Cold Facts Digital – The go-to place for Cryogenics and Superconductivity

How much heat energy does LN2 contain per lb.?

I would like to know how much heat energy liquid nitrogen contains per lb. In other words, per lb. of liquid, how many BTUs of heat would N2 absorb in the process of coming up to about 60F? I want to capture the cold energy of nitrogen as it vaporizes...

Software for thermophysical properties of helium down to 1K

What are the options when it comes to software for thermophysical properties of helium at temperatures down to 1K? I know Hepak – is it still the most commonly used package?

Refilling process of a helium cryogenic plant

I’m trying to collect some information about the refilling process of a helium cryogenic plant. Due to the physiologic losses I expect to have to foreseen a periodic refilling of helium. Our plant will be characterized by a refrigerator/liquefactor. A control cryostat with 4.5 K LHe coming from the liquefactor...

What's the best gas to use for pulse GMAW?

I have a 78″ ID vessel, 3/8″ thick shells, ½” heads, from SA-240-304L, which will have an ASME U-Stamp and I am planning on sub-arcing the seams and using pulse GMAW (ER308L for both) for the nozzles. I am comfortable with the SAW, but I am wondering about the best...

Manufacturer of liquid pump for use at 170 K

We’re in need of a liquid pump for use at 170 K in our refrigerator to pump Paratherm cryogenic heat transfer fluid. Can anyone suggest a manufacturer? Our flow rate is 16 liters/minute, and a head of 10 m. The specific gravity of the fluid is 0.85 and the viscosity...

Question about configuration of an 80 K helium circuit

I have a question about a possible configuration of an 80 K helium circuit from our cryogenic plant. A helium flow at 80 K and 18 bar is needed at the customer’s inlet. In order to decouple the refrigerator from the customer, I thought to propose the following solution: –...

Latest in Defining Cryogenics

Regenerators

Regenerators or regenerative heat exchangers are a key component of cryocoolers such as pulse tube cryocoolers (Cold Facts, August 2014). Regenerator performance greatly affects the coefficient of performance of cryocoolers. Improvements in regenerator design and, in particular, regenerator materials have been an important factor in the improvement of the performance...

Pulse Tube Cryocoolers

The development of pulse tube cryocoolers has been a significant topic of research and development over the past 20 or so years. Pulse tube cryocoolers have a number of advantages over other types of cryocoolers and are now available commercially. In order to understand pulse tube cryocoolers, it’s best to...

Thermal Expansion

Thermal expansion refers to the change in size (length or volume) that a material undergoes as its temperature changes. In cryogenic systems this effect can be quite large and must be allowed for in the design. In isotropic materials, which include most engineering materials, the thermal expansion is the same...

Latest in Cryo Central

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...

Latest in Ask the Experts

Any experience with Tungsten or Tantalum metal springs in a low temp environment?

I would like to use metal springs made of Tungsten or Tantalum in low temperature environment. Does anybody have any experience with such springs? More precisely, I would like to make compression springs by rolling tungsten or tantalum wire on a rod. I expect that, typically, the spring constant will...

Standards & specifications for pipe & tube couplings

I am interested in finding out more about cryogenic applications and what standards, specifications and test methods (ASTM, etc.) are required for qualification of pipe and tube couplings.

Looking for a test house to test the static coefficient of friction under cryogenic conditions

I am looking to find a test house that is capable of testing the static coefficient of friction under cryogenic conditions. We can be flexible on most of the test parameters, including the test coupon configuration, but we’re looking for a test house that can provide the following test environment:...

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...

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