EA017555B1 - Method for fine crushing of lump material and apparatus for realization thereof - Google Patents

Abstract

The invention relates to crushing of solid materials and can be used in the mining, building, chemical and other industries for fine crushing of lump materials of any strength, the fine fraction of which ranges from 30 to 10 mm. The technical object of the claimed invention is aimed at increasing the output of finely comminuted lumps of materials of different strength, reducing electric power inputs required for fine crushing, developing a technically simple design of an apparatus for fine crushing of lump materials. The inventive method for fine crushing of lump material in a disc mill involves transporting initial material under effect of gravity and centrifugal forces to a crushing area between two co-rotating discs. The axes of rotation of the discs are positioned at an angle to each other and the working surface thereof is shaped in the form of an inner cone, crushing lumps of material in the area where the disks are nearest to one another, and discharging the crushed product by centrifugal forces. The discs are rigidly attached to each other and synchronously rotate so that pieces of material which are bound by the discs are additionally forcedly transported to a crushing area, crushing thereof to smaller size, repeating lumps transporting in a radial direction by centrifugal forces, their compression and further crushing. The technical result is achieved by introducing an additional step of lump transporting in a bound state, using forces in the direction perpendicular to the surfaces of working members for lump crushing and arising in the phase where synchronously co-rotating disks combined in a system of disks, come closerto one another, the axes of rotation of which are positioned at an angle to each other, so bigger lumps of the finished product are comminuted additionally by intensive impact forces.

Description

The invention relates to a technology for crushing solid materials and can be used in mining, construction, chemical, metallurgical and other industries for fine crushing of lumpy materials of a small fraction of 30-10 mm of any strength.

State of the art

Several methods are known for crushing bulk material. The scheme for organizing the crushing process in them includes the processes of supplying the starting material to the crushing zone, breaking up the piece (s) and transporting the finished product outside the crusher. Moreover, in the existing crushing methods, mainly two main types of destruction of pieces of material are realized - crushing or free impact, and the material is transported by gravity or centrifugal forces.

So, in jaw and cone crushers (Handbook of ore dressing, vol. 1, M., 1972, p. 122148), the piece is destroyed by quasistatic crushing between the working surfaces (cheeks, cones) with the horizontal direction of the loads. In this case, the supply of source material and the conclusion of the finished product are carried out in the vertical direction due to the action of gravity. This is shown schematically in FIG. 1a. The use of known methods for fine crushing is limited by the low productivity of these processes in a small fraction, mainly associated with the dependence of the speed of passage of the material in the crushing zone on the action of gravity. Ultimately, it is this dependence that determines the limiting frequency of oscillations of moving elements (cheeks, cones) and, accordingly, the ultimate crushing performance. In addition, these methods are ineffective for fine crushing for structural reasons. For this reason, in existing industrial processing schemes, grinding of a fraction of 30-10 mm of materials of medium and high strength is usually carried out in ball or rod drum mills. The process of destruction of materials in such mills is purely probabilistic in nature and is accompanied by significant energy consumption, which is 1-2 orders of magnitude higher than the energy consumption for crushing a similar size class in crushers. This significantly affects the total cost of the final product.

A similar structure to the organization of the crushing process in the method of crushing materials by high-pressure roller crushers (roller presses) (US patent No. 4357287), which consists in creating high-intensity stress state in the material passing between two rollers (Fig. 1b).

The main difference between this scheme and the previous one is that the generated stress state is volumetric, and the effect is directed to the flow of bulk material, which implies a significant increase in crushing performance. The disadvantage of this method is its limited use for crushing materials of high strength.

Among the crushing methods that realize loading by free blow, one can distinguish crushing by centrifugal-impact devices, hammer and rotary crushers. Rotor and hammer type crushers are designed for crushing materials of low strength.

In the method of crushing by centrifugal impact devices (see, for example, US patent No. 4921173) (Fig. 1c), pieces of the initial product are fed vertically into the workspace due to free fall, then they are given a high speed in the radial direction in the rapidly rotating accelerating device. The destruction of the piece occurs due to the free hit of the piece on the armor. The conclusion of the finished class is also due to the free fall of the pieces. The disadvantage of this method is the low efficiency of its use for crushing materials of small size class (below 15-20 mm), especially for materials of medium and high strength, due to the small mass of the piece and, therefore, its low kinetic energy.

