Garbage Disposer Basics - How They Work
Garbage disposers are pretty simple--and they all work on a similar principle. They put a flat plate that has small, rotating, steel mashers, and an inner disposer wall that has serrated "teeth" to work to do the job of grinding your food waste.
A motor inside the unit rotates the flat plate in the food-grinding area. When you switch the unit on, the mashers are forced to swing toward the outside of the spinning plate.
There are two types of disposers:
These are activated by a wall switch. When you place food in the disposer and switch it on, the mashers force the food against the serrated teeth of the inner wall and shred it. The shredded food then falls through small holes between the spinning plate and the inside walls, and is diverted into the drain pipe.
The job of the rubber shield at the top of the disposer is to keep fast-moving food particles from being ejected out of the disposer. The stopper lets you plug the sink to hold water when you're not using the disposer to grind food scraps.
Batch feed disposers function exactly like continuous feed disposers, except that, to switch them on, you place a special stopper in the disposer opening and turn it. The stopper activates a switch that turns on the disposer.