Purification mechanism and process of oligomer ether-containing heteropoly acid

Abstract

This invention discloses a purification mechanism and process for removing heteropolyacids from oligopolyethers. The invention relates to the field of chemical technology, and particularly to a purification mechanism and process for removing heteropolyacids from oligopolyethers. It includes an inorganic membrane filtration device for purifying oligopolyethers containing heteropolyacids. The inorganic membrane filtration device includes a tank and a cleaning mechanism for cleaning the inorganic membrane. The cleaning mechanism includes: a guiding component, comprising a support plate slidably mounted inside the tank; and an execution component, comprising a bracket rotatably mounted through the lower end of the support plate, with a fixed first water spray pipe passing through the lower end of the bracket and a rotatably mounted second water spray pipe passing through the lower end of the bracket. A rotatably mounted first connecting pipe is sleeved on the first water spray pipe. The cleaning mechanism performs comprehensive rinsing of the inner wall of the tank, the inner and outer walls of the inner inorganic membrane, the pores of the inner inorganic membrane, and the inner and outer walls of the outer inorganic membrane.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, specifically to a purification mechanism and process for removing impurities and polyacids from oligopolyethers. Background Technology

[0002] Inorganic membrane filtration purification is an effective method for removing heteropolyacids from oligoethers. This method uses an inorganic membrane filtration device to filter the oligoether stock solution containing heteropolyacids, thereby achieving purification. The process is simple to operate, pollution-free, and the separated heteropolyacids can be recovered and reused, significantly reducing production costs. Furthermore, the heteropolyacid content in the purified oligoether can be controlled below 50 ppm, demonstrating excellent purification performance.

[0003] According to CN101348565B, a purification process for oligoethers containing heteropolyacids is disclosed. This technology discloses a purification process for oligoethers containing heteropolyacids, wherein the oligoether is polytetramethylene ether glycol with a number average molecular weight between 300 and 6000. The oligoether stock solution containing heteropolyacids is filtered through an inorganic membrane filtration device to achieve purification. The temperature of the oligoether stock solution is 30–90°C. The inorganic membrane used in the inorganic membrane filtration device is one of ceramic membrane, metal membrane, or metal oxide membrane, and the average pore size of the inorganic membrane is 0.01–0.2 μm. This process has the following advantages: "The heteropolyacids in the oligoether are removed by an inorganic membrane filtration device, resulting in a heteropolyacid content of less than 50 ppm after purification, with good purification effect; moreover, the process is simple to operate, pollution-free, and the separated heteropolyacids can be recycled and reused, significantly reducing production costs."

[0004] The above-mentioned method uses an inorganic membrane filtration device to filter the oligoether stock solution containing heteropolyacids, thereby achieving purification. However, after filtration and purification, impurities may be adsorbed or deposited on the surface of the inorganic membrane, forming a contamination layer. Conventional physical cleaning methods for inorganic membranes typically include backwashing and low-pressure, high-flow-rate cleaning. However, in actual operation, if the low-pressure, high-flow-rate cleaning method is used, due to the relatively internal location of the inorganic membrane, hard-to-reach dead zones can easily form during the cleaning process. Impurities in these areas are difficult to remove effectively, thus weakening the overall cleaning effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a purification mechanism and process for removing impurities and polyacids from oligopolyethers. It features a cleaning mechanism that thoroughly rinses the inner wall of the inorganic membrane filtration device, the inner and outer walls of the inner inorganic membrane, the pores of the inner inorganic membrane, and the inner and outer walls of the outer inorganic membrane.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a purification mechanism for removing heteropolyacids from oligoethers includes an inorganic membrane filtration device for purifying oligoethers containing heteropolyacids. The inorganic membrane filtration device includes a tank and a cleaning mechanism for cleaning the inorganic membrane. The cleaning mechanism includes:

[0007] Guide components, including a support plate that is slidably mounted inside the tank;

[0008] The execution component includes a bracket rotatably mounted through the lower end of a support plate, a first water spray pipe fixed through the lower end of the bracket, a second water spray pipe rotatably mounted through the lower end of the bracket, a first connecting pipe rotatably mounted on the first water spray pipe, and the other end of the first connecting pipe rotatably mounted to the second water spray pipe, a third water spray pipe fixed at the lower end of the bracket, a second connecting pipe rotatably mounted on the second water spray pipe, and the other end of the second connecting pipe communicating and fixedly connected to the third water spray pipe, a water spray cover rotatably mounted on the first water spray pipe, and a folded hose connected to the upper end of the first water spray pipe;

[0009] A drive component is mounted on the guide component and is used to control the rotation of the guide component.

