CZ392598A3 - Apparatus for feeding material into a crusher - Google Patents

Abstract

The invention concerns a device for moving forward the material for a knife hog (10) with horizontal axis wherein is arranged a circular grinding track (14) and which driven in rotation at a speed higher than the critical speed such that the material being ground is maintained on the grinding track by centrifugal force. The device consists of a knife (20) placed inside the drum, in the upper descending part, so as to scrape the material layer from the track, and of a deflecting blade (22) provided under the knife to intercept the material particles scraped by the latter and divert them towards the hog outlet. In order to facilitate the disintegration of the material layer by the knife and its dispersion, the knife (20) is arranged such that its active surface forms an angle alpha between +15 DEG and -50 DEG with the radial plane bearing on its edge.

Description

DEVICE FOR MOVING MATERIAL TO

CRUSHERS

Technical field

The present invention relates to crushers comprising a drum having a horizontal axis within which a circular grinding belt is provided and which comprises means for rotating the drum at a speed exceeding a critical speed such that the grinding material is held on the belt by centrifugal force; inside the drum there is a wheel positioned so as to be able to move and push on the belt and a device for moving the material from one edge of the belt to the other, consisting of a knife or blade located inside the drum at its upper sloping part from the belt, and on the other hand by at least one deflection plate, located below the knife, for picking up the material separated by the knife and leading it to the crusher outlet.

BACKGROUND OF THE INVENTION

A crusher of this type is described in French Patent No. 91 09788. In this crusher, the active knife surface forms an angle of approximately - 45 ° with the radial surface passing through the knife edge, and the material layer is in some cases separated from the agglomerate belt. if we wish to dry the material with hot gas.

SUMMARY OF THE INVENTION

It is an object of the present invention to ensure that the material layer is broken and scattered by the knife, which makes it possible to improve heat exchange when the material is to be dried using hot gases and, if necessary, to facilitate grain selection by size to allow selective material delivery. Another object of the invention is to reduce the wear of the knife and possibly the deflecting plate.

The material shifting device of the present invention is characterized in that the active surface of the knife forms an angle of -50 ° to + 15 ° with the radial surface passing through the edge of the knife.

Blowing nozzles, supplied with compressed gas and directed at the belt, can be suitably connected to the blade to complete its action. Thanks to these nozzles, it will be possible to avoid contact between the edge of the knife and the web or material layer adhering to the web, and consequently reduce the wear of the knife. In addition, the nozzles will help scatter the material.

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The deflection plate may consist of a shallow box having an air permeable top and filled with air or other gas under pressure. By reducing the friction of the material on the plate, this arrangement will reduce its wear. In addition, the gas streams discharged through the top of the plate may be oriented appropriately to effect selective feed of material.

Brief overview of the drawings

The characteristics of the invention will become more apparent from the study of the following description, which refers to the accompanying drawings which show, without limitation, the manner of carrying out the invention:

Giant. 1 is a schematic representation of a vertical cross section of a crusher comprising the present invention

Giant. 2 is a partial illustration of the crusher of FIG. 1 taken on a large scale.

DETAILED DESCRIPTION OF THE INVENTION

The crusher shown in the drawings is formed by a drum 10 having a horizontal axis supported by wheels 12 allowing it to rotate about its axis. The drum is rotationally driven by conventional means (not shown), for example a motor device and a reducer, the output shaft of which bears a pinion engaging a gear mounted to the drum.

The drum is covered from the inside by friction plates forming a circular grinding strip 14.

The wheel 16 is mounted inside the drum so that it can move on the belt as the drum rotates. The wheel is provided with bearing pins mounted in bearings directed by sliding guides or levers and subjected to the action of springs or jacks to allow the wheel to be pushed onto the ground belt by a predetermined, adjustable force. This fastening system is conventional and is not shown in the drawings.

In operation, the drum is rotatably driven in the direction of arrow R at a rate such that all material is centrifuged and pressed onto the belt.

