Calculate the filter screen pressure drop
Thread Content
This post was last edited by ccysll on 1/9/2019 at 10:27. Only the following formula could be found on Baidu, but this formula only accounts for the pressure drop caused by the filter housing; it does not take into account the pressure drop due to the filter element itself. The main pressure drop in a filter should occur across the filter element, especially with fine-mesh filters. I wonder if any of the forum members have a formula for the pressure drop caused by the filter element. https://wenku.baidu.com/view/a0040b1dc281e53a5802ff53.html?sxts=1546933879724
The image wasn’t uploaded; please upload it again. Many people have reported that they are unable to send pictures, so I will show everyone how to do it. https://bbs.hcbbs.com/thread-2249064-1-1.html (Source: Haichuan Chemical Industry Forum Website)
This post was last edited by li*nji on 2019-1-9 at 11:22. The Bernoulli energy balance equation is P3 + vfu3²/2g = P2 + vfu2²/2g + Pg – Pf. The pressure at the surface of the filter cake equals the filtration loss of the filter cake plus the loss in the filter bed. Different filtration media have different filtration resistances, and thus different pressure drops as well.
Dear forum member, do you actually use this formula to calculate the filter pressure drop in practice?
This post was last edited by li*nji on 2019-1-9 at 13:35. There are many methods; different filtration media require different approaches. Often, the filtration media come with data such as resistance test results, which can be used directly. Theoretically, it is still definitely the Bernoulli equation.
I guess no one would calculate it that way, haha.
Below is the calculation formula used by one of our suppliers, which takes into account the resistance of the mesh:
4. Resistance calculation
1. Inlet resistance coefficient ζj – fixed value
2. Mesh opening resistance coefficient ζwk – obtained from a table
3. Mesh resistance coefficient ζw – obtained from a table
4. Outlet tee resistance coefficient ζst – fixed value
5. Reynolds number of the fluid inside the pipe, Re = VDN/ηv
6. Relative roughness of the pipe wall, ε/Dwn
7. Pipe friction coefficient λ – fixed value
8. Pipe length L – based on production specifications
9. Pipe wear resistance coefficient ζλ = λL/DN
10. Total resistance coefficient ζ = V²/2v
11. Dynamic pressure of the fluid inside the pipe, Pd – fixed value
12. Total resistance of the filter screen, △P = ζPd
4. Resistance calculation
1. Inlet resistance coefficient ζj – fixed value
2. Mesh opening resistance coefficient ζwk – obtained from a table
3. Mesh resistance coefficient ζw – obtained from a table
4. Outlet tee resistance coefficient ζst – fixed value
5. Reynolds number of the fluid inside the pipe, Re = VDN/ηv
6. Relative roughness of the pipe wall, ε/Dwn
7. Pipe friction coefficient λ – fixed value
8. Pipe length L – based on production specifications
9. Pipe wear resistance coefficient ζλ = λL/DN
10. Total resistance coefficient ζ = V²/2v
11. Dynamic pressure of the fluid inside the pipe, Pd – fixed value
12. Total resistance of the filter screen, △P = ζPd