Continuous filtering device

Abstract

The utility model provides a continuous filtering device which comprises a first-stage filtering system, a second-stage filtering system, a third-stage filtering system, a fourth-stage filtering system, a fifth-stage filtering system, a cleaning and regenerating system and a purging system which are sequentially connected, the cleaning and regenerating system is connected with the first-stage filtering system, the second-stage filtering system, the third-stage filtering system and the fourth-stage filtering system, and the purging system is connected with the third-stage filtering system; the first-stage filtering system is provided with a first-stage cleaning inlet and a first-stage slag discharging opening, and the first-stage cleaning inlet is connected with the cleaning regeneration system; the second-stage filtering system is provided with a second-stage backwashing inlet and a second-stage backwashing outlet, and the second-stage backwashing inlet is connected with the cleaning regeneration system; the third-stage filtering system is provided with a third-stage backwashing inlet, a third-stage backwashing outlet, a forward blowing inlet and a reverse blowing inlet, and the third-stage backwashing inlet is connected with the cleaning regeneration system; the fourth-stage filtering system is provided with a fourth-stage backwashing inlet and a fourth-stage backwashing outlet, and the fourth-stage backwashing inlet is connected with the cleaning regeneration system. According to the continuous filtering device, through multi-stage filtering, solid impurities can be removed, and continuous filtering is carried out.

Description

Technical Field

[0001] This application relates to the field of filter technology, and more particularly to a continuous filtration device. Background Technology

[0002] The low recycling rate of materials such as polyester and polyurethane is mainly due to the textile industry's use of large quantities of dyes and pigments, and the extreme difficulty in filtering and purifying them during the recycling process, which affects the reusability of the recycled materials. This issue has become a major bottleneck in the chemical recycling of polyester and polyurethane materials. Summary of the Invention

[0003] The purpose of this application is to provide a continuous filtration device that can filter the alcoholysis liquid after the alcoholysis of polyester and polyurethane in stages, effectively removing impurities such as dyes, pigments and catalysts, and solving the problem of the limitation of the reuse of polyester and polyurethane in the prior art.

[0004] To achieve one of the above-mentioned objectives, one embodiment of this application provides a continuous filtration device, comprising a primary filtration system, a secondary filtration system, a tertiary filtration system, a quaternary filtration system, and a quinary filtration system connected in sequence. The continuous filtration device further includes a cleaning and regeneration system and a purging system. The cleaning and regeneration system is connected to the primary filtration system, the secondary filtration system, the tertiary filtration system, and the quaternary filtration system, respectively, and the purging system is connected to the tertiary filtration system.

[0005] The primary filtration system is equipped with a primary cleaning inlet and a primary slag discharge outlet, the primary cleaning inlet being connected to the cleaning and regeneration system; the secondary filtration system is equipped with a secondary backwash inlet and a secondary backwash outlet, the secondary backwash inlet being connected to the cleaning and regeneration system; the tertiary filtration system is equipped with a tertiary backwash inlet, a tertiary backwash outlet, and a forward air inlet and a reverse air inlet for connecting to the purging system, the tertiary backwash inlet being connected to the cleaning and regeneration system; the quaternary filtration system is equipped with a quaternary backwash inlet and a quaternary backwash outlet, the quaternary backwash inlet being connected to the cleaning and regeneration system.

[0006] As a further improvement of one embodiment of this application, the primary filtration system includes two primary filters connected in parallel, the secondary filtration system includes one secondary filter, the tertiary filtration system includes two tertiary filters connected in parallel, the quaternary filtration system includes two quaternary filters connected in parallel, and the quinary filtration system includes two quinary filters connected in parallel; the cleaning and regeneration system is connected to the two primary filters, the one secondary filter, the two tertiary filters, and the two quaternary filters respectively, and the purging system is connected to the two tertiary filters.

[0007] As a further improvement of one embodiment of this application, the primary filtration system further includes a primary centrifugal pump for feeding the liquid to be filtered into the primary filter.

