Test Method

Abstract

The application relates to the technical field of water purifiers, in particular to a testing method, which comprises the following steps: injecting the same volume of concentrated water and pure water into a concentrated water tank and a pure water tank respectively, and the liquid levels of the concentrated water and the pure water are equal, wherein the concentrated water tank and the pure water tank are communicated through a reverse osmosis membrane; after water injection is completed, the liquid levels L W and L [ of the concentrated water and the pure water are recorded respectively after water is still permeated for a predetermined time; the concentrated water and the pure water in the concentrated water tank and the pure water tank are discharged; the concentrated water and the pure water are injected into the concentrated water tank and the pure water tank respectively again, so that the concentrated water and the pure water are located at the liquid levels L W and L P respectively; after water injection is completed, the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank are detected respectively, and the value of AC is obtained by calculating C1-C0; after the concentrated water is still permeated for a T time, the difference AM of the total salt mass before and after the salt permeation of the pure water tank is calculated; and the K value is calculated according to a permeation coefficient calculation formula, that is, the testing method is provided to test the salt permeation performance of the RO membrane.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water purifiers, in particular to a test method. BACKGROUND

[0002] The household reverse osmosis (RO) water purifier with large flux has a "first cup of water" problem, that is, after a long standby or shutdown, the desalination rate of a certain volume of water discharged after starting is low. The reason is that the RO membrane has an interception effect on ions, and there is a large concentration difference between the water before the membrane and the water after the membrane, the water before the membrane is concentrated water, and the water after the membrane is pure water. Due to the driving of the concentration difference, the ions on the concentrated water side will gradually penetrate through the RO membrane into the pure water side. Therefore, the salt permeability of different RO membrane sheets is different, and the existing RO membrane detection means in the household water purification industry mainly focuses on flux and desalination rate.

[0003] However, there is no test method for the salt permeability of the RO membrane in the existing industry. SUMMARY

[0004] The purpose of the present application is to provide a test method for testing the salt permeability of the RO membrane.

[0005] According to the first aspect of the present application, a test method is provided, which comprises:

[0006] Injecting the same volume of concentrated water and pure water into the concentrated water tank and the pure water tank respectively, and the liquid level of the concentrated water is equal to that of the pure water, wherein the concentrated water tank and the pure water tank are communicated through a reverse osmosis membrane;

[0007] After water injection is completed, record the liquid levels L W and L P of the concentrated water and the pure water respectively after water static penetration for a predetermined time;

[0008] Draining the concentrated water and the pure water from the concentrated water tank and the pure water tank;

[0009] Injecting the concentrated water and the pure water into the concentrated water tank and the pure water tank respectively again, so that the concentrated water and the pure water are located at liquid levels L W and L P respectively;

[0010] After water injection is completed, detecting the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank respectively, and calculating ΔC by C1-C0;

[0011] After static salt permeation for T time, calculating the total salt mass difference ΔM before and after salt permeation in the pure water tank; then calculating the K value according to the permeation coefficient calculation formula, that is,

[0012] Wherein, S is the effective area of the reverse osmosis membrane, b is the thickness of the reverse osmosis membrane, and K is the permeation coefficient.

[0013] In any of the above technical solutions, further, the water is stationary penetration for a predetermined time, respectively record the liquid level L W and L P , and according to the liquid level L P of pure water, the volume of pure water V P ;

[0014] After the stationary salt penetration T time, the TDS value C t of the pure water in the pure water tank is detected;

[0015] Then ΔM = (C t -C0) × V P .

[0016] In any of the above technical solutions, further, the water is stationary penetration for a predetermined time, respectively record the liquid level L W and L P , and according to the liquid level L P and L W , the volume ratio R of pure water and concentrated water is calculated;

[0017] Then,

[0018] In any of the above technical solutions, further, the test method further comprises setting a pure water supply tank, a concentrated water supply tank, a pure water supply pump, a concentrated water supply pump and a control system;

[0019] Wherein, the concentrated water supply tank is communicated with the concentrated water tank through the concentrated water supply pump, and the pure water supply tank is communicated with the pure water tank through the pure water supply pump;

[0020] The step of injecting the same volume of concentrated water and pure water into the concentrated water tank and the pure water tank respectively comprises:

