The refractory lining plays a critical role for the total performance and reliable operation of the furnace. It can be the controlling factor in the success or failure of a furnace. The service life of the furnace depends mainly on the operating life of the refractory lining.
The following practices can be adopted while carrying out the refractory lining, in order to ensure longer operating life of the refractory lining.
The quality of the refractories used in pot furnace floor needs to be consistent and assured. Blocks are to be procured from reputed manufacturers, as the quality of such blocks can be expected to be uniform.
Using larger refractory blocks
The use of larger blocks reduces the number of joints while constructing a furnace lining. However, this does not always result in improvement of performance. The manufacturing of large blocks requires a high-capacity press for developing uniform property characteristics. Hence, it is necessary to consider the dimensions of the block and its properties to ensure its suitability for a particular application. Further, random samples from the procured lots should be analyzed to verify the manufacturer’s claim with the results obtained from sample analyses.
Use of anti-corrosive coating
The floor of the furnace is likely to be damaged due to the spillage of charge materials containing alkalis or due to contact with molten glass in case of pot failure. Sparking and corrosion are the main causes of wear and tear of refractories in industrial processes. The glass industry is no exception. Bricks with resistance to sparking and corrosion are preferable for using on the floor of the glass melting furnaces. Anti-corrosion coating materials particularly suitable for alkali attack could be considered. The coating should be uniform, and may be 5 mm thick.
The qualities of mortar used in the furnace lining should be similar to the refractory qualities and properties. Low shrinkage (less than 1%) high-alumina mortar should be used for joining the high-alumina blocks.
Anchors are used for almost all types of refractory applications. These are mostly metallic type. Lining failures due to inadequacies in the anchoring system are very common. Selecting the proper metallurgy, anchor dimensions, configurations, and spacing are very important to achieve the maximum service life of the lining. Where metal liners are used over the lining, the mechanical design should be sound and allow free movement of the liner on one end from its fixed positions.
blocks used in furnace lining should be accurate in dimensions and warpage-free.