EP0420731A1 - Knifecrusher-shredder for refuse - Google Patents

Abstract

The subject of the present invention is a refuse grinder-cum-shredder with knives. The refuse grinder-cum-shredder comprising at least one shaft rotated about its axis and carrying several cutting members (1), the cutting members having at least two teeth (2) and being designed to cooperate with opposing cutting members, the shaft being mounted in a frame and provided with means whereby it can rotate at variable speeds about its axis, is characterised in that - each of the teeth (2) constitutes a projecting portion on the periphery of a central circular portion and is bounded by an end face (3), two side faces (4), and a front profile (5) and rear profile (6) relative to the direction of rotation, - the front profile (5) is indented in section to give each of the ridges (7) between said profile (5) and the side faces (4) a cutting angle, and - each of the ridges between the front profile (5) and an adjacent side face (4) runs along a concave curve so as to produce a scissor action with the opposing cutting member. <IMAGE>

Description

The present invention relates to a shredder shredder with knife waste.

The disposal and treatment of household and industrial waste raises increasing difficulties given the constant increase in the volume of waste to be treated. A step common to many treatment processes is the reduction of waste volume. This reduction in volume is generally obtained using hammer, blade or knife grinders.

Different types of blade mills have been developed. Some have a shaft provided at its periphery with uniformly spaced knives which exert a shearing effect with fixed knives carried by the crusher housing. Other shredders comprise two substantially horizontal parallel shafts, capable of rotating in opposite directions around their axis of rotation, the shafts carrying cutting members constituted by a circular part surrounding the shaft and a tooth projecting from the periphery of the circular part. In other devices, the cutting member comprises symmetrical hooked teeth so that the grinding can be carried out whatever the direction of rotation of the shaft.

Other mills, as described in French patent 2,508,344, have two pairs of shafts, each pair of shafts constituting a level of grinding. In the first level of grinding, two counter-rotating shafts each carry a series of serrated rings and a first grinding is carried out. In the second level, two counter-rotating trees each carry a series of serrated crowns; the number and speed of rotation of these crowns have been doubled, and the thickness of the crowns has been reduced by half compared to the first level.

The aim sought by the successive modifications proposed is to improve the performance of the mills. These include increasing the fineness of grinding, allowing heterogeneous feeding (in volume or in kind waste to be reduced) and to avoid yield losses due to the fact that certain pieces to be ground (cardboard boxes, metal cans, etc.) tend to wrap around knives. In the latter case, the parts are driven by the knives, they are crushed and they greatly reduce the performance of the knives.

The device according to the invention makes it possible to effectively remedy these drawbacks.

The subject of the present invention is a waste shredder-shredder comprising at least one shaft driven in rotation about its axis and carrying several cutting members (1) provided with at least two teeth (2) and intended to cooperate with members antagonistic cutting, the shaft being mounted in a frame and provided with means allowing its rotation at variable speeds around its axis. The frame comprises, at its upper part, a hopper-shaped feed device and, at its lower part, a device for collecting crushed and / or shredded waste. The crusher-shredder according to the invention is characterized in that
- each of the teeth (2) constitutes a projecting part on the periphery of a circular central part and is delimited by an end face (3), two lateral faces (4), a front profile (5) and a profile rear (6) relative to the direction of rotation,
- The front profile (5) is hollowed out to ensure a cutting angle at each of the edges (7) between said profile (5) and the side faces (4).
- Each of the edges between the front profile (5) and an adjacent side face (4) extends along a concave curve so as to cause shearing with the opposing cutting member.

The groove of the hollow cut profile may have a V-shaped section. A top angle of 90 ° will give a cutting angle of 45 °.

The profile groove may also have a U-shaped section. The cutting angle will then be more acute.

Any other section, and in particular a section in the form of a concave arc of a circle, can be used, provided that it provides a cutting angle suitable for the material to be ground. The existence of the groove as defined above in the front profile (5) of the teeth of the cutting member makes it possible to have two parallel cutting edges per tooth.

In a variant of the shredder-shredder according to the invention, the end face (3) is also hollow cut to ensure a cutting angle at each of the edges between said end face and the side faces, and a point with the intersection between each lateral face (4) with the end face and the hollow-cut profile.

The presence of such points makes it possible to pierce the material in order to entrain it and thus shred it.

