Cross-flow filtration assembly and cross-flow filtration device

Abstract

The utility model discloses cross -flow filtration assembly and cross -flow filtration device, solve the technical problem of preventing the fracture of internal filter type columnar cross -flow filtration filter core. Including outer cylinder and through filter core first end positioning installation sealing structure and filter core second end positioning installation sealing structure install in the internal filter type columnar cross -flow filtration filter core of outer cylinder, filter core first end positioning installation sealing structure and filter core second end positioning installation sealing structure all contain the inside plate spare and outside plate spare of mutual superposition installation, and the distribution has first step hole on the inside plate spare, and the distribution has the second step hole of the coaxial setting of one -to -one correspondence with each first step hole on the outside plate spare, and first step hole is installed on the corresponding internal filter type columnar cross -flow filtration filter core, and the small hole end of first step hole and the big hole end of second step hole all are towards the direction of the middle direction of internal filter type columnar cross -flow filtration filter core. Avoided the internal filter type columnar cross -flow filtration filter core to receive greater axial force.

Description

Technical Field

[0001] This utility model relates to cross-flow filtration components and cross-flow filtration devices. Background Technology

[0002] Nickel sulfate is an important nickel compound widely used in electroplating, nickel batteries, and catalyst production. It primarily originates from the smelting of nickel ores (nickel sulfide and laterite). Nickel ore smelting processes are mainly divided into two categories: hydrometallurgical and pyrometallurgical processes. Hydrometallurgical processes include high-pressure ammonia leaching, high-pressure acid leaching, and reduction roasting-acid leaching, while pyrometallurgical processes include smelting in electric furnaces, flash furnaces, and blast furnaces. Nickel ore smelting is an upstream resource development link, providing the necessary nickel-containing raw materials for nickel sulfate production, forming a close industrial chain relationship. High-nickel matte, ferronickel, nickel oxide, or nickel-containing solutions produced during nickel ore smelting become direct raw materials for nickel sulfate production.

[0003] Nickel sulfate production mainly employs three methods: the sulfuric acid process, the extraction process, and the leaching process. The sulfuric acid process uses sodium carbonate precipitation to prepare nickel carbonate, which is then converted into nickel sulfate. The extraction process is primarily used to remove sodium ions from the solution. The leaching process directly uses high-nickel matte as raw material, leaching it with sulfuric acid followed by crystallization to obtain the final product. However, the nickel ore smelting process introduces various impurities, such as iron, copper, cobalt, manganese, zinc, and lead ions, which can affect the quality of the final nickel sulfate product.

[0004] To obtain high-purity nickel sulfate, various purification technologies are employed in industrial production to remove impurities from the smelting process. Chemical purification utilizes the precipitation differences of different metals at different pH values ​​to remove impurities such as iron and copper; organic solvent extraction can selectively extract nickel ions and effectively separate sodium and calcium ions; ion exchange is suitable for deep removal of trace impurities such as lead and zinc; liquid membrane separation, electrodialysis, and crystallization separation are used for further purification. The selection of these purification technologies directly depends on the type and content of impurities in the upstream smelting products, reflecting the close integration between nickel ore smelting and nickel sulfate production processes.

[0005] In the purification process described above, filters are required to remove suspended solids and particulate impurities from the nickel sulfate solution. Currently, filters with polyethylene (PE) filter elements, or simply PE filters, are primarily used. Due to the corrosive nature of nickel sulfate solutions and their low pH value, PE materials are widely used because of their excellent acid and alkali corrosion resistance and relatively low cost. However, PE filters suffer from limitations such as limited filtration accuracy, short service life, susceptibility to clogging, and low filtration efficiency. This results in the filtered nickel sulfate solution still containing a large amount of tiny suspended solids and colloidal impurities, making it difficult to meet the requirements for high-purity nickel sulfate (especially battery-grade nickel sulfate).

[0006] The applicant noted that silicon carbide ceramic filter cartridges, as a novel filtration medium, possess significant potential advantages in the purification of nickel sulfate solutions. Compared to polyethylene (PE) filter cartridges, silicon carbide ceramic filter cartridges exhibit higher initial flux (600-800 L / m²h vs. 200-400 L / m²h) and better flux retention (retaining 85% after 100 hours, while PE filter cartridges typically retain only 30%). Experiments show that after filtration using silicon carbide ceramic filter cartridges, the content of impurity ions (such as Fe and Cu) in the nickel sulfate solution is significantly reduced, and the nickel sulfate mass content can be increased from 99.96% to 99.99%, meeting battery-grade nickel sulfate standards.

[0007] However, the following challenges were encountered in the development of silicon carbide filter cartridges suitable for nickel sulfate solutions: First, according to the structural design of traditional cross-flow filters, one cross-flow filter achieves primary filtration. Therefore, to adopt a graded cross-flow filtration method, different cross-flow filters need to be set in series. This not only results in a large footprint for the entire cross-flow filtration system, but also requires each of the different cross-flow filters set in series to be equipped with its own circulation pipeline and control system, which increases equipment investment costs, energy consumption and maintenance difficulty.

[0008] Secondly, currently commercially available silicon carbide ceramic filter cartridges for cross-flow filtration are mainly internal filtration columnar cross-flow filter cartridges (referring to hollow cylindrical cross-flow filter cartridges where the liquid to be filtered permeates from the inside to the outside of the cartridge, impurities are trapped by the inner wall of the cartridge, and the clear liquid passes through the cartridge wall and is collected on the outside of the cartridge). Furthermore, most are multi-channel internal filtration columnar cross-flow filter cartridges ("multi-channel" means that the cartridge has multiple axial channels). Because silicon carbide is a relatively brittle material, these types of internal filtration columnar cross-flow filter cartridges are relatively short, and the filtration area of ​​a single cartridge is small. This results in traditional cross-flow filters requiring a large number of internal filtration columnar cross-flow filter cartridges connected in parallel to obtain sufficient filtration area and throughput.

[0009] Third, in traditional cross-flow filters, the traditional installation method for the internal filter columnar cross-flow filter element requires applying a certain axial load to the internal filter columnar cross-flow filter element. However, silicon carbide is a brittle material, and this traditional installation method is prone to causing the internal filter columnar cross-flow filter element to break and be damaged.

