■ boiler WNS-type and SZS sub-type two kinds of structure. WNS-type boiler is a typical horizontal structure of the three return all wet back boiler combustion environment, wave oven lamps, expansion of fire-burning, expansion of radiant heating surface, boiler small size, elegant appearance. ■ SZS-type structure for the water pipes, furnace volume large enough heating surface for low calorific value fuel. ■ automatic control, simple, safe and reliable. ■ application of fuel: light oil, heavy oil, natural gas, coal gas, liquefied gas and so on. ■ boiler capacity 0.5-20T / H (0.35-14MW).