Production apparatus for cyclic esters

Abstract

A production apparatus for cyclic esters, the production apparatus comprising: a barrel (10), which comprises a material chamber (101), and a feed inlet, a melt outlet (112) and at least one vacuum vent that are in communication with the material chamber (101); a hollow shaft (20) passing through the barrel (10) along a material feeding direction, wherein the hollow shaft (20) is provided with a medium chamber (201) therein; and several hollow disks (30) disposed in the barrel (10) along the feeding direction, wherein the hollow disks (30) are disposed on the outer periphery of the hollow shaft (20); and a medium flow channel (301) in communication with the medium chamber (201) is provided in each hollow disk (30), at least part of the medium flow channel (301) being a spiral from the outside to the inside, and / or the medium flow channel (301) comprising a plurality of parallel medium sub-channels (305). After entering the medium chamber (201), a heat medium flows into the medium flow channels (301) and is uniformly distributed within the hollow disks (30) via the medium flow channels (301). The hollow shaft (20) and the hollow disks (30) cooperate with each other to uniformly heat oligomers in the material chamber (101), thereby avoiding carbonization and coking caused by the non-uniform heating of the oligomers.

Description

Equipment for producing cyclic esters Technical Field

[0001] This invention relates to the field of production equipment, and more specifically to a production equipment for cyclic esters. Background Technology

[0002] Cyclic esters are esters with a cyclic structure. Common cyclic esters include glycolide, lactide, and vinylene carbonate. Taking the production process of glycolide as an example, one of the synthetic routes for glycolide is a "two-step method." Specifically, the first step uses glycolic acid or glycolate esters as raw materials to prepare polyglycolic acid (PGA) oligomers through polycondensation. The second step generates glycolide through the cleavage and cyclization of the PGA oligomers.

[0003] The most common method for pyrolyzing PGA oligomers is melt depolymerization. As the pyrolysis reaction proceeds, the viscosity of the melt increases. If the material is heated unevenly, carbonization and coking can easily occur. Carbonization and coking not only result in low raw material conversion rates and low heat transfer efficiency, but also can lead to localized overheating and further coking. In severe cases, production needs to be interrupted, the reaction equipment cleaned, and the normal operation of the process disrupted. Therefore, it is urgent to improve existing production equipment to address these problems. Summary of the Invention

[0004] The present invention is made to solve the above-mentioned technical problems, and its purpose is to provide a production equipment for cyclic esters, which can solve the problem that the cracking of PGA oligomers easily leads to carbonization and coking in the prior art.

[0005] This application discloses a production apparatus for cyclic esters, comprising: a barrel having a material chamber, and an inlet, a melt outlet, and at least one vacuum vent communicating with the material chamber; a hollow shaft passing through the barrel along the material feeding direction, the hollow shaft having a medium chamber; a plurality of hollow disks arranged in the barrel along the feeding direction, the hollow disks being located on the outer periphery of the hollow shaft, the hollow disks having medium channels communicating with the medium chamber, at least a portion of the medium channels being spiral from the outside to the inside, and / or the medium channels including a plurality of parallel medium sub-channels.

[0006] Optionally, the hollow disk includes a first disk, a second disk, and a groove wall structure, all arranged around a hollow shaft. The area defined between the first disk, the second disk, and the hollow shaft is a receiving cavity. The groove wall structure is located in the receiving cavity, and the opposite sides of the groove wall structure are fixed to the first disk and the second disk, respectively. The first disk, the second disk, and the groove wall structure cooperate to form a medium flow channel.

[0007] Optionally, the hollow shaft has a flow channel inlet and a flow channel outlet, each corresponding to the hollow disk; the medium flow channel includes an inner flow channel, at least one intermediate flow channel, an outer flow channel, and a transition flow channel. The inner flow channel and the outer flow channel are arranged opposite each other in a direction away from the hollow shaft and are connected through the transition flow channel. The intermediate flow channel is located between the inner flow channel and the outer flow channel; the flow channel inlet, inner flow channel, transition flow channel, outer flow channel, intermediate flow channel, and flow channel outlet are connected in sequence.

[0008] Optionally, the tank wall structure includes N first partitions, which extend from the outer periphery of the hollow shaft to the outer periphery of the hollow disk and are connected to the outer periphery of the hollow disk. The N first partitions divide the medium flow channel into N+1 parallel medium sub-flow channels; where N is greater than or equal to 1; the hollow shaft is provided with a flow channel inlet and a flow channel outlet for each medium sub-flow channel.

[0009] Optionally, the hollow disk also includes a pusher structure located at one end of the hollow disk away from the hollow shaft, and multiple pusher structures are arranged in a spiral staggered manner in the feeding direction; the pusher structure has a base part and lateral extension parts located on both sides of the base part, the base part is connected to the outer periphery of the first disk and the second disk respectively, and the lateral extension parts are formed by extending from the base part to the outer side of the first disk and the second disk.

[0010] Optionally, multiple hollow discs are arranged relatively close to each other to form a disc group, and multiple disc groups are arranged along the feed direction of the hollow shaft, with adjacent disc groups spaced apart; along the feed direction, the number of hollow discs in the disc group gradually decreases.

[0011] Optionally, multiple hollow discs in the same disc group are fixedly connected. The first disc of the hollow disc on the first side of the disc group and the second disc of the hollow disc on the second side of the disc group are both welded and fixed to the hollow shaft. They are located at the connection between adjacent hollow discs in the disc group and are in contact with or spaced from the hollow shaft. The first side and the second side of the disc group are two opposite sides of the disc group along the feed direction.