[0010] Fourth, filtration experiments using multi-channel internal filter columnar cross-flow filter cartridges for nickel sulfate solutions revealed that the inlet end of the multi-channel internal filter columnar cross-flow filter cartridge is more prone to clogging than other parts of the cartridge. The reason for this is that the inlet end of the multi-channel internal filter columnar cross-flow filter cartridge is at the initial contact point between the cartridge and the liquid to be filtered. This location has the highest concentration of suspended particles, impurities, and precipitates in the nickel sulfate solution. Metal ions in the nickel sulfate solution easily aggregate to form insoluble precipitates or colloids. Furthermore, the rapid change in flow direction and turbulence when the liquid to be filtered enters the multi-channel internal filter columnar cross-flow filter cartridge create a low-velocity zone or vortex zone at the inlet end, which facilitates the sedimentation and adhesion of suspended particles. Summary of the Invention

[0011] The first aspect is to provide a cross-flow filter assembly, which mainly solves the technical problem of preventing the breakage of the internal filter column cross-flow filter element.

[0012] To address this technical problem, the first aspect of the cross-flow filtration assembly includes an outer cylinder and an inner columnar cross-flow filter element installed within the outer cylinder via a first-end positioning and sealing structure and a second-end positioning and sealing structure. The two ends of the outer cylinder are the input end for the liquid to be filtered and the output end for the concentrate. A clear liquid chamber is formed between the outer cylinder and the inner columnar cross-flow filter element, and between the first-end positioning and sealing structure and the second-end positioning and sealing structure. A clear liquid output port communicating with the clear liquid chamber is provided on the outer cylinder. A concentrate chamber and a liquid-to-filter chamber are formed in the outer cylinder in the areas outside the first-end positioning and sealing structure and the area outside the second-end positioning and sealing structure, respectively. The input end for the liquid to be filtered communicates with the liquid-to-filter chamber, and the output end for the concentrate communicates with the concentrate chamber. Both the first-end positioning and sealing structure and the second-end positioning and sealing structure include inner and outer plates stacked on top of each other. The inner plates have first-step holes, and the outer plates have holes corresponding to the various... The first-step holes are coaxially arranged with the second-step holes in a one-to-one correspondence. The first-step holes are fitted onto the corresponding internal filter columnar cross-flow filter element. The small end of the first-step hole and the large end of the second-step hole both face the middle direction of the internal filter columnar cross-flow filter element. The inner diameter of the small end of the first-step hole is larger than the outer diameter of the internal filter columnar cross-flow filter element, and the inner diameter of the large end of the second-step hole is smaller than the inner diameter of the large end of the first-step hole. The inner diameter of the small end of the second-step hole is smaller than the outer diameter of the internal filter columnar cross-flow filter element. A sealing component is installed on the wall of the large hole of the first-step hole. The sealing component is axially pressed between the inner step surface of the first-step hole and the end face of the outer plate and includes at least one sealing ring and at least one sealing ring pressure ring. The inner walls of these sealing rings are tightly attached to the outer wall of the corresponding internal filter columnar cross-flow filter element. The distance between the inner step surface of the second-step hole in the first-end positioning and sealing structure of the filter element and the inner step surface of the second-step hole in the second-end positioning and sealing structure of the filter element is greater than the length of the internal filter columnar cross-flow filter element.

[0013] Based on the cross-flow filter assembly in the first aspect mentioned above, in order to further solve the technical problem of reliably connecting the inner and outer plates, the inner and outer plates, which are stacked on top of each other, are connected by threaded connectors.

[0014] Based on the cross-flow filter assembly described in the first aspect above, to further address the technical issue of improving the ease of assembly and maintenance of the cross-flow filter assembly, the following is proposed: The outer cylinder is divided into an intermediate cylinder and a first end cylinder and a second end cylinder located at opposite ends of the intermediate cylinder; the first end cylinder and the intermediate cylinder are connected via a first set of flanges, which includes a first intermediate cylinder side flange fixed to the intermediate cylinder and a first end cylinder side flange fixed to the first end cylinder. The first intermediate cylinder side flange and the inner plate of the first end positioning and sealing structure of the filter element are composed of the same plate; the second end cylinder and the intermediate cylinder are connected via a second set of flanges, which includes a second intermediate cylinder side flange fixed to the intermediate cylinder and a second end cylinder side flange fixed to the second end cylinder. The second intermediate cylinder side flange and the inner plate of the second end positioning and sealing structure of the filter element are composed of the same plate.

[0015] Based on the cross-flow filter assembly of the first aspect mentioned above, in order to further solve the technical problem of improving the installation reliability of the outer plate of the first end positioning and sealing structure of the filter element, the first set of flanges also includes a first intermediate flange formed by extending outward from the edge of the outer plate of the first end positioning and sealing structure of the filter element, and the first intermediate flange is sandwiched between the first intermediate cylinder side flange and the first end cylinder side flange.

[0016] Based on the cross-flow filter assembly of the first aspect mentioned above, in order to further solve the technical problem of improving the installation reliability of the outer plate of the second end positioning and sealing structure of the filter element, the second set of flanges also includes a second intermediate flange formed by extending outward from the edge of the outer plate of the second end positioning and sealing structure of the filter element, and the second intermediate flange is sandwiched between the second intermediate cylinder side flange and the second end cylinder side flange.

[0017] Based on the cross-flow filtration component in the first aspect mentioned above, in order to further solve the technical problem of improving the filtration efficiency of the internal filter column cross-flow filter element, the internal filter column cross-flow filter element adopts a multi-channel internal filter column cross-flow filter element.

[0018] Secondly, a cross-flow filtration device is provided, which solves the technical problem of applying the cross-flow component of the first aspect to the cross-flow filtration device, effectively improving the structural compactness of the cross-flow filtration device, and reducing manufacturing and usage costs.

