CN111270543B

CN111270543B - Refiner grinding disc, refiner rotor and refiner with refiner grinding disc

Info

Publication number: CN111270543B
Application number: CN202010126118.4A
Authority: CN
Inventors: 亚历山大·葛帅德
Original assignee: Andritz China Ltd
Current assignee: Andritz China Ltd
Priority date: 2020-02-27
Filing date: 2020-02-27
Publication date: 2022-06-21
Anticipated expiration: 2040-02-27
Also published as: CN111270543A

Abstract

The invention relates to a refiner disc, characterized in that at least part of the refiner edges of the refiner disc are designed to be wavy in the radial direction and at least part of the refiner edges of the refiner disc are designed to be wavy in the axial direction. The present invention aims to increase the sharpening length by corrugating the flow channels in the radial direction as well as in the axial direction. This enables the sharpening length to be increased significantly, enabling the grinding disc diameter and hence the idle power to be reduced.

Description

Refiner grinding disc, refiner rotor and refiner with refiner grinding disc

Technical Field

The invention relates to a refiner disc and a refiner rotor. In addition, the invention also relates to a refiner with the refiner grinding disc. The refiner grinding disc relates to a disc grinding disc, a conical grinding disc and a cylindrical grinding disc.

Background

Refining is used in essentially all paper mills worldwide and it is one of the most energy intensive process stages in a paper mill. From the maximum benefit of all customers, the energy consumption for refining should be reduced and still maintain the desired fiber properties. Low consistency refining of fiber pulp suspensions is a common practice for improving fiber properties and strength, and includes chemical pulping, mechanical pulping, and fiber recovery. In particular, for the most commonly used type of double disc refiner, various disc models exist on the market. The load (for reducing the gap between the discs) is used to apply the refining energy needed to achieve a specific fibre characteristic. Typically, the refining consistency is between 4-5%. In this process, fiberization of the fibers and cutting of the fibers occurs. Cutting/chopping of fibers is in most cases an undesirable side effect, and it is therefore always desirable to improve fibrosis and reduce chopping of fibers. A greater sharpening length helps to achieve this goal. Refining strength (specific blade load) and thus blade length of refiner discs is a major factor in the recent improvements of equipment suppliers. The improved manufacturing process allows for smaller ribs or grooves, increasing the number of sharpening edges and thus enabling a reduction in the grinding disc diameter, which means a reduction in energy consumption (lower idling power). However, even the best manufacturing methods have some limitations.

Disclosure of Invention

The inventive concept aims to increase the sharpening length by corrugating the flow channels in the radial direction as well as in the axial direction. This enables the sharpening length to be increased significantly, enabling the grinding disc diameter and hence the idle power to be reduced.

To this end, the invention provides a refiner disc, at least part of the refiner edges of which are designed to be wavy in the radial direction and at least part of the refiner edges of which are designed to be wavy in the axial direction. Unlike the straight sharpening edge of a conventional millstone, the wavy sharpening edge significantly increases the length of the refiner's sharpening edge. In particular, the partial sharpening edges are wavy both in the radial direction and in the axial direction, which further increases the length of the disc sharpening edge.

The increased length of the refiner blade improves pulp fiberization and fiber-to-fiber binding capacity, resulting in higher paper product strength at lower refining strengths. Furthermore, in refiners with the same refining capacity, the length of the refining edge is often inversely proportional to the area of the refiner disc. Thus, an increase in the length of the refining edge means a decrease in the area of the diaphragm for the same refining capacity, whereby a refiner of smaller size can be obtained with the same refining effect. The investment costs are reduced since smaller equipment can be used for the same purpose. At the same time, the no-load power of the refiner can also be reduced, thus having lower energy consumption.

According to one embodiment of the invention, the degree of waviness of the refining edges of the refiner discs in the radial direction increases gradually from the pulp inlet side in the centre of the disc to the pulp outlet side at the periphery of the disc. Preferably, the ratio of waviness of the refiner disc in the radial direction is between 1:1.15 and 1:1.45 at the pulp inlet side of the centre of the disc and at the pulp outlet side of the periphery of the disc.

According to one embodiment of the invention, the waviness of the grinding edges of the refiner disc in the axial direction increases gradually from the pulp inlet side in the centre of the disc to the pulp outlet side at the periphery of the disc. Preferably, the ratio of the waviness of the refiner disc in the axial direction is between 1:1.2 and 1:1.6 at the pulp inlet side of the centre of the disc and the pulp outlet side of the periphery of the disc.

