Heat transfer reactor for p-nitrobenzoic acid production

Abstract

This utility model relates to the technical field of p-nitrobenzoic acid production equipment, and in particular to a heat transfer reactor for p-nitrobenzoic acid production. The reactor includes a vessel body, with a hollow rotating shaft open at one end rotatably connected to the top of the vessel body. One end of the rotating shaft extends to the outside of the vessel body and is rotatably connected to a fixed pipe, which is connected to the vessel body. A fluid tank is provided on the vessel body. Through the hollow rotating shaft, heat transfer oil in the fluid tank is introduced into the interior of the rotating shaft via output and input pipes, thereby achieving the purpose of heat transfer to the interior of the vessel body. Combined with existing jacketed heating structures, the p-nitrotoluene raw material can be heated from both the inside and outside of the vessel body, thus solving the problem.

Description

Technical Field

[0001] This utility model relates to the technical field of p-nitrobenzoic acid production equipment, and in particular to a heat transfer reactor for p-nitrobenzoic acid production. Background Technology

[0002] The heat transfer reactor for the production of p-nitrobenzoic acid is a type of chemical reactor. It is mainly used in the process of oxidizing p-nitrotoluene or other raw materials to produce p-nitrobenzoic acid under the action of oxidants such as nitric acid. Its core function is to control the reaction temperature through a heat transfer system, such as a jacket or coil, and then through a control system and structure. It also achieves uniform mixing of materials through a stirring device. At the same time, it uses corrosion-resistant materials to resist the erosion of strong corrosive media such as nitric acid, ensuring that the reaction proceeds safely and efficiently.

[0003] In the production of p-nitrobenzoic acid, p-nitrotoluene reacts with nitric acid in a constant-temperature environment provided by a heat transfer reactor to produce p-nitrobenzoic acid. The heat transfer reactor typically employs a jacketed heat exchanger, where a jacket is installed on the outside of the reactor. During heating, steam or other heating media is introduced into the jacket, and a stirrer inside the reactor agitates the p-nitrotoluene feedstock, ensuring uniform heating. However, relying solely on a jacketed heat exchanger for heating the p-nitrotoluene feedstock results in a prolonged initial heating time for the p-nitrobenzoic acid within the reactor. Furthermore, the oxidation reaction of the p-nitrobenzoic acid feedstock at high temperatures generates a significant amount of heat, further increasing the reactor temperature. Simply using a jacketed heat exchanger for temperature regulation is insufficient for rapid cooling, thus affecting the reaction efficiency of p-nitrobenzoic acid.

[0004] Based on the above situation, it is necessary to design a heat transfer reactor for the production of p-nitrobenzoic acid to solve the above problems. Utility Model Content

[0005] This invention provides a heat transfer reactor for the production of p-nitrobenzoic acid, thereby solving the problem of low temperature regulation efficiency in the prior art.

[0006] The technical problem solved by this utility model is achieved by the following technical solution:

[0007] A heat transfer reactor for the production of p-nitrobenzoic acid includes a reactor body. A hollow rotating shaft with an opening at one end is rotatably connected to the top of the reactor body. One end of the rotating shaft extends to the outside of the reactor body and is rotatably connected to a fixed pipe. The fixed pipe is connected to the reactor body. A fluid tank is provided on the reactor body. An output pipe and an input pipe are respectively connected to the output end and the input pipe. The ends of the output pipe and the input pipe away from the fluid tank pass through the fixed pipe and extend into the interior of the rotating shaft.

[0008] Preferably, the fluid tank is equipped with a heat exchanger, which is composed of several fins. The vessel body is equipped with an exhaust valve, and the output end of the exhaust valve is connected to a gas guide pipe, which passes through the heat exchanger.

[0009] Preferably, a drive motor is installed on the top of the vessel body, the output end of the drive motor is connected to a drive gear, a driven gear is rotatably connected to the top of the vessel body, the driven gear is connected to a rotating shaft, and the driven gear meshes with the drive gear.