[0019] The second aspect of the cross-flow filtration device includes: a circulation pipeline comprising a main pipe for the liquid to be filtered and a main pipe for the concentrate, wherein the main pipe for the liquid to be filtered and the main pipe for the concentrate are connected in series via a circulation pump during operation; a first set of cross-flow filtration components comprising at least two first cross-flow filtration components mounted in parallel on the main pipe for the liquid to be filtered and connected to the main pipe for the liquid to be filtered; a second set of cross-flow filtration components comprising second cross-flow filtration components mounted in a one-to-one correspondence with each of the first cross-flow filtration components on the main pipe for the concentrate, wherein the output end of the concentrate is connected to the main pipe for the concentrate; and a cross-flow filtration component series pipeline comprising a concentrate output end connected to each of the first cross-flow filtration components and a series connection between the output end of each of the first cross-flow filtration components and the main pipe for the concentrate. The corresponding second cross-flow filtration assembly has a guide pipe between the liquid to be filtered inlet end; during operation, the liquid to be filtered in the main liquid to be filtered enters each of the first cross-flow filtration assemblies for first cross-flow filtration to separate into a first concentrate and a first clear liquid. The first concentrate enters the corresponding second cross-flow filtration assembly through the corresponding guide pipe for second cross-flow filtration to separate into a second concentrate and a second clear liquid. The second concentrate is collected in the concentrate main pipe and then returned to the liquid to be filtered main pipe by the circulation pump. The first clear liquid and the second clear liquid are discharged from the cross-flow filtration device. Each of the first cross-flow filtration assemblies and each of the second cross-flow filtration assemblies adopts the cross-flow filtration assembly of the first aspect mentioned above.

[0020] Based on the cross-flow filtration device mentioned in the second aspect above, in order to further solve the technical problem of optimizing the spatial layout structure of the cross-flow filtration device and improving space utilization efficiency and engineering practicality, the following is proposed: the main pipe for the liquid to be filtered and the main pipe for the concentrate are arranged parallel in the horizontal direction; each first cross-flow filtration component is a vertical cross-flow filtration component and is installed side by side above the main pipe for the liquid to be filtered, with the lower end of each first cross-flow filtration component being the input end of the liquid to be filtered and the upper end being the output end of the concentrate; each second cross-flow filtration component is a vertical cross-flow filtration component and is installed side by side above the main pipe for the concentrate, with the upper end of each second cross-flow filtration component being the input end of the liquid to be filtered and the lower end being the output end of the concentrate; each guide pipe is connected between the upper end of the corresponding first cross-flow filtration component and the upper end of the corresponding second cross-flow filtration component.

[0021] Based on the cross-flow filtration device mentioned in the second aspect above, in order to further solve the technical problem of gas accumulation in the cross-flow filtration device being difficult to discharge, the following is proposed: each guide tube is an inverted U-shaped tube, and the top of each inverted U-shaped tube is also connected to an exhaust pipe.

[0022] Based on the cross-flow filtration device in the second aspect mentioned above, in order to further solve the technical problem of providing an external supply channel for the liquid to be filtered for the cross-flow filtration device, the cross-flow filtration device includes an inlet pipe, which is connected to the main pipe for the liquid to be filtered and / or the main pipe for the concentrate, and is used to provide an external supply channel for the liquid to be filtered.

[0023] Based on the cross-flow filtration device in the second aspect mentioned above, in order to further solve the technical problem of providing a concentrated liquid discharge channel for the cross-flow filtration device, the cross-flow filtration device includes a concentrated liquid pipeline, which is connected to the main pipe of the liquid to be filtered and / or the main pipe of the concentrated liquid, for providing a concentrated liquid discharge channel.

[0024] Based on the cross-flow filtration device in the second aspect mentioned above, in order to further solve the technical problem of providing a clear liquid collection and discharge channel for the cross-flow filtration device, the cross-flow filtration device includes a clear liquid pipeline, which is connected to the clear liquid output port of each first cross-flow filtration component and each second cross-flow filtration component, for providing a discharge channel for the first and second clear liquids.

[0025] The cross-flow filter assembly of this utility model uses a specially designed first-end positioning and sealing structure and a second-end positioning and sealing structure to install an internal columnar cross-flow filter element. The inner diameter of the small hole at the first step is larger than the outer diameter of the internal columnar cross-flow filter element, forming a gap. The inner wall of the sealing ring is tightly attached to the outer wall of the filter element, forming a flexible seal. Furthermore, the distance between the inner step surface of the second step hole in the first-end positioning and sealing structure and the inner step surface of the second step hole in the second-end positioning and sealing structure is greater than the length of the internal columnar cross-flow filter element. This avoids the internal columnar cross-flow filter element being subjected to large axial forces, effectively reducing the risk of breakage during installation and use, especially for internal columnar cross-flow filter elements made of brittle materials such as silicon carbide.

[0026] This utility model's cross-flow filtration device integrates a first set of cross-flow filtration components and a second set of cross-flow filtration components, which share a common circulation pipeline. During operation, the liquid to be filtered in the main filtration pipe enters each of the first cross-flow filtration components for first-stage cross-flow filtration, separating into a first concentrate and a first clear liquid. The first concentrate then enters the corresponding second cross-flow filtration components via corresponding guide pipes for second-stage cross-flow filtration, separating into a second concentrate and a second clear liquid. The second concentrate collects in the concentrate main pipe and is then returned to the main filtration pipe via a circulation pump. The first and second clear liquids are discharged from the cross-flow filtration device. Therefore, this cross-flow filtration device effectively solves the problems of large footprint, high equipment investment cost, high energy consumption, and difficult maintenance associated with traditional cross-flow filters where a single cross-flow filter performs first-stage filtration, requiring different cross-flow filters connected in series for a multi-stage cross-flow filtration system.

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present 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. Attached Figure Description

[0028] The accompanying drawings, which form part of this specification, are used to aid in understanding the present invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the present invention, but do not constitute an undue limitation on the present invention.

[0029] Figure 1 This is an external view of the cross-flow filtration device (skid-mounted equipment) according to an embodiment of the present utility model.

[0030] Figure 2 for Figure 1 The diagram shows the front view of the cross-flow filter device.

[0031] Figure 3 for Figure 1 The cross-flow filter device shown is shown in top view.

[0032] Figure 4 for Figure 1 The cross-flow filter device shown is viewed from the right.