[0021] The concentrated water and pure water are prepared in advance, and the prepared concentrated water and pure water are injected into the concentrated water supply tank and the pure water supply tank respectively;

[0022] The control system controls the concentrated water supply pump and the pure water supply pump to start, and injects the same volume V1 and V2 of concentrated water and pure water into the concentrated water tank and the pure water tank respectively;

[0023] The test method further comprises setting a pure water drainage pump and a concentrated water drainage pump;

[0024] Wherein, the pure water drainage pump communicates with the pure water tank, and the concentrated water drainage pump communicates with the concentrated water tank;

[0025] The step of draining the concentrated water and pure water in the concentrated water tank and the pure water tank comprises:

[0026] The control system controls the start of the concentrate drain pump and the pure water drain pump to drain the concentrate and pure water from the concentrate tank and the pure water tank.

[0027] In any of the above technical solutions, the test method further includes setting up a pure water flow meter, a concentrated water flow meter, a concentrated water float, and a pure water float;

[0028] The pure water flow meter is installed between the pure water supply pump and the pure water tank, and the concentrated water flow meter is installed between the concentrated water supply pump and the concentrated water tank.

[0029] The concentrated water float is positioned on the surface of the concentrated water in the concentrated water tank, and the pure water float is positioned on the surface of the pure water in the pure water tank.

[0030] When concentrated water is injected into the concentrated water tank from the concentrated water supply tank, the volume of concentrated water injected into the concentrated water tank is controlled by opening and closing the concentrated water supply pump, and the concentrated water flow meter records the flow rate Q1. When pure water is injected into the pure water tank from the pure water supply tank, the volume of pure water injected into the pure water tank is controlled by opening and closing the pure water supply pump, and the pure water flow meter records the flow rate Q2. Wherein, Q1 = V1, Q2 = V2.

[0031] In any of the above technical solutions, further, after water injection is completed and the water has been allowed to settle and infiltrate for a predetermined time, the liquid levels L of the concentrated water and the pure water are recorded respectively. W and L P And according to the liquid level L P and L W The steps to calculate the volume ratio R of pure water to concentrated water include:

[0032] After a predetermined time of static infiltration, the control system records the liquid level L of the concentrated water float. W And according to the concentrated water float level L W The volume of concentrated water V is calculated from the cross-sectional area Sw of the concentrated water tank. W ;

[0033] The control system records the pure water float level L. P And according to the pure water float level L P With respect to the cross-sectional area S of the pure water tank P Calculate the volume V of pure water P ;

[0034] but,

[0035] In any of the above technical solutions, further, concentrated water and pure water are injected again into the concentrated water tank and the pure water tank respectively, so that the concentrated water and pure water are respectively at liquid level L. W and L PThe steps include:

[0036] The control system controls the concentrated water supply pump and the pure water supply pump to start, respectively injects concentrated water and pure water into the concentrated water tank and the pure water tank, so that the concentrated water float ball and the pure water float ball are located at liquid levels L W and L P , respectively.

[0037] At this time, according to the concentrated water float ball liquid level L W and the concentrated water tank cross-sectional area S W , the concentrated water volume V W is calculated; according to the pure water float ball liquid level L P and the pure water tank cross-sectional area S P , the pure water volume V P is calculated.

[0038] In any of the above technical solutions, further, the test method further includes setting a concentrated water tank TDS meter and a pure water tank TDS meter.

[0039] The concentrated water tank TDS meter is arranged in the concentrated water tank, and the pure water tank TDS meter is arranged in the pure water tank.

[0040] After the water injection is completed, the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank are detected respectively, and the step of calculating C1-C0 to obtain ΔC includes:

[0041] The control system controls the concentrated water tank TDS meter and the pure water tank TDS meter to detect the initial TDS values C1 and C0 of the concentrated water and the pure water respectively, and calculates C1-C0 to obtain ΔC.

[0042] After the salt permeation T time is static, the step of detecting the TDS value C t of the pure water in the pure water tank includes:

[0043] After the salt permeation T time is static, the control system controls the pure water tank TDS meter to detect the TDS value C t of the pure water in the pure water tank.

[0044] In any of the above technical solutions, further, the test method further includes setting a concentrated water sealing ring, a pure water sealing ring, and a sealing clamp.

