EP3132902A1 - Device for cutting solid materials - Google Patents

Abstract

The invention relates to a device for cutting solid materials, comprising at least two helical turns, which are arranged so that they rotate about a common axis of rotation, are arranged in opposite directions to each other in their direction of action, and that a cutting movement between the helical turns takes place.

Description

The invention relates to a device for cutting solid materials according to the preamble of patent claim 1.

State of the art

In addition to drum and disc chippers, slicers offer an additional technical solution for shredding solid materials (mainly logs and branches). Screw chippers are mainly used for the production of coarser clippings as a drum and disc chipper.

Conventionally, screw chippers are made in two conical and cylindrical screw designs. In conical worm design, the material is fed axially below the worm shaft to the smaller diameter worm. Due to the rotation of the conical shape of the screw about the axis, the material is pressed against a radial counter-blade and a lateral support, pulled in and sheared off by the decreasing distance of the counter-blade to the screw. The material must slide under full pressure of the cutting force along the counter-blade and the support. A correspondingly high power requirement and a very high storage stability of the screw are necessary. The shredded material is transported axially through the rotating screw flight to the end of the screw where it is fed with various systems, e.g. Conveyor or throw blower applied. Since the shredded material is transported through the entire screw, it often comes in practice to block the winding.

In the case of a cylindrical worm design, the material is fed laterally at a defined angle to the axis of rotation of the worm. The rotation of the screw, the material is pressed against a laterally inclined counter blade and a support, fed and sheared. The material must slide under full pressure of the cutting force along the counter-blade and the support. A correspondingly high power requirement and a very high storage stability of the screw is needed. The comminuted material is transported by ejector in the screw winding radially out of the screw and discharged for example with a conveyor belt.

Both systems, in addition to the problem of high power consumption and the need for high storage stability nor the problem that, in particular, the end of the supplied material and branches can be cross in the screw winding and are no longer crushed to the full extent. In addition, the material is stored at e.g. no longer reliably sheared off by resharpening gap between screw winding and counter blade, which also leads to larger Schnittgutstücken. These can be used in the further use of the cuttings e.g. In automatic firing systems often lead to disturbances such as clogging of feed units, etc. Therefore, coarse chippings so far found hardly used in practice in small combustion plants.

Examples of screw chippers according to the prior art are in German Utility Model DE 202011004698 U1 and the European Patent Number EP 000001872921 B1 described.

Therefore, it is an object of this invention to provide an apparatus for crushing solid materials, in which the material with low power requirement is reliably crushed, whereby the material is automatically drawn in by the cutting movement and the structure of the crop can be influenced.

This object is achieved by the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

According to the invention, a device for cutting solid materials, comprising at least two spiral-shaped windings which are arranged such that they rotate about a common axis of rotation, are arranged counter to one another in their effective direction in such a way that a cutting movement takes place between the spiral-shaped windings.

A counter blade which is fixed as in prior art systems and on which the material must slide along under full cutting force is therefore not required. The force required to cut the material is significantly lower.

In a preferred embodiment, the helical windings are further arranged to each other such that the cutting force of each individual turn acts on the same axis of rotation and is received within the worm.

As a result, the main cutting force is not transmitted through the bearing of the screw. Only the torque of the screw, which acts when crushing the material on the support, must be absorbed by the storage of the screw.

In a further preferred embodiment, the helical windings are further arranged such that an angle of the direction of action of the first helical winding to the direction of action of the second helical winding between 30 ° and 180 ° is that the effective directions against each other that a supplied material by the cutting movement is pulled into the device. Preferably, the direction of action of the first helical winding is at an angle between -30 ° and + 60 ° to the axis of rotation, and the effective direction of the second helical winding at an angle between 30 ° and 160 ° to the axis of rotation, wherein the effective directions are opposite to each other.

The opposite arrangement of the windings ensures that the material is gripped from both sides. As a result, the material is reliably drawn in and crushed by one another at an angle of the cutting surfaces of less than 180 °. The addition of a collection system, for example by means of rollers, belts or the like is not necessary.

In a further preferred embodiment, at least one breakthrough is arranged on at least one helical winding. As a result, as the turns become larger, the shredded material can be dissipated through the opening (s) in the winding (s). This prevents clogging of the winding (s).

In a further preferred embodiment, at least one receptacle is arranged at a distance from at least one of the spiral-shaped windings. By this distance, the crushed material can be discharged from the screw.

