Sampling system in methyl methacrylate production

Abstract

The invention provides a sampling system in methyl methacrylate production. A product outlet A of a reaction kettle is connected with an inlet of a decolorizing tank, and a product outlet B of the reaction kettle is connected with an inlet of a distillation tank; the outlet of the distillation tank is connected with the inlet of the decolorizing tank; the outlet of the decolorizing tank is connected with the inlet of the rectifying tower; a pump A is arranged on the side face of the reaction kettle, a liquid inlet pipe is installed at an inlet of the pump A, a liquid outlet pipe is installed at an outlet of the pump A, a sampling pipe is arranged on the liquid outlet pipe, the end of the sampling pipe corresponds to the position of an inlet of a liquid collecting tank, an outlet of the liquid collecting tank is connected with the tower bottom of the rectifying tower through a recycling pipe, and a valve A is arranged on the recycling pipe. According to the sampling system, residual liquid in the liquid collecting tank is recycled into the rectifying tower under the negative pressure condition of the rectifying tower, and the purposes of recycling sampling residual materials, reducing the hazardous waste treatment cost and improving the sampling safety are achieved on the premise that the whole system is not affected. The sampling system has the advantages of being reasonable in design, high in practicability and easy to operate.

Description

TECHNICAL FIELD

[0001] The present application relates to material recycling technical field, specifically relates to a kind of sampling system in methyl methacrylate production. BACKGROUND

[0002] Methyl methacrylate is an important organic compound, dissolved in ethanol and other organic solvents, the compound is mainly used for organic glass monomer, plastic, adhesive, impregnating agent, etc., with wide application. Methyl methacrylate is flammable and explosive, there is a risk of burning and explosion, and has toxicity, easy to harm human body, therefore, protection is particularly important when operating.

[0003] In the synthesis process of methyl methacrylate, purity is the key parameter of control, usually the purity of product needs to be controlled above 99.95%, in order to ensure product quality, 3 times of sampling is needed every shift in production process, frequent sampling test not only causes product waste, but also increases the risk of leakage and burning and explosion; in addition, waste produced by sampling enters low boiling point storage tank, is sent to incinerator for incineration, increases the cost of hazardous waste treatment, and wastes manpower and material resources.

[0004] The current methyl methacrylate preparation device is provided with a pump on the reaction kettle, the inlet of the pump is communicated with the middle and lower part of the reaction kettle, the outlet of the pump is communicated with the middle and upper part of the reaction kettle, a sampling port is opened on the connecting pipeline between the pump and the middle and upper part of the reaction kettle, and the sampling port is connected with a sampling barrel; the sample taken is treated as hazardous waste after use, causing waste.

[0005] It can be seen that it is of great significance to provide a sampling system capable of reducing sampling sample waste, saving hazardous waste treatment cost and improving sampling safety for methyl methacrylate product purity control. SUMMARY

[0006] In view of this, the present application provides a kind of sampling system in methyl methacrylate production, specifically a kind of sampling system including reaction kettle, pump A, distillation tank, decoloring tank and rectifying column;In the sampling system, sampling pipe is arranged on the liquid outlet pipe of pump A, the end of sampling pipe is connected with the inlet of liquid collection tank, the outlet of liquid collection tank is connected with the bottom of rectifying column through recovery pipe, and valve A is arranged on the recovery pipe. In the sampling system, the residual liquid in the liquid collection tank is recovered into the rectifying column by using the negative pressure condition of the rectifying column, which achieves the purposes of recovering residual material of sampling, reducing hazardous waste treatment cost and improving sampling safety without affecting the whole system. The sampling system has the advantages of reasonable design, high practicability and easy operation.

[0007] The technical scheme of the present application is as follows: A kind of sampling system in methyl methacrylate production, including reaction kettle, distillation tank, decoloring tank and rectifying column; The product outlet A of the reactor is connected to the inlet of the decolorization tank, and the product outlet B of the reactor is connected to the inlet of the distillation tank; the outlet of the distillation tank is connected to the inlet of the decolorization tank; and the outlet of the decolorization tank is connected to the inlet of the distillation column. Pump A is installed on the side of the reactor. Pump A has an inlet pipe installed at its inlet and an outlet pipe installed at its outlet. The inlet pipe is connected to the bottom of the reactor, and the outlet pipe is connected to the upper middle part of the reactor. A sampling tube is installed on the liquid outlet pipe, and the end of the sampling tube corresponds to the inlet position of the liquid collection tank. The outlet of the liquid collection tank is connected to the bottom of the distillation column through a recovery pipe, and valve A is installed on the recovery pipe. After sampling, the residual liquid flows into the collection tank and is stored in a sealed container. When the liquid level in the collection tank reaches a certain level, valve A is opened, and the liquid in the collection tank enters the distillation column under negative pressure. This process avoids the waste caused by the residual liquid of the sample spilling everywhere after sampling, and also protects the safety of workers, achieving the goals of less sample waste, less hazardous waste disposal, and high sampling safety.

