Parallel backwashing physical filter device and seawater edible salt system

Abstract

This utility model provides a parallel backwashing physical filtration device and a seawater-to-edible-salt system, belonging to the field of edible-salt production. The parallel backwashing physical filtration device includes: a physical filtration section for filtering seawater to obtain clean seawater; a clean seawater tank; and a physical cleaning section for physically cleaning the physical filtration section with clean seawater when the physical filtration section stops filtering. The physical filtration section has: a screen-type physical filtration module for filtering seawater to obtain coarse seawater; and a membrane-type physical filtration module for filtering the coarse seawater to obtain clean seawater. The physical cleaning section includes: a backwashing unit that connects the screen-type and membrane-type physical filtration modules to the clean seawater tank, respectively, and uses clean seawater to backwash the membrane-type and screen-type physical filtration modules; and a drainage unit for discharging the backwashed wastewater.

Description

Technical Field

[0001] This utility model relates to the field of edible salt production, specifically to a parallel backwashing physical filtration device and a seawater edible salt production system. Background Technology

[0002] Traditional methods of salt production from seawater mainly include boiling and solar evaporation. Boiling involves using heat to evaporate and concentrate brine, a method generally used for industrial salt production but consuming a large amount of electricity. Solar evaporation involves introducing seawater into salt pans at high tide. The seawater is first introduced into higher-lying areas and then flows through tidal channels to lower-lying areas under gravity. These areas are divided into multiple sections according to elevation, with the brine concentration gradually increasing. The seawater then flows to even lower crystallization ponds for further sun exposure, resulting in sea salt crystallization and edible salt. The advantages of solar evaporation for edible salt production are energy efficiency and the production of eco-friendly salt. However, its disadvantages include a long drying time (typically 15-20 days), a large production cycle, and significant susceptibility to weather conditions (e.g., rain), a large land area required for salt pan production, and the increasing labor costs associated with these factors. Therefore, developing new technologies for producing edible salt from seawater is urgently needed.

[0003] Existing technologies include a type of membrane-based freshwater production process, which mainly involves seawater collection, addition of flocculants for sedimentation, addition of scale inhibitors, filtration, and reverse osmosis treatment. The reverse osmosis process yields freshwater and a medicated brine solution. This medicated brine solution contains flocculants and scale inhibitors, and can be used to produce industrial salt, but not edible salt. In this freshwater production process, without the addition of flocculants and scale inhibitors, the filtration structure is easily clogged and difficult to clean, rendering it unusable.

[0004] Based on this, the inventors improved upon the aforementioned membrane-based freshwater production technology, creating a new, efficient, and energy-saving seawater-to-edible-salt system, and specifically designed a new filtration device structure. Utility Model Content

[0005] This invention was developed to solve the above-mentioned problems. Its purpose is to provide a parallel backwashing physical filtration device that is not easily clogged even without the addition of flocculants and scale inhibitors during the filtration process, and also to provide a new, efficient, and energy-saving seawater-to-edible salt system.

[0006] This utility model provides a parallel backwashing physical filtration device, characterized by: a physical filtration section for filtering seawater to obtain clean seawater; a clean seawater tank for storing clean seawater; and a physical cleaning section for physically cleaning the physical filtration section using clean seawater from the clean seawater tank when the physical filtration section stops filtering. The physical filtration section includes: a screen-type physical filtration module for filtering seawater to obtain coarse seawater; and a membrane-type physical filtration module connected to the screen-type physical filtration module for filtering the coarse seawater to obtain clean seawater. The physical cleaning section includes: a backwashing unit that connects the screen-type physical filtration module and the membrane-type physical filtration module to the clean seawater tank, and backwashes the membrane-type physical filtration module and the screen-type physical filtration module using clean seawater; and a drainage unit for discharging the backwashed wastewater.

[0007] The parallel backwashing physical filtration device provided by this utility model may also have the following features: The filter screen type physical filtration module includes: a filter screen input unit for inputting seawater; a filter screen body for filtering the seawater; and a filter screen output unit for outputting the filtered seawater. The filter screen body has an inlet, a filter screen section, an outlet, and a cross-flow outlet. The inlet is connected to the filter screen input unit, and the outlet is connected to the filter screen output unit. A portion of the seawater flowing in from the inlet passes through the mesh of the filter screen section from the outside to the inside and flows out from the outlet, while another portion flows through the outside of the mesh and flows out from the cross-flow outlet. The membrane type physical filtration module includes: a membrane input unit for... The system includes: input coarse seawater filtered by a screen-type physical filtration module; a filter membrane body for filtering the coarse seawater to obtain clean seawater; and a filter membrane output unit connected to a clean seawater tank for outputting clean seawater to the clean seawater tank. The filter membrane body has a third inlet, a filter membrane section, a third outlet, and a third cross-flow outlet. The third inlet is connected to the outlet of the screen-type filter body. Part of the seawater flowing in from the third inlet passes through the membrane pores of the filter membrane section from the outside to the inside and flows out from the third outlet. The other part flows through the outside of the membrane pores and flows out from the third cross-flow outlet. The outlet of the screen-type physical filtration module and the third outlet are both connected to the clean seawater tank through a backwashing unit.

[0008] The parallel backwashing physical filtration device provided by this utility model may also have the following feature: the physical cleaning unit further includes an air scrubbing unit, which is used at least for air scrubbing the membrane-type physical filtration module. The air scrubbing unit includes an air pump, an air pipe, and an air valve. The air pump is connected to the air pipe, and the air valve is installed on the air pipe and used to control the airflow rate through the air pipe.

[0009] The filter membrane filter body also has a third air inlet and a third exhaust port. The third air inlet is connected to the air pipe and is used to introduce gas to perform air scrubbing on the filter membrane. The third exhaust port is used to discharge gas.

[0010] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the drainage unit includes a cross-flow pipe and a flow regulating valve. The cross-flow pipe is connected to a third cross-flow port. The flow regulating valve is installed on the cross-flow pipe and is used to regulate the flow rate of the cross-flow pipe under the control of the control unit. The flow regulating valve includes a valve body and a drive unit. The valve body is a ball valve or a shut-off valve. The drive unit includes: a servo motor with a servo controller. The servo controller is connected to the control unit and receives its instructions to adjust the output torque of the servo motor. A worm gear is driven to rotate by the servo motor and has helical teeth. A worm wheel has tooth grooves that mesh with the helical teeth. The worm wheel axis is perpendicular to the worm axis. The position of the worm wheel is fixed. The worm wheel is driven by the worm to rotate around its own axis. A transmission component is connected to the valve body. The transmission component is driven by the worm wheel to control the opening and closing degree of the valve body. The power shaft of the servo motor and the length direction of the worm are denoted as the first direction. The axial direction of the worm wheel and the transmission component is denoted as the second direction. The first direction is perpendicular to the second direction. When the valve body is a stop valve, the transmission components include a lead screw and an anti-rotation ring. The anti-rotation ring is fixed in position and is used to allow the lead screw to pass through and prevent it from rotating around its own axis. The lead screw is threadedly connected to a worm gear, and the worm gear rotates around its axis, thereby driving the lead screw to move along its length. The valve body includes: a stop valve body having an inlet pipe and an outlet pipe, the inlet pipe and the outlet pipe having an inlet flow channel and an outlet flow channel respectively, the inlet flow channel and the outlet flow channel intersecting; and a stop valve core, the stop valve core being connected to the lead screw and driven by it to move along its length and at least partially passing through the inlet flow channel, so that the valve cone of the stop valve core has different degrees of blockage at the intersection of the inlet flow channel and the outlet flow channel, thereby changing the flow rate of the outlet flow channel. The maximum radial outer diameter of the valve cone is at least 0.01mm to 0.2mm smaller than the inner diameter of the inlet flow channel. When the valve body is a ball valve, the transmission component is rod-shaped. One end of the transmission component is fixed to the worm gear and rotates coaxially with it. The other end is connected to the ball with the flow channel of the ball valve, thereby driving the ball to rotate to adjust the opening and closing degree of the flow channel.

[0011] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the filter screen input unit includes a main water inlet pipe and a first control valve, a main water inlet flow meter, and a main water inlet pressure sensor installed on the main water inlet pipe; the filter membrane output unit includes: a filter membrane outlet pipe connected to a clean seawater tank; a fourth control valve installed on the filter membrane outlet pipe for opening or closing the filter membrane outlet pipe; a filter membrane outlet pressure sensor installed on the filter membrane outlet pipe for detecting the pressure of the clean seawater flowing out of the filter membrane outlet pipe; and a filter membrane outlet flow meter installed on the filter membrane outlet pipe for detecting the flow rate of the clean seawater flowing out of the filter membrane outlet pipe. When the main water inlet pipe is closed, the backwashing unit performs backwashing. At this time, the clean seawater flows sequentially through the third outlet, the third inlet, and the outlet of the filter screen filter body before flowing out from the first crossflow port.

[0012] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the backwashing unit includes: a backwashing main pipe connected to a clean seawater tank; a second backwashing branch pipe connected to the backwashing main pipe and the outlet of the filter screen body respectively; a third backwashing branch pipe connected to the backwashing main pipe and the third outlet respectively; a backwashing pump installed on the backwashing main pipe to provide backwashing power; a second backwashing control valve installed on the second backwashing branch pipe for controlling whether the backwashing pipe is connected; and a third backwashing control valve installed on the third backwashing branch pipe for controlling whether the third backwashing pipe is connected.

