The main function of the heating furnace is to heat the billet to 1000-1250°C until it reaches sufficient plasticity to be rolled into the desired cross-section, size, or shape through a hot rolling mill. The required rolling temperature varies based on the material's chemical composition and grade. Depending on the metallurgical performance of the raw materials and production rates, the heating furnace's heating rate must also meet specific requirements and goals. During the heating furnace treatment process, the material continuously flows through the furnace, heating the raw material to a certain temperature.
Heating furnaces can be categorized into various types, including continuous heating furnaces, walking beam furnaces, regenerative furnaces, and roller hearth furnaces. The selection of the appropriate furnace type depends on factors such as heating capacity, material grade, and material shape. The heating furnace used for metal heat treatment is also referred to as a heat treatment furnace. The furnace used for preheating steel ingots before initial rolling or for homogenizing the internal temperature of steel ingots is known as a soaking pit furnace.
The heating furnace primarily consists of a refractory material (dense insulating material)-lined heat storage chamber, a furnace chamber that supports and transports the heated components, the furnace body, and a heat recovery system. Fuels like petroleum, natural gas, electricity, and coal are used as the main heat sources. Furnace temperature and pressure are controlled automatically or manually.
Refractory materials play a crucial role in controlling energy consumption and improving heating furnace efficiency. The service life of the refractory material lining and the production efficiency of the heating furnace largely depend on the proper selection of refractory materials, refractory material design results, and accurate construction methods.
The purpose of the refractory material lining in the heating furnace is to prevent heat loss from the furnace body, ensuring that the outer surface temperature of the furnace remains relatively low. This helps maintain safe working conditions around the heating furnace and contributes to achieving the target of unit fuel consumption. The design structure of refractory materials also takes into account minimizing heat loss from side walls, furnace roofs, and furnace bottoms to the greatest extent possible.