[0010] Preferably, the input pipe includes a short oil outlet pipe, a long oil outlet pipe, and a conduit oil outlet pipe. The input ends of the short oil outlet pipe and the long oil outlet pipe extend into the interior of the rotating shaft. The conduit oil outlet pipe is connected to the interior of the fluid tank. The output ends of the short oil outlet pipe and the long oil outlet pipe are connected to the input end of the conduit oil outlet pipe. A three-way valve is provided at the connection point of the short oil outlet pipe, the long oil outlet pipe, and the conduit oil outlet pipe. An oil pump is provided on the conduit oil outlet pipe.

[0011] Preferably, the output pipe includes a short inlet pipe, a long inlet pipe, and an inlet conduit. The output ends of the short inlet pipe and the long inlet pipe extend into the interior of the rotating shaft. The inlet conduit is connected to the interior of the fluid tank. The input ends of the short inlet pipe and the long inlet pipe are connected to the output ends of the inlet conduit. A three-way valve is provided at the common connection of the short inlet pipe, the long inlet pipe, and the inlet conduit. An oil pump is provided on the inlet conduit.

[0012] Preferably, the oil inlet conduit is provided with a heat-insulating shell, which is fitted onto the oil inlet conduit, and a heating element is provided inside the heat-insulating shell for heating the oil inlet conduit; the oil inlet conduit is also provided with a temperature sensor, which is located between the heating element and the output end of the oil inlet conduit.

[0013] The beneficial effects of this invention are as follows: Through a hollow rotating shaft, heat-conducting oil in the fluid tank is introduced into the interior of the rotating shaft using output and input pipes, thereby achieving the purpose of transferring heat to the interior of the vessel. Combined with the existing jacketed heating structure, the p-nitrotoluene raw material can be heated from both the inside and outside of the vessel. Compared with using the jacket alone to heat or maintain the temperature inside the vessel, by setting up this device, the heat conduction method is matched with the heat conduction method of the jacket, thus making the heating and temperature maintenance effects inside the vessel more efficient. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0017] Figure 3 This is a partial structural diagram of the present invention. Figure 1 ;

[0018] Figure 4 This is a partial structural diagram of the present invention. Figure 2 ;

[0019] Figure 5 This is a schematic diagram of the heating element structure of this utility model.

[0020] In the diagram, 1. vessel body; 2. rotating shaft; 3. fixed pipe; 4. fluid tank; 5. heat exchanger; 6. fins; 7. exhaust valve; 8. air guide pipe; 9. drive motor; 10. driving gear; 11. driven gear; 12. short oil outlet pipe; 13. long oil outlet pipe; 14. oil outlet conduit; 15. three-way valve one; 16. oil pump one; 17. short oil inlet pipe; 18. long oil inlet pipe; 19. oil inlet conduit; 20. three-way valve two; 21. oil pump two; 22. insulation shell; 23. heating element; 24. temperature sensor; 25. controller; 26. stirring plate; 27. drive shaft. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0022] Reference Figures 1-5As shown, a heat transfer reactor for the production of p-nitrobenzoic acid includes a reactor body 1, which is a commonly used heat transfer reactor in the production of p-nitrobenzoic acid. A temperature sensing device is installed on the reactor body 1 to monitor the internal temperature of the reactor body 1. The oxidation reaction temperature of p-nitrobenzoic acid is generally 100°-120°. The reactor body 1 is also equipped with a jacketed heating assembly. The main structure is that a heat insulation layer is installed on the outside of the reactor body 1, and then a heat-conducting component is installed inside the heat insulation layer. Heat can be transferred to the reactor body 1 by electric heating or steam heating, thereby raising the internal temperature of the reactor body 1. This heating method is a commonly used heating method. The specific details are not described in detail.