Known methods of crushing lump materials using disk mills. Closest to the method according to the technical essence is the method implemented by the device according to US patent No. 1072193, which implements free-kick loading. The destruction of the material is carried out here with the help of two conical disks rotating in the same direction at high speed, and the axis of rotation are located at an angle to each other. The source material through a hole in the disk enters the space between the disks, after which it is discarded by centrifugal forces to the periphery.

The destruction of the piece occurs due to stresses arising upon impact in the piece. The finished class is also removed by centrifugal forces through an adjustable gap between the rotating discs. The method manages to provide significant feed rates of crushed material to the fracture zone, as well as a high discharge rate of the finished class through the use of centrifugal forces. The disadvantage of this method is the ineffective organization of the destruction process due to its probabilistic nature. The stresses arising during impacts are not high enough, this limits the applicability of the method to relatively weak materials.

- 1 017555

Closest to the device in technical essence is a device for crushing (US patent No. 1072193), including a system of two rotating shafts, one of which is hollow, the other is solid. The integral shaft is placed inside the hollow so that the axis of rotation of the shafts do not match. The shafts are connected using a ball joint, which allows for unidirectional rotation of the shafts. At the ends of the shafts conical disks are installed, which are the working bodies of the crusher. Common features of this invention with the claimed device are the rotation of the disks in one direction, the location of the axes of rotation of the disks at an angle to each other.

The disadvantages of the known device are as follows.

1. Significant dimensions of the device - the length of the device is 6-7 times greater than the diameter of the working body. This, apparently, is associated with the level of development of technology of that time and, accordingly, the need to increase the ratio of leverage. Slow-speed transmission cannot provide the transmission of moments necessary for the destruction of rocks with a strength of more than 10-12 units. on the scale of prof. Protodyakonova.

2. The technical complexity of the device, which does not meet modern requirements of reliability, maintainability and high operating costs when processing large volumes of materials.

3. The lack of a system to protect the device from breakdowns when ingestible bodies are hit.

4. The absence of a sealed discharge casing that prevents the spread of dust outside the device.

5. The device does not provide for the use of high energy material discharged at high speed for impact destruction.

6. The device does not provide synchronization of rotation of the grinding organs, which sharply reduces the efficiency of crushing, and also makes it impossible to use grinding organs with a complex profile, for example, gear.

SUMMARY OF THE INVENTION

An object of the invention is to eliminate these drawbacks, increase the performance of fine crushing of lump materials of various strengths, reduce energy consumption for processes of fine crushing, create a simple design of a device for fine crushing of lump material.

The problem is solved in that the method of fine crushing of lumpy material in a disk-type mill, including the transportation of the source material due to gravity and centrifugal forces to the crushing zone between two disks rotating in the same direction, the axis of rotation of which are located at an angle to each other and which have , each, the working surface in the form of an inner cone, the destruction of pieces of material in the zone of convergence of the disks and the output of the crushed product due to centrifugal forces, differs in that they use disks, raschayuschiesya synchronously with ensuring clamping pieces of material forced conveying pieces of associated discs in convergence zone discs their destruction with decreasing their size, the repetition of pieces of motion in radial direction under the action of centrifugal forces, and their clamp further destruction.

It is advisable to additionally grind the crushed product by sending pieces of material exiting the device due to centrifugal forces to armor lining.

The problem is also solved by a device for fine crushing of lumpy materials, containing a stationary support stand and a rotating part mounted on it, including a first disk having a central loading hole, and a lower disk, the axis of rotation of which is inclined to the axis of rotation of the first disk, both disks having, each, a working surface in the form of an inner cone, in which according to the invention both disks are rigidly interconnected to ensure their synchronous rotation.

In addition, the second disk can be mounted on a pestle with a supporting spherical surface, the first disk and pestle with a second disk are mounted on a massive flywheel pulley so that the pestle rests with its supporting spherical surface on the supporting inner spherical surface of the flywheel pulley on which it is mounted finger-lead, which is included in the groove located on the axis on the spherical surface of the pestle to provide a rigid force connection of the two disks and the synchronization of their rotation.

