JP2004076204A - Multi-cylinder type dryer device for paper machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove adhesive material attached to the outer periphery of a dryer cylinder in a multi-cylinder type dryer device for a paper machine. <P>SOLUTION: The multi-cylinder type dryer device for the paper machine has a shower 4, a doctor 2a for removing the attachment and a doctor 3a for removing water. The shower 4 is arranged at the downstream side in the rotation direction of a first dryer cylinder 11 arranged at the most upstream side from the separating point of the paper on the periphery of the first dryer cylinder 11, and jets a cleaning liquid to the outer periphery 11a. The doctor 2a for removing the attachment is arranged at the downstream side of the shower 4 at the outer periphery of the first dryer cylinder 11 in the rotation direction so that the tip may slide on the outer periphery 11a, and may rake the attachment of the outer periphery 11a of the first dryer cylinder, softened by receiving the cleaning liquid from the shower 4. The doctor 3a for removing the water is arranged at the downstream side from the doctor 2a for removing the attachment in the rotation direction so that the tip may slide on the outer periphery 11a, and may rake the water on the outer periphery 11a of the first dryer cylinder. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-cylinder dryer device for a papermaking machine, comprising a doctor at least in a dryer cylinder disposed at an upstream portion.
[0002]
[Prior art]
A papermaking machine (papermaking machine) includes a paper layer forming step (former) for forming a paper layer from a paper raw material liquid, and a dewatering step (press part) for pressing and dewatering the formed high moisture content wet paper. A drying step (dryer part) of drying the wet paper having a reduced moisture content by dehydration with a plurality of dryer cylinders is provided in order from the upstream side.
[0003]
In a state-of-the-art papermaking machine, there is no so-called open draw portion in which the wet paper web travels in the air by itself in the press part, and the wet paper web runs while being supported by a press felt or an impermeable belt. For this reason, in the press part, since there is no open draw from the suction pickup that receives the wet paper from the former to the vacuum transfer roll that transfers the dewatered wet paper to the dryer part, paper breakage occurs. Is gone.
[0004]
Techniques related to such a paper machine without an open draw are disclosed in, for example, US Pat. No. 4,483,745, US Pat. No. 5,792,320, US Pat. No. 5,951,821, and the like. I have.
[0005]
[Problems to be solved by the invention]
By the way, in the dryer part, no breakage should occur due to the open-open draw such as supporting the wet paper with canvas in each part, but actually, several dryer cylinders on the upstream side ( In particular, paper breakage often occurred in the uppermost stream (first dryer cylinder). It has been found that the cause is that wet paper sticks to the surface (outer peripheral surface) of the dryer cylinder in the dryer cylinder on the upstream side.
[0006]
In other words, since the wet paper sent to the dryer part contains moisture and an adhesive component (adhesive substance) on its surface, the moisture adhering to the outer peripheral surface of the dryer cylinder when the wet paper is pressed against the outer peripheral surface of the dryer cylinder by the canvas. Adhesives such as adhesives and adhesive substances function as an adhesive, and the wet paper sticks to the outer peripheral surface of the dryer cylinder. Adhesion of moisture and adhesive substances to the outer peripheral surface of the dryer cylinder is more remarkable in the dryer cylinder on the upstream side. Therefore, the wet paper on the outer peripheral surface of the dryer cylinder (especially, the first dryer cylinder on the uppermost stream) is increased. And cause paper breaks.
[0007]
For example, FIG. 3 is a schematic side view showing the upstream portion (near the first dryer cylinder) of the dryer part (multi-cylinder dryer device) of the papermaking machine developed in the process of devising the present invention. As shown in (1), the wet paper web 10 is supported and transferred by a felt or a water-impermeable belt 19a of the final press of the press part, and is transferred to the first dryer cylinder canvas 17a by an open draw through the vacuum transfer roll 20. When the wet paper web 10 is pressed against the first dryer cylinder 11 by the first dryer cylinder canvas 17a, the wet paper web 10 is stuck to the surface (outer peripheral surface) 11a of the first dryer cylinder 11, and point A Thus, even if the first dryer cylinder canvas 17a is separated from the first dryer cylinder outer peripheral surface 11a, the canvas 17a travels as it is stuck to the first dryer cylinder outer peripheral surface 11a against the centrifugal force.
[0008]
After that, the second dryer cylinder canvas 17b presses the wet paper 10 against the first dryer cylinder outer peripheral surface 11a from the point B to the point C, but after the point C, the wet paper 10 is separated from the first dryer cylinder outer peripheral surface 11a. To be supported by the second dryer cylinder canvas 17b. However, in addition to the suction effect of the negative pressure (pressure difference from the first dryer cylinder 11 side) by the wet paper suction vacuum box 7 and the wet paper reversing vacuum roll 6, the jet air flow of the paper peeling air jet 53 is used. Even when the paper peeling force is applied, the wet paper web 10 travels to the point D while the wet paper web 10 is stuck to the outer peripheral surface 11a of the first dryer cylinder.
