JPS63165594A - Moisture profile control apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a moisture profile control device in a dryer part of a paper machine, a dryer for flat wet objects such as nonwoven fabrics, and the like.

(Prior art) The schematic structure of a dryer part in a conventional paper machine is described in the first part.
Shown in Figure 4. First, the wet paper made in the wet part is dehydrated in the press part and sent to the dryer part.

The wet paper paper 19 that has entered the dryer part is pressed and heated by a canvas 20 on the surface of a plurality of dryer rolls 1 arranged in a staggered manner and heated by steam, and the moisture is evaporated. In the figure, 21 is a canvas roll, and 25 is a hood that shields the dryer part from the outside air.

FIG. 13 shows a sectional view of the dryer roll used here. Steam 22 for heating is supplied to the dryer roll 1 via a rotary joint 23. In addition, the wet paper 19 pressed onto the outer peripheral surface of the dryer roll 1 is dried by steam from the inner surface of the roll, and the drain 7 generated due to the heat removed by the wet paper 19 is caused by the pressure difference between the steam. Drain discharge hopper 6 that opens close to the inner circumferential surface of the dryer roll by utilizing (pressure difference between steam supply and exhaust)
, is discharged to the outside via the discharge pipe 24 and the rotary joint. The drain 7 generated here forms a rim-shaped film on the inner peripheral surface of the dryer roll 1 due to centrifugal force when the dryer roll 1 rotates at a high speed (about 300 m/min or more). This phenomenon is generally called the rimming phenomenon.

In the conventional dryer having the above configuration, (11) the moisture content of the wet paper is not uniform in the width direction at the entrance of the dryer part due to unevenness in the dehydration rate in the pressing step, which is the previous step.

(2) Due to the method of discharging the drain inside the dryer roll, a difference in drain film thickness occurs in the longitudinal direction of the surface, and the heat transfer coefficient is not uniform in the width direction.

(3) The evaporation rate of wet paper becomes uneven in the width direction due to the temperature and humidity distribution inside the hood, the flow of hot air due to ventilation, etc.

(4) Non-condensable gas remains inside the dryer roll,
The surface temperature of the dryer roll becomes non-uniform in the longitudinal direction.

For these reasons, the moisture distribution in the width direction of the final product often becomes uneven.

Therefore, as shown in Figure 10, in order to improve the heat transfer coefficient within the dryer roll, spoiler bars are installed at arbitrary positions and lengths along the width direction of the dryer roll, and It has been attempted to correct moisture unevenness by changing the directional heat transfer coefficient. In other words, if the spoiler bar is installed on the inner surface of the dryer roll corresponding to the area with high moisture in the width direction of the wet paper, the heat transfer coefficient in that area will be improved and evaporation will be promoted, so the moisture value in other areas will be reduced. As the weather approaches, the uneven moisture content will be corrected.

The conventional method for attaching a spoiler bar to a dryer roll is as follows: (1) The spoiler bar itself is composed of a permanent magnet and is attracted to the inner surface of the dryer roll.

(2) Mechanically fix it to the inner surface of the dryer roll using bands, bolts, etc.

Such methods have been adopted.

(Problem to be solved by the invention) Now, in order to control the moisture profile using a conventional spoiler bar, it is necessary to record moisture unevenness during operation in advance, stop operation, and wait for the dryer roll to cool down. The operator entered the dryer roll and changed the position of the spoiler bar based on the records. Therefore, the dryer stop time becomes longer, the operating efficiency deteriorates, and the operating conditions (atmosphere in the hood, condition of drain in the dryer roll, etc.) at the time when data was recorded to temporarily stop the operation change. There are problems such as the effect becoming less effective.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a moisture profile control device that can change the operating position of a spoiler bar in response to an external signal without stopping operation.

(Means for Solving the Problems) Therefore, the present invention provides a moisture profile control device in the width direction of a continuous sheet dryer, in which a spoiler bar is divided into a large number of parts in the longitudinal direction of the dryer roll surface, and the spoiler bar is divided into a plurality of parts in response to an external signal. The present invention is configured such that any spoiler bar among the spoiler bars can be brought into contact with and separated from the inner surface of the dryer roll, and this is used as a means for solving the above-mentioned problem.

