A fast and accurate detection device and test method for hollow fiber membrane performance

Abstract

The present invention discloses a fast and accurate detection device and test method for the performance of hollow fiber membranes. The detection device includes at least one test unit with a sealing air device for fixing the membrane filaments to be tested, a pressure fluid input system directly connected to one end of the test unit, and an output pipe of the pressure fluid arranged at the other end of the test unit. The present invention breaks through the limitation that the previous membrane filament detection equipment must use a thin rope to bind or glue to connect the membrane filament samples to be tested, and greatly improves the timeliness of membrane filament detection while ensuring the accuracy of detection. The use of a specially designed sealing device eliminates the process of preparing samples for membrane filament detection, saves detection costs, and ensures detection accuracy; the present invention can be simply and quickly installed and sealed, greatly improving the speed and efficiency of membrane performance detection, which is beneficial to the quality control of membrane products on the production line.

Description

Technical Field

[0001] The present invention relates to the field of hollow fiber membrane performance detection, and in particular to a rapid detection device and a test method for hollow fiber membrane performance. The detection device is particularly suitable for rapid and accurate detection of the performance of a liner hollow fiber composite membrane. Background Art

[0002] With the rapid development of the national economy and the continuous improvement of people's living standards, the requirements for environmental safety, especially water environment safety, are getting higher and higher. In order to obtain more stable and higher quality effluent water, more and more membrane water treatment technologies are being used in sewage treatment and drinking water treatment processes. Among them, hollow fiber ultra / microfiltration membranes are being used more and more widely, and liner-reinforced hollow fiber composite membranes with higher mechanical strength and service life have been rapidly developed due to their superior performance. With the continuous increase in the output of hollow fiber membranes, strict control of membrane quality during the production process has also put forward higher and higher requirements for the rapid detection technology of hollow fiber membrane performance. The faster the membrane performance detection, the faster the quality control response of the production process, and the more stable the performance and quality of the membrane.

[0003] like Figure 1a As shown, the lined hollow fiber composite membrane (referred to as membrane filament in the industry) is mainly composed of a coated surface separation layer 010 and a braided tube 020 or other types of supporting materials, which are responsible for the functions of separation and support strength respectively. The surface separation layer 010 is a filter membrane with a microporous structure. Water cannot pass through the membrane without pressure. The internal braided tube 020 or support layer is woven from polymer fibers, and the wall pores are large, so water can easily flow radially and axially therein. At present, the method of connecting the membrane filament to the equipment for rapid determination of membrane performance (including membrane flux, membrane bubble point, etc.) generally uses a needle tube inserted into the inner hole of the membrane filament, and then uses a thin rope to tie the end of the membrane filament to the needle to achieve a sealing effect. Due to the large pores of the internal braided tube wall and a large thickness (about 0.5-2mm), it is impossible to obtain an effective seal, especially when water is pressurized during testing, the water will flow out of the braided tubes at both ends of the membrane filament, so that the membrane performance cannot be accurately obtained. In order to overcome this deficiency, a sealing glue is used to strengthen the seal, that is, by bonding the membrane filament to the test pipe, a good sealing effect can be obtained. However, the glue needs a certain amount of time to solidify, so the test samples need to be prepared in advance, which affects the timeliness of the test and cannot meet the needs of rapid testing of membrane performance on the production line. Figure 1b As shown, there are also some difficulties in detecting hollow fiber membranes (referred to as membrane fibers in the industry) that are not lined with braided tubes. For example, if glue is used for sealing, it is time-consuming and cannot provide rapid detection. If ropes are used for binding, the force is difficult to control due to manual binding, and the force is insufficient, the seal is not firm, and there is a risk of being washed out by water pressure. If the force is too strong, there is a risk of rupturing the membrane fibers.

[0004] So far, the rapid detection of membrane fibers has always been difficult to balance timeliness and accuracy. Therefore, it is becoming increasingly important to prepare a hollow fiber membrane fiber detection device that can easily and quickly connect the membrane fiber sample to be tested and obtain a reliable sealing effect, thereby accurately measuring the membrane fiber performance, in order to produce hollow fiber membranes with stable and reliable quality. A hollow fiber membrane detection device that has both timeliness and accuracy is of great significance to the research and development and production of hollow fiber membranes. Summary of the invention

[0005] In order to solve the problem that the existing hollow fiber membrane (referred to as membrane filament in the industry) performance detection equipment is difficult to balance the timeliness and accuracy of the detection, the present invention proposes a hollow fiber membrane performance detection equipment and testing method that is simple and fast to install and has accurate and reliable detection results. The detection equipment can simultaneously improve the detection speed and accuracy of membrane filament performance, provide a guarantee for the control of membrane filament quality during the membrane filament production process, thereby improving product quality and market competitiveness.

