Bag filter is a new type of filter system. The inner part of the filter is supported by a metal net basket. The liquid flows in from the inlet and flows out from the outlet after being filtered by the bag.At present, bag filter is widely used in pharmaceutical industry, and with the rapid development of pharmaceutical industry, the market size of bag filter is expected to further expand.
In the face of a variety of bag filter on the market, the industry suggested that the user selects the bag filter, need to collect the name of the medium, operating temperature, operating pressure, design temperature, pressure, intercept, particle size and flow rate, viscosity, allowed pressure drop and solid content, changing the process parameters such as cycle, choose suitable bag filter.
At present, some users have reported that the filter bag of bag filter is blocked during operation. What should we do?Experienced technical personnel in the industry believe that the main reasons for the blockage of the filter bag are high filtration speed, fine dust, sticky dust, poor ash removal, paste, condensation, hardening, etc.
In addition, if the filter wind speed of the dust collector exceeds the design standard of the filter bag, it is easy to cause the fine dust in the flue gas to enter the fiber of the filter bag and cause the clogging resistance of the filter bag to rise.
In view of this situation, the industry said that the use of coated filter material, coated filter material or the surface of the filter bag to do pre-coated ash treatment, is a better method.For dust with large viscosity, it is necessary to reduce the filtration wind speed, or increase the pressure of pulse injection, or adopt off-line pulse ash filter bag cleaning method. A better method is to increase the filtration area, reduce the filtration wind speed, and extend the service life of the filter bag.
When the filter bag is blocked because of poor dust removal, how to solve it?It is understood that the poor ash removal of the filter bag mainly includes the frequency of ash removal and the long time of ash removal.
The industry pointed out that the frequency of ash removal, ash removal pressure is too large easy to make the fabric of the filter bag loose so as to increase the fine dust in the flue gas blocking filter bag.Soot cleaning time is too long will be the initial powder layer on the surface of the filter bag were purged, cause the loss of filter bag filtration precision, and if time is too short, clear ash on the surface of the filter bag dust is not entirely clear ash clean, immediately began to filter, dust accumulated on the surface of filter bag, filter bag caused by the blockage, solve this problem, can adjust the blowing through several commissioning after control instrument.
Water is also a common cause of filter bag blockage, the cause of water content is usually low temperature condensation, especially in the treatment of high temperature flue gas, the following method can be used for such a situation.
First, avoid improper boot;Second, avoid starting up when the dust collector resistance is large;Third, avoid starting at a lower dew point.It is understood that if the dust remover runs below the dew point, it is easy to cause problems, if the air intake distribution is not uniform, it is also easy to cause local corrosion of the shell of the dust remover, therefore, it should avoid the dust remover work below the dew point.If it is inevitable to turn on the machine at low temperature, an insulation device, such as steam insulation or electric heating insulation, should be used.
In addition, air infiltration can also cause the filter bag to block.The industry said that air infiltration often occurs in the dust collector flange, access door or dust remover activity device, if the seal is not strict, external air into the dust remover, when dealing with high temperature smoke, will produce low temperature inside the dust remover area, resulting in low temperature condensation, corrosion dust remover, resulting in filter bag paste bag or board.