KR950014935B1 - Web transfer device - Google Patents

Abstract

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Description

Wetland Transfer Device

1 is a side view of the wetland transport apparatus according to the first embodiment of the present invention.

2 is an explanatory diagram when the wetland is transferred from the hard roll (press center roll) in FIG. 1 to the belt.

3 is an explanatory diagram when transferring the wetland to the belt from the hard roll of the present invention.

4 is an explanatory diagram when the wetland is transferred from the belt to the next felt.

5 is a cross-sectional view when transferring the wetland from the belt to the next felt.

6 is a cross-sectional view showing another example of the structure of the belt when transferring the wetland from the copper felt to the next felt.

7 is a side view of the wetland transport apparatus according to a second embodiment of the present invention.

8 is a side view showing a conventional notification operation.

9 is a side view showing the relationship between the wetland and the press apparatus in the conventional press section.

10 is a side view of a conventional notification device.

11 is a side view of a conventional notification device.

* Explanation of symbols for main parts of the drawings

1: wire part 2: wetland

3: suction pick-up roll 4: pick-up felt

8a: press center roll 8b: top roll

12: felt 50,56: pressure roll

51: vacuum roll 52: belt drive roll

53: tension roll 54: belt guide roll

55: endless belt 57: elastic portion

58: home 59: the body

60 cell 61 seal packing

62: hole 63: vacuum box

64: hole 65: dish hole shape

66: support trolley 70: pressure roll

71: vacuum roll 72: belt driving roll

73: tension roll 74: guide roll

75: belt 76: support trolley

78: canvas 79: full width beam

80: shower 81: cleaning roll

83: doctor

The present invention relates to a wetland transport apparatus in a paper machine press part.

In general, the role of the press part in the initial process is to increase the concentration to about 40% to 45% by pressurizing the wetlands dehydrated to 15 to 18% in the upstream wire with a roll or the like, and then transfer it to the dryer part in the next step. have. 9 shows an example of a conventional high speed press apparatus used in the press section. In FIG. 9, the wetland 2 having a moisture content of about 88% formed by the wire portion 1 is sucked by the suction pick-up roll 3 and is attached to the pick-up felt 4 to be transported. 4) and the first felt 1P of the double felt formed by the 1P felt 5, the suction roll 6 and the first groove roll 7a, the porous felt 4, 5 Dehydration is carried out up and down as indicated by the arrows A and B in the drawing. In addition, the suction roll 6 is sucked by the vacuum and is held on the back surface of the pick-up felt 4, and is inverted so that the surface has a smooth roll, that is, a press center roll 8a coated with natural granite, artificial stone, rubber, or the like. And dehydration to the pick-up felt 4 by the second press 2P of the single felt formed by the second groove roll 7b. Here, the wetland 2 is transferred to the press center hole 8a, which is denser than the pick-up felt 4, and again in the third press 3P formed by the copper roll 8a and the third groove roll 7c (3P). ) Dehydrated to the felt 9, the moisture value is about 55 to 60%, and is transferred to the next stage press (press 4) or to the dryer part of the next process.

Next, the outline of the notification operation in the conventional apparatus will be described. The wetland 2 dehydrated in the 3rd press 3P is attached to the surface of the center roll 8a and peeled off by the doctor 10. As shown by 2 ', it falls to the full width press fit 11 once. In this state, since it is difficult to transfer the wetland of the full width to the next stage press or the dryer unit, a method of transferring the wetland (tail) of a wide width first and then spreading it in full width is adopted. Then, the notification of the tail starts with making a tail of arbitrary width by a high-pressure water jet (not shown) at the wire portion. In this case, in FIG. 8, both or one side of the paper roll 15 and the lead-in felt trolley 17 are moved to the position indicated by the dotted lines such as 15 'and 17', and the tail passes. After ensuring easy space, the air is ejected from the air nozzle of the carrier jet 19, the tail is peeled off from the press center roll 8a, and the seal 21 is placed on the felt 21 of the next press as shown in (2 "). Then it is transferred to the next stage press.

