An integrated degassing and elutriation system for polyolefin material

Abstract

The application relates to the technical field of chemical machinery, and discloses a degassing and elutriation integrated system for polyolefin materials, which comprises a polyolefin material extruder, a buffer hopper connected to the lower end of the polyolefin material extruder through a first pipeline, a first pneumatic slide valve connected to the lower end of the buffer hopper through the first pipeline, a first rotary valve connected to the lower end of the first pneumatic slide valve through the first pipeline, a conveying device connected to the lower end of the first rotary valve through the first pipeline, an elutriation device connected to the conveying device, a degassing device connected to the lower end of the elutriation device, a packaging device connected to the lower end of the degassing device, and a waste gas treatment device connected to the upper end of the elutriation device. The application improves product quality, reduces the initial investment cost of the system and the operation and maintenance cost in the future.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical machinery, in particular to a degassing and elutriation integrated system for polyolefin materials. BACKGROUND

[0002] Polyolefin materials have been widely used at present, especially for new polyolefin materials such as EVA / LDPE / POE, which are widely used in the fields of foamed shoe materials, functional shed films, packaging films, hot melt adhesives, electric wires and cables, toys and the like due to their excellent performance. With the increasing demand at home and abroad, a plurality of production devices for new materials are being built in China.

[0003] In the production process of EVA / LDPE / POE, a large amount of monomers such as ethylene and vinyl acetate (VOC) remains in the EVA / LDPE / POE particles after the polymerization and granulation processes, and is continuously precipitated. The aggregation and residue of these volatiles can cause safety problems in the production process. The role of the degassing system is to blow the particulate material with a large amount of air within a certain time to remove the volatiles and bring them into the downstream RTO system for harmless treatment. Only after the particles are sufficiently degassed can they be transported, packaged, transported and the like.

[0004] At present, the requirements for the quality and packaging of plastic particles are becoming more and more stringent, and the degree of automation is also increasing. Since qualified plastic particles cannot contain too much dust, otherwise it will cause unstable or unqualified quality of downstream products, therefore, before packaging, the plastic particles must be elutriated to remove dust and drawn material.

[0005] At present, the production process of EVA / LDPE is controlled by foreign well-known processes such as ExxonMobil, Lyondellbasell, ECI Group and Dow Chemical, and most of the degassing systems are also introduced in combination with the device patent. The self-research and application in this field in China are still in a blank state.

[0006] Therefore, a degassing and elutriation integrated system for polyolefin materials is provided. SUMMARY

[0007] The purpose of the present application is to overcome the existing defects and provide a degassing and elutriation integrated system for polyolefin materials, which improves the product quality and reduces the system investment cost and the operation and maintenance cost in the future.

[0008] The technical scheme for achieving the above-mentioned purpose is as follows:

[0009] An integrated system for degassing and washing polyolefin materials includes a polyolefin material extruder, the lower end of which is connected to a buffer hopper via a first pipe, the lower end of which is connected to a first pneumatic sliding plate valve via the first pipe, the lower end of which is connected to a first rotary valve via the first pipe, the lower end of which is connected to a conveying device via the first pipe, the conveying device is connected to a washing device, the lower end of which is connected to a degassing device, the lower end of which is connected to a packaging device, and the upper end of which is connected to a waste gas treatment device.

[0010] Preferably, it also includes a start-stop control device for the control system; the start-stop control device adopts a PLC automatic control system.

[0011] Preferably, a first high level switch and a first low level switch are respectively provided at the top and bottom of one side of the buffer hopper.

[0012] Preferably, the conveying device includes a pipeline network, which is connected to a first pneumatic butterfly valve via a second pipeline. The first pneumatic butterfly valve is connected to a flow regulating valve via the second pipeline. The flow regulating valve is connected to a ball valve via the second pipeline. The ball valve is connected to a first pressure transmitter via the second pipeline. The first pressure transmitter is connected to a feeding shoe via the second pipeline. The feeding shoe is connected to the washing device via the first pipeline. The lower end of the first rotary valve is connected to the feeding shoe via the first pipeline.

