EP0620043A2 - Desintegrator for solid objects - Google Patents

Abstract

The apparatus according to the invention comprises a support (1) in the form of a box which is open at the top and at the bottom, a substantially horizontal rotor (6) mounted inside the box and carrying at least one knife (13) which rotates with it passing between mating knives (15), an active face of which points towards the rotor, and preferably exhibits teeth, these mating knives being capable of moving independently of one another and having their own return means, for example swinging on a pivot (12) parallel to the rotor. Means for setting the mating knives into forced swinging may be provided. The mating knives may be removed individually. <IMAGE>

Description

The present invention relates to an apparatus for fragmenting solid objects, and in particular industrial and domestic waste, for recycling.

Among the multiple fragmentation devices in use, that described in document FR-A-2,254,371 stands out for its properties of adaptation to objects of various types, both fragile and flexible. This device comprises a hopper-support with an inlet opening at the top and an outlet opening at the bottom, a rotor, with a horizontal axis, carrying radial knives, and a set of counter-knives, integral with the hopper- support, between which the knives pass when the rotor rotates. These counter-knives are grouped into a comb and a counter-comb, an object driven by the rotor in its rotation successively encountering the comb and then the counter-comb.

The active surface of the comb cutters is straight and serrated, that is to say that it has notches which constitute stops which stop the movement of an object to be fragmented.

In practical embodiments in accordance with this patent, the axial interval between a knife of the rotor and the adjacent counter knives of the comb is relatively large, for example 5 to 10 mm, and this part of the apparatus functions as a grinder, while the axial interval between a rotor knife and the adjacent counter-blades of the counter-comb is much smaller, for example 0.5 to 1 mm, so that this part works in shears, hence the name "shredder -shear "frequently given to this type of device.

The device operates at relatively low speeds of rotation of the rotor, for example of the order of 20 revolutions per minute, so that it is not very noisy. When an object too strong to be ground occurs, a rotation in the opposite direction of about one revolution makes it possible to evacuate it by an auxiliary orifice located beyond the comb, in the normal direction of rotation.

An earlier document, FR-A-2,127,685, had described a fairly similar device, in which, however, the counter knives were mounted on a common "anvil", which could pivot relative to the hopper-support around an axis parallel to that of the rotor. The advantage of this arrangement was that, if an object that was too strong appeared, the anvil, with the counter knives, moved away from the rotor to let this object pass. A return cylinder then returned the anvil to the normal position. This system was combined with a smooth shape, and curved towards the rotor, of the active face of the counter knives, intended to facilitate the evacuation of unbelievable objects, but which reduced the effectiveness of the apparatus for fragmenting the other objects.

The document US-A-4,917,310, which corresponds to the preamble of claim 1, describes an apparatus which differs from that of FR-A-2,127,685 in that the counter-knives are straight, but especially in that the counter-knives are movable independently of each other, and provided with return means which can be constituted by hydraulic jacks connected to a pneumatic accumulator. This provision brings some improvement in efficiency, but this is offset by an increase in the complication.

The document SU-A-697.186 describes a device for breaking blocks of reinforced concrete, in which these blocks, sliding on a flat support, are struck by a tool driven by a vertical reciprocating movement thanks to an eccentric system. Concrete seems to fall apart under repeated impact and release the reinforcing bars. There is nothing to suggest that these alternative movements can be effective in a device operating by shearing to fragment solid objects which may have a certain flexibility, such as waste, and to prevent jamming.

The present invention originates from research for the improvement of existing materials with regard to concerns their efficiency, reducing the loss of time in the presence of an object that is difficult to grind, as well as reducing the risk of jamming and improving the maintenance cost.

It was unexpectedly found that significant improvements were obtained if the counter knives were individually put into forced vibration.

• un support en forme de caisson, avec au moins une ouverture d'admission en haut et une ouverture de sortie en bas, ce support définissant un passage vertical,
• un rotor monté dans le support de façon à pouvoir tourner sur un axe sensiblement horizontal sans pouvoir se déplacer le long de cet axe, ce rotor portant au moins un couteau qui s'écarte de l'axe,
• au moins deux contre-couteaux faisant saillie en direction de l'axe du rotor, le couteau du rotor passant entre les contre-couteaux pendant sa rotation, chacun des contre-couteaux présentant une surface active tournée vers le rotor et étant mobile sur le support indépendamment des autres, de telle façon que sa surface active peut être déplacée en s'éloignant du rotor, des moyens de rappel étant prévus pour ramener lesdites surfaces actives dans une position normale, fixée à l'avance, les moyens de rappel d'un contre-couteau étant indépendants de ceux des autres contre-couteaux,
     cet appareil comprenant des moyens pour mettre les contre-couteaux en oscillation forcée.