[0013] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the filter screen output unit includes: a filter screen outlet pipe, which is connected to the outlet of the filter screen filter body and the third inlet; a second control valve, which is installed on the filter screen outlet pipe and is used to open or close the filter screen outlet pipe; the drainage unit also includes a third drain pipe, which is connected to the connecting pipe between the second control valve and the third inlet.

[0014] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the filter screen body includes at least two filter screens, which are connected in parallel between the filter screen input unit and the filter screen output unit. The mesh size of the at least two filter screens gradually decreases along the water production direction from the filter screen input unit to the filter screen output unit. The backwashing unit backwashes the at least two filter screens respectively or performs step-by-step backwashing in the direction opposite to the water production direction from the filter screen input unit to the filter screen output unit.

[0015] The parallel backwashing physical filtration device provided by this utility model may also have the following features: the filter membrane filter body further includes a filter membrane housing, a third inlet, a third outlet, and a third crossflow outlet are all provided on the filter membrane housing, the third inlet is provided at the lower part of the filter membrane housing, the filter membrane drain outlet is provided at the bottom of the filter membrane housing, the third outlet is provided at the upper part of the filter membrane housing, the third crossflow outlet is provided at the top of the filter membrane housing, the filter membrane is detachably provided inside the filter membrane housing, the filter membrane filter body includes at least two filter membrane filters, the at least two filter membrane filters are connected in parallel, and the backwashing unit backwashes the at least two filter membrane filters respectively.

[0016] This utility model also provides a seawater-to-edible-salt system, characterized in that it includes: the above-mentioned parallel backwashing physical filtration device; and a reverse osmosis mechanism for reverse osmosis treatment of clean seawater to obtain concentrated brine, which is used to produce edible salt.

[0017] Functions and effects of utility models

[0018] This invention provides a parallel backwashing physical filtration device, comprising a physical filtration section and a clean seawater tank. The physical filtration section includes a screen-type physical filtration module and a membrane-type physical filtration module. The screen-type module filters seawater to obtain coarse seawater, while the membrane-type module filters the coarse seawater to obtain clean seawater. The clean seawater tank stores the clean seawater. Clean seawater is thus prepared through the physical filtration section.

[0019] This parallel backwashing physical filtration device also includes a physical cleaning section, which comprises a backwashing unit and a drainage unit. When the physical filtration section stops filtering, the backwashing unit uses clean seawater from the clean seawater tank to backwash the membrane-type and mesh-type physical filtration modules. Backwashing prevents these filtration structures from being clogged by impurities in the seawater, ensuring that the membrane-type and mesh-type physical filtration modules can prepare clean seawater for extended periods. Furthermore, this backwashing is a physical cleaning process, avoiding the addition of flocculants and scale inhibitors during filtration. Therefore, the clean seawater produced by the physical filtration section is free of flocculants and scale inhibitors, and the concentrated brine obtained after subsequent reverse osmosis treatment is also chemical-free and can be used to produce edible salt.

[0020] This invention also provides a seawater-to-edible-salt system, comprising the aforementioned parallel backwashing physical filtration device and a reverse osmosis mechanism. The clean seawater, free of flocculants and scale inhibitors, produced by the parallel backwashing physical filtration device, undergoes reverse osmosis treatment to obtain concentrated brine. This concentrated brine can be crystallized into edible salt after a short period of sun exposure. Compared to existing methods of salt production from raw seawater through sun exposure, this significantly shortens the salt production time, improves the efficiency and profitability of edible salt production, reduces the adverse effects of weather on salt production, and greatly saves land resources, reducing labor and land costs. This seawater-to-edible-salt system is a new, efficient, energy-saving, and economically significant system. Attached Figure Description

[0021] Figure 1 This is a block diagram of the seawater-to-edible-salt system in Embodiment 1 of this utility model;

[0022] Figure 2 This is a schematic diagram of the physical filtration device in Embodiment 1 of this utility model;

[0023] Figure 3 yes Figure 2 Enlarged diagram of the part Figure 1 ;

[0024] Figure 4 This is a cross-sectional view of the first filter screen in Embodiment 1 of this utility model;

[0025] Figure 5 This is a cross-sectional view of the second filter screen in Embodiment 1 of this utility model;

[0026] Figure 6 yes Figure 2 Enlarged diagram of the part Figure 2 ;

[0027] Figure 7 This is a cross-sectional view of the membrane filter in Embodiment 1 of this utility model;

[0028] Figure 8 This is a perspective view of the first type of flow regulating valve in Embodiment 1 of this utility model;

[0029] Figure 9 This is a perspective view of the second type of flow regulating valve in Embodiment 1 of this utility model;

[0030] Figure 10 This is a cross-sectional view of the first type of flow regulating valve in Embodiment 1 of this utility model;

[0031] Figure 11 This is a schematic diagram of the physical filtration device in Embodiment 2 of this utility model. Detailed Implementation

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] To make the technical means, creative features, objectives and effects of this utility model easy to understand, the following embodiments, in conjunction with the accompanying drawings, will specifically describe the parallel backwashing physical filtration device and the seawater edible salt production system of this utility model.

[0034] Figure 1 This is a block diagram of the seawater-to-edible-salt system in Embodiment 1 of this utility model.

[0035] like Figure 1 As shown, this embodiment provides a seawater-to-edible-salt system 200, including: a physical filtration device 22, a reverse osmosis mechanism 23, and a moving device 25. The physical filtration device 22 is used to filter seawater to obtain clean seawater. The reverse osmosis mechanism 23 is used to perform reverse osmosis treatment on the clean seawater to obtain fresh water and concentrated brine. The concentrated brine is used to produce edible salt after sun-drying.

[0036] The mobile unit 25 has a container, in which the physical filtration device 22 and the reverse osmosis unit 23 are housed. The container has standard container dimensions, for example, 6m long, 2.4m wide, and 2.6m high. This allows the entire seawater-to-salt system 200 to be moved and transported by means of vehicles such as trucks, ships, or cranes.

[0037] Figure 2 This is a schematic diagram of the physical filtration device in Embodiment 1 of this utility model.

[0038] like Figure 2As shown, in this embodiment, the physical filtration device 22 is a parallel backwashing type physical filtration device, including a physical filtration section 221, a clean seawater tank 24, a physical cleaning section 222, and a control section. The physical filtration section 221 filters seawater to obtain clean seawater. The clean seawater tank 24 stores clean seawater. The physical cleaning section 222 physically cleans the physical filtration section 221 using clean seawater from the clean seawater tank 24 when the physical filtration section 221 stops filtering. The control section controls the filtration of the physical filtration section 221 and the physical cleaning of the physical cleaning section 222.

[0039] Figure 3 yes Figure 2 Enlarged diagram of the part Figure 1 .

[0040] like Figure 2 and Figure 3 As shown, the physical filtration unit 221 has a filter screen type physical filtration module 2211 and a filter membrane type physical filtration module 2212.

[0041] The filter-type physical filtration module 2211 is used to filter seawater to obtain coarsely filtered seawater. The filter-type physical filtration module 2211 includes a filter input unit, a filter body, a filter output unit, and a first controller (not shown in the figure).

[0042] The filter input unit is used to input seawater and includes a main inlet pipe 22111 and a first control valve 221111, a main inlet flow meter 221112, and a main inlet pressure sensor 221113 installed on the main inlet pipe 221111. The first control valve 221111 is used to open or close the main inlet pipe 22111 under the control of a first controller. The main inlet flow meter 221112 and the main inlet pressure sensor 221113 are used to detect the flow rate and pressure of the seawater flowing through the inlet pipe 22111, respectively.

[0043] The filter body is used to filter seawater and includes at least two filter screens connected in series between the filter screen input unit and the filter screen output unit. The mesh size of the at least two filter screens gradually decreases along the water production direction from the filter screen input unit to the filter screen output unit.

[0044] In this embodiment, the filter body includes two filter screens, referred to as the first filter screen 22112 and the second filter screen 22113, respectively.

[0045] Figure 4 This is a cross-sectional view of the first filter screen in Embodiment 1 of this utility model.

[0046] like Figure 4As shown, the first filter screen 22112 has a first filter screen housing 221121, a first filter screen mounting part 221122, a first filter screen part 221123, a first water inlet 221124, a first water outlet 221125, a first air inlet 221126, a first exhaust outlet 221127, and a first crossflow outlet 221128.

[0047] The top of the first filter housing 221121 is an openable and closable cover. The first filter part 221123 is installed inside the first filter housing 221121 via the first filter mounting part 221122. The first filter part 221123 is cylindrical, with a blind end at the bottom and a filter screen on its peripheral wall. The mesh diameter of the filter screen is 200-400 μm, preferably 250-300 μm, and it has an opening at the top.

[0048] Both the first inlet 221124 and the first outlet 221125 are located on the first filter housing 221121, with the first inlet 221124 situated at the lower part of the first filter housing 221121 and the first outlet 221125 situated at the upper part of the first filter housing 221121. The first inlet 221124 is connected to the main inlet pipe 22111 for introducing seawater. The first outlet 221125 is used to output the filtered seawater.

[0049] A connecting pipe for connecting to the second filter 22113 is connected to the first water outlet 221125, and a second control valve 22115 is installed on the connecting pipe.

