A purification apparatus for crude adipic acid

Abstract

This invention relates to the technical field of adipic acid production equipment, specifically to a purification device for crude adipic acid, comprising a filter tank and a filter element. The filter element is inserted into the filter tank and includes a filter cloth, a riser pipe, and multiple filter tubes. Several connecting holes are provided on the circumferential sidewalls of the filter tubes, connecting the filter tubes and the filter tank. The multiple filter tubes are evenly arranged circumferentially around the riser pipe. The filter cloth is a ring structure and is fitted over the outside of the multiple filter tubes. The riser pipe has multiple axially arranged branch pipes, each branch pipe having a connecting hole on its circumferential sidewall, which connects to the first connecting hole. In use, the raw liquid is first filtered through the filter cloth to become a clear liquid. The clear liquid enters the filter tube through the first connecting hole, then enters the riser pipe through the connecting hole and the bottom of the riser pipe, and finally exits from the riser pipe. By providing multiple connecting holes axially on the circumferential sidewalls of the riser pipe, the filter cake layer can be evenly distributed, thereby improving the filtration effect of crude adipic acid.

Description

Technical Field

[0001] This invention relates to the field of adipic acid production equipment technology, and in particular to a purification device for crude adipic acid. Background Technology

[0002] Crude adipic acid is a primary product obtained by separating adipic acid synthesis liquid produced by the oxidation of cyclohexane. After a series of processing steps, it can be converted into refined adipic acid. Refined adipic acid can not only be used as a major raw material for polyurethane and nylon salts, but also for the production of various ester products, as a plasticizer and high-grade lubricant. Various chemicals synthesized from adipic acid have the characteristics of being lightweight, mildew-proof, insect-proof, high-strength, high-melting-point, corrosion-resistant, and impact-resistant, and are therefore widely used.

[0003] The purification process of crude adipic acid includes multiple steps such as crystallization, thickening, centrifugation, and drying. In the thickening step, a candle filter can be used for filtration and thickening. In related technologies, such as the reference with authorization announcement number CN210145609U, a novel filter element and a filter containing the filter element are disclosed. When the filter is in use, the liquid enters the tank through the raw liquid inlet. In the tank, the liquid passes through the cylindrical filter cloth from the outside of the filter element, collects in the vertical groove, and enters the filter tube through the horizontal slit. The filtrate in the filter tube enters the riser tube from the bottom of the filter tube and flows out from the filtrate outlet at the top of the riser tube. Under the action of the filtration pressure difference, the cylindrical filter cloth is tightly attached to the filter tube and the riser tube, and the particles in the liquid are intercepted on the surface of the cylindrical filter cloth.

[0004] While the aforementioned filter containing the novel filter element improves the filtration efficiency of the raw liquid to some extent, it was found in the actual filtration process of crude adipic acid that a filter cake layer needs to be formed on the filter cloth first in order to effectively intercept adipic acid crystals. However, due to the long length of the filter tube and the fact that the liquid can only flow in through the bottom of the riser pipe, the filter cake layer is mainly located in the lower half of the filter tube when it is initially formed. This not only affects the passage of liquid, but also, as the filter cake layer gradually forms, it exhibits an uneven distribution with less at the top and more at the bottom, making it difficult to control the thickening concentration of crude adipic acid. Summary of the Invention

[0005] Therefore, it is necessary to provide a purification device for crude adipic acid to address the problems of long filtration time and poor filtration effect of current candle filters in the process of thickening crude adipic acid.

[0006] The above objectives are achieved through the following technical solutions:

[0007] A purification apparatus for crude adipic acid, comprising:

[0008] Filter canister;

[0009] A filter element is inserted into the filter canister and includes a filter cloth, vertically arranged riser pipes, and multiple filter tubes. Each filter tube has several connecting holes (I) on its circumferential sidewall, connecting the filter tube and the filter canister. The multiple filter tubes are evenly arranged circumferentially around the riser pipes. The filter cloth is annular and sleeved around the multiple filter tubes. The riser pipe has multiple axially arranged branch pipes, each branch pipe having a connecting hole (II) on its circumferential sidewall, which connects to the first connecting hole.

