Maleic anhydride preparation device with anti-blocking heat exchanger

Abstract

The maleic anhydride preparation device with the anti-blocking heat exchanger comprises an oxidation reactor, a solvent absorption tower, a tail gas absorption tower and a solvent desorption tower, the oxidation reactor is communicated with the solvent absorption tower through a first pipeline, a solvent inlet pipeline is arranged above the side wall of the solvent absorption tower, and the tail gas absorption tower is communicated with the solvent desorption tower through a second pipeline. The top is communicated with the tail gas absorption tower through a tail gas pipeline; a solvent extraction pipeline is arranged at the bottom of the solvent absorption tower, a solvent extraction pump is arranged on the solvent extraction pipeline, the solvent extraction pipeline is communicated with the solvent desorption tower through the solvent extraction pipeline, the solvent absorption tower is further provided with a solvent circulation pipeline, a heat exchanger is arranged on the solvent circulation pipeline, and the heat exchanger comprises a main body; heat exchange tubes are arranged around the inner wall of the main body, a stirring shaft is arranged on the axis of the main body, and stirring paddles are arranged on the stirring shaft. By arranging the stirring paddle in the heat exchanger, solids separated out due to cooling can be prevented from being gathered in the heat exchanger, the heat exchange effect is improved, and the heat exchanger is prevented from being blocked.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical equipment, in particular to a maleic anhydride preparation device with an anti-blocking heat exchanger. Background Art

[0002] Maleic anhydride, also known as maleic anhydride, is an important organic raw material with a wide range of applications. It serves as a fixative for epoxy resins and a component of intermediate fibers in organic synthesis. It is also widely used in various industries. The main methods for separating maleic anhydride during its production process include water absorption and organic solvent (DBP) absorption. The water absorption method is relatively technologically backward, limiting production capacity and causing severe equipment corrosion, requiring regular cleaning. Organic solvent absorption is a more common method used internationally and is currently the primary method for maleic anhydride absorption in China. The preparation of maleic anhydride involves a side reaction involving the formation of water. When maleic anhydride comes into contact with water, it produces maleic acid. Maleic acid has low solubility in organic solvents (DBP) and a relatively high melting point, around 130°C. It easily accumulates in heat exchangers, causing blockages. Utility Model Content

[0003] In view of this, the utility model provides a maleic anhydride preparation device with an anti-blocking heat exchanger, which can prevent maleic acid generated by hydrolysis of maleic anhydride from clogging the heat exchanger, causing equipment shutdown and affecting production.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A maleic anhydride preparation device with an anti-blocking heat exchanger includes an oxidation reactor, a solvent absorption tower, a tail gas absorption tower and a solvent decomposition tower. The oxidation reactor is connected to the solvent absorption tower through a first pipeline. A solvent inlet pipeline is provided above the side wall of the solvent absorption tower, and the top is connected to the tail gas absorption tower through a tail gas pipeline. A solvent production pipeline is provided at the bottom of the solvent absorption tower, and a solvent production pump is provided on the solvent production pipeline, which is connected to the solvent decomposition tower through the solvent production pipeline. It is characterized in that: the solvent absorption tower is also provided with a solvent circulation pipeline, and a heat exchanger is provided on the solvent circulation pipeline. The heat exchanger includes a main body, a heat exchange tube is provided around the inner wall of the main body, a stirring shaft is provided on the axis, and a stirring paddle is provided on the stirring shaft.

[0006] Furthermore, a crude maleic anhydride receiving pipeline is provided at the upper end of the solvent analysis tower, the crude maleic anhydride receiving pipeline is connected to an intermediate storage tank, and the intermediate storage tank is connected to the crude maleic anhydride storage tank through a second pipeline.

[0007] Furthermore, a solvent recovery pipeline is provided at the lower end of the solvent analysis tower, and the solvent recovery pipeline is connected to the solvent intermediate storage tank.

[0008] Furthermore, a liquid level gauge is provided in the solvent absorption tower, and the liquid level gauge is provided with an upper limit and a lower limit.

[0009] Furthermore, the liquid level meter is electrically connected to the solvent extraction pump and the solvent circulation pump respectively.

[0010] Furthermore, an upper head and a lower head are respectively provided at the upper and lower ends of the main body, the upper head is provided with a circulating water outlet, and the lower head is provided with a circulating water inlet.

[0011] Furthermore, circulating water is passed through the heat exchange tube.

[0012] Furthermore, the upper head and the lower head are connected through a heat exchange pipe.

[0013] Furthermore, the stirring paddle is fan-shaped.

