GB2218010A

GB2218010A - Improvements in or relating to mineral breakers

Info

Publication number: GB2218010A
Application number: GB8810397A
Authority: GB
Inventors: Richard Harley
Original assignee: WELLER ENGINEERING Ltd
Current assignee: WELLER ENGINEERING Ltd
Priority date: 1988-05-03
Filing date: 1988-05-03
Publication date: 1989-11-08
Also published as: GB8810397D0

Abstract

A mineral breaker comprises a rotatable drum (5) provided with teeth (11, 12) on its surface (9). First and second breaker means (13, 18) are provided. Each is spaced from the drum surface (5) and a means (15, 20) is provided to regulate the spacings. The first breaker means (13) carries out a preliminary reduction of the mineral and the mineral is then further reduced in size by the second breaker means (18). <IMAGE>

Description

Improvements in or relating to Mineral Breakers This invention relates to an apparatus for breaking mineral.

It is well known to reduce the size of mineral, such as coal, using an apparatus comprising a drum rotatable about its longitudinal axis and carrying teeth on its cylindrical surface. A breaking means such as a plate is located adjacent to, but spaced from, the surface. In use, large pieces of mineral are fed to the drum and are reduced in size by being crushed between the breaking means and the teeth of the rotating drum.

It is an object of the present invention to provide a mineral breaker which enables the final size of the mineral to be more carefully controlled.

According to the present invention there is provided an apparatus for breaking mineral comprising: (i) a frame (ii) a drum mounted on the frame for rotation about its longitudinal axis and carrying a plurality of mineral-breaking teeth on its cylindrical surface, (iii) a means of rotating the drum about its axis, (iv) first breaker means mounted on the frame adjacent to, and spaced from, the cylindrical surface of the drum so that mineral is subjected to a preliminary size reduction by the action of said first breaking means and said teeth.

(v) a means of adjusting the spacing between the first breaker means and the cylindrical surface of the drum, (vi) a second breaker means mounted on the frame adjacent to, and spaced from, the cylindrical surface of the drum so that the preliminarily reduced mineral is subjected to a secondary size reduction by the action of said second breaking means and said teeth, and (vii) a means of-adjusting the spacing between the second breaker means and the cylindrical surface of the drum.

In accordance with a particularly preferred embodiment the teeth include relatively short teeth and relatively long teeth. Preferably the first breaker means comprises a breaker plate mounted for pivotal movement about an axis parallel to said longitudinal axis in which case the means of adjusting the spacing between it and the drum may comprise a shaft which is secured to the first breaker means and which is axially moveable so as to cause pivotal movement of the breaker plate about its axis towards and away from the drum.

Also, it is preferred for the second breaker means to comprise an assembly of tines laterally spaced from one another and mounted for pivotal movement about an axis parallel to said longitudinal axis, adjacent tines defining pockets through which the teeth pass as the drum rotates. In this case, the means of adjusting the spacing between the second breaker means and the drum may comprise a shaft which is secured to the second breaker means and which is axially moveable so as to cause pivotal movement of the assembly of tines about its axis towards and away from the drum. The pivotal axis of the breaker plate is advantageously co-incident with the pivotal axis of the assembly of tines.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a top view of an apparatus in accordance with the invention, Figure 2 is a side view of the apparatus shown in Figure 1, and Figure 3 is a section along line III-III of the apparatus of Figure 2.

Referring now to the drawings, the apparatus comprises a generally rectanguloid frame comprising first and second side members 1 and 2 and first and second end members 3 and 4. The top of the frame is generally open so as to allow mineral to be introduced and the bottom of the frame is generally open so as to allow the broken mineral to be discharged.

Bearings (not shown) are provided in end walls 3 and 4 and a drum 5 is mounted in the bearings for rotation about its longitudinal axis 6. The drum 5 is rotated about its axis 6 in the direction indicated by the arrow in Figure 3 by means of an electric motor 30 to which the drum is connected by means of a reduction gear box 31. The electric motor and reduction gear box are essentially conventional. If desired, the motor 30 may be in line as shown by the chain dotted line. The drum is attached to the output shaft of the gear box 31 by means of a spliced coupling shown schematically and denoted by reference numeral 7.

A plurality of teeth in the form of cutting picks is provided on cylindrical surface 9 of the drum 5. These picks are welded to the drum surface 9 so that they are disposed in a series of lines 10 inclined to the longitudinal axis 6. Thus, the picks generally occupy a helical configuration with respect to the surface 9 of the drum. The disposition of the picks and their lengths are selected in dependance upon the desired size of the final mineral product. However, the teeth include relatively short teeth such as that denoted by reference numeral 11 and relatively long teeth such as that denoted by reference numeral 12.

The path of the tips of teeth 11 as the drum 5 rotates is denoted by reference numeral 11' and similarly the path of the tips of teeth 12 is denoted by reference numeral 12'. Generally each line 10 will include one relatively long tooth and these teeth will be located at intervals along the axis of the drum 5.

