Continuous purification and recovery system for polyethylene glycol

Abstract

The utility model relates to the technical field of purification and recovery of polyethylene glycol, in particular to a continuous purification and recovery system of polyethylene glycol, which comprises a kettle body, at least two purification bins, a filter body, a collection bin and a backflow bin, the inside of the kettle body is provided with an array along the axis, and the upper parts of the purification bins are fixedly communicated with a liquid inlet pipe and a pressurizing pipe; the bottom of the axis of the kettle body is fixedly provided with a collection bin and a collection pipe, the side wall of the collection pipe is communicated with the purification bin, the end part of the collection pipe is communicated with the bottom of the collection bin, the purification bin is internally and fixedly provided with a filter body, the bottom of the purification bin is fixedly provided with a backflow bin, and the side wall of the backflow bin is fixedly provided with a backflow pipe; through asynchronous purification of the plurality of purification bins, when a certain component is damaged, continuous purification operation can still be ensured through work of other purification bins, so that the stability of the continuous purification operation can be ensured, and the problem that the continuous purification process of polyethylene glycol is easy to interrupt and unstable is solved.

Description

Technical Field

[0001] This utility model relates to the field of polyethylene glycol purification technology, specifically a continuous purification and recovery system for polyethylene glycol. Background Technology

[0002] In existing continuous purification processes for polyethylene glycol (PEG), purified PEG needs to be output. However, the purified PEG is mainly retained on one side and the surface of the filter. For example, when using an ultrafiltration membrane to purify PEG, the concentrated PEG is mainly located on the feed side and surface of the ultrafiltration membrane. Over long-term use, the filter is prone to impurities or damage on its surface, affecting the purification effect and efficiency of PEG. To ensure the purification effect and efficiency, the filter needs to be cleaned or replaced regularly. However, cleaning the filter will lead to the interruption of the continuous purification process.

[0003] Therefore, this invention provides a continuous purification and recovery system for polyethylene glycol to solve the above problems. Utility Model Content

[0004] The technical problem to be solved by this invention is that the existing continuous purification process of polyethylene glycol is prone to interruption and instability.

[0005] This utility model provides the following technical solution: a continuous purification and recovery system for polyethylene glycol, comprising a vessel body, a purification chamber, a filter body, a collection chamber, and a reflux chamber. At least two purification chambers are arranged in an array along the axis inside the vessel body. An inlet pipe and a pressurization pipe are fixedly connected to the upper part of each purification chamber. A collection chamber is fixedly installed at the bottom of the vessel body axis. The purification chamber and the collection chamber are connected through a collection pipe. A filter body is fixedly installed at the bottom of each purification chamber. A reflux chamber is fixedly installed at the bottom of each filter body. A reflux pipe is fixedly installed at the bottom of the reflux chamber.

[0006] At least two filter elements are fixedly installed inside the purification chamber, and the inlet pipe and the pressure boosting pipe are arranged horizontally and circumferentially in an alternating manner.

[0007] The booster pipe is fixedly connected to the variable frequency speed control booster pump.

[0008] The purification chamber is fixedly installed on both sides of the upper surface of the filter body with a concentrate outlet and a purge port respectively. The concentrate outlet is connected to the collection chamber through a collection pipe.

[0009] A spray nozzle is fixedly installed on the upper surface of the filter inside the purification chamber.

[0010] The beneficial effects of this utility model are as follows:

[0011] 1. This utility model achieves continuous purification and improves purification efficiency by using multiple purification chambers to output purified polyethylene glycol in turn through asynchronous purification processes. Furthermore, the asynchronous output of purified polyethylene glycol by multiple purification chambers ensures continuous purification operation even if the filter or a component in any one purification chamber is damaged, thus guaranteeing the stability of continuous purification operation. At the same time, it can also recover insufficiently concentrated polyethylene glycol in the reflux chamber for further purification and concentration, reducing raw material waste and improving the concentration effect.

[0012] 2. This invention gently purges the concentrated polyethylene glycol at the filter body through the concentrate outlet and purge port, which can quickly collect the purified polyethylene glycol without damaging the filter body, thus improving the purification efficiency. Furthermore, multiple purification chambers take turns cleaning the filter body, which ensures continuous purification and improves purification efficiency while keeping the filter body clean and ensuring stable purification effect and efficiency. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0015] Figure 2 This is a cross-sectional structural diagram of the vessel body of this utility model.

