SU1761282A1 - Tower mill - Google Patents

Abstract

Use: in the mining, chemical, construction and other fields of industry. The tower mill includes a housing in the form of a fixed vertical drum 1 auger 2 located therein, a drive 3 loading device 4, discharge openings 5, a cylindrical insert 6 with perforation 7 attached to the bottom 9 of housing 1 in its lower part in the wall of the housing 1. and with the other end welded to the ring 10, supporting the inner walls of the housing 1, the height of the insert from the bottom of the housing is

Description

The invention relates to the field of grinding materials and can be used in the mining, chemical, construction and other industries.

The closest in technical essence and the achieved result is a tower mill, including a housing in the form of a stationary vertical drum, a rotary auger in it, a loading device, discharge openings.

The disadvantage of this mill is low productivity.

This disadvantage is due to the fact that when the mill operates between the screws and the inner walls of the casing, the balls are arranged in several layers, as a result of which their degree of mobility from layer to layer decreases. As a result, the last layers of the balls are practically left without movement, they do not participate in the grinding process, and around

with

The fixed wall layer of the balls cemented by the material to be ground is developed.

This layer prevents the exit of the finished material through the discharge openings, which leads to overloading of the mill

The purpose of the invention is to increase the productivity of the mill due to efficient material unloading.

The goal is achieved by those. that the mill tower comprising a housing in the form of a stationary vertical drum a rotary auger located in it a loading device and discharge openings are provided with a cylindrical insert mounted coaxially to the drum, one end of which is attached to the bottom of the case and the second is supported by a ring on the inside wall of the case. the inserts are (08-1,4) 5 where 5 is the pitch of the helix and the width of the ring is (0 4-0 7) L where L is the distance between VJ o

Yu

00

Yu

do the inner wall of the housing and the outer edge of the screw.

Fig 1 is a general view of a tower mill; in fig. 2 shows section A-A in FIG. one; in fig. 3 - tower mill, filled with balls; in fig. 4 is a cylindrical insert with a ring in isometry.

The tower mill includes a housing in the form of a stationary vertical drum 1, a screw 2 located therein, an actuator 3, a loading device 4, discharge openings 5 in the walls of the housing 1 in its lower part, a cylindrical insert 6 with perforation 7 attached by one end with bolts 8 to the bottom 9 housing 1, and the other end welded to the ring 10, supporting the inner wall of the housing 1.

The height of the insert from the bottom 9 is (0.8-1.4) 5, where S is the pitch of the helix, and the width of the ring is (0.4-0 7) L, where L is the distance between the inner wall of the housing 1 and the outer edge of the screw 2.

With a ring width of less than 0.4L, the distance from the outer edge of the screw to the insert increases, respectively, the number of layers of balls in this zone increases.

The balls adjacent to the insert are not very mobile, because the energy for transferring motion from the auger to the balls at such a distance is not enough, which makes it difficult to unload the material through the holes in the insert and leads to a decrease in the productivity of the mill.

With a ring width of more than 0.7L, the insert, respectively, approaches the auger. In this case, the balls with a large force are pressed against the insert, which leads to intensive wear of the insert, auger and balls. In addition, in this case, there is a periodic jamming of the screw with balls, which leads to breakdowns of the drive and other parts of the mill, significantly reduces the service life of the mill and reduces its performance.

With an insert height of more than 1.45, both crushed and undersized material is displaced through the holes in the insert.

Increasing the level of unloading brings it closer to the unloading device, which reduces the residence time of the material in

the mill, and therefore the required grinding size and productivity are not achieved.

When the insert height is less than 0.85, the decrease in productivity is explained by the insufficient total area of the outlet openings in the insert, which leads to material retention in the working area, overloading the mill and overgrinding of useful components.

The mill is loaded with balls 11 of which, during operation, a fixed wall layer 12 is formed against the inner walls of the casing (Fig. 4).

The height of the mill is 1400 mm, the diameter of the drum 1 of the mill is 300 mm, the diameter of the screw 2 is 200 mm, the distance between the outer edge of the screw 2 and the inner wall of the housing 1 is 50 mm, the pitch of the helix is 200 mm.

Tower mill works as follows.

The source material is fed through the loading device 4 into the working area of the housing 1.

As the balls 11 driven by the rotating screw 2 move through the layer, the material is crushed and, under the action of gravity, falls into the lower part of the mill. The balls displace the crushed material through the holes 7 of the cylindrical insert 6 and further through the discharge holes 5.

Claims (1)

Invention Formula A tower mill, comprising a housing in the form of a stationary vertical drum, a rotary auger located therein, a loading device and discharge openings, characterized in that, in order to increase the mill performance by efficiently unloading the material, the mill is fitted with a cylindrical insert installed coaxially to the drum which is attached to the bottom of the housing, and the other is supported by the ring on the inner wall of the housing, wherein the insert height is (0.8-1.4) 3, where S is the auger spiral pitch, and Irina ring is (0.4 to 0.7) 1, where L- distance between the inner wall of the housing and the outer edge of the screw. v to 4i about : . with, C 3 o L -i O / FIG. four