[0010] Furthermore, each of the branch pipes is fixedly fitted with a frustum-shaped limiting part, with the small end of the limiting part facing upwards, and the second connecting hole is opened on the limiting part; each of the branch pipes is fitted with an adjusting sleeve, the adjusting sleeve having an inner side wall and an outer side wall, and an annular connecting hole three provided on the inner side wall, the adjusting sleeve being able to slide along the axial direction of the branch pipe, and having corresponding first and second positions before and after sliding; when in the first position, the third connecting hole and the second connecting hole are not connected to each other, and when in the second position, the third connecting hole and the second connecting hole are connected; a regulating valve is inserted inside the adjusting sleeve, the regulating valve being disposed through the inner side wall and the outer side wall of the adjusting sleeve, the regulating valve being configured to, when gas with a preset pressure is filled into the filter canister, under the action of the limiting part, be able to introduce the gas inside the filter pipe into the adjusting sleeve.

[0011] Furthermore, the regulating valve includes a valve cylinder with openings at both ends. The axis of the valve cylinder is perpendicular to the axis of the regulating sleeve. The left end of the valve cylinder penetrates the outer wall of the regulating sleeve, and the right end is suspended and inserted inside the regulating sleeve. A valve core and a push rod are elastically connected inside the valve cylinder. Both the valve core and the push rod extend along the axial direction of the valve cylinder and can slide along the axial direction of the valve cylinder. The valve core is configured to open or close the left opening of the valve cylinder. The push rod cooperates with the conical stop of the limiting part and is configured to open or close the right opening of the valve cylinder.

[0012] Furthermore, the regulating valve also includes an elastic element, which is inserted inside the valve cylinder and located between the valve core and the push rod. Under the action of the elastic element, the valve core and the push rod tend to move away from each other.

[0013] Furthermore, the elastic element includes a compression spring.

[0014] Furthermore, the regulating valve is located between two adjacent filter tubes.

[0015] Furthermore, there are multiple regulating valves.

[0016] Furthermore, the number of filter elements is multiple.

[0017] Furthermore, the filter tube is made of PVC.

[0018] Furthermore, the filter cloth is made of PP or PE.

[0019] The beneficial effects of this invention are:

[0020] The purification device for crude adipic acid provided by this invention, in use, transforms the raw liquid into a clear liquid after filtration through a filter cloth. The clear liquid enters the filter tube through a first connecting hole, then enters the space between the filter tube and the riser tube through the first connecting hole, and then enters the interior of the riser tube through a second connecting hole and the bottom of the riser tube, finally being discharged from the riser tube. By providing multiple second connecting holes along the axial direction on the circumferential sidewall of the riser tube, the raw liquid can enter the riser tube both axially and from the bottom of the riser tube, thereby helping to ensure a uniform axial distribution of the filter cake layer. This avoids affecting the flowability of the clear liquid and facilitates control of the thickening concentration of crude adipic acid, improving the production quality of adipic acid.

