Polyester polyol synthesis process and synthesis system thereof

Abstract

The invention discloses a polyester polyol synthesis process and a polyester polyol synthesis system, and belongs to the technical field of polyester polyol synthesis. The synthesis process comprises the steps of raw material addition, reaction, rectification, alcohol separation, unloading and the like. The synthesis system comprises a reaction kettle, a rectifying tower and a tail gas absorption device. A heating jacket with a baffling mechanism is arranged outside the reaction kettle, and a stirring mechanism is arranged inside the reaction kettle, so that the heat utilization rate of a heating medium can be improved and the reaction is accelerated. The tail gas absorption device pressurizes tail gas through a tail gas pressurization box and then sends the tail gas into a tail gas absorption box, and the gas-liquid contact rate and the absorption rate are improved through multiple sets of stirring and gas distribution structures. The device is reasonable in design, can accurately control the reaction temperature, efficiently separate products and improve the utilization rate of a heating medium and the absorption rate of tail gas, and has relatively high social use value and application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of polyester polyol synthesis, and in particular to a polyester polyol synthesis process and a synthesis system thereof. Background Art

[0002] In the field of polyester polyol synthesis technology, efficient and high-quality synthesis processes and systems have always been the goal pursued by the industry. At present, there are many problems with traditional polyester polyol synthesis processes and systems. In terms of synthesis technology, temperature control is not precise enough, which may lead to unstable reaction rate and affect product quality and yield. The separation process is inefficient and cannot effectively separate water, alcohols and other substances in the reaction, resulting in waste of raw materials and increased production costs. In terms of the synthesis system, the heat medium utilization rate of the heating device is not high, and the heat cannot be fully utilized to heat the material, affecting the reaction efficiency. At the same time, during the long-term use of the reactor, the outer wall and internal heating components are prone to accumulate dirt, which not only reduces the thermal conductivity, but also may cause corrosion to the equipment and affect the service life of the equipment.

[0003] In addition, the treatment of tail gas generated during the synthesis process is not perfect. The traditional tail gas absorption device has a low absorption rate, insufficient gas-liquid contact, and cannot effectively remove organic waste gas in the tail gas, causing environmental pollution.

[0004] In summary, the existing polyester polyol synthesis process and system need to be improved urgently to meet the industry's demand for efficient, environmentally friendly and high-quality production. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a polyester polyol synthesis process and a synthesis system thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A polyester polyol synthesis process comprises the following steps:

[0008] S1: Raw materials added

[0009] First, nitrogen is blown into the reactor as a protective gas, adipic acid is added to the reactor using a crane, and then the glycol raw materials are pumped into the reactor;

[0010] S2: Reaction

[0011] The reaction is carried out under normal pressure. The reactor is connected to the distillation tower. The stirring in the reactor is turned on. The reactor is heated while stirring. The reaction temperature is controlled at 130°C. The temperature of the reactor is slowly increased and the reaction is carried out slowly.

[0012] S3: Distillation

[0013] The water and other volatile gases produced in the reaction enter the distillation tower through the pipeline. The temperature in the tower continues to rise. At this time, the cooling water reflux valve is opened to control the temperature at the top of the distillation tower at 100-108°C. The water produced by the reaction is evaporated through the distillation tower and condensed, and then discharged through the steam trap. Other substances in the distillation tower are refluxed to the reactor, and the alcohol gas is refluxed to the reactor after condensation. After 1-2 hours of reaction, the temperature at the top of the distillation tower begins to drop. At this time, most of the condensation water produced by the reaction has been separated, and the reaction is completed.

[0014] S4: Alcohol separation

[0015] The temperature of the reactor is raised to about 230℃, and the temperature is kept constant for 2 hours. The alcohol is evaporated, condensed and recovered in the storage tank. After the product specifications are qualified, the oil pump is turned on for indirect cooling. The alcohol recovered in the recovery tank is recycled and used in the next production;

[0016] S4: Unloading

[0017] The cooled polyol intermediate is pumped into a storage tank by a pump at the bottom of the reactor for storage and standby use.