Consequently, the invention provides an apparatus for fragmenting solid objects, comprising:

• a box-shaped support, with at least one inlet opening at the top and one outlet opening at the bottom, this support defining a vertical passage,
• a rotor mounted in the support so as to be able to rotate on a substantially horizontal axis without being able to move along this axis, this rotor carrying at least one knife which deviates from the axis,
• at least two counter knives projecting towards the rotor axis, the rotor knife passing between the counter knives during its rotation, each of the counter knives having an active surface facing the rotor and being movable on the support independently of the others, so that its active surface can be moved away from the rotor, return means being provided to return said active surfaces to a normal position, fixed in advance, the return means of a counter knife being independent of those of other counter knives,
  this apparatus comprising means for putting the counter knives in forced oscillation.

According to an advantageous embodiment, when the return means is a fluid cylinder, the device is equipped with means for vibrating the fluid contained in the fluid cylinder, this cylinder then constituting both a return means and a setting means in vibration of the counter knife.

• il est prévu des moyens pour régler l'amplitude des oscillations,
• l'amplitude des oscillations est limitée par une masse d'élastomère ou un ou plusieurs ressorts,
• les contre-couteaux sont montés pour pivoter sur un arbre parallèle à l'axe du rotor, cet arbre de pivotement est placé à faible distance du centre de gravité de chaque contre-couteau, tout en étant en dehors du volume balayé par les couteaux du rotor,
• les contre-couteaux sont montés pour pivoter sur un arbre parallèle à l'axe du rotor, de telle façon qu'au repos, un plan passant par les axes dudit arbre et du rotor passe à peu près au milieu de la surface active de chaque rotor.

In other interesting ways:

• means are provided for adjusting the amplitude of the oscillations,
• the amplitude of the oscillations is limited by a mass of elastomer or one or more springs,
• the counter knives are mounted to pivot on a shaft parallel to the axis of the rotor, this pivot shaft is placed a short distance from the center of gravity of each counter knife, while being outside the volume swept by the knives of the rotor,
• the counter knives are mounted to pivot on a shaft parallel to the axis of the rotor, so that at rest, a plane passing through the axes of said shaft and of the rotor passes approximately in the middle of the active surface of each rotor.

It has also been established that the structure of the invention lends itself to obtaining structures which are easy to dismantle, the cost of use of which can be lowered.

According to the preferred embodiments indicated above, a counter knife is carried by a pivot mounted in a fixed position relative to the support and parallel to the axis of the rotor. One can however conceive other realizations. For example, the counter-knives can be guided on straight or curved slides, or else return means, formed in particular of springs or blocks of elastomer, could constitute by themselves the guide means.

As return means, in addition to the metal springs or elastomer blocks of which we have just spoken, it is also possible to provide fluid cylinders. These can be simplified, for example consisting of a projection integral with the counter knife and penetrating into a suitable cavity of the support.

Advantageously, the normal position, fixed in advance, of a counter knife is defined by a stop against which the counter knife is pushed by the return means.

It will be observed that, if the apparatus comprises several rotors, the counter knives may be common to these rotors, with an active face facing each of them.

Advantageously, the active surface of the counter knives has a plurality of teeth capable of retaining an object in the process of fragmentation, to facilitate its shearing by a rotor knife, passing between two adjacent counter knives.

This particularity has been described in FR-A-2,254,371. In an apparatus according to the invention, its efficiency is appreciably improved thanks to the mobility of the knives.

Advantageously, this feature is combined here with a shape of the active surface of the counter knife such that the tops of the teeth are located on a curve whose concavity is turned towards the axis of the rotor.

The exact optimal shape of the active surface of a counter knife must be determined experimentally. It will even appear to non-specialists, that this shape: size and orientation of the teeth, curvature of the entire surface, etc. is unlikely to be the same for the fragmentation of parts made of flexible plastic material reinforced with fibers. or glass bottles, for example.

Provision may also be made for the rotor blade (s) to have an active surface comprising teeth.

We will now describe two particular embodiments of the invention which have the effect of reducing the costs of using the device.

It has been found, with the use of devices according to the prior art, that the counter knives situated in the central zone wear out faster than the others. When they have reached a wear such that their efficiency is reduced, the whole of the box support must be changed.

