JPH07138894A - Twin-wire former - Google Patents

Abstract

PURPOSE:To obtain the good paper quality, enable rapid exchange of sheet formation and reduce the amount of brokes in relation to a gap part controlling means for a twin-wire former of a paper machine. CONSTITUTION:This twin-wire former is provided by inputting operating conditions scheduled in starting the operation of a new paper grade to a computer 22, thereby actuating worm jacks 14, 15, 16 and 17, setting the dimensions of the opening degree of an inlet 1 for jetting a raw material stock, changing the landing point of the raw material stock to No.1 wire 3 and No.2 wire 4 and thereby preventing the paper quality from deteriorating and paper defects from occurring. Since the regulation is carried out while detecting the formation value with an on-line wet web defect sensor (a formation meter 23), a wet web having high reliability is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gap control device for a twin wire former of a papermaking machine.

[0002]

2. Description of the Related Art An example of a twin wire device in a conventional papermaking machine is shown in FIG. In FIG. 14, the raw material liquid 2 ejected from the inlet 1 is No. 2 wires 4 and N
o. No. 1 is sandwiched between the wires 3. It is dehydrated by the initial dehydrator 5 arranged on the two-wire side.

No. The white water dewatered to the 1-wire side is behind the initial dewatering device 5, and is no. It is scraped off by the water deflector 8 arranged on the one wire side.

Subsequently, No. Further dehydration is performed by the dehydration device 6 and the dehydration roll 7 arranged on the two-wire side. Near the exit side of this part, the paper layer formation is almost completed.

No. 2 at the separation of both wires. The wet paper 12 transferred to the 2-wire side is transferred to the felt 13 of the press part by the suction roll 11.

FIG. 5 shows that the raw material liquid 2 ejected from the inlet 1 is No. 2 wire 4 and no. 1 shows a state of being sandwiched between one wire 3. Further, the alternate long and short dash line portion (enlarged view) of this figure is shown in FIG. (However, the wire is shown as a solid line instead of a dotted line for the sake of accuracy.)

In FIG. 6, the raw material liquid 2 landed on the wire is immediately dehydrated and an initial fiber mat is formed. Therefore, No. Breast roll 9 on the 2 wire side
The initial dewatering device (forming shoe) 5 is fixed, and the operation is performed while adjusting the following four geometrical values (including coordinates).

That is, W = slice lip position L size (raw material liquid discharge angle θ ₁ is determined by L / B) X = slice opening B size Y = raw material liquid No. 2 Position of 2 wire landing point (Adjust the inlet body angle in order to determine the No. 2 wire collision angle θ ₂ of the raw material liquid.) Z = No. Position of 1 wire landing point (position of forming roll 10 is determined)

FIG. 9 shows an explanatory view of a device having four worm jacks for adjusting these numerical values. Also, by operating the W adjustment worm jack 14, L
FIG. 10 shows an explanatory diagram for adjusting the dimensions, FIG. 11 shows an explanatory diagram of the X adjustment worm jack 15, and FIG. 12 shows an explanatory diagram of the Y adjustment worm jack 16.
An explanatory view of the adjustment worm jack 17 is shown in FIG.

In the above adjustment, the operation of each drive system is manually performed while observing the condition of the jetted raw material liquid in the gap portion, both wires and the dehydrating device and the paper quality.

[0011]

By the way, FIG. 7 shows No. 1 of the inlet raw material liquid. A state in which the two-wire landing point is brought close to the breast roll 9 is shown, and if it is brought too close to the breast roll, the pumping action of the breast roll causes rapid dehydration, which causes a problem that pinholes or defects occur in the wet paper.

On the contrary, No. The 2 wire landing point is located after the tip of the initial dewatering device 5, and the inlet raw material liquid and N
o. If the gap between the two wires is increased (not shown), the free surface length of the raw material liquid becomes longer, the surface is disturbed, and N
o. 2 Wires or air around the breast rolls, which is carried by the inlet raw material liquid, are entrained, and speckled paper defects occur on the wet paper.