[0018] A polyester polyol synthesis system comprises a reaction kettle, a distillation tower and a tail gas absorption device, wherein the reaction kettle is connected to the distillation tower, the distillation tower comprises a tower top condenser, and the tower top condenser is connected to the tail gas absorption device through a pipeline;

[0019] The top of the reactor is provided with a feeding port, the bottom of the reactor is provided with a discharging port, a stirring mechanism is provided inside the reactor, a heating jacket is provided outside the reactor, and a baffle mechanism is provided inside the heating jacket;

[0020] The tail gas absorption device comprises a tail gas absorption box, and a tail gas pressurizing box is installed on the top of the tail gas absorption box.

[0021] Preferably, the stirring mechanism comprises a first stirring rod, which is driven to rotate by a first rotating motor installed on the top of the reaction kettle, and a plurality of first stirring branches are fixed to the outside of the first stirring rod.

[0022] Preferably, the deflection mechanism comprises a plurality of annular baffles, which are equidistantly distributed from top to bottom, and are staggeredly fixed to the heating jacket and the reactor.

[0023] Preferably, a scraping mechanism is further provided inside the heating jacket, and the top and bottom ends of the scraping mechanism are both mounted on a first annular guide rail fixed on the inner wall of the heating jacket.

[0024] Preferably, permanent magnets A are fixed to the top and bottom of the scraping mechanism, and permanent magnets B are installed on the outer wall of the reactor through a second annular guide rail, and permanent magnets A and B attract each other through the heating jacket.

[0025] Preferably, the scraping mechanism includes a horizontal scraper and a vertical scraper, which are fixed by a connecting frame, the vertical scraper is in contact with the outer wall of the reactor, and the horizontal scraper is in contact with the annular baffle, and sliders are fixed at the top and bottom ends of the scraping mechanism, and the two sliders are respectively slidably installed on the two first annular guide rails.

[0026] Preferably, a first gear ring is fixed on the second annular guide rail, a vertical shaft is rotatably mounted on the outer wall of the heating jacket, first spur gears are fixed to the top and bottom ends of the vertical shaft, and the two first spur gears are respectively meshed with the two first gear rings, a second rotating motor is also fixed on the outer wall of the heating jacket, a first bevel gear is fixed to the output shaft of the second rotating motor, a second bevel gear is fixed to the outside of the vertical shaft, and the first bevel gear is meshed with the second bevel gear.

[0027] Preferably, the exhaust gas pressurization box is connected to an air intake pipe, a reciprocating screw is rotatably installed in the exhaust gas pressurization box, the reciprocating screw is driven to rotate by a third rotating motor at the top of the exhaust gas pressurization box, a lifting piston is installed in the exhaust gas pressurization box, and the lifting piston is threadedly installed on the outside of the reciprocating screw;

[0028] A vertically arranged guide rod is fixed on the inner wall of the top end of the exhaust gas pressurizing box, and the guide rod movably penetrates through the guide hole;

[0029] A ventilation conduit is fixed to the bottom end of the reciprocating screw rod, the bottom end of the ventilation conduit extends to the inside of the tail gas absorption box, and a one-way valve is installed on the bottom end of the ventilation conduit and the air intake pipe.

[0030] Preferably, a second spur gear is fixed to the outside of the ventilation duct, a plurality of second stirring rods are rotatably installed inside the exhaust gas absorption box, a plurality of second stirring branches are installed on the second stirring rods, a third spur gear is fixed to the top of the second stirring rod, a plurality of third spur gears surround the second spur gear, and the third spur gears are meshed with the second spur gears;

[0031] A connector is fixed at the bottom end of the ventilation duct, and the connector is rotatably installed in a connecting sleeve fixed at the bottom end of the exhaust gas absorption box. A vent hole is provided on the connector, and multiple first gas distribution pipes are connected around the connecting sleeve. One end of the first gas distribution pipe away from the connecting sleeve is bent and vertically upward, and the top of the first gas distribution pipe is connected to a vertical pipe, and a second gas distribution pipe is fixed on the vertical pipe, and multiple gas distribution holes are provided on the second gas distribution pipe;

