Seawater desalination device and process

Abstract

The invention discloses a seawater desalination device and process, and relates to the field of seawater desalination treatment equipment.The seawater desalination device comprises a seawater pretreatment module, a multi-channel desalination module and a fresh water treatment module which are sequentially connected, and the multi-channel desalination module comprises a reservoir and three desalination channels; the first desalination channel and the second desalination channel both adopt a reverse osmosis method to desalinate seawater, the third desalination channel adopts an evaporation method to desalinate seawater, a heat exchange pipe is arranged in the reservoir and is connected with an external solar heat collection plate, the temperature in the reservoir is increased through solar energy, and the evaporation desalination efficiency is greatly improved; the three desalination channels do not influence each other, compared with a single reverse osmosis membrane desalination process, the seawater desalination efficiency is integrally improved, energy consumption is not obviously improved, and the seawater desalination device is reasonable in structural design and suitable for application.

Description

Technical Field

[0001] The present invention relates to the field of seawater desalination equipment, and in particular to a seawater desalination device and process. Background Art

[0002] With the development of economy and the continuous improvement of people's living standards, the demand for water is also increasing. Not only the amount of water used for domestic purposes is increasing, but also the amount of water used for urban greening, road maintenance and industrial use is increasing day by day, and the latter uses a huge amount of water. The current situation of the shortage of available fresh water resources in the world is becoming increasingly obvious, prompting many regions and countries to look for new water sources. Among the many water sources, seawater desalination is one of the important ways to solve the shortage of water resources. Seawater desalination refers to the removal of salt, impurities, microorganisms and other substances in seawater to make it fresh water that can be used directly.

[0003] There are many seawater desalination technologies, such as distillation, reverse osmosis, freezing, multi-stage flash evaporation, electrodialysis, etc., but the energy consumption is generally very high. With the development of technology, seawater desalination technology is also constantly improving and perfecting, and the relatively low energy consumption reverse osmosis method is gradually being used on a large scale, but the high pressure has high requirements for equipment, the membrane is easily contaminated, and needs to be replaced frequently, the efficiency is limited, and the trace elements in the seawater will also be filtered out, affecting the water quality. Therefore, further reducing the energy consumption of seawater desalination and improving the efficiency of seawater desalination still requires continuous research and improvement. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a seawater desalination device and process to further reduce the energy consumption of seawater desalination and improve the efficiency of seawater desalination.

[0005] The present invention is achieved through the following technical solutions: A seawater desalination device comprises a seawater pretreatment module, a multi-channel desalination module and a freshwater treatment module connected in sequence, wherein the multi-channel desalination module comprises a water reservoir and three desalination channels, wherein the first desalination channel comprises a second booster pump and a reverse osmosis membrane assembly, wherein the second booster pump is connected to the water reservoir, and the reverse osmosis membrane assembly is connected to the second booster pump; the second desalination channel comprises a freshwater tank and a reverse osmosis bottom plate, wherein the freshwater tank is arranged at the bottom of the water reservoir, and the reverse osmosis bottom plate is arranged between the freshwater tank and the water reservoir; the third desalination channel comprises a solar energy collector plate, a heat exchange tube, a sealed chamber and a water collecting tank, wherein an arc-shaped light-transmitting sealed chamber is arranged above the water reservoir, wherein a heat exchange tube is arranged in the water reservoir, wherein the heat exchange tube is connected to a solar energy collector plate arranged outdoors, wherein a circulation pump is arranged on a connecting pipe between the heat exchange tube and the solar energy collector plate, and wherein the water collecting tank is arranged on the ground at the bottom of the sealed chamber and is in close contact with the inner wall of the sealed chamber.

[0006] Further optimized, an osmotic pressure reducing module is provided between the second booster pump and the water storage tank in the first desalination channel, and the osmotic pressure reducing module comprises a first booster pump, an ultrafiltration component and a water storage tank connected in sequence, and the second booster pump is connected to the water storage tank.

[0007] Further optimized, the wastewater outlet of the ultrafiltration component is connected to a first energy recovery device, and the wastewater outlet of the reverse osmosis membrane component is connected to a second energy recovery device.

