Equipment for continuously crystallizing trimellitic anhydride into anhydride
By using a continuous trimellitic anhydride crystallization anhydride production equipment, which employs flash evaporation and multi-stage heating technology, the problems of low efficiency and easy corrosion of existing equipment have been solved, achieving efficient and low-energy trimellitic anhydride production.
Patent Information
- Application Number
- CN202423307123.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing trimellitic anhydride production equipment has shortcomings in terms of production efficiency and equipment operation, especially the low efficiency of intermittent heating evaporation in the crystallization kettle and the complex and easily corroded stirring evaporation equipment in the crystallization tower.
A continuous trimellitic anhydride crystallization anhydride production equipment is adopted, which utilizes flash evaporation and multi-stage heating methods. Acetic acid and light components are continuously removed through inner and outer ring feed pipelines, conical and inverted conical flash plates, and multi-stage heating plates. Mechanical stirring is avoided, and gravity feeding is used to ensure product quality and efficiency.
It enables continuous feeding and heating of materials, reduces energy consumption, improves the efficiency of light component removal, reduces side reactions, has a simple and easy-to-maintain equipment structure, produces high-quality products, and has high working efficiency.
Smart Images
Figure CN223732144U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to crystallization equipment technical field, specifically a kind of continuous trimellitic anhydride crystallization equipment. BACKGROUND
[0002] Trimellitic anhydride (TMA) is abbreviated as trimellitic anhydride, which has wide application in the production of PVC resin plasticizer, polyimide resin paint, water-soluble alkyd resin, epoxy resin curing agent, impregnant of low-voltage and pulse power container, film, water treatment agent and surfactant, etc.
[0003] At present, the main production method of trimellitic anhydride is that trimethylbenzene is dissolved in acetic acid, and trimellitic acid is produced by reacting with air or oxygen under the action of catalyst. After removing acetic acid and light components, trimellitic acid is crystallized, and finally anhydrous reaction is carried out to obtain product. The method of intermittent heating evaporation or crystallization tower stirring evaporation crystallization is mainly used in the crystallization of trimellitic acid. The intermittent heating evaporation of crystallization kettle has the advantages of simple operation and lowest cost, and the disadvantages are long heating time, many side reactions and low efficiency. The crystallization tower stirring evaporation crystallization has the advantages of obvious efficiency improvement, and the disadvantages are complex equipment structure, easy to appear corrosion in high temperature environment, high maintenance rate and certain influence on crystallization effect by mechanical stirring.
[0004] In view of the above situation, the equipment for the light component removal and crystallization process of trimellitic anhydride needs to be further improved, especially in the balance point of production efficiency and equipment running state. INVENTION CONTENTS
[0005] The utility model aims at providing a kind of continuous trimellitic anhydride crystallization equipment, which adopts flash evaporation and multi-stage heating, so that trimethylbenzene can continuously remove acetic acid and light components after oxidation and produce good crystallinity, to ensure that the quality and reaction efficiency of product can meet the demand.
[0006] To solve the above technical problems, the utility model provides a kind of continuous trimellitic anhydride crystallization equipment, which comprises a crystallization kettle and a discharge kettle arranged at the bottom of the crystallization kettle and communicated with it, the crystallization kettle is sequentially provided with a top gas phase outlet from top to bottom, and a feeding section and a multi-stage crystallization section arranged in the kettle body of the crystallization kettle,
[0007] The feeding section comprises a plurality of homogeneous feeders, a conical flash plate and an inverted conical flash plate, the plurality of homogeneous feeders comprises an inner ring feeding pipeline and an outer ring feeding pipeline, the inner ring feeding pipeline and the outer ring feeding pipeline are suspendedly installed in the feeding section of the crystallization kettle and are fixed by a suspension pipe support, the suspension pipe support is welded and fixed between the inner ring feeding pipeline, the outer ring feeding pipeline and the kettle body of the crystallization kettle, two symmetrical feeding pipes with the same diameter are respectively installed on the inner ring feeding pipeline and the outer ring feeding pipeline, the feeding pipes extend out of the kettle body of the crystallization kettle and are connected with external feeding pipelines through flanges, a plurality of discharge ports are arranged on the inner ring feeding pipeline and the outer ring feeding pipeline in an inclined manner, the conical flash plate is arranged below the outer ring feeding pipeline, the inverted conical flash plate is arranged below the conical flash plate, the conical flash plate is fixed by a suspension support between the conical flash plate and the kettle body of the crystallization kettle, the inverted conical flash plate is fixedly connected with the inner wall of the kettle body of the crystallization kettle, and a first opening is arranged at the bottom of the inverted conical flash plate.
