A steam boiler is a water containing vessel which transfers heat generated by a fuel source into steam, which is then piped and directed to points where it could be used while running industrial equipment. The basic idea here is to convert water to steam using a source of heat.
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.
Coal-fired boilers are applied in various industries for the industrial and civil uses to generate steam and hot water. The steam is mainly used for production and the hot water is mainly used for heating and daily use.
If the following three conditions occur during the burning and flame out process of a gas-fired boiler, the furnace is likely to blow up.
1.The residual gas content in the furnace reaches the ignition limit at the start-up phase of the furnace.
2.The fuel content in the furnace reaches the ignition limit after several times failure of ignition.
3.The fuel is sprayed out because of the halfway extinction of the flame. And, the temperature of the furnace can not meet the spontaneous combustion condition of the sprayed fuel. However, the content of the sprayed fuel reaches the ignition limit.
Loads vary, and a power plant must be capable of handling the minimum load, the maximum load, and any load variations. Boiler selection is often dictated by the variation in load demand, rather than by the total quantity of steam or hot water required. There are three basic types of load variations: seasonal, daily, and instantaneous.
Evaporation phase occurs in water wall tubes. Evaporation is the process to convert water into steam. Therefore water wall tubes should be designed and constructed to provide high heat absorption, minimum excess air level and highest boiler efficiency. Construction of water wall tubes should be also constructed to prevent air leakage into steam boiler, eliminate amount of heat losses and permit high heat release and combustion rate in the furnace.
Construction of water wall tubes must provide high quality of the supporting component such as tubes, casing, refractory, lagging, tile, fin, and so on. Best construction will reduce heat loss and maintenance. Construction of water wall tubes can be classified into four types such as:
Water, which is the primary fluid inside the closed metal container of the industrial boiler, is heated to an atmospheric temperature and a pressure higher than the external one. Once the steam is generated, it advances through the pipes.
