Device for recovering methylbenzene in trimebutine maleate production

Abstract

The invention belongs to the technical field of chemical engineering, and particularly relates to a device for recovering methylbenzene in trimebutine maleate production. In a waste heat recovery mechanism, a plurality of heat release pipes, a control assembly and a plurality of connectors are matched; according to the toluene distillation retort, adaptive adjustment can be performed according to the height of a mixed solution in the distillation retort and the heat source temperature of a toluene source, so that the distribution area of the heat release pipe in the distillation retort is enlarged or reduced, the heat exchange effect is improved, and the situation of invalid heat exchange is avoided; furthermore, on one hand, the sealing sheets in the connector can play roles in separating the internal space of the heat release pipes, forcing the toluene source to be conveyed and increasing the heat exchange time and area, and on the other hand, the sealing sheets can meet the requirement for adjusting the distance between the heat release pipes without influencing airflow conveying.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and particularly relates to a device for recovering toluene in the production of trimebutine maleate. Background Art

[0002] During the production of the drug trimebutine maleate, according to the current production process, toluene is used as a catalyst to participate in the drug reaction, and the toluene needs to be evaporated after the reaction is completed. In order to reduce production costs and improve resource utilization, the evaporated toluene will be recovered and reused. Currently, the most common recovery method is condensation recovery. However, due to the toluene involved in drug production and the residual impurities in the recovery process, if the toluene is directly condensed and recycled, the purity of the toluene will be insufficient, which will affect the production of the drug. Therefore, before condensation recovery, it will be combined with water to perform an azeotropic distillation purification. However, the current general distillation purification equipment does not recover enough or does not recover the heat of the evaporated toluene source during recovery. On the one hand, it causes waste of heat energy and leads to increased production consumption. On the other hand, the flexibility of toluene recovery is not high, and it is difficult to make targeted adjustments to the temperature of the toluene source itself and the liquid level state in the distillation tank. Summary of the Invention

[0003] The purpose of the present invention is to provide a device for recovering toluene in the production of trimebutine maleate, so as to solve the problems mentioned in the background technology.

[0004] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0005] A device for recovering toluene in trimebutine maleate production comprises a distillation tank, wherein the upper end of the distillation tank is provided with a distillation outlet for connecting to an external condenser to recover distilled clean toluene and water, the lower end of the distillation tank is provided with a liquid drain port for discharging the remaining distilled solution, and the side of the distillation tank is provided with a liquid inlet and a waste heat outlet, wherein the liquid inlet is used to inject toluene solution or water, and the waste heat outlet is used to input toluene vapor containing waste heat. The device is characterized in that:

[0006] Also includes:

[0007] A waste heat recovery mechanism is provided in the distillation tank, wherein the input port of the waste heat recovery mechanism is connected to the waste heat outlet, and the discharge port of the waste heat recovery mechanism is connected to an external container;

[0008] The waste heat recovery mechanism consists of a control component, a heat release pipe, a connector and a base. The control component is arranged on the tank cover of the distillation tank, and the base is arranged at the bottom of the distillation tank. The number of the heat release pipes is several and they are evenly arranged in the distillation tank, and several of the heat release pipes are located between the control component and the base. The number of the connectors is several and they are arranged between two adjacent heat release pipes, and the connector connects the two adjacent heat release pipes.

[0009] Preferably, the control assembly includes a cylinder and a top plate, the cylinder is fixedly arranged at the upper end of the distillation tank, and the output shaft of the cylinder is slidingly sealed and extends into the distillation tank, the top plate is fixedly connected to the output shaft of the cylinder and connected to the uppermost heat release tube.

[0010] Preferably, the connector includes an elastic member, a connecting air pipe and a sealing piece. The elastic member is arranged between two adjacent heat-releasing tubes. The connecting air pipe and the heat-releasing tube are integrally formed and the air path is connected. The connecting air pipe of the heat-releasing tube is sealed and connected to the adjacent heat-releasing tube by sliding up and down. The sealing piece is fixedly arranged in the heat-releasing tube and corresponds to the position of the connecting air pipe.