More specifically, a slip ring is installed at the end of the dryer roll shaft so that an external signal is applied to the inside of the dryer roll during operation, and the dryer roll is automatically divided in the longitudinal direction of the inner surface of the dryer roll upon receiving the external signal. The spoiler bar arranged in this manner can be brought into contact with and separated from the inner surface of the dryer roll at any part in the same direction, and the heat transfer coefficient at any part in the longitudinal direction of the dryer roll can be changed.

(Function) If a spoiler bar located at any part in the longitudinal direction of the plurality of split spoiler bars arranged in the longitudinal direction of the inner surface of the dryer roll is made to be able to move toward and away from the inner surface of the dryer roll, the spoiler bar will move toward the inner surface of the dryer roll. At the point where it is in contact with, the drain will be in the state shown in Figure 11,
The rimmed drain is stirred to improve the heat transfer coefficient in that area. Further, in areas where the spoiler bar is not in contact, a complete rimming condition occurs as shown in FIG. 12, resulting in poor heat transfer at these areas. Figure 9 shows the difference in heat transfer coefficient between the spoiler bar contact area and the non-contact area. As is clear from the figure, by placing the spoiler bar in contact with the inner surface of the dryer roll that corresponds to areas with high moisture content in the paper width direction, and separating the spoiler bar from areas of the dryer roll that correspond to areas with low moisture content, the spoiler bar can be moved in the paper width direction. Changes the degree of dryness and corrects uneven moisture.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings. Embodiments of the present invention are shown in FIGS. 1 to 8. FIG. 1 shows the dryer roll 1 with the spoiler bar 2 attached and detached at any location along its surface length.

In the embodiment shown in FIG. 1, a spoiler bar 2 is inserted into the interior of the dryer roll 1 from the center of the end opposite to the steam supply side.
A holding arm 4 is provided to protrude along the axis. Same holding arm 4
2. The spoiler bar is divided into many pieces along its length.
2 and - are arranged side by side in a cylindrical shape via a radially extending intermediate member. Further, a slip ring 3 is provided at the protruding shaft end of the holding arm of the dryer roll l. The slip ring 3 provided at the shaft end of this dryer roll l is
It has the number of terminals corresponding to the number of divisions in the surface length direction of the spoiler bar 2, and upon receiving a signal from this slip ring 3, the spoiler bar 2 in an arbitrary part is attached to the dryer roll 1.
It comes into contact with and separates from the inner surface of the This contact/separation means is shown in FIGS. 2 to 7.

In the example shown in FIG. 2, an inner cylinder 9 and an outer cylinder 10 are used as intermediate members extending radially from the holding arm 4, and both cylinders 9,
10 are fitted together so that the outer cylinder 10 slides in the longitudinal direction and expands and contracts in its entire length. A sheath heater 8 whose one end is fixed to the holding arm 4 and connected to an external signal line is provided in both cylinders 9 and 10, and a spring 5 made of a shape memory alloy surrounds the sheath heater 8, and a spring 5 made of a shape memory alloy is attached to each end of the sheath heater 8. It is fixedly disposed on the holding arm 4 and the spoiler bar 2.

The example shown in FIG. 3 is an example that does not have the holding arm 4, and a large number of spoiler bars 2 arranged in parallel on the same circumference are attached to one bar 5' made of shape memory alloy. ,
A sheath heater 8 connected to an external signal line is provided so as to surround the bar 5'.

The example shown in FIG. 4 is also an example without the holding arm 4, in which a large number of spoiler bars 2 arranged in parallel on the same circumference are divided into several groups, and each group is fixed to a fixed bar 16. , same fixed bar 1
Spring 5 made of shape memory alloy is connected to the adjacent ends of 6.
It is connected by . A sheath heater 8 connected to an external signal line is inserted through each spring 5.

The examples shown in Figures 2, 3, and 4 above all use a shape memory alloy as the contact/separation element of the spoiler bar 2, and an external signal (current) is transmitted to any point in the longitudinal direction of the dryer roll. It is applied to the sheath heater 8 to heat the spoiler bar contact/separation element connected to the spoiler bar 2 to a transformation temperature, thereby separating any spoiler bar 2 from the inner surface of the dryer roll l. In the example shown in FIG. 3, a bimetallic element can be used instead of the shape memory alloy as the spoiler bar attachment/detachment element.

