Retaining bricks are widely used in burners in regenerative combustion technology, arranged between burner bricks and honeycomb ceramic heat regenerators, which play the role of fire retaining and fixed protection of honeycomb ceramic heat regenerators, and have an important impact on the service life of honeycomb ceramic heat regenerators. Especially for the honeycomb regenerative burner, due to its compact structure, it is difficult to leave space in the furnace wall or inside the burner to form a sediment chamber or a channel to change the direction of flue gas flow, so the use of retaining bricks in the high temperature section of the front of the burner can not only reduce the radiation effect of high temperature furnace gas on the front honeycomb ceramic heat regenerator, but also resist the erosion of part of the iron oxide scale on the front honeycomb ceramic heat regenerator.
If the retaining brick is not properly designed or installed, it is easy to cause the secondary combustion of high-temperature flue gas in the regenerative chamber, which not only leads to the easy burning and short life of the retaining brick, but also leads to the problems of cracking, collapse, melting and softening of the honeycomb ceramic regenerator, which has a negative effect on the energy-saving effect and safe and stable operation of the entire regenerative combustion system.
The fire retaining brick can be used in various regenerative combustion systems with honeycomb body, and is used at the front end of the honeycomb ceramic heat storage body of the regenerative heating furnace, and its function is to protect the honeycomb ceramic heat storage body and prolong the service life of the honeycomb ceramic heat storage body. Therefore, high temperature resistance and thermal shock performance are the primary factors for the selection of fire retaining bricks.
At present, the main materials of fire-retaining bricks are high aluminum, corundum, molten corundum, zirconium corundum, chromium corundum and silicon carbide, and its appearance and structure are mainly designed according to the conditions of the regenerator and kiln.