A garbage disposal unit (also known as a waste disposal unit, garbage
disposer, garburator, etc.) 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) in diameter—to pass through plumbing.
The garbage disposal unit was invented in 1927 by John W. Hammes, an architect working in Racine, Wisconsin. He applied for a patent in
1933 which 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 “Disposal”.
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 After a 21-month study with the NYC Department of Environmental Protection, the ban was rescinded in 1997 by local law 1997/071.
In 2008, the city of Raleigh, North Carolina attempted a ban on the replacement and installation of garbage disposers, which also extended to outlying towns sharing the city’s municipal sewage system, but rescinded the ban one month later.
HOW DOES IT WORK?
A high-torque, insulated electric motor, usually rated at 250–750 W ( 1 ⁄ 3 –1 hp) for a domestic unit, spins a circular turntable mounted horizontally above it. Induction motors rotate at 1,400–2,800 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, also known as series-wound motors, rotate at higher speeds, 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.
Inside the grinding chamber, there is a rotating metal turntable onto which the food waste drops. Two swiveling and sometimes also two fixed metal impellers mounted on top of the plate near the edge then fling the food waste against the grind ring repeatedly. Sharp cutting edges in the grind ring break down the waste until it is small enough to pass through openings in the ring, and sometimes it goes through a third stage where an under-cutter disk further chops the food up, then it is flushed down the drain.
Usually, there is a partial rubber closure, known as a splashguard, 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.
COMMON ISSUES
Garbage disposals can finicky. They need to be tightened, loosened, and re-tightened again. They can even become so loud that you can barely hear the television. If your garbage disposal won’t turn on, or if you’re experiencing some of the earlier-mentioned issues, call the Master Plumbers. Master Tech Service Corp, where help is next door.