Icyball

Icyball is a name given to two early refrigerators, one made by Australian Sir Edward Hallstrom in 1923, and the other design patented by David Forbes Keith of Toronto (filed 1927, granted 1929), and manufactured by American Powel Crosley Jr., who bought the rights to the device. Both devices are unusual in design in that they did not require the use of electricity for cooling. They can run for a day on a cup of kerosene, allowing rural users lacking electricity the benefits of refrigeration. The Crosley Icyball is as an example of a gas-absorption refrigerator, as can be found today in recreational vehicles or campervans. Unlike most refrigerators, the Icyball has no moving parts, and instead of operating continuously, is manually cycled. Typically it is charged in the morning for 1.5 hours, and provides cooling throughout the heat of the day. Absorption refrigerators and the more common mechanical refrigerators both cool by the evaporation of refrigerant. (Evaporation of a liquid causes cooling, as for example, liquid sweat on the skin evaporating cools, and the reverse process releases much heat.) In absorption refrigerators, the buildup of pressure due to evaporation of refrigerant is relieved not by suction at the inlet of a compressor, but by absorption into an absorptive medium (water in the case of the Icy Ball). The Icyball system moves heat from the refrigerated cabinet to the warmer room by using ammonia as the refrigerant. It consists of two metal balls: a hot ball, which in the fully charged state contains the absorber (water) and a cold ball containing liquid ammonia. These are joined by a pipe in the shape of an inverted U. The pipe allows ammonia gas to move in either direction. After approximately a day's use (varying depending on load), the Icyball stops cooling, and needs recharging. The Icyball is removed from the refrigerated cabinet, and the cold ball, from which all the ammonia has evaporated during the previous cycle, is submerged in cool water.