阅读说明：本技术 一种造纸用脱水装置及其脱水方法 (Papermaking dehydration device and dehydration method thereof ) 是由 李文斌 于 2021-01-14 设计创作，主要内容包括：本发明提出了一种造纸用脱水装置及其脱水方法,所述造纸用脱水装置包括上压榨辊、下压榨辊和压缩气刮刀,所述下压榨辊位于所述上压榨辊的上方并与所述上压榨辊相切,纸从上压榨辊和下压榨辊之间经过进行压榨脱水；所述下压榨辊的表面覆盖有盲孔,所述压缩气刮刀设于所述下压榨辊的表面,所述压缩气刮刀中的空气出口背向所述纸面而面向所述盲孔；压缩气体进入压缩气缸刀后经所述空气出口吹向盲孔,以排出盲孔内的水。本发明造纸用脱水装置在对纸张进行脱水后能够有效地防止回湿。(The invention provides a dewatering device for papermaking and a dewatering method thereof, wherein the dewatering device for papermaking comprises an upper press roll, a lower press roll and a compressed air scraper, the lower press roll is positioned above the upper press roll and is tangent to the upper press roll, and paper passes through between the upper press roll and the lower press roll for press dewatering; the surface of the lower squeezing roller is covered with blind holes, the compressed air scraper is arranged on the surface of the lower squeezing roller, and an air outlet in the compressed air scraper faces away from the paper surface and faces the blind holes; compressed gas enters the compression cylinder cutter and then is blown to the blind hole through the air outlet so as to discharge water in the blind hole. The dewatering device for papermaking can effectively prevent rewetting after dewatering paper.)

1. The dewatering device for papermaking is characterized by comprising an upper press roll, a lower press roll and a compressed air scraper, wherein the lower press roll is positioned above the upper press roll and tangent to the upper press roll, and paper passes between the upper press roll and the lower press roll to be pressed and dewatered; the roll surface of the lower squeezing roll is covered with blind holes, the compressed air scraper is arranged on the roll surface of the lower squeezing roll, and an air outlet in the compressed air scraper faces away from the paper surface and faces the blind holes; compressed gas enters the compression cylinder cutter and then is blown to the blind hole through the air outlet so as to discharge water in the blind hole.

2. The dewatering device for papermaking according to claim 1, wherein the compressed air scraper comprises an air knife body and a scraper blade arranged on the outer surface of the air knife body, and the scraper blade is attached to the roll surface of the press roll; an air cavity is arranged in the air knife body, and the air outlet is positioned on one side of the scraper.

3. The dewatering apparatus for papermaking according to claim 2, wherein the air outlet is an elongated slit matching the length of the doctor blade.

4. The papermaking dewatering apparatus of claim 3, wherein the length of the scraper blade and the length of the air outlet are adapted to cover the width of the roll surface of the lower press roll.

5. The dewatering apparatus for papermaking according to claim 1, wherein the blind holes have a diameter of 2-3mm and a pitch of 5-12 mm.

6. The dewatering apparatus for papermaking according to claim 1, further comprising a surge tank, wherein the compressed gas is pressurized by the surge tank and then enters the compressed cylinder blade through the connecting pipe.

7. The dewatering apparatus for papermaking according to claim 6, wherein a first hand valve is provided at an end of the communication pipe adjacent to the compressed air blade.

8. The dewatering apparatus for papermaking according to claim 6, wherein a second hand valve is provided at an end of the communication pipe adjacent to the surge tank.

9. The dewatering device for papermaking according to claim 6, wherein the communication duct is further provided with an automatic opening and closing valve which is linked with the papermaking machine.

10. A dewatering method for a dewatering apparatus for papermaking according to any one of claims 1 to 9, characterized by comprising the steps of:

step 1, passing paper through a space between an upper squeezing roller and a lower squeezing roller, and simultaneously driving the upper squeezing roller and the lower squeezing roller to dewater the paper;

step 2, in the transmission process of the upper squeezing roller and the lower squeezing roller, compressed air in the compressed air scraper is blown to blind holes on the surface of the lower squeezing roller from an air outlet; wherein, the air pressure of the compressed air in the compressed air scraper is 150-300 KPa.

Technical Field

The invention relates to the technical field of papermaking mechanical equipment, in particular to a papermaking dehydration device and a dehydration method thereof.

Background

The papermaking industry is a large energy-consuming household, steam consumption is one of resource consumption, resource saving is the requirement for building a resource-saving environment-friendly society, how to reduce resource waste is also an examination faced by the papermaking industry, and along with the improvement of environmental awareness of people, energy conservation and emission reduction are also the basis of sustainable development of the papermaking industry.

At present, paper is dried mainly by means of squeezing dehydration and drying dehydration, and drying saves 5% of steam when the water content of a paper web pressing part is reduced by 1% theoretically; however, a part of the water released from the pressing part is thrown out, and the other part of the water clings to the surface of the press roll and rotates along with the surface of the press roll to return to the paper surface again, so that the moisture is returned, and the steam consumption is high during drying. Therefore, there is an urgent need for a dehydration apparatus capable of preventing rewetting.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a dewatering device for papermaking and a dewatering method thereof, which can effectively prevent rewetting.

