Polyester three-stage injection system

Abstract

The utility model relates to the technical field of polyester production equipment, in particular to a polyester three-stage injection system which comprises a three-stage injection pump, a liquid seal tank, a first-stage liquid discharging pipe, a second-stage liquid discharging pipe, a third-stage liquid discharging pipe, a flushing pipe, a first-stage spraying pipe, a second-stage spraying pipe and a third-stage spraying pipe. The two ends of the flushing pipe are connected with the esterification system and the three-stage injection pump respectively and used for introducing hot ethylene glycol / hot butanediol in the esterification system into the three-stage injection pump, and the first-stage spraying pipe, the second-stage spraying pipe and the third-stage spraying pipe are all arranged on the top of the three-stage injection pump and used for conducting hot flushing on the three-stage injection pump. The bottom of the three-stage injection pump is respectively connected with a first-stage liquid discharging pipe, a second-stage liquid discharging pipe and a third-stage liquid discharging pipe; and the first-stage liquid discharging pipe, the second-stage liquid discharging pipe and the third-stage liquid discharging pipe are respectively communicated with the liquid seal groove. The polyester three-stage injection system aims to solve the problems of device vacuum fluctuation and product performance reduction caused by blockage of a vacuum system in the polyester production process.

Description

TECHNICAL FIELD

[0001] The utility model relates to polyester production equipment technical field, concretely relates to a polyester three stage jet system. BACKGROUND

[0002] According to the polycondensation reaction principle of PET polyester or PBT polyester, needs through vacuum system to take out the glycol or butanediol steam produced by polycondensation reaction from polycondensation reaction kettle constantly, reduces the product concentration, to make the reaction equilibrium move to the positive direction, and in the process of glycol or butanediol steam taking out reaction kettle, will some oligomers, materials and small molecules etc. are entrained into the vacuum system, along with the polyester device long time operation, the entrained material accumulated in the vacuum system increases, will lead to the nozzle, downcomer etc. of the three stage jet pump in the vacuum system to be blocked, thereby leading to the vacuum ability of vacuum system to decline, even vacuum loss, thermal degradation and thermal oxygen degradation aggravate, seriously influence the progress of polycondensation reaction, and can make the performance of polyester product decline, especially the hue of product. When the vacuum system is blocked, generally can only rely on cold glycol or butanediol to flush the nozzle and pipeline, or use external force to knock downcomer, and the processing speed is slow, and the effect is very little, and it is easy to lead to accident expansion.

[0003] Therefore, the inventor provides a polyester three stage jet system. CONTENT OF UTILITY MODEL

[0004] (1) technical problem to be solved

[0005] The utility model embodiment provides a polyester three stage jet system, solves the technical problem that the device vacuum fluctuation, product performance decline of polyester production process because of vacuum system blockage.

[0006] (2) technical scheme

[0007] The utility model provides a polyester three stage jet system, including three stage jet pump, liquid seal groove, first stage downcomer, second stage downcomer, third stage downcomer, flush pipe, first stage shower pipe, second stage shower pipe and third stage shower pipe, wherein, both ends of flush pipe are connected with esterification system and three stage jet pump respectively and are used for introducing hot glycol / hot butanediol in esterification system to three stage jet pump, first stage shower pipe, second stage shower pipe and third stage shower pipe all are set up in the top of three stage jet pump and are used for carrying out hot flushing to each stage nozzle and pipeline in three stage jet pump, the bottom of three stage jet pump is connected with first stage downcomer, second stage downcomer and third stage downcomer respectively, first stage downcomer, second stage downcomer and third stage downcomer are communicated with liquid seal groove respectively.

[0008] Further, the polyester three-stage jetting system further comprises a first-stage spray valve, a second-stage spray valve and a third-stage spray valve, which are arranged on the corresponding first-stage spray pipe, second-stage spray pipe and third-stage spray pipe respectively.

[0009] Further, the polyester three-stage jetting system further comprises a first-stage flush valve, a second-stage flush valve and a third-stage flush valve, which are arranged on the flush pipe, and are connected with the corresponding first-stage spray pipe, second-stage spray pipe and third-stage spray pipe respectively.

