RU2704865C1 - Method for disintegration of lump raw material - Google Patents

Abstract

FIELD: disintegrators and crushing devices.

SUBSTANCE: invention relates to grinding, dispersion and mechanical activation of materials, including nanostructure materials, and can be used in mining and construction industries, in power engineering, in process plants of concentrating mills, in schemes of preparation of solid fuel for combustion and in production lines for preparation of fodders for farm animals. Novelty is in the method for disintegration of lump raw material additionally creating a pressure gradient in the gaps between rows of destructive elements (beaters) of the movable and fixed discs by initiating in said gaps air velocity, for this purpose destructive elements (beaters) are installed so that their contour in radial direction from center to periphery formed profile of two isosceles trapezoids having common small base, one of which narrows from disk center to its periphery at an angle α=(60÷70)°, and second expands at opening angle f=(15÷25)° from the small base to the periphery, wherein to reinforce the ventilation effect occurring in the gaps on the generatrix of the radial surface of the rotating disc, the ventilation blades are uniformly arranged, which are mechanically fixed to the said surface, and in grinding process on disintegrated raw material is exposed to compressed air jet from compressor, which is supplied to loading point of said raw material, wherein at the end of the disintegration process, the preliminarily ground raw material particles through the discharge hole are accelerated by the air flow to the side surface of the collecting funnel, in the process of collision with which the final disintegration is carried out. When using the claimed method productivity of 1,900 kg/h has been achieved. Average dispersion of milled fluoroanhydrite is 6 mcm. During disintegration of fluoroanhydrite by prototype method, productivity does not exceed 1,200 kg/h, and average dispersion of milled fluoroanhydrite does not decrease below 12 mcm.

EFFECT: claimed method compared to the prototype method increased productivity by 1,6 times, and dispersed nature of the raw material particles by more than 2 times.

1 cl, 3 dwg

Description

The invention relates to methods and devices for fine grinding, mixing, horizontal and vertical transportation, and mechanical activation of materials, including nanostructure, and can be used in chemical, construction and other industries, for the processing of solid lump raw materials, in particular waste chemical production, for example fluorohydrite, to the disintegration of lumpy rock mass, which contains particles of the useful component in a separate form, or in breed splices.

A known method of enrichment of raw materials with metal inclusions. The method includes feeding the feedstock into the space of the working chamber, which has a bottom part and a lid, exposure to destructive elements, distribution to components that contain and do not contain metal (I. M. Kelina "Ore dressing", M .: Nedra, 1979 , p. 93).

The disadvantage of this method is its low productivity due to the cyclical nature of the disintegration cycle. The method has limited use, since it allows you to separate the feedstock, which is characterized by low strength, or raw materials, which are represented by splices of strong and low strength components.

The method requires preliminary preparation of the feedstock, which negatively affects the cost of the final commercial product.

A known method of disintegration of lumpy raw materials, which is implemented in a method of enrichment of raw materials with metal inclusions.

The known method includes supplying lumpy raw materials to a limited space of the working chamber, exposing the raw materials to the bottom with destructive elements, disintegrating the raw materials and imparting centrifugal particles to the particles before colliding with the side wall of the working chamber and its cover, removing disintegrated raw materials from the side opening in the working chamber and from its bottom (Patent of Ukraine for the invention No. 64672).

The disadvantage of this method is that during the disintegration of raw materials, which consists of high-strength particles, the process of their destruction takes a long period of time.

The closest technical solution, selected as a prototype, is the method described in the patent (SU 1704821 A1, IPC B02C 13/22, publ. 15.01.1991). The disembrator that implements the prototype method comprises a housing, inside of which a rotor and a fixed disk with concentrically mounted rows of pins are vertically located, a loading and unloading pipe. In this case, the pins are distributed on a movable disk in a circle located closer to the center of the disk, and are made in cross section in the form of a rectangular shape. The remaining pins mounted on the movable disk are evenly distributed over concentric circles, remote from the central part of the disk made in the form of a trapezoidal shape with an angle of inclination of the working planes to the radial plane of 4-6 °. The pins located on the concentric circles of the fixed disk are made in the form of an isosceles trapezoid with concave lateral sides 9, the center of curvature of which is located above the smaller base at a distance equal to 0.6-0.8 of the height of the trapezoid, and the radius is 2.5-3.0 her heights.

