Device and method for testing permeation filtration performance of hollow fiber membrane

Abstract

The invention provides equipment and a method for testing permeation filtration performance of a hollow fiber membrane. The equipment comprises a rack, a clamp assembly, a circulating detection system, a control panel, a raw material tank and a wastewater tank, the clamp assembly comprises an upper clamp, a lower clamp, a sealing ring and a driving device; wherein the upper clamp and the lower clamp are provided with cavities for accommodating hollow fiber membrane filaments, so that the upper clamp, the lower clamp and the sealing ring are spliced to form a closed space, and the lower clamp is also provided with two hole channels communicated with the cavities; quick connectors are arranged on two sides of the sealing ring, inlet ends of the hollow fiber membrane filaments are connected with the raw material tank through the quick connectors, and outlet ends of the hollow fiber membrane filaments are connected with the wastewater tank through the quick connectors; the circulating detection system comprises an adsorption separation device, a circulating pump and a detection unit; the adsorption separation device is connected with one hole channel, and the adsorption separation device is sequentially connected with the circulating pump and the detection unit. According to the invention, accurate measurement of the penetration amount of the single hollow fiber membrane silk can be realized.

Description

Technical Field

[0001] The present invention relates to the field of hollow fiber membrane detection, and particularly to an apparatus and method for testing the permeation filtration performance of hollow fiber membranes. Background Art

[0002] Hollow fiber membranes are a type of filtration material and have important applications in the fields of water treatment, chemistry, medicine, etc.

[0003] Advanced membrane separation processes often rely on the separation performance of membrane materials, so it is necessary to measure their performance. During the process of developing membrane materials, it is often necessary to go through processes such as manufacturing the membrane, encapsulating the components, and testing the permeation filtration performance of the membrane module. After the membrane module is made into a finished product through the above processes, the membrane performance can be measured to obtain more accurate performance data. However, encapsulating multiple membrane filaments into a membrane module requires a large amount of membrane material and time, which undoubtedly prolongs the overall development cycle and greatly increases the R & D cost. Summary of the Invention

[0004] The purpose of the present invention is to provide an apparatus for testing the permeation filtration performance of hollow fiber membranes, which can accurately measure the permeation flux of a single hollow fiber membrane filament, aiming at the problems existing in the prior art.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An apparatus for testing the permeation filtration performance of hollow fiber membranes, comprising a frame, a fixture assembly, a circulation detection system, a control panel, a raw material tank, and a waste water tank;

[0007] The fixture assembly includes an upper fixture, a lower fixture, a sealing ring, and a driving device; the lower fixture is fixedly installed on the frame; a liftable and slidable lifting platform is provided on the frame, and the upper fixture is installed on the lifting platform directly above the lower fixture; the sealing ring is detachably installed on the lower fixture; the driving device is installed on the frame and connected to the lifting platform; wherein, the upper fixture and the lower fixture are provided with cavities for accommodating hollow fiber membrane filaments, so that the upper fixture, the lower fixture, and the sealing ring are combined to form a sealed space, and the lower fixture is also provided with two channels communicating with the cavity; quick connectors are provided on both sides of the sealing ring, the inlet end of the hollow fiber membrane filament is connected to the raw material tank through the quick connector, and the outlet end is connected to the waste water tank through the quick connector;

[0008] The circulation detection system includes an adsorption and separation device, a circulation pump, and a detection unit; the adsorption and separation device is connected to one of the channels, and the circulation pump and the detection unit are sequentially connected after the adsorption and separation device, and the detection unit is connected to the other channel to form a circulation;

[0009] The driving device and the circulation pump are respectively connected to the control panel.

[0010] Further, the detection unit is a high-precision balance.

[0011] Further, the detection unit is a gel permeation chromatograph detector.

[0012] Further, the detection unit is a conductivity tester.

[0013] Further, a first temperature sensor and a second temperature sensor are respectively provided at the quick connectors at both ends of the inlet and outlet of the hollow fiber membrane filament; before the quick connector at the inlet end of the hollow fiber membrane filament, a diaphragm pump for controlling the flow rate is connected; the lifting table is equipped with a heater for controlling the temperature and a third temperature sensor for detecting the temperature.