[0012] Optionally, a second partition is provided radially inside the hollow shaft, which divides the medium cavity into a first medium cavity and a second medium cavity arranged sequentially along the feeding direction; the first medium cavity includes a first inlet cavity and a first outlet cavity, which are separated from each other by a conveying pipe or a shelf; the second medium cavity includes a second inlet cavity and a second outlet cavity, which are separated from each other by a conveying pipe or a shelf.

[0013] Optionally, the outer circumferential surface of the barrel is provided with multiple jackets, at least one of the multiple jackets corresponds to the melt outlet in the feeding direction, and / or, at the position corresponding to the melt outlet, the outer circumferential part of the hollow shaft is not provided with a hollow disk or the provided hollow disk is a sector-shaped disk.

[0014] Optionally, the material barrel is provided with at least one liquid level regulating plate; wherein the liquid level regulating plate is movably inserted into the lower bottom of the material barrel and can adjust the radial distance between it and the hollow shaft, and / or, the liquid level regulating plate is provided with a liquid level regulating hole with an adjustable opening size.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention discloses a production apparatus for cyclic esters, comprising: a barrel having a material chamber, and an inlet, a melt outlet, and at least one vacuum vent communicating with the material chamber; a hollow shaft passing through the barrel along the material feeding direction, wherein a medium chamber is disposed in the hollow shaft; a plurality of hollow disks disposed in the barrel along the feeding direction, wherein the hollow disks are disposed on the outer periphery of the hollow shaft, and a medium flow channel communicating with the medium chamber is disposed in the hollow disk, wherein at least a portion of the medium flow channel is spiral from the outside to the inside, and / or the medium flow channel includes a plurality of parallel medium sub-flow channels.

[0017] In this way, after the heat medium enters the medium cavity, it will flow into the medium channel and be distributed relatively evenly in the hollow disk with the help of the medium channel. The hollow disk can also increase shear and flow. The hollow shaft and the hollow disk can cooperate with each other to achieve relatively uniform heating of the oligomers in the material cavity, so as to avoid carbonization and coking caused by uneven heating of the oligomers, thereby reducing the frequency of cleaning the equipment and ensuring the orderly production of cyclic esters. Attached Figure Description

[0018] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0019] Figure 1 is a structural schematic diagram of a production device according to an embodiment of the present invention; Figure 2 is an enlarged view of section I in Figure 1; Figure 3 is a structural schematic diagram of a hollow disc according to an embodiment of the present invention; Figure 4 is an enlarged view of a hollow disc according to an embodiment of the present invention; Figure 5 is an enlarged view of a hollow disc according to another embodiment of the present invention; Figure 6 is a schematic diagram of the medium flow channel of a hollow disc according to an embodiment of the present invention; Figure 7 is a schematic diagram of the medium flow channel of a hollow disc according to another embodiment of the present invention; Figure 8 is a schematic diagram of the medium flow channel of a hollow disc according to yet another embodiment of the present invention; Figure 9 is an enlarged view of a hollow disc according to yet another embodiment of the present invention; Figure 10 is a schematic diagram of the layout of a pusher structure according to an embodiment of the present invention; Figure 11 is a structural schematic diagram of a scraper according to an embodiment of the present invention; Figure 12 is a structural schematic diagram of a scraper according to another embodiment of the present invention; Figure 13 is a structural schematic diagram of a hollow shaft according to an embodiment of the present invention; Figure 14 is a structural schematic diagram of a hollow shaft according to another embodiment of the present invention; Figure 15 is a structural schematic diagram of a liquid level regulating plate according to an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 10-Cylinder, 11-Cylinder wall, 12-Sealing plate, 112-Mel outlet, 101-Material chamber, 102-Vacuum vent, 13-Jacket, 14-Level regulating plate, 15-Baffle plate, 16-Pull rod, 20-Hollow shaft, 201-Medium chamber, 211-Flow channel inlet, 212-Flow channel outlet, 202-First medium chamber, 204-First feed chamber, 205-First discharge chamber, 203-Second medium chamber, 206-Second feed chamber, 207-Second discharge chamber, 221-First inlet, 222-First outlet, 223-Second inlet, 224-Second outlet, 21-Second partition, 22-First layer plate, 23-Second layer plate, 24-Conveying pipe, 30-Hollow disc, 301-Medium flow channel, 3011-Inner flow channel, 3012-Outer flow channel, 3013-Transition flow channel, 3014-Intermediate flow channel, 31-First disc, 32-Second disc, 33-Trench wall structure, 35-First partition, 36-Pushing structure, 361-Base part, 362-Lateral extension part, 302-Receiving cavity, 303-First receiving cavity, 304-Second receiving cavity, 305-Medium sub-flow channel, 3-Disc assembly, 306-Main hollow disc, 307-Auxiliary hollow disc, 308-Circular disc, 309-Fan-shaped disc, 40-Scraper, 50-Weld. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0022] It should be noted that these and other accompanying drawings are merely illustrative and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention. The technical solution of the present invention will now be described in conjunction with Figures 1 to 15.

[0023] As shown in Figures 1 and 2, this invention discloses a production apparatus for cyclic esters, which can be glycolide, lactide, vinylene carbonate, etc. The production apparatus includes a material cylinder 10, a hollow shaft 20, and a hollow disk 30. The material cylinder 10 includes a cylinder wall 11 and a sealing plate 12. The cylinder wall 11 is a cylindrical structure with openings at both ends. The sealing plate 12 is disposed at the opening positions on both sides of the cylinder wall 11. The cylinder wall 11 and the sealing plate 12 form a material cavity 101.