[0032] The vertical pipe is connected to the first gas distribution pipe through a rotary joint, a fourth spur gear is fixed to the top of the vertical pipe, a second gear ring is rotatably mounted on the inner wall of the tail gas absorption box, a first meshing tooth is arranged at the top of the second gear ring, a second meshing tooth is arranged at the inner ring of the second gear ring, and the fourth spur gear meshes with the second meshing tooth;

[0033] A fourth rotating motor is fixed on the outer wall of the exhaust gas absorption box, a fifth spur gear is fixed to the output shaft of the fourth rotating motor, and the fifth spur gear is meshed with the first meshing teeth.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The baffle mechanism extends the heat medium flow path and improves the heat utilization rate of the heat medium. The heat medium forms an S-shaped flow channel between multiple annular baffles, extending the heat medium flow path and residence time, and repeatedly utilizing the heat of the heat medium to heat the material.

[0036] 2. The scraping mechanism is convenient for cleaning and maintenance. The scraping mechanism includes a horizontal scraper and a vertical scraper, which can scrape the annular baffle and the outer wall of the reactor respectively to prevent dirt accumulation, reduce thermal efficiency and corrosion of parts.

[0037] 3. Automatically drive the scraping mechanism. Through the cooperation of the second rotating motor, the first bevel gear, the second bevel gear, the vertical shaft, the first straight gear, the first gear ring and other components, the scraping mechanism can be automatically moved, which is easy to operate.

[0038] 4. Exhaust gas pressurization improves absorption rate. The exhaust gas pressurization box presses the exhaust gas into the absorption liquid in the exhaust gas absorption box through reciprocating screw rods, lifting pistons and other components. The high-pressure exhaust gas increases the gas-liquid contact rate, thereby improving the absorption rate.

[0039] 5. Stirring promotes absorption. The rotation of the ventilation tube drives the second stirring rod to rotate, and the absorption liquid is stirred through the second stirring branch, further improving the contact rate between the gas and the absorption liquid and promoting absorption.

[0040] 6. Uniform gas distribution improves absorption rate. The connector at the bottom of the ventilation duct cooperates with multiple first gas distribution pipes, so that the gas intermittently enters each first gas distribution pipe and is ejected from the gas distribution holes on the second gas distribution pipe. At the same time, the rotation of the vertical pipe further improves the gas distribution degree, ensuring that the ejected gas has sufficient pressure, while increasing the gas distribution range and effect, and improving the absorption rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a three-dimensional diagram of the reaction kettle of the present invention;

[0043] Figure 2It is a cross-sectional view of a heating jacket in a reactor of the present invention;

[0044] Figure 3 It is a schematic diagram of the installation of the second rotating electrical machine of the present invention;

[0045] Figure 4 It is a cross-sectional view of the reactor of the present invention;

[0046] Figure 5 for Figure 4 A zoomed-in detail of position A in the middle;

[0047] Figure 6 for Figure 4 Enlarged detail of position B in the middle;

[0048] Figure 7 It is an enlarged detail view of the scraping mechanism of the present invention;

[0049] Figure 8 for Figure 7 Enlarged detail image of the middle C position;

[0050] Fig. 9 This is a front view of the tail gas absorption device of the present invention;

[0051] Fig.10 A cross-sectional view of the tail gas absorption device of the present invention from a first viewing angle;

[0052] Fig.11 A cross-sectional view of the tail gas absorption device of the present invention from a second viewing angle;

[0053] Fig.12 This is a schematic diagram of the distribution position of the first gas distribution pipe of the present invention (the connector and the connecting sleeve are combined together);

[0054] Fig.13 This is a schematic diagram of the distribution position of the first gas distribution pipe of the present invention (the connector and the connection sleeve are separated);

[0055] Fig.14 for Fig.13 Enlarged detail image of the middle D position;

