Electrodialysis membrane stack structure and household water purifier

Abstract

The utility model discloses an electrodialysis membrane stack structure and a household water purifier, the electrodialysis membrane stack structure comprises a first exchange membrane, a second exchange membrane, a third exchange membrane, a first area separation net and a second area separation net which are arranged between a first electrode and a second electrode, the first exchange membrane is arranged on one side close to the first electrode; the second exchange membrane is arranged between the first exchange membrane and the third exchange membrane; the third exchange membrane is arranged on one side close to the second electrode; the first area separation net is arranged between the first exchange membrane and the second exchange membrane; the second area separation net is arranged between the second exchange membrane and the third exchange membrane; the first area separation net and the second area separation net are different in thickness. On the premise of guaranteeing the recovery rate of raw water, compared with the prior art, the device is simpler in structure, smaller in occupied space and lower in production cost.

Description

Technical Field

[0001] The utility model relates to the field of water treatment, in particular to an electrodialysis membrane stack structure and a household water purifier with the electrodialysis membrane stack structure. Background Art

[0002] Electrodialysis technology is a membrane technology driven by electricity. Due to its low energy consumption, high raw water recovery rate, long life, ion selectivity and other characteristics, it is widely used in the field of industrial water treatment. In recent years, it has also been used in household water purifiers. The existing electrodialysis membrane stack fresh water screen and concentrated water screen are basically the same in structure except for the different positions of the inlet and outlet.

[0003] Fresh water chamber, concentrated water chamber and polar water chamber are important components of the electrodialysis process, used to separate and concentrate ions. Their distinction and functions are as follows:

[0004] Diluate Compartment: The diluate compartment is a region in an electrodialysis unit where ion selectivity is achieved by blocking specific types of ions through an ion exchange membrane (cation exchange membrane or anion exchange membrane). In the diluate compartment, water is separated into cleaner fresh water because the ions in it are blocked from passing through, resulting in a lower concentration of ionic solutions in the water.

[0005] Concentrate Compartment: The concentrate compartment is also an area in the electrodialysis device. In contrast to the fresh water compartment, the ions in it can migrate freely. The concentration of the solution in the concentrate compartment increases with the action of the electric field, thereby achieving the concentration of ions.

[0006] Ion-Exchange Membrane Compartment: The Ion-Exchange Membrane Compartment is the area between the fresh water compartment and the concentrated water compartment, including the ion exchange membrane. The ion exchange membrane acts as a partition between the fresh water compartment and the concentrated water compartment, so that the ions in the fresh water compartment and the concentrated water compartment will not mix directly.

[0007] The existing electrodialyzer mainly includes three water circuits: fresh water circuit, concentrated water circuit, and polar water circuit, which correspond to the fresh water chamber, concentrated water chamber, and polar water chamber respectively. The concentrated water circuit is equipped with a concentrated water circulation pump and a concentrated water intermediate water tank to improve the raw water recovery rate. With the current electrodialysis membrane stack structure technology, if the concentrated water is not recycled, the raw water recovery rate is less than 50%. In addition, the TDS value of the effluent can be adjusted by adjusting the current at both ends of the electrodialyzer.

[0008] At present, reverse osmosis membrane water purifiers are the mainstream in the household market. In recent years, TDS adjustable water purifiers are a technology that mixes the water produced by the reverse osmosis membrane with its influent water. When electrodialysis technology is used in household water purifiers, the problem is that concentrated water cannot be recycled in smaller water purifiers.

[0009] According to the above water circuit division of the existing electrodialysis technology, the concentrate circuit is equipped with a concentrate circulation pump and a concentrate intermediate water tank to improve the raw water recovery rate. The concentrate is sent to the membrane stack through the concentrate circulation pump from the concentrate intermediate water tank, flows out through the concentrate chamber of the membrane stack, most of it returns to the concentrate intermediate water tank, and a small part is discharged before entering the concentrate intermediate water tank. As compensation for the discharge of concentrate, raw water is replenished into the concentrate intermediate water tank, and the replenishment flow rate is equal to the discharge of concentrate. This operation mode requires the use of a concentrate circulation pump, a concentrate intermediate water tank, a raw water replenishment system, etc., which requires a large enough space, and the household water purifier does not have the required space for stable operation.

