) pump in the Emergency Core Cooling System (ECCS) play a crucial role during an accident, and their reliability is of paramount importance. Some key issues involved with pumps in nuclear plant system include the performance of RCP under two-phase flow conditions, piping vibration due to pump operating in two-phase flows, and reliability of LPSI pumps
ALT-II toroidal belt limiter biasing experiments on TEXTOR
International Nuclear Information System (INIS)
Doerner, R.; Boedo, J.A.; Gray, D.S.
1991-01-01
Edge electric fields have been related to H-mode-like behaviour. The experiments reported here are an attempt to control the SOL profiles by electrostatic biasing of the full toroidal-belt limiter ALT-II. The specific goals are: influencing the edge particle flows, particle removal, power deposition and the global confinement. The ALT-II pump limiter is a full toroidal belt located at 45 o below the outer midplane and consisting of eight graphite covered blades which can be independently biased. Particle scoops located behind the limiter neutralize and direct the incoming plasma into the pumping ducts. (author) 5 refs., 3 figs
International Nuclear Information System (INIS)
Casada, D.
1995-01-01
There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed
Impulse pumping modelling and simulation
International Nuclear Information System (INIS)
Pierre, B; Gudmundsson, J S
2010-01-01
Impulse pumping is a new pumping method based on propagation of pressure waves. Of particular interest is the application of impulse pumping to artificial lift situations, where fluid is transported from wellbore to wellhead using pressure waves generated at wellhead. The motor driven element of an impulse pumping apparatus is therefore located at wellhead and can be separated from the flowline. Thus operation and maintenance of an impulse pump are facilitated. The paper describes the different elements of an impulse pumping apparatus, reviews the physical principles and details the modelling of the novel pumping method. Results from numerical simulations of propagation of pressure waves in water-filled pipelines are then presented for illustrating impulse pumping physical principles, and validating the described modelling with experimental data.
Reactor recirculation pump test loop
International Nuclear Information System (INIS)
Taka, Shusei; Kato, Hiroyuki
1979-01-01
A test loop for a reactor primary loop recirculation pumps (PLR pumps) has been constructed at Ebara's Haneda Plant in preparation for production of PLR pumps under license from Byron Jackson Pump Division of Borg-Warner Corporation. This loop can simulate operating conditions for test PLR pumps with 130 per cent of the capacity of pumps for a 1100 MWe BWR plant. A main loop, primary cooling system, water demineralizer, secondary cooling system, instrumentation and control equipment and an electric power supply system make up the test loop. This article describes the test loop itself and test results of two PLR pumps for Fukushima No. 2 N.P.S. Unit 1 and one main circulation pump for HAZ Demonstration Test Facility. (author)
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Pumps. 157.126 Section 157.126... Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.126 Pumps. (a) Crude oil must be supplied to the COW machines by COW system pumps or cargo pumps. (b) The pumps under paragraph...
International Nuclear Information System (INIS)
Timmermans, Francis; Vandervorst, Jean.
1981-01-01
Safety device for longitudinally leak proofing the shaft of a pump in the event of the fracture of the dynamic seal separating the pump fluid high pressure chamber from the low pressure chamber. It is designed for fitting to the primary pumps of nuclear reactors. It includes a hollow cyclindrical piston located coaxially around the pump shaft and normally housed in a chamber provided for this purpose in the fixed housing of the dynamic seal, and means for moving this piston coaxially so as to compress a safety O ring between the shaft and the piston in the event of the dynamic seal failing [fr
International Nuclear Information System (INIS)
Casada, D.A.
1994-01-01
There are a variety of stressors that can affect the operation of centrifugal pumps. These can generally be classified as: Mechanical; Hydraulic; Tribological; Chemical; and Other (including those associated with the pump driver). Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump
Supercritical waste oxidation pump investigation
International Nuclear Information System (INIS)
Thurston, G.; Garcia, K.
1993-02-01
This report investigates the pumping techniques and pumping equipment that would be appropriate for a 5,000 gallon per day supercritical water oxidation waste disposal facility. The pumps must boost water, waste, and additives from atmospheric pressure to approximately 27.6 MPa (4,000 psia). The required flow ranges from 10 gpm to less than 0.1 gpm. For the higher flows, many commercial piston pumps are available. These pumps have packing and check-valves that will require periodic maintenance; probably at 2 to 6 month intervals. Several commercial diaphragm pumps were also discovered that could pump the higher flow rates. Diaphragm pumps have the advantage of not requiring dynamic seals. For the lower flows associated with the waste and additive materials, commercial diaphragm pumps. are available. Difficult to pump materials that are sticky, radioactive, or contain solids, could be injected with an accumulator using an inert gas as the driving mechanism. The information presented in this report serves as a spring board for trade studies and the development of equipment specifications
A method for evaluating horizontal well pumping tests.
Langseth, David E; Smyth, Andrew H; May, James
2004-01-01
Predicting the future performance of horizontal wells under varying pumping conditions requires estimates of basic aquifer parameters, notably transmissivity and storativity. For vertical wells, there are well-established methods for estimating these parameters, typically based on either the recovery from induced head changes in a well or from the head response in observation wells to pumping in a test well. Comparable aquifer parameter estimation methods for horizontal wells have not been presented in the ground water literature. Formation parameter estimation methods based on measurements of pressure in horizontal wells have been presented in the petroleum industry literature, but these methods have limited applicability for ground water evaluation and are based on pressure measurements in only the horizontal well borehole, rather than in observation wells. This paper presents a simple and versatile method by which pumping test procedures developed for vertical wells can be applied to horizontal well pumping tests. The method presented here uses the principle of superposition to represent the horizontal well as a series of partially penetrating vertical wells. This concept is used to estimate a distance from an observation well at which a vertical well that has the same total pumping rate as the horizontal well will produce the same drawdown as the horizontal well. This equivalent distance may then be associated with an observation well for use in pumping test algorithms and type curves developed for vertical wells. The method is shown to produce good results for confined aquifers and unconfined aquifers in the absence of delayed yield response. For unconfined aquifers, the presence of delayed yield response increases the method error.
International Nuclear Information System (INIS)
Ito, Koji; Suetake, Norio; Aizawa, Toshie; Nakasaki, Masayoshi
1998-01-01
The present invention provides an electromagnetic pump suitable to a recycling pump for liquid sodium as coolants of an FBR type reactor. Namely, a stator module of the electromagnetic pump of the present invention comprises a plurality of outer laminate iron core units and outer stator modules stacked alternately in the axial direction. With such a constitution, even a long electromagnetic pump having a large number of outer stator coils can be manufactured without damaging electric insulation of the outer stator coils. In addition, the inner circumferential surface of the outer laminate iron cores is urged and brought into contact with the outer circumferential surface of the outer duct by an elastic material. With such a constitution, Joule loss heat generated in the outer stator coils and internal heat generated in the outer laminate iron cores can be released to an electroconductive fluid flowing the inner circumference of the outer duct by way of the outer duct. (I.S.)
Off-pump coronary artery bypass surgery in severe left ventricular dysfunction.
Azarfarin, Rasoul; Pourafkari, Leili; Parvizi, Rezayat; Alizadehasl, Azin; Mahmoodian, Roghaiyeh
2010-02-01
Our aim was to examine hospital outcomes of coronary artery bypass surgery in patients with and without left ventricular dysfunction, with regard to the surgical technique (off- or on-pump). Between March 2007 and March 2008, 689 consecutive patients underwent isolated first-time coronary artery bypass; 127 had ejection fractions fractions >30% (group 2). Data of preoperative risk profiles and hospital outcomes were collected prospectively. Off-pump operations were performed in 49 (38.6%) patients in group 1 and 196 (34.9%) in group 2. The incidences of infectious, neurologic, and cardiac complications postoperatively were significantly higher in group 1. In multivariate analysis, preoperative ejection fraction operations, but no significant difference in mortality was observed between those undergoing off-pump or conventional surgery in either group. Off-pump surgery helped to limit the increased morbidity rate after coronary bypass in patients with ventricular dysfunction.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Pumps. 154.1135 Section 154.1135 Shipping COAST GUARD... Pumps. (a) Water to the water spray system must be supplied by: (1) A pump that is only for the use of the system; (2) A fire pump; or (3) A pump specially approved by the Commandant (CG-522). (b...
Directory of Open Access Journals (Sweden)
Marius Stan
2018-02-01
Full Text Available Centrifugal pumps are widely used in the industry, especially in the oil and gas sector for fluids transport. Classically, these are designed to transfer single phase fluids (e.g., water at high flow rates and relatively low pressures when compared with other pump types. As part of their constructive feature, centrifugal pumps rely on seals to prevent air entrapment into the rotor during its normal operation. Although this is a constructive feature, water should pass through the pump inlet even when the inlet manifold is damaged. Modern pumps are integrated in pumping units which consist of a drive (normally electric motor, a transmission (when needed, an electronic package (for monitoring and control, and the pump itself. The unit also has intake and outlet manifolds equipped with valves. Modern systems also include electronic components to measure and monitor pump working parameters such as pressure, temperature, etc. Equipment monitoring devices (vibration sensors, microphones are installed on modern pumping units to help users evaluate the state of the machinery and detect deviations from the normal working condition. This paper addresses the influence of air-water two-phase mixture on the characteristic curve of a centrifugal pump; pump vibration in operation at various flow rates under these conditions; the possibilities of using the results of experimental investigations in the numerical simulations for design and training purposes, and the possibility of using vibration and sound analysis to detect changes in the equipment working condition. Conclusions show that vibration analysis provides accurate information about the pump’s functional state and the pumping process. Moreover, the acoustic emission also enables the evaluation of the pump status, but needs further improvements to better capture and isolate the usable sounds from the environment.
Near quantum limited amplification from inelastic Cooper-pair tunneling
Hofheinz, Max; Jebari, Salha; Blanchet, Florian; Grimm, Alexander; Hazra, Dibyendu; Albert, Romain; Portier, Fabien
Josephson parametric amplifiers approach quantum-limited noise performance but require strong external microwave pump tones which make them more difficult to use than DC powered amplifiers: The pump tone can affect the device under test and requires expensive room-temperature equipment. Inelastic Cooper pair tunneling processes through a small DC voltage-biased Josephson junction, where a tunneling Cooper pair dissipates its energy 2 eV in the form of two photons are reminiscent of parametric down conversion. We show that these processes can be used to provide amplification near the quantum limit without external microwave pump tone. We explain the measured gain and noise based on the P (E) theory of inelastic Cooper pair tunneling and general fluctuation-dissipation relations.
High average power diode pumped solid state lasers for CALIOPE
International Nuclear Information System (INIS)
Comaskey, B.; Halpin, J.; Moran, B.
1994-07-01
Diode pumping of solid state media offers the opportunity for very low maintenance, high efficiency, and compact laser systems. For remote sensing, such lasers may be used to pump tunable non-linear sources, or if tunable themselves, act directly or through harmonic crystals as the probe. The needs of long range remote sensing missions require laser performance in the several watts to kilowatts range. At these power performance levels, more advanced thermal management technologies are required for the diode pumps. The solid state laser design must now address a variety of issues arising from the thermal loads, including fracture limits, induced lensing and aberrations, induced birefringence, and laser cavity optical component performance degradation with average power loading. In order to highlight the design trade-offs involved in addressing the above issues, a variety of existing average power laser systems are briefly described. Included are two systems based on Spectra Diode Laboratory's water impingement cooled diode packages: a two times diffraction limited, 200 watt average power, 200 Hz multi-rod laser/amplifier by Fibertek, and TRW's 100 watt, 100 Hz, phase conjugated amplifier. The authors also present two laser systems built at Lawrence Livermore National Laboratory (LLNL) based on their more aggressive diode bar cooling package, which uses microchannel cooler technology capable of 100% duty factor operation. They then present the design of LLNL's first generation OPO pump laser for remote sensing. This system is specified to run at 100 Hz, 20 nsec pulses each with 300 mJ, less than two times diffraction limited, and with a stable single longitudinal mode. The performance of the first testbed version will be presented. The authors conclude with directions their group is pursuing to advance average power lasers. This includes average power electro-optics, low heat load lasing media, and heat capacity lasers
Root cause analysis of pump valve failures of three membrane pump systems
Buijs, L.J.; Eijk, A.; Hooft, L. van
2014-01-01
This paper will present the root cause analysis and the solution of fatigue failures of the pump valves of three membrane pump systems installed on a chemical plant of Momentive in Pernis, the Netherlands. The membrane pumps were installed approximately 30 years ago. Each system has encountered
Pump audit identifies the energy consumers; Pump Audit identifiziert gezielt die Energieverschwender
Energy Technology Data Exchange (ETDEWEB)
Siekemann, Ralf [Grundfos GmbH, Erkrath (Germany)
2011-03-14
Engineering and services, which enhance and secure the energy efficiency of pump systems, are demanded. Speed-regulated pumps, included high efficient motors and a service philosophy, be designed on value conservation and cost control, are as well as professional ''pump-audits''. (orig./GL)
Pump polarization insensitive and efficient laser-diode pumped Yb:KYW ultrafast oscillator.
Wang, Sha; Wang, Yan-Biao; Feng, Guo-Ying; Zhou, Shou-Huan
2016-02-01
We theoretically and experimentally report and evaluate a novel split laser-diode (LD) double-end pumped Yb:KYW ultrafast oscillator aimed at improving the performance of an ultrafast laser. Compared to a conventional unpolarized single-LD end-pumped ultrafast laser system, we improve the laser performance such as absorption efficiency, slope efficiency, cw mode-locking threshold, and output power by this new structure LD-pumped Yb:KYW ultrafast laser. Experiments were carried out with a 1 W output fiber-coupled LD. Experimental results show that the absorption increases from 38.7% to 48.4%, laser slope efficiency increases from 18.3% to 24.2%, cw mode-locking threshold decreases 12.7% from 630 to 550 mW in cw mode-locking threshold, and maximum output-power increases 28.5% from 158.4 to 221.5 mW when we switch the pump scheme from an unpolarized single-end pumping structure to a split LD double-end pumping structure.
Scavenged body heat powered infusion pump
International Nuclear Information System (INIS)
Bell, Alexander; Ehringer, William D; McNamara, Shamus
2013-01-01
An infusion pump powered by body heat is investigated in this paper, with the goal of addressing the needs of dermal wound healing. The infusion pump incorporates a Knudsen gas pump, a type of thermally driven pump, to pneumatic push the pharmaceutical agent from a reservoir. Two designs are considered: an integrated pump and reservoir, and a design with cascaded pump and reservoir. Thermal models are developed for both pumps, and the simulations agree well with the experimental results. The integrated pump and reservoir design uses hydrophobic materials to prevent a flow from occurring unless the infusion pump is placed on a human body. Flow rates in the µL min −1 range for the integrated pump and reservoir, and approximately 70 µL min −1 for the cascaded pump were obtained. The dynamic behavior of the cascaded pump is described based on the thermal models. Multiple copies of the cascaded pump are easily made in series or parallel, to increase either the pressure or the flow rate. The flow rate of multiple pumps in series does not change, and the pressure of multiple pumps in parallel does not change. (paper)
Test of a cryogenic helium pump
International Nuclear Information System (INIS)
Lue, J.W.; Miller, J.R.; Walstrom, P.L.; Herz, W.
1981-01-01
The design of a cryogenic helium pump for circulating liquid helium in a magnet and the design of a test loop for measuring the pump performance in terms of mass flow vs pump head at various pump speeds are described. A commercial cryogenic helium pump was tested successfully. Despite flaws in the demountable connections, the piston pump itself has performed satisfactorily. A helium pump of this type is suitable for the use of flowing supercritical helium through Internally Cooled Superconductor (ICS) magnets. It has pumped supercritical helium up to 7.5 atm with a pump head up to 2.8 atm. The maximum mass flow rate obtained was about 16 g/s. Performance of the pump was degraded at lower pumping speeds
Improved reliability of residential heat pumps; Foerbaettrad driftsaekerhet hos villavaermepumpar
Energy Technology Data Exchange (ETDEWEB)
Haglund Stignor, Caroline; Larsson, Kristin; Jensen, Sara; Larsson, Johan; Berg, Johan; Lidbom, Peter; Rolfsman, Lennart
2012-07-01
manufacturer and that he/she surveys parameters indicating if satisfying operating conditions are maintained. Another example that could improve the reliability is that the heat pump system is regularly checked by a professional heat pump service technician. Components with sometimes poor quality can for example be temperature sensors, valves and circulations pumps. Compressor failures are often due to the fact that the heat pump of some reason, operates too much outside or close to the usage limits for the compressor and are not necessarily due to poor quality of the component itself.
Improved reliability of residential heat pumps; Foerbaettrad driftsaekerhet hos villavaermepumpar
Energy Technology Data Exchange (ETDEWEB)
Haglund Stignor, Caroline; Larsson, Kristin; Jensen, Sara; Larsson, Johan; Berg, Johan; Lidbom, Peter; Rolfsman, Lennart
2012-07-01
manufacturer and that he/she surveys parameters indicating if satisfying operating conditions are maintained. Another example that could improve the reliability is that the heat pump system is regularly checked by a professional heat pump service technician. Components with sometimes poor quality can for example be temperature sensors, valves and circulations pumps. Compressor failures are often due to the fact that the heat pump of some reason, operates too much outside or close to the usage limits for the compressor and are not necessarily due to poor quality of the component itself.
International Nuclear Information System (INIS)
Skalicky, A.
1976-01-01
The suspension is described of nuclear reactor circulating pumps enabling their dilatation with a minimum reverse force consisting of spacing rods supported with one end in the anchor joints and provided with springs and screw joints engaging the circulating pump shoes. The spacing rods are equipped with side vibration dampers anchored in the shaft side wall and on the body of the circulating pump drive body. The negative reverse force F of the spacing rods is given by the relation F=Q/l.y, where Q is the weight of the circulating pump, l is the spatial distance between the shoe joints and anchor joints, and y is the deflection of the circulating pump vertical axis from the mean equilibrium position. The described suspension is advantageous in that that the reverse force for the deflection from the mean equilibrium position is minimal, dynamic behaviour is better, and construction costs are lower compared to suspension design used so far. (J.B.)
International Nuclear Information System (INIS)
Casada, D.
1994-01-01
There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous spectral vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition: advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed
Cladding-pumped ytterbium-doped fiber laser with radially polarized output.
Lin, Di; Daniel, J M O; Gecevičius, M; Beresna, M; Kazansky, P G; Clarkson, W A
2014-09-15
A simple technique for directly generating a radially polarized output beam from a cladding-pumped ytterbium-doped fiber laser is reported. Our approach is based on the use of a nanograting spatially variant waveplate as an intracavity polarization-controlling element. The laser yielded ~32 W of output power (limited by available pump power) with a radially polarized TM (01)-mode output beam at 1040 nm with a corresponding slope efficiency of 66% and a polarization purity of 95%. The beam-propagation factor (M(2)) was measured to be ~1.9-2.1.
1975-01-01
A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.
Heebner, John E.; Sridharan, Arun K.; Dawson, Jay Walter; Messerly, Michael J.; Pax, Paul H.
2016-09-20
Cladding-pumped Raman fiber lasers and amplifiers provide high-efficiency conversion efficiency at high brightness enhancement. Differential loss is applied to both single-pass configurations appropriate for pulsed amplification and laser oscillator configurations applied to high average power cw source generation.
George, C.M.
1957-12-31
A liquid piston gas pump is described, capable of pumping minute amounts of gas in accurately measurable quantities. The pump consists of a flanged cylindrical regulating chamber and a mercury filled bellows. Sealed to the ABSTRACTS regulating chamber is a value and having a gas inlet and outlet, the inlet being connected by a helical channel to the bellows. A gravity check valve is in the gas outlet, so the gas passes through the inlet and the helical channel to the bellows where the pumping action as well as the metering is accomplished by the actuation of the mercury filled bellows. The gas then flows through the check valve and outlet to any associated apparatus.
A Magnetocaloric Pump for Lab-On-Chip Technology: Phase I Report
Energy Technology Data Exchange (ETDEWEB)
Love, L.J.
2004-04-05
A magnetocaloric pump provides a simple means of pumping fluid using only external thermal and magnetic fields. The principle, which can be traced back to the early work of Rosensweig, is straightforward. Magnetic materials tend to lose their magnetization as the temperature approaches the material's Curie point. Exposing a column of magnetic fluid to a uniform magnetic field coincident with a temperature gradient produces a pressure gradient in the magnetic fluid. As the fluid heats up, it loses its attraction to the magnetic field and is displaced by cooler fluid. The impact of such a phenomenon is obvious: fluid propulsion with no moving mechanical parts. Until recently, limitations in the magnetic and thermal properties of conventional materials severely limited practical operating pressure gradients. However, recent advancements in the design of metal substituted magnetite enable fine control over both the magnetic and thermal properties of magnetic nanoparticles, a key element in colloidal based magnetic fluids (ferrofluids). This manuscript begins with a basic description of the process and previous limitations due to material properties. This is followed by a review of existing methods of synthesizing magnetic nanoparticles as well as an introduction to a new approach based on thermophilic metal-reducing bacteria. We compare two compounds and show, experimentally, significant variation in specific magnetic and thermal properties. We develop the constitutive thermal, magnetic, and fluid dynamic equations associated with magnetocaloric pump and validate our finite element model with a series of experiments. Preliminary results show a good match between the model and experiment as well as approximately an order of magnitude increase in the fluid flow rate over conventional magnetite based ferrofluids operating below 80 C. Finally, as a practical demonstration, we describe a novel application of this technology: pumping fluids at the &apos
Inservice testing of vertical pumps
International Nuclear Information System (INIS)
Cornman, R.E. Jr.; Schumann, K.E.