[0010] Preferably, the guide assembly further includes grooves formed at both ends of the support plate, shaft brackets fixed on both sides of the upper end of the grooves, rollers rotatably mounted on the inner wall of the shaft brackets, guide rails fixed on the inner walls of both ends of the tank, with the rollers located inside the guide rails, and cylinders mounted on both sides of the top of the tank for driving the support to lift.

[0011] Preferably, the execution component further includes a first water hole at the upper end of the first water pipe, a second water hole and a third water hole at the upper end of the second water pipe, and a fourth water hole at the upper end of the first water pipe.

[0012] Preferably, the execution component further includes a first bidirectional nozzle installed at the lower end of the second water spray pipe and a second bidirectional nozzle installed at the lower end of the third water spray pipe.

[0013] Preferably, the drive assembly includes a driven pulley fixed to the outer wall of the upper end of the first water spray pipe, a motor mounted on one side of the top of the support plate, a driving pulley mounted at the output end of the motor, and a belt installed between the driving pulley and the driven pulley, a sun gear fixed to the center of the bottom of the support plate, and a planetary gear fixed to the outer wall of the upper end of the second water spray pipe and meshing with the sun gear for transmission.

[0014] Preferably, the cleaning mechanism further includes a position sensor installed at the bottom of the support plate and a sensor installed at the bottom of the guide rail.

[0015] Preferably, the inorganic membrane filtration device further includes an inner inorganic membrane and an outer inorganic membrane installed at the lower end of the tank, a sealing cap installed at the upper end of the inner inorganic membrane, a water inlet fixed at the upper end of the tank and connected to the upper end of the folded hose, a door hinged at the front end of the tank, a liquid level sensor installed on the outer wall of the tank, and a pipeline assembly provided at the lower end of the tank for feeding, discharging and draining.

[0016] Preferably, the pipeline assembly includes a liquid hopper fixed to the bottom of the tank, the lower end of the liquid hopper being connected to a fixed liquid inlet pipe and a first valve installed on the liquid inlet pipe, one end of the liquid inlet pipe being connected to a fixed liquid outlet pipe and a second valve installed on the liquid outlet pipe, and an inner drain pipe and an outer drain pipe being fixedly connected between the lower end of the tank and the liquid outlet pipe, and a third valve and a fourth valve being installed on the inner drain pipe and the outer drain pipe, respectively.

[0017] This invention also discloses a purification process for removing impurities and polyacids from oligoethers, comprising the following steps:

[0018] S1: First, the oligopoly ether stock solution containing heteropoly acids and at a temperature of 20-90°C in the storage tank is transported to the inorganic membrane filtration device. The heteropoly acids and macromolecules are trapped on the membrane surface and in the membrane pores, while the oligopoly ether passes smoothly through the inorganic membrane.

[0019] S2: Then, the oligoether stock solution is continuously circulated between the inorganic membrane filtration device and the storage tank for purification by pressurizing the circulating pump.

[0020] Preferably, the inorganic membrane in S1 is one or more of ceramic membrane, metal membrane, glass membrane and molecular sieve membrane.

[0021] This invention provides a purification mechanism and process for removing impurities and polyacids from oligoethers. Compared with existing technologies, it has the following advantages:

[0022] 1. When internal cleaning is required, the guide component controls the execution component to descend, and then the drive component drives the execution component to rotate, so that the sprayed cleaning fluid can rinse the inner wall of the tank, the inner and outer walls of the inner inorganic membrane, and the inner and outer walls of the outer inorganic membrane. Furthermore, when the water spray cover is placed on the upper end of the inner inorganic membrane, the cleaning fluid entering the first water spray pipe enters the water spray cover through the fourth water hole and is sprayed downwards, thereby rinsing the membrane pores of the inner inorganic membrane, removing impurities and dirt from the filter medium, and achieving comprehensive cleaning of the interior of the inorganic membrane filtration device.