[0010] Therefore, the miniaturization and integration of the water circuit of household water purifiers is a technical problem that needs to be urgently solved in the application of electrodialysis technology in household water purifiers. Utility Model Content

[0011] A series of simplified concepts are introduced in the utility model content section, which are all simplifications of the prior art in the field, which will be further described in detail in the specific implementation section. The utility model content section of the utility model does not mean to attempt to define the key features and necessary technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0012] The technical problem to be solved by the utility model is to provide an electrodialysis membrane stack structure which is simpler in structure, occupies less space and has lower production cost than the prior art while ensuring the raw water recovery rate.

[0013] And, a household water purifier that is smaller and more highly integrated than the existing technology while ensuring the raw water recovery rate.

[0014] In order to solve the above technical problems, the utility model provides an electrodialysis membrane stack structure, including two first exchange membranes 2, a second exchange membrane 4, a third exchange membrane 6, a first regional separation net 8 and a second regional separation net 9 arranged between a first electrode 1 and a second electrode 7;

[0015] A first exchange membrane 2, which is arranged on a side close to the first electrode 1;

[0016] A second exchange membrane 4, which is arranged between the first exchange membrane 2 and the third exchange membrane 6;

[0017] A third exchange membrane 6, which is arranged on a side close to the second electrode 7;

[0018] A first regional separator 8, which is arranged between the first exchange membrane 2 and the second exchange membrane 4;

[0019] A second regional separation network 9, which is arranged between the second exchange membrane 4 and the third exchange membrane 6;

[0020] The first region partitioning net 8 and the second region partitioning net 9 have different thicknesses.

[0021] The first exchange membrane 2, the second exchange membrane 4, the third exchange membrane 6, the first regional separation net 8 and the second regional separation net 9 can all be realized by using existing technologies, and their specific structures are not the key improvement points of the utility model. The key improvement point of the utility model is that the two first exchange membranes 2, the second exchange membrane 4, the third exchange membrane 6, the first regional separation net 8 and the second regional separation net 9 between the first electrode 1 and the second electrode 7 form a new electrodialysis membrane stack structure.

[0022] Preferably, the electrodialysis membrane stack structure is further improved, the first electrode 1 is an anode, and the second electrode 7 is a cathode.

[0023] Preferably, the electrodialysis membrane stack structure is further improved, and the first exchange membrane 2 and the third exchange membrane 6 are cation exchange membranes;

[0024] The second exchange membrane 4 is an anion exchange membrane.

[0025] Preferably, the electrodialysis membrane stack structure is further improved, and a concentrated water chamber 3 is formed between the first exchange membrane 2 and the second exchange membrane 4;

[0026] A fresh water chamber 5 is formed between the second exchange membrane 4 and the third exchange membrane 6;

[0027] The thickness of the second region partitioning net 9 is greater than the thickness of the first region partitioning net 8 .

[0028] In order to solve the above technical problems, the utility model provides a household water purifier, wherein the water path of the household water purifier has any one of the above electrodialysis membrane stack structures, and further comprises:

[0029] The first filter 10 is arranged in the front water channel of the electrodialysis membrane stack structure 11 and is connected to external water;

[0030] The electrodialysis membrane stack structure 11 is formed with a concentrated water discharge port and an extreme water discharge port;

[0031] A second filter 12, which is connected to the rear end water channel of the electrodialysis membrane stack structure 11;

[0032] The third filter 13 is connected to the rear end water channel of the second filter 12 and has a purified water outlet.

[0033] Optionally, the first filter 10 is PP cotton or a microfiltration membrane.

[0034] Optionally, the second filter 12 is an activated carbon filter element.

[0035] Optionally, the activated carbon filter element is a carbon rod or a carbon fiber.

[0036] Optionally, the third filter 13 is an ultrafiltration membrane.

[0037] The other structures of the household water purifier are not the key improvements of the present invention. The key improvement of the present invention is the water circuit of the household water purifier composed of the first filter 10 , the electrodialysis membrane stack structure 11 , the second filter 12 and the third filter 13 .

[0038] The utility model can at least achieve the following technical effects:

[0039] 1. The electrodialysis membrane stack structure provided by the utility model replaces the existing electrodialysis membrane stack's concentrated water chamber partition and fresh water chamber partition with two partitions of different thicknesses, removing the structure and components required for concentrated water circulation. Concentrated water is no longer recycled, but is directly discharged like fresh water and polar water. The thickness of the fresh water chamber partition must be greater than that of the concentrated water chamber partition. The greater the difference in thickness between the two, the higher the raw water recovery rate. Under the premise of ensuring the recovery rate, the electrodialysis membrane stack structure is streamlined, and the miniaturization and high integration of the electrodialysis membrane stack structure are achieved. At the same time, the production cost can be reduced because the structure and components required for concentrated water circulation are eliminated.