1994-01-01
This paper focuses on the problems that may occur with vertical pumps while inservice tests are conducted in accordance with existing American Society of Mechanical Engineers Code, Section XI, standards. The vertical pump types discussed include single stage, multistage, free surface, and canned mixed flow pumps. Primary emphasis is placed on the hydraulic performance of the pump and the internal and external factors to the pump that impact hydraulic performance. In addition, the paper considers the mechanical design features that can affect the mechanical performance of vertical pumps. The conclusion shows how two recommended changes in the Code standards may increase the quality of the pump's operational readiness assessment during its service life
International Nuclear Information System (INIS)
Li, Jing; Yang, SuHui; He, Tao
2014-01-01
Fiber-like Er:YLuAG laser rods were tested for continuous-wave (CW) and Q-switched operation. Two narrow-band laser diodes emitting at 1532 nm were used as pump sources. The pump power was confined in the laser rods via total internal reflection. In CW mode, a maximum output power of 7.2 W was measured from a 30 mm long Er:YLuAG laser rod, corresponding to an optical–optical efficiency of 26% and a slope efficiency of 78%. Er:YLuAG and Er:YAG lasers were compared experimentally and exhibited comparable performance, while the measured central wavelength of the Er:YLuAG laser was 1644.75 nm, slightly longer than the central wavelength of the Er:YAG laser in the same experimental circumstances. In Q-switched mode, an output energy of 3.5 mJ was obtained from a 25 mm Er:YLuAG laser rod with a pulse duration of 100 ns and a pulse repetition frequency of 100 Hz. The pulsed output had near-diffraction-limited beam quality with M 2 values of 1.13 and 1.11 in the x and y directions, respectively. (letter)
Directory of Open Access Journals (Sweden)
Thomas NIED-MENNINGER
2009-01-01
Full Text Available In modern vehicles the steering systems are still widely equipped with power-assisted steering pumps. In most cases vane pumps are used which limit the fluid volume flow in dependence of required pressure and running speed by a special design of the internal control valve. This control valve internally redirects the volume flow inside the pump leading still to unnecessary fluid circulation. Variable displacement pumps now offer an additional opportunity to eliminate the internal volume flow in dependence of the required load with reduced losses and hence increased efficiency. This is realized by a variable adjustment of the displacement cells, but simultaneously the variable force and load distributions inside the pump make the acoustic optimization even more difficult. In this paper the kinematics of the vane pump are modelled with a combined analytical and numerical approach. The data out of this model are used as input data for the hydraulic model of the variable displacement vane pump with a commercial tool. Both models are validated with data from test rig investigations. With this validated virtual prototype different design options are developed and finally successfully investigated on a test rig and in a passenger vehicle.
Kumar, Vijay; Kesari, Shreekant; Chowdhury, Rajib; Kumar, Sanjiv; Sinha, Gunjan; Hussain, Saddam; Huda, M Mamun; Kroeger, Axel; Das, Pradeep
2013-01-01
Indoor residual spraying (IRS) is a proven tool to reduce visceral leishmaniasis vectors in endemic villages. In India IRS is being done with stirrup pumps, whereas Nepal, Bangladesh, and other countries use compression pumps. The present study was conducted with the objectives to compare the efficiency, cost and user friendliness of stirrup and compression pumps. The study was carried out in Gorigawan village of the Vaishali district in north Bihar and included a total population of 3259 inhabitants in 605 households. Spraying with 50 per cent DDT was done by two teams with 6 persons per team under the supervision of investigators over 5 days with each type of pump (10 days in total using 2 stirrup pumps and 3 compression pumps) by the same sprayers in an alternate way. The spraying technique was observed using an observation check list, the number of houses and room surfaces sprayed was recorded and an interview with sprayers on their satisfaction with the two types of pumps was conducted. On average, 65 houses were covered per day with the compression pump and 56 houses were covered with the stirrup pump. The surface area sprayed per squad per day was higher for the compression pump (4636 m²) than for the stirrup pump (4102 m²). Observation showed that it was easy to maintain the spray swath with the compression pump but very difficult with the stirrup pump. The wastage of insecticide suspension was negligible for the compression pump but high for the stirrup pump. The compression pump was found to be more user friendly due to its lower weight, easier to operate, lower operation cost, higher safety and better efficiency in terms of discharge rate and higher area coverage than the stirrup pump.
Sodium removal disassembly and examination of the Fermi secondary sodium pump
International Nuclear Information System (INIS)
Maffei, H.P.; Funk, C.W.; Ballif, J.L.
1974-01-01
The Fermi secondary pump is a centrifugal single stage design. The pump had been operated more than 42,000 hours between 450 and 800 0 F. Sodium was drained from the pump in 1973 and the system was back filled with carbon dioxide. The pump was fabricated for 2.25 Cr-1 Mo Croloy steel. Prior to cleaning the pump was inerted and heated with 150 0 F nitrogen using the pump casing as the containment vessel. The water-vapor-nitrogen process was used in three increasing stages of water concentration. The hydrogen concentration in the discharge line was followed as an indicator of the sodium-water reaction rate. Upon completion of the hydrogen evolution, the pump was rinsed several times with hot water. Six pounds of sodium were removed from the pump during a process cycle of 79 hours including rinsing. The maximum pump temperature recorded was 175 0 F with no variation exceeding 10 0 F. The hydrogen concentration in the effluent provided a very satisfactory index for control of the reaction by adjustment of the water-vapor concentration feed to the system. Rinsing effectiveness was limited by a pool of water in the volute that was not drainable with the available system hook up. Sodium and its compounds were removed from all internal surfaces that could be observed by the first stage of disassembly. All such surfaces were coated with a black deposit. Areas above the sodium liquid level were coated with a vermillion colored oxide. Sodium was found on the (1) threads of the impeller nut lock screw, (2) impeller nut-tapered shaft interface, and (3) vapor deposited sodium was found in the oil seal
Radionuclide kineventriculographic evaluation of the heart pump function in valvular prosthesis
Energy Technology Data Exchange (ETDEWEB)
Ivanov, Zh; Shejretova, E; Trindev, P; Topalov, V; Denchev, S; Khadzhikostova, Kh
1986-01-01
The heart pump function was investigated by the methods of radionuclide kineventriculography, standart opaque ventryculography and echocardiography. The statistical analysis revealed lack of correlation for the ejection fraction, determined by the three methods. The methodological advantages of radionuclide kineventriculography are pointed out for exact and objective evaluation of the ejection fraction of the left cardiac ventricle, as well as some limitations in the application of this index in the clinical assessment of the heart pump function in patients, indicated for valvular prosthesis.
Pump system characterization and reliability enhancement
International Nuclear Information System (INIS)
Staunton, R.H.
1998-01-01
Pump characterization studies were performed at the Oak Ridge National Laboratory (ORNL) to review and analyze six years (1990-1995) of data from pump systems at domestic nuclear plants. The studies considered not only pumps and pump motors but also pump-related circuit breakers and turbine drives (i.e., the pump system). One significant finding was that the number of 'significant' failures of the pump circuit breaker exceeds the number of significant failures of the pump itself. The study also shows how regulatory code testing was designed for the pump only and therefore did not lead to the discovery of other significant pump system failures. Potential diagnostic technologies, both experimental and mature, suitable for on-line and off-line pump testing were identified. The study does not select or recommend technologies but proposes diagnostic technologies and monitoring techniques that should be further evaluated/developed for making meaningful and critically-needed improvements in the reliability of the pump system. (author)
Monitoring of a heat pump to energy recovery and process temperature control
Energy Technology Data Exchange (ETDEWEB)
Kaneps, M
1986-03-01
This reports on the development and implementation of a heat pump monitoring program detailing the application and adaptation of standard commercial heat pump equipment for the extraction and use of themal energy from ocean source seawater along Canada's Atlantic Coast. The specific application was a lobster holding facility owned by Clearwater Lobsters Limited of Halifax, Nova Scotia. Examination of the daata indicated the heat pump system could extract and use thermal energy at or near initial design conditions. The lobsters were able to be held at consistently lower temperatures which improved product quality and reduced shrinkage. Influx of seawater debris, marine growth, and dryland pound heat gain were indentified as the only major problems. The information gathered from the monitoring study indicated that heat pump systems can be adapted to extract and utilize thermal energy from ocean source seawater. 50 figs., 123 tabs.
In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.
da Silva, Cibele; da Silva, Bruno Utiyama; Leme, Juliana; Uebelhart, Beatriz; Dinkhuysen, Jarbas; Biscegli, José F; Andrade, Aron; Zavaglia, Cecília
2013-11-01
The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational
Darrieus wind-turbine and pump performance for low-lift irrigation pumping
Hagen, L. J.; Sharif, M.
1981-10-01
In the Great Plains about 15 percent of the irrigation water pumped on farms comes from surface water sources; for the United States as a whole, the figure is about 22 percent. Because of forecast fuel shortages, there is a need to develop alternative energy sources such as wind power for surface water pumping. Specific objectives of this investigation were to: design and assemble a prototype wind powered pumping system for low lift irrigation pumping; determine performance of the prototype system; design and test an irrigation system using the wind powered prototype in a design and test an farm application; and determine the size combinations of wind turbines, tailwater pits, and temporary storage reservoirs needed for successful farm application of wind powered tailwater pumping systems in western Kansas. The power source selected was a two bladed, 6 m diameter, 9 m tall Darrieus vertical axis wind turbine with 0.10 solidity and 36.1 M(2) swept area.
Resonantly diode-pumped continuous-wave and Q-switched Er:YAG laser at 1645 nm.
Chang, N W H; Simakov, N; Hosken, D J; Munch, J; Ottaway, D J; Veitch, P J
2010-06-21
We describe an efficient Er:YAG laser that is resonantly pumped using continuous-wave (CW) laser diodes at 1470 nm. For CW lasing, it emits 6.1 W at 1645 nm with a slope efficiency of 36%, the highest efficiency reported for an Er:YAG laser that is pumped in this manner. In Q-switched operation, the laser produces diffraction-limited pulses with an average power of 2.5 W at 2 kHz PRF. To our knowledge this is the first Q-switched Er:YAG laser resonantly pumped by CW laser diodes.
Viability of using different types of main oil pipelines pump drives
Zakirzakov, A. G.; Zemenkov, Yu D.; Akulov, K. A.
2018-05-01
The choice of the pumping units' drive of main oil pipelines is of great importance both for design of pipelines and for modernization of existing ones. At the beginning of oil pipeline transport development, due to the limited number and types of energy sources, the choice was not difficult. The combustion energy of the pumped product was often the only available energy resource for its transportation. In this regard, the pipelines that had autonomous energy sources favorably differed from other energy consumers in the sector. With the passage of time, with the development of the country's electricity supply system, the electric drive for power-line equipment of oil pipelines becomes the dominant type of a pumping station drive. Nowadays, the traditional component is an essential factor when choosing some type of the drive. For many years, oil companies have been using electric drives for pumps, while gas transport enterprises prefer self-contained gas turbines.
Harding, Andrew D
2012-01-01
The use of infusion pumps that incorporate "smart" technology (smart pumps) can reduce the risks associated with receiving IV therapies. Smart pump technology incorporates safeguards such as a list of high-alert medications, soft and hard dosage limits, and a drug library that can be tailored to specific patient care areas. Its use can help to improve patient safety and to avoid potentially catastrophic harm associated with medication errors. But when one independent community hospital in Massachusetts switched from older mechanical pumps to smart pumps, it neglected to assign an "owner" to oversee the implementation process. One result was that nurses were using the smart pump library for only 37% of all infusions.To increase pump library usage percentage-thereby reducing the risks associated with infusion and improving patient safety-the hospital undertook a continuous quality improvement project over a four-month period in 2009. With the involvement of direct care nurses, and using quantitative data available from the smart pump software, the nursing quality and pharmacy quality teams identified ways to improve pump and pump library use. A secondary goal was to calculate the hospital's return on investment for the purchase of the smart pumps. Several interventions were developed and, on the first of each month, implemented. By the end of the project, pump library usage had nearly doubled; and the hospital had completely recouped its initial investment.
BIOMATERIALS FOR ROTARY BLOOD PUMPS
VANOEVEREN, W
Rotary blood pumps are used for cardiac assist and cardiopulmonary support since mechanical blood damage is less than with conventional roller pumps. The high shear rate in the rotary pump and the reduced anticoagulation of the patient during prolonged pumping enforces high demands on the
Evaluation of Ti-Zr-V (NEG) Thin Films for their pumping speed and pumping Capacity
International Nuclear Information System (INIS)
Bansod, Tripti; Sindal, B K; Kumar, K V A N P S; Shukla, S K
2012-01-01
Deposition of NEG thin films onto the interior walls of the vacuum chambers is an advanced technique to convert a vacuum chamber from a gas source to an effective pump. These films offer considerably large pumping speed for reactive gases like CO, H 2 etc. A UHV compatible pumping speed measurement system was developed in-house to measure the pumping speed of NEG coated chambers. To inject the fixed quantity of CO and H 2 gas in pumping speed measurement set-up a calibrated leak was also developed. Stainless steel chambers were sputter coated with thin film of Ti-Zr-V getter material using varied parameters for different compositions and thickness. Pumping capacity which is a function of sorbed gas quantities was also studied at various activation temperatures. In order to optimize the activation temperature for maximum pumping speed for CO and H 2 , pumping speeds were measured at room temperature after activation at different temperatures. The experimental system detail, pumping performance of the NEG film at various activation temperatures and RGA analysis are presented.
Review of magnetohydrodynamic pump applications
Directory of Open Access Journals (Sweden)
O.M. Al-Habahbeh
2016-06-01
Full Text Available Magneto-hydrodynamic (MHD principle is an important interdisciplinary field. One of the most important applications of this effect is pumping of materials that are hard to pump using conventional pumps. In this work, the progress achieved in this field is surveyed and organized according to the type of application. The literature of the past 27 years is searched for the major developments of MHD applications. MHD seawater thrusters are promising for a variety of applications requiring high flow rates and velocity. MHD molten metal pump is important replacement to conventional pumps because their moving parts cannot stand the molten metal temperature. MHD molten salt pump is used for nuclear reactor coolants due to its no-moving-parts feature. Nanofluid MHD pumping is a promising technology especially for bioapplications. Advantages of MHD include silence due to no-moving-parts propulsion. Much progress has been made, but with MHD pump still not suitable for wider applications, this remains a fertile area for future research.
Factors governing sustainable groundwater pumping near a river
Energy Technology Data Exchange (ETDEWEB)
Zhang, Y.; Hubbard, S.S.; Finsterle, S.
2011-01-15
The objective of this paper is to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsaturated zone and riverbed clogging. We quantify river clogging by calibrating a time-dependent riverbed permeability function based on knowledge of pumping rate, river stage, and temperature. The dynamics of the estimated riverbed permeability reflects clogging and scouring mechanisms. Our results indicate that (1) riverbed permeability is the dominant factor affecting infiltration needed for sustainable RBF production; (2) dam operation can influence pumping efficiency and prevent the development of an unsaturated zone beneath the riverbed only under conditions of sufficient riverbed permeability; (3) slow river velocity, caused by dam raising during summer months, may lead to sedimentation and deposition of fine-grained material within the riverbed, which may clog the riverbed, limiting recharge to the collector wells and contributing to the development of an unsaturated zone beneath the riverbed; and (4) higher river flow velocities, caused by dam lowering during winter storms, scour the riverbed an thus increase its permeability. These insights can be used as the basis for developing sustainable water management of a RBF system.
International Nuclear Information System (INIS)
Kaya, Durmus; Yagmur, E. Alptekin; Yigit, K. Suleyman; Kilic, Fatma Canka; Eren, A. Salih; Celik, Cenk
2008-01-01
In this paper, 'energy efficiency' studies, done in a big industrial facility's pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data. Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated. The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems
21 CFR 880.5725 - Infusion pump.
2010-04-01
... Infusion pump. (a) Identification. An infusion pump is a device used in a health care facility to pump fluids into a patient in a controlled manner. The device may use a piston pump, a roller pump, or a... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Infusion pump. 880.5725 Section 880.5725 Food and...
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel pumps. 23.991 Section 23.991... § 23.991 Fuel pumps. (a) Main pumps. For main pumps, the following apply: (1) For reciprocating engine installations having fuel pumps to supply fuel to the engine, at least one pump for each engine must be directly...
Reactor coolant pump monitoring and diagnostic system
International Nuclear Information System (INIS)
Singer, R.M.; Gross, K.C.; Walsh, M.; Humenik, K.E.
1990-01-01
In order to reliably and safely operate a nuclear power plant, it is necessary to continuously monitor the performance of numerous subsystems to confirm that the plant state is within its prescribed limits. An important function of a properly designed monitoring system is the detection of incipient faults in all subsystems (with the avoidance of false alarms) coupled with an information system that provides the operators with fault diagnosis, prognosis of fault progression and recommended (either automatic or prescriptive) corrective action. In this paper, such a system is described that has been applied to reactor coolant pumps. This system includes a sensitive pattern-recognition technique based upon the sequential probability ratio test (SPRT) that detects incipient faults from validated signals, an expert system embodying knowledge bases on pump and sensor performance, extensive hypertext files containing operating and emergency procedures as well as pump and sensor information and a graphical interface providing the operator with easily perceived information on the location and character of the fault as well as recommended corrective action. This system is in the prototype stage and is currently being validated utilizing data from a liquid-metal cooled fast reactor (EBR-II). 3 refs., 4 figs
Theoretical Model for the Performance of Liquid Ring Pump Based on the Actual Operating Cycle
Directory of Open Access Journals (Sweden)
Si Huang
2017-01-01
Full Text Available Liquid ring pump is widely applied in many industry fields due to the advantages of isothermal compression process, simple structure, and liquid-sealing. Based on the actual operating cycle of “suction-compression-discharge-expansion,” a universal theoretical model for performance of liquid ring pump was established in this study, to solve the problem that the theoretical models deviated from the actual performance in operating cycle. With the major geometric parameters and operating conditions of a liquid ring pump, the performance parameters such as the actual capacity for suction and discharge, shaft power, and global efficiency can be conveniently predicted by the proposed theoretical model, without the limitation of empiric range, performance data, or the detailed 3D geometry of pumps. The proposed theoretical model was verified by experimental performances of liquid ring pumps and could provide a feasible tool for the application of liquid ring pump.
Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn
2015-08-01
In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.
International Nuclear Information System (INIS)
Banerjee, I.; Chandresh, B.G.; Guha, K.C.; Sarkar, S.
2015-01-01
Dry vacuum pumping systems attracts many applications because of its inherent capability of corrosion free pumping. It becomes a common trait of application in Thermo Nuclear Fusion, Semi conductor, Isotope separation industries etc. Thermo nuclear fusion requires a train of specially sealed roots pump backed by suitable capacity dry screw or reciprocating pump. Similarly corrosive fluoride gas pumping requires hermetically sealed specially designed dry scroll vacuum pump. Plant emergency operation however involves train of specially sealed roots pump backed with scroll pump for faster evacuation. In our attempt an indigenously designed scroll pump and associated system are designed to pump corrosive gases in a way to confine the corrosion product within the system. In order to execute the design, a numerical code for low pressure application is developed
Improving Reliability of a fire-fighting pump set with Axiomatic Design
Directory of Open Access Journals (Sweden)
Arcidiacono Gabriele
2017-01-01
Full Text Available This paper introduces a case study featuring Axiomatic Design and Multi-Level Hierarchical model (MLH applied to redesign a fire-fighting pump set. In particular, two different design concepts are presented to be applied to the supporting frame of the system to limit a vibration problem that can arise during potential malfunctioning of the fire-fighting pump. The selection of the best design has been carried out through reliability evaluation process and through the cost of failure based on the MLH model.
Vacuum pumping concepts for ETF
International Nuclear Information System (INIS)
Homeyer, W.G.
1980-09-01
The Engineering Test Facility (ETF) poses unique vacuum pumping requirements due to its large size and long burn characteristics. These requirements include torus vacuum pumping initially and between burns and pumping of neutralized gas from divertor collector chambers. It was found that the requirements could be met by compound cryopumps in which molecular sieve 5A is used as the cryosorbent. The pumps, ducts, and vacuum valves required are large but fit with other ETF components and do not require major advances in vacuum pumping technology. Several additional design, analytical, and experimental studies were identified as needed to optimize designs and provide better design definition for the ETF vacuum pumping systems
Energy Technology Data Exchange (ETDEWEB)
Iguchi, M.; Sawada, T.; Sugiyama, W. [Akita University, Akita (Japan). Faculty of Mining; Watanabe, M.
1997-04-25
A spiral grooved vacuum pump and a compound molecular pump (the combination of a spiral grooved pump and a turbomolecular pump) are widely used in the thin-film industry for processes such as semiconductor production. Pumping performance is high at pressures below 1 000 Pa and low at pressures above 1000 Pa when the clearance between rotor and stator is on the order of 0.1 mm, which is the practical value for industrial use. The double spiral grooved vacuum pump is thought to have better pumping performance at such high pressures than the conventional spiral grooved vacuum pump. The aim of this study is to investigate the feasibility of use of the double spiral grooved vacuum pump at pressures above 1000 Pa. A double spiral grooved vacuum pump with a rotor of 150 mm diameter and 190 mm length has been designed and manufactured. Its pumping performance has been tested by experiments. The test results show the improvement in the performance at pressures above 1000 Pa compared to the conventional spiral grooved vacuum pump. 2 refs., 12 figs., 2 tabs.
International Nuclear Information System (INIS)
Formigoni, C.
1998-01-01
A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it
A simplified heat pump model for use in solar plus heat pump system simulation studies
DEFF Research Database (Denmark)
Perers, Bengt; Andersen, Elsa; Nordman, Roger
2012-01-01
Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here...
Design and optimization of a Holweck pump via linear kinetic theory
Naris, Steryios; Koutandou, Eirini; Valougeorgis, Dimitris
2012-05-01
The Holweck pump is widely used in the vacuum pumping industry. It can be a self standing apparatus or it can be part of a more advanced pumping system. It is composed by an inner rotating cylinder (rotor) and an outer stationary cylinder (stator). One of them, has spiral guided grooves resulting to a gas motion from the high towards the low vacuum port. Vacuum pumps may be simulated by the DSMC method but due to the involved high computational cost in many cases manufactures commonly resort to empirical formulas and experimental data. Recently a computationally efficient simulation of the Holweck pump via linear kinetic theory has been proposed by Sharipov et al [1]. Neglecting curvature and end effects the gas flow configuration through the helicoidal channels is decomposed into four basic flows. They correspond to pressure and boundary driven flows through a grooved channel and through a long channel with a T shape cross section. Although the formulation and the methodology are explained in detail, results are very limited and more important they are presented in a normalized way which does not provide the needed information about the pump performance in terms of the involved geometrical and flow parameters. In the present work the four basic flows are solved numerically based on the linearized BGK model equation subjected to diffuse boundary conditions. The results obtained are combined in order to create a database of the flow characteristics for a large spectrum of the rarefaction parameter and various geometrical configurations. Based on this database the performance characteristics which are critical in the design of the Holweck pump are computed and the design parameters such as the angle of the pump and the rotational speed, are optimized. This modeling may be extended to other vacuum pumps.