[0023] 2. The bearing plate is driven to rise and fall by the output end of the cylinder. It is lowered during cleaning and raised during filtration and purification. In addition, during the lifting and falling of the bearing plate, the rollers are driven by the shaft frame to roll along the inside of the guide rail, thereby improving the smoothness and stability of the lifting and falling of the bearing plate.

[0024] 3. The cleaning fluid, after being pressurized, enters the folded hose through the inlet, then enters the first spray pipe and is sprayed outwards. At the same time, another part of the cleaning fluid entering the first spray pipe enters the first connecting pipe through the first water hole, then enters the second spray pipe through the second water hole and is sprayed outwards. Meanwhile, another part of the cleaning fluid entering the second spray pipe flows through the third water hole, passes through the second connecting pipe, enters the third spray pipe, and is sprayed outwards. This connects the first spray pipe, the second spray pipe, the third spray pipe, and the spray cover, allowing them to share a common water source. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0026] Figure 2 This is a cross-sectional view of the present invention;

[0027] Figure 3 This is a partial cross-sectional view of the inorganic membrane filtration device in use according to the present invention;

[0028] Figure 4 This is a schematic diagram of the cleaning mechanism in this invention;

[0029] Figure 5 This is a schematic diagram of the bottom structure of the cleaning mechanism in this invention;

[0030] Figure 6 This is a cross-sectional view of the cleaning mechanism in this invention;

[0031] Figure 7 For the present invention Figure 6 A schematic diagram of the structure of part A in the middle;

[0032] Figure 8 This is a schematic diagram of the structure of the execution component in this invention;

[0033] Figure 9 This is a schematic diagram of the structure of the first water spray pipe in this invention;

[0034] Figure 10 This is a flow chart of the purification process for removing polyacids from oligopolyethers in this invention.

[0035] In the diagram: 1. Inorganic membrane filtration device; 11. Tank; 12. Piping assembly; 121. Liquid hopper; 122. Inlet pipe; 123. Drain pipe; 124. Internal drain pipe; 125. External drain pipe; 126. First valve; 127. Second valve; 128. Third valve; 129. Fourth valve; 13. Inner inorganic membrane; 14. Outer inorganic membrane; 15. Sealing cap; 16. Inlet; 17. Tank door; 18. Liquid level sensor; 2. Cleaning mechanism; 21. Guide assembly; 211. Support plate; 212. Groove; 213. Shaft bracket; 214. Roller; 215. Guide rail; 216. Cylinder; 22. Actuator assembly Components; 221, bracket; 222, first water spray pipe; 223, second water spray pipe; 224, first connecting pipe; 225, third water spray pipe; 226, second connecting pipe; 227, water spray cover; 228, first water hole; 229, second water hole; 2210, third water hole; 2211, fourth water hole; 2212, folded hose; 2213, first bidirectional nozzle; 2214, second bidirectional nozzle; 23, drive assembly; 231, driven pulley; 232, motor; 233, driving pulley; 234, belt; 235, sun gear; 236, planetary gear; 24, position sensor; 25, sensing element. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1-10 This invention provides a purification mechanism and process technology solution for removing heteropolyacids from oligopolyethers: The purification mechanism for removing heteropolyacids from oligopolyethers includes an inorganic membrane filtration device 1 for purifying oligopolyethers containing heteropolyacids. The inorganic membrane filtration device 1 includes a tank 11, and a cleaning mechanism 2 is provided on the inorganic membrane filtration device 1 for cleaning the inorganic membrane. The cleaning mechanism 2 includes:

[0038] The guide assembly 21 includes a support plate 211 that is slidably mounted inside the tank body 11;

[0039] The execution component 22 includes a bracket 221 that is rotatably mounted through the lower end of the support plate 211, a first water spray pipe 222 that is fixed through the lower end of the bracket 221, a second water spray pipe 223 that is rotatably mounted through the lower end of the bracket 221, a first connecting pipe 224 that is rotatably mounted on the first water spray pipe 222, and the other end of the first connecting pipe 224 that is rotatably mounted on the second water spray pipe 223, a third water spray pipe 225 that is fixed at the lower end of the bracket 221, a second connecting pipe 226 that is rotatably mounted on the second water spray pipe 223, and the other end of the second connecting pipe 226 that is connected and fixed to the third water spray pipe 225, a water spray cover 227 that is rotatably mounted on the first water spray pipe 222, and a folded hose 2212 connected to the upper end of the first water spray pipe 222.