[0021] Furthermore, by setting up an adjusting sleeve and a regulating valve, when the filter tank is not filled with raw liquid, the adjusting sleeve remains in the first position under the action of gravity, and the connecting holes three and two are not connected to each other, ensuring sealing. When the filter tank is filled with raw liquid, the adjusting sleeve can move axially to the second position under the action of buoyancy, so that the connecting holes three and two are connected, ensuring that the clear liquid can normally enter the riser pipe through the connecting hole two. When the raw liquid is discharged in the forward direction and the liquid level is below the adjusting sleeve, the adjusting sleeve can move axially to the first position under the action of gravity to seal the connecting hole two, preventing gas from being directly discharged from the riser pipe through the connecting hole two, thus improving... The efficiency of gas-driven raw liquid is improved by the regulating valve introducing gas from inside the filter tube into the regulating sleeve and temporarily storing it under the action of the limiting part during the movement of the regulating sleeve. When the forward air intake ends, the regulating sleeve can move axially, connecting the three connecting holes and the two connecting holes. This allows the gas inside the regulating sleeve to enter the riser pipe through the three connecting holes, thereby driving the clear liquid inside the riser pipe to flow out of the riser pipe, reducing the amount of clear liquid returning to the riser pipe, and improving the accuracy of the crude adipic acid thickening concentration. When reverse blowing occurs, the gas drives the regulating sleeve to move axially, thereby blowing gas evenly from all the connecting holes, improving the back-blowing effect. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of a crude adipic acid purification apparatus provided in an embodiment of the present invention;

[0023] Figure 2 This is a top view schematic diagram of a crude adipic acid purification apparatus provided in an embodiment of the present invention;

[0024] Figure 3 for Figure 2 Sectional view along the AA direction;

[0025] Figure 4 A three-dimensional structural schematic diagram of the filter element of the crude adipic acid purification device provided in an embodiment of the present invention;

[0026] Figure 5 This is a cross-sectional view of the filter element of a crude adipic acid purification device according to an embodiment of the present invention.

[0027] Figure 6 for Figure 5 A magnified schematic diagram of the structure at point B in the middle.

[0028] in:

[0029] 1. Filter canister; 11. End cap; 12. Adjusting pipe; 13. Air inlet pipe; 14. Intermediate pipe; 15. Support leg;

[0030] 2. Filter element; 21. Lifting pipe; 211. Branch pipe; 2111. Connecting hole two; 22. Filter tube; 221. Connecting hole one; 23. Adjusting sleeve; 231. Connecting hole three; 24. Adjusting valve; 241. Valve cylinder; 242. Valve core; 243. Push rod; 244. Compression spring; 25. Upper mounting base; 26. Lower mounting base. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] The serial numbers assigned to components in this document, such as "first," "second," etc., are merely used to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0034] like Figures 1 to 6 As shown, an embodiment of the present invention provides a purification device for crude adipic acid, which is used to purify crude adipic acid. The device includes a filter tank 1 and a filter element 2. The filter element 2 is inserted into the filter tank 1 and includes a filter cloth, vertically arranged riser pipes 21, and multiple filter tubes 22. Several connecting holes 221 are provided on the circumferential sidewall of each filter tube 22, connecting the filter tube 22 and the filter tank 1. The multiple filter tubes 22 are evenly arranged circumferentially around the riser pipes 21. The filter cloth is an annular structure and is fitted over the outside of the multiple filter tubes 22. The riser pipes 21 have multiple axially arranged branch pipes 211, each branch pipe 211 having a connecting hole 2111 on its circumferential sidewall, which connects to the connecting hole 221. For example, the number of filter tubes 22 can be six, evenly arranged circumferentially.

[0035] Specifically, in this embodiment, such as Figure 1 As shown, the filter tank 1 is a cylindrical structure with an open top. An end cap 11 is detachably connected to the top of the filter tank 1 by bolts. The end cap 11 is used to close or open the filter tank 1. An air inlet pipe 13 is fixedly installed inside the end cap 11. The air inlet pipe 13 is used to introduce air with a preset pressure into the filter tank 1. An regulating pipe 12 is installed at the bottom of the filter tank 1. The regulating pipe 12 is used to introduce raw liquid into the filter tank 1 or to discharge liquid inside the filter tank 1. An intermediate pipe 14 is installed on the outer peripheral wall of the filter tank 1 near the top. The intermediate pipe 14 is used to discharge clear liquid or to introduce air with a preset pressure into the riser pipe 21. Four support legs 15 are installed on the outer peripheral wall of the filter tank 1 near the bottom. The support legs 15 are used to support the filter tank 1.

