EP1616625B1 - Comminution device and method of operating the same - Google Patents

Abstract

The device has a housing (20) with a lockable feeding opening (3). A first outlet (4) is provided for a fine fraction (11) and a second outlet (5) for a rough fraction (12) or a mixture of rough and fine fractions. A chamber (21) is provided with a cutter and a classifier. A driver (7) for the cutter (6) is operable in a maximum capacity range above a no-load operation. A catch (30) has an air lock configuration for the feeding opening. An ejector (50) for the second outlet of the rough fraction and an electronic control (8) provides indirect drive power on the catch as well as the ejection mechanism, in which when cutting up the fraction material from the meal area is output, a classifier is operable and the rough fraction ejection is intermittently activated (50). During intervals, the drive power can be influenced such that it oscillates around a desired value within the maximum capacity range between a relative maximum and minimum values back and forth. An independent claim is included for a method of operating the device.

Description

The invention relates to a device for the mechanical comminution of a heterogeneous starting material according to the preamble of claim 1 and to a method for operating the comminution device. The feedstock, which is obtained for example as a product in a recycling process, in particular in the shredding of car wrecks, is a heterogeneous mixture containing fibers, textiles, foams, plastics, wood parts, paper, wires, electrical cables, other metals and / or other inorganic, especially mineral substances.

Out DE-A 15 07 557 is a continuously operated crushing device known.

Continuously operated comminution devices or comminuting devices can be used as comminution stages in one method, with comminution being able to be achieved by about a factor of 2 to 5 in each case. The residence time of a crop in a continuously operated device is usually too short for more efficient shredding to take place. In order to obtain a degree of comminution in which an end product with a defined fragment or particle size distribution, for example as fuel, can be used, a plurality of such comminution stages connected in series must therefore be provided.

A batch-type crushing device which has the features described in the preamble of claim 1, is out DE-A 196 00 482 known.

• solche Vorrichtungen müssen grösser sein;
• eine Zuführung des Einsatzguts in die Vorrichtung sowie Abführung der durch die Behandlung entstanden Produkte, die beispielsweise in Form einer Fein- und einer Grobfraktion vorliegen, muss getaktet durchgeführt werden;
• das Einsatzgut wird in Fragmente zerkleinert, deren Grössen über ein breites, wenig geeignetes Spektrum ("Kornverteilungskurve") verteilt sind;
• der Leistungsbedarf eines Antriebs für die Zerkleinerungsmaschine variiert oberhalb einer Leerlaufleistung über einen breiten Bereich, wobei Stromspitzen mit entsprechenden mechanischen Belastungen auftreten;
• für den grössten Teil der Produktionszeit ist die Maschine ungünstig ausgelastet, wodurch sich eine mittlere Durchsatzleistung ergibt, die relativ niedrig ist;
• eine Erwärmung bei der Bearbeitung des Einsatzguts hat eine Produkterhitzung zur Folge, die schwer kontrollierbar ist und die eine erhöhte Geruchsbelastung sowie Brand- und Explosionsgefahr mit sich bringt.

Shredding devices, which are batchwise (ie, batch or batch), work cycle machines, are a cheaper alternative, but have some disadvantages:

• such devices must be larger;
• a supply of the feedstock into the device and removal of the products resulting from the treatment, which are present for example in the form of a fine fraction and a coarse fraction, must be carried out in cycles;
• the feed is crushed into fragments whose sizes are over broad, poorly suited spectrum ("grain distribution curve") are distributed;
• the power requirement of a drive for the crusher varies above an idle power over a wide range, with current spikes with corresponding mechanical loads;
• for the most part of the production time, the machine is unfavorably utilized, resulting in a mean throughput which is relatively low;
• Heating during processing of the feedstock results in product heating which is difficult to control and which entails an increased odor load as well as a risk of fire and explosion.

The object of the invention is to provide a device for mechanical comminution of a heterogeneous starting material, which has improvements in terms of the disadvantages mentioned. This object is achieved by the defined in claim 1 crushing device.

