Equipment for continuously melting polyphenylene sulfide resin to remove low-molecular substances and use method

Abstract

The invention relates to the technical field of polyphenylene sulfide impurity removal, in particular to equipment for continuously melting polyphenylene sulfide resin to remove low-molecular-weight substances and a use method.The equipment comprises a melting extraction mechanism, a condensation mechanism, a vacuum stabilization mechanism, a tail gas treatment mechanism and a collection mechanism, and the melting extraction mechanism communicates with a treatment container of the collection mechanism; a condensing pipe of the condensing mechanism is arranged in the treatment container, the top end of the treatment container is communicated with the vacuum stabilizing mechanism, and the vacuum stabilizing mechanism is communicated with the tail gas treatment mechanism. According to the equipment for continuously melting the polyphenylene sulfide resin to remove the low-molecular-weight substances and the using method, the backflow-preventing extraction screw rod stably extracts the low-molecular-weight substances in time during melting and prevents the low-molecular-weight substances from being condensed and refluxed, meanwhile, the vacuum stabilizing mechanism automatically adjusts the vacuum degree in the equipment, and therefore the low-molecular-weight substances can be continuously removed. And the vacuum degree is always in a stable range.

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene sulfide impurity removal, and in particular to a device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances and a use method thereof. Background Art

[0002] High-performance polyphenylene sulfide special engineering plastics have been developed rapidly in China in the past decade or so due to their wide application, and the market demand is strong. Polyphenylene sulfide fiber-grade powder can be made into filaments and staple fibers, etc. Due to its good textile processing performance and excellent chemical resistance, thermal stability, high temperature resistance and flame retardancy, it is widely used in environmental protection, flue dust removal, high-temperature filtration in the chemical industry, and aerospace fields, such as high-temperature flue filter bags for coal-fired boilers in thermal power plants, waste incineration, etc., corrosion-resistant filter cloths in papermaking and chemical industries, drying belts and needle-punched felts in the electrical industry; new energy battery diaphragms, special cable sheaths; flame-retardant fabrics in the aerospace industry, etc. In recent years, its application in hydrogen energy water electrolysis hydrogen production diaphragms has been more prominent.

[0003] At present, the synthesis of polyphenylene sulfide resin is basically synthesized in solvent. Although it has undergone washing, purification, drying and other processes, the finished resin powder still contains a certain amount of solvent, oligomers and other low molecular weight substances. And the specific gravity of polyphenylene sulfide is 1.35 g / cm 3 , but the bulk density of the powder is about 0.72-0.33g / cm 3 The lowest is only 0.33 g / cm 3 The specific gravity of the fiber is about 1.35-1.38 g / cm 3 From this, we can see that the air content in the powder accumulation is as high as more than 70%. During granulation, the air will directly enter the twin screw along with the powder material. These low molecular weight substances in the resin are also vaporized due to high temperature heating and extrusion. To avoid these low molecular weight substances affecting the quality of the next product, they must be removed in time.

[0004] The traditional method is to discharge or suck out from the vertical interface above the twin screw, and there is no stable control system to adjust the suction volume in time according to the change of the amount of gas generated by the extracted object. When the gas volume is large, low molecular weight substances are not sucked out in time. When the gas volume is small, the melt is sucked out and the suction pipeline is blocked. At the same time, it is easy for condensate to flow back into the melt at the exhaust port, thus affecting the quality of the finished product. There is also a method of sucking from the side of the twin screw, but the side suction effect is not as good as the suction effect directly above the twin screw. Summary of the invention

[0005] The purpose of the present invention is to provide a device and a method for continuously removing low-molecular substances from polyphenylene sulfide resin by melting, which can timely and stably extract low-molecular substances during melting and prevent low-molecular substances from condensing and refluxing.

[0006] To achieve the above-mentioned purpose, the present invention provides an apparatus for continuously melting polyphenylene sulfide resin to remove low-molecular substances, comprising a melt extraction mechanism, a condensation mechanism, a vacuum stabilization mechanism, an exhaust gas treatment mechanism and a collection mechanism, the melt extraction mechanism is connected to a processing container of the collection mechanism, a condensation tube of the condensation mechanism is provided in the processing container, the top of the processing container is connected to the vacuum stabilization mechanism, and the vacuum stabilization mechanism is connected to the exhaust gas treatment mechanism.

