JPH06235184A - Twin-wire machine - Google Patents

Abstract

PURPOSE:To always get the optimum wire lap angle even in the case of thick raw material thickness by automatically adjusting the relative position of a dehydration shoe and an autoslice shoe of a paper machine having high frequency of product grade switching. CONSTITUTION:The frequency and areal weight of raw material and the paper- making speed are inputted from an input key-board. The autoslice position setting data meeting the inputted conditions is selected from the autoslice tip position setting data stored in a computer 19 and actuators 14, 15 for shifting the autoslice are actuated according to the selected data to fix the relative position of the shoes. The tip position 10 of the autoslice shoe is displayed on the display of the computer 19.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art The operation of a conventional twin wire device will be described with reference to FIGS. 7 to 9. A raw material 2 ejected from an inlet 1 is sandwiched between a No. 1 wire 3 and a No. 2 wire 4, and a No. 2 It is dehydrated by a dehydrator 5 arranged on the side of the wire 4. The white water dehydrated to the No. 1 wire 3 side by the dehydration device 5 is scraped off by a so-called auto slice shoe 10 which is a leading shoe of the dehydration device 6 arranged on the No. 1 wire 3 side behind the dehydration device 5. Further, the raw material is dehydrated by the dehydrator 6, and the formation of the paper layer is almost completed near the exit side of this portion. Subsequently, dehydration is performed by the dehydrator arranged on the No. 2 wire 4 side. Further, the wet paper web 12 that has moved to the No. 2 wire 4 side at the part where both wires are separated is dehydrated by the dehydration device 8 and the dehydration roll 9 and transferred to the felt 13 of the press part. Further, the adjustment of the relative position between the final dehydration shoe 11 of the dehydration apparatus 5 and the automatic slice shoe 10 is performed by the worm jack 14 attached to the dehydration apparatus 5 or the worm jack 15 attached to the dehydration apparatus 6.

[0003]

In the conventional apparatus described above, the raw material 16 between the two wires dehydrated by the dehydration apparatus 5 for initial dehydration is the automatic slice shoe 10 at the head of the dehydration apparatus 6 at the rear of the dehydration apparatus 11. The thickness t of the raw material when passing through the section varies depending on operating conditions such as basis weight, raw material properties, and machine speed. Dehydration shoe 11 at the end of the dehydration device 5
When the thickness t of the raw material 16 is changed according to a change in operating conditions while keeping the relative positional relationship between the dehydration device 6 and the leading automatic slice shoe 10 constant, the No. 1 wire 3 for the dehydration shoe 11 and the automatic slice shoe 10, The wrap angle of No. 2 wire 4 also changes. As shown in FIG. 8, when the raw material thickness becomes thicker than when the raw material thickness t is small, the wire wrap angle θ also becomes large as shown in FIG. 9 and acts on the rear end portion of the dehydration shoe 11 and the front end portion of the auto slice shoe 10. The thicker the raw material is, the larger the applied pressure becomes.

Therefore, if the raw material pressure in this portion becomes excessive, the fiber network formed up to that point is discarded, so the wire wrap angle θ to the dehydration shoe 11 and the auto slice shoe 10 does not increase in this portion. Similarly, the relative position of the dehydration shoe 11 and the auto slice shoe 10 is set to the worm jack 15 (or the worm jack 1).
It was necessary to adjust 4). However, in a paper machine having a high basis change frequency that operates in a wide grammage range and a wide variety of paper grades, it is necessary to frequently operate the warm jacks 15 or 14 in accordance with various grades. Therefore, a great deal of labor is required for this operation, and there is a problem that the paper quality cannot be maintained at a high level if the paper is changed without performing this operation. The present invention is intended to solve the above-mentioned conventional problems by making it possible to automatically adjust the length of the worm jack based on data obtained from past driving experience.

[0005]

[Means for Solving the Problems] Therefore, according to the present invention, the raw material ejected from the inlet is immediately dehydrated or after being dehydrated in advance with No.2 wire, and then sandwiched between No.1 wire and No.2 wire. .1 The dewatering that comes out through the wire is scraped off by the leading dewatering shoe of the dewatering device installed on the No. 1 wire side,
In a twin-wire machine with so-called auto-slicing, it is possible to automatically adjust the relative positional relationship in the material thickness direction between the auto-slice dewatering shoe and the final dewatering shoe of the dewatering apparatus placed in front of it. Yes, this is a means for solving the problem. Further, the present invention, the automatic slice position adjustment is performed by changing the position of the automatic slice in a preset range, the formation at the time of driving at each position is detected by the online ground total,
It has a self-learning function that stores the auto slice position at the time of formation best together with the papermaking conditions at that time, and uses it as the data for determining the auto slice position during the subsequent operation, and this is the means for solving the problem. is there.

