A multi-stage membrane separation device for deep purification of strontium salt solution

Abstract

This invention discloses a multi-stage membrane separation device for deep purification of strontium salt solutions, comprising a base, the base being divided into multiple regions by partitions, each region having a vertical support, a cylinder fixed within the support, and a piston slidably disposed within each cylinder; a filter screen is disposed at a certain distance from the inner wall of the cylinder in the lower part of the cylinder; an inlet pipe penetrating into the filter screen and an outlet pipe penetrating between the inner wall of the cylinder and the filter screen are respectively disposed on both sides of the cylinder, and the outlet pipe between adjacent cylinders is connected to the inlet pipe of the next cylinder; compared with the prior art, this invention solves the problems of low filtration efficiency, easy clogging of the filter screen, incomplete slag discharge, and poor coordination of multi-stage linkage in existing membrane separation devices when processing high-purity strontium salt solutions through innovative multi-stage series structure design and precise mechanical linkage control.

Description

Technical Field

[0001] This invention relates to the field of separation and purification technology, specifically a multi-stage membrane separation device for the deep purification of strontium salt solutions. Background Technology

[0002] Membrane separation technology, as a highly efficient, energy-saving, and modular separation method, has been widely used in the field of chemical separation in recent years. In the purification of salt solutions, researchers have attempted to use multi-stage membrane separation processes, achieving stepwise purification of target ions through multi-stage cascade filtration. Some existing technologies also attempt to introduce methods such as ultrasonic vibration to clean the membrane surface, thereby reducing concentration polarization and membrane fouling problems. However, existing multi-stage membrane separation devices still have significant shortcomings in practical applications for the preparation of high-purity strontium salts:

[0003] In existing equipment, most membrane modules are independently driven or simply connected in series, lacking mechanical linkage design. This makes it difficult to precisely coordinate pressure matching and flow control between stages, affecting the overall stability and filtration efficiency of the system. When processing high-concentration salt solutions, filter cake and concentration polarization layers easily form on the membrane surface, causing a rapid decline in filtration flux. Although some units are designed with external vibration or backwashing mechanisms, these often require shutdown and are difficult to completely remove the dense filter cake adhering to the inner wall of the filter screen, affecting continuous production capacity and filter lifespan. Existing units mostly rely on gravity or simple valve control for concentrate discharge, resulting in incomplete sludge removal. Residual concentrate easily dries and scales inside the unit, affecting the purity of subsequent batches and increasing the difficulty and workload of equipment cleaning and maintenance.

[0004] Therefore, it is necessary to provide a multi-stage membrane separation device for the deep purification of strontium salt solutions to solve the problems mentioned in the background art. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage membrane separation device for deep purification of strontium salt solutions, comprising a base, characterized in that the base is divided into multiple regions by a partition, each region is provided with a vertical support, a cylinder is fixed in the support, and a piston is slidably disposed in each cylinder;

[0006] The lower part of the cylinder is provided with a filter screen at a certain distance from the inner wall of the cylinder. The cylinder is provided with an inlet pipe that penetrates into the filter screen and an outlet pipe that penetrates between the inner wall of the cylinder and the filter screen layer, respectively. The outlet pipe between adjacent cylinders is connected to the inlet pipe of the next cylinder.

[0007] Furthermore, each of the cylinders is provided with a bottom plate that can be raised and lowered and opened and closed.

[0008] Furthermore, the lower part of the bracket is rotatably equipped with multiple eccentric wheels, the upper part of the eccentric wheels is attached to the bottom of the base plate, the lower part of the base plate is equipped with a liftable support cylinder, and the side of the eccentric wheels is attached to the side wall of the support cylinder.

[0009] Furthermore, a support spring is provided below the support cylinder.

[0010] Furthermore, a pressure rod is slidably passed through the center of the base plate, and the pressure rod is connected to the support cylinder in a way that restricts sliding.

[0011] Furthermore, each of the brackets has a lower cylinder inside its base at a corresponding position. The pressure rod slides through the lower cylinder, and a rotating disk is fixed at the bottom of the pressure rod. A friction disk driven by a motor is provided at a certain distance below the rotating disk inside the lower cylinder.

