Desolventizing kettle for chemical production

Abstract

The utility model relates to the technical field of desolventizing kettles, in particular to a desolventizing kettle for chemical production. Comprising a kettle body, an annular inner sleeve is concentrically fixed in the upper end of the kettle body, an annular cavity is formed between the inner sleeve and the kettle body, an annular gap is formed between the lower end of the inner sleeve and the inner wall of the kettle body, the upper end of the inner sleeve is fixedly communicated with a material pipe, and the upper end of the material pipe is located above the kettle body; a plurality of connecting rods are fixed on the outer ring of the one-way bearing, scrapers are fixed on the connecting rods, the scrapers are positioned in the annular gap, and the scrapers are respectively in sliding contact with the inner wall of the kettle body and the inner sleeve. According to the reaction kettle, materials are added into the annular cavity, and the materials in the annular cavity flow down along the inner wall of the kettle body through the annular gap, so that the heating efficiency of the materials is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of a desolventizing kettle, in particular to a desolventizing kettle for chemical production. Background Art

[0002] 2-Amino-5-chloro-N,3-dimethylbenzamide is often used as an intermediate of the pesticide chlorantraniliprole or a pharmaceutical intermediate. In the production process of 2-amino-5-chloro-N,3-dimethylbenzamide, 2-nitro-3-methylbenzoic acid needs to be esterified to obtain 3-methyl-2-nitrobenzoic acid methyl ester; then 3-methyl-2-nitrobenzoic acid methyl ester is aminated to obtain 2-nitro-N,3-dimethylbenzamide; then 2-nitro-N,3-dimethylbenzamide is reduced to obtain 2-amino-N,3-dimethylbenzamide, and finally 2-amino-N,3-dimethylbenzamide is chlorinated to obtain 2-amino-5-chloro-N,3-dimethylbenzamide.

[0003] A desolventizing kettle is required for the amination of methyl 3-methyl-2-nitrobenzoate. The specific steps are as follows: add methanol and methyl 3-methyl-2-nitrobenzoate to the stirring kettle and stir, while turning on the tail gas absorption. Control the temperature at 20-25°C and add methylamine methanol solution. After the addition is completed, control the temperature at 20-25°C for 2h, then heat it to 35°C for 2h, and then heat it to 45°C for 2h. For sampling control, the raw material is required to be ≤1%. If it is unqualified, extend the insulation time or add methylamine alcohol. After passing the test, transfer to the desolventizing kettle to heat up and desolventize at normal pressure, desolventize to 80°C in the kettle, stop heating, change to vacuum desolventizing, and stop vacuum until the material in the kettle becomes thick. Add water to the kettle, stir and cool to 25°C, discharge and filter, wash once, and dry the material at 70-75°C. The mother liquor is recovered into the kettle, and hydrochloric acid is added to adjust the pH to 1-2. The precipitated solid is 2-nitro-3-methylbenzoic acid, which is centrifuged at 25-30℃ and dried at 80℃. It can be put into production after the content is tested and qualified.

[0004] In the prior art, the patent document with application number CN202222581309.7 discloses a desolventizing kettle for chemical production. In the traditional desolventizing kettle, the material is directly injected into the kettle body from the feed port of the kettle body, stirred and heat-transferred by the stirring mechanism, and finally heated to the set temperature. The heating efficiency is low, which is not conducive to improving the desolventizing efficiency. To this end, in the technical scheme of the patent, the material entering the feed pipeline is dispersed and sprayed into the kettle body through the annular horizontal distribution cavity and the distribution nozzle. At the same time, since the axis of the distribution nozzle intersects with the upper part of the inner wall of the kettle body, the material is first sprayed on the side wall of the kettle body, and then most of it flows downstream, fully absorbing the heat transfer of the heating jacket and being preheated, so that part of the solvent therein is directly vaporized. During the feeding process, the stirring mechanism is used to further improve the desolventizing efficiency, solving the problem of low desolventizing efficiency and long time consumption of the existing desolventizing kettle. However, the material needs to be pressurized when it is dispersed and sprayed into the kettle body through the distribution nozzle, and additional pressurizing equipment for the material needs to be installed. At the same time, the material distribution nozzle is located in the kettle body, and it is inconvenient to clear the material distribution nozzle when it is blocked. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a desolventizing kettle for chemical production which can improve the heating efficiency of materials, has stable operation and can avoid the risk of blockage.

