Removal of metallic scale and corrosion products generally requires chemical cleaning. Acid or chelant cleaning procedures vary greatly depending on individual circumstances. Chemical cleaning can improve the boiler heat rate and reduce the number of tube failures. It typically improves the stability of boiler chemistry.
To guarantee the successful and efficient shell boiler operation, the user must:
1)Know the conditions, environment, and demand characteristics of the plant, and accurately specify these conditions to the boiler manufacturer.
2)Provide a boiler house layout and installation that promotes good operation and maintenance.
3)Select the control systems that allow the boiler to operate safely and efficiently.
4)Select the control systems that will support the boiler in supplying dry steam to the plant at the required pressure(s) and flowrate(s).
5)Identify the fuel to be used and, if necessary, where and how the fuel reserve is to be safely stored.
In the operation of gas-fired steam/hot water boiler, it need continuous water supply to ensure the water volume in the drum. Once water shortage occurs, it will cause the boiler dry burning problem, which will further result in the boiler failure and other problems.
The economizer is a heat exchanger equipment which utilizes heat recovery of flue gases to heat feedwater. It can increase boiler efficiency, reduce the temperature of flue gas and save the fuel by absorbing recovery of flue gases. Besides, the feedwater is heated through the economizer before it is supplied into steam drum to decrease the thermal stress of the steam drum wall caused by temperature difference, which can improve the operating conditions of steam drum and prolong the service life of the steam drum.
In a water tube steam boiler, unlike a fire tube, water circulates inside the tubes. The heat that is generated and the combustion gases that surround the tubes heat the water that circulates inside them. Many water-tube boilers operate according to the principle of natural water circulation.
The capacity of this type of boiler can be enhanced by increasing the number of tubes in the boiler.
