SU996589A1 - Press section of paper-making machine - Google Patents

Description

(54) PRESS PART of the PREPARING MACHINE

 The invention is intended for use in the pulp and paper industry and is a press for dewatering a web on paper and board making machines.

There are various designs n; spring parts.

A known installation for cutting the blade, which includes two press shafts, one of which is covered by press felt and a backing net. Moisture, pressed from the dehydrated canvas, passes through the cloth into the cells of the backing mesh, from which it is either sucked away or blown out with compressed air using a camera installed in the mesh after it leaves the pressing zone. Cl.

Also known is a paper machine press, which includes two large shaft diameters (500750 mm and more) and one small shaft: diameter (5-20 times smaller) placed between them, allowing for improved dewatering compared to conventional and suction presses . (The axis of the small shaft is slightly offset by

relative to the plane passing through the axes of the large shafts 2 j

There is a known water-withdrawing device in the wet part of a paper machine, consisting of several rollers arranged parallel to each other (with a smooth outer surface), of which at least two rollers are used as upper

10 rollers interact with moving cloth (carrying a moist dehydrated canvas) and are set apart from each other; i development under one of the sections-. 5 pounds like a suction chamber GZ.

These structures do not provide sufficient intensity, dehydration and do not provide the necessary compaction of the web, which reduces the quality of the products produced.

The closest to the invention is the press section of the papermaking machine, which comprises a perforated shaft covered by two endless cloths, sealing rollers and connected to a pressure chamber pressure source. For removal of water from the canvas and condensate

A chute 4 is installed under the press shaft.

This device dehydrates the web, however, the density of the web does not increase, which adversely affects the quality of some types of paper and cardboard.

The purpose of the invention is to intensify the dewatering process and improve paper quality.

This goal is achieved by the fact that the press section of a paper machine, containing a perforated shaft covered by two endless felt, sealing rollers and connected to a pressure source, has a series of clamping rollers mounted above the sealing rollers and forming pressure chambers with them. The rollers have diameters that decrease in the course of movement of the web to be processed.

The drawing shows the principle scheme of the press section;

The press section includes a perforated shaft 1, covered by two infinite felt-upper 2 and lower 3 (or grids), sealing rollers 4 mounted above the perforated shaft and contacting with it, hermetic pressure chambers 5.

The sealing rollers 4 are made with a reduced HIS along the web’s movement diameters. Above and in between they are set the pressure shafts b.

Each of the pressure chambers 5 is formed by three shafts - two adjacent sealing 4 and pressure roller b located above them in the gap, which are in pairs in contact with each other and with the perforated shaft 1.

In this case, between the rollers 4 and the perforated shaft 1, a linear pressure increases during the movement of the web under the action of the pressure rollers b.

The chambers at the ends are closed with sealing shields; and they have fittings for the supply of compressed air or steam (not shown).

The device works as follows

A paper web to be processed is fed into the gap between the cloths 2 and 3. When the grids are moving, the web is facing one of the chambers 5 (the first one to move the web). Pressure 5 is created in chamber 5 under the action of hot compressed air (air or steam from a vacuum compressor.) Air from the pressure chamber penetrates through the top cloth 2 into the fabric. in the web (between the fibers) is displaced by compressed air or steam. Thus, under the effect of increasing successively from the chamber to the chamber, the dewatering of the paper web occurs.

Thus, the proposed device, by providing an increase in the density of the dehydrated web, intensifies the process. improves paper quality

Claims (3)

1. The patent of England W 1127174, class, D 2 A, 1962. 2, CHIA Patent No. 3331734, Cl, 162-358, 1965, 3. The patent of Germany No. 1253032, class, 55 d, 16/05, 1961, 4, USSR Author's Certificate 394483, class, D 21 F 3/96, (prototype).