A method and apparatus for solid phase polycondensation of bottle-grade polyester chips

Abstract

The present invention belongs to the technical field of chemical equipment, and specifically relates to a method and equipment for solid phase polycondensation of bottle-grade polyester chips, the equipment comprising a main reactor, an inner annular cylinder and an outer annular cylinder are arranged in the main reactor, a plurality of air supply holes I are opened on the peripheral wall of the inner annular cylinder, a plurality of air supply holes II are opened on the peripheral wall of the outer annular cylinder, and the air supply holes I and II are arranged horizontally; a transverse blowing nitrogen gas flow from inside to outside is formed in the radial direction of the main reactor through the air supply holes I, and a transverse blowing nitrogen gas flow from outside to inside is formed in the radial direction of the main reactor through the air supply holes II. The method of the present invention adopts double-sided transverse blowing nitrogen technology, and the transverse blowing nitrogen gas flow from inside to outside and the transverse blowing nitrogen gas flow from outside to inside act on the polyester chips, avoiding the formation of vortexes by nitrogen, and can effectively reduce the suspension of the polyester chips, avoid long-term reaction, thereby avoiding the yellowing of the polyester chips and the deterioration of the color value, thereby obtaining polyester chips with stable quality.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment, and in particular relates to a method and equipment for solid phase polycondensation of bottle-grade polyester chips. Background Art

[0002] Solid state polycondensation (SSP) refers to the polycondensation reaction of monomers or prepolymers under solid conditions. It is a process of heating monomers or prepolymers with low molecular weight to above the glass transition temperature and below the melting point for condensation reaction. Through solid state polycondensation, the molecular weight is increased, residues are removed, the molecular weight distribution is optimized, and the mechanical properties are improved. At present, solid state polycondensation has been applied in the production of high-quality polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.

[0003] The solid phase polycondensation reaction is mainly carried out in the main reactor. The preheated PET slices enter the main reactor for polycondensation reaction. The byproducts such as acetaldehyde and water produced in the process are taken out by nitrogen. Among them, the nitrogen enters the bottom of the main reactor through the annular nitrogen distributor. In actual use, it is found that the product discharged from the bottom of the main reactor is partially yellow and the color stability is poor. Summary of the invention

[0004] The present invention aims to provide a method and equipment for solid phase polycondensation of bottle-grade polyester chips to solve the problem of poor color stability of products.

[0005] In order to achieve the above-mentioned purpose, the scheme of the present invention is: a method for solid phase polycondensation of bottle-grade polyester chips, the main reactor used in the method includes, from top to bottom, a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone, a seventh zone, an eighth zone, a ninth zone and a tenth zone, the first zone to the ninth zone are cylindrical, and the tenth zone is conical; when the polyester chip raw material falls from the first zone to the tenth zone and passes through the junction of the ninth zone and the tenth zone, the polyester chip is subjected to a transverse nitrogen gas flow from inside to outside and from outside to inside in the radial direction of the main reactor.

[0006] The present invention also provides a device for solid phase polycondensation of bottle-grade polyester chips, comprising a main reactor, wherein the main reactor comprises, from top to bottom, a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone, a seventh zone, an eighth zone, a ninth zone and a tenth zone, wherein the first zone to the ninth zone are cylindrical, and the tenth zone is conical; the ninth zone and the tenth zone are provided with a cone, a composite cone, an annular ear plate and a plurality of diverter plates I, wherein the plurality of diverter plates I are fixedly connected to the outer wall of the cone along the circumference of the cone, a cavity I is provided inside the cone, a cavity II is provided inside the diverter plate I, and the cavity II is connected with the cavity I, a transverse sealing plate is provided inside the cavity I, a plurality of air holes are provided on the transverse sealing plate, and an inner annular cylinder is provided on the bottom surface of the transverse sealing plate , a plurality of air supply holes Ⅰ are provided on the peripheral wall of the inner annular cylinder; a support sheet is provided at the bottom end of the composite cone, and an end of the support sheet away from the composite cone is fixedly connected to the inner peripheral wall of the tenth zone, the top of the composite cone passes through the inner annular cylinder and probes into the cavity Ⅰ, and an air chamber Ⅰ is formed between the inner peripheral wall of the inner annular cylinder, the bottom surface of the transverse sealing plate and the outer peripheral wall of the composite cone, an outer annular cylinder is provided on the outer periphery of the composite cone, and a plurality of air supply holes Ⅱ are provided on the peripheral wall of the outer annular cylinder, and the air supply holes Ⅰ and Ⅱ are both horizontally arranged, and an air chamber Ⅱ is formed between the outer peripheral wall of the outer annular cylinder, the bottom surface of the annular ear plate and the inner peripheral wall of the main reactor, and a cavity Ⅲ is provided inside the annular ear plate, and the cavity Ⅲ is connected with the air chamber Ⅱ, and the cavity Ⅲ and the cavity Ⅱ are both connected with a nitrogen delivery pipe.