[0056] In the figure: 1 reactor, 101 first rotating motor, 102 feeding port, 103 discharging port, 104 first stirring rod, 105 first stirring branch, 2 heating jacket, 201 annular baffle, 3 scraping mechanism, 301 first annular guide rail, 302 permanent magnet A, 303 second annular guide rail, 304 first gear ring, 305 second rotating motor, 306 first bevel gear, 307 vertical shaft, 308 second bevel gear, 309 first straight gear, 310 permanent magnet B, 4 horizontal scraper, 401 connecting frame, 402 vertical scraper, 403 slider, 5 tail gas absorption box, 6 tail gas pressurization box, 601 inlet Air pipe, 602 one-way valve, 603 reciprocating screw rod, 604 third rotating motor, 605 lifting piston, 606 guide rod, 7 ventilation duct, 701 second spur gear, 702 air vent, 703 connector, 8 connecting sleeve, 801 first gas distribution pipe, 802 rotary joint, 803 vertical pipe, 804 second gas distribution pipe, 805 gas distribution hole, 806 fourth spur gear, 9 second gear ring, 901 first meshing tooth, 902 second meshing tooth, 903 fourth rotating motor, 904 fifth spur gear, 10 second stirring rod, 1001 third spur gear, 1002 second stirring branch. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] A polyester polyol synthesis process comprises the following steps:

[0060] S1: Raw materials added

[0061] First, nitrogen is blown into the reactor 1 as a protective gas, adipic acid is added into the reactor 1 by crane, and then the glycol raw material is pumped into the reactor 1;

[0062] S2: Reaction

[0063] The reaction is carried out under normal pressure. The reactor 1 is connected to the distillation tower. The stirring in the reactor 1 is turned on. The reactor 1 is heated while stirring. The reaction temperature is controlled at 130°C. The temperature of the reactor 1 rises slowly and the reaction proceeds slowly.

[0064] S3: Distillation

[0065] The water and other volatile gases produced in the reaction enter the distillation tower through the pipeline, and the temperature in the tower continues to rise. At this time, the cooling water reflux valve is opened to control the temperature at the top of the distillation tower at 100-108°C. The water produced by the reaction is evaporated through the distillation tower and then condensed and discharged through the steam trap. Other substances in the distillation tower are refluxed to the reactor 1, and the alcohol gas is refluxed to the reactor 1 after condensation. After the reaction for 1-2 hours, the temperature at the top of the distillation tower begins to drop. At this time, most of the condensation water produced by the reaction has been separated, and the reaction is completed;

[0066] S4: Alcohol separation

[0067] The temperature of the reactor is raised to about 230℃, and the temperature is kept constant for 2 hours. The alcohol is evaporated, condensed and recovered in the storage tank. After the product specifications are qualified, the oil pump is turned on for indirect cooling. The alcohol recovered in the recovery tank is recycled and used in the next production;

[0068] S4: Unloading

[0069] The cooled polyol intermediate is pumped into a storage tank by a pump at the bottom of the reactor 1 for storage and standby use.

[0070] Example 2

[0071] Reference Figure 1-14 , a polyester polyol synthesis system, comprising a reactor 1, a distillation tower and a tail gas absorption device, the reactor 1 is connected to the distillation tower, the distillation tower comprises a tower top condenser, and the tower top condenser is connected to the tail gas absorption device through a pipeline;

[0072] The top of the reactor 1 is provided with a feeding port 102, the bottom of the reactor 1 is provided with a discharging port 103, a stirring mechanism is provided inside the reactor 1, a heating jacket 2 is provided outside the reactor 1, and a baffle mechanism is provided inside the heating jacket 2;

[0073] The heat medium is introduced into the heating jacket 2, and the path of the heat medium flow is extended by the baffle mechanism to improve the utilization rate of the heat of the heat medium;

[0074] The tail gas absorption device includes a tail gas absorption box 5, and a tail gas pressurizing box 6 is installed on the top of the tail gas absorption box 5. The non-condensable tail gas in the condenser is passed into the tail gas absorption device for filtration and absorption. The organic waste gas in the tail gas is absorbed by the organic absorption liquid. The organic absorption liquid is added to the tail gas absorption box 5. The tail gas is pressurized by the tail gas pressurizing box 6 and then enters the absorption liquid. The high-pressure tail gas can increase the contact rate between gas and liquid and improve the absorption rate.

