RU2485236C2 - Compact device for pressing paper or cardboard - Google Patents

Abstract

FIELD: textiles, paper.

SUBSTANCE: compact device consists of a central shaft and peripheral press rolls. Pressing of wet fabric is carried out mechanically between two nets under pressure from their tension and centrifugal forces arising during rotation of special central movable segments of the central shaft forming pressing areas with the peripheral press rolls.

EFFECT: invention provides creation of a compact high-efficient press with obtaining of the maximum unit pressures with almost uninterrupted optimal pressing of wet fabric of paper or cardboard.

1 dwg

Description

The compact device for pressing paper or cardboard is designed to mechanically squeeze a wet sheet between two nets.

The device can be used as a press part of paper and paperboard machines in the pulp and paper industry.

Currently, there are various types of press parts installed between the mesh and drying parts of paper-and-cardboard machines intended for mechanical extraction between the shafts of a wet web of paper or paperboard with an initial dryness of 18 ÷ 22% to an ultimate dryness of 35 ÷ 45%.

An example of such devices can be press parts of machines described in the information [1, 3, 5, 6].

Installed on machines with a working speed of up to 1000 m / min with a maximum specific pressure on the press of up to 120 kg / cm, they are ineffective in operation due to the high energy intensity, significant discontinuity between the pressing zones of a paper or cardboard web, upon repeated wetting, structural changes and breakage of the wet web in the free sections of its wiring in the press section.

The disadvantage of such devices is also the large size with the presence of a large number of massive beds, ligaments, levers with pressure diaphragms and other equipment, which increases the energy consumption and the complexity of the service.

Recently, compact combination presses, as well as belt presses and high-intensity belt presses of a frame type with large shafts of about 1200 mm in diameter, designed to work with a specific pressure of about 1200 kg / cm to obtain a dry sheet after the press of about 50%, are also known. .

An example of such devices may be the press parts of machines described in patents [2, 7, 8, 9].

However, they have the above disadvantages.

Closest to the technical nature of the proposed device, the press part of the machine (patent RU 2126864 C1, 02.27.1999) is also not without these drawbacks.

The purpose of the invention is the creation of a compact high-performance press with obtaining maximum specific pressures with almost continuous optimal pressing of a wet sheet of paper or cardboard mechanically between the shafts.

The essence of the proposed device is the use of centrifugal energy generated by the rotation of special movable original elements of the central shaft, creating press zones with peripheral shafts for pressing a wet sheet of paper or cardboard between two grids.

The proposed device, the so-called "orbital" press, is designed for pressing various types of paper or cardboard weighing 12 ÷ 300 g / m ² at a machine speed of about 500 ÷ 3000 m / min with a specific pressure of up to 2000 kg / cm.

The device can also be used for pressing other tape elastoplastic materials.

The design of the device is shown in the drawing.

The device is a central perforated cylinder (1) with four press shafts (2) and an upper clamping shaft (3) planetary located on the periphery. A distinctive feature of this design of the press part is the provision of pressing a crude web of paper or cardboard between two nets to a dryness of 50 ÷ 70% due to the formation of pressing zones between the four outer segments (4) of the central shaft (1) that are extended by rotating at high speed and (1) 2).

Structurally, the “planetary” press is made in the form of two massive stationary frames with press shafts fixed inside them with spring screw clamping mechanisms. The central press shaft (1) with a diameter of about 1300 mm is made in the form of a cantilever type perforated cylinder, hollow with stiffeners, with three bearings, two of which are designed for operation, and the third is for changing grids.

Four outer movable segments (4) of the central press shaft (1) are made of carbide material, are fixedly mounted on rods (5), freely moving in the holes of the perforated central press shaft (1), and are fixed movably in spring couplings (6), which, in turn, are fixed motionlessly on the hollow axis (7) of the central press shaft (1).

The press is driven through the hollow axis (7) of the central shaft (1) and the coupling from the engine.

Small-bending press shafts (2) are a tubular structure made of an outer thick-walled pipe made of carbide material with internal supports fixed to the core. The shaft bearings are mounted inside the press frame.

The press part is equipped with a tray for collecting circulating water (8), a device for draining the wet-air mixture (9), and other equipment necessary for its operation.

The device operates as follows.

A canvas of paper or cardboard with a moisture content of about 18 ÷ 22% is transferred by means of a re-suction device from the net part to the press part.

Dehydrated by the tension of two grids (10, 11), centrifugal forces arising from the rotation of the central press shaft (1), and squeezed by four pressing zones between the movable segments (4) and the press shafts (2) to a dryness of the order of 50 ÷ 70%, the web of paper or paperboard is transferred by way of transfer to the drying section.

The pressing pressure is regulated by means of double-sided spring screw clamps of the press shafts (2).

Claims (1)

A compact device for pressing paper or cardboard, consisting of central and peripheral press shafts, characterized in that, in order to reduce the energy intensity and laboriousness of costs, the wet sheet is pressed mechanically between two grids under the action of pressure from their tension and centrifugal forces arising from rotation of special movable segments of the central shaft, forming with the peripheral press shafts of the pressing zone.

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