[0006]

In the present invention, data relating to the optimum length of the worm jack for each operating condition obtained from past experience is stored in the computer, and the target condition at the time of changing paper is automatically input. The target value of the worm jack length is calculated, the actuator is operated until the sensor signal value related to the worm jack length reaches the target value, and the wire wrap to the dehydration shoe and the auto slice shoe is adjusted to adjust the raw material pressure. To keep the value at an appropriate value. In addition, in order to know the proper worm jack length under the paper grade operating conditions that have not been implemented yet, the worm is operated while changing the worm jack length on a test basis, and the formation value is detected by online land total, The sensor signal data relating to the warm jack length is stored, and this data is used as a target value under the same conditions from the next time to optimize the raw material pressure.

As a result, when the operating conditions (basis weight, kind of raw material, speed, etc.) planned at the start of operation of a new paper grade are input to the computer, the worm jack is activated and the dehydration shoe and the auto slice shoe are moved relative to each other. The position changes and the wire wrap angle to the dehydration shoe and auto slice shoe changes. For example, when changing the paper from a low grammage paper grade to a high grammage paper grade, if the warm jack is not operated, the thickness t of the raw material at the position of the dehydration shoe and the auto slice shoe increases. ,
Usually, the wire wrap angle θ to the dehydration shoe and the auto slice shoe increases, and the pressure acting on the raw material also increases. However, by inputting the following operating conditions to the computer immediately before changing the machine, the worm jack operates so that the wire wrap angle θ to the dehydration shoe and auto slice shoe does not increase excessively, and the raw material pressure becomes excessive. To prevent the adverse effect on paper quality.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments of the drawings. FIG. 1 is a schematic view of a twin wire apparatus according to a first embodiment of the present invention, and FIG. 3 is a view from the arrow Z to Z in FIG. 1, and FIG. 5 is a control block diagram in the first embodiment device. In FIG. 1, reference numeral 17 is a land total, 18 is a formation index calculation device, and 19 is a calculator. The other configurations of the twin wire device are the same as those of the conventional twin wire device. The total formation 17 detects the formation in the papermaking process, and the formation index calculation device 18 is a device for calculating the formation index based on the detected value from the total formation 17. Further calculator 1
As shown in FIG. 6, the reference numeral 9 has a function of calculating an auto slice operation amount, oscillating an operation signal, and displaying an auto slice position.

In the above apparatus, the tip position of the auto slice shoe 10 is determined as follows. First, in FIG. 5, when the type of raw material, the basis weight, and the machine speed are input with the input keyboard, the auto slice position setting data that is stored in the computer and matches the conditions input with the input keyboard is selected. The setting data is selected, and the automatic slicing operation amount obtained by calculating from the automatic slicing current position data by the sensor 20 such as a rotary encoder or an operating transformer is converted into a signal,
The tip end position of the auto slicing shoe 10 is brought to an appropriate position according to each operating condition by transmitting to an actuator 21 for operating the auto slice (for example, a worm jack driven by a pulse motor) to operate. Further, the tip position of the auto slice shoe 10 can calculate the signal of the position sensor 20 and display the result on the screen of the computer 19.

Next, the second embodiment according to the present invention will be described with reference to the control block diagram of FIG. 6. In this example, when a new paper grade having no setting data of the tip position of the auto slice shoe 10 is made (the current data It is characterized in that the optimum auto slice position inspection test result (in the case of an operating range exceeding the range) is stored in the computer and this result is used as the setting data from the next time. The auto slice shoe position of the device shown in FIG. It is adjusted as follows. First, input the driving castle condition and the auto slice shoe position to be tested. The computer calculates an auto slice operation amount corresponding to the input auto slice test position, sends an operation signal to the auto slice actuating actuator, and sets the auto slice shoe position. Start papermaking under the input operating conditions. The formation in the papermaking process is detected by the online formation sensor 17, and the formation index is calculated by the formation index calculation device 18. The position of the auto slice shoe is changed multiple times according to the instructions of the computer, and the formation index corresponding to each position is calculated. The actual operation is performed at the auto slice shoe position where the best formation index is obtained in this test. The position of the auto slice shoe corresponding to the best formation at that time is stored in the computer together with the operating condition, and is used for the next setting under the same operating condition.