In order to achieve the aim, the invention provides a dewatering device for papermaking, which comprises an upper press roll, a lower press roll and a compressed air scraper, wherein the lower press roll is positioned above the upper press roll and tangent to the upper press roll, and paper passes between the upper press roll and the lower press roll to be pressed and dewatered; the roll surface of the lower squeezing roll is covered with blind holes, the compressed air scraper is arranged on the roll surface of the lower squeezing roll, and an air outlet in the compressed air scraper faces away from the paper surface and faces the blind holes; compressed gas enters the compression cylinder cutter and then is blown to the blind hole through the air outlet so as to discharge water in the blind hole.

Further, the compressed air scraper comprises an air knife body and a scraper arranged on the outer surface of the air knife body, and the scraper is attached to the surface of the squeezing roller; an air cavity is arranged in the air knife body, and the air outlet is positioned on one side of the scraper.

Further, the air outlet is an elongated gap matched with the length of the scraper.

Furthermore, the diameter of the blind hole is 2-3 mm.

Furthermore, the distance between the blind holes is 5-12 mm.

Furthermore, the device also comprises a pressure stabilizing tank, and compressed gas enters the compression cylinder cutter through a connecting pipeline after being stabilized by the pressure stabilizing tank.

Furthermore, one end of the communication pipeline, which is close to the compressed air scraper, is provided with a first hand valve.

Furthermore, a second hand valve is arranged at one end, close to the surge tank, of the communication pipeline.

Furthermore, the communicating pipeline is also provided with an automatic switch valve linked with the paper machine.

On the other hand, the invention also discloses a dewatering method of the dewatering device for papermaking, which comprises the following steps:

step 1, passing paper through a space between an upper squeezing roller and a lower squeezing roller, and simultaneously driving the upper squeezing roller and the lower squeezing roller to dewater the paper;

step 2, in the transmission process of the upper squeezing roller and the lower squeezing roller, compressed air in the compressed air scraper is blown to blind holes on the surface of the lower squeezing roller from an air outlet; wherein, the air pressure of the compressed air in the compressed air scraper is 150-300 KPa.

Compared with the prior art, the invention has the following advantages: according to the dewatering device for papermaking, the roll surface of the lower squeezing roll is covered with the blind holes, water entering the blind holes is blown out of the blind holes through the compressed air scrapers in the process of dewatering paper by the upper squeezing roll and the lower squeezing roll, and meanwhile, the water blown out of the roll surface of the lower squeezing roll is scraped off by the compressed air scrapers, so that the dryness of the squeezed paper can be effectively improved, the rewetting is prevented, and the consumption of drying steam is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view showing the construction of a dewatering apparatus for papermaking according to the present invention;

FIG. 2 is a detail view of the roll surface of the lower squeeze roll;

fig. 3 is a schematic structural view of a compressed air scraper.

The attached drawings are as follows: 1, pressing a roller; 2, pressing rolls; 201 a blind hole; 3, compressing the air scraper; 301 air knife body; 302 a squeegee; 303 an air outlet; 304 an air inlet; 4, a pressure stabilizing tank; 5 connecting a pipeline; 501 a first hand valve; 502 second hand valve; 503 automatic on-off valve; 6 driving the roller.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 and 2, the embodiment of the invention discloses a dewatering device for papermaking, which comprises an upper press roll 1, a lower press roll 2 and a compressed air scraper 3, wherein the lower press roll 2 is positioned above the upper press roll 1 and is tangent to the upper press roll 1, and paper passes between the upper press roll 1 and the lower press roll 2 to be pressed and dewatered; the roll surface of the lower press roll 2 is covered with a blind hole 201, the compressed air scraper 3 is arranged on the roll surface of the lower press roll 2, and an air outlet 303 in the compressed air scraper 3 faces the blind hole 201 away from the paper surface; compressed gas enters the compression cylinder cutter and then blows towards the blind hole 201 through the air outlet 303 to discharge water in the blind hole 201.

Specifically, as shown in fig. 3, the compressed air scraper 3 comprises an air knife body 301 and a scraper 302 arranged on the outer surface of the air knife body 301, and the scraper 302 is attached to the surface of the press roll; the air knife body 301 is provided with an air chamber (not shown), and an air outlet 303 is provided at one side of the scraper 302.

In use, as shown in fig. 1, paper passes through between the upper press roll 1 and the lower press roll 2, and is squeezed and dewatered through the transmission of the upper press roll 1 and the lower press roll 2; with the high-speed rotation of the upper press roll 1 and the lower press roll 2, most of water is thrown out under the action of gravity, and a small part of water clings to the blind holes 201 on the surface of the lower press roll 2 and rotates along with the roll surface; when the roll surface with water in the blind hole 201 rotates to the compressed air scraper 3, the compressed air in the compressed air scraper 3 blows towards the blind hole 201 through the air outlet 303, so that the water remained in the blind hole 201 is blown out, and finally the water blown out is scraped by the scraper 302, so that the water on the roll surface of the lower squeezing roll 2 can be effectively removed, and the moisture return is avoided. The invention can effectively reduce the consumption of drying steam

As shown in fig. 1, felt is provided between the paper and the upper press roll 1 to prevent direct contact between the paper and the upper press roll 1; similarly, a felt is arranged between the paper and the lower squeezing roller 2 to avoid the paper and the lower squeezing roller 2; thereby avoiding marks on the upper press roll 1 and the lower press roll 2. Wherein the coarse cotton cloth on the upper press roll 1 and the coarse cotton cloth on the lower press roll 2 are respectively driven by the driving rolls, so that the coarse cotton cloth and the driving paper synchronously move forwards.

