SU977013A1 - Centrifugal mill - Google Patents

Description

The invention relates to equipment for fine grinding of materials and can be used in the mining, metallurgical industry, in the production of building materials mainly in cases where, along with high grinding fineness, mechanical activation is required, reaching; shock impulse.

A centrifugal mill is known having a feeding device, a cylindrical body and a rotor with a central shaft and several separators with balls freely inserted in their pockets [1].

The disadvantage of the device is that with an increase in grinding fineness -ή, the impact of the balls that occurs when they meet with particles of the material decreases, and further grinding occurs mainly by abrasion and crushing of the particles, and therefore the mechanical activation of materials is low.

Closest to the proposed is a centrifugal mill containing a cylindrical housing with a rotor placed inside, made- 30

NNm in the form of a hollow cylinder, and grinding bodies [21.

In the known device, the rigid fastening of the protrusions on the rotor and the housing, and, as a consequence, high resistance to the passage between the grinding media. as well as the transfer of grinding and activation energy by these projections to the grinding media causes intensive wear of the rotor. The gap between the housing and the rotor, as well as the presence of protrusions between them, limits the size of the pieces of material supplied to the mill, which reduces the efficiency of the mill.

The purpose of the invention is to increase the reliability and efficiency of the mill.

This goal is achieved by the fact that in a centrifugal mill containing a cylindrical body with a rotor placed inside it, made in the form of a hollow cylinder, and grinding bodies, the rotor is perforated and filled with grinding bodies.

In addition, the holes on the surface of the rotor can be located along a helical line.

In Fig .. 1 'shows a centrifugal mill, General view; figure 2 - ras3 position of the balls in the mill; in Fig. 3 the geometric dimensions of the hole and the grinding body.

The centrifugal mill contains a cylindrical housing 1 with a cooled jacket, a hollow cylindrical rotor 2, a drive pulley 3, a loading neck 4, an opening 5 in the bottom of the housing for the exit of the finished product, grinding balls 6 filling the space between the housing 1 and the rotor 2, as well as located in the inner cavity of the rotor 2. At the points of intersection of the helical line and the generatrix on the outer cylindrical surface of the rotor 2, there are centers of through holes 7, the diameter of which corresponds to the condition

2d - ^{1 (} 'where (A is the thickness of the rotor wall in the zone of the hole;

- the diameter of the balls placed in the cavity of the rotor;

d ₀ is the diameter of the Holes.

The derivation of this formula is explained in FIG.

Based on the condition that

we get

The mill operates as follows.

The balls in the cavity of the rotating rotor 2 are centrifuged, and the group of balls in the layer adjacent to the side. wall, it enters holes 7, the diameter of which is smaller than the diameter of the balls, but their size is such that part of the volume of each ball extends beyond the outer cylindrical surface of the rotor. This group of balls instead of hard protrusions on the rotor, in a known device, collides with grinding media filling the space between the rotor 2 and the housing 1, · '' propagating shock pulses throughout the ball loading of the mill. The source material enters through the neck 4 and is preliminarily crushed in the cavity of the rotor 2 to the size of particles capable of penetrating through the annular gaps between the balls 6 and the body of the rotor 2 at the moments of impact and rebound of the balls that previously covered the holes in the side wall. The subsequent grinding stage occurs in the space between the rotor 2 and the body. catfish 1. The removal of the crushed material 'is carried out in one of two ways, depending on the requirements for grinding fineness and the level of mechanical activation: removal for free under its own weight through holes 5 in the bottom of the body; in case of reduced mill productivity and increased grinding time, removal is carried out by a stream of air pumped by a rotating rotor; while the mill is located horizontally. The removal of the product with a horizontal arrangement of the mill is facilitated by the location of the holes in the rotor wall along a helical line on its outer surface.

Tests of a centrifugal mill showed an increase in the reliability and efficiency of its operation compared to the known mill.

Claims (2)

the position of the balls in the forest; in FIG. the geometrical dimensions of the hole and the grinding body. The centrifugal mill contains a cylindrical body 1 with a cooled jacket, a hollow cylindrical rotor 2, a drive pulley 3, a loading neck 4, a hole 5 in the bottom of the body to exit the finished product, mealyuash balls 6, filling the space between the body 1 with an irrigator 2, also located inside the cavity of the rotor 2. At the intersection of the helix and forming on the outer cylindrical surface of the rotor 2 are the centers of the through holes 7, the diameter of which corresponds to condition 2 (. where SL is the wall thickness of the rotor in the hole the diameter of the balls placed in the cavity poTopaj do is the diameter of the holes. The derivation of this formula explains fig.Z. Based on the condition that H.f {, Y. - Dt-1L / we get the Mill works as follows The balls in the cavity of the rotating rotor 2 are centrifuged, and the group of balls in the layer adjacent to the side wall enters holes 1, whose diameter is less than the diameter of the balls, but their size is such that some of the volume of each ball is outside the outer cylindrical surface rotor. This group of balls instead of rigid protrusions on the rotor, in the known device, collides with grinding bodies filling the space between the rotor 2 and the body, spreading shock impulses to the entire ball loading of the mill. The source material enters through the throat 4 and is pre-crushed in the cavity of the rotor 2 to the size of particles that can penetrate through the annular gaps between the balls 6 and the telo rotor 2 at the moments of impact and rebound of the balls that previously closed the holes in the side wall. The subsequent grinding step takes place in the space between the rotor 2 and the housing. Catfish 1. The removal of crushed material is carried out in one of two ways, depending on the requirements for grinding fineness and the level of mechanical activation: removal is applied under its own weight through the holes 5 in the bottom of the housing; in the case of reduced mill performance and increased grinding time, the removal is carried out by a stream of air pumped by a rotating rotor; at the same time the mill is located horizontally. Removal of the product: when the mill is horizontal, the holes in the wall of the rotor along a helix on its outer surface facilitate the location of the mill. Tests of a centrifugal mill have shown an increase in the reliability and efficiency of its operation in comparison with the known mill. Claims 1. A centrifugal mill comprising a cylindrical body with a rotor made in the form of a hollow cylinder and grinding bodies housed inside, wherein, in order to increase the fineness and efficiency of the mill, the rotor is perforated and filled with grinding bodies. 2. Mill according to claim 1, differ -. y with the fact that the holes on the surface of the rotor are located on the screw INII. The source of information taken into account during the examination 1. USSR author's certificate number 395111, cl. B 02 C 15/08, 1974. 2. The patent of Germany No. 1233237, cl. B 02 C 17/00, 1967 (prototype). ///////// TSC MZZZZZZZZi, UhUUhU ySSS  .J J J J J , 1 g U77U7 / 7 / 7UU 7/7 / 7777УУ7 /. F Y ////} yy //// A X