A fluidized bed equipped with a filter screen and a method for installing the filter screen.

Abstract

This invention proposes a fluidized bed with a filter screen and a method for installing the filter screen. The fluidized bed includes an overflow weir and a tower body. The overflow weir is located radially inside the tower body and is lower than the highest point of the fluidized bed. The fluidized bed also includes a filter screen made of nylon. The filter screen has two parallel edges, which correspond to a first connecting part and a second connecting part of the filter screen, respectively. The installation method includes the following steps: fixing the first connecting part of the filter screen to the outer circumferential surface of the overflow weir along its circumference; connecting the second connecting part of the filter screen to the fluidized bed so that the uppermost end of the filter screen is higher than the overflow weir; checking the gap between the first connecting part of the filter screen and the outer circumferential surface of the overflow weir. If the gap is less than or equal to a gap threshold, the installation is complete; if it is greater than the gap threshold, the above steps are repeated to reinstall the filter screen. Applying this invention not only prevents resin loss from the top of the tower in the fluidized bed but also provides high corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgy for uranium mining, specifically to a fluidized bed equipped with a filter screen and a method for installing the filter screen. Background Technology

[0002] In the field of uranium hydrometallurgy, uranium-containing solutions undergo mass transfer through full contact with resin within an ion exchange system to achieve uranium extraction. Based on the properties of the uranium-containing solution, operating methods, and production capacity, ion exchange systems are mainly classified into fixed-bed, moving-bed, and fluidized-bed systems. Fluidized-bed systems are widely used in uranium hydrometallurgy due to their unique advantages. They are particularly suitable for processing uranium-containing solutions with high solids content, giving them a significant advantage in processing complex ore leachates. In fluidized-bed operation, the resin loading is only half the actual bed volume. When the uranium-containing solution is introduced into the fluidized bed, the resin is fluidized by the solution, forming a dynamic suspension. By precisely controlling the linear velocity of the uranium-containing solution, the resin expansion rate can reach 100%. This expansion rate control is crucial for ensuring sufficient resin fluidization within the fluidized bed, maximizing the contact area and mass transfer efficiency between the resin and the uranium-containing solution, thereby improving uranium extraction efficiency. To further optimize the operating performance of the fluidized bed, an enlarged section is installed at the top of the fluidized bed tower. Due to its larger diameter, the linear velocity of this section decreases accordingly, thereby reducing the expansion rate of the resin and achieving separation of the resin and solution. Subsequently, the depleted uranium solution overflows and flows out through the collection tray.

[0003] Since fixed-bed and moving-bed systems are filled with resin, existing technologies typically use stainless steel filters to separate the resin from the depleted uranium solution after uranium extraction. Specifically, CN119285161A proposes a fluidized bed-dual-membrane deep defluorination device, comprising several fluidized bed reactors. The inlet of each fluidized bed reactor is connected to an inlet pipe via a first solenoid valve. A stainless steel filter is located at the lower end of the fluidized bed reactor, with seed crystals distributed below the filter. Above the filter is a fluidized bed clarification zone. The fluidized bed outlet is connected to the ultrafiltration inlet of a first ultrafiltration membrane column via a first high-pressure diaphragm pump. The ultrafiltration product outlet of the first ultrafiltration membrane column is connected to a regulating tank. The regulating tank is connected to the reverse osmosis inlet of a reverse osmosis membrane column via a second high-pressure diaphragm pump. The reverse osmosis outlet of the reverse osmosis membrane column is connected to a product water tank.

[0004] However, existing fluidized bed filters suffer from technical problems such as poor acid resistance, complex replacement, and high cost, which cannot meet the needs of actual production. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the first aspect of the present invention provides a fluidized bed equipped with a filter screen. The fluidized bed includes an overflow weir and a tower body. The overflow weir is located radially inside the tower body and is lower than the highest height of the fluidized bed. The fluidized bed also includes a filter screen made of nylon. The filter screen is arranged circumferentially around the overflow weir and radially outside the overflow weir. At least some solid particles in the fluid overflowing from the overflow weir can be intercepted by the filter screen.