FIG. 10 is a view showing an operation state in which the wetland 2 is shifted from the center roll 8a of the conventional press to the next fourth press felt 21 as described above. In FIG. 10, the wetland dewatered by the 3P felt 9 is pressed against the press center roll 8a with a strong force for dewatering, and is attached to the press center roll 8a. The wetland attached to the press center roll 8a needs to be peeled from the presser roll in order to transfer to the subsequent press, so that the operation speed of the subsequent press is operated at a speed higher than that of the preceding process. This increased songdo powder is called a draw, but this draw creates a tension in the wetland, and the force acts to peel the wetland from the press center roll by opposing the adhesive force with the press center roll. At this time, the appropriate tension in the wetland acts on the full width of the open draw part (where the wetland is not supported by felt or roll). This tension causes the wetland to grow thicker. It is thought that the amount of the wetland is concentrated on the separation of the wetland where the tension increases, but the amount of the wetland is partially different due to the nonuniformity such as the fiber amount, the fiber dispersion, and the distribution of the materials, and causes the nonuniformity of the stress. This causes partly the destruction of the wetland, resulting in the complete breaking of the species. In addition, when the open error is long, the partially concentrated amount (and thus the stress) increases in proportion to the length of the open draw, thus increasing the risk of paper breaking. Therefore, open draw needs to be as short as possible. An example of such a measure is shown in FIG. In the arrangement of the press center roll 8a and the suction roll in FIG. 11, the open draw can be shortened, and only one open draw part is provided.

In FIG. 11, when the suction roll is pressed against the press center roll 8a, aiming at the open draw young to prevent paper break, the speed of the felt or canvas wrapped around the suction roll is equal to that of the press center roll. At the same speed. As a result, no draw occurs, and therefore, the wetland cannot be separated from the center roll by the tension of the wetland. In addition, the peeling force of the wetland by the vacuum pressure of the suction roll acts only after the nip because the air permeability of the press center roll is not sufficient. As a result, the wetland cannot be separated from the press center roll only by the vacuum pressure of the suction roll, and the wetland is attached to the press center roll by adhesive force with the press center roll. Thus, in order to strip the wetland from the press center roll, a draw is required and a minimum of open draw must be left. For this reason, the above-mentioned paper breaking problem is not fundamentally solved.

By the way, in recent years, the speed of papermaking machines is remarkable, and in the conventional papermaking machines, some machines are operated near 1300m / min, and there are many needs of 1500m / min. Among the demands for speeding up paper machines, one major problem is the transfer of wetlands between press sections and between press sections and dryers.

That is, in the related art, the wetland tail is peeled from the press center roll by the air nozzle and then sent to the next step as described above. However, the wetland is difficult to peel off from the press center roll at a high speed. In order to stably peel from a roll, it is necessary to enlarge the draw (speed difference) between presses or a press and a dryer. However, the wetland concentration after the press part is about 40 to 45%, the strength is very low compared to the dry paper, and the wetland in the above section is a so-called open draw, which is not supported by felt or the like. It is easy to break, for example, once the paper passes through the normal operation, if there is any fluctuation, the paper is likely to break.

Therefore, in the present invention, in order to separate wetlands from hard rolls (press center rolls or top rolls), an elastic belt is used, and the thickness of the belt is used by using the thickness reduction of the belt generated when the belt is pressed against the hard roll. The belt surface was stretched by an amount suitable for the reduction, thereby causing a gap between the wetland and the hard roll. In order to remove the wetland from the hard roll between the belts or to transfer the wetland attached to the belt to the next felt or canvas, a small diameter penetrating the groove or the belt is installed in the circumferential direction in advance on the surface of the belt. The hole was formed, and the cover of the vacuum box was covered by the felt or canvas of the next step was pressed into the wetland, and the means such as conveying the wetland to the felt or the canvas of the next step by the pressure of the air passing through the wetland was determined. . Thereby, an object of this invention is to solve the said problem.

For this reason, the present invention, in the wetland transfer device of the initial press, the end face where the copper transfer device is in contact with the wetland is elastic because it is elastic, and the endless surface formed of a material that is less elastic in the side that is not in contact with the wetland And a hard roll arranged opposite to the belt, the belt is pressed against the hard roll via the wetland to deform the belt so that the wetland can be separated from the hard roll and transferred to the belt. .

According to the present invention, the surface of the elastic belt in contact with the wetland always runs in contact with the wetland. At this time, the surface of the elastic belt always runs at the same speed as or faster than the wetland, and since the deformation of the elastic belt disappears, especially after the maximum pressure, the speed increases, and as a result, the wetland is separated from the press center roll. Tension can be generated in the state of open draw zero.