[0006] In order to achieve the above purpose, the technical solution provided by the utility model is:

[0007] A desolventizing kettle for chemical production comprises a kettle body, wherein the lower end of the kettle body is fixedly connected with a discharge pipe, an annular inner sleeve is concentrically fixed inside the upper end of the kettle body, an annular cavity is formed between the inner sleeve and the kettle body, an annular gap is arranged between the lower end of the inner sleeve and the inner wall of the kettle body, the upper end of the inner sleeve is fixedly connected with a material pipe, the upper end of the material pipe is located above the kettle body, a stirring assembly is concentrically connected to the kettle body for rotation, a one-way bearing is arranged on the upper sleeve of the stirring assembly, a plurality of connecting rods are fixed on the outer ring of the one-way bearing, a scraper is fixed on the connecting rod, the scraper is located in the annular gap, the scraper is in sliding contact with the inner wall of the kettle body and the inner sleeve respectively, a flange is arranged on the inner wall of the kettle body below the inner sleeve, and the upper end of the flange is connected to the inner wall of the kettle body through a conical transition.

[0008] Specifically, the inner diameter of the flange is smaller than the inner diameter of the annular gap.

[0009] Specifically, a jacket is provided in the side wall of the kettle body, and an inlet pipe and an outlet pipe connected with the jacket are fixed on the kettle body.

[0010] Specifically, the upper end of the kettle body is fixedly connected with a connecting pipe.

[0011] Specifically, the stirring assembly includes a rotating rod rotatably connected to the kettle body, a plurality of blades are fixedly mounted on the rotating rod inside the kettle body, a support is fixed at the lower end of the kettle body, the lower end of the rotating rod is rotatably connected to the support, a one-way bearing is mounted on the rotating rod, and the inner ring of the one-way bearing is fixedly connected to the rotating rod.

[0012] Specifically, a motor is fixed to the upper end of the kettle body, and the output shaft of the motor is fixedly connected to the upper end of the rotating rod.

[0013] Specifically, the flange is located below the connecting rod.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. The utility model adds materials into the annular cavity, and the materials in the annular cavity flow down along the inner wall of the kettle through the annular gap, thereby improving the heating efficiency of the materials.

[0016] 2. By arranging a scraper in the annular gap, the scraper can rotate with the rotating rod, and the scraper can scrape off the crystallized material in the annular gap to ensure the smooth flow of the annular gap.

[0017] 3. The scraper is connected to the rotating rod through a connecting rod and a one-way bearing. When the rotating rod rotates in one direction, the scraper is not driven to rotate under the action of the one-way bearing. The rotating rod can drive the blade to rotate at high speed and stir the material. During the high-speed stirring of the material, the scraper, the kettle body and the inner sleeve can be prevented from wearing. When the rotating rod rotates in the other direction, the scraper is driven to rotate and the annular gap is cleared under the action of the one-way bearing. Therefore, the service life of the scraper can be extended and excessive wear of the scraper, kettle body and inner sleeve can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the utility model.

[0019] Figure 2 for Figure 1 AA section view.

[0020] Figure 3 Schematic diagram of the interior of the kettle.

[0021] Figure 4 for Figure 3 The enlarged view of area B in the figure. The names of the parts in the figure are:

[0022] 1 Kettle

[0023] 2. Material tube

[0024] 3 Inlet pipe

[0025] 4 Outlet

[0026] 5 Inner sleeve

[0027] 6 Ring cavity

[0028] 7 Rotating rod

[0029] 8 Motor

[0030] 9 Support

[0031] 10 blades

[0032] 11 One-way bearing

[0033] 12 Connecting rod

[0034] 13 Scraper

[0035] 14 Flange

[0036] 15 Cone

[0037] 16. Pipeline

[0038] 17 Jacket 18 Connecting pipe. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0040] Example 1: Reference Figure 1-Figure 4 As shown, a desolventizing kettle for chemical production includes a kettle body 1, and a discharge pipe 16 is fixedly connected to the lower end of the kettle body 1.

