Here's a good pivture of a compacter, which we've always used for disposal at supermarkets, department stores, etc. Usually there's a chute which opens into the back of the store for easy dumping. Sometimes you still have to take the trash outside and dump it into the compacter by hand.
The large trash bin looks something like this, except it usually has two doors on top that open at an angle, horizontally, by hand. When I find a good picture I'll add it here.

http://www.pandawaste.ie/compact.htm