Since the blades have a structure in which the degree of waviness gradually increases from the slurry inlet side to the slurry outlet side, the length of the blades can be further increased, and at the same time, the blades having a corrugated structure may exert a blocking effect on the slurry, and such a blocking effect may increase as the degree of waviness increases. This hindering effect can increase the residence time of the pulp in the flow channel and further improve the fiberization of the pulp, and thus can improve the refining effect of the refiner. Furthermore, the centrifugal force will increase gradually from the pulp inlet side to the pulp outlet side, which will enhance the hindering effect of the sharpening correspondingly to the above-mentioned increasing degree of waviness. In particular, if the sharpening edge has a structure in which the degree of waviness gradually increases from the slurry inlet side to the slurry outlet side both in the radial direction and in the axial direction, the length of the sharpening edge further increases and the hindering effect is further enhanced.

According to one embodiment of the invention, the refiner disc is divided into a plurality of sector areas radiating outwards from the centre of the disc, the wavy refining edges being arranged only in a few of said sector areas.

According to one embodiment of the invention, the refiner disc is divided into a plurality of concentric annular zones radiating outwards from the centre of the disc, the wavy refining edges being arranged in only a few of said concentric annular zones.

The invention also provides a refiner comprising a rotor and a stator fitted with refiner discs according to the various embodiments described above and combinations thereof, wherein the refiner discs of the rotor and stator have matching wave-like shapes.

Furthermore, the invention also provides a rotor for a double disc refiner, comprising a rotor body, which is designed to be adapted to be floatingly connected with a central area to a rotary drive shaft and which is fitted with refiner discs with refining edges both towards the drive motor side of the drive motor and away from the gap adjustment side of the drive motor when mounted, wherein a number of circumferentially extending openings communicating the refining zones of the rotor body on the drive motor side and the gap adjustment side are arranged close to the central area of the rotor body, at least one of the refiner discs on both sides of the rotor body being a refiner disc according to the above embodiments and combinations thereof.

According to one embodiment of the invention, the rotor body has a straight sharpening on the gap adjustment side and a wavy sharpening on the drive motor side. According to another embodiment of the invention the sharpening edges of said grinding discs of the rotor body have a greater degree of waviness on the drive motor side than on the gap adjustment side, so that the fluid pumping effect from the drive motor side of said rotor body to the gap adjustment side is enhanced. In the present embodiment and its various modifications, the comparison of the waviness of the sharpening blade on the drive motor side and the gap adjustment side is referred to. The greater degree of waviness on the drive motor side than on the gap adjustment side contributes to restricting the flow on the drive motor side. In this way, the fluid pumping effect from the drive motor side clearance adjustment side of the rotor body is enhanced.

The advantages of this embodiment according to the invention are: a better and more stable grinding effect is realized; lower energy consumption is achieved due to more efficient refining; the service life of the grinding disc is also prolonged; and thus reduces down time and idle power.

The invention also relates to a refiner comprising a rotor for a double disc refiner according to the above embodiments and combinations thereof; and two fixedly mounted stators. The rotor is designed to be adapted to rotate between the two stators, wherein each stator is arranged with a grating disc with grating edges on the side facing the rotor, the wavy shape of the grating edges of the stator's grating disc matching the wavy shape of the grating edges of the respective side of the rotor, respectively, so as to form a refining zone with the rotor on the side of the drive motor and the side of the gap adjustment, respectively.

Drawings

Fig. 1 schematically shows the main configuration of a double disc refiner;

FIG. 2 schematically illustrates an example design of a prior art sharpening disk having a straight sharpening structure;

fig. 3 schematically shows a design example of a grinding disc with sharpening edges wavy in the radial and axial directions, and also shows a cross-sectional view taken along the line a-a.

In the figures, identical or similar features have identical reference numerals.