[0008] In this invention, a material recovery pipe is added to the sampling tube and connected to the bottom of the distillation column. The vacuum inside the distillation column is used to promptly recover the residual methyl methacrylate in the collection tank back into the distillation column, thereby achieving material recovery and avoiding waste of finished methyl methacrylate caused by frequent sampling. In addition, the collection tank can effectively prevent leakage of methyl methacrylate and improve sampling safety.

[0009] Preferably, the reaction vessel includes a body that is smaller at the top and larger at the bottom. Because the temperature is too high during the reaction process, when methanol and water are added to the reaction vessel during the esterification process, methanol and water are easily discharged from product outlet A along with methyl methacrylate. This not only increases the impurities in the product but also leads to incomplete reaction, affecting reaction efficiency and effect. The design of being smaller at the top and larger at the bottom can reduce the discharge of methanol and water, and improve the reaction effect and efficiency.

[0010] Preferably, the main body has an open upper structure, with a cover plate on the top surface of the main body and a baffle strip on the inner side of the main body, the baffle strip being arranged along the height direction of the main body; a limiting groove is provided under the cover plate, the limiting groove corresponding to the top end position of the baffle strip; in use, the top end of the baffle strip is placed in the limiting groove to achieve positional correspondence.

[0011] Preferably, an inlet is provided on the cover plate, and methanol and water are added into the reactor as needed; a diversion pipe is provided at the inlet, and the outlet of the diversion pipe is located at the connection between the baffle and the main body; this setting can minimize the loss of methanol and water when adding methanol and water.

[0012] Preferably, a motor is provided on the cover plate, and the output shaft of the motor is connected to the stirring paddle, which is located inside the body; the connection between the baffle strip and the body is divided into side A and side B, where side B is the side where the liquid is directly impacted when the stirring paddle agitates the liquid, and the diversion pipe is located on side A; this arrangement allows methanol and water to smoothly enter the reaction solution to participate in the reaction, thereby improving the reaction effect.

[0013] Preferably, the decolorizing tank is equipped with a filter screen, and an activated carbon layer is provided on the filter screen; a collection tank is provided between the decolorizing tank and the distillation column, and a vacuum pump is connected to the collection tank, with the outlet of the collection tank connected to the inlet of the distillation column; in use, the outlet of the decolorizing tank is sealed to the inlet of the collection tank, and then the vacuum pump is started to create a negative pressure state in the collection tank, thereby filtering the light-colored methyl methacrylate in the decolorizing tank.

[0014] Preferably, the liquid collection tank is equipped with graduation lines, and valve A is opened and closed to control the amount of liquid in the collection tank. When the liquid in the collection tank reaches the specified graduation line, valve A is opened, and the liquid in the collection tank directly enters the distillation column under vacuum, avoiding liquid spillage during sampling and improving sampling safety.

[0015] Preferably, a valve B is provided on the sampling tube, and the valve B is used to control the sampling.

[0016] Preferably, the sampling tube is provided with a sampling head, which is located at the end of the sampling tube; the sampling head has a tapered structure, and its bottom outlet corresponds to the top inlet of the liquid collection tank; after sampling, the sampling head corresponds to the top inlet of the liquid collection tank to avoid problems such as liquid spillage.

[0017] Preferably, a pump B is provided on the side of the distillation column, with the inlet of pump B connected to the bottom of the column and the outlet of pump B connected to the lower middle part of the distillation column.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The sampling system of the present invention can recover materials in a timely manner through the recovery pipe and the distillation column, avoiding the long-term open storage of flammable and explosive materials and eliminating safety hazards.

[0019] 2. The sampling system of the present invention can effectively reduce waste generation and can promptly recycle the generated waste, saving hazardous waste treatment costs.

[0020] 3. The sampling tube used in this invention avoids the need for manual dumping of the sampling bucket, thus improving work efficiency by 100%; and in this process, it effectively improves the safety of sampling. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the sampling system.

