A device for the controlled release of hydroquinone polymerization inhibitor in filters for acrylic acid and ester plants

Abstract

The utility model discloses a kind of for hydroquinone polymerization inhibitor slow-release device in acrylic acid and ester device filter, belong to acrylic acid and ester device field, including the slow-release device body installed in basket filter inside, the slow-release device body includes the upper shell of stainless steel and the lower shell of stainless steel, the filter bag is filled in the filling cavity, the filter bag is loaded with the resin pellet of adsorbing hydroquinone, the utility model is equipped with the cooperation of filter bag and upper shell and lower shell with resin pellet, a large amount of water-absorbing resin is wrapped in filter bag, then put into stainless steel net shell to prevent extrusion deformation, by filter bag, acrylic acid polymer and resin can be isolated in use, avoid resin into process pipeline, polymerization inhibitor slow-release device increases the concentration of polymerization inhibitor in filter, to reduce the concentration of filter position free radical, slow down the chain growth rate of polymer, can reduce filter cleaning frequency, reduce the number of times that staff contact acrylic acid, acrylic ester.

Description

Technical Field

[0001] This utility model relates to the field of acrylic acid and ester equipment, specifically to a device for slow-release of hydroquinone polymerization inhibitor in filters of acrylic acid and ester equipment. Background Technology

[0002] In acrylic acid and ester plants, acrylic acid and acrylate monomers can produce polymers due to local overheating, excessive residence time on trays, impurity catalysis, and polymerization inhibitor failure. Conventional polymerization inhibition methods include adding liquid-phase polymerization inhibitors to the reflux line of the cooler at the top of the tower, introducing polymerization-inhibiting air into the tower, and using 45° bends in the bottom extraction line to reduce eddy current generation. To reduce the accumulation and blockage of polymers in the plant, basket filters are often installed at the pump inlet to separate polymers from pipeline impurities.

[0003] However, when basket filters process acrylic and ester polymers, a large number of polymers containing free radicals are separated inside the filter element. The concentration of free radicals is higher than that inside the pipe, which increases the rate of polymer formation inside the filter element. This makes it easier for polymers to polymerize quickly and form polymers with larger molecular weights that clog the filter, resulting in frequent filter cleaning. Utility Model Content

[0004] The purpose of this invention is to provide a hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester equipment. By increasing the concentration of the polymerization inhibitor in the filter, the concentration of free radicals at the filter site is reduced and the chain growth rate of the polymer is slowed down, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester equipment, comprising a slow-release device body installed inside a basket filter, the slow-release device body comprising a stainless steel upper shell and a stainless steel lower shell, the upper shell being inserted into the interior of the lower shell, a filling cavity being formed between the upper shell and the lower shell, the filling cavity being filled with a filter bag, and the filter bag containing resin beads that adsorb hydroquinone.

[0006] Preferably, the resin microspheres are sodium polyacrylate resin particles, and the diameter of the resin microspheres is 300μm±0.2μm.

[0007] Preferably, the filter bag is a long strip-shaped polyacrylonitrile filter bag, and the filter bag is a 100-mesh acrylic filter bag.

[0008] Preferably, the upper shell includes a trumpet-shaped stainless steel mesh and a cylindrical mesh shell, with the trumpet-shaped stainless steel mesh integrally formed at the upper end of the cylindrical mesh shell.

[0009] Preferably, the lower shell comprises a cylindrical stainless steel mesh shell and an annular stainless steel mesh, wherein the diameter of the stainless steel mesh shell is larger than the diameter of the annular stainless steel mesh, and the cylindrical mesh shell is located between the stainless steel mesh shell and the annular stainless steel mesh.

[0010] Preferably, both the upper and lower shells are mesh shells made of 316 stainless steel, and the upper and lower shells are connected by threads.

[0011] Preferably, the outer and inner walls of the cylindrical mesh shell are provided with threaded sections, and the inner wall of the stainless steel mesh shell and the outer wall of the annular stainless steel mesh are provided with threads that match the cylindrical mesh shell.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. This utility model uses a filter bag containing resin balls, which, in conjunction with the upper and lower shells, encapsulates a large amount of absorbent resin within the filter bag. A stainless steel mesh shell is then placed inside to prevent deformation due to compression. The filter bag isolates the acrylic polymer and resin during use, preventing the resin from entering the process pipeline. The polymerization inhibitor slow-release device increases the concentration of polymerization inhibitor in the filter, thereby reducing the concentration of free radicals at the filter site and slowing down the polymer chain growth rate. This reduces the frequency of filter cleaning and minimizes the number of times employees come into contact with acrylic acid and acrylates.