[0033] Figure 5 for Figure 1 An enlarged view of the circulation pipeline in the cross-flow filtration device shown.

[0034] Figure 6 for Figure 1 An enlarged view of the venting pipe in the cross-flow filter device shown.

[0035] Figure 7 for Figure 1 An enlarged view of the concentrate pipeline in the cross-flow filtration device shown.

[0036] Figure 8 for Figure 1 An enlarged view of the inlet pipeline in the cross-flow filtration device shown.

[0037] Figure 9 for Figure 1 An enlarged view of the clear liquid pipeline in the cross-flow filtration device shown.

[0038] Figure 10 for Figure 1 A cross-sectional view of the first cross-flow filtering component in the cross-flow filtering device shown.

[0039] Figure 11 for Figure 10 The cross-flow filter assembly shown is a cross-sectional view of the sealing structure installed at the first end of the filter element.

[0040] Figure 12 for Figure 10 The cross-sectional view shown is of the sealing structure installed at the second end of the filter element in the cross-flow filter assembly.

[0041] Figure 13 for Figure 10 The diagram shows the usage of the sealing structure for positioning and installing the first end of the filter element in the cross-flow filter assembly.

[0042] Figure 14 A photomicrograph of the asymmetric membrane structure of a multi-channel internal filtration columnar cross-flow filter cartridge (made of silicon carbide material).

[0043] Figure 15 This is a PID (piping and instrumentation) diagram of the equipment for removing impurities from nickel sulfate solution according to an embodiment of this utility model.

[0044] The diagram is labeled as follows: Circulation pipeline 11, main pipe for filtration liquid 111, main pipe for concentrate liquid 112, first cross-flow filter assembly 12, first cross-flow filter assembly 121, second cross-flow filter assembly 13, second cross-flow filter assembly 131, cross-flow filter assembly series pipeline 14, guide pipe 141, exhaust pipeline 15, liquid inlet pipeline 16, concentrate pipeline 17, clear liquid pipeline 18, outer cylinder 21, first end positioning and sealing structure of filter element 22, second end positioning and sealing structure of filter element 23, internal filter columnar cross-flow filter element 3, multi-channel internal filter columnar cross-flow filter element inlet baffle ring 4, intermediate cylinder 211, first end cylinder 212, second end cylinder 213, inner side plate 241, outer side plate 242, sealing ring 243, sealing ring pressure ring 244, first step hole H1, second step hole H2. Detailed Implementation

[0045] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0046] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0047] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0048] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0049] I. Cross-flow filtration device according to an embodiment of this utility model.

[0050] like Figures 1 to 9 As shown, the cross-flow filtration device in this embodiment mainly includes a circulation pipeline 11, a first set of cross-flow filtration components 12, a second set of cross-flow filtration components 13, and a cross-flow filtration component series pipeline 14.

[0051] The circulation pipeline 11 includes a main pipe 111 for the liquid to be filtered and a main pipe 112 for the concentrate, which are arranged parallel to each other in the horizontal direction. During operation, the main pipe 111 for the liquid to be filtered and the main pipe 112 for the concentrate are connected in series by a circulation pump (separately configured, to be included in the skid-mounted equipment), so that the concentrate in the main pipe 112 can be returned to the main pipe 111 for the liquid to be filtered by the circulation pump, and then circulated to the main pipe 112 for the concentrate through the first set of cross-flow filter components 12, the cross-flow filter component series pipeline 14, and the second set of cross-flow filter components 13.

[0052] The first cross-flow filtration assembly 12 includes at least two first cross-flow filtration assemblies 121 installed in parallel above the main pipe of the liquid to be filtered. Each first cross-flow filtration assembly 121 is a vertical cross-flow filtration assembly, with its lower end being the input end of the liquid to be filtered and connected to the main pipe 111 of the liquid to be filtered, and its upper end being the output end of the concentrate.

[0053] The second cross-flow filter assembly 13 includes a second cross-flow filter assembly 131 installed above the concentrate main pipe 112 in a one-to-one correspondence with each of the first cross-flow filter assemblies 121. Each second cross-flow filter assembly 131 is also a vertical cross-flow filter assembly, with its upper end being the input end of the liquid to be filtered and its lower end being the output end of the concentrate and connected to the concentrate main pipe 112.

[0054] The cross-flow filtration assembly series pipeline 14 includes a guide pipe 141 connecting the concentrate output end of each first cross-flow filtration assembly 121 and the filtrate input end of the corresponding second cross-flow filtration assembly 131. Each guide pipe 141 is in the shape of an inverted U-shape (see...). Figure 1 and Figure 4 Each inverted U-shaped tube is also connected to an exhaust pipe 15 at its top, which is used to discharge the gas accumulated in the crossflow filter device.

[0055] In addition, the cross-flow filtration device also includes an inlet pipe 16, a concentrate pipe 17, and a clear liquid pipe 18. The inlet pipe 16 is connected to the main pipe 111 for the liquid to be filtered, providing a supply channel for the external liquid to be filtered. The concentrate pipe 17 is connected to the bottom of both the main pipe 111 and the concentrate main pipe 112, providing a channel for the discharge of the concentrate. The clear liquid pipe 18 is connected to the clear liquid outlet of each of the first cross-flow filtration components 121 and each of the second cross-flow filtration components 131, providing a channel for the discharge of the first and second clear liquids.

[0056] When the above-mentioned cross-flow filtration device is working, the liquid to be filtered in the main pipe 111 enters each of the first cross-flow filtration components 121 for first cross-flow filtration to separate into a first concentrate and a first clear liquid. The first concentrate enters the corresponding second cross-flow filtration component 131 through the corresponding guide pipe 141 for second cross-flow filtration to separate into a second concentrate and a second clear liquid. The second concentrate is collected in the concentrate main pipe 112 and then returned to the main pipe 111 of the liquid to be filtered by the circulation pump. The first clear liquid and the second clear liquid are discharged from the cross-flow filtration device.