[0009]
When the wet paper web 10 is peeled off from the first dryer cylinder 11 at the point D, a part of the paper fibers on the surface of the wet paper web 10 remains on the outer peripheral surface of the dryer cylinder together with the adhesive substance, thereby causing a defect on the surface of the wet paper web 10. At the same time, strain stress remains in the wet paper web 10, and furthermore, when the wet paper web 10 is stretched by the draw between D and E, a strain stress is generated in the wet paper web 10 and causes paper breakage.
[0010]
By the way, if the moisture of the wet paper at the entrance of the dryer part is reduced, sticking of the wet paper to the outer peripheral surface of the dryer cylinder is weakened. From the viewpoint of energy saving, it is preferable to reduce the moisture of the wet paper at the entrance of the dryer part. By increasing the linear pressure of the press in the press part, or by adopting a shoe press in the press part, the dryer part is reduced. Although the reduction of the moisture content of the wet paper web at the inlet is promoted, the sticking of the wet paper web to the outer peripheral surface of the dryer cylinder is inevitably caused.
[0011]
In some cases, a surfactant is applied as a release agent to reduce the adhesive force on the outer peripheral surface of the dryer cylinder.However, the surfactant adheres to the surface of the wet paper web and causes fibers on the surface of the wet paper web. This also causes the surface strength of the wet paper to decrease, and causes a problem that the surfactant remaining on the paper affects the subsequent printing on the paper. Therefore, such means is generally difficult to apply, and it is difficult to eliminate sticking of wet paper to the outer peripheral surface of the dryer cylinder.
[0012]
In addition, if the adhesive substance contained in the paper surface or paper fiber loosened from the paper surface adheres to the outer peripheral surface of the dryer cylinder, then when the wet paper 10 comes into contact with the outer peripheral surface of the dryer cylinder, Since the affinity between the adhesive substance and the wet paper 10 is large, when the wet paper 10 is peeled from the outer peripheral surface of the dryer cylinder, the adhesive substance on the outer peripheral surface side of the dryer cylinder transfers more paper fibers together with the adhesive substance on the surface of the wet paper 10 to the dryer cylinder. Since the wet paper web 10 is peeled off on the outer peripheral surface side, the wet paper web 10 receives more damage and the frequency of paper breakage increases.
[0013]
In particular, as the papermaking speed increases, the influence of the adhesive substance increases, and the frequency of paper breakage increases. To suppress this, as shown in FIG. In addition to the paper separating doctor 51 to be used, a doctor (doctor for removing attached matter) 52 for removing an adhesive substance is provided (US Pat. No. 5,951,821 discloses a configuration equipped with two doctors). The ceramic is sprayed on the outer peripheral surface of the dryer cylinder with good releasability. However, when the doctor 52 for removing adhering matter and the dryer cylinder sprayed with ceramic on the cylinder surface are also provided, papermaking is also performed. When the speed is increased to, for example, about 1800 m / min or more, paper breakage also occurs.
[0014]
The present invention has been devised in view of such a problem, and it is possible to remove an adhesive substance contained in paper fibers adhering to the outer peripheral surface of a dryer cylinder, thereby suppressing the occurrence of paper breakage in the dryer cylinder even in high-speed papermaking. It is an object of the present invention to provide a multi-cylinder dryer for a papermaking machine, which is capable of performing the above-mentioned operations.
[0015]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the multi-cylinder dryer for a papermaking machine according to the present invention is a multi-cylinder dryer for a papermaking machine, wherein the rotation direction is greater than the paper separation point on the outer periphery of the first dryer cylinder disposed at the most upstream position. A shower disposed on the downstream side for injecting the cleaning liquid toward the outer peripheral surface of the first dryer cylinder; and a tip of the outer periphery of the first dryer cylinder downstream of the shower in the rotational direction from the first dryer cylinder. An adhering matter removing doctor that is disposed so as to be in sliding contact with the outer peripheral surface and scrapes off adhering matter on the outer peripheral surface of the first dryer cylinder that has been softened by receiving the cleaning liquid from the shower; The distal end is disposed on the downstream side in the rotation direction from the adhering matter removing doctor so as to slide on the outer peripheral surface of the first dryer cylinder, and scrapes off moisture on the outer peripheral surface of the first dryer cylinder. It is characterized in that it includes a doctor for partial removal (claim 1).