[0016] In the diagram: 1. Reactor body; 2. Purification chamber; 21. Inlet pipe; 211. First solenoid valve; 22. Pressure boosting pipe; 221. Second solenoid valve; 23. Concentrate outlet; 231. Third solenoid valve; 24. Purge port; 241. Fourth solenoid valve; 3. Filter body; 4. Collection chamber; 41. Collection pipe; 42. Liquid collection pipe; 5. Reflux chamber; 51. Reflux pipe; 52. Reflux pump; 53. Sampling valve; 54. Drain pipe; 6. Sampling port; 7. Backflush head. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Therefore, the following detailed description of the embodiments of this utility model is not intended to limit the scope of the claimed utility model, but merely represents some embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0018] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0019] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and "back side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this utility model is conventionally placed during use. These terms are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0020] It should also be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] This disclosure aims to address the problem of instability and easy interruption in existing continuous purification processes of polyethylene glycol (PEG). Therefore, this disclosure proposes a continuous purification and recovery system for PEG, comprising a vessel body 1, purification chambers 2, a filter body 3, a collection chamber 4, and a reflux chamber 5. At least two purification chambers 2 for purifying PEG are arranged in an axial array inside the vessel body 1. The upper part of each purification chamber 2 is fixedly connected to an inlet pipe 21 for inputting crude PEG raw material and a pressure boosting pipe 22 for slowly increasing the pressure during purification. The inlet pipe 21 and the pressure boosting pipe 22 are arranged in a staggered, annular pattern along the axis of the vessel body 1. A collection chamber 4 for collecting purified polyethylene glycol is fixedly installed at the bottom of the shaft. The side wall of the collection tube 41 is connected to the purification chamber 2, and the end of the collection tube 41 is connected to the bottom of the collection chamber 4. A filter body 3 for concentrated polyethylene glycol is fixedly installed inside the purification chamber 2. A reflux chamber 5 is fixedly installed at the bottom of the purification chamber 2. A reflux tube 51 is fixedly installed at the bottom of the reflux chamber 5. The other end of the reflux tube 51 is fixedly connected to any of the purification chambers 2. A reflux pump 52 is fixedly installed in the reflux tube 51.

[0022] In this embodiment, four purification chambers 2 are arranged in an array along the axis inside the vessel body 1. A collection pipe 41 is fixedly installed in the axis inside the vessel body 1 and is in contact with the four purification chambers 2 but not connected at the same time.

[0023] The bottom of the collection chamber 4 is fixedly connected to a liquid collection pipe 42, through which the purified polyethylene glycol in the collection chamber 4 can be discharged for subsequent operations.

[0024] It should be noted that each purification chamber 2 is individually and fixedly connected to an inlet pipe 21 and a pressure boosting pipe 22. A first solenoid valve 211 is fixedly installed on the inlet pipe 21 to control its opening and closing, and a second solenoid valve 221 is fixedly installed on the pressure boosting pipe 22 to control its opening and closing. The pressure boosting pipe 22 is fixedly connected to an external variable frequency speed-regulating boosting pump, thereby enabling active control of the injected pressure. Furthermore, by controlling the valves and the variable frequency speed-regulating boosting pump, the pressure, feed rate, and continuous purification time during the continuous purification process of crude polyethylene glycol raw materials can be controlled, thus controlling the concentration of concentrated polyethylene glycol in the purification chamber 2. Additionally, the purification chamber 2 and the reflux chamber 5 are interconnected as a single structure, with the reflux chamber 5 located at the bottom of the purification chamber 2.

[0025] It should be noted that the filter 3 in this embodiment can adopt any structure in the prior art that can concentrate and purify crude polyethylene glycol raw materials. In this embodiment, an ultrafiltration membrane is preferably used to retain polyethylene glycol macromolecules while allowing small molecule impurities and solvents to pass through, thereby achieving the concentration and purification of polyethylene glycol.

[0026] It should be noted that the embodiments disclosed herein pertain to continuous purification, that is, the crude polyethylene glycol raw material is continuously fed in for purification.

[0027] At least two filter elements 3 are fixedly installed inside the purification chamber 2, thereby continuously purifying the crude polyethylene glycol raw material through multiple filter elements 3, thus improving the purification effect of the crude polyethylene glycol raw material. The inlet pipe 21 and the pressure boosting pipe 22 are arranged horizontally and circumferentially in a staggered manner.

[0028] The crude polyethylene glycol (PEG) raw material is fed into the purification chamber 2 through the inlet pipe 21 and continuously purified and concentrated through the filter 3. The retained PEG macromolecules are concentrated and purified on the upper surface of the filter 3. Small molecule impurities and solvents pass through the filter 3 and enter the reflux chamber 5 at the bottom. Operators periodically check whether the small molecule impurities and solvents in the reflux chamber 5 contain PEG. If PEG is detected, the reflux pump 52 is activated, thereby transferring the small molecule impurities and solvents back to any of the purification chambers 2 through the reflux pipe 51 for recovery and further purification. If the reflux chamber 5 does not contain PEG, it can be directly discharged through the drain pipe 54 connected to the side wall.