FIG. 8 shows a state in which the gap between the forming roll 10 and the inlet raw material liquid is made small and close.
In this case, the pumping action of the forming roll causes rapid dehydration, resulting in pinholes and defects in the wet paper.

Further, the gap between the forming roll and the inlet raw material liquid is widened so that the inlet raw material liquid No. When the 1-wire landing point is above the proper position (not shown), the length of the free surface of the raw material liquid becomes long, the surface disorder becomes strong, and the air around the forming roll is entrained,
Spot-like defects occur on the wet paper.

In particular, in a paper machine with a high basis change frequency that operates in a wide basis weight range and a wide variety of paper grades, the lip opening
When the machine speed is changed significantly, the landing position of the raw material liquid on both wires changes, so it is necessary to adjust the landing position of the raw material liquid by operating the four worm jacks 14, 15, 16, 17 described above. there were. If this adjustment is time-consuming, a large amount of waste paper will be produced, and paper quality cannot be maintained at a high level until the adjustment is completed.

[0016]

As a structure for solving the above-mentioned problems of the prior art, the twin wire foamer of the present invention has a wire former gap having major specifications such as W, X, Y and Z. Equipped with a gap part control system that has a geometric numerical value (including coordinate) calculation function, and by inputting the above numerical values as operating conditions,
Calculate the operation signal of each numerical position adjustment actuator,
Each actuator is operated and optimized.
It should be noted that the input can be selected from either the landing position of each wire of the raw material liquid or the gap between the raw material liquid and each wire.

The optimum worm jacks 14, 15, 16, 17 for each operating condition obtained from past experience.
The data related to the length of the worm is stored in the computer, and the target value of the worm jack length is automatically calculated by inputting the target condition at the time of changing the paper, and the sensor related to the worm jack length is calculated. Until the signal value reaches the target value, the above-mentioned W, X, Y, Z actuators are operated to maintain the dewatering pressure at the proper value in the initial dewatering device that does not involve the air around the rolls. Solve the problem.

Further, since the above-mentioned Y and Z have a higher degree of freedom than in the past, it is possible to input the gap data as described below, and the input can be selected in any case.
In addition, a sensor detection value or geometric calculation is displayed for this gap. Y ′ = No. No. 2 wire landing position (described above) or No. 2 supported on the raw material liquid 2 and breast roll surface. 2 Gap between two wires (not shown) Z ′ = No. The position of the wire 1 landing point (described above), or No. 1 supported on the raw material liquid 2 and the surface of the forming roll. Gap with 1 wire (not shown)

In order to know the proper worm jack length under the operating conditions of the paper grade which has not been carried out, the twin wire foamer was operated while changing the worm jack length described above on a test basis. The above-mentioned worm jack length in the proper formation is detected by detecting the formation value with the online land total (including traverse type defect detectors such as formation, pinhole, streak, bare track, etc.) installed in a place where the wet paper can be seen directly. It has a self-learning function that stores the sensor signal data related to the height together with the papermaking conditions at that time and uses it as data for determining four geometrical numerical position during the subsequent operation.

In addition, when the land total is not installed, confirmation is made by trial paper making, the manual setting is made at an appropriate position, and the system value for each worm jack at this time is stored and reproduced at the time of paper making again.

[0021]

With the twin wire foamer of the present invention having the above-described structure, when the operating conditions (basis weight, raw material type, machine speed, etc.) that are planned at the start of operation of a new paper grade are input to the computer, the worm jack 14 , 15, 16, 17
Is operated, the inlet opening B (slice angle), the raw material liquid discharge angle θ ₁ (determined by L / B), and the raw material liquid No. of the inlet. 1 and No. 2 The landing point on the wire changes.

For example, when changing the paper from a low grammage paper grade to a high grammage paper grade, in the wire part having the initial dewatering device as shown in FIG. 6, the thickness of the raw material liquid 2 from the inlet is increased. t becomes thicker.