[0024] The barrel 10 is used for the entry of oligomers and the production of cyclic esters. Specifically, the barrel wall 11 of the barrel 10 is provided with an inlet (not shown in the figure), a melt outlet 112, and at least one vacuum vent 102, all of which are connected to the material chamber 101. The inlet and the melt outlet 112 are located on the barrel wall 11 along the material feeding direction X, and the melt outlet 112 is usually located at the bottom of the barrel wall 11, while the vacuum vent 102 is located at the top of the barrel wall 11. The vacuum vent 102 is used to evacuate the material chamber 101 to gradually increase the vacuum degree of the material chamber 101, while allowing the cyclic esters to evaporate. Taking the production process of glycolide as an example, oligomers and other materials enter the barrel 10 through the inlet and are heated in the barrel 10 to undergo a cracking reaction to generate glycolide. Subsequently, glycolide escapes from the vacuum vent 102 in the gas phase, while the residue flows out from the melt outlet 112.

[0025] The sealing plate 12 has through holes. The hollow shaft 20 passes through one of the through holes into the material chamber 101 and exits through the other. A bearing can be installed at the through hole position to accommodate the hollow shaft 20 and ensure its smooth rotation. An organic seal structure (not shown in the figure) is also provided between the hollow shaft 20 and the through hole of the sealing plate 12 to ensure sealing. Please refer to Figure 3. A medium chamber 201 is provided in the hollow shaft 20. The medium chamber 201 is used to introduce a hot medium such as hot oil. The hot medium can transfer heat to the material chamber 101 to heat the oligomers in the material chamber 101, thereby generating glycolide.

[0026] Several hollow discs 30 are arranged in the feed direction X in the material cylinder 10, and the hollow discs 30 are located on the outer periphery of the hollow shaft 20. The thickness of a single hollow disc 30 is between 2mm and 15mm, preferably between 3mm and 8mm, to ensure sufficient strength.

[0027] Referring to Figure 6, a medium flow channel 301 is provided within the hollow disk 30, connecting to the medium cavity 201. At least a portion of the medium flow channel 301 is spiral-shaped from the outside to the inside. Thus, after the hot medium in the medium cavity 201 flows into the medium flow channel 301, it can flow spirally from the outside to the inside of the hollow disk 30 and back to the medium cavity 201, achieving a relatively uniform distribution of the hot medium within the hollow disk 30. Alternatively, as shown in Figure 8, the medium flow channel 301 includes multiple parallel medium sub-flow channels 305. After the hot medium in the medium cavity 201 flows into the hollow disk 30, it flows along the multiple parallel medium sub-flow channels 305 within the hollow disk 30 and back to the medium cavity 201, also achieving a relatively uniform distribution. Alternatively, as shown in Figure 7, the medium flow channel 301 includes multiple parallel medium sub-flow channels 305. Each medium sub-flow channel 305 is at least partially spiral from the outside to the inside. While the hot medium flows along the multiple parallel medium sub-flow channels 305 in the hollow disk 30, it can also flow spirally from the outside of the hollow disk 30 to the inside of the hollow disk 30 in each medium sub-flow channel 305 and flow back to the medium cavity 201.

[0028] It should also be noted that the hollow disc 30 can increase shear and flow. It can be seen that the hollow shaft 20 and the hollow disc 30 can work together to achieve more uniform heating of the oligomers in the material chamber 101, thus avoiding carbonization and coking caused by uneven heating of the oligomers, thereby reducing the frequency of equipment cleaning and ensuring the orderly production of cyclic esters.

[0029] The following is a further introduction to the hollow disk 30:

[0030] As shown in Figures 3 to 6. In this embodiment, the hollow disk 30 includes a first disk 31, a second disk 32, and a groove wall structure 33. The first disk 31, the second disk 32, and the groove wall structure 33 are all arranged around the outer periphery of the hollow shaft 20. The area defined between the first disk 31, the second disk 32, and the hollow shaft 20 is a receiving cavity 302. For example, the first disk 31 and the second disk 32 are both inclined. The hollow shaft 20 is sleeved on the inner periphery of the first disk 31 and the second disk 32. The outer periphery of the first disk 31 and the second disk 32 are inclined to each other and connected, so that the receiving cavity 302 is an annular chamber with a triangular cross-section.

[0031] The groove wall structure 33 is disposed in the receiving cavity 302, and the opposite sides of the groove wall structure 33 are fixed to the first disk 31 and the second disk 32 respectively. The first disk 31, the second disk 32 and the groove wall structure 33 cooperate to form the medium flow channel 301.

[0032] Specifically, the tank wall structure 33 includes a tank sidewall and a chassis. The chassis of the tank wall structure 33 divides the receiving cavity 302 into a first receiving cavity 303 and a second receiving cavity 304. The area defined between the first disc 31, the chassis and the hollow shaft 20 is the first receiving cavity 303, and the area defined between the second disc 32, the chassis and the hollow shaft 20 is the second receiving cavity 304.

[0033] The base of the groove wall structure 33 has a first surface facing the first disk 31 and a second surface facing the second disk 32, with groove sidewalls respectively located on the first and second surfaces of the base. The groove sidewalls located in the first receiving cavity 303 connect the first disk 31 and the base on their opposite sides, forming a medium flow channel 301 between the first disk 31, the groove sidewalls, and the base. Similarly, the groove sidewalls located in the second receiving cavity 304 connect the second disk 32 and the base on their opposite sides, forming a medium flow channel 301 between the second disk 32, the groove sidewalls, and the base. Furthermore, the base can be a solid disk structure, so that the medium flow channels 301 in the first receiving cavity 303 and the second receiving cavity 304 are not interconnected; alternatively, the base can have a hollow structure to reduce weight, thus allowing the medium flow channels 301 in the first receiving cavity 303 and the second receiving cavity 304 to communicate with each other.