[0010] Further, at least one of the first-stage flush valve, second-stage flush valve and third-stage flush valve is a vacuum plug valve.

[0011] Further, the polyester three-stage jetting system further comprises a first-stage downcomer short pipe, a second-stage downcomer short pipe and a third-stage downcomer short pipe, which are communicated with the liquid seal groove through the corresponding detachable first-stage downcomer short pipe, second-stage downcomer short pipe and third-stage downcomer short pipe respectively.

[0012] Further, the length of the first-stage downcomer short pipe, second-stage downcomer short pipe and third-stage downcomer short pipe is 400-1000mm.

[0013] Further, the two ends of the first-stage downcomer short pipe, second-stage downcomer short pipe and third-stage downcomer short pipe are connected by flanges.

[0014] (3)Beneficial effects

[0015] In conclusion, the polyester three-stage jetting system of the present application can introduce hot ethylene glycol or hot butylene glycol from the esterification system to the three-stage jetting system through the flush pipe, and can perform hot flushing on the nozzles and pipelines of the three-stage jetting pump, so as to clean the entrained materials such as oligomers, materials and small molecules in the vacuum system in time, and effectively prevent the entrained materials from remaining in the vacuum system and causing system blockage. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0017] Figure 1 is a structural schematic diagram of a polyester three-stage injection system provided by an embodiment of the present application.

[0018] In the figure,

[0019] 1-three-stage injection pump; 2-liquid seal groove; 3-first-stage downflow pipe; 4-second-stage downflow pipe; 5-third-stage downflow pipe; 6-first-stage spray valve; 7-second-stage spray valve; 8-third-stage spray valve; 9-flushing pipe; 10-first-stage flushing valve; 11-second-stage flushing valve; 12-third-stage flushing valve; 13-first-stage downflow pipe short connection; 14-second-stage downflow pipe short connection; 15-third-stage downflow pipe short connection; 16-first-stage spray pipe; 17-second-stage spray pipe; 18-third-stage spray pipe. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments, and covers any modification, replacement and improvement of parts, components and connection modes without departing from the spirit of the present application.

[0021] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0022] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", etc. indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying 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 limiting the present application.

[0023] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement" and "installation" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] During the process of ethylene glycol or butanediol steam extraction reaction kettle, some oligomers, materials and small molecules are entrained into the vacuum system. With long time running of the polyester device, the entrained materials accumulated in the vacuum system increase, which can cause the nozzle and liquid down pipe of the third stage jet pump in the vacuum system to be blocked, thereby causing the vacuum capacity of the vacuum system to decrease, and even the vacuum to be lost. After the vacuum system is blocked, the nozzle and pipeline can be flushed by cold ethylene glycol or butanediol, or the pipeline is knocked by external force, the processing speed is slow, the effect is very small, and the accident is easily enlarged. The decrease of the vacuum capacity can seriously affect the progress of the polycondensation reaction, cause the thermal degradation and thermal oxidative degradation to be intensified, and can make the performance of the polyester product decrease, especially the color phase of the product.

[0025] Figure 1 is a structural schematic diagram of a polyester three-stage jet system provided by an embodiment of the present application, and referring to Figure 1 The system can include a three-stage jet pump 1, a liquid seal groove 2, a first-stage liquid down pipe 3, a second-stage liquid down pipe 4, a third-stage liquid down pipe 5, a flushing pipe 9, a first-stage spraying pipe 16, a second-stage spraying pipe 17 and a third-stage spraying pipe 18. The two ends of the flushing pipe 9 are connected with an esterification system and the three-stage jet pump 1 respectively and are used to introduce hot ethylene glycol / hot butanediol in the esterification system into the three-stage jet pump 1. The first-stage spraying pipe 16, the second-stage spraying pipe 17 and the third-stage spraying pipe 18 are all arranged at the top of the three-stage jet pump 1 and are used to heat flush the nozzles and pipelines in the three-stage jet pump 1. The bottom of the three-stage jet pump 1 is connected with the first-stage liquid down pipe 3, the second-stage liquid down pipe 4 and the third-stage liquid down pipe 5 respectively. The first-stage liquid down pipe 3, the second-stage liquid down pipe 4 and the third-stage liquid down pipe 5 are communicated with the liquid seal groove 2 respectively.

