They are systems operating at low pressure and high temperature. It is preferred in drying and oven fixing processes where high temperature requirement is required in the industry. Hot gases formed as a result of combustion pass through the combustion chamber, which we call the first pass, and are transported towards the second smoke pipes to the rotating front. Gases passing through the front smoke box are collected here and directed to the cyclone. After leaving the cyclone, he goes to the chimney and is thrown out of it. As it works with the principle of overhead combustion, coal burns completely and pollutes the environment to a minimum. The feed water of the boiler is prepared in the front furnace and this high temperature water is sent to the boiler. In this way, a rapid steam production takes place. Boat, loading and helix, coal silo, reducers turning the helix, fresh air fan are the main elements that make up the system. The burning event takes place in what we call the boat. The part that provides coal transportation to the boat is the boat spiral and the part that carries the coal to the silo is the loading spiral. Since fuel is loaded to the boiler through the helix, the combustion takes place from below. Unburned coal particles do not spread into the environment, as a complete combustion takes place.