[0036] More specifically, to facilitate the installation of the riser pipe 21 and filter pipe 22, the purification device for crude adipic acid is also configured to include an upper mounting base 25 and a lower mounting base 26, such as... Figure 4As shown, the riser tube 21 and filter tube 22 are both installed with their top ends inserted into the bottom of the upper mounting base 25 and their bottom ends inserted into the top of the lower mounting base 26. They are detachably connected to the upper mounting base 25 and the lower mounting base 26 by bolts. The filter cloth is installed with its top end sleeved on the outside of the upper mounting base 25 and detachably connected to the upper mounting base 25 by clamps. Its bottom end sleeved on the outside of the lower mounting base 26 and detachably connected to the lower mounting base 26 by clamps.

[0037] More specifically, for ease of installation of filter element 2, such as Figure 3 As shown, multiple connecting pipes are horizontally and side by side fixedly installed on the inner circumferential wall of the filter tank 1 near the top, and the right end of the connecting pipe is connected to the middle pipe 14. An installation pipe is vertically and penetratingly installed on the bottom circumferential side wall of the connecting pipe. The upper mounting seat 25 is threaded or fixedly sleeved on the lower end of the installation pipe during installation, so that the riser pipe 21 is connected through the installation pipe, the connecting pipe and the middle pipe 14.

[0038] More specifically, to facilitate the placement of the stock solution and the clarified solution, the purification device for crude adipic acid is also configured to include a stock solution tank and a clarified solution tank.

[0039] During operation, the raw solution is first introduced into the filter tank 1 through the regulating pipe 12. After being filtered through the filter cloth, the raw solution becomes a clear liquid, with some crude adipic acid remaining on the filter cloth. The clear liquid enters the filter tube 22 through the first connecting hole 221, then enters the space between the filter tube 22 and the riser tube 21 through the first connecting hole 221, and then enters the riser tube 21 through the second connecting hole 2111 and the bottom of the riser tube 21. Finally, it is discharged from the riser tube 21 into the raw solution tank. As filtration proceeds, when the preset filtration time or the pressure inside the filter tank 1 reaches the set value, it indicates that the crude adipic acid on the filter cloth has crystallized to form a filter cake layer of a certain thickness. At this point, the introduction of raw solution into the filter tank 1 is stopped, and the clear liquid is simultaneously introduced into the clear liquid tank. Then, air is introduced into the filter tank 1 through the air inlet pipe 13. Air at a preset pressure is introduced, and the original liquid is filtered through the filter cloth and becomes a clear liquid under the impetus of the air. The clear liquid enters the filter tube 22 through the first connecting hole 221, and then enters the space between the filter tube 22 and the riser tube 21 through the first connecting hole 221. Then it enters the interior of the riser tube 21 through the second connecting hole 2111 and the bottom of the riser tube 21, and finally exits from the riser tube 21 into the clear liquid tank. Then, air at a preset pressure is introduced into the riser tube 21 through the intermediate pipe 14. The air enters the space between the filter tube 22 and the riser tube 21 through the second connecting hole 2111, and then exits through the first connecting hole 221 to wash away the filter cake layer adhering to the filter cloth and let it fall into the liquid to form adipic acid with a set thickening concentration. Finally, it is discharged from the regulating pipe 12.

[0040] By providing multiple connecting holes 2111 along the axial direction on the circumferential sidewall of the riser pipe 21, the raw liquid can enter the riser pipe 21 both axially and from the bottom of the riser pipe 21. This helps to ensure that the filter cake layer is evenly distributed along the axial direction, thus avoiding affecting the flowability of the clear liquid and facilitating the control of the thickening concentration of crude adipic acid, thereby improving the production quality of adipic acid.