[0016]
The outer peripheral surface of the first dryer cylinder is preferably formed of ceramic (claim 2).
Further, a paper separation doctor for guiding the paper separation from the first dryer cylinder during paper passing is provided near the paper separation point on the outer periphery of the first dryer cylinder in the rotation direction upstream of the shower in the rotation direction. (Claim 3).
[0017]
Further, it is preferable that the attached matter removing doctor is made of a material having relatively high rigidity, and the doctor for removing moisture is made of a material having relatively low rigidity.
Specifically, it is preferable that the adhering matter removing doctor is made of SK steel (claim 5), and the moisture removing doctor is made of fiber reinforced resin or phosphor bronze. Preferred (claims 6 and 7).
[0018]
Further, the outer periphery of a single or continuous plurality of dryer cylinders from the upstream side of the plurality of dryer cylinders continuously arranged immediately downstream of the first dryer cylinder is located near the paper separation point during paper passing. A paper release doctor for guiding paper release from the dryer cylinder is provided, and a distal end of the outer periphery of the dryer cylinder is provided on the downstream side in the rotation direction of the paper release doctor so as to be in sliding contact with the outer peripheral surface of the dryer cylinder. It is preferable that the apparatus further includes a second deposit removing doctor for scraping off deposits on the outer peripheral surface of the dryer cylinder.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a multi-cylinder dryer for a papermaking machine according to an embodiment of the present invention. FIG. 1 is a schematic side view showing the vicinity of a first dryer cylinder, and FIG. It is a typical side view which shows a part of 1-5 dryer cylinders) and its front process (press part).
[0020]
The papermaking machine (papermaking machine) according to the present invention includes, in order from the upstream side, equipment such as a wire part (paper layer forming step), a press part (dewatering step), and a dryer part (drying step). There is no open draw (unsupported space where no wet paper is supported) from the to the exit of the press part. The multi-cylinder dryer for the papermaking machine is equipped in the dryer part.
[0021]
Although not shown, downstream of the dryer part, a glossing step and a winding step are further provided in this order from the upstream side, and the web dewatered in the press part and the dryer part has its surface smoothed in the glossing step. In the winding process, it is made into a rolled paper product.
As shown in FIG. 2, the wet paper web 10 dehydrated by the press part is sent from the downstream side of the press part (final press) while being supported by a felt (or impermeable belt) 19a, and is subjected to a vacuum transfer roll (suction pickup roll). ) 20 through an open draw to transfer to the first dryer cylinder canvas 17a and to be introduced into the dryer part. At this time, the suction force of the suction vacuum box 21 together with the vacuum transfer roll 20 assists the transfer of the wet paper 10 to the first dryer cylinder canvas 17a.
[0022]
In the final press, the wet paper web 10 supported by the lower felt 19c and sent from the upstream press is transferred to the upper felt 19b by an open draw through a vacuum transfer roll (suction pickup roll) 24. Pressure is applied between the press rolls 22 and 23 through a side felt 19b and a felt (or a water-impermeable belt) 19a on the lower side to dehydrate. The felt (or water-impermeable belt) 19c is formed by the guide rolls 31a and the like, the felt (or the water-impermeable belt) 19b is formed by the guide rolls 31b to 31f, and the felt (or the water-impermeable belt) 19a is formed by the guide rolls 31g to 31k. , Each of which is guided.
[0023]
The multi-cylinder dryer device provided in the dryer part is provided between a number of dryer cylinders 11, 12, 13,..., And between the dryer cylinders in the same manner as that already described in the subject section (FIG. 3). , A vacuum box 7 for sucking wet paper and a vacuum roll 6 for reversing wet paper, canvases 17a, 17b, 17c,... The heated paper 10 is gradually dried by the surfaces (outer peripheral surfaces) 11a, 12a, 13a,... Of the heated dryer cylinders 11, 12, 13,.
[0024]
Although FIG. 2 shows the first to fifth dryer cylinders 11 to 15 on the upstream side, a number of dryer cylinders are further provided downstream. Also, the canvas for the dryer cylinder is shown from the first dryer cylinder canvas 17a on the upstream side to the third dryer cylinder canvas, but the third dryer cylinder canvas is further provided downstream.
[0025]
Further, the outer peripheral surface 11a of the first dryer cylinder 11 is sprayed with ceramic.
Each of the dryer cylinder canvases 17a to 17c is guided and guided by guide rolls 32g to 32s and the like which are in contact with each other. Then, as shown in FIG. 2, the wet paper web 10 introduced into the dryer part is pressed against the first dryer cylinder 11 by the first dryer cylinder canvas 17a, and the surface (outer peripheral surface) 11a of the first dryer cylinder 11 is formed. When the first dryer cylinder canvas 17a is separated from the first dryer cylinder outer peripheral surface 11a at the point A, the canvas 17a is still adhered to the first dryer cylinder outer peripheral surface 11a against the centrifugal force. It travels in a state and is heated and dried.
