JPH0657335B2 - Moisture content control device for coating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to improvement of controllability of water content control at the start of coating in a coating amount control device.

<Prior Art> An outline of a coating control device will be described with reference to FIG. Reference numeral 1 is a base paper roll, 2 is a base paper pulled out for coating, and 3 is a take-up roll of a paper 2 which has been coated on both sides.

4 is a first coating means for applying a paint to one surface of the paper 2, and 5 is a first B / M for measuring the moisture content and basis weight of the paper before coating.
A total of 6 is a first dryer for drying the paper which has passed through the coating means 4.

7 is a second for applying paint to the other surface of the paper 2 that has passed through the dryer 6
A coating means, 8 is a second B / M meter for measuring the moisture content and basis weight of the paper before coating, and 9 is a second dryer for drying the paper which has passed through the coating means 4.

A third B / M meter 10 measures the moisture content and basis weight of the paper 2 that has passed through the second layer 9.

Reference numeral 11 is a measured value calculation means, which is the first, second, and third B /
The measured values M ₁ , M ₂ , and M ₃ of the M meters 5, 8, and ₁₀ are input to calculate the difference between the measured value on the downstream side and the measured value on the upstream side regarding the basis weight and the moisture content, and the first coating The coating amount measurement value PV ₁₁ by the means 4, the moisture content measurement value PV ₁₂ on the output side of the dryer 6, and the coating amount measurement value PV ₁₂ by the second coating means 7 and the dryer 9
The measured moisture content value PV ₂₂ on the output side is output. The coating amount and the water content are controlled to the target set values based on these measured values.

FIG. 4 is an enlarged view of the coating means 4 and the first dryer 6, and the applicator roll 15 in which the lower portion is dipped in the paint 14 in the fan ten 13 with respect to the paper 2 run by the backing roll 12. Are operated to contact with each other, the paint is adhered to the paper through the applicator roll, and a part of the adhered paint is scraped off by the blade 16 to control the coating amount. Reference numeral 17 is an actuator for operating the angle of the flade.

The moisture content is controlled by manipulating the amount of hot air supplied to each dryer. Reference numeral 18 is a supply line of the hot air H to the first dryer 6, 19 is a supply amount control valve, and 20 is a moisture content controller, which controls and calculates the deviation between the moisture content measured value PV ₁₂ and the set value SV _12. operating the control valve 19 by the control output MV _12.

An example of a control loop for controlling the water content in the steady state in the coating amount control device having such a configuration will be described with reference to FIG. 5 for the first dryer 6. DCS indicates the controller side, and P indicates the process side.

The operation output MV ₁₂ of the moisture content controller 20 is the first addition means 21.
The first feedforward signal FF ₁ is added by the second feedforward signal FF ₂
Are added, and the addition operation output MV ₁₂ ′ of these feedforward signals is supplied to the control valve 19.

Reference numeral 23 denotes a first feedforward calculation means, which is a first feedforward signal FF ₁ for executing compensation of a water content variation caused by the coating amount operation based on the coating amount operation amount MV _11.
Change amount ΔFF ₁ is calculated for each control cycle by ΔFF ₁ = K ₁ · ΔMV ₁₁ (1) and transmitted to the adding means 21.

24 is a second feed-forward computing means, controlling the change amount ΔFF2 second feed-forward signal FF2 to perform compensation of coating quantity before the moisture content vary based on the moisture content measurements PV ₀₁ before coating cycle For each time, ΔFF ₂ = −K ₂ (PV _{01n −PV 01n−1} ) (2) is calculated and transmitted to the adding means 22.

The change amount ΔMV ₁₂ of the operation output of the controller 20 is the deviation E _n.
, ΔMV ₁₂ = 100 {(E _n −E _n−1 ) + E _n / T} / PB
(3) Therefore, the change amount ΔM of the operation output MV ₁₂ ′ to the control valve 19 is
V ₁₂ ′ is ΔMV ₁₂ ′ = ΔFF ₁ + ΔFF ₂ + ΔMV ₁₂ (4).

<Problems to be solved by the invention> With such a configuration, the moisture content in the steady state is well controlled by feedforward compensation of the coating amount operation output and the moisture content variation before coating. It is difficult to control the water content at the time of application because it is difficult to control the water content appropriately when the coating speed changes, so to avoid solid coating (undried) due to excessive coating, The operation for supplying a constant operation output to the control valve 19 is performed so as to cause overdrying by manual intervention.

That is, when the coating is started, the water content is fixed by a fixed manual operation, the coating is started up only by controlling the coating amount, and the control is switched to the steady control after the coating amount is stabilized.

Therefore, there is a problem that the operator's operation at the start is complicated and requires experience, and the controllability of the water content at the start is poor.

An object of the present invention is to provide a coating amount control device which can solve such problems.

<Means for Solving Problems> In the present invention which achieves such an object, a moisture content operation output (MV) obtained by control calculation of a deviation between a moisture content sensor measured value (PV) and a moisture content set value (SV). ) Controls the operation end of the hot air dryer, and the first feedforward signal (FF ₁ ) based on the coating amount operation output and the second feedforward signal (F ₁ ) based on the measured value of the moisture content sensor before coating.
A water content control device for a coating machine that adds F ₂ ) to the water content operation output has the following configuration.

