How is the bag filter selected according to the flow rate? Generally speaking, in order to be interchangeable, we try to use standard size filter bags. When the flow is not very large, try to choose a filter bag; try to choose a filter with a smaller size, so that the maintenance will be more convenient. When the flow rate is large, consider using double-bag, three-bag or more filter bags. In the case of high operating pressure (or design pressure), it is not appropriate to use too many filter bags.
The bag filter is the same as other forms of filters, and the determination of the filter area is the key to the selection. If the filter area is too large, it is not only uneconomical, but also sometimes inconvenient to the operation; if the filter area is selected too small, it will bring inconvenience to the operation, and in severe cases, the filter will not be able to be used. It is particularly important to choose a suitable filter area.
The filter area of the bag filter is determined by the medium flow, allowable pressure drop, operating pressure, medium viscosity, and filter bag characteristics.
1. Preliminarily determine the number of filter bags according to the medium flow, operating pressure and the normal flow of the filter bags with the selected precision and size tested in water.
2. According to the actual flow of each filter bag and the viscosity of the medium to judge whether it exceeds the allowable pressure drop range. If the calculated pressure drop does not exceed the allowable pressure drop, the filter bag is available; if the allowable pressure drop is exceeded, the number of filter bags needs to be increased. Then calculate the pressure drop according to the increased filter bag until the pressure drop is appropriate. It is worth noting that it only needs to be considered when the viscosity of the medium is relatively large, or when the viscosity of the medium is far away from that of water. Among them, special attention should be paid to the pressure drop of the filter bag and not the pressure drop of the filter. When calculating, the allowable pressure drop of the filter needs to be subtracted from the pressure drop generated by the filter other than the filter bag (such as the pressure drop at the inlet and outlet of the filter). Viscosity is an important factor that needs to be calculated, and another need to be calculated is the bag changing cycle.
3. Combining the solid content or solid content distribution map of the medium provided by the process (the process will only provide it if conditions permit), the flow rate of the medium and the dirt or oil capacity of the filter bag, we can calculate the bag change cycle. Determine whether an operation cycle is satisfied according to the bag changing cycle. If it is not satisfied, the number of filter bags needs to be increased. According to the number of filter bags and the filter area of each filter bag (in the filter bag parameters), the filter area can be obtained.
Once the number of filter bags is determined, it is easy to select the appropriate filter model. I hope the above sharing can be helpful for you to choose a bag filter. If you want to know more about the bag filter or have needs in this regard, please feel free to contact us for consultation.