[0026]
Thereafter, the second dryer cylinder canvas 17b presses the wet paper 10 against the first dryer cylinder outer peripheral surface 11a from the point B to the point C. However, after the point C, the wet paper web 10 separates from the first dryer cylinder outer peripheral surface 11a and is separated from the second dryer cylinder 11a. When transferring the wet paper 10 to the second dryer cylinder canvas 17b side away from the outer peripheral surface 11a of the first dryer cylinder, the vacuum box for sucking wet paper is adapted to run while being supported by the cylinder canvas 17b. In addition to the suction effect of the negative pressure (pressure difference from the first dryer cylinder 11 side) by the vacuum roll 7 and the wet paper reversing vacuum roll 6, the paper peeling force by the jet air flow of the paper peeling air jet 5 is applied. ing.
[0027]
The wet paper web 10 transferred to the second dryer cylinder canvas 17b side travels along the outer peripheral surface of the wet paper web reversal vacuum roll 6 together with the second dryer cylinder canvas 17b by the suction force of the wet paper web reversal vacuum roll 6. Then, while being supported by the second dryer cylinder canvas 17b, it runs along the outer peripheral surface of the next third dryer cylinder 17 and is heated and dried.
[0028]
In this way, heating and drying are performed while traveling along the outer peripheral surface of each dryer cylinder while being supported by the dryer cylinder canvas. For example, when the wet paper web 10 is delivered to a different dryer cylinder canvas, such as when proceeding from the third dryer cylinder 17 to the next wet paper reversal vacuum roll 6, as described above, the wet paper suction vacuum box is used. The wet paper 10 is separated from the dryer cylinder by giving a suction effect of negative pressure (pressure difference from the first dryer cylinder 11 side) by the vacuum roll 7 and the wet paper reversing vacuum roll 6. Of course, in addition to this, the paper peeling force by the jet air flow of the paper peeling air jet 5 may be appropriately applied.
[0029]
By the way, in the vicinity of the paper separation point on the outer periphery of each of the dryer cylinders 11, 12, 13,... (Slightly closer to the cylinder rotation direction than the paper separation point), each of the dryer cylinders 11, 12, 13,. Are provided with paper separating doctors 1a, 1b, 1c,... For ensuring that the wet paper web 10 is separated from the outer peripheral surface of the dryer cylinder in the vicinity of the paper separating point.
[0030]
In the case of the present multi-cylinder dryer, upstream dryer cylinders (here, first, second, third dryer cylinders 11, 12, and 13) are provided with dryers 1a, 1b, and 1c in addition to the paper separating doctors 1a, 1b, and 1c. Adhered matter removing doctors 2a, 2b, and 2c that scrape off adhering materials containing adhesive components that adhere to the outer peripheral surface of the cylinder are provided slightly closer to the cylinder rotation direction than the paper separating doctors 1a, 1b, and 1c.
[0031]
In addition, in addition to the paper separating doctor 1a and the adhering matter removing doctor 2a, the cleaning liquid is applied to the outer peripheral surface of the dryer cylinder on the dryer cylinder on the very upstream side (here, the first dryer cylinder 11 at the uppermost stream). Is provided, and a water removing doctor 3a for scraping water on the outer peripheral surface of the dryer cylinder is provided.
[0032]
The shower 4 is located on the downstream side in the rotation direction from the paper separation point on the outer periphery of the first dryer cylinder 11, on the downstream side in the rotation direction from the paper separation doctor 1 a, and on the upstream side in the rotation direction from the attached matter removal doctor 2 a. It is arranged in. Therefore, when the cleaning liquid is sprayed from the shower 4 toward the outer peripheral surface 11a of the first dryer cylinder 11, the deposit containing the adhesive component adhered to the outer peripheral surface 11a is softened including the cleaning liquid. The adhering matter removing doctor 2a scrapes off the adhering matter softened on the outer peripheral surface 11a of the first dryer cylinder, so that the adhering matter can be easily removed from the outer peripheral surface 11a of the dryer cylinder. .
[0033]
In addition, since the shower 4 is arranged so as to be hidden by the paper separating doctor 1a with respect to the running wet paper 10, the cleaning liquid from the shower 4 is hardly applied to the running wet paper 10. In addition, the jetting direction and the jetting angle of the cleaning liquid from the shower 4 are set so that the cleaning liquid does not fall on the wet paper web 10.