The disintegration of raw materials in the prototype method is as follows. The source material through the loading pipe enters the working chamber, where it is subsequently crushed on concentrically mounted rows of rotor pins and fixed disk pins and is discharged through the discharge pipe. When the working surfaces of the pins of the rotor of the rotor of the disassembler wear, they are reversed. The implementation of the pins of the specified shape and parameters provides a direct central impact with the particles of the crushed material without sliding and abrasion, which helps to increase the uniformity of the grinding product and the life of the pins. The ability of the dismantle to operate in reverse mode also significantly increases the service life. Direct impact leads to uniform wear of the working surfaces of the pins, which leaves the grinding quality unchanged throughout the life of the pins.

The disadvantage of this grinder is that according to the working hypothesis developed by I.A. Hint [Hint I.A. On the main problems of mechanical activation. Tallinn, 1977. Preprint 1.], activation is determined by three parameters: the speed of impact, the number of strokes and the time interval between subsequent strokes. Grinding elements with a round cross-section give the material the widest gamut of types of impact from direct impact to sliding with various angles of inclination, the activation of the material occurs over a wide range of forces from pure compression to shear forces, in the direct impact zone the material is activated by compression forces, and the product it is obtained predominantly of a large fraction, in the zone of a sliding impact the material is activated by shear forces, and the product is obtained mainly of a small fraction. In the dismounter that implements the prototype method, there is no sliding and abrasion of particles of crushed raw materials, so it is impossible to achieve the maximum grinding fineness.

These disadvantages are due to the fact that there are no circulating flows in the working chamber that affect the displacement speed inside the grinding chamber of the raw material particle.

A significant duration of the processing of raw materials occurs due to the fact that the process of disintegration is significantly affected by the speed of collision of the particles of raw materials with destructive elements. In the prototype method, this speed is small, since the particles move along the gaps between the beams only under the influence of gravitational and centrifugal forces, which create insignificant dynamic forces and give individual particles relatively low acceleration in the direction from the loading hole to the discharge hole located in the peripheral part of the chamber grinding. The loss of particle velocity during movement requires a multi-cycle dynamic action to grind them to a given size.

When implementing the known method in a device for the disintegration of mineral raw materials, it is difficult to create excess pressure inside the working chamber, which complicates the conditions for the removal of crushed particles and creates conditions for the deposition of these particles inside the working chamber.

The technical problem to which the invention is directed is to increase the speed of movement of particles of disintegrated raw materials inside the disintegrator and to intensify the grinding process.

The solution to this problem is achieved by the fact that in the method of disintegrating lumpy raw materials, which includes supplying lumpy raw materials to a limited space of the grinding chamber, inside of which there are vertically two parallel disks, on radially fixed planes facing each other, with gaps relative to each other, which destroy elements (beats), the destruction of pieces of raw materials by imparting centrifugal acceleration to the particles due to the rotation of one of the disks, and their collision with the side wall of the working chamber and destructive elements (bills), and the extraction of disintegrated raw materials through the discharge openings in the working chamber, additionally create a pressure gradient in the gaps between the rows of destructive elements (bills) of the movable and stationary disks by initiating a high-speed air flow in the said gaps, for this, destructive elements (bills) ) are set so that their contour in the radial direction from the center to the periphery forms a profile of two isosceles trapezoids having a common small base, one of which tapers from the center of the disk to its periphery at an angle α = (60 ÷ 70) °, and the second expands at an opening angle f = (l5 ÷ 25) ° from a small base to the periphery, and to enhance the ventilation effect that occurs in the gaps on the generatrix on the radial surface of the rotary disk are evenly arranged ventilation blades that are mechanically fixed with the said surface, and during the grinding process, the disintegrated raw materials are affected by a stream of compressed air from the compressor, which is fed to the loading place of the said raw materials, while at the finish m stage of the disintegration process, pre-crushed particles of raw materials accelerated by the air flow through the discharge opening are sent to the side surface of the collecting funnel, in the process of collision with which the final disintegration is carried out.

In FIG. 1 schematically shows a cross section of a disintegrator that implements the inventive method. In FIG. 2. a fixed disk (stator) is shown, and in FIG. 3 - movable disk (rotor).

