Due to process requirements, the rotary kiln needs to change fire every 20 minutes or so to make it burn more fully, which will cause instantaneous high temperature to reach 220-250℃ or even higher. Therefore, although the normal temperature is around 160℃, the instantaneous temperature is high and frequent. Conventional fuels are natural gas, natural gas + petroleum coke and petroleum coke. Due to combustion problems, the dust contains sticky substances, which makes it easy to stick to the filter bag. Therefore, the dust collector for rotary kiln exhaust gas and smoke purification basically uses high temperature and corrosion resistant filter bags.
Its characteristics are as follows
- The exhaust gas of the rotary kiln is dry desulfurized, so the nutmeg dust concentration entering the dust collector is large. Basically, the dust inlet concentration is 1000-1500g/m3. Therefore, the scouring of the dust filter bag surface is relatively strong, and it needs to be wear-resistant, or the coating strength should be large to prevent the film from falling off.
- The dust is relatively fine and has strong corrosiveness. In order to meet the emission requirements, ultrafine fibers or trilobal fibers are generally used to improve the accuracy of the filter.
- The general dust emission requirement is 10mg/m3.
- The filtration wind speed is within 0.7m/min.
- Due to different fuels, the viscosity of the dust and the high flue gas temperature.
Solutions
- Currently, the conventional filter bag material is p84 (proportion 20-30%) + PTFE impregnation treatment, with a gram weight of 700 or 750g/m2; the proportion of P84 varies mainly according to the inlet concentration and filtration wind speed. Generally, the inlet concentration is 1000mg/m3 and the wind speed is lower than 0.7m/min, and the proportion of p84 is low. It can be used for more than 3 years under normal working conditions.
- Some glass rotary machines also use a coated filter material of more than 800g/m2, which requires a thick film and strong fastness. A few industrial and mining companies use PTFE50%+pps50% filter bag solutions, and the filter bag weighs 620g/m2.
Product Parameter Comparison
| Filter Bag Type | Applicable Fuel | Peak Temp Resistance | Weight | Key Features |
| P84+PTFE Impregnated | Natural Gas / Mixed Fuels | 250°C | 700-750g/m² | High-temperature & corrosion resistance, long lifespan |
| P84+PTFE Membrane-Coated | Petroleum Coke Fuel | 220°C | 800g/m²+ | Anti-adhesion, anti-caking, robust membrane adhesion |
| PTFE+PPS Composite | Mixed Operating Conditions | 200°C | 620g/m² | Cost-effective, moderate anti-adhesion |