[0008] Further optimized, the reverse osmosis bottom plate includes a support frame, several support plates and a reverse osmosis membrane, the support frame is fixed on the fresh water tank, several support columns are fixed to the bottom of the support frame, several support plates are detachably fixed to the support frame, filter holes are opened on the support plates, the reverse osmosis membrane is laid and fixed on the support plates, and the reverse osmosis bottom plate separates the fresh water tank and the water reservoir into two spaces, and the seawater in the water reservoir penetrates into the fresh water tank by its own gravity.

[0009] In a further optimized manner, a water guide bar is provided on the inner wall of the sealed chamber, the water guide bar faces the water collecting tank, and the water collecting tank is connected to the fresh water tank.

[0010] Further optimized, a heat-insulating layer is provided on the outer side of the water reservoir.

[0011] Further optimized, the terrain where the solar collector plate is located is lower than the heat exchange tubes in the water reservoir, and the heat exchange tubes are spiral-shaped and evenly distributed in the water reservoir.

[0012] Further optimized, the seawater pretreatment module includes a seawater tank, a BAF tank, a clarification tank and a security filter connected in sequence, and the security filter is connected to the water storage tank.

[0013] Further optimized, the fresh water treatment module includes a filtration tank, a mineralization tank and a chlorine tank connected in sequence, and the fresh water outlet end of the fresh water tank and the reverse osmosis membrane assembly is connected to the filtration tank.

[0014] Further optimized, a seawater desalination process includes the following steps: A. The seawater is pretreated through a seawater pretreatment module to remove suspended matter, colloids, and particulate matter in the seawater, sterilize, disinfect, and kill algae, and then enter the reservoir; B. The seawater in the reservoir is desalinated through three channels. The first channel is initially filtered through an ultrafiltration component to reduce the osmotic pressure, and then reverse osmosis filtration is performed through a reverse osmosis membrane component to obtain fresh water that flows into the filter tank; the second desalination channel uses the gravity of the water stored in the reservoir to penetrate into the fresh water tank through the reverse osmosis bottom plate, and then flows into the filter tank; the third desalination channel is desalinated through evaporation, and the sealed chamber, heat exchange tubes and insulation layer are all intended to increase the temperature of the seawater in the reservoir and improve the evaporation efficiency. The evaporated water vapor condenses on the inner wall of the sealed chamber, and then flows to the water collection tank, then enters the fresh water tank, and finally flows into the filter tank; C. The fresh water in the filter tank is then filtered, mineralized, and disinfected to become domestic water or industrial water.

[0015] The beneficial effects of the present invention are: The desalination device of the present invention adopts three desalination channels, which do not affect each other. Compared with a single reverse osmosis membrane desalination process, the desalination efficiency of seawater is improved as a whole without significantly increasing energy consumption. The structure design is reasonable and suitable for application.

[0016] In the present invention, both the first and second desalination channels use the reverse osmosis method to desalinate seawater. In the first channel, an ultrafiltration component is arranged in front of the reverse osmosis membrane component, which can intercept a part of the salt in advance, reduce the osmotic pressure of the reverse osmosis membrane component, and then reduce the water supply pressure. Both wastewater outlets are equipped with energy recovery devices to reduce energy consumption. The second desalination channel relies on its own gravity osmosis in the water reservoir, does not need to consume electricity, and can improve the desalination efficiency to a certain extent.

[0017] The third desalination channel of the present invention adopts evaporation method to desalinate seawater. The sealed chamber adopts tempered glass or other light-transmitting materials. A heat exchange pipe is arranged in the water reservoir, which is connected to an external solar collector. The temperature in the water reservoir is increased by solar energy, thereby improving the evaporation desalination efficiency. The sealed chamber is arc-shaped, and water vapor condenses on the inner wall of the sealed chamber, is collected in the water collecting tank, and then flows into the fresh water tank.

[0018] The fresh water treatment module of the present invention subsequently performs unified treatment on the fresh water. The fresh water produced by the evaporation method improves the shortcomings of poor water quality and lack of trace elements of the reverse osmosis fresh water to a certain extent, and relieves the pressure of the mineralization link. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the process of the present invention.