In a further preferred embodiment, the device further comprises a support at a distance from at least one of the helical turns. This overlay can be arranged at a distance from the winding or turns such that the material to be shredded can be greater in thickness / diameter than the outer diameter of at least one turn. The unprocessed material in the case of one turn is then correspondingly comminuted by another turn. Smaller turns reduce the production costs of the turns and reduce the power requirement of the cutting process.

In a further preferred embodiment, a knife is arranged at least at one of the helical turns at the transition between the helical turns. The knife bridges the gap between the turns, which becomes larger, above all, by re-sharpening the turns. This reliably shears off the material.

In a further preferred embodiment, the angle between the cutting surfaces of the helical turns to each other between 90 ° and 200 °. At a smaller angle of the cutting surfaces to each other, the cut is more peeling, whereby the clippings receives a fan-like structure primarily in woody materials. At a larger angle of the cutting surfaces to each other, the cut is more cutting, whereby the cut material has massive pieces.

In a further preferred embodiment, the angle between the free surfaces of the helical turns is between 90 ° and 180 °. With a larger angle of the open spaces to each other, the feed speed of the material increases and the Schnittgutstücke be larger.

• Figuren 1a-1c jeweils eine Schneckenwindung gemäß unterschiedlichen Ausführungen.
• Fig. 2a-2b eine Schnittdarstellung einer Vorrichtung gemäß einer Ausführung der vorliegenden Erfindung.
• Fig. 3 eine Schnittdarstellung einer Vorrichtung gemäß einer weiteren Ausführung der vorliegenden Erfindung.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

• Figures 1a-1c one screw turn according to different versions.
• Fig. 2a-2b a sectional view of a device according to an embodiment of the present invention.
• Fig. 3 a sectional view of a device according to another embodiment of the present invention.

In the following description of the figures, the same elements or functions are provided with the same reference numerals.

The novel device for cutting solid materials is based on at least two screw windings, each having a cutting geometry and are arranged in opposite directions to each other in their direction of action, that the material is fed independently and thereby crushed. FIGS. 1a to 1c show various possibilities, such as individual screw windings can be performed. The essential feature of a screw is that at least one flank is spirally wound about an axis X, the so-called winding. In this case, the flank winds per revolution about a pitch P along the effective direction W. The in FIG. 1 A screw shown a turn 1 with effective direction W perpendicular to the axis of rotation X. The in FIG. 1b shown snail shows a turn 2 with effective direction W along or parallel to the axis of rotation X. In between, any directions of action are possible. In the Figure 1c shown snail shows, for example, a winding 3 with effective direction W of about 45 ° to the rotation axis X.

To perform a cutting work, the winding must have a cutting edge. This is achieved by the arrangement of the cutting surface 11 and free surface 12 at an angle a to each other. The angle a is usually between 20 ° and 90 °.

As a rule, the pitch P is constant, but it can also be variable in course. The effective direction W is usually linear, but can also be curved in course.

FIG. 2a shows a possible embodiment of how two windings 10 and 20 can be arranged to each other. In this case, the angle g of the direction of action W1 of the first turn 10 to the rotation axis X is between -30 ° and + 30 °, and the angle i of the effective direction W2 of the second turn 20 to the rotation axis X between 60 ° and 150 °. In a preferred variant, the direction of action W1 of the winding 10 is parallel to the axis of rotation X and the direction of action W2 of the winding 20 is perpendicular to the axis of rotation X. The effective directions W1 and W2 run in opposite directions. The material 4 to be processed, preferably wood, rests on a support 3 and is fed to the windings 10 and 20 at the pull-in angle c to the axis of rotation X. In an arrangement of the direction of action W1 of the winding 10 at an angle f between 30 ° and 180 ° to the direction of action W2 of the winding 20 is detected by the rotation of the windings 10 and 20 about the rotation axis X, the material 4 on both sides of the windings 10 and 20, independently retracted and crushed.