[0075] The stirring mechanism includes a first stirring rod 104, which is driven to rotate by a first rotating motor 101 installed on the top of the reactor 1, and a plurality of first stirring branches 105 are fixed to the outside of the first stirring rod 104;

[0076] The first rotating motor 101 can drive the first stirring rod 104 to rotate, and the reacting material can be stirred through the first stirring branch 105 to accelerate the reaction.

[0077] Example 3

[0078] Reference Figure 1-14 The difference between this embodiment and embodiment 2 is that the baffle mechanism includes a plurality of annular baffles 201, the annular baffles 201 are equidistantly distributed from top to bottom, and the annular baffles 201 are staggered and fixed to the heating jacket 2 and the reactor 1;

[0079] The heat medium flows alternately between the layers of annular baffles 201 to form an S-shaped flow channel, thereby extending the heat medium flow path and the heat medium residence time, thereby repeatedly utilizing the heat of the heat medium to heat the material.

[0080] Example 4

[0081] Reference Figure 1-14 The difference between this embodiment and embodiment 2 is that a scraping mechanism 3 is further provided inside the heating jacket 2, and the top and bottom ends of the scraping mechanism 3 are both mounted on a first annular guide rail 301 fixed on the inner wall of the heating jacket 2, and a permanent magnet A302 is fixed on the top and bottom ends of the scraping mechanism 3, and a permanent magnet B310 is mounted on the outer wall of the reactor 1 through a second annular guide rail 303, and the permanent magnet A302 and the permanent magnet B310 attract each other through the heating jacket 2;

[0082] When the permanent magnet B310 is driven to rotate around the outer wall of the reactor 1, the permanent magnet A302 can be driven to rotate along by the magnetic force, thereby driving the scraping mechanism 3 to move.

[0083] Among them, the scraping mechanism 3 includes a horizontal scraper 4 and a vertical scraper 402, which are fixed by a connecting frame 401, the vertical scraper 402 contacts the outer wall of the reactor 1, and the horizontal scraper 4 contacts the annular baffle 201. Sliders 403 are fixed to the top and bottom ends of the scraping mechanism 3, and the two slides 403 are respectively slidably installed on the two first annular guide rails 301. During the movement of the scraping mechanism 3, the outer wall of the reactor 1 will be scraped by the vertical scraper 402, and the surface of the annular baffle 201 will be scraped by the horizontal scraper 4, so that the cleaning and maintenance of the interior of the heating jacket 2 is more convenient, and can prevent dirt accumulation, resulting in reduced thermal conductivity and corrosion of internal parts of the heating jacket 2.

[0084] In order to drive the scraping mechanism 3 to move, a first gear ring 304 is fixed on the second annular guide rail 303, a vertical shaft 307 is rotatably mounted on the outer wall of the heating jacket 2, first spur gears 309 are fixed on the top and bottom ends of the vertical shaft 307, and the two first spur gears 309 are respectively meshed with the two first gear rings 304, a second rotary motor 305 is also fixed on the outer wall of the heating jacket 2, a first bevel gear 306 is fixed on the output shaft of the second rotary motor 305, a second bevel gear 308 is fixed on the outside of the vertical shaft 307, and the first bevel gear 306 is meshed with the second bevel gear 308;

[0085] By turning on the second rotating motor 305, the vertical shaft 307 can be driven to rotate through the meshing of the first bevel gear 306 and the second bevel gear 308, thereby driving the first spur gear 309 to rotate. Furthermore, the first spur gear 309 can be engaged with the first gear ring 304 to drive the driving permanent magnet B310 to rotate around the outer wall of the reactor 1, thereby driving the scraping mechanism 3 to move.

