A polyglycerol ester distillation production system and control method

Abstract

The present application relates to the technical field of polyglycerol ester production, and particularly relates to a polyglycerol ester distillation production system and a control method; comprising a stirred tank, a multi-stage vacuum pump assembly, a multi-stage distiller, a temperature control assembly and a controller, the stirred tank is used for polyglycerol ester reaction, the material obtained by the stirred tank reaction is subjected to distillation operation in the multi-stage distiller, the multi-stage vacuum pump assembly is used for vacuumizing operation of the multi-stage distiller, and the temperature control assembly is used for temperature regulation of the multi-stage distiller; the controller is in electrical connection with the stirred tank, the multi-stage vacuum pump assembly, the multi-stage distiller and the temperature control assembly respectively; the automation degree of polyglycerol ester production is improved, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of polyglycerol ester production technology, and in particular to a polyglycerol ester distillation production system and control method. Background Technology

[0002] Polyglycerol fatty acid esters are a new type of highly efficient nonionic surfactant, often abbreviated as polyglycerol esters. They are used in various foods as emulsifiers, stabilizers, thickeners, and anti-caking agents. They are produced by the esterification reaction of natural glycerol and fatty acids at high temperatures.

[0003] Existing methods for controlling polyglycerol production require feeding the necessary materials into a reactor, where an esterification reaction takes place to generate polyglycerol. However, these methods suffer from low levels of automation in both the individual steps and the relationships between them.

[0004] Therefore, there is an urgent need to provide a polyglycerol ester distillation production system and control method to improve the automation level and production efficiency of polyglycerol ester production compared with existing technologies. Summary of the Invention

[0005] This invention addresses the technical problems existing in the prior art and provides a polyglycerol ester distillation production system and control method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A polyglycerol ester distillation production system includes a stirred tank, a multi-stage vacuum pump assembly, a multi-stage distillation apparatus, a temperature control assembly, and a controller. The stirred tank reacts with polyglycerol ester, and the resulting substance enters the multi-stage distillation apparatus for distillation. The multi-stage vacuum pump assembly evacuates the multi-stage distillation apparatus, and the temperature control assembly regulates the temperature of the multi-stage distillation apparatus. The controller is electrically connected to the stirred tank, the multi-stage vacuum pump assembly, the multi-stage distillation apparatus, and the temperature control assembly. The multi-stage still includes a primary still, a secondary still, and a tertiary still connected in sequence. The multi-stage vacuum pump assembly includes a primary Roots vacuum pump, a secondary Roots vacuum pump, and a tertiary Roots vacuum pump connected in sequence. The tertiary Roots vacuum pump is connected to the primary, secondary, and tertiary vacuum devices, respectively. The primary, secondary, and tertiary vacuum devices are connected to the primary, secondary, and tertiary stills, respectively. Each primary, secondary, and tertiary still is equipped with a pressure sensor to detect a first pressure value, a second pressure value, and a third pressure value in real time. The controller adjusts the rotational speed of the variable frequency motors connected to the primary, secondary, and tertiary Roots vacuum pumps based on the first, second, and third pressure values.

[0007] Furthermore, the temperature control component includes an air-cooled radiator, a cooling oil unit, and a heat transfer oil unit. The heat transfer oil unit is circulatedly connected to the first-stage still, the second-stage still, and the third-stage still, respectively. The cooling oil unit is connected to the air-cooled radiator and is circulatedly connected to the first-stage still, the second-stage still, and the third-stage still, respectively.

[0008] Furthermore, the stirring vessel includes a vessel body, with a stirring shaft passing through the upper end of the vessel body. A second motor is fixedly connected to the upper end of the stirring shaft, and the lower end of the stirring shaft is rotatably connected to the interior of the vessel body. Multiple sets of stirring blades are hinged on the stirring shaft, and the multiple sets of stirring blades are spaced apart along the axial direction of the stirring shaft.

