SZS series boiler is designed with longitudinal double drums and " D " type chamber structure. Furnace is placed on the right and convection tube bank is on the left, super heater is arranged at convection tube bank. The body is fixed on the basement by middle and both end flexible supports and make the boiler expand horizontally sideways. Around the furnace is membrane water cooling tube wall. Furnace and tube bank are totally separated by the membrane water tube cooling wall at the left side of the furnace. The back part of bundle is sparse shift structure, front part is aligned structure. Smoke from furnace outlet enters re-burning chamber, convection tube bank area and then from left front part enters spiral fine coil economizer and condenser, and finally is discharged to atmosphere through chimney.