[0057] The aforementioned cross-flow filtration device integrates a first set of cross-flow filtration components 12 and a second set of cross-flow filtration components 13, which share a common circulation pipeline 11. During operation, the liquid to be filtered in the main filtration pipe 111 enters each of the first cross-flow filtration components 121 for first-stage cross-flow filtration, separating to form a first concentrate and a first clear liquid. The first concentrate then enters the corresponding second cross-flow filtration component 131 via the corresponding guide pipe 141 for second-stage cross-flow filtration, separating to form a second concentrate and a second clear liquid. The second concentrate is collected in the concentrate main filtration pipe 112 and then returned to the main filtration pipe 111 via a circulation pump. The first and second clear liquids are discharged from the cross-flow filtration device. It is evident that this cross-flow filtration device can effectively solve the problems of large footprint, high equipment investment cost, high energy consumption, and high maintenance difficulty caused by the traditional cross-flow filter structure design, where a single cross-flow filter is used for primary filtration, requiring different cross-flow filters to be connected in series when adopting a graded cross-flow filtration method.

[0058] This cross-flow filtration device connects the first set of cross-flow filtration components 12 and the second set of cross-flow filtration components 13 in a one-to-one correspondence. Simultaneously, each cross-flow filtration component (a collective term for each first cross-flow filtration component 121 and each second cross-flow filtration component 131) is installed in parallel within the same circulation pipeline 11. This cleverly expands the overall filtration area without requiring additional equipment floor space. The main pipe 111 for the liquid to be filtered and the main pipe 112 for the concentrate are connected in series via a circulation pump to form a unified circulation pipeline 11. The concentrate output end of each first cross-flow filtration component 121 is directly connected to the liquid input end of the corresponding second cross-flow filtration component 131 via a guide pipe 141, forming multiple parallel series filtration pathways. This ensures that even when using multi-channel internal filter columnar cross-flow filter cartridges made of silicon carbide material with a small individual filtration area, the cross-flow filtration device can still provide sufficient total filtration area and throughput.

[0059] In addition, by installing the first set of cross-flow filter components 121 and the second set of cross-flow filter components 131 on the main pipe 111 of the liquid to be filtered and the main pipe 112 of the concentrate respectively, and connecting them flexibly through the guide pipe, it is easy to disassemble, clean and replace each cross-flow filter component individually, which greatly improves the maintenance efficiency and service life of the cross-flow filter device.

[0060] II. Structure of the cross-flow filter component.

[0061] like Figures 10 to 13 As shown, each of the first cross-flow filter components 121 and each of the second cross-flow filter components 131 (collectively referred to as cross-flow filter components) has the same structure, each including an outer cylinder 21 and an inner filter type columnar cross-flow filter element 3 installed in the outer cylinder 21 through a first end positioning and sealing structure 22 and a second end positioning and sealing structure 23.

[0062] The area between the outer cylinder 21 and the inner filter column cross-flow filter element 3, and between the first end positioning and sealing structure 22 and the second end positioning and sealing structure 23 of the filter element, forms a clear liquid chamber. The outer cylinder 21 is provided with a clear liquid outlet that communicates with the clear liquid chamber.

[0063] The area above the sealing structure 22 at the first end of the filter element in the outer cylinder 21 of each first cross-flow filter assembly 121 is a concentrated liquid chamber. The concentrated liquid output end of the first cross-flow filter assembly 121 is connected to the concentrated liquid chamber. The area below the sealing structure 23 at the second end of the filter element in the outer cylinder 21 of each first cross-flow filter assembly 121 forms a liquid chamber to be filtered. The liquid to be filtered input end of the first cross-flow filter assembly 121 is connected to the liquid chamber to be filtered.

[0064] The area above the first end positioning and sealing structure 22 in the outer cylinder 21 of each second cross-flow filter assembly 131 is the chamber for the liquid to be filtered. The input end of the second cross-flow filter assembly 131 is connected to the chamber for the liquid to be filtered. The area below the second end positioning and sealing structure 23 in the outer cylinder 21 of each second cross-flow filter assembly 131 forms a concentrated liquid chamber. The output end of the second cross-flow filter assembly 131 is connected to the concentrated liquid chamber. It can be seen that both the first cross-flow filter assembly 121 and the second cross-flow filter assembly 131 use an internal filtration columnar cross-flow filter element 3, which is fixed in the outer cylinder 21 by the first end positioning and sealing structure 22 and the second end positioning and sealing structure 23. However, in the flow direction, the liquid to be filtered in the first cross-flow filter assembly 121 enters from the bottom and the first concentrated liquid exits from the top; while in the second cross-flow filter assembly 131, the liquid to be filtered (i.e., the first concentrated liquid) enters from the top and the second concentrated liquid exits from the bottom. In this way, the first concentrated liquid of the first cross-flow filter component 121 can be directly introduced into the input end of the liquid to be filtered of the corresponding second cross-flow filter component 131 through the guide pipe 141, while maintaining the consistency of the structure of the first cross-flow filter component 121 and the second cross-flow filter component 131.

[0065] Specifically, the internal filtration columnar cross-flow filter element 3 adopts a multi-channel internal filtration columnar cross-flow filter element. More specifically, the multi-channel internal filtration columnar cross-flow filter element is made of silicon carbide material.

[0066] The traditional installation method for the internal filter type columnar cross-flow filter element 3 requires applying a certain axial load to it. However, silicon carbide is a brittle material, and this traditional installation method easily leads to breakage and damage to the internal filter type columnar cross-flow filter element 3. Therefore, in the design of the first and second end positioning and sealing structures of the filter element, an innovative concept of "non-pressurized floating support" was proposed. This concept reduces the axial pressure on the internal filter type columnar cross-flow filter element 3 by allowing axial floating, while using a more reasonable radial sealing method to ensure a sealing effect. Thus, the first and second end positioning and sealing structures were designed as follows and have been verified in practice.

