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He II: From the Lab to an Engineering Fluid

Dr. John Weisend II traces the evolution of He II as a cryogenic coolant, discussing both its applications and the research and development activities required to apply He II to large-scale systems.

History of the CSA Website

In 1991, the World Wide Web came into being at CERN, with other scientific laboratories around the world following close behind. In early 1995, Joel Fuerst undertook the development of a website for CSA.

A Half Century of Cryogenics and CSA

"1964 seems just like yesterday to me, yet it was 50 years ago. The Cryogenic Society of America was born that year, and I was just beginning my professional career in cryogenics." Dr. Ray Radebaugh reviews some of the industry's and CSA's major advances from 1964 to the present.

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Mixed Refrigerant Cycles

Most cryogenic refrigeration systems, both large scale systems and cryocoolers, use helium as a working fluid. There are a number of advantages to helium, not the least of which is that helium remains a fluid down to the lowest achievable temperatures. In order to freeze helium, pressures of over 20...

Fountain Pumps and He II Phase Separators

Helium II (He II), the second liquid phase of the 4He isotope described in this column in Cold Facts Spring 2010 (http://2csa.us/he2), can be modeled as consisting of two interpenetrating fluids. One, the superfluid component, has zero viscosity and entropy and the other, the normal fluid component, has nonzero viscosity...

Turboexpanders

A vital technology in the refrigerators and liquefiers described in Cold Facts Volume 31 Number 3 is that of turboexpanders. These devices are rotating machines in which the process fluid (e.g., helium) does work against the turboexpander while moving from high pressure to a lower pressure and thus is cooled....

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...

Approximating pressure changes over time in cryogenic cylinders

I am an Air Resources Engineer with the California Air Resources Board (CARB). My senior management has asked me to investigate approximating pressure changes over time in cryogenic cylinders that contain LNG. So far, I have taken a stab at the problem, seeking to take a back-of-the-envelope approach (as directed...