EP0328126B1 - Method and device for sorting spent glass - Google Patents

Abstract

In order to sort spent glass, fragments with an edge length between 5 and 50 mm are produced by means of a crusher. They are cleaned and divided up into a plurality of fractions according to size by means of a classifier and the fragments with edge lengths below 5 mm are collected as mixed glass. The fragments of each fraction are fed separately from collecting containers (8a to 8c) by means of a conveying device (9) to storage containers (10) in each case, from which the fragments are individually fed to a respective multiplicity of assigned slides (12 and 15 to 17). Colour detection units, preferably light transmitters and receivers measuring for absorption, are provided for detecting the glass colour (colourless, green, brown; non-transparent, non-glass material). As a function of the value of the light transmission, the fragments are fed to predetermined adjacent slides and via the slides directed into assigned sorting containers (18 to 21), sorted according to colours (Fig. 1). <IMAGE>

Description

The invention relates to a device for sorting waste glass with a crusher for crushing waste glass into fragments up to an edge length of 5 - 50 mm, a fragment sorter for separating splinters and small parts with edge lengths below 5 mm, a conveyor device which separates the fragments into one Separation device transferred, a color recognition unit to differentiate between transparent and colored glass and sorting containers for holding the different colored glass fragments.

The invention also relates to a method for sorting waste glass, wherein the waste glass is broken up into fragments up to an edge length of 5 to 50 mm and fragments with edge lengths below 5 mm are collected as mixed glass, and the remaining fragments are separated, the separated fragments are fed to a color detection unit and the color-coded fragments are then fed depending on the color-assigned sorting containers.

Waste glass is usually in a mixture of different colored glass. A separation into the different color components is necessary for an economical recycling of the old glass. This applies in particular to colorless waste glass, since even small amounts of colored glass, such as green or brown glass, preclude recycling for the production of objects made of colorless glass. It is also important that the sorting of waste glass also reliably removes the non-glass components such as porcelain, earthenware or ceramic parts.

In known methods for sorting waste glass (DE 33 26 129 A1; DE 34 45 428 A1), the waste glass fragments, in particular fragments of hollow glass or also the entire waste hollow containers, such as bottles, are separated in the size obtained and by a detection unit conveyed through with a light transmitter and receiver and transferred to sorting containers separately from each other by means of evaluation electronics according to color. With the known The old glass parts must be relatively large in order to be reliably detected by the recognition unit with regard to their color. Glass pieces with an edge length of only a few cm cannot be sorted using the known methods, so that these fragments are lost for recycling. However, even larger glass fragments cannot be separated reliably with the known methods, because the fragments are transported in very different positions past the detection unit through the beam path between the light transmitter and receiver, and thereby fragments of approximately the same shape and color with very different values of the light flow to lead. Flat and upright fragments conveyed through the recognition unit parallel to the light rays are often not recognized and are therefore not fed to the correct sorting container. This also applies to curved, larger fragments, which the light rays can pass depending on their position.

A sorting system for sorting waste glass is known from US Pat. No. 3,802,558. This device reduces the size of the waste glass by means of pulverization, and then the fragments are cleaned. Small and very large glass fragments are sorted out, the rest in any size sorted in a photometric sorting device according to their color. The respective fragments are detected in free fall or with a horizontal component in free flight by appropriate color sensors.

The very irregularly shaped and also differently heavy glass fragments, which arise unpredictably in the crusher, react very differently to the photo detectors depending on their random position in the trajectory. So it could well happen that a flat fragment, for example, passes straight through to the light beam of a photodetector, but the next one is shaped in the same way so that the beam runs exactly through the surface. Glass fragments also have very different trajectories depending on their size and shape in the resulting air resistance, since different parabolas are described in each case. Both effects significantly affect the accuracy of the system, possibly by errors of 500 or more percent.