[0014] A method for testing the permeation filtration performance of a hollow fiber membrane includes the following steps:

[0015] 1) Fix the hollow fiber membrane filament on the lower fixture, and connect its inlet and outlet ends to the quick connectors on both sides of the sealing ring respectively;

[0016] 2) Operate the driving device to press down the upper fixture, seal it with the lower fixture and the sealing ring, and completely wrap the hollow fiber membrane filament inside the cavity;

[0017] 3) Introduce the raw material into the hollow fiber membrane filament, so that after the raw material is filtered by the hollow fiber membrane filament, the permeate filters out into the cavity; turn on the circulation pump, so that the permeate flows through the adsorption separation device and the detection unit in sequence, the permeate adsorbs moisture through the adsorption separation device, and then enters the detection unit and continuously circulates in a closed loop;

[0018] 4) Through the mass increment m(t) measured by the detection unit over time, the circulation time T, and the effective area S of the hollow fiber membrane filament m , the permeation flux per unit area of the membrane filament within a certain time is measured, satisfying:

[0019]

[0020] Further, after step 3) includes the step:

[0021] 3-1) Set a diaphragm pump in front of the inlet end of the hollow fiber membrane filament, set a first temperature sensor and a second temperature sensor at both ends of the inlet and outlet of the hollow fiber membrane filament respectively, and set a heater and a third temperature sensor on the lifting table; after turning on the circulation pump, adjust the diaphragm pump to adjust the flow rate of the raw material; adjust the circulation pump to adjust the circulation flow rate; adjust the heater to adjust the overall temperature of the fixture assembly, and detect the temperature through the first temperature sensor, the second temperature sensor and the third temperature sensor.

[0022] The present invention provides an apparatus and method for testing the permeation filtration performance of hollow fiber membranes, which can test the filtration performance of at least a single hollow fiber membrane filament, and adopts the methods of adsorbing and removing moisture and cumulative detection in a closed loop to achieve accurate testing of trace permeates. The apparatus has a simple structure, can greatly shorten the R & D cycle of hollow fiber membrane products, and save R & D costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. is a schematic diagram of the conical hole structure of an apparatus for testing the permeation filtration performance of a hollow fiber membrane provided by the present invention.

[0024] Figure 2 FIG. is a schematic diagram of the stepped hole structure of an apparatus for testing the permeation filtration performance of a hollow fiber membrane provided by the present invention.

[0025] Figure 3 FIG. is a schematic diagram of the principle of membrane filament potting. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions of the present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0027] Embodiment 1

[0028] As Figures 1 to 2 shown, an apparatus for testing the permeation filtration performance of a hollow fiber membrane provided by the present invention includes a frame 1, a fixture assembly, a circulation detection system, a control panel 4, a raw material tank 5, and a waste water tank 6.

[0029] The fixture assembly includes an upper fixture 21, a lower fixture 22, a sealing ring 25, and a driving device 24; the lower fixture 22 is fixedly installed on the frame 1; a lift table 23 that can slide up and down is provided on the frame 1, and the upper fixture 21 is installed on the lift table 23 directly above the lower fixture 22; the sealing ring 25 is detachably installed on the lower fixture 22; the driving device 24 is installed on the frame 1 and connected to the lift table 23; wherein, cavities 26 for accommodating hollow fiber membrane filaments 0 are provided on the upper fixture 21 and the lower fixture 22, so that the upper fixture 21, the lower fixture 22, and the sealing ring 25 are combined to form a closed space, and two channels 28 communicating with the cavities 26 are also provided on the lower fixture 22; quick connectors 27 are provided on both sides of the sealing ring 25, the inlet end of the hollow fiber membrane filament 0 is connected to the raw material tank 5 through the quick connector 27, and the outlet end is connected to the waste water tank 6 through the quick connector 27;

[0030] The circulation detection system includes an adsorption separation device 31, a circulation pump 32, and a detection unit 33; the adsorption separation device 31 is connected to one of the channels 28, and the circulation pump 32 and the detection unit 33 are connected in sequence after the adsorption separation device 31, and the detection unit 33 is connected to the other channel 28 to form a circulation.

