阅读说明：本技术 一种气体净化膜接触角动态检测系统及方法 (Dynamic detection system and method for contact angle of gas purification membrane ) 是由 仲兆祥 武军伟 邢卫红 周群 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种气体净化膜接触角动态检测系统及方法,一种气体净化膜接触角动态检测系统,包括光源、气体净化膜载物台、成像系统、计算机、支撑平台,所述光源、气体净化膜载物台、成像系统呈直线固定于支撑平台上,成像系统与计算机相连；气体净化膜载物台包括活动法兰、上固定法兰、隔离网、筒体、出气口、干燥剂、下固定法兰、盲板、气体流量控制器、缓冲罐、引风机、压差传感器。该检测系统可在气体过滤状态下测量膜表面接触角,完成气体净化膜接触角的动态检测。(The invention discloses a dynamic detection system and a dynamic detection method for a contact angle of a gas purification film, wherein the dynamic detection system for the contact angle of the gas purification film comprises a light source, a gas purification film objective table, an imaging system, a computer and a supporting platform, wherein the light source, the gas purification film objective table and the imaging system are linearly fixed on the supporting platform, and the imaging system is connected with the computer; the gas purification membrane objective table comprises a movable flange, an upper fixed flange, an isolation net, a cylinder, a gas outlet, a drying agent, a lower fixed flange, a blind plate, a gas flow controller, a buffer tank, an induced draft fan and a differential pressure sensor. The detection system can measure the contact angle of the surface of the membrane in a gas filtering state, and complete the dynamic detection of the contact angle of the gas purification membrane.)

1. A gas purification film contact angle dynamic detection system is characterized by comprising a light source (1), a gas purification film object stage (2), an imaging system (3), a computer (4) and a supporting platform (5), wherein the light source (1), the gas purification film object stage (2) and the imaging system (3) are linearly fixed on the supporting platform (5), and the imaging system (3) is connected with the computer (4);

the gas purification membrane object stage (2) comprises a movable flange (201), an upper fixed flange (202), an isolation net (203), a cylinder body (204), a gas outlet (205), a drying agent (206), a lower fixed flange (207), a blind flange (208), a gas flow controller (209), a buffer tank (210), an induced draft fan (211) and a differential pressure sensor (212), wherein the upper fixed flange (202) and the lower fixed flange (207) are fixed at the upper end and the lower end of the cylinder body (204), the movable flange (201) and the upper fixed flange (202) are provided with matched flange holes (2021), the upper fixed flange (202) is welded with a support screen (2022), the isolation net (203) is positioned in the middle of the cylinder body (204), the gas outlet (205) is positioned at the lower part of the cylinder body (204), the drying agent (206) is filled in the cylinder body (204) and positioned at the lower part of the isolation net (203), the blind flange (208) and the, gas outlet (205) link to each other through gas pipeline and gas flow controller (209) inlet end, and gas flow controller (209) give vent to anger the end and link to each other with buffer tank (210) through gas pipeline, and draught fan (211) link to each other with buffer tank (210) through gas pipeline, and gas flow controller (209) pass through signal line and computer (4) link to each other, pressure differential sensor (212) link to each other with barrel (204) through the pressure pipe, and pressure differential signal passes through signal line and transmits to computer (4).

2. The dynamic detection system for the contact angle of the gas purification membrane as claimed in claim 1, wherein the diameter of the cylinder (204) is 2-10cm, and the diameter of the movable flange (201) is 4-12 cm.

3. The dynamic detection system for the contact angle of the gas purification membrane as claimed in claim 1, wherein the supporting screen (2022) is a stainless steel screen with a screen aperture of 5-100 μm.

4. The dynamic detection system of contact angle of gas purification membrane as claimed in claim 1, wherein said desiccant (206) is silica gel or molecular sieve particles with a particle size of 1-5 mm.