[0008] As a further improvement of one embodiment of this application, the primary filter adopts a three-stage continuous sedimentation device, which includes a primary sedimentation tank, a secondary sedimentation tank and a tertiary sedimentation tank connected in sequence. The volume of the primary sedimentation tank accounts for 40-60% of the total volume of the three-stage continuous sedimentation device, the secondary sedimentation tank accounts for 30-40% of the total volume of the three-stage continuous sedimentation device, and the tertiary sedimentation tank accounts for 10-30% of the total volume of the three-stage continuous sedimentation device. Each sedimentation tank is provided with a primary cleaning inlet at the top and a primary slag discharge outlet at the bottom.

[0009] As a further improvement of one embodiment of this application, the secondary filter adopts a stainless steel wedge-shaped filter screen with a filtration accuracy of 30-100μm.

[0010] As a further improvement to one embodiment of this application, the secondary filtration system also includes a secondary centrifugal pump connected to the secondary filter.

[0011] As a further improvement of one embodiment of this application, it also includes a slag discharge system disposed on the secondary filter, the slag discharge system including a slag press, a scraper and a drive mechanism for providing power to the scraper.

[0012] As a further improvement of one embodiment of this application, the three-stage filter adopts a titanium rod filter element or a metal powder sintered filter element, with a filtration accuracy of 0.22-5μm, and the filter element arrangement adopts a tube-type or candle-type arrangement.

[0013] As a further improvement of one embodiment of this application, the three-stage filtration system further includes a filter aid preparation tank connected to the three-stage filter, and a filter aid centrifugal pump is connected between the three-stage filter and the filter aid preparation tank.

[0014] As a further improvement of one embodiment of this application, the three-stage filtration system further includes a centrifuge connected to the three-stage filter, and a three-stage centrifugal pump is connected between the three-stage filter and the centrifuge.

[0015] As a further improvement of one embodiment of this application, the four-stage filter uses a silicon carbide ceramic filter element with a filtration accuracy of 10-100 nm.

[0016] As a further improvement of one embodiment of this application, the five-stage filter employs an activated carbon adsorption device.

[0017] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0018] In the continuous filtration device provided in this application, the liquid to be filtered can remove most of the impurities and color through five-stage filtration. Simultaneously, a cleaning and regeneration system and a purging system are installed in the continuous filtration device to clean and regenerate the filtration system, achieving continuous filtration and improving the working efficiency of the continuous filtration device. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the continuous filtration device in the embodiments of this application.

[0020] 11. Primary filter; 111. Primary cleaning inlet; 112. Primary slag discharge outlet; 12. Primary centrifugal pump;

[0021] 21. Secondary filter; 211. Secondary backwash inlet; 212. Secondary backwash outlet; 213. Drive mechanism; 22. Secondary centrifugal pump;

[0022] 31. Three-stage filter; 311. Backflush inlet; 312. Three-stage backwash outlet; 313. Forward flush inlet; 314. Three-stage backwash inlet; 315. Three-stage slag discharge outlet; 32. Filter aid preparation tank; 321. Filter aid centrifugal pump; 34. Three-stage centrifugal pump; 35. Centrifuge;

[0023] 41. Four-stage filter; 411. Four-stage backwash inlet; 412. Four-stage backwash outlet; 42. Four-stage centrifugal pump;

[0024] 51. Activated carbon adsorption device;

[0025] 61. Backwashing agent supply tank; 62. First centrifugal pump; 63. Backwashing pipeline;

[0026] 71. Gas main inlet pipe; 72. Purge pipe. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0028] The terms used in this document, such as “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” indicating spatial relative positions, are used for illustrative purposes to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. The terms “spatial relative positions” may be intended to include different orientations of the equipment in use or operation other than those shown in the figures.

