Refractory masonry structure inside double-chamber kiln

Double-Chamber Kiln Refractory Lining Structure

The construction of a double-chamber kiln of a light-burned dolomite manufacturer adopts a domestic double-chamber kiln with a “double C structure”. Its internal refractory masonry structure is shown in Figure 1. The double-chamber kiln lining structure is divided into cooling zone, calcining zone, and preheating zone from bottom to top. They are built with refractory materials with good high-temperature resistance, wear resistance, and thermal insulation performance. The two kiln chambers are constructed with an intermediate channel and 8 cooling pillars. The outer ring bricklayer of the kiln is counted from the bottom of the kiln chamber, a total of 194 layers.

The cooling belt and the bottom of the steel structure are leveled with low cement castables, and then the cooling belt is laid. From the 1st to the 40th floor, from the steel shell structure outward, coating material, two layers of fiberboard, insulation bricks, and high-strength clay bricks are used in sequence. The thickness of the fiberboard is 30mm, the thickness of the insulation brick is 230mm, and the thickness of the high-strength clay brick is 260mm. When laying each layer of bricks, expansion joints are reserved in the circular ring of the kiln brick layer at a certain distance.

From the 41st to the 82nd floor, as the kiln height gradually approaches the calcining zone area, the working temperature increases accordingly, and the brick lining working layer is changed to high-alumina refractory bricks.

The middle channel is equipped with a fire door. It is used to observe the ash accumulation during the kiln shutdown, and a template is required during masonry.

The calcining zone has the highest temperature, which can reach 1100℃. Considering the calcination characteristics and temperature, the working layer of the 83rd to 161st layers of bricks on the outer ring of the kiln is built with mullite refractory bricks. From the steel shell structure to the outside, it is built with coating material, two layers of fiberboard, insulation bricks, and mullite bricks in sequence.

Anchors are welded on the bottom of the steel structure and the supporting structure inside the kiln, and castables are used for masonry. At the same time, thermocouples are evenly arranged in the inner and outer ring areas of each kiln chamber to detect the calcination of the kiln.

The 162nd to 194th brick lining working layer is built with high-strength clay bricks as part of the preheating zone.

The entire kiln structure should be strictly symmetrical. In order to ensure the construction period, the masonry of the two kiln chambers can be carried out at the same time. During the masonry process, overlapping of brick joints should be avoided, and the mortar should be applied in sufficient and uniform amounts.