5. The method for dynamically detecting the contact angle of the gas purification membrane by using the system for dynamically detecting the contact angle of the gas purification membrane as claimed in any one of claims 1 to 4, is characterized by comprising the following steps:

the method comprises the following steps: cutting a gas purification membrane material, placing the gas purification membrane material on an upper fixed flange (202), and fixing and sealing the gas purification membrane material by using a movable flange (201);

step two: starting a light source (1) and an imaging system (3), dripping liquid drops with a certain volume on the surface of the gas purification film, and shooting the initial state of the liquid drops by using the imaging system (3);

step three: starting an induced draft fan (211), adjusting the gas permeation speed of the gas purification membrane by adjusting a gas flow controller (209), shooting the state of liquid drops on the surface of the gas purification membrane at different permeation speeds by an imaging system (3), and detecting the pressure difference of two sides of the gas purification membrane by a pressure difference sensor (212);

step four: and (4) calculating a contact angle by the computer, recording the contact angle, the gas permeation speed and the pressure difference between two sides of the gas purification membrane under different filtering speeds, and drawing a contact angle dynamic data curve by taking the gas permeation speed as an abscissa and the contact angle and the pressure difference between two sides of the gas purification membrane as an ordinate.

6. The method for dynamically detecting the contact angle of the gas purification membrane as claimed in claim 5, wherein in the first step, the movable flange (201), the gas purification membrane and the fixed flange (202) are sealed by gaskets.

7. The method for dynamically detecting the contact angle of the gas purification membrane as claimed in claim 5, wherein the volume of the liquid drop in the second step is 3-20 μ L, and the type of the liquid drop is deionized water or n-hexadecane.

8. The method for dynamically detecting the contact angle of the gas purification membrane as claimed in claim 5, wherein the gas permeation speed of the gas purification membrane in the third step is 0.1-5 m/min.

9. The method for dynamically detecting the contact angle of the gas purification membrane as claimed in claim 5, wherein the contact angle calculation method in step four is a cone method.

Technical Field

The invention relates to the field of surface performance testing of gas purification membranes, in particular to a system and a method for dynamically detecting a contact angle of a gas purification membrane.

Background

The gas purifying membrane is a novel gas purifying material and has the advantages of uniform pore diameter, large gas flux, small running resistance, long service life and the like. The gas purification membrane is widely applied to the fields of industrial tail gas purification, superfine powder recovery, factory ventilation purification, indoor air purification, personal hygiene protection and the like. The gas purification membrane is easily polluted by water or oily aerosol in the using process, and water drops or oil drops easily block a filter pore channel, so that the running resistance is increased, and the purification efficiency is reduced. The hydrophobic and oleophobic modification of the surface of the gas purification membrane can effectively enhance the water resistance and oil pollution resistance of the membrane material. The modified oil contact angle and water contact angle are important parameters for representing the hydrophobic and oleophobic properties of the membrane material. At present, a common solid surface contact angle testing device and method are adopted for testing the contact angle of the gas purification membrane, and the device and method are static detection methods, but the influence of contact angle data, filtering speed and other filtering parameters on a contact angle in a gas filtering state cannot be obtained.

Disclosure of Invention

The invention discloses a dynamic detection system and a dynamic detection method for a contact angle of a gas purification membrane, which can measure the contact angle of the surface of the membrane in a gas filtration state and complete the dynamic detection of the contact angle of the gas purification membrane.

The technical scheme of the invention is as follows:

a dynamic detection system for a contact angle of a gas purification film comprises a light source, a gas purification film objective table, an imaging system, a computer and a supporting platform, wherein the light source, the gas purification film objective table and the imaging system are linearly fixed on the supporting platform, and the imaging system is connected with the computer;

the gas purification membrane stage comprises a movable flange, an upper fixing flange, an isolation net, a cylinder body, a gas outlet, a drying agent, a lower fixing flange, a blind plate, a gas flow controller, a buffer tank, a draught fan and a pressure difference sensor, wherein the upper fixing flange and the lower fixing flange are fixed at the upper end and the lower end of the cylinder body, the movable flange and the upper fixing flange are provided with matched flange holes, the upper fixing flange is welded with a support screen, the isolation net is positioned in the middle of the cylinder body, the gas outlet is positioned at the lower part of the cylinder body, the drying agent is filled in the cylinder body and positioned at the lower part of the isolation net, the blind plate and the lower fixing flange are provided with matched flange holes, the gas outlet is connected with the gas inlet end of the gas flow controller through a gas pipeline, the gas outlet end of the gas flow controller is connected with the buffer tank through a gas pipeline, the differential pressure signal is transmitted to the computer through a signal wire.

