RU2783845C2 - Mill for milling materials of different hardness and particle size - Google Patents

Abstract

FIELD: milling.

SUBSTANCE: invention relates to a mill for milling different materials. The mill contains drives 8 and case 4 equipped with loading hopper 5 and unloading hopper 6, in which main roller 1 is placed, installed with the possibility of rotation and driven by main drive 8. Main roller 1 is equipped with a replaceable wear-resistant rim. From both sides of main roller 1, along a circumference, there are guiding rings overlapping its diameter and located in such a way that to prevent loss of milled material from a milling slot. In case 4, at least three small millstones 2, 3, 3', axes of which are parallel to an axis of main roller 1, are installed with the possibility of rotation and sliding. They are located in a direction of its rotation along the circumference between loading hopper 5 and unloading hopper 6. All millstones 2, 3, 3' are equipped with compression devices 7 providing their movement to main roller 1. At the same time, first millstone 2 is equipped with its own drive by means of elongated ends of its shaft, protruding from bearing nodes, wherein the driven shaft is installed in rolling bearings. Bearing nodes of millstones 2, 3, 3' are equipped with guiding grooves located with the possibility of installation into guides in sidewalls of case 4 of the mill. Guiding grooves are equipped with channels for lubricant and are faced along their circumference with sliding plates with lubricating grooves. Bearing nodes of first millstone 2 are connected with a cross-beam, on which a rod of compression devices 7 is installed through axial ball bearings.

EFFECT: mill provides milling of materials of different hardness and particle size.

7 cl, 7 dwg

Description

Technical field

The invention relates to devices for grinding materials of different hardness and particle size, such as, for example, materials for the production of cement, cement clinker, lime, limestone, ores and pigments and similar materials.

State of the art

Ball mills and/or vertical disc mills are still used to grind the aforementioned materials of varying hardness and particle size. The main disadvantage of ball drum mills is the asymmetric grinding process, due to the indefinable contact between the grinding charge and the structural elements of the mill, which leads to low energy efficiency of grinding. Known vertical disc mills operate with low grinding efficiency, which can only be improved by re-feeding the crushed material under the grinding disc. Known shredders have significant dimensions and weight, and also have other disadvantages that make their work energy-intensive with the existing long period of grinding.

For grinding materials, high-pressure roller presses are also used, containing two rollers pressed against each other, and the grinding is completed after one passage of the material between these rollers. The disadvantage of high-pressure roller presses is their high traction force, which leads to rapid wear of the grinding rolls and other press components. In addition, significant traction conditions require a robust design of all equipment, which leads to an increase in production costs.

An "intermediate-pressure multi-roll press for grinding granular materials" is known from CZ patent No. 292 489, it contains one driven roll and at least two grinding rolls that do not have their own drives, while their axes are parallel to the axis of the said driven roll. The diameter of the grinding roll is equal, at most, to half the diameter of said driven roll, and the grinding rolls are mechanically mounted in such a way that support gaps are created between the surface of each roll and the near surface of said driven roll, the height of which decreases in the direction of rotation of said driven roll. Each grinding roll is equipped with devices that ensure their rotation, provided by the driven roll. The longitudinal axes of the grinding rolls are in planes passing through the axis of the driven roll, and deviate from the vertical plane divided by the axis of the driven roll, gradually increasing the angles α, β, γ.

диаметра валка для измельчения.In addition, "Granular Material Grinding Mill" is known from the published patent application CZ PV 2002-1541, it comprises a driven grinding roll and at least two grinding millstones rotating parallel to the grinding roll, the axes of which are parallel to the axis of said grinding roll. grinding and which are equipped with devices that provide support on the grinding roll, and which are installed in a sliding manner in the direction of the grinding roll in such a way that gaps are created between their surfaces and the proximal surface of the said roll, the dimensions of which can be adjusted in the radial direction. At least the first millstone is provided with its own drive, while the millstones have the same or different diameter, the value of which is, at a maximum,

grinding roll diameter.

The "Intermediate Pressure Multi-Roll Press" and "Granular Material Grinding Mills" described above represent only the state of the art, they have disadvantages and do not provide a solution to the technical problem mentioned above.