[0031] The driving device 24 and the circulation pump 32 are respectively connected to the control panel.

[0032] The present invention can accurately test the performance of a single hollow fiber membrane filament 0, thus saving the encapsulation process and being of great help in reducing the R & D cycle of hollow fiber membranes. It adopts the method of closed-loop circulation and cumulative detection of permeate, and reduces interference by adsorbing moisture through the adsorption separation device 31. The specific working principle is as follows:

[0033] After the hollow fiber membrane filament 0 is fixed, the driving device 24 is controlled to make the upper fixture 21 tightly closed. Raw materials are introduced into the hollow fiber membrane filament 0 through the quick connector 27. Under the action of pressure, the permeate penetrates into the cavity 26. At this time, the circulation pump 32 drives the permeate to flow out through the channel 28, and after passing through the adsorption separation device 31 and the detection unit 33 in sequence, it flows back to the cavity 26 through another channel 28 to form a closed-loop circulation.

[0034] In the above process, the adsorption separation device 31 can adsorb the moisture in the permeate. The adsorption separation device 31 is preferably an adsorption separation bottle filled with silica gel particles, which can absorb substances accounting for about 20 - 30% of its own mass. The permeate after removing the interfering substances flows into the detection unit 33, and the detection unit 33 conducts cumulative detection on the circulating permeate, so as to measure high-precision data for trace amounts of permeate.

[0035] Regarding the independent testing ability for a single hollow fiber membrane filament 0, the device innovatively develops a miniaturized dynamic sealing system. Through the precisely machined fixture assembly, the non-destructive sealing of a single hollow fiber membrane filament 0 can be achieved. This design breaks through the technical bottleneck that traditional testing must be encapsulated into a membrane module, enabling researchers to directly characterize the performance of a single hollow fiber membrane filament 0 in the prototype stage. Practical applications show that this technology significantly shortens the new product development cycle and greatly reduces the material cost per single test, only consuming a small section of hollow fiber membrane filament sample.

[0036] The closed-loop circulation system of this device has achieved a qualitative leap in detection accuracy through a unique fluid path design. The permeate driven by the circulation pump 32 undergoes a complete circulation path of "cavity 26 → pore 28 → adsorption and separation device 31 → detection unit 33 → pore 28 → cavity 26" in a closed loop. This design has multiple technical advantages: First, through continuous circulation, the system accumulates the concentration of trace permeate within the detection unit 33, solving the error caused by transient flow fluctuations in traditional single-pass detection; Second, the closed-loop structure completely isolates external environmental interference, avoiding secondary pollution problems such as solvent volatilization and gas dissolution commonly found in open systems. More importantly, the dynamic equilibrium mechanism of continuous dehydration of the adsorption and separation device 31 during the circulation process enables the system to not only remove moisture interference in real time but also maintain a stable circulation flow. Experimental data shows that compared with traditional open detection systems, this closed-loop circulation solution has significantly improved detection sensitivity and can accurately detect the data of trace permeate filtered by a single hollow fiber membrane filament 0.

[0037] Preferably, the detection unit 33 is a high-precision balance.

[0038] Preferably, a first temperature sensor and a second temperature sensor (not shown) are respectively provided at the quick connectors 27 at both ends of the inlet and outlet of the hollow fiber membrane filament 0; before the quick connector 27 at the inlet end of the hollow fiber membrane filament 0, a diaphragm pump (not shown) for controlling the flow rate is connected; the lifting table 23 is equipped with a heater (not shown) for controlling the temperature and a third temperature sensor (not shown) for detecting the temperature.

[0039] Taking the membrane distillation process test as an example, the raw material is hot water, and the permeate is water vapor.

