Membrane pressure water purification device

Abstract

The present invention relates to a membrane pressure water purification device, belonging to the field of water treatment technology. The device comprises a membrane assembly, a pump, and an electrolytic desalination unit. The electrolytic desalination unit comprises a diaphragm electrolytic cell, anode and cathode electrodes, and a power supply for supplying power to the electrodes. The diaphragm electrolytic cell is divided into an anode cell and a cathode cell by a diaphragm. The anode cell's outlet is connected to the membrane assembly's water inlet via a first pipeline. The membrane assembly's concentrate outlet is connected to the anode cell's water inlet and the cathode cell's water inlet via a second pipeline and a third pipeline, respectively. The third pipeline is provided with a wastewater separator. During operation, a portion of the concentrate discharged from the concentrate outlet is combined with tap water through the second pipeline, flows through the anode cell, and then enters the membrane assembly. The remaining portion of the concentrate is passed through the third pipeline, the wastewater separator, and then flows through the cathode cell before being discharged from the cathode cell's outlet. Because the device achieves the recycling and reuse of membrane concentrate, it significantly reduces concentrate discharge and achieves high water efficiency.

Description

Technical Field

[0001] The invention relates to a device for preparing pure water or purified water by utilizing membrane pressure technology, and belongs to the technical field of water treatment. Background Art

[0002] Among the numerous water purifiers currently available on the market, reverse osmosis water purifiers, or pure water machines, are undoubtedly the most effective in terms of water purification. Theoretically, impurities are largely removed from municipal tap water after it passes through a reverse osmosis membrane. While there's considerable debate about the health benefits of drinking pure water produced by reverse osmosis, facing increasing water pollution and the increasing difficulty in ensuring the safety of drinking water, more and more people are choosing reverse osmosis water purifiers.

[0003] The biggest criticism of reverse osmosis water purifiers is that they inevitably produce a considerable amount of wastewater (salt water) when working, resulting in a waste of water resources. This is particularly intolerable for my country, which is severely short of water resources, so the country has had to introduce relevant standards to limit it. GB34914-2017 "Limited Values ​​and Water Efficiency Grades of Reverse Osmosis Water Purifiers" divides water efficiency into levels 1 to 5, which are 60%, 55%, 50%, 45% and 35% respectively. Level 5 35% water efficiency is the red line for purified water production rate, that is, the water efficiency limit value. The introduction of water efficiency standards will inevitably force reverse osmosis water purifier manufacturers to accelerate technological innovation to avoid being eliminated by the market. However, to date, there has been no reverse osmosis water purifier that can adapt to the water conditions in China's vast territory and truly meet or even exceed the level 1 60% water efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to make the water efficiency of the device using membrane pressure to extract and purify water reach the above-mentioned national level 1 and above standards.

[0005] The technical solution proposed by the present invention to solve the above-mentioned technical problems is: a membrane pressure water purification device, comprising a membrane assembly, a pump and an electrolytic desalination unit, the electrolytic desalination unit comprising a diaphragm electrolytic cell, a cathode and a cathode electrode and a power supply for supplying power to the anode and a cathode electrode, the diaphragm electrolytic cell is divided into an anode cell and a cathode cell by a diaphragm, the cathode electrode is located in the cathode cell, and the anode electrode is located in the anode cell; the water outlet of the anode cell is connected to the water inlet of the membrane assembly through a first pipeline, and the concentrated water outlet of the membrane assembly is connected to a second pipeline and a third pipeline respectively, the second pipeline is connected to the water inlet of the anode cell, the third pipeline is connected to the water inlet of the cathode cell, and the third pipeline is provided with a wastewater ratio.

[0006] When the above-mentioned membrane pressure water purification device is working, a part of the concentrated water discharged from the concentrated water outlet passes through the second pipeline, merges with tap water at the water inlet of the anode tank, flows through the anode tank, and then enters the membrane assembly. The other part of the concentrated water passes through the third pipeline, merges with the wastewater, flows through the cathode tank, and is discharged from the water outlet of the cathode tank.