[0041] A jacket 17 is provided in the side wall of the kettle body 1, and an inlet pipe 3 and an outlet pipe 4 connected to the jacket 17 are fixed on the kettle body 1. The heat transfer oil enters the jacket 17 from the inlet pipe 3 and is discharged from the outlet pipe 4. The heat transfer oil in the jacket 17 can heat the material in the kettle body 1.

[0042] An annular inner sleeve 5 is concentrically fixed inside the upper end of the kettle body 1, an annular cavity 6 is formed between the inner sleeve 5 and the kettle body 1, an annular gap is arranged between the lower end of the inner sleeve 5 and the inner wall of the kettle body 1, and a material pipe 2 is fixedly connected to the upper end of the inner sleeve 5, and the upper end of the material pipe 2 is located above the kettle body 1.

[0043] The material passing pipe 2 enters the annular cavity 6 , and the material in the annular cavity 6 flows out through the annular gap and contacts the inner wall of the kettle body 1 . The material flowing downward along the inner wall of the kettle body 1 can be quickly heated by the heat transfer oil in the jacket 17 .

[0044] A stirring assembly is coaxially connected to the kettle body 1, and a one-way bearing 11 is sleeved on the stirring assembly. A plurality of connecting rods 12 are fixed to the outer ring of the one-way bearing 11, and a scraper 13 is fixed to the connecting rod 12. The scraper 13 is located in the annular gap and is in sliding contact with the inner wall of the kettle body 1 and the inner sleeve 5 respectively.

[0045] In the early stage of the feeding process, due to the high temperature of the inner wall of the kettle body 1, the material is easy to crystallize and adhere to the annular gap when the material begins to contact the inner wall of the kettle body 1. The crystallization of the material is easy to block the annular gap, and the material crystals need to be removed regularly. The purpose of setting the scraper 13 is to scrape off the material crystals in the annular gap.

[0046] Specifically, the stirring assembly includes a rotating rod 7 rotatably connected to the kettle body 1, a plurality of blades 10 are sleeved and fixed on the rotating rod 7 in the kettle body 1, a support 9 is fixed in the lower end of the kettle body 1, and the lower end of the rotating rod 7 is rotatably connected to the support 9. A motor 8 is fixed to the upper end of the kettle body 1, and the output shaft of the motor 8 is fixedly connected to the upper end of the rotating rod 7. A one-way bearing 11 is sleeved on the rotating rod 7, and the inner ring of the one-way bearing 11 is fixedly connected to the rotating rod 7.

[0047] In this embodiment, when the rotating rod 7 drives the blade 10 to rotate in the positive direction at a high speed to stir the material in the kettle body 1, under the one-way idling effect of the one-way bearing 11 and the friction between the scraper 13 and the inner wall of the kettle body 1 and the inner sleeve 5, the outer ring of the one-way bearing 11, the connecting rod 12 and the scraper 13 do not rotate.

[0048] When the material crystals in the annular gap need to be cleaned, the rotating rod 7 can drive the blade 10 to rotate in the reverse direction at a low speed. At this time, the one-way bearing 11 and the rotating rod 7 rotate synchronously, and the outer ring of the one-way bearing 11, the connecting rod 12 and the scraper 13 rotate. During the rotation of the scraper 13, the material crystals in the annular gap are scraped and cleaned.

[0049] The scraper 13 is rotated only when the material crystals in the annular gap need to be cleaned, thereby preventing the scraper 13, the inner wall of the kettle body 1 and the inner sleeve 5 from being excessively worn.

[0050] A flange 14 is provided on the inner wall of the kettle body 1 below the inner sleeve 5, and the flange 14 is integrally formed with the kettle body 1. The flange 14 is located below the connecting rod 12. The upper end of the flange 14 is transitionally connected to the inner wall of the kettle body 1 through a conical surface 15. The inner diameter of the flange 14 is smaller than the inner diameter of the annular gap.