[0014] 2. This utility model achieves continuous release of the polymerization inhibitor by installing the main body of the slow-release device into the filter screen of a basket filter and using the concentration difference.

[0015] 3. This utility model achieves polymerization inhibition under conditions such as easy polymerization trays and long-term transportation of acrylic acid by improving the adsorption materials and the types of polymerization inhibitors and adjusting the packaging form, which has great practical value. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0018] Figure 3 This is a schematic diagram of the exploded structure of this utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the present invention installed at the filter location;

[0020] Figure 5 This is a schematic diagram of the cross-linked superabsorbent resin particles of this invention adsorbing hydroquinone.

[0021] In the diagram: 1. Lower shell; 11. Stainless steel mesh shell; 12. Annular stainless steel mesh; 2. Upper shell; 21. Trumpet-shaped stainless steel mesh; 22. Cylindrical mesh shell; 3. Filling cavity. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Acrylic acid polymerization inhibitor components, including hydroquinone, copper acetate, AI-61R, phenothiazine, and hydroquinone monomethyl ether, are often dissolved in high-purity acrylic acid and pumped into the tower as a polymerization inhibitor. However, the solubility of hydroquinone in acrylic acid is not high, which causes the polymerization inhibitor to easily settle in the polymerization inhibitor tank, resulting in low concentrations at various locations within the unit. The effect of low polymerization inhibitor concentration is not significant at locations with low free radical concentrations. Due to impurity catalysis, long residence time, etc., the free radicals in acrylic acid increase, and the low polymerization inhibitor concentration is insufficient to consume the free radicals, leading to the formation of a large amount of polymer. This phenomenon is particularly evident in basket filters.

[0024] To address the problem of filter clogging caused by the generation of large amounts of polymer, this invention provides a technical solution: a hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants, such as... Figure 1-4 As shown, the device includes a slow-release device body installed inside a basket filter. The slow-release device body includes a stainless steel upper shell 2 and a stainless steel lower shell 1. The upper shell 2 is inserted into the interior of the lower shell 1, and a filling cavity 3 is formed between the upper shell 2 and the lower shell 1. The filling cavity 3 is filled with a filter bag, and the filter bag contains resin beads that adsorb hydroquinone.

[0025] By using a filter bag containing resin beads in conjunction with the upper shell 2 and the lower shell 1, a large amount of water-absorbing resin is wrapped in the filter bag. Then, a stainless steel mesh shell 11 is placed inside to prevent compression and deformation. The filter bag can isolate the acrylic polymer and resin during use, preventing the resin from entering the process pipeline. By placing the main body of this slow-release device into the basket filter screen, the polymerization inhibitor is continuously released through the concentration difference. The polymerization inhibitor slow-release device increases the concentration of polymerization inhibitor in the filter, thereby reducing the concentration of free radicals at the filter site and slowing down the chain growth rate of the polymer. This can reduce the frequency of filter cleaning and reduce the number of times employees come into contact with acrylic acid and acrylates.

[0026] The resin microspheres are sodium polyacrylate resin particles, and the diameter of the resin microspheres is 300μm±0.2μm.

[0027] Using cross-linked superabsorbent polymer (SAP) particles as the adsorbent material, specifically sodium polyacrylate with a particle size of 300 μm, the adsorption of hydroquinone and its polymerization inhibition in a flowing acrylic acid environment were confirmed, as shown in Table 1 below.

[0028] Table 1

[0029]

[0030] Table 1 shows that hydroquinone is a water-soluble solid and can be fully absorbed in a saturated aqueous solution using porous, adsorbent materials. The subsequent addition of a large amount of acrylic acid reduces the solubility of hydroquinone, allowing it to be immobilized and stored in the adsorbent material in large quantities. Figure 5 As shown;

[0031] The filter bag is a long, strip-shaped polyacrylonitrile filter bag, specifically a 100-mesh acrylic filter bag. A large number of absorbent resin particles are encapsulated within this 100-mesh acrylic (homogeneous polyacrylonitrile) filter bag, which is then placed inside a specially made 316 stainless steel mesh shell 11 to prevent deformation from compression. The nylon mesh isolates the acrylic polymer and resin during use, preventing the resin from entering the process pipeline. When in use, this device must be placed within a basket filter screen, and the concentration difference enables the continuous release of the polymerization inhibitor.

[0032] The upper shell 2 includes a trumpet-shaped stainless steel mesh 21 and a cylindrical mesh shell 22. The trumpet-shaped stainless steel mesh 21 is integrally formed on the upper end of the cylindrical mesh shell 22, which facilitates fixing the filter bag in the filling cavity 3 using the trumpet-shaped stainless steel mesh 21 and the cylindrical mesh shell 22.