[0041] In some embodiments, each branch pipe 211 is fixedly fitted with a frustum-shaped limiting part, with the small end of the limiting part facing upwards, and a second connecting hole 2111 is opened on the limiting part; each branch pipe 211 is fitted with an adjusting sleeve 23, the adjusting sleeve 23 has an inner side wall and an outer side wall, and an annular connecting hole 231 is provided on the inner side wall. The adjusting sleeve 23 can slide along the axial direction of the branch pipe 211, and has a first position and a second position before and after sliding. When in the first position, the third connecting hole 231 and the second connecting hole 2111 are not connected to each other. When in the second position, the third connecting hole 231 and the second connecting hole 2111 are connected; an adjusting valve 24 is inserted inside the adjusting sleeve 23. The adjusting valve 24 is provided through the inner side wall and the outer side wall of the adjusting sleeve 23. The adjusting valve 24 is configured to introduce the gas inside the filter tube 22 into the adjusting sleeve 23 under the action of the limiting part when gas with a preset pressure is filled into the filter canister 1.

[0042] Specifically, in this embodiment, such as Figure 5 As shown, the cross-sectional shape of the adjusting sleeve 23 is set to "D" shape, the connecting hole 3 231 is set near the bottom of the adjusting sleeve 23, and the adjusting sleeve 23 is set to contact the outer peripheral wall of the outer side wall and the outer peripheral wall of all the filter tubes 22 during installation.

[0043] Initially, under the action of gravity, the adjusting sleeve 23 is held in the first position, and the connecting hole 3 231 and the connecting hole 2111 are not connected to each other to ensure sealing. During use, the raw liquid is first introduced into the filter tank 1 through the adjusting pipe 12. When the raw liquid exceeds the adjusting sleeve 23, the adjusting sleeve 23 can move upward along the axis to the second position under the action of buoyancy, so that the connecting hole 3 231 and the connecting hole 2111 are connected, ensuring that the clear liquid can normally enter the riser pipe 21 through the connecting hole 2111. After the raw liquid is filtered by the filter cloth, it becomes clear liquid. Some crude adipic acid remains on the filter cloth. The clear liquid enters the filter tube 22 through the connecting hole 1 221, then enters the space between the filter tube 22 and the riser pipe 21 through the connecting hole 1 221, then enters the riser pipe 21 through the connecting hole 2111 and the bottom of the riser pipe 21, and finally is discharged from the riser pipe 21 into the raw liquid tank.

[0044] As filtration proceeds, when the preset filtration time or the pressure inside filter tank 1 reaches the set value, it indicates that the coarse adipic acid crystals on the filter cloth have formed a filter cake layer of a certain thickness. First, the flow of raw liquid into filter tank 1 is stopped, and simultaneously, the clarified liquid is introduced into the clarified liquid tank. Then, air with a preset pressure is introduced into filter tank 1 through air inlet pipe 13. With the introduction of air, the raw liquid is filtered through the filter cloth and becomes clarified liquid under the push of the air. When the liquid level is below the adjusting sleeve 23, the adjusting sleeve 23 can move axially downwards to the first position under the action of gravity to seal the connecting hole 2111, preventing gas from directly exiting from the riser pipe 21 through the connecting hole 2111, thus improving the efficiency of gas pushing the raw liquid. During the movement of the adjusting sleeve 23... Under the action of the limiting part, the regulating valve 24 can introduce the gas inside the filter tube 22 into the regulating sleeve 23 for temporary storage. When the forward air intake ends, the regulating sleeve 23 can move axially, so that the connecting hole 3 231 and the connecting hole 2111 are partially connected, so that the gas inside the regulating sleeve 23 can enter the riser tube 21 through the connecting hole 3 231, thereby driving the clear liquid inside the riser tube 21 to flow out of the riser tube 21, reducing the amount of clear liquid backflow in the riser tube 21, and improving the accuracy of the crude adipic acid thickening concentration. When air with a preset pressure is introduced into the riser tube 21 through the intermediate tube 14, the air drives the regulating sleeve 23 to move axially, thereby blowing air evenly from all the connecting holes 1 221, improving the backflushing effect.