[0050] The first cross-flow port 221128 can share a port with the first inlet 221124, or they can be set separately. In this embodiment, the filter membrane drain port 221228 is set separately at the lower part of the first filter screen housing 221121. In this embodiment, the first cross-flow port 221128 and the first inlet 221124 are arranged opposite to each other. Most of the seawater flowing in from the first inlet 221124 passes through the mesh of the filter screen on the outer wall of the first filter screen 221123 and enters the interior of the first filter screen 221123, thereby realizing the filtration function. The filtered seawater flows out of the first filter screen 221123 through the opening at the top and then flows out from the first outlet 221125; a small portion flows through the outside of the mesh and then flows out from the first cross-flow port 221128. This cross-flow operation allows dirt and impurities on the filter membrane to loosen and even detach. Furthermore, the detached dirt and impurities can be discharged through the first cross-flow port 221128, reducing dirt accumulation and extending the backwashing interval. The first cross-flow port 221128 is also connected to the first drain pipe 22231 for discharging the cross-flow wastewater (dirty water) and backwash wastewater (dirty water). A cross-flow drain valve 22235 is installed on the first cross-flow port 221128.

[0051] Both the first air inlet 221126 and the first exhaust port 221127 are located in the first filter housing 221121. The first air inlet 221126 is located at the bottom center of the first filter housing 221121 and is used to introduce gas to perform air cleaning of the mesh of the first filter section 221123. The first exhaust port 221127 is located at the top center of the first filter housing 221121 and is used to exhaust gas to prevent the air pressure inside the first filter housing 221121 from increasing during air cleaning. A solenoid valve F1 is installed on the first exhaust port 221127.

[0052] During filtration, the first controller controls the first control valve 221111 and the second control valve 22115 to open, and the cross-flow sewage control valve 22235 opens to a certain extent. At this time, the first air inlet 221126 and the first exhaust port 221127 are both in a non-flowing gas state.

[0053] After the first filter screen 22112 has been running for a period of time, it needs to be physically cleaned. During physical cleaning, air wiping is performed first, followed by backwashing.

[0054] When air scrubbing is required, the first controller controls the first control valve 221111, the second control valve 22115 and the cross-flow sewage control valve 22235 to close. At this time, the first air inlet 221126 and the first exhaust port 221127 are both in the air-flow state.

[0055] During backwashing after air scrubbing, the first controller controls the first control valve 221111 to close the main water inlet pipe 22111, and the cross-flow sewage control valve 22235 is opened to the maximum extent. Clean seawater is introduced from the first outlet 221125 to backwash the mesh of the first filter screen section 221123 from the inside to the outside. The backwashed sewage is discharged from the first cross-flow outlet 221128. The first cross-flow outlet 221128 also serves as a sewage outlet.

[0056] Figure 5 This is a cross-sectional view of the second filter screen in Embodiment 1 of this utility model;

[0057] like Figure 5 As shown, the second filter screen 22113 has a second filter screen housing 221131, a second filter screen mounting part 221132, a second filter screen part 221133, a second water inlet 221134, a second water outlet 221135, a second air inlet 221136, a second exhaust outlet 221137, and a second crossflow outlet 221139.

[0058] The top of the second filter housing 221131 is an openable and closable cover. The second filter part 221133 is installed inside the second filter housing 221131 via the second filter mounting part 221132. The second filter part 221133 is cylindrical, with a blind end at the bottom and a filter screen on its peripheral wall. The mesh diameter of the second filter part 221133 is smaller than that of the first filter part 221123, ranging from 100-300 μm, preferably 120-180 μm. The top of the second filter part 221133 has an opening.

[0059] Both the second inlet 221134 and the second outlet 221135 are located on the second filter housing 221131, with the second inlet 221134 situated at the lower part of the second filter housing 221131 and the second outlet 221135 situated at the upper part of the second filter housing 221131. The second inlet 221134 is connected to the first outlet 221125 via a connecting pipe equipped with a third control valve 221138 for controlling the opening and closing of the connecting pipe. The second inlet 221134 is used to introduce seawater filtered by the first filter 221123. The second outlet 221135 is used to output coarsely filtered seawater filtered by the second filter mounting part 221132.

[0060] The second cross-flow port 221139 is disposed on the second filter screen housing 221131 and at the lower part of the second filter screen housing 221131. In this embodiment, the second cross-flow port 221139 and the second inlet 221134 are disposed adjacent to each other. Most of the seawater flowing in from the second inlet 221134 passes through the mesh of the filter screen on the outer wall of the second filter screen 221133 and enters the interior of the second filter screen 221133, thereby achieving the filtration function. The coarsely filtered seawater flows out of the second filter screen 221133 through the opening at the top and then flows out from the second outlet 221135; a small portion flows through the outside of the mesh and then flows out from the second cross-flow port 221139. This cross-flow operation mode can, on the one hand, loosen or even remove dirt and impurities on the filter membrane, and on the other hand, the removed dirt and impurities can be discharged from the second cross-flow port 221139, thereby reducing the accumulation of dirt and extending the backwashing interval.

[0061] The second air inlet 221136 and the second exhaust outlet 221137 are both located in the second filter housing 221131. The second air inlet 221136 is located at the bottom center of the second filter housing 221131 and is used to introduce gas to perform air cleaning of the mesh of the second filter section 221133. The second exhaust outlet 221137 is located at the top center of the second filter housing 221131 and is used to exhaust gas to prevent the air pressure inside the second filter housing 221131 from increasing during air cleaning. A solenoid valve F2 is installed on the second exhaust outlet 221137.

[0062] The filter output unit is used to output the coarsely filtered seawater after being filtered by the second filter 22113. The filter output unit includes a filter outlet pipe 22114 and a second control valve 22115.

[0063] The filter screen outlet pipe 22114 is connected to the second outlet 221135 and the membrane-type physical filtration module 2212. The second control valve 22115 is installed on the filter screen outlet pipe 22114 and is used to open or close the filter screen outlet pipe 22114 under the control of the first controller.

[0064] The first filter 22112 and the second filter 22113 can be backwashed simultaneously, or the second filter 22113 can be backwashed first and then the first filter 22112 can be backwashed (i.e., backwashing in stages).

[0065] Figure 6 yes Figure 2 Enlarged diagram of the part Figure 2 .

[0066] like Figure 2 and Figure 6 As shown, the membrane-type physical filtration module 2212 is connected to the mesh-type physical filtration module 2211 and is used to perform membrane filtration on coarse seawater to obtain clean seawater. The membrane-type physical filtration module 2212 includes a membrane input unit, a membrane filtration body, a membrane output unit, and a second controller. The controller is used to control the mesh membrane input unit, the membrane filtration body, and the membrane output unit.

[0067] The filter membrane input unit is used to input coarsely filtered seawater after being filtered by the filter screen physical filtration module 2211. It has a filter membrane water supply pipe 22121, which is connected to the filter screen water outlet pipe 22114.

[0068] The membrane filter body is used for ultrafiltration of coarse seawater to obtain clean seawater, and includes at least two membrane filters 22122, all of which are connected in parallel. The two membrane filters 22122 have the same structure.

[0069] Figure 7 This is a cross-sectional view of the membrane filter in Embodiment 1 of this utility model.

[0070] like Figure 6 and Figure 7As shown, each membrane filter 22122 includes a membrane housing 221221, a membrane mounting portion 221222, a membrane portion 221223, a third inlet 221224, a membrane portion 221223, a third outlet 221225, a third cross-flow port 221227, a third air inlet 221226, a third exhaust port, and a membrane drain port 221228. In this embodiment, the third cross-flow port 221227 also serves as the third exhaust port.

[0071] The filter membrane housing 221221 has detachable ends, specifically secured by bolts. The filter membrane section 221223 is detachably mounted inside the filter membrane housing 221221 via the filter membrane mounting section 221222. After a certain period of use, the filter membrane section 221223 can be replaced. The filter membrane section 221223 includes multiple ultrafiltration membrane fibers with a filtration area of ​​20-100 m² and a pore size of 0.01-0.2 μm. The ultrafiltration membrane fibers are preferably formed by a foaming process.

[0072] Both the third inlet 221224 and the third outlet 221225 are located on the filter membrane housing 221221, with the third inlet 221224 located at the lower part of the filter membrane housing 221221 and the third outlet 221225 located at the upper part of the filter membrane housing 221221. The third crossflow outlet 221227 is located on the filter membrane housing 221221 and at the top of the filter membrane housing 221221.

[0073] The third inlet 221224 is connected to the second outlet 221135. Coarsely filtered seawater flows in through the third inlet 221224. A portion of it passes through the membrane pores of the filter membrane filaments 221223 from the outside to the inside, becoming clean seawater that flows out through the third outlet 221225. The other portion flows through the outside of the membrane pores and then flows out through the third crossflow outlet 221227. The turbidity of the clean seawater is less than 1 NTU.

[0074] The third air inlet 221226 is disposed on the filter membrane housing 221221 and at the bottom of the filter membrane housing 221221. It is used to introduce gas to perform gas scrubbing on the membrane fibers of the filter membrane section 221223. The third exhaust port is used to discharge gas. In this embodiment, the third crossflow port 221227 also serves as the third exhaust port.