The attached matter removing doctor 2a is made of a material having a relatively high rigidity so as to overcome the load caused by the adhesion of the attached matter to be scraped off. Although the doctor 2a for removing deposits is made of SK steel having relatively high rigidity, the material is not limited to SK steel as long as it has a rigidity that can overcome the load of the deposits to be scraped. .
[0034]
The water removing doctor 3a is made of a relatively low-rigidity flexible material that can follow fine irregularities on the outer peripheral surface 11a of the dryer cylinder in order to scrape off the outer peripheral surface 11a of the dryer cylinder. Here, the water removing doctor 3a is formed of a fiber reinforced resin such as carbon fiber reinforced plastic (CFRP) as a material, but other fiber reinforced resin or phosphor bronze having relatively low rigidity is used as a material to remove water. Even if the doctor 3a is configured, it is possible to ensure the ability to follow fine irregularities on the outer peripheral surface 11a of the dryer cylinder.
[0035]
In addition, when the deposit is quickly softened with respect to the cleaning liquid from the shower 4, the deposit removing doctor 2 a is disposed close to the shower 4 and the cleaning liquid from the shower 4 is disposed. If it takes a little time to soften the adhering substance, the adhering substance removing doctor 2a may be appropriately separated from the shower 4. The moisture removing doctor 3a may be arranged close to the attached matter removing doctor 2a. Of course, these are arranged in a limited space in consideration of maintainability.
[0036]
The adhering matter removing doctors 2b and 2c provided in the second and third dryer cylinders 12 and 13 are also made of a material having a relatively high rigidity so as to overcome the adhesive load of the adhering matter to be scraped off. Although the material is made of SK steel, the material is not limited to SK steel as long as it has a rigidity that can overcome the load of the material to be scraped off. The first and second dryer cylinders 12 and 13 are provided in the first dryer cylinder 11 using only the third dryer cylinder 13 or the material of the adhering matter removing doctors 2b and 2c of both the second and third dryer cylinders 12 and 13. A lower rigidity than the attached substance removing doctor 2a may be used.
[0037]
In addition, depending on the shape setting, material setting, and reinforcing structure of the tip, a high-rigidity doctor can be configured even with a fiber-reinforced resin, so that a fiber-reinforced resin with high rigidity can also be applied to a doctor for removing deposits.
Of course, the fiber reinforced resin used for the above-mentioned water removing doctor 3a is a general low rigidity fiber reinforced resin.
[0038]
Since the multi-cylinder dryer for a papermaking machine as one embodiment of the present invention is configured as described above, a relatively large amount of water is sent from the final press to the dryer part (the multi-cylinder dryer). The wet paper web 10 also contains a large amount of an adhesive component, and adheres and accumulates on the outer peripheral surface 11a of the first dryer cylinder. It is softened by the washing liquid and scraped off by the attached matter removing doctor 2a.
[0039]
In addition, since the material 2 having high rigidity is used for the adhering substance removing doctor 2a so as to overcome the adhesive load of the adhering substance, the tip of the adhering substance removing doctor 2a follows the fine irregularities on the outer peripheral surface 11a of the dryer cylinder. However, the adhering matter is removed, but water containing the cleaning liquid cannot be removed, and a water film remains on the outer peripheral surface 11a of the dryer cylinder. However, moisture remaining on the outer peripheral surface 11a of the dryer cylinder is scraped off by the moisture removing doctor 3a. In particular, since the moisture removing doctor 3a is made of a soft material having low rigidity, the tip of the adhering matter removing doctor 2a can follow fine irregularities of the dryer cylinder outer peripheral surface 11a, and the dryer cylinder outer peripheral surface 11a The remaining water can be reliably removed.
[0040]
Therefore, when the outer peripheral surface 11a of the dryer cylinder subsequently comes into contact with the wet paper 10 from the final press, the first outer peripheral surface 11a of the first dryer cylinder is in a state in which the attached matter and moisture have been removed, and the outer peripheral surface 11a of the first dryer cylinder 11a The paper separation from is not impaired.
In other words, in addition to the suction effect of the negative pressure (pressure difference from the first dryer cylinder 11 side) by the wet paper suction vacuum box 7 and the wet paper reversal vacuum roll 6, the jet air flow of the paper peeling air jet 5 is used. When the paper peeling force is applied, the wet paper 10 is reliably separated from the first dryer cylinder outer peripheral surface 11a at a predetermined paper separation point from the first dryer cylinder outer peripheral surface 11a. When peeled from the dryer cylinder 11, a part of the paper fibers on the surface of the wet paper web 10 hardly remain on the outer peripheral surface of the dryer cylinder together with the adhesive substance, so that the generation of defects on the surface of the wet paper web 10 can be suppressed. Further, the wet paper 10 is not stretched by the draw between D and E (FIG. 3) due to the sticky substance, so that the wet paper 10 is hardly subjected to strain stress, and the occurrence of paper breakage can be prevented.