[0009] Furthermore, the stirred tank is equipped with a filter plate inside, which is fixedly connected to the inner side wall of the tank. The lower end of the stirring shaft is rotatably connected to the upper part of the filter plate. The filter plate has multiple filter holes, and a baffle is rotatably connected inside the filter plate. The baffle has multiple connecting holes. A first motor is fixedly connected to the outer wall of the tank. A gear is fixedly connected to the output end of the first motor. A rack is provided on the outer periphery of the baffle. The rack meshes with the gear. When the first motor rotates, the amount of space connecting the corresponding connecting holes and filter holes can be adjusted.

[0010] Furthermore, a heating pipe and a cooling pipe are wound around the inner side wall of the vessel body, the heating pipe being connected to the heat transfer oil unit, and the cooling pipe being connected to the cooling oil unit.

[0011] A control method for a polyglycerol ester distillation production system includes the following steps: S1. Polyglycerol and fatty acids are input into the mixing vessel according to the set ratio. The controller controls the rotation speed of the stirring shaft according to the total input mass of the mixing vessel. At this time, the connecting hole and the corresponding filter hole are completely disconnected. S2. After the reaction in the stirred tank reaches the end of the reaction time, the state of the connecting hole and the corresponding filter hole is adjusted to be connected. The controller controls the amount of space connected between the connecting hole and the corresponding filter hole according to the total input mass in the stirred tank. S3. The reactants from the stirred tank are sequentially fed into the primary, secondary, and tertiary distillers. The primary, secondary, and tertiary Roots vacuum pumps are started to perform vacuuming operations. The pressure values ​​of the primary, secondary, and tertiary distillers are monitored in real time, and the speeds of the primary, secondary, and tertiary Roots vacuum pumps are dynamically adjusted. At the same time, the temperature is controlled through the cooling oil unit and the heat transfer oil unit.

[0012] Furthermore, in step S1, the controller controls the rotational speed of the stirring shaft based on the total input mass of the stirred tank. Specifically, the method is as follows: The total input mass per unit time in the stirred tank is denoted as M, which is calculated by summing the output mass of polyglycerol and fatty acids. A first, second, and third mass threshold are set, where the first mass threshold is less than the second mass threshold, and the second mass threshold is less than the third mass threshold, respectively expressed as follows: , , Specific adjustments will be made based on the specific circumstances: (1) When At that time, the controller controls the speed of the second motor to be... ; (2) When At that time, the controller controls the speed of the second motor to be... ; (3) When At that time, the controller controls the speed of the second motor to be... ; In the above formula, Indicates the rotational speed of the first stirring shaft. This is expressed as the rotational speed of the second stirring shaft. This indicates the rotational speed of the third stirring shaft.

[0013] Furthermore, an angle sensor is embedded in the outer wall of each stirring blade. The rotational speed corresponds to a minimum tilt angle of 30° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 60° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 90° for all stirring blades; The tilt angle of the stirring blade mentioned above is the tilt angle in a coordinate system with the hinge point between each stirring blade and the stirring shaft as the origin, the horizontal direction as the X coordinate, and the vertical direction as the Y coordinate. Determine whether it has been achieved , , The specific method for determining the rotation speed is as follows: after adding raw materials into the mixing vessel, gradually increase the rotation speed of the mixing shaft. The controller receives the value detected by the angle sensor in real time, and then determines whether the corresponding rotation speed has been reached based on the tilt angle of all the mixing blades.

[0014] Furthermore, in step S2, the controller controls the amount of space P connecting the connecting holes and the corresponding filter holes based on the total input mass inside the mixing vessel. The specific method is as follows: (1) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: ; (2) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: ; (3) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: .

[0015] Furthermore, in step S3, the pressure values ​​of the first-stage, second-stage, and third-stage distillers are monitored in real time, and the rotational speeds of the first-stage, second-stage, and third-stage Roots vacuum pumps are dynamically adjusted. The specific method is as follows: Set the pressure value detected by the first-stage distillation unit to the first pressure value. The pressure value detected by the secondary distiller is the second pressure value. The pressure value detected by the three-stage distillation unit is the third pressure value. Set the vacuum level, and add the local atmospheric pressure to the set pressure value. The analysis will be divided into the following categories: (1) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage and third-stage Roots vacuum pumps until... ; (2) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and ; (3) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and ; (4) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ; (5) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ; (6) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ,and ; (7) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... , , All greater than ; The increase in rotational speed in (7) is twice that in (3), and the increase in rotational speed in (1), (2), (4), (5), and (6) is the same as that in (3).