[0029] For example, if the device in the figure is flipped, a unit described as being "below" or "under" other units or features will be "above" other units or features. Therefore, the exemplary term "below" can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatially related descriptive terms used herein will be interpreted accordingly.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] This application provides a continuous filtration device, such as... Figure 1 As shown, the continuous filtration device includes a primary filtration system, a secondary filtration system, a tertiary filtration system, a quaternary filtration system, and a quinary filtration system connected in sequence. The continuous filtration device also includes a cleaning and regeneration system and a purging system. The cleaning and regeneration system is connected to the primary filtration system, the secondary filtration system, the tertiary filtration system, and the quaternary filtration system, respectively, and the purging system is connected to the tertiary filtration system.

[0032] The primary filtration system is provided with a primary cleaning inlet 111 and a primary slag discharge outlet 112, and the primary cleaning inlet 111 is connected to the cleaning and regeneration system; the secondary filtration system is provided with a secondary backwash inlet 211 and a secondary backwash outlet 212, and the secondary backwash inlet 211 is connected to the cleaning and regeneration system; the tertiary filtration system is provided with a tertiary backwash inlet 314, a tertiary backwash outlet 312, and a forward air inlet 313 and a reverse air inlet 311 for connecting to the purging system, and the tertiary backwash inlet 314 is connected to the cleaning and regeneration system; the quaternary filtration system is provided with a quaternary backwash inlet 411 and a quaternary backwash outlet 412, and the quaternary backwash inlet 411 is connected to the cleaning and regeneration system.

[0033] The continuous filtration device provided in this application is sequentially configured with a primary filtration system, a secondary filtration system, a tertiary filtration system, and a quaternary filtration system. It can filter the liquid to be filtered (such as the alcoholysis liquid after polyester alcoholysis, hereinafter referred to as alcoholysis liquid) stage by stage, effectively removing impurities such as dyes, pigments, and catalysts from the liquid to be filtered. Finally, the remaining trace impurities are removed by an activated adsorption device, resulting in an impurity-free liquid to be filtered. To achieve continuous filtration, this application includes a cleaning and regeneration system and a purging system in the continuous filtration device to facilitate cleaning and regeneration of the filtration system and prevent the filtration efficiency from decreasing due to impurities clogging the system.

[0034] Furthermore, the primary filtration system includes two primary filters 11 connected in parallel; the secondary filtration system includes one secondary filter 21; the tertiary filtration system includes two tertiary filters 31 connected in parallel; the quaternary filtration system includes two quaternary filters 41 connected in parallel; and the quinary filtration system includes two quinary filters 51 connected in parallel. A cleaning and regeneration system is connected to the two primary filters 11, the one secondary filter 21, the two tertiary filters 31, and the two quaternary filters 41, respectively. A purging system is connected to the two tertiary filters 31. Figure 1 Only one primary filter 11, one tertiary filter 31, one quaternary filter 41, and one quinary filter 51 are shown.

[0035] As can be seen, the filtration precision of the primary, secondary, tertiary, quaternary, and quinary filtration systems gradually increases to filter out smaller impurities. Two primary filters (11), two tertiary filters (31), and two quaternary filters (41) are provided, with the two filters of the same level taking turns for filtration; that is, while one filter is performing filtration, the other filter of the same level is being cleaned and regenerated. Similarly, two quinary filters (51) are provided; while one quinary filter (51) is having its activated carbon filter element replaced, the other quinary filter (51) is performing the filtration operation. This allows the continuous filtration device to perform uninterrupted filtration.

[0036] In some embodiments, a centrifugal pump 12 is provided at the front end of the primary filter 11 to deliver the liquid to be filtered into the primary filter 11. Further, the primary filter 11 employs a three-stage continuous sedimentation device, which includes a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank connected in sequence. The volume of the primary sedimentation tank accounts for 40-60% of the total volume of the three-stage continuous sedimentation device; the volume of the secondary sedimentation tank accounts for 30-40% of the total volume; and the volume of the tertiary sedimentation tank accounts for 10-30% of the total volume. Each sedimentation tank has a primary cleaning inlet 111 at the top and a primary slag discharge outlet 112 at the bottom.

[0037] The filtrate is first pumped into the primary sedimentation tank by the primary centrifugal pump 12. Impurities such as dyes and pigments settle to the bottom of the primary sedimentation tank, and the clear liquid on the upper part flows into the secondary sedimentation tank through the upper overflow port. After sedimentation, the filtrate enters the tertiary sedimentation tank.

