The boiler can be divided into soft coal boiler, high sulfur coal boiler, liquid fuel boiler, coal fired boiler and fire tube boiler by the fuel. Both water-fire tube boiler and horizontal fire tube boiler belong to the fire tube boiler. The horizontal fire tube boiler is designed according to the former boiler, two returns tube of which is altered into single return tube. And the previous braced tablet is changed into arched tube plate with no braced plate stress. For this reason, the inspection and maintenance space as well steam and water separation space are obviously increasing. American CB, Fulton, Cochran are represent famous brands of fire tube boiler in the worldwide. The overwhelming majority boiler manufactures in China focus on producing fire tube boiler.
The exhaust gas which is produced after fuel burst following through fire box or fire tube heat the fire box or water and steam mixture, which is called fire tube boiler. And the fire tube boiler is also called shell boiler. A little cylinder, pipe (what is called fire tube), other shell body (what is called boiler furnace) compose of the basic structure of the big cylinder in the fire tube boiler. The interlayer which is formed by fire tube and big cylinder fills water, the fire tube and the boiler furnace containing flame and exhaust gas as burst chamber and funnel.
The advantages of fire tube boiler are following. It has big volume, strong heat storage capacity and simple structure, installation and operation. But the fire tube boiler has weak evaporation intensity low vapor pressure. The working conditions are bad because the boiler shell and internal components are heat up directly. Besides, the strength of boiler shell is weakened because of trapping and large storage. The vapor heating surface which lies out in the cylinder is called shell boiler or fire tube boiler.
The use and maintenance cost analysis of the fire tube boiler will be introduced in detail in the following. First, the fire tube boiler is not sensitive to the water quality. Conventional resin softening is pretty god without chemical medicine. Second, the structure of the fire tube boiler is reliable, and the operation and maintenance are convenient with long life. It has not booster hidden danger. Third, the boiler manufactures in China almost produce the fire tube boiler, the burners of which are Europe and America famous brands in common. And the purchase of fittings is convenient and fast, just because of this, the user cannot be strict by the fire tube manufactures.
The customers of fire tube boiler are very broad, for example, mining, enterprises, hotels, schools, government, public constructions, hospitals and all kinds of invest environment and situation. Both five-star hotels (Shangri-La, Sheraton, and Hilton) and Multinational Corporation (Coca-Cola, Pepsi) also use the fire tube boiler.