■ The boiler adopts the latest research results, such as: arched tube plate, screw-thread smoke tube, hot-water boiler backwater ejection technology, solving the pot-type boiler tube plate crack at the lower part of the drum, drum kits, water-wall tube breakage, low thermal efficiency, low output, and poor adaptability of coal.
■ Combustion: fuel from the coal scuttle falls in front of the stove grate. During operation, after coal preheating, dry distillation, ignition, and combustion, the slag drops into the slag bucket, then is removed out of the furnace by a slagging machine at any time. The furnace arch uses a herringbone arch, improving the conditions of ignition. Flue gas forms a vortex between the throat of the front and rear arch, mixed with air. After combustion, flue gas enters the two-wing flue, through the front smoke box into the thread smoke tube, then goes through cast-iron economizer (hot-water boiler not needed), dust collector, and finally is discharged by the lead fan to the chimney.
■ Boiler water circulation progresses on natural circulation and ejection. The radiation heating surface is the left and right side cold-water wall. The two wings of the boiler furnace are the main convection heating surface. The thread smoke tubes in the boiler furnace are convection heating surfaces. The boiler furnace is separated by fold smoke wall — firebox and re-burning chamber. The boiler main body is covered by a three-dimensional shape plate shell.