Acetone condensation and recovery device for producing waterborne polyurethane resin

Abstract

The utility model discloses an acetone condensation recovery device for producing waterborne polyurethane resin, which relates to the technical field of polyurethane production devices and comprises a synthesis kettle, a dispersion kettle mounted below the synthesis kettle and a desolventizing kettle mounted below the dispersion kettle, and a first desolventizing connector and a second desolventizing connector are arranged at the top of the desolventizing kettle. The first desolventizing connector is connected with a first condenser, a second condenser is connected below the first condenser, a first storage tank is arranged on one side of the second condenser, a vacuum pump and a plate type condenser are arranged on the other side of the second condenser, and an electromagnetic three-way valve is arranged between the vacuum pump and the plate type condenser. An air inlet and an air outlet of the vacuum pump are respectively connected with a second condenser and an electromagnetic three-way valve, the electromagnetic three-way valve is connected with a second desolventizing interface, a third interface of the electromagnetic three-way valve is connected with a plate type condenser, and a second storage tank is arranged below the plate type condenser. According to the device, the recovery rate of acetone is obviously improved, the waste of acetone is reduced, and meanwhile, the pollution to the environment is also avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of polyurethane production equipment, and in particular to an acetone condensation and recovery device for producing waterborne polyurethane resin. Background Technology

[0002] In the production of waterborne polyurethane resins, acetone is a key solvent, mainly used to reduce the viscosity of the reaction system and promote emulsification. However, acetone residue in the final product may lead to product performance degradation and cause environmental and safety problems. Therefore, how to efficiently recover acetone is a crucial issue.

[0003] Existing acetone recovery technologies mostly employ single-stage condensation or intermittent vacuum distillation processes. While these methods can recover acetone, they suffer from limitations such as a single condensation temperature (usually only room temperature cooling) and short gas-liquid contact time. This results in insufficient capture of low-concentration acetone vapor, leading to a single-pass recovery rate of only 30%-50%. In particular, during high-vacuum desolventizing (-0.08 to -0.095 MPa), incomplete condensation causes some acetone vapor to directly enter the vacuum pump and be emitted, resulting in significant solvent loss and severely impacting the acetone recovery rate. Furthermore, these methods fail to meet environmental regulations and safe production requirements. Utility Model Content

[0004] This invention provides an acetone condensation and recovery device for producing waterborne polyurethane resin, aiming to solve the problems of low recovery rate, poor condensation efficiency and solvent loss in existing acetone recovery technologies.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An acetone condensation and recovery device for producing waterborne polyurethane resin includes a synthesis reactor, a dispersion reactor installed below the synthesis reactor, and a solvent removal reactor installed below the dispersion reactor. The top of the solvent removal reactor is provided with a first solvent removal port and a second solvent removal port. The first solvent removal port is connected to a first pipeline, and the end of the first pipeline is connected to a first condenser. Below the first condenser is a second pipeline, the end of which is connected to a second condenser. One side of the second condenser is provided with a first storage tank for collecting the acetone condensed from the first and second condensers, and the other side is provided with a vacuum pump and a plate condenser. An electromagnetic three-way valve is provided between the vacuum pump and the plate condenser. The inlet and outlet of the vacuum pump are respectively connected to a third pipe and a fourth pipe. The end of the third pipe is connected to the second condenser. The end of the fourth pipe is connected to the first interface of the electromagnetic three-way valve. The second interface of the electromagnetic three-way valve is connected to a fifth pipe. The end of the fifth pipe is connected to the second desolvation interface. The third interface of the electromagnetic three-way valve is connected to a sixth pipe. The end of the sixth pipe is connected to the plate condenser. A second storage tank for collecting acetone after condensation is provided below the plate condenser.

[0007] Furthermore, the top and bottom of the first condenser are respectively provided with a first air inlet and a first exhaust outlet, the first air inlet is connected to the first pipeline, and the first exhaust outlet is connected to the second pipeline.

[0008] Furthermore, the top and one side of the second condenser are respectively provided with a second air inlet and a second exhaust outlet, the second air inlet is connected to the second pipeline, and the second exhaust outlet is connected to the third pipeline.

