Causes of condensation in bag filter and treatment methods for condensation

Causes of condensation in bag filter and treatment methods for condensation

When processing high-temperature and high-humidity gases,if the gas temperature is lower than the dew point during operation,water vapor will condense,causing the filter bag to become damp,and a large amount of dust will adhere to the surface of the filter bag,blocking the pores of the filter bag,and the compressed air cannot be cleaned,causing the filter bag to become sticky.The cleaning function of the sticky bag fails,the resistance is too large,and the operating conditions deteriorate.To prevent condensation and sticking of the bag,keep the processing temperature 25 to 35 degrees higher than the dew point.When used to process high-temperature and high-humidity gases,a temperature detection alarm device should be installed at the entrance for monitoring,and thermal insulation materials such as rock wool should be installed outside the shell for insulation.Condensation in bag filter.Before the dust removal system stops running,the humid gas in the device is discharged and replaced with dry air to prevent condensation.After the production equipment stops running,the dust removal fan should be extended for a period of time before shutting down.

Solutions to condensation in bag dust collectors 1.Reduce air leakage in dust collectors:(1)The discharge port of the dust collector should use an air lock device with good sealing performance.Currently,pneumatic or electric air lock valves are mainly used.A two-stage air lock device can be used.The air leakage rate of a pulse bag dust collector should be controlled within the range of≤3%.(2)During the manufacturing and installation of the dust collector,the JC/T532 welding standard must be strictly followed for welding.Welding leakage 2.Stabilize the flue gas temperature within a small range:When the treated flue gas temperature is too high,cooling measures such as lowering the operating temperature and releasing cold air must be taken immediately;when the flue gas temperature is too low,heating measures such as increasing the operating temperature must be taken immediately.Make the flue gas temperature stable within the specified range to ensure the normal and stable operation of the dust collector and reduce condensation.3.Strictly control the water spraying volume of the humidifying tower:When the cooling device at the end of the cement dry process kiln adopts a humidifying tower,the water spraying volume cannot be increased by unilaterally pursuing the cooling effect.The water spraying volume of the humidifying tower must be strictly controlled while ensuring the inlet temperature of the dust collector.The humidifying tower should use a spray gun as much as possible to make the sprayed water fine and uniform,and achieve the cooling and tempering effect with a small amount of water.4.Strengthen the thermal insulation measures of the dust collector:The shell of the dust collector adopts thermal insulation measures.The thermal insulation of the dust collector generally adopts rock wool,aluminum silicate board,pearl expansion rock and other thermal insulation materials with low thermal conductivity,good thermal insulation performance,low water absorption rate and good heat resistance.The thermal conductivity of the material is generally no more than 0.23W/m.K.The thickness of the thermal insulation material should be determined according to the geographical location,and can be determined according to the calculation formula of the"control unit heat loss method".5.Reduce the temperature difference and treatment between the pulse injection gas and the flue gas inside the dust collector:The commonly used gas supply for compressed gas in China is The main route is:compressed air-gas tank-gas source triplex-air bag-pulse valve.This air supply method has the advantages of low investment and simple equipment,but when the outside air temperature is too low,the compressed gas is not fully processed and condensation is easy to occur.When the outside air temperature is too low and the air compressor station is far away,the air supply route can be:compressed air-gas tank-gas source triplex-air dryer-air heater-air bag(air bag is covered with insulation material)-pulse valve.This air supply method is sufficient and comprehensive,and the temperature difference between the pulse-blown gas and the flue gas inside the dust collector is small,and condensation is not easy to occur.