User:Milton Beychok/Sandbox: Difference between revisions

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An '''expansion turbine''', also referred to as a '''turboexpander''' or '''turbo-expander''', is a centrifugal or axial flow [[turbine]] through which a high [[pressure]] [[gas]] is expanded to produce work that is typically used to drive a [[gas compressor]].  Because work is extracted from the expanding high [[pressure]] gas, the expansion is an [[isentropic]] process (i.e., a constant [[entropy]] process) and the low pressure exhaust gas from the turbine is at a very low [[temperature]], often  as low as 200 K (-100 °F) or less. Turbo-expanders are very widely used as sources of [[refrigeration]] in industrial processes such as the extraction of [[ethane]] and [[Natural gas processing|natural gas liquids]] (NGLs) from [[natural gas]]<ref>[http://freepatentsonline.com/US6915662.html Demethanzer]</ref>; the [[liquefaction of gases]];<ref>[http://www.nzic.org.nz/ChemProcesses/production/1K.pdf BOC (NZ) publication]: use search function for keyword "expansion"</ref><ref>[http://www.hydrogen.energy.gov/pdfs/progress05/v_e_1_shimko.pdf US Department of Energy Hydrogen Program]</ref> and other low-temperature processes.
An '''expansion turbine''', also referred to as a '''turboexpander''' or '''turbo-expander''', is a centrifugal or axial flow [[turbine]] through which a high [[pressure]] [[gas]] is expanded to produce work that is typically used to drive a [[gas compressor]].   
 
Because work is extracted from the expanding high [[pressure]] gas, the expansion is an [[isentropic]] process (i.e., a constant [[entropy]] process) and the low pressure exhaust gas from the turbine is at a very low [[temperature]], often  as low as 200 K (-100 °F) or less. Turbo-expanders are very widely used as sources of [[refrigeration]] in industrial processes such as the extraction of [[ethane]] and [[Natural gas processing|natural gas liquids]] (NGLs) from [[natural gas]]<ref>[http://freepatentsonline.com/US6915662.html Demethanzer]</ref>; the [[liquefaction of gases]];<ref>[http://www.nzic.org.nz/ChemProcesses/production/1K.pdf BOC (NZ) publication]: use search function for keyword "expansion"</ref><ref>[http://www.hydrogen.energy.gov/pdfs/progress05/v_e_1_shimko.pdf US Department of Energy Hydrogen Program]</ref> and other low-temperature processes.
 
In 1939, [[Pyotr Kapitza]] of [[Russia]] suggested the use of a centrifugal turbine for the isentropic expansion of gases to produce refrigeration. Since then, centrifugal expansion turbines have takrn over almost 100 percent of the gas liquefaction and other low-temperature industrial requirements.


==References==
==References==
{{reflist}}
{{reflist}}

Revision as of 01:54, 6 July 2008

An expansion turbine, also referred to as a turboexpander or turbo-expander, is a centrifugal or axial flow turbine through which a high pressure gas is expanded to produce work that is typically used to drive a gas compressor.

Because work is extracted from the expanding high pressure gas, the expansion is an isentropic process (i.e., a constant entropy process) and the low pressure exhaust gas from the turbine is at a very low temperature, often as low as 200 K (-100 °F) or less. Turbo-expanders are very widely used as sources of refrigeration in industrial processes such as the extraction of ethane and natural gas liquids (NGLs) from natural gas[1]; the liquefaction of gases;[2][3] and other low-temperature processes.

In 1939, Pyotr Kapitza of Russia suggested the use of a centrifugal turbine for the isentropic expansion of gases to produce refrigeration. Since then, centrifugal expansion turbines have takrn over almost 100 percent of the gas liquefaction and other low-temperature industrial requirements.

References