Sorting devices are known from FR 25 76 008 and EP 0 248 281 A2, with which complete glass bottles are fed to a sorter via a type of chute for separating ceramic parts.

EP 0 211 139 A3 proposes a glass collection container in which complete bottles or hollow glass are sorted in the glass container during the collection, which makes them extremely heavy and costly.

Theoretical considerations on the separation of white glass from colored glass are made by Rudolf Germer in: "Measure + Check", Volume 19 (1983) page 286. Proposed solutions are not given.

Experience has shown that with the previous processes, the degree of purity of the colorless waste glass by mixing with stained glass is unsatisfactory and in most cases is not sufficient to use this waste glass for the renewed manufacture of objects from colorless glass.

The invention has for its object to remedy this situation and to design a device and a method of the type mentioned in the introduction in such a way that with high utilization of the waste glass obtained a significantly better, i.e. glass of different colors is separated more securely.

This object is achieved by a generic device in that the crusher is followed by a classifier and collecting containers for several fractions of differently sized fragments, that the fragments are fed continuously and unrestrained to the color recognition unit on channel-shaped slides and pass through them and that further channel-shaped ones pass through Guide slides from the color detection unit to the sorting containers and that the color detection unit is provided with transfer devices arranged downstream, with which the fragments are transferred from the first to one of the further channel-shaped slides depending on the measured values of the color detection unit.

Alternatively, this object is achieved by a generic device in that the crusher is followed by a classifier and collecting container for several fractions fragments of different sizes are provided, that the fragments run on trough-shaped slides from the separating device, that the trough-shaped slides are equipped with two retainers which can be transferred into the path of movement of the fragments, effective detectors being arranged upstream of the detectors in each case on two different levels, and that the color detection unit Subsequent transfer device are provided with which, depending on the measured values of the color recognition unit, the fragments are released on the same trough-shaped slide or transferred to another slide and passed on to the respective sorting containers for the different types of glass.

A method according to the invention is characterized in that the fragments are divided into several fractions in size, and that the fragments slide on trough-shaped slides while the color recognition is carried out and are fed to the respective sorting containers for the different types of glass on further trough-shaped slides.

An alternative method according to the invention is characterized in that the fragments are divided into several fractions in size, that the fragments of each fraction are stopped in their movement on a trough-shaped slide and one or more times to recognize the color and light transmission of individual resting positions exposed to two different levels of light transmitters and receivers and depending on the respective mean value of the light flow then either released on the same trough-shaped slide or transferred to a different slide and forwarded to the respective sorting container for the different types of glass.

In contrast to the known devices and methods, the waste glass parts, such as bottles, glasses and the like, as well as the fragments, are comminuted according to the invention, so that they have a maximum edge length, which in the known methods is already in the lower limit or below it . This crushing of the old glass parts or broken pieces creates shards that are mostly flat and level and sorted according to their size.

Because these relatively small panes are exposed to the color detection unit, the largely flat design of the small fragments means that they cannot be detected, as is possible with hollow glass fragments of larger dimensions depending on the shape and position of the fragment in the region of the detection unit.

Cleaning the fragments before they are fed to the color recognition unit further improves the safety of the measurement; because persistent dirt or paper residues are removed.

It has proven to be expedient if the fragments are exposed to the action of colored light rays from the light transmitter in order to recognize the color and translucency. This results in larger differences in the light flow in the differently colored fragments. Experiments have shown that not only is the separation of the fragments of colorless glass from those of stained glass improved, but the separation effect between fragments of brown and green glass is also improved.

Two different process alternatives have proven their worth. An alternative is that the individual fragments are fed to the color recognition unit continuously and unrestrained and pass through them, and that the color recognition unit receives an absorption signal during the passage of the fragment and feeds it to evaluation electronics that determine the color of the fragment from the absorption curve.

It is particularly expedient if, from the time course of the absorption curve of a fragment, only the middle area is used to determine the color of the fragment.

