GB/T 42269-2022
Determination of pore size for membranes—Gas permeation method (English Version)
- Standard No.
- GB/T 42269-2022
- Language
- Chinese, English version preview
- Release Date
- 2022
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 42269-2022
- Scope
- This document describes a method for determining the average pore size of separation membranes using the gas permeation method. This document is applicable to the test of the average pore diameter of flat membranes and hollow fiber membranes with a pore diameter of 0.01 μm to 0.2 μm in a dry state.
- Introduction
Analysis and implementation points of the standard
Advanced interpretation of the scope of application
This standard is applicable to the pore size characterization of organic/inorganic separation membranes using inert gas (based on N2), focusing on the following technical features:
- Applicable membrane types: ? Samples in wet state need to be pre-dried ■ Applicable to porous ceramic membranes ? Hydrophilic membranes require special pretreatment
- Test boundary: The dominant flow mode is determined by the Knudsen number Kn=λ/d (ratio of free path λ to pore size d)
- Range assurance: Equipment
temperature control of ±1°C ,pressure standard second-level accuracy > support
Key technology configuration matrix
Components Specification parameters Periodic verification Flat plate permeation pool △Pressure tolerance>1000kpa ■Embedded porous 316L stainless steel support plate ?Annual inspection of O-rings■Bolt gap calibration Hollow fiber fixture □Adaptive sealing seat■Inspection under a magnifying glass with a broken wire rate<0.5% ?Monthly inspection of joint air tightness Soap film metering device ■Conical tube accuracy gradient (0-500mL segmented compensation) △Volume calibration correction
Standardized lean implementation plan
Pre-saturation treatment control: Carry out 5 pressure shock inflations (ΔP ≥ test pressure 75%) under 23℃±1, RH50±10% environment to eliminate pore size shrinkage and deformation
Ultrafiltration membrane maintenance case of water treatment plant
When a sewage plant in Guizhou selected PES membrane components with different formulas, after selecting products with pore size standard deviation lower than 0.03μm according to this method, the RO system rejection rate increased by 17%, and multiple inflation and deflation were implemented in accordance with Chapter 7 to confirm that the residual oxygen content of the system was <300ppm
Permeability model and algorithm derivation
Key formulaCombined with Velocity slip theory correction:
- Strathmann corrected macroscopic flow equation
Jtotal=C?*d*σ-0.5 + C?*(d/η)^2*pm
- ETS Regress module is used in industrial projects to perform intercept convergence iterative operations
GB/T 42269-2022 Referenced Document
- GB/T 20103-2006 Technical terms for membrane separation
- GB/T 2918-2018 Standard environment for conditioning and testing of plastic specimens
- GB/T 8979-2008 Pure nitrogen and high purity nitrogen and ultra pure nitrogen
GB/T 42269-2022 history
- 2022 GB/T 42269-2022 Determination of pore size for membranes—Gas permeation method