RU2752871C1 - Classifying device - Google Patents

Abstract

FIELD: ore separation.

SUBSTANCE: proposed invention relates to classifying devices for unloading drum mills and can be used in ore-grinding and other mills, and can also be used as a screen unit in scrubber trommels. The classifying device in the form of a truncated cone consists of grates connected by rings into a single frame. The grates are installed at an indirect angle to the cone generatrix and have a rounded outer non-working surface and a flat inner working surface that is not parallel to the tangent line to the circle of the axial section of the cone. The grates are rotated by their flat inner working surface in the direction of rotation of the device to meet the classified material.

EFFECT: increasing efficiency of separating the classified product into two fractions, minimizing the clogging of the sifting surface of the classifying device with ore, as well as increasing the useful life of the device.

1 cl, 2 dwg

Description

The invention relates to classifying devices for unloading drum mills, and can be used in ore grinding and other mills. The solution is also recommended for scrubber-butar as a sowing system.

From the prior art known useful model "Butara drum mill" (patent RU No. 14144 from 26.01.2000, IPC В02С 17/18, publ. 10.07.2000). Butara of a drum mill, including a body in the form of a truncated cone with a spiral on the inner surface, is equipped with a bell installed at the outlet of the spiral. The bell has a conveying function without a spiral. The proposed design of the drum mill, with a small material consumption, provides the classification and movement of the material.

The disadvantages of this utility model are that the bell mouth performs only a transport function, and the bell does not classify the scrap of mills of the first stage of grinding, which is a mixture of metal elements of grinding balls after abrasive wear in mills of the first stage of grinding and ore particles of natural material, which does not increases the productivity of the mill of the second stage of grinding and increases the load on the crushing equipment or increases the circulating load, depending on the technological scheme.

Known invention "Butar for ore grinding mill" (patent RU No. 844047 from 24.07.1978, В02С 17/18, publ. 07.07.1981). Butar for ore grinding mills, containing a housing with a device for returning under-ground material, a feed opening with a bell and a drain opening with a diaphragm, as well as L-shaped conveying partitions. In order to simplify the design and improve the quality of the product grinding classification, the device for returning the under-ground material is made in the form of a series of annular discs inside the body and interconnected by means of transporting partitions, and a transporting device is mounted inside the bell.

The disadvantages of this invention are that the bell of the butar has the greatest abrasive wear compared to the barrel of the butar, since it is in the bell that the coarse material settles as much as possible due to the obstacle in the bell formed by the screw conveyor and the annular disc, the movement of the pulp, which leads to frequent replacement of the butar and increases equipment downtime. This design of the butary, which has a bell, is applicable only on mills with central discharge without grates, since the presence of a lump of ore, for example, as in wet semi-autogenous grinding mills, leads to backfilling of the butary.

Also known is the invention of "Butara drum mill" (patent SU No. 1175550 dated 03.16.1984, В02С 17/18, publ. 08/30/1985). The butara of a drum mill contains a conical-cylindrical body with a flange for attachment to the end of the mill discharge trunnion and a device for withdrawing a thin class, as well as a device for withdrawing a large class.

The disadvantage of this useful model is that the butar bell is only a device for the withdrawal of a large class, as well as the butar has a complex structure and inaccessible working surfaces, which will not allow to quickly restore worn out units during scheduled preventive maintenance, and this will lead to frequent replacement butar. The restoration of the bootar is complicated by the complete dismantling of all partitions and the bell. The shape of the butar, namely the discharge side for the withdrawal of fine particles, is arranged in such a way that the slurry will flow down the outside of the butar and will be partially retained on the outside during its rotation. With this design of discharging bottles, the discharged fine particles will partially mix with the finished product in the receiving box for the finished product, which will lead to the loss of the essence of the invention.