[0012] Furthermore, a connecting plate is provided at a certain distance above the piston inside each cylinder, and the center of the connecting plate is connected to the piston via a telescopic shaft.

[0013] Furthermore, multiple grooves are circumferentially distributed on the upper surface of the piston, and an arc-shaped scraper is slidably disposed on each groove, the outer edge of the scraper being able to fit against the inner wall of the filter screen.

[0014] A sliding plate is provided between the piston and the connecting plate and sleeved on the outer wall of the telescopic shaft. The sliding plate is hinged to each scraper through a push rod.

[0015] Furthermore, a pressure spring is provided between the connecting plate and the slide.

[0016] Furthermore, a crankshaft is rotatably mounted on the base above each cylinder, and the crankshaft is hinged to the connecting plate inside each cylinder via a connecting rod, with the adjacent connecting rod crankshafts rotating at an angle of 180°.

[0017] One end of the crankshaft is connected to the drive motor via a synchronous belt device.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] By connecting multiple filter cylinders in series and using the permeate from the previous stage as the feed liquid for the next stage of repeated filtration, multi-stage gradient purification of strontium salt solutions is achieved. Each stage of filtration further removes trace impurities, resulting in a product with a purity far exceeding that of a single-stage filtration device, meeting the stringent high-purity requirements of nuclear, pharmaceutical, and electronic-grade strontium salts.

[0020] By utilizing the cooperation between the eccentric wheel and the support cylinder, a pressure self-locking mechanism is formed under filtration and pressurization. When the piston applies pressure, the horizontal component force generated by the eccentric wheel cancels out each other, keeping the bottom plate tightly closed under high pressure. This completely eliminates leakage problems during the filtration process and ensures that all solutions must pass through the filter screen for separation, thus guaranteeing the yield and preventing the short-circuit discharge of unfiltered raw liquid.

[0021] The scraper operates synchronously during the filtration process. When the filter screen deforms due to pressure, the pressure spring continuously applies pressure, ensuring the scraper remains tightly against the inner wall of the filter screen, effectively scraping away the adhering concentrate and filter cake in real time. This design effectively prevents membrane pore clogging, significantly extends the filter screen's lifespan, maintains stable high-flux filtration, and avoids frequent downtime for cleaning.

[0022] The device features automatic triggering of the slag discharge action and centrifugal-assisted cleaning. When the filtration cycle ends, the piston presses down on the pressure rod, automatically releasing the self-locking state of the eccentric wheel and opening the bottom plate for slag discharge. Simultaneously, the friction disc and rotating disc work together to drive the bottom plate to rotate at high speed, using centrifugal force to completely eject any residual concentrate, preventing its adhesion and accumulation on the bottom plate. This effectively prevents cross-contamination between different batches, ensuring production continuity and cleanliness.

[0023] The crankshaft and connecting rod drive design, especially the 180° crankshaft rotation angle between adjacent connecting rods, ensures that the pistons of adjacent cylinders move in opposite directions. This design not only synchronizes the liquid discharge of the previous cylinder with the liquid inlet of the next cylinder, ensuring smooth fluid transport within the multi-stage system, but also balances the overall operating load, reduces vibration, and lowers the energy consumption of the drive motor. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a multi-stage membrane separation device for the deep purification of strontium salt solutions.

[0025] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0026] Figure 3 This is a top view of the structure of the present invention;

[0027] Figure 4 This is a schematic diagram of the internal structure of the cylinder of the present invention;

[0028] Figure 5 This is a schematic cross-sectional view of the cylinder body of the present invention with the piston at the top.

[0029] Figure 6 This is a schematic cross-sectional view of the cylinder body of the present invention with the piston positioned at the bottom.

[0030] Figure 7 This is a schematic diagram of the piston and connecting plate of the present invention;

[0031] In the diagram: 1. Base; 2. Partition plate; 3. Support; 4. Cylinder; 41. Filter screen; 42. Lower cylinder; 43. Inlet pipe; 44. Outlet pipe; 45. Base plate; 46. Pressure rod; 47. Eccentric wheel; 48. Support spring; 49. Support cylinder; 410. Rotating disk; 411. Friction disk; 5. Piston; 51. Slide groove; 52. Scraper; 53. Push rod; 54. Slide plate; 6. Connecting plate; 61. Telescopic shaft; 62. Pressure spring; 7. Connecting rod; 8. Crankshaft; 9. Synchronous belt; 10. Drive motor. Detailed Implementation

[0032] Please see Figures 1-7 In this embodiment of the invention, a multi-stage membrane separation device for deep purification of strontium salt solution includes a base 1, which is divided into multiple regions by a partition 2. Each region is provided with a vertical support 3, a cylinder 4 is fixed in the support 3, and a piston 5 is slidably arranged in each cylinder 4.