[0014] Furthermore, the stirring paddles are provided with 3 to 5

[0015] The beneficial effects of the utility model are:

[0016] The utility model provides a maleic anhydride production device with an anti-clogging heat exchanger, comprising an oxidation reactor, a solvent absorption tower, a tail gas absorption tower, and a solvent desorption tower. The solvent absorption tower is further provided with a solvent circulation pipeline, and the solvent circulation pipeline is provided with a heat exchanger. The heat exchanger comprises a main body, a heat exchange tube is arranged around the inner wall of the main body, and a stirring shaft is provided on the axis thereof, and the stirring shaft is provided with a stirring paddle. The provision of the stirring paddle within the heat exchanger can prevent solids precipitated due to cooling from accumulating within the heat exchanger, thereby improving the heat exchange efficiency and preventing heat exchanger clogging. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 A schematic diagram of a maleic anhydride preparation device with an anti-blocking heat exchanger provided by the utility model;

[0019] Figure 2 for Figure 1 Schematic diagram of the structure of the heat exchanger shown in;

[0020] Figure 3 for Figure 2 Another structural diagram of the heat exchanger shown in;

[0021] Figure 4 for Figure 3 Sectional view along AA;

[0022] Figure 5 for Figure 3 Cross-sectional view along BB;

[0023] In the figure: 100, maleic anhydride preparation device with anti-blocking heat exchanger; 200, solvent circulation pipeline; 1, oxidation reactor; 2, solvent absorption tower; 21, solvent inlet pipeline; 22, first pipeline; 23, inlet pipeline; 24, solvent circulation pump; 25, heat exchanger; 251, motor; 252, stirring shaft; 2521, stirring paddle; 253, upper head; 254, main body; 2541, heat exchange tube; 255, lower head; 256, circulation Circulating water outlet; 257, circulating solvent outlet; 258, circulating solvent inlet; 259, circulating water inlet; 26, outlet pipeline; 27, solvent production pipeline; 271, solvent production pump; 28, tail gas pipeline; 29, liquid level meter; 3, tail gas absorption tower; 4, solvent analysis tower; 41, crude maleic anhydride receiving pipeline; 42, solvent recovery pipeline; 5, intermediate storage tank; 51, second pipeline; 6, crude maleic anhydride storage tank; 7, solvent intermediate storage tank. DETAILED DESCRIPTION

[0024] The present invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention.

[0025] like Figure 1 As shown, the present invention provides a maleic anhydride preparation device 100 with an anti-blocking heat exchanger, comprising an oxidation reactor 1, a solvent absorption tower 2, a tail gas absorption tower 3, and a solvent desorption tower 4. The oxidation reactor 1 is connected to the solvent absorption tower 2 via a first pipeline 22, the inlet of the first pipeline 22 into the solvent tower being above the liquid level; a solvent inlet pipeline 21 is provided above the side wall of the solvent absorption tower 2, and the top is connected to the tail gas absorption tower via a tail gas pipeline 28; a solvent extraction pipeline 27 is provided at the bottom of the solvent absorption tower 2, and a solvent extraction pump 271 is provided on the solvent extraction pipeline 27, which is connected to the solvent desorption tower 4 via the solvent extraction pipeline 27. In order to increase the concentration of maleic anhydride in the solvent entering the solvent analysis tower 4, the solvent absorption tower is further provided with a solvent circulation pipeline 200, which includes a solvent circulation pump 24 and a heat exchanger 25. The circulating solvent enters the solvent circulation pump 24 through the inlet pipeline 23, and the solvent circulation pump 24 transports the circulating solvent into the heat exchanger 25. After heat exchange, the circulating solvent returns to the solvent absorption tower 2 through the outlet pipeline 26 to absorb maleic anhydride again.

[0026] A crude maleic anhydride receiving pipeline 41 is provided at the upper end of the solvent decomposition tower 4, and the crude maleic anhydride receiving pipeline 41 is connected to the intermediate storage tank 5, and the intermediate storage tank 5 is connected to the crude maleic anhydride storage tank 6 through a second pipeline 51; a solvent recovery pipeline 42 is provided at the lower end of the solvent decomposition tower 4, and the solvent recovery pipeline 42 is connected to the solvent intermediate storage tank 7.

[0027] During operation of the maleic anhydride production apparatus 100 with a blockage-resistant heat exchanger, gas containing maleic anhydride enters solvent absorption tower 2 from oxidation reactor 1 via first pipeline 22. Absorption solvent enters solvent absorption tower 2 from the top of the solvent absorption tower via solvent inlet line 21. Within solvent absorption tower 2, the gas containing maleic anhydride fully combines with the absorption solvent, and the maleic anhydride and a small amount of organic byproducts are absorbed by the absorption solvent. Air, carbon monoxide, carbon dioxide, and the like enter tail gas absorption tower 3 via tail gas line 28. A portion of the absorption solvent accumulated at the bottom of the solvent absorption tower enters solvent desorption tower 4 via solvent extraction line 27, while a portion enters heat exchanger 25 via solvent recirculation line 200, through solvent recirculation pump 24, and then re-enters solvent absorption tower 2 to continue absorbing maleic anhydride. The concentration of maleic anhydride in the solvent entering the solvent desorption tower can be controlled by adjusting the ratio of solvent extraction and recirculation.