[0007] The working principle and beneficial effect of this scheme are as follows: In this scheme, nitrogen is divided into two streams and enters the main reactor. One stream of nitrogen enters cavity I through cavity II, then enters air chamber I through the air hole, and flows out through air supply hole I, forming a horizontal nitrogen flow blowing from inside to outside in the radial direction of the main reactor; the other stream of nitrogen enters air chamber II through cavity III, then flows out through air supply hole II, forming a horizontal nitrogen flow blowing from outside to inside in the radial direction of the main reactor. In this way, two groups of horizontal nitrogen flows act on the polyester chips to cool the polyester chips and take away by-products such as acetaldehyde and water.

[0008] More importantly, in the conventional main reactor, nitrogen is only input into the main reactor through an annular nitrogen distributor (specifically, the nitrogen flow in the conventional main reactor is initially blown downward), and the temperature of the nitrogen flow increases during the downward transportation process, and after encountering the conical surface in the main reactor, an oblique upward flow is formed. In this process, eddies are easily formed in some areas, which causes some polyester chips to suspend for a long time, prolongs the reaction time, and makes the product color value worse and yellow. In this scheme, the nitrogen flow from the inside to the outside and the nitrogen flow from the outside to the inside are blown out horizontally to form a horizontal nitrogen flow, which changes the transportation direction of the nitrogen flow and avoids the formation of eddies. The polyester chips can fall smoothly under the action of gravity, effectively reducing the suspension of the polyester chips at the junction of the ninth zone and the tenth zone, avoiding long-term reaction, thereby obtaining polyester chips with stable quality and improving the stability of product quality.

[0009] Optionally, a baffle is fixedly connected to one end of the annular ear plate away from the inner circumferential wall of the main reactor.

[0010] In this solution, the baffle can prevent the polyester chips from entering the air chamber II through the air supply hole II.

[0011] Optionally, the height of the baffle is less than or equal to half the height of the air supply hole II.

[0012] In this solution, the height of the baffle is limited to prevent the baffle from having a significant impact on the direction of the nitrogen gas flow blown out through the air supply hole II, thereby ensuring that the nitrogen gas flow blown out through the air supply hole II remains horizontal.

[0013] Optionally, the first to eighth zones are each provided with a diverter component, the diverter component comprising a cylinder and a plurality of diverter sheets II, the plurality of diverter sheets II are distributed along the circumference of the cylinder, and the diverter sheets II in two adjacent diverter components are staggered in the vertical direction.

[0014] In this solution, the diversion component is used to disperse the polyester chips fed from the top of the main reactor, so that the polyester chips have good dispersibility and uniform fluidity.

[0015] Optionally, the top of the main reactor is connected to a negative pressure suction pipe, and one end of the negative pressure suction pipe away from the main reactor is connected to a nitrogen purification device.

[0016] In this scheme, a negative pressure suction pipe and a nitrogen purification device are used to suck out the nitrogen in the main reactor, and take away by-products such as acetaldehyde and water, thereby promoting the solid phase polycondensation reaction to proceed in the forward direction, achieving active exhaust, and realizing nitrogen recovery.

[0017] Optionally, a gas flow meter and a thermometer are installed on the nitrogen delivery pipe.

