On-line adding device of polyester reverse esterification kettle

Abstract

The utility model discloses a polyester reverse esterification kettle on-line adding device which comprises a first esterification kettle and a second esterification kettle, a batching pipeline is arranged between the first esterification kettle and the second esterification kettle, and a three-monomer on-line injection system is arranged on one side of the batching pipeline. A second static mixer, a dynamic mixer and a pneumatic valve are sequentially arranged on the batching pipeline between the three-monomer on-line injection system and the second esterification kettle, and materials prepared by the three-monomer preparation system are injected into a connecting pipeline through the three-monomer on-line injection system; and then the mixture enters the second static mixer and the dynamic mixer to be mixed and then is injected into the second esterification kettle through the pneumatic valve. The transformation from production of extinction products to production of cationic products can be quickly realized in the five-kettle process, so that the productivity and the quality of the products are ensured, and benefits are created for enterprises to be maximized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of cation production, and particularly relates to a polyester reverse esterification kettle on -line adding device. BACKGROUND

[0002] In the spinning production process, when producing cation products, it is generally necessary to produce through a three-kettle process or a two-esterification horizontal reaction kettle process at present, and many of the existing spinning enterprises still use the original five-kettle process device of the China Textile Academy. Since the existing five-kettle process device of the China Textile Academy does not have a device for on-line addition of cations, it can only produce ordinary semi-dull or full-dull products and cannot produce cation products. For enterprises, it is too costly and difficult to popularize to replace the existing five-kettle process device with a three-kettle process device, and it is difficult to transform between cation and semi-dull products. Therefore, the existing original five-kettle process device of the China Textile Academy needs to be modified to enable the existing five-kettle process device of the China Textile Academy to realize rapid and low-cost transformation from production of dull products to production of cation products, thereby maximizing the benefits of enterprises. SUMMARY

[0003] In order to solve the technical problems existing in the prior art, the purpose of the present application is to provide a polyester reverse esterification kettle on-line adding device, which can enable the five-kettle process to rapidly realize transformation from production of dull products to production of cation products, ensure the production capacity and quality of products, and maximize the benefits of enterprises.

[0004] To solve the above-mentioned technical problems, the present application adopts the following technical solutions:

[0005] A polyester reverse esterification kettle on-line adding device, comprising a first esterification kettle and a second esterification kettle, a dosing pipeline is arranged between the first esterification kettle and the second esterification kettle, a three-monomer on-line injection system and a three-monomer preparation system are arranged on one side of the dosing pipeline, a second static mixer, a dynamic mixer and a pneumatic valve are further arranged in sequence on the dosing pipeline between the three-monomer on-line injection system and the second esterification kettle, and the prepared material of the three-monomer preparation system is injected into the connecting pipeline through the three-monomer on-line injection system, then enters the second static mixer and the dynamic mixer for mixing, and is injected into the second esterification kettle through the pneumatic valve.

[0006] Preferably, an EG injection system is further arranged on the dosing pipeline, and a tube-in-tube heat exchanger is arranged between the EG injection system and the three-monomer on-line injection system.

[0007] Preferably, the melt temperature after injection of EG through the EG injection system is 247-250℃, and the melt temperature after cooling through the tube-in-tube heat exchanger is 240±2℃.

[0008] Preferably, the dosing pipeline is further provided with an EG injection system, the EG injection system comprising an EG delivery pipeline, two EG injection valves arranged in series on the dosing pipeline, a flow regulating valve arranged on the EG delivery pipeline, the two EG injection valves being in communication with the EG delivery pipeline, the EG injection valves being arranged at the front end of the trimmer injection valves, and a first static mixer being arranged between the EG injection valves and the trimmer injection valves.

[0009] Preferably, the trimmer online injection system comprises a trimmer flow meter, two trimmer injection valves arranged in series on the dosing pipeline, and the two trimmer injection valves being in communication with the trimmer preparation system through the trimmer flow meter.

[0010] Preferably, the dosing pipeline between the first esterification kettle and the trimmer online injection system is sequentially provided with a second esterification delivery pump and an esterification flow meter, and the second esterification delivery pump is arranged in parallel.

[0011] Preferably, the utility model further comprises a heat medium system, and all the material delivery pipelines are jacketed pipelines, and the jacketed pipelines are in communication with the heat medium system.

