Garbage disposal unit - wikipedia Garbage disposal unit `` Garbage disposal '' redirects here. For the mass - scale disposal of waste, see waste management. A garbage disposal unit installed under a kitchen sink. A garbage disposal unit ( also known as a garbage disposal, waste disposal unit, garbage disposer, or in Canadian English a garburator ) is a device, usually electrically powered, installed under a kitchen sink between the sink 's drain and the trap. The disposal unit shreds food waste into pieces small enough -- generally less than 2 mm ( 0.079 in ) -- to pass through plumbing. Garbage disposal units are used extensively in United States households, but are far less common elsewhere. Contents 1 History 2 Adoption 3 Rationale 4 Operation 5 Environmental impact 6 References 7 External links History The garbage disposal was invented in 1927 by John W. Hammes, an architect working in Racine, Wisconsin. He applied for a patent in 1933 that was issued in 1935. His InSinkErator company put his disposer on the market in 1940. Hammes ' claim is disputed, as General Electric introduced a garbage disposal unit in 1935, known as the Disposall. In many cities in the United States in the 1930s and the 1940s, the municipal sewage system had regulations prohibiting placing food waste ( garbage ) into the system. InSinkErator spent considerable effort, and was highly successful in convincing many localities to rescind these prohibitions. Many localities in the United States prohibited the use of disposers. For many years, garbage disposals were illegal in New York City because of a perceived threat of damage to the city 's sewer system. After a 21 - month study with the NYC Department of Environmental Protection, the ban was rescinded in 1997 by local law 1997 / 071, which amended section 24 - 518.1, NYC Administrative Code. In 2008, the city of Raleigh, North Carolina attempted a ban on the replacement and installation of garbage disposals, which also extended to outlying towns sharing the city 's municipal sewage system, but rescinded the ban one month later. Adoption In the United States, some 50 % of homes had disposal units as of 2009, compared with only 6 % in the United Kingdom and 3 % in Canada. In Sweden, some municipalities encourage the installation of disposers so as to increase the production of biogas. Some local authorities in Britain subsidize the purchase of garbage disposal units in order to reduce the amount of waste going to landfill. Rationale Food scraps range from 10 % to 20 % of household waste, and are a problematic component of municipal waste, creating public health, sanitation and environmental problems at each step, beginning with internal storage and followed by truck - based collection. Burned in waste - to - energy facilities, the high water - content of food scraps means that their heating and burning consumes more energy than it generates ; buried in landfills, food scraps decompose and generate methane gas ; a greenhouse gas which contributes to climate change. The premise behind the proper use of a disposal is to effectively regard food scraps as liquid ( averaging 70 % water, like human waste ), and use existing infrastructure ( underground sewers and wastewater treatment plants ) for its management. Modern wastewater plants are effective at processing organic solids into fertilizer products ( known as biosolids ), with advanced facilities also capturing methane for energy production. Operation The parts of a garbage disposal A high - torque, insulated electric motor, usually rated at 250 -- 750 W ( 1⁄3 to 1 horsepower ) for a domestic unit, spins a circular turntable mounted horizontally above it. Induction motors rotate at 1,400 -- 1,800 rpm and have a range of starting torques, depending on the method of starting used. The added weight and size of induction motors may be of concern, depending on the available installation space and construction of the sink bowl. Universal motors rotate at higher speeds ( about 2,800 rpm ), have high starting torque, and are usually lighter, but are noisier than induction motors, partially due to the higher speeds and partially because the commutator brushes rub on the slotted commutator. Contaminated water leaking on to the commutator can lead to major damage, which is why most garbage disposals today use induction motors. The higher starting torque of those appliances with a permanent magnet motor ensures in most cases that there will be no blockage. Inside the grinding chamber there is a rotating metal turntable onto which the food waste drops. Two swiveling metal impellers mounted on top of the plate near the edge then fling the food waste against the grind ring repeatedly. Grooves in the grind ring break down the waste until it is small enough to pass through openings in the ring, whereupon it is flushed down the drain. Usually, there is a partial rubber closure on the top of the disposal unit to prevent food waste from flying back up out of the grinding chamber. It may also be used to attenuate noise from the grinding chamber for quieter operation. There are two main types of garbage disposals -- continuous feed and batch feed. Continuous feed models are used by feeding in waste after being started and are more common. Batch feed units are used by placing waste inside the unit before being started. These types of units are started by placing a specially designed cover over the opening and twisting it to allow magnets in the cover to align with magnets in the unit. Because it is covered during operation, it is quieter than continuous feed models. Small slits in the cover allow water to flow through. Batch feed models are also safer, since the top of the disposal is covered during operation, preventing foreign objects from falling in. Waste disposal units may jam, but can usually be cleared either by forcing the turntable round from above or by turning the motor using a hex - key wrench inserted into the motor shaft from below. Especially hard objects accidentally or deliberately introduced, such as metal cutlery, can damage the waste disposal unit and become damaged themselves, although recent advances have been made to minimize such damage. More problematic are drain blockages caused by shredded waste that is fibrous, e.g., artichoke leaves, or starchy, e.g., potato peelings. Some higher - end units have an automatic reversing jam clearing feature. By using a slightly more - complicated centrifugal starting switch, the split - phase motor rotates in the opposite direction from the previous run each time it is started. This can clear minor jams, but is claimed to be unnecessary by some manufacturers : Since the late 1970s most disposal units have swivel impellers which make reversing unnecessary. Some other kinds of garbage disposal units are powered by water pressure, rather than electricity. Instead of the turntable and grind ring described above, this alternative design has a water - powered unit with an oscillating piston with blades attached to chop the waste into fine pieces. Because of this cutting action, they can handle fibrous waste. Water - powered units take longer than electric ones for a given amount of waste and need fairly high water pressure to function properly. Environmental impact Kitchen waste disposal units increase the load of organic carbon that reaches the water treatment plant, which in turn increases the consumption of oxygen. Metcalf and Eddy quantified this impact as 0.04 pound of biochemical oxygen demand per person per day where disposers are used. An Australian study that compared in - sink food processing to composting alternatives via a life cycle assessment found that while the in - sink disposal performed well with respect to climate change, acidification, and energy usage, it did contribute to eutrophication and toxicity potentials. This may result in higher costs for energy needed to supply oxygen in secondary operations. However, if the waste water treatment is finely controlled, the organic