Industrial steam boiler is the machine equipment which heats water to a certain parameter and produce high temperature steam. Steam boiler belongs to special equipment, the design, processing, manufacturing, installation and use of the boiler must be subject to the supervision of the technical supervision department, the users can only use the steam boiler if they have obtained the boiler usage certificate. According to fuel (electricity, oil, gas), steam boilers can be divided into three types: electric steam boilers, oil-fired steam boilers and gas-fired steam boilers. Users should pay attention to the boiler model, manufacturer and auxiliary machine configuration and operating costs when selecting industrial steam boilers.

During the operation of the industrial steam boiler, the heating equipment (burner) releases heat, which is first absorbed by the water-cooling wall by radiative heat transfer, and the water of the water-cooled wall boiling and vaporizes, generating a large amount of steam into the steam drum for steam-water separation. The separated saturated steam enters the superheater and continues to absorb the heat of the flue gas at the top of the furnace and the horizontal flue and the tail flue by radiation and convection, and the superheated steam reaches the required working temperature. Simply put, the water is heated into steam in the drum, and the heat is emitted from the furnace, which is the principle of the steam boiler.
At present, industrial steam boilers are an important source of power for many industries, and they bring huge economic benefits and also cause a large amount of energy consumption. As energy prices continue to rise, increasing the thermal efficiency of boilers and reducing operating fuel costs have become the focus of attention. Reduce the sewage rate so that energy saving can do the following：1. Do a good job in water treatment, improve the quality of boiler feed water, reduce its salt content and alkalinity, and make boiler feed water meet relevant standards; 2. Proficiency in the sewage operation technology, remove impurities from the boiler water as much as possible, increase the concentration of sewage, improve the sewage discharge effect, and discharge according to the structural characteristics of the boiler, water quality test, and heat load; 3. The use of advanced sewage equipment, such as boiler automatic sewage device, the selection of qualified tap water, recycling of sewage, indirectly reduce the sewage rate. Another example, the sewage through the heater to supply boiler feed water and heating.
Reasonable sewage discharge from industrial steam boilers can not only regulate and control boiler water quality, prevent boiler fouling or corrosion, but also be an effective measure to improve boiler thermal efficiency. In order to make the boiler water quality meet the national standards, the alkalinity and salt content of the water should be controlled by properly discharging the impurities, mud, and scale. Furthermore, the cleaning of heating surface is guaranteed, qualified steam quality is satisfied, and the service life of boiler is prolonged. In order to save energy, the steam and waste heat of the boiler sewage should be recycled as much as possible to reduce unnecessary losses, thereby achieving energy conservation. Boiler sewage management is an important task about energy saving. In today's global energy shortage and rising energy prices, industrial steam boiler sewage heat recovery system has far-reaching practical significance.