MBZ direct coal-fired hot air furnace consists of MBL coal burner, high-temperature pueifying room and air mixing room.

Bituminous coal (soft coal) is fed into coal hopper through coal feeder. The coal at a certain height is delivered into burning hearth of coal burner by chain gate.

Combustion fan sends air into burner, hot gas produced by burning coal erupts from fire outlet of coal burner and enters in high-temperature purifying room at about 1000deg.C then mixes into a certain amount of fresh air, the mixture at the wanted temperature flows into dryer(such as spray tower, rotary dryer, oven, drying house, flash dryer, fluidized bed etc.)to dry material. Temperature of hot air can be adjustable according to the demand. When hot air is supplied continuously, its temperature fluctuates within ±5 deg.C.