Ethylene glycol on-line replacement device and replacement method

Abstract

The application discloses an ethylene glycol online replacement device and a replacement method, relates to the technical field of ethylene glycol filtering replacement, and comprises a filtering separation cylinder, a liquid inlet is arranged on the upper side wall of the filtering separation cylinder, a liquid outlet is arranged on the lower side wall of the filtering separation cylinder, a waste discharge port is arranged on the position close to the bottom of the filtering separation cylinder, and a flow guide cylinder coaxial with the filtering separation cylinder is arranged in the filtering separation cylinder. The ethylene glycol recovery liquid containing impurities entering the filtering separation cylinder is first guided to the outside of the flow guide cylinder instead of directly impacting the filter core by arranging the flow guide cylinder coaxial with the filtering separation cylinder in the filtering separation cylinder, and the spiral downward flow paths are formed between the outside of the flow guide cylinder and the inner wall of the filtering separation cylinder by the multiple spiral blades on the outer periphery of the flow guide cylinder, so that the colloidal particle residues migrate to the lower end of the flow guide cylinder along the liquid before entering the filter core, and thus the probability of the colloidal particle residues directly adhering to the surface of the filter core is reduced.

Description

Technical Field

[0001] This invention relates to the field of ethylene glycol filtration and replacement technology, and particularly to an online ethylene glycol replacement device and replacement method. Background Technology

[0002] Ethylene glycol is an important medium in the production process of polyester fibers. It repeatedly participates in flow and heat exchange during polyester reaction, recycling, rinsing and reuse, and auxiliary feeding. As the production line operates continuously, the ethylene glycol recovery liquid is prone to carrying polyester oligomer agglomerates, gel-like impurities, fine PTA powder particles, fine IPA powder particles, and suspended particles. These particles have certain adhesion, agglomeration, and suspension properties. If they directly enter the subsequent reuse pipeline, metering pipeline, or filter cartridge, they can easily form local clogging on the surface of the filter cartridge, causing the filtration pressure difference to rise rapidly, affecting the stability of ethylene glycol reuse, and increasing the frequency of shutdown for cleaning.

[0003] Existing ethylene glycol recovery liquid filtration equipment mostly adopts ordinary basket filters, dual-cylinder switching filters, or single-stage filter cartridge filtration structures. These types of equipment typically allow impurities in the ethylene glycol to directly enter the filter cartridge or filter basket area, and the colloidal residue is intercepted by the filter cartridge surface. However, the colloidal residue lacks an effective pre-separation path before entering the filter surface. Especially for polyester oligomer agglomerates and gel-like impurities, they are prone to concentrated adhesion on the filter cartridge inlet side, leading to localized clogging of the filter cartridge. Although some equipment is equipped with backwashing, scraper, or sewage discharge structures, these mainly target the subsequent cleaning of impurities already attached to the filter surface. They cannot directionally migrate, intercept, and collect the colloidal residue before it comes into contact with the filter cartridge, and still suffer from problems such as insufficient filtration stability, high filter cartridge load, and poor continuity of the replacement process.

[0004] Therefore, it is necessary to invent an online ethylene glycol displacement device and displacement method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide an online ethylene glycol displacement device and displacement method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an online ethylene glycol replacement device, comprising a filter separation cylinder, wherein the upper side wall of the filter separation cylinder is provided with a liquid inlet, the lower side wall of the filter separation cylinder is provided with a liquid outlet, a waste discharge port is provided near the bottom of the filter separation cylinder, a guide cylinder is provided inside the filter separation cylinder and arranged coaxially with the filter separation cylinder, and a guide seat is provided on the upper part of the guide cylinder corresponding to the liquid inlet; The outer periphery of the guide tube is provided with multiple spiral blades, which are disposed between the outer periphery of the guide tube and the inner wall of the filter separation tube, and extend spirally along the height direction of the guide tube. The lower end of the outer wall of the guide tube is provided with a blocking strip, and the blocking strip is provided with a slag-blocking lip. The blocking strip and the slag-blocking lip are used to block the granular slag material that migrates to the lower end of the guide tube as it flows downward with the spiral. The guide tube is equipped with a filter element inside. The filter element is eccentrically positioned relative to the guide tube, so that an uneven inner flow space is formed between the outer wall of the filter element and the inner wall of the guide tube. The liquid inside the guide tube passes through the filter element from the outside to the inside. The guide tube is provided with an inclined inner baffle plate inside, and the inner baffle plate is located in the inner flow space; The inner cavity of the filter element is connected to the liquid outlet, and the bottom of the filter separation cylinder forms a bottom slag collection chamber, which is connected to the waste discharge port.

[0007] Preferably, the filter separation cylinder has two connected in parallel, the bottom of the two filter separation cylinders is provided with a skid base, the liquid inlet of the two filter separation cylinders is respectively connected to the liquid inlet pipeline, and the liquid outlet of the two filter separation cylinders is respectively connected to the liquid outlet pipeline.