[0045] The concentrated water tank is provided with a concentrated water opening, and the pure water tank is provided with a pure water opening, a concentrated water sealing groove is arranged in the periphery of the concentrated water opening, a pure water sealing groove is arranged in the periphery of the pure water opening, the pure water sealing ring fills the pure water sealing groove, and the concentrated water sealing ring fills the concentrated water sealing groove.

[0046] The sealing clamp clamps the outer walls of the concentrate sealing tank and the pure water sealing tank, so that the concentrate sealing ring and the pure water sealing ring clamp the reverse osmosis membrane.

[0047] According to a second aspect of this application, a testing method is provided, the testing method comprising:

[0048] The same volume of concentrated water and pure water are injected into the concentrated water tank and the pure water tank respectively, and the liquid levels of the concentrated water and pure water are equal. The concentrated water tank and the pure water tank are connected by a reverse osmosis membrane.

[0049] After water injection is completed and the water has been allowed to settle and infiltrate for a predetermined time, the liquid levels L of the concentrated water and pure water are recorded respectively. W and L P At that time, based on the pure water level L P Calculate the volume V of pure water P ;

[0050] Drain the concentrated water and pure water from the concentrated water tank and the pure water tank;

[0051] Concentrated water and pure water are injected again into the concentrated water tank and the pure water tank respectively, so that the concentrated water and pure water are respectively at liquid level L. W and L P ;

[0052] After water injection is completed, the initial TDS values ​​C1 and C0 of the concentrate and pure water in the concentrate tank and the pure water tank are measured respectively, and ΔC is obtained by calculating C1-C0.

[0053] After a settling time T for salt permeation, the TDS value C of the pure water in the pure water tank is measured. t And record the liquid level L of the pure water in the pure water tank. t And based on the pure water level L t Calculate the volume V of pure water t ;

[0054] The K value is then calculated using the permeability coefficient formula.

[0055] Where S is the effective area of ​​the reverse osmosis membrane, b is the thickness of the reverse osmosis membrane, and K is the permeability coefficient.

[0056] The salt permeation performance of the RO membrane was tested according to the test method of this application.

[0057] Specifically, the K value is calculated according to the permeability coefficient formula, that is...

[0058] Once the test is completed, the salt permeation coefficient K of the RO membrane is measured, which can be used to evaluate the salt permeation performance of the RO membrane.

[0059] In order to make the above objectives, characteristics and advantages of the present application more apparent, the following preferred embodiments will be specifically described below with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0061] Figure 1 Fig. 1 shows the overall flowchart of the test method according to the embodiments of the present application;

[0062] Figure 2 Fig. 2 shows the installation schematic diagram of the reverse osmosis membrane according to the embodiments of the present application;

[0063] Figure 3 Fig. 3 shows the control flowchart of the control chip according to the embodiments of the present application.

[0064] Fig. 1 shows the overall flowchart of the test method according to the embodiments of the present application; DETAILED DESCRIPTION

[0065] The following detailed description is provided to help the reader obtain a full understanding of the methods, devices and / or systems described herein. However, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent to those skilled in the art after understanding the disclosure of the present application. For example, the order of the operations described herein is merely an example, and is not limited to the order set forth herein, and changes that will be apparent to those skilled in the art after understanding the disclosure of the present application can be made except for the operations that must occur in a specific order. In addition, the description of features known in the art can be omitted in order to improve clarity and brevity.

[0066] The features described can be implemented in different ways, and are not to be interpreted as being limited to the examples described herein. Rather, the examples are provided as a description of embodiments that, as of this time and based on knowledge of the applicant, represent the most practical and preferred implementations of the methods, devices and / or systems described herein.

[0067] Throughout the specification, when an element (such as a layer, region or substrate) is referred to as being "on" another element, "connected to" another element, "coupled to" another element, "adjacent to" another element, "on top of" another element or "covering" another element, it can be directly on, connected, coupled, adjacent, on top of, or covering the other element, or one or more other elements can be interposed therebetween. In contrast, when an element is referred to as being "directly on", "directly connected to", "directly coupled to", "directly adjacent to", "directly on top of", or "directly covering" another element, there are no other elements interposed therebetween.

[0068] As used herein, the term "and / or" includes any one of the listed items and any combination of any two or more of the listed items.

