ceramic fibre blanket

Heat loss through the furnace walls comprises two components: convective heat loss and conductive heat loss. Heat loss through the furnace walls is calculated using the following formula:

Based on the above calculations and selection criteria for heat loss through the furnace walls, the batch-type heating furnace utilises high-performance refractory castables for the integral casting of the furnace walls, whilst a composite insulation layer structure is employed to optimise the furnace’s thermal insulation. The composite furnace wall is divided into four layers. The low-cement castable in the working layer possesses excellent high-temperature resistance, particularly in the heating section of the furnace wall, which significantly extends the overall service life of the furnace lining. The lightweight bricks in the secondary working layer not only provide excellent high-temperature thermal insulation but also serve to anchor the brick supports, preventing the cantilevered anchor bricks from being subjected to stress during the compaction of the castable. The outer layer, comprising ceramic fibre boards and ceramic fibre blankets, provides excellent thermal insulation. Due to the materials’ low specific heat capacity and low thermal conductivity, the furnace lining retains very little heat, resulting in rapid furnace heating and improved combustion efficiency. The surface temperatures of the furnace body are shown in Table 1.

Outer furnace temperature after insulation with