Composite Design of Low Thermal Conductivity Mullite Brick for Application to Cement Kiln

In order to restrain cement kiln shell's thermal loss and potential safety hazard, composite design is employed of working layer, thermal-preservation layer and thermal insulation layer. Thermal-preservation layer's boundary and strain is analyzed and overall thermal conductivity is calculated. The result shows that sinusoidal curve boundary combination between working layer and thermal-preservation layer, slope-shape with angle of 135 degrees between thermal-preservation layer and thermal insulation layer could relieve strain concentration. Composite mullite brick comprehensive thermal conductivity decreases from the working layer 2.74W.m(-1).K(-)1 to 1.50W.m(-1).K-1. When applied in cement kiln, temperature of kiln shell is lower 50 degrees C to 70 degrees C than using normal bricks.