Based on the principle of liquid-liquid replacement method, the instrument realizes automaticdatacollection, analysis and calculation through an integrated system, and is suitable for measuringthepore size distribution of ultra-filtration membranes and micro-filtration membranes.
The liquidfluxof the membrane is calculated from the trans-membrane pressure and the corresponding liquidflowrate. With the rapid development of the membrane industry, the membrane pore size and fluxanalyzerwill become a necessary professional instrument for colleges and universities, scientific researchinstitutes, production enterprises, environmental protection, measurement, quality inspectionandother related units. , metal and other membrane materials, product development, productionqualitycontrol, use failure.
ASTM F316-2003, ASTM D6767-2002, ASTM E1294-1999, ISO 4003-1990, GB/T 14041.1-2007, HY/T 051-1999, HY/T 064-2002
2.1 Dimension: 480*420*230
2.2 Working medium: water, organic solvent
2.3 Flow: 0-10mL/min
2.4 Working pressure: 0-1Mpa
2.5 Aperture measuring range: 8nm-200nm
2.6 Pipeline interface: 8mm
2.7 Weight: 20kgs
2.8 Environment temperature (℃) ：4 ～ 40；
Aperture test range：0.08～ 500um According to the basic principle of the liquid-liquid exclusion method, the pores of the membrane arefilled with wetting liquid, and another liquid incompatible with it is used as the osmotic hydraulic pressure toenterthe pores of the membrane. The larger the value, the easier it is for the wetting fluid to be dischargedbythepermeate, that is, the largest pores are first opened by the permeate. In the same way, the channel that isfinally opened is the smallest, and the diameter of the channel can be calculated fromthe openingpressure. Calculated as follows.
where d is the pore size, γ is the interfacial tension between the wetting fluid and the permeate, θisthe contact angle between the wetting fluid and the membrane material, and P is the opening pressureThrough the corresponding relationship between the permeate flow and pressure, the pore size distributionof the membrane material can be calculated according to the mathematical model.
ASTM F316-2003 Standard Test Methods for Pore Size Characteristics of Membrane Filters by BubblePoint and Mean Flow Pore Test;
ASTM D6767-2002 Standard Test Method for Pore Size Characteristics of Geotextiles by CapillaryFlowTest;
ASTM E1294-1999 Standard Test Method for Pore Size Characteristics of Membrane Filters UsingAutomated Liquid Porosimeter;
ISO 4003-1990 Permeable sintered metallic materials - Determination of pore size ;
GB/T 14041.1-2007 Hydraulic transmission, filter element, verification of structural integrityanddetermination of initial bubble point;
HY/T 051-1999 Test method for hollow fiber microporous membrane;
HY/T 064-2002 Test method for tubular ceramic microporous membrane
Main functions of membrane pore size and flux analyzer: maximum pore size, average pore size, poresizedistribution, pure water or other liquid flux.
(1) The maximum pore size increases with the increase of the permeate pressure. When a stable permeateflow rate begins to be detected, it means that the first channel (ie, the largest channel) is opened. Thepressure value at this time can be calculated by entering the above formula. maximumaperture. Thisinstrument adopts a high-precision flow detector, which can automatically determine and measurethemaximum aperture.
(2) As the average pore size increases with the pressure of the permeate, accurately measure the relationshipbetween the permeate flow and pressure (commonly known as the "wet curve"). When the wettingliquidiscompletely removed, slowly reduce the permeate pressure and accurately measure the permeate again. Curveversus pressure (commonly known as "dry curve"). Divide the ordinate value of the "dry curve" datapointby 2 to obtain a new set of data points, and draw the curve, which is commonly known as the "semi-drycurve". The average pore size can be calculated according to the pressure corresponding to the intersectionof the "semi-dry curve" and the "wet curve", as shown in the example below. The average pore sizethuscalculated is also known as the "flux median pore size", that is, the pore size above and belowthis poresizecontribute half to the membrane flux.
(3) Pore size distribution By comparing the difference between the "wet curve" and the "dry curve", theporesize distribution of the membrane material can be obtained by calculating with a certain mathematical model,and the pore size distribution diagram and the cumulative pore size distribution diagramare drawnbythecalculation software.
(4) Pure water flux Using pure water as the permeable medium, and accurately measuring the relationshipbetween water flow and pressure, the pure water flux F can be calculated:
Among them, Q is the flow rate of pure water, A is the membrane area, and P is the pressure.
(5) Liquid flux In addition to pure water, the instrument can also measure the permeation fluxof otherliquids, the method is the same as above