SZL packaged water-tube steam boiler is the double-cylinder, water-tube assembly, chain grate boiler.
Two cylinders are laid at the upper and lower level of boiler longitudinally along the center. Front section
of the upper cylinder and water-cooled tubes at side walls form the radiation-heating area in the hearth.
While the rear section and tube bank in the lower cylinder serve as convection-heating area. Coal
economizer is mounted at the rear of boiler. Some heat of hot combustion fume is absorbed by the hearth.
Then hot combustion heat flows to the convection heating area through cooling chamber and exhausts
outside with the chimney via coal economizer, dust collector and draught fan.