[0026] In the above embodiment, in actual production process, we can set the periodic flushing time according to the vacuum operation cycle, in addition, when the vacuum of the device presents a downward trend during operation, we can also arrange flushing work immediately. The hot ethylene glycol or hot butylene glycol of the esterification system is introduced to the three-stage jet system through the flushing pipe 9, and the nozzle and pipeline of the three-stage jet pump 1 are hot-flushed, so as to clean the oligomers, materials and small molecules and other entrainment in the vacuum system in time, effectively preventing the entrainment from remaining in the vacuum system and causing system blockage. Taking the flushing of the first-stage jet pump as an example, the first-stage flushing valve 10 and the first-stage spraying valve 6 are opened, the hot ethylene glycol or hot butylene glycol enters the system through the flushing pipe 9 and the first-stage spraying pipe 16, and the nozzle and pipeline of the first-stage jet pump are hot-flushed, and the valve is repeatedly opened and closed for 2-3 times to ensure good flushing effect. After the flushing of the first-stage jet pump is completed, the first-stage flushing valve 10 and the first-stage spraying valve 6 are closed, and the second-stage flushing valve 11 and the second-stage spraying valve 7 are opened to flush the second-stage jet pump, and the three-stage jet pump system is flushed in turn. The polyester three-stage jet system can effectively prevent the vacuum system from being blocked, prolong the operation cycle of the vacuum system, improve the vacuum effect, and stabilize the quality of the polyester product.

[0027] As an optional embodiment, as shown in Figure 1 The polyester three-stage jet system further comprises a first-stage spraying valve 6, a second-stage spraying valve 7 and a third-stage spraying valve 8, which are respectively arranged on corresponding first-stage spraying pipe 16, second-stage spraying pipe 17 and third-stage spraying pipe 18; the first-stage flushing valve 10, the second-stage flushing valve 11 and the third-stage flushing valve 12 are arranged on the flushing pipe 9, and are respectively connected with the corresponding first-stage spraying pipe 16, second-stage spraying pipe 17 and third-stage spraying pipe 18.

[0028] Specifically, by using the spraying valve and the flushing valve in cooperation, the nozzles and pipelines of the three-stage jet pump are sequentially hot-flushed by sequentially opening the flushing valves. Taking the flushing of the first-stage jet pump as an example, the first-stage flushing valve 10 and the first-stage spraying valve 6 are opened, the hot ethylene glycol or hot butylene glycol enters the system through the flushing pipe 9 and the first-stage spraying pipe 16, and the nozzle and pipeline of the first-stage jet pump are hot-flushed, and the valve is repeatedly opened and closed for 2-3 times to ensure good flushing effect. After the flushing of the first-stage jet pump is completed, the first-stage flushing valve 10 and the first-stage spraying valve 6 are closed, and the second-stage flushing valve 11 and the second-stage spraying valve 7 are opened to flush the second-stage jet pump, and the three-stage jet pump system is flushed in turn. The first-stage flushing valve 10, the second-stage flushing valve 11 and the third-stage flushing valve 12 are all vacuum cock valves.

[0029] As an optional embodiment, as shown in Figure 1As shown, the polyester tertiary injection system further comprises a first-stage lower liquid pipe short connection 13, a second-stage lower liquid pipe short connection 14 and a third-stage lower liquid pipe short connection 15, and the first-stage lower liquid pipe 3, the second-stage lower liquid pipe 4 and the third-stage lower liquid pipe 5 are respectively communicated with the liquid seal tank 2 through the corresponding detachable first-stage lower liquid pipe short connection 13, the second-stage lower liquid pipe short connection 14 and the third-stage lower liquid pipe short connection 15.