[0069] Although terms such as "first", "second" and "third" can be used herein to describe various members, components, regions, layers or sections, these members, components, regions, layers or sections are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer or section from another member, component, region, layer or section. Thus, the first member, component, region, layer or section referred to in the examples described herein can also be referred to as the second member, component, region, layer or section without departing from the teachings of the examples.

[0070] For ease of description, spatial relationship terms such as "on", "upper", "beneath", and "lower" can be used herein with respect to the orientation of one element relative to another element as shown in the drawings. Such spatial relationship terms can be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, the element described as being on "top of" or the "upper" other element would then be oriented "below" or "lower" relative to the other element. Accordingly, the term "on" encompasses both an "on" and "under" orientation depending on the spatial orientation of the device. The device can be oriented in other ways (e.g., rotated 90 degrees or at other orientations) and an appropriate modification to the spatial relationship terminology would be made to accommodate those orientations.

[0071] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including" and "has" are listed means the stated features, integers, operations, components, elements and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, operations, components, elements and / or combinations thereof.

[0072] Variations in the shapes illustrated in the drawings can occur as a result of manufacturing processes and / or tolerances. Thus, the examples described herein are not limited to the specific shapes illustrated in the drawings, but include variations in shapes that occur during manufacturing.

[0073] Features of the examples described herein can be combined with one another in a variety of ways. Furthermore, although the examples described herein have a variety of configurations, other configurations are possible in which the examples are practiced.

[0074] The present application provides a test method for testing the salt permeability of a RO membrane.

[0075] The K value is calculated according to the formula,

[0076] The salt permeability coefficient K of the RO membrane is measured after the test, and the salt permeability of the RO membrane can be evaluated.

[0077] The specific test concept and principle of the present application are as follows:

[0078] (1) Salt permeation amount formula:

[0079] The concentration difference between the concentrated water side and the pure water side of the RO membrane is the main driving force for the salt ions to permeate through the membrane;

[0080] The larger the area of the RO membrane, the greater the probability of salt ions contacting or colliding with the membrane, and the more salt ions permeate through the membrane;

[0081] The thicker the RO membrane, the more difficult it is for ions to permeate through the membrane, and the fewer ions can permeate through the membrane;

[0082] The longer the permeation time, the more salt ions permeate through the membrane.

[0083] Therefore, the amount of salt ions permeating through the membrane is directly proportional to the concentration difference between the two sides of the membrane, the effective area of the membrane, and the permeation time, and inversely proportional to the thickness of the membrane. Thus, the salt permeation formula is:

[0084] Q = ΔC x T x S / b x K (2-1);

[0085] wherein:

[0086] Q is the amount of salt ion permeation; ΔC is the concentration difference between the two sides of the membrane at the initial stage of salt permeation; T is the permeation time; S is the effective area of ​​the membrane; b is the membrane thickness; and K is the permeation coefficient.

[0087] According to the formula described in (2-1), ΔC can be obtained by measuring the TDS values ​​of the water on both sides of the membrane with a TDS meter and calculating the difference; T can be obtained by measuring with a stopwatch, timer, alarm clock, etc.; S (effective area of ​​the membrane) is a constant value in this test method; b (membrane thickness) can be measured with a micrometer.

[0088] (2) Osmotic pressure offset:

[0089] In the actual testing process, the concentration difference across the membrane leads to an osmotic pressure difference (when the volumes of concentrated water and pure water are equal). This osmotic pressure difference causes pure water to permeate through the membrane, offsetting the osmotic pressure caused by the concentration difference. This results in a concentration on the pure water side, with a reduced volume, leading to an increase in the TDS value. Therefore, to accurately test the salt permeability of the membrane, it is necessary to eliminate the phenomenon of pure water concentration caused by osmotic pressure. Therefore, the testing method of this application first adds equal volumes of concentrated water and pure water to the cavities on both sides of the membrane, allowing the pure water to permeate through the membrane under osmotic pressure, creating a height difference between the two cavities. Then, the liquid levels in both cavities are recorded. After recording the liquid levels, the water in both cavities is drained, and concentrated water and pure water are added back to the recorded liquid levels. At this point, the effect of osmotic pressure can be ignored, and the system only experiences salt permeation through the membrane.