Detailed Description

Fig. 1 schematically shows the main configuration of a double disc refiner. Its fiberizer rotor includes: a rotor body 1, said rotor body 1 having a drive motor side 4 facing the drive motor when mounted and a gap adjustment side 5 (refiner door side, with gap adjustment means 16 mounted) facing away from the drive motor, both sides of said rotor body 1 being arranged with a refiner disc 2 with a number of refiner blades 6; two stators, the rotor body 1 being designed to be adapted to rotate between the two stators 3, wherein each stator 3 is arranged with a grinding disc 2 with a grinding edge 6 on the side facing the rotor body 1, whereby a refining zone 7 is formed by the rotor body 1 and the respective stator 3 on the drive motor side 4 and the gap setting side 5 of the rotor body 1, respectively; wherein the rotor body 1 is designed to be floating attached in the central area to a rotating drive shaft 15 passing through the central area of the stator 3. Wherein, near the central area of the rotor body 1, there are arranged several, here kidney-shaped openings extending in the circumferential direction of the refining zone 7 communicating the drive motor side 4 and the gap adjustment side 5 of the rotor body 1.

Figure 2 schematically shows an example of a prior art design of a grinding disc with a straight sharpening structure. In this design example, the refiner disc has a straight blade structure and a straight flow channel, and the refiner disc is divided into a plurality of sector areas radiating outwards from the centre of the disc, wherein the straight blades in different sector areas have different angles to the radial direction. This fan-shaped arrangement can also be used in grinding disks with a corrugated blade structure.

Fig. 3 schematically shows a design example of a grinding disc with sharpening edges wavy in the radial and axial directions, and also shows a cross-sectional view taken along the line a-a. As shown, the sharpening has a sharpening wavy in the radial and axial directions. The refiner discs are divided into a plurality of concentric annular zones radiating outwardly from the centre of the disc. The wavy sharpening edges may be arranged in several of said plurality of concentric annular regions. The path-wavy sharpening edges can have different angles to the radial direction overall in different concentric annular regions.

According to a first embodiment of the invention, at least part of the refiner discs are designed to be wavy in the radial direction and at least part of the refiner discs are designed to be wavy in the axial direction. Wherein the waviness degree of the grinding edges of the grinding disc of the refiner in the radial direction is gradually increased from the pulp inlet side at the center of the grinding disc to the pulp outlet side at the periphery of the grinding disc. Preferably, the ratio of the waviness of the refiner discs in the radial direction is between 1:1.15 and 1:1.45 at the pulp inlet side of the centre of the disc and at the pulp outlet side of the periphery of the disc.

According to a second embodiment of the invention at least part of the refiner discs are designed to be wavy in radial direction and at least part of the refiner discs are designed to be wavy in axial direction. Wherein the waviness degree of the grinding edges of the grinding disc of the refiner in the axial direction is gradually increased from the pulp inlet side at the center of the grinding disc to the pulp outlet side at the periphery of the grinding disc. Preferably, the ratio of the waviness of the refiner disc in the axial direction is between 1:1.2 and 1:1.6 at the pulp inlet side of the centre of the disc and the pulp outlet side of the periphery of the disc.

According to a third embodiment of the invention, at least part of the refiner edges of the refiner disc are designed to be wavy in the radial direction and in the axial direction, and the degree of waviness of the refiner disc in the radial direction and in the axial direction increases gradually from the pulp inlet side in the centre of the disc to the pulp outlet side in the periphery of the disc. Preferably, the ratio of waviness of the refiner disc in the radial direction is between 1:1.15 and 1:1.45 and the ratio of waviness of the refiner disc in the axial direction is between 1:1.2 and 1:1.6, at the slurry inlet side of the centre of the disc and at the slurry outlet side of the periphery of the disc.

According to a fourth embodiment of the invention a refiner is provided comprising a rotor and a stator equipped with refiner discs according to any of the embodiments one to three, wherein the refiner discs of the rotor and the stator have matching wave-like shaped refining edges.

According to a fifth embodiment of the invention a rotor for a double disc refiner as shown in fig. 1 is provided, at least one of the refiner discs 2 on both sides of the rotor body 1 being a refiner disc according to any of the embodiments one to three.

According to a sixth embodiment of the invention the rotor body of the double disc refiner rotor of fig. 1 has straight blades on the gap adjustment side and wavy blades on the drive motor side.

According to a seventh embodiment of the invention, the grinding edges of the grinding discs of the rotor body of the double disc refiner rotor of fig. 1 have a greater waviness on the drive motor side than on the gap adjustment side, so that the fluid pumping effect from the drive motor side of the rotor body to the gap adjustment side is enhanced.

