1. Drum: The function of the drum is to collect, store, purify steam and make up water. The drum of the
hot water boiler is filled with hot water, while the lower drum of the
steam boiler is filled with hot water, the lower part of the upper drum is hot water, the upper part is the steam space, the surface of the water is called the water surface, and the location of the steam-water boundary is called water line.
2. Water cooling wall: The cooling wall is the radiant heating surface arranged around the furnace. It is the main heating surface of the boiler.
3. Convection tube bundle: The flow tube bundle is the convection heating surface of the boiler. It absorbs the heat of high temperature flue gas, and the heat absorption is related to the flow rate of flue gas, the arrangement of pipes, and the way of flue gas flushing.
4. Descending pipe: The main function is to transport the water in the drum to the lower header, so that the heating surface pipe has enough circulating water to ensure reliable operation.
5. Header: It mainly collects and distributes pot water to ensure reliable water supply for each heating surface pipe or to collect water or soda mixture from each pipe. Generally, the header should not be exposed to radiant heat to avoid the generation of internal water. Bubble cooling is not good, overheating burns out.
6. Superheater: The superheater is the auxiliary heating surface of the steam boiler. Its function is to draw saturated steam from the upper drum under the condition of constant pressure, and then heat it to evaporate the water in the saturated steam and make the steam temperature. Raise, improve steam quality, become superheated steam.
7. Coal economizer: The coal economizer is a heat exchanger that is arranged in the flue at the tail of the boiler and uses the waste heat of the exhaust gas temperature to increase the temperature of the feed water. Generally speaking, every time the water temperature at the outlet of the economizer increases by 1°C, the exhaust gas temperature of the boiler decreases by 2-3°C on average, and the feed water temperature does not increase by 6-7°C. Save 1% of coal, and generally, boilers equipped with economizers can save 5-10% of coal.
Any parts of the boiler can be found at
https://www.boilermanufactory.com/products/parts/ 