[0090] Therefore, the salt permeation rate can be calculated using the following formula:

[0091] Q(ΔM)=C t V t -C0V P (2-2)

[0092] In the formula:

[0093] Q represents salt ion permeation; C t V represents the TDS value on the pure water side at the end of salt permeation. t C0 is the volume of the pure water side at the end of salt permeation; C0 is the TDS value of the pure water side at the beginning of salt permeation; V0 is the volume of the pure water side at the beginning of salt permeation.

[0094] After completing the above osmotic pressure offsetting operation, the volume change on the pure water side is negligible, and formula (2-2) can be simplified to:

[0095] Q = (C t -C0)×V P (2-3)

[0096] Combining (2-1) and (2-3), we obtain the formula:

[0097] The salt permeability coefficient of a specific membrane can then be calculated.

[0098] Based on the above test concept and principles, the following refers to... Figures 1 to 3 The test methods described in some embodiments of this application are described in detail.

[0099] First, the testing apparatus used in the testing method of this application includes (such as...) Figure 1 As shown):

[0100] 1011 Reverse osmosis membrane, 102 Pure water tank, 103 Concentrate tank, 104 Pure water float, 105 Float tank, 106 Pure water flow meter, 107 Concentrate flow meter, 108 Concentrate supply tank, 109 Pure water supply tank, 110 Concentrate supply pump, 111 Concentrate drain pump, 112 Concentrate tank TDS meter, 113 Control chip, 114 Display screen, 115 Pure water tank TDS meter, 116 Pure water drain pump, 117 Pure water supply pump, 118 Concentrate float, 201 Pure water sealing ring, 202 Pure water sealing groove, 203 Sealing clamp, 204 Concentrate sealing ring.

[0101] The concentrate tank 103 and the pure water tank 102 are connected by a reverse osmosis membrane 1011. As an example, such as... Figure 2 As shown, the concentrate tank 103 is provided with a concentrate opening, the pure water tank 102 is provided with a pure water opening, and a concentrate sealing groove is provided around the concentrate opening (concentrate sealing groove). Figure 2 (Not shown), a pure water sealing groove 202 is provided around the pure water opening, a pure water sealing ring 201 fills the pure water sealing groove 202, and a concentrated water sealing ring 204 fills the concentrated water sealing groove; a sealing clamp 203 clamps the outer walls of the concentrated water sealing groove and the pure water sealing groove 202 so that the concentrated water sealing ring 204 and the pure water sealing ring 201 clamp the reverse osmosis membrane 1011.

[0102] Among them, such as Figure 1 As shown, the concentrate supply tank 108 is connected to the concentrate tank 103 via the concentrate supply pump 110, and the pure water supply tank 109 is connected to the pure water tank 102 via the pure water supply pump 117.

[0103] The pure water flow meter 106 is installed between the pure water supply pump 117 and the pure water tank 102, and the concentrate flow meter 107 is installed between the concentrate supply pump 110 and the concentrate tank 103.

[0104] Both the pure water tank 102 and the concentrated water tank 103 are equipped with vertical strip float channels 105. The concentrated water float 118 is located on the concentrated water surface of the strip float channel 105 in the concentrated water tank 103, and the pure water float 104 is located on the pure water surface of the strip float channel 105 in the pure water tank 102.

[0105] The pure water discharge pump 116 is connected to the pure water tank 102, and the concentrated water discharge pump 111 is connected to the concentrated water tank 103.

[0106] The concentrated water tank TDS meter 112 is arranged in the concentrated water tank 103, and the pure water tank TDS meter 115 is arranged in the pure water tank 102.

[0107] The test method based on the test device includes (as shown in Figure 1 and Figure 3 ):

[0108] S1, the reverse osmosis membrane 1011 is installed in the reverse osmosis membrane installation part 101 (the reverse osmosis membrane installation part 101 includes a sealing clamp 203).

[0109] S2, prepare concentrated water and pure water of a certain concentration in advance, and inject the prepared concentrated water and pure water into the concentrated water supply tank 108 and the pure water supply tank 109 respectively;

[0110] S3, the display transmits the water permeation time T' value, the pure water volume V2 value and the concentrated water volume V1 value, and starts the system.

[0111] S4, the control chip 113 controls the concentrated water supply pump 110 and the pure water supply pump 117 to start according to the input instruction, and injects the same volume V1 and V2 of concentrated water and pure water into the concentrated water tank 103 and the pure water tank 102 respectively.