[0006] The present invention proposes a device for quickly and accurately detecting the performance of hollow fiber membranes, which includes at least one test unit with a sealing device for fixing the membrane filaments to be tested, an adjustable pressure fluid input system directly connected to one end of the test unit, and an output pipe of the pressure fluid arranged at the other end of the test unit.

[0007] Preferably, the sealing device includes a tubular shell, a tubular sealing mechanism arranged in the shell, and a connecting mechanism that fixes the sealing mechanism in the shell; the top of the shell and the top of the corresponding sealing mechanism are provided with a through hole for one end of the membrane thread to be tested to be inserted into the sealing mechanism, and the lower port of the sealing mechanism is closed by a sealing ring; the connecting mechanism includes a base threadedly connected to the inner hole of the lower end of the shell, a needle tube arranged in the middle of the base and connected to the outside at one end, the other end of the needle tube passes through the sealing ring and is inserted into the sealing mechanism and connected to the inner hole of the membrane thread to be tested; when the shell and the base are tightened, the inner surface of the base is pressed against the outer end surface of the sealing ring.

[0008] Preferably, the pressure fluid is gas and liquid; the test unit is a water pool, and a sealing device for fixing the membrane filament to be tested is provided at each of the two lateral ends of the water pool; the pressure fluid input system includes a first pipeline for inputting pressure liquid into the inner hole at one end of the membrane filament to be tested, a main water valve, a flow meter, a water pressure gauge and an inlet valve arranged in sequence on the first pipeline; a second pipeline for inputting pressure gas connected in parallel with the first pipeline, a pressure reducing valve, a pressure gauge and a main air valve arranged in sequence on the second pipeline.

[0009] Preferably, the output pipeline includes an internal pressure cross-flow outlet pipe connected to the inner hole at the other end of the membrane filament to be tested, and the cross-flow outlet pipe is provided with an internal pressure outlet valve; and an internal pressure water collecting outlet pipe with an internal pressure water collecting valve is arranged on the lower side of the test unit.

[0010] Preferably, the water pool is provided with a sealing cover; a bypass for external pressure testing is provided on the first pipeline between the water pressure gauge and the inlet valve, the bypass is provided with a water inlet valve, and the bypass is connected to the water pool.

[0011] Preferably, the output pipeline also includes an external-pressure cross-flow water outlet pipe connected to the water pool, and the external-pressure cross-flow water outlet pipe is provided with an external-pressure outlet valve; the internal-pressure cross-flow water outlet pipe also bypasses an external-pressure water collecting outlet pipe with an external-pressure water collecting valve.

[0012] The present invention also provides a testing method using the hollow fiber membrane performance rapid and accurate testing equipment, the basic steps are: respectively installing and fixing the two ends of the membrane filament to be tested on the sealing device in the testing unit; according to the test items of the membrane filament performance, respectively selecting the membrane flux or membrane bubble point of the membrane filament internal pressure mode to test, or selecting the membrane flux of the membrane filament external pressure mode to test.

[0013] Preferably, the test of the membrane flux in the membrane filament internal pressure mode comprises the following steps:

[0014] Select the corresponding pressure liquid and test waterway for the test, control the relevant valves on the test waterway, input the pressure liquid into the inner cavity of the membrane to be tested, and make the flow rate and pressure of the pressure liquid reach the set value of the test, and start timing the pre-pressurization time;

[0015] When the device runs for a set pre-pressure time, the filtered liquid output by the test unit begins to be collected. When the set filtration time is reached, the collection ends, and finally the membrane flux of the internal pressure mode of the membrane filament to be tested is calculated.