Hereinafter, the wetland transfer apparatus in the paper machine press unit according to the embodiment of the present invention will be described with reference to the accompanying drawings. 1 to 7 show an embodiment of the present invention. FIG. 1 shows an embodiment in which the wetland transfer apparatus according to the present invention is applied to the fourth press 4P from the third press 3P of the paper machine press section. The wetland formed in the wire part 1 in FIG. 1 suction-attaches to the pick-up felt 4 in the vacuum which acts on the suction pick-up roll 3, and is the press center roll which is a hard rod of the 3rd press 3P ( Attached to 8a) and conveyed are the same as in the prior art. The wetland conveying apparatus for sending the wetland 2 from the press center roll 8a to the next step is a pressure roll for pressing the elastic endless belt 55 and the copper belt to the press center roll 8a via the wetland. 50 and 56, a belt driving roll 52 for driving the copper belt, a tension roll 53 for tensioning the copper belt, a belt guide roll 54 and a pressure roll 50, 56 To a press center roll 8a. Further, by the above configuration, the pressure roll 56 may be disposed at a position where the belt is keyed on the center roll 8a, and the elastic belt may be prevented from decreasing in thickness.

Next, an operation of separating the wetland from the press center 8a based on the above configuration will be described with reference to FIG. 2. In FIG. 2, when the elastic belt 55 having a small height 59 is pressed against the press center roll 8a at a position t ₂ away from the surface in contact with the wetland, the elastic belt is pressed. The running speed of the core is constant and is pressed by the press roll _In section ₁ , the belt surface velocity facing the wetland is equal to the surface velocity of the center roll, ignoring the thickness of the wetland. Therefore, the surface speed of the press center roll 8a is V, the radius of the press center roll 8a is R, the distance from the core on the nip center line to the surface contacting the paper is t'2, and the thickness of the paper is If ignored, the speed of the body is

It becomes

On the other hand, in the section θ ₂ from the nip point E formed by the press center roll 8a and the pressure roll 50 until the belt is separated from the pressure roll 50, the belt surface speed of the side in contact with the wetland is If the radius of the pressure roll 50 is r, the distance from the core 59 to the belt surface is t ₂ , and the distance from the core 59 to the belt surface is t ₁ ,

It becomes

In general, R>t'2 because the interval of θ ₂ the belt surface speed of

Is almost equal to. In the conventional method of separating wetlands by open draw, the draw is usually about 3 to 4% or less, so if t ₂ / (r + t ₁ ) is about 1.0% in consideration of slippage between the belt and the wetlands, The draw required for the separation of the wetland from the center roll can be obtained. The wetland roadway can be controlled by controlling the sliding pressure between the wetland and the belt surface by controlling the pressing force of the press center roll of the pressure roll and causing a change in the belt thickness t'2.

Next, the transfer mode of the wetland on the 4P belt from the belt 55 in the back step of the wetland transfer device will be described with reference to FIG. In FIG. 4, the 4P felt 12 is pressed against the belt by the vacuum roll 51. As shown in FIG. The vacuum roll 51 is composed of a cell 60 having a plurality of holes 62, a vacuum box 63 and a seal packing 61 to prevent leakage of air between the vacuum box and the cell. The vacuum pump (not shown) is connected to 63 by piping. The belt 55 is composed of a core 59 reinforced by wire cross or the like which has strength and little stretching even when a tensile force is applied, and an elastic portion 57 that allows elastic expansion and contraction. The surface of the elastic part 57 is formed with grooves 58 (FIG. 5) continuous in the circumferential length direction, and a plurality of grooves 58 are formed in the width direction. The elastic portion 57 is designed to increase the hardness so as to be closer to the joint surface with the core 59 so as to reduce the stretching, and measures are taken so that peeling does not occur with the core. When a vacuum force acts on the vacuum roll 51, the air G passes through the plural grooves 58 formed in the belt, passes through the wetland 2 and the 4P felt 12, and flows into the vacuum box 63. The wetland attached to the belt by the air flow through the wetland is transferred to the 4P felt 12, and the process moves to the fourth press of the next step. The belt outer example shown in FIG. 4 has shown the example of the groove formed in the circumferential length direction, As shown in FIG. 6, you may form the hole 64 which penetrates a belt instead of a groove | channel. In addition, the hole formed in the vacuum roll cell 60 may be formed into a dish-shaped hole 65 in order to largely hold the opening ratio of the surface in contact with the felt, whereby the wetland can be more reliably transferred to the felt side.

Next, a second embodiment according to the present invention will be described with reference to FIG. This second embodiment differs from that of the first embodiment in that the belt is pressed against the press center roll 8a by one pressure roll 50, thereby causing the wetland to be separated from the press center roll 8a. have. In FIG. 7, one pressure roll 50 is pressed toward the press center roll 8a. Moreover, the support trolley 66 is provided in the side which opposes the pressure roll 50, and the felt 12 is comprised so that it may have a slight winding angle with respect to the pressure roll 50. As shown in FIG. For this reason, the jersey which is separated from the press center roll 8a by the action of the belt 55 is immediately inserted into the belt and the felt, and is surely conveyed to the back process without falling from the belt. Moreover, the vacuum roll 51 is comprised so that it may keystroke to the 4th press top roll 8b, and a wetland is conveyed to the top roll 8b in the state supported by the vacuum force by this.

