Automatic oil or gas fired boilers series WNS have two types. One is steam boiler, and the other is hot water boiler. The capacity of steam boiler is 1~10t/h, working pressure is 0.7~1.6MPa. Output of the hot water boiler is 0.7~10.5MW, water service temperature is 95 or 115 degree, water return temperature is 70 degree. This series of boilers are adopted the structure of horizontal, internal- combustion, three-pass and full wet back. The combustion chamber consists of corrugated internal furnace and wet smoke box. The fuel oil is atomized and injected into the combustion chamber from the burner, here it's burnt into smoke of high temperature. The smoke enters the second pass threaded smoke tubes after the radiation and the convection heat transfer occurred in the furnace and the smoke box, then it's back to the third pass smoke tubes, and proceeds with the convection heat transfer again. At last it passes the rear smoke box and is dispelled via the chimney.

The characters of this series of boilers: Adopted the structure of full wetback. The high temperature smoke is surrounded by water. It can not only utilize the heating surface efficiently, but also prevent the rear smoke box from being destroyed by the high temperature smoke because of the structure of dry back.