SU1678448A1 - Ball mill - Google Patents

Abstract

The invention relates to equipment for fine grinding, in particular to ball mills, and can be used in the grinding of various materials in the building materials industry, mining, chemical and energy industries. The purpose of the invention is to intensify the grinding process. The ball mill is made in the form of a drum 1, the inner surface of which is lined with interchangeable armored plates 2. Energy-exchange lining elements are attached to the drum by means of paws. New in the ball mill is that the energy-exchanging lining elements are inclined in the direction of rotation of the drum, the lower end of each energy-exchanging lining element is at the intersection of the forming surfaces of this energy-exchanging lining element and energy-exchanging lining element,. located in the same row on the opposite side of the drum. The forming surface of each energy-exchanging lining element is a part of a logarithmic spiral 1zpf-ly. 5 silt, (L

Description

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The invention relates to equipment for grinding materials, in particular to ball mills, and can be used in the building materials industry, as well as in the energy, ore dressing and chemical industries.

The purpose of the invention is to intensify the grinding process.

FIG. Figure 1 shows the mill drum, cross section; FIG. 2, 3 — sections A — A and B — B in FIG. 1, respectively, in FIG. 4 is a diagram of the installation of energy-exchange lining elements (EFE); in fig. 5 - kinematic scheme of grinding bodies.

The ball mill contains a cylindrical drum 1 (Fig. 1), the inner surface of which is lined with replaceable armor plates 2 and energy-exchange lining elements (EFE) 3-14, attached to the drum by means of paws 15. The drum 1 is equipped with end caps with loading 16 and unloading 17 axles installed in bearings 18 and 19. In the drum 1 is a perforated output grille 20, EFE 3-6 (Fig, 2) forms the first row, EFE 7-10 (Fig. 3) form the second row and EFE 11 -14 (Fig. 2) form the third series, etc. The lower ends 21 and 22 of each of the EFE 3 and 5, located in one row, for example, the first, are at the intersection of, for example, generatrix 23, this EPA 3 and generatrix 24, EFE 5, located in the same row, on the opposite side drum 1. The lower ends 25 and 26 of the EFE 6 and 4 are located at the intersection of the forming 27 and 28 EFE 6 and 4, located in the same row on opposite sides of the drum 1 of the mill. The distance between the lower end of each EFE 3-14 and the inner surface of the drum is equal to h () d. For example, the distance between the lower end of 22 EFE 5 (Fig. 2) and the inner surface of the drum 1 is h. Forming, for example, 23, 24 , 27, 28 of each of the EPE 3-14 are part of a logarithmic spiral. Each of EFE 3-14 is made inclined in the direction of rotation of the drum 1 of the mill indicated by arrow 29 (FIG. 2, 3) EFE 3-6 located in the first row are offset relative to EFE 7-10 (FIG. 1) located in the second row, and EFE 11–14, located in the third row, are displaced relative to EFE 7–10, located in the second row, EFE 3–14 are located in the fixed bed (AE) 30 of the load 31 (Fig. 4). The grinding bodies 32 move under the influence of EFE 3-14 along characteristic trajectories 33-37,

Ball mill works as follows.

The drum 1 (FIG. 1) of the mill rotates in the direction shown by arrow 29 (FIG.

2, 3), while the grinding bodies 32 (Fig. 1) are enthralling with EFE 3-14, move in the cross section of the mill drum along the trajectory 33-37 (Fig. 5), grinding the material with impact, crushing and abrasion. As the particles are crushed, the material moves along the longitudinal axis of the mill drum to the output grid 20. Then, the finished product passes through the holes in the output grid 20 into the unloading pin 17 and is removed from the mill.

In the cross section of the load 31 (FIG. 4) of ball-type drum mills, there is an AE 30. The grinding bodies 32 located in

0 НЯ 30, not only do not participate in the grinding process, but also form stagnant zones that prevent the longitudinal movement of particles of the crushed material. The volume of stagnant zones in ball drum mills reaches 50% of the total mass of grinding bodies. For example, the mass of grinding media loaded into a mill 4x13.5 m is 240 tons - the mass of grinding bodies forming a stagnation zone (located in AE) is about 120 tons, i.e. 120 grinding bodies are inefficiently involved in the grinding process.

It is known that NN 30 is located in the central part of the load 31 at a distance of 5 (8-10) c1, where d is the diameter of the weighted average ball 31 (Fig. 4) from the inner surface of the mill drum (Fig 2). In connection with this, the lower ends 21-24 of each of the EFE 3-6 must be located in

0 beginning AE, i.e. at height h (8-10) d.

