排序方式: 共有54条查询结果,搜索用时 15 毫秒
41.
42.
Gas mixing and solids mixing were studied in a geometrically and dynamically scaled cold model fluid coker stripper. Tracer gas (helium) was first injected into the stripper standpipe to quantify total gas entrainment into the underflow stream. Tracer gas was then injected into the upper reactor and lower stripper separately to investigate gas mixing in the stripper. The stripping efficiency was found to depend strongly on operating conditions (solids circulation rate, stripping gas velocity) as well as on the baffle configuration in the stripper. Unsteady state measurements were also obtained in an effort to understand gas dispersion in the stripper. The results show that gas mixing is most intensive in the stripper core. To study solids mixing and residence time distribution in the stripper, solid tracer particles impregnated with salt were injected into the reactor and detected at the top of the stripper and standpipe. The results indicate that axial dispersion of solids in the presence of the baffles could be represented by axially dispersed plug flow. 相似文献
43.
长庆榆林气田有低产气井(配产≤2×104m3/d)44口,占总井数的44.45%。为合理开发气田,在总结气田开采以来低产井生产特征及经济成本构成的基础上,对单井技术配产和单井经济产量配产分别进行了论述,确定了气井合理开发保本产量,并对保本产量以上和以下低产气井合理开发进行了经济技术探讨,为充分发挥低产气井产能,促进科学、高效开发气田提供了相应对策。 相似文献
44.
45.
T. Spickermann M.J. Borden R.J. Macek R.W. Shaw C.S. Feigerle I. Sugai 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,590(1-3):25
To accumulate high-intensity proton pulses, the Los Alamos Proton Storage Ring (PSR) uses the charge-exchange injection method. H− ions merge with already circulating protons in a bending magnet, and then are stripped off their two electrons in a carbon stripper foil. The circulating protons continue to interact with the foil. Despite efforts to minimize the number of these foil hits, like “painting” of the vertical phase space, they cannot totally be eliminated. As a result, foil heating and probably also radiation damage limit the lifetime of these foils. In recent years, LANL has collaborated with KEK to improve the carbon foils in use at PSR, and these foils now last typically for about 2 months. Recently, an alternative in the form of corrugated diamond foils has been proposed for use at SNS. These foils have now been tested in PSR production for a year, and have already shown to be at least as enduring as the LANL/KEK carbon foils. Advantages of the diamond foil concept, as well as some noteworthy differences that we observed with respect to the LANL carbon foils, will be discussed here. 相似文献
46.
Yasuhiro Takeda Michikazu Kinsho Jyunichiro Kamiya Isao Sugai Yoshiro Irie Osamu Takeda Hiroki Takahashi 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,590(1-3):213
The Japan Proton Accelerator Research Complex (J-PARC) has been under construction in Tokai-mura, Ibaraki, Japan. Three independent charge stripper devices are set up at the injection line of the 3 GeV Rapid Cycling Synchrotron (RCS). The H− beam accelerated by a 181 MeV Linac is charge-exchanged to a H+ beam by the first stripper foil, and then injected into the RCS. The H0 and H− fractions of the beam, which are not stripped by the first stripper foil, are converted into a H+ beam by the second and the third stripper foils.We have designed the charge exchange devices by adopting the transfer-rod system for moving the foils in a vacuum. We have fabricated a new type of transfer-rod, which can move over a distance of 1500 mm.We have also developed a new telescope system to observe possible wrinkles and pinholes of the foil. The system withstands more than 1 MGy of radiation dose and has a resolution of 250 μm at a distance of 10 m from an object. 相似文献
47.
48.
49.
A.G. Muirhead J.K. Heighway 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,655(1):61-63
It is easy to say “Just float and mount the carbon foils". However learning the art can be more difficult than old masters have shown it to be. In this article we will share our experience of some difficulties we have had at Australian National University (ANU). We also present results from some in beam endurance testing of foils using carbon supplied by Vacuum Technology (Germany), Micromatter (Canada) and those made at the ANU (Australia). 相似文献
50.
Connie S. Jolivet Shawn A. Miller John O. Stoner Jr. Peter Ladd 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,590(1-3):47
The Spallation Neutron Source (SNS) currently under construction at Oak Ridge National Laboratory, Oak Ridge, Tennessee, is planned to initially utilize carbon stripper foils having areal densities approximately 260 μg/cm2. The projected design requires that each foil be supported by only one fixed edge. For stability of the foil, additional support is to be provided by carbon fibers. The feasibility of manufacturing and shipping such mounted carbon foils produced by arc evaporation was studied using two prototypes. Production of the foils is described. Fibers were chosen for satisfactory mechanical strength consistent with minimal interference with the SNS beam. Mounting of the fibers, and packaging of the assemblies for shipping are described. Ten completed assemblies were shipped to SNS for further testing. Preliminary evaluation of the survivability of the foils in the SNS foil changer is described. 相似文献