[0008] Preferably, the flow guide seat is located at the upper end of the flow guide cylinder, and the flow guide seat is provided with a flow guide groove. One end of the flow guide groove is corresponding to the liquid inlet, and the other end of the flow guide groove extends to the outer periphery of the flow guide cylinder, so that the ethylene glycol-containing recovery liquid entering from the liquid inlet first enters the outer pre-separation area between the inner wall of the flow guide cylinder and the filter separation cylinder.

[0009] Preferably, a plurality of the spiral blades are arranged at intervals along the outer periphery of the guide tube, the inner edge of the spiral blades is connected to the outer wall of the guide tube, and the outer edge of the spiral blades is in contact with the inner wall of the filter separation tube, so that a wall-mounted spiral downward channel is formed between adjacent spiral blades.

[0010] Preferably, the barrier bar is disposed along the lower end of the outer wall of the guide tube and located at the end of the wall-adhering spiral downward channel. The slag-blocking lip is connected to the side of the barrier bar facing the wall-adhering spiral downward channel, so that the granular slag material migrating to the lower end of the guide tube along the wall-adhering spiral downward channel is retained by the barrier bar and the slag-blocking lip.

[0011] Preferably, the lower end of the guide tube is provided with a constricted guide ring, which is connected to the lower end opening of the guide tube. The constricted guide ring converges from the outer periphery of the lower end of the guide tube towards the inside of the guide tube, so as to guide the liquid that has spiraled down the outside of the guide tube into the inside of the guide tube.

[0012] Preferably, the axis of the filter element is offset relative to the axis of the guide tube, so that an inner narrow flow gap and an inner wide flow gap are formed between the outer wall of the filter element and the inner wall of the guide tube. The inner baffle is disposed on the liquid flow path from the inner narrow flow gap to the inner wide flow gap, and a temporary storage area for temporarily storing colloidal residue is formed below the inner baffle.

[0013] Preferably, the inside of the guide tube is provided with two sets of waste discharge and slag guiding components. The two sets of waste discharge and slag guiding components are respectively located at both ends of the inner baffle plate. Each waste discharge and slag guiding component is provided with a waste discharge and slag guiding channel. One end of the waste discharge and slag guiding channel is connected to the temporary storage area, and the other end of the waste discharge and slag guiding channel is connected to the bottom slag collection cavity, so that when the waste discharge port is opened, the granular slag in the temporary storage area enters the bottom slag collection cavity through the waste discharge and slag guiding channel.

[0014] Preferably, the lower end of the filter element is connected to an eccentric connecting bend, the eccentric connecting bend is connected to a discharge pipe, the discharge pipe is connected to the liquid outlet, the bottom of the filter separation cylinder is provided with a separator plate, the separator plate is arranged around the eccentric connecting bend, the outer periphery of the separator plate is in contact with the inner wall of the filter separation cylinder, and the bottom slag collection cavity is formed above the separator plate.

[0015] A displacement method for an online ethylene glycol displacement device includes the following steps: S1. Liquid Inlet Guidance: The impurity-containing ethylene glycol recovery liquid in the polyester fiber production line is fed into the filter separation cylinder through the liquid inlet, and the impurity-containing ethylene glycol recovery liquid is guided to the outside of the guide cylinder through the guide seat; S2, Spiral Pre-Separation: The ethylene glycol-containing recovery liquid flows downward in a spiral along the outside of the guide tube under the guidance of the spiral blades, causing the granular residue to migrate to the lower end of the guide tube; S3. Lower end blocking slag: The blocking strip and the slag-blocking lip block the granular slag material migrating to the lower end of the guide tube. Ethylene glycol, which has been pre-separated on the outside, enters the interior of the guide tube. S4. Secondary separation by inner deflection: Ethylene glycol entering the guide tube migrates from the narrow side to the wide side in the inner flow space formed by the eccentric setting of the filter element. The inner baffle plate performs secondary separation of residual colloidal particles and slag. S5. Filter cartridge filtration liquid: Ethylene glycol passes through the filter cartridge from the outside to the inside and is discharged from the outlet; S6. Regular waste discharge and cleaning: The waste discharge port is opened during regular cleaning to allow the colloid slag and slag-containing waste liquid in the bottom slag collection chamber to be discharged through the waste discharge port.