The height H of each EFE 3-14 (Fig. 2) must be such that, affecting the grinding bodies 32, located in the AE 30 of each of the EFE 3-14, the menstrual trajectory 325 37 of the movement of the grinding bodies so that all the grinding bodies 32 , located in AEs 30, made a movement, thereby grinding the particles of the material. Such a height H EFE is provided by the fact that if a vertex is a point, for example, EFE 5 is located at the intersection of its generator 25 with the generator 28 EFE 6 located in front of EFE 5 in the direction 26 of the rotation of the drum 1 of the mill. The upper point of the EFE b is located at the intersection of its generator 28 with the generator 23 of the EFE 3, located in front of the EFE 6. The upper point of the EFE 3 is located at the intersection of its generator 23 with the forming 27 of the EFE 4 located in front of the EFE 3. The upper point of the EFE 4 is located at the intersection its generatrix 27 with generatrix 24 EFE 5, located in front of EFE 4. Such an arrangement of the upper points is characteristic of each of the subsequent EFE 7-14.

If the height H of each of the EPE 3-14 is less than the recommended, then not all the grinding bodies 32 located on HN 30 begin to move, as a result, the effectiveness of the grinding process is not possible. If the height H of each of EPE 3-14 is greater than recommended, then the trajectories 33-37 of the movement of the grinding bodies 32 constituting the load 31 change in such a way that they hit the inner surface of the drum 1 and the EPE, causing premature wear of the lining 2 and EFE 3-14. At the same time, the productivity of the mill on the finished product also decreases, as the grinding bodies 32 strike in those zones of lining 2 and EFE 3-14, in which there are no particles of the material being crushed.

If the lower ends 21, 22, 25 and 26 of each of the EFE will be located at a height greater than H () d, for example at a height of h 17d, then some of the grinding bodies 32 located on HN 30 will remain stationary, as a result of which the efficiency of the process chopping will increase enough. If the lower ends 21, 22, 25 and 26 of each of the EFE will be located at a height less than h 8d, for example 7d, then the EFE will capture the grinding bodies 32, effectively grinding the material, thereby not affecting the efficiency of the grinding processes. .

The 23, 24, 27, and 28 generators of each of the EPE are part of a logarithmic spiral. This condition ensures minimal wear of the EFE surface. If the surface of an EPE is made, for example, flat - forming 23, 24, 27 and 28 are straight lines, then the EPE wear out in the middle part especially quickly, which leads to their premature failure. If the 23,24 27 and 28 forming surfaces of each of the EFE are curved in the opposite direction, this also leads to rapid wear of the EFE and significantly changes the paths 33-37 of the movement of the grinding bodies 32, as a result of which the efficiency of the grinding process rises slightly.

EFE 3-14 should be tilted in the direction 29 of the rotation of the mill drum. This ensures a minimal increase in power,

spent on the additional movement of the grinding bodies 32 and the destruction of the stagnant zone in the AE 30. If the EFE 3-14 is tilted in the opposite direction, for example, changing the direction 29 of the rotation of the drum 1 to the opposite, the kinetics (trajectories 33-37) of the movement of the grinding bodies 32 will significantly change , the efficiency of the grinding process decreases, the power consumption increases several times.

The installation of EFE according to the proposed scheme in a laboratory mill of 0.5x2.0 m made it possible to increase the productivity of the mill from 90 to 187 kg / h, while the drive power consumption increased by 30%, the specific power consumption reduced (due to an increase in productivity) from

40 to 25.6 kWh / t.

Clinker rotary kilns of fraction (-2) (, 63) mm to 10% of the residue on sieve 008 (80 µm) were ground.

The application of the proposed technical solution is possible in serial ball drum mills, provides increased productivity and reduced specific energy consumption.

Claims (1)

1. A ball mill containing a drum loaded with grinding bodies with end caps placed in rows with an offset along the perimeter of the drum into . with each of the two rows of rows arranged, energy-exchange lining elements, loading and unloading trunnions, characterized in that, in order to intensify the grinding process, energy-exchange lining elements are inclined in the direction of rotation of the drum; the lower end of each energy-exchange lining element is located at the intersection of the forming surfaces of this energy-exchange lining element and energy-exchange lining element located in the same row on the opposite side of the drum, and the upper end of each energy-exchange lining element is located at the intersection of the forming surfaces of this energy-exchange element and the energy-exchange lining element located in front of it the direction of rotation of the mill drum, wherein the forming of each energy-exchanging lining element has the shape of a part of a logarithmic spiral. 2 Mill Pop 1.If is different with the fact that the distance between the lower end 716784488 each energy-exchange lining bath of the mill is equal to h (8-10) d, where d of the element and the inner surface of the bar is the diameter of the medium-weighted ball. 31 FIG. four. Yu thirty 34 37