[0033] The lower part of the cylinder 4 is provided with a filter screen 41 at a certain distance from the inner wall of the cylinder 4. The cylinder 4 is provided with an inlet pipe 43 that penetrates into the filter screen 41 and an outlet pipe 44 that penetrates between the inner wall of the cylinder 4 and the filter screen 41, respectively. The outlet pipe 44 between adjacent cylinders 4 is connected to the inlet pipe 43 of the next cylinder 4.

[0034] The strontium salt solution to be purified first enters the inlet pipe 43 of the first cylinder 4 and is guided to the inside of the filter screen 41. Under the pressure provided by the piston 5, the solvent and small molecule components in the solution pass through the filter screen 41 and enter the interlayer between the filter screen 41 and the inner wall of the cylinder 4. The liquid entering the interlayer becomes the first-stage permeate and flows out through the outlet pipe 44 of the cylinder 4. The concentrated liquid trapped by the filter screen 41 remains in the lower part of the cylinder inside the filter screen 41.

[0035] The first-stage permeate flowing out of the outlet pipe 44 of the first cylinder 4 is connected to the inlet pipe 43 of the second cylinder. The first-stage permeate obtained after the first-stage filtration becomes the raw material liquid that needs to be filtered again in the second stage. This process is repeated in multiple cylinders 4. Each time the solution passes through the filter screen 41, it is a purification of the solution.

[0036] In this embodiment, each of the inlet pipe 43 and outlet pipe 44 is equipped with a one-way valve.

[0037] In this embodiment, each of the cylinders 4 is provided with a bottom plate 45 that can be raised and lowered and opened and closed.

[0038] In this embodiment, the lower part of the bracket 3 is rotatably provided with a plurality of eccentric wheels 47, the upper part of the eccentric wheels 47 is attached to the bottom of the base plate 45, the lower part of the base plate 45 is provided with a liftable support cylinder 49, and the side of the eccentric wheels 47 is attached to the side wall of the support cylinder 49.

[0039] In this embodiment, a support spring 48 is provided below the support cylinder 49.

[0040] In other words, under the action of the support spring 48, the support cylinder 49 is at the bottom of the base plate 45. At this time, the eccentric wheel 47 is also in contact with the side wall of the support cylinder 49. The downward movement of the piston 5 exerts downward pressure on the base plate 45, which is applied to each eccentric wheel 47, generating torque that acts horizontally into the support cylinder 49. Since the horizontal forces exerted by each eccentric wheel 47 on the support cylinder 49 cancel each other out, a self-locking effect is generated, so that the downward pressure of the base plate 45 will not push the base plate 45 down, thereby keeping the bottom of the cylinder 4 sealed and ensuring that the solution is discharged from the outlet pipe 44.

[0041] In this embodiment, a pressure rod 46 is slidably passed through the center of the base plate 45, and the pressure rod 46 is slidably connected to the support cylinder 49.

[0042] In other words, when the piston 5 moves downward to fit against the pressure rod 46 and continues downward, it will push the pressure rod 46 down, and the support cylinder 49 will also move down against the elastic force of the support spring 48. At this time, the side of the eccentric wheel 47 loses support and loses its self-locking function, and the bottom plate 45 moves down. At this time, the concentrate is discharged from the bottom of the cylinder 4 into the base 1.

[0043] In this embodiment, a lower cylinder 42 is provided inside the base 1 at the corresponding position of each bracket 3. The pressure rod 46 slides through the lower cylinder 42, and a rotating disk 410 is fixed at the bottom of the pressure rod 46. A friction disk 411 driven by a motor is provided at a certain distance below the rotating disk 410 inside the lower cylinder 42.

