How to prevent condensation in dust filter bags

In use, it is necessary to prevent the gas from cooling below the dew point in the bag chamber, especially when using the bag filter under negative pressure. Since the outer shell often leaks air, the temperature of the gas in the bag room is lower than the dew point, and the filter bag will be damp, so that the dust is not loosely attached to the filter bag, but sticks to the filter bag, blocking the fabric holes and causing dust removal. If it fails, the pressure drop of the dust collector is too large, and it cannot continue to operate. To prevent condensation, the temperature of the gas in the dust collector and its system must be kept at 25-35°C higher than its dew point (for example, the dew point temperature of the kiln-milling machine is 58°C, and the operating temperature should be above 90°C), To ensure the good use of the filter bag. The measures are as follows:

1) Add a raw material storage shed. In cement production, the water content of various raw materials, fuels and mixtures varies. If they are placed in a fixed shed to prevent rain, the water content of the material can be greatly reduced, which is an effective measure to reduce the water content of the material. This situation is relatively common in cement plants in southern my country, but some of the material sheds are too small, and some are not. Therefore, it is difficult to use the bag filter.

2) Reduce air leakage. The air leakage in the gap of the dust collector body should be controlled below 3.5%. In the dust collector system, the air leakage of the process equipment, such as the closed ash discharge valve at the discharge port of the ball mill, the air leakage of the closed ash discharge valve under the dust collector, and the pipe flange connection, etc., are often ignored by the maintenance and management personnel. Therefore, , increasing the unnecessary air leakage and worsening the operating conditions of the bag filter.

3) The dust-laden gas should be evenly distributed in the dust collector to prevent eddy currents from appearing in the corners, which will reduce the amount of gas passing here and cause local low temperature to cause condensation problems.

4) Do a good job of heat preservation and rain protection for dust collectors, pipes and other related places. Practice has proved that good insulation measures can make the temperature difference between the inlet and outlet of the bag filter very small, which is an effective measure to prevent condensation.

5) Take appropriate heating measures. If a far-infrared electric heater or electric heater is installed in the dust collector, or a radiator is added in the bag room, the flue gas temperature of the main engine can be appropriately increased.

6) Strengthen the temperature monitoring of the dust collector and the dust removal system, so as to grasp the operating conditions of the bag filter and prevent condensation.