[0067] Both the first end positioning and sealing structure 22 and the second end positioning and sealing structure 23 of the filter element include an inner plate 241 and an outer plate 242 stacked on top of each other. The inner plate 241 has first stepped holes H1 distributed on it, and the outer plate 242 has second stepped holes H2 coaxially arranged corresponding to each of the first stepped holes H1. The first stepped holes H1 are fitted onto the corresponding internal filter columnar cross-flow filter element 3. The small end of the first stepped hole H1 and the large end of the second stepped hole H2 both face the center of the internal filter columnar cross-flow filter element 3. The inner diameter D11 of the small end of the first stepped hole H1 is larger than the outer diameter D3 of the internal filter columnar cross-flow filter element 3. The inner diameter D22 of the large end of the second stepped hole H2 is smaller than the inner diameter D12 of the large end of the first stepped hole H1. The inner diameter D21 of the small end of the second stepped hole H2 is smaller than the outer diameter D3 of the internal filter columnar cross-flow filter element 3. A sealing assembly is installed on the wall of the large hole of the first stepped hole H1. The sealing assembly is axially pressed between the inner stepped surface of the first stepped hole H1 and the end face of the outer plate 242, and includes at least one sealing ring 243 and at least one sealing ring pressure ring 244. The inner walls of these sealing rings 243 are in close contact with the outer wall of the corresponding internal filter columnar cross-flow filter element 3. The distance between the inner stepped surface of the second stepped hole H2 in the first end positioning and sealing structure 22 and the inner stepped surface of the second stepped hole H2 in the second end positioning and sealing structure 23 is greater than the length of the internal filter columnar cross-flow filter element 3.

[0068] The internal filter type columnar cross-flow filter element 3 is installed through a specially designed first-end positioning and sealing structure 22 and second-end positioning and sealing structure 23. The inner diameter D11 of the small hole end of the first step hole H1 is larger than the outer diameter of the internal filter type columnar cross-flow filter element 3, forming a gap. The inner wall of the sealing ring 243 is tightly attached to the outer wall of the filter element to form a flexible seal. Furthermore, the distance between the inner step surface of the second step hole H2 in the first-end positioning and sealing structure 22 and the inner step surface of the second step hole H2 in the second-end positioning and sealing structure 23 is greater than the length of the internal filter type columnar cross-flow filter element 3. This avoids the internal filter type columnar cross-flow filter element 3 being subjected to large axial forces, effectively reducing the risk of breakage of the internal filter type columnar cross-flow filter element 3, especially the internal filter type columnar cross-flow filter element 3 made of brittle materials such as silicon carbide, during installation and use.

[0069] Typically, the inner plate 241 and the outer plate 242, which are stacked on top of each other, are connected by threaded connectors.

[0070] In a preferred embodiment, the outer cylinder 21 is divided into an intermediate cylinder 211 and a first end cylinder 212 and a second end cylinder 213 located at both ends of the intermediate cylinder 211, respectively. The first end cylinder 212 is connected to the intermediate cylinder 211 via a first set of flanges. The first set of flanges includes a first intermediate cylinder side flange fixed to the intermediate cylinder 211 and a first end cylinder side flange fixed to the first end cylinder 212. The first intermediate cylinder side flange and the inner plate 241 of the first end positioning and sealing structure 22 of the filter element are composed of the same plate. The second end cylinder 213 is connected to the intermediate cylinder 211 via a second set of flanges. The second set of flanges includes a second intermediate cylinder side flange fixed to the intermediate cylinder 211 and a second end cylinder side flange fixed to the second end cylinder 213. The second intermediate cylinder side flange and the inner plate 241 of the second end positioning and sealing structure 23 of the filter element are composed of the same plate.

[0071] The first set of flanges also includes a first intermediate flange formed by extending outward from the edge of the outer plate 242 of the first end of the filter element positioning and mounting sealing structure 22, the first intermediate flange being sandwiched between the first intermediate cylinder side flange and the first end cylinder side flange.

[0072] The second set of flanges also includes a second intermediate flange formed by extending outward from the edge of the outer plate 242 of the second end of the filter element positioning and mounting sealing structure 23. The second intermediate flange is sandwiched between the second intermediate cylinder side flange and the second end cylinder side flange.

[0073] By designing the outer cylinder 21 of the cross-flow filter assembly as a combination of an intermediate cylinder 211 and two end cylinders 212 and 213, and innovatively combining the inner plate 241 of the first end positioning and sealing structure 22 of the filter element with the first intermediate cylinder side flange, and the inner plate 241 of the second end positioning and sealing structure 23 of the filter element with the second intermediate cylinder side flange, and extending the edge of the outer plate 242 of the first end positioning and sealing structure 22 of the filter element outward to form a first intermediate flange and clamping it between the first intermediate cylinder side flange and the first end cylinder side flange, and extending the edge of the outer plate 242 of the second end positioning and sealing structure 23 of the filter element outward to form a second intermediate flange and clamping it between the second intermediate cylinder side flange and the second end cylinder side flange, a high degree of structural integration and modularity is achieved. This design not only simplifies the number of parts and reduces manufacturing costs, but also allows the entire cross-flow filter assembly to be easily disassembled and reassembled during maintenance.

[0074] In addition, generally speaking, each end face mating pair in the first set of flanges is provided with an end face sealing ring, and similarly, each end face mating pair in the second set of flanges is provided with an end face sealing ring.

[0075] III. Multi-channel internal filter type columnar cross-flow filter element.

[0076] Figure 14 A photomicrograph of the asymmetric membrane structure of a multi-channel internal filtration columnar cross-flow filter cartridge (made of silicon carbide material).

[0077] like Figure 14 As shown, the aforementioned cross-flow filtration device and cross-flow filtration assembly use a multi-channel internal filtration columnar cross-flow filter element made of silicon carbide material. The silicon carbide material has an asymmetric membrane structure comprising a silicon carbide filter membrane layer, a silicon carbide transition layer, and a silicon carbide support layer arranged sequentially along the liquid permeation direction.