Disclosure of the essence of the invention

To a large extent, the mill for grinding materials of various hardness and particle size eliminates the previously mentioned disadvantages; the mill contains drives and a mill housing equipped with a loading hopper and an unloading hopper, the main grinding roll is rotatably mounted in the housing, driven by the main drive, equipped with a removable wear-resistant rim and having guide rings around the circumference on both sides, overlapping its diameter, located in such a way as to prevent the loss of crushed raw materials from the grinding gap. In addition, the mill housing includes at least three small millstones for grinding installed in it with the possibility of rotation and sliding, the axes of which are parallel to the axis of the specified main grinding roll, and they are located in the direction of its rotation around the circumference between the loading hopper and the unloading hopper.

All small millstones for grinding are equipped with devices that ensure their movement towards the main grinding roll, and the first small millstone is provided with its own drive through elongated ends of its shaft protruding from bearing assemblies containing said driven shaft in antifriction bearings. The essence of the invention lies in the fact that these millstone bearing assemblies are provided with guide grooves located in such a way that they ensure installation in the guides in the side walls of the mill housing. The guide grooves are provided with lubrication channels and are covered around their circumference by sliding plates with lubrication grooves. The bearing assemblies of the first millstone for grinding are connected by a transverse beam, on which the rod of the compression device rests through an axial ball bearing.

To ensure the correct operation of the mill, it is preferable that the bearing assemblies of the second and third millstones are also connected, identically to the first millstone, with transverse beams on which the rods of the compression devices rest through axial ball bearings. Unlike the first millstone, the compression devices of the second and third millstones may form part of their bearing bodies. Preferably, one anti-friction millstone bearing is axially fixed and the other is axially floating.

In particular cases, the drive of the first millstone can be provided either by a hydraulic motor, or by a mechanical gearbox, or by a belt or chain gear, and the movement with pressure, like the movement of other millstones, is carried out by compression devices, which can be hydraulic and / or pneumatic cylinders. or springs. In addition, it is preferable that the removable rims of the millstones as well as the main grinding roll be made of a high quality wear-resistant material, while the forgings are made of chromium-nickel steel, and, in addition, this material is provided with a hard facing layer for highly abrasive materials.

Brief description of the drawings

The essence of the invention is illustrated by the following illustrations:

Fig. 1 - general view of the mill in a partial section, perpendicular to the axes of the main roll and millstones;

Fig. 2 - the first millstone in a section passing through the vertical axis of its compression device and the perpendicular axis of its roll;

Fig. 3 - the first millstone in the cross section A-A, indicated in FIG. 2;

Fig. 4 - detail B, indicated in Fig. 2;

Fig. 5 - detail C, indicated in Fig. 3;

Fig. 6 - made without a drive of the second and/or third millstones, the bodies of which are connected by a transverse beam similarly to the first millstone;

Fig. 7 shows an alternative embodiment of the second and/or third unpowered millstone, where the compression devices are integrated directly into their bearing assemblies without hinged pistons.

Implementation of the invention

The mill for grinding materials of various hardness and particle size includes drives 8, 23 and a mill housing 4, equipped with a loading hopper 5 and an unloading hopper 6, in which the main grinding roller 1 is placed, mounted for rotation and driven by the main drive 8, and the main grinding roll 1 is provided with a replaceable wear-resistant rim and is equipped on both sides with guide rings around the circumference, overlapping its diameter, located in such a way as to prevent the loss of crushed raw materials from the grinding gap. In addition, at least three small millstones 2, 3, 3' are installed in the mill housing 4 with the possibility of rotation and sliding, the axes of which are parallel to the axis of the main roll 1, and they are located in the direction of its rotation along the circumference between the discharge hopper 5 and the discharge hopper 6 All millstones 2, 3, 3' are equipped with compression devices 7, which ensure their movement towards the main roll 1.