[0016] The technical effects and advantages of this invention are as follows: 1. This invention provides a guide tube arranged coaxially with the filter separation cylinder inside the filter separation cylinder, and a guide seat corresponding to the liquid inlet is set on the upper part of the guide tube. This allows the ethylene glycol recovery liquid containing impurities entering the filter separation cylinder to be guided to the outside of the guide tube first, instead of directly impacting the filter element. At the same time, multiple spiral blades on the outer periphery of the guide tube form a spiral downward flow path between the outside of the guide tube and the inner wall of the filter separation cylinder. This allows the colloid residue to migrate with the liquid to the lower end of the guide tube before entering the filter element, thereby reducing the probability of the colloid residue directly adhering to the surface of the filter element. 2. This invention sets a barrier strip at the lower end of the outer wall of the guide tube and sets a slag-blocking lip on the barrier strip, so that the granular slag migrating to the lower end of the guide tube along the spiral downward path is blocked and retained, thereby allowing the granular slag to enter the bottom slag collection chamber instead of directly entering the internal filtration area of ​​the guide tube, forming a pre-filtration separation path of "outer spiral pre-separation - lower end barrier slag interception". This can address the problems of easy adhesion, agglomeration and clogging of filter elements by polyester oligomer agglomerates, gel-like impurities and fine powder particles, and reduce the initial filtration load of the filter element. 3. By setting the filter element eccentrically relative to the guide tube, the present invention creates an uneven inner flow space between the outer wall of the filter element and the inner wall of the guide tube. Ethylene glycol entering the guide tube forms a biased flow trajectory from the narrow side to the wide side in this inner flow space. The residual colloid residue is further separated by the inclined inner baffle plate, so that the small amount of colloid residue entering the guide tube can be intercepted and temporarily stored, reducing the risk of it continuing to adhere to the outer periphery of the filter element and causing local blockage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a cross-sectional schematic diagram of the filter separation cylinder structure of the present invention.

[0019] Figure 3 This is a schematic cross-sectional view of the filter separation cylinder structure of the present invention. Figure 1 .

[0020] Figure 4 This is a schematic cross-sectional view of the filter separation cylinder structure of the present invention. Figure 2 .

[0021] Figure 5 This is a schematic diagram of the filter element structure of the present invention.

[0022] Figure 6 This is a schematic diagram of the guide tube structure of the present invention.

[0023] Figure 7 This is a cross-sectional schematic diagram of the guide tube structure of the present invention.

[0024] Figure 8This is an exploded view of the filter separation cylinder structure of the present invention.

[0025] In the diagram: 1. Filter separator; 11. Liquid inlet; 12. Liquid outlet; 13. Waste outlet; 2. Flow guide tube; 21. Flow guide seat; 211. Flow guide groove; 22. Spiral blade; 23. Barrier strip; 231. Slag-blocking lip; 24. Flow guide ring; 25. Inner baffle plate; 26. Waste discharge guide component; 261. Waste discharge guide channel; 3. Filter element; 31. Eccentric connecting bend; 32. Discharge pipe; 33. Divider plate; 4. Sliding base. Detailed Implementation

[0026] 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figures 1 to 8 As shown, the online ethylene glycol replacement device provided by the present invention is essentially an online ethylene glycol replacement device capable of spiral pre-separation, lower end slag interception, inner secondary separation, and periodic waste discharge of impurity ethylene glycol before filter cartridge filtration.

[0028] In terms of specific structural installation, the structural body can be constructed according to the inventive concept of this embodiment. In this embodiment, no special limitations are imposed.

[0029] In this embodiment, an online ethylene glycol replacement device is provided. This device is used for online filtration and replacement of impurity ethylene glycol recovery liquid in a polyester fiber production line. The impurity ethylene glycol recovery liquid has ethylene glycol as a continuous liquid phase and carries polyester oligomer agglomerates, gel-like impurities, fine PTA powder particles, fine IPA powder particles, and suspended particulate impurities. In this embodiment, the above-mentioned impurities are collectively referred to as granular residue. The device includes a filter separator 1, which is preferably a vertical cylindrical ethylene glycol-resistant metal cylinder. It can be formed by rolling and welding stainless steel plates or by processing corrosion-resistant alloy steel cylinders. The upper side wall of the filter separator 1 is provided with a liquid inlet 11, the lower side wall is provided with a liquid outlet 12, and a waste discharge port 13 is provided near the bottom. The liquid inlet 11 is used to receive the ethylene glycol recovery liquid containing impurities from the polyester fiber production line. The liquid outlet 12 is used to discharge the ethylene glycol filtered by the filter element 3. The waste discharge port 13 is used to discharge the colloid residue and slag-containing waste liquid in the bottom slag collection chamber during periodic cleaning. During normal filtration and replacement, the waste discharge port 13 is in a closed state.

[0030] In this embodiment, two filter separation cylinders 1 can be provided, and the two filter separation cylinders 1 are arranged in parallel. The bottom ends of the two filter separation cylinders 1 are both set on the skid base 4. The skid base 4 can adopt a welded steel frame or a channel steel welded base structure to facilitate the skid-mounted installation of the whole machine next to the ethylene glycol recovery liquid pipeline. The liquid inlet 11 of the two filter separation cylinders 1 are respectively connected to the liquid inlet pipeline, and the liquid outlet 12 of the two filter separation cylinders 1 are respectively connected to the liquid outlet pipeline. The two filter separation cylinders 1 can participate in filtration replacement at the same time, or the single cylinder can be operated and the other cylinder can be cleaned and maintained through an external valve group, thereby improving the continuity of the online ethylene glycol replacement process.