The absorption measurement provides a value which, based on an undisturbed normal level achieved in the absence of glass fragments, characterizes the amount of light which does not remain in the waste glass fragment due to absorption or other losses.

The following guidelines are quite informal: Colorless, clear waste glass absorbs light and is recognized as existing, but it absorbs significantly less light than brown or green waste glass. This effect can be enhanced by the selection of certain colored, especially red, light frequencies. In addition, an improved distinction between green and brown glass can be achieved.

The differences in this measuring method are so great that a typical source of error is practically eliminated. Of course, the absorption of a thick glass is normally greater than that of a thin glass.

Due to the crushing of roughly the same size (due to the classification) of essentially flat fragments, however, it is ensured that, as in the case of unfavorably located irregularly shaped bottles, multiple radiation of one and the same glass layer does not occur. However, even very thick, colorless glass still has a significantly lower absorption value than thin stained glass. This enables a safe separation.

Even lightly tinted glass components that occasionally appear in the old glass can be separated out in this way.

A further improvement occurs through the use of only the average values of the time curve of the absorption curve. This becomes clear when you imagine a piece of glass broken off at the edges. Here, the absorption curve initially decreases only slowly, since due to the extremely small thickness of the glass, only a little light is absorbed by it. In the middle area, however, the correct value is determined, while at the end again Measurement errors are conceivable. In order to avoid individual errors caused by punctiform holes in the middle of the glass fragment, which occur only relatively rarely, an average value can be taken over this measuring range with the help of evaluation electronics. Instead of the mean value, minimum, maximum or specially directed values can also be taken from the measurement and used for diagnosis and detection.

The second alternative for a method according to the invention is characterized in that the fragments of each fraction for the detection of the color and light transmission are exposed individually or several times to light transmitters and receivers which are effective in two different levels and depending on the respective mean value of the light flow are fed to the sorting containers via the separate conveyors.

With this method, no continuous measurement is carried out; instead, the broken glass is exposed to effective light transmitters and receivers in a stationary position on two different levels. This also ensures a reliable measured value.

• a) einem Brecher zur Zerkleinerung von Altglas,
• b) einem dem Brecher nachgeordneten Klassierer und Sammelbehältern für mehrere Fraktionen unterschiedlich großer Bruchstücke,
• c) einem Bruchstücksortierer zur Abtrennung von Splittern und Kleinteilen,
• d) einer Förderrichtung, die von den Sammelbehältern die Bruchstücke der einzelnen Fraktionen zu einer Vereinzelungseinrichtung überführt,
• e) rinnenförmige Rutschen, die von der Vereinzelungseinrichtung zu einer Farberkennungseinheit führen,
• f) weitere rinnenförmige Rutschen, die von der Farberkennungseinheit zu Sortierbehältern führen,
• g) der Farberkennungseinheit nachgeordnete Überführungseinrichtungen, mit denen in Abhängigkeit von Meßwerten der Farberkennungseinheit die Bruchstücke von der ersten auf eine der weiteren rinnenförmigen Rutschen überführt werden.

To implement the method, a device is proposed with:

• a) a crusher for shredding waste glass,
• b) a classifier downstream of the crusher and collecting containers for several fractions of fragments of different sizes,
• c) a fragment sorter for separating fragments and small parts,
• d) a conveying direction which transfers the fragments of the individual fractions from the collecting containers to a separating device,
• e) trough-shaped slides leading from the separating device to a color detection unit,
• f) further trough-shaped slides leading from the color recognition unit to sorting containers,
• g) transfer devices arranged downstream of the color detection unit, by means of which the fragments are transferred from the first to one of the further channel-shaped slides as a function of measured values of the color detection unit.

According to the invention, the fragments are fed to the respective color recognition units according to fractions of the different sized fragments on slides.

According to one alternative, their movement on the slides to identify their color is stopped in their movement and then either released on the same slide or transferred to another slide and forwarded to the respective sorting containers for the different types of glass. According to the second alternative, there is no braking of the fragments, but rather a continuous measurement.

