Refrigerator





History of the Refrigerator


Back in time a long time ago, around 500 B.C. the Egyptians and Indians made ice on cold nights by setting water out in earthenware pots and keeping the pots wet. In the 18th century England, servants collected ice in the winter and put it into icehouses, where the sheets of ice were packed in salt, wrapped in strips of flannel and stored underground to keep them frozen until summer. Before the refrigerator or “ice box” was introduced people used snow and ice to keep their food cool, which was either found locally or brought down from the mountains. Cellars and caves were also used to refrigerate food. Meat and fish were preserved in warm weather by salting or smoking. The first cellars were holes dug into the ground and lined with wood or straw and packed with refrigeration for most of history.
At the beginning of the 19th century, ice boxes were used in England. These ice boxes were typically made of wood, lined with tin or zinc and insulated with various materials including cork, sawdust or seaweed. They were used to hold blocks of ice and refrigerate food. Ice was delivered as needed (people simply hung the “Ice Today” sign in their window for the delivery man) and a drip pan collected the melted water which then had to be emptied daily.
Natural ice was harvested, distributed and used in both commercial and home applications in the mid-1800s. The ice trade between Boston and the South was one of the first casualties of the Civil War. Warm winters in 1898 and 1890 created severe shortages of natural ice in the U.S. This stimulated the use of mechanical refrigeration for the freezing and storage of fish and in the brewing, dairy and meat packing industries. During the nineteenth century, numerous experimental devices were developed in an effort to achieve practical artificial refrigeration. Compressed ether machines were built in Pennsylvania by Oliver Evans in 1805 and in Australia by James Harrison in 1855, and Dr. John Gorrie in Florida built an expanding air-cooling machine in 1844. In 1851 Dr. John Gorrie created the first commercial ice making machine to cool the air for his yellow fever patients. Soon thereafter, refrigeration and freezing became popular methods of preserving foods for transport or storage, and in place where natural ice was not available.
Refrigeration is the process of removing heat from an enclosed space, or from a substance, to lower its temperature. A refrigerator uses the evaporation of a liquid to absorb heat. The liquid, or refrigerant used in a refrigerator evaporates at an extremely low temperature creating freezing temperatures inside the refrigerator.
William Cullen at the University of Glasgow demonstrated the first known artificial refrigeration in 1748. However, he did not use his discovery for any practical purpose. In 1805, an American inventor, Oliver Evans, designed the first refrigerator machine.
The development of mechanical refrigeration systems began in the early19th century and arose mainly from the needs of meat producers in the USA, South America, Australia and New Zealand, who were facing many difficulties in shipping their produce to their export markers in Europe. Many experimental systems were built in the 1830s, utilizing the cooling effect produced by the expansion of compressed air or carbon dioxide or by the evaporation of volatile fluids such as ammonia. The first meat freezing plant was built in Australia in 1861. This company had its own slaughterhouse, freezing plant and cold store and used ammonia compression freezing system.
By 1870, ships were successfully transporting chilled beef (cooled to one or two degrees below freezing point) in insulated holds cooled by ice mixed with salt (a technique which lowers the freezing point of ice and hence the temperature) but this method could only be used on the relatively short trips from the USA to Europe.
In 1925 American inventor and industrialist Clarence Birdseye came up with a method of freezing that did not rob food of its flavor. His method, called quick freezing operated on the premise that the faster the freezing, the less danger there was that ice crystals would rupture the cell walls of the food item. Some of the foods that Clarence Birdseye subjected to quick freezing were peas, spinach, rasberries, cherries, fish and meat.
The development