Thermal insulation method of silica brick hot blast stove

Abstract

The invention discloses a thermal insulation method of a silica brick hot blast stove. The thermal insulation method comprises the following steps: 1) stove firing circulation: when the temperature at the arch crown is lower than a first temperature or the temperature of silica bricks in the middle of the stove is close to a second temperature, starting stove firing; when the temperature at the arch crown achieves a third temperature or flue temperature achieves a fourth temperature, stopping stove firing and starting thermal insulation; when the temperature at the arc crown is stable and the flue temperature is heated to the fourth temperature, stopping circulation of stove firing, and adopting back-blowing stove firing; and 2) back-blowing stove firing: introducing combustion-supporting air into a cold air pipeline, and providing back-blowing cold air for a hot-blast stove, when back-blowing achieves arch crown and the temperature is not increased and begins to decline, stopping back-blowing, performing thermal insulation by adopting firing stove circulation, and sequentially circulating. The stove firing and air supply integration can be realized by utilizing the self pipeline of the hot-blast stove, and the thermal insulation purpose of the silica brick hot-blast stove can be achieved; the energy consumption can be reduced while the thermal insulation purpose can be met; and the operation is simple and easy and can be realized by utilizing the original pipeline of the hot-blast furnace without the need of new equipment, thus being small in investment.

Description

technical field [0001] The invention relates to an air supply system in the technical field of blast furnace ironmaking, in particular to a hot blast stove system that provides high blast temperature for a blast furnace. Background technique [0002] The hot blast stove heats the cold air to the temperature required by the blast furnace and supplies it to the blast furnace to improve the benefit and efficiency of blast furnace ironmaking. During the normal production process of the blast furnace, the hot blast stove continuously provides hot air for the blast furnace. The hot blast stove built with silica bricks cannot be shut down, and insulation measures need to be taken. There are two reasons: one is that the silica content of silica bricks is above 94%, and the properties of silica bricks are closely related to the crystal transformation of silica. The silicon dioxide has many crystal forms and volume changes at low temperatures, so the thermal stability of silica bricks...

AI Technical Summary

Problems solved by technology

[0002] The hot blast stove heats the cold air to the temperature required by the blast furnace and supplies it to the blast furnace to improve the benefit and efficiency of blast furnace ironmaking. During the normal production process of the blast furnace, the hot blast stove continuously provides hot air for the blast furnace. The hot blast stove built with silica bricks cannot be shut down, and insulation measures need to be taken. There are two reasons: one is that the silica content of silica bricks is above 94%, and the properties of silica bricks are closely related to the crystal transformation of silica. SiO2 has many crystal forms and volume changes at low temperatures, so the thermal stability of silica bricks at low temperatures is very poor.

Above 573°C, silicon dioxide changes from β-quartz to α-quartz. As the temperature continues to rise, the crystal form changes relatively little, and the structure is similar. 573°C is the critical temperature to ensure the life of silica bricks; , when the blast furnace is put into production again, the hot blast stove needs to be re-ignited for drying. It is difficult to ignite and the oven takes a long time, and it cannot quickly provide hot air for the blast furnace production, which affects normal production

It is difficult to control the air intake when using this method for cooling, and the grate and pillars in the lower part of the hot blast stove are not cooled uniformly, but the cooling near the manhole is better, and the parts far away from the manhole cannot be effectively cooled, posing a safety risk

Images