Design and optimization of a Holweck pump via linear kinetic theory
International Nuclear Information System (INIS)
Naris, Steryios; Koutandou, Eirini; Valougeorgis, Dimitris
2012-01-01
The Holweck pump is widely used in the vacuum pumping industry. It can be a self standing apparatus or it can be part of a more advanced pumping system. It is composed by an inner rotating cylinder (rotor) and an outer stationary cylinder (stator). One of them, has spiral guided grooves resulting to a gas motion from the high towards the low vacuum port. Vacuum pumps may be simulated by the DSMC method but due to the involved high computational cost in many cases manufactures commonly resort to empirical formulas and experimental data. Recently a computationally efficient simulation of the Holweck pump via linear kinetic theory has been proposed by Sharipov et al [1]. Neglecting curvature and end effects the gas flow configuration through the helicoidal channels is decomposed into four basic flows. They correspond to pressure and boundary driven flows through a grooved channel and through a long channel with a T shape cross section. Although the formulation and the methodology are explained in detail, results are very limited and more important they are presented in a normalized way which does not provide the needed information about the pump performance in terms of the involved geometrical and flow parameters. In the present work the four basic flows are solved numerically based on the linearized BGK model equation subjected to diffuse boundary conditions. The results obtained are combined in order to create a database of the flow characteristics for a large spectrum of the rarefaction parameter and various geometrical configurations. Based on this database the performance characteristics which are critical in the design of the Holweck pump are computed and the design parameters such as the angle of the pump and the rotational speed, are optimized. This modeling may be extended to other vacuum pumps.
Goldman, Jeffrey H.; Harvey, A.; Lovell, T.; Walker, David H.
1994-01-01
analyzed in ideal single and two-stage thermodynamic cycles. Top candidates were analyzed assuming realistic component limits and system pressure drops, and were evaluated for other considerations such as safety, environmental impact, and commercial availability. A maximum coefficient of performance (COP) of 56 percent of the Carnot ideal was achievable for a three-stage CFC-11 cycle operating under the flight conditions above. The program was completed by defining a control scheme and by researching and selecting the major components, compressor and heat exchangers, that could be used to implement the thermodynamic cycle selected. Special attention was paid to using similar technologies for the SIRF and flight heat pumps resulting in the commercially available equivalent of the flight unit. A package concept was generated for the components selected and mass and volume estimated.
Energy-Saving Optimization of Water Supply Pumping Station Life Cycle Based on BIM Technology
Qun, Miao; Wang, Jiayuan; Liu, Chao
2017-12-01
In the urban water supply system, pump station is the main unit of energy consumption. In the background of pushing forward the informatization in China, using BIM technology in design, construction and operations of water supply pumping station, can break through the limitations of the traditional model and effectively achieve the goal of energy conservation and emissions reduction. This work researches the way to solve energy-saving optimization problems in the process of whole life cycle of water supply pumping station based on BIM technology, and put forward the feasible strategies of BIM application in order to realize the healthy and sustainable development goals by establishing the BIM model of water supply pumping station of Qingdao Guzhenkou water supply project.
Energy Technology Data Exchange (ETDEWEB)
NONE
2010-06-15
These proceedings summarise the presentations made at the 16{sup th} annual meeting held by the Swiss Federal Office of Energy's Heat Pump Research Program in Burgdorf, Switzerland. The proceedings include contributions on large-scale heat pumps, components and the activities of the heat pump promotion society. A summary of targets and trends in energy research in general is presented and an overview of the heat pump market in 2009 and future perspectives is given. International work within the framework of the International Energy Agency's heat pump group is reviewed, including solar - heat pump combinations. Field-monitoring and the analysis of large-scale heat pumps are discussed and the importance of the use of correct concepts in such installations is stressed. Large-scale heat pumps with carbon dioxide as working fluid are looked at, as are output-regulated air/water heat pumps. Efficient system solutions with heat pumps used both to heat and to cool are discussed. Deep geothermal probes and the potential offered by geothermal probes using carbon dioxide as a working fluid are discussed. The proceedings are rounded off with a list of useful addresses.
Pump trials for charged liquids
International Nuclear Information System (INIS)
Moroni, J.C.; Niver, A.
1964-01-01
The pumps intended for the circulation of charged and radioactive liquids have particular qualities. The choice of such a pump has called for endurance tests with various types of equipment: a Goodyear volumetric screw pumps, and RICHIER, Klein and SCHABAVER centrifugal pumps. The latter, fitted with a special oakum, gave the best results. (authors) [fr
Enzyme-Powered Pumps: From Fundamentals to Applications
Ortiz-Rivera, Isamar
substances, like mercury, cyanide and azide, were designed using urease and catalase-powered pumps, respectively, with limits of detection well below the concentrations permitted by the Environmental Protection Agency (EPA). Chapter 4 demonstrates that, apart from their applicability as sensors, enzyme pumps can also be used for stimuli-responsive release, if the architecture applied for the design of the enzyme pump consists of a porous scaffold (e.g. hydrogel), that serves both as the platform for enzyme immobilization and as the host for guest molecules to be released. These proof-of-concept devices were developed with the idea of using the flows generated by enzymatic catalysis to power cargo release, only in the presence of the correct stimuli (e.g. release of insulin in the presence of glucose; release of antidotes in the presence of a toxic agent). In the cases studied, cargo release was directly proportional to the concentration of enzyme substrate in solution, highlighting the sensitivity of the device and its potential for drug delivery purposes. (Abstract shortened by Proquest.).
Clinical usefulness of limited sampling strategies for estimating AUC of proton pump inhibitors.
Niioka, Takenori
2011-03-01
Cytochrome P450 (CYP) 2C19 (CYP2C19) genotype is regarded as a useful tool to predict area under the blood concentration-time curve (AUC) of proton pump inhibitors (PPIs). In our results, however, CYP2C19 genotypes had no influence on AUC of all PPIs during fluvoxamine treatment. These findings suggest that CYP2C19 genotyping is not always a good indicator for estimating AUC of PPIs. Limited sampling strategies (LSS) were developed to estimate AUC simply and accurately. It is important to minimize the number of blood samples because of patient's acceptance. This article reviewed the usefulness of LSS for estimating AUC of three PPIs (omeprazole: OPZ, lansoprazole: LPZ and rabeprazole: RPZ). The best prediction formulas in each PPI were AUC(OPZ)=9.24 x C(6h)+2638.03, AUC(LPZ)=12.32 x C(6h)+3276.09 and AUC(RPZ)=1.39 x C(3h)+7.17 x C(6h)+344.14, respectively. In order to optimize the sampling strategy of LPZ, we tried to establish LSS for LPZ using a time point within 3 hours through the property of pharmacokinetics of its enantiomers. The best prediction formula using the fewest sampling points (one point) was AUC(racemic LPZ)=6.5 x C(3h) of (R)-LPZ+13.7 x C(3h) of (S)-LPZ-9917.3 x G1-14387.2×G2+7103.6 (G1: homozygous extensive metabolizer is 1 and the other genotypes are 0; G2: heterozygous extensive metabolizer is 1 and the other genotypes are 0). Those strategies, plasma concentration monitoring at one or two time-points, might be more suitable for AUC estimation than reference to CYP2C19 genotypes, particularly in the case of coadministration of CYP mediators.
High temperature thermoacoustic heat pump
Energy Technology Data Exchange (ETDEWEB)
Tijani, H.; Spoelstra, S. [Energy research Centre of the Netherlands, 1755 ZG Petten (Netherlands)
2012-06-15
Thermoacoustic technology can provide new types of heat pumps that can be deployed in different applications. A thermoacoustic heat pumps can for example be applied in dwellings to generate cooling or heating. Typically, space and water heating makes up about 60% of domestics and offices energy consumption. The application of heat pumps can contribute to achieve energy savings and environmental benefits by reducing CO2 and NOx emissions. This paper presents the study of a laboratory scale thermoacoustic-Stirling heat pump operating between 10C and 80C which can be applied in domestics and offices. The heat pump is driven by a thermoacoustic-Stirling engine. The experimental results show that the heat pump pumps 250 W of heat at 60C at a drive ratio of 3.6% and 200 W at 80C at a drive ratio of 3.5 %. The performance for both cases is about 40% of the Carnot performance. The design, construction, and performance measurements of the heat pump will be presented and discussed.
High Temperature Thermoacoustic Heat Pump
Energy Technology Data Exchange (ETDEWEB)
Tijani, H.; Spoelstra, S. [ECN Biomass and Energy Efficiency, Petten (Netherlands)
2012-07-15
Thermoacoustic technology can provide new types of heat pumps that can be deployed in different applications. Thermoacoustic heat pumps can for example be applied in dwellings to generate cooling or heating. Typically, space and water heating makes up about 60% of domestic and office energy consumption. The application of heat pumps can contribute to achieve energy savings and environmental benefits by reducing CO2 and NOx emissions. This paper presents the study of a laboratory scale thermoacoustic-Stirling heat pump operating between 10C and 80C which can be applied in domestics and offices. The heat pump is driven by a thermoacoustic-Stirling engine. The experimental results show that the heat pump pumps 250 W of heat at 60C at a drive ratio of 3.6 % and 200 W at 80C at a drive ratio of 3.5 %. The performance for both cases is about 40% of the Carnot performance. The design, construction, and performance measurements of the heat pump will be presented and discussed.
International Nuclear Information System (INIS)
Wang, Y T; Li, W J; Pan, L L; Yu, J T; Zhang, R H
2013-01-01
The analytical model of thermally induced diffraction losses for a Gaussian pump beam are derived as functions of the mode-to-pump ratio and pump power in end-pumped Nd-doped lasers considering the energy transfer upconversion effects. The mode-to-pump ratio is optimized based on it. The results show that the optimum mode-to-pump ratio with the thermally induced diffraction losses is less than 0.65, and it is less than the results in which the thermally induced diffraction losses are neglected. The theoretical model is applied to a diode-end-pumped Nd:GdVO 4 laser operating at 1342 nm, and the theoretical calculations are in good agreement with the experimental results. (paper)
Energy Technology Data Exchange (ETDEWEB)
1979-01-01
This article looks at the pump industry as a whole, its historical links with the mining industry, their parallel develop ment, and at the individual manufacturers and pumps, services and auxillary products they have to offer.
Photoacoustic imaging of lymphatic pumping
Forbrich, Alex; Heinmiller, Andrew; Zemp, Roger J.
2017-10-01
The lymphatic system is responsible for fluid homeostasis and immune cell trafficking and has been implicated in several diseases, including obesity, diabetes, and cancer metastasis. Despite its importance, the lack of suitable in vivo imaging techniques has hampered our understanding of the lymphatic system. This is, in part, due to the limited contrast of lymphatic fluids and structures. Photoacoustic imaging, in combination with optically absorbing dyes or nanoparticles, has great potential for noninvasively visualizing the lymphatic vessels deep in tissues. Multispectral photoacoustic imaging is capable of separating the components; however, the slow wavelength switching speed of most laser systems is inadequate for imaging lymphatic pumping without motion artifacts being introduced into the processed images. We investigate two approaches for visualizing lymphatic processes in vivo. First, single-wavelength differential photoacoustic imaging is used to visualize lymphatic pumping in the hindlimb of a mouse in real time. Second, a fast-switching multiwavelength photoacoustic imaging system was used to assess the propulsion profile of dyes through the lymphatics in real time. These approaches may have profound impacts in noninvasively characterizing and investigating the lymphatic system.
Fast breeder reactor electromagnetic pump
International Nuclear Information System (INIS)
Araseki, Hideo; Murakami, Takahiro
2008-01-01
Main pumps circulating sodium in the FBR type reactor have been mechanical types, not electromagnetic pumps. Electromagnetic pump of 1-2 m 3 /min has been used as an auxiliary pump. Large sized electromagnetic pumps such as several hundred m 3 /min have not been commercialized due to technical difficulties with electromagnetic instability and pressure pulsations. This article explained electromagnetic and fluid equations and magnetic Reynolds number related with electromagnetic pumps and numerical analysis of instability characteristics and pressure pulsations and then described applications of the results to FBR system. Magnetic Reynolds number must be chosen less than one with appropriate operating frequency and optimum slip of 0.2-0.4. (T. Tanaka)
Centrifugal pumps: fundamentals and classification
International Nuclear Information System (INIS)
Solar Manuel, A. M.
2009-01-01
Centrifugal pumps are usually employed to impulse water to elevate it, dose it or give it pressure or speed. They can be used with clean water or loaded with high solid concentration and don't work properly with air or another gas flow. There are another less used pumps, coming from volumetric or ram pumps to magnetic ones for specific uses. Centrifugal ones are rotokinetic pumps, like peripherical or lateral channel pumps. They work in a different way that non rotational kinetic ones and static ones. The work approaches their pre definition, selection, installation, operation and maintenance. It also review their morphology, hidromechanic principles and the basic elements pumps are made of. (Author)
International Nuclear Information System (INIS)
Dickinson, R.J.; Pennell, W.E.; Wasko, J.
1984-01-01
A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance
Pump-Enhanced Continuous-Wave Magnetometry Using Nitrogen-Vacancy Ensembles
DEFF Research Database (Denmark)
Ahmadi, Sepehr; El-Ella, Haitham A. R.; Hansen, Jørn Otto Bindslev
2017-01-01
a bandwidth up to 159 Hz, and an extracted sensitivity ofapproximately 3 nT/√Hz, with further enhancement limited by thenoise floor of the lock-in amplifier and the laser damage threshold of theoptical components. Exploration of the microwave and optical pump-rateparameter space demonstrates a linewidth...
Kirol, L.D.
1987-02-11
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.
Energy Technology Data Exchange (ETDEWEB)
Kaya, Durmus; Yagmur, E. Alptekin [TUBITAK-MRC, P.O. Box 21, 41470 Gebze, Kocaeli (Turkey); Yigit, K. Suleyman; Eren, A. Salih; Celik, Cenk [Engineering Faculty, Kocaeli University, Kocaeli (Turkey); Kilic, Fatma Canka [Department of Air Conditioning and Refrigeration, Kocaeli University, Kullar, Kocaeli (Turkey)
2008-06-15
In this paper, ''energy efficiency'' studies, done in a big industrial facility's pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data. Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated. The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems. (author)
Rentian, Zhang; Honggeng, Zhu; Arnold, Jaap; Linbi, Yao
2010-06-01
Compared with vertical-installed pumps, the propeller (bulb tubular) pump systems can achieve higher hydraulic efficiencies, which are particularly suitable for low-head pumping stations. More than four propeller pumping stations are being, or will be built in the first stage of the S-to-N Water Diversion Project in China, diverting water from Yangtze River to the northern part of China to alleviate water-shortage problems and develop the economy. New structures of propeller pump have been developed for specified pumping stations in Jiangsu and Shandong Provinces respectively and Variable Frequency Drives (VFDs) are used in those pumping stations to regulate operating conditions. Based on the Navier-Stokes equations and the standard k-e turbulent model, numerical simulations of the flow field and performance prediction in the propeller pump system were conducted on the platform of commercial software CFX by using the SIMPLEC algorithm. Through optimal design of bulb dimensions and diffuser channel shape, the hydraulic system efficiency has improved evidently. Furthermore, the structures of propeller pumps have been optimized to for the introduction of conventional as well as permanent magnet motors. In order to improve the hydraulic efficiency of pumping systems, both the pump discharge and the motor diameter were optimized respectively. If a conventional motor is used, the diameter of the pump casing has to be increased to accommodate the motor installed inside. If using a permanent magnet motor, the diameter of motor casing can be decreased effectively without decreasing its output power, thus the cross-sectional area is enlarged and the velocity of flowing water decreased favorably to reduce hydraulic loss of discharge channel and thereby raising the pumping system efficiency. Witness model tests were conducted after numerical optimization on specific propeller pump systems, indicating that the model system hydraulic efficiencies can be improved by 0.5%˜3.7% in
Pump cavitation and inducer design
International Nuclear Information System (INIS)
Heslenfeld, M.W.; Hes, M. de
2002-01-01
Details of past work on sodium pump development and cavitation studies executed mainly for SNR 300 were reported earlier. Among the requirements for large sodium pumps are long life (200000 hours up to 300000 hours) and small size of impeller and pump, fully meeting the process and design criteria. These criteria are the required 'Q, H, r characteristics' in combination with a low NPSH value and the avoidance of cavitation damage to the pump. The pump designer has to develop a sound hydraulic combination consisting of suction arrangement, impeller design and diffuser. On the other hand the designer is free to choose an optimal pump speed. The pump speed in its turn influences the rotor dynamic pump design and the pump drive. The introduction of the inducer as an integral part of the pump design is based on following advantages: no tip cavitation; (possible) cavitation bubbles move to the open centre due to centrifugal forces on the fluid; the head of the inducer improves the inlet conditions of the impeller. The aim of an inducer is the increase in the suction specific speed (SA value) of a pump whereby the inducer functions as a pressure source improving the impeller inlet conditions. With inducer-impeller combinations values up to SA=15000 are realistic. With the use of an inducer the overall pump sizes can be reduced with Ca. 30%. Pumps commonly available have SA values up to a maximum of ca. 10000. A development programme was executed for SNR 300 in order to reach an increase of the suction specific speed of the impeller from SA 8200 to SA 11000. Further studies to optimize pumps design for the follow up line introduced the 'inducer acting as a pre-impeller' development. This programme was executed in the period 1979-1981. At the FDO premises a scale 1 2.8 inducer impeller combination with a suction specific speed SA=15000 was developed, constructed and tested at the water test rig. This water test rig is equipped with a perspex pipe allowing also visualisation
International Nuclear Information System (INIS)
Honda, Kazuya; Uehara, Tamotsu; Arai, Yoshinori; Kashima, Masahiro; Tsukimura, Naoki; Honda, Masahiko; Iwai, Kazuo; Terakado, Masaaki; Shinoda, Koji
2002-01-01
A study was conducted to evaluate the efficacy of pumping manipulation treatment for closed lock of the temporomandibular joint (TMJ) disorder using limited cone beam X-ray CT for dental use. The subjects were 20 patients with TMJ closed lock. Arthrography and pumping manipulation treatment were performed, and the correlation between maximal mouth opening and arthrographic findings was examined. Arthrography showed 16 cases of anterior disk displacement, and 4 cases of sideways displacement. Disk configuration showed 15 abnormal cases and 3 cases of disk perforation. Before treatment, mouth opening distance was 24.2 mm and 1 week after treatment it was 34.4 mm. After 3 months this had improved significantly to 41.0 mm. Comparison of mouth opening distance with arthrographic findings showed that disk perforation was significantly different after 3 months. These results suggest that pumping manipulation treatment might be useful in patients with TMJ closed lock without internal derangement or disk perforation. (author)
LENUS (Irish Health Repository)
Marshall, Cornelius
2012-02-03
Electrical failure during cardiopulmonary bypass (CPB) has previously been reported to occur in 1 of every 1500 cases. Most heart-lung machine pump consoles are equipped with built-in battery back-up units. Battery run times of these devices are variable and have not been reported. Different conditions of use can extend battery life in the event of electrical failure. This study was designed to examine the run time of a fully charged battery under various conditions of pump speed, pressure loads, pump boot material, multiple pump usage, and battery life. Battery life using a centrifugal pump also was examined. The results of this study show that battery life is affected by pump speed, circuit pressure, boot stiffness, and the number of pumps in service. Centrifugal pumps also show a reduced drain on battery when compared with roller pumps. These elements affect the longevity and performance of the battery. This information could be of value to the individual during power failure as these are variables that can affect the battery life during such a challenging scenario.
LMR [liquid metal reactor] centrifugal pump coastdowns
International Nuclear Information System (INIS)
Dunn, F.E.; Malloy, D.J.
1987-01-01
A centrifugal pump model which describes the interrelationships of the pump discharge flowrate, pump speed, shaft torque and dynamic head has been implemented based upon existing models. Specifically, the pump model is based upon the dimensionless-homologous pump theory of Wylie and Streeter. Given data from a representative pump, homologous theory allows one to predict the transient characteristics of similarly sized pumps. This homologous pump model has been implemented into both the one-dimensional SASSYS-1 systems analysis code and the three-dimensional COMMIX-1A code. Comparisons have been made both against other pump models (CRBR) and actual pump coastdown data (EBR-II and FFTF). Agreement with this homologous pump model has been excellent. Additionally, these comparisons indicate the validity of applying the medium size pump data of Wylie and Streeter to a range of typical LMR centrifugal pumps
International Nuclear Information System (INIS)
Smith, J.P.; Baxi, C.B.; Reis, E.; Schaffer, M.J.; Schaubel, K.M.; Menon, M.M.
1991-11-01
A cryocondensation pump will be installed in the baffle chamber of the DIII-D tokamak in the spring of 1992. The design is complete and fabrication of this pump is in progress. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long, in the lower outer corner of the vacuum vessel interior. It consists of a 1 m 2 liquid helium cooled surface surrounded by a liquid nitrogen cooled shield to limit the heat load on the helium cooled surface. The stainless steel liquid nitrogen shell has a copper coating on it to enhance thermal conductivity, but the coating is broken to keep the toroidal electrical resistance high. The liquid nitrogen cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. The whole pump is supported off the water cooled vacuum vessel wall. Key design considerations were: how to accommodate the temperature differences between the various components, developing low heat leak paths for the various supports, and maintaining electrical insulation in a low pressure environment in the presence of induced voltage spikes. A single point ground for the system was used to limit disruption induced currents and the resulting electro-mechanical forces on the pump. A testing program was used to develop coating techniques to enhance heat transfer and emissivity of the various surfaces. Fabrication tests were done to determine the best method of attaching the liquid nitrogen flow tubes to their shield surfaces. A prototype sector of the pump was built to verify fabrication and assembly techniques
Diaphragm Pump With Resonant Piezoelectric Drive
Izenson, Michael G.; Kline-Schoder, Robert J.; Shimko, Martin A.
