Paraffin oil decolorizing tank and paraffin oil decolorizing device

Abstract

The utility model provides a paraffin oil decolorizing tank and a paraffin oil decolorizing device. The wax oil decolorizing tank comprises a tank body and a filter element assembly arranged in the tank body. The filter element assembly is annular, the filter element assembly is provided with an annular decoloring layer, and the decoloring layer divides the interior of the tank body into a first cavity and a second cavity which are independent from each other; in the radial direction of the filter element assembly, the first cavity is located on the outer side of the decolorizing layer, and the second cavity is located on the inner side of the decolorizing layer. The tank body is provided with a liquid inlet and a liquid outlet; the liquid inlet is communicated with the first chamber, and the liquid outlet is communicated with the second chamber. According to the technical scheme, the utilization rate of the filler of the decolorizing layer of the decolorizing tank is higher; flow and efficiency can be taken into account, the decolored oil quality is stable, and the energy consumption and the solid waste generation amount are relatively small.

Description

Technical Field

[0001] The present application relates to the technical field of diaphragm production, and in particular to a paraffin oil decolorization tank and a paraffin oil decolorization device. Background Art

[0002] At present, in the manufacture of lithium battery wet-process diaphragms, paraffin oil is mixed with base material PE (polymer polyethylene) and extruded at high temperature. After casting, it is biaxially stretched, extracted, heat-set, and rolled to make the base film material. Among them, paraffin oil is crucial as a pore-forming agent in the phase separation step. After phase separation occurs in the casting process, it is dissolved in the extraction process and forms a mixed liquid with dichloromethane or other solvents. After distillation and purification, it is put back into use; in this process, high-temperature extrusion and high-temperature distillation steps are involved, which will produce some oxidative impurities and pigment accumulation, especially when mineral oil is used directly; due to the harsh use conditions of lithium battery diaphragms, the purity (quality) of paraffin oil will cause serious defects in the appearance of the film, affecting the installation and use of the battery cell; therefore, the preliminary paraffin oil obtained by distillation needs to be further treated by decolorization and impurity removal. Quartz sand is generally used as an adsorption and purification material in the industry to decolorize and remove impurities from paraffin oil, which improves the quality of oil products while reducing production costs; the core of the decolorization equipment is the decolorization tank.

[0003] There are two main structures of existing decolorization tanks. One type of decolorization tank is a column decolorization tank. Paraffin oil is injected from the top of the decolorization layer, and the paraffin oil flows out from the liquid outlet after passing through the decolorization layer downward. The utilization rate of the decolorization layer in this type of decolorization tank is high, but to achieve the decolorization effect, the decolorization layer needs to have a large thickness, so it will produce relatively large resistance, making the overall flow of the equipment too small, and the decolorization flow of a single set of equipment (when the size is the same) is insufficient; and a large post-pump pressure needs to be applied; the equipment sealing requirements are high.

[0004] The other is a plate-type decolorization tank, where paraffin oil enters the decolorization layer from the top and then flows out from the horizontal outlet of the decolorization layer. Although this type of decolorization tank can increase the filtration flow rate, the forces at each point in the cross section of the decolorization layer are completely different due to different resistance and pressure. The larger the size of the decolorization layer in the horizontal direction, the lower the filler utilization efficiency of the decolorization layer; the larger the size of the decolorization layer in the vertical direction, the lower the filler utilization efficiency of the decolorization layer. Utility Model Content

[0005] The purpose of the present application is to provide a paraffin oil decolorization tank and a paraffin oil decolorization device.

[0006] The embodiment of the present application is implemented as follows:

[0007] In the first aspect, the embodiment of the present application provides a paraffin oil decolorization tank, comprising a tank body and a filter element assembly disposed inside the tank body. The filter element assembly is annular, and has an annular decolorization layer, and the decolorization layer divides the interior of the tank body into an independent first chamber and a second chamber; in the radial direction of the filter element assembly, the first chamber is located on the outside of the decolorization layer, and the second chamber is located on the inside of the decolorization layer. The tank body is provided with a liquid inlet and a liquid outlet; the liquid inlet is connected to the first chamber, and the liquid outlet is connected to the second chamber.

