In the rotary grate combustion system, from the moment the coal is poured from the service bunker into the grate, it moves into the furnace with the rotation speed of the grate. As soon as it enters the furnace for the first time, with the effect of radiation heat, the coal first begins to release its moisture, gasification with the increase of temperature and release volatile-flammable hydrocarbons and complete the constant carbon combustion in the further parts of the grill. All components of the charcoal continue to burn until the end of the grill.