In addition, the first disk is preferably mounted on a package of two plates, between which compression springs are located with the possibility of movement in the vertical direction due to the compression of the spring in the event of crushing of solid bodies.

The device may also contain a shelter in the form of a housing containing a conical loading chute and armor mounted around the perimeter of the housing against the discharge gap between the disks for impact grinding of the product.

In addition, the disks can be made with protrusions and depressions of the gear shape, and the protrusions of the upper disk are included in the hollows of the lower disk.

Preferably, the ratio of the radius of the discs to the length of the pestle is in the range of 1: 1.51: 4, and the angle of inclination of the axes of rotation of the discs is in the range of 0.5-3 °.

- 2 017555

In the proposed method of fine crushing of lumpy material in a disk-type mill (Fig. 1e), which includes the processes of feeding the source material into the interdisc space due to gravity TP1d, transporting the source material into the crushing zone by centrifugal forces in the horizontal direction TP1c.s. and output crushed product also using centrifugal forces TR2ts.s. additionally, the process of transporting a piece in the bonded state of TRsv is introduced, and the destruction of the pieces is carried out due to forces having a direction perpendicular to the surfaces of the working bodies and arising in the approach phase of two synchronously rotating disks connected into a single system whose rotation axes are angled to each other .

The transport of pieces rigidly fixed between the working bodies of the crusher, which is implemented due to the synchronization of rotation and the rigid relationship of the rotating disks, provides for the forced retraction of pieces of material in the crushing zone and, thus, allows to organize the most effective intensive dynamic action on the piece during which the piece is destroyed.

Thus, the connectedness and cyclicality of the rotational movement of the disks make it possible to compose a system of equally effective elements of the crushing process and, as a result, obtain a high-speed closed conveyor of interconnected, time-coordinated processes of transport and destruction of pieces of material. The execution of all necessary functions is then localized in zones (Fig. 2). So, the transport function of the initial product TR1c.s is performed primarily in zone A, zone B is the zone of the connected movement of the piece Trcv and crushing of Dr1 and zone B is the unloading zone of TP2c.s. All these processes occur in parallel, while the performance of both individual elements of the crushing process, and the whole process as a whole is determined by the number of revolutions of the disk system and can be limited only by purely technical reasons.

The synchronization of rotation of the disks allows the use of working surfaces of the gear shape to ensure that the protrusions of the upper disk enter the troughs of the lower one, which makes it possible to significantly increase the efficiency of crushing of bulk material due to the formation of bending stresses in the piece.

In addition, for the most complete use of the kinetic energy of pieces of crushed material flying at high speed from the device, it provides for the installation of special armor around the perimeter of the casing, which allows to finish pieces of the finished product Dr2, weakened during the crushing operation, Dr1 due to shock loads.

An important advantage of the scheme for organizing the crushing process proposed in the method is the possibility of realizing increased gripping angles of a piece and, therefore, high degrees of crushing. The bound state of a piece, as experience shows, can be realized at angles a and opening of working bodies up to 45 °.

List of drawings

In FIG. 1a-d show diagrams of known crushing methods, FIG. 1e is a diagram of the proposed crushing method.

In FIG. Figure 2 shows the zones of the disk on which the processes of transport (zone A), associated movement (zone B), and unloading (zone C) of the material take place.

In FIG. 3 is a schematic diagram of a device for implementing the crushing method.

In FIG. 4 is a detailed diagram of the proposed device, an axial section.

Preferred Embodiment

The method of fine crushing of bulk material is as follows (Fig. 3).

The material, having fallen onto the lower disk 4 under the action of centrifugal forces, moves along its surface towards the periphery to the place where the size of the piece and the size of the gap between the disks 4 and 5 are the same. Then, moving in conjunction with synchronously rotating disks, the piece is forcibly sent to the zone of convergence of the disks (crushing zone), where it is intensively squeezed and destroyed. In the process of destruction, the size of the piece becomes smaller than the gap, this allows the piece to continue moving under the action of centrifugal forces in the radial direction to the periphery of the disks 4 and 5 to the place where the size of the piece and the distance between the disks coincide again. As the discs approach, the piece is re-clamped and destroyed. This is repeated several times. Having reached a size smaller than the distance between the edges of the disks, the crushed material is removed by centrifugal forces from the crushing zone. After that, he is quickly discarded outside the crushing device and, hitting the armor 14 installed opposite the discharge gap, is subjected to additional destruction. Thus, the grinding of weakened pieces of material due to intense impact loads occurs.