[0023] To address the inefficiency of using only jacketed heating, a hollow rotating shaft 2 with an opening at one end is rotatably connected to the top of the vessel body 1. One end of the rotating shaft 2 extends to the outside of the vessel body 1 and is rotatably connected to a fixed pipe 3. Several stirring plates 26 are connected to the outer wall of the rotating shaft 2 for stirring the liquid phase inside the vessel body 1. The fixed pipe 3 is connected to the vessel body 1 via a bracket. A fluid tank 4 is provided on the vessel body 1, which stores a heat transfer medium, such as heat transfer oil. The main purpose is to transfer heat, so there is no limitation on the type of medium. The use of heat transfer oil as a heat transfer medium is existing technology and will not be described in detail. The output and input ends of the fluid tank 4 are connected to output and input pipes, respectively. The ends of the output and input pipes away from the fluid tank 4 pass through the fixed pipe 3 and extend into the rotating shaft 2. In addition, for convenient electrical control of the device, a controller 25 is also included.

[0024] In use, under the control of the controller 25, the heat transfer medium in the fluid tank 4 can be introduced into the rotating shaft 2 through the output pipe. At this time, the rotating shaft 2 receives the heat from the heat transfer medium, which will raise the temperature. When p-nitrotoluene raw material is added into the vessel body 1, the heat on the rotating shaft 2 will be transferred to the p-nitrotoluene raw material. Then, with the cooperation of the jacket heating method, the p-nitrotoluene raw material can be heated from the inside and outside of the vessel body 1. Compared with using the jacket alone to heat or keep the temperature constant inside the vessel body 1, by setting this device, its heat transfer method is matched with the heat transfer method of the jacket, which makes the heating and temperature constant effect inside the vessel body 1 more efficient.

[0025] In this process, the oxidation reaction between p-nitrotoluene and nitric acid produces gas, which needs to be periodically released when it remains inside the reactor body 1. Therefore, to avoid heat loss and save energy, a heat exchanger 5, consisting of several fins 6, is installed inside the fluid tank 4. An exhaust valve 7 is installed on the reactor body 1, with its output end connected to a gas guide pipe 8. The gas guide pipe 8 passes through the heat exchanger 5. The high-temperature gas discharged from the exhaust valve 7 enters through the input end of the gas guide pipe 8 and exits through its output end. When the gas passes through the gas guide pipe 8, it will be heated and its temperature will rise. When the gas guide pipe 8 passes through the heat exchanger 5 inside the fluid tank 4, it will transfer heat to the heat exchanger 5, and then transfer heat to the gas guide medium in the fluid tank 4. This allows the heat transfer medium to carry the temperature in the fluid tank 4, reducing the power consumption during subsequent heating. Finally, the gas passing through the heat exchanger 5 will be discharged from the output end of the gas guide pipe 8, which is connected to the waste gas treatment equipment for purifying the waste gas. This waste gas treatment equipment is existing technology and is not shown in the figure.

[0026] Furthermore, refer to Figure 3 As shown, a drive motor 9 is installed on the top of the vessel body 1. The output end of the drive motor 9 is connected to a drive gear 10. A driven gear 11 is rotatably connected to the top of the vessel body 1. The driven gear 11 is connected to the rotating shaft 2. The driven gear 11 meshes with the drive gear 10. The output end of the drive motor 9 drives the drive gear 10 to rotate through the drive shaft 27, which in turn drives the driven gear 11 to rotate. Finally, it drives the rotating shaft 2 to rotate, which in turn drives the stirring plate 26 to stir the liquid phase in the vessel body 1.