[0016] Preferably, the test of the bubble point of the membrane filaments comprises the following steps:

[0017] Select the corresponding pressure gas and test gas circuit for the test, control and adjust the relevant valves on the test gas circuit, and make the pressure of the pressure gas reach the set value of the test; add clean water to the test unit until the membrane wire to be tested is submerged, and then input the pressure gas into the inner cavity of the membrane wire to be tested;

[0018] When bubbles appear on the surface of the membrane filament to be tested, the pressure value of the pressure gas at this time is recorded as the maximum bubble point; when a large number of bubbles suddenly appear on the surface of the membrane filament to be tested, the pressure value of the pressure gas at this time is recorded as the average bubble point.

[0019] Preferably, the test of membrane flux in the external pressure mode of the membrane filament comprises the following steps:

[0020] Seal the test unit with a sealing cover to ensure that the test unit is well sealed;

[0021] Selecting corresponding pressure liquid and test water circuit for testing, controlling relevant valves on the test water circuit, directly inputting the pressure liquid into the inner cavity of the test unit; and making the flow rate and pressure of the pressure liquid reach the test set value;

[0022] After the external pressure water collection outlet pipe in the output pipeline connected to the inner hole of the membrane filament to be tested starts to discharge water, the pressure liquid is allowed to run for the set pre-pressure time, and the filtered liquid output by the external pressure water collection outlet pipe begins to be collected. When the set filtration time is reached, the collection is terminated, and finally the membrane flux of the external pressure mode of the membrane filament to be tested is calculated.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention can test multiple membrane properties at the same time by integrating the water circuit of the membrane flux test and the gas circuit of the membrane bubble point test of the membrane filament; and through modular design and assembly, multiple membrane filament samples can also be tested at the same time, which greatly shortens the time of membrane filament testing, greatly improves the timeliness of membrane filament detection while ensuring detection accuracy, and provides the most powerful foundation for factory production management and product research and development. The present invention breaks through the limitations of previous membrane filament detection equipment that must use thin ropes or glue to connect the membrane filament samples to be tested, and adopts a specially designed sealing device, which eliminates the process of preparing samples for membrane filament detection, saves detection costs, and ensures detection accuracy; the present invention can be simply and quickly installed and sealed, greatly improving the speed and efficiency of membrane performance detection, which is beneficial to the quality control of membrane products on the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a , Figure 1b They are schematic diagrams of the structures of lined hollow fiber composite membrane and unsupported hollow fiber membrane;

[0026] Figure 2 A schematic diagram of the structure of the sealing device provided by the present invention;

[0027] Figure 3 A schematic diagram of a first embodiment of a device for detecting membrane flux and membrane bubble point in an internal pressure mode of a membrane filament;

[0028] Figure 4 It is a schematic diagram of a second embodiment of a membrane flux and membrane bubble point device capable of simultaneously detecting the internal pressure modes of multiple membrane filaments;

[0029] Figure 5 A schematic diagram of a third embodiment of a device for detecting the membrane flux, membrane bubble point and membrane flux of a membrane filament in an internal pressure mode and an external pressure mode;

[0030] Figure 6 It is a schematic diagram of the fourth embodiment of the membrane flux device capable of simultaneously detecting the membrane flux, membrane bubble point and external pressure mode of multiple membrane filaments. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments and drawings.

[0032] The invention provides a fast and accurate detection device for the performance of hollow fiber membranes, please refer to Figure 4 , generally comprises one or more parallel test units 100, the test unit is a container, inside of which is provided a sealing device for fixing the performance of the hollow fiber membrane (membrane filament) to be tested. It also comprises an adjustable pressure fluid input system 200 directly connected to the left end of all the test units, and an output pipe 300 of the pressure fluid arranged at the right end of the test unit. That is, the pressure fluid passes through the membrane filament to be tested, and finally the performance parameters of the membrane filament to be tested, such as membrane flux and membrane bubble point, are measured according to the condition of the fluid permeated from the membrane filament to be tested.

[0033] Figure 1a Shown is a schematic diagram of the structure of the lined hollow fiber composite membrane; Figure 1b The schematic diagram of the structure of the hollow fiber membrane without lining support is shown. The membrane fibers of these two structures can be used as the membrane fibers to be tested in the present invention.