[0086] Example 5

[0087] Reference Figure 1-14 The difference between this embodiment and embodiment 2 is that an intake pipe 601 is connected to the exhaust gas pressurizing box 6, a reciprocating screw 603 is rotatably installed in the exhaust gas pressurizing box 6, and the reciprocating screw 603 is driven to rotate by a third rotating motor 604 at the top of the exhaust gas pressurizing box 6, a lifting piston 605 is installed in the exhaust gas pressurizing box 6, and the lifting piston 605 is threadedly installed on the outside of the reciprocating screw 603, and a vertically arranged guide rod 606 is fixed on the inner wall of the top of the exhaust gas pressurizing box 6, and the guide rod 606 movably penetrates 605 through the guide hole;

[0088] When the third rotating motor 604 is turned on, it can drive the reciprocating screw 603 to rotate, and then drive the lifting piston 605 to move up and down. A ventilation duct 7 is fixed to the bottom end of the reciprocating screw 603. The bottom end of the ventilation duct 7 extends to the interior of the exhaust gas absorption box 5, and a one-way valve 602 is installed on the bottom end of the ventilation duct 7 and the intake pipe 601. The one-way valve 602 on the intake pipe 601 ensures that the gas in the exhaust gas pressurization box 6 can only go out but not enter. The one-way valve 602 on the ventilation duct 7 ensures that the gas in the exhaust gas pressurization box 6 can only go out but not enter, thereby ensuring that the exhaust gas is directly pressurized and pressed into the absorption liquid in the exhaust gas absorption box 5 during the movement of the lifting piston 605. The high-pressure exhaust gas can increase the contact rate between gas and liquid, and improve the absorption rate.

[0089] Among them, a second spur gear 701 is fixed to the outside of the ventilation duct 7, a plurality of second stirring rods 10 are rotatably installed inside the exhaust gas absorption box 5, a plurality of second stirring branches 1002 are installed on the second stirring rod 10, a third spur gear 1001 is fixed to the top of the second stirring rod 10, a plurality of third spur gears 1001 surround the second spur gear 701, and the third spur gears 1001 are meshed with the second spur gear 701;

[0090] When the reciprocating screw 603 rotates, it can drive the ventilation duct 7 to rotate, and then drive the second spur gear 701 to rotate. Through the engagement of the second spur gear 701 with the third spur gear 1001, multiple second stirring rods 10 can be driven to rotate, and the absorption liquid is stirred through the second stirring branch 1002, thereby increasing the contact rate between the gas and the absorption liquid and promoting absorption.

[0091] A connector 703 is fixed at the bottom end of the ventilation duct 7, and the connector 703 is rotatably installed in the connecting sleeve 8 fixed at the bottom end of the exhaust gas absorption box 5. A vent hole 702 is provided on the connector 703, and a plurality of first gas distribution pipes 801 are connected around the connecting sleeve 8. One end of the first gas distribution pipe 801 away from the connecting sleeve 8 is bent and vertically upward, and a vertical pipe 803 is connected to the top of the first gas distribution pipe 801. A second gas distribution pipe 804 is fixed on the vertical pipe 803, and a plurality of gas distribution holes 805 are provided on the second gas distribution pipe 804.

[0092] During the rotation of the ventilation duct 7, the connector 703 rotates relative to the connecting sleeve 8, so that the air holes 702 are alternately aligned with the first gas distribution pipes 801, so that the gas can intermittently enter the first gas distribution pipes 801 and be ejected from the gas distribution holes 805 on the second gas distribution pipes 804. Only one first gas distribution pipe 801 is ventilated at a time, which ensures that the ejected gas has sufficient pressure while increasing the range of gas distribution. The second gas distribution pipes 804 are different from each other, which can further improve the gas distribution effect and the absorption rate.

[0093] The vertical pipe 803 is connected to the first gas distribution pipe 801 through a rotating joint 802. A fourth spur gear 806 is fixed to the top of the vertical pipe 803. A second gear ring 9 is rotatably installed on the inner wall of the exhaust gas absorption box 5. A first meshing tooth 901 is provided at the top of the second gear ring 9, and a second meshing tooth 902 is provided on the inner ring of the second gear ring 9. The fourth spur gear 806 meshes with the second meshing tooth 902. A fourth rotating motor 903 is fixed to the outer wall of the exhaust gas absorption box 5. A fifth spur gear 904 is fixed to the output shaft of the fourth rotating motor 903. The fifth spur gear 904 meshes with the first meshing tooth 901. When the fourth rotating motor 903 is turned on, the fifth spur gear 904 can be driven to rotate. The second gear ring 9 can be driven to rotate by the meshing of the fifth spur gear 904 with the first meshing tooth 901, and then the vertical pipe 803 can be driven to rotate by the meshing of the second meshing tooth 902 with the fourth spur gear 806, which drives the second gas distribution pipe 804 to rotate accordingly, thereby further improving the gas distribution degree.

