Bag filter design and selection

1. Pressure loss in the absence of more appropriate design experience, at lower filtration rate can be 75 × 9.8 Pa as a typical data. However, if taking a high filtration rate, or the presence of viscous or low porosity of the dust layer, should be taken slightly higher number. 2. That gas cloth than the filtration rate. It is with the dust bag area (m2) of the ratio of gas flow to be filtered (m3 / min), which is dimensionless m3 / min.m2 = m / min. This is the unit of velocity, which represents the average gas velocity through the dust bag, not considered to be an area of many fibers constituting the web occupied. For this reason, it is often called again “apparent surface speed.” The filtration rate is a very important factor in determining the performance of the baghouse. Filtration rate is too high will cause the pressure loss is too large, reducing the dust removal efficiency, and dust bag clogged prematurely. However, increasing the filtration rate can reduce the need for baghouse filtration area, which can handle the same volume of gas with a small dust removal equipment. For a set of design parameters (ie type dust collector, cleaning agencies, dust bag fiber material and fabric structure, dust properties and the like) there is an optimum filtration rate. In general, fine dust than coarse dust taken filtration rate should be lower, smaller than dust often use large dust filtration rate. Pulse, reverse jet dust collector can be compared vibrating, reverse airflow filtration speed made higher. For vibratory and reverse flow dust collector for ordinary dust filtration velocity can be used 0.9m / min. Both investment and maintenance from both the perspective of someone recommended feed and grain dust filter and the maximum speed of flour respectively, 0.98 and 0.75m / min. 3. Filter area into the dust of the gas flow rate (m3 / min) divided by the selected filtration rate (m / min), to obtain the actual needs of the textile area (m2). Due to temperature changes, as well as additional changes in the air, into the house dust precipitator volume of gas is not necessarily the same as the same volume of production process discharged. If there is a change in the ESP application traffic situations, we need to make a judgment whether it is by Peak traffic or to calculate the average flow filter area. In addition, it should also consider the reserve precipitator dust bag fabric, for cleaning, inspection and maintenance. 4. How much compartment housing structure of a bag filter needs to be relatively easy to identify. After the decision of each compartment dust bag area, it is necessary to determine the most advantageous dust bag length, diameter and arrangement pitch. Usually the length of the dust bag is preferably spaced not less than 50 mm; particularly long (eg more than 3 meters) of the dust bag spacing should be bigger. Dust bag should be grouped between the two groups left channel. If there is only one side of the channel, dust bag having a diameter of 150 mm, each group should not be more than three or four rows of the bag; each having a diameter of 300 mm should not be more than two rows. If both sides of the channel, 150 millimeters in diameter should not be more than eight rows, 300 mm in diameter should not be more than four rows. The channel width of 450 to 600 mm. N = total number of dust bag depends on the vibration mechanism used. Typically, a group within a group of bag vibrating mechanism manipulation. A compartment can contain several group bag.