[0027] The input pipes include an oil outlet short pipe 12, an oil outlet long pipe 13, and an oil outlet conduit 14. The input ends of the oil outlet short pipe 12 and the oil outlet long pipe 13 extend into the interior of the rotating shaft 2. The oil outlet conduit 14 is connected to the interior of the fluid tank 4. The output ends of the oil outlet short pipe 12 and the oil outlet long pipe 13 are connected to the input ends of the oil outlet conduit 14. A three-way valve 15 is provided at the connection point of the oil outlet short pipe 12, the oil outlet long pipe 13, and the oil outlet conduit 14. An oil pump 16 is provided on the oil outlet conduit 14. Under the action of the oil pump 16, the heat transfer oil located inside the rotating shaft 2 is introduced into the fluid tank 4 through the oil outlet short pipe 12 or the oil outlet long pipe 13. The selection of the oil outlet long pipe 13 or the oil outlet short pipe 12 is determined by the controller 25 of the three-way valve 15. The three-way valve 15 is an electric valve that can be remotely controlled by the controller 25.

[0028] Reference Figure 4As shown, the output pipe includes an oil inlet short pipe 17, an oil inlet long pipe 18, and an oil inlet conduit 19. The output ends of the oil inlet short pipe 17 and the oil inlet long pipe 18 extend into the interior of the rotating shaft 2. The oil inlet conduit 19 is connected to the interior of the fluid tank 4. The input ends of the oil inlet short pipe 17 and the oil inlet long pipe 18 are connected to the output ends of the oil inlet conduit 19. A three-way valve 20 is provided at the common connection of the oil inlet short pipe 17, the oil inlet long pipe 18, and the oil inlet conduit 19. An oil pump 21 is provided on the oil inlet conduit 19. Under the action of the oil pump 21, the heat transfer oil located inside the fluid tank 4 is introduced into the rotating shaft 2 along the oil inlet short pipe 17 or the oil inlet long pipe 18. The selection of the oil inlet long pipe 18 or the oil inlet short pipe 17 is determined by the controller 25 of the three-way valve 20. The three-way valve 20 is also an electric valve and can be remotely controlled by the controller 25.

[0029] Reference Figure 3 as well as Figure 5 As shown, the oil inlet conduit 19 is further provided with a heat insulation shell 22, which is sleeved on the oil inlet conduit 19, and a heating element 23 is provided inside the heat insulation shell 22 for heating the oil inlet conduit 19; the oil inlet conduit 19 is also provided with a temperature sensor 24, which is located between the heating element 23 and the output end of the oil inlet conduit 19.

[0030] When the internal temperature of the vessel body 1 is too low, the fluid tank 4 introduces its internal heat transfer oil into the rotating shaft 2 through the oil inlet pipe 19 and the oil inlet short pipe 17. The heat transfer oil is located at the bottom of the rotating shaft 2. Then, the heat of the heat transfer oil is transferred to the rotating shaft 2 and then to the interior of the vessel body 1. As heat transfer oil is continuously added, the heat transfer oil with a higher temperature is located in the upper layer inside the rotating shaft 2, while the heat transfer oil with a relatively lower temperature due to heat exchange is located in the lower layer inside the rotating shaft 2. At this time, the heat transfer oil located in the lower layer inside the rotating shaft can be introduced into the fluid tank 4 through the oil inlet long pipe 18, thus forming a circulation and continuously replacing the heat transfer oil inside the rotating shaft 2, so that the rotating shaft 2... Heat is continuously transferred into the vessel body 1. When the temperature inside the vessel body 1 is too high and heat transfer oil is needed for temperature control, the fluid tank 4 introduces the heat transfer oil inside into the rotating shaft 2 through the oil inlet pipe 19 and the oil inlet long pipe 18. Because the temperature of the heat transfer oil is lower than the liquid phase temperature inside the vessel body 1, the heat absorption temperature of the heat transfer oil rises. The heat transfer oil that has risen will be located in the upper layer inside the rotating shaft 2. At this time, the heat-absorbing heat transfer oil is introduced into the fluid tank 4 through the oil outlet short pipe 12. The heat can be dissipated by the heat exchanger 5. The heat is discharged through the exhaust gas in the gas duct 8. By using this method, the heat transfer oil inside the rotating shaft 2 can be circulated, thereby improving the efficiency of heat exchange.

