DZL series package boiler is a horizontal three-pass water and fire pipe chain grate boiler, which uses medium-sized bituminous coal. The boiler body is vertical single drum, and the threaded pyrotechnic tube is arranged in the drum to form a convection heating surface, and the drum and the water walls on both sides constitute a radiation heating surface of the furnace. The combustion equipment uses light chain grate, the whole package is finished in the factory. The electric control makes the governor stepless speed regulation, the limit parameter alarm and the interlock protection.