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Title: Continuous flow system for controlling phases separation near λ transition

As demands on 3He are increasing and conventional 3He production through tritium decay is decreasing, alternative 3He production methods are becoming economically viable. One such possibility is to use entropy filters for extraction of the 3He isotope from natural gas. According to the phase diagram of the 3He, its solidification is impossible by only lowering of the temperature. Hence during the cooling process at stable pressure we can reach λ-point and pass to the special phase - He II. The total density of HeII is a sum of the two phases: normal the superfluid ones. It is possible to separate these two phases with an entropy filter - the barrier for the classically-behaving normal phase. This barrier can also be used to separate the two main isotopes of He: 4He and 3He, because at temperatures close to the 4He-λ-point the 3He isotope is part of the normal phase. The paper presents continuous flow schemes of different separation methods of 3He from helium commodity coming from natural gas cryogenic processing. An overall thermodynamic efficiency of the 3He/4He separation process is presented. A simplified model of continuous flow HeI -HeII recuperative heat exchanger is given. Ceramic and carbon porous plugs have beenmore » tested in entropy filter applications.« less
Authors:
;  [1] ; ; ;  [2] ; ;  [3]
  1. Wrocław University of Technology, Wybrzeże Wyspiańskiego 27,50-560 Wrocław (Poland)
  2. Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17,60-179 Poznań (Poland)
  3. Polish Oil and Gas Company, Odolanow, ul. Krotoszynska 148, 63-430 Odolanow (Poland)
Publication Date:
OSTI Identifier:
22263940
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:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CERAMICS; COOLING; DENSITY; EFFICIENCY; ENTROPY; EXTRACTION; HEAT EXCHANGERS; HELIUM; NATURAL GAS; PHASE DIAGRAMS; SOLIDIFICATION; SUPERFLUIDITY; TRITIUM