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses a stirring vessel to stir the raw materials and then inputs the material generated in the stirring vessel into a multi-stage distillation vessel for distillation. During the distillation operation, a multi-stage vacuum pump assembly is used to evacuate the multi-stage distillation vessel and collect the pressure value of the multi-stage distillation vessel in real time. Based on the real-time pressure value, the speed of the multi-stage vacuum pump is dynamically adjusted according to different situations, which improves the degree of automation of polyglycerol production and also improves production efficiency.

[0017] (2) In this invention, for the stirring reaction in the stirring vessel, the rotation speed of the stirring shaft is dynamically adjusted according to the total input mass entering the stirring vessel, and the amount of space between the connecting hole and the corresponding filter hole is adjusted accordingly, which can further improve the degree of automation of polyglycerol production and improve production efficiency.

[0018] (3) By setting up a multi-stage Roots vacuum pump, the present invention provides precise vacuum regulation for the multi-stage distillation system; at the same time, by setting up an air-cooled radiator, a cooling oil unit and a heat transfer oil unit, the temperature of the distillation system can be regulated, ensuring that the working temperature of the distillation system is more precise.

[0019] (4) The present invention sets a rotating baffle in the filter plate in the stirred tank, the filter plate is provided with filter holes and the baffle is provided with connecting holes. By rotating the baffle, the amount of communication between the connecting holes and the filter holes can be adjusted, thereby realizing the flow rate of the reactants output in the stirred tank, thus controlling the production level with high efficiency; and the stirring blades are hinged on the stirring shaft in the stirred tank. By controlling the rotation speed of the stirring shaft, the angle of the stirring blades unfolding under centrifugal action can be realized, thereby adjusting the stirring range, better controlling the stirring effect, and making the stirring effect better. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a cross-sectional view of the structure of the stirring vessel of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Stirring vessel; 11. Vessel body; 12. Heating tube; 13. Cooling tube; 14. Stirring shaft; 15. Stirring blade; 16. Filter plate; 17. Baffle; 18. Rack; 19. Gear; 110. First motor; 111. Second motor; 2. First-stage Roots vacuum pump; 21. First-stage vacuum equipment; 3. Second-stage Roots vacuum pump; 31. Second-stage vacuum equipment; 4. Third-stage Roots vacuum pump; 41. Third-stage vacuum equipment; 5. First-stage distillation apparatus; 6. Second-stage distillation apparatus; 7. Third-stage distillation apparatus; 8. Air-cooled radiator; 9. Cooling oil unit; 10. Heat transfer oil unit. Detailed Implementation

[0023] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] like Figure 1As shown, the present invention provides a polyglycerol ester distillation production system, including a stirred tank 1, a multi-stage vacuum pump assembly, a multi-stage distillation apparatus, a temperature control assembly, and a controller. The stirred tank 1 is used to mix polyglycerol esters for production. The polyglycerol esters obtained from the reaction in the stirred tank 1 are then distilled in the multi-stage distillation apparatus. The multi-stage vacuum pump assembly performs a vacuum operation on the multi-stage distillation apparatus, and the temperature control assembly regulates the temperature of the multi-stage distillation apparatus. The controller is electrically connected to the stirred tank 1, the multi-stage vacuum pump assembly, the multi-stage distillation apparatus, and the temperature control assembly.

[0025] The multi-stage still includes a primary still 5, a secondary still 6, and a tertiary still 7. The primary still 5, secondary still 6, and tertiary still 7 are connected in series. The primary still 5 is connected to the output end of the stirred tank 1. Pressure sensors are installed on the primary still 5, secondary still 6, and tertiary still 7. The pressure sensors are used to detect the pressure values ​​inside the primary still 5, secondary still 6, and tertiary still 7 in real time.