[0031] The filter separation cylinder 1 is provided with a guide cylinder 2 arranged coaxially with the filter separation cylinder 1. The guide cylinder 2 is preferably a hollow cylindrical structure extending along the height direction of the filter separation cylinder 1. The guide cylinder 2 can be installed in the filter separation cylinder 1 through an upper support, a lower positioning member or a connection structure with the guide seat 21, so that the guide cylinder 2 and the filter separation cylinder 1 are kept in a coaxial position. The guide cylinder 2 is used to divide the internal space of the filter separation cylinder 1 into an outer pre-separation area located outside the guide cylinder 2 and an inner filtration area located inside the guide cylinder 2, so that the ethylene glycol-containing recovery liquid first completes spiral pre-separation outside the guide cylinder 2, and then enters the guide cylinder 2 to complete secondary separation by deflection and filter filtration.

[0032] The upper part of the guide tube 2 is provided with a guide seat 21 corresponding to the liquid inlet 11. The guide seat 21 is located at the upper end of the guide tube 2 and connected to the guide tube 2. The guide seat 21 is provided with a guide groove 211. One end of the guide groove 211 is corresponding to the liquid inlet 11, and the other end of the guide groove 211 extends to the outer periphery of the guide tube 2. The guide groove 211 is an arc-shaped groove, which is used to guide the impurity ethylene glycol recovery liquid entering from the liquid inlet 11 to the outside of the guide tube 2, so that the impurity ethylene glycol recovery liquid first enters the outer pre-separation area between the guide tube 2 and the inner wall of the filter separation tube 1, and avoids the impurity ethylene glycol recovery liquid directly impacting the filter element 3 after entering from the liquid inlet 11.

[0033] Multiple spiral blades 22 are provided on the outer periphery of the guide tube 2. The multiple spiral blades 22 are arranged between the outer periphery of the guide tube 2 and the inner wall of the filter separation tube 1, and extend spirally along the height direction of the guide tube 2. The multiple spiral blades 22 can be arranged at intervals along the outer periphery of the guide tube 2. The inner edge of the spiral blades 22 is connected to the outer wall of the guide tube 2, and the outer edge of the spiral blades 22 is in contact with or approximately in contact with the inner wall of the filter separation tube 1, so that a wall-attached spiral downward channel is formed between adjacent spiral blades 22. The ethylene glycol-containing recovery liquid is guided into the wall-attached spiral downward channel after being guided by the guide groove 211, and forms a spiral downward flow along the outer side of the guide tube 2. The colloid residue migrates downward along the inner wall of the filter separation tube 1 and the outer side of the guide tube 2 under the action of the spiral flow, thereby completing the first pre-separation before entering the filter element 3.

[0034] The lower end of the outer wall of the guide tube 2 is provided with a barrier strip 23. The barrier strip 23 is preferably provided along the lower end of the outer wall of the guide tube 2 and located at the end of the spiral downward channel attached to the wall. The barrier strip 23 can adopt a segmented barrier strip structure. The barrier strip 23 is provided with a slag-blocking lip 231. The slag-blocking lip 231 is connected to the side of the barrier strip 23 facing the spiral downward channel attached to the wall. The slag-blocking lip 231 can be a folded edge structure extending in the direction of liquid flow, so that the colloid slag material migrating to the lower end of the guide tube 2 along the spiral downward channel attached to the wall is retained by the barrier strip 23 and the slag-blocking lip 231.

[0035] The lower end of the guide tube 2 is provided with a constricted guide ring 24. The constricted guide ring 24 is connected to the lower end opening of the guide tube 2. The constricted guide ring 24 is drawn from the outer periphery of the lower end of the guide tube 2 into the interior of the guide tube 2. The constricted guide ring 24 adopts an arc-shaped constriction ring structure, which is used to guide the liquid that has spiraled down through the outside of the guide tube 2 into the interior of the guide tube 2. At the same time, it makes it easier for the colloid slag material that is retained near the barrier bar 23 and the slag-blocking lip 231 to collect in the bottom slag collection chamber at the bottom of the filter separation tube 1.