[0013] Preferably, the washing device includes a washing unit, the lower end of which is connected to the degassing device, the right end of which is connected to a hydrocarbon analyzer via a third pipe, the hydrocarbon analyzer via the third pipe to a first temperature transmitter, the first temperature transmitter via the third pipe to a second pneumatic butterfly valve, the second pneumatic butterfly valve via the third pipe to a bag filter, the lower end of which is connected to a manual sliding valve via the third pipe, the lower end of which is connected to a second rotary valve via the third pipe, the lower end of which is connected to a ton bag via the third pipe, the feeding shoe via the first pipe to the washing unit, the upper end of which is connected to the waste gas treatment device via the third pipe, and a third pneumatic butterfly valve is provided on a branch of the third pipe between the first temperature transmitter and the second pneumatic butterfly valve.

[0014] Preferably, a first sight glass is provided on the side of the washing device, a first differential pressure transmitter is provided on one side of the bag filter, and a second high-level switch is provided at the lower end of the other side of the bag filter.

[0015] Preferably, the degassing device includes a degassing fan, which is connected to a heat exchanger via a fourth pipe. The heat exchanger is connected to a second temperature transmitter via the fourth pipe. The second temperature transmitter is connected to a multi-function filter via the fourth pipe. The multi-function filter is connected to the degassing chamber in three separate paths via the fourth pipe. The lower end of the washer is connected to the degassing chamber.

[0016] Preferably, a second differential pressure transmitter is provided on one side of the multi-stage filter, a third high-level switch is provided at the lower end of the other side of the multi-stage filter, a drain valve is connected to the lower end of the multi-stage filter, a high-high-level switch, a fourth high-level switch and a second low-level switch are provided sequentially from top to bottom on one side of the degassing chamber, and a second pressure transmitter is provided at the upper end of the degassing chamber.

[0017] Preferably, the lower end of the degassing chamber is connected to a second pneumatic sliding plate generator, and the lower end of the second pneumatic sliding plate generator is connected to the packaging device through a fifth pipe.

[0018] Preferably, the heat exchanger is cooled by circulating water through a CHWS (hot water supply pipe) supply pipe and a CHWR (hot water return pipe) return pipe, and a temperature regulating valve is installed on the CHWR return pipe.

[0019] The beneficial effects of this invention are as follows: This invention utilizes a degassing fan as an air source to wash materials during material conveying, removing dust and fibrous materials. This reduces equipment configuration, saves investment and maintenance costs, and lowers energy consumption. A normal configuration requires a washer, a centrifugal washer, a dust collector, a rotary valve, valves, and instruments, while the degassing silo washing system only requires a washer. The bag filter and rotary valve can directly utilize the exhaust gas from the degassing system's bag filter and second rotary valve, reducing equipment investment by more than 60%. The polyolefin material is conveyed to the washer via a conveying device. After passing through the degassing fan, the washing air enters the washer and washes the polyolefin material. The washed polyolefin material then enters the degassing chamber and finally the packaging device. The dust from the washing process is discharged into the bag filter. Finally, the material is collected in ton bags. A degassing fan provides washing air to the polyolefin material in the washing machine, reducing the dust content falling into the degassing chamber. The dust content in the degassing chamber can be controlled below 50 ppm. With an airflow regulating device, the dust content can be reduced to below 30 ppm, meeting the requirement of direct packaging at the bottom of the degassing chamber. After reducing the dust content in the degassing chamber, the washing frequency can also be reduced accordingly, thereby reducing wastewater generation and further saving operating costs. The washing machine is equipped with a first viewing mirror, allowing direct observation of the washing effect. This invention reduces system configuration, lowers the dust content of the finished polyolefin material, increases production safety, improves product quality, and simultaneously reduces the initial investment cost and subsequent operation and maintenance costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an integrated system for degassing and washing polyolefin materials according to the present invention.