[0040] The drive component 23 is disposed on the guide component 21 and is used to control the rotation of the guide component 21.

[0041] In this embodiment, when the inorganic membrane filtration device 1 finishes purifying the oligomeric ether and needs to be cleaned internally, the guide component 21 controls the execution component 22 to descend, and the drive component 23 drives the execution component 22 to rotate, so that the sprayed cleaning liquid can rinse the inner wall of the tank 11, the inner and outer walls of the inner inorganic membrane 13, and the inner and outer walls of the outer inorganic membrane 14; and when the water spray cover 227 covers the upper end of the inner inorganic membrane 13, the cleaning liquid entering the first water spray pipe 222 enters the water spray cover 227 through the fourth water hole 2211 and is sprayed downward, thereby rinsing the membrane pores of the inner inorganic membrane 13, removing impurities and dirt from the filter medium, and achieving comprehensive cleaning of the interior of the inorganic membrane filtration device 1.

[0042] Specifically, the guide assembly 21 also includes grooves 212 formed at both ends of the support plate 211, shaft brackets 213 fixed on both sides of the upper end of the grooves 212, rollers 214 rotatably mounted on the inner wall of the shaft brackets 213, guide rails 215 fixed on the inner walls of both ends of the tank body 11, with the rollers 214 located inside the guide rails 215, and cylinders 216 mounted on both sides of the top of the tank body 11 for driving the support bracket 221 to rise and fall.

[0043] In this embodiment, when the bearing plate 211 is driven to rise and fall by the output end of the cylinder 216, the bearing plate 211 drives the roller 214 to roll along the inside of the guide rail 215 through the shaft frame 213, thereby improving the smoothness and stability of the bearing plate 211 during the lifting process.

[0044] Specifically, the execution component 22 also includes a first water hole 228 opened at the upper end of the first water pipe 222, a second water hole 229 and a third water hole 2210 opened at the upper end of the second water pipe 223, and a fourth water hole 2211 opened at the upper end of the first water pipe 222.

[0045] In this embodiment, the cleaning fluid is pressurized and enters the folded hose 2212 from the inlet 16, then enters the first spray pipe 222 and is sprayed out. At the same time, another part of the cleaning fluid entering the first spray pipe 222 enters the first connecting pipe 224 through the first water hole 228, then enters the second spray pipe 223 through the second water hole 229 and is sprayed out. Meanwhile, another part of the cleaning fluid entering the second spray pipe 223 flows through the third water hole 2210, passes through the second connecting pipe 226, enters the third spray pipe 225, and is sprayed out.

[0046] Specifically, the execution component 22 also includes a first bidirectional nozzle 2213 installed at the lower end of the second water spray pipe 223 and a second bidirectional nozzle 2214 installed at the lower end of the third water spray pipe 225. When the execution component 22 revolves, it drives the first bidirectional nozzle 2213 and the second bidirectional nozzle 2214.

[0047] In this embodiment, the first bidirectional nozzle 2213 can rinse and clean the angle between the outer wall of the inner inorganic membrane 13 and the bottom of the tank 11 and the angle between the inner wall of the outer inorganic membrane 14 and the bottom of the tank 11. Similarly, the second bidirectional nozzle 2214 can rinse and clean the angle between the outer wall of the outer inorganic membrane 14 and the bottom of the tank 11 and the lower end angle of the inner wall of the tank 11.

[0048] Specifically, the drive assembly 23 includes a driven pulley 231 fixed to the upper outer wall of the first water spray pipe 222, a motor 232 mounted on one side of the top of the support plate 211, a drive pulley 233 mounted at the output end of the motor 232, and a belt 234 installed between the drive pulley 233 and the driven pulley 231, a sun gear 235 fixed to the center of the bottom of the support plate 211, and a planetary gear 236 fixed to the upper outer wall of the second water spray pipe 223 and meshing with the sun gear 235 for transmission.

[0049] In this embodiment, the output end of the motor 232 drives the active pulley 233 to rotate in conjunction with the belt 234, which in turn drives the driven pulley 231 to rotate. The driven pulley 231 drives the first water spray pipe 222 to rotate via the bracket 221. At the same time, when the bracket 221 rotates, it also drives the second water spray pipe 223 and the third water spray pipe 225 to revolve. During the revolution, the second water spray pipe 223 rotates via the planetary gear 236 in conjunction with the sun gear 235.