[0007] Furthermore, the mesh size of the filter screen is 0.4mm to 0.6mm.

[0008] Furthermore, the filter screen has quadrilateral mesh openings and is woven in a plain weave pattern.

[0009] Furthermore, the filter screen includes two or more sub-filter screens, and the thickness of each sub-filter screen is 0.45mm to 0.55mm.

[0010] Furthermore, the filter screen also includes an anti-crystallization coating, which is disposed on the surface of the filter screen, and the thickness of the anti-crystallization coating is 3-5 mm. .

[0011] Furthermore, the filter screen includes two parallel sides, which correspond to the first connecting part and the second connecting part of the filter screen respectively; the first connecting part is fixed to the outer circumferential surface of the overflow weir along the circumference of the overflow weir, and the uppermost end of the filter screen is higher than the overflow weir.

[0012] Furthermore, the filter screen includes a flexible component that extends circumferentially along the overflow weir, and the first connecting portion of the filter screen is fixed to the outer circumferential surface of the overflow weir via the flexible component along the circumferential direction of the overflow.

[0013] Furthermore, the two ends of the flexible component are connected by snap fasteners, which can adjust the tension of the flexible component.

[0014] Furthermore, the fluidized bed also includes a circumferential groove, which is formed on the outer circumferential surface of the overflow weir, and the flexible component is at least partially located in the circumferential groove.

[0015] Furthermore, the fluidized bed also includes a support structure, which is fixed to the tower body circumferentially, and the filter screen also includes a drawstring, which is located at the second connection part of the filter screen and is connected to the support structure.

[0016] Furthermore, the fluidized bed also includes two or more spray devices, which are fixed to the support structure circumferentially and located radially outside the filter screen.

[0017] Furthermore, the cleaning medium sprayed by the spraying device is acidic.

[0018] To achieve the above objectives, the first aspect of the present invention provides a fluidized bed filter installation method for a fluidized bed with a filter installed, the installation method comprising the following steps: The first connecting part of the filter screen is fixed to the outer circumferential surface of the overflow weir along the circumferential direction of the overflow weir; The second connecting part of the filter screen is connected to the fluidized bed, and the uppermost end of the filter screen is higher than the overflow weir. Check the gap between the first connection of the filter screen and the outer circumference of the overflow weir. If it is less than or equal to the gap threshold, the installation is complete; if it is greater than the gap threshold, repeat the above steps to reinstall the filter screen.

[0019] Further, the first connecting portion of the filter screen is fixed to the outer peripheral surface of the overflow weir along the circumferential direction of the overflow weir, including: The first connecting part of the filter screen is fixed to the outer circumferential surface of the overflow weir using a flexible component surrounding the overflow weir.

[0020] Further, connecting the second connecting portion of the filter screen to the fluidized bed includes, The second connecting part of the filter screen is connected to the support structure fixed to the tower body to realize the connection between the second connecting part of the filter screen and the fluidized bed.

[0021] Further, connecting the second connecting portion of the filter screen to the support structure includes, The support structure and the drawstring located at the second connecting part are connected to achieve the connection between the second connecting part of the filter screen and the support structure.

[0022] Furthermore, the gap threshold between the first connecting part of the filter screen and the outer peripheral surface of the overflow weir is less than 5 mm.

[0023] By applying the above-described technical solution of the present invention, at least the following technical effects are achieved: 1. In this invention, the filter screen is made of nylon and is placed at the top of the fluidized bed tower. This not only prevents the loss of resin at the top of the fluidized bed tower, but also has high corrosion resistance.

[0024] 2. In this invention, the nylon filter screen is inexpensive, which can significantly reduce costs compared to the stainless steel filter screen.

