EP2599554A2 - Device for grinding dispensed products - Google Patents

Abstract

The device has a rotor (9) rotated at an axis within a housing and equipped with rotor knives (12) over a circumference. The rotor is loaded over a feed chute (25) formed by axle-parallel longitudinal walls (26) and transverse walls. The longitudinal walls comprise an aperture (27) in a circumference-near region of the rotor. The aperture is closed and released by a driven flap (28). A hydraulic drive for the flap comprises an actuator i.e. cylinder piston unit, and a hydraulic accumulator (36). The actuator is directly subjected with driving power from the hydraulic accumulator. The hydraulic accumulator is in a form of a bubble storage unit.

Description

The invention relates to a device for comminuting feed material according to the preamble of patent claim 1.

The field of application of the above-mentioned devices is in addition to the general comminution of solid pourable feedstock, inter alia, in the processing of waste or the recovery of recyclables in the course of recycling. Examples include plastics, rubber, wood, waste wood, paper, cardboard, textiles, collections from the dual system and the like called as possible feedstock. In the case of this type of feed material, it can not be ruled out that foreign matter contained therein can also be supplied to the comminution with the feed material. If these foreign bodies, due to their size and / or their material, are not accessible to comminution, there is the risk that components of the comminuting device will suffer considerable damage, with the result of repair-related machine downtimes. There is therefore a great deal of interest on the part of the generic device operators to take measures to avoid such damage.

Both the DE 28 19 611 as well as the DE 1 931 250 disclose a hammer mill for grinding garbage and similar waste, in which no or hardly crushable fractions of the waste upstream of the crushing zone are continuously separated from the feed. For this purpose, an opening is arranged in the region of the feed shaft close to the rotor, which opening is closed by means of a spring-loaded or weight-loaded flap. The non-crushable feed material is driven by the rotation of the crushing tools, pressed against the flap. Under the applied pressure, the flap opens, so that foreign bodies pass through the released opening into a subsequent shaft, which leads out of the device. It proves to be disadvantageous that the bias of the flap of the movement of the excreted Guts always counteracts and thus hinders a rapid removal of foreign bodies.

The EP 0 687 503 A1 describes a roller shredder with a rotor whose distributed over the circumference crushing elements are arranged on a gap and cooperate with radially engaging in the gaps stationary comb teeth. The Comb teeth sit non-rotatably on a common shaft, which is coupled with a hydraulic servo motor. By activating the servomotor, the shaft can be rotated about its axis and thus the comb teeth can be pivoted from a rest position into an operating position. To ensure escape of the comb teeth in the presence of foreign bodies, the supply lines to the actuators are depressurized, causing a pivoting of the comb teeth.

From the DE 299 07 584 U1 Finally, a granulator is known in which in the event that foreign matter in the feed material should make the interruption of the crushing process necessary, a complete housing side wall is hinged. In such a case open foreign body can be removed laterally of the crushing zone. The unfolding movement of the side wall is controlled by a limiting moment acting on the side wall. When the limit torque is exceeded, the locking of the housing side wall and a telescopic arrangement causes their Aufschwenkbewegung. However, the size and weight of the hinged wall part cause relatively high inertial forces to counteract the incipient folding movement. In addition, there is the causally predetermined time sequence of the release of the locking device and the subsequent unfolding of the side wall, which leads to a total considerable reaction time until the onset of folding movement and thus increases the risk that the device is damaged by the action of foreign bodies.

Against this background, the object of the invention is to eliminate as completely as possible the risk of damage to comminution devices due to the action of foreign bodies in the comminution process, or at least to further reduce it.

This object is achieved by a device having the features of patent claim 1.

Advantageous embodiments will be apparent from the dependent claims.

The invention is based on the recognition that it can not be prevented that foreign objects can reach the immediate area of the comminuting zone with the feed material, where they are clamped between the rotor and the stator. Is a Shredding the foreign body due to their size, shape and / or material composition is not possible, foreign bodies are often the cause of damage to the device. Here, especially in rigid machine designs, the kinetic energy inherent in the rotor is fed undiminished into the machine construction, where as a result an overstressing of machine parts occurs.