[0050] Specifically, the cleaning mechanism 2 also includes a position sensor 24 installed at the bottom of the support plate 211 and a sensor 25 installed at the bottom of the guide rail 215.

[0051] In this embodiment, when the support plate 211 moves the position sensor 24 downward and makes contact with the sensing element 25, it stops moving downward; and at this time, the water spray cover 227 just covers the upper end of the inner inorganic membrane 13.

[0052] Specifically, the inorganic membrane filtration device 1 also includes an inner inorganic membrane 13 and an outer inorganic membrane 14 installed at the lower end of the tank 11, a sealing cap 15 installed at the upper end of the inner inorganic membrane 13, a water inlet 16 fixed at the upper end of the tank 11 and connected to the upper end of the folded hose 2212, a door 17 hinged at the front end of the tank 11, a liquid level sensor 18 installed on the outer wall of the tank 11, and a pipeline assembly 12 provided at the lower end of the tank 11 for feeding, discharging and draining.

[0053] In this embodiment, when the inorganic membrane filtration device 1 purifies the oligoether, the sealing cap 15 is installed on the upper end of the inner inorganic membrane 13 to prevent the oligoether from overflowing from the upper end during the purification process; when the cleaning mechanism 2 is needed to clean the inside of the inorganic membrane filtration device 1, the sealing cap 15 is removed from the upper end of the inner inorganic membrane 13 to avoid causing movement interference to the cleaning mechanism 2.

[0054] Specifically, the pipeline assembly 12 includes a liquid hopper 121 fixed to the bottom of the tank body 11. The lower end of the liquid hopper 121 is connected to a fixed liquid inlet pipe 122, and a first valve 126 is installed on the liquid inlet pipe 122. One end of the liquid inlet pipe 122 is connected to a fixed liquid outlet pipe 123, and a second valve 127 is installed on the liquid outlet pipe 123. An inner drain pipe 124 and an outer drain pipe 125 are fixedly connected between the lower end of the tank body 11 and the liquid outlet pipe 123, and a third valve 128 and a fourth valve 129 are respectively installed on the inner drain pipe 124 and the outer drain pipe 125.

[0055] In this embodiment, when the inorganic membrane filtration device 1 purifies the oligoether, the first valve 126 and the fourth valve 129 are opened, and the second valve 127 and the third valve 128 are closed; when the inorganic membrane filtration device 1 needs to be cleaned, all valves are opened.

[0056] This invention also discloses a purification process for removing impurities and polyacids from oligoethers, comprising the following steps:

[0057] S1: First, the oligopoly ether stock solution containing heteropoly acids and at a temperature of 20-90°C in the storage tank is transported to the inorganic membrane filtration device 1. The heteropoly acids and macromolecules are trapped on the membrane surface and in the membrane pores, while the oligopoly ether passes smoothly through the inorganic membrane.

[0058] S2: Then, the oligoether stock solution is continuously circulated between the inorganic membrane filtration device 1 and the storage tank for purification by pressurizing the circulating pump.