[0018] In this solution, the gas flow meter on the nitrogen delivery pipe is used to display the nitrogen flow rate, and the thermometer is used to display the nitrogen temperature, providing data support for the staff to adjust the nitrogen flow rate and nitrogen temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a device for solid phase polycondensation of bottle-grade polyester chips in Example 1 of the present invention;

[0020] Figure 2 It is a partial longitudinal cross-sectional view of the main reactor in Example 1 of the present invention;

[0021] Figure 3 for Figure 2 A is an enlarged schematic diagram;

[0022] Figure 4Schematic diagram of the distribution of two adjacent flow diversion components in the first embodiment of the present invention;

[0023] Figure 5 The present invention is a schematic diagram of the structure of a device for solid phase polycondensation of bottle-grade polyester chips in the second embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is further described in detail through specific implementation methods:

[0025] The marks in the drawings of the specification include: main reactor 1, first zone 101, second zone 102, third zone 103, fourth zone 104, fifth zone 105, sixth zone 106, seventh zone 107, eighth zone 108, ninth zone 109, tenth zone 110, cone 2, cavity I 201, composite cone 3, annular ear plate 4, cavity III 401, baffle 410, diverter plate I 5, cavity II 501, transverse sealing plate 6, air hole 601, inner annular cylinder 7, air supply hole I 701, air chamber I 8, support plate 9, outer annular cylinder 10, air supply hole II 1001, air chamber II 11, nitrogen delivery pipe 12, diverter component 13, cylinder 1301, diverter plate II 1302, negative pressure suction pipe 14, nitrogen purification device 15, discharge valve 16, gas flow meter 17, thermometer 18.

[0026] Embodiment 1

[0027] This embodiment provides a method for solid phase polycondensation of bottle-grade polyester chips, such as Figure 1 As shown, the main reactor 1 used in the method includes, from top to bottom, a first zone 101, a second zone 102, a third zone 103, a fourth zone 104, a fifth zone 105, a sixth zone 106, a seventh zone 107, an eighth zone 108, a ninth zone 109 and a tenth zone 110, the first zone 101 to the ninth zone 109 are cylindrical, and the tenth zone 110 is conical; the polyester chip raw material falls from the first zone 101 to the tenth zone 110, and when passing through the connection between the ninth zone 109 and the tenth zone 110, the polyester chip is subjected to a transverse nitrogen flow from inside to outside and from outside to inside in the radial direction of the main reactor 1. In this way, when the polyester chips fall to the junction of the ninth zone 109 and the tenth zone 110, two sets of relative horizontal blowing nitrogen gas flows act on the polyester chips. Compared with the traditional method of blowing nitrogen downward, the double-sided horizontal blowing of nitrogen in this embodiment can avoid the formation of vortexes of nitrogen, thereby effectively reducing the suspension of the polyester chips at the junction of the ninth zone 109 and the tenth zone 110, avoiding long-term reaction, thereby avoiding yellowing of the polyester chips and deterioration of color value, thereby obtaining polyester chips with stable quality.

[0028] This embodiment also provides a device for solid phase polycondensation of bottle-grade polyester chips, through which the above method is implemented. Figure 1As shown: it includes a main reactor 1, which includes a first zone 101, a second zone 102, a third zone 103, a fourth zone 104, a fifth zone 105, a sixth zone 106, a seventh zone 107, an eighth zone 108, a ninth zone 109 and a tenth zone 110 from top to bottom. The first zone 101 to the ninth zone 109 are cylindrical, and the tenth zone 110 is conical.

[0029] Combination Figure 2 As shown, the ninth zone 109 and the tenth zone 110 are provided with a cone 2, a composite cone 3, an annular ear plate 4 and a plurality of diverter sheets Ⅰ5, and the plurality of diverter sheets Ⅰ5 ​​are welded to the outer wall of the cone 2 along the circumference of the cone 2, and the outer ends of the diverter sheets Ⅰ5 ​​are welded to the inner circumferential wall of the ninth zone 109. In this embodiment, the number of diverter sheets Ⅰ5 ​​is six. The cone 2 is provided with a cavity Ⅰ201, and the diverter sheets Ⅰ5 ​​are provided with a cavity Ⅱ501, and the cavity Ⅱ501 is connected to the cavity Ⅰ201; a transverse sealing plate 6 is welded in the cavity Ⅰ201, and the cavity Ⅱ501 is connected to the cavity Ⅰ201. Figure 3 As shown, a plurality of air holes 601 are provided on the transverse sealing plate 6, an inner annular cylinder 7 is welded to the bottom surface of the transverse sealing plate 6, a plurality of air supply holes I 701 are provided on the peripheral wall of the inner annular cylinder 7, and the plurality of air supply holes I 701 are arranged along the circumference of the inner annular cylinder 7. In addition, the plurality of air holes 601 on the transverse sealing plate 6 all fall within the range of the inner annular cylinder 7.