2007-01-01
make it oscillate at the resonance frequency of the spring and- mass structure. This frequency could be made high enough (of the order of 400 Hz) that the masses of all components could be made conveniently small. The resonance would amplify the relatively small motion of the piezoelectric stack (a stroke of the order of 10 m) to a diaphragm stroke of the order of 0.5 mm. The exact amplification factor would depend on the rate of damping of oscillations; this, in turn, would depend on details of design and operation, including (but not limited to) the desired pressure rise and volumetric flow rate. In order to obtain resonance with large displacement, the damping rate must be low enough that the energy imparted to the pumped fluid on each stroke is much less than the kinetic and potential energy exchanged between the mass and spring during each cycle of oscillation. To minimize the power demand of the pump, a highly efficient drive circuit would be used to excite the piezoelectric stack. This circuit (see Figure 2) would amount to a special-purpose regenerative, switching power supply that would operate in a power-source mode during the part of an oscillation cycle when the excitation waveform was positive and in a power-recovery mode during the part of the cycle when the excitation waveform was negative. The circuit would include a voltage-boosting dc-to-dc converter that would convert between a supply potential of 24 Vdc and the high voltage needed to drive the piezoelectric stack. Because of the power-recovery feature, the circuit would consume little power. It should be possible to build the circuit as a compact unit, using readily available components.
Electroosmotic pumps for microflow analysis
Wang, Xiayan; Wang, Shili; Gendhar, Brina; Cheng, Chang; Byun, Chang Kyu; Li, Guanbin; Zhao, Meiping; Liu, Shaorong
2009-01-01
With rapid development in microflow analysis, electroosmotic pumps are receiving increasing attention. Compared to other micropumps, electroosmotic pumps have several unique features. For example, they are bi-directional, can generate constant and pulse-free flows with flow rates well suited to microanalytical systems, and can be readily integrated with lab-on-chip devices. The magnitude and the direction of flow of an electroosmotic pump can be changed instantly. In addition, electroosmotic pumps have no moving parts. In this article, we discuss common features, introduce fabrication technologies and highlight applications of electroosmotic pumps. PMID:20047021
An analysis of solar assisted ground source heat pumps in cold climates
International Nuclear Information System (INIS)
Emmi, Giuseppe; Zarrella, Angelo; De Carli, Michele; Galgaro, Antonio
2015-01-01
Highlights: • The work focuses on solar assisted ground source heat pump in cold climates. • Multi-year simulations of SAGSHP, are carried out in six cold locations. • GSHP and SAGSHP are compared. • The effect of total borehole length on the heat pump energy efficiency is studied. • A dedicated control strategy is used to manage both solar and ground loops. - Abstract: Exploiting renewable energy sources for air-conditioning has been extensively investigated over recent years, and many countries have been working to promote the use of renewable energy to decrease energy consumption and CO_2 emissions. Electrical heat pumps currently represent the most promising technology to reduce fossil fuel usage. While ground source heat pumps, which use free heat sources, have been taking significant steps forward and despite the fact that their energy performance is better than that of air source heat pumps, their development has been limited by their high initial investment cost. An alternative solution is one that uses solar thermal collectors coupled with a ground source heat pump in a so-called solar assisted ground source heat pump. A ground source heat pump system, used to heat environments located in a cold climate, was investigated in this study. The solar assisted ground source heat pump extracted heat from the ground by means of borehole heat exchangers and it injected excess solar thermal energy into the ground. Building load profiles are usually heating dominated in cold climates, but when common ground source heat pump systems are used only for heating, their performance decreases due to an unbalanced ground load. Solar thermal collectors can help to ensure that systems installed in cold zones perform more efficiently. Computer simulations using a Transient System Simulation (TRNSYS) tool were carried out in six cold locations in order to investigate solar assisted ground source heat pumps. The effect of the borehole length on the energy efficiency of
A Magnetocaloric Pump for Lab-On-A-Chip Technology: Phase I Report
Energy Technology Data Exchange (ETDEWEB)
Love, LJL
2004-05-08
A magnetocaloric pump provides a simple means of pumping fluid using only external thermal and magnetic fields. The principle, which can be traced back to the early work of Rosensweig, is straightforward. Magnetic materials tend to lose their magnetization as the temperature approaches the material's Curie point. Exposing a column of magnetic fluid to a uniform magnetic field coincident with a temperature gradient produces a pressure gradient in the magnetic fluid. As the fluid heats up, it loses its attraction to the magnetic field and is displaced by cooler fluid. The impact of such a phenomenon is obvious: fluid propulsion with no moving mechanical parts. Until recently, limitations in the magnetic and thermal properties of conventional materials severely limited practical operating pressure gradients. However, recent advancements in the design of metal substituted magnetite enable fine control over both the magnetic and thermal properties of magnetic nanoparticles, a key element in colloidal based magnetic fluids (ferrofluids). This manuscript begins with a basic description of the process and previous limitations due to material properties. This is followed by a review of existing methods of synthesizing magnetic nanoparticles as well as an introduction to a new approach based on thermophilic metal-reducing bacteria. We compare two compounds and show, experimentally, significant variation in specific magnetic and thermal properties. We develop the constitutive thermal, magnetic, and fluid dynamic equations associated with magnetocaloric pump and validate our finite element model with a series of experiments. Preliminary results show a good match between the model and experiment as well as approximately an order of magnitude increase in the fluid flow rate over conventional magnetite based ferrofluids operating below 80 C. Finally, as a practical demonstration, we describe a novel application of this technology: pumping fluids at the &apos
Pump Early, Pump Often: A Continuous Quality Improvement Project.
Spatz, Diane L; Froh, Elizabeth B; Schwarz, Jessica; Houng, Kathy; Brewster, Isabel; Myers, Carey; Prince, Judy; Olkkola, Michelle
2015-01-01
Research demonstrates that although many mothers initiate pumping for their critically ill children, few women are successful at maintaining milk supply throughout their infants' entire hospital stay. At the Garbose Family Special Delivery Unit (SDU) at the Children's Hospital of Philadelphia, we care for mothers who have critically ill infants born with complex cardiac and congenital anomalies. Human milk is viewed as a medical intervention at our institution. Therefore, nurses on the SDU wanted to ensure best practice in terms of pumping initiation. This article describes a continuous quality improvement project that ensured mothers pumped early and often. Childbirth educators can play a key role in preparing mothers who are anticipating an infant who will require hospitalization immediately post-birth.
International Nuclear Information System (INIS)
Belyaev, S.G.; Puzanov, A.I.; Belikov, V.P.; Dizik, B.S.
1990-01-01
Hydrodynamic loads appearing in the flow-through part of pump aggregates of the system of auxiliary water supply in NPP with variations in the operation modes are investigated. It is shown that during operation of centrifugal pumps the position of the mode on the pump characteristic plot must be controlled. When the mode point exceeds the limits of the working zone it results in a considerable increase of dynamic loads: pressure pulsation and vibration. As the flow rate increase the decrease in dynamic loads is recorded at low frequencies of about 2-4 Hz
A Comparative Cycle and Refrigerant Simulation Procedure Applied on Air-Water Heat Pumps
DEFF Research Database (Denmark)
Mader, Gunda; Palm, Björn; Elmegaard, Brian
2012-01-01
A vapor compression heat pump absorbs heat from the environment at a low temperature level and rejects heat at a high temperature level. The bigger the difference between the two temperature levels the more challenging is it to gain high energy efficiency with a basic cycle layout as found in most...... small capacity heat pump applications today. Many of the applicable refrigerants also reach their technical limits regarding low vapor pressure for very low source temperatures and high discharge temperatures for high sink temperatures. These issues are especially manifest for air-water heat pumps. Many...... alternative cycle setups and refrigerants are known to improve the energy efficiency of a vapor compression cycle and reduce discharge temperatures. However not all of them are feasible for small capacity heat pumps from a cost and complexity point of view. This paper presents a novel numerical approach...
Improvements relating to electromagnetic pumps
International Nuclear Information System (INIS)
Davidson, D.F.
1975-01-01
Reference is made to electromagnetic pumps suitable for use in pumping molten Na, and particularly to annular linear induction pumps that may for example be used to pump molten Na at temperatures up to 650 0 in situations where it is not possible to provide cooling. Previous designs of such pumps have employed disk-shaped coils around the outside of the annulus, the coils being energised from a three-phase power supply to produce a travelling radial field. The pump system described obviates the necessity for joints between the coils. It also allows the use of all types of high temperature insultation, simplified manufacture, and enables the windings to be located on the inside of the annulus. Full constructional details are given. (U.K.)
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Bilge pumps. 119.520 Section 119.520 Shipping COAST... Ballast Systems § 119.520 Bilge pumps. (a) Each vessel must be provided with bilge pumps in accordance... have a portable hand bilge pump that must be: (1) Capable of pumping water, but not necessarily...
Reactor coolant pumps for nuclear reactors
International Nuclear Information System (INIS)
Harand, E.; Richter, G.; Tschoepel, G.
1975-01-01
A brake for the pump rotor of a main coolant pump or a shutoff member on the pump are provided in order to prevent excess speeds of the pump rotor. Such excess speeds may occur in PWR type reactors with water at a pressure below, e.g., 150 bars if there is leakage from a coolant line associated with the main coolant pump. As a brake, a centrifugal brake depending upon the pump speed or a brake ring arranged on the pump housing and acting on the pump rotor, which ring would be activated by pressure differentials in the pump, may be used. If the pressure differences between suction and pressure sockets are very small, a controlled hydraulic increase of the pressure force on the brake may also be provided. Furthermore, a turbine brake may be provided. A slide which is automatically movable in closing position along the pump rotor axis is used as a shutoff element. It is of cylindrical configuration and is arranged concentrically with the rotor axis. (DG) [de
Reversible oxidative modification: a key mechanism of Na+-K+ pump regulation.
Figtree, Gemma A; Liu, Chia-Chi; Bibert, Stephanie; Hamilton, Elisha J; Garcia, Alvaro; White, Caroline N; Chia, Karin K M; Cornelius, Flemming; Geering, Kaethi; Rasmussen, Helge H
2009-07-17
Angiotensin II (Ang II) inhibits the cardiac sarcolemmal Na(+)-K(+) pump via protein kinase (PK)C-dependent activation of NADPH oxidase. We examined whether this is mediated by oxidative modification of the pump subunits. We detected glutathionylation of beta(1), but not alpha(1), subunits in rabbit ventricular myocytes at baseline. beta(1) Subunit glutathionylation was increased by peroxynitrite (ONOO(-)), paraquat, or activation of NADPH oxidase by Ang II. Increased glutathionylation was associated with decreased alpha(1)/beta(1) subunit coimmunoprecipitation. Glutathionylation was reversed after addition of superoxide dismutase. Glutaredoxin 1, which catalyzes deglutathionylation, coimmunoprecipitated with beta(1) subunit and, when included in patch pipette solutions, abolished paraquat-induced inhibition of myocyte Na(+)-K(+) pump current (I(p)). Cysteine (Cys46) of the beta(1) subunit was the likely candidate for glutathionylation. We expressed Na(+)-K(+) pump alpha(1) subunits with wild-type or Cys46-mutated beta(1) subunits in Xenopus oocytes. ONOO(-) induced glutathionylation of beta(1) subunit and a decrease in Na(+)-K(+) pump turnover number. This was eliminated by mutation of Cys46. ONOO(-) also induced glutathionylation of the Na(+)-K(+) ATPase beta(1) subunit from pig kidney. This was associated with a approximately 2-fold decrease in the rate-limiting E(2)-->E(1) conformational change of the pump, as determined by RH421 fluorescence. We propose that kinase-dependent regulation of the Na(+)-K(+) pump occurs via glutathionylation of its beta(1) subunit at Cys46. These findings have implications for pathophysiological conditions characterized by neurohormonal dysregulation, myocardial oxidative stress and raised myocyte Na(+) levels.
DURATION LIMIT OF LASER PULSES EMITTED FROM A Ce-DOPED CRYSTAL SHORT CAVITY
Directory of Open Access Journals (Sweden)
Le Hoang Hai
2017-11-01
Full Text Available Based on the rate equation set for broadband cavities, the dependence of pulse duration on cavity and pumping parameters is analyzed. The cavity uses a Ce-doped crystal as a gain medium. Computation results show the variation of the pulse width with the change of cavity length, mirror reflectivity, pumping energy and pumping pulse duration. A significant influence of multiple-pulse operation in limiting pulse duration is realized and a pulse-width of the order 200 ps is found to be the limit for the direct generation of ultraviolet single picosecond pulses from a Ce:LLF short cavity.
Development of new design mechanical seal tester for Primary Loop Recirculation Pump (PLR Pump)
International Nuclear Information System (INIS)
Fukushima, Naoki; Koshiba, Koremutsu
1995-01-01
The mechanical seal for a Primary Loop Recirculation Pump (PLR Pump) is an important part of a BWR plant. This study describes a new mechanical seal tester developed to certify mechanical seal performance before installation in a PLR Pump on site. (author)
Gulgazov, Vadim N.; Jackson, Gordon S.; Lascola, Kevin M.; Major, Jo S.; Parke, Ross; Richard, Tim; Rossin, Victor V.; Zhang, Kai
1999-09-01
The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modern telecommunication systems originates from optical amplifiers. In addition, modern optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems. Erbium-doped amplifiers currently dominate optical amplifier usage. These amplifiers absorb pump light at 980 nm and/or 1480 nm, and achieve gain at wavelengths around 1550 nm. 980 nm pumps achieve better noise figures and are therefore used for the amplification of small signals. Due to the quantum defect, 1480 nm lasers deliver more signal photon per incident photon. In addition, 1480 nm lasers are less expensive than 980 nm lasers. Thus, 1480 nm pump lasers are used for amplification in situations where noise is not critical. The combination of these traits leads to the situation where many amplifiers contain 980 nm lasers to pump the input section of the Er- doped fiber with 1480 nm lasers being used to pump the latter section of Er fiber. This can be thought of as using 980 nm lasers to power an optical pre-amplifier with the power amplification function being pump with 1480 nm radiation. This paper will focus on 980 nm pump lasers and the impact that advances in 980 nm pump technology will have on optical amplification systems. Currently, 980 nm technology is rapidly advancing in two areas, power and reliability. Improving reliability is becoming increasingly important as amplifiers move towards employing more pump lasers and using these pump lasers without redundancy
Diode-laser-pump module with integrated signal ports for pumping amplifying fibers and method
Savage-Leuchs,; Matthias, P [Woodinville, WA
2009-05-26
Apparatus and method for collimating pump light of a first wavelength from laser diode(s) into a collimated beam within an enclosure having first and second optical ports, directing pump light from the collimated beam to the first port; and directing signal light inside the enclosure between the first and second port. The signal and pump wavelengths are different. The enclosure provides a pump block having a first port that emits pump light to a gain fiber outside the enclosure and that also passes signal light either into or out of the enclosure, and another port that passes signal light either out of or into the enclosure. Some embodiments use a dichroic mirror to direct pump light to the first port and direct signal light between the first and second ports. Some embodiments include a wavelength-conversion device to change the wavelength of at least some of the signal light.
Inherent Limitations in Mid-Wave and Long-Wave-IR Upconversion Detector
DEFF Research Database (Denmark)
Barh, Ajanta; Tseng, Yu-Pei; Pedersen, Christian
2017-01-01
Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper.......Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper....
The Causes and Prevention Measures of Stuck Pump Phenomenon of Rod-pumped Well in CBM Field
Yonggui, Mei
2018-02-01
In the process of CBM field exploitation, in order to realize the drainage equipment to work continuous stably, the article pays attention to study and solve the stuck pump problem, and aim of reducing reservoir damage and lowing production costs. Through coal particles stuck pump experiment and sediment composition analysis, we find out five primary cause of stuck pump phenomenon: sand from coal seam, sediment from ground, iron corrosion, iron scrap caused by eccentric wear, coal cake. According to stuck pump mechanism, the article puts forward 8 measures to prevent stuck pump phenomenon, and the measures are focused on technology optimization, operation management and drainage process control. After 7 years production practice, the yearly stuck pump rate has dropped from 8.9% to 1.2%, and the pump inspection period has prolonged 2 times. The experiment result shows that pure coal particles cannot cause stuck pump, but sand, scrap iron, and iron corrosion are the primary cause of stuck pump. The article study and design the new pipe string structure that the bottom of the pipe string is open. This kind of pipe string applied the sedimentation terminal velocity theory to solve the stuck pump phenomenon, and it can be widely used in CBM drainage development.
International Nuclear Information System (INIS)
Takenaga, H.; Sakasai, A.; Kubo, H.
2001-01-01
Particle pumping characteristics were compared between pumping from the inner side private flux region (IPP) and pumping from both sides of the private flux region (BPP) in the JT-60U W shaped divertor, and between JT-60U IPP and pumping in the DIII-D lower baffled divertor. The pumping flux for BPP is smaller than that for IPP by about a factor of 2 with weak in-out asymmetry of recycling neutral flux and by a factor of 3.5-6.5 with strong in-out asymmetry. The reduction of the pumping flux for BPP is consistent with Monte Carlo simulations, where backflow at the outer pumping slot is observed due to in-out recycling asymmetry. The pumping flux in DIII-D at I p =0.8 MA and B T =1.6 T is comparable to or smaller than that for JT-60U IPP at I p =1.0 MA, B T =3.8 T and I p =1.5 MA, B T =3.5 T in the same density regime. In the DIII-D divertor with pumping from the private flux region, the pumping flux decreases with increasing in-out asymmetry. The pumping flux normalized by the integrated D α emission over the whole plasma exhibits a similar dependence on the distance between the pumping slot and the strike point in JT-60U IPP and the DIII-D lower divertor with pumping through the outer divertor plasma region. (author)
Mechanical pumping at low temperature
Energy Technology Data Exchange (ETDEWEB)
Perin, J.P.; Claudet, G.; Disdier, F.
1994-12-31
This new concept consists of a mechanical pump able to run at low temperature (25 K). Since gas density varies inversely with temperature, the pump could deliver much higher mass flow rate than at room temperature for a given size. Advantages of this concept are reduction of an order of magnitude in size and weight when compared to a conventional pump scaled to perform the same mass flow rate at room temperature. Results obtained at 80 K and 25 K with a Holweck type molecular drag pump of 100 mm diameter and with few stages of a turbomolecular pump running at the same temperatures, are given. This pump would be a solution to allow continuous tritium extraction and minimize the mass inventory for the ITER (International Tokamak Experiment Reactor). 5 figs., 2 tabs., 4 refs.
Factors governing sustainable groundwater pumping near a river.
Zhang, Yingqi; Hubbard, Susan; Finsterle, Stefan
2011-01-01
The objective of this paper was to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsaturated zone and riverbed clogging. We quantify river clogging by calibrating a time-dependent riverbed permeability function based on knowledge of pumping rate, river stage, and temperature. The dynamics of the estimated riverbed permeability reflects clogging and scouring mechanisms. Our results indicate that (1) riverbed permeability is the dominant factor affecting infiltration needed for sustainable RBF production; (2) dam operation can influence pumping efficiency and prevent the development of an unsaturated zone beneath the riverbed only under conditions of sufficient riverbed permeability; (3) slow river velocity, caused by dam raising during summer months, may lead to sedimentation and deposition of fine-grained material within the riverbed, which may clog the riverbed, limiting recharge to the collector wells and contributing to the development of an unsaturated zone beneath the riverbed; and (4) higher river flow velocities, caused by dam lowering during winter storms, scour the riverbed and thus increase its permeability. These insights can be used as the basis for developing sustainable water management of a RBF system. Journal compilation © 2010 National Ground Water Association. No claim to original US government works.
Thermally Actuated Hydraulic Pumps
Jones, Jack; Ross, Ronald; Chao, Yi
2008-01-01
Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research
Walker, D.; Fischbach, D.; Tetreault, R.
1996-01-01
The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.
Zhang, Ruiliang; Qu, Yanchen; Zhao, Weijiang; Chen, Zhenlei
2017-03-20
A high energy, widely tunable Si-prism-array coupled terahertz-wave parametric oscillator (TPO) has been demonstrated by using a deformed pump. The deformed pump is cut from a beam spot of 2 mm in diameter by a 1-mm-wide slit. In comparison with a small pump spot (1-mm diameter), the THz-wave coupling area for the deformed pump is increased without limitation to the low-frequency end of the tuning range. Besides, the crystal location is specially designed to eliminate the alteration of the output position of the pump during angle tuning, so the initially adjusted nearest pumped region to the THz-wave exit surface is maintained throughout the tuning range. The tuning range is 0.58-2.5 THz for the deformed pump, while its low frequency end is limited at approximately 1.2 THz for the undeformed pump with 2 mm diameter. The highest THz-wave output of 2 μJ, which is 2.25 times as large as that from the pump of 1 mm in diameter, is obtained at 1.15 THz under 38 mJ (300 MW/cm2) pumping. The energy conversion efficiency is 5.3×10-5.
Thermomechanical piston pump development
Sabelman, E. E.
1971-01-01
A thermally powered reciprocating pump has been devised to replace or augment an electric pump for the transport of temperature-control fluid on the Thermoelectric Outer Planet Spacecraft (TOPS). The thermally powered pump operates cyclically by extracting heat energy from the fluid by means of a vapor-pressure expansion system and by using the heat to perform the mechanical work of pumping. A feasibility test unit has been constructed to provide an output of 7 cu in during a 10- to 100-second cycle. It operates with a fluid input temperature of 200 to 300 F and a heat sink temperature of 0 to 30 F.
Multi-stage internal gear/turbine fuel pump
Energy Technology Data Exchange (ETDEWEB)
Maier, Eugen; Raney, Michael Raymond
2004-07-06
A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.
Experimental study on the simple water hammer pump; Kan`igata water hammer pump ni kansuru kenkyu
Energy Technology Data Exchange (ETDEWEB)
Muto, M; Ushiyama, I [Ashikaga Institute of Technology, Tochigi (Japan)
1997-11-25
Outlined herein are experimental results with a water hammer pump. It is a unique pump in that it depends only on potential energy of water to pump-up water. Water flows downwards from a reservoir at a high position into the pump , and is released from the exhaust valve. When velocity of water flowing in the pipe reaches a certain level, hydraulic force exceeds gravity of the exhaust valve to rapidly closes it, which is accompanied by rapid increase in pressure in the pump. High-pressure water flows into the air chamber, after pushing up the lifting valve, to compress air in the chamber. The lifting valve is closed, when pressure in the air chamber exceeds that in the pump, to pump up water in the chamber through the lifting pipe. Closure of the lifting valve produces a negative pressure within the pump, which, together with gravity of the exhaust valve, opens the valve again. The pump lifts water at 1.64l/min under the conditions of head: 3m and lift: 6m at an efficiency of 48.1%. 1 ref., 4 fig., 2 tab.