The comminution takes place completely between the two cutting turns 10 and 20. Thus, no counter cutting edge is necessary, on which the material 4 has to slide along full cutting pressure, only the support 3 must counteract the torque of the screw 100 comprising the turns 10 and 20. As a result, the cutting force required is significantly lower than with existing systems. In addition, the main cutting force within the screw 100 occurs and need not be absorbed by the bearing of the screw 100. The angle d of the cutting surfaces 11 of the respective turns 10 and 20 to each other influences the cutting behavior and thus the nature of the cut material and is preferably between 90 ° and 200 °. When cutting wood or materials of similar nature, the material is peeled at a smaller angle d more than cut and the cut gets a fan-like structure. With a larger angle d, ie when the angle is in the direction of 180 ° and larger, the peeling effect is reduced and more massive pieces are cut. In addition, the material 4 is cut by the turns 10 and 20 from both sides simultaneously toward the center. Especially with wood-like materials, this leads to less chipping due to the material structure and thus to less fines in the clippings.

The pitch P of the windings 10 and 20 in combination with the angle e of the open spaces 12 of the windings 10 and 20 to each other influence the feed rate of the material 4 and the size of the cut material.
With a larger pitch P, the feed speed of the material 4 increases and the pieces of cuttings become larger. The angle e is preferably between 90 ° and 180 °. With a larger angle e, the feed speed of the material 4 also increases and the pieces of cuttings become larger. The pitch P and the arrangement of the cutting surface 11 and free surface 12 to the respective direction of action W1 or W2 may be identical in both windings 10 and 20, but also different. This influences on the one hand the pull-in angle c of the material 4, on the other hand the resulting structure of the cut material.

In principle, the screw 100 with several turns may consist of one part or of several parts joined together with, for example, one turn each.

Some of the material shredded by the winding 10 falls radially out of the winding 10, in part it pushes the winding 10 axially through the winding 20.
The material shredded by the winding 20 conveys the winding 20 to the winding 10. The winding 10 additionally pushes the material through the winding 20. In addition, at least one breakthrough 9 may be present in the turn 20, whereby the hitherto resulting cut material is removed by the cutting movement. This additionally prevents clogging of the winding 20.

For removal of the cut material from the screw 100 is preferably between the winding 20 and the receptacle 6, a distance 8 and radially outwardly at least one opening necessary. This opening 8 with an opening can be produced, for example, by screwing or welding the winding 20 and receptacle 6 by means of spacer bolts 5 or the like.

A gap 7 between the windings 10 and 20, which possibly arises by re-sharpening the turns 10 and 20 or the cut surfaces 11 or 12, can be bridged with a knife (not shown) in order to ensure reliable shearing of the cut material.

In the FIG. 2b shown height h of the support 3 to the winding 10 may be zero or greater. If the height h is greater than zero, ie the support 3 lies below the winding 10, then the thickness or the diameter of the supplied material 4 can be greater than the outer diameter of the winding 10. A portion of the material 4 can pass above and below the winding 10 on the winding 10 over, but is then crushed by the winding 20.

FIG. 3 shows a further embodiment of how two windings 30 and 40 can be arranged to each other. In this case, the angle g of the effective direction W1 of the first turn 30 to the axis of rotation X is between 30 ° and 60 °, and the angle i of the effective direction W2 of the second turn 40 to the axis of rotation X is between 30 ° and 60 °. The effective directions W1 and W2 run in opposite directions. The material 4 rests on a support 3 and is supplied to the turns 30 and 40 at an angle c to the axis of rotation X. In an arrangement of the direction of action W1 of the winding 30 at an angle f between 30 ° and 180 ° to the direction of action W2 of the winding 40 is detected by the rotation of the windings 30 and 40 about the rotation axis X, the material 4 on both sides of the windings 30 and 40, independently retracted and crushed.
The comminution takes place between the two intersecting turns 30 and 40. Thus, no counter-blade is necessary, on which the material 4 must slide along full cutting pressure, only the support 3 must counteract the torque of the worm 30 and 40 comprising the screw 100. As a result, the cutting force required is significantly lower than with existing systems. In addition, the main cutting force within the screw 100 occurs and need not be absorbed by the bearing of the screw 100. The angle d of the cutting surfaces 11 of the respective turns 30 and 40 to each other influences the cutting behavior and thus the quality of the cut material and is preferably between 90 ° and 200 °. When cutting wood or materials of similar nature, the material is peeled at a smaller angle d more than cut and the cut gets a fan-like structure. With a larger angle d, ie when the angle is in the direction of 180 ° and larger, the peeling effect is reduced and more massive pieces are cut. In addition, the material 4 is cut by the turns 30 and 40 from both sides simultaneously toward the center.

