Application of new castables in rotary kiln system

Because HN-DFB1 high-aluminum early-strength explosion-proof castables are compared with low-steel-type castables, it can shorten the 2/3 stripping, curing and baking time, which is in line with the actual condition of bricks after the factory repairs. So we tried this castable in the repair of the facility in October 1999. The part is the tail end of No. 5 kiln, the casting width is 800mm, the thickness is 120mm (the same height as the clay brick), and the nail is quoted " ;V” shape, model Φ 10× 90 heat-resistant steel, the distribution of dowels is shown in Figure 1. Use the A132 welding rod to fully weld the bottom of the nail to the cylinder, and strictly follow the construction process regulations provided by the casting material manufacturer.

So far after the kiln fire, the No. 5 kiln has been in operation for three and a half years. In addition to several irregular cracks and slight wear on the surface, this casting part is completely intact, and it is also firmer with the clay bricks. It is expected that the furnace age can be used. Up to 5 years.

Figure 1 Distribution of nails in the castable section of HN-DFB1 in No.5 kiln

2 Application of HN-20 mullite castable in kiln mouth

In order to prevent the kiln cylinder from being washed and ablated by high temperature clinker and flue gas, the kiln mouth of the rotary kiln is inlaid with heat-resistant steel plate retaining bricks, which are fixed by screws to the kiln mouth cylinder, and then Then refractory bricks are placed on the bricks. This part of the special situation of the refractory brick itself is poorly prefabricated, and is not subject to the erosion of high-temperature clinker and ablation of high-temperature flue gas, sometimes accompanied by the appearance of the cylinder, the susceptibility of refractory brick leakage . In order to solve this problem, based on the experience and effectiveness of the No. 5 kiln castable, we used the kiln interview in No. 6 kiln (model & Phi; 4m & time; 75m) in the facility repair in October 2000. HN-20 mullite castable.

    This castable has the characteristics of high temperature structure, low temperature creep rate, low thermal expansion, strong chemical corrosion resistance and thermal shock resistance, in addition to the characteristics of short-time, non-explosive when it is touched, cured and baked. Strengths. The casting width is 900mm, the thickness is 200mm, the nail at the brick is Φ 12mm× 120mm, the nail at the cylinder is Φ 12mm× 160mm, the texture, distribution and cold welding of the nail are the same as the No. 5 kiln tail. The construction method is the same. Re-repaired in June 2001, during the 8-month operation period, the No. 6 kiln did not stop the kiln due to the occurrence of kiln castables.

3 The introduction of new castables in the rotary kiln system of our factory

After the successful trial of HN-DFB1 and HN-20 castables, we used castables in several easy-to-drop brick parts in the kiln system to solve the problem of brick falling. For example, in the large mouth of the No. 5 kiln variable diameter, there is a brick block in the past. There is often a brick accident here. In the repair, the opportunity of replacing the cylinder is used, and a circle of 400 mm is cast in the coordinates of the original brick circle. The long, 120mm thick HN-DFB1 material not only serves the utility of the brick block, but also overcomes the shortage of easy bricks at the brick block. Another example is the No. 3, No. 4, No. 5 kiln mouth, which has repeatedly stopped the kiln due to the leakage of the brick lining brick. The HN-20 castable was used, and the situation has greatly improved. At the hot end and cold end bead of No. 3, No. 4, No. 5 coolers (single cylinder type), HN-20 castables have also been used very well.