At this time, if the L dimension is left as it is and only the B dimension is opened, No. 1 and No. The landing point of the raw material liquid on either side of the two wires moves in a direction approaching both roll sides (FIG. 15). When the raw material liquid lands on the roll or comes too close to the roll, vacuum action at the roll outlet side causes rapid dehydration, which may impair the quality of the paper, resulting in paper defects.

A method of adjusting the above-mentioned geometrical values will be described with reference to FIG. No. Raw material liquid thickness t up to 2 wires
Varies depending on operating conditions such as basis weight, raw material properties, and machine speed.

Each time, the slice opening B dimension is set from the inlet raw material liquid flow rate, and the inlet raw material liquid discharge angle θ
L dimension that determines ₁ (dimension in the direction in which the raw material liquid is ejected between the slice lip and the apron lip support tip) (especially L /
B relationship is important), and the free surface of the raw material liquid and the surface of breast roll 9 are held. The gap between the two wires is kept to a few millimeters, and the material liquid No. Adjust the 2-wire collision angle θ ₂ and adjust the No. Determine the position so that the 2 wire landing point is in front of the tip of the initial dewatering device 5,
Lastly, No. 2 holding the free surface of the other raw material liquid and the surface of the forming roll 10. No. 1 of the raw material liquid so as to keep the gap between the wire 1 and the wire several millimeters. 1 Determine the wire landing point. As a result, it is possible to prevent the above-described deterioration of paper quality and the occurrence of paper defects.

Since these adjustments are performed while collating with the formation value of the above-described online wet paper web defect detector, a highly reliable wet paper web can be obtained. By inputting the operating conditions obtained in this way into the computer before changing the paper, the worm jacks 14, 15, 16 and 17 are instantly operated so as to reach the optimum position where the formation optimum value is obtained. Prevent adverse effects on quality.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a schematic view of a twin wire device according to a first embodiment of the present invention, FIG. 2 is a view from the view of FIG. 1, FIG. 3 is an operation flow chart of the device according to the first embodiment of the present invention, and FIG. 5 shows an operational flowchart of the present apparatus according to the second embodiment of the present invention.

In FIG. 1, a first wire 3 and a second wire 4 are arranged opposite to each other on both sides of an inlet 1 for ejecting a raw material liquid, and an initial dewatering device 5, a dewatering device 6, a dewatering roll 7, a water deflector 8, etc. Since the arrangement of is similar to that of the conventional device described in FIG. 14, detailed description thereof will be omitted.

Reference numerals 14, 15, 16 and 17 are actuators for actuation (for example, a pulse motor drive worm jack), 14 is for the L dimension of the slice lip (see FIG. 6) (for W), and 15 is the slice opening B dimension ( L / B determines θ ₁ ) (for X), 16 is the No. of the raw material liquid. No. 2 where the wire is landed or the raw material liquid and breast roll surface support 2 wire gap (for Y), 17 is N of raw material liquid
o. No. 1 which is supported by the position of the wire landing point or the raw material liquid and the surface of the forming roll. Gap between 1 wire (Z
For each operation).

Reference numeral 22 is a computer, 23 is a land total, and 28 is a formation index calculation device. 18 is a position sensor for W, 19
Is an X position sensor, 20 is a Y position sensor, and 21 is a Z position sensor.

Next, the operation flow of this apparatus will be described with reference to FIG. Input the raw material type, basis weight, machine speed, etc. with the input keyboard in Fig. 3 (operation flow chart), then use the input keyboard from the W, X, Y, Z position setting data stored in the computer. W that matches the input conditions,
Select the X, Y, and Z position setting data, and select "Material liquid and No.
Check the indications such as "Gap between 1 wire", "Gap between raw material liquid and No. 2 wire", "Gap between breast and forming roll", "Inlet body angle", etc., and sensor such as rotary encoder or differential transformer 18, 19, 20,
The W, X, Y, Z operation amount obtained by calculation from the W, X, Y, Z present position setting data by 21 is converted into a signal,
X, Y, Z actuating actuators 14, 15, 16, 1
7 (for example, a pulse motor drive worm jack) is operated to bring the W, X, Y, and Z positions to appropriate positions according to each operating condition. Also, W, X,
For the Y and Z positions, the values obtained by calculating the signals of the position sensors 18, 19, 20, and 21 can be displayed on the screen of the computer 22.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows that the computer stores the optimum position survey test results when making a new paper grade without setting data of W, X, Y, and Z positions (when the operating range exceeds the range of the current data). The means for adjusting the W, X, Y, and Z positions described above to be used as setting data from the next time will be shown.