[0025] 3. The fluidized bed filter installation method proposed in this invention has a short replacement time, and the filter can be replaced during the normal resin transfer interval of the tower shutdown, without delaying normal production.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A flowchart of a fluidized bed filter installation method in one embodiment is provided; Figure 2 A schematic diagram of the fluidized bed structure in one embodiment is shown; Figure 3 A schematic diagram of the working principle of a fluidized bed in one embodiment is presented; Figure 4 A schematic diagram of the filter installation in one embodiment is shown; Figure 5 A schematic diagram of the spray device in one embodiment is shown; Figure 6 A graph showing the trend of resin amount change before and after filter installation in one embodiment is presented.

[0028] Reference numerals: 1. Fluidized bed; 11. Overflow weir; 12. Filter screen; 121. First connecting part; 122. Second connecting part; 123. Flexible component; 124. Closing rope; 13. Support structure; 14. Tower body; 15. Spraying device; 151. Spray pipe; 152. Nozzle. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] The present invention will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present invention.

[0031] Example

[0032] According to one aspect of the invention, a fluidized bed equipped with a filter screen is also provided, such as... Figure 2-4As shown, the fluidized bed 1 includes an overflow weir 11 and a tower body 14. The overflow weir 11 is located radially inside the tower body 14 and is lower than the highest height of the fluidized bed 1. The fluidized bed 1 also includes a filter screen 12, which is made of nylon and is arranged circumferentially outside the overflow weir 11. At least some solid particles in the fluid overflowing from the overflow weir 11 can be intercepted by the filter screen 12.

[0033] Specifically, in this embodiment, the fluid overflowing from the overflow weir 11 is a mixture of uranium-containing solution and resin, and the solid particles are resin particles. The filter screen 12 is made of acid-resistant nylon 6 material, which can withstand sulfuric acid solutions with an acidity not exceeding 20 g / L, and is well-suited for field solutions with an acidity of 3-7 g / L. During field testing, it can be used continuously for more than six months. In practical applications, the replacement cycle of the filter screen 12 is generally three months. Furthermore, the filter screen 12 made of acid-resistant nylon 6 material was tested in a uranium-containing solution (a sulfuric acid environment with a pH of 1.4-1.6) for six months without showing any corrosion, exceeding the required service life of three months.

[0034] More specifically, in this embodiment, the effective filtration area of ​​the filter screen 12 after unfolding is ≥95%, which does not affect the linear velocity of the uranium-containing solution, maintaining it at 12.4 m / h, and ensuring a resin expansion rate of 100%. The filter screen is installed at the overflow weir of the fluidized bed expansion section, with an expansion section diameter of 8.8 m, a filter screen length of 30 m, and a width of 2 m.

[0035] Further, the mesh size of the filter 12 is 0.4mm~0.6mm. The mesh of the filter 12 is quadrilateral, and the filter 12 is woven in a plain weave. Specifically, in this embodiment, as... Figure 4-6 As shown, the filter screen 12 has a square plain weave with a pore size of 0.5 mm, slightly smaller than the average particle size of the resin. This effectively intercepts the resin and fully meets the production flow rate requirements during operation. Considering the average resin particle size (0.69 ± 0.05 mm), the pore size was designed to be 0.5 mm to ensure an interception efficiency ≥ 99% while preventing clogging and increased flow resistance. The flow rate of the uranium-containing solution can meet the maximum fluidized bed throughput of 420 m³ / h. 3 / h's work requirements.

[0036] In other embodiments, the pore size of the filter 12 may also be 0.45 mm or 5.5 mm, etc.

[0037] Furthermore, the filter 12 comprises two or more sub-filters, each sub-filter having a thickness of 0.45mm to 0.55mm. Specifically, in this embodiment, the filter 12 employs a composite design with double-layer nylon mesh, each layer being 0.5mm thick. Testing has shown that this design effectively prevents the filter 12 from tearing during use.