External gear pumps operating with non-Newtonian fluids: Modelling and experimental validation
Rituraj, Fnu; Vacca, Andrea
2018-06-01
External Gear Pumps are used in various industries to pump non-Newtonian viscoelastic fluids like plastics, paints, inks, etc. For both design and analysis purposes, it is often a matter of interest to understand the features of the displacing action realized by meshing of the gears and the description of the behavior of the leakages for this kind of pumps. However, very limited work can be found in literature about methodologies suitable to model such phenomena. This article describes the technique of modelling external gear pumps that operate with non-Newtonian fluids. In particular, it explains how the displacing action of the unit can be modelled using a lumped parameter approach which involves dividing fluid domain into several control volumes and internal flow connections. This work is built upon the HYGESim simulation tool, conceived by the authors' research team in the last decade, which is for the first time extended for the simulation of non-Newtonian fluids. The article also describes several comparisons between simulation results and experimental data obtained from numerous experiments performed for validation of the presented methodology. Finally, operation of external gear pump with fluids having different viscosity characteristics is discussed.
Pumps for German pressurized water reactors
Energy Technology Data Exchange (ETDEWEB)
Dernedde, R.
1984-01-01
The article describes the development of a selection of pumps which are used in the primary coolant system and the high-pressure safety injection system and feed water system during the past 2 decades. The modifications were caused by the step-wise increasing power output of the plants from 300 MW up to 1300 MW. Additional important influences were given be the increased requirements for quality assurance and final-documentation. The good operating results of the delivered pumps proved that the reliability is independent of the volume of the software-package. The outlook expects that consolidation will be followed by additional steps for the order processing of components for the convoy pumps. KW: main coolant pump; primary system; boiler feed pump; reactor pump; secondary system; barrel insert pump; pressure water reactor; convoy pump; state of the art.
Acres, R. L.
1972-01-01
Design and development of two types of pumps for handling liquefied gases are discussed. One pump uses mechanical valve shift and other uses pneumatic valve shift. Illustrations of pumps are provided and detailed description of operation is included.
A generic pump/compressor design for circulation of cryogenic fluids
International Nuclear Information System (INIS)
Jasinski, T.; Honkonen, S.C.; Sixsmith, H.; Stacy, W.D.
1986-01-01
This paper describes the development of a second-generation centrifugal circulator for cryogenic fluids. The circulator is designed to operate over a wide range of flow rate and pressure rise and can be used for the pumping of liquid and compression of vapor at temperatures down to liquid helium (4 K). The machine incorporates self-acting gas journal bearings, a permanent magnet axial thrust bearing, and a variable speed induction motor drive to provide for reliable, maintenance-free operation. The paper provides design details of the pump. Calculated performance characteristics are also presented along with a general discussion regarding limitations of the present system
A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing
Directory of Open Access Journals (Sweden)
Mohammed-Baker Habhab
2016-11-01
Full Text Available Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.
A Laminar Flow-Based Microfluidic Tesla Pump via Lithography Enabled 3D Printing.
Habhab, Mohammed-Baker; Ismail, Tania; Lo, Joe Fujiou
2016-11-23
Tesla turbine and its applications in power generation and fluid flow were demonstrated by Nicholas Tesla in 1913. However, its real-world implementations were limited by the difficulty to maintain laminar flow between rotor disks, transient efficiencies during rotor acceleration, and the lack of other applications that fully utilize the continuous flow outputs. All of the aforementioned limits of Tesla turbines can be addressed by scaling to the microfluidic flow regime. Demonstrated here is a microscale Tesla pump designed and fabricated using a Digital Light Processing (DLP) based 3D printer with 43 µm lateral and 30 µm thickness resolutions. The miniaturized pump is characterized by low Reynolds number of 1000 and a flow rate of up to 12.6 mL/min at 1200 rpm, unloaded. It is capable of driving a mixer network to generate microfluidic gradient. The continuous, laminar flow from Tesla turbines is well-suited to the needs of flow-sensitive microfluidics, where the integrated pump will enable numerous compact lab-on-a-chip applications.
Directory of Open Access Journals (Sweden)
Yo Tanaka
2014-05-01
Full Text Available Lab-on-a-chip technology is promising for the miniaturization of chemistry, biochemistry, and/or biology researchers looking to exploit the advantages of a microspace. To manipulate fluid on a microchip, on-chip pumps are indispensable. To date, there have been several types of on-chip pumps including pneumatic, electroactive, and magnetically driven. However these pumps introduce polymers, metals, and/or silicon to the microchip, and these materials have several disadvantages, including chemical or physical instability, or an inherent optical detection limit. To overcome/avoid these issues, glass has been one of the most commonly utilized materials for the production of multi-purpose integrated chemical systems. However, glass is very rigid, and it is difficult to incorporate pumps onto glass microchips. This paper reports the use of a very flexible, ultra-thin glass sheet (minimum thickness of a few micrometers to realize a pump installed on an entirely glass-based microchip. The pump is a peristaltic-type, composed of four serial valves sealing a cavity with two penetrate holes using ultra-thin glass sheet. By this pump, an on-chip circulating flow was demonstrated by directly observing fluid flow, visualized via polystyrene tracking particles. The flow rate was proportional to the pumping frequency, with a maximum flow rate of approximately 0.80 μL/min. This on-chip pump could likely be utilized in a wide range of applications which require the stability of a glass microchip.
Prelas, Mark
2016-01-01
This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....
Diode-Pumped Mode-Locked LiSAF Laser; FINAL
International Nuclear Information System (INIS)
None
1996-01-01
Under this contract we have developed Cr(sup 3+):LiSrAlF(sub 6) (Cr:LiSAF, LiSAF) mode-locked lasers suitable for generation of polarized electrons for CEBAF. As 670 nm is an excellent wavelength for optical pumping of Cr:LiSAF, we have used a LIGHTWAVE developed 670 nm diode pump module that combines the output of ten diode lasers and yields approximately 2 Watts of optical power. By the use of a diffraction limited pump beam however, it is possible to maintain a small mode size through the length of the crystal and hence extract more power from Cr:LiSAF laser. For this purpose we have developed a 1 Watt, red 660nm laser (LIGHTWAVE model 240R) which serves as an ideal pump for Cr:LiSAF and is a potential replacement of costly and less robust krypton laser. This new system is to compliment LIGHTWAVE Series 240, and is currently being considered for commercialization. Partially developed under this contract is LIGHTWAVEs product model 240 which has already been in our production lines for a few months and is commercially available. This laser produces 2 Watts of output at 532 nm using some of the same technology developed for production of the 660nm red system. It is a potential replacement for argon ion lasers and has better current and cooling requirements and is an excellent pump source for Ti:Al(sub 2)O(sub 3). Also, as a direct result of this contract we now have the capability of commercially developing a mode-locked 100MHz Cr:LiSAF system. Such a laser could be added to our 100 MHz LIGHTWAVE Series 131. The Series 131 lasers provide pico second pulses and were originally developed under another DOE SBIR. Both models of LIGHTWAVE Series 240 lasers, the fiber coupled pump module and the 100MHz LiSAF laser of Series 131 have been partially developed under this contract, and are commercially competitive products
An experimental study on pump clogging
International Nuclear Information System (INIS)
Isono, M; Nohmi, M; Uchida, H; Kawai, M; Kudo, H; Kawahara, T; Miyagawa, K; Saito, S
2014-01-01
For sewage pump that various foreign substance is flowed into, anti-clogging performance is a factor as important as pump efficiency in order to avoid clogging trouble by foreign substance. Many investigations about pump inner flow and pump efficiency estimation have been carried out conventionally in order to realize coexistence with anti-clogging performance and pump performance. And these results have been reflected in construction of the running water section design method. As a index of anti-clogging performance, ''impeller passage diameter'' which is diameter of spherical solid that can pass through the pump is used widely. And there are various type of the sewage pump which have large impeller passage diameter. However real cause of clog is not a solid, and it is fibrous material such as towel and clothes, vinyl and paper diaper. In most case these material accumulate in the pump, so that clog is occurred. In this study, for the purpose of quantification of anti-clogging performance against fibrous materials, the factor that affect to clogging of pump was investigated by pump model test using a string. The test is done based on Taguchi method. In this test, type of the pump model, diameter of the string, material of the string, length of the string and flow rate are selected for the factor, and the effect that they have on the clogging of the pump was investigated. As a result of this test, it was made clear that length of the string has a strong influence on the clogging of the pump. And from the result of this test, evaluation method of anti-clogging performance of the pump against fibrous material by using string was considered. According to the result of above test based on Taguchi method, it was assumed that quantification of anti-clogging performance against fibrous materials is possible by flowing plural strings into the pump and calculating the probability of passing. Plurality sewage pumps of different types were evaluated based
Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source
Directory of Open Access Journals (Sweden)
Jiří Fink
2016-07-01
Full Text Available In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP. The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space heating. Electricity for the heat pumps is generated by a central CHP unit, which also provides thermal energy to a district heating system. The paper reviews recent smart grid control approaches for central and distributed levels. An online algorithm is described based on the earliest deadline first theory that can be used on the aggregator level to control the CHP and to give signals to the heat pump controllers if they should start or should wait. The central controller requires only a limited amount of privacy-insensitive information from the heat pump controllers about their deadlines, which the heat pump controllers calculate for themselves by model predictions. In this way, a robust heat pump and CHP control is obtained, which is able to minimize energy demand and results in the desired thermal comfort for the households. The simulations demonstrate fast computation times due to minor computational and communication overheads.
International Nuclear Information System (INIS)
Tanguy, L.
1978-01-01
In order to meet the requirements of nuclear industry for the transfer of corrosive, toxic, humidity sensitive or very pure gases, different types of pumps were developped and commercialized. Their main characteristics are to prevent pollution of the transfered fluid by avoiding any contact between this fluid and the lubricated parts of the machine, and to prevent a contamination of the atmosphere or of the fluid by a total tightness. Patellar pumps have been particularly developped because the metallic bellows are quite reliable and resistant in this configuration. Two types are described: patellar pumps without friction and barrel pumps whose pistons are provided with rings sliding in the cylinders without lubrication [fr
Baxter elastomeric pumps: Feasibility of weight estimates.
Chambers, Carole R; Pabia, Mica; Sawyer, Michael; Tang, Patricia A
2017-09-01
Purpose Elastomeric pumps are used to infuse a 46-h fluorouracil protocol and patients are asked to visually inspect the pump daily. The pump has a variability of ±10% and there are additional patient variables that can increase this. The feasibility of weighing the pump rather than a visual inspection along with the secondary objective to confirm the pump's variability in real world conditions was undertaken. Methods Empty pumps were weighed using both pharmacy and kitchen scales. Pumps upon completion of the 46-h infusion were also weighed using both pharmacy and kitchen scales. Results The kitchen scale was as accurate as the pharmacy grade scale. Disconnected pumps showed the expected variability from using these infusor pumps along with a few showing greater variability likely due to patient variables. Conclusion Weighing pumps appears to be feasible both at the pharmacy and home level. Next steps would be to weigh pumps during the infusion to validate an alternate method to simple visual inspection for patients to confirm proper infusing of the pump at their home.
Experimental Realization of a Quantum Spin Pump
DEFF Research Database (Denmark)
Watson, Susan; Potok, R.; M. Marcus, C.
2003-01-01
We demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic fluctuations of pumped current, made spin-dependent by the a......We demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic fluctuations of pumped current, made spin......-dependent by the application of an in-plane Zeeman field. Spin currents are measured by placing the pump in a focusing geometry with a spin-selective collector....
Residual heat removal pump retrofit program
International Nuclear Information System (INIS)
Dudiak, J.G.; McKenna, J.M.
1990-01-01
Residual Heat Removal (RHR) pumps installed in pressurized water reactor power plants are used to provide the removal of decay heat from the reactor and to provide low head safety injection in the event of loss of coolant in the reactor coolant system. These pumps are subjected to rather severe temperature and pressure transients, therefore, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. RHR pumps have traditionally been a significant maintenance item for many utilities. The close-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. The casing separation requires the loosening of numerous highly torqued studs. Once the casing is separated, the impeller is dropped from the motor shaft to allow removal of the mechanical seal and casing cover from the motor shaft. Galling of the impeller to the motor shaft is not uncommon. The RHR pump internals are radioactive and the separation of the pump casing to perform routine maintenance exposes the maintenance personnel to high radiation levels. The handling of the impeller also exposes the maintenance personnel to high radiation levels. This paper introduces a design modification developed to convert the close-coupled RHR pumps to a coupled configuration
Analysis of the pump-beam path in corner-pumped slab laser
International Nuclear Information System (INIS)
Chen Li; Qiang Liu; Mali Gong; Gang Chen; Ping Yan
2007-01-01
The propagation of the pump radiation in active slab elements is considered. Conditions of the total internal reflection of the pump radiation are obtained, and are used to construct a series of graphical illustrations of reflection characteristics of different active elements. (control of laser radiation parameters)
Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes
Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.
2016-05-01
A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.
MK-III function tests in JOYO. Primary main cooling pump
International Nuclear Information System (INIS)
Isozaki, Kazunori; Saito, Takakazu; Sumino, Kouzo; Karube, Kouji; Terano, Toshihiro; Sakaba, Hideo; Nakai, Satoru
2004-06-01
MK-III function test (SKS-1) that was carried out from October 17, 2001 through October 23, 2001 using MK-III transition core configuration and MK-III function tests (SKS-2) was carried out from January 27, 2003 through February 13, 2003 using MK-III core configuration. The major function tests results of primary cooling system were shown as follows; (1) The stability of the primary main pump flow control system was confirmed on both CAS (cascade) mode and Man (manual) mode. Also no divergence of flow and revolution of the pump were observed at step flow change disturbance. (2) The main motor was shifted to run-back flow control operation in about 54 seconds after scram. The flow rate and pump revolution at run-back operation of A and B cooling system were 167 m 3 /h and 117 rpm, 185m 3 /h and 118 rpm respectively. The pump revolution was within the design target revolution 122 rpm ± 8 rpm and the flow was over the 10% of the rated flow. (3) The pony motor was engaged in operation in about 39 seconds after the primary main pump trip. The flow rate and pump revolution at the pony motor operation of A and B cooling system were 180 m 3 /h and 124 rpm, 190 m 3 /h and 123 rpm respectively. These values were satisfied the design low limit of 93 rpm and 10% of the rated flow. (4) Free flow coast down time constant was longer than 10 seconds that was design shortest time at both the primary pump trip and run-back operation. (5) Pump over flow column sodium levels of both A and B cooling system at rated operating condition were NL-1550 mm and, NL-1468 mm respectively and were lower than NL-1581 mm of the design value. This result shows the new IHX pressure loss estimation was conservative. (6) It was confirmed that the primary main pump could operate with out scram for up to 0.6 seconds of external power supply loss. (author)
Passively mode-locked high power Nd:GdVO4 laser with direct in-band pumping at 912 nm
Nadimi, Mohammad; Waritanant, Tanant; Major, Arkady
2018-01-01
We report on the first semiconductor saturable absorber mirror mode-locked Nd:GdVO4 laser directly diode-pumped at 912 nm. The laser generated 10.14 W of averaged output power at 1063 nm with the pulse width of 16 ps at the repetition rate of 85.2 MHz. The optical-to-optical efficiency and slope efficiency in the mode-locked regime were calculated to be 49.6% and 67.4% with respect to the absorbed pump power, respectively. Due to the low quantum defect pumping the output power was limited only by the available pump power.
Directory of Open Access Journals (Sweden)
Omar Asdrúbal Vilca Mejía
Full Text Available Abstract Introduction: Advances in modern medicine have led to people living longer and healthier lives. Frailty is an emerging concept in medicine yet to be explored as a risk factor in cardiac surgery. When it comes to CABG surgery, randomized controlled clinical trials have primarily focused on low-risk (ROOBY, CORONARY, elevated-risk (GOPCABE or high-risk patients (BBS, but not on frail patients. Therefore, we believe that off-pump CABG could be an important technique in patients with limited functional capacity to respond to surgical stress. In this study, the authors introduce the new national, multicenter, randomized, controlled trial "FRAGILE", to be developed in the main cardiac surgery centers of Brazil, to clarify the potential benefit of off-pump CABG in frail patients. Methods: FRAGILE is a two-arm, parallel-group, multicentre, individually randomized (1:1 controlled trial which will enroll 630 patients with blinded outcome assessment (at 30 days, 6 months, 1 year, 2 years and 3 years, which aims to compare adverse cardiac and cerebrovascular events after off-pump versus on-pump CABG in pre-frail and frail patients. Primary outcomes will be all-cause mortality, acute myocardial infarction, cardiac arrest with successful resuscitation, low cardiac output syndrome/cardiogenic shock, stroke, and coronary reintervention. Secondary outcomes will be major adverse cardiac and cerebrovascular events, operative time, mechanical ventilation time, hyperdynamic shock, new onset of atrial fibrillation, renal replacement therapy, reoperation for bleeding, pneumonia, length of stay in intensive care unit, length of stay in hospital, number of units of blood transfused, graft patency, rate of complete revascularization, neurobehavioral outcomes after cardiac surgery, quality of life after cardiac surgery and costs. Discussion: FRAGILE trial will determine whether off-pump CABG is superior to conventional on-pump CABG in the surgical treatment of
Pahlevan, Niema; Gharib, Morteza
2012-11-01
Impedance pump is a simple valveless pumping mechanism that operates based on the principles of wave propagation and reflection. It has been shown in a zebrafish that a similar mechanism is responsible for the pumping action in the embryonic heart during early stages before valve formation. Recent studies suggest that the cardiovascular system is designed to take advantage of wave propagation and reflection phenomena in the arterial network. Our aim in this study was to examine if the human aorta is a passive pump working like an impedance pump. A hydraulic model with different compliant models of artificial aorta was used for series of in-vitro experiments. The hydraulic model includes a piston pump that generates the waves. Our result indicates that wave propagation and reflection can create pumping mechanism in a compliant aorta. Similar to an impedance pump, the net flow and the flow direction depends on the frequency of the waves, compliance of the aorta, and the piston stroke.
The development of a cavitation free sodium pump for the breeder reactor
International Nuclear Information System (INIS)
Baladi, J.Y.; Nyilas, C.P.
1986-01-01
The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents a sample of the experimental results
Full sized tests on a french coolant pump under two-phase flow
International Nuclear Information System (INIS)
Huchard, J.C.; Bore, C.; Dueymes, E.
1997-01-01
The French Safety Authorities required EDF to demonstrate the ability of the new N4 main coolant pump to withstand two-phase flow conditions without damage. Therefore three full sized tests, simulating a bleeding flow on the primary system, were performed on a laboratory test loop under real operating conditions (temperature = 290 deg. C, pressure = 155 b, flowrate = 7 m 3 /s; electrical power = 7 MW). The maximum value of the mean void fraction reached 75 %. The outcome of the tests is very positive: the mechanical behaviour of the main coolant pump is good, even at high void fraction. The maximum vibration levels were below the limits fixed by the manufacturer. Correlations between the mechanical behaviour of the pump and the pressure pulsation in the test loop have been found. (authors)
Reactor coolant pump service life evaluation for current life cycle optimization and license renewal
International Nuclear Information System (INIS)
Doroshuk, B.W.; Berto, D.S.; Robles, M.
1990-01-01
This paper reports that as part of the plant life cycle management and license renewal program, Baltimore Gas and Electric Company (BG and E) has completed a service life evaluation of their reactor coolant pumps, funded jointly by EPRI and performed by ABB Combustion Engineering Nuclear Power. Two of the goals of the BG and E plant life cycle management and license renewal program, and of this current evaluation, are to identify actions which would optimize current plant operation, and ensure that license renewal remains a viable option. The reactor coolant pumps (RCPs) at BG and E's Calvert Cliffs Units 1 and 2 are Byron Jackson pumps with a diffuser and a single suction. This pump design is also used in many other nuclear plants. The RCP service life evaluation assessed the effect of all plausible age-related degradation mechanisms (ARDMs) on the RCP components. Cyclic fatigue and thermal embrittlement were two ARDMs identified as having a high potential to limit the service life of the pump case. The pump case is a primary pressure boundary component. Hence, ensuring its continued structural integrity is important
Sludge pumping in water treatment
International Nuclear Information System (INIS)
Solar Manuel, M. A.
2010-01-01
In water treatment processes is frequent to separate residual solids, with sludge shape, and minimize its volume in a later management. the technologies to applicate include pumping across pipelines, even to long distance. In wastewater treatment plants (WWTP), the management of these sludges is very important because their characteristics affect load losses calculation. Pumping sludge can modify its behavior and pumping frequency can concern treatment process. This paper explains advantages and disadvantages of different pumps to realize transportation sludge operations. (Author) 11 refs.
International Nuclear Information System (INIS)
Hellborg, R.; Hakansson, K.; Faarinen, M.; Kiisk, M.; Persson, P.; Skog, G.; Stenstroem, K.
2002-01-01
A recirculating terminal pumping system has been installed in the 3 MV Pelletron tandem accelerator in Lund. An extremely limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass spectrometry, will be given. (author)
International Nuclear Information System (INIS)
Cho, G.S.; Cho, B.H.
1981-01-01
As to the backscatter instability which is one of nonlinear three-wave resonant interactions, the reflectivity(r) in the case of homogeneous-slab medium is calculated, assuming all the three wavepackets negligible damping caused by medium. The expression has turned out such that r = tanh 2 KAsub(p)L, where K, Asub(p), and L are the constant coupling coefficient, the constant pump-wave amplitude, and the thickness of the medium engaged in the interaction each. When this result is interpreted in terms of the stimulated Brillouin back-scattering in a so-called underdense plasma in controlled fusion, we find the reflectivity twice as large as that by others in the limit of large pump-wave damping, and unfitting to former experiments in the independence on the incident laser-light intensity. We see the incompatibility rise chiefly from neglecting the damping of pump-wave in the plasma. In contrast to the former results by others in the limit of large pump-wave damping, our result might be regarded as that for cases of negligible pump-wave damping, in general stimulated back-scattering phenomena. (author)
Vivitron dead section pumping tests
International Nuclear Information System (INIS)
Heugel, J.; Bayet, J.P.; Brandt, C.; Delhomme, C.; Krieg, C.; Kustner, F.; Meiss, R.; Riehl, R.; Roth, C.; Schlewer, B.; Six, P.; Weber, A.