[0036] The guide tube 2 is equipped with a filter element 3. The filter element 3 can be a cylindrical filter element, a sintered metal filter element, an ethylene glycol-resistant pleated filter element, or other cylindrical filter elements suitable for filtering ethylene glycol recovery liquid. The filter element 3 is eccentrically set relative to the guide tube 2, specifically, the axis of the filter element 3 is offset relative to the axis of the guide tube 2, so that an uneven inner flow space is formed between the outer wall of the filter element 3 and the inner wall of the guide tube 2. This inner flow space includes an inner narrow flow gap and an inner wide flow gap. Ethylene glycol that has been pre-separated on the outside and enters the interior of the guide tube 2 will generate an offset flow trajectory in this inner flow space, migrating from the inner narrow flow gap to the inner wide flow gap. The liquid inside the guide tube 2 passes through the filter element 3 from the outside to the inside, and the filtered ethylene glycol enters the inner cavity of the filter element 3.

[0037] The guide tube 2 has an inclined inner baffle 25 inside. The inner baffle 25 is located in the inner flow space formed between the filter element 3 and the guide tube 2, and is set on the liquid flow path that migrates from the inner narrow flow gap to the inner wide flow gap. The inner baffle 25 can be an arc plate or an inclined baffle structure. One side is set close to the inner wall of the guide tube 2, and the other side extends towards the outer periphery of the filter element 3. The liquid entering the guide tube 2 flows from the narrow side to the wide side under the action of the deflection trajectory formed by the eccentric setting of the filter element 3. When the residual colloidal particles migrate with the liquid, they come into contact with the inner baffle 25 and are intercepted for a second time. A temporary storage area for temporarily storing the colloidal particles is formed below the inner baffle 25, thereby reducing the risk of the residual colloidal particles continuing to adhere to the outer surface of the filter element 3.

[0038] The guide tube 2 is equipped with two sets of waste discharge and slag guiding components 26. The two sets of waste discharge and slag guiding components 26 are located at both ends of the inner baffle plate 25. The waste discharge and slag guiding components 26 are vertical slag guiding troughs or slag guiding blocks with internal cavities. The waste discharge and slag guiding components 26 are equipped with waste discharge and slag guiding channels 261. One end of the waste discharge and slag guiding channel 261 is connected to the temporary storage area below the inner baffle plate 25, and the other end of the waste discharge and slag guiding channel 261 is connected to the bottom slag collection chamber. During normal filtration and replacement, the waste discharge port 13 is closed, and the granular slag in the temporary storage area is mainly retained below the inner baffle plate 25. When the waste discharge port 13 is opened, the bottom slag collection chamber and the waste discharge and slag guiding channel 261 form a waste discharge flow path towards the waste discharge port 13, so that the granular slag in the temporary storage area enters the bottom slag collection chamber through the waste discharge and slag guiding channel 261 and is discharged through the waste discharge port 13 along with the slag-containing waste liquid.

[0039] The lower end of the filter element 3 is connected to an eccentric connecting bend 31. The eccentric connecting bend 31 is used to adapt to the discharge position of the filter element 3 after it is eccentrically set relative to the guide cylinder 2. The eccentric connecting bend 31 is connected to a discharge pipe 32, which is connected to the outlet 12. The filtered ethylene glycol in the inner cavity of the filter element 3 is discharged from the filter separation cylinder 1 in sequence through the eccentric connecting bend 31, the discharge pipe 32 and the outlet 12. The eccentric connecting bend 31 can be a bent pipe, an offset joint or an eccentric adapter pipe structure. The discharge pipe 32 can be a horizontal discharge pipe or a zigzag discharge pipe structure to adapt to the lower outlet 12 of the filter separation cylinder 1.

[0040] The bottom of the filter separator 1 is provided with a separator 33, which surrounds the eccentric connecting bend 31. The outer periphery of the separator 33 is in contact with the inner wall of the filter separator 1. A bottom slag collection chamber is formed above the separator 33. The separator 33 adopts a disc-shaped structure. Its outer periphery can be sealed to the inner wall of the filter separator 1 through a sealing ring, or it can be connected to the filter separator 1 through a detachable clamping part or a fixing part. The separator 33 is used to form a relatively independent slag collection space at the bottom of the filter separator 1, so that the colloidal slag generated by the spiral pre-separation, slag interception and inner secondary separation can be collected in the bottom slag collection chamber. The bottom slag collection chamber is connected to the waste discharge port 13 so that it can be discharged through the waste discharge port 13 during periodic cleaning.