[0075] The filter membrane drain port 221228 can share a port with the third inlet port 221224, or it can be set separately. In this embodiment, the filter membrane drain port 221228 is set separately at the bottom of the filter membrane housing 221221, and is connected to the third inlet port 221224. The two are connected together and then lead to the filter membrane section 221223 through a pipeline. The filter membrane drain port 221228 is also connected to a third drain pipe 22233, and the third drain pipe 22233 is equipped with a third drain valve 22237 for controlling the flow rate of the third drain pipe 22233. The third drain valve 22237 is used to control the flow rate of the drain pipe under the control of the second controller.

[0076] A flow control pipe 22234 is connected to the third flow control port 221227, and a flow control valve 22238 is installed on the flow control pipe 22234.

[0077] Figure 8 This is a perspective view of the first type of flow regulating valve in Embodiment 1 of this utility model. Figure 9 This is a perspective view of the second type of flow regulating valve in Embodiment 1 of this utility model.

[0078] like Figure 8 and Figure 9 As shown, the flow regulating valve 22238 includes a drive unit and a valve body. The valve body is either a ball valve or a gate valve; in this example, a ball valve is preferred.

[0079] Figure 10 This is a cross-sectional view of the first type of flow regulating valve in Embodiment 1 of this utility model.

[0080] like Figure 8 and Figure 10 As shown, when the valve body is a shut-off valve, the flow regulating valve 22238 includes a drive unit 61 and a valve body 62. The drive unit 61 includes a housing 611, a bearing seat 612, a dust cover 613, a worm gear 614, a servo motor 615, a worm 616, a transmission component 617, and a sensor (not shown in the figure).

[0081] The housing 611 serves as the outer shell of the transmission part in the drive unit 61, and its material is stainless steel. The housing 611 has an opening.

[0082] The bearing housing 612 is provided at the opening on the housing 611 and has a through passage thereon.

[0083] The dust cover 613 is bolted to the bearing housing 612 to prevent dust and other foreign objects from falling into the housing 611 through the opening on the housing 611 and / or the channel of the bearing housing 612. The dust cover 613 is made of stainless steel.

[0084] The worm gear 614 is disposed in the internal space formed by the housing 611 and the bearing seat 612. The upper and lower ends of the worm gear 614 are indirectly abutted to the lower surface of the bearing seat 612 and the bottom of the housing 611 through the thrust bearing 1, so that it will not produce axial displacement when rotating around its own axis. The cylindrical outer surface of the worm gear 614 has several tooth grooves.

[0085] The servo motor 615 is mounted on the side wall of the housing 611, and its drive shaft passes through the interior of the housing 611. The servo motor 615 has a servo controller, which is connected to the control unit and receives its commands to adjust the output torque of the drive shaft of the servo motor 615.

[0086] The worm gear 616 is directly connected to the power shaft of the servo motor 615 and is driven by it to rotate around its own axis. The worm gear 616 has multiple helical teeth that mesh with tooth grooves. In this embodiment, the worm gear 616 is made of stainless steel.

[0087] The worm 616 is located inside the housing 611 and next to the worm wheel 614. The rotation of the worm 616 causes the helical teeth to advance along the axial direction of the worm 616, thereby causing the worm wheel 614 to rotate around its own central axis.

[0088] In this embodiment, the length direction of the power shaft of the servo motor 615 and the worm gear 616 is referred to as the first direction.

[0089] The transmission component 617 includes a lead screw 6171 and an anti-rotation ring 6172.

[0090] The lead screw 6171 is a T-shaped lead screw, which passes through and is threadedly connected to the worm gear 614 along its axis. When the worm gear 614 rotates around its own axis, it drives the lead screw 6171 to move along its length. In this embodiment, the axial direction of the worm gear 614 and the lead screw 6171 is denoted as the second direction, and the first direction is perpendicular to the second direction. The entire flow regulating valve 22238 has a horizontal structure. Preferably, the lead screw 6171 and the worm gear 614 are configured as a ball screw structure.

[0091] The anti-rotation ring 6172 is held by the bearing housing 612 and the dust cover 613, and is used to allow one end of the lead screw 6171 to pass through and prevent the lead screw 6171 from rotating around its own axis when it is displaced along its length.

[0092] The sensor (not shown in the figure) is a proximity sensor, located in the internal space formed by the dust cover 613 and the bearing housing 612, and above the end of the lead screw 6171 that passes through the anti-rotation ring 6172. It is used to detect the axial displacement distance of the lead screw 6171. The sensor is connected to a servo controller, which adjusts the output torque of the power shaft of the servo motor 615 based on the sensor data.

[0093] The valve body 62 includes a shut-off valve core 620 and a shut-off valve body. Both the shut-off valve core 620 and the shut-off valve body are made of duplex steel.

[0094] The shut-off valve core 620 is made of duplex steel. The shut-off valve core 620 is threaded to the end of the lead screw 6171 away from the anti-rotation ring 6172, and its valve cone 620a extends through the bottom of the housing 611. The shut-off valve core 620 is driven by the lead screw 6171 to move along its length.

[0095] The shut-off valve body includes a transition unit 621, a connection unit 622, an inlet unit 623, and an outlet unit 624.

[0096] The adapter unit 621 is an adapter flange, located at the bottom opening of the housing 611, and fixed to the bottom of the housing 611 by bolts. The adapter unit 621 and the housing 611 are sealed by a sealing ring. The valve core 620 has one end with a valve cone 620a that movably passes through the adapter unit 621.

[0097] The connecting unit 622 includes a first connecting section 6221, a radial water outlet section 6222, and a second connecting section 6223.

[0098] The outer diameter of the first connecting section 6221 is smaller than the outer diameter of the adapter unit 621. The first connecting section 6221 and the adapter unit 621 are fixed and connected by a threaded detachable screw connection, and the screw connection is sealed by several sealing rings.

[0099] The outer diameter of the radial water outlet section 6222 is the same as that of the first connecting section 6221 and is integrally connected to it. The peripheral wall of the radial water outlet section 6222 has a number of water outlet holes 4.

[0100] The outer diameter of the second connecting section 6223 is larger than the outer diameter of the radial water outlet section 6222, and it is integrally connected with the connecting section 6223.

[0101] The water inlet unit 623 is a water inlet pipe with an annular valve seat 623a at one end. The end of the water inlet unit 623 with the valve seat 623a is detachably screwed to the second connecting section 6223, and the inner diameter of the valve seat 623a is at most 0.01mm to 0.02mm larger than the maximum outer diameter of the valve cone 620a. The water inlet unit 623 has a water inlet channel 623b inside, which communicates with the second connecting section 6223.

[0102] In this embodiment, the main body of the water inlet unit 623 is sealed with the second connecting section 6223 by a sealing ring, and the valve seat 623a at its end is also sealed with the second connecting section 6223 by a sealing ring.

[0103] The water outlet unit 624 includes a rotating component 6241 and a water outlet pipe 6242.

[0104] The rotating component 6241 is rotatably ring-fixed onto the radial water outlet section 6222 and is clamped together by the adapter unit 621 and the second connecting section 6223. The rotating component 6241 and the radial water outlet section 6222 are connected through the water outlet hole 4. The rotating component 6241 is sealed to the adapter unit 621 by a sealing ring, and the rotating component 6241 is sealed to the second connecting section 6223 by a sealing ring.

[0105] The outlet pipe 6242 is detachably screwed to the side wall of the rotating component 6241 by a thread and sealed by a sealing ring. The outlet pipe 6242 has an outlet channel 6242a inside, which communicates with the internal space of the rotating component 6241.

[0106] The first type of flow control valve 22238 is suitable for both high-pressure (6-15MPa) and low-pressure (0-6MPa) operating conditions. Its operation process is as follows:

[0107] S10, the servo motor 615 operates, driving the worm 616 to rotate around its own axis. The rotation of the worm 616 causes the helical teeth 616a to advance along the axial direction of the worm 616, thereby forming continuous line contact with the worm wheel teeth 614a and forcing the worm wheel 614 to rotate around its own central axis.

[0108] S20, one end of the lead screw 6171 passes through the anti-rotation ring 6172, so it will not rotate around its own axis; the worm gear 614 rotates around its own central axis, and through the threaded connection with the lead screw 6171, it drives the lead screw 6171 to move along its length direction.

[0109] S30, after the lead screw 6171 is displaced along its length, it drives the shut-off valve core 620 and its valve cone 620a to move in the internal space formed by the radial water outlet section 6222, the second connecting section 6223, the valve seat 623a and the water inlet unit 623. This changes the degree of blockage of the valve cone 620a at the intersection of the water inlet channel 623b and the water outlet channel 6242a, thereby ultimately changing the flow rate of the water input from the water inlet channel 623b when it is output from the water outlet channel 6242a.

[0110] During the above steps S10 to S30, the servo controller of the servo motor 615 adjusts the torque of the output shaft of the servo motor 615 by detecting the displacement distance of the lead screw 6171 by the sensor.

[0111] like Figure 9 As shown, when the valve body is a ball valve, the flow regulating valve 22238 includes a drive unit 61b and a valve body unit 62b. This second type of flow regulating valve 22238 is suitable for both high-pressure (6-15MPa) and low-pressure (0-6MPa) operating conditions.

[0112] The structure of drive unit 61b is similar to that of drive unit 61, the only difference being:

[0113] 1. The transmission component of the drive unit 61b is rod-shaped and does not have the anti-rotation ring 6172 in the first type of flow regulating valve. Therefore, in this second type of flow regulating valve, the transmission component is driven by the turbine to rotate around the axis.