[0021] In the diagram: 1. Polyolefin material extruder; 2. Buffer hopper; 3. First pneumatic sliding plate valve; 4. First rotary valve; 5. First pipeline; 21. First high level switch; 22. First low level switch; 61. Piping network; 62. First pneumatic butterfly valve; 63. Flow regulating valve; 64. Ball valve; 65. First pressure transmitter; 66. Feed shoe; 67. Second pipeline; 71. Washer; 72. Hydrocarbon analyzer; 73. First temperature transmitter; 74. Second pneumatic butterfly valve; 75. Bag filter; 76. Manual sliding plate valve; 77. Second rotary valve; 78. Ton bag; 79. Third pipeline; 710. Third pneumatic butterfly valve; 711. First sight glass; 751. First pressure... Differential pressure transmitter; 752, Second high level switch; 81, Degassing fan; 82, Heat exchanger; 83, Second temperature transmitter; 84, Multi-function filter; 85, Degassing chamber; 86, Fourth pipeline; 87, Second pneumatic slide gate; 9, Fifth pipeline; 821, CHWS water supply pipe; 822, CHWR water return pipe; 823, Temperature regulating valve; 841, Second differential pressure transmitter; 842, Third high level switch; 843, Drain valve; 851, High-high level switch; 852, Fourth high level switch; 853, Second low level switch; 854, Second pressure transmitter; 10, Packaging device; 11, Waste gas treatment device; 12, Start-stop control device. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1The present invention discloses an integrated system for degassing and washing polyolefin materials, comprising a polyolefin material extruder 1, wherein the lower end of the polyolefin material extruder 1 is connected to a buffer hopper 2 via a first pipe 5, the lower end of the buffer hopper 2 is connected to a first pneumatic sliding valve 3 via a first pipe 5, the lower end of the first pneumatic sliding valve 3 is connected to a first rotary valve 4 via a first pipe 5, the lower end of the first rotary valve 4 is connected to a conveying device via a first pipe 5, the conveying device is connected to a washing device, the lower end of the washing device is connected to a degassing device, the lower end of the degassing device is connected to a packaging device 10, and the upper end of the washing device is connected to a waste gas treatment device 11.

[0025] The embodiment also includes a start-stop control device 12 for controlling the system; the start-stop control device 12 adopts a PLC automatic control system to realize the fully automatic start-stop of the system.

[0026] In this embodiment, a first high level switch 21 and a first low level switch 22 are respectively installed at the top and bottom of one side of the buffer hopper 2. These switches can control the speed of the polyolefin material extruded by the polyolefin material extruder 1. When the polyolefin material level is higher than the first high level switch 21, the first high level switch 21 will send a signal and display an alarm signal on the start / stop control device 12 to remind the operator to check and maintain the material.

[0027] In this embodiment, the conveying device includes a pipeline network 61, which is connected to a first pneumatic butterfly valve 62 via a second pipe 67. The first pneumatic butterfly valve 62 is connected to a flow regulating valve 63 via the second pipe 67. The flow regulating valve 63 is connected to a ball valve 64 via the second pipe 67. The ball valve 64 is connected to a first pressure transmitter 65 via the second pipe 67. The first pressure transmitter 65 is connected to a feeding shoe 66 via the second pipe 67. The feeding shoe 66 is connected to a washing device via a first pipe 5. The lower end of the first rotary valve 4 is connected to the feeding shoe 66 via the first pipe 5.

[0028] To start the conveying device, first close the flow regulating valve 63 and open the first pneumatic butterfly valve 62. The flow regulating valve 63 adjusts the required conveying air volume according to the set ball valve 64. Then, start the first rotary valve 4. After the first rotary valve 4 is started, open the first pneumatic sliding valve 3 at the outlet of the buffer hopper 2. The first pressure transmitter 65 monitors the conveying pressure in real time. The air source sprays out from the pipeline 61, thereby conveying the polyolefin material to the washing machine 71.

[0029] In this embodiment, the washing device includes a washing machine 71. The lower end of the washing machine 71 is connected to a degassing device. The right end of the washing machine 71 is connected to a hydrocarbon analyzer 72 via a third pipe 79. The hydrocarbon analyzer 72 is connected to a first temperature transmitter 73 via the third pipe 79. The first temperature transmitter 73 is connected to a second pneumatic butterfly valve 74 via the third pipe 79. The second pneumatic butterfly valve 74 is connected to a bag filter 75 via the third pipe 79. The lower end of the bag filter 75 is connected to a manual sliding valve 76 via the third pipe 79. The lower end of the manual sliding valve 76 is connected to a second rotary valve 77 via the third pipe 79. The lower end of the second rotary valve 77 is connected to a ton bag 78 via the third pipe 79. The feeding shoe 66 is connected to the washing machine 71 via a first pipe 5. The upper end of the bag filter 75 is connected to a waste gas treatment device 11 via the third pipe 79. A third pneumatic butterfly valve 710 is provided on a branch of the third pipe 79 between the first temperature transmitter 73 and the second pneumatic butterfly valve 74.