[0041]
Further, since no water film remains on the outer peripheral surface 11a of the dryer cylinder, not only does the wet paper 10 not stick to the outer peripheral surface 11a of the dryer cylinder, but also the absorption of moisture of the wet paper on the outer peripheral surface 11a of the dryer cylinder is suppressed. 10 is also suppressed.
Since the outer peripheral surface 11a of the first dryer cylinder 11 is formed of ceramic, minute holes are formed in the surface of the ceramic, so that the peeling force between the wet paper and the outer peripheral surface of the dryer cylinder is small and the paper separation property is small. On the other hand, the moisture retention of the water on the outer peripheral surface of the dryer cylinder is relatively high, and the deposit containing the adhesive component easily adheres to the dryer cylinder surface, and the water film is easily formed. Becomes more likely to stick to the outer peripheral surface of the dryer cylinder.
[0042]
However, as described above, the adhering matter is surely removed by the adhering matter removing doctor, and the water film remaining on the outer peripheral surface 11a of the dryer cylinder after the removing of the adhering matter is surely removed by the moisture removing doctor 3a. Deposits containing an adhesive component are less likely to adhere to the cylinder outer peripheral surface 11a, and the releasability of the wet paper web 10 from the dryer cylinder outer peripheral surface 11a is ensured, and a decrease in the moisture content of the wet paper web 10 is promoted.
[0043]
Although the second and third dryer cylinders 12 and 13 on the upstream side are not as large as the first dryer cylinder 11, deposits containing adhesive components adhere to the outer peripheral surfaces 12a and 13a of the dryer cylinder. As the first and second dryer cylinders 11 and 12 are provided with the adhering substance removing doctors 2b and 2c for scraping off the adhering substances on the surfaces 12a and 13a, the wet paper 10 can be easily separated from the paper and can be prevented from being broken. Since the adhesion of moisture on the surfaces 12a and 13a can be suppressed, the decrease in the moisture content of the wet paper web 10 is promoted.
[0044]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be variously modified and implemented without departing from the gist of the present invention.
For example, since the adhesion of the deposits on the outer peripheral surface of the dryer cylinder decreases as going to the downstream side of the multi-cylinder dryer, the doctor for removing the deposits may be singly or continuously connected to an appropriate number of dryer cylinders from the upstream side. It may be provided.
[0045]
Further, in the above embodiment, the shower 4 and the water removing doctor 3a are provided only in the first dryer cylinder 11 at the uppermost stream. However, the shower 4 and the moisture removing doctor 3a may be further provided in the downstream dryer cylinder. good.
[0046]
【The invention's effect】
As described above, according to the multi-cylinder dryer for a papermaking machine of the present invention (claim 1), the most upstream first dryer cylinder of the multi-cylinder dryer has a wet paper web contacting the outer peripheral surface of the dryer cylinder. Due to the high moisture content, deposits containing adhesive substances (fine fibers, conduits, ash, etc.) adhere (adhere) to the outer peripheral surface (surface) of the dryer cylinder, and these deposits serve as an adhesive and the wet paper Although it is not preferable because it sticks to the outer peripheral surface of the dryer cylinder and causes paper breakage, spraying the cleaning liquid from the shower onto the adhered substance to make the adhered substance contain moisture makes it easier to peel off the adhered substance from the outer peripheral surface of the dryer cylinder. The attached matter in the state can be scraped off by the attached matter removing doctor.
[0047]
On the other hand, when trying to scrape off deposits containing adhesive components at the tip of the doctor with the deposit removal doctor, there is a gap between the tip of the doctor and the outer peripheral surface of the dryer cylinder. The water content of the cleaning solution and the like cannot be scraped off. As a result, a thin water film remains on the outer peripheral surface of the dryer cylinder after the foreign matter is scraped off from the outer peripheral surface of the dryer cylinder by the adhering substance removing doctor. It is not preferable because it acts to adhere to the surface. In particular, the wet paper increases the moisture content by the amount of the absorbed water, and the strength of the wet paper is reduced. In addition, the peeling force of the wet paper on the outer peripheral surface of the dryer cylinder (that is, when removing the wet paper from the outer peripheral surface of the dryer cylinder). The required force) increases as the moisture content of the wet paper increases, so that the wet paper tends to stick to the outer peripheral surface of the dryer cylinder, which causes paper breakage. However, in the present multi-cylinder dryer for a papermaking machine, a water removal doctor is provided downstream of the adhering matter removal doctor in the rotation direction, the leading end of which is in sliding contact with the outer peripheral surface of the first dryer cylinder. The water film on the outer peripheral surface of the dryer cylinder is removed by the removing doctor, and the above-mentioned problem is solved.