[0114] 2. The sensor is an angle sensor, used to detect the rotation amplitude of the transmission component.

[0115] The valve body 62b is a ball valve. One end of the transmission component is fixed to the turbine and rotates coaxially with it. The other end is connected to the ball with a flow channel of the ball valve, thereby driving the ball to rotate to adjust the opening and closing degree of the flow channel.

[0116] When the second type of flow regulating valve 22238 is working, the controller of the servo motor adjusts the torque of the output shaft of the servo motor by detecting the self-rotation amplitude of the transmission component by the sensor.

[0117] The membrane output unit is connected to the clean seawater tank 24 and is used to output clean seawater to the clean seawater tank 24 for storage. The membrane output unit includes a membrane outlet pipe 22123, a fourth control valve 22124, a membrane outlet pressure sensor 22125, and a membrane outlet flow meter 22126.

[0118] The filter membrane outlet pipe 22123 is connected to the third outlet 221225 and the clean seawater tank 24. A fourth control valve 22124 is installed on the filter membrane outlet pipe 22123 and is used to open or close the filter membrane outlet pipe 22123 under the control of the controller. A filter membrane outlet pressure sensor 22125 is installed on the filter membrane outlet pipe 22123 and is used to detect the pressure of the clean seawater flowing out of the filter membrane outlet pipe 22123. A filter membrane outlet flow meter 22126 is installed on the filter membrane outlet pipe 22123 and is used to detect the flow rate of the clean seawater flowing out of the filter membrane outlet pipe 22123.

[0119] The second controller is also connected to the filter membrane outlet water pressure sensor 22125 and the filter membrane outlet water flow meter 22126, and controls the flow regulating valve 22238 to regulate the flow of the cross-flow pipe 22234 according to the pressure and flow.

[0120] The control unit also controls the flow regulating valve 22238 based on the pressure and flow detected by the total inlet flow meter 221112, the total inlet pressure sensor 221113, the filter membrane outlet pressure sensor 22125, and the filter membrane outlet flow meter 22126.

[0121] When the second control valve 22115 is closed, the third outlet 221225 is also used to introduce clean seawater to backwash the membrane fibers of the filter membrane section 221223, and the wastewater after backwashing is discharged from the filter membrane drain port 221228.

[0122] The physical cleaning unit 222 includes a backwashing unit 2221, an air scrubbing unit 2222, and a drainage unit 2223.

[0123] like Figure 2 As shown, the backwashing unit 2221 connects the screen-type physical filtration module 2211 and the membrane-type physical filtration module 2212, as well as the clean seawater tank 24, to backwash the membrane-type physical filtration module 2212 and the screen-type physical filtration module 2211 using clean seawater. The backwashing unit 2221 includes a backwashing main pipe 22211, a first backwashing branch pipe 22212, a second backwashing branch pipe 22213, a third backwashing branch pipe 22214, a first backwashing valve 22216, a second backwashing valve 22217, a third backwashing control valve 22218, and a backwashing pump 22215.

[0124] The backwash main pipe 22211 is connected to the cleaning seawater tank 24.

[0125] The first backwash branch pipe 22212 is connected to the first outlet 221125 and the backwash main pipe 22211 respectively. The first backwash valve 22216 is installed on the first backwash branch pipe 22212 and is used to control whether the first backwash branch pipe 22212 is connected under the control of the control unit.

[0126] The second backwash branch pipe 22213 is connected to the backwash main pipe 22211 and the second filter outlet 221135, respectively. The second backwash valve 22217 is installed on the second backwash branch pipe 22213 and is used to control whether the second backwash branch pipe 22213 is connected under the control of the control unit.

[0127] The third backwash branch pipe 22214 is connected to the backwash main pipe 22211 and the third outlet 221225 respectively. The third backwash control valve 22218 is installed on the third backwash branch pipe 22214 and is used to control whether the third backwash pipe 22214 is connected under the control of the controller.

[0128] The backwash pump 22215 is installed on the backwash main pipe 22211 and provides power for backwashing. In this embodiment, the backwash pump 22215 is installed closer to the clean seawater tank 24 than the connection points of the first backwash branch pipe 22212, the second backwash branch pipe 22213, and the third backwash branch pipe 22214 with the backwash main pipe 22211.

[0129] The air scrubbing unit 2222 is used at least for air scrubbing the membrane-type physical filtration module 2212, and includes an air pump 22221, an air inlet pipe 22222, and an air valve 22223. The air pump is connected to the air inlet pipe 22222, which is divided into three branches connected to the first air inlet 221126, the second air inlet 221136, and the third air inlet 221226, respectively. Each of these three air inlets 22222 is equipped with an air valve 22223, thereby controlling the opening and closing of the corresponding pipeline and the flow rate under the control of the control unit.

[0130] During air scouring, the first screen filter 22112, the second screen filter 22113, and the membrane filter 22122 can be air scouring simultaneously. At this time, all three air valves 22223 are open, and the exhaust ports of each filter are also open. After air scouring for a certain period of time, the exhaust ports are closed, and air continues to be supplied to discharge the wastewater after air scouring through the drain ports of each filter under air pressure. Alternatively, the first screen filter 22112, the second screen filter 22113, and the membrane filter 22122 can be air scouring separately. Simply control the corresponding air valve 22223 and exhaust port to open. After air scouring for a certain period of time, close their exhaust ports, and continue to supply air to discharge the wastewater after air scouring through the corresponding drain ports under air pressure.

[0131] like Figure 2 As shown, the drainage unit 2223 is used at least to discharge the wastewater after air scrubbing and backwashing, including a first drain pipe 22231, a second drain pipe 22232, a third drain pipe 22233, a cross-flow pipe 22234, a fourth drain pipe, a first cross-flow drain valve 22235, a second cross-flow drain valve 22236, a third drain valve 22237, a flow regulating valve 22238, and a fourth drain valve 22239.

[0132] The first sewage pipe 22231 is connected to the first cross-flow port 221128 (a combined sewage cross-flow port). The first cross-flow sewage valve 22235 is installed on the first sewage pipe 22231 and is used to control the drainage flow rate of the first sewage pipe 22231.

[0133] The second drain pipe 22232 is connected to the second cross-flow port 221139 (a combined drain and cross-flow port). The second cross-flow drain valve 22236 is installed on the second drain pipe 22232 and is used to control the drainage flow rate of the second drain pipe 22232.

[0134] The third drain pipe 22233 is connected to the filter membrane drain port 221228. The third drain valve 22237 is installed on the third drain pipe 22233 and is used to control the drainage flow rate of the third drain pipe 22233.

[0135] The cross-flow pipe 22234 is connected to the third cross-flow port 221227. The flow regulating valve 22238 is installed on the cross-flow pipe 22234 to control the flow rate of liquid discharge and gas discharge in the cross-flow pipe 22234, thereby regulating the membrane pressure of the membrane filter 22122.

[0136] The fourth drain pipe is connected to the second inlet 221134. The fourth drain valve 22239 is installed on the fourth drain pipe to control the drainage flow rate of the fourth drain pipe.

[0137] The process by which the control unit controls the physical filtration unit 221 to perform filtration is as follows:

[0138] The first control valve 221111, the third control valve 221138, the second control valve 22115, and the fourth control valve 22124 are all open; the first cross-flow drain valve 22235, the second cross-flow drain valve 22236, and the flow regulating valve 22238 are all opened to a certain extent to allow liquid to drain from each cross-flow outlet; the third drain valve 22237 and the fourth drain valve 22239 are both closed. The pump pumps seawater into the first screen filter 22112 for filtration, then it flows into the second screen filter 22113 for further filtration to obtain coarse seawater, and then flows into the membrane filter 22122 for ultrafiltration to obtain clean seawater. The clean seawater flows into the clean seawater tank 24 for storage.

[0139] After the filter unit 221 has been running for a period of time, it needs to be physically cleaned. The control unit controls the physical cleaning unit 222 to perform physical cleaning on the physical filter unit 221 in several different ways, which can be selected according to different actual needs:

[0140] Method 1 involves first performing air wiping, and then backwashing the membrane filter 22122, the second screen filter 22113, and the first screen filter 22112 in sequence (also known as step-by-step backwashing).

[0141] Specifically as follows:

[0142] Step 1-1: First control valve 221111, third control valve 221138, second control valve 22115, and fourth control valve 22124 are all closed.

[0143] Steps 1-2: Turn on the air pump 22221, open all three air valves 22223, and open the exhaust ports of each filter. After air wiping for a certain period of time, close the exhaust ports of each filter, open the first cross-flow drain valve 22235 to its maximum, open the third drain valve 22237 and the fourth drain valve 22239, continue to circulate air, and discharge the wastewater after air wiping through the drain ports of each filter under air pressure. Then close the three air valves 22223.

[0144] In steps 1-3, the first control valve 221111 and the fourth control valve 22124 are closed, the third control valve 221138 and the second control valve 22115 are opened, and among the valves of the drainage unit 2223, only the first cross-flow sewage valve 22235 is open, and the rest are closed.