[0009] Furthermore, the first condenser and the second condenser are respectively provided with a first drain port and a second drain port on the same side; the top of the first storage tank is provided with a vertically arranged drain pipe, and one side of the drain pipe is provided with an inclined first receiving pipe and a second receiving pipe, the ends of the first receiving pipe and the second receiving pipe are respectively connected to the first drain port and the second drain port.

[0010] Furthermore, a check valve is installed on the aforementioned second pipeline.

[0011] Furthermore, the first desolventizing interface and the second desolventizing interface are respectively provided with a first solenoid valve and a second solenoid valve.

[0012] Furthermore, the aforementioned air inlet and the aforementioned air outlet are respectively equipped with a third solenoid valve and a fourth solenoid valve.

[0013] Furthermore, the plate condenser is provided with a third air inlet and a third liquid outlet on one side and at the bottom, respectively. The third air inlet is connected to the sixth pipeline, and the third liquid outlet is connected to the second storage tank.

[0014] As can be seen from the above description of the structure of this utility model, this utility model has the following advantages:

[0015] This invention employs a multi-stage condensation and vacuum pump-assisted recovery scheme, which effectively vaporizes acetone in waterborne polyurethane emulsions and condenses it twice. Part of the acetone is recovered through a continuous condensation process in the first and second condensers. Furthermore, the combination of an electromagnetic three-way valve and a vacuum pump ensures that uncondensed acetone can re-enter the desolventizing vessel for reheating and evaporation, achieving secondary recovery of acetone. The acetone recovery rate can reach ≥99%, significantly improving the acetone recovery rate, reducing acetone waste, and also avoiding environmental pollution caused by the emission of gases containing unrecovered acetone into the air. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] Figure reference numerals: 10-Synthesis vessel; 20-Dispersion vessel; 30-Desolventizing vessel; 31-First desolventizing port; 311-First pipeline; 32-Second desolventizing port; 40-First condenser; 401-First air inlet; 402-First exhaust port; 403-First liquid drain port; 41-Second pipeline; 411-Check valve; 42-Second condenser; 421-Second air inlet; 422-Second exhaust port; 423-Second liquid drain port; 50-First storage vessel Storage tank; 51-Drain pipe; 511-First liquid receiving pipe; 512-Second liquid receiving pipe; 60-Vacuum pump; 61-Air inlet; 611-Third pipeline; 62-Exhaust port; 621-Fourth pipeline; 70-Plate condenser; 71-Third air inlet; 72-Third drain port; 80-Solenoid three-way valve; 81-First interface; 82-Second interface; 821-Fifth pipeline; 83-Third interface; 831-Sixth pipeline; 90-Second storage tank. Detailed Implementation

[0018] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0019] Reference Figure 1An acetone condensation and recovery device for producing waterborne polyurethane resin includes a synthesis reactor 10, a dispersion reactor 20 installed below the synthesis reactor 10, and a solvent removal reactor 30 installed below the dispersion reactor 20. The top of the solvent removal reactor 30 is provided with a first solvent removal port 31 and a second solvent removal port 32. A first solenoid valve (not shown in the figure) and a second solenoid valve (not shown in the figure) are respectively installed on the first solvent removal port 31 and the second solvent removal port 32. The first solvent removal port 31 is connected to a first pipeline 311, the end of which is connected to a first condenser 40. A second pipeline 41 is connected below the first condenser 40, the end of which is connected to a second condenser 42. A first storage tank 50 is provided on one side of the second condenser 42 for collecting the acetone condensed from the first condenser 40 and the second condenser 42. On the other side, a vacuum pump 60 and a plate condenser 70 are provided. Between the vacuum pump 60 and the plate condenser 70, there is an electromagnetic three-way valve 80 for changing the direction of gaseous acetone. The inlet 61 and outlet 62 of the vacuum pump 60 are respectively connected to a third pipe 611 and a fourth pipe 621. The end of the third pipe 611 is connected to the second condenser 42. The end of the fourth pipe 621 is connected to the first interface 81 of the electromagnetic three-way valve 80. The second interface 82 of the electromagnetic three-way valve 80 is connected to a fifth pipe 821. The end of the fifth pipe 821 is connected to the second desolvation interface 32. The third interface 83 of the electromagnetic three-way valve 80 is connected to a sixth pipe 831. The end of the sixth pipe 831 is connected to the plate condenser 70. Below the plate condenser 70, there is a second storage tank 90 for collecting the condensed acetone.

