Dishwasher is a machine that washes dishes, utensils, and other items used to prepare and eat food and drink beverages. Before the development of dishwashers, people washed all dishes by hand, which requires more time and effort than machine washing. People frequently use dishwashers in restaurants and homes. Most dishwashers work automatically.
A dishwasher is a large metal box with a waterproof lining and a water-tight door. The operator puts dirty dishes in one or more racks inside the box and adds dishwashing detergent in a special compartment. The operator then closes the door and sets the controls, which may adjust washing time, water temperature, and drying method.
Inside the dishwasher, a water pump creates powerful streams of soapy water that wash the food off the dishes. The streams come from spray arms at the bottom or top of the dishwasher. An electric motor spins the spray arms during washing. The racks hold the dishes and keep them separate from one another, enabling them to be washed on all sides. After washing and rinsing, the pump removes dirty water from the dishwasher.
Extremely hot water is essential to killing bacteria, which can grow on dirty dishes and make people sick. Many dishwashers use an electric heating element to heat the water before washing. After washing, the heating element is sometimes used to help dry the dishes by heating the air inside the dishwasher.
Joel Houghton, an American inventor, patented an early hand-powered dishwasher in 1850. In 1886, the American Josephine Cochrane invented a fully mechanical dishwasher. Cochrane, a wealthy socialite, invented the dishwasher to prevent her servants from chipping the dishes during washing. Cochrane’s dishwasher was displayed at the 1893 World’s Columbian Exposition in Chicago. It became popular in restaurants and hotels. Household dishwashers and other home appliances became more popular after World War II (1939-1945), in part due to the availability of the steel used to make them.
See also Cochrane, Josephine Garis .