The teeth of the cutting members may have two hollow-cut profiles. Such a configuration is particularly advantageous when the direction of rotation of the shaft carrying the cutting members can be reversed, the front profile becoming rear profile and vice versa. In this case, the two profiles of a tooth are preferably concave, the concavity of one of the profiles being the reverse of the concavity of the other profile.

Each cutting member has at least two teeth. It advantageously comprises from 3 to 6.

In a particularly advantageous embodiment, the teeth of a cutting member have different lengths. By tooth length is meant the distance between the end face of a tooth and the axis of the shaft carrying the knives. As the torque on the shaft is constant, by decreasing the radius of a tooth, the shearing force is increased. By varying the radii on a movable knife, the efficiency of the mill is increased. It also increases the empty volume between the knives, allowing waste to be better "swallowed" by the crusher avoiding the cylinder effect which occurs when the teeth are too close.

When the shredder-shredder according to the invention is intended to cut materials which are easily cut, such as than cardboard for example, it is advantageous to use cutting members in which the two points formed on each tooth at the intersection of the lateral faces (4), the end face (3) and the front profile ( 5) are truncated.

Indeed, the cardboard is cut very easily, but it tends not to be entrained. The flat surface of the truncated points drives the cardboard without piercing it towards the following teeth which shred it.

The cutting members are threaded on a shaft in a conventional manner. For example, spacer tubes having a width slightly greater than that of the teeth of the opposing cutting members are inserted between two knives. It is also possible to use cutting members comprising a hub projecting from a lateral face of the cutting member and having a length at least equal to the thickness of the opposing cutting member.

The arrangement of the cutting members on a shaft is such that these cutting members rotate between the opposing cutting members.

The movable cutting members are preferably made of high-strength cast steel. Their faces are adjusted so that the knife thickness is constant and the cutting edges sharpened.

In a particular embodiment of the invention, the shredder-shredder comprises a single shaft carrying several cutting members, the teeth of which cooperate with fixed opposing cutting members carried by the frame. The teeth of the movable cutting members are aligned with the spaces existing between the fixed opposing cutting members. The fixed opposing cutting members can be formed by cast steel teeth. In this case, the fixed teeth are delimited by an end face (3 ′), two lateral faces (4 ′), a front profile (5 ′) and a rear profile (6 ′) relative to the direction of rotation,
- the front profile (5 ′) is hollowed out to ensure a cutting angle at each of the edges (7 ′) between said front profile (5 ′) and the lateral faces (4 ′),
- the edge (7 ′) between the front profile (5 ′) and a lateral face (4 ′) extends along a concave curve,
- The front profile of the fixed teeth being opposite the front profile of the teeth of the movable cutting members. Objects which are gripped by the movable teeth during the rotation of the shaft then undergo shearing due to the interaction between fixed teeth and movable teeth. When the front profile and the rear profile of the teeth of the movable knives are hollowed out and have a concave shape, the shaft can rotate in either direction, which is useful when it is necessary to perform a clearing in reverse following a blockage.

In this variant, it is advantageous to separate the cutting members from the movable shaft by spacers which are not simply tubular, but by spacers which are made of cast steel of the same hardness as the movable cutting members and which are provided one or more teeth, the end face of which has a profile complementary to that of the fixed teeth of the opposing cutting members. The teeth of such spacers preferably have a cutting front face and a rear face. These spacers will help increase the capacity of the mill both in volume and effort.

The opposing cutting members can also be constituted by teeth obtained by flame cutting. In this case, the front face advantageously comprises transverse cutting generators. The rear face of each of the fixed teeth may also include transverse cutting generators. These cross cutting generators reduce the cutting effort. During grinding, materials such as cardboard or plastic are well shredded. For relatively thick and hard wood, the transverse cutting edges act as a wedge and the force of penetration into the wood is reduced, the force being exerted on a generator; the wood bursts and is immediately chipped. The same phenomenon will occur when reverse gear, if the rear faces of the fixed teeth also include these transverse cutting generators.

In another embodiment of the invention, the opposing cutting members are carried by a second shaft substantially parallel to the first, the speed of rotation of the second shaft being less than that of the first, the directions of rotation being opposite.

The opposing cutting members are provided with at least two teeth, each tooth (2˝) constituting a projecting part on the periphery of a central circular part and being delimited by an end face (3˝), two faces lateral (4˝), a front profile (5˝) and a rear profile (6˝) relative to the direction of rotation.