[0038] Furthermore, the filter screen 12 also includes an anti-crystallization coating, which is disposed on the surface of the filter screen 12, and the thickness of the anti-crystallization coating is 3-5 mm. Specifically, in this embodiment, the thickness of the anti-crystallization coating is 4 mm. The anti-crystallization coating is made of epoxy resin, preferably phenolic epoxy resin, which has excellent corrosion resistance and can effectively inhibit the crystallization and adhesion of materials on the coating surface.

[0039] It should be noted that the anti-crystallization coating refers to a continuous coating structure formed on the surface of a substrate by coating and curing a resin-based material. The anti-crystallization coating can reduce crystallization on the surface of the filter screen and improve the corrosion resistance of the filter screen.

[0040] In other embodiments, the thickness of the anti-crystallization coating may also be 3. Or 5 The anti-crystallization coating material can also be fluorinated resin, siloxane modified resin, bisphenol A type epoxy resin, and vinyl ester resin, etc.

[0041] Furthermore, the filter screen 12 includes two parallel sides, which correspond to the first connecting part 121 and the second connecting part 122 of the filter screen 12 respectively; the first connecting part 121 is fixed to the outer peripheral surface of the overflow weir 11 along the circumference of the overflow weir 11, and the uppermost end of the filter screen 12 is higher than the overflow weir 11.

[0042] Furthermore, the filter screen 12 includes a flexible component 123 extending circumferentially along the overflow weir 11. The first connecting portion 121 of the filter screen 12 is fixed to the outer circumferential surface of the overflow weir 11 via the flexible component 123. The two ends of the flexible component 123 are connected by snap fasteners, which can adjust the tension of the flexible component 123. The fluidized bed 1 also includes a circumferential groove formed on the outer circumferential surface of the overflow weir 11, with the flexible component 123 partially located within the groove. Specifically, in this embodiment, the flexible component 123 is a connecting rope surrounding the overflow weir 11, with both ends connected to snap fasteners, thereby binding and fixing the filter screen 12 to the outer circumferential surface of the overflow weir 11 to prevent resin overflow. The snap fasteners ensure structural stability after assembly and facilitate quick replacement and maintenance of the filter screen 12.

[0043] It should be noted that the circumferential groove is part of the outer circumferential surface of the overflow weir 11.

[0044] Preferably, the buckle is made of 316 stainless steel, and the flexible component 123 is prefabricated and connected to the filter screen. The buckle is prefabricated and connected to the flexible component 123, so there is no need to assemble the buckle and the flexible component 123 during installation.

[0045] Furthermore, the fluidized bed 1 also includes a support structure 13, which is fixed to the tower body 14 circumferentially. The filter screen 12 also includes a drawstring rope 124, which is located at the second connecting portion 122 of the filter screen 12 and is connected to the support structure 13. Specifically, in this embodiment, the support structure 13 is located radially outside the overflow weir 11 and is fixed to the top of the tower body 14.

[0046] In other embodiments, the top of the tower body 14 is higher than the overflow weir 11, and the second connecting part 122 of the filter screen 12 can also be directly fixed to the inner wall of the tower body 14, so that the uppermost end of the filter screen 12 is higher than the overflow weir 11.

[0047] Furthermore, the fluidized bed 1 also includes two or more spray devices 15, which are fixed to the support structure 13 circumferentially and located on the outer side of the filter screen 12. The cleaning medium sprayed by the spray device 15 is acidic.

[0048] Specifically, such as Figure 5As shown, in this embodiment, the spraying device 15 includes a spray pipe 151 and multiple nozzles 152. The spray pipe 151 is fixed to the support structure 13 circumferentially, and the multiple nozzles 152 are arranged circumferentially along the spray pipe 151. The cleaning medium sprayed by the spraying device 15 is dilute sulfuric acid with a concentration of 2 g / L. The spraying device 15 can spray the cleaning medium onto the filter screen 12 to rinse the surface of the filter screen 12. The anti-crystallization coating can further improve the filter screen's resistance to corrosion. Preferably, the nozzle 151 has a diameter of 1 mm and a spacing of 100 mm, and the spraying direction is at a 45° angle to the filter screen surface. The spray pipe 151 is made of acid-resistant nylon. The spraying device 15 rinses the filter screen 12 once a day for 5 minutes each time.