The first millstone 2, together with the main grinding roll 1, extracts raw materials from the hopper 5, ensuring its distribution over the entire width of the main grinding roll 1 and its preliminary grinding. The first millstone 2 is provided with its own drive through the elongated ends 10 of its shaft 9 protruding from the bearing units 11, where each elongated end 10 has one drive device 23. The shaft 9 of the first millstone 2, like other millstones 3, 3', is installed in antifriction bearings 12 housed in bearing housings 11 provided with guide grooves 13 which can be fitted into guides in the side walls of the mill housing 4. The guide grooves 13 are provided with replaceable sliding plates 14 made of a special slippery material and are provided with lubrication grooves 15 to allow the distribution of lubricant. The lubricant is supplied to the friction surface through the channels for lubrication 16. The bearing units 11 move in the guide grooves 13 together with all the millstones 2, 3, 3' in the radial direction. The millstones 2, 3, 3' move and exert pressure in the direction of the main roll 1 with the help of a compression device 7 (for example, a hydraulic cylinder) ending with a rod 17. The bearing units 11 of the first millstone 2 are connected by a transverse beam 18, on which said rod 17 of the compression device rests. 7 when installed in an axial ball bearing 19. The axial ball bearing 19 absorbs the compression force, and the leaf springs 21 installed absorb the traction force. The leaf spring 21 is prestressed, which also determines the gap in the ball bearing 19. The entire assembly is bolted to the cross beam 18 using the cover 22. The millstones 2, 3, 3' move along the guide depending on the height of the layer of ground material. The changeable rim 20 is attached to the shaft 9 of the first millstone 2, like the other millstones 3, 3' it is made of a wear resistant material, the forgings are made of nickel chromium steel and in addition this material is provided with a hard facing layer for highly abrasive materials.

The second and third millstones 3, 3' have the same design as the first millstone 2; however, they do not have drives, but can have, as mentioned above, bearing units 11, which are also connected to transverse beams 18, on which rods 17 of compression devices 7 are supported, installed in axial ball bearings 19, see Fig. 6. These millstones 3, 3' move only along the layer of material to be ground, while the grinding itself is carried out using the pressure generated by the compression devices 7. In an alternative embodiment, the second and third millstones 3, 3 ^' do not have a transverse beam 18, but these compression the devices 7 are directly bolted into their bearing assemblies 11 without hinge support, see FIG. 7. One anti-friction bearing 12 of the millstones 2, 3, 3' is axially fixed and the other is axially floating.

As already mentioned, the first millstone 2 is driven either by a hydraulic motor and/or a mechanical gearbox, or by a belt or chain gear, while the pressurization of the first millstone 2 as well as the other millstones 3, 3 is provided by compression devices 7 containing hydraulic and /or pneumatic cylinders or springs.

Since the applied pressure is an order of magnitude greater than the effect of the traction force, the described design solution reduces the own height of the equipment compared to other hinged supports and at the same time allows tilting within the axial clearances in the guide grooves 13 of the bearing assemblies 11, thereby preventing the occurrence of additional bending loads to the rods 17. The support zones are sealed against the penetration of contaminants from the grinding zone by using a special seal with high resistance to dust generated during the grinding process.

The grinding of the material, according to Fig. 1 is carried out between the main roll 1 and three millstones 2, 3, 3'. The speed of the first millstone 2 can be either adjustable or fixed. The speed is chosen so that either the speed of rotation of the first millstone 2 is equal to the speed of the main roll 1, or it can be adjusted so that the speeds of rotation of the first millstone 2 and the main roll 1 are different, thus providing the spreading effect of the crushed material. The rotational movement of the other two millstones 3, 3' is caused by grinding the material to be ground between the roller 1 and said millstones 2, 3, 3'. Before starting the grinding process, the burrs 2, 3, 3' can be raised to their upper position, thus creating a maximum gap between the first burr 2 and the main roll 1.