[0008] The decolorization layer of the decolorization tank provided in the above technical solution is annular, and the paraffin oil passes through the decolorization layer from the outside of the decolorization layer and reaches the inside of the decolorization layer. When the paraffin oil fills the cavity and enters the infiltration cavity, the shortest path of the paraffin oil infiltration movement is consistent everywhere, that is, the resistance and pressure are consistent everywhere, so that the utilization rate of the decolorization sand is close to 100%, reducing the amount of solid waste generated. And compared with the existing column decolorization tank, the decolorization tank provided by the above technical solution has a larger flow rate; compared with the existing plate decolorization tank, the utilization rate of the filler forming the decolorization layer in the decolorization tank provided by the above technical solution is higher; it can take into account both flow and efficiency, the quality of the decolorized oil is stable, and the energy consumption and the amount of solid waste generated are relatively small.

[0009] In combination with the first aspect, in some embodiments, the filter element assembly includes a filter screen, a first support plate, a filter membrane and a second support plate coaxially arranged in sequence from the outside to the inside; the first support plate and the second support plate both have a porous structure for paraffin oil to pass through; there is a first annular gap between the first support plate and the filter membrane, and the first annular gap is filled with bleaching sand to form the bleaching layer.

[0010] In the above technical solution, the first support plate and the second support plate can play a supporting role to form a certain space for accommodating the bleaching sand. The filter screen and the filter membrane can filter out larger particles in the paraffin oil on the one hand, and prevent the bleaching from passing through on the other hand.

[0011] In combination with the first aspect, in some embodiments, the difference between the outer diameter and the inner diameter of the first annular gap is 100 to 500 mm.

[0012] In the above technical scheme, correspondingly, the thickness of the bleaching layer is in the range of 50 to 250 mm, and the paraffin oil can pass through the bleaching layer of the above thickness relatively easily. On the first hand, the flow rate of the liquid outlet is larger. On the second hand, the pressure of the paraffin oil supplied to the bleaching tank can be lower, which can reduce the system operating pressure accordingly; on the third hand, the influence of gravity on the movement trajectory of the paraffin oil can be reduced, so that the utilization rate of the bleaching sand in the bleaching layer is higher.

[0013] In combination with the first aspect, in some embodiments, a second annular gap is provided between the first support plate and the filter screen, and a difference between an outer diameter and an inner diameter of the second annular gap is 2-6 mm.

[0014] Due to the existence of the second annular gap, after the paraffin oil enters the second annular gap, an oil layer can be formed between the filter screen and the first support plate, which can effectively avoid the problem of uneven osmotic pressure after the filter screen and the first support plate are fitted together due to the mismatch of the apertures of the filter screen and the first support plate.

[0015] In combination with the first aspect, in some embodiments, the top of the tank body is provided with a first opening for installing the filter element assembly into the interior of the tank body, and the first opening is covered with a cover plate assembly, and the cover plate assembly is detachably sealed and connected to the tank body.

[0016] In the above technical solution, the filter element assembly can be taken out from the tank body for replacement by disassembling the cover plate assembly.

[0017] In combination with the first aspect, in some embodiments, the cover plate assembly includes an outer cover plate and an inner cover plate, the outer cover plate is annular, the outer ring of the outer cover plate is covered on the first opening, the inner cover plate is circular, the inner ring of the outer cover plate is connected to the periphery of the inner cover plate; the outer cover plate is also detachably connected to the filter element assembly.

[0018] In combination with the first aspect, in some embodiments, an outer diameter of the outer cover plate is greater than or equal to a diameter of the first support plate, and an inner diameter of the outer cover plate is greater than or equal to a diameter of the second support plate.

[0019] In combination with the first aspect, in some embodiments, the lower portion of the tank body includes an annular bottom plate and a conical shell, the edge of the conical shell is fixedly connected to the inner ring of the bottom plate, one end of the conical shell is sealed to the bottom of the second support plate, and the other end of the conical shell extends in a direction away from the tank body and gradually becomes smaller; the liquid outlet is arranged at the end of the conical shell away from the tank body.