[0145] Steps 1-4: The first backwash valve 22216 and the second backwash valve 22217 are closed, the third backwash valve 22218 is opened, and the backwash pump 22215 is turned on. Clean seawater is drawn from the clean seawater tank 24 to the third outlet 221225 of the membrane filter 22122, flows from the third inlet 221224 to the second screen filter 22113 (also with the corresponding outlet inlet and outlet outlet), and then flows to the first screen filter 22112, enters from its first outlet 221125, and is discharged from the first cross-flow port 221128 (the combined outlet for sewage cross-flow) through the first sewage pipe 22231.

[0146] Method 2 involves first performing air wiping, and then backwashing the first screen filter 22112, the second screen filter 22113, and the membrane filter 22122 respectively.

[0147] Specifically as follows:

[0148] Step 2-1 is the same as step 1-1 in method 1.

[0149] Step 2-2 is the same as step 1-2 in method 1.

[0150] In steps 2-3, the first control valve 221111, the fourth control valve 22124, the third control valve 221138, and the second control valve 22115 are all closed. Among the valves of the drainage unit 2223, the first cross-flow drain valve 22235, the second cross-flow drain valve 22236, and the third drain valve 22237 are opened, while the rest are closed.

[0151] Steps 2-4: The first backwash valve 22216, the second backwash valve 22217, and the third backwash valve 22218 are all opened, and the backwash pump 22215 is turned on. Clean seawater is drawn from the clean seawater tank 24 to the outlets of the first screen filter 22112, the second screen filter 22113, and the membrane filter 22122, and discharged from the corresponding drain outlets of each filter.

[0152] Method 3 involves air wiping and backwashing only one or both of the membrane filter 22122, the second screen filter 22113, and the first screen filter 22112.

[0153] For example, when only air scouring and backwashing are performed on membrane filter 22122, the specific process is as follows:

[0154] Step 3-1: The first control valve 221111, the second control valve 22115, and the fourth control valve 22124 are all closed.

[0155] Step 3-2: Air pump 22221 is turned on, and the vent valve 22223 on the vent pipe corresponding to membrane filter 22122 is opened, while the other vent valves are closed. The exhaust port of membrane filter 22122 is opened. After air scrubbing for a certain period of time, all exhaust ports are closed, and the third drain valve 22237 is opened. Air continues to flow, and the wastewater after air scrubbing is discharged through the filter membrane drain port 221228 of membrane filter 22122 under air pressure. Then, the vent valve 22223 is closed.

[0156] Step 3-3: The first control valve 221111, the second control valve 22115, and the fourth control valve 22124 are all closed, and the third drain valve 22237 is opened.

[0157] Steps 3-4: The first backwash valve 22216 and the second backwash valve 22217 are closed, the third backwash valve 22218 is opened, and the backwash pump 22215 is turned on to draw clean seawater from the clean seawater tank 24 to the third outlet 221225 of the membrane filter 22122 and discharge it from the membrane drain outlet 221228.

[0158] The above three methods are just examples. In actual use, it is not limited to these three. Any physical cleaning method that can be achieved according to the connection structure of the physical filter device 22 in this embodiment is acceptable.

[0159] Functions and effects of Example 1

[0160] This invention provides a parallel backwashing physical filtration device, comprising a physical filtration section and a clean seawater tank. The physical filtration section includes a screen-type physical filtration module and a membrane-type physical filtration module. The screen-type module filters seawater to obtain coarse seawater, while the membrane-type module filters the coarse seawater to obtain clean seawater. The clean seawater tank stores the clean seawater. Clean seawater is thus prepared through the physical filtration section.

[0161] This parallel backwashing physical filtration device also includes a physical cleaning section, which comprises a backwashing unit and a drainage unit. When the physical filtration section stops filtering, the backwashing unit uses clean seawater from the clean seawater tank to backwash the membrane-type and mesh-type physical filtration modules. Backwashing prevents these filtration structures from being clogged by impurities in the seawater, ensuring that the membrane-type and mesh-type physical filtration modules can prepare clean seawater for extended periods. Furthermore, this backwashing is a physical cleaning process, avoiding the addition of flocculants and scale inhibitors during filtration. Therefore, the clean seawater produced by the physical filtration section is free of flocculants and scale inhibitors, and the concentrated brine obtained after subsequent reverse osmosis treatment is also chemical-free and can be used to produce edible salt.

[0162] Furthermore, since the parallel backwashing physical filtration device also includes a control unit, the control unit can automatically control the filtration of the physical filtration unit and the physical cleaning of the physical cleaning unit, which can facilitate high-frequency backwashing and ensure the smooth progress of the preparation of clean seawater.

[0163] Furthermore, the filter-type physical filtration module includes: a filter input unit for inputting seawater; a filter body for filtering the seawater; and a filter output unit for outputting the filtered seawater. The filter body has an inlet, a filter section, an outlet, and a cross-flow outlet. The inlet is connected to the filter input unit, and the outlet is connected to the filter output unit. Part of the seawater flowing in from the inlet passes through the mesh of the filter section from the outside to the inside and flows out from the outlet. The other part flows through the outside of the mesh and flows out from the cross-flow outlet. This cross-flow operation can loosen or even remove dirt and impurities on the filter screen. On the other hand, the removed dirt and impurities can be discharged from the cross-flow outlet, reducing the accumulation of dirt and extending the backwashing interval.

[0164] The membrane-type physical filtration module includes: a membrane input unit for inputting coarsely filtered seawater after passing through a mesh-type physical filtration module; a membrane filter body for further filtration of the coarsely filtered seawater to obtain clean seawater; and a membrane output unit connected to a clean seawater tank for outputting clean seawater to the clean seawater tank. The membrane filter body has a third inlet, a membrane section, a third outlet, and a third cross-flow outlet. The third inlet is connected to the outlet of the mesh filter body. Seawater flowing in from the third inlet passes through the membrane pores of the membrane section from the outside in and flows out from the third outlet, while another portion flows through the outside of the membrane pores and flows out from the third cross-flow outlet. Both the outlet of the mesh-type physical filtration module and the third outlet are connected to the clean seawater tank via a backwashing unit. This cross-flow operation loosens and even removes dirt and impurities from the membrane. Furthermore, the removed dirt and impurities can be discharged through the cross-flow outlet, reducing dirt accumulation and extending the backwashing interval.

[0165] Furthermore, the physical cleaning unit also includes an air scrubbing unit, which can perform air scrubbing on the screen-type physical filtration module and the membrane-type physical filtration module. The air scrubbing unit includes an air pump, an air pipe, and an air valve. The air pump is connected to the air pipe, and the air valve is installed on the air pipe and is used to control the air flow rate of the air pipe under the control of the control unit. The membrane filter body also has a third air inlet and a third air outlet, and the screen filter body also has a first air inlet, a first air outlet, a second air inlet, and a second air outlet. The first, second, and third air inlets are connected to the air pipe and are used to introduce gas to perform air scrubbing on the corresponding screen and membrane parts, vibrating the screen and membrane, causing dirt and impurities on them to loosen or even fall off.

[0166] Furthermore, since the drainage unit includes a cross-flow pipe and a flow regulating valve, the cross-flow pipe is connected to the third cross-flow port, and the flow regulating valve is installed on the cross-flow pipe to regulate the flow rate of the cross-flow pipe under the control of the control unit. The flow rate of the cross-flow pipe can be precisely regulated through this flow regulating valve, thereby regulating the membrane pressure of the filter membrane section and ensuring the normal operation of ultrafiltration.

[0167] Furthermore, since the flow regulating valve includes a valve body and a drive unit, the valve body is a ball valve or a gate valve, preferably a ball valve. The drive unit includes: a servo motor with a servo controller, the servo controller being connected to the control unit and receiving its commands to adjust the output torque of the servo motor; a worm gear, directly driven to rotate by the servo motor, having helical teeth; a worm wheel, having tooth grooves that mesh with the helical teeth, the worm wheel's axis direction being perpendicular to the worm's axis direction, the worm wheel's position being fixed, and the worm wheel being driven to rotate around its own axis by the worm; and a transmission component connected to the valve body, the transmission component being driven by the worm wheel to control the opening and closing degree of the valve body. Here, the power shaft of the servo motor and the length direction of the worm are denoted as the first direction, and the axial direction of the worm wheel and the transmission component is denoted as the second direction, the first direction being perpendicular to the second direction.

[0168] Therefore, the flow regulating valve in this embodiment has the following beneficial effects:

[0169] (1) Using a servo motor with a servo controller can make the flow regulation extremely accurate and resolution, with the characteristics of precise pressure adjustment and fast response speed, without relying on manual or simple electric drive (no manufacturer has used servo motors in regulating valves under the current technology).

[0170] (2) The flow regulating valve is horizontal and has a compact overall structure. It is suitable for seawater salt production systems integrated in the small space of a container and has a stable center of gravity, so it will not tip over due to vibration.

[0171] (3) The vertical axis design of the worm gear makes the flow regulating valve self-locking and will not be forced to change the regulating range due to excessive water pressure, making it suitable for both high pressure (6-15MPa) and low pressure (0-6MPa) working conditions.