[0007] Furthermore, the third pipeline is also provided with a stop valve connected in parallel with the wastewater ratio.

[0008] Furthermore, a filter is provided at the water inlet of the anode tank, and the second pipeline is connected to the inlet of the filter.

[0009] Furthermore, the water outlet of the cathode tank is also connected to a brine tank.

[0010] Furthermore, the membrane assembly is a reverse osmosis membrane assembly or a nanofiltration membrane assembly. The wastewater ratio adopts a flow limiting valve.

[0011] The beneficial effects of the present invention are: 1) since part of the concentrated water generated by the membrane assembly (reverse osmosis membrane or nanofiltration membrane assembly) flows back to the anode tank, the membrane concentrated water is recycled and reused, thereby greatly reducing the discharge of concentrated water, thereby reaching level one or above in GB34914-2017 "Water Efficiency Limit Values ​​and Water Efficiency Grades of Reverse Osmosis Water Purifiers"; 2) since part of the concentrated water can remove cations after flowing through the anode tank, the deionization burden of the membrane assembly can be reduced; 3) the other part of the concentrated water generated by the membrane assembly flows through the cathode tank, can continue to absorb cations and then be discharged, thereby reducing the wastewater ratio; 4) tap water (source water) and circulating concentrated water can also be oxidized in the anode tank to kill harmful substances such as bacteria and microorganisms in the water, thereby improving the working environment of the membrane assembly and increasing the service life of the membrane assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The membrane pressure water purification device of the present invention will be further described below with reference to the accompanying drawings.

[0013] Figure 1 It is a schematic diagram of the structure of the membrane pressure water purification device in Example 1.

[0014] Figure 2 It is a schematic diagram of the structure of the membrane pressure water purification device of Example 2.

[0015] Figure 3 It is a schematic diagram of the structure of the membrane pressure water purification device of Example 3.

[0016] Figure 4 It is a schematic diagram of the structure of the membrane pressure water purification device of Example 4. DETAILED DESCRIPTION

[0017] Example 1

[0018] The membrane pressure water purification device of this embodiment is as follows Figure 1 As shown, it includes a membrane assembly 1 and a pump 2, as well as an electrolytic desalination unit 3. The electrolytic desalination unit includes a diaphragm electrolytic cell, cathode and anode electrodes 4 and 5, and a power supply (not shown in the figure) for supplying power to the cathode and anode electrodes 4 and 5. The diaphragm electrolytic cell is divided into an anode cell 7 and a cathode cell 8 by a diaphragm 6. The cathode electrode 4 is located in the cathode cell 8, and the anode electrode 5 is located in the anode cell 7. The outlet of the anode cell 7 is connected to the water inlet of the membrane assembly 1 through a first pipeline 9. The concentrated water outlet of the membrane assembly 1 is connected to a second pipeline 10 and a third pipeline 11, respectively. The second pipeline 10 is connected to the water inlet of the anode cell, and the third pipeline 11 is connected to the water inlet of the cathode cell 8. The third pipeline is provided with a wastewater separator 12. The wastewater separator 12 is generally equipped with a flow limiting valve.

[0019] The membrane assembly in this embodiment can be a reverse osmosis membrane assembly or a nanofiltration membrane assembly.

[0020] During operation of the membrane pressure water purification device of this embodiment, a portion of the brine discharged from the brine outlet of the membrane assembly 1 flows through the second pipeline 10 and merges with the city tap water at the water inlet of the anode cell 7. The brine then flows through the anode cell 7 and enters the membrane assembly 1. This means that a portion of the brine discharged from the membrane assembly 1 is circulated back into the membrane assembly 1. Another portion of the brine discharged from the brine outlet of the membrane assembly 1 flows through the third pipeline 11 and the wastewater ratio 12 into the cathode cell 8. After flowing through the cathode cell 8, it is converted into concentrated brine and discharged from the water outlet of the cathode cell 8. By setting the wastewater ratio 12, a small amount of this brine (the other portion of the brine discharged) flows into the cathode cell 8 before being discharged, allowing a large amount of the brine (the portion of the brine discharged) to be recycled, significantly reducing wastewater discharge. This allows the device to easily meet the Class 1 or higher standards in accordance with GB34914-2017, "Limited Values ​​and Grades of Water Efficiency for Reverse Osmosis Water Purifiers."