It should be noted that the nature of the interaction of a piece in a bound state with synchronously rotating disks allows for the implementation of a harmonic curve of voltage unfolding in time with minimization of shear stresses, ensures guaranteed fracture of the piece, and also significantly reduces the wear of working bodies. In addition, the dynamic nature of the impact allows to achieve high degrees of crushing.

- 3 017555

The most effectively proposed method of fine crushing of bulk material can be implemented in the proposed device (Fig. 4).

The device consists of a frame 22, on which a vertical support column 1 is installed, which is also a sliding bearing of the entire rotating system of the device. A bearing sleeve 16 of antifriction material is pressed into the support column 1. On the support stand 1, the flywheel pulley 2 rotates, into which the pest 3 is inserted, supported by the supporting spherical surface on the inner spherical surface of the flywheel pulley 2. The cylindrical part of the pest 3 is inserted into the bearing sleeve 16, the axis of which is inclined to the axis of the device (axis of the upper disc 7 ) at an angle β °. the axis of the pestle 3 and the axis of the device intersect at point 0, which coincides with the center of the supporting spherical surfaces of the pestle 3 and the flywheel pulley 2. On the upper plane of the pestle 3, a movable lower disk 4 is installed and fixed, having a working surface in the shape of an inner cone. The conical protrusion in the center of the disk 4 is designed for better distribution of the material when loading. In the spherical surface of the flywheel pulley 2, a finger-lead 19 is pressed in, which enters the groove of the pestle 3 on its spherical surface along a sliding fit. On the flywheel pulley 2 through the remote bushings 12 using high-strength studs 8 installed a package of a base plate 5, springs 11 and a pressure plate 6. The package is assembled using bolts 10 and tightened with nuts 9 on the studs.

On the base plate 5, a fixed armor 7 is installed and bolted, having a working surface in the form of an inner cone and a central opening for loading material. The washer 20 mounted on the lower end of the pestle 3 is bolted and serves to prevent the pestle and the entire rotating system from moving in the vertical direction.

The device is driven by a V-belt (Fig. 4) or a gear drive from an electric motor. The flywheel pulley 2, the V-belt drive and the motor pulley are isolated from the rest of the device space by a hermetic casing 15. The device is covered by a housing 13 with a conical estrus mounted on it to supply material to be ground. On the housing 13 opposite the slits of the grinding organs are fixed around the entire perimeter of the armor 14 (armor lining), designed for impact destruction of pieces of material discharged from the grinding organs at high speed.

In the plate of the bed of the device there are windows (Fig. 4), connected in the lower part of the plate in a single heat and used to unload the finished product from the device for further processing.

The device operates as follows.

When the electric motor is turned on, the rotational movement is transmitted by means of a V-belt drive to the flywheel pulley 2, which rotates on a fixed vertical support post 1. Together with the flywheel pulley, all the associated parts rotate. Finger-leash 19 transmits the rotation of the pestle 3, providing the rotation of the lower disk 5 synchronous with the flywheel pulley 2. The base plate 5 also rotates synchronously with the flywheel pulley 2, on which the upper disc 7 is mounted. The synchronization of rotation of the lower 4 and upper 7 discs creates an effect forced transport of pieces of material into crushing zone B, and the rigid kinematic connection of these disks provides a complete transfer of the breaking load from the working bodies to pieces of material. Due to the fact that the cylindrical part of the pestle 3 is installed in an eccentrically located bearing sleeve 16, and its spherical part rests on the inner spherical surface of the flywheel pulley 2, the axis of rotation of the pestle 3 is shifted by a predetermined angle β relative to the axis of rotation of the flywheel pulley 2. For this reason, the distance between the surfaces of the lower and upper disks 4 and 7 during their rotation is not the same and varies at the periphery of the disks 4 and 7 from the minimum b to the maximum B value (Fig. 3). Destructive stresses occur when a piece in a bound state moves to zone B — the zone of approach of the disks (Fig. 2). The magnitude of the loads resulting from this is determined by the ratio of K to the radius K. of the 4.7 discs to the length b of the pestle 3 (K = K / b), as well as to the angle β. As practice has shown, the ratio K is optimal in the range from 1: 1.5 to 1: 4. With a ratio less than 1: 1.5, it is not possible to ensure the implementation of destructive forces, with a ratio greater than 1: 4, the degree of crushing of the material sharply decreases. The angle β is in the range of 0.5-3 ° and depends on the overall dimensions of the device and the desired particle size distribution of the finished product.