[0012] Preferably, the heat medium system comprises a heat medium feed pipeline, a heat medium return pipeline, two heat medium circulating pumps and an exhaust pipeline.

[0013] Preferably, the trimmer preparation system comprises a trimmer slurry preparation tank, a trimmer slurry delivery pump, a trimmer reaction kettle, a trimmer reaction kettle heat medium heating pump, a trimmer solution filter, a trimmer intermediate cooling adjusting tank, a trimmer product filter, a trimmer product tank and a trimmer product feed pump.

[0014] Preferably, the melt filter system comprises two melt delivery pumps connected to the discharge pipeline of the final polycondensation kettle through a three-way pipeline, and a double-polyester filter arranged at the discharge end of the melt delivery pump.

[0015] Compared with the prior art, the utility model has the beneficial effects that:

[0016] A trimer online injection system is added on the dosing pipeline between the first esterification kettle and the second esterification kettle, so that the trimer can be mixed with the esterification product in the dosing pipeline and then injected into the second esterification kettle, and the current five-kettle process device of the China Textile Academy can not only produce ordinary semi-dull or full-dull products, but also produce cationic products, so that the existing five-kettle process device of the China Textile Academy can realize rapid and low-cost transformation of cationic and semi-dull products, and create maximum benefits for enterprises. However, directly mixing in the dosing pipeline and then injecting into the second esterification kettle for stirring can easily cause uneven reaction, resulting in too high agglomeration ratio, incomplete reaction, and too large annual fluctuation of the final melt, which affects the product quality. Therefore, a second static mixer, a dynamic mixer and a pneumatic valve are sequentially added on the dosing pipeline between the trimer online injection system and the second esterification kettle, so that the two melts can be fully mixed, and the melt reaction in the second esterification kettle is more uniform. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is an overall structure schematic diagram of the polyester reverse esterification kettle online adding device in the utility model;

[0018] Figure 2 It is an overall system structure schematic diagram of the improved utility model;

[0019] In the drawing: 1, esterification product flowmeter; 2, second esterification product delivery pump; 3, first esterification kettle; 4, second esterification kettle; 5, first pre-shrinking kettle; 6, process column; 7, second pre-shrinking kettle; 8, final shrinkage kettle; 9, pre-shrinking filter; 10, first esterification product delivery pump; 11, pneumatic valve; 12, dynamic mixer; 13, second static mixer; 14, dosing pipeline; 15, tube-in-tube heat exchanger; 20, trimer preparation system; 21, trimer slurry preparation tank; 22, trimer solution filter; 23, trimer reaction tank; 24, trimer reaction tank heating medium heating pump; 25, trimer slurry delivery pump; 26, trimer intermediate cooling adjustment tank; 27, trimer finished product filter; 28, trimer finished product feeding pump; 29, trimer finished product tank; 30, heating medium system; 31, heating medium circulating pump; 32, heating medium feeding pipe; 33, heating medium return pipe; 34, exhaust pipe; 40, melt filter system; 41, double polyester filter; 42, melt delivery pump; 50, EG injection system; 51, first static mixer; 52, EG injection valve; 53, flow regulating valve; 54, EG delivery pipeline; 60, trimer online injection system; 61, trimer flowmeter; 62, trimer flow control valve; 63, trimer injection valve. DETAILED DESCRIPTION

[0020] The application will be further described below in conjunction with the drawings and specific embodiments, it should be noted that the following described embodiments or technical features can be combined with each other to form new embodiments without conflict.

[0021] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0022] The terms "first", "second", etc. in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in a "or" relationship.