Since the fragments have relatively small dimensions, only slides with correspondingly small dimensions are required. A plurality of slides can thus be connected to the respective storage container without difficulty, so that a high throughput can be achieved by the parallel operation of the slides. Because the fragments due to their gravity are moved along the inclined slides, the energy required to convey the fragments is kept low.

By arranging several storage containers with assigned devices for separating the fragments and subsequent slides, the different fractions of the fragments can be sorted simultaneously and separated into common sorting containers according to the color of the fragments, so that there again fragments of different dimensions but the same glass color to be collected. Non-glass components can be safely separated from the glass fragments due to their opacity and can be collected in a separate container.

In order to separate the fragments coming from the crusher from dirt and paper parts and to improve the recognizability of the color of the fragments, a cleaning device can be provided between the classifier and the crusher, for example a washing device in which the broken material acts on water becomes.

Since the arrangement is generally equipped with a large number of slides and this also results in a corresponding large number of light transmitters and receivers, a significant simplification can be achieved in that all light transmitters are connected to a common light source via glass fiber light guides.

The bottom of the slides is preferably lined with glass, which enables the glass fragments to be moved particularly smoothly and without friction.

A particularly preferred embodiment of the slides is achieved in that the slides each have a U-shaped cross section with a width which corresponds to 1.3 to 1.4 times the maximum edge length of the fragments of the respective fraction, and that light transmitters and receivers are arranged above or below the bottom of the slides.

This prevents jamming of the glass fragments during their sliding movement on the slides. At the same time, it is ensured that the fragments lie flat on the channel bottom and reach the respective color recognition units in this position.

This is an advantage in both alternatives. This prevents small fragments of glass from being able to pass unnoticed or incorrectly classified at the respective measuring points, in particular the light rays in the chutes.

In devices that work with stopped glass fragments, a particularly favorable design is possible in that the mutually assigned slides are arranged one above the other and have closable and releasable bottom openings by the retainer, the bottom openings being arranged offset from the upper to the lower slide in the conveying direction and the bottom slide is designed as a continuous channel.

It is expedient if the supports are designed as electromagnetically or pneumatically operable, held in the bottom opening and movable through them and in a pivoting part closing the bottom opening in the plane of the bottom. This is particularly the case when the swivel parts are designed as flaps or swivel wedges with tapering in the conveying direction, and each swivel part is mounted at its end pointing in the conveying direction via a swivel axis on a two-armed lever held between springs acting in opposite directions, on each arm of which an electromagnet engages.

Since the individual fragments or fragments are placed flat on the bottom of the trough-shaped slides by the light emitter, the possibility of a particularly favorable arrangement of the light transmitter and receiver results from the fact that in a device with retainers in front of each floor opening of each slide a light transmitter and receivers are arranged normal to the bottom of the slide and a light transmitter and receiver are arranged perpendicularly to it and light passage openings are provided in the area of the central longitudinal line of the bottom and in the side walls of the slide just above the bottom.

In the case of a device with continuous measurement, an arrangement of the light transmitters and receivers is preferred in which one of these two elements is arranged above and below the floor.

The transfer device also has flaps or swivel wedges. However, these do not have the function of the above-mentioned pickup. These are flaps arranged in the bottom of the slide after the evaluation electronics. These only have to be switched back and forth between two positions or functions, namely a continuous position and an open position. In the continuous position, the bottom of the slide is closed by the flap, so that the fragments or fragments are unimpeded can pass through the slide to be fed to a sorting bin. In the open position, the fragments or fragments pass through the bottom of the channel-shaped slide onto a further slide underneath. This in turn is equipped with a flap, the position of which can be specified simultaneously by the evaluation electronics. Possibly. the fragments reach a third slide underneath.