[0020] During production, an acetone-containing aqueous polyurethane emulsion is sequentially transported from the synthesis reactor 10 and dispersion reactor 20 to the solvent extraction reactor 30. Then, the jacket of the solvent extraction reactor 30 (not shown in the figure) is heated, causing the liquid acetone in the reactor 30 to rapidly vaporize into steam. Next, the vacuum pump 60 is activated, drawing a vacuum through the third pipeline 611 to the first condenser 40 and the second condenser 42, allowing the acetone-containing vapor to enter and condense in both condensers. During this process, some of the acetone that has been converted from gaseous to liquid state flows into the first storage tank 50. Then, the exhaust port 62 of the vacuum pump 60 is opened, and the third port 83 of the electromagnetic three-way valve 80 is closed, allowing... The uncondensed steam returns to the desolventizing vessel 30 for secondary heating, and then undergoes secondary condensation again through the first condenser 40 and the second condenser 42. During this process, some of the acetone that has been converted from gaseous to liquid will flow back into the first storage tank 50. Then, the second port 82 of the electromagnetic three-way valve 80 is closed and the third port 83 is opened. The remaining unliquefied steam is introduced into the plate condenser 70 for condensation. The condensed liquid acetone flows into the second storage tank 90, and the remaining gas is discharged into the air. After this condensation step, the acetone recovery rate can reach ≥99%, which not only significantly improves the acetone recovery rate, but also meets environmental regulations and safety production requirements.

[0021] Reference Figure 1 The first condenser 40 has a first air inlet 401 at its top and a first exhaust port 402 at its bottom. The first air inlet 401 is connected to the first pipeline 41, and the first exhaust port 402 is connected to the second pipeline 41. The second condenser 42 has a second air inlet 421 at its top and a second exhaust port 422 on its side. The second air inlet 421 is connected to the second pipeline 41, and a check valve 411 is installed on the second pipeline 41. The second exhaust port 422 is connected to the third pipeline 611. This arrangement effectively diverts and controls the gas condensation process at different stages. The cooperation between the first condenser 40 and the second condenser 42 also allows the gas to be cooled gradually in multiple stages, avoiding overloading a single condenser and significantly improving cooling efficiency. Furthermore, the check valve 411 on the second pipeline 41 prevents backflow of gas, ensuring the stability of the airflow direction and the normal operation of the system.

[0022] Reference Figure 1The first condenser 40 and the second condenser 42 are respectively provided with a first drain port 403 and a second drain port 423 on the same side; the top of the first storage tank 50 is provided with a vertically arranged drain pipe 51, and one side of the drain pipe 51 is provided with an inclined first receiving pipe 511 and a second receiving pipe 512. The ends of the first receiving pipe 511 and the second receiving pipe 512 are respectively connected to the first drain port 403 and the second drain port 423. By connecting the drain ports of the first condenser 40 and the second condenser 42 respectively to the receiving pipe 51 in the first storage tank 50, and by adopting the design of the vertical drain pipe 51 and the inclined receiving pipe, the effective collection of liquid acetone is realized, ensuring the smooth discharge of liquid acetone during the condensation process, avoiding the occurrence of liquid accumulation, and improving the drainage efficiency of the system.

[0023] Reference Figure 1 The vacuum pump 60 has a third solenoid valve (not shown in the figure) and a fourth solenoid valve (not shown in the figure) at its inlet 61 and outlet 62, respectively. This configuration allows for precise control of the gas flow and ensures the normal operation of the vacuum pump under different working conditions.

[0024] Reference Figure 1 The plate condenser 70 has a third air inlet 71 and a third liquid outlet 72 on one side and bottom, respectively. The third air inlet 71 is connected to the sixth pipeline 831, and the third liquid outlet 72 is connected to the second storage tank 90. ​​The top of the second storage tank 90 is also provided with a vent for gas discharge (not shown in the figure). With this setting, the inflow of gas and the discharge of liquid in the plate condenser 70 can be effectively guided, ensuring the smooth entry of gas and the timely discharge of liquid acetone during the condensation process. At the same time, the remaining gas can be smoothly discharged through the vent of the second storage tank 90, avoiding gas accumulation and excessive pressure, ensuring the efficient operation of the entire condensation process, and guaranteeing the stability and reliability of the system.