[0030] The composite cone 3 has an appearance of two cones spliced ​​together, specifically, the circular surfaces of the two cones are connected. Six support sheets 9 are welded to the bottom end of the composite cone 3, and the six support sheets 9 are evenly distributed along the circumference of the composite cone 3. The end of the support sheet 9 away from the composite cone 3 is welded to the inner circumferential wall of the main reactor 1. The top of the composite cone 3 passes through the inner annular tube 7 and probes into the cavity Ⅰ201. An air chamber Ⅰ8 is formed between the inner circumferential wall of the inner annular tube 7, the bottom surface of the transverse sealing plate 6 and the outer circumferential wall of the composite cone 3. The bottom end of the air chamber Ⅰ8 has a gap to prevent the accumulation of polyester slices in the air chamber Ⅰ8; an outer annular tube 10 is provided on the outer periphery of the composite cone 3. A plurality of air supply holes Ⅱ1001 are opened on the circumferential wall of the outer annular tube 10. The plurality of air supply holes Ⅱ1001 are arranged along the circumference of the outer annular tube 10, and the air supply holes Ⅰ701 and the air supply holes Ⅱ1001 are both arranged horizontally; an air chamber Ⅱ11 is formed between the outer circumferential wall of the outer annular tube 10, the bottom surface of the annular ear plate 4 and the inner circumferential wall of the main reactor 1. The bottom end of the air chamber Ⅱ11 has a gap to prevent the accumulation of polyester slices in the air chamber Ⅱ11. The annular ear plate 4 is provided with a cavity III 401 inside, and the cavity III 401 is connected to the air chamber II 11, and the cavity III 401 and the cavity II 501 are both connected to the nitrogen delivery pipe 12. The inner end of the annular ear plate 4 (i.e., the end of the annular ear plate 4 away from the inner peripheral wall of the main reactor 1) is welded with a baffle 410, and the height of the baffle 410 is less than or equal to half the height of the air supply hole II 1001; in this embodiment, the height of the baffle 410 is half the height of the air supply hole II 1001, thereby preventing the polyester chips from entering the air chamber II 11 through the air supply hole II 1001, and ensuring that the baffle 410 will not have a significant impact on the direction of the nitrogen gas flow blown out through the air supply hole II 1001, ensuring that the nitrogen gas flow blown out through the air supply hole II 1001 remains horizontal. In addition, the bottom edge of the cone 2 only blocks the upper half of the air supply hole Ⅰ701, so that the polyester chips can be prevented from entering the air chamber Ⅰ8 through the air supply hole Ⅰ701, and it can also be ensured that the bottom edge of the cone 2 will not have a significant impact on the direction of the nitrogen flow blown out through the air supply hole Ⅰ701, ensuring that the nitrogen flow blown out through the air supply hole Ⅰ701 remains horizontal.

[0031] Combination Figure 4 As shown, the first zone 101 to the eighth zone 108 are each provided with a flow dividing member 13, the flow dividing member 13 comprises a cylinder 1301 and a plurality of flow dividing sheets II 1302, the plurality of flow dividing sheets II 1302 are distributed along the circumference of the cylinder 1301, and the flow dividing sheets II 1302 in two adjacent flow dividing members 13 are staggered in the vertical direction. In this embodiment, there are eight flow dividing sheets II 1302 in each flow dividing member 13, and the outer ends of the flow dividing sheets II 1302 are welded to the inner peripheral wall of the main reactor 1.

[0032] The top of the main reactor 1 is connected to a negative pressure suction pipe 14, and the end of the negative pressure suction pipe 14 away from the main reactor 1 is connected to a nitrogen purification device 15. In this embodiment, the nitrogen purification device 15 is a bag back-blowing filter. A discharge valve 16 is installed at the bottom of the main reactor 1, and the discharge valve 16 has an air lock device.

