What are the lining refractory materials for each part of the blast furnace hot blast stove?

The refractory configuration analysis of each part of the blast furnace hot blast stove is shared by the refractory brick manufacturers.

The blast furnace hot blast stove is a regenerative heat exchanger, mainly to provide a high temperature heating environment for the combustion air of the blast furnace to achieve high operating air temperature, generally 1200~1350℃. The common matching hot blast furnaces for blast furnaces are 3~4. In order to meet the requirements of high temperature heat source and long service time of hot blast furnaces, the refractory materials for hot blast furnaces should have the characteristics of high temperature resistance and high pressure resistance, good creep resistance, large specific heat capacity, and good thermal conductivity. .

According to the structure of each part of the hot blast stove and the influence of the furnace condition, the refractory materials for the hot blast stove can be divided into two parts: high temperature and low temperature. High temperature parts: including the upper part of the combustion chamber, checker bricks on the upper part of the regenerator, large wall bricks, top of the furnace, etc.; middle and low temperature parts: including the middle and lower parts of the combustion chamber, checkered bricks at the middle and lower parts of the regenerator, large wall bricks, and outlet parts, etc. .

According to the structure of the hot blast stove, it can be divided into: the top of the furnace, the large wall of the regenerator, the checker brick, the partition wall, the large wall of the combustion chamber, the burner and other parts.

1. Refractory at the top of the furnace:

The top of the furnace is located in the high temperature area inside the hot blast furnace, where the refractory material directly contacts the hot air and flue gas. The refractory material with strong thermal shock resistance and creep resistance should be selected. Generally, silica bricks and low creep clay bricks can be used. High alumina bricks, high alumina insulation bricks, mullite bricks, light clay bricks, andalusite bricks, acid-resistant spray paint, clay spray paint, etc.

2. Refractory materials for the large wall of the regenerator:

The large wall of the regenerator is a large wall of the hot blast stove body, where the upper temperature is relatively high, and the air temperature in the middle and lower parts is relatively low. The upper part of the large wall of the regenerator can use silica bricks, low creep high alumina bricks, and high aluminum heat insulation. Bricks, mullite bricks, light clay bricks, acid-resistant spray paint, light spray paint, etc.

In the middle part, low creep high alumina bricks, mullite bricks, andalusite bricks, light clay bricks, clay spray paint, light spray paint, etc. can be used.

The lower part can use clay bricks, high alumina bricks, light clay bricks, high alumina insulation bricks, clay castables, light spray paints, heat-resistant concrete, etc.

3. Refractory materials for checker bricks:

The upper high-temperature zone of the checker bricks of the regenerator should be made of refractory materials with good high-temperature volume stability, corrosivity and creep resistance. The middle and lower parts bear greater pressure from the upper refractory materials. In addition to satisfying its creep performance, it also needs to require good performance of its normal temperature compressive strength and thermal shock stability.

The upper part of the checker bricks generally uses silicon checker bricks and high-aluminum checker bricks, the middle part uses low-creep high-aluminum checker bricks and high-aluminum checker bricks, and the lower part uses low-creep high-aluminum checker bricks and clay checker bricks.

In addition, the regenerator of the spherical hot blast stove generally uses refractory balls to replace checker bricks, the most common is high alumina refractory balls, and clay refractory balls can be used in low temperature areas.

4. Refractory materials for partition walls:

The partition wall is a refractory brick wall that separates the regenerator and the combustion chamber. The height of the partition wall is generally 400~700mm higher than the checker bricks of the regenerator to ensure uniform air distribution. Due to the large temperature difference between the two sides of the partition wall, the thermal expansion difference of the wall becomes larger, which causes the refractory material of the partition wall to deform, bend and crack. Therefore, silica bricks and high alumina bricks can be used on the upper part of the refractory material of the partition wall.

High-alumina bricks and high-aluminum insulation bricks can be used in the middle, and low-creep high-alumina bricks and high-aluminum insulation bricks can be used in the thermal shock part.

Clay bricks and light clay bricks can be used for the lower part.

5. Refractory materials for the large wall of the combustion chamber:

The large wall of the combustion chamber is basically the same as the refractory material of the regenerator. The upper part can use silica bricks, high alumina bricks, high alumina insulation bricks, light silica bricks, light clay bricks, spray paint, etc.

High-alumina bricks, low-creep high-alumina bricks, high-alumina insulation bricks, light clay bricks, spray paint, etc. can be used in the middle.

The lower part can use clay bricks, high alumina bricks, lightweight clay bricks, spray paint, heat-resistant concrete, etc.

6. Burner nozzle:

The burner nozzle is the equipment that sends the gas mixed air into the combustion chamber for combustion. There are metal and ceramic materials. At present, most of the ceramic burners are used. In order to ensure the air tightness, integrity and service life of the burner nozzle, It is required that the linear expansion coefficient and creep resistance of the refractories here are good, so the burner nozzle can be made of mullite, mullite-cordierite, high-aluminum-cordierite, high-aluminum castable preforms, etc.

7. Refractory materials for other parts of the hot blast stove:

(1) Refractory materials for hot air pipes, including main air supply pipes, branch pipes and hot air surrounding pipes. Generally, it is made of light clay bricks, and the hot air outlet and the main air duct interface can be made of high-alumina bricks and mullite bricks. The hot blast stove surrounding pipe and the air supply branch pipe can be integrally poured with high-alumina cement refractory castable and phosphate refractory castable.

(2) The hot air valve is made of refractory materials, so both sides are heated and subjected to mechanical vibration, corrosion and temperature changes. The masonry life of clay bricks and high alumina bricks is 6 to October, and high alumina cement refractory castables are used. Pouring molding life can reach about 1.5 years.

(3) Refractory materials are used for the flue and chimney. The flue chimney is mainly used for the discharge of flue gas. The flue gas is longer than the flue gas. Therefore, the flue refractory materials can be built with clay bricks, and the chimney can be poured by concrete. The lower part is laid with clay bricks as a protective layer.