The apparatus includes a first breaker means in the form of a breaker plate 13 supported along its length by three spaced carriers 14. Each carrier 14 is mounted for pivotal motion about a shaft 15 extending between the end walls 3 and 4 and parallel to axis 6.

Each carrier 14 includes an arm 16 to which a shaft 17 is pivotally attached so that axial movement of the shafts 17 causes the carriers 14 and hence plate 13 to pivot about the shaft 15 towards and away from the drum surface 9. As a consequence of such pivotal movement, the spacing between the plate 13 and the drum 5 can be adjusted. Shafts 17 pass through a part of the frame and their axial movement can be effected in any desired manner such as hydraulically or mechanically, externally of the apparatus.

The apparatus includes a second breaker means located below the first breaker means and comprising a plurality of L-shaped tines 18 laterally spaced from one another. Each tine has a free first end located adjacent to the cylindrical surface 9 of the drum 5 and a second end pivotally mounted on the shaft 15.

Adjacent tines are connected together by linking members 20 so as to form a single assembly of tines.

Two of the tines are each pivotally connected at points intermediate their first and second ends to shafts 21 passing through the frame so that axial movement of the shafts 21 causes the assembly of tines to pivot about shaft 15 towards and away from the drum surface 9. Any suitable means may be provided externally of the apparatus, to cause axial movement of the shafts 21 such as hydraulic or mechanical means. As the tines pivot about shaft 15, the spacing between the free ends of the tines and the peripheral surface 9 of drum 5 varies. As can be seen from Figure 1, members 19 are provided near the free ends of adjacent tines to define pockets through which the picks 11 and 12 pass on rotation of the drum 5. The size of the pockets depends upon the size of the picks on the drum 5.Bars 32 are also provided between adjacent tines to form a grid through which undersized mineral can pass.

In use of the apparatus the drum 5 is rotated by the motor 7 and large pieces of mineral such as coal (typically of size 400-500 mm) are charged into the apparatus from the top. The pieces of mineral are crushed between the breaker plate 13 and the larger picks 12 of the drum 5 and thereby become rapidly reduced to a more acceptable working size. The spacing between the breaker plate 13 and the surface of the drum 5 is adjusted by axial movement of shafts 15 in dependence upon the input size of the material. The mineral which has been subjected to a preliminary reduction in size by the first breaker means is then crushed between the tines 18 and the teeth 11 and 12.

This further reduces the mineral to a desired final size e.g. 50 mm. This final size can be controlled to some extent by adjusting the spacing between the free ends of the tines 18 and the drum surface 9 by axially moving the shafts 20 by a desired amount. The finally reduced mineral is then discharged from the bottom of the apparatus. The apparatus produces a low percentage of fines since it does not require small picks to act on large input material which is the primary cause of such fines.

The final size can be selected in dependence on the users requirement by fitting a tine assembly having an appropriate inter-tine spacing and by fitting a drum having teeth 11 and 12 of an appropriate size.

The tine assembly and drum can be readily replaced for this purpose.

Claims

1. An apparatus for breaking mineral comprising: (i) a frame (ii) a drum mounted on the frame for rotation about its longitudinal axis and carrying a plurality of mineral-breaking teeth on its cylindrical surface, (iii) a means of rotating the drum about its axis, (iv) first breaker means mounted on the frame adjacent to, and spaced from, the cylindrical surface of the drum so that mineral is subjected to a preliminary size reduction by the action of said first breaking means and said teeth.

(v) a means of adjusting the spacing between the first breaker means and the cylindrical surface of the drum, (vi) a second breaker means mounted on the frame adjacent to, and spaced from, the cylindrical surface of the drum so that the preliminarily reduced mineral is subjected to a secondary size reduction by the action of said second breaking means and said teeth, and (vii) a means of adjusting the spacing between the second breaker means and the cylindrical surface of the drum.

2. An apparatus as claimed in claim 1 wherein the teeth include relatively short teeth and relatively long teeth.

3. An apparatus as claimed in claim 1 or 2 wherein the first breaker means comprises a breaker plate mounted for pivotal movement about an axis parallel to said longitudinal axis.

4. An apparatus as claimed in claim 3 wherein the means of adjusting the spacing between the first breaker means and the drum comprises a shaft which is secured to the first breaker means and which is axially moveable so as to cause pivotal movement of the breaker plate about its axis towards and away from the drum.

5. An apparatus as claimed in any one of claims 1 to 4 wherein the second breaker means comprises an assembly of tines laterally spaced from one another and mounted for pivotal movement about an axis parallel to said longitudinal axis, adjacent tines defining pockets through which the teeth pass as the drum rotates.

6. An apparatus as claimed in claim 5 wherein the means of adjusting the spacing between the second breaker means and the drum comprises a shaft which is secured to the second breaker means and which is axially moveable so as to cause pivotal movement of the assembly of tines about its axis towards and away from the drum.

7. An apparatus as claimed in claim 5 or 6 when appendant to claim 3 or 4 wherein said axis of the breaker plate is co-incident with said axis of the assembly of tines.

8. An apparatus for breaking mineral substantially as hereinbefore described in the accompanying drawings.