Also known is the invention "A device for separating agglomerate into fractions" (patent RU No. 2262992 dated 06.21.2002, В07В 1/22, publ. 20.12.2003). A device for separating agglomerate into fractions, contains a loading mechanism, two cylindrical rotating drums with grate bars movably fixed on them, a dividing partition located between the cylindrical drums, which is, in cross-section, an isosceles triangle with apex facing upwards, while the cylindrical drums are installed under angle to the horizontal plane with the possibility of rotation in opposite directions relative to each other, and the grates are located along the drums with the formation of longitudinal slots and are fixed on the end disks of the cylindrical drums by means of axes with the possibility of rotation around them at an angle limited by the surfaces of the end disks.

The disadvantage of this invention is that the device has a complex design due to the use of pivotally movable grates, high metal consumption due to the use of two cylindrical rotating drums, increased abrasive wear due to the effect of the material on the grate from the outer and inner sides, a large number of mechanical components. wear due to the use of a large number of hinges. In the process of abrasive wear, the gap between the grates increases due to the deflection of the grates, since the grates are not fastened to each other in the middle, which is impossible in this design of the device. All these disadvantages make the efficiency of the classification of the device short-lived, and the use of the device itself is costly.

Also known is the invention "Scrubber unit" (patent RU No. 2212940 dated 19.12.2001, В03В 5/02, publ. 27.09.2003). The device includes a base frame with a loading and receiving hopper and an unloading chute installed on it, a friction drive containing support and driving rollers, a scrubber-butar, consisting of a disintegrating, sowing and outlet staves, an annular threshold installed between the disintegrating and sowing staves, a thrust roller fixed to the base frame. The disintegrating, sowing and output stakes are made in the form of a single cylindrical body, and in the sowing stave of the body there are rectangular windows, across which metal plates are fixed outside the body, and a rim with stiffening ribs, coupled with a thrust roller, is fixed on the border of the sowing and output stakes outside the body. The sowing holes are shaped like an inverted truncated cone.

The disadvantage of this invention is that the scrubber-butara classifies the material into only two fractions, poor circulation of the material in the sowing station due to the obstacle to sliding of the material when turning the scrubber-butara, which is formed by the intervals of the sowing stand body between rectangular windows, since the linings are located from the outside and thereby create rectangular grooves in the sowing stave body, which prevents the material from sliding down when the scrubber is turned, and also worsens the unloading of the "plus" class material, lingering in the sowing stave in the grooves. Poor material circulation results in low material classification performance and increased abrasive wear of the sowing string. Also, due to the use of square pads, the sowing holes have a very small difference in the width of the gap between the pads on the inner and outer sides of the sowing row, and this will lead to material jamming between the pads and a decrease in the usable area for classification, which in turn will reduce the classification performance and will increase the abrasive wear of the sowing string.

The closest analogue in technical essence and the achieved result (selected as a prototype) is "Classifying device for unloading a ball mill and a semi-autogenous grinding mill with a magnetic metal scrap catcher" (patent RU No. 116795 from 11.01.2012, В07В 1/18, publ. 10.06.2012). Classifying device for unloading ball mill and semi-autogenous grinding mill with magnetic metal scrap catcher, installed on the discharge throat of the semi-autogenous grinding mill. The classifier unit fixed to the discharge throat is a hydraulic drum screen (it can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid), the side faces of which are sieves (perforated, metal, polyurethane), the metal scrap is removed using a magnetic catcher in the form of a sector installed between two screens, and the end screen, for large screening, can be made in the form of a cylinder, a multifaceted prism, a truncated cone or a truncated pyramid. The classifier consists of three zones.

The disadvantages of this design of the invention is that the third zone - the end classifier (screen) - mounted on the flange of the magnetic catcher, which is a hydraulic drum screen, the side edges of which are sieves, has a low classification performance. The low classification of the third zone is due to the screening surface in the form of a sieve, since the holes of the sieve are clogged with ore as a result of the multifaceted shape of the enlarged material. The end screen has a high metal content when using metal screens. The use of polyurethane sieves increases the cost of the structure. The use of the screw in the end device requires periodic replacement due to its abrasive wear. The listed disadvantages lead to a decrease in the useful life.