[0029] It should be noted that detecting whether small molecule impurities and solvents in the reflux chamber 5 contain polyethylene glycol is a very mature technology in the prior art, and any existing method capable of detecting polyethylene glycol can be used. In this embodiment, a sampling valve 53 is fixedly installed in the reflux chamber 5. The sample in the reflux chamber 5 is obtained through the sampling valve 53 for testing, thereby determining whether small molecule impurities and solvents contain polyethylene glycol.

[0030] A collection pipe 41 is fixedly installed at the axis of the vessel body 1. Concentrate outlets 23 and purge ports 24 are fixedly installed on the symmetrical sides of the upper surface of the filter body 3 in the purification chamber 2. The concentrate outlets 23 and purge ports 24 on the multiple purification chambers 2 are arranged along the axis of the vessel body 1, with the concentrate outlets 23 located horizontally circumferentially outside the purge ports 24. A third solenoid valve 231 is fixedly installed at the concentrate outlet 23 to control its opening and closing. A fourth solenoid valve 241 is installed inside the purge port 24 to control its opening and closing, thereby preventing concentrated and purified polyethylene glycol from entering the purge port 24. The concentrate outlet 23 is connected to the collection pipe 41, the end of the collection pipe 41 is connected to the collection chamber 4, and the purge port 24 is connected to an external fan.

[0031] After any purification chamber 2 has concentrated polyethylene glycol to a predetermined concentration, that purification chamber 2 stops feeding, while the other purification chambers 2 continue feeding. An external fan is activated, and the third solenoid valve 231 and the fourth solenoid valve 241 at the concentrated liquid outlet 23 and purge port 24 of the purification chamber 2 where feeding has stopped are opened. This allows air to gently purge the concentrated polyethylene glycol solution through the air supply pipe and purge port 24, causing the concentrated polyethylene glycol in the purification chamber 2 to exit from the concentrated liquid outlet 23 and enter the collection pipe 41. The polyethylene glycol then flows from the concentrated liquid through the collection pipe 41 into the collection chamber 4 for storage. During this process, the other purification chambers 2 that have not yet concentrated polyethylene glycol to the predetermined concentration continue feeding.

[0032] It should be noted that in this embodiment, the purification chamber 2 has a sampling port 6 on the side wall of the filter body 3. A small amount of sample is then obtained through the sampling port 6 using a syringe with a piston structure for testing, thereby determining the concentration of polyethylene glycol at the filter body 3. The syringe is prior art, therefore its structure will not be described in detail.

[0033] It should be noted that the filter body 3 is detachably installed in the purification chamber 2. In addition to discharging concentrated polyethylene glycol from the concentrate outlet 23 and the purge port 24, the operator can also periodically remove the filter body 3 and gently scrape or dip the concentrated polyethylene glycol on the surface, thereby fully obtaining the concentrated polyethylene glycol.

[0034] It should be noted that nitrogen is used as the gas because it does not readily react with polyethylene glycol at room temperature and pressure. The pressure of the nitrogen gas gently purging through the purge port 24 is controlled at 0.01-0.05 MPa to avoid damaging the filter element 3, i.e., the ultrafiltration membrane, and to prevent splashing of the polyethylene glycol concentrate.

[0035] A backflush head 7 is fixedly installed below the filter body 3. The backflush head 7 is used to pass in deionized water, phosphate buffer solution, or acetate buffer solution. During use, the operator can periodically activate the backflush head 7 to control the deionized water, phosphate buffer solution, or acetate buffer solution to backflush the filter body 3 from bottom to top, thereby ensuring the filtration efficiency of the filter body 3.

[0036] It should be noted that the deionized water, phosphate buffer solution, or acetate buffer solution after backwashing will enter the reflux chamber 5 to test for the presence of polyethylene glycol. If polyethylene glycol is present, the reflux pump 52 will be activated to return the rinsed solution to any of the purification chambers 2 for purification. If polyethylene glycol is not present, it can be directly discharged through the drain pipe 54 connected to the side wall of the reflux chamber 5.

[0037] In operation, the first solenoid valve 211 on the inlet pipe 21 is opened, and crude polyethylene glycol raw material is injected through the inlet pipe 21. Then, the second solenoid valve 221 on the pressure boosting pipe 22 is opened to slowly increase the pressure. This pressure forces the crude polyethylene glycol raw material through multiple filter bodies 3 for purification. The filter bodies 3 sequentially trap large polyethylene glycol molecules while allowing small molecule impurities and solvents to pass through, thereby improving the purification and concentration of polyethylene glycol. The small molecule impurities and solvents passing through the filter bodies 3 enter the reflux chamber 5 at the bottom. The operator periodically obtains samples from the reflux chamber 5 through the sampling valve 53 for testing to determine whether the small molecule impurities and solvents contain polyethylene glycol. If not, they are directly discharged through the drain pipe 54 at the bottom of the reflux chamber 5. If they do contain polyethylene glycol, the reflux pump 52 is activated, allowing the small molecule impurities and solvents in the reflux chamber 5 to enter any purification chamber 2 for continuous purification.