[0020] In combination with the first aspect, in some embodiments, the bottom plate is provided with a slot, and the filter element assembly is detachably disposed in the slot.

[0021] In the above technical solution, by providing a slot on the bottom plate to detachably connect the filter element assembly, on the one hand, it can facilitate the disassembly and assembly of the filter element assembly, and on the other hand, it can position the filter element assembly during the installation process of the filter element assembly.

[0022] In the second aspect, an embodiment of the present application provides a paraffin oil decolorization device, including a paraffin oil preheating tank, and the paraffin oil decolorization tank provided in the first aspect; the preheating tank is connected to a heat exchange device for heating the paraffin oil and a paddle mechanism for stirring the paraffin oil; the liquid outlet of the paraffin oil preheating tank is connected to the liquid inlet of the paraffin oil decolorization tank through a pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of a paraffin oil decolorization device provided in an embodiment of the present application;

[0025] Figure 2 A schematic cross-sectional view of a paraffin oil decolorization tank provided in an embodiment of the present application;

[0026] Figure 3 An exploded view of the paraffin oil decolorization tank provided in an embodiment of the present application.

[0027] Icons: 100-paraffin oil decolorization tank; 110-tank body; 111-first chamber; 112-second chamber; 113-liquid outlet; 114-bottom plate; 115-conical shell; 120-filter element assembly; 121-decolorization layer; 122-first support plate; 123-second support plate; 130-cover plate assembly; 131-outer cover plate; 132-inner cover plate; 133-lifting ring; 200-paraffin oil preheating tank; 300-heat exchange device; 400-drive motor; 500-circulation pump. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of this application, it should be noted that the terms "center", "upper", "lower", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0032] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] The present application provides a paraffin oil decolorization device. Figure 1 As shown, it includes a paraffin oil preheating tank 200 and a paraffin oil decolorization tank 100 connected to the paraffin oil preheating tank 200. The liquid outlet 113 of the paraffin oil preheating tank 200 is connected to the liquid inlet of the paraffin oil decolorization tank 100, so that the paraffin oil preheated by the paraffin oil preheating tank 200 is sent into the paraffin oil decolorization tank 100.

[0035] The paraffin oil preheating tank 200 is connected to a heat exchange device 300 for heating the paraffin oil. The paraffin oil in the paraffin oil preheating tank 200 is heated by the heat exchange device 300 under the action of the circulation pump 500, and the heated paraffin oil returns to the paraffin oil preheating tank 200. Further, the paraffin oil preheating tank 200 is also connected to a paddle mechanism, which is provided with a paddle having one end located in the paraffin oil preheating tank 200 and the other end located outside the paraffin oil preheating tank 200 and connected to a drive motor 400. The paddle mechanism rotates under the action of the drive motor 400 to make the temperature of the paraffin oil in the paraffin oil preheating tank 200 uniform.

[0036] In some embodiments of the present application, the paraffin oil decolorization tank 100 includes a tank body 110 and a filter element assembly 120 disposed inside the tank body 110. The filter element assembly 120 provided in the present application is annular, and the filter element assembly 120 has an annular decolorization layer 121, and the decolorization layer 121 separates the interior of the tank body 110 into an independent first chamber 111 and a second chamber 112. In the radial direction of the filter element assembly 120, the first chamber 111 is located on the outside of the decolorization layer 121, and the second chamber 112 is located on the inside of the decolorization layer 121. The liquid inlet of the tank body 110 is connected to the first chamber 111, and the liquid outlet 113 is connected to the second chamber 112. Among them, the decolorization layer 121 can be a structure with a color absorption function formed by the accumulation of fillers such as decolorization sand.

[0037] Combination Figure 2 and Figure 3 It is not difficult to know that, since the decolorizing layer 121 separates the interior of the tank body 110 into the first chamber 111 and the second chamber 112 which are independent of each other, the paraffin oil entering the first chamber 111 from the liquid inlet can only enter the second chamber 112 after passing through the decolorizing layer 121, and then be discharged from the liquid outlet 113, thereby ensuring that all the paraffin oil will be processed through the decolorizing layer 121. Figure 3 The direction indicated by the solid arrow is the flow direction of the paraffin oil.