[0023] As Figure 1 and Figure 2As shown, the current five-kettle process device of the institute generally includes a first esterification kettle 3, a second esterification kettle 4, a first pre-condensation kettle 5, a second pre-condensation kettle 7, a final condensation kettle 8, a process column 6, a first esterification conveying pump 10, a pre-condensation filter 9, and a melt filter system 40. The first esterification kettle 3, the second esterification kettle 4, the first pre-condensation kettle 5, the second pre-condensation kettle 7, and the final condensation kettle 8 are connected in series through pipelines. The process column 6 is in communication with the first esterification kettle 3 and the second esterification kettle 4. The melt in the second pre-condensation kettle 7 is injected into the pre-condensation filter 9 through the first esterification conveying pump 10, filtered, and then injected into the final condensation kettle 8. Finally, the melt is filtered through the melt filter system, conveyed to a spinning booster pump through a pipeline, and then distributed to each dosing pump for a spinning assembly to spin. However, the current five-kettle process device of the institute is difficult to produce cationic products. Therefore, in order to solve this problem, the existing device is modified as follows. An online addition device for a polyester reverse esterification kettle is provided. A dosing pipeline 14 is arranged between the first esterification kettle 3 and the second esterification kettle 4. A three-monomer online injection system 60 and a three-monomer preparation system 20 are arranged on one side of the dosing pipeline 14. A second static mixer 13, a dynamic mixer 12, and a pneumatic valve 11 are sequentially arranged on the dosing pipeline 14 between the three-monomer online injection system 60 and the second esterification kettle 4. The prepared material of the three-monomer preparation system 20 is injected into the connecting pipeline through the three-monomer online injection system 60, mixed in the second static mixer 13 and the dynamic mixer 12, and then injected into the second esterification kettle 4 through the pneumatic valve 11.

[0024] Based on the melt conveying system of the five-kettle process device of the institute, the three-monomer online injection system 60 and the three-monomer preparation system 20 are connected on the dosing pipeline 14 between the first esterification kettle 3 and the second esterification kettle 4. Thus, the three-monomer can be mixed with the esterification product in the dosing pipeline 14 and then injected into the second esterification kettle 4. The current five-kettle process device of the institute can not only produce ordinary semi-dull or full-dull products, but also produce cationic products. When producing cationic products, there is no need to replace equipment, which is easy to promote. The existing five-kettle process device of the institute can be quickly and low-cost transformed to produce cationic and semi-dull products, thereby maximizing the benefits of enterprises. However, the simple mixing in the dosing pipeline 14 and then the direct injection into the second esterification kettle 4 for stirring can cause uneven reaction, resulting in too high agglomeration ratio, incomplete reaction, and too large viscosity fluctuation of the final condensation melt, which affects the product quality. Therefore, the dynamic mixer 12 is arranged on the pipeline after mixing, so that the two melts can be fully mixed, and the melt in the second esterification kettle 4 can be more uniformly reacted.

[0025] Further improvement is that the trimmer online injection system 60 includes a trimmer flow meter 61, two trimmer injection valves 63 arranged in series on the dosing pipeline 14, and a trimmer flow control valve 62 arranged between the trimmer flow meter 61 and the two trimmer injection valves 63. The trimmer flow control valve 62 and the trimmer flow meter 61 are linked to control the opening degree of the trimmer flow control valve 62 by the maximum output of the trimmer flow meter 61, and the trimmer flow control valve 62 is used to assist in controlling the output flow of the trimmer flow meter 61. In use, even if the trimmer flow meter 61 malfunctions, the trimmer flow can still be controlled by the trimmer flow control valve 62 to avoid over-injection or insufficient injection of trimmer.

[0026] Further improvement is that the dosing pipeline 14 is also provided with an EG injection system 50, which includes an EG delivery pipeline 54, two EG injection valves 52 arranged in series on the dosing pipeline 14, and a flow regulating valve 53 arranged on the EG delivery pipeline 54. The two EG injection valves 52 are in communication with the EG delivery pipeline 54, and the EG injection valves 52 are arranged at the front end of the trimmer injection valves 63. A first static mixer 51 is arranged between the EG injection valves 52 and the trimmer injection valves 63.

[0027] Since the melt flowing out of the first esterification kettle 3 is about 255 degrees, and the reaction temperature of the trimmer is above 245 degrees, direct injection of trimmer into the esterification mixture can easily cause accelerated agglomeration. Therefore, before the esterification mixture is injected into the trimmer, fresh EG is injected through the EG delivery pipeline 54 to cool the esterification mixture, thereby avoiding the problem of accelerated agglomeration caused by the injection of trimmer. In order to ensure that the injected EG reaches the required temperature, and to avoid the esterification mixture being too low in temperature due to rapid cooling or not being cooled enough, the two EG injection valves 52 are used to inject EG in different areas, which can effectively solve this problem. The use of two trimmer injection valves 63 allows the melt to be injected in sections, thereby achieving higher uniformity of mixing and more accurate injection amount. After the EG injection valves 52 inject EG, the esterification mixture is in a flowing state, which can easily cause uneven cooling of the esterification mixture, leading to premature reaction of the trimmer when it comes into contact with the esterification mixture that has not been cooled. Therefore, a first static mixer 51 is arranged between the EG injection valves 52 and the trimmer injection valves 63 to effectively avoid uneven cooling.