[0059] Specifically, the inorganic membrane in S1 is one or more of ceramic membranes, metal membranes, glass membranes, and molecular sieve membranes.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A purification mechanism for removing polyacids from oligoethers, characterized in that: The inorganic membrane filtration device (1) is used for purifying oligoethers containing heteropoly acids. The inorganic membrane filtration device (1) includes a tank (11), an inner inorganic membrane (13) and an outer inorganic membrane (14) installed at the lower end of the tank (11), a sealing cap (15) installed at the upper end of the inner inorganic membrane (13), a water inlet (16) fixed at the upper end of the tank (11) and connected to the upper end of a folded hose (2212), a door (17) hinged at the front end of the tank (11), and a liquid level sensor (18) installed on the outer wall of the tank (11). A pipeline assembly (12) is provided at the lower end of the tank (11) for feeding, discharging and draining. A cleaning mechanism (2) is provided on the inorganic membrane filtration device (1) for cleaning the inorganic membrane. The cleaning mechanism (2) includes: The guide assembly (21) includes a support plate (211) that is slidably mounted inside the tank (11). The execution component (22) includes a bracket (221) rotatably mounted through the lower end of the support plate (211), a first water spray pipe (222) fixed through the lower end of the bracket (221), a second water spray pipe (223) rotatably mounted through the lower end of the bracket (221), a first connecting pipe (224) rotatably mounted on the first water spray pipe (222), and the other end of the first connecting pipe (224) rotatably mounted on the second water spray pipe (223), a third water spray pipe (225) fixed at the lower end of the bracket (221), a second connecting pipe (226) rotatably mounted on the second water spray pipe (223), and the other end of the second connecting pipe (226) communicating and fixedly connected to the third water spray pipe (225), a water spray cover (227) rotatably mounted on the first water spray pipe (222), and a folded hose (2212) connected to the upper end of the first water spray pipe (222). The drive assembly (23) includes a driven pulley (231) fixed to the upper outer wall of the first water spray pipe (222), a motor (232) mounted on one side of the top of the support plate (211), a drive pulley (233) mounted at the output end of the motor (232), and a belt (234) installed between the drive pulley (233) and the driven pulley (231), a sun gear (235) fixed at the bottom center of the support plate (211), and a planetary gear (236) fixed to the upper outer wall of the second water spray pipe (223) and meshing with the sun gear (235) for transmission.

2. The purification mechanism for removing impurities from polyacids in oligoethers according to claim 1, characterized in that: The guide assembly (21) also includes grooves (212) formed at both ends of the support plate (211), a shaft frame (213) fixed on both sides of the upper end of the groove (212), a roller (214) rotatably mounted on the inner wall of the shaft frame (213), a guide rail (215) fixed on both inner walls of both ends of the tank body (11), and the roller (214) located inside the guide rail (215), and a cylinder (216) installed on both sides of the top of the tank body (11) for driving the support (221) to lift.

3. The purification mechanism for removing impurities from polyacids in oligoethers according to claim 1, characterized in that: The execution component (22) further includes a first water hole (228) opened at the upper end of the first water pipe (222), a second water hole (229) and a third water hole (2210) opened at the upper end of the second water pipe (223), and a fourth water hole (2211) opened at the upper end of the first water pipe (222).

4. The purification mechanism for removing impurities from polyacids in oligoethers according to claim 1, characterized in that: The execution component (22) also includes a first bidirectional nozzle (2213) installed at the lower end of the second water pipe (223) and a second bidirectional nozzle (2214) installed at the lower end of the third water pipe (225).

5. The purification mechanism for removing impurities from polyacids in oligoethers according to claim 2, characterized in that: The cleaning mechanism (2) also includes a position sensor (24) installed at the bottom of the support plate (211) and a sensor (25) installed at the bottom of the guide rail (215).

6. The purification mechanism for removing impurities from polyacids in oligoethers according to claim 1, characterized in that: The pipeline assembly (12) includes a liquid hopper (121) fixed to the bottom of the tank (11), the lower end of the liquid hopper (121) is connected to a fixed inlet pipe (122), and a first valve (126) is installed on the inlet pipe (122). One end of the inlet pipe (122) is connected to a fixed drain pipe (123), and a second valve (127) is installed on the drain pipe (123). An inner drain pipe (124) and an outer drain pipe (125) are fixedly connected between the lower end of the tank (11) and the drain pipe (123), and a third valve (128) and a fourth valve (129) are respectively installed on the inner drain pipe (124) and the outer drain pipe (125).

7. A purification process for removing polyacids from oligoethers, characterized in that: The purification apparatus for removing polyacids from oligoethers according to any one of claims 1-6 includes the following steps: S1: First, the oligo ether stock solution containing heteropoly acid and at a temperature of 20-90°C in the storage tank is transported to the inorganic membrane filtration device (1). The heteropoly acid and macromolecular substances are trapped on the membrane surface and in the membrane pores, while the oligo ether passes smoothly through the inorganic membrane. S2: Then, the oligoether stock solution is continuously circulated between the inorganic membrane filtration device (1) and the storage tank for purification by pressurizing the circulating pump.

8. The purification process for removing impurities and polyacids from oligoethers according to claim 7, characterized in that: The inorganic membrane in S1 is one or more of ceramic membranes, metal membranes, glass membranes, and molecular sieve membranes.

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