The History of the Refrigerator
The refrigerator for preserving food in the home began with devices for the manufacture of ice - for producing, so to say, a mechanical winter in the warmth of summer.
It was the old practice to collect ice in the winter months and store it in ice-houses. Thus underground ice-houses of the eighteenth century may often be seen in the grounds of English country houses. Methods of storage improved, and naturally ice was commonly used until the last century.
The first man to produce ice by mechanical means was the eminent Scottish physician and chemist William Cullen (1710-1790), who wrote in 1755 An Essay on the Cold produced by Evaporating Fluids. Cullen made use of a powerful vacuum pump to bring about the rapid evaporation of water in an enclosed space at ordinary temperatures. The heat required for evaporation was absorbed from the rest of the water, so lowering its temperature and causing it to freeze.
Since considerable quantities of water vapour had to be removed at low suction-pressures, Cullen's machine was not very efficient. It was improved by another Scottish scientist, Sir John Leslie, who introduced a flat dish containing sulphuric acid under the receiver of the air-pump, the acid absorbing the water vapour. The system was next improved about 1850 by Edmund Carre, with a machine which had to be replenished frequently with fresh acid, owing to continual dilution of the acid by water. In 1878 F. Windhausen devised a machine in which the dilute acid could be concentrated and used again. In 1883 a dairy company in Bays-water in London was using an improved version of Windhausen's machine to make about twelve tons of ice a day.
The refrigerator as we know it begins with Jacob Perkins, who patented a vapour-compression machine in London in 1834. Ether was compressed by a single-acting vertical compressor, and the heat of the compression was removed by passing the fluid through a coil immersed in water. The ether was then allowed to expand through a valve into a chamber near the bottom of a cistern of water; the low temperature produced by the evaporation of the expanding ether was thus transmitted to the surrounding water. Perkins's apparatus was sounder in principle than in operation, and twenty-one years went by before it was made effective by James Harrison of Australia (British Patent No. 747 of 1856).
Ether was one possible refrigerant. About 1876 Professor Carl von Linde of Munich introduced refrigeration by the compression of ammonia, designing a machine substantially unaltered to the present day, although new refrigerants have been introduced. Ammonia is still common for industrial plants, but since it is poisonous, safer materials have been developed, particularly for domestic use. Thus one family of new refrigerants, introduced in 1932, consists of a group of fluorinated hydrocarbons.
Low temperature could be produced not only by vapour compression but by the absorption of vapour, a system which goes back to 1860, when Ferdinand Carre introduced his Artificial Ice Machine. This consisted of two vessels. One contained a strong solution of ammonia, the other at first was empty and surrounded by cold water. The ammonia solution was heated by a stove, and the ammonia gas driven off into the second vessel, where it condensed and gave up its latent heat to the water outside. After a while the ammonia solution became very dilute, whereupon the stove was removed, and the ammonia vessel was also surrounded by cold water. As a result, the condensed ammonia in the second vessel began to evaporate, and in so doing exerted a refrigerating effect, the ammonia gas being reabsorbed by the now weak solution in the first vessel. It was an intermittent operation, but Carre also designed a continuously operating system; a modified form of ammonia-absorption machine in which the condensed ammonia is made to evaporate by contact with a stream of hydrogen, was devised some thirty years ago in Sweden, and is much used for domestic refrigeration since it involves no moving mechanical parts.
Though refrigeration was devised and developed to produce ice, obviously it was possible to stop short with producing cold - a cold storage chamber, which did the work of ice with more efficiency and without the mess. Refrigeration, like vacuum-cleaning, had also developed as industrial plant: the problem was also to reduce refrigeration to the domestic refrigerator - to the now familiar 'fridge' - as it was to reduce vacuum-cleaning to the vacuum-cleaner. This was done between 1910 and 1920, in the United States, the first kitchen refrigerators having the familiar look of the old kitchen icebox.