[0045] In a further embodiment, the regulating valve 24 is configured to include a valve cylinder 241 with openings at both ends. The axis of the valve cylinder 241 is perpendicular to the axis of the regulating sleeve 23. The left end of the valve cylinder 241 penetrates the outer wall of the regulating sleeve 23, and the right end is suspended and inserted inside the regulating sleeve 23. A valve core 242 and a push rod 243 are elastically connected and inserted inside the valve cylinder 241. Both the valve core 242 and the push rod 243 extend along the axial direction of the valve cylinder 241 and can slide along the axial direction of the valve cylinder 241. The valve core 242 is configured to open or close the left opening of the valve cylinder 241. The push rod 243 cooperates with the conical stop of the limiting part and is configured to open or close the right opening of the valve cylinder 241.

[0046] Specifically, in this embodiment, such as Figure 6 As shown, the regulating valve 24 is located below the connecting hole 231. The valve core 242 is configured as a T-shaped structure and has a vertically arranged vertical disc part 1 and a horizontal rod part 2. The vertical disc part 1 is used to close or open the left opening of the valve cylinder 241. The top rod 243 is configured as a T-shaped structure and has a vertically arranged vertical disc part 2 and a horizontal rod part 2. The vertical disc part 2 is used to close or open the right opening of the valve cylinder 241. A slot is provided on the left side wall of the vertical disc part 2 for the horizontal rod part of the valve core 242 to be inserted. The right end of the horizontal rod part 2 slides against the conical surface of the limiting part.

[0047] When the liquid level is below the adjusting sleeve 23, the adjusting sleeve 23 can move axially downward to the first position under the action of gravity. During the movement of the adjusting sleeve 23, the push rod 243 moves to the left under the guidance of the conical surface of the limiting part, causing the right opening of the valve cylinder 241 to open. As air is continuously injected, the valve core 242 moves to the right under the action of pressure difference, causing the left opening of the valve cylinder 241 to open, and air is injected into the adjusting sleeve 23 and temporarily stored. When the forward air intake ends, due to the large area of ​​the top surface of the adjusting sleeve 23... Given the area of ​​the bottom end face, under the condition that the internal pressure of the adjusting sleeve 23 remains constant, the upward force on the adjusting sleeve 23 is greater than the downward force. Under the action of the force difference, the adjusting sleeve 23 can move upward along the axial direction, so that the connecting hole 3 231 and the connecting hole 2111 are partially connected. This allows the gas inside the adjusting sleeve 23 to enter the inside of the riser pipe 21 through the connecting hole 3 231, thereby driving the clear liquid inside the riser pipe 21 to flow out of the riser pipe 21, reducing the amount of clear liquid backflow in the riser pipe 21, and improving the accuracy of the crude adipic acid thickening concentration.

[0048] In a further embodiment, the regulating valve 24 is configured to also include an elastic element, which is inserted inside the valve cylinder 241 and located between the valve core 242 and the push rod 243. Under the action of the elastic element, the valve core 242 and the push rod 243 tend to move away from each other.

[0049] Specifically, in this embodiment, the elastic element is configured to include a compression spring 244, such as... Figure 6 As shown, the compression spring 244 is sleeved on the horizontal rod portion one of the valve core 242, with its left end abutting against the right disc surface of the vertical disc portion one of the valve core 242 and its right end abutting against the left disc surface of the vertical disc portion two of the push rod 243.

[0050] In other embodiments, to prevent air from entering the regulating sleeve 23, the regulating valve 24 is positioned between two adjacent filter tubes 22, thereby preventing the left opening of the valve cylinder 241 from being blocked by the outer peripheral wall of the filter tube 22.