[0028] Further improvement is that the EG injection system 50 and the trimonomer online injection system 60 are provided with a shell-and-tube heat exchanger 15, the temperature of the mixed melt after the EG is added is about 247-250℃, and the temperature of the melt after being cooled by the shell-and-tube heat exchanger 15 is 240±2℃.

[0029] Because too much EG is easy to cause excessive reaction of the mixed melt, resulting in too high esterification rate and affecting product quality, the shell-and-tube heat exchanger 15 is added between the EG injection system 50 and the trimonomer online injection system 60, the temperature of the melt after the EG is added is first reduced to about 247-250℃, and then the melt is cooled to a temperature of 240±2℃ by the shell-and-tube heat exchanger 15, so that the injection conditions of the trimonomer are met, and the problem of excessive addition of EG is avoided.

[0030] Further improvement is that the trimonomer injection valve 63 and the dynamic mixer 12 are provided with a second static mixer 13.

[0031] Because the distance of the mixed melt to the second esterification kettle 4 is short, the problem of uneven proportion of the two melts is caused by directly entering the dynamic mixer 12 for mixing, resulting in local excessive agglomeration of one kind of melt, and the problem of blockage is easy to occur subsequently, therefore, the mixed melt is premixed in the second static mixer 13 before entering the dynamic mixer 12, so that the proportion of the two melts is close, and then the two melts are mixed by the second static mixer 13 and then enter the dynamic mixer 12 for mixing, which can effectively solve the problem of melt agglomeration in the later stage and avoid the blockage of the pipeline.

[0032] Further improvement is that the dosing pipeline 14 between the first esterification kettle 3 and the trimonomer online injection system 60 is sequentially provided with a second esterification conveying pump 2 and an esterification flowmeter 1, and the second esterification conveying pump 2 is two and is arranged in parallel.

[0033] Because there is no conveying pump on the existing dosing pipeline 14, the flow rate is unstable, and after the EG and the trimonomer are added, the problem of insufficient flow rate and uneven dosing is easy to occur, therefore, in order to ensure the conveying amount of the esterification product, the second esterification conveying pump 2 and the esterification flowmeter 1 are sequentially added to the dosing pipeline 14 between the first esterification kettle 3 and the trimonomer online injection system 60, and the combination of the second esterification conveying pump 2 and the esterification flowmeter 1 can effectively control the conveying amount and mixing condition of the esterification product, so as to ensure the stability of the conveying of the esterification product, and especially, the second esterification conveying pump 2 is two and is arranged in parallel, so that when one of them needs to be maintained, the other one can be used for feeding, thereby ensuring the continuity of the conveying of the esterification product.

[0034] Further improvement is that the trimmer preparation system 20 comprises a trimmer slurry preparation tank 21, a trimmer slurry delivery pump 25, a trimmer reaction tank 23, a trimmer reaction tank 23 heat medium heating pump, a trimmer solution filter 22, a trimmer intermediate cooling adjustment tank 26, a trimmer finished product filter 27, a trimmer finished product tank 29 and a trimmer finished product feeding pump 28.

[0035] The trimmer melt is prepared by the trimmer preparation system 20, and after preparation, the melt is controlled by the trimmer finished product feeding pump 28 to the trimmer flow meter 61 for metering and then mixed with the esterification melt, so that the structure is simpler and the precision of the injected trimmer melt after preparation is higher.

[0036] Further improvement is that the melt filtering system 40 comprises two melt delivery pumps 42 connected by a three-way pipeline to the discharge pipe of the final polycondensation kettle 8 and a double-polyester filter 41 arranged at the discharge end of the melt delivery pump 42.