In FIG. 1, FIG. 2 and FIG. 3 the following designations are introduced: 1 - the body of the grinding chamber; 2 - loading pipe, 3 - loading hole; 4 - discharge hole; 5 - fixed disk (stator); 6 - movable disk (rotor); 7 - working elements (bills) on a fixed disk (stator); 8 - working elements (bills) on a movable disk (rotor); 9 - ventilation blades; 10 - axis of the drive shaft; 11, 12 - ball bearing; 13 - discharge pipe; 14 - compressor; 15 - collecting funnel.

For clarity and explanation of the invention, FIG. 2 and Fig. 3. A separate fragment A is highlighted, showing on an enlarged scale the arrangement of the beats on the stator (Fig. 2) and the rotor (Fig. 3), as well as some additional notation. In FIG. 2 (stator) the following additional designations are introduced: R - radius of the stator disk; r is the radius of the loading hole; H - the height of the tapering trapezoid; h is the height of the expanding trapezoid, D is the large base of the tapering trapezoid; d is the small base of the tapering trapezoid. In FIG. 3, the same designations are introduced as in FIG. 2, only R is the radius of the rotor disc. FIG. 3 differs from FIG. 2 by the fact that in the rotor (Fig. 3) there is no loading opening and ventilation blades 9 are additionally introduced.

The invention consists in the following. The source material through the loading pipe 2 enters through the loading hole 3 into the working chamber 1. The rotor 6 is driven by a drive, the axis of which 10 is mechanically connected to the center of the rotor 6 through a ball bearing 11, 12. The source material falls on the first row of grinding elements (beats) 7 , 8 of the stator 5 and rotor 6. As a result of an impact on these elements and the surfaces of the movable and fixed disks, the particles of material are destroyed and discarded to the following grinding elements of the stator and so on. At the same time, a stream of compressed air is supplied through the discharge pipe 13 from the compressor 14 to the area of the incoming feedstock. The crushed particles of raw materials are picked up by a stream of compressed air, accelerated and again collided with the working elements (bills) and the wall of the chamber 1. The blades 9 located on the forming surface of the rotor 6 contribute to giving the moving particles a directed movement along the contour from the loading hole 3 to the discharge hole 4.

Impact elements (beats) both on the stator (Fig. 1, Fig. 2) and on the rotor (Fig. 1, Fig. 3) are installed with gaps in the radial direction from the center to the periphery so that their contour forms a profile of two isosceles trapezoid with a common small base d, one of which tapers from the center of the disk to its periphery at an angle α = (60 ÷ 70) °, and the second expands at an opening angle f = (15 ÷ 25) ° from the small base to the periphery.

The ranges of narrowing angles and expansion angles of the above trapeziums are due to the desire to maximize the speed of movement of particles of disintegrable raw materials. It is known that the highest velocity stream of air or liquid flow reaches if it is passed through with the so-called Laval nozzle. The optimum size of the Laval nozzle has at the angles of narrowing and expansion of the above cones mentioned above.

The contours of the beats, both on the stator and on the rotor, form a figure similar to the cross section of the Laval nozzle. In the process of rotation of the movable disk with complete mutual overlap of the shock elements of the movable and stationary disk, their cavity forms a figure similar to the cross section of the Laval nozzle. Laval nozzle, (tapering - expanding nozzle) is a channel narrowed in the middle. The Laval nozzle serves to accelerate the gas flow passing through it, under certain conditions, to speeds above the speed of sound. The compressed air entering the grinding chamber, as well as the configuration of the beat arrangement, contribute to the creation of a high-speed air flow in the working area of the said chamber. The high-speed air flow that occurs when moving between the rows of rotor and stator beams creates a strong vacuum inside the chamber, sucking in disintegrated particles and giving them high speeds, which significantly increases the intensity of disintegration and the degree of grinding (disintegration) of the raw material particles. Since the kinetic energy of the particles increases as a result of the action of a stream of compressed air on them, then when these particles collide with the working elements and the chamber wall, they are further effectively ground. After this procedure, the crushed material is discharged through the discharge opening 4. The kinetic energy of the crushed particles of raw materials at the exit of the discharge opening 4 under the action of the accelerating action of a jet of compressed air and centrifugal force acquire a high speed, and, therefore, high kinetic energy. At the exit of these high-energy particles from the discharge opening 4, they fall on the lateral surface of the collecting funnel 15. The high kinetic energy of these particles upon impact with the surface of the collecting funnel 15 is spent on the energy of additional destruction of these particles and they are further crushed.