[0044] In other words, when the pressure rod 46 and the base plate 45 move down, the rotating disk 410 also moves down and comes into contact with the friction disk 411. At this time, the friction disk 411 driven by the motor drives the rotating disk 410 to rotate, causing the pressure rod 46 and the base plate 45 to rotate as well, so that the concentrated liquid remaining on the base plate 45 is thrown out into the base 1 under centrifugal force.

[0045] In this embodiment, a connecting plate 6 is provided at a certain distance above the piston 5 inside each cylinder 4, and the center of the connecting plate 6 is connected to the piston 5 through a telescopic shaft 61.

[0046] In this embodiment, multiple grooves 51 are circumferentially distributed on the upper surface of the piston 5, and an arc-shaped scraper 52 is slidably disposed on each groove 51. The outer side of the scraper 52 can fit against the inner wall of the filter screen 41.

[0047] A sliding plate 54 is provided between the piston 5 and the connecting plate 6 and is sleeved on the outer wall of the telescopic shaft 61. The sliding plate 54 is hinged to each scraper 52 by a push rod 53.

[0048] In this embodiment, a pressure spring 62 is provided between the connecting plate 6 and the slide 54.

[0049] In other words, when the connecting plate 6 moves downward, the compression spring 62 first pushes the slide plate 54 down, causing each push rod 53 to push each scraper 52 outward to ensure that the scraper 52 is in contact with the filter screen 41. Then, the connecting plate 6 continues to move downward, which will push the piston 5 to move down as a whole to apply pressure to the solution in the cylinder 4.

[0050] When the filter screen 41 is slightly deformed under pressure, the scraper 52 will also slide outward to keep in contact with the filter screen 41, ensuring that the generated flow on the inner wall of the filter screen 41 can be scraped off.

[0051] In this embodiment, a crankshaft 8 is rotatably mounted on the base 1 above each cylinder 4. The crankshaft 8 is hinged to the connecting plate 6 inside each cylinder 4 via a connecting rod 7, and the crankshaft rotation angle of adjacent connecting rods 7 is 180°.

[0052] One end of the crankshaft 8 is connected to the drive motor 10 via a synchronous belt device 9.

[0053] In other words, the drive motor 10 can drive each link 7 to push the connecting plate 6 to reciprocate, and the reciprocating strokes of adjacent connecting plates 6 are opposite, so that the permeate in the previous cylinder 4 can be sucked into the next cylinder 4.

[0054] In practice, the strontium salt solution to be purified enters through the inlet pipe 43 of the first cylinder 4. Due to the presence of the one-way valve, the liquid flows in one direction and is guided to the inside of the filter screen 41. The piston 5 continues to move downward under the drive of the crankshaft 8, applying pressure to the solution inside the cylinder 4. The solvent and small strontium salt molecules in the solution pass through the filter screen 41 and enter the interlayer between the filter screen 41 and the inner wall of the cylinder, forming the first-stage permeate. The retained concentrate is temporarily stored in the lower part of the cylinder inside the filter screen. The first-stage permeate flows out through the outlet pipe 44 of the first cylinder and enters the inlet pipe 43 of the second cylinder, becoming the second-stage raw material liquid. The above process is repeated sequentially in multiple cylinders 4 connected in series. Each stage of filtration is a purification of the solution. Since the crankshaft rotation angle of the adjacent connecting rods is 180° and the piston movement direction of the adjacent cylinders is opposite, this design makes the action of the previous cylinder discharging the permeate synchronized with the action of the next cylinder drawing in the raw material liquid, realizing the smooth transmission of fluid.

[0055] While piston 5 presses down to filter, connecting plate 6 continues to move downward, first compressing pressure spring 62. The spring force pushes slide plate 54 down, and slide plate pushes scraper 52 outward along slide groove 51 through push rod 53, so that the outer edge of scraper 52 fits tightly against the inner wall of filter screen 41. When filter screen 41 is slightly deformed under high pressure, pressure spring 62 continues to apply thrust, so that scraper 52 always follows the contour of inner wall of filter screen and maintains a close fit. In the reciprocating motion of piston 5, scraper 52 scrapes off the concentrate and filter cake attached to inner wall of filter screen to prevent filter screen blockage and maintain filtration efficiency.

