PVC suspension polymerization discharging, filtering and cleaning device

Abstract

The utility model relates to the technical field of PVC (polyvinyl chloride) slurry filtration, in particular to a PVC suspension polymerization discharging, filtering and cleaning device, which comprises a PVC polymerization kettle, a slurry filter, a slurry intermediate treatment device, a centrifugal machine, a mother liquor tank and a nitrogen buffer tank, a second slurry pipeline is communicated between the slurry filter and the slurry intermediate treatment device, a third slurry pipeline is communicated between the slurry intermediate treatment device and the centrifugal machine, the centrifugal machine is communicated with a filter cake conveying device, and a mother liquor pipeline is communicated between the centrifugal machine and the mother liquor tank; a first backwashing pipeline is communicated between the mother liquor tank and the slurry filter; and a nitrogen purging pipeline is communicated between the nitrogen buffer tank and the slurry filter. The PVC slurry filtering device is reasonable and compact in structure and convenient to use, the PVC slurry filtering efficiency is improved, and the safety productivity of enterprises is also improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to PVC slurry filtering technical field, and it is a PVC suspension polymerization discharge filter cleaning device. BACKGROUND

[0002] Polyvinyl chloride (Polyvinyl chloride) is one of commonly used thermoplastics, and a chemical enterprise adopts PVC suspension polymerization process to prepare PVC product.

[0003] The principle of PVC suspension polymerization process is that vinyl chloride monomer, desalted water, steam, initiator, dispersing agent or other solution are input into polymerization kettle to carry out polymerization reaction, and then PVC slurry is obtained, and the PVC slurry is filtered, stripped, dried and sieved to obtain PVC product. In the PVC slurry filtering link, PVC plasticizer condenses on the filter screen of the filtering equipment and the inner wall of the filtering equipment, and also blocks the discharge port of the filtering equipment, resulting in reduced filtering efficiency. Therefore, the filtering equipment needs to be cleaned regularly to remove the larger plasticizer filtered in the filter screen. In this process, the cleaning efficiency of the filtering equipment is low, which directly affects the operation time of the polymerization kettle and reduces the production efficiency of the PVC product. In addition, during the process of removing the larger plasticizer in the filter screen, the residual vinyl chloride gas in the filtering equipment escapes, which is easy to cause poisoning accidents of on-site workers and may also cause fire and explosion risks.

[0004] In summary, there is an urgent need for a PVC suspension polymerization discharge filter cleaning device to solve the problems of low cleaning efficiency of the filtering equipment and high risk coefficient of cleaning operation. SUMMARY

[0005] The utility model provides a kind of PVC suspension polymerization discharge filter cleaning device, overcome the above prior art deficiency, it can effectively solve the low cleaning efficiency and high risk coefficient of cleaning operation of existing PVC suspension polymerization discharge filter cleaning.

[0006] The technical scheme of the utility model is realized through the following measures: a PVC suspension polymerization discharge filtering and cleaning device, including PVC polymerization kettle, slurry filter, slurry intermediate processing device, centrifuge, mother liquor water tank, nitrogen buffer tank, first slurry pipeline is fixedly connected between PVC polymerization kettle bottom outlet and slurry filter lower part first import, second slurry pipeline is fixedly connected between slurry filter upper part outlet and slurry intermediate processing device import, third slurry pipeline is fixedly connected between slurry intermediate processing device outlet and centrifuge import, the filter cake transport device is fixedly arranged at centrifuge bottom first outlet, mother liquor water pipeline is fixedly connected between centrifuge bottom second outlet and mother liquor water tank import, first backwashing pipeline is fixedly connected between mother liquor water tank top outlet and slurry filter lower part second import, nitrogen purge pipeline is fixedly connected between nitrogen buffer tank outlet and slurry filter top import.