[0031] The oil pump 16, oil pump 21, three-way valve 15, three-way valve 20, drive motor 9, heating element 23, and temperature sensor 24 mentioned above are all electrically connected to the controller 25 and are regulated by the controller 25. The temperature sensor 24 outputs a temperature value signal to the controller 25. After receiving the temperature value signal, the controller 25 controls the output of the heating element 23, thereby raising the temperature of the heat transfer medium flowing in the oil inlet pipe 19, and finally raising the temperature of the heat transfer medium to the required temperature.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A heat transfer reactor for the production of p-nitrobenzoic acid, comprising a reactor body (1), characterized in that, The top of the vessel body (1) is rotatably connected to a hollow rotating shaft (2) with an opening at one end. One end of the rotating shaft (2) extends to the outside of the vessel body (1) and is rotatably connected to a fixed pipe (3). The fixed pipe (3) is connected to the vessel body (1). The vessel body (1) is provided with a fluid tank (4). The output end and the input end of the fluid tank (4) are respectively connected to an output pipe and an input pipe. The ends of the output pipe and the input pipe that are away from the fluid tank (4) pass through the fixed pipe (3) and extend into the interior of the rotating shaft (2).

2. The heat transfer reactor for the production of p-nitrobenzoic acid according to claim 1, characterized in that, The fluid tank (4) is equipped with a heat exchanger (5), which is composed of several fins (6). The vessel body (1) is equipped with an exhaust valve (7), and the output end of the exhaust valve (7) is connected to a gas guide pipe (8). The gas guide pipe (8) passes through the heat exchanger (5).

3. The heat transfer reactor for the production of p-nitrobenzoic acid according to claim 2, characterized in that, A drive motor (9) is installed on the top of the vessel body (1). The output end of the drive motor (9) is connected to a drive gear (10). A driven gear (11) is rotatably connected to the top of the vessel body (1). The driven gear (11) is connected to the rotating shaft (2). The driven gear (11) meshes with the drive gear (10).

4. The heat transfer reactor for the production of p-nitrobenzoic acid according to claim 1, characterized in that, The input pipe includes an oil outlet short pipe (12), an oil outlet long pipe (13), and an oil outlet conduit (14). The input ends of the oil outlet short pipe (12) and the oil outlet long pipe (13) extend into the interior of the rotating shaft (2). The oil outlet conduit (14) is connected to the interior of the fluid tank (4). The output ends of the oil outlet short pipe (12) and the oil outlet long pipe (13) are connected to the input ends of the oil outlet conduit (14). A three-way valve (15) is provided at the connection point of the oil outlet short pipe (12), the oil outlet long pipe (13), and the oil outlet conduit (14). An oil pump (16) is provided on the oil outlet conduit (14).

5. The heat transfer reactor for the production of p-nitrobenzoic acid according to claim 1, characterized in that, The output pipe includes an oil inlet short pipe (17), an oil inlet long pipe (18), and an oil inlet conduit (19). The output ends of the oil inlet short pipe (17) and the oil inlet long pipe (18) extend into the interior of the rotating shaft (2). The oil inlet conduit (19) is connected to the interior of the fluid tank (4). The input ends of the oil inlet short pipe (17) and the oil inlet long pipe (18) are connected to the output ends of the oil inlet conduit (19). A three-way valve (20) is provided at the common connection of the oil inlet short pipe (17), the oil inlet long pipe (18), and the oil inlet conduit (19). An oil pump (21) is provided on the oil inlet conduit (19).

6. The heat transfer reactor for the production of p-nitrobenzoic acid according to claim 5, characterized in that, The oil inlet conduit (19) is provided with a heat insulation shell (22), which is fitted onto the oil inlet conduit (19). The heat insulation shell (22) is provided with a heating element (23) inside the heat insulation shell (22), which is used to heat the oil inlet conduit (19). The oil inlet conduit (19) is also provided with a temperature sensor (24), which is located between the heating element (23) and the output end of the oil inlet conduit (19).

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