[0007] Preferably, the melting screw of the melting extraction mechanism is connected to a pipeline, an anti-backflow extraction screw is provided in the inclined section of the pipeline, a heating and insulation sleeve is provided on the pipeline sleeve at the anti-backflow extraction screw, and the top end of the anti-backflow extraction screw is connected to the processing container through a pipeline.

[0008] Preferably, the exhaust pipe of the vacuum stabilization mechanism is connected to the top of the processing container, and the end of the exhaust pipe is connected to the exhaust gas processing mechanism.

[0009] Preferably, the exhaust pipe is provided with a temperature detection component, a pressure detection component and a vacuum pump in sequence between the processing container and the exhaust gas processing mechanism.

[0010] Preferably, the water inlet and the water outlet of the condenser are located on both sides of the exhaust pipe, the condenser is in a spiral structure in the processing container, and the end of the pipe is located at the lowest point of the condenser.

[0011] Preferably, the diameter of the lower part of the processing container gradually decreases, and the bottom of the processing container is connected to the collection bucket of the collection mechanism through a switch valve.

[0012] Preferably, the temperature detection component includes an inlet water flow control valve and an outlet water temperature detector. The inlet of the condenser is provided with an inlet water flow control valve, and the outlet water temperature detector is provided at the outlet of the condenser.

[0013] The method for using the above-mentioned device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances comprises the following steps: S1. Turn on the vacuum stabilization mechanism to extract the air in the processing container to form a negative pressure in the processing container, and automatically control the vacuum degree according to the actual value of the vacuum degree measured by the pressure detection component; S2, turn on the condensation mechanism, the condensed water enters the condensation tube through the water inlet, and then flows out through the water outlet; S3, the polyphenylene sulfide powder is melted in the melting extraction mechanism, and the low molecular weight substances therein enter the processing container through the pipeline; S4. Low molecular weight substances are condensed by the condenser in the processing container, fall to the bottom of the processing container, and finally enter the collection mechanism.

[0014] Preferably, in S3, the heating and heat preservation jacket is turned on to prevent the low molecular weight substances from condensing and then flowing back.

[0015] Therefore, the present invention adopts a device and a method for using the above-mentioned structure to continuously melt polyphenylene sulfide resin to remove low-molecular substances. The anti-reflux extraction screw extracts low-molecular substances in a timely and stable manner during melting, and prevents the low-molecular substances from condensing and refluxing. At the same time, the vacuum stabilization mechanism automatically adjusts the vacuum degree in the equipment so that the vacuum degree is always within a stable range.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances according to the present invention; Figure 2 yes Figure 1 A in the enlarged view; Figure 3 yes Figure 1 Enlarged view of point B in .

[0018] Reference numerals: 1. Melting screw; 2. Pipeline; 3. Anti-backflow extraction screw; 4. Processing container; 5. Condenser; 6. Exhaust pipe; 7. Temperature detection component; 8. Pressure detection component; 9. Vacuum pump; 10. Exhaust gas treatment mechanism; 11. Collection barrel; 12. Switch valve; 13. Heating and insulation cover; 14. Water inlet control valve; 15. Water outlet temperature detector. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features or features mentioned in the specific examples mentioned in the present invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0020] Example 1 like Figure 1 As shown, the present invention provides a device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances, including a melt extraction mechanism, a condensation mechanism, a vacuum stabilization mechanism, an exhaust gas treatment mechanism 10 and a collection mechanism. The melt extraction mechanism is connected to the processing container 4 of the collection mechanism, and a condensation pipe 5 of the condensation mechanism is provided in the processing container 4. The top of the processing container 4 is connected to the vacuum stabilization mechanism, and the vacuum stabilization mechanism is connected to the exhaust gas treatment mechanism 10.