The invention brings an appreciable gain if it is provided that the knife holders are mounted separately from each other in a removable manner, by being threaded on a common holding piece consisting of a bar parallel to the axis of the rotor, and, advantageously, that the knife holders are mounted separately from each other in a removable manner, by being threaded on a common holding piece consisting of a bar parallel to the axis of the tree.

It is thus possible to replace only the worn or damaged counter knives, or to swap them with those of the lateral regions, less worn, etc.

Advantageously, for a similar purpose, there are provided several knives threaded on the rotor separately from each other, without possible rotation relative to the rotor, and advantageously interchangeable with one another.

The invention will now be described in more detail with the aid of a practical example, illustrated with the aid of the drawings, among which:

Figure 1 is a simplified overview, in exploded perspective, of the crusher.

Figure 2 is a section along line II-II of Figure 1.

FIG. 3 is a detail view illustrating a variant of the embodiment of FIG. 2.

Figure 4 is a detail view illustrating a variant of the rotor.

The apparatus described by way of example comprises a support 1, consisting of two side panels 2, 3, vertical in the whole, connected together by two vertical plates with ends 4, 5. The assembly thus defines a passage vertical, generally rectangular in shape. Inside this passage extends a horizontal rotor shaft 6, mounted for rotation on bearings 7, 8, carried by the end plates 4, 5. One of the end plates 5 further carries a motor drive 9 of the rotor.

One of the side panels 3 has a vertical surface in the direction of the rotor, while the other panel 2 has an inclined upper part 10, which gives a hopper shape to the interior passage of the support.

A pivot 12, parallel to the axis of the rotor 6, is mounted in holes provided in the end plates 4, 5. Only one of these holes, 12A, is shown in FIG. 1. The pivot 12 can slide at through these holes, for disassembly. It is located towards the lower part of the side panel 2, below the inclined part 10, without projecting into the interior passage of the support. It can be provided that the pivot 12 is immobilized in rotation on its axis, or that it can pivot on itself.

The rotor 6 carries a series of knives 13, which are constituted as a thick plate, cut in the general shape of an S, with two active faces whose concavity is turned forward in the direction of rotation symbolized by the arrow 14. L he end of each active face constitutes a tooth directed towards the front.

FIG. 4 shows a variant where the active face of the rotor 13 has a plurality of teeth 13A.

The knives are mounted on the rotor, which passes through them in their central part, without possible rotation. For this, as shown in Figure 2, the rotor has a hexagonal section, as well as the central bore of the knife. This allows the use of identical knives, offset from each other by a sixth of a turn. Of course, one can give a shape, for example grooved, to the rotor, and a shape corresponding to the bore of the knives.

The counter knives 15 are interposed between the knives 13. Each counter knife 15 is mainly constituted as a plate of generally triangular shape. It will be observed that, in the example described, the knives and counter-knives are constituted as plates with edges parallel and perpendicular to the axis of the rotor. This provision, which facilitates their obtaining, is not imperative, one can conceive, for example, that the knives decrease in thickness by deviating from the axis of the rotor, or vice versa, and the counter knives have a section adapted to keep constant the axial interval between a knife and the adjacent counter knife.

The active face 16 of the counter knife has a concavity facing upwards and towards the axis of the rotor. It has teeth 17, the shape of which is not given with precision, since it closely depends on the nature of the objects to be treated. It will however be observed that these teeth advantageously have a flank turned opposite to the direction of rotation 14 of the rotor, and which makes, with the direction of the objects which strike it, an angle close to 90 °, while the opposite flank of each tooth is on the contrary close to a parallel to the path of the objects entrained by the knives 13. A second side 18 of each triangular plate constituting a counter-knife 15 carries a sleeve 19 directed parallel to the axis of the rotor, and which is crossed by the fixed pivot 12, while allowing the pivoting of the counter knife around this shaft. The connection between the sleeve 19 and the counter knife 15 is ensured by two spacer plates 20, parallel to the plate 15, integral with the latter, and offset with respect to the latter in the axial direction.

At rest, the counter knife extends from the vicinity of the lower edge of the inclined portion 10 of the side panel 2 to the vicinity of the rotor 6. It deviates a little from the latter under the thrust of an object to fragment.

The thickness of the plates 20, and / or the length of the sleeves 19 are calculated to ensure the desired spacing between two adjacent counter knives.