[0048]
When the outer peripheral surface of the first dryer cylinder is formed of ceramic, the peeling force between the wet paper web and the outer peripheral surface of the dryer cylinder is small because fine holes are formed in the surface of the ceramic, and the paper releasability is improved. On the other hand, the water retention of the water on the outer peripheral surface of the dryer cylinder is relatively high, and deposits containing an adhesive component easily adhere to the surface of the dryer cylinder. It becomes easy to stick. However, as described above, the adhering matter is surely removed by the adhering matter removing doctor, and the water film remaining on the outer peripheral surface of the dryer cylinder after removing the adhering matter is surely removed by the moisture removing doctor. Adhered matter containing an adhesive component is less likely to adhere to the surface, the releasability of the wet paper web from the outer peripheral surface of the dryer cylinder is secured, and a decrease in the moisture content of the wet paper web is promoted (claim 2).
[0049]
When a paper separation doctor for guiding paper separation from the first dryer cylinder at the time of paper passing is provided near the paper separation point on the outer periphery of the first dryer cylinder in the rotation direction upstream of the shower, The paper separation doctor can surely guide the paper separation from the first dryer cylinder during paper formation.
When scraping off the adhering substance containing a large amount of adhesive substance that adheres (adheres) to the outer peripheral surface of the dryer cylinder from the outer peripheral surface of the dryer cylinder, even if moisture is contained in the adhering substance, it is necessary to remove the adhering substance with a doctor blade. It is necessary to press the tip firmly against the outer peripheral surface of the dryer cylinder.However, if the doctor's rigidity is low, the doctor loses the load when scraping off the adhering substance containing a large amount of this adhesive substance and scrapes off the adhering substance. Although it is not possible, the deposit removal doctor is made of a material having relatively high rigidity, so that the deposit can be reliably scraped off without losing the load to the doctor (claim 4).
[0050]
In addition, when water (water film) attached to the outer peripheral surface of the dryer cylinder is scraped off, it is necessary that the distal end of the doctor slide following the minute shape change of the outer peripheral surface of the dryer cylinder, and if the doctor has high rigidity, The followability of the tip of the doctor to the outer peripheral surface of the dryer cylinder deteriorates.However, the distal end of the doctor follows the minute shape change of the outer peripheral surface of the dryer cylinder by forming the moisture removal doctor from a material with relatively low rigidity. As a result, the water film can be scraped off efficiently (claim 4).
[0051]
If the deposit removing doctor is made of SK steel, the SK steel has high rigidity, so that the doctor can securely remove the deposit without losing the load when scraping off the deposit containing a large amount of the adhesive substance. (Claim 5).
If the water removal doctor is made of fiber reinforced resin, the fiber reinforced resin has relatively low rigidity and flexibility, so the tip of the doctor slides following the minute shape change on the outer peripheral surface of the dryer cylinder. Water film can be scraped off efficiently. Of course, since the fiber is reinforced, the durability is secured (claim 6).
[0052]
If the water removal doctor is made of phosphor bronze, phosphor bronze has relatively low rigidity and flexibility, so the tip of the doctor can follow the minute shape change on the outer surface of the dryer cylinder to make sliding contact. The water film can be scraped off efficiently (claim 7).
[0053]
The outer periphery of a single or continuous plurality of dryer cylinders from the upstream side of the plurality of dryer cylinders arranged immediately downstream of the first dryer cylinder is located near the paper separation point, A paper separating doctor for guiding the paper separating from the cylinder is provided, and a distal end of the dryer cylinder outer periphery is disposed on the downstream side in the rotation direction from the paper separating doctor so as to be in sliding contact with the outer peripheral surface of the dryer cylinder, If a second attached matter removing doctor for scraping off the attached matter on the outer peripheral surface of the dryer cylinder is provided, the attached matter on the outer peripheral surface of the dryer cylinder can be efficiently removed.
[0054]
That is, in the second and subsequent dryer cylinders of the multi-cylinder dryer device, the amount of the attached matter on the outer peripheral surface of the dryer cylinder is reduced, so that the attached matter can be easily removed even if the attached matter does not contain moisture. . Therefore, the adhering matter on the outer peripheral surface of the dryer cylinder can be removed only by scraping off the adhering matter on the outer peripheral surface of the dryer cylinder without supplying moisture to the adhering surface of the dryer cylinder.