The number of slides can be selected depending on how many colors the glass fragments are to be split into. Usually a slide is provided for colorless, green and brown glass and one for ceramics and other non-glass components.

The flaps can be designed as a simplified embodiment of the swivel parts provided in the first alternative.

The drawing shows two exemplary embodiments of the invention in schematic representations.

Fig. 1

schaubildartig eine Prinzipdarstellung einer Vorrichtung zur Durchführung des Verfahrens gemäß der Erfindung,

Fig. 2

die Prinzipdarstellung eines Speicherbehälters mit nachgeordneten Sortiereinrichtungen,

Fig. 3

in vergrößerter Darstellung die Einzelheit A der Anordnung nach Fig. 2,

Fig. 4

eine Schnittdarstellung des Bereiches zwischen Farberkennungseinheit und Sortierbehälter gemäß einer zweiten Ausführungsform,

Fig. 5

in vergrößerter Darstellung die Einzelheit B der Anordnung nach Fig. 4,

Fig. 6

einen Schnitt längs der Linie D-D in Fig. 5.

Show it:

Fig. 1

a schematic diagram of a device for implementing the method according to the invention,

Fig. 2

the basic representation of a storage container with downstream sorting devices,

Fig. 3

the detail A of the arrangement of FIG. 2 in an enlarged view,

Fig. 4

2 shows a sectional illustration of the area between the color recognition unit and the sorting container according to a second embodiment,

Fig. 5

4 shows the detail B of the arrangement according to FIG.

Fig. 6

a section along the line DD in Fig. 5th

According to the overall arrangement according to FIG. 1, the waste glass obtained is fed in the direction of arrow 1 via a funnel 2 to a crusher 3, in which the waste glass is comminuted in such a way that mostly fragments with an edge length of 5 to 50 mm are produced.

The waste glass leaving the crusher 3 reaches a conveyor 4, to which a washing device 5 is assigned, by means of which the broken waste glass located on the conveyor 4 is acted upon by water jets 5a. As a result of the washing process, the paper parts adhering to the fragments and the dust adhering to the fragments are washed off and also smaller pieces of glass are washed away. The water provided with the above-mentioned impurities and glass splinters is passed over a separating or separating device not shown in the drawing, so that the water freed from the impurities and splinters can be fed to the washing device 5 again.

Instead of such a washing device 5, other cleaning devices would also be conceivable that work, for example, with air or sandblasting.

Via the discharge end of the conveyor 4, the fragments remaining and washed on the conveyor enter a classifier 6, which is designed as a screen classifier and through which the supplied glass fragments are sorted into several fractions of different sizes. The fragments with an edge length below reach the classifier of 5 mm in the collecting container 7, from which they can be removed as a mixing glass for further processing.

Sorted fragments with edge lengths of 5 to 50 mm are collected separately in the remaining collecting containers 8a to 8c, so that three fractions of different sized fragments are obtained, with differently colored glass fragments as well as porcelain, clay and ceramic fragments being mixed .

The individual fractions from the collecting containers 8a to 8c are now transferred separately to a conveyor device 9, of which only one is shown in FIG. 1. In practice, each collecting container 8a to 8c is assigned a conveyor device 9 of this type, via which the glass fragments reaching this conveyor device are transferred into a storage container 10.

Each storage container 10 is equipped with a device for separating the glass fragments fed to it. 1 shows such a separating device 11 in the form of a slide connected to the storage container 10. The separation of the fragments can take place, for example, in that the storage container 10 is designed as a vibrating vibration container with correspondingly installed baffles, which ensure that the glass fragments reach the slide 11 designed as a separation device and are then separated on the slide. From the separating device 11 in the form of the slide, the glass fragments reach a first inclined, channel-shaped slide 12, which in the example shown has two Holders 13 and 13a which can be transferred into the movement path of the fragments are equipped. Detection units 14 and 14a, respectively, are arranged directly upstream of the hold-ups 13 and 13a in each case, with each detection unit consisting of light transmitters and receivers which are each active in two different levels. The detection units 14 and 14a are connected to evaluation electronics (not shown in FIG. 1) and central control devices for the individual detectors 13 and 13a.

