The 20 ton coal gas fired steam boiler has high thermal efficiency and low emission. Its packaged type layout saves occupied area and transportation cost. Background.Perfect amounts of steam and power is needed in paper-making. Huaxi Paper Co., Perfect Transfer Cart. recently purchased one set of gas steam boiler,SZS type watertube steam boiler, burning coal gas. The company has their own captive power plant burning coal fuel, and the coal fired power plant produces coal gas every day.