SU827664A1 - Device for drying webs - Google Patents

Description

one

The invention is intended for use primarily in the pulp and paper industry and can also be used in the textile, chemical and other industries.

A device for drying roll materials is known, including its two rows of drying cylinders covered by a single cloth or net, i.e. an endless belt covering successively the cylinders of the upper and lower rows, the drying cylinders of the upper row — ordinary, with a smooth surface, for contact drying, the cylinders of the lower row are perforated, with the creation of a vacuum inside the cylinder, intended for drying with an air inlet 1.

The disadvantage of this device is the need to use cylinders for drying with air throughput, which are very complex and costly, requiring the supply of hot air to the web, which is associated with the use of heat exchangers and ventilation equipment. The reliability of the device due to the presence of numerous unreliable elements is low, and operating costs are high.

Another disadvantage of the device with cylinders for drying with air suction is the impossibility of drying materials with low air permeability, because for drying such materials air suction is inefficient and requires a very large amount of energy to create a high vacuum.

A device for drying roll materials is also known, comprising two horizontal rows of drying cylinders.

arranged one above the other, the endless belt transported by the drying material 2. The drying material together with the transporting belt (net or cloth) is sequentially wrapped around the drying cylinders from the upper and lower rows.

In this device, the dried material is supported by the conveyor belt all the way along the material, therefore the risk of breaks is reduced. In this device, the dried material is in contact only with drying cylinders of one row; on the cylinders of another row, the dried material is

on the conveyor belt and is not in contact with the heated surface of the drying cylinder. Heat transfer is thus derived from drying cylinders of only one row. Therefore the intensity

Drying in such a device is low.

The closest to the invention is a device for drying roll materials, which contains drying cylinders installed in two rows and encompassing their endless belt with supporting rollers 3.

The disadvantage of such devices is the low reliability of their work, due to frequent breaks of the paper web in the zones of its transition from cylinder to cylinder, when the paper moves in a free area without contact. Frequent breaks degrade the performance of the device.

The purpose of the invention is to increase the reliability of the device.

This is achieved by supporting the rollers in pairs between adjacent drying cylinders of one of the rows in such a way that the endless belt covers successively a drying cylinder of one row, a first supporting roller, a drying cylinder of the second row and a second supporting roller, and the supporting rollers can be made perforated.

The drawing schematically shows the proposed device.

The device includes two rows of drying cylinders 1, placed as usual, in a checkerboard pattern, a belt 2 transporting the dried material, with which the dried material contacts all the way through the device (the dried material is not shown in the drawing), the supporting rollers 3 and 4, placed in pairs between adjacent drying cylinders.

The support rollers 3 and 4 may be located in the lower or upper row of drying cylinders.

For example, when the rollers are located between the drying cylinders of the lower row (as shown in the drawing), they are mounted below the axes of these cylinders.

In this case, the tape 2 covers successively a drying cylinder 1, for example, the lower row, the supporting roller 3, i.e. 4, also with a preferred coverage angle of more than 180 °, and then a drying cylinder 1 of the lower row.

The supporting rollers can be made perforated and suctioned (to prevent the dried material from breaking during the change of its direction of movement on the surface of the supporting roller).

The device works as follows.

The dried material, followed along with the conveyor belt 2, is successively wrapped around the drying cylinders 1 of both rows and the supporting rollers 3 and 4 (as described above).

Being on the surface of the drying cylinders of both rows, the dried material is in contact with their heated surface only on one side, with the conveyor belt 2 pressed against it, and is subjected to intensive drying. By supporting the material with a tape along its entire path, the material is prevented from oscillating and breaking off, i.e., a continuous wiring of the web is achieved, which contributes to improving the reliability of the device.

Claims (3)

1. A device for drying roll materials containing drying cylinders arranged in two rows and an endless belt enclosing them with support rollers, characterized in that, in order to increase the reliability of the device, the support rollers are installed in pairs between adjacent drying cylinders of one of the rows in such a way that the endless belt covers successively a drying cylinder of one row, a first supporting roller, a drying cylinder of the second row and a second supporting roller. 2. A device according to claim 1, characterized in that the support rollers are perforated. Sources of information taken into account in the examination 1. The patent of Germany No. 2357183, cl. D 21F 5/00, 1975. 2. US patent number 3503139, cl. 34-111, 1961. 3. Eidlin I. Ya. Papermaking and finishing machines, - M., 1970, p. 307 (prototype). i. -L