There are four main types of refractory balls: high-aluminum refractory balls, silica refractory balls, magnesium-aluminum refractory balls, and porcelain balls.

Currently, there are many high-aluminum refractory balls on the market, which are mostly used in spherical hot blast stoves with an area of less than 450m3. The refractory balls used in the regenerator of hot blast stoves will be affected by the periodic alternation of hot and cold at high temperatures and the erosion or slag bonding of alkaline gas dust. High-aluminum refractory balls are used in the high-temperature zone of the upper part of the pebble bed. The refractory degree and load softening temperature can meet the requirements, but the thermal stability and slag resistance are insufficient. Surface cracks and slag bonding will occur, resulting in poor air permeability of the bed and shortened ball cleaning cycle.

The silicon content of siliceous refractory balls is over 92%, and they have strong resistance to acidic slag corrosion, but their thermal stability at low temperatures is poor. Silica refractory balls are used in the high-temperature zone of the upper part of the pebble bed. Under high temperature and large gradient temperature changes, the surface of the ball will crack seriously, the resistance to alkaline gas dust erosion is poor, the slag bonding phenomenon will be serious, and ball cleaning will be difficult.

The core of the ball hot air stove is the ball bed. The ball bed is made of natural accumulation of equal-diameter refractory balls. It is divided into upper and lower sections according to the ball diameter and material. What kind of ball is best for high temperature areas? Let’s take a look at the performance of magnesium refractory balls.

Magnesia refractory balls have strong resistance to alkaline slag erosion. It has poor thermal stability and volume stability, but has strong thermal conductivity. In addition to the advantages of magnesia refractory products, it also has the thermal stability of high-aluminum refractory balls and silica refractory balls. Compared with magnesia-aluminum refractory balls, the thermal conductivity, heat capacity and thermal conductivity of magnesia refractory balls are greatly improved. , its thermophysical properties are superior.

Compared with high-aluminum refractory balls and silica refractory balls, magnesium-aluminum refractory balls have a higher material density, which increases the unit pebble bed mass and the pebble bed quality coefficient. Moreover, the high-temperature performance of magnesium-aluminum refractory balls is stable. It can be used safely for a long time under the temperature conditions of 1 350 ~ 1 450 C in the high temperature zone of the upper part of the ball bed of the ball hot air stove. The comprehensive resistance to slag corrosion is better than that of high-aluminum refractory balls and silica refractory balls.

As for porcelain balls, they generally have a small diameter and are often used for filling in glass kilns.