[0172] Furthermore, the valve body is a stop valve, and the transmission components include a lead screw and an anti-rotation ring. The anti-rotation ring is fixed in position and is used to allow the lead screw to pass through and prevent it from rotating around its own axis. The lead screw is threadedly connected to a worm gear, and the worm gear rotates around its axis, thereby driving the lead screw to move along its length direction. The valve body includes: a stop valve body having an inlet pipe and an outlet pipe, the inlet pipe and the outlet pipe having an inlet flow channel and an outlet flow channel respectively, the inlet flow channel and the outlet flow channel intersecting; and a stop valve core, the stop valve core being connected to the lead screw and driven by it to move along its length direction and at least partially passing through the inlet flow channel, so that the valve cone of the stop valve core has different degrees of blockage at the intersection of the inlet flow channel and the outlet flow channel, thereby changing the flow rate of the outlet flow channel. The maximum radial outer diameter of the valve cone is at least 0.01mm to 0.2mm smaller than the inner diameter of the inlet flow channel. This design gives the flow control valve extremely high adjustment accuracy. Flow can be adjusted by controlling the axial displacement of the shut-off valve core. At the same time, the taper of the valve cone can be adjusted according to actual needs. The smaller the taper of the valve cone, the greater the accuracy of flow adjustment, thus meeting the high precision requirements of flow regulation. Furthermore, the anti-rotation ring ensures that the lead screw only makes axial displacement and does not rotate around its own axis, thereby reducing energy loss in the worm gear drive process (preventing the lead screw from being driven by the worm gear to rotate around its axis).

[0173] Furthermore, the shut-off valve body includes: a transition unit for the valve core with a valve cone end to pass through; a connecting unit including a first connecting section, a radial outlet section, and a second connecting section, wherein the first connecting section communicates with the transition unit, the radial outlet section communicates with the first connecting section and its outer diameter is smaller than that of the first connecting section, the peripheral wall of the radial outlet section has several outlet holes, the second connecting section communicates with the radial outlet section and its outer diameter is larger than that of the radial outlet section; an inlet unit including an inlet pipe communicating with the second connecting section; and an outlet unit including a rotating component and an outlet pipe, wherein the rotating component is rotatably fixed to the radial outlet section and clamped by the transition unit and the second connecting section, and the rotating component and the outlet pipe are connected. This configuration allows the outlet pipe of the outlet unit to rotate 360° around the axial direction of the connecting unit, meeting the needs of applying a regulating valve in a small space (the container housing the seawater-to-salt system has a compact structure, requiring minimal space wastage).

[0174] Furthermore, by configuring the lead screw and worm gear as ball screws, the water flow in the inlet channel can exert an axial force on the shut-off valve core toward the anti-rotation ring before the flow valve adjusts the flow (by controlling the servo motor to drive the worm gear to rotate). This causes the lead screw to press axially toward the anti-rotation ring, driving a slight displacement of the balls, thereby creating axial preload on the lead screw and worm gear and eliminating backlash during the relative displacement process of the lead screw and worm gear.

[0175] Furthermore, the valve body is a ball valve, and the transmission component is rod-shaped. One end of the transmission component is fixed to a worm gear and rotates coaxially with it, while the other end is connected to the ball valve's ball with a flow channel, thereby driving the ball to rotate and adjust the opening and closing degree of the flow channel. This design makes the overall structure of the flow regulating valve simple and easy to maintain.

[0176] Furthermore, the drive unit also includes: a housing, serving as the outer shell of the drive unit; a bearing housing, located at the upper opening of the housing, with the worm gear positioned within the internal space formed by the housing and the bearing housing. The upper and lower ends of the worm gear axially are indirectly abutted against the lower surface of the bearing housing and the bottom of the housing via thrust bearings, respectively, preventing axial displacement during rotation around its own axis. The transmission component extends through the bottom of the housing and connects to the valve body; and a sensor, used to detect the movement or rotation amplitude of the transmission component. The sensor is connected to a servo controller, which adjusts the torque of the servo motor based on the sensor data. This configuration has the following beneficial effects: (1) The housing protects against external contaminants affecting the worm gear transmission structure; (2) The thrust bearings fix the worm gear (preventing axial displacement) while reducing energy loss during rotation around its own axis; (3) The servo controller accurately controls the axial displacement or rotation of the transmission component based on the displacement or angle detection data from the sensor, providing real-time feedback to improve the efficiency and accuracy of flow regulation. This avoids the problem of inaccurate torque control due to a lack of real-time feedback mechanisms.

[0177] Furthermore, the shut-off valve core and the transmission component are detachably threaded together; the adapter unit and the first connecting section are detachably threaded together and sealed with a sealing ring; the rotating component and the outlet pipe are detachably threaded together; and the second connecting section and the inlet pipe are detachably threaded together and sealed with a sealing ring. This design ensures high sealing performance for each component while allowing for detachable connections, supporting quick replacement and effectively reducing downtime for maintenance.

[0178] Furthermore, the valve body is made of duplex steel, the worm gear is made of stainless steel, and the worm wheel is made of brass. This design allows the valve body to withstand seawater corrosion over a long period of time.

[0179] Furthermore, because the filter input unit includes a main inlet pipe and a first control valve, a main inlet flow meter, and a main inlet pressure sensor installed on the main inlet pipe, and the filter output unit includes: a filter outlet pipe connected to a clean seawater tank; a fourth control valve installed on the filter outlet pipe for opening or closing the filter outlet pipe; a filter outlet pressure sensor installed on the filter outlet pipe for detecting the pressure of the clean seawater flowing out of the filter outlet pipe; and a filter outlet flow meter installed on the filter outlet pipe for detecting the flow rate of the clean seawater flowing out of the filter outlet pipe, when the main inlet pipe is closed, the backwashing unit performs backwashing. At this time, the clean seawater flows sequentially through the third outlet, the third inlet, and the outlet of the filter body, and then flows out from the first cross-flow port. The control unit is also connected to the filter outlet pressure sensor and the filter outlet flow meter, and controls the flow regulating valve to adjust the flow rate of the cross-flow port according to the pressure and flow rate. Therefore, the membrane pressure of the filter section can be precisely and efficiently adjusted to ensure the normal operation of ultrafiltration.

[0180] Furthermore, the backwashing unit includes: a backwashing main pipe connected to a clean seawater tank; a second backwashing branch pipe connected to the backwashing main pipe and the outlet of the filter screen body, respectively; a third backwashing branch pipe connected to the backwashing main pipe and the third outlet, respectively; a backwashing pump installed on the backwashing main pipe to provide backwashing power; a second backwashing control valve installed on the second backwashing branch pipe to control whether the backwashing pipe is connected under the control of the control unit; and a third backwashing control valve installed on the third backwashing branch pipe to control whether the third backwashing pipe is connected under the control of the control unit. Therefore, different backwashing methods can be used as needed: backwashing two membrane filters, the second screen filter, and the first screen filter simultaneously; backwashing two membrane filters first, and then backwashing the second screen filter and the first screen filter in sequence; or backwashing any one or any two of the membrane filter, the second screen filter, and the first screen filter.

[0181] Furthermore, the filter output unit includes: a filter outlet pipe connected to the outlet of the filter body and a third inlet; a second control valve installed on the filter outlet pipe for opening or closing the filter outlet pipe under the control of the control unit; and a third drain pipe connected to the connecting pipe between the second control valve and the third inlet. When the second control valve is closed, the membrane physical filtration module can be backwashed, and the wastewater after backwashing can be discharged through the third drain pipe.

[0182] Furthermore, because the filter body includes at least two filters connected in series between the filter inlet unit and the filter outlet unit, and the mesh size of the at least two filters gradually decreases along the water production direction from the filter inlet unit to the filter outlet unit, multi-stage filtration can filter seawater to meet the feed water quality requirements of subsequent ultrafiltration. Compared to single-stage filtration, it is less prone to clogging. The backwashing unit backwashes at least two filters individually or performs step-by-step backwashing in the opposite direction to the water production direction from the filter inlet unit to the filter outlet unit. Backwashing can be performed on filters requiring backwashing based on their degree of clogging.

[0183] Furthermore, because the filter membrane body also has a filter membrane housing, the third inlet, the third outlet, and the third cross-flow port are all located on the filter membrane housing. The third inlet is located at the bottom of the filter membrane housing, the filter membrane drain outlet is located at the bottom of the filter membrane housing, the third outlet is located at the top of the filter membrane housing, and the third cross-flow port is located at the top of the filter membrane housing. The filter membrane is detachably installed inside the filter membrane housing. This arrangement facilitates ultrafiltration of the filter membrane body, ensures smooth cross-flow operation, and ensures smooth and rapid discharge of wastewater during air scrubbing and backwashing.

[0184] Furthermore, because the membrane filtration unit includes at least two membrane filters connected in parallel, the total water production of ultrafiltration can be increased. The backwashing unit backwashes at least two membrane filters separately, ensuring the normal operation of each membrane filter.

[0185] This embodiment also provides a seawater-to-edible-salt system, including the aforementioned parallel backwashing physical filtration device and reverse osmosis mechanism. The clean seawater, free of flocculants and scale inhibitors, produced by the parallel backwashing physical filtration device, undergoes reverse osmosis treatment to obtain concentrated brine. This concentrated brine can be crystallized into edible salt after a short period of sun exposure. Compared to existing methods of salt production from raw seawater through sun exposure, this significantly shortens the salt production time, improves the efficiency and profitability of edible salt production, reduces the adverse effects of weather on salt production, and greatly saves land resources, reducing labor and land costs. This seawater-to-edible-salt system is a new, efficient, energy-saving, and economically significant system.