[0112] At this time, when the concentrated water supply tank 108 injects concentrated water into the concentrated water tank 103, the concentrated water flow meter 107 records the flow Q1 by controlling the opening and closing of the concentrated water supply pump to control the volume of concentrated water injected into the concentrated water tank, and when the pure water supply tank 109 injects pure water into the pure water tank 102, the pure water flow meter 106 records the flow Q2 by controlling the opening and closing of the pure water supply pump to control the volume of pure water injected into the pure water tank (wherein Q1=V1, Q2=V2).

[0113] S5, after the water injection is completed, the water is still permeated for T' time (i.e. after the volume of the pure water tank 102 is concentrated), the control chip 113 records the liquid level L W of the concentrated water floating ball 118, and calculates the volume V W of the concentrated water according to the liquid level L W of the concentrated water floating ball and the cross-sectional area Sw of the concentrated water tank; the control chip 113 records the liquid level L P of the pure water floating ball 104, and calculates the volume V P of the pure water according to the liquid level L P of the pure water floating ball and the cross-sectional area S P of the pure water tank.

[0114] S6, the control chip 113 controls the start of the concentrate drain pump 111 and the pure water drain pump 116 to drain the concentrate and pure water from the concentrate tank 103 and the pure water tank 102.

[0115] S7, concentrate and pure water are injected into concentrate tank 103 and pure water tank 102 respectively again: control chip 113 controls the start of concentrate supply pump 110 and pure water supply pump 117, injecting concentrate and pure water into concentrate tank 103 and pure water tank 102 respectively, so that concentrate float 118 and pure water float 104 are respectively at liquid level L. W and L P At this time, based on the concentrated water float level L... W With the cross-sectional area S of the concentrate tank W Calculate the volume of concentrated water V W According to the pure water float level L P With the cross-sectional area S of the pure water tank P Calculate the volume V of pure water P .

[0116] S8. After water injection is completed, the control chip 113 controls the TDS meter 112 of the concentrate tank and the TDS meter 115 of the pure water tank to detect the initial TDS values ​​C1 and C0 of the concentrate and pure water respectively, calculate C1-C0 to obtain ΔC, store the data and output it to the display screen 114.

[0117] S9, static salt permeation.

[0118] S10, after a settling salt permeation time T, the control chip 113 controls the TDS meter 115 of the pure water tank to detect the TDS value C of the pure water in the pure water tank 102. t .

[0119] The value of K is then calculated using the formula:

[0120] S11, the control chip 113 starts the concentrate drain pump 111 and the pure water drain pump 116 to drain the water from the concentrate tank 103 and the pure water tank 102 respectively, and the display screen 114 displays the test data and the words "Test completed".

[0121] Furthermore, it is worth mentioning that, in order to make the testing method more accurate, step S5 can also be based on the liquid level L. P and L W Calculate the volume ratio R of pure water to concentrated water;

[0122] but, Furthermore,

[0123] Specifically, the control system records the concentrated water float level L. W And based on the concentrated water float level L W The volume of concentrate V is calculated from the cross-sectional area Sw of the concentrate tank.W ; control system records pure water floating ball liquid level L P , and according to pure water floating ball liquid level L P and pure water tank cross-sectional area S P to calculate pure water volume V P ; then,

[0124]

[0125] Because, in the later standing salt permeation, due to the volume difference between the concentrated water tank and the pure water tank, the volume difference makes the salt permeation relatively fast, so the volume ratio is adjusted to balance the test method.

[0126] In addition, it is worth mentioning that in step S10, after standing salt permeation T time, the volume of pure water in pure water tank 102 will change slightly. Therefore, in order to test the accuracy, after standing salt permeation T time, control chip 113 can also record the liquid level L t of pure water in pure water tank 102, and according to the liquid level L t of pure water, calculate the pure water volume V t .

[0127] Therefore, the second aspect of the present application provides a separate test method (except in step S10, the pure water volume V t needs to be calculated, and the rest of the steps are the same as the test method of the first aspect). The test method of the second aspect of the present application calculates the K value according to the formula:

[0128] After further considering the R parameter, then

[0129] In summary, the present application cuts different RO membranes to a specific size, prepares concentrated water and pure water according to relevant requirements, and inputs a specific test time after adding concentrated water and pure water into the water tank, starts the system, and waits for the test to be completed. The salt permeation coefficient of the membrane can be measured, so that the salt permeation performance of the membrane can be evaluated.