In the embodiment of the present invention, the length of the scraper 302 and the air outlet 303 can cover the width of the roll surface of the lower press roll 2. The scraper 302 of the compressed air scraper 3 is parallel to the roll surface of the lower press roll 2, so that the scraper 302 can completely cling to the roll surface; and the length of the scraper 302 is not less than the width of the roll surface, and covers the width of the roll surface of the lower press roll 2, so that water on the roll surface can be completely scraped.

Further, the air outlets 303 are elongated slots matching the length of the scraper 302, so that the compressed air can uniformly cover the width area of the lower press roll 2, thereby completely blowing out the water in the blind holes 201. The width of the long gap is preferably 0.3-1mm, so that water in the blind hole 201 can be blown out, and waste caused by overlarge gap and overlarge airflow is avoided.

Further, the diameter of the blind hole 201 is preferably 2-3mm to ensure that water can be efficiently introduced into the blind hole 201. The distance between the blind holes 201 is 5-12mm, so that the roller surface of the lower press roller 2 is not firm when the distance between the blind holes 201 is less than 5mm, and the roller surface is easy to be damaged in the transmission dehydration process; in addition, if the pitch is larger than 12mm, the number of blind holes 201 is small, and water cannot be efficiently introduced into the blind holes 201. The depth of the blind hole 201 is 6-10mm, so that water can be effectively guided into the blind hole 201, and compressed air can be guaranteed to effectively blow out the water in the blind hole 201.

Further, the dewatering device for papermaking further comprises a pressure stabilizing tank 4, wherein the pressure stabilizing tank is used for stabilizing the pressure of compressed gas so as to prevent the pressure of the compressed gas at the air outlet 303 of the compressed gas scraper 3 from being kept stable, and further ensure that water in the blind hole 201 can be effectively blown out; compressed gas enters the compression cylinder cutter through the connecting pipeline 5 after being stabilized by the pressure stabilizing tank 4. Specifically, the air inlet 304 is arranged on the compression cylinder knife, the air inlet 304 and the air outlet 303 are respectively communicated with the air cavity, and compressed air in the connecting pipeline 5 enters the air cavity through the air inlet 304. The gas pressure after the pressure stabilization of the pressure stabilization tank 4 is preferably 150-300KPa, which can not only ensure that the water in the blind hole 201 is blown out, but also avoid waste caused by too large gas flow.

Wherein, one end of the communicating pipe close to the compressed air scraper 3 is provided with a first hand valve 501, which is convenient for the maintenance of the compressed air scraper; one end of the communicating pipeline, which is close to the surge tank 4, is provided with a second hand valve 502, which is convenient for adjusting the size of the air flow. In addition, the communicating pipeline is also provided with an automatic switch valve 503 linked with the paper machine so as to be automatically switched on and off according to the start and stop of the paper machine; when the paper machine starts to work, the automatic switch valve 503 is automatically opened, and compressed gas enters the air cavity of the compressed gas scraper 3; when the paper machine stops working, the automatic switch valve 503 is automatically closed, and the compressed air cannot enter the air cavity of the compressed air blade 3.

On the other hand, the invention also discloses a dewatering method of the dewatering device for papermaking, which comprises the following steps:

step 1, passing paper through a space between an upper squeezing roller and a lower squeezing roller, and simultaneously driving the upper squeezing roller and the lower squeezing roller to dewater the paper;

step 2, in the transmission process of the upper squeezing roller and the lower squeezing roller, compressed air in the compressed air scraper is blown to blind holes on the surface of the lower squeezing roller from an air outlet; wherein, the air pressure of the compressed air in the compressed air scraper is 150-300 KPa.

Furthermore, when the compressed air scraper blows out water in the blind holes, the scraper is tightly attached to the surface of the lower squeezing roller to scrape off the water blown out from the blind holes on the surface of the lower squeezing roller, and therefore rewetting is avoided to a greater extent.

In conclusion, in the dewatering device for papermaking, the roll surface of the lower press roll 2 is covered with the blind holes 201, water entering the blind holes 201 is blown out of the blind holes 201 through the compressed air scraper 3 in the process that the upper press roll 1 and the lower press roll 2 dewater paper, and meanwhile, the compressed air scraper 3 is used for scraping off the water blown out of the roll surface of the lower press roll 2, so that the dryness of the pressed paper can be effectively improved, the rewetting is prevented, and the consumption of drying steam is further reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.