The cutting members of one of the shafts are aligned with the spaces between the cutting members of the other shaft. In this embodiment, the two shafts rotate in opposite directions with different speeds. The difference in rotational speed is determined according to the waste to be shredded. This difference in speed has the effect of cleaning the cutting members by differential sliding of the teeth relative to each other and of preventing two opposite teeth from finding themselves in the same relative position after a rotation of 360 ° around. of the shaft axis, thus facilitating shredding.

The teeth of the fastest tree attack the teeth of the slowest tree on the front profile of the latter, but also on their rear profile. It is therefore particularly advantageous to use, for the slow shaft, cutting members whose front and rear profiles, and the end profile are hollowed out, the front profile and the rear profile preferably having a concave shape. reverse each other. The shearing then occurs both on the front profile and on the rear profile of the teeth of the cutting members of the slowest shaft, clearly improving the performance of the device.

In a variant of the invention, the teeth of the two shafts have their two hollow-cut profiles. In that case, shearing takes place even if the direction of rotation of the two shafts is reversed.

• - la fig. 1 est une vue latérale d'un organe de coupe;
• - la fig. 2a est une vue en coupe suivant la ligne I-I de l'organe de coupe de la fig. 1;
• - la fig. 2b est une variante de la vue en coupe suivant I-I de la fig. 1;
• - la fig. 3 est une vue suivant la direction A de l'organe de coupe de la fig. 1;
• - la fig. 4 est une vue oblique d'une variante d'une extrémité de dent;
• - la fig. 5 est une vue latérale d'une variante d'organe de coupe;
• - la fig. 6a est une vue en coupe suivant II-II de la fig. 5;
• - la fig. 6b est une variante de la fig. 6a;
• - la fig. 7 est une vue de l'organe de coupe de la fig. 5 dans la direction B;
• - la fig. 8 est une vue en plan d'un broyeur à un arbre;
• - la fig. 9 est une vue en coupe suivant la ligne III-­III de la fig. 8;
• - la fig. 10 est une vue en plan d'un broyeur à deux arbres;
• - la fig. 11 est une vue en coupe suivant la ligne IV-IV de la fig. 10;
• - la fig. 12 est une vue oblique d'une variante d'une extrémité de dent d'organe de coupe mobile;
• - la fig. 13 est une vue latérale d'une variante d'une dent d'un organe de coupe antagoniste fixe;
• - la fig. 14 est une vue suivant C de la dent de la fig. 14;
• - la fig. 15 est une vue en perspective d'une variante d'une dent d'un organe de coupe antagoniste fixe;
• - la fig. 16 est une vue latérale d'une entretoise;
• - la fig. 17 est une vue en coupe selon la ligne V-V de la fig. 16.
• - la fig. 18 est une vue en coupe suivant a-a de la fig. 15.

Different embodiments of the invention are described below, with reference to the accompanying drawings, in which:

• - fig. 1 is a side view of a cutting member;
• - fig. 2a is a sectional view along line II of the cutting member of FIG. 1;
• - fig. 2b is a variant of the sectional view along II of FIG. 1;
• - fig. 3 is a view in direction A of the cutting member of FIG. 1;
• - fig. 4 is an oblique view of a variant of a tooth end;
• - fig. 5 is a side view of an alternative cutting member;
• - fig. 6a is a sectional view along II-II of FIG. 5;
• - fig. 6b is a variant of FIG. 6a;
• - fig. 7 is a view of the cutting member of FIG. 5 in direction B;
• - fig. 8 is a plan view of a single shaft crusher;
• - fig. 9 is a sectional view along line III-III of FIG. 8;
• - fig. 10 is a plan view of a two-shaft mill;
• - fig. 11 is a sectional view along the line IV-IV of FIG. 10;
• - fig. 12 is an oblique view of a variant of a tooth end of a movable cutting member;
• - fig. 13 is a side view of a variant of a tooth of a fixed opposing cutting member;
• - fig. 14 is a view along C of the tooth of FIG. 14;
• - fig. 15 is a perspective view of a variant of a tooth of a fixed opposing cutting member;
• - fig. 16 is a side view of a spacer;
• - fig. 17 is a sectional view along the line VV of FIG. 16.
• - fig. 18 is a sectional view along aa of FIG. 15.