[0034] As shown in Figure 6, the hollow shaft 20 is provided with a flow channel inlet 211 and a flow channel outlet 212. Both the flow channel inlet 211 and the flow channel outlet 212 are connected to the medium cavity 201, and both the flow channel inlet 211 and the flow channel outlet 212 are provided corresponding to the hollow disk 30.

[0035] In one embodiment, the medium flow channel 301 includes an inner flow channel 3011, an outer flow channel 3012, at least one intermediate flow channel 3014, and a transition flow channel 3013. The inner flow channel 3011, intermediate flow channel 3014, and outer flow channel 3012 are all flow channels extending along an arcuate path and arranged circumferentially around the hollow axis 20, while the transition flow channel 3013 extends radially along the hollow axis 20. The inner flow channel 3011 and outer flow channel 3012 are arranged opposite each other in a direction away from the hollow axis 20, and are connected by the transition flow channel 3013. The intermediate flow channel 3014 is located between the inner flow channel 3011 and the outer flow channel 3012.

[0036] The inlet 211 extends into the inner channel 3011, and the outlet 212 extends into the intermediate channel 3014 adjacent to the inner channel 3011. Thus, the inlet 211, the inner channel 3011, the transition channel 3013, the outer channel 3012, the intermediate channel 3014, and the outlet 212 are connected in sequence. The hot medium in the medium cavity 201 flows into the hollow disk 30 through the inlet 211, and then flows into the inner channel 3011, the transition channel 3013, the outer channel 3012, and the intermediate channel 3014 in sequence. Finally, it flows back into the medium cavity 201 through the outlet 212, thereby making the hot medium more evenly distributed in the hollow disk 30 and better achieving uniform heating of the oligomer in the material cavity 101.

[0037] Furthermore, rotary joints can be optionally connected to both the flow channel inlet 211 and the flow channel outlet 212 for the entry and exit of the heat medium.

[0038] Furthermore, multiple intermediate flow channels 3014 are arranged in a direction away from the hollow axis 20, and the multiple intermediate flow channels 3014 are connected in sequence, such as three or four intermediate flow channels 3014, to further improve the uniformity of the distribution of the heat medium in the hollow disk 30.

[0039] Furthermore, as shown in Figure 7, the tank wall structure 33 also includes N first partitions 35. The first partitions 35 extend from the hollow shaft 20 along the outer periphery of the hollow disk 30 and connect with the outer periphery of the hollow disk 30, so as to divide the receiving cavity 302 of the hollow disk 30 into N+1 flow channel arrangement areas around the hollow shaft 20, and divide the medium flow channel 301 into N+1 medium sub-flow channels 305; where N is a positive integer greater than or equal to 1. The flow channel arrangement areas are distributed in a fan shape, and the medium sub-flow channels 305 are correspondingly arranged in the flow channel arrangement areas.

[0040] Correspondingly, the hollow shaft 20 is provided with a channel inlet 211 and a channel outlet 212 for each medium sub-channel 305, which enables the medium sub-channels 305 to be parallel, further improving the uniformity of the heat medium in the hollow disk 30.

[0041] Furthermore, as shown in Figures 4 and 7, the first partition 35 in the first receiving cavity 303 is connected to the first disk 31 and the chassis of the groove wall structure 33 on its two opposite sides, so as to divide the medium flow channel 301 in the first receiving cavity 303 into multiple medium sub-flow channels 305; the first partition 35 in the second receiving cavity 304 is connected to the second disk 32 and the chassis on its two opposite sides, so as to divide the medium flow channel 301 in the second receiving cavity 304 into multiple medium sub-flow channels 305, so as to further improve the uniformity of heat medium distribution.

[0042] Figure 8 is a schematic diagram of the medium flow channel of a hollow disk according to another embodiment. Similarly, the groove wall structure 33 in the hollow disk 30 includes a groove sidewall, a base, and N first partitions 35. The specific arrangement of the base and the first partitions 35 is the same as in the above embodiment, and will not be repeated. The difference is that the medium flow channel 301 in this embodiment only includes N+1 parallel medium sub-flow channels 305. The groove sidewall extends from the hollow shaft 20 along the outer periphery of the hollow disk 30 and is at a certain distance from the outer periphery of the hollow disk 30 to form a channel connecting the flow channel inlet 211 and the flow channel outlet 212 in the same medium sub-flow channel 305.

[0043] Optionally, as shown in Figures 1 and 3, multiple hollow disks 30 are arranged along the feed direction X, and these multiple hollow disks 30 are arranged relatively close to each other to form disk groups 3. Multiple disk groups 3 are arranged along the feed direction X of the hollow shaft 20, with adjacent disk groups 3 spaced apart. The inner peripheries of adjacent hollow disks 30 in disk groups 3 are connected to each other. Along the feed direction X, the number of hollow disks 30 in each disk group 3 gradually decreases.

[0044] During the pyrolysis reaction of oligomers, the material viscosity is lower near the feed end in the barrel 10, so the hollow disks 30 can be arranged more densely. For example, the hollow disks 30 in the disk group 3 can be arranged in groups of 3 to 7 to move the oligomers up, making it easier to form a film and accelerate the generation rate of monomers. As the oligomers gradually pyrolyze to form glycolide, the further away from the feed end, the higher the viscosity of the material in the barrel 10. Higher viscosity makes it easier to form a film, so the further away from the feed end, the more sparse the arrangement of the hollow disks 30 can be. For example, the hollow disks 30 in the disk group 3 can be arranged in groups of 1 to 3 to increase the heat transfer efficiency.

