The Einstein Refrigerator is a type of refrigerator co-invented in 1926 by Albert Einstein and former student Leó Szilárd. It is a single pressure absorption refrigerator, similiar in design to the gas absorption refrigerator . The Einstein Refrigerator is portable; made of inexpensive, nonmoving parts; operates silently; and is very reliable. However, ammonia (one of its components) leaks can be dangerous.

On November 11, 1930, patent number US1781541 was awarded to Albert Einstein and Leó Szilárd. The patent covered a thermodynamic refrigeration cycle, with no moving parts, providing cooling at a constant pressure, with only heat as an input. The refrigeration cycle used ammonia (pressure equalizing fluid), butane (refrigerant), and water (absorbing fluid).

Einstein undertook this invention as a way of helping along his former student. He used the knowledge he had acquired during his years at the Swiss Patent office to get solid patents for the invention in several countries. The refrigerator was not immediately put into commercial production, but rights to use the patents were sold to companies such as Electrolux of Sweden, and the funds obtained supported Szilárd for several years. Electrolux manufactures a similar design invented by Platen and Munters in 1926 under the brand name Dometic.

See also

• Refrigeration
• Refrigeration cycle

References

• Dannen, Gene. The Einstein-Szilard Refrigerator. Scientific American. January 1997. 6 pages.
• Einstein, A., L. Szilard, "Refrigeration" (Appl: 16 Dec. 1927; Priority: Germany, 16 Dec. 1926) Pat. No. 1,781,541 (United States), 11 Nov. 1930.
• Einstein, A., L. Szilard, "Accompanying notes and remarks for Pat. No. 1,781,541". Mandeville Special Collections Library USC. Box 35, Folder 3, 1927. pp. 52.
• Einstein, A., L. Szilard, "Improvements Relating to Refrigerating Apparatus." (Appl: 16 Dec. 1927; Priority: Germany, 16 Dec. 1926). Pat. No. 282,428 (United Kingdom). Complete accept.: 5 Nov. 1928.

External links

• Delano, Andrew, "Design Analysis of the Einstein Refrigeration Cycle". Georgia Institute of Technology. June 1998.
• Goettling, Gary, "Einstein Refrigerator".
• Flanigan, Allen, "Patent Potpourri". uspto.gov.
• Einstein, A., L. Szilard, "Refrigeration" (Appl: 16 Dec. 1927; Priority: Germany, 16 Dec. 1926) Pat. No. 1781541 (United States), 11 Nov. 1930. patent. uspto.gov.
• [www.uni-oldenburg.de/histodid/] (german site) A workgroup of the University Oldenburg is beginning to rebuild the original concept - i.e. a total mass of around 400 kg and alcohol in the refrigeration cycle. The project will be finished in 2005.