According to an eighth embodiment of the invention there is provided a refiner comprising a rotor for a double disc refiner according to any of the fifth to seventh embodiments; and two fixedly mounted stators. The rotor is designed to be adapted to rotate between the two stators, wherein each stator is arranged with a grating disc with grating edges on the side facing the rotor, the wavy shape of the grating edges of the stator's grating disc matching the wavy shape of the grating edges of the corresponding side of the rotor, respectively, to form a refining zone with the rotor on the side of the drive motor and on the side of the gap adjustment, respectively.

The foregoing describes preferred embodiments of the present invention, but the spirit and scope of the present invention is not limited to the specific disclosure herein. Those skilled in the art can freely combine and expand the above-described embodiments in accordance with the teachings of the present invention to make further embodiments and applications within the spirit and scope of the present invention. The spirit and scope of the present invention are not to be limited by the specific embodiments but by the appended claims.

List of reference numerals

1 rotor body

2 grinding disc

3 stator

4 driving motor side

5 clearance adjusting side

6 sharpening blade

7 refining area

15 axle

16 gap adjusting device.

Claims

1. A grinding disc of a pulping machine, which is characterized in that,

at least part of the blades of the refiner disc are designed to be wavy in both radial and axial directions, and the degree of waviness of the blades of the refiner disc in the radial direction gradually increases from the pulp inlet side at the center of the disc to the pulp outlet side at the periphery of the disc.

2. A refiner disc according to claim 1,

the waviness degree of the grinding edges of the grinding disc of the refiner in the axial direction gradually increases from the slurry inlet side of the center of the grinding disc to the slurry outlet side of the periphery of the grinding disc.

3. A refiner disc according to claim 2,

the refiner disc is divided into a plurality of sector areas radiating outwardly from the centre of the disc, the wavy blades being arranged only in a number of the sector areas.

4. A refiner disc according to claim 2,

the refiner disc is divided into a plurality of concentric annular zones radiating outwardly from the centre of the disc, the wavy refiner edges being arranged in only a number of the concentric annular zones.

5. A refiner disc according to claim 1,

the ratio of the waviness of the grinding edges of the refiner disc in the axial direction is between 1:1.2 and 1:1.6 at the pulp inlet side of the disc center and the pulp outlet side of the disc periphery.

6. A refiner disc according to claim 1,

the ratio of the waviness of the grinding edges of the refiner disc in the radial direction is between 1:1.15 and 1:1.45 on the pulp inlet side of the disc center and the pulp outlet side of the disc periphery.

7. A refiner comprising a rotor and a stator fitted with a refiner disc according to any of claims 1-6, wherein the refiner discs of the rotor and stator have matching wave-like shaped refining edges.

8. A rotor for a double disc refiner, comprising:

a rotor body (1) which is designed to be connected in a floating manner to a rotary drive shaft (15) in the central region and which is equipped with a grinding disk (2) having a grinding edge (6) both on the drive motor side (4) facing the drive motor and on the gap adjustment side (5) facing away from the drive motor during assembly;

wherein a plurality of circumferentially extending openings communicating the refining zone (7) of the rotor body (1) on the drive motor side (4) and the gap adjustment side (5) are arranged in a position close to the central area of the rotor body (1),

it is characterized in that the preparation method is characterized in that,

at least one of the refiner discs on both sides of the rotor body (1) is a refiner disc according to any of claims 1-6.

9. The rotor of claim 8,

the rotor body (1) has a straight sharpening on the gap adjustment side (5) and a wavy sharpening on the drive motor side (4).

10. The rotor of claim 8,

the sharpening edges of the grinding discs of the rotor body (1) have a greater degree of waviness on the drive motor side (4) than on the gap adjustment side (5) so that the fluid pumping effect from the drive motor side (4) to the gap adjustment side (5) of the rotor body (1) is enhanced.

11. A refiner, comprising:

a rotor of a double disc refiner as claimed in any one of claims 8 to 10; and

two fixedly mounted stators between which the rotor is designed to be adapted to rotate, wherein each stator is arranged on the side facing the rotor with a grating disc with its grating edges having a wave-like shape matching the wave-like shape of the grating edges of the respective side of the rotor, respectively, to form a refining zone with the rotor on the drive motor side and the gap adjustment side, respectively.