In each of the above embodiments, the position of the auto slice shoe 10 affects the paper quality as a relative position to the final dehydration shoe 11 of the dehydrating device 5 on the wire 4 side. Instead of changing the position, the position of the final dewatering shoe 11 of the dewatering device 5 may be changed. The present invention also relates to the inlet 1 shown in FIG.
The same can be applied to the twin wire device of the type in which the raw material 2 spouted from the above is dehydrated in advance in the fourdrinier portion 22 as in the case of the twin wire device shown in FIG.

[0012]

As described in detail above, according to the present invention, the following excellent effects are exhibited. (1) Generally, when changing from low basis weight papermaking to high basis weight papermaking, the thickness t of the raw material between the final dehydration shoe of the wire part dehydrator and the auto slicing shoe becomes thicker, and therefore auto slicing is performed. The wire wrap angle θ at the shoe portion becomes large, and the raw material pressure P acting at this portion
(Fig. 2) is also large, but when using the automatic slice position adjusting device according to the present invention, a computer selects an appropriate auto slice shoe position under the input operating conditions, and the actuator is driven to automatically move to the proper position. Since the slice shoe moves, when changing to a high basis weight,
Even if the thickness t of the raw material in the auto slice shoe portion becomes thick, the wire wrap angle θ does not become excessive, and the raw material pressure P in this portion can be maintained at an appropriate value and good paper quality can be maintained. (2) Even with a new paper grade that does not have past data of the proper auto-slice position, the proper position can be determined in a short time by testing the proper auto-slice position using the online land total. (3) When making various paper grades, better paper quality can be obtained for any paper grade by using this adjusting device, as compared with the case where the automatic slice shoe position is not adjusted. (4) When making various paper grades, the optimum position of the auto slice shoe is automatically set by using this adjusting device, compared to the conventional device that manually sets the auto slice shoe position for each paper grade. Therefore, it is possible to save labor and quickly change the paper.

[Brief description of drawings]

FIG. 1 is a side view showing an outline of a twin wire device according to a first embodiment of the present invention.

FIG. 2 is a detailed view of an X portion in FIG. 1, and is an explanatory view showing a raw material pressure near an auto slice shoe position.

FIG. 3 is a view taken in the direction of arrows Z to Z in FIG.

FIG. 4 is a side view showing an outline of a twin wire device of a type in which dehydration is performed by a fourdrinier portion.

FIG. 5 is a control block diagram of the first embodiment device of the present invention.

FIG. 6 is a control block diagram of a second embodiment device of the present invention.

FIG. 7 is a side view showing an outline of a conventional twin wire device.

8 is a detailed view of a portion Y in FIG. 7, and is an explanatory view of a wire wrap angle near the auto slice shoe.

FIG. 9 is an explanatory diagram of a raw material pressure in a conventional twin wire device.

[Explanation of symbols]

 1 Inlet 2 Raw material 3 No. 1 wire 4 No. 2 wire 5, 6, 7, 8 Dewatering device 9 Vacuum roll 10 Auto slice shoe 11 Dehydrating shoe 12 Wet paper 13 Felt 14, 15 Warm jack 16 Raw material 17 Total land 18 Combined index calculator 19 Calculator 20 Position sensor 21 Actuator 22 Long net

Claims (5)

[Claims] 1. A raw material ejected from an inlet is immediately dehydrated or after being dehydrated in advance with a No. 2 wire, and then a No. 1 wire and
In a twin wire device with a so-called auto slice, which is sandwiched between No.2 wires and the dehydration that comes out through the No.1 wire is scraped off by the dewatering shoe at the head of the dehydration device installed on the No.1 wire side. The twin wire device is characterized in that the relative positional relationship in the raw material thickness direction between the auto-slice dehydration shoe and the final dehydration shoe of the dehydrator arranged in front of it can be automatically adjusted. 2. The twin wire device according to claim 1, wherein the relative positional relationship is adjusted by adjusting an auto slice position. 3. The twin wire device according to claim 1, wherein the relative positional relationship is adjusted by adjusting a position of a final dehydration shoe of a dehydrator installed before the auto slicing. 4. The automatic slice position adjustment is carried out by changing the position of the automatic slice within a preset range, and the formation at the time of operation at each position is detected by online formation total, 3. The twin wire device according to claim 2, further comprising a self-learning function of storing the auto slice position of No. 1 together with the papermaking conditions at that time and using it as data for determining the auto slice position at the time of subsequent operation. 5. Instead of adjusting the position of the auto slice,
The twin wire device according to claim 4, wherein the position of the final dehydration shoe of the dehydrator installed before the auto slicing is adjusted.