According to the main reasons for damage to the ceramic honeycomb body of the regenerative heating furnace during use, solutions are proposed, hoping to provide help for the production, selection and widespread application of honeycomb bodies. Only through continuous in-depth research on regenerative heating furnaces can the advantages of this technology be better utilized.
Through the analysis of the four main factors that affect the damage of the regenerator, and based on the actual use conditions, targeted solutions are proposed.
solution
01In the selection of ceramic honeycomb materials, the aluminum content should not be pursued blindly. The higher the aluminum content, the higher the refractoriness, but the worse the thermal shock resistance. It is best to use two materials in the same regenerator chamber. Corundum, mullite, cordierite (or similar materials) are used in order from the direction inside the furnace to the direction outside the furnace to achieve the best optimization of thermal shock resistance and refractory resistance.
02 In actual production, the air-fuel ratio should be strictly controlled to reduce the oxidation and burning loss of the steel billet, and control the production of ferrous oxide, thereby preventing ferrous oxide from being sucked into the regenerative burner and causing damage to the honeycomb body.
03 Incomplete combustion of gas will cause secondary combustion in the regenerator, causing damage to the honeycomb body. When designing the burner, the angle and distance of the two nozzles and the momentum ratio of the two jets should be fully considered. At the same time, the air-fuel ratio is controlled to ensure complete combustion of gas. In this way, there is no problem of secondary combustion in the honeycomb body.
04 The hole spacing and wall thickness of ceramic honeycomb should be selected appropriately. The holes are in two forms. The first layer near the furnace adopts a thick-walled structure with large holes, and the rest adopts a thin-walled structure with small holes. In order to pursue a maximum specific surface area, we cannot choose a hole structure that is too fine, which will affect the strength and make it easy to get clogged. There is a partial gap (arc surface connection) between each layer of honeycomb body to smooth the air flow and avoid dust blockage. Select the appropriate commutation time according to the hole spacing and wall thickness. Through theoretical calculations and with reference to the actual use of heating furnaces in many steel plants, the small hole thin-walled regenerator mostly adopts a spacing of 2.8~3mm, a wall thickness of 0.8~1mm, and a reversing time of 30~60s. Longer reversing time is beneficial to the service life of key equipment such as reversing valves.