[0021] The polyphenylene sulfide resin powder is melted in the melting extraction mechanism, and low molecular weight substances such as air, moisture, oligomers, solvents that are not cleaned up, and oligomers produced by decomposition at high temperature are extracted into the processing container 4. After entering the processing container 4, the low molecular weight substances fall to the bottom of the processing container 4 under the condensation of the condensation mechanism, and then enter the collection mechanism to be collected. The vacuum stabilization mechanism keeps the vacuum degree in the processing container 4 within a stable range, ensuring that the low molecular weight substances enter the processing container 4 through the melting extraction mechanism.

[0022] like Figure 2 As shown, the melting screw 1 of the melting extraction mechanism is connected to the pipeline 2, an anti-backflow extraction screw 3 is provided in the inclined section of the pipeline 2, the pipeline 2 at the anti-backflow extraction screw 3 is provided with a heating and insulation sleeve 13, and the top end of the anti-backflow extraction screw 3 is connected to the processing container 4 through the pipeline 2.

[0023] The melting screw 1 is a twin screw, which melts the polyphenylene sulfide powder, and the low molecular weight substances and a small amount of condensate produced enter the processing container 4 through the pipe 2. The anti-backflow extraction screw 3 scrapes off the condensate attached to the inner wall of the inclined section of the pipe 2, and sends the condensate to the processing container 4. The setting of the heating and insulation sleeve 13 heats the pipe 2 at the anti-backflow extraction screw 3 to prevent the condensate from flowing back into the melting screw 1 along the pipe 2, and cooperates with the anti-backflow extraction screw 3 to effectively solve the problem of condensate backflow.

[0024] The exhaust pipe 6 of the vacuum stabilization mechanism is connected to the top of the processing container 4, and the end of the exhaust pipe 6 is connected to the tail gas treatment mechanism 10. The vacuum stabilization mechanism controls the vacuum degree of the equipment so that the equipment can stably extract low molecular substances, and the tail gas treatment mechanism 10 processes the gas extracted from the exhaust pipe 6 to avoid air pollution.

[0025] like Figure 3 As shown, the exhaust pipe 6 is provided with a temperature detection component 7, a pressure detection component 8 and a vacuum pump 9 in sequence between the processing container 4 and the tail gas treatment mechanism 10. The pressure detection component 8 is a structure used for pressure detection in the prior art such as a pressure gauge. The pressure detection component 8 detects the pressure value and adjusts the vacuum pump 9 according to the obtained data to ensure a stable vacuum degree. On the one hand, it timely prevents insufficient vacuum and insufficient extraction, and on the other hand, it prevents the vacuum from being too low, which causes the polyphenylene sulfide melt to be extracted and wastes energy and power, solving these two major weaknesses of traditional extraction.

[0026] The temperature detection component 7 includes an inlet water flow control valve 14 and an outlet water temperature detector 15. The inlet water flow control valve 14 is provided at the water inlet of the condenser 5, and the outlet water temperature detector 15 is provided at the water outlet of the condenser 5. The inlet water flow control valve 14 and the outlet water temperature detector 15 are used in combination to ensure the cooling effect of the condenser 5.

[0027] The water inlet and outlet of the condenser 5 are located on both sides of the exhaust pipe 6. The condenser 5 is in a spiral structure in the processing container 4, and the end of the pipe 2 is located at the lowest point of the condenser 5. The temperature detection component 7 detects the temperature in the exhaust pipe 6, and controls the water inlet and outlet flow of the condenser 5 according to the exhaust temperature to ensure that as many low molecular substances as possible are condensed and collected in the collection bucket 11, thereby reducing the cost of exhaust gas treatment.

[0028] The diameter of the lower part of the processing container 4 gradually decreases, and the bottom of the processing container 4 is connected to the collection barrel 11 of the collection mechanism through the switch valve 12. The switch valve 12 controls the low molecular weight substances in the collection barrel 11 from the processing container 4, and closing the switch valve 12 facilitates the replacement of the collection barrel 11.

[0029] Example 2 The method for using the device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances in Example 1 comprises the following steps: S1. Turn on the vacuum stabilization mechanism to draw out the air in the processing container 4, so that negative pressure is formed in the processing container 4 and the pipeline 2, and the vacuum degree is automatically controlled according to the actual value of the vacuum degree measured by the pressure detection component 8.