carbon in the food may help to keep the bacterial decomposition running, as carbon may be deficient in that process. This increased carbon serves as an inexpensive and continuous source of carbon necessary for biologic nutrient removal. One result is larger amounts of solid residue from the waste - water treatment process. According to a study at the East Bay Municipal Utility District 's wastewater treatment plant funded by the EPA, food waste produces three times the biogas as compared to municipal sewage sludge. The value of the biogas produced from anaerobic digestion of food waste appears to exceed the cost of processing the food waste and disposing of the residual biosolids ( based on a LAX Airport proposal to divert 8,000 tons / year of bulk food waste ). In a study at the Hyperion ( Los Angeles ) sewage treatment works, disposer use showed minimal to no impact on the total biosolids byproduct from sewage treatment and similarly minimal impact on handling processes as the high volatile solids destruction ( VSD ) from food waste yield a minimum amount of solids in residue. Energy usage is not high ; typically 500 - 1500 W of power is used, comparable to an electric iron, but only for a very short time, totaling approximately 3 - 4 kWh of electricity per household per year. Daily water usage varies, but is typically one gallon of water per person per day, comparable to an additional toilet flush. One survey of these food processing units found a slight increase in household water use. References Jump up ^ Shpiner, Ron. `` The Effect of Domestic Garbage Grinding on Sewage Systems and Wastewater Treatment Plants ''. Submitted to Jump up ^ Denise DiFulco ( August 23, 2007 ). `` Grist for the Daily Grind ''. The Washington Post. Retrieved 2009 - 10 - 22. Jump up ^ US 2012680, Hammes, John W., `` Garbage disposal device '', published 22 May 1933, issued 27 August 1935 Jump up ^ `` General Electric History 1935 - 1945 ''. Retrieved 23 May 2013. Jump up ^ `` Kitchen Grinder for Waste Displaces Garbage Pail '', Popular Mechanics, 64 ( 4 ) : 542, October 1935 ; see hand written note at top of page of archive edition Jump up ^ Specter, Michael ( 22 June 1992 ). `` Only in New York : Garbage Disposers, Banned, Stir Debate ''. New York Times. Most major cities banned garbage disposers after World War II, driven by worries that ground food would clog sewer pipes beneath their booming neighborhoods... But a series of studies from universities and the not completely disinterested plumbing industry showed that the additional waste from ground food scraps would rarely harm a city sewage system. Jump up ^ RACINE, WIS. `` Cox of In - Sink - Erator dies of cancer at 84. ''. Archived from the original on 20 October 2007. Jump up ^ `` Insinkerator on its heritage ''. Insinkerator.com. Archived from the original on 2011 - 07 - 13. Retrieved 2011 - 04 - 23. Jump up ^ `` The Impact of Food Waste Disposers in Combined Sewer Areas of New York City '' ( PDF ). Retrieved 2011 - 04 - 23. Jump up ^ `` LOCAL LAW 71 OF 1997 ''. nyccouncil.info. Archived from the original on 15 November 2004. Jump up ^ `` City of Raleigh Council Approves Ban On New And Replacement Garbage Disposals ''. Raleigh-nc.org. 2011 - 04 - 18. Retrieved 2011 - 04 - 23. Jump up ^ `` Disposals to Grind on in Raleigh ''. WRAL.com. Capitol Broadcasting Company. April 15, 2008. Archived from the original on 2011 - 06 - 14. Jump up ^ American Housing Survey ( U.S. Census Bureau, 2009 ) Jump up ^ Leo Hickman ( 2006 - 08 - 21 ). `` Leo Hickman : Is it OK... to use a food waste disposer Money The Guardian ''. London : Money.guardian.co.uk. Retrieved 2011 - 04 - 23. Jump up ^ `` Water Canada - Everything but the Kitchen Sink - Water Canada ''. Water Canada. Jump up ^ Anna Gustafsson ( 2008 - 09 - 01 ). `` Slopad avgift för avfallskvarn Stockholm SvD '' ( in Swedish ). Svd.se. Retrieved 2011 - 04 - 23. Jump up ^ Brat, Ilan ( 2008 - 02 - 27 ). `` Going Global By Going Green ''. Wall Street Journal. ISSN 0099 - 9660. Retrieved 2017 - 03 - 03. Jump up ^ `` Municipal Solid Waste in the United States : 2009 Facts and Figures '' ( PDF ). United States Environmental Protection Agency. December 2010. Retrieved 2011 - 05 - 26. Jump up ^ `` Greenhouse Gases and the Role of Composting : A Primer for Compost Producers '' ( PDF ). US Composting Council. 