[0045] Optionally, the inner periphery of the first disk 31 and the inner periphery of the second disk 32 in the hollow disk 30 can be welded to the hollow disk 30 to form an annular weld 50. However, in order to maintain the flexibility of the disk assembly 3 and reduce the welding difficulty, the embodiment of the present invention adopts the following method:

[0046] As shown in Figure 4, multiple hollow disks 30 in the same disk group 3 are fixedly connected to each other. The first disk 31 of the hollow disk 30 on the first side of the disk group 3 and the second disk 32 of the hollow disk 30 on the second side of the disk group 3 are both welded and fixed to the hollow shaft 20, and a weld 50 is formed at the intersection. The first disk 31 and the second disk 32 are arranged sequentially along the feed direction X. The first side and the second side of the disk group 3 are two opposite sides of the disk group 3 along the feed direction X.

[0047] Located at the connection point of adjacent hollow disks 30 in disk group 3, it is in contact with or spaced from the hollow shaft 20. The connection point of adjacent hollow disks 30 is the connection position between the inner periphery of the first disk 31 of one of the adjacent hollow disks 30 and the inner periphery of the second disk 32 of the other.

[0048] In this way, firstly, only the two opposite sides of the disc assembly 3 intersect with the hollow shaft 20 to form weld seams 50, while other positions are not connected to the hollow shaft 20. This reduces the number of welding points and lowers the welding difficulty while ensuring the sealing between the disc assembly 3 and the hollow shaft 20. Secondly, due to the reduction in the number of connection points with the hollow shaft 20, the multiple hollow discs 30 in the disc assembly 3 have a certain degree of flexibility, thereby reducing the stress generated by the hollow discs 30.

[0049] Optionally, as shown in Figure 4, the outer periphery of the chassis of each groove wall structure 33 in the disk group 3 is connected to the outer periphery of the first disk 31 and the outer periphery of the second disk 32 respectively, and its inner periphery is in contact with or spaced from the hollow shaft 20. That is, only the two opposite sides of the disk group 3 form a weld 50 with the hollow shaft 20, so that the disk group 3 maintains a certain flexibility.

[0050] In some alternative implementations, as shown in Figure 5, the outer periphery of each chassis in the disk assembly 3 is in contact with or spaced from the outer periphery of the first disk 31 and the outer periphery of the second disk 32, respectively, and its inner periphery is welded to the hollow shaft 20. That is, a weld 50 is formed between the two opposite sides of the disk assembly 3 and the hollow shaft 20, and a weld 50 is formed between the chassis and the hollow shaft 20, so that the disk assembly 3 maintains a certain degree of flexibility.

[0051] Of course, the hollow shaft 20 can also be welded to the inner periphery of the chassis, and the outer periphery of the chassis can be connected to the outer periphery of the first disc 31 and the outer periphery of the second disc 32 respectively. This will not be described in detail here.

[0052] The structure of the empty disk 30 in other embodiments of the present invention is described below with reference to Figures 9 and 10. The structure of the empty disk 30 differs from that in Figures 3 to 5 as follows:

[0053] The hollow disk 30 also includes a pusher structure 36 located at the end of the hollow disk 30 away from the hollow shaft 20. The pusher structure 36 can be a solid body or hollow inside. The first disk 31 and the second disk 32 are arranged opposite each other, for example, parallel to each other or forming an angle. The pusher structure 36 is connected to the ends of the first disk 31 and the second disk 32 respectively. The pusher structure 36, the first disk 31, the second disk 32 and the hollow shaft 20 form a receiving cavity 302.

[0054] The pushing structure 36 has a base portion 361 and a lateral extension portion 362. The base portion 361 is connected to the outer periphery of the first disc 31 and the outer periphery of the second disc 32, respectively. The lateral extension portion 362 is formed by extending from the base portion 361 outwards from the first disc 31 and the second disc 32 to offset the area between the ends of the first disc 31 and the second disc 32. The medium flow channel 301 may extend into the pushing structure 36, or it may not extend into the pushing structure 36. By setting the pushing structure 36, the material can be pushed forward, while improving the film distribution efficiency and enhancing the agitation effect on the material.

[0055] Furthermore, as shown in Figure 10, multiple pusher structures 36 are arranged in a spiral staggered manner in the feed direction X. The spiral layout makes the material closer to a horizontal flow. There is no mixing of the material in the flow direction, but complete mixing is achieved in the radial direction. Therefore, the flow velocity is uniform in the cross section perpendicular to the flow direction.

[0056] The hollow disks 30 shown in Figures 9 and 10 can also form disk groups 3. Specifically, the spacing between adjacent hollow disks 30 in the same disk group 3 is smaller than the spacing between adjacent disk groups 3. It can be understood that, along the feeding direction X, when the length of the pusher structure 36 is greater than the maximum width between the first disk 31 and the second disk 32, the first disk 31 and the second disk 32 of each hollow disk 30 in the same disk group are welded to the hollow shaft 20.

[0057] The following describes other components in the production equipment:

[0058] As shown in Figure 11, the production equipment also includes multiple scrapers 40. Each scraper 40 is fixed to the material cylinder 10 and extends into the material chamber 101. One scraper 40 corresponds to the outer surface of at least one hollow disc 30. Here, "corresponding" means that a gap is reserved between the outer surface of the hollow disc 30 and / or the outer peripheral surface of the hollow shaft 20 and the cutting edge of the scraper 40. For example, the outer surface of one hollow disc 30 and the outer peripheral surface of the hollow shaft 20 may both correspond to the scraper 40, or opposite outer surfaces of two adjacent hollow discs 30 may correspond to the scraper 40, or only the outer peripheral surface of the hollow shaft 20 may correspond to the scraper 40.