[0078] The multi-channel internal filtration columnar cross-flow filter element made of silicon carbide employs an asymmetric membrane structure composed of three functionally defined components: the innermost silicon carbide filter membrane layer serves as the actual filtration layer, possessing precisely controlled micro- and nano-sized pores (in this embodiment, the average pore size of the silicon carbide filter membrane layer is 40 nm), responsible for trapping particulate matter of a specific size, and is the key component determining the filter element's separation accuracy; the middle silicon carbide transition layer serves as a connecting layer, with a pore size distribution that gradually increases from the outside to the inside (in this embodiment, the average pore size of the silicon carbide transition layer is 0.5 micrometers), providing support for the upper filter membrane and reducing liquid permeation resistance, ensuring a smooth change in resistance as the fluid passes through each layer; the outermost silicon carbide support layer has a larger pore size (in this embodiment, the average pore size of the silicon carbide support layer is 8 micrometers), providing structural stability and pressure resistance for the entire multi-channel internal filtration columnar cross-flow filter element, enabling it to withstand the high pressure and shear force during the cross-flow filtration process.

[0079] IV. Multi-channel internal filtration columnar cross-flow filter cartridge with inlet baffle ring.

[0080] In the filtration experiment of nickel sulfate solution using the above-mentioned multi-channel internal filter columnar cross-flow filter element, it was found that the inlet end of the multi-channel internal filter columnar cross-flow filter element was more prone to clogging than other parts of the filter element. The reason for this is that the inlet end of the multi-channel internal filter columnar cross-flow filter element is located at the initial contact point between the filter element and the liquid to be filtered. At this point, the concentration of suspended particles, impurities, and precipitates in the nickel sulfate solution is the highest. Metal ions in the nickel sulfate solution easily aggregate to form insoluble precipitates or colloids. In addition, when the liquid to be filtered enters the multi-channel internal filter columnar cross-flow filter element, a sharp change in flow direction and turbulence occur, creating a low-velocity zone or vortex zone at the inlet end, which is conducive to the sedimentation and adhesion of suspended particles.

[0081] Therefore, as an improvement, a multi-channel internal filtration columnar cross-flow filter cartridge inlet baffle ring 4 is detachably installed in the small holes of the second step holes H2 in the sealing structure 23 at the second end of the filter cartridge of each of the first cross-flow filter components 121. The multi-channel internal filtration columnar cross-flow filter cartridge inlet baffle ring 4 includes a baffle ring body, in which inlet through holes are densely distributed. These inlet through holes are used to guide the liquid to be filtered, which flows through the small holes to the inlet end of the multi-channel internal filtration columnar cross-flow filter cartridge, into the inlet end of the multi-channel internal filtration columnar cross-flow filter cartridge.

[0082] The inlet baffle ring 4 of the multi-channel internal filter columnar cross-flow filter element ensures that the liquid to be filtered passes through the inlet hole before entering the multi-channel internal filter columnar cross-flow filter element, preventing large particles of impurities from directly contacting and clogging the inlet end of the multi-channel internal filter columnar cross-flow filter element. At the same time, the detachable design of the baffle ring facilitates cleaning and replacement, effectively extending the service life of the multi-channel internal filter columnar cross-flow filter element and improving the stability of the cross-flow filter assembly.

[0083] In this embodiment, one end of the baffle ring body is provided with a countersunk hole for filter element installation, and the inlet end of the multi-channel internal filtration columnar cross-flow filter element is adapted to be installed in the countersunk hole. This design allows the inlet end of the multi-channel internal filtration columnar cross-flow filter element to be accurately positioned on the baffle ring body, ensuring that the liquid to be filtered can be directly and evenly introduced into each channel of the multi-channel internal filtration columnar cross-flow filter element after passing through the inlet hole, avoiding uneven filtration caused by obstruction of some channels.

[0084] To ensure that the inlet baffle ring 4 of the multi-channel internal filter columnar cross-flow filter element does not detach from its installation position during use, the outer wall of the baffle ring body is provided with an axial positioning structure for axially engaging with a corresponding positioning structure on the inlet channel to prevent the baffle ring body from dislodging from the inlet channel. Specifically, the axial positioning structure is a flange that directly engages with the corresponding second-step hole to form a reliable axial positioning.

[0085] In practical applications, the axial force acting on the baffle body at the inlet end of the multi-channel internal filter columnar cross-flow filter element and the axial force acting on the flange at the second step hole are a pair of opposing forces. This force balance design ensures that the inlet baffle 4 of the multi-channel internal filter columnar cross-flow filter element is in a stable stress state and will not shift or loosen due to the impact force generated by the liquid flow.

[0086] The inlet baffle ring 4 of the multi-channel internal filtration columnar cross-flow filter cartridge is a one-piece molded plastic component. This integrated design avoids the leakage risk associated with complex assembly and also reduces manufacturing costs. Considering the characteristics of corrosive liquids such as nickel sulfate solution, the inlet baffle ring 4 of the multi-channel internal filtration columnar cross-flow filter cartridge is made of polytetrafluoroethylene (PTFE). PTFE has excellent chemical corrosion resistance, a low coefficient of friction, and good temperature stability, enabling it to operate stably for extended periods under various harsh conditions without affecting its filtration performance due to chemical reactions or physical deformation.

[0087] The above-mentioned cross-flow filtration device is used to assemble a nickel sulfate solution purification device (such as...). Figure 15 As shown, the equipment for removing impurities from the nickel sulfate solution consists of three cross-flow filtration devices connected in parallel. These cross-flow filtration devices are used to perform ultrafiltration treatment on the nickel sulfate solution raw material obtained from nickel ore smelting.

[0088] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of this utility model.