[0040] The incremental mass m(t) accumulated by the high-precision balance over time can be used to measure the permeation flux per unit area of the hollow fiber membrane filament 0 within a certain period of time. The calculation formula is as follows:

[0041]

[0042] In the formula, S m is the effective area of the hollow fiber membrane filament 0, and T is the circulation time.

[0043] It can be seen that this method can not only measure the average permeation amount of the hollow fiber membrane filament 0 within a certain period of time but also be used to detect the change in the permeation characteristics of the hollow fiber membrane filament 0 over time, that is, the durability of the membrane filament.

[0044] During the test, the inlet and outlet temperatures on the hot water side are measured by the first temperature sensor and the second temperature sensor installed at the inlet and outlet of the hollow fiber membrane filaments 0. The temperature of the hot water is controlled by a water tank outside the device for storing raw materials, and the flow rate is controlled by a diaphragm pump. On the permeate side, the circulating flow rate is controlled by a circulating pump 32. The temperature of the upper fixture 21 is controlled by a third temperature sensor and a heater on the lifting platform 23 connected to the upper fixture 21.

[0045] By changing the detection unit 33, the present invention can also be used for membrane separation applications where both sides are solutions. For example, in the membrane separation of effective components of traditional Chinese medicine, the detection unit 33 can be replaced with a gel permeation chromatograph to detect the molecular weight of the permeate through gel permeation chromatography.

[0046] Alternatively, in the membrane distillation process for seawater desalination, the detection unit 33 can be replaced with a conductivity tester to measure the filtration performance of a single membrane filament.

[0047] Embodiment 2

[0048] The present invention also provides a method for testing the permeation filtration performance of hollow fiber membranes, including the following steps:

[0049] 1) Fix the hollow fiber membrane filaments 0 on the lower fixture 22, and connect the two ends of its inlet and outlet to the quick connectors 27 on both sides of the sealing ring 25;

[0050] 2) Operate the driving device 24 to press down the upper fixture 21, seal it with the lower fixture 22 and the sealing ring 27, and completely wrap the hollow fiber membrane filaments 0 inside the cavity 26;

[0051] 3) Introduce raw materials into the hollow fiber membrane filaments 0, so that after the raw materials are filtered by the hollow fiber membrane filaments 0, the permeate is filtered out into the cavity 26; turn on the circulating pump 32 to make the permeate flow through the adsorption separation device 31 and the detection unit 33 in sequence. The permeate is adsorbed with water by the adsorption separation device 31 and then enters the detection unit 33 to continuously circulate in a closed loop;

[0052] 4) Based on the mass increment m(t) measured by the detection unit 33 over time, the circulation time T, and the effective area S of the hollow fiber membrane filaments 0 m , the permeation flux per unit area of the hollow fiber membrane filaments 0 within a certain period of time is measured, satisfying:

[0053]

[0054] The main technical point of this method is to eliminate errors through time accumulation. By internal circulation, the accumulated mass is measured, and even extremely small masses can be used to measure the permeation flux by this method. And

[0055] Preferably, after step 3), the following step is included:

[0056] 3-1) A diaphragm pump is arranged in front of the inlet end of the hollow fiber membrane filament 0, a first temperature sensor and a second temperature sensor are respectively arranged at both the inlet and outlet ends of the hollow fiber membrane filament 0, and a heater and a third temperature sensor are arranged on the lifting table 23; after the circulation pump 32 is started, the diaphragm pump is adjusted to adjust the flow rate of the raw material; the circulation pump 32 is adjusted to adjust the circulation flow rate; the heater is adjusted to adjust the overall temperature of the fixture assembly, and the temperature is detected by the first temperature sensor, the second temperature sensor and the third temperature sensor.

[0057] This preferred step is mainly used to debug the flow rate and temperature of each node, make various parameters more reasonable, and create a better test environment.

[0058] The present invention also provides a device for testing the permeation filtration performance of hollow fiber membranes, which can accurately test the filtration performance of a single unencapsulated hollow fiber membrane filament 0. The accuracy is guaranteed by a closed-loop circulation and adsorption process. Thus, the device can greatly reduce the R & D cycle of hollow fiber membranes, reduce the R & D cost, and improve the R & D efficiency. Moreover, the detection unit 33 of the device can be replaced with different instruments according to different needs to achieve different effects.