[0038] In some embodiments of the present application, the filter element assembly 120 and the decolorizing layer 121 are both annular structures, that is, the filter element assembly 120 and the decolorizing layer 121 have axially penetrating through holes inside, and the peripheral surfaces of the filter element assembly 120 and the decolorizing layer 121 are both cylindrical surfaces, and the cross-section in the radial direction is annular. In some other embodiments, the filter element assembly 120 and the decolorizing layer 121 can also be an annular structure with a rectangular cross-section, that is, at least one of the filter element assembly 120 and the decolorizing layer 121 is an annular structure with a rectangular cross-section. Among them, the cross-section is a cross-section perpendicular to the axial direction, and the rectangular cross-section means that the outermost contour line of the cross-section perpendicular to the axial direction is a rectangle.

[0039] In the embodiment where the decolorization layer 121 is a circular ring structure, when the paraffin oil passes through the decolorization layer 121, the shortest path of the paraffin oil in each place in the decolorization layer 121 is consistent, that is, the resistance and pressure are consistent at each place, so that the utilization rate of the filler in the decolorization layer 121 is close to 100%, thereby reducing the amount of solid waste generated. The effective permeability area of ​​the decolorization layer 121 is 2πrh, where r is the inner diameter of the decolorization layer 121 and h is the height of the decolorization layer 121 (that is, the size of the decolorization layer 121 in its own axial direction). The effective permeability area of ​​the decolorization layer 121 in the filter element assembly 120 provided in the present application is relatively large. Therefore, when the liquid outlet 113 is required to have the same flow rate, the paraffin oil in the first chamber 111 in the decolorization tank provided in the present application does not need to have a large pressure, and the system operating pressure can also be reduced accordingly, reducing some operating energy consumption. Therefore, the paraffin oil decolorization tank 100 with a ring-shaped decolorization layer 121 provided in the present application can take into account both flow rate and efficiency, the quality of the decolorized oil is stable, and the energy consumption and solid waste generation are relatively small; because the paraffin oil undergoes a circulating heating and stirring step at an appropriate temperature in the paraffin oil preheating tank 200 before entering the paraffin oil decolorization tank 100, the viscosity of the paraffin oil is reduced and the fluidity is increased, so it can pass through the decolorization layer 121 more efficiently.

[0040] Furthermore, in some embodiments, the filter element assembly 120 and the decolorization layer 121 are arranged to coincide with each other along their axes.

[0041] In some embodiments of the present application, the filter element assembly 120 includes a filter screen, a first support plate 122, a filter membrane, and a second support plate 123, which are arranged in sequence from the outside to the inside. There is a first annular gap between the first support plate 122 and the filter membrane, and the annular gap is filled with decolorized sand as a filler to form a decolorization layer 121. It is not difficult to understand that the filter screen and the filter membrane play a filtering role, which can block larger particles from passing through. On the one hand, it can effectively reduce the entry of decolorized sand, and on the other hand, it can prevent the decolorized sand from passing through, so as to limit the decolorized sand in the first annular gap to form a decolorization layer 121; the first support plate 122 and the second support plate 123 have a porous structure to allow paraffin oil to pass through. The aperture of the porous structure of the first support plate 122 and the second support plate 123 is preferably in the range of 5 to 10 mm, which is convenient for paraffin oil to pass through, and can make the first support plate 122 and the second support plate 123 have good strength. Furthermore, the filter screen, the first support plate 122, the filter membrane and the second support plate 123 are all coaxially arranged to make the thickness of the decolorization layer 121 uniform, and the resistance of the paraffin oil passing through the decolorization layer 121 from all radial directions of the decolorization layer 121 is equal, which can further improve the utilization rate of the filler forming the decolorization layer 121. The precision of the filter screen is 80-100 meshes, which can prevent the filler of the decolorization layer 121 from overflowing. The precision of the filter membrane is higher, and only small molecules such as paraffin oil can pass through.