[0020] Figure 2 It is a structural schematic diagram of the sealed chamber in the present invention.

[0021] In the figure: 1. water reservoir; 2. fresh water tank; 3. sealed chamber; 4. heat exchange tube; 5. solar collector; 6. circulation pump; 7. water guide bar; 8. connecting pipe; 9. water collecting tank; 10. insulation layer; 11. reverse osmosis bottom plate; 12. support column; 21. water outlet pipe. DETAILED DESCRIPTION

[0022] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "left", "right", "front", "back", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0023] like Figure 1-Figure 2 As shown, the present invention provides a seawater desalination device, including a seawater pretreatment module, a multi-channel desalination module and a freshwater treatment module connected in sequence, wherein the multi-channel desalination module includes a reservoir 1 and three desalination channels, and the seawater is first pretreated by the pretreatment module for impurity removal, sterilization, etc., and the pretreated seawater flows into the reservoir, and then desalinated through the three desalination channels, and finally mineralized. The three desalination channels do not affect each other, and the desalination efficiency of seawater is improved as a whole, without significantly increasing energy consumption.

[0024] The first desalination channel uses reverse osmosis to desalinate seawater, including a second booster pump and a reverse osmosis membrane assembly. The second booster pump is connected to the water reservoir, the reverse osmosis membrane assembly is connected to the second booster pump, and the second booster pump pressurizes water to the reverse osmosis membrane assembly for desalination filtration.

[0025] The second desalination channel also uses reverse osmosis to desalinate seawater, including a freshwater tank 2 and a reverse osmosis bottom plate 11. The freshwater tank is arranged at the bottom of the reservoir 1, and the reverse osmosis bottom plate 11 is arranged between the freshwater tank 2 and the reservoir 1 to separate the two into two spaces. The seawater stored in the reservoir 1 relies on its own gravity to overcome the osmotic pressure and infiltrate into the freshwater tank 2 to complete the desalination filtration.

[0026] The third desalination channel uses evaporation to desalinate seawater, including a solar collector 5, a heat exchange tube 4, a sealed chamber 3 and a water collection tank 9. An arc-shaped light-transmitting sealed chamber 3 is provided above the water reservoir 1. Sunlight directly penetrates the sealed chamber to accelerate the evaporation of seawater in the water reservoir 1. A heat exchange tube 4 is provided in the water reservoir 1. The heat exchange tube 4 is connected to the solar collector 5 arranged outdoors. A circulating pump 6 is provided on the connecting pipe between the heat exchange tube 4 and the solar collector 5. The heat exchange tube is filled with antifreeze and other media to transfer the heat absorbed by the solar collector to the water reservoir, further accelerating the evaporation efficiency. The water collection tank 9 is provided on the ground in the sealed room and is close to the inner wall of the sealed room. The evaporated water vapor condenses on the inner wall of the sealed room and then flows into the water collection tank 9.

[0027] As a preferred embodiment, an osmotic pressure reducing module is further provided between the second booster pump and the water reservoir in the first desalination channel, and the osmotic pressure reducing module includes a first booster pump, an ultrafiltration component and a water storage tank connected in sequence, the first booster pump is connected to the water reservoir, and the second booster pump is connected to the water storage tank. The ultrafiltration component can intercept a portion of the salt in advance, reduce the osmotic pressure of the reverse osmosis membrane component, and thus reduce the water supply pressure, reduce energy consumption, and delay the service life of the reverse osmosis. It should be noted in the actual environment that if the lighting environment is good and the water temperature in the water reservoir is higher than 50 degrees, it is necessary to consider setting a buffer tank between the booster pump and the water reservoir to reduce the water temperature to adapt to the optimal filtration temperature of the filtration component.

[0028] As a preferred embodiment, the wastewater outlet of the ultrafiltration component is connected to a first energy recovery device, and the wastewater outlet of the reverse osmosis membrane component is connected to a second energy recovery device. The energy recovery device can greatly reduce the energy consumption of the booster pump, wherein the energy recovery device is a prior art, and its connection is as follows: Figure 1 As shown, no further elaboration is given.

