Pickling device for polytetrafluoroethylene microporous membrane

Abstract

The utility model relates to a polytetrafluoroethylene microporous membrane pickling device which comprises a first washing bin, a first pickling bin, a second pickling bin and a second washing bin. The device can effectively remove environmental dust particles existing on the surface of the membrane and metal ions such as calcium, iron and magnesium ions introduced in the production process, so that the membrane can reach ultrahigh cleanliness, and the problem of dissolution of the metal ions in the use process of the membrane can also be solved. The membrane produced by the device can be used for filtering gas and liquid in industries such as biological medicines, ultra-pure reagents, semiconductors and the like with higher requirements on the cleanliness of the filter membrane.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of pickling device in polytetrafluoroethylene biaxially oriented film production process, make the film produced can reach higher cleanliness, specifically a kind of polytetrafluoroethylene film cleaning device. BACKGROUND

[0002] Polytetrafluoroethylene microporous membrane is widely used in gas-solid separation and liquid-solid separation fields.In some high-end fields, such as biological medicine, ultrapure reagent and semiconductor industry, there are high requirements on the cleanliness of filter material itself, such as the concentration of particulate matter on the membrane surface and the dissolution of metal on the membrane surface.It is difficult to meet the requirements of the cleanliness of polytetrafluoroethylene microporous membrane produced in non-clean workshops, because the contact between the environment dust and the equipment surface during the forming process of polytetrafluoroethylene microporous membrane leads to the presence of a large amount of particulate matter and metal ions such as calcium, iron, magnesium and sodium in the polytetrafluoroethylene membrane.Therefore, a device for cleaning the membrane is added during the production process of the membrane to achieve the purpose of producing polytetrafluoroethylene membrane with high cleanliness. SUMMARY

[0003] The utility model provides a kind of polytetrafluoroethylene microporous membrane pickling device, to solve the problem that the introduction of environmental impurities causes membrane pollution and the dissolution of metal ions during the use of membrane during the production process of polytetrafluoroethylene microporous membrane, the cleanliness of polytetrafluoroethylene membrane produced by the cleaning process is high, and the filtration performance of polytetrafluoroethylene membrane before and after cleaning is basically unchanged.

[0004] The technical solution of the utility model is as follows:

[0005] A kind of polytetrafluoroethylene microporous membrane pickling device, comprising a first washing bin, a first pickling bin, a second pickling bin and a second washing bin connected in sequence.The first washing bin is provided with a driven feed roller outside the inlet, and the polytetrafluoroethylene microporous membrane is conveyed, a plurality of driven feed rollers are arranged in a broken line shape in the bin, and the polytetrafluoroethylene microporous membrane is conveyed, and spraying devices are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane;the first pickling bin is provided with a first guide roller at the inlet, a plurality of horizontally arranged driven feed rollers are arranged at the lower part, an ultrasonic wave generating device and a dilute acid purification device are arranged at the bottom of the first pickling bin, and a dilute acid PH value monitoring probe is arranged at the lower part of the first pickling bin;the second pickling bin is provided with a second guide roller at the inlet, a plurality of horizontally arranged driven feed rollers are arranged at the lower part, a concentrated acid purification device is arranged at the bottom of the second pickling bin, and a concentrated acid PH value monitoring probe is arranged at the lower part of the second pickling bin;the second washing bin is divided into two bins by a partition, a cleaning liquid conveying device is arranged at the bottom of the front bin after cleaning, a discharge roller is arranged in the rear bin, a water washing PH value monitoring probe is arranged at the lower end of the discharge roller, and a plurality of driven feed rollers are arranged in a broken line shape in the second washing bin, and spraying devices are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane.

[0006] Further, the internal materials of the device are all selected from fluorine alkoxy vinyl ether copolymer (PFA) or PTFE material.

[0007] Further, the conveying speed of the polytetrafluoroethylene microporous membrane in the whole device is 2-20 m / min.