The peeling operation of the wetland in the second embodiment will be described with reference to FIG. 3, and as shown in FIG. 3, the elastic belt is in contact with the center roll 8A between the points C and D. As shown in FIG. The belt surface velocity in contact with the wetland is the same as the web velocity at point E where the pressure is maximized. If the distance from the core under the nip to the surface of the belt in contact with the wetland is t'2,

Since the belt surface speed in contact with marsh θ ₂ in the interval

From the point C near the wetland on the press center roll, the belt surface speed decreases, and at the maximum pressure point E (the distance from the core to the belt surface t ₂ ) is equal to the wetland speed. After that, we're going to speed up again and leave D The interval of ₂ is

It is possible to drive at a speed of and obtain a draw required for peeling off the wetland from the press center roll.

In this embodiment, when the wetland is transferred from the top roll 8b of the fourth press to the drier section of the next step, the same operation as described above is performed. That is, the wetland transfer device is composed of a pressure roll 70, a belt drive roll 72, a tension roll 73, a guide roll 74 belt 75 and a vacuum roll 71 in a dryer canvas loop. The wetland separated from the top roll 8b by the action of the belt 75 pressed by the pressure roll 70 is inserted into the canvas 78 and the belt 75 at the support trolley 76. The vacuum roll 71 is transferred to the canvas by the vacuum action and conveyed to the dryer unit.

As described in detail above, in any of the first and second embodiments, the surface of the elastic belt in contact with the wetland always travels in contact with the paper, and always travels at the same speed or faster than the wetland, especially after the maximum pressure pressure. Since the speed increases, tension for peeling the wetland from the press center roll can be generated in the state of open draw zero. In any of the above embodiments, as shown in Figs. 4 and 5, since the hole is formed in the surface of the belt through the groove or the small hole, the groove or the small hole passes through the wetland 2 through the groove 2; Since suction of air is performed to a vacuum roll, a wetland can be conveyed to the next felt or canvas reliably. In addition, the wetland formed in the wire part 1 is conveyed together with a belt, felt or canvas to the dryer part after being sucked by the suction pick-up roll, so that the open drawer part which only the wetland is conveyed disappears and paper breaking does not occur. . In addition, although not specifically explained, in any embodiment, a pressure roll, a belt driving roll, a tension roll, a guide roll, etc. are supported by the full width beam 79 which has a cantilever mechanism, and the arrangement structure which is convenient for changing a belt is considered. It is.

Moreover, you may install the shower 80, the cleaning roll 81, and the doctor 83 as needed for cleaning a belt. In addition, the notification method in the dryer part can also employ a conventional method of making a tail in the wire part when the dryer structure is difficult to transport the wetland of the full width, and spreading the tail to the full width paper after the tail is notified in the dryer part. have. However, the fiber of the cut surface of the tail by high pressure water may be connected again by the nip in a press part. In such a case, you may provide the high pressure water jet 84 for tail making after the last press of a press part. In each of the embodiments, the elastic belt is pressed against the hard roll by a rotating pressure roll. However, the elastic belt need not be rotated, and the belt-contacting portion may have an arc shape. At this time, by using a lubricating liquid between the belt and the surface of the pressing apparatus where the arc shape stops, friction between the belt and the arcuate surface body, heat generation and the like can be prevented.

As described in detail above, according to the present invention, there is no open draw between presses, or presses and dryers, which have been obstacles of conventional speed increase, and thus paper breakage is reduced, and the initial speed increase and mechanical efficiency of the machine are reduced. This is greatly improved. In addition, since a considerable amount of skill is required and time-consuming notification work is unnecessary, the safety is improved and the first operation time of the paper machine is also increased. In this regard, it is possible to achieve excellent effects such as improved mechanical efficiency.

Claims (1)

In the wetland conveying apparatus of the papermaking press, the surface where the copper conveying apparatus is in contact with the wetland is elastic and elastic, and the surface which is not in contact with the wetland is endless belt formed of a material having a small amount of elasticity. A wetland conveying apparatus having a hard roll disposed to face each other, wherein the belt is pressed against the hard roll via a wetland to generate deformation in the belt, and the wetland can be separated from the hardroll and transferred to the belt.