[0030] Specifically, the corresponding lower liquid pipe short connection is arranged at the connection position of each stage lower liquid pipe and the top of the liquid seal tank 2, and when the lower liquid pipe is blocked or cleaned regularly, the short connection can be detached to dredge the lower liquid pipe, which is simple, convenient and fast. Further, the length of the first-stage lower liquid pipe short connection 13, the second-stage lower liquid pipe short connection 14 and the third-stage lower liquid pipe short connection 15 is 400-1000mm, and the two ends of the first-stage lower liquid pipe short connection 13, the second-stage lower liquid pipe short connection 14 and the third-stage lower liquid pipe short connection 15 are connected by flanges, which facilitates the quick dredging and cleaning of the sundries in the lower liquid pipe after the short connection is detached.

[0031] It should be clear that each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments. The utility model is not limited to the specific steps and structures described above and shown in the drawings. Moreover, for the sake of brevity, the detailed description of known methods and techniques is omitted.

[0032] The above is only the embodiment of the present application, and is not limited to the present application. Without departing from the scope of the present application, the present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the scope of claims of the present application.

Claims

1. A tertiary injection system for a polyester, characterized in that The three-stage jet pump (1), the liquid seal tank (2), the first-stage downcomer (3), the second-stage downcomer (4), the third-stage downcomer (5), the flushing pipe (9), the first-stage spray pipe (16), the second-stage spray pipe (17) and the third-stage spray pipe (18); wherein, the flushing pipe (9) is connected with the esterification system and the three-stage jet pump (1) at two ends respectively and is used for introducing the hot ethylene glycol / hot butylene glycol in the esterification system into the three-stage jet pump (1), the first-stage spray pipe (16), the second-stage spray pipe (17) and the third-stage spray pipe (18) are all arranged on the top of the three-stage jet pump (1) and are used for hot flushing the nozzles and pipelines of each stage in the three-stage jet pump (1), the bottom of the three-stage jet pump (1) is connected with the first-stage downcomer (3), the second-stage downcomer (4) and the third-stage downcomer (5) respectively, and the first-stage downcomer (3), the second-stage downcomer (4) and the third-stage downcomer (5) are communicated with the liquid seal tank (2) respectively.

2. The tertiary injection system of claim 1, wherein, The first-stage spray valve (6), the second-stage spray valve (7) and the third-stage spray valve (8) are further included, and the first-stage spray valve (6), the second-stage spray valve (7) and the third-stage spray valve (8) are arranged on the corresponding first-stage spray pipe (16), second-stage spray pipe (17) and third-stage spray pipe (18) respectively.

3. The tertiary injection system of claim 1, wherein, The first-stage flushing valve (10), the second-stage flushing valve (11) and the third-stage flushing valve (12) are further included, and the first-stage flushing valve (10), the second-stage flushing valve (11) and the third-stage flushing valve (12) are all arranged on the flushing pipe (9), and the first-stage flushing valve (10), the second-stage flushing valve (11) and the third-stage flushing valve (12) are connected with the corresponding first-stage spray pipe (16), second-stage spray pipe (17) and third-stage spray pipe (18) respectively.

4. The tertiary injection system of claim 3, wherein, The first-stage flushing valve (10), the second-stage flushing valve (11) and the third-stage flushing valve (12) are all vacuum cock valves.

5. The tertiary injection system of claim 1, wherein, The first-stage downcomer short connection (13), the second-stage downcomer short connection (14) and the third-stage downcomer short connection (15) are further included, and the first-stage downcomer (3), the second-stage downcomer (4) and the third-stage downcomer (5) are communicated with the liquid seal tank (2) through the corresponding detachable first-stage downcomer short connection (13), second-stage downcomer short connection (14) and third-stage downcomer short connection (15) respectively.

6. The tertiary injection system of claim 5, wherein, The length of the first-stage downcomer short connection (13), the second-stage downcomer short connection (14) and the third-stage downcomer short connection (15) is 400-1000mm.

7. The tertiary injection system of claim 5, wherein, The two ends of the first-stage downcomer short connection (13), the second-stage downcomer short connection (14) and the third-stage downcomer short connection (15) are all connected by flanges.

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