JPS6313275Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wake air removal device that can be applied to a dryer of a paper machine.

In conventional paper machine dryers, the wet paper is hung in a meandering manner between the top and bottom dryers arranged in a staggered manner. It was crimped to the dryer roll at the bottom.

That is, the canvas forms a continuous ring at the upper and lower parts, and runs continuously on the roll surfaces of multiple top dryer cylinders, bottom dryer cylinders, canvas rolls, etc., and also wet paper that has been running from the previous process. is heated and pressed by a canvas onto the surface of a dryer cylinder heated by steam,
Between the plurality of top and bottom dryer cylinders, the wet paper runs independently without being supported by a canvas, and the water is sequentially evaporated and dried.

Further, in the above process, as the wet paper web runs and the dryer cylinder rotates, wet paper paper surface wake air and dryer surface wake air are formed on each surface. The wet paper paper surface wake air and the dryer surface wake air enter into a wedge shape between the wet paper paper and the outer surface of the dryer cylinder to form an air layer.

As the wet paper runs and the dryer cylinder rotates as described above, wake air is formed on each surface, and this wake air creates an air layer between the wet paper and the outer surface of the dryer cylinder. However, since the thermal conductivity of this air layer is low, it inhibits heat transfer from the outer surface of the dryer cylinder to the wet paper, reducing drying efficiency. Therefore, the conventional apparatus had the disadvantage of requiring a large number of dryer cylinders.

The present invention was proposed in order to eliminate the above-mentioned drawbacks of the conventional method.A small roll is pressed into contact with the dryer cylinder in front of the inner side where the wet paper is crimped with the canvas.
The wake air removal device is designed to cut off the wake air on the surface of the dryer at the nip part, reverse the direction of travel of the wet paper paper and the direction of rotation of the small roll, and remove the wake air on the surface of the wet paper in a state where it is scraped out. This is what we intend to provide.

The embodiments of the present invention will be described below with reference to the drawings. Figures 1 and 2 show embodiments of the present invention,
The difference from the conventional method is that the wet paper 2 of the dryer cylinder 3
Other than that, the small roll 7 is installed in pressure contact with the dryer cylinder 3 on the entrance side of the dryer cylinder 3 before the wet paper paper 2 is pressed against the canvas 1, but the rest is the same as the conventional one.

Now, as in the conventional case, the wet paper 2 is placed in each of the plurality of dryer cylinders 3, and
The gap between the wet paper 2 and the small roll 7 is made small on the entrance side before being crimped with the canvas 1 (on the inside).
The same small roll 7 is pressed against the dryer cylinder 3,
Install. This small roll 7 is adapted to roll in a direction opposite to the traveling direction of the wet paper web 2 in the direction of arrow 8 by the rotation of the dryer cylinder 3. It is also possible to drive the small rolls 7 at the same speed as the dryer cylinder. In addition, the small roll 7 can also be a metal roll in addition to a rubber-wrapped roll.

Next, to explain the operation, the wet paper web 2 that has been dehydrated by a press (not shown) in the previous process and has traveled to the dryer part forms wake air 5 on the wet paper paper surface, and the dryer cylinder 3 Surface wake air 6 is formed, and the air 5 and 6 try to enter into a wedge shape between the wet paper web 2 and the outer surface of the dryer cylinder 3, but the dryer surface wake air 6 is formed between the small roll 7 and the dryer cylinder It is shut off at the nip 9 between the two.

Also, the direction of rotation is opposite to the direction of travel of wet paper 2,
It has a small roll 7 rolling in the direction of arrow 8, and the gap between the small roll 7 and the wet paper paper 2 is small, so that the wake air 5 on the surface of the wet paper paper is scraped outward by the rotating airflow of the roll. and remove it. In this way, there is no air layer between the dryer cylinder and the wet paper, and the wet paper 2 receives direct heat transfer from the outer surface of the plurality of steam-heated dryer cylinders 3.
Drys efficiently.

As explained in detail above, in the present invention, a small roll is pressed against the dryer cylinder before the wet paper is pressed onto the canvas, so that wake air on the surface of the wet paper and the surface of the dryer flows between the dryer cylinder and the wet paper. It does not enter the air and form an air layer. Therefore, the heat transfer from the outer surface of the dryer cylinder to the wet paper is not inhibited, and the drying efficiency does not decrease, eliminating the disadvantage of requiring a large number of dryer cylinders as in the past. Can be removed.

[Brief explanation of the drawing]

FIG. 1 is a side view of a wake air removal device in a dryer showing an embodiment of the present invention, and FIG. 2 is a perspective view thereof. Explanation of the main parts of the figure, 1...canvas, 2...
Wet paper, 3... Dryer cylinder, 5... Wet paper surface wake air, 6... Dryer surface wake air, 7...
small roll.

Claims (1)

[Scope of utility model registration request] In a dryer for drying wet paper, a small roll is pressed against the dryer cylinder in front of the inner side where the wet paper is pressed onto the canvas, and the direction of rotation of the small roll is reversed to the traveling direction of the wet paper. Flow air removal device.