[0011] Preferably, the elastic member is a spring sheet, and among the plurality of elastic members, from top to bottom in terms of horizontal height, the minimum stretching elastic force of the elastic member on the lower side is greater than the sum of the maximum contraction elastic forces of the plurality of elastic members on the upper side.

[0012] Preferably, the connecting air pipe is located on one side inside the heat release pipe and has a conical structure, and the maximum diameter of the conical structure of the connecting air pipe is less than or equal to the inner diameter of the connecting air pipe.

[0013] Preferably, the sealing piece is tiltedly arranged in the heat release tube, and the sealing piece completely separates the space in the heat release tube. A perforation is opened at the point where the sealing piece and the inner diameter center of the heat release tube coincide, and the size of the perforation matches the size of the connecting air pipe. An elastic spacer is provided in the perforation.

[0014] Preferably, the elastic spacer is composed of a plurality of thin sheets, the plurality of thin sheets are evenly distributed and completely cover the perforation, and adjacent thin sheets are not connected to each other.

[0015] Preferably, the base is provided with a collecting tank, which is connected to an external container. The waste heat outlet is connected to the top plate via a hose, the extendable length of the hose is greater than the sum of the movable strokes of several heat release tubes, and the hose is connected to the air path of the uppermost heat release tube.

[0016] Compared with the prior art, this application has at least the following advantages:

[0017] Through the coordination of the waste heat recovery mechanism, the heat release tubes, the control components, and the connectors, adaptive adjustments can be made according to the height of the mixed solution in the distillation tank and the heat source temperature of the toluene source itself, so that the distribution area of ​​the heat release tubes in the distillation tank is expanded or reduced, thereby improving the heat exchange effect and avoiding the occurrence of ineffective heat exchange.

[0018] Furthermore, the sealing piece in the connector can, on the one hand, separate the internal space of the heat release tube, force the toluene source to be transported, and increase the heat exchange time and area; on the other hand, it can meet the spacing adjustment between several heat release tubes without affecting the air flow transport. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further illustrated by means of the following non-limiting examples.

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 It is a structural cross-sectional view of the present invention.

[0022] Figure 3 for Figure 2 Enlarged schematic diagram of point A in the middle.

[0023] Figure 4 It is a structural schematic diagram of the preheating recovery mechanism of the present invention.

[0024] Figure 5 Schematic diagram of the structure of the sealing sheet of the present invention.

[0025] Distillation tank 1, distillation outlet 11, liquid discharge port 12, liquid inlet 13, residual heat outlet 14, heat release pipe 2, base 3, collecting tank 31, cylinder 4, top plate 41, elastic member 5, connecting air pipe 6, sealing piece 61, perforation 62, elastic spacer 63, hose 7. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1-5 As shown, a device for recovering toluene in the production of trimebutine maleate includes a distillation tank 1. The upper end of the distillation tank 1 is provided with a distillation outlet 11 for connecting to an external condenser to recover distilled clean toluene and water. The lower end of the distillation tank 1 is provided with a drain port 12 for discharging the remaining distilled solution. The side of the distillation tank 1 is provided with a liquid inlet 13 and a waste heat outlet 14. The liquid inlet 13 is used to inject toluene solution or water, and the waste heat outlet 14 is used to input toluene vapor containing waste heat. The device also includes:

[0028] A waste heat recovery mechanism is provided in the distillation tank 1, wherein the input port of the waste heat recovery mechanism is connected to the waste heat port 14, and the discharge port of the waste heat recovery mechanism is connected to an external container;

[0029] The waste heat recovery mechanism consists of a control component, a heat release pipe 2, a connector and a base 3. The control component is arranged on the tank cover of the distillation tank 1, and the base 3 is arranged at the bottom of the distillation tank 1. The number of heat release pipes 2 is several and they are evenly arranged in the distillation tank 1, and several heat release pipes 2 are located between the control component and the base 3. The number of connectors is several and they are arranged between two adjacent heat release pipes 2, and the connector connects the two adjacent heat release pipes 2.