Against this background, the basic idea of the invention is to eliminate foreign bodies in the region in front of the comminution zone via an opening, even before they can cause damage. The opening can be closed with a flap, whereby the drive for opening and closing the flap takes place with the aid of a prestressed energy store. To perform the flap movement, it only requires a relaxation of the energy storage, which causes a sudden opening of the flap. In this way, extremely short reaction times from the detection of the foreign body to the opening of the flap can be achieved, which ensure a safe and reliable elimination of foreign bodies from the device even before they enter the crushing zone. The risk that devices are damaged by foreign body action is thereby significantly reduced compared to known devices.

According to an advantageous embodiment of the invention, a hydraulic drive for the flap is provided, wherein the biased energy storage is formed by a hydraulic accumulator. The biased in the hydraulic accumulator pressure medium, for example, a hydraulic oil, is in communication with a cylinder piston unit, the actuating piston is articulated to perform the pivoting movement of the flap. In this case, in an advantageous embodiment of the invention, the bias voltage can be generated by compressing a gas, for example nitrogen, or by elastic pre-deformation of a mechanical spring. This results in the advantage that with only a few machine parts high actuating forces for the flap can be achieved. By using a hydraulic drive, the wear on machine parts is minimized and, moreover, a high level of operational reliability is achieved.

In a first embodiment of the invention, the flap is associated with a single cylinder piston unit. However, in order to increase the actuating forces and actuating speed, the pivoting drive for the flaps can also be two cylinder-piston units include, which are articulated in each case at the opposite flap ends. In this case, each of the two cylinder piston units can be fed from a hydraulic accumulator assigned to it alone, or both cylinder piston units are supplied via a common hydraulic accumulator. With the resulting redundancy in terms of the cylinder piston units and / or hydraulic accumulator, the reliability of the device according to the invention can be significantly increased.

In order to ensure that the pivotal movement of the flap is carried out at a consistently high speed, the invention provides in an advantageous development that the volume of the hydraulic accumulator corresponds to 5 times to 10 times the stroke volume of the cylinder piston unit (s) assigned to it. In this way, it is ensured that the pressure drop in the hydraulic system, which accompanies the onset of relaxation of the energy accumulator, does not lead to a significant reduction in the pivoting speed.

The bias of the hydraulic accumulator is advantageously carried out with the aid of a gas which is preferably biased at 40 bar to 200 bar, most preferably at 100 bar to 200 bar. This makes it possible to extend the actuator piston of the cylinder piston unit with great force and constant high speed over the entire stroke.

In order to increase the pivoting movement of the flap further, the invention is provided in an advantageous development of the hydraulic oil flow cross-section of the hydraulic line at least as large as the pressurized cross-sectional area of the actuating piston, preferably at least twice as large. In this way, even low flow velocities of the hydraulic oil lead to disproportionately large stroke speeds of the actuating piston, which support a sudden opening of the flap. In this sense, suitable stroke velocities of the actuating piston are in a range of more than 0.5 m / s. Preferred are lifting speeds of at least 1 m / s, preferably at least 1.5 m / s and most preferably at least 2 m / s.

According to a particularly preferred embodiment of the invention, a stop is provided against which the lower longitudinal edge of the flap during the closing movement moves. The stop is displaceable in the radial direction with respect to the rotor axis, but at the same time fixed to the device with a defined retention force. If the defined retention force is exceeded, a movement of the stop begins against the closing movement of the flap. The causative force is exerted by the feed material, which, driven by the rotor, presses against the surface facing the feed chute at the stop. The movement of the stop initiates a minimum pivotal movement of the flap, which can serve as an additional signal for triggering the preloaded hydraulic drive and which contributes to further increasing the operational safety.

The invention will be explained in more detail with reference to an embodiment shown in the drawings, from which further features and advantages of the invention will be apparent.

Fig. 1

einen Querschnitt durch eine erfindungsgemäße Vorrichtung entlang der in Fig. 3 dargestellten Linie I - I,

Fig. 2

eine Ansicht auf die in Fig. 1 dargestellte Vorrichtung entlang der in Fig. 3 dargestellten Linie 11 - 11,

Fig. 3

einen Längsschnitt durch die in Fig. 1 dargestellte Vorrichtung entlang der dortigen Linie III - III, und

Fig. 4

einen Querschnitt durch den Bereich einer Statoreinrichtung in größerem Maßstab.