2008. Retrieved 2011 - 05 - 26. Jump up ^ Zito, Kelly ( 2009 - 07 - 24 ). `` Food waste helps power wastewater plant ''. Articles.sfgate.com. Retrieved 2011 - 04 - 23. Jump up ^ `` Sumter Water & Wastewater Plants and Maintenance ''. Sumtersc.gov. Archived from the original on June 8, 2009. Retrieved 2011 - 04 - 23. Jump up ^ Home Depot 's web site Archived November 9, 2016, at the Wayback Machine. lists 1⁄3, 1⁄2, 5⁄8, 3⁄4, and 1 HP models Jump up ^ Kirby Palm. `` Garbage Disposal power on ''. Nettally.com. Retrieved 2011 - 04 - 23. Jump up ^ `` Noise from universal motors vs. induction motors at howstuffworks.com ''. Home.howstuffworks.com. 2000 - 04 - 01. Retrieved 2011 - 04 - 23. Jump up ^ Solos, Heather ( 2 June 2010 ). `` How to Fix a Stuck or Locked Up Garbage Disposal ''. Home Ec 101. Retrieved 7 May 2015. Jump up ^ `` Magnet and induction motors in Commodore Disposers ''. Joneca.com. Archived from the original on 2011 - 07 - 13. Retrieved 2011 - 04 - 23. Jump up ^ Paul, Donna ( 1999 - 12 - 16 ). `` New Garbage Disposal Runs on Water Power, NY Times, December 16, 1999 ''. New York Times. Retrieved 2011 - 04 - 23. Jump up ^ `` Trash - Talking The Garbage Disposal : Examination Of A Not So Green US Export ''. TreeHugger. Retrieved 2011 - 04 - 23. Jump up ^ Tchobanoglous, G., F. Burton. 1991 `` Wastewater Engineering -- Treatment, Disposal, and Reuse ''. 3rd. Edition, Metcalf & Eddy. Jump up ^ Lundie, S. ; Peters, G. ( 2005 ). `` Life Cycle Assessment of Food Waste Management Options ''. Journal of Cleaner Production. 13 ( 3 ) : 275 -- 286. doi : 10.1016 / j. jclepro. 2004.02. 020. Jump up ^ Rosenwinkel, K. - H. and D. Wendler. Institute for Water Quality and Waste Management, University of Hanover ( ISAH ). `` Influences of Food Waste Disposers on Sewerage System, Wastewater Treatment and Sludge Digestion ''. Jump up ^ `` Archived copy '' ( PDF ). Archived ( PDF ) from the original on 2011 - 09 - 28. Retrieved 2010 - 10 - 22. ^ Jump up to : Hernanadez, Gerald L., Kenneth R. Redd, Wendy A. Wert, An Min Liu, and Tim Haug. `` Hyperion Advanced Digestion Pilot Program ''. Jump up ^ Karlberg, Tina and Erik Norin. VA - FORSK REPORT, 1999 - 9. `` Food Waste Disposers -- Effects on Wastewater Treatment Plants. A Study from the Town of Surahammar ''. Jump up ^ New York City Department of Environmental Protection. June 1997. `` The Impact of Food Waste Disposers in Combined Sewer Areas of New York City ''. Jump up ^ Hickman, Leo ( August 8, 2006 ). `` Is it OK... to use a food waste disposer ''. The Guardian. London. Retrieved May 3, 2010. Jump up ^ Karlberg, Tina and Erick Norin. VA - FORSK REPORT, 1999 - 9. `` Food Waste Disposers -- Effects on Wastewater Treatment Plants. A Study from the Town of Surahammar ''. External links How to maintain a Garbage Disposal repair, a how - to article from wikiHow Retrieved from `` https://en.wikipedia.org/w/index.php?title=Garbage_disposal_unit&oldid=804750361 '' Categories : Home appliances Waste treatment technology Products introduced in 1935 Food waste Hidden categories : CS1 Swedish - language sources ( sv ) Webarchive template wayback links All articles with unsourced statements Articles with unsourced statements from February 2016 Articles with unsourced statements from July 2016 All articles with specifically marked weasel - worded phrases Articles with specifically marked weasel - worded phrases from July 2016 Talk Contents About Wikipedia Čeština Dansk Deutsch Español Français 한국어 Ido Íslenska Italiano Nederlands 日本 語 Polski Svenska Edit links This page was last edited on 10 October 2017, at 22 : 24. About Wikipedia

Question: where does the food go in the garbage disposal
Answer: plumbing