New question in “Ask the Experts”: Design length of transition tubes
The question is: Are there any rules of thumb for the design length of transition tubes in order to prevent condensation at the room temperature end?
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Rules of thumb for the design length of transition tubes
Are there any rules of thumb for the design length of transition tubes in order to prevent condensation at the room temperature end? By “transition tube,” I mean some standard size (O.D. and wall thickness) type 304 stainless steel tube with either 4 K or 80 K at one end...
Cuprate superconductors defy convention
To engineers, it’s a tale as old as time: Electrical current is carried through materials by flowing electrons. But physicists at the University of Illinois and the University of Pennsylvania found that for copper-containing superconductors, known as cuprates, electrons are not enough to carry the current.
Assessment of the Storage of Crude Helium in Reserves in Europe or Elsewhere
The following paper entitled, “Assessment of the storage of crude helium in reserves in Europe or elsewhere,” by Ralph Scurlock and Richard Clarke, was presented at the Cryogenics Conference in Dresden in September 2012. The full text of the paper appears below; download the presentation slides.
The Future of Helium? A paper presented at the Cryogenics conference in Dresden
The following paper entitled, "The Future of Helium? A global agency to oversee production, storage, supply and use of helium gas and liquid," by Ralph Scurlock and Richard Clarke, was presented at the Cryogenics Conference in Dresden in September 2012. The full text of the paper appears below.
BNSF to test liquefied natural gas in road locomotives
BNSF will begin testing a small number of locomotives using liquefied natural gas (LNG) as an alternative fuel later this year, BNSF chairman and CEO Matthew K. Rose announced at the CERAWeek conference on March 6.
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Dewar
A dewar is a type of cryostat named after Sir James Dewar, the researcher who first developed the concept of a vacuum insulated container with silvered walls to reflect thermal radiation. Dewar was the first to liquefy hydrogen, and he created the device to store his discovery. The thermos bottle...
Stirling and Gifford-McMahon Cryocoolers
Stirling and Gifford-McMahon (GM) cryocoolers are two of the most commonly used cryocoolers in cryogenics. Both devices have a significant industrial base and operate at a wide range of temperatures and capacities. The thermodynamic cycles for both of these cryocoolers are quite similar. The Stirling cycle consists of a compressor,...
Liquefied Natural Gas (LNG)
A significant commercial application of cryogenics is the liquefaction, transport and storage of natural gas. Liquefied Natural Gas (LNG) is generally 95 percent methane with a few percent ethane and much lower concentrations of propane and butane. LNG liquefies at 111.6 K. Unlike many applications of cryogenics, the motivation for...
Air Separation and Liquefaction
by Nils Tellier, PE, President, EPSIM Corporation (CSA CSM) nils@epsim.us All illustrations courtesy EPSIM Corporation Background History of Air Separation and Liquefaction This section builds on a rich history of methods to develop deep refrigeration and cryogenic liquefaction during the 19th Century. You are encouraged to read Cryo Central’s History...
Bose-Einstein Condensate
A Bose-Einstein condensate, first proposed in 1925 by Albert Einstein based on work done by Satyendra Nath Bose (the same Bose from whom the term boson is derived), is a super-cold state of matter in which almost all of the individual atoms have “condensed” down to the lowest possible quantum...
Cold Technology for Pest Control
While it does not reach temperatures cold enough to be called cryogenic, carbon dioxide snow is at the heart of a new way of dealing with unwanted pests. It utilizes a quick freezing process that takes advantage of the properties of carbon dioxide snow and has a number of benefits...
Cryogenic Finishing
The following 3 articles discuss the uses and procedures of various type of cryogenic finishing. 1) By Robin A. Rhodes, Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Cryogenic Deflashing is employed to remove undesired residual mold flash that remains on molded parts after they are removed or ejected from the...
Seeking recommendations for commercial sensors
I would like to measure vibrations in small LHe cryostats. Could anybody recommend commercial sensors which would be suitable for the purpose? I am interested in the frequency range between 1Hz and a couple of KHz, with particular attention to the low frequency side.
Estimating cost of carbon steel, pure helium storage tanks
In order to perform an indicative cost assessment of our helium cryogenic plant (still in the design phase), I need an estimation of the cost of carbon steel room temperature pure helium storage tanks. The storage pressure is 20 bar. Can anyone give me suggestions about how to estimate the...
Supplier of pressure sensor that works down to 4.2 K
In an actual experiment we would like to measure the static pressure in a cryostat in the range between one and four bar. Therefore we are looking for some (more or less) cheap pressure sensors that work in liquid helium in the pressure range up to five bar. Unfortunately all...
Looking for reference/textbook suggestions
Can you suggest some reference textbooks for practical thermodynamics applications in cryogenic fields? I need textbooks with cryogenics calculations and examples, dimensioning procedures, second principle applications in cryogenics, heat load calculations, cryogenic pump application, etc. Do such books exist? Does any similar source of information exist?