[0037] The current discharge pipe of the final polycondensation kettle 8 only has two melt delivery pumps 42 and a set of double-polyester filter 41. Multiple spinning production lines are connected to the outlet of the double-polyester filter 41, and there is a problem of short cycle of the double-polyester filter 41 during transportation, which easily leads to insufficient time for filter replacement when switching filters, causing the standby online filter to be blocked and passive shutdown. Therefore, a set of double-polyester filter 41 connected with one of the melt delivery pumps 42 is added to one side of the original double-polyester filter 41, so that the melt discharge pipe of the final polycondensation kettle 8 forms two sets of parallel melt delivery pumps 42 and double-polyester filters 41. The melt in the final polycondensation kettle 8 can be supplied to different spinning booster pumps through the two sets of parallel melt delivery pumps 42 and double-polyester filters 41, thereby avoiding the problem that the medium-term is short and one of the filters cannot be replaced in time due to the large flow when maintaining a single double-polyester filter 41, and the passive shutdown caused by filter maintenance no longer occurs.

[0038] Further improvement is that it also comprises a heat medium system 30, and all the added material delivery pipelines are jacketed pipelines, which are communicated with the heat medium system 30.

[0039] The heat medium system 30 can heat and keep warm all the added delivery pipelines, avoiding the situation that the temperature of the flowing melt is too low. The heat medium system 30 is composed of a heat medium feeding pipe 32, a heat medium return pipe 33, two heat medium circulating pumps 31 and an exhaust pipe 34. The heat medium enters the jacketed pipeline through the heat medium feeding pipe 32 and finally returns through the heat medium return pipe 33. The steam generated in the jacketed pipeline is discharged outward through the exhaust pipe 34, avoiding damage of the pipeline due to excessive internal pressure and avoiding the occurrence of a large amount of local vacuum inside.

[0040] The above embodiments are only the preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application, and any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.

Claims

1. An online addition device for a polyester transesterification reactor, comprising a first esterification reactor (3) and a second esterification reactor (4), characterized in that: A dispensing pipeline (14) is provided between the first esterification vessel (3) and the second esterification vessel (4). A three-monomer online injection system (60) and a three-monomer preparation system (20) are provided on one side of the dispensing pipeline (14). A second static mixer (13), a dynamic mixer (12) and a pneumatic valve (11) are also provided on the dispensing pipeline (14) between the three-monomer online injection system (60) and the second esterification vessel (4) in sequence. The material prepared by the three-monomer preparation system (20) is injected into the connecting pipeline through the three-monomer online injection system (60), and then enters the second static mixer (13) and the dynamic mixer (12) for mixing. After mixing, it is injected into the second esterification vessel (4) through the pneumatic valve (11).

2. The online addition device for a polyester transesterification reactor according to claim 1, characterized in that: The feed line (14) is also equipped with an EG injection system (50), and a shell-and-tube heat exchanger (15) is provided between the EG injection system (50) and the three-monomer online injection system (60).

3. The online addition device for a polyester transesterification reactor according to claim 2, characterized in that: The melt temperature after EG is injected through the EG injection system (50) is 247~250℃, and the melt temperature after being cooled by the shell and tube heat exchanger (15) is 240±2℃.

4. The online addition device for a polyester transesterification reactor according to claim 3, characterized in that: The EG injection system (50) includes an EG delivery pipeline (54), two EG injection valves (52) connected in series on the batching pipeline (14), and a flow regulating valve (53) on the EG delivery pipeline (54). The two EG injection valves (52) are connected to the EG delivery pipeline (54). The EG injection valves (52) are located at the front end of the three-monomer online injection system (60). A first static mixer (51) is provided between the EG injection valves (52) and the three-monomer online injection system (60).

5. The online addition device for a polyester transesterification reactor according to claim 1, characterized in that: The three-unit online injection system (60) includes a three-unit flow meter (61) and two three-unit injection valves (63) connected in series on the dispensing pipeline (14). The two three-unit injection valves (63) are connected to the three-unit preparation system (20) through the three-unit flow meter (61).

6. The online addition device for a polyester transesterification reactor according to claim 1, characterized in that: A second esterification pump (2) and an esterification flow meter (1) are sequentially installed on the feed pipeline (14) between the first esterification reactor (3) and the three monomer online injection system (60). Two second esterification pumps (2) are arranged in parallel.

7. An online addition device for a polyester transesterification reactor according to any one of claims 1 to 6, characterized in that: It also includes a heat medium system (30), and all the added material conveying pipelines are jacketed pipes, which are connected to the heat medium system (30).

8. The online addition device for a polyester transesterification reactor according to claim 7, characterized in that: The heat medium system (30) consists of a heat medium feed pipe (32), a heat medium return pipe (33), two heat medium circulation pumps (31) and an exhaust pipe (34).

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