[0038] Furthermore, a secondary centrifugal pump 22 is connected between the primary filter 11 and the secondary filter 21. After the filtrate is settled by the three-stage continuous sedimentation device, the supernatant enters the secondary filter 21 through the secondary centrifugal pump 22.

[0039] In some embodiments, the secondary filter 21 uses a stainless steel wedge-shaped filter screen with a filtration accuracy of 30-100μm, and the filter screen with the required filtration accuracy can be selected as needed.

[0040] Furthermore, the continuous filtration device also includes a sludge removal system installed in the secondary filter 21. The sludge removal system includes a sludge press, a scraper, and a drive mechanism 213 that powers the scraper. By installing the sludge removal system in the secondary filter 21, the drive mechanism 213 powers the scraper to scrape the filter residue off the filter screen. The rotating scraper presses the filter residue against the sludge press, which then compresses the residue. The filtrate returns to the secondary filter, while the dry residue is directly discharged. This allows for simultaneous production and sludge cleaning, as well as solid-liquid separation of waste residue, reducing waste volume, lowering production costs, and extending the cleaning interval of the secondary filter 21.

[0041] In some embodiments, the tertiary filter 31 uses titanium rods or sintered metal powder filter elements with a filtration accuracy of 0.22-5μm, and the filter elements are arranged in a tubular or candle-like manner.

[0042] Furthermore, the three-stage filtration system also includes a filter aid preparation tank 32 connected to the three-stage filter 31, and a filter aid centrifugal pump 321 connected between the three-stage filter 31 and the filter aid preparation tank 32. Before filtration by the three-stage filter 31, a layer of filter aid is formed on the surface of the filter element, which can effectively improve the filtration effect of the filter element. Specifically, before filtration by the three-stage filter 31, filter aid is prepared in the filter aid preparation tank 32, and the prepared filter aid is sent into the three-stage filter 31 by the filter aid centrifugal pump 321. After a certain thickness of filter aid is formed on the surface of the filter element, filtration can begin.

[0043] In some embodiments, the fourth-stage filter 41 uses a silicon carbide ceramic filter element with a filtration accuracy of 10–100 nm.

[0044] In some embodiments, the five-stage filter employs an activated carbon adsorption device 51, which can be used to adsorb the remaining trace impurities and complete the removal of impurities.

[0045] In some embodiments, a four-stage centrifugal pump 42 is provided between the four-stage filter 41 and the activated carbon adsorption device 51 to send the liquid to be filtered after passing through the four-stage filter 41 into the activated carbon adsorption device 51.

[0046] The "stage" in the primary centrifugal pump 12, secondary centrifugal pump 22, tertiary centrifugal pump 34 and quaternary centrifugal pump 42 in this application does not indicate a difference in the power they provide, but is only used to distinguish centrifugal pumps in different positions.

[0047] The cleaning and regeneration system includes a backwash agent supply tank 61, a first centrifugal pump 62, and a backwash pipeline 63. The backwash pipeline 63 connects the backwash agent supply tank 61 to the primary cleaning inlet 111 of the primary filter 11, the backwash agent supply tank 61 to the secondary backwash inlet 211 of the secondary filter 21, the backwash agent supply tank 61 to the tertiary backwash inlet 314 of the tertiary filter 31, and the backwash agent supply tank 61 to the quaternary backwash inlet 411 of the quaternary filter 41. The first centrifugal pump 62 is used to deliver the backwash agent in the backwash agent supply tank 61 into the primary filter 11, secondary filter 21, tertiary filter 31, and quaternary filter 41 through the backwash pipeline 63.

[0048] The purging system includes a gas main inlet pipe 71 and a purging pipe 72 that are interconnected. The gas main inlet pipe 71 is connected to an external gas source. The purging pipe 72 has two pipes, one of which is connected to the forward blow inlet 313 of the three-stage filter 31, and the other is connected to the back blow inlet 311 of the three-stage filter 31.

