The DZL series quick fitting boiler is the horizontal tri-returning water and fire pipes chain grating boiler, which uses medium quality soft coal.　The boiler body is a single cylinder type, portrait arrangement; there are left and right double rows of fire pipe bundles inside the boiler cylinder to form convection heat receiving surfaces, the boiler cylinder to form convection heat receiving surfaces, the boiler cylinder and water-cooling walls at both sides shape the furnace radiation heat receiving surfaces; the combustion equipment uses light chain grating; exit shop in whole machine & quick fitting type. The electric control realizes grating step free timing, the extreme parameter alarm and inter-lock protection. Features of this series of boiler: compact structure, small volume; convenient installation, cheap in construction; mechanized coal feeding and cinder removal; the output of the boiler is presented as sufficientand high efficiency .It is the most appreciated form of equipment for extensive steam supplying for medium and small enterprises and public heating.