The crushed material, reaching the last row of beats, is thrown out at high speed through the discharge opening 4, and is sent through a pipeline to a cyclone battery. At the same time, fresh material is continuously sucked into the nozzle 2, maintaining a constant cycle of mixing, grinding and pumping.

An example of a specific implementation. Using the proposed method, grinding of fluorohydrite was carried out, which from the storage hopper, with a metering screw, is dispensed in batches to grind the granules into a hammer mill (metering is carried out by calibrating and maintaining the required speed by the electric metering screw of the metering screw). After the hammer mill, fluorohydrite entered the disintegrator (Fig. 1) through the loading pipe 2 and the loading hole 3.

The dismembrator was made in the form of a movable (rotor) 6 and a fixed 5 (stator) disk. The diameter of both disks was the same (Fig. 2) and was (Fig. 3) 2 R = 513 mm. The stator and rotor were divided into 6 equal segments, on which the beats were installed so that their location formed the contour of two trapezoids - tapering at an angle α = 66 °, and expanding at an angle f = 20 °. The dimensions D of the large and small d bases of the tapering trapezoid were equal to 72.5 mm and 25 mm, respectively (Fig. 2 and Fig. 3).

On the movable and fixed disks on the surfaces facing each other, tapering and expanding trapezoids were located on the sides, respectively 8 and 10 rows of shock elements (bills) 7 and 8, respectively. At the same time, a gap was formed between the rows of the movable and stationary disks, uniformly varying from 26 mm closer to the center to 14 mm at the most remote radii. The convergence angle of the first truncated cone was 66 °, and the expansion angle of the second cone was 20 °.

An additional peripheral contour was made on the rotor in the form of ventilation blades 8, which had the form of plates rotated 45 ° to the direction of rotation of the disk. Using the above-mentioned plates, an air stream was created inside the grinding chamber, which, passing through the rows of beats, the contour of which formed the cross section of the Laval nozzles, was accelerated to high speeds, capturing disintegrated particles of raw materials, intensively crushing and destroying them to small sizes. Compressed air with a pressure of 1.0 MPa (of the order of 10 kg / cm ² ) was supplied from the compressor 14 through the discharge pipe 13 to the loading area of the feedstock. To create a jet of compressed gas, the SB4 / S-50 LB30 compressor unit was used.

Using the proposed method, a productivity of 1900 kg / h was achieved. The average dispersion of ground fluorohydrite was 6 μm. When disintegrating fluorohydrite by the prototype method, the productivity did not exceed 1200 kg / h, and the average dispersion of ground fluorohydrite did not decrease below 12 microns.

Thus, the claimed method compared with the method of the prototype allowed to increase 1.6 times, and the dispersion of the particles of raw materials to reduce more than 2 times.

Claims (1)

A method of disintegrating lumpy raw materials, which includes feeding lumpy raw materials to a limited space of the grinding chamber, inside of which there are vertically two parallel disks, on the planes facing each other which are radially fixed, with gaps relative to each other, destructive elements - bills, destruction of pieces of raw materials by giving it particles of centrifugal acceleration due to the rotation of one of the disks and their collision with the side wall of the working chamber and destructive elements - bills and extraction of disintegration raw materials through the discharge opening in the working chamber, characterized in that they additionally create a pressure gradient in the gaps between the rows of destructive elements - beats of the movable and stationary disks by initiating a high-speed air flow in the said gaps, for this, the destructive elements - beats are installed so that the contour radially from the center to the periphery formed the profile of two isosceles trapezoids having a common small base, one of which tapers from the center of the disk to its perpendicular iferia at an angle α = (60 ÷ 70) °, and the second expands at an opening angle f = (15 ÷ 25) ° from the small base to the periphery, and to increase the ventilation effect that occurs in the gaps, they are evenly placed on the radial surface of the rotating disk ventilation blades, which are mechanically fixed to the said surface, and during the grinding process, the disintegrated raw materials are affected by a stream of compressed air from the compressor, which is supplied to the place of loading of the said raw materials, while at the finishing stage of the process it is disintegrated I accelerated flow of air pre-ground particles of raw material through the outlet opening directed to the side surface of the collecting funnel, during which the collision with the final disintegration is performed.

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