[0038] Operators periodically monitor the polyethylene glycol concentration at filter body 3. When the polyethylene glycol at filter body 3 in a certain purification chamber 2 is concentrated to the predetermined concentration, the first solenoid valve 211 and the second solenoid valve 221 on the inlet pipe 21 and the pressurization pipe 22 of the purification chamber 2 that has completed polyethylene glycol purification are closed to stop feeding and pressurization. For the polyethylene glycol in the other purification chambers 2 that has not been concentrated to the predetermined concentration, feeding continues for purification. Then, the third solenoid valve 231 and the fourth solenoid valve 241 at the concentrate outlet 23 and the purge port 24 are opened and the external fan is started, so that the air blows gently through the purge port 24 to gently blow the polyethylene glycol concentrate on the surface of the filter body 3, so that the polyethylene glycol concentrate passes through the concentrate outlet 23 and enters the collection pipe 41, so that the polyethylene glycol concentrate enters the collection chamber 4 along the collection pipe 41 for collection, and the continuously purified polyethylene glycol in the collection chamber 4 is discharged through the collection pipe 42 for subsequent operations.

[0039] During use, operators regularly take turns cleaning the filter media 3 in each purification chamber 2 to ensure the purification effect of the filter media 3. When cleaning the filter media 3 in any purification chamber 2, the backwash head 7 is activated to input deionized water, so that the deionized water cleans the filter media 3 from bottom to top, thereby achieving backwashing to ensure the concentration effect of polyethylene glycol by the filter media 3.

[0040] This embodiment of the invention achieves continuous purification of polyethylene glycol (PEG) by having multiple purification chambers 2 alternately output concentrated PEG to a predetermined concentration, thereby improving the purification efficiency of PEG. Furthermore, it allows for the recovery and re-purification and concentration of partially concentrated PEG, i.e., small molecule impurities and PEG contained in the solvent, reducing raw material waste and improving the concentration effect. Moreover, even if the purified PEG from the multiple purification chambers 2 outputs asynchronously, continuous purification can still be maintained through the operation of the remaining purification chambers 2 even if the filter 3 or a component in any one of the purification chambers 2 is damaged, thus ensuring the stability of the continuous purification operation.

[0041] 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 continuous purification and recovery system for polyethylene glycol, comprising a vessel (1), a purification chamber (2), a filter (3), a collection chamber (4), and a reflux chamber (5), characterized in that: At least two purification chambers (2) are arranged in an array along the axis inside the vessel body (1). The upper part of the purification chamber (2) is fixedly connected to the liquid inlet pipe (21) and the pressure boosting pipe (22). A collection chamber (4) is fixedly installed at the bottom of the axis of the vessel body (1). A collection pipe (41) is fixedly installed at the axis of the vessel body (1). The side wall of the collection pipe (41) is connected to the purification chamber (2). The end of the collection pipe (41) is connected to the bottom of the collection chamber (4). A filter body (3) is fixedly installed inside the purification chamber (2). A reflux chamber (5) is fixedly installed at the bottom of the purification chamber (2). A reflux pipe (51) is fixedly installed on the side wall of the reflux chamber (5).

2. The continuous purification and recovery system for polyethylene glycol according to claim 1, characterized in that: At least two filter bodies (3) are fixedly installed inside the purification chamber (2), and the liquid inlet pipe (21) and the pressure boosting pipe (22) are arranged horizontally and circumferentially in an alternating manner.

3. The continuous purification and recovery system for polyethylene glycol according to claim 2, characterized in that: The purification chamber (2) is fixedly installed with a concentrate outlet (23) and a purge port (24) on the symmetrical sides of the upper surface of the filter body (3), and the concentrate outlet (23) is located on the horizontal circumferential outer side of the purge port (24).

4. The continuous purification and recovery system for polyethylene glycol according to claim 3, characterized in that: A first solenoid valve (211) for controlling the opening and closing is fixedly installed on the inlet pipe (21), a second solenoid valve (221) for controlling the opening and closing of the booster pipe (22) is fixedly installed on the booster pipe (22), a third solenoid valve (231) for controlling the opening and closing of the concentrate outlet (23) is fixedly installed at the concentrate outlet (23), and a fourth solenoid valve (241) for controlling the opening and closing of the purge port (24) is installed inside the purge port (24).

5. The continuous purification and recovery system for polyethylene glycol according to claim 4, characterized in that: A backflush head (7) is fixedly installed below the filter body (3).

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