Analysis of air leakage of kiln bag filter in cement plant

1. Affect the stability of the kiln system: For the dust removal equipment operated by negative pressure, a large amount of air can be poured into the air leakage, and the effective air volume of the kiln system drawn by the tail exhaust fan is reduced, which affects the output of the kiln.

2. Dust leakage of the equipment: When the dust collector is normally filtered, the internal working environment is negative pressure. When cleaning the ash, the power comes from an air compressor or a reverse blower. The cleaning state will make the cleaning unit in a positive pressure working environment. When the equipment leaks , The dust will be sprayed to the outside through the leakage point at a high speed under the action of cleaning power, causing pollution of the workplace.

3. Increase the running resistance: the dust collector is originally operated under negative pressure, and the leaking air is positive pressure gas, which changes the working environment in the dust collector. When the air leakage is serious, positive pressure dust is formed in front of the dust collector, and the equipment operation resistance changes from the original The difference between the absolute value of the front and back pressure becomes the sum of the two absolute values, which greatly increases the running resistance.

4. Condensation inside the equipment: Because the kiln tail is mostly combined with a kiln and a raw meal vertical mill to remove dust, the kiln tail flue gas is mostly cooled by a humidifying tower, ignoring the influence of air leakage, the moisture content of the kiln tail flue gas reaches 10%, and the The subsequent dew point temperature is 45℃～55℃. It is worth noting that the kiln tail flue gas contains SO2. After dust removal, the SO2 content in the outlet flue gas in the standard state is generally 100mg\m3～200mg\m3. Acid will increase the dew point, especially SO3 (at 500℃～600 ℃ is converted from SO2) plays an important role in dew point. When the content of SO3 in the filter medium reaches 0.05%, the dew point can be raised to 150℃. The influx of a large amount of cold air reduces the operating temperature, especially in the cold winter, air leakage may easily cause condensation on the paste bag and the inner wall, which affects the normal use of the dust collector.

5. Equipment corrosion: In normal operation, the working pressure in the dust collector can reach -1000Pa～-2500Pa. In rainy days, the high negative pressure in the equipment draws rainwater into the dust collector through the poorly sealed manhole door and spills it on the spray pipes and flowers. On the inner wall of the board, the clean air box and the inner wall of the filter bag, in case of heavy rain or even serious water leakage, the inner wall of the equipment is seriously corroded.