[0008] Further, the lower active feeding roller in the first water washing bin is a drainage roller with the same structure size, and one end of the drainage roller is provided with a tilting function with a tilting range of 5-15°, so that the water on the surface of the washed membrane is tilted and drained.

[0009] Further, in the first acid washing bin, the acid is one of hydrochloric acid, sulfuric acid and nitric acid, and the mass concentration is 10-70%, the dilute acid purification device is used to remove the particulate impurities in the acid, the filtration precision is 200 nm, and the purification speed is 1.0-1000 m 3 / h.

[0010] Further, in the second acid washing bin, the concentrated acid is the same as that in the first acid washing bin, and the mass concentration is 70-98%, the concentrated acid purification device is used to remove the particulate impurities in the concentrated acid, the filtration precision is 10 nm-200 nm, and the purification speed is 1.0-1000 m 3 / h.

[0011] Further, the cleaning liquid conveying device conveys the cleaned liquid to the first acid washing bin.

[0012] Further, the number of the active feeding rollers arranged in each bin is 3 or more.

[0013] Further, the nozzle pressure of the spraying device is 1-5 bar, the spraying device in the first water washing bin is 2 groups or more, and the spraying device in the second water washing bin is 4 groups or more.

[0014] The present application has the following beneficial effects:

[0015] By using the device, the first water washing bin can preliminarily remove the problem that air dust in the production process of the polytetrafluoroethylene microporous membrane pollutes the surface of the membrane. The dilute acid cleaning can remove the metal ions on the surface of the membrane, the concentrated acid cleaning can remove the deep layer metal ions on the surface of the membrane, and the liquid after the second water washing bin is washed can be returned to the first acid washing bin to supplement the acid solution to achieve the purpose of reducing consumption. At the same time, the acid purification device can not only ensure the purity of the acid, but also reduce the waste of the acid. In the case of not affecting the performance of the membrane, the polytetrafluoroethylene microporous membrane with high cleanliness and low metal ion dissolution is produced. The cleaned polytetrafluoroethylene microporous membrane can be applied to the gas-solid and liquid-solid filtration in the biological medicine, high-purity acid and high-purity reagent, semiconductor and other industries. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a device schematic diagram of the present application.

[0017] Explanation of reference signs: 101, first water washing bin, 102, second water washing bin, 201, first acid washing bin, 202, second acid washing bin, 1, feeding roller, 2, spraying device, 3, drainage roller, 4, first guide roller, 5, second guide roller, 6, dilute acid PH value monitoring probe, 7, dilute acid purification device, 8, ultrasonic wave generating device, 9, concentrated acid purification device, 10, cleaning liquid conveying device, 11, concentrated acid PH value monitoring probe, 12, water washing PH value monitoring probe, 13, discharging roller, 14, partition plate. DETAILED DESCRIPTION

[0018] The technical scheme of the utility model is described more clearly and completely in combination with the drawings and the specific embodiments of the utility model. The following embodiments are only used for illustrating the utility model, but are not used for limiting the implementation range of the utility model.

[0019] A polytetrafluoroethylene microporous membrane pickling device comprises a first water washing bin 101, a first acid washing bin 201, a second acid washing bin 202 and a second water washing bin 102 connected in sequence. The first water washing bin 101 is provided with a driving feeding roller 1 outside the inlet for conveying the polytetrafluoroethylene microporous membrane, and a plurality of driving feeding rollers 1 are arranged in a broken line shape in the bin for conveying the polytetrafluoroethylene microporous membrane, and spraying devices 2 are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane. The first acid washing bin 201 is provided with a first guide roller 4 at the inlet, and a plurality of driving feeding rollers 1 are arranged horizontally at the lower part, and the first acid washing bin 201 is provided with an ultrasonic wave generating device 8 and a dilute acid purification device 7 at the bottom, and a dilute acid PH value monitoring probe 6 is arranged at the lower part of the first acid washing bin 201. The second acid washing bin 202 is provided with a second guide roller 5 at the inlet, and a plurality of driving feeding rollers 1 are arranged horizontally at the lower part, and the second acid washing bin 202 is provided with a concentrated acid purification device 9 at the bottom, and a concentrated acid PH value monitoring probe 11 is arranged at the lower part of the second acid washing bin 202. The second water washing bin 102 is divided into two bins by a partition plate 14, a cleaning liquid conveying device 10 is arranged at the bottom of the front bin, a discharging roller 13 is arranged in the rear bin, a water washing PH value monitoring probe 12 is arranged at the lower end of the discharging roller 13, and a plurality of driving feeding rollers 1 are arranged in a broken line shape in the second water washing bin 102, and spraying devices 2 are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane.