[0028] Furthermore, a liquid level gauge 29 is provided in the solvent absorption tower 2. The liquid level gauge 29 is provided with an upper limit and a lower limit. The liquid level gauge 29 is electrically connected to the solvent extraction pump 271 and the solvent circulation pump 24 respectively. Specifically, when the solvent liquid level in the solvent absorption tower 2 is higher than the upper limit, the flow rate of the solvent circulation pump 24 and the solvent extraction pump 271 is automatically increased. When the solvent liquid level in the solvent absorption tower 2 is lower than the lower limit, the flow rate of the solvent circulation pump 24 and the solvent extraction pump 271 is automatically reduced.

[0029] like Figures 2 to 5 As shown, the heat exchanger 25 includes a cylindrical body 254, with an upper end cap 253 and a lower end cap 255 at the upper and lower ends of the body 254, respectively. The upper end cap 253 is provided with a circulating water outlet 256, and the lower end cap 255 is provided with a circulating water inlet 259. A heat exchange tube 2541 is provided along the inner wall of the body 254, connecting the upper end cap 253 and the lower end cap 255 through the heat exchange tube 2541, and cooling water flows through the heat exchange tube 2541. A circulating solvent outlet 257 is provided at the upper end of the outer wall of the body 254, and a circulating solvent inlet 258 is provided at the lower end. A stirring shaft 252 is provided on the inner axis of the body 254. A stirring paddle 2521 is mounted on one end of the stirring shaft 252 within the body 254, and a motor 251 is provided on the end that rises above the upper end cap 253. The motor 251 can drive the stirring paddle 2521 to rotate.

[0030] Furthermore, the stirring paddles 2521 are fan-shaped and can stir the liquid in the main body 254 when rotating. There are 3 to 5 stirring paddles 2521, preferably 5.

[0031] During operation, the circulating solvent enters the heat exchanger body 254 through the circulating solvent inlet 258, and exchanges heat with the heat exchange tube 2541 for cooling. After cooling, maleic acid will precipitate in the circulating solvent. Under the stirring of the stirring paddle 2521, the amount of maleic acid accumulated on the outer wall of the heat exchange tube 2541 is reduced, thereby improving the heat exchange efficiency and avoiding blockage of the heat exchanger 25, thereby increasing the continuous operation time of the device.

[0032] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the scope of the present invention. The technical scope of this utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A maleic anhydride production device with an anti-blocking heat exchanger, comprising an oxidation reactor, a solvent absorption tower, a tail gas absorption tower, and a solvent desorption tower, wherein the oxidation reactor is connected to the solvent absorption tower via a first pipeline, a solvent inlet pipeline is provided above the side wall of the solvent absorption tower, and the top is connected to the tail gas absorption tower via a tail gas pipeline; a solvent extraction pipeline is provided at the bottom of the solvent absorption tower, and a solvent extraction pump is provided on the solvent extraction pipeline, which is connected to the solvent desorption tower via the solvent extraction pipeline, characterized in that: The solvent absorption tower is also provided with a solvent circulation pipeline, the solvent circulation pipeline is provided with a heat exchanger, the heat exchanger includes a main body, heat exchange tubes are provided around the inner wall of the main body, a stirring shaft is provided on the axis of the main body, and a stirring paddle is provided on the stirring shaft.

2. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 1, characterized in that: A crude maleic anhydride receiving pipeline is provided at the upper end of the solvent analysis tower. The crude maleic anhydride receiving pipeline is connected to an intermediate storage tank. The intermediate storage tank is connected to the crude maleic anhydride storage tank through a second pipeline.

3. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 2, characterized in that: A solvent recovery pipeline is provided at the lower end of the solvent analysis tower, and the solvent recovery pipeline is connected to the solvent intermediate storage tank.

4. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 3, wherein: A liquid level gauge is provided in the solvent absorption tower, and the liquid level gauge is provided with an upper limit and a lower limit.

5. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 4, characterized in that: The liquid level meter is electrically connected to the solvent extraction pump and the solvent circulation pump respectively.

6. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 5, characterized in that: The upper and lower ends of the main body are respectively provided with an upper head and a lower head, the upper head is provided with a circulating water outlet, and the lower head is provided with a circulating water inlet.

7. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 6, characterized in that: Circulating water is passed through the heat exchange tube.

8. The maleic anhydride production device with an anti-blocking heat exchanger according to claim 7, characterized in that: The upper head and the lower head are connected through a heat exchange pipe.

9. The device for producing maleic anhydride with an anti-blocking heat exchanger according to claim 8, characterized in that: The stirring paddle is fan-shaped.

10. The maleic anhydride production device with an anti-blocking heat exchanger according to claim 9, characterized in that: There are 3 to 5 stirring paddles.

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