This spacing is equal to the thickness of a knife 13, increased by twice the axial clearance provided between a knife and the adjacent counter knife. It will be noted that spacer sleeves 19A are provided, in a similar manner between the knives 13, to establish between them a spacing equal to the thickness of a counter knife, increased by twice the value of the axial clearance provided.

The thickness of the knives and the counter knives, as well as the axial clearances, and therefore the spacing between the knives and the successive counter knives, are adaptable according to the nature of the material of the objects to be ground, as well as the shape, dimensions and granulometry both of these objects and of the products that one wishes to obtain.

The plates 20 also carry an arm 21, which extends upwards parallel to the side 18, and the extension of which passes substantially through the axis of the pivot 12. The arm 21 carries a stop 22, perpendicular to the arm 21, and whose axis is in the plane of the counter knife 15. This stop 22 enters a closed bottom shell 23, which is fixed to the inclined part 10 of the side panel 2. A mass of elastomer 24 is interposed between the stop 22 and a support plate 25 located in the vicinity of the bottom of the shell 23. An adjustment screw 26 makes it possible to move the support plate 25 more or less away from the bottom of the shell.

Alternatively, the adjusting screw 26 is mounted in the arm 21, to act on the stop 22. This arrangement allows easier access to the screw 21. In addition, the support plate 25 can then be removed, the mass of elastomer 22 then coming to bear against the bottom of the shell 23.

It will be appreciated that a force exerted on the counter knife and resulting from the thrust of an object driven in the direction of the arrow 14 by a knife 13 tends to pivot the counter knife around the pivot 12, and by Consequently, the mass of elastomer 24 is crushed. The latter then develops a restoring torque, and the successive shocks of the objects to be treated on the counter-knife put the latter in a state of vibratory oscillations which is then damped.

By actuating the adjusting screw 26, the amplitude of the oscillations can be varied. The frequency of this can be modified, at equal amplitude, by changing the mass of elastomer 24.

A stop 27 limits the amplitude of the pivoting in the opposite direction of the counter knife, it prevents the latter from coming into contact with the rotor and defines its normal position.

It will be noted that it is possible to replace the mass of elastomer 24 by one or more springs, for example a stack of Belleville washers.

According to a variant illustrated in FIG. 3, the arm 21 carries a projection 30, forming a piston, which penetrates into a cylinder 31, connected to a vibratory source 32 of pressurized fluid, such as oil, and to an accumulator of gas pressure 33. The fluid keeps the counter knife in a state of forced oscillation, while when an object to be fragmented rotates the counter knife on the pivot 12, the presence of the accumulator 33 causes the cylinder 31 acts as an elastic reminder.

An individual accumulator is provided for each counter knife, so that each of these is subjected to its own oscillatory regime. It will be noted in this regard that document US-A-4,917,310 does not provide a specific accumulator for each counter knife.

In the arrangement shown, the return means 20 to 26, 30, 31 are located before the pivot 12, in the direction of rotation of the rotor 13, indicated by the arrow 14. Those skilled in the art will understand that other arrangements are possible. It suffices that the return means are arranged to oppose a pivoting of the counter-knife resulting from the passage of an object to be ground.

• le centre de gravité G du porte-couteau 15 est à une distance aussi faible que possible du pivot 12, compte tenu du fait que ce pivot doit être extérieur au volume balayé par les couteaux 13 du rotor.
• le plan qui contient les axes du pivot 12 et du rotor 6, qui est symbolisé par la ligne A-A de la figure 2, passe à peu près au milieu de la surface active 16 du contre-couteau.

However, the arrangement shown has the following advantageous features:

• the center of gravity G of the knife holder 15 is as small as possible from the pivot 12, taking into account the fact that this pivot must be outside the volume swept by the blades 13 of the rotor.
• the plane which contains the axes of the pivot 12 and of the rotor 6, which is symbolized by the line AA in FIG. 2, passes approximately in the middle of the active surface 16 of the counter knife.

These two features combine to provide a very solid unit, at equal weight, with reduced inertia in the case of forced oscillation, and thanks to which the moments of the couples created by the friction and shocks caused by the objects to be fragmented are balanced. the best.

If it is desired to replace a counter knife with another, it suffices to slide the pivot 12 through the bore 12A of the plate 4, for example by introducing a temporary holding rod in the corresponding bore of the plate 5. When the the end of the pivot 12 has just passed the counter-knife that is to be replaced, it suffices to move the provisional retaining rod back by a length corresponding to the length of the sleeve 19 or to the distance between the external faces of the plates 20. The counter knife is then released and can be replaced. Of course, it is also possible to slide the pivot 12 through the hole in the plate 5.