Especially with wood-like materials, this leads to less chipping due to the material structure and thus to less fines in the clippings.

The pitch P of the turns 30 and 40 in combination with the angle e of the open spaces 12 of the turns 30 and 40 to each other influence the feed rate of the material 4 and the size of the cut material. With a larger pitch P, the feed speed of the material 4 increases and the pieces of cuttings become larger. The angle e is preferably between 90 ° and 180 °. With a larger angle e, the feed speed of the material 4 also increases and the pieces of cuttings become larger. The pitch P and the arrangement of the cutting surface 11 and free surface 12 to the respective effective direction W1 or W2 can be identical, but also different in both windings 30 and 40. This influences on the one hand the pull-in angle c of the material 4, on the other hand the resulting structure of the cut material.

In principle, the screw 100 with several turns may consist of one part or of several parts joined together with, for example, one turn each.

The material 4 shredded by the windings 30 and 40 partially falls radially out of the turns 30 and 40, in part pushing the turns 30 and 40 along their directions of action W1 and W2 to the end of the turns 30 and 40 and falling through them Rotation through the cavity or the gap L out of the screw 100 out.

In addition, in each individual turn 30 and 40 at least one opening 9 through the turns 30 and / or 40 may be present, whereby the hitherto produced cut material is removed by the cutting movement. This additionally prevents clogging of the turns 30 and / or 40.

For removal of the cut material between the turns 30 and 40 and the respective receptacle 6 a distance 8 and radially to the outside at least one opening are necessary. This distance 8 with opening, for example, by screwing or welding of the winding 30 and / or 40 and the associated receptacle 6 means Spacer 5 or the like can be generated. A gap 7 between the turns 30 and 40, which possibly arises by re-sharpening the turns 30 and 40 or the cut surfaces 11 or 12, can be bridged with a knife (not shown) in order to ensure reliable shearing of the cut material.

In the FIGS. 2a and 3 shown arrangements of the windings 10 and 20 or 30 and 40 with respect to the axis of rotation are only examples and can over the in FIGS. 2a and 3 shown arrangements can be varied as desired. It is only important that the angles d and e lie in the above-described ranges.

Claims (10)

Apparatus for cutting solid materials comprising at least two helical windings (10, 20, 30, 40) arranged such that - turn them around a common axis of rotation (X), - In their effective direction (W1, W2) are arranged in opposite directions to each other that a cutting movement between the helical turns (10, 20, 30, 40) takes place. The apparatus according to claim 1, wherein the helical turns (10, 20; 30, 40) are further arranged to each other such that the cutting force of each first turn (10; 30) and the cutting force of the further turns (20; 40) are the same Rotation axis (X) act, whereby the cutting force is absorbed within the screw (100). Apparatus according to claim 1 or 2, wherein the helical windings (10, 20; 30, 40) are further arranged to each other such that an angle (f) of the direction of action (W1) of the first helical winding (10; 30) to the direction of action (W2 ) of the second helical winding (20; 40) is between 30 ° and 180 °, that the effective directions (W1, W2) run against each other, that a fed material (4) is drawn by the cutting movement in the device. Apparatus according to claim 3, wherein the direction of action (W1) of the first helical turn (10; 30) is at an angle (g) between -30 ° and + 60 ° to the axis of rotation (X), and the direction of action (W2) of the second helical Winding (20; 40) at an angle (i) between 30 ° and 160 ° to the axis of rotation (X), and the directions of action (W1, W2) are opposite to each other. Device according to one of the preceding claims, wherein at least one passage (9) is arranged on at least one helical winding (10, 20, 30, 40). Device according to one of the preceding claims, wherein at least one receptacle (6) at a distance (8) to at least one of the spiral-shaped windings (10, 20, 30, 40) is arranged. Apparatus according to any one of the preceding claims, wherein the apparatus further comprises a support (3) at a distance (h) from at least one of the helical turns (10, 20, 30, 40). Device according to one of the preceding claims, wherein at least one of the helical windings (10, 20, 30, 40) at the transition (7) between the helical turns (10, 20, 30, 40), a knife is arranged. Device according to one of the preceding claims, wherein an angle (d) between the cutting surfaces (11) of the helical turns (10, 20; 30, 40) is between 90 ° and 200 °. Device according to one of the preceding claims, wherein an angle (e) between the free surfaces (12) of the helical turns (10, 20; 30, 40) is between 90 ° and 180 °.

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