[0020] Further, the materials inside the device are all selected from fluorine alkoxy vinyl ether copolymer (PFA) or PTFE material.

[0021] Further, the conveying speed of the polytetrafluoroethylene microporous membrane in the whole device is 2-20 m / min.

[0022] Further, the active feeding roller 1 at the lower part in the first water washing bin 101 is a drainage roller 3 with the same structure size, and one end of the drainage roller 3 has a tilting function with a tilting range of 5-15°, so that the water on the washed film surface is tilted and drained.

[0023] Further, in the first acid washing bin 201, the acid is one of hydrochloric acid, sulfuric acid and nitric acid, and the mass concentration is 10-70%; the dilute acid purification device 7 is used to remove the particulate impurities in the acid, the filtration precision is 200 nm, and the purification speed is 1.0-1000 m 3 / h.

[0024] Further, in the second acid washing bin 202, the concentrated acid is the same as that in the first acid washing bin 201, and the mass concentration is 70-98%; the concentrated acid purification device 9 is used to remove the particulate impurities in the concentrated acid, the filtration precision is 10 nm-200 nm, and the purification speed is 1.0-1000 m 3 / h.

[0025] Further, the cleaning liquid conveying device 10 conveys the cleaned liquid to the first acid washing bin 201.

[0026] Further, the number of the active feeding rollers 1 arranged in each bin is 3 or more.

[0027] Further, the nozzle pressure of the spraying device 2 is 1-5 bar, the spraying device in the first water washing bin 101 is 2 groups or more, and the spraying device in the second water washing bin 102 is 4 groups or more.

[0028] The working process of the device is as follows:

[0029] Through the feeding roller 1, the polytetrafluoroethylene microporous film is sent into the first water washing bin 101, and the film feeding speed is set to 4.0 m / min. At the same time, two groups of spraying devices 2 vertically spray the film, the nozzle pressure is 1.0 bar, and the used solution is ultrapure water. The liquid on the cleaned film is drained through the drainage roller 3 with one end tilted by 10°.

[0030] After the first water washing is completed, the film layer is completely immersed in the acid solution by entering the first acid washing bin 201 through the first guide roller 4. The acid in the first acid washing bin 201 is dilute sulfuric acid with a concentration of 10%. At the same time, the ultrasonic generator 8 works to perform ultrasonic cleaning on the film surface. The dilute acid purification device 7 circulates and filters the dilute acid solution to remove the particulate matters above 200 nm in the solution. The dilute acid PH value detection device 6 detects the concentration of the dilute acid to ensure that the concentration is maintained stable. After cleaning, the film enters the second acid washing bin 202.

[0031] Through the second guide roller 5 into the second pickling acid pickling warehouse 202, the acid in the second pickling warehouse 202 is concentrated sulfuric acid with a concentration of 70%, and the film layer is completely immersed in the concentrated acid solution. The concentrated acid purification device 9 circulates and filters the dilute acid solution to remove particles above 50nm in the solution. The concentrated acid PH value detection device 11 monitors the concentration of concentrated acid to ensure timely replenishment of concentrated acid.