That is, a means for further adding the third feedforward signal (FF ₃ ) based on the measured value of the coating amount sensor to the above moisture content operation output is provided, and when the coating speed is increased at the start of coating, the above-mentioned first Switching means is provided for starting addition of the three feedforward signals and interrupting addition of the third feedforward signal when the measured value of the moisture content sensor falls within an allowable range.

<Operation> In a steady operation state, the first feedforward signal based on the coating amount operation output and the second feedforward signal based on the measured value of the moisture rate sensor before coating are added to the moisture rate operation output. Then, the third feedforward signal based on the measured value of the coating amount sensor is further added to the moisture content operation output only during the period when the coating speed at the beginning of coating is in the process of increasing the speed, so that the transient operating state. However, the paper quality tends to converge to the target value.

<Example> An example of the present invention will be described with reference to FIG. Description of the same elements as those described in FIG. 5 will be omitted, and description of the characteristic portion will be added.

On the control device side, 25 is a third adding means,
The feedforward calculation output FF ₃ from the feedforward calculation means 26 is added to the operation output MV ₂ of the controller 20.

Further, when the effect correction of the coating speed by the third feedforward signal is effective and the measured value of the moisture content sensor is within the allowable range, the addition of the third feedforward signal is cut off, so that the steady state Since the control state is entered, the third feedforward signal does not interfere with the steady-state operation.

The third feedforward calculation means 26 executes the third feedforward signal FF in order to compensate the variation in the water content at the start due to the variation in the coating amount due to the variation in the speed, based on the measured coating amount PV11. Change amount of ₂ ΔFF
ΔFF ₃ = K ₃ PV _11n −PV _11n−1 ) (5) is calculated for each control cycle and transmitted to the adding means 25.

Therefore, the change amount ΔM of the operation output MV ₁₂ ′ to the control valve 19
V ₁₂ ′ is ΔMV ₁₂ ′ = ΔFF ₁ + ΔFF ₂ + ΔFF ₃ + ΔMV ₁₂ (6) by adding ΔFF ₃ to the equation (4).

Reference numeral 27 is a sequence control device, which receives the coating start command ST and the controllable flag FL for which the measured values of the B / M meter and the like are in a steady state, and receives the controller 20 and the first to third feedforward calculation means 23, 24. , 26 to send a start signal.

FIG. 2 is a flow chart showing the procedure of the operation. First, after the initial condition is satisfied, when the controllable flag is confirmed by the coating start command, the timer T ₁ is started and a certain waiting time is set, and then the deviation of the water content exceeds a certain allowable range. In the case of, the control by the total operation output ΔMV ₁₂ ′ by the calculation of the equation (6) is executed, and when the deviation of the water content is within the allowable range, the supply of the third feedforward signal FF ₃ is cut off and the normal feed is performed. Move to forward control.

The embodiment described above is an example of control on the first dryer 6 side, but the present invention can be similarly applied to the second dryer 9 side.

<Effects of the Invention> As described above, according to the present invention, it is possible to appropriately compensate for the third fluctuation of the water content due to the fluctuation of the coating amount due to the speed change at the start of coating, by the feedforward signal. This makes it possible to automate the moisture content control at the beginning of coating, improve the controllability of the moisture content control, and contribute to the operator's burden, reduction of waste paper, and energy saving.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a flow chart diagram showing a signal processing procedure, FIG. 3 is a conceptual diagram of a coating machine control device, and FIG. 4 is a coating means and a dryer portion. FIG. 5 is a configuration diagram showing an example of a conventional technique. 11 ... Measured value calculating means, 18 ... Hot air supply pipe, 19
...... Control valve, 20 ...... Moisture content controller 21,22,25
...... First, second, third adding means, 23, 24, 26 ......
First, second, third feedforward signal calculation means, 2
7: Sequence control device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuaki Hashimoto, Inventor No. 3 Aomori Yachi, Kawara Wood, Aomori Prefecture No. Yokogawa Electric Co., Ltd. (72) Inventor Kazushi Takano 2-9-32 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Co., Ltd. (56) References JP 63-54977 (JP, A) 61-40387 (JP, Y2)

Claims (1)

[Claims] 1. A moisture content operation output (M) obtained by control calculation of a deviation between a moisture content sensor measured value (PV) and a moisture content set value (SV).
V) controls the operation end of the hot air dryer, and also controls the first feedforward signal (FF ₁ ) based on the coating amount operation output and the second feedforward signal (FF ₂₎ based on the measurement value of the moisture content sensor before coating. ) Is added to the moisture content operation output, a means for further adding a third feedforward signal (FF ₃ ) based on the measured value of the coating amount sensor to the moisture content operation output. When the coating speed is increased at the start of coating, the addition of the third feedforward signal is started, and when the measured value of the moisture content sensor is within the allowable range, the addition of the third feedforward signal is started. A water content control device for a coating machine, which is provided with a switching means for shutting off.