The technical problem of the present invention is to increase the productivity of the separation of the grinding products of the classifying device for the discharge of the drum mill, as well as the use of more durable equipment for the above purpose.

The technical result of the claimed invention is the effective separation of the classified product into two fractions, minimization of clogging of the screening surface of the classifier with ore, as well as an increase in the useful life of the device.

The technical problem is solved due to the fact that the classifying device in the form of a truncated cone consists of grates connected by rings into a single frame, according to the invention, the grates are installed at an oblique angle to the generatrix of the cone and have a rounded outer non-working surface and a flat inner working surface that does not parallel to the tangent line to the circle of the axial section of the cone.

The grates are turned by their flat inner working surface in the direction of rotation of the said device to meet the material to be classified.

The technical result is achieved by the fact that the arrangement of the grates in the classifying device forms three angles of inclination of the grates, which creates the effect of rolling the product during rotation. The described effect makes it possible to minimize clogging of the screening surface of the classifying device with ore, and the shape of the classifying device in the form of a truncated cone provides a smooth increase in the gap between the grates, thereby the product is evenly distributed along the entire length of the device by rolling larger particles through small ones. At the same time, the rounded outer non-working surface minimizes the contact area of the grate with the classified material, which increases the useful life of the device.

The proposed invention is illustrated by drawings:

FIG. 1 shows a section of a classifier;

FIG. 2 shows a fragment of the section of the classifier according to AA.

The classifying device (1) is made in the form of a truncated cone and contains grates (2) connected into a single frame by means of a small-diameter ring (3) and a large-diameter ring (4). In the center, the grates are connected to the outer non-working side by a ring (5), which allows you to keep the size of the gaps between the grates during operation. The grates have a rounded outer non-working surface (7) and a flat working inner surface (8), which is turned in the direction of rotation of the mill to meet the classified material and forms an angle (9) with a tangent straight line to the circumference of the axial section of the classifier. Also, the grates themselves are located at an oblique angle (10) to the generatrix of the classifier cone. The conical shape of the classifier forms an angle (11) with the horizontal plane. Between the grates (1) there are slots (12) of equal size, uniformly expanding from a small-diameter ring (3) to a large-diameter ring (4). FIG. 1 also shows a butara (13) with a screw (14), a product (15) entering the screening, classified material (16), plus class (17).

The operation of the invention is illustrated by the example of unloading a drum mill.

From the discharge throat of the mill, the product (15) goes to screening in the butar (13) of the drum mill. The material to be classified (16) is advanced by the rotation of the auger (14) towards the classifying device (1) and is discharged onto the grate (2). During rotation, the product is picked up by the flat working inner surface (8) of the grate, the finer fraction is rolled over the corner (9) and discharged through the slot (12) at the beginning of the bell, and the rest of the product rises in the direction of rotation of the mill, at the same time due to three angles of inclination (9, 10, 11) grates, the effect of forced rolling of the product towards the unloading side occurs, which allows the "minus" class to be efficiently unloaded through the slots (12). The rounded outer non-working surface (7) of the grate (2) minimizes the total contact area of the grate (2) with the minus class passing through the slots (12), thus only the flat working inner surface (8) of the grate is exposed to the main abrasive wear. The "plus" class (17) remaining in the grate is fed to the crushing.

The proposed invention is durable in operation, it allows you to improve the quality of the finished class, rationally redistribute the grinding energy, which ensures high performance of separation of grinding products. The classifier can be installed on any type of butar flange or a butar scrubber as a sowing stave.

Claims (2)

1. Classifying device in the form of a truncated cone, consisting of grates connected by rings into a single frame, characterized in that the grates are installed at an oblique angle to the generatrix of the cone and have a rounded outer non-working surface and a flat inner working surface that is not parallel to the tangent line to the circle axial section of the cone. 2. The device according to claim 1, characterized in that the grates are turned by their flat inner working surface in the direction of rotation of the device to meet the classified material.

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