[0130] Finally, it should be pointed out that the above-described embodiments are only specific implementations of the present application, which are used to illustrate the technical solutions of the present application, but not to limit them. The protection scope of the present application is not limited to this. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily think of changes to the technical solutions recorded in the foregoing embodiments within the technical scope disclosed by the present application, or make equivalent replacements to some technical features. These modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application.

Claims

1. A test method characterized by, The test method comprises: Injecting the same volume of concentrated water and pure water into the concentrated water tank and the pure water tank respectively, and the liquid level of the concentrated water is equal to that of the pure water, wherein the concentrated water tank and the pure water tank are communicated through a reverse osmosis membrane; After water injection, the liquid levels L of the concentrated water and the pure water are recorded respectively after the water is still permeated for a predetermined time W and L P ; Draining the concentrated water and pure water from the concentrated water tank and the pure water tank; Again, the concentrated water and the pure water are injected into the concentrated water tank and the pure water tank, respectively, so that the concentrated water and the pure water are located at liquid levels L W and L P , respectively. After the water injection is completed, the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank are detected respectively, and ΔC is obtained by calculating C1-C0; After the salt permeation T time is kept, the difference ΔM of the total mass of salt before and after the salt permeation of the pure water tank is calculated; K value is calculated according to the permeability coefficient calculation formula, that is Wherein, S is the effective area of the reverse osmosis membrane, b is the thickness of the reverse osmosis membrane, and K is the permeation coefficient.

2. The test method of claim 1, wherein, After the water is stationary permeated for a predetermined time, the liquid level L of the concentrated water and the pure water are recorded respectively W and L P , and the pure water volume V P is calculated according to the liquid level L P of the pure water After the salt permeation T time of standing, the TDS value C of the pure water in the pure water tank also needs to be detected t ; then ΔM = (C t - C0) x V P .

3. The test method of claim 2, wherein, After the water is stationary permeated for a predetermined time, the liquid levels L W and L P of the concentrated water and the pure water are recorded respectively P and L W The volume ratio R of the pure water to the concentrated water is calculated according to the liquid levels L then, 4. The test method of claim 3, wherein, The test method further comprises setting a pure water supply tank, a concentrated water supply tank, a pure water supply pump, a concentrated water supply pump and a control system; Wherein, the concentrated water supply tank is communicated with the concentrated water tank through the concentrated water supply pump, and the pure water supply tank is communicated with the pure water tank through the pure water supply pump; The step of injecting the same volume of concentrated water and pure water into the concentrated water tank and the pure water tank respectively comprises: Preparation of concentrated water and pure water, and injection of the prepared concentrated water and pure water into the concentrated water supply tank and the pure water supply tank respectively; The control system controls the concentrated water supply pump and the pure water supply pump to start, and injects the same volume V1 and V2 of concentrated water and pure water into the concentrated water tank and the pure water tank respectively; The test method further comprises setting a pure water drainage pump and a concentrated water drainage pump; Wherein, the pure water drainage pump communicates with the pure water tank, and the concentrated water drainage pump communicates with the concentrated water tank; The step of draining the concentrated water and pure water from the concentrated water tank and the pure water tank comprises: The control system controls the concentrated water drainage pump and the pure water drainage pump to start, so as to drain the concentrated water and pure water from the concentrated water tank and the pure water tank.

5. The test method of claim 4, wherein, The test method further comprises setting a pure water flow meter, a concentrated water flow meter, a concentrated water float ball and a pure water float ball; Wherein, the pure water flow meter is arranged between the pure water supply pump and the pure water tank, and the concentrated water flow meter is arranged between the concentrated water supply pump and the concentrated water tank; The concentrated water float ball is arranged on the concentrated water liquid surface in the concentrated water tank, and the pure water float ball is arranged on the pure water liquid surface in the pure water tank; When the concentrated water supply tank injects concentrated water into the concentrated water tank, the opening and closing of the concentrated water supply pump are controlled to control the volume of the concentrated water injected into the concentrated water tank, and the concentrated water flow meter records the flow Q1; when the pure water supply tank injects pure water into the pure water tank, the opening and closing of the pure water supply pump are controlled to control the volume of the pure water injected into the pure water tank, and the pure water flow meter records the flow Q2; wherein, Q1=V1, Q2=V2.