[0094] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0095] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A polyester polyol synthesis process, characterized in that: The following steps are involved: S1: Raw materials added First, nitrogen is blown into the reaction kettle (1) as a protective gas, adipic acid is added into the reaction kettle (1) by crane, and then the glycol raw material is pumped into the reaction kettle (1); S2: Reaction The reaction is carried out under normal pressure. The reactor (1) is connected to a distillation tower. The stirring in the reactor (1) is turned on. The reaction is heated while stirring. The reaction temperature is controlled at 130° C. The temperature of the reactor (1) is slowly increased and the reaction is slowly carried out. S3: Distillation The water and other volatile gases generated in the reaction enter the distillation tower through the pipeline. The temperature in the tower continues to rise. At this time, the cooling water reflux valve is opened to control the temperature at the top of the distillation tower at 100-108°C. The water generated by the reaction is evaporated through the distillation tower and then condensed and discharged through the steam trap. The other substances in the distillation tower are refluxed to the reactor (1). The alcohol gas is condensed and refluxed to the reactor (1). After the reaction for 1-2 hours, the temperature at the top of the distillation tower begins to drop. At this time, most of the condensation water generated by the reaction has been separated and the reaction is completed. S4: Alcohol separation The temperature of the reactor was raised to about 230°C and kept at a constant temperature for 2 hours. The alcohol was evaporated, condensed and recovered into the storage tank. After the specifications of the product were analyzed and qualified, the oil pump was turned on for indirect cooling. The alcohol recovered in the recovery tank is recycled and used in the next production; S4: Unloading The cooled polyol intermediate is pumped into a storage tank by a pump at the bottom of the reactor (1) for storage and standby use.

2. A polyester polyol synthesis system, applied to a polyester polyol synthesis process as claimed in claim 1, comprising a reaction kettle (1), a distillation tower and a tail gas absorption device, characterized in that: The reactor (1) is connected to a distillation tower, the distillation tower comprises a tower top condenser, and the tower top condenser is connected to a tail gas absorption device via a pipeline; The top of the reactor (1) is provided with a feeding port (102), the bottom of the reactor (1) is provided with a discharging port (103), a stirring mechanism is provided inside the reactor (1), a heating jacket (2) is provided outside the reactor (1), and a baffle mechanism is provided inside the heating jacket (2); The tail gas absorption device comprises a tail gas absorption box (5), and a tail gas pressurizing box (6) is installed on the top of the tail gas absorption box (5).

3. A polyester polyol synthesis system according to claim 2, characterized in that: The stirring mechanism comprises a first stirring rod (104), the first stirring rod (104) is driven to rotate by a first rotating motor (101) installed at the top of the reaction kettle (1), and a plurality of first stirring branches (105) are fixed outside the first stirring rod (104).

4. A polyester polyol synthesis system according to claim 2, characterized in that: The deflection mechanism comprises a plurality of annular baffles (201), the annular baffles (201) being equidistantly distributed from top to bottom, and the annular baffles (201) being staggered and fixed to the heating jacket (2) and the reaction kettle (1).

5. A polyester polyol synthesis system according to claim 2, characterized in that: The interior of the heating jacket (2) is also provided with a scraping mechanism (3), and the top and bottom ends of the scraping mechanism (3) are both mounted on a first annular guide rail (301) fixed on the inner wall of the heating jacket (2).

6. A polyester polyol synthesis system according to claim 5, characterized in that: A permanent magnet A (302) is fixed to the top and bottom of the scraping mechanism (3), and a permanent magnet B (310) is installed on the outer wall of the reaction kettle (1) via a second annular guide rail (303). The permanent magnet A (302) and the permanent magnet B (310) attract each other through the heating jacket (2).