[0051] At the later stage of the feeding process, due to the decrease in the discharge pressure of the annular gap, part of the material cannot contact the inner wall of the kettle body 1. In this embodiment, by providing a flange 14, the inner diameter of the flange 14 is smaller than the inner diameter of the annular gap. The material flowing from the annular gap can all flow downward along the flange 14, which can ensure that the material is effectively in contact with the flange 14 and the inner wall of the kettle body 1, thereby improving the heating efficiency of the material. In this embodiment, the material can be in contact with the inner wall of the kettle body 1 and the flange 14 without increasing the feed pressure in the middle.

[0052] During the desolventizing process, the gaseous solvent is discharged through the material pipe 2. The material pipe 2 can also be connected to a vacuum pump to vacuum desolventize the material in the kettle body 1. After desolventizing, the material can be discharged from the discharge pipe 16.

[0053] Embodiment 2: Based on Embodiment 1, refer to Figure 1 As shown, the upper end of the kettle body 1 is fixedly connected with a connecting pipe 18. When performing vacuum desolventizing, the material pipe 2 is closed, so that the connecting pipe 18 is connected to the vacuum pump, and the gas phase solvent is discharged from the connecting pipe 18, and the material pipe 2 is only used for adding materials. There is no need to alternately connect the material pipe 2 with the feeding pipeline and the vacuum pump, which is more convenient to operate.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A desolventizing kettle for chemical production, comprising a kettle body (1), the lower end of the kettle body (1) is fixedly connected to a row of pipes (16), characterized in that: An annular inner sleeve (5) is coaxially fixed inside the upper end of the kettle body (1), an annular cavity (6) is formed between the inner sleeve (5) and the kettle body (1), an annular gap is provided between the lower end of the inner sleeve (5) and the inner wall of the kettle body (1), a material pipe (2) is fixedly connected to the upper end of the inner sleeve (5), the upper end of the material pipe (2) is located above the kettle body (1), a stirring assembly is coaxially rotatably connected inside the kettle body (1), a one-way bearing (11) is provided on the upper sleeve of the stirring assembly, and the outer end of the one-way bearing (11) is A plurality of connecting rods (12) are fixed on the ring, and a scraper (13) is fixed on the connecting rod (12). The scraper (13) is located in the annular gap, and the scraper (13) is in sliding contact with the inner wall of the kettle body (1) and the inner sleeve (5) respectively. A flange (14) is provided on the inner wall of the kettle body (1) below the inner sleeve (5), and the upper end of the flange (14) is transitionally connected to the inner wall of the kettle body (1) through a conical surface (15), and the inner diameter of the flange (14) is smaller than the inner diameter of the annular gap.

2. A desolventizing kettle for chemical production according to claim 1, characterized in that: A jacket (17) is provided in the side wall of the kettle body (1), and an inlet pipe (3) and an outlet pipe (4) which are in communication with the jacket (17) are fixed on the kettle body (1).

3. A desolventizing kettle for chemical production according to claim 1, characterized in that: The upper end of the kettle body (1) is fixedly connected with a connecting pipe (18).

4. A desolventizing kettle for chemical production according to claim 1, characterized in that: The stirring assembly comprises a rotating rod (7) rotatably connected to the kettle body (1); a plurality of blades (10) are sleeved and fixed on the rotating rod (7) in the kettle body (1); a support (9) is fixed in the lower end of the kettle body (1); the lower end of the rotating rod (7) is rotatably connected to the support (9); a one-way bearing (11) is sleeved on the rotating rod (7); and the inner ring of the one-way bearing (11) is fixedly connected to the rotating rod (7).

5. A desolventizing kettle for chemical production according to claim 4, characterized in that: A motor (8) is fixed to the upper end of the kettle body (1), and an output shaft of the motor (8) is fixedly connected to the upper end of the rotating rod (7).

6. A desolventizing kettle for chemical production according to claim 1, characterized in that: The flange (14) is located below the connecting rod (12).

7. A desolventizing kettle for chemical production according to claim 1, characterized in that: The flange (14) is integrally formed with the kettle body (1).

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