[0030] In this embodiment, a first sight glass 711 is provided on the side of the washing machine 71, which can be used to directly observe the washing effect; a first differential pressure transmitter 751 is provided on one side of the bag filter 75. The first differential pressure transmitter 751 is used to monitor the differential pressure of the bag filter 75 in real time. If the differential pressure exceeds the set alarm value, the first differential pressure transmitter 751 will send a signal and display an alarm status on the start-stop control device 12, alerting the operator that the bag filter needs to be inspected and maintained; a second high level switch 752 is provided at the lower end of the other side of the bag filter 75. When the material level in the bag filter 75 is higher than the second high level switch 752, the second high level switch 752 will send a signal and display an alarm signal on the start-stop control device 12, reminding the operator to inspect and maintain.

[0031] Start the washing device, open the second pneumatic butterfly valve 74 and the third pneumatic butterfly valve 710 between the washer 71 and the bag filter 75, and then start the second rotary valve 77 at the bag filter 75 and the discharge port. It begins to blow and clean the inside of the bag filter 75. The dust collected by the bag filter 75 is discharged into the waste ton bag 78 through the second rotary valve 77, while the clean gas is discharged to the waste gas treatment device 11. Since the second rotary valve 77 has the dual function of air lock and unloading, it can ensure synchronous operation with the bag filter 75.

[0032] In this embodiment, the degassing device includes a degassing fan 81, which is connected to a heat exchanger 82 via a fourth pipe 86. The heat exchanger 82 is connected to a second temperature transmitter 83 via the fourth pipe 86. The second temperature transmitter 83 is connected to a multi-function filter 84 via the fourth pipe 86. The multi-function filter 84 is connected to the degassing chamber 85 in three separate paths via the fourth pipe 86. The lower end of the washer 71 is connected to the degassing chamber 85.

[0033] A second differential pressure transmitter 841 is installed on one side of the multi-stage filter 84, and a third high-level switch 842 is installed at the lower end of the other side of the multi-stage filter 84. A steam trap 843 is connected to the lower end of the multi-stage filter 84. The lower layer of the multi-stage filter 84 has a demisting function, capturing and collecting free water in the fourth pipe 86, which is then discharged through the steam trap 843. The upper layer of the multi-stage filter 84 filters impurities from the air to prevent them from affecting product quality. The multi-stage filter 84 is equipped with a third high-level switch 842 and a second differential pressure transmitter 841. When the water level in the multi-stage filter 84 is higher than the third high-level switch 842, the third high-level switch 842 will send a signal. When the multi-stage filter 84 exceeds the set differential pressure value, the second differential pressure transmitter 841 will send a signal and display an alarm signal on the start / stop control device 12 to remind the operator to check and maintain it. A high-level switch 851, a fourth high-level switch 852 and a second low-level switch 853 are arranged sequentially from top to bottom on one side of the degassing chamber 85. A second pressure transmitter 854 is arranged at the upper end of the degassing chamber 85.

[0034] In this embodiment, the lower end of the degassing chamber 85 is connected to the second pneumatic slide plate generator 87, and the lower end of the second pneumatic slide plate generator 87 is connected to the packaging device 10 through the fifth pipe 9.

[0035] In this embodiment, the heat exchanger 82 is cooled by circulating water through the CHWS water supply pipe 821 and the CHWR water return pipe 822. A temperature regulating valve 823 is installed on the CHWR water return pipe 822 to control the temperature of the degassing air to the temperature required by the product.

[0036] Start the degassing device; start the degassing fan 81 and the multi-function filter 84. The heat exchanger 82 controls the temperature of the air to the required temperature of the product through the temperature regulating valve 823. The multi-function filter 84 captures and collects the free water in the fourth pipe 86 and discharges it through the drain valve 843. It also filters impurities in the air to prevent impurities from affecting the product quality. The air source is then blown into the degassing chamber 85 to provide washing air for the whole system. The washed material falls into the degassing chamber 85 at the bottom of the washer 71 and finally enters the packaging device 10 for direct packaging of the material.