[0030] S2, the condensation mechanism is turned on, and the condensed water enters the condensation tube 5 through the water inlet and then flows out through the water outlet.

[0031] S3. The polyphenylene sulfide powder is melted in the melting extraction mechanism, and the low molecular weight substances therein are extracted into the processing container 4 through the pipeline 2 and the anti-reflux extraction screw, and the heating and heat preservation sleeve 13 of the anti-reflux extraction screw 3 is turned on to prevent the low molecular weight substances from condensing in the pipeline 2 at the anti-reflux extraction screw 3 and then flowing back.

[0032] S4. The low molecular weight substances are condensed by the condenser 5 in the processing container 4, fall to the bottom of the processing container 4, and finally enter the collection mechanism.

[0033] Therefore, the present invention adopts a device and a method for continuously melting polyphenylene sulfide resin to remove low-molecular substances with the above structure, so as to timely and stably extract low-molecular substances during melting and prevent low-molecular substances from condensing and refluxing.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances, characterized in that: It includes a melting extraction mechanism, a condensing mechanism, a vacuum stabilizing mechanism, an exhaust gas treatment mechanism and a collecting mechanism. The melting extraction mechanism is connected to a processing container of the collecting mechanism. A condensing tube of the condensing mechanism is arranged in the processing container. The top of the processing container is connected to the vacuum stabilizing mechanism, and the vacuum stabilizing mechanism is connected to the exhaust gas treatment mechanism.

2. The device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances according to claim 1, characterized in that: The melting screw of the melting extraction mechanism is connected with a pipeline, an anti-backflow extraction screw is arranged in the inclined section of the pipeline, a heating and heat preservation sleeve is arranged on the pipeline sleeve at the anti-backflow extraction screw, and the top end of the anti-backflow extraction screw is connected with a processing container through a pipeline.

3. The device for continuously removing low molecular weight substances from polyphenylene sulfide resin by melting according to claim 2, characterized in that: The exhaust pipe of the vacuum stabilization mechanism is communicated with the top of the processing container, and the end of the exhaust pipe is communicated with the tail gas processing mechanism.

4. The device for continuously removing low molecular weight substances from polyphenylene sulfide resin by melting according to claim 3, characterized in that: The exhaust pipe is provided with a temperature detection component, a pressure detection component and a vacuum pump in sequence between the processing container and the tail gas processing mechanism.

5. The device for continuously removing low molecular weight substances from polyphenylene sulfide resin by melting according to claim 4, characterized in that: The water inlet and the water outlet of the condenser are located on both sides of the exhaust pipe. The condenser is in a spiral structure in the processing container, and the end of the pipe is located at the lowest point of the condenser.

6. The device for continuously removing low molecular weight substances from polyphenylene sulfide resin by melting according to claim 1, characterized in that: The diameter of the lower part of the processing container gradually decreases, and the bottom of the processing container is connected with the collection bucket of the collection mechanism through a switch valve.

7. The device for continuously removing low molecular weight substances from polyphenylene sulfide resin by melting according to claim 5, characterized in that: The temperature detection component comprises an inlet water volume control valve and an outlet water temperature detector. The inlet of the condenser is provided with an inlet water volume control valve, and the outlet water temperature detector is provided at the outlet of the condenser.

8. A method for using the device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1, starting the vacuum stabilization mechanism to extract the air in the processing container to form a negative pressure in the processing container, and automatically controlling the vacuum degree according to the actual value of the vacuum degree measured by the pressure detection component; S2, turn on the condensation mechanism, the condensed water enters the condensation tube through the water inlet, and then flows out through the water outlet; S3, the polyphenylene sulfide powder is melted in the melting extraction mechanism, and the low molecular weight substances therein are extracted into the processing container through the pipeline and the anti-backflow extraction screw; S4. Low molecular weight substances are condensed by the condenser in the processing container, fall to the bottom of the processing container, and finally enter the collection mechanism.

9. The method for using the device for continuously melting polyphenylene sulfide resin to remove low molecular weight substances according to claim 8, characterized in that: In S3, the heating and insulation jacket is turned on to prevent the low molecular weight substances from condensing and then flowing back.

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