Analysis of the problem by shrinkage of insulation ceramic fiber module in kiln 2

 Last issue we introduced the cause of shrinkage cracks in insulation ceramic fiber module in kiln. This issue we continue to introduce the improvements and solutions to the problems of shrinkage cracks in insulation ceramic fiber module in kiln.

 Currently commonly used methods are:

1. Using the elasticity of the thickness of the fiber blanket, lining a fiber blanket strip between the modules; or arranging the modules horizontally and vertically

2. Increase the amount of compression of insulation ceramic fiber modules, and compress the modules as tight as possible

After adopting the above method, the surface of the fiber wall is flat and has no crack at normal temperature. However, after a period of heating operation, shrinkage cracks still occur, and the all-fiber furnace body composed of the insulation ceramic fiber modules is impossible to reduce or avoid the heat shrinkage crack by these methods because:

(1) The fiber blanket constituting the insulation ceramic fiber modules has good elasticity at normal temperature, especially in the thickness direction. However, during the heating process, the fiber blanket gradually loses its elasticity, softens, and shrinks, and the fibers in the fiber blanket may be glassy fibers or crystalline fibers.

(2) One of the characteristics of ceramic fibers and products made of ceramic fiber is the heating linear shrinkage.

If the insulation ceramic fiber modules are made long enough to be equal to or larger than the inside furnace dimension , and the heat shrink cracks are left outside of the furnace. Then the problem of heat shrinkage crack of the insulation ceramic fiber modules is solved.

Above all the shrinkage crack between the insulation ceramic fiber modules cannot be solved by the resilience of the fiber blanket; it is also impossible to solve this problem by increasing the amount of module compression or the degree of extrusion between the modules.

This issue we introduced the improvements and solutions to the problems of shrinkage cracks in insulation ceramic fiber module in kiln. Hope this can bring help to furnace builders.