[0008] The plurality of crystallization sections are sequentially arranged from top to bottom, each crystallization section comprises a conical heating plate and an inverted conical heating plate arranged in sequence from top to bottom, the conical heating plate is also fixed by a suspension support between the conical heating plate and the kettle body of the crystallization kettle, the inverted conical heating plate is welded and fixed with the inner wall of the crystallization kettle, the top of the conical heating plate of the first crystallization section is arranged below the first opening, the bottom of the inverted conical heating plate of each crystallization section is provided with a second opening, and the second opening of the inverted conical heating plate of the upper crystallization section is arranged above the top of the conical heating plate of the lower crystallization section.
[0009] Further, the conical flash plate and the inverted conical flash plate are both jacket structures, and high-temperature hot water is introduced into the inside of the conical flash plate and the inverted conical flash plate.
[0010] Further, the conical heating plate and the inverted conical heating plate are also both jacket structures.
[0011] Specifically, the plurality of crystallization sections comprise six stages, the inside of the conical heating plate and the inverted conical heating plate of the first to third stages are introduced into high-temperature hot water, the temperature of the high-temperature hot water ranges from 120 to 220 DEG C, and the inside of the conical heating plate and the inverted conical heating plate of the fourth to sixth stages are introduced into heat-conducting oil.
[0012] Further, each crystallization section is provided with a lateral gas phase outlet, the lateral gas phase outlet is arranged on the side wall of the crystallization kettle and is located below the inverted conical flash plate and the inverted conical heating plate.
[0013] Further, the kettle body of the discharging kettle is a jacket structure, and heat-conducting oil is introduced into the jacket of the kettle body.
[0014] Further, the pressure in the crystallization kettle is -0.085±0.005 MPa.
[0015] Further, the height ratio of the feeding section to the crystallizer is 1:3.5-6.5, and the height ratio of each crystallization section to the crystallizer is 1:2.5-5.5.
[0016] The present utility model has the advantages of:
[0017] 1. The material is continuously fed and heated in the light component removal crystallization process, which is lower in energy consumption and higher in system light component removal efficiency than the traditional intermittent heating method.
[0018] 2. The device has a clear and simple structure, is easy to operate and maintain, has good corrosion resistance, and is conducive to long-term continuous operation.
[0019] 3. Different heating media are used in the initial and middle-late heating processes of the material, which ensures that the material will not be cooled too quickly to reduce the light component removal rate and will not be overheated to cause the material to produce impurities due to side reactions.
[0020] 4. The device uses gravity continuous feeding and does not use mechanical stirring to force discharging, but slowly flows downward on the surface of the flash evaporation plate and the heating plate to simulate the natural crystallization process, thereby producing better trimellitic acid.
[0021] 5. The light components removed from the material quickly pass through the top and lateral gas line pipes to be quickly removed, which reduces the probability of the light components re-entering the material and further improves the work efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical scheme of the present utility model, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present utility model, and those skilled in the art can obtain other drawings according to these drawings without creative labor.
[0023] Figure 1 is a structural cross-sectional view of the crystallization anhydride forming equipment of the present utility model;
[0024] Figure 2 is an installation schematic view of the inner ring feeding pipeline and the outer ring feeding pipeline of the crystallization anhydride forming equipment of the present utility model;
[0025] Figure 3 is an installation schematic view of the conical flash evaporation plate of the crystallization anhydride forming equipment of the present utility model;
[0026] Figure 4 is an installation schematic view of the conical heating plate of the crystallization anhydride forming equipment of the present utility model.
[0027] In the figure: 1-top gas phase outlet, 2-inner ring feed line, 3-outer ring feed line, 4-cone flash plate, 5-inverted cone flash plate, 6-cone heating plate, 7-inverted cone heating plate, 8-lateral gas phase outlet, 9-first opening, 10-second opening, 11-discharge kettle, 12-hanging pipe rack, 13-feed pipe, 14-hanging support. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the utility model specification. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.
