How Does a Garbage Disposal Work?

Powered by electricity, the disposal uses a small motor (typically 1 hp or less) to rotate a blade that quickly chops anything you put into the disposal's grinding chamber. This part of the process can be deduced just by operating a garbage disposal, but there is more to it than that. There is also an impeller and plate system that pushes the chopped particles down the drain.

The drain from the dishwasher also runs to the garbage disposal. That means those bits of food waste get the grinding they need before passing through the plumbing, too.

Note: one misconception is that all disposals have blades. Contrary to popular belief, the spinning mechanism on most garbage disposals today does not use a blade. It uses two lugs mounted on a steel plate (they spin in unison). For the sake of facilitating understanding in conversation, we still refer to it as a blade because that's what everybody calls it.