[0059] The scraper 40 can adopt a fixed blade type, hinge type or spring type structure. During the rotation of the hollow shaft 20, the scraper 40 can clean away excessive carbides accumulated on the surface of the hollow disk 30 and / or the hollow shaft 20, preventing carbides from accumulating and affecting production.

[0060] The scraper 40 can also adopt the irregular structure shown in Figure 12. Specifically, the hollow disk 30 includes a main hollow disk 306 and an auxiliary hollow disk 307. The surface area of ​​the auxiliary hollow disk 307 is smaller than that of the main hollow disk 306. One auxiliary hollow disk 307 corresponds to one main hollow disk 306, and the two are arranged at intervals, which are defined as the same group. Further, the end of the main hollow disk 306 and the end of the auxiliary hollow disk 307 in the same group are provided with a pusher structure 36 at the same position. The pusher structures 36 of multiple groups of hollow disks are arranged in a spiral staggered manner in the feed direction X. The scraper 40 is located in the gap between the main hollow disk 306 and the auxiliary hollow disk 307 in the same group to clean the carbides on the two opposite surfaces of the main hollow disk 306 and the auxiliary hollow disk 307; the scraper 40 is provided with a bending structure to adapt to the pushing structure 36 on the main hollow disk 306; at the same time, since the main hollow disk 306 and the auxiliary hollow disk 307 are different sizes, the scraper 40 is provided with a groove on the side facing the auxiliary hollow disk 307 to accommodate the pushing structure 36 of the auxiliary hollow disk 307.

[0061] The hollow shaft 20 is described in further detail below:

[0062] In some embodiments, FIG13 is a structural diagram of a hollow shaft according to an embodiment of the present invention. As shown in the figure, a second partition 21, a first layer plate 22 and a second layer plate 23 are radially arranged inside the hollow shaft 20. The second partition 21 divides the medium cavity 201 into a first medium cavity 202 and a second medium cavity 203 arranged sequentially along the feed direction X.

[0063] The first layer plate 22 is disposed in the first medium cavity 202 along the feeding direction X, dividing the first medium cavity 202 into a first feed cavity 204 and a first discharge cavity 205, which are indirectly connected. The second layer plate 23 is disposed in the second medium cavity 203 along the feeding direction X, dividing the second medium cavity 203 into a second feed cavity 206 and a second discharge cavity 207, which are indirectly connected.

[0064] Referring again to Figures 6 and 13, the first end of the hollow shaft 20 extends out of the material cylinder 10 and is located close to the first medium cavity 202. Two quick connectors are provided at the first end of the hollow shaft 20. One quick connector is connected to the first inlet 221, and the other quick connector is connected to the first outlet 222. The medium enters the first feed cavity 204 through the first inlet 221, and then enters the medium flow channel 301 through the flow channel inlet 211. After being evenly distributed in the hollow disk 30 through the medium flow channel 301, the medium enters the first discharge cavity 205 through the flow channel outlet 212 and flows out through the first outlet 222.

[0065] Similarly, the second end of the hollow shaft 20 extends outside the material cylinder 10 and is positioned close to the second medium cavity 203. Two quick connectors are provided at the second end of the hollow shaft 20; one quick connector connects to the second inlet 223, and the other quick connector connects to the second outlet 224. The medium enters the second feed cavity 206 through the second inlet 223, then enters the medium flow channel 301 through the flow channel inlet 211. After being evenly distributed across the hollow disks 30 in the medium flow channel 301, the medium then enters the second discharge cavity 207 through the flow channel outlet 212 and flows out through the second outlet 224.

[0066] Thus, in the first aspect, the temperatures of the first medium chamber 202 and the second medium chamber 203 can be controlled independently. Specifically, the material near the feed end has a lower viscosity, so the temperature of the medium introduced into the first medium chamber 202 can be appropriately lowered to fully heat the material in the first half of the hollow shaft 20 and slow down coking. Conversely, the material near the discharge end has a higher viscosity, so the temperature of the medium introduced into the second medium chamber 203 can be appropriately increased to facilitate the formation of cyclic esters and ensure orderly production. In the second aspect, different media can be introduced into the first medium chamber 202 and the second medium chamber 203 according to their heating temperature and properties to ensure uniform and effective flow of the media within the hollow shaft 20.

[0067] Figure 14 is a structural diagram of a hollow shaft according to another embodiment of the present invention. Similarly, a second partition 21 is radially arranged inside the hollow shaft 20, which divides the medium cavity 201 into a first medium cavity 202 and a second medium cavity 203 arranged sequentially along the feed direction X. A conveying pipe 24 also passes through the hollow shaft 20 and through the medium cavity 201. The first medium cavity 202 is divided into a first inlet cavity 204 and a first outlet cavity 205 by the conveying pipe 24. The first inlet cavity 204 is located within the conveying pipe 24, and the first outlet cavity 205 is the interlayer between the hollow shaft 20 and the conveying pipe 24. The second medium cavity 203 is divided into a second inlet cavity 206 and a second outlet cavity 207 by the conveying pipe 24. The second inlet cavity 206 is located within the conveying pipe 24, and the second outlet cavity 207 is the interlayer between the hollow shaft 20 and the conveying pipe 24.

[0068] The hollow shaft in Figure 14 is applicable to situations where there are multiple media sub-channels 305. Specifically, referring to Figures 7, 8, and 14, after the medium enters the first feed chamber 204 of the conveying pipe 24, it will enter the media channel 301 through the channel inlet 211, i.e., each media sub-channel 305, and then flow into the first discharge chamber 205 through the channel outlet 212, i.e., the interlayer between the hollow shaft 20 and the conveying pipe 24. Similarly, after the medium enters the second feed chamber 206 of the conveying pipe 24, it will enter the media channel 301 through the channel inlet 211, and then flow into the second discharge chamber 207 through the channel outlet 212, i.e., the interlayer between the hollow shaft 20 and the conveying pipe 24.

