The Refrigerator
Primitive refrigeration required natural forming ice to be stored and insulated in icehouses during the winter, providing a cold sanctuary for perishable foods during the summer. For many reasons, such as the transportation, the availability, and the impracticality of maintenance in some climates, this natural ice refrigeration method was crude at best. Improved food transportation and storage aided the continental expansion of the United States, eventually reaching coast to coast and spanning a wide variety of climate regions.
Refrigeration is a cyclic thermodynamic process. A substance, called the refrigerant, is enclosed in various pipes and undergoes rapid vaporization and expansion. This requires energy, which is drawn from the surrounding space in the form of heat. This process leaves the surrounding volume colder than before. By filling the surrounding volume with liquid water, the process draws heat from the water until it dropped below its freezing point and became ice (Schroeder). Oliver Evans was an American inventor who worked with various thermodynamic inventions (heat pumps and refrigerators). He invented his own steam engine modifications to James Watt's model, but his most important work was with the refrigerator. In 1805, Oliver Evans realized that by employing the cyclic process of extracting heat from water in a closed system (Bellis "Inventors"). It wasn't until the 1850's that proper* refrigerants were developed and that the process was made cyclic and continuous in practice.
The refrigerator is arguable one of the most important inventions in the 1800s. Refrigeration linked two incredibly significant inventions and revolutionized the expansion of America. The refrigerators used the recently invented steam engine to drive the vacuum pump (which allows the refrigerant to vaporize readily). Then the refrigerators were integrated into the recently developed railroads, providing a dependable form of long distance transportation of many perishable goods, particularly meats. The refrigerator allowed perishable food to be stored and preserved longer independent of the season or the climate region. Eventually, railroad cars were outfitted with refrigeration and suddenly the ability to transport what had been local products around the country became possible (Bellis "Inventors"). People didn’t have to harvest ice during the winter and store it for the summer. They didn’t have to preload a train with ice for a long trip. They could merely rely on a refrigeration unit and the availability of liquid water (not nearly as scarce as ice), and they could reliably produce ice along the trip and preserve the products. This intimate link between steam engines, railroads, and refrigeration drastically changed the American frontier.
*Now we know that these early refrigerants were not environmentally friendly
Refrigeration is a cyclic thermodynamic process. A substance, called the refrigerant, is enclosed in various pipes and undergoes rapid vaporization and expansion. This requires energy, which is drawn from the surrounding space in the form of heat. This process leaves the surrounding volume colder than before. By filling the surrounding volume with liquid water, the process draws heat from the water until it dropped below its freezing point and became ice (Schroeder). Oliver Evans was an American inventor who worked with various thermodynamic inventions (heat pumps and refrigerators). He invented his own steam engine modifications to James Watt's model, but his most important work was with the refrigerator. In 1805, Oliver Evans realized that by employing the cyclic process of extracting heat from water in a closed system (Bellis "Inventors"). It wasn't until the 1850's that proper* refrigerants were developed and that the process was made cyclic and continuous in practice.
The refrigerator is arguable one of the most important inventions in the 1800s. Refrigeration linked two incredibly significant inventions and revolutionized the expansion of America. The refrigerators used the recently invented steam engine to drive the vacuum pump (which allows the refrigerant to vaporize readily). Then the refrigerators were integrated into the recently developed railroads, providing a dependable form of long distance transportation of many perishable goods, particularly meats. The refrigerator allowed perishable food to be stored and preserved longer independent of the season or the climate region. Eventually, railroad cars were outfitted with refrigeration and suddenly the ability to transport what had been local products around the country became possible (Bellis "Inventors"). People didn’t have to harvest ice during the winter and store it for the summer. They didn’t have to preload a train with ice for a long trip. They could merely rely on a refrigeration unit and the availability of liquid water (not nearly as scarce as ice), and they could reliably produce ice along the trip and preserve the products. This intimate link between steam engines, railroads, and refrigeration drastically changed the American frontier.
*Now we know that these early refrigerants were not environmentally friendly
Sources:
Schroeder, D. V. (2000). Chapter 4: Engines and Refrigerators. An introduction to thermal physics (). San Francisco, CA: Addison Wesley.
Bellis, M. Inventors. About.com Inventors. Retrieved April 11, 2014, from http://inventors.about.com/library/inventors/blrefrigerator.htm for the history details
Schroeder, D. V. (2000). Chapter 4: Engines and Refrigerators. An introduction to thermal physics (). San Francisco, CA: Addison Wesley.
Bellis, M. Inventors. About.com Inventors. Retrieved April 11, 2014, from http://inventors.about.com/library/inventors/blrefrigerator.htm for the history details