[0049] According to a second aspect of the present invention, a method for installing a fluidized bed filter screen is also provided. The fluidized bed 1 includes an overflow weir 11 and a tower body 14. The overflow weir 11 is located radially inside the tower body 14 and is lower than the highest height of the fluidized bed 1. The fluidized bed 1 also includes a filter screen 12 made of nylon. The filter screen 12 includes two parallel sides, which correspond to a first connecting portion 121 and a second connecting portion 122 of the filter screen 12, respectively. Figure 1 As shown, the installation method includes the following steps: S1, the first connecting part 121 of the filter screen 12 is fixed to the outer peripheral surface of the overflow weir 11 along the circumferential direction of the overflow weir 11.

[0050] It should be noted that the only difference between the first connecting part 121 and the second connecting part 122 is that after the filter 12 is installed, the first connecting part 121 is located below the second connecting part 122.

[0051] In this embodiment, as Figure 2-3 As shown, the fluidized bed 1 includes an overflow weir 11 and a filter screen 12, with the overflow weir 11 located at the top of the fluidized bed 1.

[0052] Furthermore, fixing the first connecting portion 121 of the filter screen 12 to the outer peripheral surface of the overflow weir 11 along the circumference of the overflow weir 11 includes using a flexible member 123 surrounding the overflow weir 11 to fix the first connecting portion 121 of the filter screen 12 to the outer peripheral surface of the overflow weir 11 along the circumference of the overflow weir 11. Even further, the two ends of the flexible member 123 are connected by snap-fit ​​connections, and the snap-fit ​​connections can adjust the tension of the flexible member 123. The fluidized bed 1 also includes a circumferential groove, which is formed on the outer peripheral surface of the overflow weir 11, and the flexible member 123 is partially located in the circumferential groove.

[0053] Specifically, the flexible component 123 is a connecting rope that surrounds the overflow weir 11. Both ends of the flexible component 123 are connected by buckles. After the first connecting part 121 of the filter screen 12 is initially fixed to the outer circumference of the overflow weir 11 by the flexible component 123 along the circumference of the overflow weir 11, the tension of the flexible component 123 is adjusted using the buckles, so that the filter screen 12 is finally bound and fixed to the outer circumference of the overflow weir 11 to prevent resin overflow. The buckles not only ensure the structural stability after assembly, but also facilitate the quick replacement and maintenance of the filter screen 12.

[0054] Preferably, the buckle is made of 316 stainless steel, and the flexible component 123 is prefabricated and connected to the filter screen. The buckle is prefabricated and connected to the flexible component 123, so there is no need to assemble the buckle and the flexible component 123 during installation.

[0055] S2, connect the second connecting part 122 of the filter screen 12 to the fluidized bed 1 and make the uppermost end of the filter screen 12 higher than the overflow weir 11.

[0056] Furthermore, the fluidized bed 1 also includes a support structure 13, which is fixed to the tower body 14 circumferentially and is higher than the overflow weir 11. Connecting the second connecting portion 122 of the filter screen 12 to the fluidized bed 1 includes connecting the second connecting portion 122 of the filter screen 12 to the support structure 13 fixed to the tower body 14, thereby achieving the connection between the second connecting portion 122 of the filter screen 12 and the fluidized bed 1. Even further, connecting the second connecting portion 122 of the filter screen 12 to the support structure 13 includes connecting the support structure 13 and the closing rope 124 located at the second connecting portion 122, thereby achieving the connection between the second connecting portion 122 of the filter screen 12 and the support structure 13.