[0069] It is understandable that the interlayer between the hollow shaft 20 and the conveying pipe 24 can also be the feed chamber, while the discharge chamber is located in the conveying pipe 24. Accordingly, the flow channel inlet 211 is set on the hollow shaft 20, and the flow channel outlet 212 extends from the hollow shaft 20 into the conveying pipe 24. After the medium enters the feed chamber, that is, the interlayer between the hollow shaft 20 and the conveying pipe 24, it will enter the medium flow channel 301 through the flow channel inlet 211, and then flow into the conveying pipe 24 through the flow channel outlet 212.

[0070] The structure of the feed cylinder 10 is described in further detail below:

[0071] Multiple vacuum vents 102 can be provided along the feed direction X, and at least one vacuum vent 102 is provided in the pre-reaction section and at least one vacuum vent 102 is provided in the post-reaction section, thereby accelerating the removal of gaseous products such as glycolide from the production device.

[0072] Furthermore, a gas-liquid separation plate can be installed at the inlet of the vacuum vent 102 to separate entrained polymers. The gas-liquid separation plate can be of various structures such as a flat plate, an arc-shaped plate, or a conical plate. A heat transfer medium jacket can be installed on the gas-liquid separation plate to maintain its temperature. Even further, the hollow shaft 20 is horizontally eccentrically positioned inside the barrel 10, with the distance between the hollow shaft 20 and the top of the barrel wall 11 being greater than the distance between the hollow shaft 20 and the bottom of the barrel wall 11. This creates a gas-liquid separation space between the vacuum vent 102, the hollow disk 30, and the material, reducing gas-liquid entrainment in the product.

[0073] Optionally, as shown in Figures 1 and 2, a jacket 13 is provided on the outer peripheral surface of the barrel 10. The jacket 13 can maintain the temperature inside the barrel 10, thus more effectively ensuring the decomposition reaction of the oligomers in the barrel 10.

[0074] Furthermore, multiple jackets 13 are arranged sequentially along the feed direction X. In the feed direction X, at least one of the multiple jackets 13 corresponds to the melt outlet 112. Each jacket 13 is independent of each other so as to perform zoned temperature control for its corresponding area. For example, the temperature in the pre-reaction section of the barrel 10 can be lowered to slow down coking, and the temperature in the post-reaction section of the barrel 10 can be raised to facilitate the production of glycolide.

[0075] In a more specific implementation scheme, in order to facilitate the discharge of molten material from the melt outlet 112, the hollow disk 30 may not be provided at the melt outlet 112 of the barrel 10, and the temperature may be controlled solely by a jacket 13 separately provided at the rear end, as follows:

[0076] If a hollow disk 30 is not provided on the outer periphery of the hollow shaft 20 at the position corresponding to the melt outlet 112, the area corresponding to the melt outlet 112 will not be heated by the hollow disk 30. Instead, the temperature will be controlled separately by the jacket 13 corresponding to the melt outlet 112 to prevent abnormalities such as coking at the outlet position.

[0077] In some alternative embodiments, the hollow disk 30 disposed on the hollow shaft 20 at the position corresponding to the melt outlet 112 is a sector disk 309, as detailed below:

[0078] As shown in Figures 1 and 2, the hollow disks 30 include circular disks 308 and sector disks 309. The arc of the sector disk 309 is smaller than that of the circular disk 308. For example, the circular disk 308 is a complete ring, while the sector disk 309 is a 180° semi-ring, or a sector ring of 240°, 120°, etc. The area where the sector disk 309 is located corresponds to the melt outlet 112 along the radial direction of the hollow axis 20. Compared with the circular disk 308, the sector disk 309 has a weaker agitation force on the material and does not affect the discharge of the melt material from the melt outlet 112. In this way, the material in the area near the melt outlet 112 can be heated by the sector disk 309, which can also prevent abnormalities such as coking at the discharge position.

[0079] Optionally, at least one level regulating plate 14 is provided in the feed cylinder 10 along the feed direction X. The level regulating plate 14 is movably inserted into the lower bottom of the feed cylinder 10 and its radial distance from the hollow shaft 20 can be adjusted, thus regulating the liquid level in different reaction sections of the feed cylinder 10. Specifically, the material viscosity in the first stage of the reaction in the feed cylinder 10 is lower, so the liquid level in the first stage can be raised by the level regulating plate 14 to better move the material and facilitate the reaction. The viscosity in the second stage of the reaction in the feed cylinder 10 is higher, so the liquid level in the second stage can be lowered by the level regulating plate 14 to prevent coking. For example, two level regulating plates 14 can be provided to divide the interior of the feed cylinder 10 into a high liquid level section, a medium liquid level section, and a low liquid level section along the feed direction X, so as to better correspond the liquid level and viscosity of the material and facilitate the reaction.

[0080] In some alternative embodiments, the liquid level regulating plate 14 may adopt the structure shown in FIG15. Specifically, the liquid level regulating plate 14 is also provided with a liquid level regulating hole, the size of which is adjustable.

[0081] Specifically, the liquid level regulating plate 14 is movably connected to the liquid level regulating hole and the liquid baffle 15. The liquid baffle 15 is connected to the pull rod 16, which extends away from the liquid baffle 15 and is movably inserted into the feed cylinder 10. By pulling the pull rod 16, the liquid baffle 15 can be moved to adjust the opening size of the liquid level regulating hole, thereby adjusting the liquid level height of the corresponding reaction section in the feed cylinder 10.