[0026] The multi-stage vacuum pump assembly includes a first-stage Roots vacuum pump 2, a second-stage Roots vacuum pump 3, a third-stage Roots vacuum pump 4, a first-stage vacuum device 21, a second-stage vacuum device 31, and a third-stage vacuum device 41. The first-stage Roots vacuum pump 2, the second-stage Roots vacuum pump 3, and the third-stage Roots vacuum pump 4 are connected sequentially. The third-stage Roots vacuum pump 4 is connected to the first-stage vacuum device 21, the second-stage vacuum device 31, and the third-stage vacuum device 41, respectively. The first-stage vacuum device 21 is connected to the first-stage distillation apparatus 5, the second-stage vacuum device 31 is connected to the second-stage distillation apparatus 6, and the third-stage vacuum device 41 is connected to the third-stage distillation apparatus 7. The first-stage Roots vacuum pump 2, the second-stage Roots vacuum pump 3, and the third-stage Roots vacuum pump 4 are each connected to a variable frequency motor.

[0027] The temperature control assembly includes an air-cooled radiator 8, a cooling oil unit 9, and a heat transfer oil unit 10. The input of the air-cooled radiator 8 is connected to the cold source output of the first-stage still 5, the second-stage still 6, and the third-stage still 7, respectively. The output of the air-cooled radiator 8 is connected to the input of the cooling oil unit 9, and the output of the cooling oil unit 9 is connected to the cold source input of the first-stage still 5, the second-stage still 6, and the third-stage still 7, respectively. The input of the heat transfer oil unit 10 is connected to the heat source input of the first-stage still 5, the second-stage still 6, and the third-stage still 7, respectively. The output of the heat transfer oil unit 10 is connected to the heat source output of the first-stage still 5, the second-stage still 6, and the third-stage still 7, respectively. The cooling oil unit 9 is used to provide a low-temperature environment for the multi-stage still, and the heat transfer oil unit 10 is used to provide a high-temperature environment for the multi-stage still.

[0028] For the first-stage still 5, a cold source circulation loop is formed through the cooling oil unit 9 – the cold source input terminal of the first-stage still 5 – the cold source output terminal of the first-stage still 5 – the air-cooled radiator 8 – cooling oil unit 9; and a heat source circulation loop is formed through the heat transfer oil unit 10 – the heat source input terminal of the still – the heat source output terminal of the still – heat transfer oil unit 10. For the second-stage still 6, a cold source circulation loop is formed through the cooling oil unit 9 – the cold source input terminal of the second-stage still 6 – the cold source output terminal of the second-stage still 6 – the air-cooled radiator 8 – cooling oil unit 9. A cold source circulation loop is formed through the heat transfer oil unit 10, the heat source input end of the distiller, and the heat source output end of the distiller. For the three-stage distiller 7, a cold source circulation loop is formed through the cooling oil unit 9, the cold source input end of the three-stage distiller 7, the cold source output end of the three-stage distiller 7, the air-cooled radiator 8, and the cooling oil unit 9. A heat source circulation loop is formed through the heat transfer oil unit 10, the heat source input end of the distiller, and the heat source output end of the distiller.

[0029] The controller dynamically adjusts the rotation speeds of the first-stage Roots vacuum pump 2, the second-stage Roots vacuum pump 3, and the third-stage Roots vacuum pump 4 based on the real-time pressure values ​​detected in the first-stage distillation unit 5, the second-stage distillation unit 6, and the third-stage distillation unit 7, so as to achieve the set vacuum level in the first-stage distillation unit 5, the second-stage distillation unit 6, and the third-stage distillation unit 7.

