Boiler-working process (schematic diagram and combustion system diagram of a 120 t/h natural cycle coal-fired power station boiler).
The coal is first ground into powder by a coal mill.
Pulverized coal is carried by air and burned in the furnace through burners mounted on the furnace wall.
The gas temperature at the center of the flame reaches 1500~1600℃.
The evaporative heating surface of the boiler is installed on the inner wall of the furnace, forming a water-cooling wall, absorbing the radiant heat of the high-temperature flame and flue gas in the furnace, making the flue gas temperature at the outlet of the furnace drop to 1000~1150℃.
The upper part of the water wall of the rear wall (at the entrance of the horizontal flue) consists of a sparse sequence of slag tubes to prevent slagging.
Ash blowers are also used to prevent ash or slagging on the heating surface of the boiler.