[0186] Furthermore, since the seawater salt production system also includes a container, the parallel backwashing physical filtration device and the reverse osmosis mechanism are all installed inside the container, which occupies a small area, and the entire seawater salt production system can be moved and transported by means of vehicles, ships, tower cranes, etc.

[0187] Example 2

[0188] Figure 11This is a schematic diagram of the physical filtration device in Embodiment 2 of this utility model.

[0189] like Figure 11 As shown, Embodiment 2 provides a physical filtration device 22A, which differs from the physical filtration device 22 of Embodiment 1 in the following ways:

[0190] Difference 1: In Example 2, the first inlet 221124 and the first crossflow outlet 221128 are combined into one, and the third inlet 221224 and the filter membrane drain outlet 221228 are combined into one.

[0191] Difference 2: In Example 2, neither the first filter 22112 nor the second filter 22113 has an air inlet or an exhaust outlet. The air scrubbing unit 2222 is only connected to the membrane filter 22122.

[0192] The other structures are the same as in Example 1, and will not be described again here.

[0193] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A parallel type backwash type physical filter device, characterized by, include: The physical filtration section is used to filter seawater to obtain clean seawater; A clean seawater tank is used to store the clean seawater; The physical cleaning unit is used to physically clean the physical filtration unit using clean seawater from the clean seawater tank when the physical filtration unit stops filtering. The physical filtration section includes: A filter-type physical filtration module is used to filter the seawater to obtain coarsely filtered seawater; and A membrane-type physical filtration module, connected to the mesh-type physical filtration module, is used to perform membrane filtration on the coarse seawater to obtain clean seawater. The physical cleaning unit includes: A backwashing unit connects the screen-type physical filtration module and the membrane-type physical filtration module to the clean seawater tank, respectively, and uses the clean seawater to backwash the membrane-type physical filtration module and the screen-type physical filtration module; and The drainage unit is used to discharge the wastewater after backwashing.

2. The parallel type backwash type physical filter device according to claim 1, Its features are: in, The filter-type physical filtration module includes: The filter input unit is used to input seawater; A filter screen body for filtering the seawater; and The filter output unit is used to output the filtered seawater. The filter body includes an inlet, a filter screen, an outlet, and a crossflow outlet. The inlet is connected to the filter screen input unit, and the outlet is connected to the filter screen output unit. Seawater flowing in from the inlet passes through the mesh of the filter screen from the outside to the inside and flows out from the outlet, while the other part flows through the outside of the mesh and flows out from the crossflow outlet. The membrane-type physical filtration module includes: The filter membrane input unit is used to input coarsely filtered seawater after being filtered by the filter-type physical filtration module. A filter membrane filtration unit is used to filter the coarse seawater to obtain clean seawater; and The filter membrane output unit is connected to the clean seawater tank and is used to output the clean seawater to the clean seawater tank. The filter membrane filter body has a third inlet, a filter membrane section, a third outlet, and a third crossflow outlet. The third inlet is connected to the outlet of the filter screen filter body. A portion of the seawater flowing in from the third inlet passes through the membrane pores of the filter membrane from the outside to the inside and flows out from the third outlet, while the other portion flows through the outside of the membrane pores and flows out from the third crossflow outlet. The outlet and the third outlet of the filter-type physical filtration module are both connected to the clean seawater tank through the backwashing unit.

3. The parallel backwashing physical filtration device according to claim 2, characterized in that: The physical cleaning unit further includes an air scrubbing unit, which is used to perform air scrubbing on the membrane-type physical filtration module. The air scrubbing unit includes an air pump, an air pipe, and an air valve. The air pump is connected to the air pipe, and the air valve is located on the air pipe and used to control the airflow rate through the air pipe. The filter membrane filter body also has a third air inlet and a third exhaust outlet. The third air inlet is connected to the air pipe and is used to introduce gas to perform air scrubbing on the filter membrane. The third exhaust outlet is used to discharge the gas.

4. The parallel type backwash type physical filter device according to claim 3, Its features are: in, The drainage unit includes a cross-flow pipe and a flow regulating valve. The cross-flow pipe is connected to the third cross-flow port, and the flow regulating valve is installed on the cross-flow pipe. The flow regulating valve comprises a valve body and a drive unit, wherein the valve body is a ball valve or a gate valve. The drive unit includes: Servo motor with servo controller; The worm gear, driven to rotate by the servo motor, has helical teeth on it; A worm gear has tooth grooves that mesh with the helical teeth. The axis of the worm gear is perpendicular to the axis of the worm. The position of the worm gear is fixed, and the worm gear is driven by the worm to rotate around its own axis. A transmission component, connected to the valve body, is driven by the worm gear to control the opening and closing degree of the valve body. The direction of the servo motor's power shaft and the length of the worm gear is designated as the first direction, and the direction of the worm gear's axis and the transmission component's axis is designated as the second direction. The first direction is perpendicular to the second direction. When the valve body is a shut-off valve, the transmission component includes a lead screw and an anti-rotation ring. The anti-rotation ring is fixed in position and is used to allow the lead screw to pass through while preventing it from rotating around its own axis. The lead screw is threadedly connected to the worm gear, and the worm gear rotates around its axis, thereby driving the lead screw to move along its length. The valve body includes: The shut-off valve body has an inlet pipe and an outlet pipe, the inlet pipe and the outlet pipe respectively have an inlet flow channel and an outlet flow channel, and the inlet flow channel and the outlet flow channel intersect; and A shut-off valve core is connected to the lead screw and is driven by it to move along its length direction, and is at least partially inserted into the inlet channel. This causes the valve cone of the shut-off valve core to have varying degrees of blockage at the junction of the inlet and outlet channels, thereby changing the flow rate of the outlet channel. The maximum radial outer diameter of the valve cone is at least 0.01 mm to 0.2 mm smaller than the inner diameter of the inlet channel. When the valve body is a ball valve, the transmission component is rod-shaped. One end of the transmission component is fixed to the worm gear and rotates coaxially with it. The other end is connected to the ball with a flow channel of the ball valve, thereby driving the ball to rotate to adjust the opening and closing degree of the flow channel.

5. The parallel type backwash type physical filter device according to claim 2, Its features are: in, The filter input unit includes a main inlet pipe and a first control valve, a main inlet flow meter, and a main inlet pressure sensor installed on the main inlet pipe. The filter membrane output unit includes: The filter membrane outlet pipe is connected to the clean seawater tank. The fourth control valve is installed on the filter membrane outlet pipe and is used to open or close the filter membrane outlet pipe. A filter membrane outlet pressure sensor is installed on the filter membrane outlet pipe to detect the pressure of clean seawater flowing out of the filter membrane outlet pipe; A filter membrane outlet flow meter, installed on the filter membrane outlet pipe, is used to detect the flow rate of clean seawater flowing out of the filter membrane outlet pipe. When the main water inlet pipe is closed, the backwashing unit performs the backwashing. At this time, clean seawater flows sequentially through the third outlet, the third inlet, and the outlet of the filter screen body, and then flows out from the first cross-flow port.

6. The parallel type backwash type physical filter device according to claim 2, Its features are: The backwashing unit includes: The backwash main pipe is connected to the clean seawater tank. The second backwash branch pipe is connected to the backwash main pipe and the outlet of the filter screen body respectively; The third backwash branch pipe is connected to the backwash main pipe and the third outlet respectively; The backwash pump is installed on the backwash main pipe and provides power for backwashing; A second backwash control valve, installed on the second backwash branch pipe, is used to control whether the backwash pipe is connected; and The third backwash control valve is installed on the third backwash branch pipe and is used to control whether the third backwash pipe is connected.

7. The parallel type backwash type physical filter device according to claim 2, Its features are: The filter output unit includes: The filter screen outlet pipe is connected to the outlet of the filter screen body and the third inlet. A second control valve is installed on the filter screen outlet pipe, used to open or close the filter screen outlet pipe. The drainage unit also includes a third drain pipe, which is connected to the connecting pipe between the second control valve and the third inlet.

8. The parallel backwashing physical filtration device according to claim 2, characterized in that: wherein The filter body includes at least two filter screens connected in series between the filter screen input unit and the filter screen output unit. The mesh size of the at least two filter screens gradually decreases along the water production direction from the filter screen input unit to the filter screen output unit. The backwashing unit backwashes the at least two filter screens respectively, or performs step-by-step backwashing in a direction opposite to the water production direction from the filter screen input unit to the filter screen output unit.

9. The parallel backwashing physical filtration device according to claim 2, characterized in that: wherein The filter membrane filtration body also has a filter membrane housing. The third inlet, the third outlet, and the third cross-flow outlet are all located on the filter membrane housing. The third inlet is located at the bottom of the filter membrane housing, the filter membrane drain outlet is located at the bottom of the filter membrane housing, the third outlet is located at the top of the filter membrane housing, and the third cross-flow outlet is located at the top of the filter membrane housing. The filter membrane section is detachably disposed within the filter membrane housing. The filter body includes at least two membrane filters connected in parallel. The backwashing unit backwashes each of the at least two membrane filters.

10. A system for producing edible salt from seawater, characterized in that, include: A parallel backwashing physical filtration device is used to filter seawater to obtain clean seawater, as described in any one of claims 1-9. as well as A reverse osmosis unit is used to treat the clean seawater by reverse osmosis to obtain concentrated brine, which is used to produce edible salt.

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