[0030] In the present application, the method for recovering toluene is azeotropic recovery, wherein the toluene source comes from the distillate after alkalization or catalytic reaction with methylbenzene during the production of the drug trimebutine maleate. In order to improve the utilization rate of toluene, reduce costs, and reduce resource waste and environmental pollution, the toluene is purified and recovered by azeotropic reaction;

[0031] During recycling, the toluene source itself has a certain amount of waste heat energy from the drug production process. To save thermal resources, a jacket method can be used to recover this part of the heat. The recycling operation method of the present application is to input the toluene source into the distillation tank 1 through the waste heat port 14. At this time, the toluene source with waste heat will pass through a plurality of heat release tubes 2 and transfer the heat to the mixed solution in the distillation tank 1 through the heat release tubes 2. It is worth noting that the mixed solution in the tank body specified in the present application generally refers to a mixed solution of water and toluene. The ratio of the toluene toluene is 86.5% and the water is 13.5% according to the currently known azeotropic ratio. To improve the heat conduction effect, the heat release tubes 2 can be made of a material with higher heat exchange efficiency, such as copper.

[0032] After the toluene source completely passes through the distillation tank 1 and transfers the heat energy, it is input into the external container for temporary storage. Since the heat of the toluene source cannot reach the azeotropic point of the mixed solution, a heating component such as a hot water rod or other device capable of heating the solution needs to be provided in the external container. Since there are many principles and structures or selected methods of the heating device, including but not limited to steam, heat, solar energy, etc., only one optional heating method that is more reasonable and suitable for the environment of this application is provided in this application. At the same time, a water pump connected to the liquid inlet 13 is also provided in the external container for pumping the heated mixed solution;

[0033] Due to the continuous evaporation of the mixed solution, the proportion of the mixed solution and the overall liquid level in the distillation tank 1 will change. At this time, the mixed solution may be replenished in the distillation tank 1, or distillation and purification may continue according to the remaining solution in the current distillation tank 1. At this time, in order to improve the recovery rate of waste heat, the contraction state of the plurality of heat release tubes 2 can be adjusted by the control component. The plurality of heat release tubes 2 are connected to each other by connectors and can be stretched and contracted to a certain extent, similar to the expansion and compression of a spring. At this time, the coverage height of all heat release tubes 2 will increase or decrease accordingly. In this way, the heat release area of ​​the heat release tubes 2 can be adjusted according to the liquid level in the distillation tank 1 to ensure that the heat release tubes 2 can be immersed in the mixed solution to release heat.

[0034] It is worth noting that the liquid level height in the distillation tank 1 can be detected by means such as a liquid level gauge, and the solution ratio of the mixed solution can be detected by a concentration detector commonly used in the chemical industry. The ambient temperature or the temperature of the mixed solution in the distillation tank 1 can be detected by a thermometer or related temperature detector or sensor, and output to an external control device such as a computer, industrial computer or related control device via wired or wireless means, so that the staff can perform corresponding operations or understand the processing situation.

[0035] The control assembly includes a cylinder 4 and a top plate 41. The cylinder 4 is fixedly arranged at the upper end of the distillation tank 1, and the output shaft of the cylinder 4 is slidingly sealed and extends into the distillation tank 1. The top plate 41 is fixedly connected to the output shaft of the cylinder 4 and connected to the uppermost heat release tube 2.

[0036] In this application, the control component is mainly used to provide a telescopic function. The cylinder 4 is selected in this application. Of course, any other device that can provide up and down telescopic force can also be selected. The top plate 41 is used to connect the output shaft of the cylinder 4 and several heat release tubes 2, and acts as a connecting component.

[0037] The connector includes an elastic part 5, a connecting air pipe 6 and a sealing piece 61. The elastic part 5 is arranged between two adjacent heat release tubes 2. The connecting air pipe 6 and the heat release tube 2 are integrally formed and the air path is connected. The connecting air pipe 6 of the heat release tube 2 is sealed and connected to the adjacent heat release tube 2 by sliding up and down. The sealing piece 61 is fixedly arranged in the heat release tube 2 and corresponds to the position of the connecting air pipe 6.

[0038] The elastic member 5 is a spring sheet. Among the elastic members 5 , from top to bottom in terms of horizontal height, the minimum stretching force of the elastic member 5 on the lower side is greater than the sum of the maximum contracting forces of the elastic members 5 on the upper side.