[0033] The process of using the equipment in this embodiment to carry out solid phase polycondensation of bottle-grade polyester chips is as follows: the raw polyester chips enter the main reactor 1 through the top of the main reactor 1, and fall in the main reactor 1 under the action of gravity. During the falling process, they are dispersed by the diverter component 13, so that the raw polyester chips have good dispersibility and uniform fluidity. The raw polyester chips fall in the main reactor 1 while undergoing solid phase polycondensation reaction at 190-210°C. During the reaction, nitrogen is input into the main reactor 1 through the nitrogen delivery pipe 12 (the nitrogen flow rate in the nitrogen delivery pipe 12 is 4000-6500Nm 3 / h, nitrogen temperature is 140-155°C), specifically, nitrogen is divided into two streams and enters the main reactor 1: one stream of nitrogen first enters cavity II 501, then enters cavity I 201, then enters air chamber I 8 through air hole 601, and flows out through air supply hole I 701, forming a transverse nitrogen flow blowing from inside to outside in the radial direction of the main reactor 1; the other stream of nitrogen enters air chamber II 11 through cavity III 401, then flows out through air supply hole II 1001, forming a transverse nitrogen flow blowing from outside to inside in the radial direction of the main reactor 1. In this way, the transverse blowing nitrogen gas flow from the inside to the outside and the transverse blowing nitrogen gas flow from the outside to the inside act on the polyester chips, achieving the contact between the nitrogen and the polyester chips, thereby achieving the cooling of the polyester chips, and sucking the gas in the main reactor 1 through the negative pressure suction pipe 14 and the nitrogen purification device 15, thereby taking away by-products such as acetaldehyde and water and the heated nitrogen, and filtering the dust in the gas, thereby promoting the reaction in the main reactor 1 to proceed in the forward direction and achieving the recovery of nitrogen.

[0034] In addition, the inventors found that in the conventional main reactor, nitrogen is input into the main reactor only through the annular nitrogen distributor (specifically, compared with the main reactor 1 in the present embodiment, the conventional main reactor lacks the inner annular tube 7 and the outer annular tube 10), and the nitrogen flows out through the air hole 601 and the air channel at the bottom of the annular ear plate 4 in the conventional main reactor (the air channel refers to the channel connecting the cavity III 401 and the air chamber II 11), forming a downward nitrogen flow in the conventional main reactor. The temperature of the nitrogen flow increases during the downward transportation process, and after encountering the conical surface in the main reactor 1, an oblique upward airflow is formed. In this process, vortices are easily formed in some areas, which causes some polyester chips to be suspended for a long time and the reaction time to be prolonged, causing the product color value to deteriorate and turn yellow, thereby affecting the quality of the polyester chips and causing unstable product quality. In the present embodiment, a lateral nitrogen gas flow from inside to outside and a lateral nitrogen gas flow from outside to inside are formed in the main reactor 1, which changes the conveying direction of the nitrogen gas flow, thereby avoiding the nitrogen gas flow from colliding with the conical surface of the composite cone 3 or the inner wall of the tenth zone 110 to form an oblique upward gas flow, thereby avoiding the formation of nitrogen vortexes, reducing the upward nitrogen gas flow force on the polyester chips, allowing the polyester chips to fall smoothly under the action of gravity, effectively reducing the suspension of the polyester chips at the junction of the ninth zone 109 and the tenth zone 110, avoiding the polyester chips from reacting for a long time, thereby obtaining polyester chips with stable quality and improving the stability of product quality.

[0035] Moreover, in the present embodiment, air supply hole I 701 and air supply hole II 1001 are staggered in the vertical direction, so that the transverse nitrogen flow from the inside to the outside and the transverse nitrogen flow from the outside to the inside are staggered in the vertical direction. Therefore, the polyester chips are vertically displaced and acted upon by transverse nitrogen flow in two directions. The polyester chips are first acted upon by the radial outward force of the main reactor 1, and then by the radial inward force of the main reactor 1, thereby making the polyester chips unbalanced and making it easier for the polyester chips to fall, thereby further reducing the probability of the polyester chips being suspended.

[0036] The polyester chips after solid phase polycondensation are discharged through the bottom of the main reactor 1 to obtain polyester chips with good color value and stable quality. During the discharge process, the nitrogen gas connected externally will seal the discharge valve 16 through the air lock device to prevent air from entering the bottom of the main reactor 1.

