Industrial boilers are welded from sturdy steel plates that are engineered to withstand intense heat and pressure - as a result of this thick steel, boilers can sometimes weigh as much as 165 tons! The construction of hot water boilers and steam boilers is very similar. They both feature a cylinder tube, otherwise known as the pressure vessel. The pressure vessel contains something called a flame tube, which is fired through a burner and a reversing chamber that feeds flue gases back through a second smoke tube. These flue gases are reversed again via an external reversing chamber. This reversing chamber sends the flue gases to the end of the boiler, in the third smoke tube pass. A major difference between hot water industrial boilers and the steam versions? Hot water boilers, as their name implies, are usually completely filled with hot water during their operation, while steam boilers are filled with water only until the ¾ mark, with the top fourth of the boiler reserved for steam.
The choice between a steam system or a thermal fluid system is governed by the process requirements. The range or process temperature is a deciding factor. If the system’s required temperature is above the freezing point of water (0°C) and below approximately 160°C, the choice is usually steam. However, if the required temperature is above 160°C, thermal fluid may be a better solution. Thermal oil heater systems can be designed with maximum operating temperatures to 325°C.
The primary objective of an industrial boiler is the generation of steam. Steam is generated by heat transfer at a constant pressure. The fluid, which is initially in a liquid state, is heated, produces a variation in its phase and becomes saturated vapour.
This saturated steam can then be used for different applications such as sterilization, fluid heating or electricity generation.