1990-10-01
Pumping tests have been conducted on a simulated accelerator dead section. The behavior of different pump types are compared and analyzed. Vacuum conditions to be expected in the Vivitron are reached and several parameters are verified. Selection of a pump for the Vivitron dead section is confirmed
Kastrup, Marc; Balzer, Felix; Volk, Thomas; Spies, Claudia
2012-07-01
Medication errors occur in approximately one out of five doses in a typical hospital setting. Patients in the intensive care unit (ICU) are particularly susceptible to errors during the application of intravenous drugs as they receive numerous potent drugs applied by syringe pumps. The aim of this study was to analyse the effects on potential harmful medication errors and to address factors that have potential for improving medication safety after the introduction of a standardized drug library into syringe pumps with integrated decision support systems. A team of physicians and nurses developed a dataset that defined standardized drug concentrations, application rates and alert limits to prevent accidental overdosing of intravenous medications. This dataset was implemented in 100 syringe pumps with the ability to log programming errors, alerts, reprogramming events and overrides ('smart pumps'). In this retrospective pilot study, all pump-related transaction data were obtained from the pump logs, by downloading the data from the pumps, covering 20 months of use between 1 April 2008 and 30 November 2009. Patient data were gathered from the electronic patient charts. The study was performed in a cardiothoracic ICU of the Charité University Hospital, Berlin, Germany. A total of 7884 patient treatment days and 133,601 infusion starts were evaluated. The drug library with the features of the dose rate was used in 92.8% of the syringe pump starts, in 1.5% of the starts a manual dosing mode without the use of the drug library was used and in 5.7% of the starts the mode 'mL/h', without any calculation features, was used. The most frequently used drugs were vasoactive drugs, followed by sedation medication. The user was alerted for a potentially harmful overdosing in 717 cases and in 66 cases the pumps were reprogrammed after the alert. During the early morning hours a higher rate of alarms was generated by the pumps, compared with the rest of the day. Syringe pumps with
Cryogenic storage tank with built-in pump
International Nuclear Information System (INIS)
Zwick, E.B.
1984-01-01
A cryogenic storage tank with a built-in pump for pumping cryogen directly from the primary storage container consistent with low boil-off losses of cryogen has an outer vessel, an inner vessel and an evacuated insulation space therebetween. A pump mounting tube assembly extends into the interior of the inner vessel and includes an inner pump mounting tube and an outer pump mounting tube joined at their lower rims to define an insulating jacket between the two tubes. The inner pump mounting tube is affixed at its upper end to the outer vessel while the outer pump mounting tube is affixed at its upper end to the inner vessel. The inner pump mounting tube defines a relatively long heat path into the cryogenic container and is itself insulated from the liquid cryogen by a pocket of trapped gas formed within the inner pump mounting tube by heated cryogen. A pump may be introduced through the inner pump mounting tube and is also insulated against contact with liquid cryogen by the trapped gas such that only the lowermost end of the pump is immersed in cryogen thereby minimizing heat leakage into the tank
Multi technical analysis of wear mechanisms in axial piston pumps
Schuhler, G.; Jourani, A.; Bouvier, S.; Perrochat, J.-M.
2017-05-01
Axial piston pumps convert a motor rotation motion into hydraulic or pneumatic power. Their compactness and efficiency of approximately 0.9 make them suitable for actuation applications especially in aeronautics. However, they suffer a limited life due to the wear of their components. In the literature, studies of axial piston pumps deal with contact between its different elements under lubrication conditions. Nevertheless, they are more focused on analytic or numerical approaches. This study consists in an experimental analysis of worn pump components to highlight and understand wear mechanisms. Piston shoes are central components in the axial piston pump since they are involved in three tribological contacts. These three contacts are thereby studied: piston shoes/swashplate, piston shoes/pistons and piston shoes/shoes hold down plate (SHDP). To perform this analysis, helicopter hydraulic pumps after different operating times have been studied. The wear damage mechanisms and wear debris are analysed using SEM observations. 3D surface roughness measurements are then used to characterize worn surfaces. The observations reveal that in the contact between shoes and swashplate, the main wear mechanism is three-body abrasive wear due to coarse carbides removal. Between shoes and pistons, wear occurs in a less severe way and is mainly due to the debris generated in the first contact and conveyed by the lubricating fluid. In the third contact, the debris are also the prime cause of the abrasive wear and the generation of deep craters in the piston shoes.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel pumps. 25.991 Section 25.991... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.991 Fuel pumps. (a) Main pumps. Each fuel pump required for proper engine operation, or required to meet the fuel system...
Design of liquid lithium pumps for FMIT
International Nuclear Information System (INIS)
Adkins, H.E.
1983-01-01
In the Fusion Materials Irradiation Test (FMIT) facility, a jet of liquid lithium is bombarded by accelerated deuterons to generate high energy neutrons for materials testing. The lithium system will include two electromagnetic pumps, a 750 gpm main pump and a 10 gpm auxiliary pump. The larger pump was designed and built in 1982, following extensive testing of a similar pump in the Experimental Lithium System. Design of the auxiliary pump has been completed, but fabrication has not started. This paper discusses the design considerations leading to selection of the Annular Linear Induction Pump (ALIP) concept for these applications. Design parameters, fabrication procedures, and results of pump testing are also reviewed
International Nuclear Information System (INIS)
Seifert, M.
2006-01-01
The condensing gas boiler is now state of the art and there is no more room for improvement in performance, technically speaking. The next logical step to improve the overall efficiency is to exploit ambient heat in combination with the primary source of energy, natural gas. That means using natural-gas driven heat pumps and gas-fired heat pumps. Based on this, the Swiss Gas Industry decided to set up a practical test programme enjoying a high priority. The aim of the project 'Gas-fired heat pump practical test' is to assess by field tests the characteristics and performance of the foreign serial heat pumps currently on the market and to prepare and promote the introduction on the market place of this sustainable natural-gas technology. (author)
Numerical modeling and design of a disk-type rotating permanent magnet induction pump
Energy Technology Data Exchange (ETDEWEB)
Koroteeva, E., E-mail: koroteeva@physics.msu.ru [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia); Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Ščepanskis, M. [Laboratory for Mathematical Modelling of Environmental and Technological Processes, University of Latvia, Rīga 1002 (Latvia); Bucenieks, I.; Platacis, E. [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia)
2016-05-15
Highlights: • The design and performance of a disk-type induction pump are described. • A 3D numerical model based on an iterative coupling between EM and hydrodynamic solvers is developed. • The model is verified by comparing with the experiments in a Pb-Bi loop facility. • The suggestions are given to estimate the pump performance in a Pb-Li loop at high pressures. - Abstract: Electromagnetic induction pumps with rotating permanent magnets appear to be the most promising devices to transport liquid metals in high-temperature applications. Here we present a numerical methodology to simulate the operation of one particular modification of these types of pumps: a disk-type induction pump. The numerical model allows for the calculation and analysis of the flow parameters, including the pressure–flow rate characteristics of the pump. The simulations are based on an iterative fully coupled scheme for electromagnetic and hydrodynamic solvers. The developed model is verified by comparing with experimental data obtained using a Pb-Bi loop test facility, for pressures up to 4 bar and flow rates up to 9 kg/s. The verified model is then expanded to higher pressures, beyond the limits of the experimental loop. Based on the numerical simulations, suggestions are given to extrapolate experimental data to higher (industrially important) pressure ranges. Using the numerical model and analytical estimation, the pump performance for the Pb-Li loop is also examined, and the ability of the designed pump to develop pressure heads over 6 bar and to provide flow rates over 15 kg/s is shown.
Mechanical pumping at low temperature
International Nuclear Information System (INIS)
Perin, J.P.; Claudet, G.; Disdier, F.
1995-01-01
This novel concept consist of a mechanical pump able to run at low temperature (25K). Since gas density varies inversely with temperature, this pump would deliver much higher mass flow rate than at room temperature for a given size. Advantages of this concept are order of magnitude reduction in size, weight, when compared to a conventional pump scaled to perform the same mass flow rate at room temperature. This pump would be a solution to allow continuously tritium extraction and minimize the mass inventory. (orig.)
High temperature industrial heat pumps
Energy Technology Data Exchange (ETDEWEB)
Berghmans, J. (Louvain Univ., Heverlee (Belgium). Inst. Mechanica)
1990-01-01
The present report intends to describe the state of the art of high temperature industrial heat pumps. A description is given of present systems on the market. In addition the research and development efforts on this subject are described. Compression (open as well as closed cycle) systems, as well as absorption heat pumps (including transformers), are considered. This state of the art description is based upon literature studies performed by a team of researchers from the Katholieke Universiteit Leuven, Belgium. The research team also analysed the economics of heat pumps of different types under the present economic conditions. The heat pumps are compared with conventional heating systems. This analysis was performed in order to evaluate the present condition of the heat pump in the European industry.
Cryosorption vacuum pumping under fusion reactor conditions
International Nuclear Information System (INIS)
Watson, J.S.; Fisher, P.W.
1977-01-01
Experiments are in progress on cryosorption pumping using a double-chevron pump with a molecular sieve pumping surface. Studies have been made with hydrogen, deuterium, helium, and deuterium-helium at 10 -7 to 3 x 10 -3 torr. Steady pumping speeds were observed for deuterium; above 10 -4 torr the speed increased with pressure until runaway occurred. At less than 10 -6 torr and low panel loading, hydrogen pumping speeds resemble those for deuterium. At higher pressures, the pump can function by condensation or sorption, and unsteady speeds are observed. Helium pumping is always by sorption, but regions of instability have been observed and defined. Deuterium-helium pumping tests showed that deuterium condensation on the panels prevents cryosorption of helium; however, compound pumps with separate panels for helium and hydrogen will be satisfactory
Benner, Steve M (Inventor); Martins, Mario S. (Inventor)
2000-01-01
A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.
Part-load pumping operation, control and behaviour
International Nuclear Information System (INIS)
1988-01-01
Twenty one papers are printed. Their main concern is with pump performance under abnormal operating conditions or when operating at part-load. The effect of part-load operation on pump performance, pump internal flow and pump cavitation and noise were considered. The pumps considered are used in a variety of situations and some case studies were discussed. One paper about part-load operation of the boiler pumps for French pressurized water reactors and one paper on pressure pulsations of centrifugal pumps at very low flowrate, are indexed separately. (U.K.)
Energy Technology Data Exchange (ETDEWEB)
Morishita, Etsuo; Suganami, Takuya; Nishida, Mitsuhiro; Kitora, Yoshihisa; Yamamoto, Sakuei; Fujii, Kosaburo
1988-02-25
An effort is made to apply a scroll machine to development of a vacuum pump. In view of mechanical simplification and load patterns, the vacuum pump uses a rotating mechanism to produce paired vortices rotating around each center. Chip seal and atmospheric pressure are utilized for axial gap sealing while a spring and atmospheric pressure for the radial gap sealing. In both gaps, the sealing direction is stationary relative to the environment during rotation, making it much easier to achieve effective sealing as compared to oscillating pumps. Since the compression ratio is high in vacuum pumps, a zero top clearance form is adopted for the central portion of vortices and an gas release valve is installed in the rotating axis. A compact Oldham coupling with a small inertia force is installed behind the vortices to maintain the required phase relations between the vortices. These improvements result in a vacuum of 1 Pa for dry operation and 10/sup -2/ Pa for oil flooded operation of a single-stage scroll machine at 1800 rpm. (5 figs, 1 tab, 4 refs)
2010-10-01
...) Highly resistant to salt water, petroleum oil, heat, and vibration. (g) If a fixed hand pump is used to... GPM). (b) A portable hand bilge pump must be: (1) Capable of pumping water, but not necessarily..., including wiring, and size and number of batteries, is designed to allow all bilge pumps to be operated...
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Pumps. 105.20-10 Section 105.20-10 Shipping COAST GUARD... DISPENSING PETROLEUM PRODUCTS Specific Requirements-Cargo Tanks § 105.20-10 Pumps. (a) Pumps for cargo... discharge side of pump if the pressure under shutoff conditions exceeds 60 pounds. When a relief valve is...
Diode-pumped Yb:Sr5(PO4)3F laser performance
International Nuclear Information System (INIS)
Marshall, C.D.; Payne, S.A.; Smith, L.K.
1995-01-01
The performance of the first diode-pumped Yb 3+ -doped Sr 5 (PO 4 ) 3 F (Yb:S-FAP) laser is discussed. We found the pumping dynamics and extraction cross-sections of Yb:S-FAP crystals to be similar to those previously inferred by purely spectroscopic techniques. The saturation fluence for pumping was measured to be 2.2 J/cm 2 using three different methods based on either the spatial, temporal, or energy transmission properties of a Yb:S-FAP rod. The small signal gain implies an emission cross section of 6.0 x 10 -20 cm 2 that falls within error bars of the previously reported value of 7.3 x 10 -20 cm 2 , obtained from spectroscopic techniques. Up to 1.7 J/cm 3 of stored energy density was achieved in a 6 x 6 x 44 mm Yb:S-FAP amplifier rod. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3 x 3 x 30 mm Yb:S-FAP rod. In a free running configuration diode-pumped slope efficiencies up to 43% were observed with output energies up to ∼0.5 J per 1 ms pulse. When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz and 500 μs pulses
Energy Technology Data Exchange (ETDEWEB)
Sun, Bo [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Koh, Yee Kan, E-mail: mpekyk@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Centre of Advanced 2D Materials, National University of Singapore, Singapore 117542 (Singapore)
2016-06-15
Time-domain thermoreflectance (TDTR) is a pump-probe technique frequently applied to measure the thermal transport properties of bulk materials, nanostructures, and interfaces. One of the limitations of TDTR is that it can only be employed to samples with a fairly smooth surface. For rough samples, artifact signals are collected when the pump beam in TDTR measurements is diffusely scattered by the rough surface into the photodetector, rendering the TDTR measurements invalid. In this paper, we systemically studied the factors affecting the artifact signals due to the pump beam leaked into the photodetector and thus established the origin of the artifact signals. We find that signals from the leaked pump beam are modulated by the probe beam due to the phase rotation induced in the photodetector by the illumination of the probe beam. As a result of the modulation, artifact signals due to the leaked pump beam are registered in TDTR measurements as the out-of-phase signals. We then developed a simple approach to eliminate the artifact signals due to the leaked pump beam. We verify our leak-pump correction approach by measuring the thermal conductivity of a rough InN sample, when the signals from the leaked pump beam are significant. We also discuss the advantages of our new method over the two-tint approach and its limitations. Our new approach enables measurements of the thermal conductivity of rough samples using TDTR.
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Fire pumps. 181.300 Section 181.300 Shipping COAST GUARD... EQUIPMENT Fire Main System § 181.300 Fire pumps. (a) A self priming, power driven fire pump must be..., the minimum capacity of the fire pump must be 189 liters (50 gallons) per minute at a pressure of not...
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Fire pumps. 118.300 Section 118.300 Shipping COAST GUARD... Fire pumps. (a) A self priming, power driven fire pump must be installed on each vessel. (b) On a..., the fire pump must be capable of delivering a single hose stream from the highest hydrant, through the...
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Fire pumps. 169.559 Section 169.559 Shipping COAST GUARD... Firefighting Equipment Firefighting Equipment § 169.559 Fire pumps. (a) Each sailing school vessel must be equipped with fire pumps as required in Table 169.559(a). Table 169.559(a)—Fire Pumps Length Exposed and...
Hanford high level waste (HLW) tank mixer pump safe operating envelope reliability assessment
International Nuclear Information System (INIS)
Fischer, S.R.; Clark, J.
1993-01-01
The US Department of Energy and its contractor, Westinghouse Corp., are responsible for the management and safe storage of waste accumulated from processing defense reactor irradiated fuels for plutonium recovery at the Hanford Site. These wastes, which consist of liquids and precipitated solids, are stored in underground storage tanks pending final disposition. Currently, 23 waste tanks have been placed on a safety watch list because of their potential for generating, storing, and periodically releasing various quantities of hydrogen and other gases. Tank 101-SY in the Hanford SY Tank Farm has been found to release hydrogen concentrations greater than the lower flammable limit (LFL) during periodic gas release events. In the unlikely event that an ignition source is present during a hydrogen release, a hydrogen burn could occur with a potential to release nuclear waste materials. To mitigate the periodic gas releases occurring from Tank 101-SY, a large mixer pump currently is being installed in the tank to promote a sustained release of hydrogen gas to the tank dome space. An extensive safety analysis (SA) effort was undertaken and documented to ensure the safe operation of the mixer pump after it is installed in Tank 101-SY.1 The SA identified a need for detailed operating, alarm, and abort limits to ensure that analyzed safety limits were not exceeded during pump operations
International Nuclear Information System (INIS)
Chan, A.M.C.; Huynh, H.M.
2004-01-01
The development of an ANC-type empirical two-phase pump model for CANDU (Canadian Deuterium) reactor primary heat transport pumps is described in the present paper. The model was developed based on Ontario Hydro Technologies' full scale Darlington pump first quadrant test data. The functional form of the ANC model which is widely used was chosen to facilitate the implementation of the model into existing computer codes. The work is part of a bigger test program with the aims: (1) to produce high quality pump performance data under off-normal operating conditions using both full-size and model scale pumps; (2) to advance our basic understanding of the dominant mechanisms affecting pump performance based on more detailed local measurements; and (3) to develop a 'best-estimate' or improved pump model for use in reactor licensing and safety analyses. (author)
Magnetohydrodynamic generator and pump system
International Nuclear Information System (INIS)
Birzvalk, Yu.A.; Karasev, B.G.; Lavrentyev, I.V.; Semikov, G.T.
1983-01-01
The MHD generator-pump system, or MHD coupling, is designed to pump liquid-metal coolant in the primary circuit of a fast reactor. It contains a number of generator and pump channels placed one after another and forming a single electrical circuit, but hydraulically connected parallel to the second and first circuits of the reactor. All the generator and pump channels are located in a magnetic field created by the magnetic system with an excitation winding that is fed by a regulated direct current. In 500 to 2000 MW reactors, the flow rate of the coolant in each loop of the primary circuit is 3 to 6 m 3 /s and the hydraulic power is 2 to 4 MW. This paper examines the primary characteristics of an MHD generator-pump system with various dimensions and number of channels, wall thicknesses, coolant flow rates, and magnetic fields. It is shown that its efficiency may reach 60 to 70%. The operating principle of the MHD generator-pump system is explained in the referenced patent and involves the transfer of hydraulic power from generator channels to pump channels using a magnetic field and electrical circuit common to both channels. Variations of this system may be analyzed using an equivalent circuit. 7 refs., 5 figs
Peristaltic pumps for waste disposal
International Nuclear Information System (INIS)
Griffith, G.W.
1992-09-01
Laboratory robots are capable of generating large volumes of hazardous liquid wastes when they are used to perform chemical analyses of metal finishing solutions. A robot at Allied-Signal Inc., Kansas City Division, generates 30 gallons of acid waste each month. This waste contains mineral acids, heavy metals, metal fluorides, and other materials. The waste must be contained in special drums that are closed to the atmosphere. The initial disposal method was to have the robot pour the waste into a collecting funnel, which contained a liquid-sensing valve to admit the waste into the drum. Spills were inevitable, splashing occurred, and the special valve often didn't work well. The device also occupied a large amount of premium bench space. Peristaltic pumps are made to handle hazardous liquids quickly and efficiently. A variable-speed pump, equipped with a quick-loading pump head, was mounted below the robot bench near the waste barrel. The pump inlet tube was mounted above the bench within easy reach of the robot, while the outlet tube was connected directly to the barrel. During operation, the robot brings the waste liquid up to the pump inlet tube and activates the pump. When the waste has been removed, the pump stops. The procedure is quick, simple, inexpensive, safe, and reliable
RND-type Drug Efflux Pumps from Gram-negative bacteria: Molecular Mechanism and Inhibition
Directory of Open Access Journals (Sweden)
Henrietta eVenter
2015-04-01
Full Text Available Drug efflux protein complexes confer multidrug resistance on bacteria by transporting a wide spectrum of structurally diverse antibiotics. Moreover, organisms can only acquire resistance in the presence of an active efflux pump. The substrate range of drug efflux pumps is not limited to antibiotics, but it also includes toxins, dyes, detergents, lipids and molecules involved in quorum sensing; hence efflux pumps are also associated with virulence and biofilm formation. Inhibitors of efflux pumps are therefore attractive compounds to reverse multidrug resistance and to prevent the development of resistance in clinically relevant bacterial pathogens. Recent successes on the structure determination and functional analysis of the AcrB and MexB components of the AcrAB-TolC and MexAB-OprM drug efflux systems as well as the structure of the fully assembled, functional triparted AcrAB-TolC complex significantly contributed to our understanding of the mechanism of substrate transport and the options for inhibition of efflux. These data, combined with the well-developed methodologies for measuring efflux pump inhibition, could allow the rational design and subsequent experimental verification of potential efflux pump inhibitors. In this review we will explore how the available biochemical and structural information can be translated into the discovery and development of new compounds that could reverse drug resistance in Gram-negative pathogens. The current literature on efflux pump inhibitors will also be analysed and the reasons why no compounds have yet progressed into clinical use will be explored.
Emira, Ahmed A.; Abdelghany, Mohamed A.; Elsayed, Mohannad Yomn; Elshurafa, Amro M; Salama, Khaled N.
2014-01-01
Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.
Emira, Ahmed A.
2014-10-09
Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.
Drug delivery device including electrolytic pump
Foulds, Ian G.; Buttner, Ulrich; Yi, Ying
2016-01-01
Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.
Capillary-Condenser-Pumped Heat-Transfer Loop
Silverstein, Calvin C.