It has been observed that, with the apparatus just described, when an object refuses to allow itself to be fragmented, if the rotor is turned in the opposite direction by only about a quarter of a turn, before resuming the normal rotation, it is very common to obtain a correct fragmentation. This is attributed to the fact that, due to the vibration of the counter knives, the object which is difficult to grind comes, after this maneuver, into contact with a counter knife in a different arrangement, which is sufficient to obtain good shearing. This avoids rejecting the unground object by a much larger reverse rotation, as is done in prior practice; This eliminates both wasted time and rejects of unusable unmilled products.

Experience has shown that, by comparison with a conventional mill of the type described in FR-A-2,254,371, the hourly throughputs, with an apparatus of the type described here, are multiplied by 2 to 3. In addition, the granulomeries obtained are much more homogeneous, which facilitates recycling, or makes it possible in cases where the too great dispersion of dimensions made it economically unacceptable with the devices of the prior art.

Claims (15)

Apparatus for the fragmentation of solid objects, comprising: a support (1) in the form of a box, with at least one inlet opening at the top and one outlet opening at the bottom, this support defining a vertical passage, a rotor (6) mounted in the support so as to be able to rotate on a substantially horizontal axis without being able to move along this axis, this rotor carrying at least one knife (13) which deviates from the axis, - at least two counter knives (15) projecting in the direction of the rotor axis, the rotor knife passing between the counter knives during its rotation, each of the counter knives having an active surface (16) facing the rotor and being movable on the support independently of the others, so that its active surface (16) can be moved away from the rotor, return means (22-26, 30-32) being provided to bring said surfaces active in a normal position, fixed in advance, the return means of a counter knife being independent of those of the other counter knives, characterized in that it comprises means (30 to 32) for putting the counter knives in forced oscillation. Apparatus according to claim 1, in which the means for returning a knife comprises a fluid cylinder (30, 31), characterized in that it is equipped with means (32) for vibrating the fluid contained in the fluid cylinder (30, 31), this jack then constituting both a return means and a means for vibrating the counter knife. Apparatus according to one of claims 1 or 2, characterized in that means (26) are provided for adjusting the amplitude of the oscillations. Apparatus according to claim 3, characterized in that the amplitude of the oscillations is limited by a mass of elastomer (24) or one or more springs. Apparatus according to one of Claims 1 to 4, in which the counter knives are mounted to pivot on a shaft parallel to the axis of the rotor, characterized in that this pivoting shaft (12) is placed at a short distance from the center of gravity of each counter knife (15), while being outside the volume swept by the blades of the rotor. Apparatus according to one of claims 1 to 5, in which the counter knives are mounted to pivot on a shaft (12) parallel to the axis of the rotor, characterized in that at rest, a plane passing through the axes of said axis shaft and rotor (6) passes approximately in the middle of the active surface of each rotor. Apparatus according to one of claims 1 to 6, characterized in that the active face of the counter knife has a plurality of teeth (17) capable of retaining an object during fragmentation. Apparatus according to claim 7, characterized in that the tops of the teeth (17) are located on a curve whose concavity is turned towards the axis of the rotor. Apparatus according to claim 7 or 8, characterized in that the teeth of the counter knife have a flank turned opposite to the direction of rotation (14) of the rotor, and which, with the direction of the objects which strike it, an angle close to 90 °, while the opposite flank of each tooth is on the contrary close to a parallel to the trajectory of the objects entrained by the knives (13). Apparatus according to one of claims 1 to 9, characterized in that the knife (s) (13) of the rotor (6) have an active surface comprising a plurality of teeth. Apparatus according to one of Claims 1 to 10, characterized in that the counter-knives (15) are mounted separately from one another in a removable manner, by being threaded on a common holding piece consisting of a bar (12) parallel to the axis of the rotor (6). Apparatus according to claim 11, characterized in that the counter knives (15) are interchangeable with each other. Apparatus according to claim 10 or 11, characterized in that the bar is mounted in holes (12A) in the walls of the support, and can slide axially in these holes for dismantling the counter knives. Apparatus according to one of claims 1 to 13, characterized in that the knives (13) are mounted separately from each other in a removable manner, being threaded, without possible rotation, on the rotor. Apparatus according to claim 14, characterized in that the knives (13) are interchangeable with each other.

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