6. The test method of claim 5, wherein, After the water injection is completed, the liquid levels L W and L P of the concentrated water and the pure water are recorded respectively after the water is static infiltrated for a predetermined time P and L W The step of calculating the volume ratio R of the pure water to the concentrated water according to the liquid levels L P and L W includes: After the water is stationary permeated for a predetermined time, the control system records the concentrated water float ball liquid level L W And according to the concentrated water float ball liquid level L W And the concentrated water tank cross-sectional area Sw calculates the concentrated water volume V W ; The control system records the pure water floating ball liquid level L P And according to the pure water floating ball liquid level L P And the pure water tank cross-sectional area S P Calculate the pure water volume V P ; then, 7. The test method of claim 5, wherein, The step of injecting the concentrated water and the pure water into the concentrated water tank and the pure water tank again, respectively, so that the concentrated water and the pure water are located at the liquid levels L W and L P , respectively, includes: The control system controls the concentrated water supply pump and the pure water supply pump to start, respectively injects concentrated water and pure water into the concentrated water tank and the pure water tank, so that the concentrated water floating ball and the pure water floating ball are respectively located at liquid levels L W and L P ; At this time, according to the concentrated water float ball liquid level L W With the concentrated water tank cross-sectional area S W The concentrated water volume V W ; According to the pure water float ball liquid level L P With the pure water tank cross-sectional area S P The pure water volume V P .

8. The test method of claim 4, wherein, The test method further comprises setting a concentrated water tank TDS meter and a pure water tank TDS meter; Wherein, the concentrated water tank TDS meter is arranged in the concentrated water tank, and the pure water tank TDS meter is arranged in the pure water tank; The step of detecting the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank respectively after the water injection is completed, and calculating ΔC by C1-C0 comprises: The control system controls the concentrated water tank TDS meter and the pure water tank TDS meter to detect initial TDS values C1 and C0 of the concentrated water and the pure water respectively, and calculates AC by C1-C0; After the T time of static salt permeation, detecting the TDS value C of the pure water in the pure water tank t comprises: After the T time of static salt permeation, the control system controls the pure water tank TDS meter to detect the TDS value C of the pure water in the pure water tank t .

9. The test method of claim 1, wherein, The test method further comprises setting a concentrated water sealing ring, a pure water sealing ring and a sealing clamp; The concentrated water tank is provided with a concentrated water opening, and the pure water tank is provided with a pure water opening; a concentrated water sealing groove is arranged in the circumferential direction of the concentrated water opening, and a pure water sealing groove is arranged in the circumferential direction of the pure water opening; the pure water sealing ring fills the pure water sealing groove, and the concentrated water sealing ring fills the concentrated water sealing groove; The sealing clamp clamps the outer wall of the concentrated water sealing groove and the pure water sealing groove, so that the concentrated water sealing ring and the pure water sealing ring clamp the reverse osmosis membrane.

10. A test method characterized by, The test method comprises: The same volume of concentrated water and pure water is injected into the concentrated water tank and the pure water tank respectively, and the liquid level of the concentrated water and the pure water is equal, wherein the concentrated water tank and the pure water tank are communicated through the reverse osmosis membrane; After water injection, the liquid levels L of the concentrated water and the pure water are recorded respectively after the water is static infiltrated for a predetermined time W and L P ; the volume V P of the pure water is calculated according to the liquid level L P of the pure water; The concentrated water and the pure water in the concentrated water tank and the pure water tank are discharged; Again, the concentrated water and the pure water are injected into the concentrated water tank and the pure water tank, respectively, so that the concentrated water and the pure water are located at liquid levels L W and L P , respectively. After the water injection is completed, the initial TDS values C1 and C0 of the concentrated water and the pure water in the concentrated water tank and the pure water tank are detected respectively, and AC is calculated by C1-C0; After the T time of standing salt permeation, the TDS value C of the pure water in the pure water tank is detected t , and the liquid level L of the pure water in the pure water tank is recorded t , and according to the liquid level L of the pure water t , the pure water volume V is calculated t ; K value is calculated according to the permeability coefficient calculation formula, Wherein, S is the effective area of the reverse osmosis membrane, b is the thickness of the reverse osmosis membrane, and K is the permeation coefficient.

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