To confirm the operability of this method of grinding, a working sample of the device with a diameter of 200 mm of working bodies was made. Granite of the Pavlovsk deposit with a strength of 15 units was taken as experimental material. on the scale of prof. Protodyakonova and ferruginous quartzites of the Mikhailovsky GOK with a strength of up to 20 units. on the scale of prof. Protodyakonova. Sample analysis was performed in the central laboratory of Mikhailovsky GOK OJSC.

Tests have shown that the device is functional, and its performance is almost independent of the strength of the material. The obtained actual data on energy consumption, productivity and degree of grinding almost coincide with theoretical calculations.

- 4 017555

Industrial applicability

Approximating the obtained results, we can conclude that this device, reproduced on an industrial scale with a diameter of the working body of 600 mm at n = 720 rpm, can replace the mill stage I grinding type MShR-3.2x3.1. The weight of the device will be no more than 8 tons, which is more than 10 times lower than the weight of the specified mill, and the installed engine power will be no more than 90 kW (versus 630 kW on the drive motor of the specified mill).

Claims (8)

CLAIM 1. The method of fine crushing of lump material in a disk-type mill, including the transportation of the source material due to gravity and centrifugal forces to the crushing zone between two disks rotating in the same direction, the axis of rotation of which are angled to each other and which each have a working surface in the form of an inner cone, the destruction of pieces of material in the zone of convergence of the disks and the output of the crushed product due to centrifugal forces, characterized in that they use disks rotating synchronously with em clamping pieces of material forced conveying pieces of associated discs in convergence zone discs their destruction with decreasing their size, the repetition of pieces of motion in radial direction under the action of centrifugal forces, and their clamp further destruction. 2. The method according to claim 1, characterized in that it further crushed the crushed product by sending pieces of material coming out of the device due to centrifugal forces to armor lining. 3. A device for fine crushing of lump materials, comprising a fixed support column and a rotating part mounted thereon, including a first disk having a central loading hole, and a lower disk, the axis of rotation of which is inclined to the axis of rotation of the first disk, both disks having each a working surface in the form of an inner cone, characterized in that both discs are rigidly connected to each other to ensure their synchronous rotation. 4. The device according to claim 3, characterized in that the second disk is mounted on a pestle with a support spherical surface, the first disk and pestle with a second disk are mounted on a massive flywheel pulley so that the pestle rests its support spherical surface on a support inner spherical surface a flywheel pulley, on which a leash pin is installed, which enters the groove located on the spherical surface of the pestle along the axis to ensure a rigid force connection of the two disks and the synchronization of their rotation. 5. The device according to claim 3, characterized in that the first disk is mounted on a package of two plates, between which there are compression springs with the ability to move in the vertical direction due to compression of the spring when it gets intolerable bodies. 6. The device according to claim 3, characterized in that it comprises a shelter in the form of a housing containing a conical loading heat and armor installed around the perimeter of the housing against the discharge gap between the disks for impact grinding of the product. 7. The device according to claim 3, characterized in that the disks are made with protrusions and depressions of a gear shape, and the protrusions of the upper disk are included in the hollows of the lower disk. 8. The device according to claim 4, characterized in that the ratio of the radius of the disks to the length of the pestle is in the range of 1: 1.5-1: 4, and the angle between the axes of rotation of the disks is in the range of 0.5-3 °.