It shows

Fig. 1

a cross section through a device according to the invention along the in Fig. 3 illustrated line I - I,

Fig. 2

a view on the in Fig. 1 shown device along in Fig. 3 illustrated line 11-11,

Fig. 3

a longitudinal section through the in Fig. 1 shown device along the local line III - III, and

Fig. 4

a cross section through the area of a stator on a larger scale.

The in the Fig. 1 to 4 The apparatus shown has a substantially symmetrical structure based on a machine base frame with two plane-parallel transverse walls 1, which are connected in their lower corners by lower longitudinal beams 2 and in their upper corners of upper longitudinal members 3 with each other. The longitudinal walls 4 are formed over their entire surface by doors 5, which are pivotable about hinges 6 for opening and closing the housing and thus ensure accessibility to the interior of the device.

On the outside of the transverse walls 1, a bracket 7 is welded in each case for receiving shaft bearings 8. The shaft bearing 8 carry a rotor 9, which is essentially formed by a rotor drum 11, in the front side in each case a stub shaft 10 rotatably engages. The two stub shafts 10 extend with their free ends through openings in the transverse walls 1 to the shaft bearings 8. The rotor 9 is fitted over its circumference with a plurality of rotor tools 12, which are spaced apart both in the circumferential direction and in the axial direction. Each rotor tool 12 is mounted replaceably in a receptacle on the lateral surface of the rotor drum 11. As indicated by the arrow 45, the rotor 9 can be operated in both directions of rotation. The circle of the rotor tools 12 is indicated by reference numeral 46 ( FIG. 4 ).

The lower peripheral portion of the rotor 9 is surrounded by a screen web, which is formed in the present example of four sieve elements 13. Each sieve element 13 consists essentially of a portafilter 14, on which a perforated screen 15 is clamped. In cross-section, two sieve elements 13 extend in mirror image over approximately a quarter of the rotor circumference ( FIG. 1 ); longitudinally two sieve elements 13 follow each other axially ( FIG. 3 ).

For pivotal mounting of the screen elements 13 16 axle bearings 17 are arranged on the inside of the transverse wall 1 and on both sides of an intermediate wall, in which the filter holder 14 are rotatably mounted. With the help of the cylinder piston units 18 on the outside of the transverse walls 1, whose movable pistons act on the portafilter 14 via adjusting levers, the sieve elements 13 can each be pivoted downwards. With the doors 5 open access to the perforated screens 15 and the rotor 9 is thus ensured.

The upper longitudinal members 3 each serve for the stationary mounting of an axially parallel stator 48, their concrete structure under FIG. 4 is explained in more detail.

The supply of the feed material via a vertical feed chute 25, the longitudinal walls 26 in the vertical direction directly to the stator 48th connect. In the connection region to the stator devices 48, the longitudinal walls 26 each have an opening 27 which extends from the one transverse wall 1 to the opposite. The transverse walls of the feed chute 25 are reinforced with respect to the transverse walls 1 of the machine base frame and continue upwards beyond the rotor 9.

Each opening 27 is closed by a flap 28 which is mounted analogously to the screen elements 13 pivotally mounted in the transverse walls of the feed chute 25. The pivot axes 29 of the flaps 28 lie in the region of the upper longitudinal edge of a flap 28, where axial bearing pins 47 are provided for this purpose. To protect the connection gap between a movable flap 28 and the upwardly continuing rigid portion of the feed chute 25, the longitudinal walls 26 have on their inner side along their lower edge each a strip-shaped skirt 30 which overlaps the upper longitudinal edge of the flap 28. On the rear side of the flaps 28, which faces away from the rotor 9, a deflector plate 33 extends over its entire length and extends inclined towards its free edge in order to prevent accumulation of material in the swivel range of the flaps 28.

Especially from Fig. 2 shows the drive of the flaps 28 via cylinder piston units 34, the cylinders are connected to the outside of the transverse walls of the feed chute 25 each fixed to the machine housing, while the movable actuating piston are each hinged to a non-rotatably mounted on the drive pin of the flaps 28 lever 35. By extending the cylinder piston units 34, the pivotal movement of the flaps 28 is generated.