[0051] In other embodiments, to improve the stability of the regulating valve 24 during movement, multiple regulating valves 24 are provided; for example, the number of regulating valves 24 can be two, such as... Figure 5 As shown, the two regulating valves 24 are symmetrically arranged.

[0052] In other embodiments, to improve the filtration efficiency of crude adipic acid, the number of filter elements 2 is set to be multiple; for example, the number of filter elements 2 can be set to three, all of which can be detachably connected to the intermediate tube 14.

[0053] In other embodiments, the filter tube 22 is made of PVC; the filter tube 22 made of PVC material not only has good chemical stability, but also has high strength and hardness.

[0054] In other embodiments, the filter cloth is made of PP or PE; filter cloths made of PP or PE materials have high filtration efficiency, low pressure loss, stable filtration efficiency, long service life, low filtration cost, good safety, and strong adaptability.

[0055] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A purification apparatus for crude adipic acid, characterized in that, include: Filter canister; A filter element is inserted into the filter canister and includes a filter cloth, vertically arranged riser pipes, and multiple filter tubes. Each filter tube has several connecting holes (I) on its circumferential sidewall, connecting the filter tube and the filter canister. The multiple filter tubes are evenly arranged circumferentially around the riser pipes. The filter cloth is annular and sleeved around the multiple filter tubes. The riser pipe has multiple axially arranged branch pipes, each branch pipe having a connecting hole (II) on its circumferential sidewall, which connects to the first connecting hole. Each of the branch pipes is fixedly fitted with a frustum-shaped limiting part, with the small end of the limiting part facing upwards. The second connecting hole is opened on the limiting part. Each of the branch pipes is fitted with an adjusting sleeve, which has an inner side wall and an outer side wall. The inner side wall is provided with an annular connecting hole three. The adjusting sleeve can slide along the axial direction of the branch pipe and has a first position and a second position before and after sliding. When it is in the first position, the connecting hole three and the connecting hole two are not connected to each other. When it is in the second position, the connecting hole three and the connecting hole two are connected. An adjusting valve is inserted inside the adjusting sleeve. The adjusting valve is provided through the inner side wall and the outer side wall of the adjusting sleeve. The adjusting valve is configured to introduce the gas inside the filter pipe into the adjusting sleeve under the action of the limiting part when the filter canister is filled with gas of a preset pressure.

2. The purification apparatus for crude adipic acid according to claim 1, characterized in that, The regulating valve includes a valve cylinder with openings at both ends. The axis of the valve cylinder is perpendicular to the axis of the regulating sleeve. The left end of the valve cylinder passes through the outer wall of the regulating sleeve, and the right end is suspended and inserted into the regulating sleeve. A valve core and a push rod are elastically connected inside the valve cylinder. Both the valve core and the push rod extend along the axial direction of the valve cylinder and can slide along the axial direction of the valve cylinder. The valve core is configured to open or close the left opening of the valve cylinder. The push rod cooperates with the conical stop of the limiting part and is configured to open or close the right opening of the valve cylinder.

3. The purification apparatus for crude adipic acid according to claim 2, characterized in that, The regulating valve also includes an elastic element, which is inserted inside the valve cylinder and located between the valve core and the push rod. Under the action of the elastic element, the valve core and the push rod tend to move away from each other.

4. The purification apparatus for crude adipic acid according to claim 3, characterized in that, The elastic element includes a compression spring.

5. The purification apparatus for crude adipic acid according to claim 1, characterized in that, The regulating valve is located between two adjacent filter tubes.

6. The purification apparatus for crude adipic acid according to claim 1, characterized in that, There are multiple regulating valves.

7. The purification apparatus for crude adipic acid according to claim 1, characterized in that, There are multiple filter elements.

8. The purification apparatus for crude adipic acid according to claim 1, characterized in that, The filter tube is made of PVC.

9. The purification apparatus for crude adipic acid according to claim 1, characterized in that, The filter cloth is made of PP or PE.

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