[0040] Accordingly, the utility model retains the electrodialysis technology as the electrical desalination technology, and changes the current at both ends of the electrodialyzer to change the desalination rate of the fresh water output, and also adjusts the TDS value of the produced water.

[0041] 2. The household water purifier provided by the utility model uses the electrodialysis membrane stack structure provided by the utility model in its water circuit. Therefore, when the electrodialysis membrane stack structure can be placed as a module in the water treatment process of the water purifier, a simple pre-treatment filter element, such as PP cotton, microfiltration membrane, etc., can be placed in front of the electrodialysis membrane stack structure. The rear section of the electrodialysis membrane stack structure only needs to place an activated carbon filter element and a post-ultrafiltration membrane filter element in the fresh water pipeline, and the concentrated water and the polar water are directly discharged. Therefore, clean water can be obtained that has been removed of ions, organic molecules, bacteria, etc., and the activated carbon filter element and the ultrafiltration membrane filter element after the electrodialysis membrane stack structure only process fresh water, which also extends the service life of the activated carbon filter element and reduces the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings of the present utility model are intended to illustrate the general characteristics of the methods, structures and / or materials used in specific exemplary embodiments of the present utility model, and to supplement the description in the specification. However, the drawings of the present utility model are schematic diagrams not drawn to scale, and thus may not accurately reflect the precise structure or performance characteristics of any given embodiment. The drawings of the present utility model should not be interpreted as limiting or restricting the range of values ​​or properties covered by the exemplary embodiments of the present utility model. The present utility model is further described in detail below in conjunction with the drawings and specific embodiments:

[0043] Figure 1 It is a schematic diagram of the structure of the electrodialysis membrane stack of the utility model.

[0044] Figure 2 The utility model is a schematic diagram of the water circuit structure of a household water purifier.

[0045] Description of Reference Numerals

[0046] First electrode 1

[0047] First exchange membrane 2

[0048] Concentrate chamber 3

[0049] Second exchange membrane 4

[0050] Freshwater Room 5

[0051] The third exchange membrane 6

[0052] Second electrode 7

[0053] First area screen 8

[0054] Second area screen 9;

[0055] First filter 10

[0056] Electrodialysis membrane stack structure11

[0057] Second filter 12

[0058] Third filter 13

[0059] External water 14

[0060] Concentrate water discharge port 15

[0061] Polar water outlet 16

[0062] Clean water outlet 17. DETAILED DESCRIPTION

[0063] The following is an explanation of the implementation of the utility model by specific specific embodiments, and those skilled in the art can fully understand the other advantages and technical effects of the utility model from the content disclosed in this specification. The utility model can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, and various modifications or changes can be made without deviating from the general design concept of the utility model. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of the utility model can be implemented in a variety of different forms and should not be interpreted as being limited to the specific embodiments described here. It should be understood that these embodiments are provided to make the disclosure of the utility model thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "coupled" to another element, the element can be directly connected or coupled to another element, or there can be an intermediate element. The difference is that when an element is referred to as "directly connected" or "directly coupled" to another element, there is no intermediate element. In all the drawings, the same reference numerals always represent the same element.

[0064] First embodiment;

[0065] refer to Figure 1 As shown, the utility model provides an electrodialysis membrane stack structure, including two first exchange membranes 2, a second exchange membrane 4, a third exchange membrane 6, a first regional separation net 8 and a second regional separation net 9 arranged between a first electrode 1 as an anode and a second electrode 7 as a cathode; a concentrated water chamber 3 is formed between the first exchange membrane 2 and the second exchange membrane 4, and a desalinated water chamber 5 is formed between the second exchange membrane 4 and the third exchange membrane 6;

[0066] A first exchange membrane 2, which is arranged on a side close to the first electrode 1;

[0067] A second exchange membrane 4, which is arranged between the first exchange membrane 2 and the third exchange membrane 6;

[0068] A third exchange membrane 6, which is arranged on a side close to the second electrode 7;

[0069] A first regional separator 8, which is arranged between the first exchange membrane 2 and the second exchange membrane 4;

[0070] A second regional separation network 9, which is arranged between the second exchange membrane 4 and the third exchange membrane 6;

[0071] The thickness of the second region separation net 9 is greater than that of the first region separation net 8 , the first exchange membrane 2 and the third exchange membrane 6 are cation exchange membranes, and the second exchange membrane 4 is an anion exchange membrane.