Claims

1. A cross-flow filtration assembly, comprising an outer cylinder and an inner-filter columnar cross-flow filter element installed in the outer cylinder via a first-end positioning and sealing structure and a second-end positioning and sealing structure, wherein the two ends of the outer cylinder are the input end of the liquid to be filtered and the output end of the concentrate, respectively. A clear liquid chamber is formed between the outer cylinder and the inner filter column cross-flow filter element, and between the first end positioning and sealing structure and the second end positioning and sealing structure of the filter element. A clear liquid outlet is provided on the outer cylinder that communicates with the clear liquid chamber. The area outside the first end of the filter element's positioning and sealing structure and the area outside the second end of the filter element's positioning and sealing structure in the outer cylinder form a concentrated liquid chamber and a liquid to be filtered chamber, respectively. The liquid to be filtered inlet is connected to the liquid to be filtered chamber, and the concentrated liquid outlet is connected to the concentrated liquid chamber. Its features are: Both the first end positioning and sealing structure and the second end positioning and sealing structure of the filter element include inner and outer plates that are stacked on each other. The inner plate has first step holes, and the outer plate has second step holes that are coaxially arranged in correspondence with each of the first step holes. The first step hole is fitted onto the corresponding internal filter column cross-flow filter element. The small end of the first step hole and the large end of the second step hole both face the middle direction of the internal filter column cross-flow filter element. The inner diameter of the small end of the first step hole is larger than the outer diameter of the internal filter column cross-flow filter element. The inner diameter of the large end of the second step hole is smaller than the inner diameter of the large end of the first step hole. The inner diameter of the small end of the second step hole is smaller than the outer diameter of the internal filter column cross-flow filter element. A sealing assembly is installed on the wall of the large hole of the first step hole. The sealing assembly is axially pressed between the inner step surface of the first step hole and the end face of the outer plate and includes at least one sealing ring and at least one sealing ring pressure ring. The inner walls of these sealing rings are in close contact with the outer wall of the corresponding internal filter columnar cross-flow filter element. The distance between the inner step surface of the second step hole in the first end positioning and sealing structure of the filter element and the inner step surface of the second step hole in the second end positioning and sealing structure of the filter element is greater than the length of the internal filter type columnar cross-flow filter element.

2. The cross-flow filtering component as described in claim 1, characterized in that: The inner and outer plates, which are stacked on top of each other, are connected by threaded connectors.

3. The cross-flow filtering component as described in claim 1, characterized in that: The outer cylinder is divided into an intermediate cylinder and a first end cylinder and a second end cylinder located at both ends of the intermediate cylinder, respectively; The first end cylinder and the intermediate cylinder are connected by a first set of flanges. The first set of flanges includes a first intermediate cylinder side flange fixed on the intermediate cylinder and a first end cylinder side flange fixed on the first end cylinder. The first intermediate cylinder side flange and the inner plate of the first end positioning and sealing structure of the filter element are composed of the same plate. The second end cylinder and the intermediate cylinder are connected by a second set of flanges. The second set of flanges includes a second intermediate cylinder side flange fixed on the intermediate cylinder and a second end cylinder side flange fixed on the second end cylinder. The second intermediate cylinder side flange and the inner plate of the second end positioning and sealing structure of the filter element are made of the same plate.

4. The cross-flow filtering component as described in claim 3, characterized in that: The first set of flanges also includes a first intermediate flange formed by extending outward from the edge of the outer plate of the first end of the filter element positioning and installing the sealing structure. The first intermediate flange is sandwiched between the first intermediate cylinder side flange and the first end cylinder side flange.

5. The cross-flow filtering component as described in claim 3, characterized in that: The second set of flanges also includes a second intermediate flange formed by extending outward from the edge of the outer plate of the second end of the filter element where the sealing structure is positioned and installed. The second intermediate flange is sandwiched between the second intermediate cylinder side flange and the second end cylinder side flange.

6. The cross-flow filtering component as described in claim 1, characterized in that: The internal filter type columnar cross-flow filter element adopts a multi-channel internal filter type columnar cross-flow filter element.

7. A cross-flow filtration device, characterized in that: include: The circulation pipeline includes a main pipe for the liquid to be filtered and a main pipe for the concentrate. During operation, the main pipe for the liquid to be filtered and the main pipe for the concentrate are connected in series via a circulation pump. The first cross-flow filtration assembly includes at least two first cross-flow filtration assemblies that are installed side by side on the main filtrate pipe and whose filtrate inlet is connected to the main filtrate pipe. The second cross-flow filter assembly includes a second cross-flow filter assembly that is installed on the concentrate main pipe in a one-to-one correspondence with each of the first cross-flow filter assemblies, and whose concentrate output end is connected to the concentrate main pipe; The cross-flow filtration assembly series pipeline includes a guide pipe connecting the concentrate output end of each first cross-flow filtration assembly and the filtrate input end of the corresponding second cross-flow filtration assembly. During operation, the liquid to be filtered in the main pipe of the liquid to be filtered enters each of the first cross-flow filtration components for first cross-flow filtration to separate into a first concentrate and a first clear liquid. The first concentrate enters the corresponding second cross-flow filtration components through the corresponding guide pipes for second cross-flow filtration to separate into a second concentrate and a second clear liquid. The second concentrate is collected in the concentrate main pipe and then returned to the main pipe of the liquid to be filtered by the circulation pump. The first clear liquid and the second clear liquid are discharged from the cross-flow filtration device. Each of the first cross-flow filtering components and each of the second cross-flow filtering components adopts the cross-flow filtering component as described in any one of claims 1-6.

8. The cross-flow filtration device as described in claim 7, characterized in that: The main pipe for the filtrate and the main pipe for the concentrate are arranged parallel to each other in the horizontal direction. Each of the first cross-flow filtration components is a vertical cross-flow filtration component and is installed in parallel above the main pipe of the liquid to be filtered. The lower end of each first cross-flow filtration component is the input end of the liquid to be filtered and the upper end is the output end of the concentrate. Each of the second cross-flow filter components is a vertical cross-flow filter component and is installed in parallel above the concentrate main pipe. The upper end of each second cross-flow filter component is the input end of the liquid to be filtered and the lower end is the output end of the concentrate. Each flow guide pipe is connected between the upper end of the corresponding first cross-flow filter component and the upper end of the corresponding second cross-flow filter component.

9. The cross-flow filtration device as described in claim 8, characterized in that: Each guide tube is in the shape of an inverted U-shape, and an exhaust pipe is connected to the top of each inverted U-shape.

10. The cross-flow filtration device according to any one of claims 7-9, characterized in that: Includes an inlet pipeline, which is connected to the main pipe of the liquid to be filtered and / or the main pipe of the concentrate, and is used to provide an external supply channel for the liquid to be filtered; And / or, including a concentrate line, which is connected to the main pipe of the liquid to be filtered and / or the main pipe of the concentrate, to provide a channel for the discharge of concentrate; And / or, includes a clear liquid pipeline connected to the clear liquid outlet of each of the first cross-flow filter components and each of the second cross-flow filter components, for providing an external discharge channel for the first and second clear liquids.

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