[0049] Because the secondary filter 21 has a relatively low filtration accuracy and is equipped with a sludge discharge system, its cleaning frequency is low, and only one secondary filter 21 is needed. When the secondary filter 21 needs to be cleaned and regenerated, the backwashing agent in the backwashing agent supply tank 61 is introduced into the secondary filter 21 through the secondary backwashing inlet 211 by the first centrifugal pump 62. After cleaning, the waste liquid with filter residue flows out from the secondary backwashing outlet 212, carrying the filter residue out of the secondary filter 21.

[0050] When one of the three-stage filters 31 needs cleaning and regeneration, firstly, the main gas inlet pipe 71 supplies gas to enter the three-stage filter 31 from the forward blow inlet 313, drying the filter aid and filter residue adhering to the filter element surface. Then, the main gas inlet pipe 71 supplies gas to enter the three-stage filter 31 from the reverse blow inlet 311, dispersing the dried filter aid and filter residue, which is then discharged from the three-stage slag discharge port 315 at the bottom of the three-stage filter 31. The three-stage filter 31 is also equipped with a tail gas discharge port for discharging the forward and reverse blow gases. The forward blow direction is the same as the flow direction of the liquid to be filtered, and the reverse blow direction is the opposite to the flow direction of the liquid to be filtered.

[0051] After the purging system finishes working, the backwashing agent in the backwashing agent supply tank 61 is fed into the three-stage filter 31 through the three-stage backwashing inlet 314 under the action of the first centrifugal pump 62. After cleaning, the waste liquid with filter aid and filter residue flows out from the three-stage backwashing outlet 312, carrying the remaining filter aid and filter residue out of the three-stage filter 31 to complete the cleaning and regeneration.

[0052] In some embodiments, the three-stage filter 31 is provided with a three-stage slag discharge port 315 at its bottom, and the three-stage filtration system further includes a centrifuge 35 connected to the three-stage filter 31 through the three-stage slag discharge port 315. Furthermore, in the continuous filtration device provided in this application, the solvent and backwashing agent in the filter aid can be the same substance during use.

[0053] When one of the three-stage filters 31 needs cleaning and regeneration, the backwashing agent in the backwashing agent supply tank 61 is introduced into the three-stage filter 31 through the three-stage backwashing inlet 314 by the first centrifugal pump 62. After cleaning, the waste liquid containing filter aid and filter cake flows out from the three-stage discharge port 315 and is then discharged to the centrifuge 35 by the three-stage centrifugal pump. After centrifugation in the centrifuge 35, the backwashing agent is returned to the filter aid addition tank 32, and the waste cake is directly discharged from the centrifuge. Thus, the cleaning and regeneration of the three-stage filter 31 is completed.

[0054] When one of the four-stage filters 41 needs to be cleaned and regenerated, the backwashing agent in the backwashing agent supply tank 61 is introduced into the four-stage filter 41 through the four-stage backwashing inlet 411 by the first centrifugal pump 62. After cleaning, the waste liquid with filter residue flows out from the four-stage backwashing outlet 412, carrying the filter residue out of the four-stage filter 41.

[0055] This application addresses the limitations of recycled polyester and polyurethane applications. The following uses the alcoholysis liquid obtained from EG alcoholysis of polyester as the filtration liquid, and employs the continuous filtration device described in this application for filtration:

[0056] After the reaction of polyester and EG with alcoholysis, the resulting alcoholysis liquid is pumped by a primary centrifugal pump 12 into a primary filter 11. The alcoholysis liquid filtered by the primary filter 11 is then discharged by a secondary centrifugal pump 22 to a secondary filter 21. The filter residue is treated by a slag discharge system and then discharged. The alcoholysis liquid then passes through the secondary filter 21 and is discharged through its outlet to a tertiary filter 31. After passing through the tertiary filter 31, the alcoholysis liquid enters a quaternary filter 41 through its outlet. Following filtration through the quaternary filter 41, the alcoholysis liquid is pumped by a quaternary centrifugal pump 42 into an activated carbon adsorption device 51 to adsorb and filter out any remaining trace impurities. The filtered alcoholysis liquid is then discharged from the continuous filtration unit through the outlet of the activated carbon adsorption device 51, completing the filtration process.