The crushed raw material is fed into the hopper 5, located in the upper part of the housing 4 of the mill. The crushed material is removed from the feed hopper 5 by the main roll 1 and is fed into the area of the first gap between the main roll 1 and the first millstone 2. The height of the crushed material is regulated by a sliding gate on the output surface of the feed hopper 5. The crushed material is evenly distributed over the entire width of the main roll 1 by the first millstone 2 at a lower grinding pressure at which it is formed and at the same time partial pre-grinding takes place. The pressure of the first millstone 2 can also be ensured by the fact that the first millstone 2, unlike the other millstones 3, 3', does not move vertically, but is fixed by means of stops and a gap between said millstone and the main roll 1. The crushed material is then released by a slight rotation of the main roll 1 and leaves the specified zone. An additional rotation of the main roll 1 advances the released and displaced crushed material to the second gap created between the main roll 1 and the second millstone 3. At this moment, the second millstone 3 acts on the crushed material with an average grinding pressure, starting the second stage of grinding, accompanied by the destruction of the grains of the crushed material. After that, the crushed material is again released by another small rotation of the main roll 1. The crushed material is fed into the third grinding gap created between the main roll 1 and the third burr 3 in a pre-crushed state, while the grinding of the material is completed at this point by applying the greatest grinding pressure (pressure of the third millstone 3). The pressure values of the individual millstones 2, 3 and 3' can be adjusted not only in ascending order, but also arbitrarily, depending on the grinding requirements. The crushed material enters the lower part of the mill into the unloading hopper 6, then moves to other conveying devices. Mill housing covers 4, not shown in the illustrations, allow for complete dust protection of the mill and are designed to release dust.

Claims (7)

1. A mill for grinding materials of various hardness and particle size, containing drives and a housing, equipped with a loading hopper and an unloading hopper, a main grinding roller is rotatably installed in the housing, driven by the main drive, equipped with a removable wear-resistant rim and having on both sides guide rings around the circumference, overlapping its diameter, located in such a way as to prevent the loss of crushed raw materials from the grinding slot, in addition, at least three additional small millstones for grinding are installed in the mill housing with the possibility of their rotation and sliding, the axes of the millstones are parallel to the axis of the specified the main roll, while the millstones are located in the direction of rotation of the main roll along its circumference between the loading hopper and the unloading hopper, all the millstones are equipped with devices that ensure their movement towards the main roll, and the first millstone is equipped with its own drive by means of elongated the ends of its shaft, protruding from the bearing assemblies, providing the location of the driven shaft in antifriction bearings, characterized in that the bearing assemblies (11) of the millstones (2, 3, 3') are provided with guide grooves (13) located so that they provide installation in guides in the side walls of the housing (4) of the mill, the guide grooves (13) are equipped with channels for lubrication (16) and are covered around their circumference with sliding plates (14) with lubrication grooves (15), and the bearing units (11) of the first millstone (2) are connected by a transverse beam (18), on which the rod (17) of the mentioned compression device (7) rests through axial ball bearings (19). 2. A mill for grinding materials of different hardness and particle size according to claim 1, characterized in that, identical to the first millstone (2), the bearing assemblies (11) of the second and third millstones (3, 3') are also connected to the indicated cross beams (18) , on which the rods (17) of the indicated compression devices (7) rest through axial ball bearings (19). 3. A mill for grinding materials of different hardness and particle size according to claim 1, characterized in that, unlike the first millstone (2), these compression devices (7) of the second and third millstones (3, 3') form part of their bearing assemblies ( eleven). 4. Mill for grinding materials of different hardness and particle size according to any one of paragraphs. 1-3, characterized in that one anti-friction bearing (12) of the millstones (2, 3, 3') is axially fixed, and the other is axially floating. 5. Mill for grinding materials of different hardness and particle size according to any one of paragraphs. 1-4, characterized in that the drive of the first millstone (2) is either a hydraulic motor, or a mechanical gearbox, or a belt or chain gear. 6. Mill for grinding materials of different hardness and particle size according to any one of paragraphs. 1-5, characterized in that said compression devices (7) of the millstones (2, 3, 3') comprise hydraulic and/or pneumatic cylinders or springs. 7. Mill for grinding materials of different hardness and particle size according to any one of paragraphs. 1-6, characterized in that the removable rim (20) of the millstones (2, 3, 3'), as well as the main roll (1), is made of high-quality wear-resistant material, while the forgings are made of chromium-nickel steel, in addition, this material equipped with a hard facing layer for highly abrasive materials.

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