The whole gas flow type include the outer stove, three set of inner stoves , and the 3ton hoisting tools.  When one inner stove have been finished carbonization, we will use the hoisting tools hoist the inner stove from the outer stove, then let the inner stove natural cooling, at the same time, we can put another inner stove into the outer stove, which will save a lot of cooling time, so the productivity effect increase a lot, it is the ideal choice for mass production of charcoal.