The adjustment method will be described step by step. First, the operating conditions and the W, X, Y, Z positions to be tested are input.

The computer inputs W, X,
Calculate W, X, Y, Z operation amount corresponding to Y, Z position,
Send the manipulated variable to the actuator for W, X, Y, Z operation,
Set W, X, Y, Z positions. "Raw material liquid and No. 1
"Gap between wire", "Gap between raw material liquid and No. 2 wire", "Gap between breast and forming roll", "Inlet body angle", etc. are displayed.

Papermaking is started under the input operating conditions.

The formation in the papermaking process is detected by the online formation sensor 23, and the formation index is calculated.

The W, X, Y, and Z positions are changed a plurality of times according to the instructions of the computer, and the formation index corresponding to each position is calculated.

In this test, actual operation is performed at the W, X, Y, Z positions where the best formation index is obtained.

W, X, Y for the formation at the time of the test,
The Z position is temporarily stored in the computer along with other operating conditions. If a set value to be used for the next setting under the same operating condition is selected from the test data of a plurality of times and designated, it is stored so that it can be used from the next time. If this designation is not made, the set value that gives the best formation index is automatically stored.

If there is no land total, the texture and other paper qualities are judged by the paper on the reel while trial-making the paper, and the optimum W, X, Y, Z position data at that time is obtained.

Although the embodiment of the present invention has been described with reference to the vertical twin wire apparatus, the applicable wire apparatus will be described with reference to FIG.
6 is a horizontal type twin wire device, which can be applied in the same manner as the vertical type.

[0042]

As described above, according to the twin wire former of the present invention, the following effects can be obtained. (1) Normally, when changing from low basis weight paper making to high basis weight paper making, the thickness t of the raw material 2 from the inlet becomes thicker in the wire part in which the initial dehydrator as shown in FIG. 6 is arranged. Even in such a case, when the position adjusting device according to the present invention is used, a proper L / B of the input operating condition is obtained.
(Adjust by grasping the L dimension and the B dimension based on the relationship of L / B),
No. 2 of the raw material liquid 2 Position of 2 wire side raw material liquid landing point (=
Y) or No. 2 of the raw material liquid 2. The position (= Z) of the raw material liquid landing point on the 1-wire side is selected by a computer, each actuator is driven, and W, X, Y, and Z can be set at appropriate positions. For this reason, good paper quality can be maintained even immediately after changing the papermaking conditions, which greatly changes the conditions.

(2) W, X, Y, Z For paper grades without past data of proper positions, W, X,
The proper position can be determined in a short time by testing the proper Y and Z positions using the online geographic total.

(3) When making various paper grades,
Since W, X, Y, and Z can be set at proper positions regardless of the papermaking conditions, better paper quality can be obtained for any paper grade.

(4) When various types of paper grades are made, as compared with the case where W, X, Y, and Z are manually set for each paper grade, by using this adjusting device, W, X, Y, and Z are automatically set.
Since X, Y, Z optimum positions are set, labor saving and
Since the paper can be changed quickly, the loss time can be reduced, energy can be saved, and the amount of waste paper can be reduced to save resources.

[Brief description of drawings]

FIG. 1 is a schematic view of a twin wire device according to a first embodiment of the present invention.

FIG. 2 is a view on arrow V in FIG.

FIG. 3 is an operation flowchart of the first embodiment device of the present invention.

FIG. 4 is an operation flowchart of the second embodiment device of the present invention.

