The function of refractory materials for hot blast stoves is to insulate heat and withstand high temperature loads. Therefore, when determining the material and thickness of furnace lining materials for various parts, it should be based on the temperature, load and thermal insulation requirements of the masonry, as well as the effect of flue gas on the masonry. It depends on the physical and chemical effects and other conditions.
The main requirements of the checker bricks in the high temperature area of the regenerator are to have good high temperature volume stability, corrosion resistance and creep resistance. Silica bricks have these characteristics and are cheap. The furnace is widely used. According to the specific situation in China, when the design temperature of the top of the hot blast stove is not less than 1400°C, on the premise of good blast furnace fuel combustion and high operation level, the preferred refractory material in the high temperature area of the hot blast stove should be silica brick. Residual quartz should be controlled at not more than 2%. For hot blast furnaces using silica bricks, attention should be paid to carefully determine the lower limit of the use of silica bricks, and a reliable temperature detection device should be set up here to ensure that the use temperature of bricks is not lower than 800°C. When the design temperature of the top of the hot blast stove is not higher than 1400°C, the use of low-creep, high-density ,high-alumina refractory materials is more suitable for China's actual situation, and can make full use of China's abundant resources. Bauxite resources. At present, the creep resistance index of foreign high-alumina refractories has reached a relatively good level. For example, the creep rate of HD bricks of Hogovin in the Netherlands is not more than 0.2% under the conditions of 1350℃, 0.2MPa, and 50h; Shinagawa, Japan The AC-8M brick index is 1300℃, 0.2MPa, and the 50h creep rate is not more than 0.2%; at present, the creep rate index of high alumina refractories in China is not more than 1% under the corresponding conditions, which is compared with the world advanced level. There is still a big gap. At the same time, in view of the current situation of producing low-creep high-alumina bricks in China, while strictly assessing the creep index of bricks, it also controls the impurities contained in the products, especially the content of alkali metals and alkaline earth metals.
For the checker bricks in the middle and lower parts of the regenerator, high alumina and clay refractories are usually used. With the increase of the height of the regenerator of the large-scale hot blast stove, the pressure of the upper checker bricks on the lower refractory materials is also increasing. In addition, according to the damage investigation of the checker bricks of the large-scale high-temperature hot blast stove abroad, the lower checker bricks are caused by the periodic temperature fluctuation. The cracking and breaking phenomenon of checkered bricks is increasing, so in addition to continuing to control the creep characteristics of the lower clay bricks, higher compressive strength and thermal shock stability times (resistance to rapid cooling and rapid heating) are proposed for the products at room temperature. requirements.
Refractory balls are used instead of checkered bricks in the regenerator of the ball-type hot blast stove. The ball-type hot blast stove, which uses refractory balls instead of checkered bricks, has applications in small blast furnaces. The refractory ball has the advantages of large thermal surface area, large heat capacity, large heat exchange area and high air temperature. The refractory ball material used in the high temperature area is usually high alumina refractory material, and the low temperature area uses clay refractory material.
Zhengzhou Shennan Refractory Co.,Ltd are professional in producing different kinds of the refractory bricks ,any demands,please don't hesitate contact with me.
 |
+86-15238007351 |
 |
+86-371-86039318 |
 |
annie@snrefractory.com |
 |
www.snrefractory.com |