[0055]
In addition, since the adhesion of the deposits to the outer peripheral surface of the dryer cylinder decreases toward the downstream side of the multi-cylinder dryer, the doctor for removing the deposits may be a single dryer or a plurality of continuous dryers from the upstream side. What is necessary is just to provide in a cylinder (the above, Claim 8).
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an upstream portion (near a first dryer cylinder) of a multi-cylinder dryer for a papermaking machine according to an embodiment of the present invention.
FIG. 2 is a schematic side view showing an upstream portion (near the first to fifth dryer cylinders) and a part of a pre-process (press part) of a multi-cylinder dryer device for a papermaking machine according to an embodiment of the present invention. FIG.
FIG. 3 is a schematic side view showing an upstream portion (near a first dryer cylinder) of a multi-cylinder dryer device of a papermaking machine developed in the process of devising the present invention.
[Explanation of symbols]
1a, 1b, 1c, 1d, 1e Doctor for separating paper
2a, 2b, 2c Doctor for removing adhering matter
3a Water removal doctor
4 shower
5 Air jet for stripping paper
6 Vacuum roll for wet paper reversal
7 Vacuum box for wet paper suction
10 Wet paper
11 1st dryer cylinder
11a Outer surface of first dryer cylinder
12 Second dryer cylinder
12a Outer peripheral surface of second dryer cylinder
13 Third dryer cylinder
13a Outer peripheral surface of third dryer cylinder
14 4th dryer cylinder
14a Outer peripheral surface of 4th dryer cylinder
15 Fifth dryer cylinder
15a Outer surface of fifth dryer cylinder
17a Canvas for 1st dryer cylinder
17b Canvas for 2nd dryer cylinder
17c Canvas for 3rd dryer cylinder
19a Felt (or impermeable belt)
19b Upper side felt
19c Lower side felt
20 Vacuum transfer roll (suction pickup roll)
21 Vacuum box for suction
22,23 Press roll
24 Vacuum transfer roll (suction pickup roll)
31a-31k Guide roll
32g-32s guide roll
51 Paper Removal Doctor
52 Doctor for removing adhering matter
53 Paper jet air jet

Claims (8)

In a multi-cylinder dryer for papermaking machines,
A shower that is disposed downstream of the paper separation point on the outer periphery of the first dryer cylinder disposed at the most upstream in the rotation direction and that sprays the cleaning liquid toward the outer peripheral surface of the first dryer cylinder;
The first dryer, which is disposed so that its distal end is slidably in contact with the outer peripheral surface of the first dryer cylinder on the downstream side in the rotation direction of the outer periphery of the first dryer cylinder with respect to the shower, and is softened by receiving the cleaning liquid from the shower. An adhering matter removing doctor that scrapes off adhering materials on the cylinder outer peripheral surface,
The tip of the outer periphery of the first dryer cylinder is disposed downstream of the adhering substance removing doctor in the rotational direction so as to be in sliding contact with the outer peripheral surface of the first dryer cylinder. A multi-cylinder dryer for a papermaking machine, comprising a doctor for removing moisture to be scraped off. The multi-cylinder dryer for a papermaking machine according to claim 1, wherein an outer peripheral surface of said first dryer cylinder is formed of ceramic. A paper separating doctor for guiding paper separation from the first dryer cylinder during paper passing is provided near the paper separation point on the outer periphery of the first dryer cylinder in the rotation direction upstream of the shower. A multi-cylinder dryer for a papermaking machine according to claim 1 or 2, characterized in that: 4. The doctor according to claim 1, wherein the doctor for removing adhering matter is made of a material having relatively high rigidity, and the doctor for removing moisture is made of a material having relatively low rigidity. A multi-cylinder dryer for a papermaking machine as described in the above. 5. The multi-cylinder dryer for a papermaking machine according to claim 4, wherein said doctor for removing adhering matter is made of SK steel. 6. The multi-cylinder dryer for a papermaking machine according to claim 4, wherein the water removing doctor is made of a fiber reinforced resin. 6. The multi-cylinder dryer for a papermaking machine according to claim 4, wherein the water removing doctor is made of phosphor bronze. The outer periphery of a single or continuous plurality of dryer cylinders from the upstream side of the plurality of dryer cylinders arranged immediately downstream of the first dryer cylinder is located near the paper separation point, A paper separating doctor for guiding the paper separating from the cylinder is provided, and a distal end of the dryer cylinder outer periphery is disposed on the downstream side in the rotation direction from the paper separating doctor so as to be in sliding contact with the outer peripheral surface of the dryer cylinder, The multi-cylinder dryer for a papermaking machine according to any one of claims 1 to 7, further comprising a second deposit removing doctor for scraping off deposits on the outer peripheral surface of the dryer cylinder. .

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