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How to prevent the filter bag from hardening?

Time : 2023-06-27 Hits : 1

The filter bag is a part of the dry dust filtering device, which is suitable for catching tiny, dry and non fibrous dust. Different industries have different regulations on dust emission standards. According to the different properties of dust and the production characteristics of various industries, the filter bags used in various industries are different.

It usually refers to the phenomenon that the air containing water releases saturated water under a certain pressure and temperature, and the temperature point when the water is released is the dew point. When the moisture content in the air remains unchanged and the temperature of the moist air is lower than the dew point temperature, water will be separated from the supersaturated air, forming condensation.

If the temperature of flue gas is approximately the same as the dew point temperature, the shell of the precipitator needs to be equipped with a heater, supplemented by an insulating layer. In addition, heating measures are taken on the inlet pipe of the precipitator to achieve better results.

The operating temperature of the dedusting equipment shall be at least 20 ℃ higher than the dew point of the blue eye filter. When dealing with high-temperature flue gas, the degree of cooling shall be properly controlled.

If the flue gas temperature is lower than the dew point, but the difference is small, the bag filter can still be used. However, the flue gas needs to be heated. But in this case, the energy consumption is too high, and the price of electric heating is more expensive. In addition, there is a more economical and effective way, that is, far infrared heating, which only heats water, not air, so as to save energy.

The operating temperature of the dust remover must be more than 20 ℃ higher than the flue gas dew point temperature. Once the flue gas condenses on the filter bag, it will cause the dust layer on the filter bag to stick hard, resulting in a rapid increase in the operating resistance of the filter bag, affecting the normal operation of the system. More importantly, SO3 in flue gas will react irreversibly with water to generate H2SO4 sulfate. Sulfuric acid will continue to act as a desiccant to the filter bag or dust, thus oxidizing and corroding the filter bag and metal parts of the equipment. Therefore, when purifying flue gas at the end of combustion process, attention must be paid to controlling flue gas temperature to prevent flue gas condensation. During use, the gas shall be prevented from cooling in the bag chamber.