[0007] The following is the further optimization or / and improvement of the above-mentioned utility model technical scheme:

[0008] The first backwashing pipeline is fixedly connected between the upper inlet of the slurry filter and the second backwashing pipeline.

[0009] The device further includes a sewage tank, a blowdown pipeline is fixedly connected between the bottom outlet of the slurry filter and the top first inlet of the sewage tank, and an exhaust pipeline is fixedly connected between the lower outlet of the slurry filter and the top second inlet of the sewage tank.

[0010] The device further includes a nitrogen generating device, and a nitrogen gas conveying pipeline is fixedly connected between the outlet of the nitrogen generating device and the top inlet of the nitrogen buffer tank.

[0011] The PVC polymerization kettle further includes a vinyl chloride pipeline fixedly connected to the top first inlet, a steam pipeline fixedly connected to the top second inlet, a polymerization aid pipeline fixedly connected to the bottom inlet, and a first gas phase recovery pipeline fixedly connected to the top outlet.

[0012] The top outlet of the slurry intermediate processing device is fixedly connected to a second gas phase recovery pipeline.

[0013] First and second conveying pumps are respectively fixedly installed on the second and third slurry pipelines, and a third conveying pump is fixedly installed on the first backwashing pipeline between the top outlet of the mother liquor water tank and the second backwashing pipeline.

[0014] A first remote pressure gauge and a first control valve are sequentially fixedly installed on the first backwashing pipeline between the third conveying pump and the second backwashing pipeline along the medium flow direction, and a second remote pressure gauge and a second control valve are sequentially fixedly installed on the nitrogen purge pipeline along the medium flow direction.

[0015] The third control valve is fixedly installed on the second slurry pipeline between the upper outlet of the slurry filter and the first conveying pump, the fourth control valve is fixedly installed on the blowdown pipeline, and the fifth control valve is fixedly installed on the exhaust pipeline.

[0016] The device further comprises a controller, and the first conveying pump, the second conveying pump, the third conveying pump, the first remote pressure gauge, the first control valve, the second remote pressure gauge, the second control valve, the third control valve, the fourth control valve and the fifth control valve are in electrical communication with the controller.

[0017] The slurry filter cleaning device is reasonable in structure, compact, convenient to use, improves the cleaning efficiency of the slurry filter, and enables the cleaning operation of the slurry filter to be safe and fast through replacement of residual vinyl chloride gas in the slurry filter by nitrogen, and further shortens the waiting time of the PVC polymerizer and improves the PVC product production rate of the enterprise. BRIEF DESCRIPTION OF DRAWINGS

[0018] BRIEF DESCRIPTION OF DRAWINGS Figure 1 The utility model discloses a process flow schematic diagram.

[0019] BRIEF DESCRIPTION OF DRAWINGS Figure 1 The codes in the drawings are as follows: 1 is a PVC polymerizer, 2 is a slurry filter, 3 is a slurry intermediate treatment device, 4 is a centrifugal machine, 5 is a mother liquor tank, 6 is a nitrogen buffer tank, 7 is a first slurry pipeline, 8 is a second slurry pipeline, 9 is a third slurry pipeline, 10 is a filter cake conveying device, 11 is a mother liquor pipeline, 12 is a first backwashing pipeline, 13 is a nitrogen purging pipeline, 14 is a second backwashing pipeline, 15 is a sewage tank, 16 is a blowdown pipeline, 17 is a nitrogen generating device, 18 is a nitrogen conveying pipeline, 19 is a vinyl chloride pipeline, 20 is a steam pipeline, 21 is a polymerization auxiliary agent pipeline, 22 is a first gas phase recovery pipeline, 23 is a second gas phase recovery pipeline, 24 is a first conveying pump, 25 is a second conveying pump, 26 is a third conveying pump, 27 is a first remote pressure gauge, 28 is a first control valve, 29 is a second remote pressure gauge, 30 is a second control valve, 31 is a third control valve, 32 is a fourth control valve, 33 is a filter screen, 34 is an exhaust pipeline, and 35 is a fifth control valve. DETAILED DESCRIPTION

[0020] The utility model is not limited by the following embodiments, and the specific implementation mode can be determined according to the technical scheme and actual situation of the utility model.