Figure 1 shows a cutting member according to the invention. The cutter shown has three teeth. Each tooth (2) has a front profile (5), a rear profile (6), side faces (4), an end face (3). The front profile (5) is hollowed out so as to make the edges (7) between the front profile and each of the side faces sharp. The hollow (10) may have a V-shaped section, at 90 ° for example (fig. 2a). It can also have a U-shaped section, or in the shape of an arc of a circle (fig. 2b). Any shape making the edges (7) cutting can be suitable.

In a preferred variant, the end face is also recessed (fig. 4). The tooth then has two cutting edges (8) at the intersection of the lateral faces (4) and the end face (3). In addition, the angles (9) located at the intersection of the lateral faces (4), the front profile (5) and the end face (3) form points which allow a better attack of the pieces to be shredded. This form is particularly useful for shredding materials such as pallet waste, wood, plastic cans.

The shredder-shredder according to the invention can be a single-shaft shredder, as illustrated in FIG. 8. The cutting members (1) are mounted on a shaft (11) and separated by spacers (12). The shaft (10) is fixed to the frame (13). Fixed teeth (14) are mounted on the frame (13). They have a width slightly less than that of the spacers (12), so that during the rotation of the shaft (11), there is no friction between the teeth (2) of the movable cutting members (1) and the fixed teeth (14).

Figure 9 is a sectional view along line III-III of Figure 8. A chute (15) allows the supply of the mill. The movable cutting members (1) are mounted on the shaft (11) so that the front profile of the teeth (2) moves towards the attack profile of the fixed teeth (14) to achieve shearing. At the base of the chassis is the support (16) of the crusher allowing the introduction of a container (17) which will receive the crushed waste.

Alternatively, the fixed teeth (14) can be produced by flame cutting. An example of such teeth is shown in FIGS. 13 and 14. This tooth comprises, on the front face, generators of transverse cut (20) and, on the rear face, generators of transverse cut (21).

Fig. 15 shows another variant of fixed tooth (14). This tooth (14), made of cast steel and fixed to the frame (13), has two lateral faces (4 ′), a front profile (5 ′), a central part (27) opposite the spacer of the members cutting (1), and a rear profile (6 ′) hollowed out. In this case, the spacer of the cutting members (1) of the movable shaft advantageously comprises teeth as shown in FIGS. 16 and 17. The spacer consists of a central circular part (22) carrying for example three teeth (23). Each tooth has a cutting front profile (24) and a rear profile (25). The end face (26) has a shape complementary to that of the central part (27) of the fixed teeth, as shown in FIG. 17. If R is the radius of the teeth and r the radius of the spacer, the ratio of the force available at the hub to the force available at the end of the teeth is R / r.

Figure 10 shows a plan view of a two-shaft shredder (18) and (19). Figure 11 is a sectional view along line IV-IV of Figure 10. the shaft (19), which is the fastest, carries cutting members whose teeth have only the front profile hollowed out. These cutting members are in accordance with FIGS. 1 to 4. The shaft (18), which is the slowest, carries opposing cutting members (1 ′) whose teeth (2 ′) have their front and rear profiles cut in hollow. These cutting members are represented on the Figures 5 to 7. The front profile (5 ′) is hollowed out, in the same way as in the cutting member of FIG. 1. The rear profile (6 ′) is also hollowed out and fig. 6a shows a sectional view along line II-II. The rear profile also has, in this embodiment, two cutting edges (7 ′). The rear profile may be convex, as for the cutting member in FIG. 1. However, it is preferably concave as shown in FIG. 5, the concavity of the profile (6 ′) being the reverse of that of the profile (5 ′). Figure 6b shows a variant of the section along the axis II-II. The end face (3 ′) is preferably cut into a hollow so as to provide cut edges (8 ′) at the intersection of the end face with each of the side faces and of the points (9 ′) (fig. 7).

Fixed teeth (22), mounted on the chassis (13), cooperate with the teeth (2 ′) of the opposing cutting members (1 ′). The width of the spacer between the cutting members (1) is slightly greater than the width of the teeth (2 ′) on the one hand, of the fixed teeth (22) on the other hand.

A chute (15) allows the feed to the mill. The cutting members (1) are mounted on the shaft (19) so that the front profile (5) of the teeth (2) moves towards the front profile of the teeth (2 ′) of the cutting members (1 ′ ) mounted on the shaft (18).