7. A polyester polyol synthesis system according to claim 5, characterized in that: The scraping mechanism (3) comprises a horizontal scraper (4) and a vertical scraper (402), the horizontal scraper (4) and the vertical scraper (402) being fixed via a connecting frame (401), the vertical scraper (402) being in contact with the outer wall of the reaction kettle (1), and the horizontal scraper (4) being in contact with the annular baffle (201), and sliders (403) being fixed at the top and bottom ends of the scraping mechanism (3), and the two sliders (403) being slidably mounted on the two first annular guide rails (301) respectively.

8. A polyester polyol synthesis system according to claim 6, characterized in that: A first gear ring (304) is fixed on the second annular guide rail (303), a vertical shaft (307) is rotatably mounted on the outer wall of the heating jacket (2), first spur gears (309) are fixed to the top and bottom ends of the vertical shaft (307), and the two first spur gears (309) are respectively meshed with the two first gear rings (304), a second rotating motor (305) is also fixed on the outer wall of the heating jacket (2), a first bevel gear (306) is fixed to the output shaft of the second rotating motor (305), a second bevel gear (308) is fixed to the outside of the vertical shaft (307), and the first bevel gear (306) is meshed with the second bevel gear (308).

9. A polyester polyol synthesis system according to claim 2, characterized in that: The exhaust gas pressurizing box (6) is connected to an air intake pipe (601), a reciprocating screw (603) is rotatably installed in the exhaust gas pressurizing box (6), the reciprocating screw (603) is driven to rotate by a third rotating motor (604) at the top of the exhaust gas pressurizing box (6), a lifting piston (605) is installed in the exhaust gas pressurizing box (6), and the lifting piston (605) is threadedly installed on the outside of the reciprocating screw (603); A vertically arranged guide rod (606) is fixed on the inner wall of the top end of the exhaust gas pressurizing box (6), and the guide rod (606) movably penetrates (605) through the guide hole; A ventilation duct (7) is fixed to the bottom end of the reciprocating screw rod (603), and the bottom end of the ventilation duct (7) extends to the interior of the tail gas absorption box (5), and a one-way valve (602) is installed on the bottom end of the ventilation duct (7) and the air inlet pipe (601).

10. A polyester polyol synthesis system according to claim 9, characterized in that: A second spur gear (701) is fixed to the outside of the ventilation duct (7), a plurality of second stirring rods (10) are rotatably mounted inside the exhaust gas absorption box (5), a plurality of second stirring branches (1002) are mounted on the second stirring rods (10), a third spur gear (1001) is fixed to the top of the second stirring rod (10), the plurality of third spur gears (1001) surround the second spur gear (701), and the third spur gears (1001) are meshed with the second spur gears (701); A connector (703) is fixed at the bottom end of the ventilation duct (7), and the connector (703) is rotatably mounted in a connecting sleeve (8) fixed at the bottom end of the exhaust gas absorption box (5). A vent hole (702) is provided on the connector (703). A plurality of first gas distribution pipes (801) are connected around the connecting sleeve (8). One end of the first gas distribution pipe (801) away from the connecting sleeve (8) is bent and vertically faces upward, and a vertical pipe (803) is connected to the top end of the first gas distribution pipe (801). A second gas distribution pipe (804) is fixed on the vertical pipe (803), and a plurality of gas distribution holes (805) are provided on the second gas distribution pipe (804). The vertical pipe (803) is connected to the first gas distribution pipe (801) via a rotary joint (802); a fourth spur gear (806) is fixed to the top of the vertical pipe (803); a second gear ring (9) is rotatably mounted on the inner wall of the tail gas absorption box (5); a first meshing tooth (901) is provided at the top of the second gear ring (9); a second meshing tooth (902) is provided at the inner ring of the second gear ring (9); and the fourth spur gear (806) meshes with the second meshing tooth (902); A fourth rotating motor (903) is fixed on the outer wall of the tail gas absorption box (5); a fifth spur gear (904) is fixed to the output shaft of the fourth rotating motor (903); and the fifth spur gear (904) meshes with the first meshing teeth (901).

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