Tertiary Air Pipe Castable
Tertiary air pipe castable is specialized developed casting refractory for rotary cement kiln tertiary air pipe. The wear of tertiary air pipe is very severe, so wear resistant castable is the best choice to prolong its service life. Tertiary air pipe castable raw materials are corundum and silicon carbide high strength aggregate, 5%~8% steel fiber, micro powder binder and additives. Corundum silicon carbide castable has high bulk density, high mechanical strength, excellent abrasion resistance, washing resistance, corrosion resistance and spalling resistance.
In large capacity pre-decomposition kiln, tertiary air temperature is about 880~950℃. To reduce heat loss and to simplify process flow, dust collecting equipment is seldom set in tertiary air pipe, therefore, air current contains large ratio of high temperature fine granules clinker, the temperature of tertiary air pipe is further increased. The main damages of tertiary air pipe castable lining are: high temperature thermal stress, sulfur and alkali corrosion, solid particles abrasion. Besides, temperature change caused shell deformation also cause stress damage of tertiary air pipe castable lining.
Tertiary Air Pipe Al2O3-SiC Castable Physiochemical Index
| Item |
Al2O3 SiC castable |
| Al2O3+SiO2 % |
≥80 |
| SiC % |
12~15 |
| Max. working temperature |
1500℃ |
| Bulk density g/cm3 |
2.85 (1450℃, 3h) |
| Crushing strength Mpa |
50 (1450℃, 3h) |
| Modulus of rupture Mpa |
6.0 (1450℃, 3h) |
| Reheating linear change rate % |
+(0.2~0.4) (1450℃, 3h) |
To prolong the service life of tertiary air pipe refractory lining, the following measures should be took:
Reduce heat loss
The structure of tertiary air pipe should be reasonably designed, temperature different between secondary air and tertiary air should be controlled below 100℃.
Reduce Air Pipe Bottom Ash Deposition
Clinker fine granules are easy to deposit at the bottom of tertiary pipe, so the air speed should be well calculated during design to reduce ash deposition.
Prong Service Life of Tertiary Air Pipe Castable Lining
RS Kiln Refractory specially designed tertiary air pipe castable has significantly longer service life than other types of castable, in most cases, the service life of corundum SiC wear resistant castable is longer than 2 years, far longer than earlier service life. Meanwhile, our experienced project technique team can help optimize tertiary air pipe structure design, the heat loss can be greatly reduced.