[0021] In the utility model, if no special instruction is given, the equipment and device used are all the equipment and device commonly known in the prior art.

[0022] In the utility model, in order to facilitate the description, the relative position relation of each component is described according to the drawings. Figure 1The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0023] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0024] Example 1: As shown in the attached document Figure 1 As shown, the PVC suspension polymerization discharge filtration and cleaning device includes a PVC polymerization reactor 1, a slurry filter 2, a slurry intermediate treatment device 3, a centrifuge 4, a mother liquor tank 5, and a nitrogen buffer tank 6. A first slurry pipeline 7 is fixedly connected between the bottom outlet of the PVC polymerization reactor 1 and the lower first inlet of the slurry filter 2. A second slurry pipeline 8 is fixedly connected between the upper outlet of the slurry filter 2 and the inlet of the slurry intermediate treatment device 3. A third slurry pipeline 9 is fixedly connected between the outlet of the slurry intermediate treatment device 3 and the inlet of the centrifuge 4. A filter cake conveying device 10 is fixedly installed at the bottom first outlet of the centrifuge 4. A mother liquor pipeline 11 is fixedly connected between the bottom second outlet of the centrifuge 4 and the inlet of the mother liquor tank 5. A first backwashing pipeline 12 is fixedly connected between the top outlet of the mother liquor tank 5 and the lower second inlet of the slurry filter 2. A nitrogen purging pipeline 13 is fixedly connected between the outlet of the nitrogen buffer tank 6 and the top inlet of the slurry filter 2.

[0025] As needed, the slurry filter 2 is equipped with a metal filter screen 33, which is used to filter out large particles of plasticizers in the PVC slurry.

[0026] As needed, the intermediate slurry treatment device 3 may include a discharge trough, a mixing trough, a wide-channel heat exchanger, a centrifuge feed trough, and a stripping tower. The discharge trough and mixing trough are used to buffer and eliminate monomers in the PVC slurry. The wide-channel heat exchanger uses the hot slurry at the bottom of the stripping tower and the cold slurry entering the tower for heat exchange, thereby increasing the inlet temperature and decreasing the outlet temperature. The centrifuge feed trough is used to buffer and mix the PVC slurry evenly before it enters the centrifuge for dehydration.

[0027] The above-mentioned PVC suspension polymerization discharge filtration and cleaning device can be further optimized and / or improved according to actual needs:

[0028] Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1 As shown, a second backwashing pipeline 14 is fixedly connected between the first backwashing pipeline 12 and the upper inlet of the slurry filter 2.

[0029] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1As shown, the device also includes a sewage tank 15, a sewage discharge pipeline 16 is fixedly connected between the bottom outlet of the slurry filter 2 and the first inlet at the top of the sewage tank 15, and an exhaust pipeline 34 is fixedly connected between the lower outlet of the slurry filter 2 and the second inlet at the top of the sewage tank 15.

[0030] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, the device also includes a nitrogen generator 17, and a nitrogen delivery pipeline 18 is fixedly connected between the outlet of the nitrogen generator 17 and the top inlet of the nitrogen buffer tank 6.

[0031] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, the first inlet at the top of the PVC polymerization reactor 1 is fixedly connected to a vinyl chloride pipeline 19, the second inlet at the top of the PVC polymerization reactor 1 is fixedly connected to a steam pipeline 20, the bottom inlet of the PVC polymerization reactor 1 is fixedly connected to a polymerization aid pipeline 21, and the top outlet of the PVC polymerization reactor is fixedly connected to a first gas phase recovery pipeline 22.

[0032] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1 As shown, the top outlet of the intermediate slurry treatment device 3 is fixedly connected to the second gas phase recovery pipeline 23.