[0032] After pickling, the film surface is sprayed vertically by 4 or more groups of spraying devices 2, and the water pressure of the spray head is 1.0bar. The acid on the film surface is washed. The liquid on the film is drained through a drainage roller 3 with one end inclined by 10°. The acid liquid in the first pickling warehouse 201 is supplemented by the cleaning liquid conveying device 10 before the second washing warehouse 102. The last group of spraying devices 2 is cleaned by the water washing PH value detection device 12 to ensure that the film surface is completely cleaned. If the PH value is less than 7, increase the spraying device until the PH value reaches about 7 and output through the discharge roller 13. After cleaning, the cleaned film can achieve the following effects: under the flow of 20 L / min of ultrapure water, 0.2μm of particles is dissolved <10 particles / mL, after soaking in 10%HCL solution for 12 hours, Fe, Ca, Mg and other ion concentrations <5ppb.

Claims

1. A polytetrafluoroethylene microporous membrane pickling device, comprising a first water washing bin (101), a first pickling bin (201), a second pickling bin (202), and a second water washing bin (102) connected in sequence, characterized in that: The first water washing bin (101) is provided with a driving feeding roller (1) outside the entrance for conveying polytetrafluoroethylene microporous membrane, and a plurality of driving feeding rollers (1) are arranged in a broken line shape in the bin for conveying polytetrafluoroethylene microporous membrane, and spraying devices (2) are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane; the first pickling bin (201) is provided with a first guide roller (4) at the entrance, and a plurality of driving feeding rollers (1) are arranged horizontally at the lower part, the bottom of the first pickling bin (201) is provided with an ultrasonic wave generating device (8) and a dilute acid purification device (7), and a dilute acid PH value monitoring probe (6) is arranged at the lower part of the first pickling bin (201); the second pickling bin (202) is provided with a second guide roller (5) at the entrance, and a plurality of driving feeding rollers (1) are arranged horizontally at the lower part, the bottom of the second pickling bin (202) is provided with a concentrated acid purification device (9), and a concentrated acid PH value monitoring probe (11) is arranged at the lower part of the second pickling bin (202); the second water washing bin (102) is divided into two bins by a partition (14), the bottom of the front bin is provided with a cleaning liquid conveying device (10) for cleaned liquid, and the rear bin is provided with a discharging roller (13), the lower end of the discharging roller (13) is provided with a water washing PH value monitoring probe (12), and a plurality of driving feeding rollers (1) are arranged in a broken line shape in the second water washing bin (102), and spraying devices (2) are arranged on both sides of the membrane surface of the polytetrafluoroethylene microporous membrane.

2. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The materials inside the device are selected from fluorine alkoxy vinyl ether copolymer (PFA) or PTFE material.

3. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The conveying speed of the polytetrafluoroethylene microporous membrane in the whole device is 2-20 m / min.

4. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The driving feeding roller (1) at the lower part in the first water washing bin (101) is a drainage roller (3) with the same structure and size, one end of the drainage roller (3) has a tilting function, and the tilting range is 5-15°, and the water on the membrane surface after washing is tilted and discharged.

5. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein In the first pickling bin (201), the acid type is one of hydrochloric acid, sulfuric acid and nitric acid, and the mass concentration is 10-70%. The dilute acid purification device (7) is used to remove particulate impurities in the acid, with a filtration accuracy of 200 nm and a purification speed of 1.0-1000 m / h. 3 / h.

6. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein In the second pickling chamber (202), the type of concentrated acid is the same as that in the first pickling chamber (201), with a mass concentration of 70-98%. The concentrated acid purification device (9) is used to remove particulate impurities from the concentrated acid, with a filtration accuracy of 10nm-200nm and a purification speed of 1.0-1000m. 3 / h.

7. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The cleaning liquid conveying device (10) conveys the cleaned liquid to the first pickling bin (201).

8. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The number of driving feeding rollers (1) arranged in each bin is 3 or more than 3.

9. The polytetrafluoroethylene microporous membrane pickling apparatus according to claim 1, wherein The nozzle pressure of the spraying device (2) is 1-5 bar, the spraying device (2) in the first water washing bin (101) is 2 groups or more than 2 groups, and the spraying device (2) in the second water washing bin (102) is more than 4 groups.

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