[0039] In the connector, the elastic member 5 plays a role in connecting two adjacent heat-releasing tubes 2 on the one hand, and in controlling the reduction of the spacing between several heat-releasing tubes 2 on the other hand. In the present application, at the height level, the minimum tensile force of the elastic member 5 on the lower side is greater than the sum of the maximum contraction forces of several elastic members 5 on the upper side. In other words, it ensures that the heat-releasing tubes 2 can shrink and move in sequence from top to bottom. Only after the upper heat-releasing tube 2 moves downward until it reaches the maximum movement stroke, the lower heat-releasing tube 2 starts to move downward again. This can avoid all the heat-releasing tubes 2 from moving downward at the same time, resulting in the connecting air pipes 6 of all the heat-releasing tubes 2 passing through the sealing piece 61, causing the toluene source to output faster, and resulting in insufficient waste heat recovery.

[0040] The connecting air pipe 6 is located on one side of the heat release pipe 2 and has a conical structure. The maximum diameter of the conical structure of the connecting air pipe 6 is less than or equal to the inner diameter of the connecting air pipe 6 .

[0041] In this way, the diameters of the exposed parts of all trachea can be unified while ensuring that the adjacent connecting trachea 6 can be connected.

[0042] The sealing piece 61 is tiltedly arranged in the heat release tube 2, and the sealing piece 61 completely separates the space inside the heat release tube 2. A through hole 62 is opened at the point where the sealing piece 61 and the inner diameter center of the heat release tube 2 coincide. The size of the through hole 62 matches the size of the connecting air pipe 6, and an elastic spacer 63 is provided in the through hole 62.

[0043] The oblique setting of the sealing piece 61 can guide the toluene source input from the upper side to be transported into the heat release pipe 2 at an accelerated speed, thereby forming a wind direction guide to reduce resistance. At the same time, the sealing piece 61 forcibly guides the flow direction of the input gas of the connecting air pipe 6, so that it cannot be transported directly downward. It must completely pass through the entire heat release pipe 2 before it can be output through the next connecting air pipe 6. In this way, a longer heat exchange distance can be provided in a relatively limited space within the smaller space of the distillation tank 1. Furthermore, when the heat of the toluene source itself is not high or the liquid level is low, it is necessary to reduce the heat exchange distance. The conveying stroke of the toluene source ensures effective heat exchange. At this time, the upper heat release tube 2 moves downward, and the connecting air pipe 6 moves downward synchronously until it passes through the perforation 62 of the sealing piece 61, wherein the elastic spacer 63 is pushed and expanded by the connecting air pipe 6. At this time, the gas input by the connecting air pipe 6 will directly correspond to the connecting air pipe 6 of the lower heat release tube 2, thereby accelerating gas transportation and reducing the heat exchange distance. Of course, as the heat release tube 2 continues to move downward, the connecting air pipe 6 of the upper heat release tube 2 will also directly extend into the connecting air pipe 6 of the lower heat release tube 2, thereby further improving the gas transportation guidance.

[0044] The elastic spacer 63 is composed of a plurality of thin sheets, which are evenly distributed and completely cover the through-hole 62 , and adjacent thin sheets are not connected to each other.

[0045] In the static state, the thin sheet remains parallel to the surface of the sealing sheet 61, thereby sealing the entire perforation 62. The thin sheet can be made of high-temperature resistant rubber such as styrene-butadiene rubber or EPDM rubber, or can be made of any material with high-temperature resistance and certain flexibility and reset elasticity such as polytetrafluoroethylene or silicone. In this way, in the static state, the elastic spacer 63 can cover most of the entire perforation 62, thereby preventing the input toluene source from passing through the perforation 62, but can meet the need for the connecting air pipe 6 to pass downward.

[0046] The base 3 is provided with a collecting groove 31, which is connected to the external container. The waste heat outlet 14 and the top plate 41 are connected by a hose 7. The extendable length of the hose 7 is greater than the sum of the movable strokes of the plurality of heat release tubes 2. The hose 7 is connected to the uppermost heat release tube 2 by an air path.