[0056] Furthermore, when piston 5 descends to its limit position, its bottom contacts the top of pressure rod 46. The piston continues to press down, pushing pressure rod 46 downward against the elastic force of support spring 48. The downward movement of pressure rod 46 causes support cylinder 49 to move downward simultaneously, resulting in the side wall of eccentric wheel 47 losing support and releasing the self-locking state. Under the action of gravity and internal pressure, bottom plate 45 opens downward, and concentrated liquid is discharged from the bottom of cylinder into base 1. At the same time as pressure rod 46 moves downward, its bottom rotating disk 410 moves downward and contacts the motor-driven... The friction disc 411 rotates, causing the rotating disc 410 and the pressure rod 46 to rotate, which in turn causes the base plate 45 to rotate. Under the action of centrifugal force, the concentrate remaining on the base plate is completely thrown out, ensuring no residue and avoiding cross-contamination between different batches. The crankshaft 8 reverses or continues to rotate, causing the piston 5 to move upward. The pressure rod 46 and the base plate 45 are reset under the action of the support spring 48. The eccentric wheel 47 is supported again and self-locked. The base plate 45 is closed, and the device enters the preparation state for the next filtration cycle.

[0057] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-stage membrane separation device for deep purification of strontium salt solutions, comprising a base (1), characterized in that, The base (1) is divided into multiple areas by a partition (2), and each area is provided with a vertical support (3). A cylinder (4) is fixed in the support (3), and a piston (5) is slidably provided in each cylinder (4). The lower part of the cylinder (4) is provided with a filter screen (41) at a certain distance from the inner wall of the cylinder (4). The cylinder (4) is provided with an inlet pipe (43) that penetrates into the filter screen (41) and an outlet pipe (44) that penetrates between the inner wall of the cylinder (4) and the filter screen (41). The outlet pipe (44) between adjacent cylinders (4) is connected to the inlet pipe (43) of the next cylinder (4).

2. The multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 1, characterized in that, Each of the cylinders (4) is provided with a bottom plate (45) that can be lifted and opened.

3. The multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 2, characterized in that, The bracket (3) is rotatably provided with multiple eccentric wheels (47) at its lower part. The upper part of the eccentric wheels (47) is attached to the bottom of the base plate (45). The base plate (45) is provided with a liftable support cylinder (49) at its lower part. The side of the eccentric wheels (47) is attached to the side wall of the support cylinder (49).

4. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 3, characterized in that, A support spring (48) is provided below the support cylinder (49).

5. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 4, characterized in that, A pressure bar (46) is slidably passed through the center of the base plate (45), and the pressure bar (46) is slidably connected to the support cylinder (49).

6. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 5, characterized in that, Each of the brackets (3) has a lower cylinder (42) inside the base (1) at the corresponding position. The pressure rod (46) slides through the lower cylinder (42), and a rotating disk (410) is fixed at the bottom of the pressure rod (46). A friction disk (411) driven by a motor is provided at a certain distance below the rotating disk (410) inside the lower cylinder (42).

7. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 1, characterized in that, A connecting plate (6) is provided at a certain distance above the piston (5) inside each cylinder (4), and the center of the connecting plate (6) is connected to the piston (5) through a telescopic shaft (61).

8. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 7, characterized in that, The piston (5) has multiple grooves (51) distributed circumferentially on its upper surface. Each groove (51) has an arc-shaped scraper (52) that slides on it. The outer side of the scraper (52) can fit against the inner wall of the filter screen (41). A slide (54) is provided between the piston (5) and the connecting plate (6) and sleeved on the outer wall of the telescopic shaft (61). The slide (54) and each scraper (52) are hinged by a push rod (53).

9. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 8, characterized in that, A pressure spring (62) is provided between the connecting plate (6) and the slide (54).

10. A multi-stage membrane separation device for deep purification of strontium salt solutions according to claim 7, characterized in that, A crankshaft (8) is rotatably mounted on the base (1) above each cylinder (4). The crankshaft (8) is hinged to the connecting plate (6) inside each cylinder (4) via a connecting rod (7), and the crankshaft rotation angle of adjacent connecting rods (7) is 180°. One end of the crankshaft (8) is connected to the drive motor (10) via a synchronous belt device (9).

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