[0057] Specifically, the support structure 13 is located radially outside the overflow weir 11, and the support structure 13 is fixed to the top of the tower body 14. After connecting the end rope 124 and the support structure 13, the end rope 124 is subjected to tension so that the second connecting part 122 of the filter screen 12 is firmly connected to the support structure 13.

[0058] In other embodiments, the top of the tower body 14 is higher than the overflow weir 11, and the second connecting part 122 of the filter screen 12 can also be directly fixed to the inner wall of the tower body 14.

[0059] Preferred, such as Figure 2-5As shown, the support structure 13 is a guardrail fixed to the top of the fluidized bed 1 tower. The closing rope 124 is fixed to the uppermost end of the filter screen 12. The closing rope 124 is made of nylon rope with a diameter of 8mm. Specifically, the closing rope 124 is cross-tied and fixed to the guardrail using other nylon ropes. The closing rope 124 serves as a traction and tensioning element, ensuring that the second connecting part 122 of the filter screen 12 is always in a taut state.

[0060] S3. Check the gap between the first connecting part 121 of the filter screen 12 and the outer peripheral surface of the overflow weir 11. If it is less than or equal to the gap threshold, the installation is completed; if it is greater than the gap threshold, repeat the above steps to reinstall the filter screen 12.

[0061] It should be noted that the gap threshold refers to the distance between the filter screen and the overflow weir along the radial direction of the overflow weir, which ensures an interception rate of over 99% for particles in the fluid. Specifically, in this embodiment, the circumferential groove is formed on the outer circumferential surface of the overflow weir 11, and the circumferential groove is a part of the outer circumferential surface of the overflow weir 11. The flexible component 123 is partially located in the circumferential groove, and the gap threshold is the distance between the bottom surface of the circumferential groove and the first connecting portion 121 of the filter screen 12.

[0062] Furthermore, the gap threshold between the first connecting portion 121 of the filter screen 12 and the outer peripheral surface of the overflow weir 11 is less than 5 mm. Specifically, in this embodiment, the average particle size of the fluid particles filtered by the filter screen is 0.69 ± 0.05 mm. When the gap threshold is less than or equal to 5 mm, the interception efficiency can be guaranteed to be greater than 99%. Therefore, in this embodiment, the gap threshold is set to 5 mm, which does not affect the linear velocity reduction effect of the expansion section (linear velocity of the expansion section is 6.23 m / h) and can also intercept the resin carried to the top by the airflow or liquid flow.

[0063] In other embodiments, the gap threshold may also be 1 mm, 2 mm, 3 mm or 4 mm.

[0064] Furthermore, such as Figure 5 As shown, the filter 12 also includes an anti-crystallization coating, which is disposed on the surface of the filter 12, and the thickness of the anti-crystallization coating is 4. The fluidized bed 1 further includes two or more spray devices 15, which are fixed to the support structure 13 circumferentially and located on the outer radial side of the filter screen 12; the cleaning medium sprayed by the spray device 15 is acidic.

[0065] Specifically, such as Figure 5As shown, in this embodiment, the spraying device 15 includes a spray pipe 151 and multiple nozzles 152. The spray pipe 151 is fixed to the support structure 13 circumferentially, and the multiple nozzles 152 are arranged circumferentially along the spray pipe 151. The cleaning medium sprayed by the spraying device 15 is dilute sulfuric acid with a concentration of 2 g / L. The spraying device 15 can spray the cleaning medium onto the filter screen 12 to rinse the surface of the filter screen 12. The anti-crystallization coating can further improve the filter screen's resistance to corrosion. Preferably, the nozzle 151 has a diameter of 1 mm and a spacing of 100 mm, and the spraying direction is at a 45° angle to the filter screen surface. The spray pipe 151 is made of acid-resistant nylon. The spraying device 15 rinses the filter screen 12 once a day for 5 minutes each time.