[0029] In one specific embodiment of the utility model, as shown in the figure, Figures 1-4 A continuous trimellitic anhydride crystallization equipment comprises a crystallization kettle and a discharge kettle 11 arranged at the bottom of the crystallization kettle and communicated with the crystallization kettle, the crystallization kettle is sequentially provided with a top gas phase outlet 1 from top to bottom, and a feed section and a plurality of crystallization sections arranged in the kettle body of the crystallization kettle,
[0030] The feed section comprises a plurality of homogeneous feeders, a cone flash plate 4 and an inverted cone flash plate 5, the plurality of homogeneous feeders comprises an inner ring feed line 2 and an outer ring feed line 3, the inner ring feed line 2 and the outer ring feed line 3 are suspendedly installed in the feed section of the crystallization kettle and fixed by a hanging pipe rack 12, the hanging pipe rack 12 is welded and fixed between the inner ring feed line 2, the outer ring feed line 3 and the kettle body of the crystallization kettle, two symmetrical feed pipes 13 of the same diameter are respectively installed on the inner ring feed line 2 and the outer ring feed line 3, and the feed pipes 13 extend out of the kettle body of the crystallization kettle and are connected with external feed lines through flanges.
[0031] The inner ring feed line 2 and the outer ring feed line 3 are both provided with a plurality of obliquely arranged discharge ports, the cone flash plate 4 is arranged below the outer ring feed line 3, the inverted cone flash plate 5 is arranged below the cone flash plate 4, the cone flash plate 4 is fixed with the kettle body of the crystallization kettle through a hanging support 14, the hanging support 14 is arranged at the bottom of the cone flash plate 4 and welded on the inner wall of the crystallization kettle, the inverted cone flash plate 5 is welded and fixedly connected with the inner wall of the kettle body of the crystallization kettle, and the bottom of the inverted cone flash plate 5 is provided with a first opening 9; the cone flash plate 4 and the inverted cone flash plate 5 are both of jacketed structures, high-temperature hot water is introduced into the inside of the cone flash plate 4 and the inverted cone flash plate 5, and the temperature range of the high-temperature hot water is 160-180 DEG C.
[0032] The multi-stage crystallization section is arranged from top to bottom, each stage of the crystallization section comprises a conical heating plate 6 and an inverted conical heating plate 7 arranged from top to bottom, the conical heating plate 6 is also fixed between the kettle body of the crystallization kettle and the suspended support 14, the suspended support 14 is arranged at the bottom of the conical heating plate 7, the suspended support 14 is welded on the inner wall of the crystallization kettle, the inverted conical heating plate 7 is welded and fixed with the inner wall of the crystallization kettle, the top of the conical heating plate 6 of the first stage of the crystallization section is arranged below the first opening 9, the bottom of the inverted conical heating plate 7 of each stage of the crystallization section is provided with a second opening 10, the second opening 10 of the upper inverted conical heating plate 7 is arranged above the top of the lower conical heating plate 6. The conical heating plate 6 and the inverted conical heating plate 7 are also of a jacket structure. The multi-stage crystallization section comprises 6 stages, the inside of the conical heating plate 6 and the inverted conical heating plate 7 of stages 1-3 are connected with high-temperature hot water, the temperature of the high-temperature hot water ranges from 180-200℃, and the inside of the conical heating plate 6 and the inverted conical heating plate 7 of stages 4-6 are connected with heat-conducting oil.
[0033] Preferably, the suspended support 14 is a design of a plurality of metal pipes which are arranged in a mesh structure in a longitudinal and transverse manner.
[0034] Each stage of the crystallization section is provided with a lateral gas phase outlet 8, the lateral gas phase outlet 8 is arranged on the side wall of the crystallization kettle and below the inverted conical flash plate 5 and the inverted conical heating plate 7.
[0035] The kettle body of the discharging kettle 11 is of a jacket structure, and heat-conducting oil is connected in the jacket. The continuous endo-1,3-dicarboxylic acid anhydride crystallization equipment is operated under negative pressure, and the pressure in the crystallization kettle is-0.085±0.005MPa.
[0036] Preferably, the height ratio of the feeding section to the crystallization kettle is 1:3.5, and the height ratio of each stage of the crystallization section to the crystallization kettle is 1:3.
[0037] In this embodiment, the m-xylene is dissolved in acetic acid, and reacts with air or oxygen under the action of catalyst to produce trimellitic acid material. The trimellitic acid material containing a large amount of light components, mainly the solvent acetic acid, water and unoxidized m-xylene in the m-xylene oxidation reaction, and a small amount of organic impurities, is uniformly sprayed on the conical flash plate 4 through the inner ring feed pipeline 2 and the outer ring feed pipeline 3 of the inner and outer ring structure, and the light components are rapidly gasified under the action of negative pressure and heating and are discharged from the system through the top gas phase outlet 1 and the lateral gas phase outlet, and the material slowly moves to the edge of the conical flash plate 4 and falls on the inverted conical flash plate 5, and the light components are gasified and discharged from the system under the action of heating on the surface of the inverted conical flash plate 5, and the material continues to slowly slide down to the central part of the inverted conical flash plate 5 and falls on the surface of the conical heating plate 6 and the inverted conical heating plate 7 of the first-stage crystallization section, and then slides down in turn, and the remaining light components in the material continue to be gasified and discharged through the lateral gas phase pipeline, and the trimellitic acid gradually crystallizes to form high-purity crystals and finally falls into the discharge kettle 11 for heating and heat preservation.