• Ein Gehäuse mit a) einer verschliessbaren Einspeiseöffnung für das Einsatzgut, b) einer ersten Austrittsöffnung für eine Feinfraktion und c) einer zweiten Austrittsöffnung für eine Grobfraktion oder ein Gemisch von Grob- und Feinfraktion.
• Einen Mahlraum mit Zerkleinerungs- und Klassierungsmitteln.
• Einen Antrieb für die Zerkleinerungsmittel, der in einem maximalen Leistungsbereich oberhalb einer Leerlaufleistung betreibbar ist.
• Einen Verschlussmechanismus für die Einspeiseöffnung, der vorzugsweise als Schleuse ausgebildet ist.
• Einen Auswurfmechanismus für die zweite Austrittsöffnung, den Grobfraktionsauswurf.
• Eine elektronische Steuerung zum indirekten Beeinflussen der Antriebsleistung durch ein direktes Einwirken auf den eintrittseitigen Verschluss- sowie den austrittseitigen Auswurfmechanismus.

The device for the mechanical comminution of a heterogeneous starting material comprises the following components:

• A housing with a) a closable feed opening for the feed, b) a first outlet opening for a fine fraction and c) a second outlet opening for a coarse fraction or a mixture of coarse and fine fraction.
• A grinding room with crushing and classifying agents.
• A drive for the shredder, which is operable in a maximum power range above an idle power.
• A closure mechanism for the feed opening, which is preferably designed as a lock.
• An ejection mechanism for the second outlet, the coarse fraction ejection.
• An electronic control for indirectly influencing the drive power by a direct action on the inlet-side closure and the exit-side ejection mechanism.

In this device, the constituents of the fine fraction arising during the comminution of the feedstock are continuously discharged from the grinding chamber through the classifying means and the first exit opening. Of the Coarse fraction ejection is activated intermittently. At time intervals between cyclically recurring pauses, which may be reduced to timings, the drive power is influenced by a controlled metered feed of the feed so that it reciprocates by a setpoint within the maximum power range between a plurality of relative maximum and minimum values ,

The dependent claims 2 to 4 relate to advantageous embodiments of the inventive crushing device. Methods for operating this shredding device are each the subject matter of claims 5 to 10.

• aufgrund einer intermittierenden Zufuhr von Einsatzgut während eines Arbeitszyklus wird die mittlere Arbeitsleistung erhöht und somit die Nutzung der Zerkleinerungsvorrichtung verbessert;
• die Feinfraktion verlässt unmittelbar während des Zerkleinerns kontinuierlich die Maschine durch Klassierungsmittel, während die Grobfraktion unzerkleinert länger in der Maschine bleibt, wodurch gründlicher zerkleinert wird;
• das unzerkleinerte Grobmaterial wird periodisch ausgeworfen, wodurch eine übermässige Produkterhitzung sowie ein progressiver Leistungsanstieg ausbleibt.

The mentioned disadvantages of the continuously or batch operated devices are reduced in the inventive approach by a semi-continuous driving:

• due to an intermittent supply of feedstock during a work cycle, the average workload is increased, thus improving the utilization of the comminution device;
• the fine fraction immediately passes through the classifier during chopping, while the coarse fraction remains uncut in the machine for longer, thereby more thoroughly crushing;
• the uncut coarse material is ejected periodically, which eliminates excessive product heating and a progressive increase in output.

The procedure with partially continuous operation is advantageous in processes in which the degree of comminution must be high and a defined fragment size distribution is required. Although the throughput is lower than in a continuous operation, but a higher degree of comminution is achieved. Compared to the batchwise mode of operation, the throughput is increased considerably. In addition, the mechanical load of the crushing means (rotor, shaft and drive) is reduced; because individual large current peaks of the batch process are converted into a plurality of smaller current peaks. The machine and Product temperature is lower in the partially continuous mode of operation thanks to continuously added feedstock.

Fig. 1

eine teilkontinuierlich betreibbare Zerkleinerungsvorrichtung zum Durchführen des erfindungsgemässen Verfahrens,

Fig. 2

ein Diagramm für die Stromaufnahme der teilkontinuierlich betriebenen Zerkleinerungsvorrichtung,

Fig. 3

ein Diagramm mit Kornverteilungskurven für das erfindungsgemässe Verfahren und

Fig. 4

ein entsprechendes Diagramm für ein bekanntes kontinuierliches Verfahren.