[0047] The collecting tank 31 is used to concentrate and guide the toluene source, and the hose 7 is used to connect the waste heat outlet 14 and the heat release pipe 2, wherein the hose 7 can be made of polytetrafluoroethylene or metal hose 7 to meet the requirements of high temperature and ductility.

[0048] It is worth noting that the pure toluene and water vapor evaporated in this application will be discharged through the distillation outlet 11, and condensed into liquid after passing through the external condenser. Due to the different densities of toluene and water, a precipitation container is set up externally. After the layers are separated and static, the pure toluene solution and the aqueous solution can be collected by the stratification characteristics to achieve the recovery of toluene.

[0049] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A device for recovering toluene in trimebutine maleate production, comprising a distillation tank, wherein the upper end of the distillation tank is provided with a distillation outlet for connecting to an external condenser to recover distilled clean toluene and water, the lower end of the distillation tank is provided with a drain port for discharging the remaining distilled solution, and the side of the distillation tank is provided with a liquid inlet and a waste heat outlet, the liquid inlet is used to inject toluene solution or water, and the waste heat outlet is used to input toluene vapor containing waste heat, characterized in that: Also includes: A waste heat recovery mechanism is provided in the distillation tank, wherein the input port of the waste heat recovery mechanism is connected to the waste heat outlet, and the discharge port of the waste heat recovery mechanism is connected to an external container; The waste heat recovery mechanism consists of a control component, a heat release pipe, a connector and a base. The control component is arranged on the tank cover of the distillation tank, and the base is arranged at the bottom of the distillation tank. The number of the heat release pipes is several and they are evenly arranged in the distillation tank, and several of the heat release pipes are located between the control component and the base. The number of the connectors is several and they are arranged between two adjacent heat release pipes, and the connector connects the two adjacent heat release pipes.

2. The device for recovering toluene in the production of trimebutine maleate according to claim 1, characterized in that: The control assembly includes a cylinder and a top plate. The cylinder is fixedly arranged at the upper end of the distillation tank, and the output shaft of the cylinder is slidingly sealed and extends into the distillation tank. The top plate is fixedly connected to the output shaft of the cylinder and is connected to the uppermost heat release tube.

3. The device for recovering toluene in the production of trimebutine maleate according to claim 2, characterized in that: The connector includes an elastic part, a connecting air pipe and a sealing piece. The elastic part is arranged between two adjacent heat release tubes. The connecting air pipe and the heat release tube are integrally formed and the air path is connected. The connecting air pipe of the heat release tube is sealed and slidably connected to the adjacent heat release tube up and down. The sealing piece is fixedly arranged in the heat release tube and corresponds to the position of the connecting air pipe.

4. The device for recovering toluene in the production of trimebutine maleate according to claim 3, characterized in that: The elastic member is a spring sheet. Among the elastic members, from top to bottom in terms of horizontal height, the minimum stretching elastic force of the elastic member on the lower side is greater than the sum of the maximum contraction elastic forces of the elastic members on the upper side.

5. The device for recovering toluene in the production of trimebutine maleate according to claim 4, characterized in that: The connecting air pipe is located on one side of the heat release pipe and has a conical structure. The maximum diameter of the conical structure of the connecting air pipe is less than or equal to the inner diameter of the connecting air pipe.

6. The device for recovering toluene in the production of trimebutine maleate according to claim 5, characterized in that: The sealing piece is tiltedly arranged in the heat release tube, and the sealing piece completely separates the space in the heat release tube. A perforation is opened at the point where the sealing piece and the inner diameter center of the heat release tube coincide. The size of the perforation matches the size of the connecting air pipe, and an elastic spacer is provided in the perforation.

7. The device for recovering toluene in the production of trimebutine maleate according to claim 6, characterized in that: The elastic spacer is composed of a plurality of thin sheets, which are evenly distributed and completely cover the perforations, and adjacent thin sheets are not connected to each other.

8. The device for recovering toluene in the production of trimebutine maleate according to claim 7, characterized in that: The base is provided with a collecting groove, which is connected to an external container. The waste heat outlet is connected to the top plate via a hose. The extendable length of the hose is greater than the sum of the movable strokes of several heat release pipes. The hose is connected to the air path of the uppermost heat release pipe.

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