[0025] This invention significantly improves the acetone recovery efficiency from waterborne polyurethane emulsions by employing a recovery scheme combining multi-stage condensation and a vacuum pump. During production, acetone is effectively vaporized from the waterborne polyurethane emulsion and recovered through two condensation processes. First, the vaporized acetone is continuously condensed from a gaseous state to a liquid state by the first condenser 40 and the second condenser 42. A portion of the acetone is successfully recovered and stored in the first storage tank 50. Then, through the coordinated operation of the electromagnetic three-way valve 80 and the vacuum pump 60, the uncondensed acetone is effectively guided back to the desolvation vessel 30 for secondary heating and evaporation. Afterward, it re-enters the first condenser 40 and the second condenser 42 for a second condensation, and finally undergoes final condensation through the plate condenser 70. This minimizes acetone waste, achieving a recovery rate of ≥99%, effectively improving acetone recovery efficiency, reducing resource waste, saving production costs, and also reducing environmental pollution.

[0026] The above are merely specific embodiments of this utility model, but the design concept of this utility model is not limited thereto. Any non-substantial modifications made to this utility model using this concept shall be considered as an infringement of the protection scope of this utility model.

Claims

1. An acetone condensation and recovery device for producing waterborne polyurethane resin, comprising a synthesis reactor, a dispersion reactor installed below the synthesis reactor, and a solvent removal reactor installed below the dispersion reactor, characterized in that: The top of the solvent extraction vessel is provided with a first solvent extraction port and a second solvent extraction port. The first solvent extraction port is connected to a first pipeline, and the end of the first pipeline is connected to a first condenser. Below the first condenser is a second pipeline, and the end of the second pipeline is connected to a second condenser. One side of the second condenser is provided with a first storage tank for collecting acetone condensed by the first and second condensers. The other side is provided with a vacuum pump and a plate condenser. An electromagnetic three-way valve is provided between the vacuum pump and the plate condenser. The inlet and outlet of the vacuum pump are respectively connected to a third pipeline and a fourth pipeline. The end of the third pipeline is connected to the second condenser. The end of the fourth pipeline is connected to the first port of the electromagnetic three-way valve. The second port of the electromagnetic three-way valve is connected to a fifth pipeline. The end of the fifth pipeline is connected to the second solvent extraction port. The third port of the electromagnetic three-way valve is connected to a sixth pipeline. The end of the sixth pipeline is connected to the plate condenser. Below the plate condenser is a second storage tank for collecting acetone condensed.

2. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 1, characterized in that: The first condenser has a first air inlet and a first exhaust outlet at its top and bottom, respectively. The first air inlet is connected to the first pipeline, and the first exhaust outlet is connected to the second pipeline.

3. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 1, characterized in that: The second condenser has a second air inlet and a second exhaust outlet on its top and one side, respectively. The second air inlet is connected to the second pipeline, and the second exhaust outlet is connected to the third pipeline.

4. The acetone condensation and recovery apparatus for producing waterborne polyurethane resin according to any one of claims 1 to 3, characterized in that: The first condenser and the second condenser are respectively provided with a first drain port and a second drain port on the same side; the top of the first storage tank is provided with a vertically arranged drain pipe, and a first liquid receiving pipe and a second liquid receiving pipe are provided on one side of the drain pipe, and the ends of the first liquid receiving pipe and the second liquid receiving pipe are respectively connected to the first drain port and the second drain port.

5. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 4, characterized in that: A check valve is installed on the second pipeline.

6. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 4, characterized in that: The first desolventizing interface and the second desolventizing interface are respectively equipped with a first solenoid valve and a second solenoid valve.

7. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 4, characterized in that: The air inlet and the air outlet are respectively equipped with a third solenoid valve and a fourth solenoid valve.

8. The acetone condensation and recovery device for producing waterborne polyurethane resin according to claim 4, characterized in that: The plate condenser is provided with a third air inlet and a third liquid outlet on one side and at the bottom, respectively. The third air inlet is connected to the sixth pipeline; the third liquid outlet is connected to the second storage tank.

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