The invention will be explained with reference to the drawings. Show it:

Fig. 1

a partially continuously operable crushing device for carrying out the method according to the invention,

Fig. 2

a diagram for the power consumption of the partially continuously operated crushing device,

Fig. 3

a diagram with grain distribution curves for the inventive method and

Fig. 4

a corresponding diagram for a known continuous process.

1. a) eine verschliessbare Einspeiseöffnung 3 für das Einsatzgut 10 (Pfeil 10),
2. b) eine erste Austrittsöffnung 4 für eine Feinfraktion 11 (Pfeile 11) und
3. c) eine zweite Austrittsöffnung 5 für eine Grobfraktion 12 oder einem Gemisch von Grob- und Feinfraktion.

In the Fig. 1 Crushing device 1 shown comprises a central part 2, which is referred to as impact reactor. Such, already from the DE-A-196 00 482 known reactor 2 is a machine with a housing 20 and the following features. The reactor housing 20 has

1. a) a closable feed opening 3 for the material 10 (arrow 10),
2. b) a first outlet opening 4 for a fine fraction 11 (arrows 11) and
3. c) a second outlet opening 5 for a coarse fraction 12 or a mixture of coarse and fine fraction.

The upper and lower closed or closable reactor housing 20 includes a cylindrical grinding chamber 21, are arranged in the crushing means 6 in the form of a rotor (wherein a plurality of rotors may be advantageous). A drive 7 for the rotor 6 is operable in a maximum power range above an idle power. The rotor 6 of the impact reactor 2, which is connected to the arranged under the grinding chamber 21 drive 7, carries hammer elements, which are not shown. The feedstock 10, which can be fed into the grinding chamber 21 by a closure mechanism 30 to the feed opening 3, namely a vertical lock 31 and / or by a screw conveyor 32, is there from the rotating rotor 6 detected. A crushing is done by impact and shear forces on the hammer elements. In addition, the comminution contributes to an interaction between constituents of the starting material 10, namely between, for example, polymers and metal parts, wherein the metal parts or plastic parts can cut thanks to sharp edges foams, films, but also textiles and other tough components.

On a cylindrical periphery 22 of the reactor housing 20 screening surfaces 40 are arranged with gap widths of, for example, 3 mm, through which fragments 11 'of the comminuted feedstock 10 can leave the machine 2 side. These fragments 11 ', which together form the fine fraction 11, are led away by a not shown, torus-shaped channel. The transport of the fine fraction 11 away from the first outlet opening 4 can be carried out by means of air or an inert gas, which is injected centrally through a line 23 into the grinding chamber 21.

Said screening surfaces 40, which cover the first outlet opening 4, are classifying means which can also be designed differently. The classifying means 40, which are arranged between the grinding chamber 21 and the first outlet opening 4 or within the first outlet opening 4, can be produced by means of sieves, sieve elements, perforated plates, slots, bars or the like. They are arranged at least in the region of a plane of rotation of the rotor 6 on the peripheral surface 22.

In the device 1 according to the invention, therefore, constituents of the fine fraction 11 which continuously form during the comminution of the feedstock 11 are expelled from the grinding chamber 21 by the classifying means 40 and the first outlet opening 4. The coarse fraction 12, which mainly consists of non-comminutable components, for example of viscoelastic polymers, is removed from the reactor housing 20 through the second exit opening 5 with an intermittently activatable ejection mechanism 50, the coarse fraction ejection. The coarse fraction ejection 50 is designed, for example, like a flap. It is also possible for a mixture of coarse and fine fractions 12, 11 to be expelled from the second outlet opening 5. The mixture can then be separated into the two fractions by means of external classification agents.