[0034] like Figure 2As shown, the sealing device specially made for the present invention comprises a tubular housing 04, a tubular sealing mechanism 03 arranged in the housing, and a connecting mechanism for fixing the sealing mechanism in the housing 04. The top of the housing and the corresponding top of the sealing mechanism are provided with a through hole for inserting one end of the membrane filament 05 to be tested into the sealing mechanism 03, and the lower end of the sealing mechanism is closed by a sealing ring 02. The connecting mechanism comprises a base 01 threadedly connected to the inner hole of the lower end of the housing 04, and a needle tube 06 arranged at the middle of the base, the lower end of which can be connected to the outside, and the upper end of the needle tube passes through the sealing ring 02 and is inserted into the sealing mechanism 03 and is connected to the inner hole of the membrane filament 05 to be tested. When the housing 04 and the base 01 are screwed together, the inner surface of the base 01 is pressed against the outer end surface of the sealing ring 02. In this way, the sealing mechanism 03 at one end can fix one end of the membrane filament 05 to be tested, and the sealing mechanisms at both ends can respectively fix the two ends of the membrane filament to be tested. On the other hand, a sealed space can be formed between the sealing mechanism 03, the membrane thread to be tested 05, the needle tube 06 and the sealing ring 02. That is, during the test, when the pressure fluid used for the test enters the sealed space axially through the wall of the membrane thread to be tested 05 and is filled, the pressure fluid used for the test will no longer leak to the two ends of the membrane thread to be tested, and the pressure fluid can only penetrate radially from the wall of the membrane thread to be tested 05 that is not wrapped by the inner circle 03 of the sealing mechanism.

[0035] like Figure 2 , 3As shown, it is a schematic diagram of the first embodiment of the membrane flux and membrane bubble point device used for detecting the internal pressure mode of a membrane filament of the present invention. It is also the basic structure of the detection device of the present invention. The pressure fluid described in the present invention is a pressure gas 11 and a pressure liquid 1, such as air and clean water. The test unit is a water pool 7, and a sealing device 6 for fixing the membrane filament 05 to be tested is respectively provided at the left and right ends of the water pool 7. When the membrane filament 05 to be tested is fixed in the water pool 7 by using the sealing device 6 provided by the present invention, the needle tube 06 of the sealing device 6 at both ends is connected to the inner hole of the membrane filament 05 to be tested, and the needle tube 06 of the sealing device 6 is also connected to the outside. The pressure-adjustable pressure fluid input system includes a first pipeline 50 for inputting the test pressure liquid 1 into the inner hole of the membrane filament 05 to be tested through the needle tube 06 of the sealing device 6 at the left end of the water pool 7, and a main water valve 2, a flow meter 3, a water pressure gauge 4 and an inlet valve 4 arranged on the first pipeline 50 in sequence. The main water valve 2 is connected to the external pressure liquid, and the inlet valve 4 is connected to the needle tube 06 of the sealing device 6. It also includes a second pipeline 60 for inputting the test pressure gas 1, which is connected in parallel to the first pipeline 50 between the main water valve 2 and the flow meter 3. The second pipeline 60 is provided with a pressure reducing valve 12, a barometer 14 and a main gas valve 13 connected to the external pressure gas 1 in sequence. The output pipeline arranged at the right end of the water pool 7 includes: an internal pressure cross-flow outlet pipe 70 connected to the inner hole at the right end of the membrane wire 05 to be tested through the needle tube 06 of the sealing device 6 at the right end, and the internal pressure cross-flow outlet pipe 70 is provided with an internal pressure cross-flow valve 9; and an internal pressure water collection outlet pipe 80 with an internal pressure water collection valve 10 arranged at the lower side of the water pool 7.

