The process and precautions of hot blast stove refractory ball replacement

Refractory ball for blast furnace ball hot blast stoves are made of bauxite as the main raw material, after batching, pressing, drying and high temperature firing. Refractory balls are used in small blast furnaces, and have superior thermal characteristics such as large heat surface area, large heat capacity, large heat exchange area, and high air temperature. It has the characteristics of high load softening temperature, good thermal shock resistance, peeling resistance and corrosion resistance.

Precautions for replacing the refractory ball of hot blast stove

The first step is to cool down the furnace before replacing the refractory ball in the furnace. Reduce in advance and send air to the hot blast stove that needs to replace the refractory ball until the vault temperature is lower than 900 ℃, and the furnace can be closed and stopped. Bring this hot blast stove to supply air in advance, until the vault temperature is lower than 900 ℃, the stove can be closed and stopped.

The second step is to shut off the gas, cold air and pressure equalizing valves after the hot blast stove is closed according to the program. Then open the flue valve, open the combustion-supporting air regulating valve to start cooling the furnace, time: 16 hours. Pay attention to the decrease of the vault temperature during the cooling of the furnace. Temporary thermocouples can be inserted into the vault of the hot blast stove, which can be controlled by the combustion-supporting air regulating valve to shorten the time as much as possible. The refractory ball can be unloaded when the vault temperature is lower than 400℃.

Note that the flue valve is in the open position during the unloading of the refractory ball and must not be closed. Later, the top manhole and ball loading hole can be opened to measure the unloading position. The hot blast stove should be reliably cut off from the main control room computer and manual valve. Dispatching and coordinating vehicles must not delay time, and the unloading field must be picked up in time to ensure that the tractor is unloaded in time.

It should be noted that if it is necessary to carry out blasting, it is necessary to prepare for protection in advance, especially to clean up the site personnel, to prevent the idle personnel from entering the site, and the safety and environmental protection personnel to supervise the site. If there is agglomeration in the hot blast stove and not suspended in the air, implement the lower unloading hole blasting; if it is suspended, implement the upper ball loading hole blasting, and try to work in the lower part. After unloading the ball, clean up the debris in the hot blast stove, block the unloading manhole and prepare to reload the ball.