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Title: Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored withmore » a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.« less
Authors:
; ; ; ; ; ;  [1] ; ;  [2] ; ;  [3] ;  [4]
  1. Fusion and Materials for Nuclear System Division, Oak Ridge National Laboratory, Oak Ridge (United States)
  2. U.S. ITER Project Office, Oak Ridge National Laboratory, Oak Ridge (United States)
  3. ITER Organization, 13115 St. Paul-lez-Durance (France)
  4. Consultant, Grenoble (France)
Publication Date:
OSTI Identifier:
22263985
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1573; Journal Issue: 1; Conference: International cryogenic materials conference, Anchorage, AK (United States), 17-21 Jun 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; COMPRESSORS; DESIGN; DEUTERIUM; EVALUATION; HELIUM; ITER TOKAMAK; MIXERS; STAINLESS STEELS; STREAMS; TUBES; VACUUM PUMPS; VACUUM SYSTEMS