[0036] Figure 3The pressure liquid 1 shown in is used to provide membrane flux testing. The pressure liquid can be supplied in the mode of a pressure water tank or in the mode of water pump pressurization. The main water valve 2 is used to control the opening and closing of the pressure liquid. And the water volume and pressure of the pressure liquid can be adjusted by the opening of the main water valve 2. The flow meter 3 is used to monitor the water flow of the pressure liquid. The inlet valve 4 is used to open and close the pressure fluid flowing through the membrane filament to be tested 05. And the water volume and pressure passing through the membrane filament to be tested can be adjusted by the opening of the valve. The water pressure gauge 5 is used to monitor the liquid pressure of the membrane filament detection pipeline to be tested. The sealing device 8 is used to connect the membrane filament to be tested 05 into the test pipeline and ensure the sealing performance. The water tank 7 is used to hold clean water and filter water. The internal pressure cross-flow valve 9 is used to control the opening and closing of the test water outlet of the membrane filament to be tested 05, thereby controlling the membrane filament filtration mode. That is, when the valve is closed, it is in dead-end filtration mode; when the valve is opened, it is in cross-flow filtration mode; at the same time, in conjunction with the main water valve 2 and the inlet valve 4, by controlling the opening of the internal pressure cross-flow valve 9, the amount of water and pressure passing through the membrane filament to be tested and the amount of cross-flow water can be accurately adjusted. When the pressure liquid 1 is supplied in the mode of a pressure water tank, the water from the internal pressure cross-flow outlet pipe 70 can be directly discharged; when the pressure liquid 1 is supplied in the mode of water pump pressurization, the water from the internal pressure cross-flow outlet pipe 70 flows back to the pool 7. The internal pressure water collection valve 10 is used to control the opening and closing of the water pool 7 drainage. When testing the membrane flux in the internal pressure mode, open the valve and use a measuring cylinder or beaker to collect the filtered clean water flowing out of the internal pressure water collection outlet pipe 80; when testing the membrane flux in the external pressure mode, close the valve. The pressure gas 11 is used to provide the pressure gas required for testing the bubble point of the internal pressure mode membrane. The pressure gas can be supplied by a pressure pipe; it can also be supplied by an air pump. The pressure reducing valve 12 is used to reduce the pressure of the pressurized gas 11 to the pressure value required for detection. The main air valve 13 is used to control the opening and closing of the conveying pressurized air 11. The gas volume and pressure of the test gas circuit can be adjusted by controlling the opening of the main air valve. The barometer 14 monitors the air pressure value in the pipeline.

[0037] like Figure 4 As shown, it is the second embodiment of the present invention. The only difference between this embodiment and the first embodiment is that the four test units 100 are connected in parallel. The fluid input system 200 can be directly connected to the left ends of all the test units. As needed, the internal pressure cross-flow outlet pipes 70 in the output pipeline 300 can also be aggregated to uniformly process the cross-flow effluent. This device can control the test of one membrane filament to be tested individually, and can also test four membrane filaments to be tested at the same time, thereby greatly improving the test efficiency of the membrane filament performance. As needed, multiple test units can also be connected in parallel, for example, three, five, etc.

[0038] like Figure 5As shown, it is the third embodiment of the present invention. The structure of this embodiment is also based on the structure of the first embodiment. The first embodiment mainly adds some facilities for detecting the membrane flux of the external pressure mode of the membrane filament. Therefore, it is necessary to set a sealing cover 16 on the water pool 7 of the first embodiment, and the sealing of the water pool needs to be maintained during operation. It is also necessary to set a bypass for external pressure testing on the first pipeline 50 between the water pressure gauge 5 and the inlet valve 4. The bypass is provided with a water inlet valve 15 and is directly connected to the inner cavity of the water pool 7. The output pipeline also includes an external pressure cross-flow water outlet pipe that is directly connected to the inner cavity of the water pool 7. The external pressure cross-flow water outlet pipe is provided with an external pressure cross-flow valve 17. An external pressure water collection water outlet pipe with an external pressure water collection valve 18 is also bypassed on the internal pressure cross-flow water outlet pipe 70 between the internal pressure cross-flow valve 9 and the sealing mechanism 6. See details. Figure 5 As shown, the water inlet valve 15 is used to control the opening and closing of the pressure liquid 1 entering the water pool 7, and the amount of water and the pressure entering the water pool 7 can be adjusted by controlling the opening of the valve. The sealing cover 16 is used to seal the water pool 7, so that a pressure water flow can be formed on the outer surface of the membrane filament 05 to be tested. The external pressure cross-flow valve 17 is used to control the opening and closing of the pressure liquid in the water pool 7 leaving the water pool, thereby controlling the filtering mode of the membrane filament to be tested. When the valve is closed, it is a dead-end filtering mode; when the valve is opened, it is a cross-flow filtering mode. At the same time, in conjunction with the main water valve 2 and the water inlet valve 15, the amount of water and the pressure passing through the outer surface of the membrane filament 05 to be tested and the amount of cross-flow water can be accurately adjusted by controlling the opening of the external pressure cross-flow valve 17. When the pressure liquid 1 is supplied in the mode of a pressure water tank, the water from the external pressure cross-flow outlet pipe can be directly discharged; when the pressure liquid 1 is supplied in the mode of water pump pressurization, the water from the external pressure cross-flow outlet pipe flows back into the water pool 7. The external pressure water collection valve 18 is used to control the opening and closing of the water filtered out from the inner surface of the membrane filament 05 to be tested. When the membrane flux in the external pressure mode is tested, the valve is opened, and the filtered liquid flowing out of the external pressure water collection outlet pipe is collected with a measuring cylinder or a beaker. When the membrane flux in the internal pressure mode is tested and the membrane bubble point is tested, the valve is closed. This set of equipment can perform the membrane flux test and the membrane bubble point test in the internal pressure mode on the membrane filament, and can also perform the membrane flux test in the external pressure mode, that is, the set of equipment can select to test the performance of the membrane filament as needed.