Further, the diameter of the cylinder body is 2-10cm, and the diameter of the movable flange is 4-12 cm.

Further characterized in that the supporting screen is a stainless steel screen with the aperture of 5-100 μm.

Further characterized in that the drying agent is silica gel or molecular sieve particles with the particle size of 1-5 mm.

A method for dynamic detection of gas purification membrane contact angle using the system of claim 1, comprising the steps of:

the method comprises the following steps: cutting a gas purification membrane material, placing the gas purification membrane material on an upper fixed flange, and fixedly sealing the gas purification membrane material by using a movable flange;

step two: starting a light source and an imaging system, dripping liquid drops with a certain volume on the surface of the gas purification membrane by using a liquid dropping needle head, and shooting the initial state of the liquid drops by using the imaging system;

step three: starting an induced draft fan, adjusting the gas permeation speed of the gas purification membrane by adjusting a gas flow controller, shooting the state of liquid drops on the surface of the gas purification membrane at different permeation speeds by an imaging system, and detecting the pressure difference of two sides of the gas purification membrane by a pressure difference sensor;

step four: and (3) calculating the contact angle by using a computer, recording the contact angle, the gas permeation speed and the pressure difference between two sides of the gas purification membrane under different filtering speeds, and drawing a contact angle dynamic data curve by taking the gas permeation speed as an abscissa and the contact angle and the pressure difference between two sides of the gas purification membrane as an ordinate.

Further, in the first step, the movable flange, the gas purification membrane and the fixed flange are sealed through gaskets.

Further, in the second step, the volume of the liquid drop is 3-20 μ L, and the kind of the liquid drop is deionized water or n-hexadecane.

Further characterized in that the gas permeation speed of the gas purification membrane in the third step is 0.1-5 m/min.

Further, the contact angle calculation method in the fourth step is a cone method.

The gas purification membrane material to be detected is fixed on the upper fixing flange on the objective table through the flange, and the support screen can play a supporting role on the gas purification membrane. The gas purification film objective table barrel is provided with a gas outlet, the induced draft fan provides negative pressure through the gas purification film objective table at the gas outlet, gas permeates the gas purification film under the action of pressure difference, liquid drops dropping on the gas purification film are changed by the contact angle under the action of the negative pressure, and the contact angle dynamic detection data are obtained by detecting and calculating through the imaging system. An isolation net is arranged in the gas contact angle objective table, the drying agent filled in the lower portion of the isolation net can absorb water vapor permeating the gas purification film, errors are generated in measurement of the amount of protective gas, measurement accuracy is improved, and the drying agent of the isolation net is isolated on the lower portion of the cylinder body to prevent the drying agent from contacting the gas purification film and causing measurement errors.

Drawings

FIG. 1 is a schematic view of a system for dynamically detecting a contact angle of a gas purification membrane according to the present invention;

FIG. 2 is a diagram of a gas purification membrane stage according to the present invention;

fig. 3 is a schematic view of an upper mounting flange according to the present invention.

The system comprises a light source 1, a gas purification membrane object stage 2, an imaging system 3, a computer 4, a support platform 5, a movable flange 201, an upper fixed flange 202, an isolation net 203, a cylinder 204, a gas outlet 205, a drying agent 206, a lower fixed flange 207, a blind plate 208, a gas flow controller 209, a buffer tank 210, an induced draft fan 211, a differential pressure sensor 212, a flange hole 2021 and a support screen 2022.

FIG. 4 is a graph showing the water contact angle and the pressure difference of the gas purification membrane according to example 1 as a function of the filtration rate.

FIG. 5 is a graph showing the contact angle and pressure difference of n-hexadecane of the gas purification membrane of example 2 as a function of the filtration rate.

FIG. 6 is a graph showing the water contact angle and the pressure difference of the gas purification membrane according to example 3 as a function of the filtration rate.

Detailed Description

The invention will be further illustrated by the following examples and description of the drawings, which are set forth below by way of illustration only. These examples are not meant to impose any limitation on the invention. It will be apparent that those skilled in the art can make various changes and modifications to the present invention within the scope and spirit of the present invention.