[0059] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A device for testing the permeability and filtration performance of a hollow fiber membrane, characterized in that: Includes rack, fixture assembly, circulation detection system, control panel, raw material tank and waste water tank; The fixture assembly includes an upper fixture, a lower fixture, a sealing ring and a driving device; the lower fixture is fixedly installed on the frame; a slidable lifting platform is provided on the frame, and the upper fixture is installed on the lifting platform directly above the lower fixture; the sealing ring is detachably installed on the lower fixture; the driving device is installed on the frame and connected to the lifting platform; wherein, a cavity for accommodating hollow fiber membranes is provided on the upper fixture and the lower fixture, so that the upper fixture, the lower fixture and the sealing ring are assembled to form a closed space, and the lower fixture is also provided with two channels connected to the cavity; quick connectors are provided on both sides of the sealing ring, the inlet end of the hollow fiber membrane is connected to the raw material tank through the quick connector, and the outlet end is connected to the wastewater tank through the quick connector; The circulation detection system includes an adsorption separation device, a circulation pump and a detection unit; the adsorption separation device is connected to one of the channels, the adsorption separation device is sequentially connected to the circulation pump and the detection unit, and the detection unit is connected to another channel to form a cycle; The driving device and the circulating pump are respectively connected with the control panel.

2. The device for testing the permeation and filtration performance of a hollow fiber membrane according to claim 1, characterized in that: The detection unit is a high-precision balance.

3. The device for testing the permeation and filtration performance of a hollow fiber membrane according to claim 1, characterized in that: The detection unit is a gel chromatography detector.

4. The device for testing the permeation and filtration performance of a hollow fiber membrane according to claim 1, characterized in that: The detection unit is a conductivity tester.

5. A device for testing the permeation and filtration performance of a hollow fiber membrane according to any one of claims 2 to 4, characterized in that: The first temperature sensor and the second temperature sensor are respectively provided at the quick joints at both ends of the inlet and outlet of the hollow fiber membrane; a diaphragm pump for controlling the flow rate is connected before the quick joint at the inlet end of the hollow fiber membrane; the lifting platform is installed with a heater for controlling the temperature and a third temperature sensor for detecting the temperature.

6. A method for testing the permeation and filtration performance of a hollow fiber membrane, based on the device of claim 1, characterized in that: The following steps are involved: 1) Fix the hollow fiber membrane on the lower fixture, and connect its inlet and outlet ends to the quick connectors on both sides of the sealing ring; 2) Operate the driving device to press the upper clamp downward to seal with the lower clamp and the sealing ring, and completely wrap the hollow fiber membrane inside the cavity; 3) Feeding raw materials into the hollow fiber membrane, filtering the raw materials through the hollow fiber membrane, and filtering out the permeate into the cavity; starting the circulation pump, allowing the permeate to flow through the adsorption separation device and the detection unit in sequence, the permeate adsorbs water through the adsorption separation device, and then enters the detection unit to continuously circulate in a closed loop; 4) The mass increment m(t) measured by the detection unit, the cycle time T, and the effective area S of the hollow fiber membrane m , test the permeation flux per unit area of ​​the membrane within a certain period of time, and meet the following requirements:

7. A method for testing the permeation and filtration performance of a hollow fiber membrane according to claim 6, characterized in that: The step 3) comprises the following steps: 3-1) A diaphragm pump is arranged in front of the inlet end of the hollow fiber membrane filament, a first temperature sensor and a second temperature sensor are respectively arranged at both ends of the inlet and outlet of the hollow fiber membrane filament, and a heater and a third temperature sensor are arranged on the lifting platform; after starting the circulation pump, the diaphragm pump is adjusted to adjust the flow rate of the raw material; the circulation pump is adjusted to adjust the circulation flow rate; the heater is adjusted to adjust the overall temperature of the fixture assembly, and the temperature is detected by the first temperature sensor, the second temperature sensor and the third temperature sensor.

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