[0039] like Figure 6 As shown, the fourth embodiment of the present invention is different from the third embodiment only in that the three test units 400 are connected in parallel. The fluid input system 500 can be directly connected to the left ends of all the test units. As needed, the internal pressure wrong flow water outlet pipes 70 in the output pipeline 600 can be combined, and the external pressure wrong flow water outlet pipes can be combined to uniformly process the wrong flow water. This set of equipment can independently control the test of one membrane filament to be tested, and can also test three membrane filaments to be tested at the same time, thereby greatly improving the test efficiency of the membrane filament performance. As needed, multiple test units can also be connected in parallel, for example, four, five, etc.

[0040] The present invention also provides a method for testing the hollow fiber membrane performance using the rapid and accurate testing device. The basic testing steps are: respectively fixing the two ends of the membrane to be tested on the sealing device in the testing unit; and respectively selecting the test bubble point and the membrane flux in the internal pressure mode according to the test items of the membrane performance, or selecting the test membrane flux in the external pressure mode. The following takes the testing device provided in the third embodiment as an example. Figure 5 As shown, the testing method of the present invention is described in detail.

[0041] 1. Perform a membrane flux test in the internal pressure mode on the membrane to be tested. The steps are as follows:

[0042] The two ends of the membrane filament 05 to be tested are respectively fixed on the sealing device 6 in the water pool 7. Select the corresponding pressure liquid 1 for testing and the test waterway - the first pipeline 50, control the relevant valves on the first pipeline, that is, close the main air valve 13, the water inlet valve 15, the external pressure cross-flow valve 17 and the external pressure water collection valve 18; open the main water valve 2, the inlet valve 4, the internal pressure cross-flow valve 9 and the internal pressure water collection valve 10, input the pressure liquid 1 into the inner cavity of the membrane filament 05 to be tested, and adjust the opening of the main water valve 2, the inlet valve 4, and the internal pressure cross-flow valve 9 at the same time, and cooperate with the flow meter 3 and the water pressure gauge 5 so that the flow and pressure of the pressure liquid 1 reach the set value of the test, and start timing the pre-pressure time.

[0043] Allow the device to run stably for a period of time, and when the device reaches the set pre-pressure time, start timing the filtration time, and at the same time place a measuring cylinder or beaker under the internal pressure water collection outlet pipe 80 on the lower side of the pool 7 to collect the output filtered liquid. When the device runs stably for a period of time and reaches the set filtration time, remove the measuring cylinder or beaker to end the collection, and stop inputting the pressure liquid 1. Finally, calculate the volume of the filtered liquid collected in the measuring cylinder or beaker, divide it by the filtration time and the inner surface area of ​​the membrane filament 05 to obtain the membrane flux of the internal pressure mode of the membrane filament to be tested.

