Find a filter selection standard
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As the title states, I want to find a filter selection standard. I found a "HG 21637-1991 Chemical Pipeline Filter" here before, but I thought it was a bit old. Please ask everyone * * , is there a newer standard? The current one is the best. Thank you very much O(∩_∩)O~
Search the forum, it should be there
Give me the parameters and leave the rest to me
1. Introduction to filters (English filter) 1.1 According to the location and purpose of filters, they can be divided into two categories: Coarse filter (English strainer) and fine filter Coarse filter is mainly used in front of pumps, flow meters, and valves to protect the equipment from being ground by large metal particles. Its accuracy is basically several hundred microns or more. Fine filtration is mainly used to purify fluids and protect process safety. Its accuracy range is basically between 1 micron and 30 microns. 1.2 According to manufacturing design requirements, it can be divided into: The filter housings of pressure vessels and non-pressure vessels are designed and manufactured according to pressure vessels to comply with GB150 or ASME standards. Non-pressure vessels shall comply with SH/T3411 or HGT 21637 standards. 1.3 According to the medium used, it can be divided into: Gas filter and liquid filter Gas filter is suitable for gas-solid separation basin and can be used for gas purification, separation and recovery, etc. Liquid filters are suitable for liquid-solid separation fields, such as lubricating oil filtration, petrochemical industry filtration, and sewage treatment. 2. Fine filter filtration area: There are three domestic industry standards for coarse filters. Therefore, as long as they are selected according to the standards, they can meet the requirements. The calculation of the filtration area of fine filters basically does not require formula calculation. The selection is mainly based on experimental data. Therefore, it is recommended to let the manufacturer choose the filter. Filter three major curves: Flow pressure difference curve (ΔP-Q), particle size and filtration ratio curve (μ-β), time and pressure curve (T-ΔP). Therefore, these three curves should be used to calculate the filter area. The most important one is the flow pressure difference curve. This curve is tested and measured by a powerful filter manufacturer. At present, the most authoritative testing method is to pass the test multiple times: ISO 4572 passed test standard multiple times. This test bench is expensive, and there are currently only 2-3 units in China. At present, the filter element testing of small domestic filter companies is a single pass test. Filter area calculation steps: 1. Determine the filtration ratio with a filtration accuracy of 25 microns, such as 200 (filtration efficiency), and determine when the filter material is. 2. According to the given pressure drop of 0.05MPa, conduct a flow pressure difference test on the filter material. Obtain the appropriate flow rate (L/min) 3. Divide the obtained flow rate by the area of the test filter material to calculate the flow rate (L/min.m2). 4. Determine the filtration area according to the flow rate and the actual application flow rate, flow rate/flow rate = filtration area 5. Determine the filter element structure type according to the selected filtration area and filter material, foldable or cylindrical winding type
Basket coarse filter selection calculation Coarse filter process calculation 1. General This process calculation is based on the standard calculation of filters for petrochemical pipelines and pumps. Reference standards SH/T 3411-1999 "Selection, Inspection and Acceptance of Filters for Petrochemical Pumps" and HG-T 21637-1991 "Chemical Pipeline Filters". This calculation only applies to the calculation of the filtration area and initial pressure drop within the filter. The filter housing complies with the GB150 standard and is not included in this calculation. 2. The calculation of the filtration area is based on the SH/T 3411-1999 standard, which stipulates that the effective filtration area is defined as: The net area of the total opening area of the support structure in the filter minus the area occupied by the filter at the opening. Therefore, when calculating the effective filtration area, the effective area of the support structure and the effective area of the filter screen are considered. According to standard requirements, the ratio of the effective filtration area of the permanent filter to the cross-sectional area of the pipeline is not less than 1.5. The filter of this project complies with the requirements for temporary filters, and the ratio of the effective filter area to the pipe cross-sectional area shall be no less than 3.0. 2.1 Pipe cross-sectional area calculation S1: The diameter of the filter inlet and outlet pipeline in this project is DN200, S1=(0.2/2)2×3.14=0.0314 m2 2.2 Calculation of the filter’s effective filtration area S2: According to the standard requirements, the area ratio is 3, that is, S2/S1=3, that is, S2= S1×3=0.0314×3=0.0942 m2 2.3 Calculation of the filter mesh area According to the project requirements, the filter mesh is required to be 0.8mm and the surface area is 0.45m2. The surface area of the blue filter element selected for this filter is 0.56 m2, the opening rate of the filter basket support structure is 50%, the filter screen is 24 mesh (can intercept particles above 0.785mm), and its effective opening rate is 56%. Therefore, the effective filtration area of the filter basket selected for this project is S=0.56×0.5×0.56=0.157 m2. The effective filtration area is greater than 2.2 and the calculated result is 0.0942 m2, so the filter area meets the requirements. 3. Initial pressure drop calculation The pressure drop calculation is calculated according to the reference formula provided by the standard. The physical quantities involved include Reynolds number, equivalent length, fluid density, viscosity, etc. Calculation formula: Symbol explanation: Δp——Pressure drop (Pa) λ——Friction coefficient (dimensionless) L——Equivalent straight pipe length (mm) D——Pipe inner diameter (mm) Re——Reynold’s number ω——Fluid linear velocity (m/s) μ——Fluid viscosity (cP) ρ——Fluid density (kg/m3) The parameters given in this project are calculated as follows: ω=（120644/780）/0.0314/3600=1.37 m/s =780×200×1.37/0.45=474933 λ=64/ Re=64/474933=0.00014 The equivalent length L is 55×103 (the equivalent length is taken according to the standard) Therefore =0.00014×(780/2)×(1.37)2×(55×103/200)=28 Pa. Therefore, the initial pressure difference of the filter is 28 Pa. Since the pressure drop of the filter is affected by many factors during normal operation, including the content of solid particles in the fluid, the relationship between filter pressure drop and operating time cannot be calculated. It is recommended that the pressure drop when replacing and cleaning the filter basket be 0.1 to 0.2MPa, and the filter basket strength design meets the process requirements of 0.4MPa.
Very loving Buzhu, thank you for your hard work O(∩_∩)O~ Thank you very much! ! !
I have the SH/T3411-1999 standard, but I don’t know how to upload it?
Where to download "HG 21637-1991 Chemical Pipeline Filter", thank you!
Nice, very useful knowledge. We make filters.