[0038] The above only discloses a preferred embodiment of the utility model, of course, cannot limit the scope of the utility model, therefore, the equivalent changes made according to the utility model claims still belong to the range covered by the utility model.
Claims
1. A continuous trimellitic anhydride crystallization into anhydride apparatus, characterized in that, The crystallization kettle is sequentially provided from top to bottom with a top gas phase outlet (1), a feeding section and a multi-stage crystallization section arranged in the kettle body of the crystallization kettle, The feeding section comprises a plurality of homogeneous feeders, a conical flash plate (4) and an inverted conical flash plate (5), the plurality of homogeneous feeders comprises an inner ring feed pipeline (2) and an outer ring feed pipeline (3), the inner ring feed pipeline (2) and the outer ring feed pipeline (3) are suspendedly installed in the feeding section of the crystallization kettle and are fixed by a suspension pipe support (12), the suspension pipe support (12) is welded and fixed between the inner ring feed pipeline (2), the outer ring feed pipeline (3) and the kettle body of the crystallization kettle, two symmetrical feed pipes (13) of the same diameter are respectively arranged on the inner ring feed pipeline (2) and the outer ring feed pipeline (3), the feed pipes (13) extend out of the kettle body of the crystallization kettle and are connected with external feed pipelines through flanges, and the inner ring feed pipeline (2) and the outer ring feed pipeline (3) are respectively provided with a plurality of inclined discharge ports; the conical flash plate (4) is arranged below the outer ring feed pipeline (3), the inverted conical flash plate (5) is arranged below the conical flash plate (4), the conical flash plate (4) is fixed with the kettle body of the crystallization kettle through a suspension support (14), the inverted conical flash plate (5) is welded and fixedly connected with the inner wall of the kettle body of the crystallization kettle, and the bottom of the inverted conical flash plate (5) is provided with a first opening (9); The multi-stage crystallization section is sequentially arranged from top to bottom, each stage of the crystallization section comprises a conical heating plate (6) and an inverted conical heating plate (7) arranged in sequence from top to bottom, the conical heating plate (6) is also fixed between the kettle body of the crystallization kettle and the suspension support (14), the inverted conical heating plate (7) is welded and fixed with the inner wall of the kettle body of the crystallization kettle, the top of the conical heating plate (6) of the first stage of the crystallization section is arranged below the first opening (9), and the bottom of the inverted conical heating plate (7) of each stage of the crystallization section is provided with a second opening (10), and the second opening (10) of the inverted conical heating plate (7) of the upper stage is arranged above the top of the conical heating plate (6) of the lower stage.
2. A continuous trimellitic anhydride crystallization to anhydride apparatus according to claim 1, wherein, The conical flash plate (4) and the inverted conical flash plate (5) are both jacket structures, and high-temperature hot water is introduced into the inside of each of the conical flash plate (4) and the inverted conical flash plate (5), and the temperature of the high-temperature hot water ranges from 120 to 220 DEG C.
3. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 1, wherein, The conical heating plate (6) and the inverted conical heating plate (7) are also both jacket structures.
4. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 3, wherein, The multi-stage crystallization section comprises six stages, the inside of the conical heating plate (6) and the inverted conical heating plate (7) of the first to third stages is introduced with high-temperature hot water, the temperature of the high-temperature hot water ranges from 120 to 220 DEG C, and the inside of the conical heating plate (6) and the inverted conical heating plate (7) of the fourth to sixth stages is introduced with heat-conducting oil.
5. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 1, wherein, Each stage of the crystallization section is provided with a lateral gas phase outlet (8), the lateral gas phase outlet (8) is arranged on the side wall of the crystallization kettle and is located below the inverted conical flash plate (5) and the inverted conical heating plate (7).
6. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 1, wherein, The kettle body of the discharging kettle (11) is a jacket structure, and heat-conducting oil is introduced into the jacket of the kettle body.
7. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 1, wherein, The pressure in the crystallization kettle is -0.085±0.005 MPa.
8. The continuous trimellitic anhydride crystallization into anhydride apparatus of claim 1, wherein, The height ratio of the feeding section to the crystallization kettle is 1:3.5-6.5; the height ratio of each crystallization section to the crystallization kettle is 1:2.5-5.5.