The hydraulic drive and the control for the pivotal movement of the flaps 28 are in Fig. 2 shown schematically. The core of the drive forms a hydraulic accumulator 36 in the form of a bladder accumulator, but which may also be formed by a piston or diaphragm accumulator. Inside the accumulator 36 is a bladder 37 made of a stretchable gas-tight material, which, as indicated by the arrow 49, can be filled with a compressible gas up to a predetermined pressure. For example, can be filled with a pressure of 40 bar to 200 bar in the bladder 37 for this purpose, which is strongly compressed. The pressure chamber 38 formed between the bubble 37 and memory 36, serves to store the pressure medium and is connected via the hydraulic lines 39 with the cylinder piston units 34. By means of valves 40, the flow through the hydraulic lines 39 can be regulated, wherein pressure sensors 41 monitor the pressure of the pressure medium in the cylinder piston units 34. The measured values of the pressure sensors 41 are transmitted via the data lines 44 to a higher-level data processing unit 43 which, if required, actuates the valves 40 via the lines 45 for setting a specific flow in the hydraulic lines 39. Further, the data processing unit 43 monitors by means of the pressure sensor 42, the pressure in the bladder 37. To control the gas supply 49 to the hydraulic accumulator 36.

Fig. 4 shows a partial cross section of the device in the region of the stator 48. The stator 48 includes a bar-shaped tool carrier 19 which extends in the longitudinal direction over the entire length of the rotor 9 and extends with its two ends beyond the transverse walls of the feed slot 25, where it removably attached is. With its underside of the tool carrier 19 rests on the upper longitudinal members 3 ( FIG. 1 ), while its upper side 51 is inclined towards the rotor 9 and thereby assumes an approximately radial aligned position. The tool carrier 19 has a transversely stepped upper side 51, wherein a stop 52 acting in the radial direction is formed by a height offset in the edge region.

The top 51 serves as a bearing surface for a plate-shaped stator 21, which may extend integrally over the entire axial length of the rotor 9 or is formed by a plurality of axially juxtaposed segments. The cooperating with the rotor tools 12 leading edge of the stator 21 is in the radial direction over the rotor 9 facing inside of the tool carrier 19 and depending on the type of application of the device may have a straight, wavy or zigzag course. In cross-section centrally arranged openings 54 serve to carry out clamping screws 23. Between the trailing edge of the stator 21 and the stop 52 a bearing strip 53 is arranged, which is loosely supported on the stop 52. On the bearing strip 53 act two axially spaced adjusting screws 24, of which in Fig. 4 only one is shown. The adjusting screws 24 extend into threaded bores which extend in the plane of the stator tool 21 from the outside of the tool carrier 19 to the bearing strip 53. By appropriately wide screwing the adjusting screws 24 in the Tool carrier 19, the position of the bearing bar 53 can be adjusted in the radial direction and thus the supernatant of the stator 21 on the inside of the tool carrier 19 and the gap width are set to the rotor tools 12.

The attachment of the stator 21 is carried out by means of a clamping plate 22 which rests with its underside on the top of the stator 21. The clamping force for the clamping attachment of the stator 21 is generated by clamping screws 23 which extend through the clamping plate 22 and the stator 21 in a threaded bore in the tool carrier 19. At the top of the clamping plate 22 in the region of the clamping screws 23 each have a surface recess 55 for receiving the screw head is arranged, which continues in the region of the screw shaft in the form of an elongated hole 56 to the underside of the clamping plate 22. The radial length of the elongated hole 56 in this case has a sufficiently large clearance relative to the screw shank in order not to hinder movements of the clamping plate 22 in the radial direction. Along the rotor 9 facing upper longitudinal edge of the clamping plate 22 extends a strip-shaped projection 32 which serves to form a pivotal movement 57 of the flap 28 limiting stop.

In the operating state, the relative position of the clamping plate 22 relative to the flap 28 and the tool carrier 19 such that the flap 28 sealingly abuts the shoulder 32 and the clamping plate 22 with its rotor 9 facing away from the longitudinal edge a clear distance from the stop 52 complies.