[0044] 2. Test the bubble point of the membrane to be tested. The steps are as follows:

[0045] The two ends of the membrane filament 05 to be tested are respectively fixed on the sealing device 6 in the pool 7. Select the corresponding pressure gas 11 for testing and the test gas circuit - the second pipeline 60, control and adjust the relevant valves on the test gas circuit, that is, close the main water valve 2, the inlet valve 4, the water inlet valve 15, the internal pressure cross-flow valve 9, the internal pressure water collection valve 10, the external pressure cross-flow valve 17 and the external pressure water collection valve 18, open the main gas valve 13, and input the pressure gas 11 into the second pipeline 60; adjust the pressure reducing valve 12 according to the value of the barometer 14, so that the gas circuit pressure, that is, the pressure value of the barometer 14, drops to the set value of the test; add clean water to the pool 7 until the membrane filament 05 to be tested is submerged, and then slowly open the inlet valve 4, input the pressure gas 11 into the inner cavity of the membrane filament 05 to be tested, and observe the surface and pressure value of the membrane filament to be tested.

[0046] When bubbles are observed on the surface of the membrane filament 05 to be tested, the pressure value of the barometer 14 at this time is recorded as the maximum bubble point; when a large number of bubbles are observed to suddenly appear on the surface of the membrane filament to be tested, the pressure value of the barometer 14 at this time is recorded as the average bubble point. That is, the membrane bubble point is the pressure value of the pressure gas 11 when the pressure gas 11 passes through the wall of the membrane filament to be tested and a certain state occurs. Close the main gas valve 13 and open the internal pressure cross-flow valve 9 to discharge the gas in the gas path. The test is completed.

[0047] 3. Perform membrane flux test in external pressure mode on the membrane filament to be tested. The steps are as follows:

[0048] The two ends of the membrane filament 05 to be tested are respectively fixed on the sealing device 6 in the water pool 7, and the water pool 7 is sealed with a sealing cover 16 to ensure that the water pool 7 is well sealed. Select the corresponding pressure liquid 1 and the test waterway for testing, control the relevant valves on the test waterway, that is, close the main air valve 13, the inlet valve 4, the internal pressure cross-flow valve 9 and the internal pressure water collection valve 10, open the main water valve 2, the water inlet valve 15, the external pressure cross-flow valve 17 and the external pressure water collection valve 18, and directly input the pressure liquid 1 into the inner cavity of the water pool 7; adjust the opening of the main water valve 2, the water inlet valve 15 and the external pressure cross-flow valve 17, and cooperate with the flow meter 3 and the water pressure gauge 5, so that the flow and pressure of the pressure liquid 1 reach the set value of the test.

[0049] After observing that the external pressure water collection outlet pipe connected to the inner hole of the membrane filament 05 to be tested in the output pipeline begins to discharge water, let the pressure liquid 1 circulate and run until the set pre-pressure time is reached, start timing the filtration time, and place a measuring cylinder or beaker under the external pressure water collection outlet pipe to collect the output filtered liquid. Let the equipment run stably for a period of time. When the set filtration time is reached, remove the measuring cylinder or beaker to end the collection and stop inputting the pressure liquid 1. Finally, calculate the volume of the filtered liquid collected in the measuring cylinder or beaker, divide it by the filtration time and the outer surface area of ​​the membrane filament to be tested, and obtain the membrane flux of the test external pressure mode.

[0050] The present invention breaks through the limitation that the previous membrane filament detection equipment must use thin ropes or glue to connect the membrane filament samples to be tested, and greatly improves the timeliness of membrane filament detection while ensuring the accuracy of detection. The specially designed sealing device eliminates the process of preparing samples for membrane filament detection, saves detection costs, and ensures detection accuracy; the present invention can be installed and sealed simply and quickly, greatly improving the speed and efficiency of membrane performance detection, which is beneficial to the quality control of membrane products on the production line.

[0051] The above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rapid and accurate detection device for hollow fiber membrane performance, characterized in that: It comprises at least one test unit having a sealing device for fixing the membrane to be tested, a pressure fluid input system directly connected to one end of the test unit, and an output pipeline of the pressure fluid arranged at the other end of the test unit; wherein, The sealing device includes a tubular shell, a tubular sealing mechanism arranged in the shell, and a connecting mechanism for fixing the sealing mechanism in the shell; the top of the shell and the top of the corresponding sealing mechanism are provided with a through hole for one end of the membrane wire to be tested to be inserted into the sealing mechanism, and the lower port of the sealing mechanism is closed by a sealing ring; the connecting mechanism includes a base threadedly connected to the inner hole of the lower end of the shell, a needle tube arranged in the middle of the base and one end of which is connected to the outside, and the other end of the needle tube passes through the sealing ring and is inserted into the sealing mechanism and connected to the inner hole of the membrane wire to be tested; when the shell and the base are tightened, the inner surface of the base is pressed against the outer end surface of the sealing ring.