[0042] Furthermore, in some embodiments, the difference between the outer diameter and the inner diameter of the first annular gap is 100 to 500 mm, and accordingly, the thickness of the bleaching layer 121 is in the range of 50 to 250 mm. Within this thickness range, paraffin oil can more easily pass through the bleaching layer 121 of the above thickness. On the first hand, the flow rate of the liquid outlet 113 is larger. On the second hand, the pressure of the paraffin oil supplied to the bleaching tank can be lower, which can reduce the system operating pressure accordingly. On the third hand, the influence of gravity on the movement trajectory of the paraffin oil can be reduced, so that the utilization rate of the bleaching sand in the bleaching layer 121 is higher.

[0043] In some embodiments, the filter element assembly 120 may also include end plates at both ends, and the above-mentioned filter screen, first support plate 122, filter membrane and second support plate 123 are connected to one end plate at one end and connected to the other end plate at the other end, and the two ends of the first annular gap are closed by the two end plates. In other embodiments, the two ends of the first annular gap may be closed by the cover plate and the bottom plate 114 of the tank body 110, that is, after the filter screen assembly is installed inside the tank body 110, one end of the first annular gap is closed by the bottom plate 114 of the tank body 110, and the bottom plate 114 carries the filler that forms the decolorization layer 121.

[0044] It is not difficult to understand that, since the aperture of the pore structure in the filter screen is different from that of the pore structure in the first support plate 122, if the two are fitted together, there will be a problem of mismatched holes, and then there will be a problem of uneven osmotic pressure after the filter screen and the first support plate 122 are fitted together. Therefore, in some embodiments, there is a second annular gap between the first support plate 122 and the filter screen. The difference between the outer diameter and the inner diameter of the second annular gap is 2 to 6 mm, so that a layer of paraffin oil film is formed in the second annular gap. When the second annular gap is filled with paraffin oil, the filter screen can be prevented from fitting with the first support plate 122, thereby overcoming the problem of uneven osmotic pressure after the filter screen and the first support plate 122 are fitted together.

[0045] In some embodiments, a first opening is provided at the top of the tank body 110, and the first opening is covered with a cover plate assembly 130, and the cover plate assembly 130 is sealed and connected to the first opening after covering the first opening. The first opening is used to load the filter element assembly 120 into the tank body 110. It is not difficult to understand that after the cover plate assembly 130 covers the first opening, the cover plate assembly 130 contacts the upper end of the filter element assembly 120 to prevent paraffin oil from passing through the gap between the cover plate assembly 130 and the filter element assembly 120, and the purpose of treating the paraffin oil cannot be achieved.

[0046] Further, the cover plate assembly 130 includes an outer cover plate 131 and an inner cover plate 132, the outer cover plate 131 is annular, the inner cover plate 132 is circular, the inner ring of the outer cover plate 131 is detachably sealed and connected to the periphery of the inner cover plate 132, and it is not difficult to understand that the cover plate assembly 130 formed by the outer cover plate 131 and the inner cover plate 132 is a circular structural member. The outer ring cover of the outer cover plate 131 is provided at the first opening and is detachably sealed and connected to the first opening.

[0047] In some embodiments, the outer diameter of the outer cover plate 131 is greater than or equal to the diameter of the first support plate 122, and the inner diameter of the outer cover plate 131 is greater than or equal to the diameter of the second support plate 123, that is, when the outer cover plate 131 covers the first opening, the outer cover plate 131 completely covers the filter element assembly 120. Figures 2 to 3 As shown, a lifting ring 133 is also provided on the side of the outer cover plate 131 facing the outside of the tank body 110, and the cover plate assembly 130 is connected to the filter element assembly 120 so that the filter element assembly 120 can be taken out from the inside of the tank body 110 while the outer cover plate 131 is lifted.

[0048] In some other embodiments, a lifting ring 133 is also provided on the side of the inner cover plate 132 facing the outside of the tank body 110, and the inner cover plate 132 is also sealedly connected to the second support plate 123 so that the filter membrane and the second support plate 123 can be removed from the interior of the tank body 110 while the inner cover plate 132 is lifted.