[0041] In this embodiment, during normal operation of the online ethylene glycol replacement device, the impurity-containing ethylene glycol recovery liquid from the polyester fiber production line enters the filter separation cylinder 1 through the inlet 11 and is guided to the outside of the guide cylinder 2 by the guide groove 211 on the guide seat 21. Under the guidance of multiple spiral blades 22, the impurity-containing ethylene glycol recovery liquid forms a wall-adhering spiral downward flow between the outside of the guide cylinder 2 and the inner wall of the filter separation cylinder 1. During this spiral flow, the granular residue migrates to the lower end of the guide cylinder 2. The granular residue that migrates to the lower end of the guide cylinder 2 is blocked by the blocking bar. 23 and the slag-blocking lip 231 block and retain the ethylene glycol after pre-separation on the outside. The ethylene glycol enters the interior of the guide cylinder 2 through the guide ring 24. The ethylene glycol entering the interior of the guide cylinder 2 migrates from the narrow inner flow gap to the wide inner flow gap in the inner flow space formed by the eccentric setting of the filter element 3. The residual colloidal slag is intercepted twice by the inner baffle 25 during the eccentric flow process and is temporarily stored below the inner baffle 25. Then, the ethylene glycol passes through the filter element 3 from the outside to the inside and is discharged through the eccentric connecting bend 31, the discharge pipe 32 and the liquid outlet 12.

[0042] After the device has been running for a period of time, the bottom slag collection chamber collects the colloid slag and slag-containing waste liquid that is guided by the spiral blade 22, blocked by the baffle bar 23, and retained by the slag-blocking lip 231. A small amount of residual colloid slag may also be temporarily stored below the inner baffle plate 25. When cleaning is required, the waste discharge port 13 is opened, and the slag-containing waste liquid in the bottom slag collection chamber is discharged through the waste discharge port 13. At the same time, the waste discharge guide channel 261 in the waste discharge guide component 26 forms a flow trajectory toward the bottom slag collection chamber and the waste discharge port 13, so that the colloid slag in the temporary storage area enters the bottom slag collection chamber with the waste discharge flow and is finally discharged through the waste discharge port 13. After the waste discharge is completed, the waste discharge port 13 is closed, and the filter separation cylinder 1 continues to perform online ethylene glycol filtration and replacement.

[0043] The present invention also provides a displacement method for an online ethylene glycol displacement device, the method comprising the following steps: S1. Liquid Inlet Guidance: Start the liquid inlet pipeline connected to the liquid inlet 11 to allow the impurity ethylene glycol recovery liquid in the polyester fiber production line to enter the filter separation cylinder 1 at a preset flow rate. After entering the filter separation cylinder 1, the impurity ethylene glycol recovery liquid first contacts the guide seat 21 and, under the guidance of the guide seat 21, deviates from the inner filtration area where the filter element 3 is located, and instead enters the outer pre-separation area between the outer side of the guide cylinder 2 and the inner wall of the filter separation cylinder 1. S2, Spiral Pre-Separation: The ethylene glycol-containing recovery liquid entering the outer pre-separation zone flows downward along the spiral flow channel defined by multiple spiral blades 22, so that the liquid forms a spiral downward state attached to the wall in the filter separation cylinder 1. The colloid residue, polyester oligomer agglomerates and fine powder particles in the ethylene glycol-containing recovery liquid gradually migrate towards the lower end of the outer wall of the guide cylinder 2 and the bottom of the filter separation cylinder 1 during the spiral flow process. S3, Lower end blocking slag: When the ethylene glycol recovery liquid containing impurities flows to the lower end of the outer wall of the guide tube 2, the blocking strip 23 and the slag-blocking lip 231 block the granular slag that migrates to this position with the downward flow of the spiral, so that the granular slag stays near the lower end of the guide tube 2 and gradually enters the bottom slag collection chamber. The ethylene glycol that has been pre-separated on the outside enters the interior of the guide tube 2 through the lower end of the guide tube 2. S4. Secondary separation by inner bias flow: The ethylene glycol entering the guide tube 2 continues to flow in the inner flow space formed by the eccentric setting of the filter element 3. The liquid migrates from the inner narrow flow gap side to the inner wide flow gap side. During this bias flow migration, the residual colloidal particles are blocked by the inclined inner baffle 25 and temporarily stored below the inner baffle 25, so that the residual colloidal particles are further separated from the main liquid flow entering the filter element 3. S5, Filter cartridge filtration: Ethylene glycol after secondary separation by internal bias flow passes through the filter cartridge 3 from the outside to the inside. The filter cartridge 3 filters the remaining suspended particles and fine colloidal particles in the ethylene glycol. The filtered ethylene glycol enters the inner cavity of the filter cartridge 3 and is discharged from the filter separation cylinder 1 through the liquid outlet 12 via the liquid outlet channel connected to the filter cartridge 3. S6. Periodic waste discharge and cleaning: When the filter separator 1 has been running for a preset time, the liquid flow rate decreases, the filtration pressure difference increases, or the slag content in the bottom slag collection chamber reaches the cleaning condition, stop the liquid inlet of the corresponding filter separator 1 or reduce its liquid inlet flow rate, and open the waste discharge port 13 to discharge the colloid slag and slag-containing waste liquid collected in the bottom slag collection chamber through the waste discharge port 13. At the same time, the residual colloid slag temporarily stored below the inner baffle plate 25 enters the bottom slag collection chamber under the action of waste discharge flow and is discharged together with the slag-containing waste liquid. After the waste discharge is completed, close the waste discharge port 13 and restore the filter separator 1 to the filtration replacement state.

