GB2157974A

GB2157974A - Pulp refining disc

Info

Publication number: GB2157974A
Application number: GB08424837A
Authority: GB
Inventors: Eduardo Zinezi
Original assignee: INOX IND COMERCIO DE ACO
Current assignee: INOX IND COMERCIO DE ACO
Priority date: 1984-04-27
Filing date: 1984-10-02
Publication date: 1985-11-06
Also published as: GB8424837D0; BR8402044A; GB2157974B

Abstract

The disc comprises a baseplate 1, with bars 2 welded at an angle thereon on both sides forming grooves 3 which are provided with pins 5 at the outer end to retain the fibers. The disc 1 has at its center, arms 7 to fix the discs to the refiner shaft by means of bolts. The refining machine includes stationary discs similarly manufactured but with bars 2 on one side only, the side facing either side of the rotating disc. <IMAGE>

Description

SPECIFICATION Refining machinery The present invention relates to refining machinery and in particularto plates for use in refining pulp or stock for paper making and like purposes. Such refining machinery conventionally uses a system of disks which are mutually rotatable.

An example of a conventional refining system is the DUOFLO SYSTEM in which the refining effect is achieved with the help of four disks, arranged as two pairs. All four disks are of the same diameter and width. One disk of each pair is fixed and the other is rotatable against the fixed disk.

The present invention provides a plate for use in refining pulp or stock for paper making and like purposes comprising a base plate having a circular path thereon divided into a plurality of segments, and a set of parallel wall members outstanding from the base plate in each segment and extending at a common angle to a radius of the path demarcating the respective segment. Preferably, the wall members are formed by bars fixed to the base plate.

Preferably, in each segment the angle between said set of wall members and the respective demarcating radius is the same, for instance about 35".

Preferably, the plates are discs. Usually each plate will have a central aperture. In the case of plates intended to be mounted for rotation on a shaft, the shaft will pass through the central aperture.

Preferably, a plurality of arms are provided extending inwardly from the wall of the aperture by means of which the plate may be fixed to a flange of the said shaft.

Preferably, the plate will have pins outstanding between outer end portions of pairs of the wall members, for instance between every other pair of wall members. These serve to retain particles in the stock or pulp being refined in use.

The invention includes a set of plates for a refining machine comprising three plates as described two plates being for fixed mounting and having said bars on only one face, and the remaining plate being for mounting for rotation between said two plates and having said bars on both faces.

The invention further includes a refining machine comprising a plate as described above or a set of plates as described above.

The invention will be illustrated by the following description of a preferred embodiment with reference being made to the accompanying drawings in which: Fig. 1 is a cross-section on a diameter of a plate according to the invention, Fig. 2 is a plan view of the plate of Fig. 1, Fig. 3 is a section on a diameter of a second form of plate according to the invention, and Fig. 4 is a plan view of the plate of Fig. 3.

The disc illustrated in Figs. 1 and 2 is intended to be the rotating disk of a machine.

The rotating disk is made up of a massive baseplate.

This baseplate may be cast in 304 stainless steel or carbon steel depending on the work needed during the refining action and according with the pH of the pulp or stock. AISI 304 stainless steel bars (2), cold re-rolled for maximum hardness and flexibility, are then welded on the pre-machined baseplate, thus forming wall members. These bars are placed on the baseplate forming an angle (13) with respect to a line passing by the center of the disc.

Alternatively regarded, each set of parallel bars falls in a segment of the disc demarcated by a pair of radii with one of which the bars of each set make an angle a which is the same for each set. The purpose of this inclination angle is to promote more or less hydration on the fiber to be refined. The spacing (3) between two adjacent bars is also variable according to the fiber to be refined.

In the embodiment shown, the mentioned bars are always welded on the baseplate (1) with the help of AISI 304 stainless steel electrodes. The welds (4) are shown in Fig. 1.

When the welding process is over, the mentioned refining discs (plates) are pivoted at the outer diameter in the spacings between the bars, with low hardness AISI 304 stainless steel pins.

These pins are soft not to provoke a friction zone at the periphery of the disc and thus cause an uneven wear at the surface of the bars. The main role of the pins is to increase the residence time of the stock between the discs, avoiding that the stock leaves the refining zone before it is properly refined.

From the center of baseplate (1) and beginning at its inner diameter (12) one can see arms (7) provided with fixation holes (6) to fix the disc on the refiner shaft.

The conventional refining system is called DUOFLO and the refining effect is achieved with the help of four discs, two right discs and two left discs; all the four discs shown the same diameter and width.

The manufacturing characteristics of the discs proposed by us are affected by the described system, keeping, however, the same purpose.

Therefore the stationary discs may be identical to those of the conventional system.

The rotating disc is different because it is in onepiece formed according to the system already described. Its baseplate (8), however, is always cast in stainless steel or carbon steel. The back of this baseplate shows relief hollows (9) as well ribs (13).

These relief hollows are meant to substantially reduce the weight of the discs, thus reducing the down time of the refiner, due to the easier operation of putting the discs in place into the refiner.

The relief hollows can be provided in a similar manner both in the stationary and rotating discs.

The stationary discs are provided with fixing holes (10) and are fixed to the refiner back-plate.