[0033] The lower shell 1 includes a cylindrical stainless steel mesh shell 11 and an annular stainless steel mesh 12. The diameter of the stainless steel mesh shell 11 is larger than the diameter of the annular stainless steel mesh 12. The cylindrical mesh shell 22 is located between the stainless steel mesh shell 11 and the annular stainless steel mesh 12. The cylindrical mesh shell 22 is fixed to the lower shell 1 by the annular stainless steel mesh 12 and the cylindrical mesh shell 22, so that the filter bag is fixed by the compression of the upper shell 2 and the lower shell 1.

[0034] Both the upper shell 2 and the lower shell 1 are mesh shells made of 316 stainless steel. The upper shell 2 and the lower shell 1 are connected by threads. The use of 316 stainless steel improves the corrosion resistance of the upper shell 2 and the lower shell 1, as well as the overall hardness of the upper shell 2 and the lower shell 1.

[0035] Both the outer and inner walls of the cylindrical mesh shell 22 are provided with threaded sections. The inner wall of the stainless steel mesh shell 11 and the outer wall of the annular stainless steel mesh 12 are provided with threads that match the cylindrical mesh shell 22, so that the upper shell 2 and the lower shell 1 are detachable, which facilitates the assembly and disassembly of the upper shell 2 and the lower shell 1.

[0036] With the 100-mesh acrylic filter bag, the filter bag is long and strip-shaped, divided into eight equal parts by knitting. 300μm sodium polyacrylate resin particles are put into the filter bag. After the filter bag is sealed, it is placed into the lower shell 1, and the mesh shell of the upper shell 2 is used to vertically place and fix the filter bag.

[0037] like Figure 4 As shown, the main body of the slow-release device is installed at the bottom of the filter's porous plate, inside the filter's metal mesh, and is fitted in place by its ring shape, without any other connections and is freely detachable.

[0038] According to the above-mentioned solution, the hydroquinone slow-release device (replaced every 7 days) was placed in the filter before the circulating pump of the acetic acid removal tower in the acrylic acid refining workshop. The filter cleaning cycle before and after the placement of the hydroquinone slow-release device was tested during normal production under the same production conditions for one month after tower washing. The results are shown in Table 2 below:

[0039] Table 2

[0040]

[0041] The results in Table 2 show that the addition of the hydroquinone slow-release device can effectively reduce the frequency of filter cleaning in both the early and late stages of device operation.

[0042] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for slow-release of hydroquinone polymerization inhibitor in filters of acrylic acid and ester plants, characterized in that: The device includes a slow-release device body installed inside a basket filter. The slow-release device body includes a stainless steel upper shell (2) and a stainless steel lower shell (1). The upper shell (2) is inserted into the interior of the lower shell (1). A filling cavity (3) is formed between the upper shell (2) and the lower shell (1). The filling cavity (3) is filled with a filter bag containing resin beads that adsorb hydroquinone.

2. The hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 1, characterized in that: The resin microspheres are sodium polyacrylate resin particles, and the diameter of the resin microspheres is 300μm±0.2μm.

3. The hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 2, characterized in that: The filter bag is a long strip-shaped polyacrylonitrile filter bag, and the filter bag is a 100-mesh acrylic filter bag.

4. The hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 3, characterized in that: The upper shell (2) includes a trumpet-shaped stainless steel mesh (21) and a cylindrical mesh shell (22), with the trumpet-shaped stainless steel mesh (21) integrally formed on the upper end of the cylindrical mesh shell (22).

5. A hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 4, characterized in that: The lower shell (1) includes a cylindrical stainless steel mesh shell (11) and an annular stainless steel mesh (12). The diameter of the stainless steel mesh shell (11) is larger than the diameter of the annular stainless steel mesh (12), and the cylindrical mesh shell (22) is located between the stainless steel mesh shell (11) and the annular stainless steel mesh (12).

6. A hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 5, characterized in that: Both the upper shell (2) and the lower shell (1) are mesh shells made of 316 stainless steel, and the upper shell (2) and the lower shell (1) are connected by threads.

7. A hydroquinone polymerization inhibitor slow-release device for use in filters of acrylic acid and ester plants according to claim 6, characterized in that: The outer and inner walls of the cylindrical mesh shell (22) are provided with threaded sections, and the inner wall of the stainless steel mesh shell (11) and the outer wall of the annular stainless steel mesh (12) are provided with threads that match the cylindrical mesh shell (22).

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