[0066] The above-described fluidized bed filter installation method enables rapid filter replacement. Specifically, in a fluidized bed, after shutdown, the uranium-containing solution feed valve is closed, taking approximately 30 seconds; the closing rope 124 of the second connecting part 122 and the flexible component 123 and buckle of the first connecting part 121 are loosened sequentially; the old filter is removed from the inspection port at the top of the tower, taking approximately 10 minutes; then, the new filter is installed in the fluidized bed through the above steps, the inspection port is closed, the feed valve is opened, and production is resumed, taking approximately 15 minutes. The entire replacement process takes ≤30 minutes, which can be completed during the resin transfer interval during normal tower shutdown, without disrupting normal production.

[0067] In some embodiments, the fluidized bed 1 is also equipped with a clogging early warning mechanism and resin loss monitoring. Specifically, the clogging early warning mechanism involves establishing a daily filter inspection procedure in conjunction with the production equipment inspection system. The filter is typically replaced every three months. If temporary clogging due to high solid content is detected, the filter is prompted to be replaced promptly to prevent damage caused by excessive liquid flow resistance. The resin loss monitoring involves setting up a resin loss monitoring interface and installing a tank downstream of the filter 12 to monitor and collect resin loss data. An infrared camera is used periodically to monitor whether resin has penetrated the filter, ensuring the filter's interception effect.

[0068] In some other embodiments, the fluidized bed 1 is also equipped with a resin recovery system, which is located behind the collection tray and can recover the outflowing resin back into the system.

[0069] In addition, to demonstrate the technical effect of the present invention, observations were made on a fluidized bed before and after the filter screen 12 was installed, specifically as follows: Figure 6 As shown. It can be seen that in June 2022 (corresponding to...) Figure 6 The horizontal axis (Jun-22) to October 2022 (corresponding to) Figure 6(x-axis Oct-22) During the period without the filter installed, the resin quantity showed a trend of first decreasing and then increasing. After the filter was installed in October 2022, the resin quantity showed a gradual increasing trend, and within the period of October 2022, several maximum values ​​of the resin quantity gradually increased from around 1500 m³ to over 1700 m³, which can effectively prevent resin loss in the fluidized bed under abnormal operating conditions.

[0070] It should be noted here that, Figure 6 The amount of resin in the column refers to the amount of resin inside the column. The minimum amount of resin is the minimum amount of resin in the design standard. When the amount of resin is lower than the minimum amount of resin, the designed recycling effect cannot be achieved. Figure 6 The horizontal axis represents the abbreviation of the month and year in English, such as Jan-22, which means January 2022.

[0071] By applying the above-described technical solution of the present invention, at least the following technical effects are achieved: 1. In this invention, the filter screen is made of nylon and is placed at the top of the fluidized bed tower. This not only prevents the loss of resin at the top of the fluidized bed tower, but also has high corrosion resistance.

[0072] 2. In this invention, the nylon filter screen is inexpensive, which can significantly reduce costs compared to the stainless steel filter screen.

[0073] 3. The fluidized bed filter installation method proposed in this invention has a short replacement time, and the filter can be replaced during the normal resin transfer interval of the tower shutdown, without delaying normal production.

[0074] The above are merely several specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0075] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0076] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A fluidized bed equipped with a filter screen, the fluidized bed (1) comprising an overflow weir (11) and a tower body (14), the overflow weir (11) being located radially inside the tower body (14), the overflow weir (11) being below the highest height of the fluidized bed (1), characterized in that, The fluidized bed (1) also includes a filter screen (12), which is made of nylon. The filter screen (12) is arranged circumferentially on the radially outer side of the overflow weir (11), so that at least some solid particles in the fluid overflowing from the overflow weir (11) can be intercepted by the filter screen (12).