[0037] The integrated degassing and washing system for polyolefin materials enables simultaneous feeding and washing, reducing the dust content in the degassing chamber 85 to below 50 ppm. With the addition of an airflow adjustment function, the dust content can be reduced to below 30 ppm, allowing the degassing chamber 85 to directly enter the packaging device 10 for packaging. The reduced dust content in the degassing chamber 85 also reduces the washing frequency, thereby decreasing wastewater generation and further saving operating costs.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated system for degassing and washing polyolefin materials, comprising a polyolefin material extruder (1), characterized in that, The lower end of the polyolefin material extruder (1) is connected to the buffer hopper (2) through the first pipe (5). The lower end of the buffer hopper (2) is connected to the first pneumatic slide valve (3) through the first pipe (5). The lower end of the first pneumatic slide valve (3) is connected to the first rotary valve (4) through the first pipe (5). The lower end of the first rotary valve (4) is connected to the conveying device through the first pipe (5). The conveying device is connected to the washing device. The lower end of the washing device is connected to the degassing device. The lower end of the degassing device is connected to the packaging device (10). The upper end of the washing device is connected to the waste gas treatment device (11). The conveying device includes a pipeline (61), which is connected to a first pneumatic butterfly valve (62) via a second pipe (67). The first pneumatic butterfly valve (62) is connected to a flow regulating valve (63) via the second pipe (67). The flow regulating valve (63) is connected to a ball valve (64) via the second pipe (67). The ball valve (64) is connected to a first pressure transmitter (65) via the second pipe (67). The first pressure transmitter (65) is connected to a feeding shoe (66) via the second pipe (67). The feeding shoe (66) is connected to the washing device via the first pipe (5). The lower end of the first rotary valve (4) is connected to the feeding shoe (66) via the first pipe (5). The washing device includes a washer (71), the lower end of which is connected to the degassing device. The right end of the washer (71) is connected to a hydrocarbon analyzer (72) via a third pipe (79). The hydrocarbon analyzer (72) is connected to a first temperature transmitter (73) via the third pipe (79). The first temperature transmitter (73) is connected to a second pneumatic butterfly valve (74) via the third pipe (79). The second pneumatic butterfly valve (74) is connected to a bag filter (75) via the third pipe (79). The lower end of the bag filter (75) is connected to a manual slide via the third pipe (79). The manual sliding valve (76) is connected to the second rotary valve (77) via the third pipe (79) at its lower end. The second rotary valve (77) is connected to the ton bag (78) via the third pipe (79) at its lower end. The feeding shoe (66) is connected to the washing machine (71) via the first pipe (5). The bag filter (75) is connected to the waste gas treatment device (11) via the third pipe (79) at its upper end. A third pneumatic butterfly valve (710) is provided on the branch of the third pipe (79) between the first temperature transmitter (73) and the second pneumatic butterfly valve (74).

2. The integrated system for degassing and washing polyolefin materials according to claim 1, characterized in that, It also includes a start-stop control device (12) for the control system; the start-stop control device (12) adopts a PLC automatic control system.

3. The integrated system for degassing and washing polyolefin materials according to claim 1, characterized in that, The buffer hopper (2) is provided with a first high level switch (21) and a first low level switch (22) at the top and bottom of one side.

4. The integrated system for degassing and washing polyolefin materials according to claim 1, characterized in that, The washing machine (71) is provided with a first sight glass (711) on its side, the bag filter (75) is provided with a first differential pressure transmitter (751) on one side, and the bag filter (75) is provided with a second high level switch (752) at the lower end of the other side.

5. The integrated system for degassing and washing polyolefin materials according to claim 1, characterized in that, The degassing device includes a degassing fan (81), which is connected to a heat exchanger (82) via a fourth pipe (86). The heat exchanger (82) is connected to a second temperature transmitter (83) via the fourth pipe (86). The second temperature transmitter (83) is connected to a multi-function filter (84) via the fourth pipe (86). The multi-function filter (84) is connected to the degassing chamber (85) in three separate paths via the fourth pipe (86). The lower end of the washer (71) is connected to the degassing chamber (85).

6. The integrated system for degassing and washing polyolefin materials according to claim 5, characterized in that, A second differential pressure transmitter (841) is provided on one side of the multi-stage filter (84), a third high level switch (842) is provided at the lower end of the other side of the multi-stage filter (84), a drain valve (843) is connected to the lower end of the multi-stage filter (84), a high-high level switch (851), a fourth high level switch (852) and a second low level switch (853) are provided sequentially from top to bottom on one side of the degassing chamber (85), and a second pressure transmitter (854) is provided at the upper end of the degassing chamber (85).

7. The integrated system for degassing and washing polyolefin materials according to claim 5, characterized in that, The lower end of the degassing chamber (85) is connected to the second pneumatic slide plate generator (87), and the lower end of the second pneumatic slide plate generator (87) is connected to the packaging device (10) through the fifth pipe (9).

8. The integrated system for degassing and washing polyolefin materials according to claim 5, characterized in that, The heat exchanger (82) is cooled by circulating water through the CHWS water supply pipe (821) and the CHWR water return pipe (822), and a temperature regulating valve (823) is provided on the CHWR water return pipe (822).

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