[0029] As a preferred embodiment, the reverse osmosis bottom plate 11 includes a support frame, a plurality of support plates and a reverse osmosis membrane. The support frame is fixed on the ground around the fresh water tank. A plurality of support columns 12 are fixed at the bottom of the support frame for auxiliary support. The plurality of support plates are detachably fixed on the support frame. The support plates are provided with filter holes. The reverse osmosis membrane is laid and fixed on the support plates. The reverse osmosis bottom plate 11 completely separates the fresh water tank 2 and the water reservoir 1 into two spaces. The seawater in the water reservoir overcomes the osmotic pressure by its own gravity, permeates through the reverse osmosis membrane and drips into the fresh water tank. A water outlet pipe 21 is provided on one side of the bottom of the fresh water tank, and fresh water flows out from the water outlet pipe 21.

[0030] As a preferred embodiment, a water guide bar 7 is provided on the inner wall of the sealed chamber 3, and the water guide bar faces the water collecting tank 9 to ensure that the water droplets condensed on the inner wall of the sealed chamber can flow into the water collecting tank. The water collecting tank is connected to the fresh water tank 2 through a connecting pipe 8, and the evaporated and desalinated fresh water directly flows into the fresh water tank for the next step of treatment.

[0031] As a preferred embodiment, a heat-insulating layer 10 is provided on the outside of the water reservoir 1 to maintain the water temperature in the water reservoir and improve the evaporation efficiency.

[0032] As a preferred embodiment, the terrain of the location of the solar collector 5 is lower than the heat exchange tube 4 in the water reservoir. The medium in the tube will rise when heated and fall when cooled under physical action. Under good sunlight, it can circulate naturally, saving energy consumption of the circulation pump. The heat exchange tube is spiral and evenly distributed in the water reservoir 1, so the heat exchange is more uniform.

[0033] As a preferred embodiment, the seawater pretreatment module includes a seawater pool, a BAF pool, a clarification pool and a security filter connected in sequence. The security filter is connected to a water reservoir. The seawater is pretreated through the seawater pretreatment module to remove suspended matter, colloids, and particulate matter in the seawater, sterilize, disinfect, and kill algae, and then enters the water reservoir.

[0034] As a preferred embodiment, the fresh water treatment module includes a filter pool, a mineralization pool and a chlorine pool connected in sequence, the fresh water tank and the fresh water outlet of the reverse osmosis membrane assembly are connected to the filter pool, and the fresh water is subsequently treated uniformly. The fresh water produced by the evaporation method improves the shortcomings of the poor quality of the reverse osmosis fresh water and the lack of trace elements to a certain extent, and relieves the pressure of the mineralization link. The fresh water in the filter pool is then filtered, mineralized, and disinfected to become domestic water or industrial water.

[0035] A seawater desalination process comprises the following steps: A. The seawater is pre-treated through the seawater pre-treatment module to remove suspended matter, colloids, and particulate matter in the seawater, sterilize, disinfect, and kill algae, and then enter the water storage tank; B. The seawater in the reservoir is desalinated through three channels. The first channel uses the ultrafiltration component to perform primary filtration to reduce the osmotic pressure, and then uses the reverse osmosis membrane component to perform reverse osmosis filtration to obtain fresh water that flows into the filter pool; the second desalination channel uses the gravity of the water stored in the reservoir to penetrate into the fresh water tank through the reverse osmosis bottom plate, and then flows into the filter pool; the third desalination channel desalinates through evaporation. The sealed chamber, heat exchange tubes and insulation layer are all designed to increase the temperature of the seawater in the reservoir and improve the evaporation efficiency. The evaporated water vapor condenses on the inner wall of the sealed chamber, then flows to the water collection tank, then enters the fresh water tank, and finally flows into the filter pool; C. The fresh water in the filter pool is then filtered, mineralized and disinfected to become domestic or industrial water.