[0049] In some embodiments of the present application, the lower part of the tank body 110 protects the annular bottom plate 114 and the conical shell 115. The bottom plate 114 is annular, the edge of the conical shell 115 is fixedly connected to the inner ring of the bottom plate 114, and one end of the conical shell 115 is sealed and connected to the bottom of the second support plate 123 to prevent the paraffin oil from leaking; the other end of the conical shell 115 extends in a direction away from the tank body 110 and gradually becomes smaller, and the liquid outlet 113 is arranged at one end of the conical shell 115 away from the tank body 110, so that the paraffin oil passing through the decolorization layer 121 flows to the liquid outlet 113.

[0050] Furthermore, in some embodiments, the base plate 114 is also provided with a slot for installing a filter element, and the filter element is detachably arranged in the slot, which, on the one hand, facilitates the disassembly and assembly of the filter element assembly 120, and on the other hand, enables the positioning of the filter element assembly 120 during the installation process of the filter element assembly 120.

[0051] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A paraffin oil decolorization tank, characterized in that: include: A tank body, wherein the tank body is provided with a liquid inlet and a liquid outlet, A filter element assembly is arranged inside the tank body, the filter element assembly is annular, and the filter element assembly has an annular decolorization layer, and the decolorization layer separates the inside of the tank body into an independent first chamber and a second chamber; in the radial direction of the filter element assembly, the first chamber is located on the outside of the decolorization layer, and the second chamber is located on the inside of the decolorization layer; The liquid inlet is communicated with the first chamber, and the liquid outlet is communicated with the second chamber.

2. The paraffin oil decolorizing tank according to claim 1, characterized in that: The filter element assembly includes a filter screen, a first support plate, a filter membrane and a second support plate which are coaxially arranged in sequence from the outside to the inside; the first support plate and the second support plate both have a porous structure for paraffin oil to pass through; there is a first annular gap between the first support plate and the filter membrane, and the first annular gap is filled with decolorizing sand to form the decolorizing layer.

3. The paraffin oil decolorizing tank according to claim 2, characterized in that: The difference between the outer diameter and the inner diameter of the first annular gap is 100 to 500 mm.

4. The paraffin oil decolorizing tank according to claim 2, characterized in that: A second annular gap is provided between the first support plate and the filter screen, and a difference between an outer diameter and an inner diameter of the second annular gap is 2-6 mm.

5. The paraffin oil decolorizing tank according to claim 2, characterized in that: The top of the tank body is provided with a first opening for installing the filter element assembly into the interior of the tank body, and the first opening is covered with a cover plate assembly, and the cover plate assembly is detachably sealed and connected to the tank body.

6. The paraffin oil decolorizing tank according to claim 5, characterized in that: The cover plate assembly includes an outer cover plate and an inner cover plate, the outer cover plate is annular, the outer ring of the outer cover plate is covered on the first opening, the inner cover plate is circular, the inner ring of the outer cover plate is connected to the periphery of the inner cover plate, and the outer cover plate is also detachably connected to the filter element assembly.

7. The paraffin oil decolorizing tank according to claim 6, characterized in that: The outer diameter of the outer cover plate is greater than or equal to the diameter of the first support plate, and the inner diameter of the outer cover plate is greater than or equal to the diameter of the second support plate.

8. The paraffin oil decolorizing tank according to claim 7, characterized in that: The lower part of the tank body includes an annular bottom plate and a conical shell, the edge of the conical shell is fixedly connected to the inner ring of the bottom plate, one end of the conical shell is sealed to the bottom of the second support plate, and the other end of the conical shell extends in a direction away from the tank body and gradually becomes smaller; the liquid outlet is arranged at the end of the conical shell away from the tank body.

9. The paraffin oil decolorizing tank according to claim 8, characterized in that: The bottom plate is provided with a slot, and the filter element assembly is detachably arranged in the slot.

10. A paraffin oil decolorization device, characterized in that: It comprises a paraffin oil preheating tank and the paraffin oil decolorizing tank as described in any one of claims 1 to 9; the paraffin oil preheating tank is connected to a heat exchange device for heating the paraffin oil and a paddle mechanism for stirring the paraffin oil; the liquid outlet of the paraffin oil preheating tank is connected to the liquid inlet of the paraffin oil decolorizing tank through a pipeline.

Images