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Stirling Cryocoolers for the LNG Market

Interest in use of Stirling cryogenerators (cryocoolers) for liquefied natural gas (LNG) applications has grown with the increasing worldwide demand for the gas. Cryogenerators act as cold heat exchangers which can directly reliquefy methane gas. They are typically used for direct liquefaction of an LNG stream, e.g. that produced from...

Minimizing Eddy Currents in Superinsulation

RUAG's study investigated various processes to structure metallic coatings to develop a better product. The aim was to retain the high reflectivity provided by the aluminum and to reduce the eddy currents to a level acceptable for different application

DeMaCo Receives Major Orders from DESY

DeMaCo, a Dutch specialist in cryogenic infrastructure, has acquired two major orders from DESY, the main shareholder of the European X-ray Free Electron Laser facility, or European XFEL for short. The purpose of the project is to produce high intensity coherent X-rays with true laser properties. The wavelength of these...

Report on 4th UK Cryogenic Cluster Day

The fourth Cryogenic Cluster Day was held on September 25 at Rutherford Appleton Laboratory near Oxford, UK, and was attended by cryogenics professionals from the UK, Austria, Germany, New Zealand, Switzerland and the US.

When is an ADR the Right Tool for the Job?

Experimentalists seeking cryogenic platforms below 250 mK have essentially two choices: Dilution Refrigeration (DR) or Adiabatic Demagnetization Refrigeration (ADR) cryostats. There are particular applications where one or the other is the best tool. In some cases, either may be equally suitable. Charlie Danaher, HPD, discusses the differences.

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Two-Phase Flows

Two-phase flows are those flows in which there is a mixture of two physical states (solid, liquid or vapor). In cryogenic applications, such flows are almost always a mixture of a cryogenic liquid along with its corresponding vapor. A mixture of liquid helium and helium vapor would be a typical...

Supercritical Fluids

A supercritical fluid is defined as a substance whose temperature and pressure exceed those of its critical point. Every pure substance has a critical point that is defined in thermodynamic space by a critical temperature and a corresponding critical pressure. For example, the critical point for helium has a critical...

Brayton Cycle

The Brayton cycle is one of the many thermodynamic cycles used to generate cooling at cryogenic temperatures. Strictly speaking, when referring to cooling we should call this the reverse Brayton cycle as the original Brayton cycle describes the process of power generation or propulsion via a gas turbine. In many...

Food Processing

Cryogenics and Food The industrial gas industry provides a host of products and services related to food. The various gases have useful and sometimes fascinating applications in food industry. “The food industry is not a homogenous industry. The needs of customers processing hamburger vs. poultry vs. strawberries vs. seafood, for...

Primary Standards

Elie K. Track Hypres, Inc. elie@hypres.com http://www.hypres.com/ Primary standards involve the exact definition and realization of units of measurement for various quantities, time, length, mass, voltage, resistance, current, etc. International agreements based on the latest scientific knowledge define those units, and their realizations vary depending on the unit itself. For...

Shrink Fitting

Robin A. Rhodes Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Shrink fitting, (or “compression fitting” as it is sometimes called), is a method used to insert a pin or bushing into a housing or other assembly requiring an extremely tight tolerance fit. It can be used as an alternative to...

Telecommunications

From the Winter 2004 issue of Cold Facts magazine The recent M-Calc IV — 4th Industry Assessment workshop discussing military and commercial applications for low-cost cryocoolers, held in November in San Diego, highlighted progress being made in cryogenics as applied in telecommunications. The reliability and long lifetime of projects now...

An Issue of Pressure and Flow Rate in a Supply Tank

Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...

Using MLI on VJ Line Joints or Cryo Storage Tanks

When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...