[0023] In the diagram, 1-Reaction vessel, 101-Body, 102-Cover plate, 103-Product outlet A, 104-Product outlet B, 2-Distillation tank, 3-Decolorization tank, 4-Distillation column, 5-Break bar, 6-Limiting groove, 7-Inlet, 8-Diverter pipe, 9-Motor, 10-Agitator, 11-Side A, 12-Side B, 13-Pump A, 14-Inlet pipe, 15-Outlet pipe, 16-Sampling pipe, 17-Collection tank, 18-Recovery pipe, 19-Valve A, 20-Valve B, 21-Sampling head, 22-Graduation line, 23-Filter screen, 24-Activated carbon layer, 25-Collection tank, 26-Vacuum pump, 27-Pump B. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0025] Combination Figure 1 The present invention provides a sampling system for the production of methyl methacrylate, comprising a reaction vessel 1, a distillation tank 2, a decolorization tank 3, and a distillation column 4; The reaction vessel 1 includes a body 101, which is wider at the bottom than at the top. Because the temperature in the reaction vessel 1 is too high during the reaction process, when methanol and water are added to the reaction vessel 1 during the esterification process, methanol and water are easily discharged from the product outlet A103 along with methyl methacrylate. This not only increases the impurities in the product but also leads to incomplete reaction, affecting reaction efficiency and effectiveness. The design of being wider at the bottom than at the top reduces the discharge of methanol and water, improving reaction efficiency and effectiveness. The main body 101 has an open structure at the top. A cover plate 102 is provided on the top surface of the main body 101. A baffle strip 5 is provided on the inner side of the main body 101. The baffle strip 5 is arranged along the height direction of the main body 101. A limiting groove 6 is provided below the cover plate 102. The limiting groove 6 corresponds to the top end of the baffle strip 5. In use, the top end of the baffle strip 5 is placed in the limiting groove 6 to achieve the corresponding position. An inlet 7 is provided on the cover plate 102, and methanol and water are added into the reactor 1 as needed; a diversion pipe 8 is provided at the inlet 7, and the outlet of the diversion pipe 8 is located at the connection between the baffle strip 5 and the body 101; this setting can minimize the loss of methanol and water when adding methanol and water. A motor 9 is mounted on the cover plate 102, and the output shaft of the motor 9 is connected to a stirring paddle 10, which is located inside the main body 101. The baffle strip 5 is divided into side A 11 and side B 12 at the connection point with the main body 101. Figure 1 The rotation direction of the stirring paddle 10 is set on side A and side B; side B 12 is the side where the liquid is directly impacted when the stirring paddle 10 stirs the liquid, and the diverter 8 is located on side A 11; this setting allows methanol and water to smoothly enter the reaction solution to participate in the reaction and improve the reaction effect. A pump A13 is provided on the side of the body 101 of the reactor 1. A liquid inlet pipe 14 is installed at the inlet of the pump A13 and a liquid outlet pipe 15 is installed at the outlet of the pump A13. The liquid inlet pipe 14 is connected to the bottom of the reactor 1 and the liquid outlet pipe 15 is connected to the upper middle part of the reactor 1. A sampling tube 16 is provided on the liquid outlet pipe 15. The end of the sampling tube 16 is connected to the inlet of the liquid collection tank 17. The outlet of the liquid collection tank 17 is connected to the bottom of the distillation column 4 through the recovery pipe 18. A valve A19 is provided on the recovery pipe 18. A valve B20 is provided on the sampling tube 16, and the valve B20 is used to control the sampling. The sampling head 21 is located at the end of the sampling tube 16. The sampling head 21 has a tapered structure, and its bottom outlet corresponds to the top inlet of the liquid collection tank 17. After sampling, the bottom end of the sampling head 21 is aligned with the inlet of the liquid collection tank 17 to avoid problems such as liquid spillage. The liquid collection tank 17 is equipped with a scale line 22. The opening and closing valve A19 controls the liquid volume in the liquid collection tank 17. When the liquid in the liquid collection tank 17 reaches the specified scale line 22, the valve A19 is opened. Under the vacuum state of the distillation column 4, the liquid in the liquid collection tank 17 directly enters the distillation column 4, avoiding the phenomenon of liquid residue spillage during sampling and improving sampling safety. The product outlet A103 of the reactor 1 is located on the cover plate 102 and is connected to the inlet of the decolorization tank 3. The product outlet B104 of the reactor 1 is connected to the inlet of the distillation tank 2; the outlet of the distillation tank 2 is connected to the inlet of the decolorization tank 3. The decolorizing tank 3 is equipped with a filter screen 23, and an activated carbon layer 24 is provided on the filter screen 23. A collection tank 25 is provided between the decolorizing tank 3 and the distillation column 4. A vacuum pump 26 is connected to the collection tank 25, and the outlet of the collection tank 25 is connected to the inlet of the distillation column 4. In use, the outlet of the decolorizing tank 3 is sealed to the inlet of the collection tank 25, and then the vacuum pump 26 is started to create a negative pressure state in the collection tank 25, thereby filtering the light-colored methyl methacrylate in the decolorizing tank 3. Pump B27 is installed on the side of distillation column 4. The inlet of pump B27 is connected to the bottom of the column, and the outlet of pump B27 is connected to the middle and lower part of distillation column 4. After sampling from sampling tube 16, the residual liquid flows into collection tank 17 and is stored in a sealed container. When the liquid in collection tank 17 reaches a certain level, valve A19 is opened, and under the negative pressure of distillation column 4, the liquid in collection tank 17 enters distillation column 4. This process avoids the waste caused by the residual liquid of the sample spilling everywhere after sampling, and also protects the safety of workers, achieving the goals of less sample waste, less hazardous waste treatment, and high sampling safety.