[0033] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1 As shown, a first delivery pump 24 and a second delivery pump 25 are fixedly installed on the second slurry pipeline 8 and the third slurry pipeline 9, respectively, and a third delivery pump 26 is fixedly installed on the first backwash pipeline 12 between the top outlet of the mother liquor tank 5 and the second backwash pipeline 14.

[0034] Example 8: It differs from Examples 1 to 7 in that: as shown in the appendix Figure 1 As shown, a first remote pressure gauge 27 and a first control valve 28 are fixedly installed in sequence along the medium flow direction on the first backflushing pipeline 12 between the third delivery pump 26 and the second backflushing pipeline 14, and a second remote pressure gauge 29 and a second control valve 30 are fixedly installed in sequence along the medium flow direction on the nitrogen purging pipeline 13.

[0035] Example 9: It differs from Examples 1 to 8 in that: as shown in the appendix Figure 1 As shown, a third control valve 31 is fixedly installed on the second slurry pipeline 8 between the upper outlet of the slurry filter 2 and the first delivery pump 24, a fourth control valve 32 is fixedly installed on the sewage pipeline 16, and a fifth control valve 35 is fixedly installed on the exhaust pipeline 34.

[0036] Example 10: It differs from Examples 1 to 9 in that, as shown in the appendix... Figure 1Also shown, the controller, the first delivery pump 24, the second delivery pump 25, the third delivery pump 26, the first remote pressure gauge 27, the first control valve 28, the second remote pressure gauge 29, the second control valve 30, the third control valve 31, the fourth control valve 32, the fifth control valve 35 are all in electrical communication with the controller.

[0037] According to the need, the PVC suspension polymerization discharge filter cleaning device, and the equipment on each pipeline, according to the production needs, the conventional valve, thermometer and pressure gauge commonly known in the art can be provided. The controller is a DCS controller, and the model of the DCS controller can be a CS3000 controller produced by Yokogawa Corporation of Japan.

[0038] In summary, the slurry filter cleaning efficiency is improved, and the residual vinyl chloride gas in the slurry filter is replaced by nitrogen, which is safe and fast to operate, thereby shortening the PVC polymerization kettle waiting time, improving the enterprise PVC product production rate, effectively avoiding the personnel poisoning, fire and explosion risk caused by the escape of toxic and harmful substances in the slurry filter, effectively reducing the incidence of occupational diseases of workers, and realizing the green and environmentally-friendly production operation mode.

[0039] The above technical features respectively constitute each embodiment of the present application, which has strong adaptability and implementation effect, and unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.

[0040] The use process of the embodiment of the utility model: first, the gas phase medium in the PVC polymerization kettle 1 enters the downstream process system for recycling treatment through the first gas phase recycling pipeline 22, the product PVC slurry in the PVC polymerization kettle 1 enters the filter screen 33 in the slurry filter 2 through the first slurry pipeline 7, the larger plasticizing material in the PVC slurry is filtered and removed, and homogeneous PVC slurry is obtained;Then, the homogeneous PVC slurry enters the slurry intermediate treatment device 3 for gas phase recycling through the second slurry pipeline 8, and the gas phase medium in the intermediate treatment device 3 enters the downstream process system for recycling treatment through the second gas phase recycling pipeline 23;Finally, the PVC slurry after cooling enters the centrifuge 4 for dewatering treatment through the third slurry pipeline 9, the PVC slurry after dewatering enters the downstream process system for drying treatment through the filter cake conveying device 10, and the water removed from the PVC slurry is stored in the mother liquor water tank 5 through the mother liquor water pipeline 11 for standby.