2. The rapid and accurate detection device according to claim 1, characterized in that: The pressure fluid is gas and liquid; the test unit is a water pool, and a sealing device for fixing the membrane wire to be tested is provided at each of the two lateral ends of the water pool; the pressure fluid input system includes a first pipeline for inputting pressure liquid into the inner hole at one end of the membrane wire to be tested, a main water valve, a flow meter, a water pressure gauge and an inlet valve arranged on the first pipeline in sequence; a second pipeline for inputting pressure gas connected in parallel with the first pipeline, a pressure reducing valve, a pressure gauge and a main gas valve arranged on the second pipeline in sequence.

3. The rapid and accurate detection device according to claim 2, characterized in that: The output pipeline includes an internal pressure cross-flow water outlet pipe connected to the inner hole of the other end of the membrane wire to be tested, and the cross-flow water outlet pipe is provided with an internal pressure outlet valve; and an internal pressure water collecting water outlet pipe with an internal pressure water collecting valve is arranged at the lower side of the test unit.

4. The rapid and accurate detection device according to claim 3, characterized in that: The water pool is provided with a sealing cover; a bypass for external pressure testing is provided on the first pipeline between the water pressure gauge and the inlet valve, the bypass is provided with a water inlet valve, and the bypass is communicated with the water pool.

5. The rapid and accurate detection device according to claim 4, characterized in that: The output pipeline also includes an external pressure cross-flow water outlet pipe connected to the water pool, and the external pressure cross-flow water outlet pipe is provided with an external pressure outlet valve; the internal pressure cross-flow water outlet pipe also bypasses an external pressure water collecting water outlet pipe with an external pressure water collecting valve.

6. A testing method using the rapid and accurate testing device as claimed in claim 5, characterized in that: The two ends of the membrane filament to be tested are respectively mounted and fixed on the sealing device in the test unit; according to the test items of the membrane filament performance, the membrane flux or membrane bubble point of the membrane filament internal pressure mode is selected to test the membrane filament, or the membrane flux of the membrane filament external pressure mode is selected to test the membrane filament.

7. The testing method according to claim 6, characterized in that: Testing the membrane flux in the internal pressure mode includes the following steps: Select the corresponding pressure liquid and test waterway for the test, control the relevant valves on the test waterway, input the pressure liquid into the inner cavity of the membrane to be tested, and make the flow rate and pressure of the pressure liquid reach the set value of the test, and start timing the pre-pressurization time; When the device runs for a set pre-pressure time, the filtered liquid output by the test unit begins to be collected. When the set filtration time is reached, the collection ends, and finally the membrane flux of the internal pressure mode of the membrane filament to be tested is calculated.

8. The testing method according to claim 6, characterized in that: Testing the membrane bubble point in internal pressure mode includes the following steps: Select the corresponding pressure gas and test gas circuit for the test, control and adjust the relevant valves on the test gas circuit, and make the pressure of the pressure gas reach the set value of the test; add clean water to the test unit until the membrane wire to be tested is submerged, and then input the pressure gas into the inner cavity of the membrane wire to be tested; When bubbles appear on the surface of the membrane filament to be tested, the pressure value of the pressure gas at this time is recorded as the maximum bubble point; when a large number of bubbles suddenly appear on the surface of the membrane filament to be tested, the pressure value of the pressure gas at this time is recorded as the average bubble point.

9. The testing method according to claim 6, characterized in that: Testing the membrane flux in the external pressure mode includes the following steps: Seal the test unit with a sealing cover to ensure that the test unit is well sealed; Selecting corresponding pressure liquid and test water circuit for testing, controlling relevant valves on the test water circuit, directly inputting the pressure liquid into the inner cavity of the test unit; and making the flow rate and pressure of the pressure liquid reach the test set value; After the external pressure water collecting outlet pipe in the output pipeline connected to the inner hole of the membrane filament to be tested starts to discharge water, and the pressure liquid is allowed to run for the set pre-pressure time, the filtered liquid output by the external pressure water collecting outlet pipe is collected. When the set filtration time is reached, the collection is terminated, and finally the membrane flux of the external pressure mode of the membrane filament to be tested is calculated.

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