[0044] It should be noted that the spiral blade 22 in this embodiment does not rely solely on gravity settling or centrifugal force to separate all the colloid particles and residues. Instead, it is used to confine the ethylene glycol-containing recovery liquid entering from the inlet 11 within the spiral downward channel between the outer side of the guide tube 2 and the inner wall of the filter separation tube 1. This allows the ethylene glycol-containing recovery liquid to form an extended flow path along the outer side of the guide tube 2 before entering the filter element 3, and to carry the colloid particles and residues to the blocking area at the lower end of the outer wall of the guide tube 2. The blocking strip 23 and the slag-blocking lip 231 located at the lower end of the outer wall of the guide tube 2 mechanically block and retain the colloid particles and residues that migrate to this position with the liquid, thereby reducing the proportion of colloid particles and residues that directly enter the interior of the guide tube 2 and impact the filter element 3.

[0045] For residual colloid residue that is not retained by the blocking strip 23 and the slag-blocking lip 231 and enters the interior of the guide tube 2 with the liquid, this embodiment sets the filter element 3 eccentrically relative to the guide tube 2, so that an inner narrow flow gap and an inner wide flow gap are formed between the outer wall of the filter element 3 and the inner wall of the guide tube 2. The ethylene glycol liquid entering the interior of the guide tube 2 forms a deflection trajectory that migrates from the narrow side to the wide side in the inner flow space. The inclined inner baffle 25 is located on this deflection trajectory and is used to intercept the residual colloid residue that migrates with the deflection trajectory for a second time, and a temporary storage area is formed below the inner baffle 25, thereby further reducing the local accumulation of residual colloid residue on the outer surface of the filter element 3.

[0046] It should also be noted that the granular residue in this embodiment includes polyester oligomer agglomerates, gel-like impurities, fine PTA powder particles, fine IPA powder particles, and suspended particulate impurities in the ethylene glycol recovery liquid from the polyester fiber production line. This embodiment does not require the above-mentioned granular residue to settle to the bottom slag collection chamber entirely by density difference. Instead, the initial filtration load of the filter element 3 is reduced by the spiral migration outside the guide tube 2, the mechanical blocking of the barrier strip 23 and the slag-blocking lip 231, the secondary separation of the eccentric filter element 3 and the inner baffle plate 25 inside the guide tube 2, and the final filtration of the filter element 3.

[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An online ethylene glycol displacement device, comprising a filter separation cylinder (1), characterized in that: The upper side wall of the filter separation cylinder (1) is provided with a liquid inlet (11), the lower side wall of the filter separation cylinder (1) is provided with a liquid outlet (12), the filter separation cylinder (1) is provided with a waste discharge port (13) near the bottom, the filter separation cylinder (1) is provided with a guide cylinder (2) arranged coaxially with the filter separation cylinder (1), and the upper part of the guide cylinder (2) is provided with a guide seat (21) corresponding to the liquid inlet (11). The outer periphery of the guide tube (2) is provided with a plurality of spiral blades (22), which are disposed between the outer periphery of the guide tube (2) and the inner wall of the filter separation tube (1) and extend spirally along the height direction of the guide tube (2); The lower end of the outer wall of the guide tube (2) is provided with a barrier strip (23), and the barrier strip (23) is provided with a slag-blocking lip (231). The barrier strip (23) and the slag-blocking lip (231) are used to block the granular slag material that migrates to the lower end of the guide tube (2) as it flows downward with the spiral. The guide tube (2) is provided with a filter element (3) inside. The filter element (3) is eccentrically arranged relative to the guide tube (2), so that an uneven inner flow space is formed between the outer wall of the filter element (3) and the inner wall of the guide tube (2). The liquid inside the guide tube (2) passes through the filter element (3) from the outside to the inside. The guide tube (2) is provided with an inclined inner baffle (25) inside, and the inner baffle (25) is located in the inner flow space; The inner cavity of the filter element (3) is connected to the liquid outlet (12), and the bottom of the filter separation cylinder (1) forms a bottom slag collection cavity, which is connected to the waste discharge port (13).

2. The online ethylene glycol displacement device according to claim 1, characterized in that: The filter separation cylinder (1) has two connected in parallel. The bottom of the two filter separation cylinders (1) is provided with a sliding base (4). The liquid inlet (11) of the two filter separation cylinders (1) is connected to the liquid inlet pipeline, and the liquid outlet (12) of the two filter separation cylinders (1) is connected to the liquid outlet pipeline.