1989-01-01
Heat being transferred supplies operating power. Capillary-condenser-pumped heat-transfer loop similar to heat pipe and to capillary-evaporator-pumped heat-transfer loop in that heat-transfer fluid pumped by evaporation and condensation of fluid at heat source and sink, respectively. Capillary condenser pump combined with capillary evaporator pump to form heat exchanger circulating heat-transfer fluids in both loops. Transport of heat more nearly isothermal. Thermal stress in loop reduced, and less external surface area needed in condenser section for rejection of heat to heat sink.
Drug delivery device including electrolytic pump
Foulds, Ian G.
2016-03-31
Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.
Quantifying the energy impact of a variable flow pump in a ground-coupled heat pump system
Energy Technology Data Exchange (ETDEWEB)
Iolova, K.; Bernier, M.A. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique; Nichols, L. [Dessau-Soprin, Montreal, PQ (Canada)
2006-07-01
The thermal behaviour of an energy-efficient public high school building was modelled using the TRNSYS multi-zone building simulation program. The architectural elements such as windows, external and internal walls, roofs, and slabs were described in detail. The two-storey Ecole du Tournant high school near Montreal is the most efficient in Quebec and the second in Canada. It consumes 79.2 per cent less source energy than a typical high school built in accordance with the Model National Energy Code of Canada for Buildings. This presentation described the case study and quantified the energy impact of replacing a constant speed pump with a pump driven by a variable frequency drive in a ground-coupled heat pump (GCHP) system that was installed in the high school. Performance data collected from an on-site energy management system showed that the annual energy consumption of the heat pumps is 33 per cent (63700 kWh) of the total energy consumption of the school while the circulating pump consumes 7.1 per cent (13702 kWh). This performance data was used to validate the energy simulations which were performed using TRNSYS 15. Simulations with variable-flow pumping showed that pumping energy consumption was reduced by about 82 per cent while the total energy used by the circulating pump and heat pumps was reduced by 18.5 per cent. 11 refs., 2 tabs., 13 figs.
Design of Pumps for Water Hydraulic Systems
DEFF Research Database (Denmark)
Klit, Peder; Olsen, Stefan; Bech, Thomas Nørgaard
1999-01-01
This paper considers the development of two pumps for water hydraulic applications. The pumps are based on two different working principles: The Vane-type pump and the Gear-type pump. Emphasis is put on the considerations that should be made to account for water as the hydraulic fluid.......KEYWORDS: water, pump, design, vane, gear....
Energy Technology Data Exchange (ETDEWEB)
Lam, K F [Bruce Engineering Department, In-Service Nuclear Projects, Ontario Hydro, North York, ON (Canada)
1991-04-01
The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced.
International Nuclear Information System (INIS)
Lam, K.F.
1991-01-01
The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced
High efficiency, variable geometry, centrifugal cryogenic pump
International Nuclear Information System (INIS)
Forsha, M.D.; Nichols, K.E.; Beale, C.A.
1994-01-01
A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions
Measurements on a PV solar pump equipped with a piston pump with a matching valve
Smulders, P.T.; Ten Thije O.G. Boonkkamp, J.; Borg, van der N.J.C.M.; Beek, van M.
1997-01-01
The work on a simple high efficient solar pump equipped with a piston pump with a matching valve, reported at the Solar World Congress in Budapest, has been continued. Quasi-static and dynamic models of the solar pump have been derived with which the operation of the system is simulated. A test rig
Energy Technology Data Exchange (ETDEWEB)
1981-12-01
The fact that heat pumps do not achieve what their manufacturers promise in costs efficiency has been realized by the market. In 1981 the sales of heat pumps decreased by 50% of the 1980 market. Public utilities give the reason as economic, since fuel oil is too cheap. The author refutes this argument and presents arguments against heat pumps.
Direct solar-pumped iodine laser amplifier
Han, Kwang S.
1987-01-01
This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.
Increasing numbers of children and adolescents with type 1 diabetes (T1D) have been placed on insulin pump therapy. Nevertheless, data are limited regarding patterns of pump use during the first year of treatment and the clinical and socioeconomic factors associated with early use of pump therapy. T...
Removal of mixing pump in tank 102-AP -- pump drop onto central pit
International Nuclear Information System (INIS)
Jimenez, R.F.
1995-01-01
The mixing pump, if dropped in the pump pit following its removal from the tank, is incapable of compromising the tank structure either locally or in a structural displacement mode to an extent which might allow dispersion of the contents. A drop from 10 ft above the pit floor (considered the maximum credible height) of a pump which is considered perfectly rigid does not approach the required perforation velocity. The velocity required to perforate requires a drop height which is physically impossible to attain with existing cranes. An analysis of the location of the deposition of the strain energy required to match the pump's impact kinetic energy, the results of which are shown in Table 2, verifies that there is no credible chance for compromise of the tank roof by such a drop
Unsatisfactory hepatic perfusion after placement of the infusaid pump: Angiographic correlation
International Nuclear Information System (INIS)
Andrews, J.C.; Williams, D.M.; Cho, K.J.; Knol, J.A.; Wahl, R.L.; Ensminger, W.D.
1988-01-01
Complete perfusion limited to the liver is essential to the success of regional chemotherapy for hepatic malignancy. Thirty-three patients with unsatisfactory hepatic artery perfusion scintigrams after surgical placement of a pump and catheter system were evaluated with selective angiography (31 cases) or digital subtraction angiography (DSA) via the pump side port (six cases). The cause of the perfusion defect was hepatic artery thrombosis (14 cases), extrahepatic flow through collaterals (13 cases), misplaced catheter (three cases), short proper hepatic artery without adequate length for mixing (two cases), and undefined (one case). DSA findings were diagnostic in only two cases. Angiographic findings directed attempted correction in 22 of 33 cases
International Nuclear Information System (INIS)
Holzhueter, E.; Migod, A.; Siekmann, H.
1977-01-01
This contribution tries to present the various factors influencing the design of cooling tower pumps. As cooling tower pumps are very often designed as concrete speral casing pumps, the suction bend construction often offers itself. The running wheel of cooling tower pumps is usually of semi-axial design, whereby one has to differ between rigid, adjustable, and resetable running wheels. Finally, the type of cooling system and the nominal width are decisive for either the construction type of the spiral casing pump or the tubular type pump. Both methods are compared in a critical way. (orig.) [de
Proper Sizing of Circulation Pumps
DEFF Research Database (Denmark)
Tommerup, Henrik M.; Nørgaard, Jørgen
2007-01-01
The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust, but the r......The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust...
Alignment analysis of a vertical sodium pump
International Nuclear Information System (INIS)
Gupta, V.K.; Fair, C.E.
1981-01-01
With the objective of identifying important alignment features of pumps such as FFTF, HALLAM, EBR II, PNC, PHENIX, and CRBR, alignment of the vertical sodium pump for the Clinch River Breeder Reactor Plant (CRBRP) is investigated. The CRBRP pump includes a flexibly coupled pump shaft and motor shaft, two oil-film tilting-pad hydrodynamic radial bearings in the motor plus a vertical thrust bearing, and two sodium hydrostatic bearings straddling the double-suction centrifugal impeller in the pump. The assembled CRBRP prototype pump shows smooth predictable vibration behavior experienced during water test. An ealier swing check of the pump shaft about the motor shaft hub demonstrated that the pump is relatively insensitive to manufacturing and assembly tolerances, a consequence of close dimensional control and unique alignment features. (orig./GL)
Compact and highly efficient laser pump cavity
Chang, Jim J.; Bass, Isaac L.; Zapata, Luis E.
1999-01-01
A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.
International Nuclear Information System (INIS)
Strauss, P.L.
1991-01-01
The privately financed 1,000 MW Rocky Point Pumped Storage Project located in central Colorado, USA, will be one of the world's highest head, 2,350 feet reversible pump/turbine projects. The project will offer an economical supply of peaking power and spinning reserve power to Colorado and other southwestern states. This paper describes how the project will be made compatible with the environmental conditions in the project area and the type of terrestrial mitigation measures that are being proposed for those situations where the project impacts the environment, either temporarily or permanently
An optimized design of rectangle pumping cell for nuclear reactor pumped laser
International Nuclear Information System (INIS)
Wan, J.-S.; Chen, L.-X.; Zhao, Z.-M.; Pan, X.-B.; Jing, C.-Y.; Zhao, X.-Q.; Liu, F.-H.
2003-01-01
Basing on our research of energy deposition in RPL (Reactor Pumped Laser) pumping cell and the laser power efficiency, a RPL test device on Pulsed Reactor has been designed. In addition, the laser beam power of the RPL test device is estimated in the paper. (author)
Miniature Scroll Pumps Fabricated by LIGA
Wiberg, Dean; Shcheglov, Kirill; White, Victor; Bae, Sam
2009-01-01
Miniature scroll pumps have been proposed as roughing pumps (low - vacuum pumps) for miniature scientific instruments (e.g., portable mass spectrometers and gas analyzers) that depend on vacuum. The larger scroll pumps used as roughing pumps in some older vacuum systems are fabricated by conventional machining. Typically, such an older scroll pump includes (1) an electric motor with an eccentric shaft to generate orbital motion of a scroll and (2) conventional bearings to restrict the orbital motion to a circle. The proposed miniature scroll pumps would differ from the prior, larger ones in both design and fabrication. A miniature scroll pump would include two scrolls: one mounted on a stationary baseplate and one on a flexure stage (see figure). An electromagnetic actuator in the form of two pairs of voice coils in a push-pull configuration would make the flexure stage move in the desired circular orbit. The capacitance between the scrolls would be monitored to provide position (gap) feedback to a control system that would adjust the drive signals applied to the voice coils to maintain the circular orbit as needed for precise sealing of the scrolls. To minimize power consumption and maximize precision of control, the flexure stage would be driven at the frequency of its mechanical resonance. The miniaturization of these pumps would entail both operational and manufacturing tolerances of pump components. In addition, the vibrations of conventional motors and ball bearings exceed these tight tolerances by an order of magnitude. Therefore, the proposed pumps would be fabricated by the microfabrication method known by the German acronym LIGA ( lithographie, galvanoformung, abformung, which means lithography, electroforming, molding) because LIGA has been shown to be capable of providing the required tolerances at large aspect ratios.
Pumping tests in nonuniform aquifers - The radially symmetric case
Butler, J.J.
1988-01-01
Traditionally, pumping-test-analysis methodology has been limited to applications involving aquifers whose properties are assumed uniform in space. This work attempts to assess the applicability of analytical methodology to a broader class of units with spatially varying properties. An examination of flow behavior in a simple configuration consisting of pumping from the center of a circular disk embedded in a matrix of differing properties is the basis for this investigation. A solution describing flow in this configuration is obtained through Laplace-transform techniques using analytical and numerical inversion schemes. Approaches for the calculation of flow properties in conditions that can be roughly represented by this simple configuration are proposed. Possible applications include a wide variety of geologic structures, as well as the case of a well skin resulting from drilling or development. Of more importance than the specifics of these techniques for analysis of water-level responses is the insight into flow behavior during a pumping test that is provided by the large-time form of the derived solution. The solution reveals that drawdown during a pumping test can be considered to consist of two components that are dependent and independent of near-well properties, respectively. Such an interpretation of pumping-test drawdown allows some general conclusions to be drawn concerning the relationship between parameters calculated using analytical approaches based on curve-matching and those calculated using approaches based on the slope of a semilog straight line plot. The infinite-series truncation that underlies the semilog analytical approaches is shown to remove further contributions of near-well material to total drawdown. In addition, the semilog distance-drawdown approach is shown to yield an expression that is equivalent to the Thiem equation. These results allow some general recommendations to be made concerning observation-well placement for pumping
Quantum pump effect induced by a linearly polarized microwave in a two-dimensional electron gas.
Song, Juntao; Liu, Haiwen; Jiang, Hua
2012-05-30
A quantum pump effect is predicted in an ideal homogeneous two-dimensional electron gas (2DEG) that is normally irradiated by linearly polarized microwaves (MW). Without considering effects from spin-orbital coupling or the magnetic field, it is found that a polarized MW can continuously pump electrons from the longitudinal to the transverse direction, or from the transverse to the longitudinal direction, in the central irradiated region. The large pump current is obtained for both the low frequency limit and the high frequency case. Its magnitude depends on sample properties such as the size of the radiated region, the power and frequency of the MW, etc. Through the calculated results, the pump current should be attributed to the dominant photon-assisted tunneling processes as well as the asymmetry of the electron density of states with respect to the Fermi energy.
Liquid metal pump for nuclear reactors
International Nuclear Information System (INIS)
Allen, H.G.; Maloney, J.R.
1975-01-01
A pump for use in pumping high temperature liquids at high pressures, particularly liquid metals used to cool nuclear reactors is described. It is of the type in which the rotor is submerged in a sump but is fed by an inlet duct which bypasses the sump. A chamber, kept full of fluid, surrounds the pump casing into which fluid is bled from the pump discharge and from which fluid is fed to the rotor bearings and hence to the sump. This equalizes pressure inside and outside the pump casing and reduces or eliminates the thermal shock to the bearings and sump tank
Effective temporal resolution in pump-probe spectroscopy with strongly chirped pulses
International Nuclear Information System (INIS)
Polli, D.; Lanzani, G.; Brida, D.; Cerullo, G.; Mukamel, S.
2010-01-01
This paper introduces a general theoretical description of femtosecond pump-probe spectroscopy with chirped pulses whose joint spectral and temporal profile is expressed by Wigner spectrograms. We demonstrate that the actual experimental time resolution intimately depends on the pulse-sample interaction and that the commonly used instrumental response function needs to be replaced by a sample-dependent effective response function. We also show that, using the proper configurations in excitation and/or detection, it is possible to overcome the temporal smearing of the measured dynamics due to chirp-induced pulse broadening and recover the temporal resolution that would be afforded by the transform-limited pulses. We verify these predictions with experiments using broadband chirped pump and probe pulses. Our results allow optimization of the temporal resolution in the common case when the chirp of the pump and/or probe pulse is not corrected and may be extended to a broad range of time-resolved experiments.
Pumping liquid metal at high temperatures up to 1,673 kelvin
Amy, C.; Budenstein, D.; Bagepalli, M.; England, D.; Deangelis, F.; Wilk, G.; Jarrett, C.; Kelsall, C.; Hirschey, J.; Wen, H.; Chavan, A.; Gilleland, B.; Yuan, C.; Chueh, W. C.; Sandhage, K. H.; Kawajiri, Y.; Henry, A.
2017-10-01
Heat is fundamental to power generation and many industrial processes, and is most useful at high temperatures because it can be converted more efficiently to other types of energy. However, efficient transportation, storage and conversion of heat at extreme temperatures (more than about 1,300 kelvin) is impractical for many applications. Liquid metals can be very effective media for transferring heat at high temperatures, but liquid-metal pumping has been limited by the corrosion of metal infrastructures. Here we demonstrate a ceramic, mechanical pump that can be used to continuously circulate liquid tin at temperatures of around 1,473-1,673 kelvin. Our approach to liquid-metal pumping is enabled by the use of ceramics for the mechanical and sealing components, but owing to the brittle nature of ceramics their use requires careful engineering. Our set-up enables effective heat transfer using a liquid at previously unattainable temperatures, and could be used for thermal storage and transport, electric power production, and chemical or materials processing.
Transformation of vibration signals in rotary blood pumps: the diagnostic potential of pump failure.
Kawahito, Koji
2013-09-01
Although non-destructive and continuous monitoring is indispensable for long-term circulatory support with rotary blood pumps, a practical monitoring system has not yet been developed. The objective of this study was to investigate the possibility of detecting pump failure caused by thrombus formation through the monitoring of vibration signals. The data acquisition equipment included vibration pickups, a charge amplifier, vibration analysis systems, and exclusive hardware. A pivot-bearing centrifugal pump with a mock circuit was investigated for vibration analysis. To simulate the four common areas of thrombus formation, we used a piece of silicon attached to each of the following four locations: the total area of the bottom of the impeller, an eccentric shape on the bottom of the impeller, a circular shape around the shaft top, and an eccentric shape on the top of the impeller. Vibration signals were picked up, and the power spectrum density analysis was performed at pump rotational speeds of 2100, 2400, and 3000 rpm. In this study, pump failure could be detected, and the types of imitation thrombi could be determined. We conclude that vibration detection with a computerized analysis system is a potentially valuable diagnostic tool for long-term circulatory support with rotary blood pumps.
Simulations of longitudinally pumped dye laser amplifier
International Nuclear Information System (INIS)
Takehisa, Kiwamu; Takemori, Satoshi
1995-01-01
Simulations of a copper laser pumped dye laser amplifier and new designs of the longitudinally pumped dye laser amplifier are presented. The simulations take the consideration of the amplified spontaneous emission (ASE). The new designs utilize a center-hole reflector instead of a dichroic mirror. The simulation results indicate that the poor spatial overlap between the pump beam and the dye beam in the transverse pumping not only reduces the laser output power, but also generates ASE strongly. The results also indicate that the longitudinal pumping is as efficient as the transverse pumping. (author)
Advanced heat pumps and their economic aspects. The case for super heat pump
International Nuclear Information System (INIS)
Yabe, Akira; Akiya, Takaji
1996-01-01
The results of the economic evaluation of the Super Heat Pump Energy Accumulation System project in Japan are reviewed. It is reported that although the initial costs of super heat pumps are higher than those of conventional systems, the calculated operating costs of a unit thermal energy produced by a super heat pump is reduced considerably. All the various system concepts with thermal/chemical storage were evaluated economically with the exception of the high temperature thermal storage systems using salt ammonia complexes and solvation. These latter systems were not further developed as pilot plants. It is advocated to accelerate the introduction of super heat pumps by facilitating their market introduction. Actual clathrate chemical storage systems have shown that the annual costs are comparable to those of an ice storage system. Clathrate systems will find their way in the market. It is concluded that most of the super heat pump systems and clathrate storage systems will be economic in the future. A big challenge however still exists in further improving the cost effectiveness of heat storage in tanks by reducing their size dramatically (to 1/10th)
Entropy, pumped-storage and energy system finance
Karakatsanis, Georgios
2015-04-01
Pumped-storage holds a key role for integrating renewable energy units with non-renewable fuel plants into large-scale energy systems of electricity output. An emerging issue is the development of financial engineering models with physical basis to systematically fund energy system efficiency improvements across its operation. A fundamental physically-based economic concept is the Scarcity Rent; which concerns the pricing of a natural resource's scarcity. Specifically, the scarcity rent comprises a fraction of a depleting resource's full price and accumulates to fund its more efficient future use. In an integrated energy system, scarcity rents derive from various resources and can be deposited to a pooled fund to finance the energy system's overall efficiency increase; allowing it to benefit from economies of scale. With pumped-storage incorporated to the system, water upgrades to a hub resource, in which the scarcity rents of all connected energy sources are denominated to. However, as available water for electricity generation or storage is also limited, a scarcity rent upon it is also imposed. It is suggested that scarcity rent generation is reducible to three (3) main factors, incorporating uncertainty: (1) water's natural renewability, (2) the energy system's intermittent components and (3) base-load prediction deviations from actual loads. For that purpose, the concept of entropy is used in order to measure the energy system's overall uncertainty; hence pumped-storage intensity requirements and generated water scarcity rents. Keywords: pumped-storage, integration, energy systems, financial engineering, physical basis, Scarcity Rent, pooled fund, economies of scale, hub resource, uncertainty, entropy Acknowledgement: This research was funded by the Greek General Secretariat for Research and Technology through the research project Combined REnewable Systems for Sustainable ENergy DevelOpment (CRESSENDO; grant number 5145)
Advances in heat pump systems: A review
International Nuclear Information System (INIS)
Chua, K.J.; Chou, S.K.; Yang, W.M.
2010-01-01
Heat pump systems offer economical alternatives of recovering heat from different sources for use in various industrial, commercial and residential applications. As the cost of energy continues to rise, it becomes imperative to save energy and improve overall energy efficiency. In this light, the heat pump becomes a key component in an energy recovery system with great potential for energy saving. Improving heat pump performance, reliability, and its environmental impact has been an ongoing concern. Recent progresses in heat pump systems have centred upon advanced cycle designs for both heat- and work-actuated systems, improved cycle components (including choice of working fluid), and exploiting utilisation in a wider range of applications. For the heat pump to be an economical proposition, continuous efforts need to be devoted to improving its performance and reliability while discovering novel applications. Some recent research efforts have markedly improved the energy efficiency of heat pump. For example, the incorporation of a heat-driven ejector to the heat pump has improved system efficiency by more than 20%. Additionally, the development of better compressor technology has the potential to reduce energy consumption of heat pump systems by as much as 80%. The evolution of new hybrid systems has also enabled the heat pump to perform efficiently with wider applications. For example, incorporating a desiccant to a heat pump cycle allowed better humidity and temperature controls with achievable COP as high as 6. This review paper provides an update on recent developments in heat pump systems, and is intended to be a 'one-stop' archive of known practical heat pump solutions. The paper, broadly divided into three main sections, begins with a review of the various methods of enhancing the performance of heat pumps. This is followed by a review of the major hybrid heat pump systems suitable for application with various heat sources. Lastly, the paper presents novel
Pitfalls of Insulin Pump Clocks
Reed, Amy J.