A device designed to provide material to the web in a direction parallel to the drum axis is located in the upper half of the drum, on the sloping portion of the circular material path. This device is of a similar type to that described in French Patent No. 91 09788. It consists of a fixed knife 20 which is placed parallel to the axis of the drum, the edge of the knife being

3 are located near the surface of the grinding belt, and one or more deflecting plates 22, located below the knife, to catch the influx of material torn from the belt by the knife and return it to the belt. Said plate is tilted about a horizontal axis parallel to the drum axis and situable about a vertical axis so that by changing its inclination and orientation it is possible to move the point at which the material falls on the belt to change the speed of the material at the point of impact and equalize speed supply of material. The orientation and inclination of the plates is controlled from outside the drum using established methods.

According to the invention, the active side of the knife 20 forms an angle alpha of + 15 ° to -50 ° with the surface P comprising the drum axis and passing through the edge of the knife. The active side of the knife is the one on which the material rests; in Fig. 2, the active side of the knife forms an angle alpha of - 5 ° with the surface P. By convention, the angle alpha is positive when the knife is positioned against the direction of the surface P when looking in the direction of rotation of the drum, and negative in the opposite case.

The nozzles 24 carried by the manifold 26 filled with compressed air are located behind the knife 20 so as to discharge air streams towards the surface of the web, i.e. between it and the edge of the knife. These air streams complete the knife operation as it separates the material layer 28 from the web and breaks it, preventing the material from passing over the edge of the knife. The knife and the manifold are supported by a beam 30 extending through the drum, the position of which relative to the drum is adjustable so as to adapt the angle alpha and the distance between the belt surface and the edge of the knife. Corresponding blade and nozzle positions may also be adjustable. Or, the nozzles may be incorporated into the knife.

The plate 22 is formed by a shallow box whose upper moans are air permeable; this wall may be, for example, of sintered material, or it may consist of a metal foil, pierced with vents, or may be of strips adapted in the form of a blind. The crate is supplied with compressed air and this air escaping through its upper side tends to take with it grains of material falling on the plate and move it out of it, reducing friction and thus wear of the plate. The top wall of the plate may be shaped (especially when formed from a perforated or openwork wall type) such that the air streams exiting through the wall have a more favorable direction and selectively act on the beads according to their size to move finer grains more quickly than coarse grains, which increases the grinding efficiency.

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The top of the plate 22 may be straight as shown or curved. Other embodiments of the knife, nozzles and deflector plates may be practiced within the scope of the present invention.

The knife, the connected nozzles and the air permeable box type plates may be introduced together as shown in the example above, or independently of one another if desired.

Devices similar to those described above may be used in a crusher comprising a feed chamber upstream of the conveyor belt and a downstream conveyor chamber. Similarly, in a crusher comprising a plurality of grinding belts placed side by side or spaced along the drum, a device may be used to transfer material from one belt to another.

Claims (5)

PATENT CLAIMS A device for moving material into a drum-type crusher (10) with a horizontal axis, which is internally equipped with a circular grinding belt (14) and rotatably driven at a speed higher than the critical speed so that the material during grinding is held on the belt by centrifugal force ; a device consisting of a knife (20) disposed within the drum at an upper sloping portion to tear off a layer of material from the belt and at least one deflection plate (22) located below the knife to receive material separated by the knife, and take it towards the crusher outlet; A device characterized in that the active side of the knife forms an angle alpha of + 15 ° to - 50 ° with the radial surface P passing through the edge of the knife. Apparatus according to claim 1, characterized in that it comprises blowing nozzles (24) supplied with compressed gas and oriented in the direction of the nas belt to finish the operation performed by the knife. Device according to claim 1 or 2, characterized in that the deflection plate (22) is hollow and is filled with compressed gas, and its top side is permeable. A device according to claim 2, characterized in that the knife (20) and the nozzles (24) are mounted on a beam (30) whose position relative to the drum (10) is adjustable. Device according to claim 2 or 4, characterized in that the nozzles are connected to a knife.