[0082] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A production apparatus for cyclic esters, characterized in that, include: The barrel (10) is provided with a material chamber (101), and is provided with an inlet, a melt outlet (112) and at least one vacuum vent (102) communicating with the material chamber (101); The material passes through the hollow shaft (20) of the cylinder (10) along the feeding direction X of the material, and the hollow shaft (20) is provided with a medium cavity (201); A plurality of hollow disks (30) are arranged in the feed direction X inside the barrel (10), and the hollow disks (30) are located on the outer periphery of the hollow shaft (20). The hollow disks (30) are provided with a medium flow channel (301) communicating with the medium cavity (201). At least a portion of the medium flow channel (301) is spiral from the outside to the inside, and / or the medium flow channel (301) includes a plurality of parallel medium sub-flow channels (305).

2. The production equipment according to claim 1, characterized in that, The hollow disk (30) includes a first disk (31), a second disk (32), and a groove wall structure (33) all arranged around the hollow shaft (20). The area defined between the first disk (31), the second disk (32), and the hollow shaft (20) is a receiving cavity (302). The groove wall structure (33) is disposed in the receiving cavity (302), and the opposite sides of the groove wall structure (33) are fixed to the first disk (31) and the second disk (32), respectively. The first disk (31), the second disk (32), and the groove wall structure (33) cooperate to form the medium flow channel (301).

3. The production equipment according to claim 2, characterized in that, The hollow shaft (20) has a flow channel inlet (211) and a flow channel outlet (212) that are both provided corresponding to the hollow disk (30); The medium flow channel (301) includes an inner flow channel (3011), at least one intermediate flow channel (3014), an outer flow channel (3012), and a transition flow channel (3013). The inner flow channel (3011) and the outer flow channel (3012) are arranged opposite to each other in a direction away from the hollow axis (20) and are connected through the transition flow channel (3013). The intermediate flow channel (3014) is located between the inner flow channel (3011) and the outer flow channel (3012). The flow channel inlet (211), the inner flow channel (3011), the transition flow channel (3013), the outer flow channel (3012), the intermediate flow channel (3014), and the flow channel outlet (212) are connected in sequence.

4. The production equipment according to claim 2, characterized in that, The channel wall structure (33) includes N first partitions (35), each first partition (35) extending from the outer periphery of the hollow shaft (20) to the outer periphery of the hollow disk (30) and connecting to the outer periphery of the hollow disk (30). The N first partitions (35) divide the medium flow channel (301) into N+1 parallel medium sub-flow channels; wherein, N is greater than or equal to 1. The hollow shaft (20) is provided with a channel inlet (211) and a channel outlet (212) for each of the medium sub-channels.

5. The production equipment according to claim 2, characterized in that, The hollow disk (30) also includes a pusher structure (36) located at one end of the hollow disk (30) away from the hollow shaft (20), and the plurality of pusher structures (36) are arranged in a spiral staggered manner in the feed direction X; The pusher structure (36) has a base portion (361) and lateral extension portions (362) located on both sides of the base portion. The base portion (361) is connected to the outer periphery of the first disk (31) and the second disk (32) respectively. The lateral extension portions (362) are formed by extending the base portion (361) outward from the first disk (31) and the second disk (32).

6. The production equipment according to any one of claims 1 to 5, characterized in that, Multiple hollow discs (30) are arranged relatively close to each other to form a disc group (3), and multiple disc groups (3) are arranged along the feed direction X of the hollow shaft (20), with adjacent disc groups (3) spaced apart; Along the feed direction X, the number of hollow disks (30) in the disk group (3) gradually decreases.

7. The production equipment according to claim 6, characterized in that, Multiple hollow disks (30) in the same disk group (3) are fixedly connected. The first disk plate (31) of the hollow disk (30) on the first side of the disk group (3) and the second disk plate (32) of the hollow disk (30) on the second side of the disk group (3) are both welded and fixed to the hollow shaft (20). They are located at the connection of adjacent hollow disks (30) in the disk group (3) and are in contact with or spaced from the hollow shaft (20). The first side and the second side of the disk group (3) are two opposite sides of the disk group (3) along the feed direction X.

8. The production equipment according to any one of claims 1 to 5, characterized in that, The hollow shaft (20) is radially provided with a second partition (21), which divides the medium cavity (201) into a first medium cavity (202) and a second medium cavity (203) arranged sequentially along the feed direction X; The first medium cavity (202) includes a first feed cavity (204) and a first discharge cavity (205), which are separated from each other by a conveying pipe (24) or a shelf. The second medium chamber (203) includes a second feed chamber (206) and a second discharge chamber (207), which are separated from each other by a conveying pipe (24) or a shelf.

9. The production equipment according to any one of claims 1 to 5, characterized in that, The outer circumferential surface of the barrel (10) is provided with a plurality of jackets (13). In the feed direction X, at least one of the plurality of jackets (13) corresponds to the melt outlet (112), and / or, At the position corresponding to the melt outlet (112), the outer periphery of the hollow shaft (20) is not provided with the hollow disk (30) or the provided hollow disk (30) is a fan-shaped disk.

10. The production equipment according to any one of claims 1 to 5, characterized in that, The feed cylinder (10) is provided with at least one liquid level regulating plate (14); wherein, The liquid level regulating plate (14) is movably inserted into the lower bottom of the material cylinder (10) and can adjust the radial distance between it and the hollow shaft (20), and / or, The liquid level regulating plate (14) is provided with an adjustable liquid level regulating hole.

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