[0072] Exemplarily, the thickness of the second region partition net 9 is 1.1 to 10 times the thickness of the first region partition net 8, preferably 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 times.

[0073] Second embodiment;

[0074] refer to Figure 1 As shown, the utility model provides a household water purifier, the water path of the household water purifier has the electrodialysis membrane stack structure of the first embodiment, and also includes:

[0075] A first filter 10 is arranged in the front waterway of the electrodialysis membrane stack structure 11 and is connected to external water 14;

[0076] The electrodialysis membrane stack structure 11 is formed with a concentrated water discharge port 15 and an extreme water discharge port 16;

[0077] A second filter 12, which is connected to the rear end water channel of the electrodialysis membrane stack structure 11;

[0078] The third filter 13 is connected to the rear end water channel of the second filter 12 and is formed with a purified water outlet 17 .

[0079] Among them, the first filter 10 can be selected from PP cotton or microfiltration membrane, the second filter 12 is an activated carbon filter element and can be selected from carbon rods or carbon fibers, and the third filter 13 is an ultrafiltration membrane.

[0080] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. It will also be understood that, unless explicitly defined herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and not interpreted in an ideal or overly formal sense.

[0081] The present invention is described in detail above through specific implementation methods and examples, but these do not constitute limitations of the present invention. Without departing from the principle of the present invention, those skilled in the art may make many modifications and improvements, which should also be considered as the protection scope of the present invention.

Claims

1. An electrodialysis membrane stack structure, characterized in that: It comprises two first exchange membranes (2) arranged between a first electrode (1) and a second electrode (7), a second exchange membrane (4), a third exchange membrane (6), a first regional separation net (8) and a second regional separation net (9); A first exchange membrane (2), which is arranged on a side close to the first electrode (1); A second exchange membrane (4) arranged between the first exchange membrane (2) and the third exchange membrane (6); A third exchange membrane (6), which is arranged on a side close to the second electrode (7); A first region separator (8) arranged between the first exchange membrane (2) and the second exchange membrane (4); A second area separator (9) arranged between the second exchange membrane (4) and the third exchange membrane (6); The first region partition net (8) and the second region partition net (9) have different thicknesses.

2. The electrodialysis membrane stack structure according to claim 1, characterized in that: The first electrode (1) is an anode and the second electrode (7) is a cathode.

3. The electrodialysis membrane stack structure according to claim 2, characterized in that: The first exchange membrane (2) and the third exchange membrane (6) are cation exchange membranes; The second exchange membrane (4) is an anion exchange membrane.

4. The electrodialysis membrane stack structure according to claim 2, characterized in that: A concentrated water chamber (3) is formed between the first exchange membrane (2) and the second exchange membrane (4); A fresh water chamber (5) is formed between the second exchange membrane (4) and the third exchange membrane (6); The thickness of the partition net (9) in the second region is greater than the thickness of the partition net (8) in the first region.

5. A household water purifier, characterized in that: The water path of the household water purifier has the electrodialysis membrane stack structure according to any one of claims 1 to 4, and further comprises: A first filter (10) is arranged in the front water channel of the electrodialysis membrane stack structure (11) and is connected to external water (14); An electrodialysis membrane stack structure (11) is formed with a concentrated water discharge port (15) and an extreme water discharge port (16); A second filter (12) connected to the rear end water channel of the electrodialysis membrane stack structure (11); The third filter (13) is connected to the rear end water channel of the second filter (12) and is formed with a purified water outlet (17).

6. The household water purifier according to claim 5, characterized in that: The first filter (10) is PP cotton or a microfiltration membrane.

7. The household water purifier according to claim 5, characterized in that: The second filter (12) is an activated carbon filter element.

8. The household water purifier according to claim 7, characterized in that: Activated carbon filters are carbon rods or carbon fibers.

9. The household water purifier according to claim 5, characterized in that: The third filter (13) is an ultrafiltration membrane.

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