[0030] like Figure 2 As shown, the stirring vessel 1 includes a vessel body 11. A heating pipe 12 and a cooling pipe 13 are wound around the inner side wall of the vessel body 11. The cooling pipe 13 is positioned close to the heating pipe 12. One end of the heating pipe 12 passes through the vessel body 11 and connects to the heat transfer oil unit 10. One end of the cooling pipe 13 passes through the vessel body 11 and connects to the cooling oil unit 9. A filter plate 16 is also provided inside the vessel body 11. The filter plate 16 is fixedly connected to the inner side wall of the vessel body 11. The lower end of the stirring shaft 14 is rotatably connected to the upper part of the filter plate 16. The filter plate 16 has multiple filter holes. A baffle 17 is rotatably connected inside the filter plate 16. The baffle 17 has multiple connecting holes, and the diameter of the connecting holes on the baffle 17 is the same as the diameter of the filter holes on the filter plate 16. A first motor 110 is fixedly connected to the outer wall of the vessel body 11. A gear 19 is fixedly connected to the output end of the first motor 110. The filter plate 16 and the vessel body 11 are extended. The outer periphery of the baffle 17 is provided with a rack 18, which meshes with the gear 19. The first motor 110 is started, driving the gear 19 to rotate, thereby realizing the rotation of the baffle 17. The controller controls the rotation angle of the baffle 17 and controls the amount of space between the filter hole and the connecting hole. The first motor 110 is a servo motor, realizing forward and reverse rotation. The pore size of the filter plate is 100 mesh, which is intended to block the reaction catalyst (enzyme) from entering the material distillation system during continuous reaction.

[0031] The upper end of the stirring shaft 14 passes through the vessel body 11, and the upper end of the stirring shaft 14 extends out of the vessel body 11 and is fixedly connected to the second motor 111. The second motor 111 drives the stirring shaft 14 to rotate. The stirring blade 15 is hinged to the stirring shaft 14. By controlling the rotation speed of the stirring shaft 14, the opening angle of the stirring blade 15 is controlled through centrifugal action. The larger the opening angle of the stirring blade 15, the larger the contact area with the material inside the vessel body 11, and the better the stirring effect is achieved.

[0032] The materials entering the stirred tank 1 include polyglycerol and fatty acids. The polyglycerol is placed in a first material tank and the fatty acids are placed in a second material tank. The first material tank is equipped with a first metering device at its output end, which is used to detect the output mass of polyglycerol in each reaction. The second material tank is equipped with a second metering device at its output end, which is used to detect the output mass of fatty acids in each reaction.

[0033] The controller controls the rotational speed of the stirring shaft 14 based on the total input mass within the stirring vessel 1 per unit time; the controller also controls the amount of space connecting the connecting hole and the corresponding filter hole based on the total input mass within the stirring vessel 1 per unit time.

[0034] The present invention also provides a method for controlling the distillation of polyglycerol esters, comprising the following steps: S1. Polyglycerol and fatty acids are input into the mixing vessel according to the set ratio. The controller controls the rotation speed of the stirring shaft according to the total input mass of the mixing vessel. At this time, the connecting hole and the corresponding filter hole are completely disconnected.

[0035] The controller controls the rotational speed of the stirring shaft based on the total input mass within the stirred tank per unit time. The specific method is as follows: The total input mass per unit time in the stirred tank is denoted as M, which is calculated by summing the output mass of polyglycerol and fatty acids. A first, second, and third mass threshold are set, where the first mass threshold is less than the second mass threshold, and the second mass threshold is less than the third mass threshold, respectively expressed as follows: , , Specific adjustments will be made based on the specific circumstances: (1) When At that time, the controller controls the speed of the second motor to be... ; (2) When At that time, the controller controls the speed of the second motor to be... ; (3) When At that time, the controller controls the speed of the second motor to be... .

[0036] In the above formula, Indicates the rotational speed of the first stirring shaft. This is expressed as the rotational speed of the second stirring shaft. This indicates the rotational speed of the third stirring shaft.

[0037] An angle sensor is embedded in the outer wall of each stirring blade. The rotational speed corresponds to a minimum tilt angle of 30° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 60° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 90° for all stirring blades. The tilt angle of the stirring blades mentioned above is the tilt angle in a coordinate system with the hinge point between each stirring blade and the stirring shaft as the origin, the horizontal direction as the X-coordinate, and the vertical direction as the Y-coordinate. The specific method for determining whether this is achieved... , , The method for determining the rotation speed is as follows: after adding raw materials into the mixing vessel, gradually increase the rotation speed of the mixing shaft. The controller receives the values ​​detected by the angle sensor in real time, and then determines whether the corresponding rotation speed has been reached based on the tilt angle of all the mixing blades.