2. The fluidized bed equipped with a filter screen according to claim 1, characterized in that, The mesh size of the filter screen (12) is 0.4mm~0.6mm; The mesh of the filter (12) is quadrilateral, and the filter (12) is woven in a plain weave pattern; The filter (12) includes two or more sub-filters, each of which has a thickness of 0.45mm to 0.55mm. The filter screen (12) further includes an anti-crystallization coating, which is disposed on the surface of the filter screen (12) and has a thickness of 3-5 mm. .

3. The fluidized bed equipped with a filter screen according to claim 2, characterized in that, The filter screen (12) includes two parallel sides, which correspond to the first connecting part (121) and the second connecting part (122) of the filter screen (12), respectively. The first connecting part (121) is fixed to the outer circumferential surface of the overflow weir (11) along the circumference of the overflow weir (11), and the uppermost end of the filter screen (12) is higher than the overflow weir (11).

4. The fluidized bed equipped with a filter screen according to claim 3, characterized in that, The filter screen (12) includes a flexible component (123) that extends circumferentially along the overflow weir (11). The first connecting portion (121) of the filter screen (12) is fixed to the outer circumferential surface of the overflow weir (11) via the flexible component (123) along the circumferential direction. The two ends of the flexible component (123) are connected by snap fasteners, and the snap fasteners can adjust the tension of the flexible component (123); The fluidized bed (1) also includes a circumferential groove, which is formed on the outer circumferential surface of the overflow weir (11), and the flexible component (123) is at least partially located in the circumferential groove.

5. The fluidized bed equipped with a filter screen according to claim 4, characterized in that, The fluidized bed (1) further includes a support structure (13), which is fixed to the tower body (14) circumferentially. The filter screen (12) further includes a drawstring (124), which is located at the second connection part (122) of the filter screen (12) and is connected to the support structure (13).

6. The fluidized bed equipped with a filter screen according to claim 5, characterized in that, The fluidized bed (1) further includes two or more spray devices (15), which are fixed to the support structure (13) circumferentially, and are located on the outer radial side of the filter screen (12); the cleaning medium sprayed by the spray device (15) is acidic.

7. A method for installing a fluidized bed filter screen, used in the fluidized bed with a filter screen installed as described in claim 6, characterized in that, The installation method Includes the following steps, The first connecting part (121) of the filter screen (12) is fixed to the outer peripheral surface of the overflow weir (11) along the circumference of the overflow weir (11); The second connecting part (122) of the filter screen (12) is connected to the fluidized bed (1) and the uppermost end of the filter screen (12) is higher than the overflow weir (11). Check the gap between the first connecting part (121) of the filter screen (12) and the outer peripheral surface of the overflow weir (11). If it is less than or equal to the gap threshold, the installation is complete; if it is greater than the gap threshold, repeat the above steps to reinstall the filter screen (12).

8. The fluidized bed filter installation method according to claim 7, characterized in that, Fixing the first connecting portion (121) of the filter screen (12) to the outer peripheral surface of the overflow weir (11) along the circumference of the overflow weir (11) includes: using a flexible member surrounding the overflow weir (11) to fix the first connecting portion (121) of the filter screen (12) to the outer peripheral surface of the overflow weir (11) along the circumference of the overflow weir (11); Connecting the second connection part (122) of the filter screen (12) to the fluidized bed (1) includes connecting the second connection part (122) of the filter screen (12) to the support structure (13) fixed to the tower body (14) to realize the connection between the second connection part (122) of the filter screen (12) and the fluidized bed (1).

9. The fluidized bed filter installation method according to claim 8, characterized in that, The second connecting portion (122) of the filter screen (12) is connected to the support structure (13), including, The support structure (13) and the drawstring located at the second connecting part (122) are connected to achieve the connection between the second connecting part (122) of the filter screen (12) and the support structure (13).

10. The fluidized bed filter installation method according to claim 7, characterized in that, The gap threshold between the first connecting part (121) of the filter (12) and the outer peripheral surface of the overflow weir (11) is less than 5 mm.

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