[0037] Embodiment 2

[0038] The difference between this embodiment and the first embodiment is that: Figure 5 As shown, in this embodiment, a gas flow meter 17 and a thermometer 18 are installed on the nitrogen delivery pipe 12. The gas flow meter 17 displays the nitrogen flow in the nitrogen delivery pipe 12, and the thermometer 18 displays the nitrogen temperature in the nitrogen delivery pipe 12, thereby providing data support for the staff to adjust the nitrogen flow and nitrogen temperature.

[0039] The above are only embodiments of the present invention. The invention is not limited to the fields involved in this implementation case. The common sense such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the present invention. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A method for solid phase polycondensation of bottle-grade polyester chips, characterized in that: The main reactor used in the method comprises, from top to bottom, a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone, a seventh zone, an eighth zone, a ninth zone and a tenth zone, wherein the first zone to the ninth zone are cylindrical, and the tenth zone is conical; when the polyester chip raw material falls from the first zone to the tenth zone and passes through the connection between the ninth zone and the tenth zone, the polyester chip is subjected to a transverse nitrogen gas flow from inside to outside and from outside to inside in the radial direction of the main reactor.

2. An apparatus for solid phase polycondensation of bottle-grade polyester chips, comprising a main reactor, characterized in that: The main reactor comprises, from top to bottom, the first zone, the second zone, the third zone, the fourth zone, the fifth zone, the sixth zone, the seventh zone, the eighth zone, the ninth zone and the tenth zone, wherein the first zone to the ninth zone are cylindrical, and the tenth zone is conical; the ninth zone and the tenth zone are provided with a cone, a composite cone, an annular ear plate and a plurality of diverter plates I, wherein the plurality of diverter plates I are fixedly connected to the outer wall of the cone along the circumference of the cone, a cavity I is provided inside the cone, a cavity II is provided inside the diverter plate I, and the cavity II is connected with the cavity I, a transverse sealing plate is provided inside the cavity I, a plurality of air holes are provided on the transverse sealing plate, an inner annular cylinder is provided on the bottom surface of the transverse sealing plate, and a plurality of delivery holes are provided on the peripheral wall of the inner annular cylinder Air hole Ⅰ; a support plate is provided at the bottom end of the composite cone, and one end of the support plate away from the composite cone is fixedly connected to the inner circumferential wall of the tenth zone, the top of the composite cone passes through the inner annular tube and explores into the cavity Ⅰ, and an air chamber Ⅰ is formed between the inner circumferential wall of the inner annular tube, the bottom surface of the transverse sealing plate and the outer circumferential wall of the composite cone, an outer annular tube is provided at the outer periphery of the composite cone, and a plurality of air supply holes Ⅱ are opened on the circumferential wall of the outer annular tube, and the air supply holes Ⅰ and Ⅱ are both horizontally arranged, and an air chamber Ⅱ is formed between the outer circumferential wall of the outer annular tube, the bottom surface of the annular ear plate and the inner circumferential wall of the main reactor, and a cavity Ⅲ is provided inside the annular ear plate, and the cavity Ⅲ is connected with the air chamber Ⅱ, and the cavity Ⅲ and the cavity Ⅱ are both connected with a nitrogen delivery pipe.

3. The device for solid phase polycondensation of bottle-grade polyester chips according to claim 2, characterized in that: One end of the annular ear plate away from the inner peripheral wall of the main reactor is fixedly connected with a baffle.

4. The device for solid phase polycondensation of bottle-grade polyester chips according to claim 3, characterized in that: The height of the baffle is less than or equal to half the height of the air supply hole II.

5. The device for solid phase polycondensation of bottle-grade polyester chips according to claim 2, characterized in that: The first to eighth zones are each provided with a flow diversion component, which includes a cylinder and a plurality of flow diversion sheets II. The plurality of flow diversion sheets II are distributed along the circumference of the cylinder, and the flow diversion sheets II in two adjacent flow diversion components are staggered in the vertical direction.

6. The equipment for solid phase polycondensation of bottle-grade polyester chips according to claim 2, characterized in that: The top of the main reactor is connected with a negative pressure suction pipe, and one end of the negative pressure suction pipe away from the main reactor is connected with a nitrogen purification device.

7. The equipment for solid phase polycondensation of bottle-grade polyester chips according to claim 2, characterized in that: A gas flow meter and a thermometer are installed on the nitrogen delivery pipe.

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