[0038] The stirred tank used in this invention is suitable for enzymatic catalytic esterification reaction systems. Due to the sensitivity of the enzymatic catalysis process to shear force, the need for carrier gas protection (such as nitrogen gas for dehydration and protection), and the extremely high requirements for the uniformity of enzyme particle suspension, the reaction efficiency is significantly improved through specific stirring structure optimization.

[0039] The methods for setting the first, second, and third quality thresholds are as follows: Figure 2 The stirring blades shown are divided into three groups, which are distributed circumferentially along the stirring shaft. From bottom to top, they are divided into the first group, the second group, and the third group. The middle horizontal position of the first group of stirring blades is the first dividing line, the middle horizontal position of the second group of stirring blades is the second dividing line, and the middle horizontal position of the third group of stirring blades is the third dividing line. The space from the first dividing line to the bottom of the reactor is the first capacity, the space from the second dividing line to the bottom of the reactor is the second capacity, and the space from the third dividing line to the bottom of the reactor is the third capacity. The total mass corresponding to half of the first capacity containing polyglycerol and the other half containing fatty acids is the first mass threshold. The total mass corresponding to half of the second capacity containing polyglycerol and the other half containing fatty acids is the second mass threshold. The total mass corresponding to half of the third capacity containing polyglycerol and the other half containing fatty acids is the third mass threshold.

[0040] S2. After the reaction time in the stirred tank is reached, the state of the connecting hole and the corresponding filter hole is adjusted to be connected. The controller controls the amount of space connected between the connecting hole and the corresponding filter hole according to the total input mass in the stirred tank.

[0041] The controller controls the space P connecting the connecting holes and the corresponding filter holes based on the total input mass in the mixing vessel. The specific method is as follows: (1) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: .

[0042] (2) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: .

[0043] (3) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: .

[0044] S3. The reactants from the stirred tank are sequentially fed into the primary, secondary, and tertiary distillers. The primary, secondary, and tertiary Roots vacuum pumps are started to perform vacuuming operations. The pressure values ​​of the primary, secondary, and tertiary distillers are monitored in real time, and the speeds of the primary, secondary, and tertiary Roots vacuum pumps are dynamically adjusted. At the same time, the temperature is controlled through the cooling oil unit and the heat transfer oil unit.

[0045] The pressure values ​​of the first-stage, second-stage, and third-stage distillers are monitored in real time, and the speeds of the first-stage, second-stage, and third-stage Roots vacuum pumps are dynamically adjusted. The specific method is as follows: Set the pressure detected by the first-stage still as the first pressure value, the pressure detected by the second-stage still as the second pressure value, and the pressure detected by the third-stage still as the third pressure value. Set the set vacuum level, and the set vacuum level plus the local atmospheric pressure is the set pressure value. Set the first pressure value to The second pressure value The third pressure value The analysis will be divided into the following categories: (1) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage and third-stage Roots vacuum pumps until... .

[0046] (2) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and .

[0047] (3) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and .

[0048] (4) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... .

[0049] (5) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... .

[0050] (6) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ,and .

[0051] (7) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... , , All greater than .

[0052] The speed of the variable frequency motor connected to the first-stage Roots vacuum pump, the second-stage Roots vacuum pump, and the third-stage Roots vacuum pump, as described in (3) and (7) above, is gradually increased. The amount of speed increase is different for each time. The amount of speed increase in (7) is greater than that in (3), preferably twice the amount of speed increase. The amount of speed increase in (1), (2), (4), (5), and (6) is the same as that in (3).