[0057] While the aforementioned primary filter 11, tertiary filter 31, and quaternary filter 41 are performing filtration, another primary filter 11, tertiary filter 31, and another quaternary filter 41 are being cleaned and regenerated. Similarly, while one quinary filter 51 is having its activated carbon filter element replaced, another quinary filter 51 is performing filtration.

[0058] Since EG is used as a reactant in the polyester depolymerization process in this application, it is usually added in excess to ensure that the polyester is depolymerized as much as possible. That is, there is still EG in the alcoholysis solution. When the cleaning and regeneration system is working, heated EG (110-170℃) can be used as the backwashing agent to avoid the monomers in the alcoholysis solution from cooling and solidifying, which would affect the filtration. The purging system can use inexpensive hot N2 (110-170℃). At the same time, to prevent the monomers obtained from depolymerization from cooling and crystallizing during the filtration process, heat insulation jackets are installed on the outside of the primary filter 11, secondary filter 21, tertiary filter 31, quaternary filter 41, and quinary filter 51. The pipelines connecting the aforementioned structures are also equipped with jacket heating to maintain the temperature at 110-170℃. The cleaning and regeneration method is as follows:

[0059] Primary filter 11 cleaning: Under the action of the first centrifugal pump 62, the hot EG in the backwashing agent supply tank 61 enters the primary filter 11 through the primary cleaning inlet 111 and flows out from the primary slag discharge port 112, carrying the filter slag out of the primary filter 11 to complete the cleaning and regeneration.

[0060] Secondary filter cleaning: Under the action of the first centrifugal pump 62, the hot EG in the backwash agent supply tank 61 enters the secondary filter 21 through the secondary backwash inlet 211, and the waste liquid flows out from the secondary backwash outlet 212, carrying the filter residue out of the secondary filter 21 to complete the cleaning and regeneration.

[0061] Three-stage filter 31 cleaning method one: First, through the purging system, hot N2 supplied by the main gas inlet pipe 71 enters the three-stage filter 31 from the forward blow inlet 313, drying the filter aid and filter residue. Then, hot N2 supplied by the main gas inlet pipe 71 enters the three-stage filter 31 from the backflush inlet 311, dispersing the dried filter aid and filter residue, which are discharged from the three-stage slag discharge port 315 at the bottom of the three-stage filter. The hot N2 is discharged from the tail gas emission port. After the purging system finishes working, under the action of the first centrifugal pump 62, hot EG in the backwash agent supply tank 61 enters the three-stage filter 31 through the three-stage backwash inlet 314 and flows out from the three-stage backwash outlet 312, carrying the remaining filter aid and filter residue out of the two-stage filter 31 to complete the cleaning and regeneration.

[0062] Three-stage filter 31 cleaning method two: Under the action of the first centrifugal pump 62, hot EG in the backwash agent supply tank 61 enters the three-stage filter 31 through the three-stage backwash inlet 314. After cleaning, the waste liquid is discharged from the three-stage slag discharge port 315 to the centrifuge 35. After centrifugation in the centrifuge 35, the EG is returned to the filter aid addition tank 32, and the waste residue is directly discharged from the centrifuge. Thus, the cleaning and regeneration of the three-stage filter 31 is completed.

[0063] After the tertiary filter 31 is cleaned, the filter aid prepared in the filter aid preparation tank 32 is sent into the tertiary filter 31 through the tertiary centrifugal pump 34, so that a layer of filter aid is formed on the surface of the filter element for later use in the next filtration. The filter aid can be prepared by adding diatomaceous earth to EG at a ratio of 1-5% (or other ratios), stirring and mixing thoroughly before use.

[0064] Four-stage filter 41 cleaning: Under the action of the first centrifugal pump 62, the hot EG in the backwash agent supply tank 61 enters the four-stage filter 41 through the four-stage backwash inlet 411 and flows out from the four-stage backwash outlet 412, carrying the filter residue out of the four-stage filter 41 to complete the cleaning and regeneration.

