The equipment of the rolling mill has strict requirements for the heating furnace

In order to strengthen the rapid deformation rolling of the steel billet, the entrance temperature of the rolling mill equipment should be maintained within the suitable temperature range allowed for the steel billet, which is around 1150 degrees Celsius. The purpose of heating the steel billet is to achieve the required thermal characteristics for rolling. It is important to avoid physical and chemical changes in the steel billet such as discoloration, decomposition, melting, and deformation. For the same type of steel billet, the entrance temperature varies with different heating furnaces. The heating temperature and holding time also affect the same type of steel billet. In general, in a regenerative heating furnace, the steel billet is stepped from a low-temperature zone to a high-temperature zone through a pusher, so the temperature at the outlet is high. The heating of the steel billet is carried out from both sides, and the steel billet does not need to be turned over, ensuring uniform and fast heating with a short time.

The outlet of the heating furnace of the rolling mill equipment has strict requirements for humidity. When the steel is not discharged, closing the furnace door can reduce air consumption and heat transfer, thereby reducing the cost of coal or gas. If the surrounding humidity is relatively high, the water vapor pressure in the rolling mill heating furnace increases, which reduces the average pushing force in the furnace. To maintain the same heating capacity, it is necessary to increase the length and width of the heating furnace, thereby increasing the investment cost.

For the same type of billet, the selected type of heating furnace is different, and the suitable relative humidity values are also different. For example, for a step-type heating furnace, since the steel billet stays in the heating furnace for a short time, a larger pushing force is required to increase the heating rate. The water vapor pressure in the outlet gas needs to be lower than half of the water vapor pressure on the surface of the outlet material. For a regenerative heating furnace, the water vapor pressure in the outlet gas is generally about 60% of the water vapor pressure on the surface of the steel billet. The production method of rolling and opening the electric arc furnace steel ingot is characterized by using a preheating furnace for heating and a roughing mill for rough rolling. For some rolling mills, it is required to ensure a certain air speed. Therefore, when constructing the heating furnace, the relationship between air volume and relative humidity should be considered. To meet the requirements of a larger air speed, a larger air volume can be used to reduce the relative humidity value, enhance the heating rate of the steel billet, and reduce high-temperature losses.

If the temperature of the heating furnace increases, the heat loss is large. If the temperature decreases and the relative humidity is relatively high, moist air may condense into water droplets in the equipment and pipes behind the steel ingot heating furnace, thereby disrupting the normal use of the heating furnace. The internal temperature change of the steel billet is an important parameter when it is heated in the heating furnace, but currently, only the surface temperature of the steel billet can be measured, and the internal temperature of the steel billet cannot be measured. The outlet temperature of the steel billet, in a continuously counter-flow operating heating furnace, air and fuel gas enter the heating furnace together for combustion, evaporating the moisture in the steel billet, facilitating the gradual increase in its temperature.