Each piece of glass fed to the trough-shaped chute 12 first reaches the pick-up 13 on its conveying path and is exposed there to the light beams of the two light transmitters effective in two planes in the rest position. The value of the light flow is measured in the evaluation electronics and, depending on this, the retainer 13 is either actuated so that the fragment is released for further movement on the conveyor trough 12 or is transferred from the conveyor trough 12 to a further conveyor trough 15 arranged downstream. When the glass fragment is released for further movement on the conveyor trough 12, the process already described in connection with the holder 13 is repeated in front of the holder 13a. The glass fragment is then either released by the retainer 13a either for further conveyance on the conveying trough 12 or transferred to the next conveying trough 15. Approved. The arrangement of the two retainers 13 and 13a in the course of the conveyor trough 12 is provided only for safety reasons in order to check the light transmittance measured by the detection unit 14 again by the detection unit 14a.

In the example it is assumed that only those fragments which consist of colorless glass are transported on the chute 12. These fragments are thus collected in the sorting container 18.

Glass fragments made of colored glass and fragments made of other non-translucent material are transferred to the next slide 15 via the retainers 13 and 13a. You get on the slide 15 again in front of the support 13, 13a of this slide, only glass fragments of brown glass being conveyed on this slide, for example, in order to get into the sorting container 19. The glass fragments which are not made of brown glass are transferred via the retainers 13 and 13a of the slide 15 to the slide 16, on which fragments of green glass are released for further conveyance into the sorting container 20 by means of the retainers 13, 13a assigned to this slide. The fragments not made of green glass pass in the manner already described through the holders 13 and 13a assigned to the slide 16 onto the slide 17 and via this slide into the sorting container 21. Accordingly, non-transparent fragments, such as porcelain fragments, are placed in the sorting container 21. Clay or other ceramics are transferred as well as those broken glass that cannot be clearly identified as colorless or brown or green fragments due to paper or dirt parts still adhering.

The slides 12 and 15 to 17 described and the sorting containers 18 to 21 assigned to them can be arranged in a plurality, for example in the form of a ring or in series, around the storage container 10, with several of the slides 12 assigned to one another and 15 to 17 can transfer the fragments into the same collection containers 18 to 21. The number of arrangements consisting of the chutes 12 and 15 to 17 per storage container thus determines the sorting capacity.

The double arrangement of the retainers 13 and 13a described for the slide for each slide with the respectively assigned recognition unit 14 to 14a can be reduced to one retainer with an assigned recognition unit.

Since the glass fragments to be sorted have only a small edge length between 5 and 50 mm, the chutes 12 and 15 to 17 can be kept relatively narrow. They expediently have a U-shaped cross section with a width which corresponds to 1.3 to 1.4 times the maximum edge length of the fragments of the respective fraction. This prevents jamming of the fragments on the one hand, but on the other hand ensures that the fragments come to rest in front of the retainers 13 and 13a in the light beams of the light emitters of the detection units 14 and 14a, which are effective in two planes, and there in their rest position by determining the light flow can be identified. Since the length of the trough-shaped chutes 12 or 15 to 17 can be measured relatively short - in practice the chute 12 is about 1 m long, while the chutes 15 to 17 can be kept much shorter - despite the multiple arrangement of the chutes, there is none large amount of material is required.

FIG. 2 gives an enlarged view of the actual one already described in connection with FIG. 1

Sorting device again, wherein in this illustration two of the slides 12 and 15 to 17, which are assigned to one another on the circumference in each case, are shown on the storage container 10.

In Fig. 2, the reference numerals used in Fig. 1 are used for the same parts.