[0036] The parts not described in detail in the present invention are all known technologies to those skilled in the art. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A seawater desalination device, comprising a seawater pretreatment module, a multi-channel desalination module and a freshwater treatment module connected in sequence, characterized in that: The multi-channel desalination module includes a water reservoir and three desalination channels. The first desalination channel includes a second booster pump and a reverse osmosis membrane assembly, wherein the second booster pump is connected to the water reservoir, and the reverse osmosis membrane assembly is connected to the second booster pump; The second desalination channel comprises a fresh water tank and a reverse osmosis bottom plate, wherein the fresh water tank is arranged at the bottom of the water reservoir, and the reverse osmosis bottom plate is arranged between the fresh water tank and the water reservoir; The third desalination channel includes a solar thermal collector, a heat exchange tube, a sealed chamber and a water collection tank. An arc-shaped light-transmitting sealed chamber is provided above the water reservoir. A heat exchange tube is provided in the water reservoir. The heat exchange tube is connected to the solar thermal collector arranged outdoors. A circulating pump is provided on the connecting pipe between the heat exchange tube and the solar thermal collector. The water collection tank is arranged on the ground at the bottom of the sealed chamber and is close to the inner wall of the sealed chamber.

2. The seawater desalination device according to claim 1, characterized in that: An osmotic pressure reducing module is also provided between the second booster pump and the water reservoir in the first desalination channel. The osmotic pressure reducing module comprises a first booster pump, an ultrafiltration component and a water storage tank connected in sequence. The second booster pump is connected to the water storage tank.

3. The seawater desalination device according to claim 2, characterized in that: The wastewater outlet of the ultrafiltration component is connected to a first energy recovery device, and the wastewater outlet of the reverse osmosis membrane component is connected to a second energy recovery device.

4. The seawater desalination device according to claim 1, characterized in that: The reverse osmosis bottom plate includes a support frame, a plurality of support plates and a reverse osmosis membrane. The support frame is fixed on the fresh water tank. A plurality of support columns are fixed on the bottom of the support frame. A plurality of support plates are detachably fixed on the support frame. Filter holes are opened on the support plates. The reverse osmosis membrane is laid and fixed on the support plates. The reverse osmosis bottom plate separates the fresh water tank and the water reservoir into two spaces. The seawater in the water reservoir penetrates into the fresh water tank by its own gravity.

5. The seawater desalination device according to claim 1, characterized in that: A water guide bar is arranged on the inner wall of the sealing chamber, and the water guide bar faces the water collecting tank, and the water collecting tank is connected with the fresh water tank.

6. The seawater desalination device according to claim 5, characterized in that: A heat-insulating layer is arranged on the outer side of the water reservoir.

7. The seawater desalination device according to claim 6, characterized in that: The terrain where the solar energy heat collecting panel is located is lower than the heat exchange tubes in the water reservoir. The heat exchange tubes are spiral-shaped and evenly distributed in the water reservoir.

8. The seawater desalination device according to claim 1, characterized in that: The seawater pretreatment module comprises a seawater pool, a BAF pool, a clarification pool and a security filter which are connected in sequence, and the security filter is connected to a water reservoir.

9. The seawater desalination device according to claim 1, characterized in that: The fresh water treatment module comprises a filter pool, a mineralization pool and a chlorine pool which are connected in sequence, and the fresh water outlet end of the fresh water tank and the reverse osmosis membrane assembly is connected to the filter pool.

10. A seawater desalination process, characterized in that: The following steps are involved: A. The seawater is pre-treated through the seawater pre-treatment module to remove suspended matter, colloids, and particulate matter in the seawater, sterilize, disinfect, and kill algae, and then enter the water storage tank; B. The seawater in the reservoir is desalinated through three channels. The first channel uses the ultrafiltration component to perform primary filtration to reduce the osmotic pressure, and then uses the reverse osmosis membrane component to perform reverse osmosis filtration to obtain fresh water that flows into the filter pool; the second desalination channel uses the gravity of the water stored in the reservoir to penetrate into the fresh water tank through the reverse osmosis bottom plate, and then flows into the filter pool; the third desalination channel desalinates through evaporation. The sealed chamber, heat exchange tubes and insulation layer are all designed to increase the temperature of the seawater in the reservoir and improve the evaporation efficiency. The evaporated water vapor condenses on the inner wall of the sealed chamber, then flows to the water collection tank, then enters the fresh water tank, and finally flows into the filter pool; C. The fresh water in the filter pool is then filtered, mineralized and disinfected to become domestic or industrial water.

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