[0065] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0066] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this application.

Claims

1. A continuous filtration device, characterized in that, The continuous filtration device includes a primary filtration system, a secondary filtration system, a tertiary filtration system, a quaternary filtration system, and a quinary filtration system connected in sequence. The continuous filtration device also includes a cleaning and regeneration system and a purging system. The cleaning and regeneration system is connected to the primary filtration system, the secondary filtration system, the tertiary filtration system, and the quaternary filtration system, respectively. The purging system is connected to the tertiary filtration system. The primary filtration system is equipped with a primary cleaning inlet and a primary slag discharge outlet, the primary cleaning inlet being connected to the cleaning and regeneration system; the secondary filtration system is equipped with a secondary backwash inlet and a secondary backwash outlet, the secondary backwash inlet being connected to the cleaning and regeneration system; the tertiary filtration system is equipped with a tertiary backwash inlet, a tertiary backwash outlet, and a forward air inlet and a reverse air inlet for connecting to the purging system, the tertiary backwash inlet being connected to the cleaning and regeneration system; the quaternary filtration system is equipped with a quaternary backwash inlet and a quaternary backwash outlet, the quaternary backwash inlet being connected to the cleaning and regeneration system.

2. The continuous filtration device according to claim 1, characterized in that, The primary filtration system includes two primary filters connected in parallel; the secondary filtration system includes one secondary filter; the tertiary filtration system includes two tertiary filters connected in parallel; the quaternary filtration system includes two quaternary filters connected in parallel; and the quinary filtration system includes two quinary filters connected in parallel. The cleaning and regeneration system is connected to the two primary filters, the one secondary filter, the two tertiary filters, and the two quaternary filters, respectively. The purging system is connected to the two tertiary filters.

3. The continuous filtration device according to claim 2, characterized in that, The primary filtration system also includes a primary centrifugal pump for feeding the liquid to be filtered into the primary filter.

4. The continuous filtration device according to claim 2, characterized in that, The primary filter employs a three-stage continuous sedimentation device, which includes a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank connected in sequence. The volume of the primary sedimentation tank accounts for 40-60% of the total volume of the three-stage continuous sedimentation device, the secondary sedimentation tank accounts for 30-40% of the total volume, and the tertiary sedimentation tank accounts for 10-30% of the total volume. Each sedimentation tank has a primary cleaning inlet at the top and a primary slag discharge outlet at the bottom.

5. The continuous filtration device according to claim 2, characterized in that, The secondary filter uses a stainless steel wedge-shaped filter screen with a filtration accuracy of 30-100μm.

6. The continuous filtration device according to claim 5, characterized in that, The secondary filtration system also includes a secondary centrifugal pump connected to the secondary filter.

7. The continuous filtration device according to claim 5, characterized in that, It also includes a slag discharge system disposed on the secondary filter, the slag discharge system comprising a slag press, a scraper, and a drive mechanism that provides power to the scraper.

8. The continuous filtration device according to claim 2, characterized in that, The three-stage filter uses titanium rod filter elements or sintered metal powder filter elements, with a filtration accuracy of 0.22-5μm. The filter elements are arranged in a tubular or candle-type configuration.

9. The continuous filtration device according to claim 8, characterized in that, The three-stage filtration system also includes a filter aid preparation tank connected to the three-stage filter, and a filter aid centrifugal pump is connected between the three-stage filter and the filter aid preparation tank.

10. The continuous filtration device according to claim 8, characterized in that, The three-stage filtration system also includes a centrifuge connected to the three-stage filter, and a three-stage centrifugal pump is connected between the three-stage filter and the centrifuge.

11. The continuous filtration device according to claim 2, characterized in that, The four-stage filter uses a silicon carbide ceramic filter element with a filtration accuracy of 10–100 nm.

12. The continuous filtration device according to claim 2, characterized in that, The five-stage filter employs an activated carbon adsorption device.

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