Simple it is to empty ashes from a Hitzer coal stove. You shake, and they drop into a pan with an airtight door in front of it.
You pull out the pan, shut the door, empty the pan and put it back in and shut the door again.
https://www.hearth.com/talk/threads/why-cant-a-woodstove-have-a-shaker-ash-pan-like-a-coal-stove.79404/
Electric plants that use coal pulverize it to the consistency of talcum powder. The smaller,finer material burns cleaner. Most people think there’s people throwing coal chunks into furnaces like in the movie Titanic.