FIG. 5 is an explanatory diagram of an initial dehydration unit for the inlet raw material liquid of the present invention.

FIG. 6 is an enlarged detailed view of FIG.

FIG. 7 shows the inlet raw material liquid No. It is an explanatory view of initial dewatering when the landing point on the two wires is close to the breast roll.

FIG. 8 shows the inlet raw material liquid No. It is explanatory drawing of initial dewatering when the landing point to 1 wire is approaching the forming roll.

9 is an explanatory diagram of a position adjusting device of symbols W, X, Y, and Z described in FIG.

10 is a symbol W shown in FIG. 3 (slice lip L dimension).
FIG. 3 is an explanatory view of the position adjusting device of FIG.

11 is an explanatory view of a position adjusting device of a symbol X (slice opening B dimension) described in FIG. 3. FIG.

FIG. 12 is a symbol Y shown in FIG. 3 (N of inlet raw material liquid)
o. It is a position adjustment device explanatory drawing of the position of the landing point on 2 wires).

FIG. 13 is a symbol Z shown in FIG. 3 (N of the inlet raw material liquid).
o. It is a position adjustment device explanatory drawing of the position of the landing point on one wire).

FIG. 14 is a schematic view showing a conventional twin wire device.

FIG. 15 is a schematic view of a vertical twin wire device to which the present invention is applied.

FIG. 16 is a schematic view of a horizontal twin wire device to which the present invention is applied.

[Explanation of symbols]

1 inlet 2 raw material liquid 3 No. 1 wire 4 No. 2 wire 5 initial dewatering device (forming shoe) 6 dewatering device (suction box) 7 dewatering roll (suction couch roll) 8 water deflector 9 breast roll 10 forming roll 11 suction roll (suction pick-up roll) 12 wet paper 13 felt 14 warm jack (For W) 15 Worm jack (for X) 16 Worm jack (for Y) 17 Worm jack (for Z) 18 Position sensor (for W) 19 Position sensor (for X) 20 Position sensor (for Y) 21 Position sensor (for Z) 22 Calculator 23 Total land 24 Actuator (for W) 25 Actuator (for X) 26 Actuator (for Y) 27 Actuator (for Z) 28 Formation index calculator R ₁ Forming roll outer diameter R ₂ Breast roll outer diameter a Postal liquid No. 2 Wire side landing point (ideal position) a ₁ No. of raw material liquid 2 Wire side landing point (defective position) b. 1 Wire side landing point (ideal position) b ₁ Raw material liquid No. 1 wire side landing point (defective position)

Claims (5)

[Claims] 1. A twin wire former for dehydrating a raw material liquid by means of a gap between first and second wires arranged opposite to each other on both sides of an inlet for ejecting the raw material liquid, wherein the twin wire former gap is provided from the inlet. When setting the relative relationship between the spouted raw material liquid, the wire of the foamer, and the wire-supporting dewatering equipment, the main specifications of the gap are input to a computer, and each operation control system is automatically linked by geometric calculation processing. A twin wire former, which is equipped with a gap control device that can be set. 2. The geometrical positioning of the raw material liquid and both wires and the wire supporting dewatering device in the gap portion of the twin wire former is confirmed by a detector for defects and quality of the full width web surface of the papermaking machine, and there is no defect. The twin wire former according to claim 1, wherein the twin wire former is set as follows. 3. The optimum relative relationship between each papermaking condition, the raw material liquid in the gap portion of the twin wire former, and the geometrical positioning of both wires and the wire supporting dehydrator is stored and reproducible. The twin wire foamer according to claim 1. 4. The twin wire former according to claim 1, wherein when the quality detector of the preceding two paragraphs is not installed in the papermaking machine, the operator can judge by a trial paper machine and use this system. . 5. The wire supporting roll is provided with a function of correcting the geometrical positioning of the raw material liquid and both wires and other wire supporting and dewatering equipment which are generated after the regrinding to reduce the outer diameter of the roll. The twin wire foamer according to claim 1.