An electronic controller 8 acts on the entrance side shutter mechanism 30 and the exit side ejection mechanism 50. With this direct action affects the electronic control 6 and the drive power in an indirect manner. Thanks to the special controller 8, which has not yet been described for the aforementioned, known device, the drive power is according to the invention in time intervals between cyclically recurring pauses influenced so that they by a setpoint within the maximum power range between a plurality of relative maximum and Minimum values oscillating: see Fig. 2 , In the diagram shown, the electrical load is represented as current intensity I (current consumption) of a partially continuously operated comminution device 1 as a function of time t. The cycle duration and duration of a cyclically recurring pause are denoted by T and p, respectively. These parameters T and p can be adjusted with respect to a desired product.

If the current I, with which the machine loads the electrical network, falls below a predetermined value, feed material 10 is nachgespieben. The cyclically pauses are provided for intermittently activating the coarse fraction ejection 50. At the end of a cycle after ejection of the coarse fraction 12, the drive power has fallen to the idling power in the rule. The feed of the feedstock 10 may be continuous or intermittent at a frequency that is at least two times, preferably three times or even a multiple, greater than the frequency of the coarse fraction discharge 50.

The controller 8 is performed with respect to power measurements 87 '(via connection line 87 between the controller 8 and the drive 7) by determining quantities proportional to the drive power, in particular measurements of the current 1 received by the drive 7. In this case, the entry-side closure mechanism 30 is controlled by means of these performance measurements 87 '. The exit-side ejection mechanism 50 can be periodically activated after predetermined intervals T of the cyclically recurring pauses by the controller 8 (the controller 8 being connected to the coarse-fraction discharge 50 by a connection line 85); but it can also be controlled by means of the power measurements 87 'is activated. Each time the ejection mechanism 50 is activated, a new cycle begins with the supply of a first rate of feedstock 10.

The feed material 10 usually leads to a dangerous development of dust during comminution, which together with air can form an ignitable mixture. The threatened by explosions impact reactor 2 is therefore equipped with a vertical pressure relief pipe 9 and a rupture disk 90. The pressure relief pipe 9 is guided over the roof. A dust-laden air or gas stream may be passed through a pipe 91 into a dedusting plant.

A regulation can also be carried out with respect to a temperature measurement or several temperature measurements in or on the grinding chamber (the controller 8 being connected to the grinding chamber 21 by a connecting line 82). The supplied feedstock 10 usually has ambient temperature and therefore exerts a cooling effect. With regard to this regulation, when a given temperature is exceeded, further starting material is recharged for cooling; or the exit-side ejection mechanism 50 is activated.

The regulation with regard to power measurement is carried out in such a way that optimum utilization is achieved by means of a temporal equalization of the machine load. This usage is measured in terms of the ratio between throughput and mean drive power. The regulation is usually carried out so that for the drive power at most 90% or 80%, preferably even less of the maximum power range is used.

The inventive comminution device 1 is usually integrated as a system component in a network-like system. In this system, with an upstream system component fine material can be pre-separated from the crop 10, so that the burden of the crushing device 1 is reduced.

The ejected coarse material 12 may be further comminuted in a downstream system component. In this case, a part of the thus treated coarse material can be returned to the crushing device 1.

The feedstock 10 may contain metals as recyclables. Such valuable substances are often enriched as well as uncovered in the coarse fraction 12. They can therefore be easily separated mechanically. After a previous recyclable material separation, the remaining material can be further treated, for example by screening or further comminution.

Fig. 3 shows a graph with logarithmic grain size distributions, which have been obtained for the inventive method (cumulative frequency of grain sizes as a function of the grain size): The curve 100 shows the distribution for the feedstock 10. The resulting distributions for the coarse fraction 12 and the fine fraction 11 are represented by the curves 120 and 110, respectively. Dash-dotted line 130 is given for a desired end product.

For comparison shows Fig. 4 a corresponding diagram for a known continuous process. There is only one product (curve 140), ie no final product separated into a coarse fraction 12 and fine fraction 11.

A shredder operating on a batch basis produced a product that had almost reached final product quality after the first size reduction stage (no diagram shown). But it is for such a crusher at least one more Crushing stage necessary. In addition, there are also the disadvantages mentioned at the beginning of the batch-operated crushing machine.

