Classification of hot blast furnaces: direct and indirect hot blast furnaces

　　The hot blast furnace was one of the most important technologies developed during the industrial revolution, because the hot blast in a hot blast furnace is the preheating of air blown into the blast furnace or other metallurgical processes, which greatly reduced fuel consumption.Hot air also allows for higher furnace temperatures, thus increasing furnace capacity.hkWBoiler Burner

　　Hot air furnace can be mainly divided into direct type of hot air furnace and indirect type of hot air furnace.The following by broad thermal energy for you to introduce the two types of hot air furnace.hkWBoiler Burner

　　The direct hot blast furnace adopts direct combustion of fuel, and forms hot air after high purification treatment, and directly touches the material to heat and dry or bake.This method USES about half as much fuel as steam or other indirect heaters.Therefore, in the case that does not affect the quality of drying products, you can use direct hot air furnace.Its fuel can be divided into: solid fuel, such as coal, coke.Liquid fuels, such as diesel, heavy oil gas fuels, such as gas, natural gas, liquid gas.The high temperature combustion gas obtained from the fuel after combustion reaction is further in contact with the outside air, mixed to a certain temperature and then directly into the drying chamber or baking room, in contact with the material to be dried, heating, evaporation of water, so as to obtain dry products.In order to utilize the heat of combustion reaction of these fuels, a fuel combustion device must be added.Such as: coal burner, oil burner, gas burner, etc.hkWBoiler Burner

　　Indirect hot air furnace is mainly used for drying materials that are not allowed to be contaminated, or for drying heat-sensitive materials with lower temperature.Such as: milk powder, pharmaceutical, synthetic resin, fine chemical and so on.This kind of heating device, that is, steam, thermal oil, flue gas as a carrier, through a variety of forms of heat exchangers to heat the air.The most essential problem of indirect hot blast furnace is heat exchange.The larger the heat exchange area, the higher the heat conversion rate, the better the energy saving effect of hot air furnace, the longer the life of furnace and heat exchanger.Conversely, the heat exchange area can also be identified from the flue gas temperature.The lower the temperature of hot air furnace smoke, the higher the heat conversion rate, the larger the heat exchange area.hkWBoiler Burner

　　Through the above description, I believe you have a deeper understanding of the hot blast furnace.If you have any questions, please call our hotline.hkWBoiler Burner