[0053] This invention uses a stirred tank to stir the raw materials for reaction, and then inputs the material generated in the stirred tank into a multi-stage still for distillation. During the distillation operation, a multi-stage vacuum pump assembly is used to evacuate the multi-stage still, and the pressure value of the multi-stage still is collected in real time. Based on the real-time pressure value, the speed of the multi-stage vacuum pump is dynamically adjusted according to different situations, which improves the degree of automation of polyglycerol ester production and also improves production efficiency.

[0054] In this invention, the stirring reaction in the stirred tank is dynamically adjusted according to the total input mass entering the stirred tank, and the amount of space between the connecting holes and the corresponding filter holes is adjusted accordingly. This can further improve the automation level of polyglycerol ester production and increase production efficiency.

[0055] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A polyglycerol ester distillation production system, characterized in that, The device includes a stirred tank, a multi-stage vacuum pump assembly, a multi-stage distillation apparatus, a temperature control assembly, and a controller. The stirred tank reacts with polyglycerol esters, and the resulting substance enters the multi-stage distillation apparatus for distillation. The multi-stage vacuum pump assembly evacuates the multi-stage distillation apparatus, and the temperature control assembly regulates the temperature of the multi-stage distillation apparatus. The controller is electrically connected to the stirred tank, the multi-stage vacuum pump assembly, and the multi-stage distillation apparatus. The multi-stage still includes a primary still, a secondary still, and a tertiary still connected in sequence. The multi-stage vacuum pump assembly includes a primary Roots vacuum pump, a secondary Roots vacuum pump, and a tertiary Roots vacuum pump connected in sequence. The tertiary Roots vacuum pump is connected to the primary, secondary, and tertiary vacuum devices, respectively. The primary, secondary, and tertiary vacuum devices are connected to the primary, secondary, and tertiary stills, respectively. Each primary, secondary, and tertiary still is equipped with a pressure sensor to detect a first pressure value, a second pressure value, and a third pressure value in real time. The controller adjusts the rotational speed of the variable frequency motors connected to the primary, secondary, and tertiary Roots vacuum pumps based on the first, second, and third pressure values.

2. The polyglycerol ester distillation production system according to claim 1, characterized in that, The temperature control component includes an air-cooled radiator, a cooling oil unit, and a heat transfer oil unit. The heat transfer oil unit is circulatedly connected to the first-stage still, the second-stage still, and the third-stage still, respectively. The cooling oil unit is connected to the air-cooled radiator and is circulatedly connected to the first-stage still, the second-stage still, and the third-stage still, respectively.

3. The polyglycerol ester distillation production system according to claim 2, characterized in that, The stirring vessel includes a vessel body, with a stirring shaft passing through the upper end of the vessel body. A second motor is fixedly connected to the upper end of the stirring shaft, and the lower end of the stirring shaft is rotatably connected to the interior of the vessel body. Multiple sets of stirring blades are hinged on the stirring shaft, and the multiple sets of stirring blades are spaced apart along the axial direction of the stirring shaft.

4. The polyglycerol ester distillation production system according to claim 3, characterized in that, The stirred tank is equipped with a filter plate, which is fixedly connected to the inner side wall of the tank. The lower end of the stirring shaft is rotatably connected to the upper part of the filter plate. The filter plate has multiple filter holes. A baffle is rotatably connected inside the filter plate. The baffle has multiple connecting holes. A first motor is fixedly connected to the outer wall of the tank. A gear is fixedly connected to the output end of the first motor. A rack is provided on the outer periphery of the baffle. The rack meshes with the gear. When the first motor rotates, the amount of space connecting the corresponding connecting holes and filter holes can be adjusted.

5. The polyglycerol ester distillation production system according to claim 3, characterized in that, Heating pipes and cooling pipes are wound around the inner side wall of the vessel body. The heating pipes are connected to the heat transfer oil unit, and the cooling pipes are connected to the cooling oil unit.