During operation of a device according to the invention, the feed material is fed to the rotor 9 via the feed chute 25, where it is first compressed between the outer circumference of the rotor 9 and the longitudinal wall 26 of the feed chute 25 before its comminution takes place in cooperation of the rotor knives 12 with the stator knives 21. If foreign bodies 50 which can not be comminuted in the feed material are also present as a result of the entrainment action of the rotor 9 in the region of the longitudinal wall 26 and are pressed there against the flap 28. If the foreign bodies 50 can not be comminuted owing to their size and / or material properties, the result is a disproportionate increase in pressure on the flap 28, which is registered by the pressure sensor 41 and reported to the data processing unit 43, where an adjustment takes place with a predetermined limit pressure. When exceeding the Limit pressure transmits the data processing unit 43, a control signal to the valves 40, which then release the flow cross-section of the hydraulic lines 39 abruptly. The hydraulic oil pressurized by the prestressed hydraulic accumulator 36 then escapes directly from the chamber 38 and actuates the relevant cylinder piston unit 34 via the lines 39. At the same time, the gas under pressure in the bladder 37 of the hydraulic accumulator 36 expands into the chamber 38 and provides it Way that the hydraulic oil is continuously pumped to the cylinder piston unit 34, resulting in a powerful and sudden opening of the flap 28. With the flap 28 open, foreign bodies 50 pass through the opening 27 out of the comminution area, even before damage can occur in the area of the stator blades 21.

Especially with smaller foreign bodies, it may turn out that they come past the flap 28 into the region of the clamping plate 22, where they exert a radial compressive force on the clamping plate 22. This pressure force counteracts the static friction force in the contact joint between clamping plate 22 and tool carrier 19, which is essentially dependent on the clamping force of the clamping screws 23 and the friction coefficients of the material pairing. If the pressure force exceeds the static frictional force, there is a radial deflection movement of the clamping plate 22, which initiates the pivoting movement 57 of the flap 28 via the projection 32. The pressure rise occurring in the cylinder piston units 34 is in turn registered by the sensors 41 and transmitted to the data processing unit 43, which then causes the opening of the flaps 28 in the manner described.

Claims (11)

Apparatus for comminuting feed material with a rotor (9) rotating about an axis within a housing, which is equipped with rotor tools (12) over its circumference and which has a feed chute (25) formed by axially parallel longitudinal walls (26) and transverse walls perpendicular thereto can be fed, wherein at least one longitudinal wall (26) in the region close to the rotor (9) has an opening (27) which can be closed and released by means of a driven flap (28), characterized in that the drive for the flap (28) comprises at least one actuator and a biased energy storage and the at least one actuator is directly acted upon by drive energy from the biased energy storage. Apparatus according to claim 1, characterized in that the drive is a hydraulic drive with at least one cylinder piston unit (34) as an actuator and at least one biased hydraulic accumulator (36) as energy storage. Apparatus according to claim 1 or 2, characterized in that the at least one energy store for generating the bias voltage comprises a mechanical spring or a compressible gas. Device according to one of claims 1 to 3, characterized in that the at least one energy storage is biased at 40 bar to 200 bar. Device according to one of claims 2 to 4, characterized in that the volume of a hydraulic accumulator (36) corresponds to the 5-fold to 10-fold displacement of its associated cylinder piston unit (34). Device according to one of claims 2 to 5, characterized in that the at least one hydraulic accumulator (36) by means of a hydraulic line (39) with its associated cylinder piston unit (34) is connected and the ratio of the flow cross-sectional area of the hydraulic line (39) to the pressurized cross-sectional area of Cylinder piston unit (34) is at least 1, preferably at least 2. Device according to one of claims 2 to 6, characterized in that the adjusting piston of the at least one cylinder piston unit (34) has a lifting speed of at least 0.5 m / s, preferably at least 1.0 m / s, most preferably at least 1.5 m / s has. Device according to one of claims 1 to 7, characterized in that the flap (28) on its the rotor (9) facing away from a deflector plate (33). Device according to one of claims 1 to 8, characterized by an automatic control with a sensor (41) for detecting the pressure on the closed flap (28) and an actuator (44) for activating the energy store upon reaching a predetermined limit pressure. Device according to one of claims 1 to 19, characterized in that the device has a stop (32) for the lower longitudinal edge of the flap (28) and the stop (32) is displaceable under load by the load in the radial direction against the stop direction. Apparatus according to claim 10, characterized in that the stop (32) of a projection (32) on the upper side of the clamping plate (22) is formed.

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