At the base of the chassis, there is a support (not shown) which raises the frame and allows the introduction of the containers intended to receive the crushed waste.

Any material entrained by the knives of the slow shaft and not having been crushed during its passage between the teeth of the fast shaft and the teeth of the slow shaft is shredded during its passage between the teeth of the slow shaft and fixed teeth. Thus the efficiency of the shredder is twofold: the efficiency of the device and the fineness of the rejected waste are increased.

Claims (18)

1. Waste crusher-shredder comprising at least one shaft driven in rotation about its axis and carrying several cutting members (1) provided with at least two teeth (2) and intended to cooperate with opposing cutting members, said shaft being mounted in a frame and provided with means allowing its rotation at variable speeds about its axis, said frame comprising, at its upper part a supply device and, at its lower part, a device for collecting crushed waste and / or shredded, characterized in that
- each tooth (2) constitutes a projecting part on the periphery of a central circular part and is delimited by an end face (3), two lateral faces (4), a front profile (5) and a rear profile (6) relative to the direction of rotation,
the front profile (5) is hollowed out to ensure a cutting angle at each of the edges (7) between said front profile (5) and the side faces (4),
- Each of the edges (7) between the front profile (5) and a side face (4) extends along a concave curve. 2. Crusher-shredder according to claim 1, characterized in that the rear profile (6) is hollow cut to ensure a cutting angle at each of the edges between said rear profile (6) and the side faces (4). 3. Crusher-shredder according to any one of claims 1 to 2, characterized in that the end face (3) is hollowed out so as to form
- a cutting angle at each of the edges between said end face (3) and the lateral faces (4)
- a point at the intersection of each lateral face (4) with the end face (3) and the hollow front profile (5). 4. Crusher-shredder according to any one of claims 1 to 3, characterized in that the groove (10) of the front profile (5), and / or the rear profile (6) and / or the end face (3) hollow cut has a U-shaped, V-shaped or arcuate section. 5. Crusher-shredder according to any one of claims 1 to 4, characterized in that, in a cutting member, the distance between the end face of a tooth and the axis of the shaft varies from one tooth to another. 6. Crusher-shredder according to any one of claims 1 to 5, characterized in that the two points formed on each tooth at the intersection of the lateral faces (4), the end face (3) and the profile front (5) are truncated. 7. Crusher-shredder according to any one of claims 1 to 6, characterized in that it comprises a single shaft carrying several cutting members, the opposing cutting members being fixed and carried by the frame. 8. Crusher-shredder according to claim 7, characterized in that the opposing cutting members are cast steel teeth. 9. Crusher-shredder according to claim 8, characterized in that the teeth are delimited by two lateral faces (4 ′), a front profile (5 ′), a rear profile (6 ′) relative to the direction of rotation, and a central part (27) hollowed out. 10. Crusher-shredder according to claim 9, characterized in that the cutting members (1) of the movable shaft are separated by spacers provided with teeth whose end face has a profile complementary to that of the central part fixed teeth which is opposite the tree. 11. Crusher-shredder according to claim 9, characterized in that the teeth of the spacer have a front face and a cutting rear face. 12. Crusher-shredder according to claim 7, characterized in that the opposing cutting members are fixed teeth obtained by flame cutting. 13. Crusher-shredder according to claim 12, characterized in that the front face of each fixed tooth comprises generators of transverse cut. 14. Crusher-shredder according to claim 13, characterized in that the rear face of each fixed tooth has generators of transverse cut. 15. Crusher-shredder according to any one of claims 1 to 6, characterized in that the opposing cutting members are carried by a second shaft substantially parallel to the first, the speed of rotation of the second shaft being less than that of the first, the directions of rotation being opposite. 16. Crusher-shredder according to claim 15, characterized in that the opposing cutting members are provided with at least two teeth, each tooth (2˝) constituting a projecting part on the periphery of a central circular part and being delimited by an end face (3˝), two lateral faces (4˝), a front profile (5˝) and a rear profile (6˝) relative to the direction of rotation. 17. Crusher-shredder according to claim 15, characterized in that the front and rear faces of each tooth of the opposing cutting members extend along a concave curve. 18. Crusher-shredder according to any one of claims 16 or 17, characterized in that the front face and / or the rear face and / or the end face of each tooth of the opposing cutting members are hollow cut to form cutting edges with the side faces.

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