2014-01-01
The objective was to raise awareness about the importance of ensuring that insulin pumps internal clocks are set up correctly at all times. This is a very important safety issue because all commercially available insulin pumps are not GPS-enabled (though this is controversial), nor equipped with automatically adjusting internal clocks. Special attention is paid to how basal and bolus dose errors can be introduced by daylight savings time changes, travel across time zones, and am-pm clock errors. Correct setting of insulin pump internal clock is crucial for appropriate insulin delivery. A comprehensive literature review is provided, as are illustrative cases. Incorrect setting can potentially result in incorrect insulin delivery, with potential harmful consequences, if too much or too little insulin is delivered. Daylight saving time changes may not significantly affect basal insulin delivery, given the triviality of the time difference. However, bolus insulin doses can be dramatically affected. Such problems may occur when pump wearers have large variations in their insulin to carb ratio, especially if they forget to change their pump clock in the spring. More worrisome than daylight saving time change is the am-pm clock setting. If this setting is set up incorrectly, both basal rates and bolus doses will be affected. Appropriate insulin delivery through insulin pumps requires correct correlation between dose settings and internal clock time settings. Because insulin pumps are not GPS-enabled or automatically time-adjusting, extra caution should be practiced by patients to ensure correct time settings at all times. Clinicians and diabetes educators should verify the date/time of insulin pumps during patients’ visits, and should remind their patients to always verify these settings. PMID:25355713
Directory of Open Access Journals (Sweden)
Kazuki Sato
2015-04-01
Full Text Available The iron acquisition systems in Pseudomonas aeruginosa are inducible in response to low-iron conditions and important for growth of this organism under iron limitation. OprM is the essential outer membrane subunit of the MexAB-OprM xenobiotic efflux pump. We designed and constructed a new model antimicrobial screening system targeting both the iron-uptake system and xenobiotic efflux pumps. The oprM gene was placed immediately downstream of the ferri-pyoverdine receptor gene, fpvA, in the host lacking chromosomal oprM and the expression of oprM was monitored by an antibiotic susceptibility test under iron depleted and replete conditions. The recombinant cells showed wild-type susceptibility to pump substrate antibiotics, e.g., aztreonam, under iron limitation and became supersusceptible to them under iron repletion, suggesting that expression of oprM is under control of the iron acquisition system. Upon screening of a chemical library comprising 2952 compounds using this strain, a compound—ethyl 2-(1-acetylpiperidine-4-carboxamido-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate—was found to enhance the efficacy of aztreonam under iron limitation, suggesting that the compound inhibits either the iron acquisition system or the MexAB-OprM efflux pump. This compound was subsequently found to inhibit the growth of wild-type cells in the presence of sublethal amounts of aztreonam, regardless of the presence or absence of dipyridyl, an iron-chelator. The compound was eventually identified to block the function of the MexAB-OprM efflux pump, showing the validity of this new method.
Sato, Kazuki; Ushioda, Kenichi; Akiba, Keiji; Matsumoto, Yoshimi; Maseda, Hideaki; Ando, Tasuke; Isogai, Emiko; Nakae, Taiji; Yoneyama, Hiroshi
2015-04-29
The iron acquisition systems in Pseudomonas aeruginosa are inducible in response to low-iron conditions and important for growth of this organism under iron limitation. OprM is the essential outer membrane subunit of the MexAB-OprM xenobiotic efflux pump. We designed and constructed a new model antimicrobial screening system targeting both the iron-uptake system and xenobiotic efflux pumps. The oprM gene was placed immediately downstream of the ferri-pyoverdine receptor gene, fpvA, in the host lacking chromosomal oprM and the expression of oprM was monitored by an antibiotic susceptibility test under iron depleted and replete conditions. The recombinant cells showed wild-type susceptibility to pump substrate antibiotics, e.g., aztreonam, under iron limitation and became supersusceptible to them under iron repletion, suggesting that expression of oprM is under control of the iron acquisition system. Upon screening of a chemical library comprising 2952 compounds using this strain, a compound-ethyl 2-(1-acetylpiperidine-4-carboxamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate-was found to enhance the efficacy of aztreonam under iron limitation, suggesting that the compound inhibits either the iron acquisition system or the MexAB-OprM efflux pump. This compound was subsequently found to inhibit the growth of wild-type cells in the presence of sublethal amounts of aztreonam, regardless of the presence or absence of dipyridyl, an iron-chelator. The compound was eventually identified to block the function of the MexAB-OprM efflux pump, showing the validity of this new method.
Cour, M; Hernu, R; Bénet, T; Robert, J M; Regad, D; Chabert, B; Malatray, A; Conrozier, S; Serra, P; Lassaigne, M; Vanhems, P; Argaud, L
2013-11-01
Manual changeover of vasoactive drug infusion pumps (CVIP) frequently lead to haemodynamic instability. Some of the newest smart pumps allow automated CVIP. The aim of this study was to compare automated CVIP with manual 'Quick Change' relays. We performed a prospective, quasi-experimental study, in a university-affiliated intensive care unit (ICU). All adult patients receiving continuous i.v. infusion of vasoactive drugs were included. CVIP were successively performed manually (Phase 1) and automatically (Phase 2) during two 6-month periods. The primary endpoint was the frequency of haemodynamic incidents related to the relays, which were defined as variations of mean arterial pressure >15 mm Hg or heart rate >15 bpm. The secondary endpoints were the nursing time dedicated to relays and the number of interruptions in care because of CVIP. A multivariate mixed effects logistic regression was fitted for analytic analysis. We studied 1329 relays (Phase 1: 681, Phase 2: 648) from 133 patients (Phase 1: 63, Phase 2: 70). Incidents related to CVIP decreased from 137 (20%) in Phase 1 to 73 (11%) in Phase 2 (Ppumps in limiting the frequency of haemodynamic incidents related to relays and in reducing the nursing workload.
Tendency of nuclear pumps for PWR primary system
International Nuclear Information System (INIS)
Shibata, Takeshi
1976-01-01
At present, large PWR power stations of more than 1,000 MW are successively constructed, and the pumps used there have become large. The progress and tendency of the technical development of main pumps in primary system are described. The increase of the capacity of power stations is accomplished by increasing the circulating coolant quantity per loop or the number of loops. Same standard primary coolant pumps are employed in the plants from 500 to 1,100 MW. The type of primary coolant pumps changed from canned type to shaft seal type, and the advantages of the shaft seal type are cheap production cost, high efficiency, and the easy utilization of inertia force. The bearings and shaft seals are thermally insulated from primary coolant. As for auxiliary pumps, reciprocating filling-up pumps and centrifugal high pressure injection pumps are used for 500 MW plants, but only centrifugal pumps are used for both purposes in 800 MW plants, and in 1,100 MW plants, the pumps of both types for separate purposes and centrifugal pumps for combined purposes are installed. Horizontal or vertical pumps of same type are used as containment vessel-spraying pumps and excess heat-eliminating pumps. The type of boric acid pumps changed from canned type to mechanical seal type. (Kako, I.)
Effects of Crust Ingestion on Mixer Pump Performance in Tank 241-SY-101: Workshop Results
International Nuclear Information System (INIS)
Brennen, C.E.; Stewart, C.W.; Meyer, P.A.
1999-01-01
In August 1999, a workshop was held at Pacific Northwest National Laboratory to discuss the effects of crust ingestion on mixer pump performance in Hanford Waste Tank 241-SY-101. The main purpose of the workshop was to evaluate the potential for crust ingestion to degrade mixing and/or damage the mixer pump. The need for a previously determined 12-inch separation between the top of the mixer pump inlet and the crust base was evaluated. Participants included a representative from the pump manufacturer, an internationally known expert in centrifugal pump theory, Hanford scientists and engineers, and operational specialists representing relevant fields of expertise. The workshop focused on developing an understanding of the pump design, addressing the physics of entrainment of solids and gases into the pump, and assessing the effects of solids and gases on pump performance. The major conclusions are summarized as follows: (1) Entrainment of a moderate amount of solids or gas from the crust should not damage the pump or reduce its lifetime, though mixing effectiveness will be somewhat reduced. (2) Air binding should not damage the pump. Vibrations due to ingestion of gas, solids, and objects potentially could cause radial loads that might reduce the lifetime of bearings and seals. However, significant damage would require extreme conditions not associated with the small bubbles, fine solids, and chunks of relatively weak material typical of the crust. (3) The inlet duct extension opening, 235 inches from the tank bottom, should be considered the pump inlet, not the small gap at 262 inches. (4) A suction vortex exists at the inlet of all pumps. The characteristics of the inlet suction vortex in the mixer pump are very hard to predict, but its effects likely extend upward several feet. Because of this, the current 12-inch limit should be replaced with criteria based on actual monitored pump performance. The most obvious criterion (in addition to current operational
Absorption heat pump for space applications
Nguyen, Tuan; Simon, William E.; Warrier, Gopinath R.; Woramontri, Woranun
1993-01-01
In the first part, the performance of the Absorption Heat Pump (AHP) with water-sulfuric acid and water-magnesium chloride as two new refrigerant-absorbent fluid pairs was investigated. A model was proposed for the analysis of the new working pairs in a heat pump system, subject to different temperature lifts. Computer codes were developed to calculate the Coefficient of Performance (COP) of the system with the thermodynamic properties of the working fluids obtained from the literature. The study shows the potential of water-sulfuric acid as a satisfactory replacement for water-lithium bromide in the targeted temperature range. The performance of the AHP using water-magnesium chloride as refrigerant-absorbent pair does not compare well with those obtained using water-lithium bromide. The second part concentrated on the design and testing of a simple ElectroHydrodynamic (EHD) Pump. A theoretical design model based on continuum electromechanics was analyzed to predict the performance characteristics of the EHD pump to circulate the fluid in the absorption heat pump. A numerical method of solving the governing equations was established to predict the velocity profile, pressure - flow rate relationship and efficiency of the pump. The predicted operational characteristics of the EHD pump is comparable to that of turbomachinery hardware; however, the overall efficiency of the electromagnetic pump is much lower. An experimental investigation to verify the numerical results was conducted. The pressure - flow rate performance characteristics and overall efficiency of the pump obtained experimentally agree well with the theoretical model.
Mono pump equipment evaluation report
International Nuclear Information System (INIS)
1992-01-01
A mobile pump has been designed, developed, and tested as part of an effort to increase oil spill response time, improve oil/water recovery efficiency and reduce cleanup and reclamation costs. The pump is mounted on an engine powered track carrier, and can be detached from the carrier and skidded into remote spill sites or transported by helicopter. The pump can safely recover highly volatile flammable substances such as condensate and gasoline, as well as heavy crude oil up to 5000 centipoise viscosity. It can pump up to 30 gal/min at zero head, and up to 1000 feet in a vertical direction. 13 figs
Multi-channel peristaltic pump for microfluidic applications featuring monolithic PDMS inlay
DEFF Research Database (Denmark)
Skafte-Pedersen, Peder; Sabourin, David; Dufva, Martin
2009-01-01
pumping system at lower flow rates. The small footprint, 40 mm by 80 mm, of the micropump renders it portable, and allows its use on microscope stages adjacent to microfluidic devices, thus reducing system dead volumes. The micropump's design allows potential use in remote and resource-limited locations...
Hydrostatic radial bearing of centrifugal pump
International Nuclear Information System (INIS)
Skalicky, A.
1976-01-01
A hydrostatic radial pump is described characterized by the fact that part of the medium off-taken from delivery is used as a lubricating medium. Two additional bodies are placed alongside a hydrostatic bearing with coils in between them and the pump shaft; the coils have an opposite pitch. The feed channel for the hydrostatic bearing pocket is linked to delivery. The coil outlets are connected to the pump suction unit. Two rotating coils placed alongside the hydrostatic bearing will considerably simplify the communication channel design and reduce the dependence on the pump shaft deflections. The addition of another rotating coil in the close vicinity of the pump shaft or directly on the shaft further increases the efficiency. The bearing can be used in designing vertical circulating pumps for the cooling circuits of nuclear reactors. (J.B.)
Geothermal heat pumps - Trends and comparisons
Energy Technology Data Exchange (ETDEWEB)
Lund, John W
1989-01-01
Heat pumps are used where geothermal water or ground temperatures are only slightly above normal, generally 50 to 90 deg. F. Conventional geothermal heating (and cooling) systems are not economically efficient at these temperatures. Heat pumps, at these temperatures, can provide space heating and cooling, and with a desuperheater, domestic hot water. Two basic heat pump systems are available, air-source and water- or ground-source. Water- and ground-coupled heat pumps, referred to as geothermal heat pumps (GHP), have several advantages over air-source heat pumps. These are: (1) they consume about 33% less annual energy, (2) they tap the earth or groundwater, a more stable energy source than air, (3) they do not require supplemental heat during extreme high or low outside temperatures, (4) they use less refrigerant (freon), and (5) they have a simpler design and consequently less maintenance.
Evaluation of personal air sampling pumps
International Nuclear Information System (INIS)
Ritter, P.D.; Novick, V.J.; Alvarez, J.L.; Huntsman, B.L.
1987-01-01
Personal air samplers are used to more conveniently obtain breathing zone samples from individuals over periods of several hours. Personal air sampling pumps must meet minimum performance levels under all working conditions to be suitable for use in radiation protection programs. In addition, the pumps should be simple to operate and as comfortable to wear as possible. Ten models of personal air sampling pumps were tested to evaluate their mechanical performance and physical characteristics. The pumps varied over a wide range in basic performance and operating features. Some of the pumps were found to have adequate performance for use in health physics air sampling applications. 3 references, 2 figures, 5 tables
Centrifugal pumps and allied machinery
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.
Modeling and Optimization of a CoolingTower-Assisted Heat Pump System
Directory of Open Access Journals (Sweden)
Xiaoqing Wei
2017-05-01
Full Text Available To minimize the total energy consumption of a cooling tower-assisted heat pump (CTAHP system in cooling mode, a model-based control strategy with hybrid optimization algorithm for the system is presented in this paper. An existing experimental device, which mainly contains a closed wet cooling tower with counter flow construction, a condenser water loop and a water-to-water heat pump unit, is selected as the study object. Theoretical and empirical models of the related components and their interactions are developed. The four variables, viz. desired cooling load, ambient wet-bulb temperature, temperature and flow rate of chilled water at the inlet of evaporator, are set to independent variables. The system power consumption can be minimized by optimizing input powers of cooling tower fan, spray water pump, condenser water pump and compressor. The optimal input power of spray water pump is determined experimentally. Implemented on MATLAB, a hybrid optimization algorithm, which combines the Limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS algorithm with the greedy diffusion search (GDS algorithm, is incorporated to solve the minimization problem of energy consumption and predict the system’s optimal set-points under quasi-steady-state conditions. The integrated simulation tool is validated against experimental data. The results obtained demonstrate the proposed operation strategy is reliable, and can save energy by 20.8% as compared to an uncontrolled system under certain testing conditions.
A finite element model for temperature induced electrohydrodynamic pumping horizontal pipes
International Nuclear Information System (INIS)
Kuo, B.S.; Chato, J.C.; Crowley, J.M.
1984-01-01
The electrohydrodynamic (EHD) pumping created by an axially traveling electric wave superimposed on a dielectric fluid with a transverse temperature field has abeen investigated using a finite element technique. Both forward wave (cooled wall) and backward wave (heated wall) modes of operation have been considered. The secondary flow generated by buoyancy effects in the cross section were included in the calculations. The driving effects of the traveling wave were calculated by assuming that only the average electric shear stress produced movement while the sinusoidally varying transient effects cancelled out. The results show that effective pumping can be achieved without the use of a grounding electrode along the axis of the tube but the design parameters have to be carefully selected. Increasing the diameter-to-wavelength ratios increases the velocities. The flow rate is maximum at an optimum frequency, about 0.8 Hz in our typical cases, but it drops off rather quickly as he frequency is either decreased or increased. The velocities were much less sensitive to heating/cooling rates (i.e., Rayleigh numbers) or changes in the magnitude of the electrical conductivity values. Although the pumping effect increases approximately as the square of the maximum applied electric potential, in practice, the electric gradients are limited by the dielectric strength of the fluid. The results indicate the EHD heat exchanger/pumps can be feasible alternatives to mechanical pumps in certain circumstances when dielectric liquids require both heat transfer and circulation
Syroid, Noah; Liu, David; Albert, Robert; Agutter, James; Egan, Talmage D; Pace, Nathan L; Johnson, Ken B; Dowdle, Michael R; Pulsipher, Daniel; Westenskow, Dwayne R
2012-11-01
Drug administration errors are frequent and are often associated with the misuse of IV infusion pumps. One source of these errors may be the infusion pump's user interface. We used failure modes-and-effects analyses to identify programming errors and to guide the design of a new syringe pump user interface. We designed the new user interface to clearly show the pump's operating state simultaneously in more than 1 monitoring location. We evaluated anesthesia residents in laboratory and simulated environments on programming accuracy and error detection between the new user interface and the user interface of a commercially available infusion pump. With the new user interface, we observed the number of programming errors reduced by 81%, the number of keystrokes per task reduced from 9.2 ± 5.0 to 7.5 ± 5.5 (mean ± SD), the time required per task reduced from 18.1 ± 14.1 seconds to 10.9 ± 9.5 seconds and significantly less perceived workload. Residents detected 38 of 70 (54%) of the events with the new user interface and 37 of 70 (53%) with the existing user interface, despite no experience with the new user interface and extensive experience with the existing interface. The number of programming errors and workload were reduced partly because it took less time and fewer keystrokes to program the pump when using the new user interface. Despite minimal training, residents quickly identified preexisting infusion pump problems with the new user interface. Intuitive and easy-to-program infusion pump interfaces may reduce drug administration errors and infusion pump-related adverse events.
METHOD FOR OPTIMIZING THE ENERGY OF PUMPS
Skovmose Kallesøe, Carsten; De Persis, Claudio
2013-01-01
The device for energy-optimization on operation of several centrifugal pumps controlled in rotational speed, in a hydraulic installation, begins firstly with determining which pumps as pilot pumps are assigned directly to a consumer and which pumps are hydraulically connected in series upstream of
Electrostatic coupling of ion pumps.
Nieto-Frausto, J; Lüger, P; Apell, H J
1992-01-01
In this paper the electrostatic interactions between membrane-embedded ion-pumps and their consequences for the kinetics of pump-mediated transport processes have been examined. We show that the time course of an intrinsically monomolecular transport reaction can become distinctly nonexponential, if the reaction is associated with charge translocation and takes place in an aggregate of pump molecules. First we consider the electrostatic coupling of a single dimer of ion-pumps embedded in the membrane. Then we apply the treatment to the kinetic analysis of light-driven proton transport by bacteriorhodopsin which forms two-dimensional hexagonal lattices. Finally, for the case of nonordered molecules, we also consider a model in which the pumps are randomly distributed over the nodes of a lattice. Here the average distance is equal to that deduced experimentally and the elemental size of the lattice is the effective diameter of one single pump. This latter model is applied to an aggregate of membrane-embedded Na, K- and Ca-pumps. In all these cases the electrostatic potential considered is the exact solution calculated from the method of electrical images for a plane membrane of finite thickness immersed in an infinite aqueous solution environment. The distributions of charges (ions or charged binding sites) are considered homogeneous or discrete in the membrane and/or in the external solution. In the case of discrete distributions we compare the results from a mean field approximation and a stochastic simulation.
Pojar, Marek; Mand'ák, Jirí; Cibícek, Norbert; Lonský, Vladimír; Dominik, Jan; Palicka, Vladimír; Kubícek, Jaroslav
2008-05-01
The aim of this study was to monitor and compare metabolic changes in the skeletal muscle during coronary artery bypass grafting surgery with and without cardiopulmonary bypass (CPB) by means of interstitial microdialysis. Glucose, lactate, pyruvate and glycerol were assessed as markers of basic metabolism and tissue perfusion. Twenty patients undergoing surgical myocardial revascularization were enrolled in this pilot study. Ten patients were operated on without CPB (group A, off-pump) and 10 patients using normothermic CPB (group B, on-pump). Interstitial microdialysis was performed by a CMA 60 (CMA/Microdialysis AB, Sweden) probe, inserted into the patient's left deltoid muscle. Microdialysis measurements were performed at 30 min intervals. Glucose, lactate, pyruvate and glycerol were measured in samples using a CMA 600 Analyser (CMA/Microdialysis AB, Sweden). Results in both groups were statistically processed and the groups were compared. Both groups were similar with regards to preoperative characteristics. Dynamic changes of interstitial concentrations of the measured analytes were found in off-pump (group A) and on-pump (group B) patients during the operation. There were no significant differences in dialysate concentrations of glucose and lactate between the groups. Significant differences were detected in pyruvate concentrations, lactate-pyruvate ratio and glycerol concentrations between off-pump versus on-pump patients. Pyruvate concentrations were higher in the off-pump group (plactate-pyruvate ratios indicating the aerobic/anaerobic metabolism status were lower in the off-pump group (pglucose, glycerol, pyruvate and lactate were found in both groups of patients (off-pump and on-pump). The presented preliminary results suggest that extracorporeal circulation during cardiac operations could compromise skeletal muscle energy metabolism.
International Nuclear Information System (INIS)
Priestman, G.H.
1990-01-01
A fluidic pump has primary and secondary vessels connected by a pipe, a displacement vessel having liquid to be delivered through a pipe via a rectifier provided with a feed tank. A drive unit delivers pressure fluid to a line to raise liquid and compress trapped gas or liquid in the space, including the pipe between the liquids in the two vessels and thus drive liquid out of the displacement vessel. The driving gas is therefore separated by the barrier liquid and the trapped gas or liquid from the liquid to be pumped which liquid could be e.g. radioactive. (author)
Mechanical design of the recirculating, terminal pumping in the Lund ...
Indian Academy of Sciences (India)
An extremly limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass spectrometry, will be ...
System control fuzzy neural sewage pumping stations using genetic algorithms
Directory of Open Access Journals (Sweden)
Владлен Николаевич Кузнецов
2015-06-01
Full Text Available It is considered the system of management of sewage pumping station with regulators based on a neuron network with fuzzy logic. Linguistic rules for the controller based on fuzzy logic, maintaining the level of effluent in the receiving tank within the prescribed limits are developed. The use of genetic algorithms for neuron network training is shown.
International Nuclear Information System (INIS)
Terada, Keiko; Okano, Tatsuo; Tsuji, Hiroshi.
1989-01-01
The conductance modulation method is designed to determine the pumping speed from a known conductance. With the method, the intrinsic pumping speed Sp and net pumping speed S * can be determined in a wide range up to near the ultimate pressure. In the present study, the pumping speed and gas discharge rate of a titanium getter pump at 77K are analyzed, and the results are compared with measurements made at room temperature. The pressure in a vacuum chamber depends on the gas load and the pumping speed. The pressure varies from P A to P B as the conductance of the orifice is changed from C A to C B . The ultimate pressure also changes from P AO to P BO . The intrinsic and net pumping speeds can be calculated from P A , P B , P AO and P BO . The major feature of the conductance modulation method is that the intrinsic and net pumping speeds can be determined from a change in the conductance without knowing the sensitivity of the vacuum meter or the flow rate of gas entering the chamber from outside. With this feature, the method is very effective for measuring the balance between the gas discharge and pumping speed near the ultimate pressure. (N.K.)
Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control
Kim, Gi-Woo; Wang, K. W.
2007-04-01
The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.