[0026] In this invention, a material recovery pipe 18 is added to the sampling pipe 16 and connected to the bottom of the distillation column 4. The vacuum inside the distillation column 4 is used to promptly recover the residual methyl methacrylate in the collection tank 17 back into the distillation column 4, thereby achieving material recovery and avoiding waste of finished methyl methacrylate caused by frequent sampling. In addition, the setting of the collection tank 17 can effectively prevent leakage of methyl methacrylate and improve sampling safety.

[0027] Although the present invention has been described in detail with reference to preferred embodiments, it is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope of the claims.

Claims

1. A sampling system for the production of methyl methacrylate, characterized in that, Includes reaction vessels, distillation tanks, decolorization tanks, and distillation columns; The product outlet A of the reactor is connected to the inlet of the decolorization tank, and the product outlet B of the reactor is connected to the inlet of the distillation tank; the outlet of the distillation tank is connected to the inlet of the decolorization tank; and the outlet of the decolorization tank is connected to the inlet of the distillation column. Pump A is installed on the side of the reactor. Pump A has an inlet pipe installed at its inlet and an outlet pipe installed at its outlet. The inlet pipe is connected to the bottom of the reactor, and the outlet pipe is connected to the upper middle part of the reactor. A sampling tube is installed on the liquid outlet pipe. The end of the sampling tube is connected to the inlet of the liquid collection tank. The outlet of the liquid collection tank is connected to the bottom of the distillation column through a recovery pipe. Valve A is installed on the recovery pipe.

2. The sampling system for methyl methacrylate production as described in claim 1, characterized in that, The reactor includes a body, which is smaller at the top and larger at the bottom.

3. The sampling system for methyl methacrylate production as described in claim 2, characterized in that, The main body has an open structure at the top, with a cover plate on the top surface and a baffle strip on the inner side of the main body, which is arranged along the height direction of the main body; a limiting groove is provided under the cover plate, and the limiting groove corresponds to the top position of the baffle strip.

4. The sampling system for methyl methacrylate production as described in claim 3, characterized in that, An inlet is provided on the cover plate, and a diversion pipe is provided at the inlet. The outlet of the diversion pipe is located at the connection between the baffle strip and the main body.

5. The sampling system for methyl methacrylate production as described in claim 4, characterized in that, A motor is installed on the cover plate, and the output shaft of the motor is connected to the stirring paddle, which is located inside the main body; the connection between the baffle strip and the main body is divided into side A and side B.

6. The sampling system for methyl methacrylate production as described in claim 1, characterized in that, The decolorization tank is equipped with a filter screen, and an activated carbon layer is placed on top of the filter screen. A collection tank is located between the decolorization tank and the distillation column, and a vacuum pump is connected to the collection tank. The outlet of the collection tank is connected to the inlet of the distillation column.

7. The sampling system for methyl methacrylate production as described in claim 1, characterized in that, The liquid collection tank is equipped with graduation lines.

8. The sampling system for methyl methacrylate production as described in claim 1, characterized in that, Valve B is installed on the sampling tube.

9. The sampling system for methyl methacrylate production as described in claim 8, characterized in that, The sampling tube is equipped with a sampling head, which is located at the end of the sampling tube. The sampling head has a tapered structure, and its bottom outlet corresponds to the top inlet of the liquid collection tank.

10. The sampling system for methyl methacrylate production as described in claim 1, characterized in that, Pump B is installed on the side of the distillation column. The inlet of pump B is connected to the bottom of the column, and the outlet of pump B is connected to the middle and lower part of the distillation column.

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