3. The online ethylene glycol displacement device according to claim 1, characterized in that: The guide seat (21) is located at the upper end of the guide cylinder (2). The guide seat (21) is provided with a guide groove (211). One end of the guide groove (211) is corresponding to the liquid inlet (11). The other end of the guide groove (211) extends to the outer periphery of the guide cylinder (2), so that the ethylene glycol-containing recovery liquid entering from the liquid inlet (11) first enters the outer pre-separation area between the guide cylinder (2) and the inner wall of the filter separation cylinder (1).

4. The online ethylene glycol displacement device according to claim 1, characterized in that: Multiple spiral blades (22) are arranged at intervals along the outer periphery of the guide tube (2). The inner edge of the spiral blades (22) is connected to the outer wall of the guide tube (2), and the outer edge of the spiral blades (22) is attached to the inner wall of the filter separation tube (1), so that a wall-attached spiral downward channel is formed between adjacent spiral blades (22).

5. The online ethylene glycol displacement device according to claim 4, characterized in that: The barrier bar (23) is disposed along the lower end of the outer wall of the guide tube (2) and located at the end of the wall-mounted spiral downward channel. The slag-blocking lip (231) is connected to the side of the barrier bar (23) facing the wall-mounted spiral downward channel, so that the granular slag material migrating to the lower end of the guide tube (2) along the wall-mounted spiral downward channel is retained by the barrier bar (23) and the slag-blocking lip (231).

6. The online ethylene glycol displacement device according to claim 1, characterized in that: The lower end of the guide tube (2) is provided with a constricted guide ring (24). The constricted guide ring (24) is connected to the lower opening of the guide tube (2). The constricted guide ring (24) is constricted from the outer periphery of the lower end of the guide tube (2) towards the inside of the guide tube (2) so as to guide the liquid that has spiraled down through the outside of the guide tube (2) into the inside of the guide tube (2).

7. The online ethylene glycol displacement device according to claim 1, characterized in that: The axis of the filter element (3) is offset relative to the axis of the guide cylinder (2), so that an inner narrow flow gap and an inner wide flow gap are formed between the outer wall of the filter element (3) and the inner wall of the guide cylinder (2). The inner baffle (25) is arranged on the liquid flow path from the inner narrow flow gap to the inner wide flow gap. A temporary storage area for temporarily storing colloid residue is formed below the inner baffle (25).

8. The online ethylene glycol displacement device according to claim 7, characterized in that: The guide tube (2) is provided with two sets of waste discharge guide components (26) inside. The two sets of waste discharge guide components (26) are located at both ends of the inner baffle plate (25). The waste discharge guide component (26) is provided with a waste discharge guide channel (261). One end of the waste discharge guide channel (261) is connected to the temporary storage area, and the other end of the waste discharge guide channel (261) is connected to the bottom slag collection cavity, so that when the waste discharge port (13) is opened, the granular slag in the temporary storage area enters the bottom slag collection cavity through the waste discharge guide channel (261).

9. The online ethylene glycol displacement device according to claim 1, characterized in that: The lower end of the filter element (3) is connected to an eccentric connecting bend (31), and the eccentric connecting bend (31) is connected to a discharge pipe (32). The discharge pipe (32) is connected to the liquid outlet (12). The bottom of the filter separation cylinder (1) is provided with a separator plate (33). The separator plate (33) is arranged around the eccentric connecting bend (31). The outer periphery of the separator plate (33) is in contact with the inner wall of the filter separation cylinder (1). The bottom slag collection cavity is formed above the separator plate (33).

10. A displacement method for an online ethylene glycol displacement apparatus, applied to the online ethylene glycol displacement apparatus according to any one of claims 1-9, characterized in that, Includes the following steps: S1, Liquid inlet guide: The impure ethylene glycol recovery liquid in the polyester fiber production line is sent into the filter separation cylinder (1) through the liquid inlet (11), and the impure ethylene glycol recovery liquid is guided to the outside of the guide cylinder (2) through the guide seat (21); S2, Spiral pre-separation: The ethylene glycol recovery liquid containing impurities flows downward in a spiral along the outside of the guide tube (2) under the guidance of the spiral blades (22), causing the granular residue to migrate to the lower end of the guide tube (2); S3, Lower end blocking slag: The blocking strip (23) and the slag-blocking lip (231) block the granular slag material migrating to the lower end of the guide tube (2), and the ethylene glycol after the pre-separation on the outside enters the interior of the guide tube (2); S4, inner side deflection secondary separation: Ethylene glycol entering the guide tube (2) migrates from the narrow side to the wide side in the inner flow space formed by the eccentric setting of the filter element (3), and the inner baffle (25) performs secondary separation of residual colloid residue. S5, Filter cartridge filtration liquid: Ethylene glycol passes through the filter cartridge (3) from the outside to the inside and is discharged from the outlet (12); S6. Regular waste discharge and cleaning: The waste discharge port (13) is opened during regular cleaning so that the granular slag and slag-containing waste liquid in the bottom slag collection chamber can be discharged through the waste discharge port (13).

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