6. A control method for a polyglycerol ester distillation production system according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Polyglycerol and fatty acids are input into the mixing vessel according to the set ratio. The controller controls the rotation speed of the stirring shaft according to the total input mass of the mixing vessel. At this time, the connecting hole and the corresponding filter hole are completely disconnected. S2. After the reaction in the stirred tank reaches the end of the reaction time, the state of the connecting hole and the corresponding filter hole is adjusted to be connected. The controller controls the amount of space connected between the connecting hole and the corresponding filter hole according to the total input mass in the stirred tank. S3. The reactants from the stirred tank are sequentially fed into the primary, secondary, and tertiary distillers. The primary, secondary, and tertiary Roots vacuum pumps are started to perform vacuuming operations. The pressure values ​​of the primary, secondary, and tertiary distillers are monitored in real time, and the speeds of the primary, secondary, and tertiary Roots vacuum pumps are dynamically adjusted. At the same time, the temperature is controlled through the cooling oil unit and the heat transfer oil unit.

7. The control method for a polyglycerol ester distillation production system according to claim 6, characterized in that, In step S1, the controller controls the rotational speed of the stirring shaft based on the total input mass of the stirred tank. The specific method is as follows: The total input mass per unit time in the stirred tank is denoted as M, which is calculated by summing the output mass of polyglycerol and fatty acids. A first, second, and third mass threshold are set, where the first mass threshold is less than the second mass threshold, and the second mass threshold is less than the third mass threshold, respectively expressed as follows: , , Specific adjustments will be made based on the specific circumstances: (1) When At that time, the controller controls the speed of the second motor to be... ; (2) When At that time, the controller controls the speed of the second motor to be... ; (3) When At that time, the controller controls the speed of the second motor to be... ; In the above formula, Indicates the rotational speed of the first stirring shaft. This is expressed as the rotational speed of the second stirring shaft. This indicates the rotational speed of the third stirring shaft.

8. The control method for a polyglycerol ester distillation production system according to claim 7, characterized in that, An angle sensor is embedded in the outer wall of each stirring blade. The rotational speed corresponds to a minimum tilt angle of 30° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 60° for all the stirring blades. The rotational speed corresponds to a minimum tilt angle of 90° for all stirring blades; The tilt angle of the stirring blade mentioned above is the tilt angle in a coordinate system with the hinge point between each stirring blade and the stirring shaft as the origin, the horizontal direction as the X coordinate, and the vertical direction as the Y coordinate. Determine whether it has been achieved , , The specific method for determining the rotation speed is as follows: after adding raw materials into the mixing vessel, gradually increase the rotation speed of the mixing shaft. The controller receives the value detected by the angle sensor in real time, and then determines whether the corresponding rotation speed has been reached based on the tilt angle of all the mixing blades.

9. The control method for a polyglycerol ester distillation production system according to claim 7, characterized in that, In step S2, the controller controls the space P connecting the connecting hole and the corresponding filter hole based on the total input mass in the mixing vessel. The specific method is as follows: (1) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: ; (2) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: ; (3) When At that time, the range of space between the controller-controlled connecting hole and the corresponding filter hole is: .

10. The control method for a polyglycerol ester distillation production system according to claim 6, characterized in that, In step S3, the pressure values ​​of the first-stage, second-stage, and third-stage distillers are monitored in real time, and the rotation speeds of the first-stage, second-stage, and third-stage Roots vacuum pumps are dynamically adjusted. The specific method is as follows: Set the pressure value detected by the first-stage distillation unit to the first pressure value. The pressure value detected by the secondary distiller is the second pressure value. The pressure value detected by the three-stage distillation unit is the third pressure value. Set the vacuum level, and add the local atmospheric pressure to the set pressure value. The analysis will be divided into the following categories: (1) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage and third-stage Roots vacuum pumps until... ; (2) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and ; (3) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... ,and ; (4) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ; (5) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ; (6) When ,and ,and At that time, gradually increase the speed of the variable frequency motor connected to the first-stage Roots vacuum pump until... ,and ; (7) When ,and ,and Gradually increase the speed of the variable frequency motors connected to the first-stage, second-stage, and third-stage Roots vacuum pumps until... , , All greater than ; The increase in rotational speed in (7) is twice that in (3), and the increase in rotational speed in (1), (2), (4), (5), and (6) is the same as that in (3).

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