Claims (9)

1. An apparatus (1) for the mechanical comminution of a heterogeneous feed material (10), including the following components:

   - a housing (20) with a) a closable feed opening (3) for the feed material, b) a first outlet opening (4) for a fine fraction (11) and c) a second outlet opening (5) for a coarse fraction (12) or a mixture of coarse and fine fraction,

   - a milling chamber (21) with comminution means and grading means (6, 40 respectively),

   - a drive (7) for the comminution means (6) which can be operated in a maximum power range above an idling power,

   - a closing mechanism (30) for the feed opening which is preferably designed as a lock (31),

   - an ejector mechanism (50) for the second outlet opening, the coarse fraction delivery (50), and

   - an electronic control (8) for indirectly influencing the drive power by a direct action on the input side closing mechanism and also on the outlet side delivery mechanism;

   in which apparatus (1), on comminution of the feed material, components (11') of the fine fraction which occur continuously can be ejected out of the milling chamber by the grading means and also by the first outlet opening and the coarse fraction delivery (50) can be intermittently activated,
   characterised in that the control (8) is configured such that the drive power can be influenced in intervals between cyclically recurring pauses by a controlled metered supply of the feed material in such a manner that it varies up and down between a plurality of relative maximum and minimum values about a desired value within the maximum power range or in that during intervals between cyclically recurring pauses the temperature in or at the milling chamber (21) can be influenced by a controlled metered supply of the feed material such that it varies up and down between a plurality of relative maximum and minimum values about a predefined temperature value.
2. An apparatus in accordance with claim 1, characterised in that the cyclically recurring pauses are provided for the intermittent activation of the coarse fraction delivery (50) and the supply of the feed material (10) takes place continually or intermittently with a frequency which is at least twice, preferably three times or a multiple of times greater in comparison with the frequency of the coarse fraction delivery (50).
3. An apparatus in accordance with claim 1 or claim 2 characterised in that the grading means (40) which are arranged between the milling chamber (21) and the first outlet opening (4), or inside the first outlet opening, are manufactured by means of screens, screen elements, perforated metal sheets, slits, rods or the like.
4. An apparatus in accordance with any one of the claims 1 to 3 characterised in that the milling chamber (21) contains at least one rotor (6) which can be rotated inside a cylindrical peripheral surface (22) as comminution means and in that the grading means (40) are arranged at least in the region of a rotational plane of the rotor on the peripheral surface.
5. A method for the operation of the comminution apparatus (1) in accordance with any one of the claims 1 to 4, characterised in that the control (8) is carried out with respect to power measurements by determination of parameters proportional to the drive power, in particular by measurements of the current (I) taken up by the drive, or is carried out with respect to at least one temperature measurement in or at the milling chamber (21), wherein the closing mechanism (30) at the input side is controlled by means of these power measurements or by means of these temperature measurements, while the outlet side delivery mechanism (50) is periodically activated in accordance with predefined intervals of the cyclically recurring pauses or also activated in a controlled manner by means of the power measurements or the temperature measurements and a new work cycle is begun with a supply of feed material (10) after activation of the delivery mechanism in each case.
6. A method in accordance with claim 5 characterised in that the regulation is carried out in such a way that an optimum utilisation with respect to the ratio between throughput rate and average drive power is achieved by means of a temporal evening out of the machine loading.
7. A method in accordance with claim 5 or claim 6 characterised in that the regulation is carried out in such a way that at most 90% or 80%, preferably even less of the maximum power range is exploited for the drive power.
8. A method in accordance with any one of the claims 5 to 7 characterised in that the comminution apparatus (1) is integrated as a system component into a network-like system in which, using an upstream system component, fine material is previously extracted from the feed material (10) for the purpose of a smaller loading of the communition apparatus.
9. A method in accordance with claim 8 characterised in that the delivered coarse material is treated further in a system component arranged downstream and in this arrangement any valuable substances such as metal parts which are possibly exposed, are separated, and/or a further comminution is carried out, wherein a part of the so-treated coarse material, in particular a fraction with smaller fragments, can be returned into the upstream comminution apparatus.

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