1. A plate for use in refining pulp or stock for paper making and like purposes comprising a base plate having a circular path thereon divided into a plurality of segments, and a set of parallel wall members upstanding from the base plate in each segment and extending at a common angle to a radius of the path demarcating the respective

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Refining machinery The present invention relates to refining machinery and in particularto plates for use in refining pulp or stock for paper making and like purposes. Such refining machinery conventionally uses a system of disks which are mutually rotatable. An example of a conventional refining system is the DUOFLO SYSTEM in which the refining effect is achieved with the help of four disks, arranged as two pairs. All four disks are of the same diameter and width. One disk of each pair is fixed and the other is rotatable against the fixed disk. The present invention provides a plate for use in refining pulp or stock for paper making and like purposes comprising a base plate having a circular path thereon divided into a plurality of segments, and a set of parallel wall members outstanding from the base plate in each segment and extending at a common angle to a radius of the path demarcating the respective segment. Preferably, the wall members are formed by bars fixed to the base plate. Preferably, in each segment the angle between said set of wall members and the respective demarcating radius is the same, for instance about 35". Preferably, the plates are discs. Usually each plate will have a central aperture. In the case of plates intended to be mounted for rotation on a shaft, the shaft will pass through the central aperture. Preferably, a plurality of arms are provided extending inwardly from the wall of the aperture by means of which the plate may be fixed to a flange of the said shaft. Preferably, the plate will have pins outstanding between outer end portions of pairs of the wall members, for instance between every other pair of wall members. These serve to retain particles in the stock or pulp being refined in use. The invention includes a set of plates for a refining machine comprising three plates as described two plates being for fixed mounting and having said bars on only one face, and the remaining plate being for mounting for rotation between said two plates and having said bars on both faces. The invention further includes a refining machine comprising a plate as described above or a set of plates as described above. The invention will be illustrated by the following description of a preferred embodiment with reference being made to the accompanying drawings in which: Fig. 1 is a cross-section on a diameter of a plate according to the invention, Fig. 2 is a plan view of the plate of Fig. 1, Fig. 3 is a section on a diameter of a second form of plate according to the invention, and Fig. 4 is a plan view of the plate of Fig. 3. The disc illustrated in Figs. 1 and 2 is intended to be the rotating disk of a machine. The rotating disk is made up of a massive baseplate. This baseplate may be cast in 304 stainless steel or carbon steel depending on the work needed during the refining action and according with the pH of the pulp or stock. AISI 304 stainless steel bars (2), cold re-rolled for maximum hardness and flexibility, are then welded on the pre-machined baseplate, thus forming wall members. These bars are placed on the baseplate forming an angle (13) with respect to a line passing by the center of the disc. Alternatively regarded, each set of parallel bars falls in a segment of the disc demarcated by a pair of radii with one of which the bars of each set make an angle a which is the same for each set. The purpose of this inclination angle is to promote more or less hydration on the fiber to be refined. The spacing (3) between two adjacent bars is also variable according to the fiber to be refined. In the embodiment shown, the mentioned bars are always welded on the baseplate (1) with the help of AISI 304 stainless steel electrodes. The welds (4) are shown in Fig. 1. When the welding process is over, the mentioned refining discs (plates) are pivoted at the outer diameter in the spacings between the bars, with low hardness AISI 304 stainless steel pins. These pins are soft not to provoke a friction zone at the periphery of the disc and thus cause an uneven wear at the surface of the bars. The main role of the pins is to increase the residence time of the stock between the discs, avoiding that the stock leaves the refining zone before it is properly refined. From the center of baseplate (1) and beginning at its inner diameter (12) one can see arms (7) provided with fixation holes (6) to fix the disc on the refiner shaft. The conventional refining system is called DUOFLO and the refining effect is achieved with the help of four discs, two right discs and two left discs; all the four discs shown the same diameter and width. The manufacturing characteristics of the discs proposed by us are affected by the described system, keeping, however, the same purpose. Therefore the stationary discs may be identical to those of the conventional system. The rotating disc is different because it is in onepiece formed according to the system already described. Its baseplate (8), however, is always cast in stainless steel or carbon steel. The back of this baseplate shows relief hollows (9) as well ribs (13). These relief hollows are meant to substantially reduce the weight of the discs, thus reducing the down time of the refiner, due to the easier operation of putting the discs in place into the refiner. The relief hollows can be provided in a similar manner both in the stationary and rotating discs. The stationary discs are provided with fixing holes (10) and are fixed to the refiner back-plate. CLAIMS

1. A plate for use in refining pulp or stock for paper making and like purposes comprising a base plate having a circular path thereon divided into a plurality of segments, and a set of parallel wall members upstanding from the base plate in each segment and extending at a common angle to a radius of the path demarcating the respective segment.

2. A plate as claimed in claim 1 wherein each segment the angle between said set of wall members and the respective demarcating radius is the same.

3. A plate as claimed in claim 2 wherein the angle is approximately 35".

4. A plate as claimed in any preceding claim having pins upstanding between outer end portions of pairs of wall members.

5. A plate as claimed in any preceding claim which is a disc.

6. A plate as claimed in any preceding claim having said sets of bars on both faces of the base plate.

7. A plate as claimed in claim 5 wherein the plate has a central aperture.

8. A plate substantially as hereinbefore described with reference to and as illustrated in Figs. 1 and 2 or 3 and 4 of the accompanying drawings.

9. A set of plates for a refining machine comprising three plates as claimed in any one of claims 1 to 6 two plates being for fixed mounting and having said bars only on one face, and the remaining plate being for mounting for rotation between said two plates and having said bars on both faces.

10. A refining machine comprising a set of plates as claimed in claim 9 or a plate as claimed in any one of claims 1 to 8.