The example shown in FIG. 5 uses an electromagnet, and a fixed electromagnet 12 is fixedly installed at a position of a guide bar 11 extending radially from the holding arm 4 at a predetermined distance from the inner surface of the dryer roll 1. A spoiler bar 2 made of an electromagnet is provided between the inner surface of the dryer roll 1 and guided by the guide bar 11 so as to slide in the radial direction of the dryer roll 1. When the spoiler bar 2 receives an external signal (current) from the slip ring 3, the surfaces facing the fixed electromagnet 12 have the same polarity, and the spoiler bar 2 is pressed against the inner surface of the dryer roll 1 by mutual repulsive force. At the same time, the spoiler bar itself tends to be attracted to the inner surface of the dryer roll 1 by its magnetic force. Conversely, when separating the spoiler bar 2 from the inner surface of the dryer roll 1, the external signal (current) to the spoiler bar 2 is turned off to eliminate the magnetism, and the spoiler bar 2 is attracted to the fixed electromagnet 12 and separated from the inner surface of the dryer roll 1.

The example shown in FIG. 6 uses gears, screws, etc., and by moving the motor 15 with an external signal from the slip ring 3 and rotating the threaded rod 14 connected by gears 13 and 13, the screw is rotated. Spoiler bar 2 with guide bar 11
It is designed so that it can be guided by the robot to move toward and away from it. A worm wheel type power transmission mechanism may be used instead of the gear 13 in this example. Further, as the motor 15, an ultrasonic motor or the like is used, which has no coil portion and is durable even in a humid atmosphere. In addition, in the examples shown in FIGS. 2 and 6, the spoiler bars 2 are individually moved to the contact and separation positions, but in these examples as well, multiple spoiler bars arranged on the same circumference are moved as shown in FIG. 2 can be made to come into contact with and separate from each other all at once by means of a fixed bar 16.

Further, the means for moving the spoiler bar 2 toward and away from the inner surface of the dryer roll 1 in response to an external signal from the slip ring 3 is not limited to the above example, and other means may be used.

As shown in FIG. 8, in the present invention, a control device 18 receives a signal from a BM meter 17 installed after the dryer part, and sends a signal to each dryer roll. The spoiler bar can be moved in and out as desired, and continuously controlled according to moisture unevenness. At this time, the contact/separation position of the spoiler bar can be arbitrarily changed for each dryer roll by the control device 18.

(Effects of the Invention) As described above in detail, according to the present invention, the spoiler bar can be automatically moved toward and away from the inner surface of the dryer roll by an external command, thereby achieving the following excellent effects. It turns out.

(1) In moisture profile control using a spoiler bar, it is possible to move the spoiler bar any desired in the longitudinal direction of the dryer roll without stopping the dryer, greatly improving operational efficiency.

(2) Since continuous control is possible according to moisture unevenness during operation, the accuracy of moisture profile control is significantly improved.

(3) Work safety is ensured because there is no need to enter the dryer roll for control.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram showing one embodiment of the present invention, FIGS. 2 to 7 are diagrams showing different specific examples of the spoiler bar contact/separation mechanism according to the present invention, and FIG. 8 is a control to which the present invention is applied. A schematic side view showing the method, FIG. 9 is an explanatory diagram showing the difference in heat transfer coefficient depending on the presence or absence of a spoiler bar, FIG. 10 is a partial cross-sectional view of a dryer roll with a profile control device using a conventional spoiler bar, and FIG. Figure 11 shows A- in Figure 10, which shows the drain agitation situation at the spoiler bar installation location.
12 is a sectional view taken along the line B-B in FIG. 10 showing the drain rimming state where there is no spoiler bar;
FIG. 13 is a sectional view of a conventional dryer roll, and FIG. 14 is a schematic side view of a conventional dryer bar. Explanation of main parts of the figures 1 - Dryer roll 2 - Spoiler bar 3 - Slip ring Patent Applicant Mitsubishi Heavy Industries, Ltd. Figure 1 Figure 2 Rhinoceros 3 Figure 4 Figure 5 Figure 6 Figure 8 Winding Figure 9 Dryer speed series Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] In the continuous sheet dryer, the spoiler bar is divided into a large number of parts in the length direction of the dryer roll surface, and any one of the divided spoiler bars can be moved toward and away from the inner surface of the dryer roll in response to an external signal. moisture profile control device.