[0041] The use process of the above embodiment further includes that after the slurry filter 2 is operated for a certain period of time, the filtered PVC plasticizing material in the slurry filter 2 will condense on the filter screen 33 and the inner wall of the slurry filter 2, and will also block the blowdown port at the bottom of the slurry filter 2. Therefore, the cleaning process of the slurry filter 2 includes that first, the liquid in the mother liquor tank 5 is used to perform high-pressure flushing on the slurry filter 2 through the first backwashing pipeline 12 and the second backwashing pipeline 14, respectively, the filtered solution enters the slurry intermediate treatment device 3 through the second slurry pipeline 8, and then enters the centrifugal machine 4 through the third slurry pipeline 9 to perform dewatering filtration; then, the PVC material after dewatering filtration enters the downstream process system through the filter cake conveying device 10 to perform drying treatment, and the moisture after dewatering filtration enters the mother liquor tank 5 through the mother liquor pipeline 11 to be stored for standby use; finally, the nitrogen gas in the nitrogen buffer tank 6 enters the slurry filter 2 through the nitrogen gas purging pipeline 13 to perform purging replacement on the residual vinyl chloride gas in the slurry filter 2, and the vinyl chloride gas replaced out of the slurry filter 2 is discharged into the sewage tank 15 through the exhaust pipeline 34.

Claims

1. A PVC suspension polymerization discharge filtration cleaning device, characterized in that The device comprises a PVC polymerization kettle, a slurry filter, a slurry intermediate treatment device, a centrifuge, a mother liquor water tank, and a nitrogen buffer tank.

2. The PVC suspension polymerization discharge filter cleaning device according to claim 1, characterized in that The first backwashing pipeline is fixedly connected between the first upper inlet of the slurry filter and the second backwashing pipeline.

3. The PVC suspension polymerization discharge filter cleaning device according to claim 2, characterized in that The device further comprises a sewage tank, and the slurry filter is fixedly connected between the bottom outlet of the slurry filter and the first top inlet of the sewage tank through a sewage pipeline.

4. The PVC suspension polymerization discharge filter cleaning device according to claim 3, characterized in that The device further comprises a nitrogen production device, and the nitrogen production device is fixedly connected between the outlet of the nitrogen production device and the top inlet of the nitrogen buffer tank through a nitrogen conveying pipeline.

5. The PVC suspension polymerization discharge filter cleaning device according to claim 1 or 2 or 3 or 4, characterized in that The PVC polymerization kettle is fixedly connected between the first top inlet of the PVC polymerization kettle and the vinyl chloride pipeline, and the second top inlet of the PVC polymerization kettle and the steam pipeline.

6. The PVC suspension polymerization discharge filter cleaning device according to claim 5, characterized in that The slurry intermediate treatment device is fixedly connected between the top outlet of the slurry intermediate treatment device and the second gas phase recovery pipeline.

7. The PVC suspension polymerization discharge filter cleaning device according to claim 2 or 3 or 4 or 6, characterized in that The first conveying pump and the second conveying pump are respectively fixedly installed on the second slurry pipeline and the third slurry pipeline.

8. The PVC suspension polymerization discharge filter cleaning device according to claim 7, characterized in that The third conveying pump is fixedly installed on the first backwashing pipeline between the third conveying pump and the second backwashing pipeline.

9. The PVC suspension polymerization discharge filter cleaning device according to claim 8, characterized in that The first remote pressure gauge and the first control valve are fixedly installed on the first backwashing pipeline between the third conveying pump and the second backwashing pipeline along the medium flow direction.

10. The PVC suspension polymerization discharge filtration and cleaning device according to claim 9, characterized in that The third control valve is fixedly installed on the second slurry pipeline between the upper outlet of the slurry filter and the first conveying pump, the fourth control valve is fixedly installed on the sewage pipeline, and the fifth control valve is fixedly installed on the exhaust pipeline. The first conveying pump, the second conveying pump, the third conveying pump, the first remote pressure gauge, the first control valve, the second remote pressure gauge, the second control valve, the third control valve, the fourth control valve, and the fifth control valve are electrically connected to the controller.

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