[0021] Example 2

[0022] The membrane pressure water purification device of this embodiment is as follows Figure 2 As shown, it is an improvement based on Example 1. In addition to being the same as Example 1, the difference is that: a stop valve 13 is also provided on the third pipeline 11 in parallel with the wastewater ratio 12. By opening the stop valve 13, the concentrated water discharged from the concentrated water outlet of the membrane assembly 1 directly flows into the cathode tank 8 and is then discharged, which can flush the cathode tank 8 or meet other flushing needs other than this device.

[0023] Example 3

[0024] The membrane pressure water purification device of this embodiment is as follows Figure 3The figure shows an improvement on the second embodiment. In addition to being the same as the second embodiment, the difference is that a filter 14 is further provided at the water inlet of the anode tank 7, and the second pipeline 10 is connected to the inlet of the filter 14. In this way, a portion of the concentrated water discharged from the membrane assembly 1 is combined with the city tap water and first flows into the filter 14 for filtration before flowing through the anode tank 7 and entering the membrane assembly 1.

[0025] Example 4

[0026] The membrane pressure water purification device of this embodiment is as follows Figure 4 As shown, it is an improvement based on Example 3. In addition to being the same as Example 3, the difference is that a brine tank 15 is also connected to the water outlet of the cathode tank 8. The concentrated brine discharged from the water outlet of the cathode tank 8 first flows into the brine tank 15 for storage, and is then discharged from the outlet of the brine tank 15 when needed.

[0027] The above description is only a preferred embodiment of the present invention, but the present invention is not limited thereto. All equivalent replacements or equivalent changes of the concepts and technical solutions according to the present invention should be included in the protection scope of the present invention.

Claims

1. A membrane pressure water purification device, comprising a membrane assembly, a pump, and an electrolytic desalination unit, wherein the electrolytic desalination unit comprises a diaphragm electrolytic cell, a cathode and cathode electrodes, and a power supply for the anode and cathode electrodes, wherein the diaphragm electrolytic cell is divided into an anode cell and a cathode cell by a diaphragm, wherein the cathode electrode is located in the cathode cell, and the anode electrode is located in the anode cell; characterized in that: The water outlet of the anode tank is connected to the water inlet of the membrane assembly through a first pipeline, and the concentrated water outlet of the membrane assembly is connected to a second pipeline and a third pipeline respectively, the second pipeline is connected to the water inlet of the anode tank, and the third pipeline is connected to the water inlet of the cathode tank, and a wastewater ratio is provided on the third pipeline; when the device is working, a part of the concentrated water discharged from the concentrated water outlet is merged with tap water at the water inlet of the anode tank through the second pipeline and flows through the anode tank and then enters the membrane assembly, and the other part of the concentrated water is discharged from the water outlet of the cathode tank through the third pipeline and the wastewater ratio and flows through the cathode tank.

2. The membrane pressure water purification device according to claim 1, characterized in that: The third pipeline is also provided with a stop valve connected in parallel with the wastewater ratio.

3. The membrane pressure water purification device according to claim 2, characterized in that: The water inlet of the anode tank is further provided with a filter, and the second pipeline is connected to the inlet of the filter.

4. The membrane pressure water purification device according to claim 3, characterized in that: The water outlet of the cathode tank is also connected to a brine tank.

5. The membrane pressure water purification device according to claim 1, characterized in that: The membrane assembly is a reverse osmosis membrane assembly or a nanofiltration membrane assembly.

6. The membrane pressure water purification device according to claim 1, characterized in that: The wastewater ratio adopts a flow limiting valve.

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