Garbage disposal
From Wikipedia, the free encyclopedia
- This article is about the kitchen appliance. For the mass-scale disposal of waste, see waste management.
A garbage disposal or garburator (Canadian English) is an electrically-powered device installed under a kitchen sink between the sink's drain and the trap. It shreds food waste into very small pieces so that they can be passed through the plumbing without clogging. Also called a food waste disposal, they are sold in North America under brand names like "Waste King" and "In-Sink-Erator", the largest manufacturer of garbage disposals.
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[edit] History
The device first became widely popular in upscale kitchens of the 1970s and 1980s, yet remains very rare in European countries, due in part to greater promotion of composting kitchen waste. Concerns over environmental impact weakened its popularity, but kitchen designers and plumbers confirm the renewed appeal of the food-waste-grinding and -liquefying apparatus that lives under the sink. For many years, garbage disposals were illegal in New York City because of a perceived threat of damage to the city's sewer system. The ban was rescinded on September 11, 1997 by local law 1997/071 which amended section 24-518.1, NYC Administrative code. [1]
[edit] Types
There are two varieties of garbage disposals. The most common is the continuous-feed version; once the unit is turned on -- usually by a switch on the wall resembling a light switch -- it continues to run and grind food until switched off. Water should always be kept running through the drain when the disposal is switched on to prevent damage to the blades. A continuous feed model can also be operated by an air switch instead of a standard electric switch. An air switch is a small button on the counter or sink which, when pressed, delivers a puff of air to a control unit mounted under the sink. The puff of air makes the control unit start or stop the unit. The main benefits of an air switch are convenience and safety. An air switch is more convenient, because it can be mounted right next to or even on the sink itself, and it is safer because being non-electric, it is safe to touch with wet hands. Less common is the batch-feed variety, which will not run until its lid has been put in place and locked; this prevents accidents whereby a child or inattentive adult tries to fish something out of the drain and the unit is accidentally switched on. The other benefit of a batch feed model is that the cover keeps foreign objects such as cutlery falling into the unit while it is running. Such accidents can damage the unit, and nearly always ruin the item dropped in too.
Some dishwashers are equipped with a small built-in garbage disposal unit which removes the need to prewash dishes.
[edit] Mechanism
A high-torque, insulated electric motor spins a round, horizontal turntable above it. The turntable is surrounded by a shredder ring, which has sharp slots. The food waste sits on the turntable, and through centrifugal force is forced to its perimeter and through the shredder ring. The turntable has a number of swiveling lugs — similar to little dull blades — attached to its topside, which assist in forcing the waste through the shredder.
Some high-end domestic disposals, like their commercial counterparts, also have a blade which revolves under the turntable called an undercutter. This blade chops the ground waste even finer, and also snips any fibrous material which could cause a drain clog. Disposals with undercutters can handle fibrous waste such as artichoke leaves which cannot be successfully ground in a standard disposal.
Another higher-end feature is automatic reversing. By using a slightly more-complicated centrifugal starting switch, the split-phase motor starts in the opposite direction with each new start. This helps the user overcome minor jams. Tougher jams can often be cleared by manually turning the motor using a hex-key wrench inserted into the motor shaft from the bottom of the disposal.
Some newer garbage disposals run completely on water pressure and not electricity. These garbage disposals require no external power, and completely eliminate the chance of electric shock. They also use a different mechanism. Instead of a turntable and grind ring found in an electric disposal, water powered disposals have an oscillating piston with blades attached to chop the waste into fine pieces. Because of this cutting action, they can handle fibrous waste and even a glass bottle, although of course this should be avoided in practice. Another advantage of a water-powered disposal is that if an item of cutlery accidentally falls in, no harm comes to it because the blades just stop. One downside of a water-powered disposal is that they take longer than an electric disposal to dispose of the same amount of waste. They also need quite high water pressure to function correctly. If such water pressure is not available, an electric disposal is a better choice.
[edit] External links
- Do-it-yourself guide to garbage disposal installation.
- Page with garbage disposal research
[edit] Videos
- Garbage disposal at YouTube. 1950s General Electric promotional film on one of the first garbage disposal units. Includes slow motion closeup footage of operation.
[edit] Cultural References
- A garbage disposal features prominently in an opening scene of Robert Redford's 1980 movie Ordinary People.