In the illustration according to FIG. 2, two devices designed as vibrating troughs 11a for separating the fragments emerging from the storage container, for example a gap located in the bottom area, are shown below the storage container 10. The storage container 10 can in turn be designed as a vibration container, so that in the area of its bottom the broken glass emerges through an exit gap located there and is separated on the vibratory conveyors 11a and fed to the respective slides 12 via controlled flaps or retainers, as already mentioned in connection with Fig. 1 has been described.

2 shows the evaluation electronics and central control device 22, which is connected both to the detection units 14 and 14a and to the pickups 13 and 13a.

From detail A of FIG. 2, which is shown in FIG. 3, it can be seen that the retainers 13 and 13a are designed as magnetically actuatable swivel parts and that in the bottom of the channel 12 and also the other channels 15 to 17 bottom openings 23 corresponding to the retainers 13 and 13a are provided. The retainers designed as swivel parts 13 can assume three different positions, of which the stopping position is shown in solid lines in FIG. 3. In the dash-dotted position 24, the retainer 13 closes the bottom opening 23 of the channel 12 in the plane of the floor, while in the position 25 moved through the bottom opening 23, the retainer 13 releases the bottom opening 23, so that one before in the holding position of the retainer 13 this lying fragment falls through the bottom opening 23 of the chute 12 onto the next channel and arrives in front of the next pick-up 13 assigned to this channel.

To actuate the retainers 13 and 13a, the retainers 13 and 13a, each designed as pivoting parts, are connected in a rotationally secure manner at their end pointing in the conveying direction of the glass fragments to a two-armed lever 26, which in turn is mounted in a stationary manner in the pivot axis 27. The two-armed lever 26 is held in the example between oppositely acting springs 28 and 29 and is connected at the end of its two arms to an electromagnet 30 and 31, which has one end as well as the ends of the springs 28 and 29 are held in a stationary U-shaped component 32.

By actuating the electromagnets 30 and 31, the retainer 13 is transferred to the various positions and, after being released by the respective magnet, is returned via the springs 28 and 29 to the hold-open position drawn out in FIG. 3.

3 also shows the design of the recognition units 14 and 14a more clearly. In the illustrated For example, one light transmitter 33 and 34 is arranged normal to the bottom of the slide 12 and the other light transmitter 35 and the associated light receiver are arranged perpendicularly to it. The light transmitter 35 and the light receiver assigned to it are provided just above the bottom of the chute 12, so that the light rays of the light transmitter 35 pass across the fragment lying at rest in front of the holder 13, while the rays emitted by the light transmitter 33 pass onto the Hit the flat side of the respective fragment. Due to the small size of the fragments as a result of the previous comminution and the guidance of these fragments in the channels 12 or 15 to 17, it can practically not happen that the fragments located in front of the pick-ups are not detected by the light beams of the detection units.

For the passage of the light through the wall of the trough 12 or the bottom of the trough, passage openings 36 and 37 are provided in the wall or the bottom, which are closed in a translucent manner.

The electrical lines of the magnets 30 and 31 and the light transmitters and receivers 33 to 35 are connected to the electronics and central control unit 22 shown in FIG. 3 via the lines indicated in FIG. 3.

The embodiment shown in FIG. 3 and described above applies to all retainers 13 and 13a and detection units 14 and 14a of the slides 12 and 15 and 16, respectively.

To supply all light transmitters 33 and 35, they can be connected to a common one via glass fiber light guides Light source must be connected. All light guides can be exposed to colored light. However, it is also possible to partially convert the light emerging at the light guides into colored light only there. Experience has shown that increased security of separation of the glass fragments according to their colors can be achieved for all detection units by using red light.

Instead of the individual sorting containers 18 to 21, with circular arrangement of the chutes 12 and 15 to 17 around a storage container 10, collecting troughs of an annular type can also be provided with corresponding discharge devices.

The described retainers 13 and 13a can also be provided instead of pivoting parts held in the bottom openings of the respective slides as side wall sections of the slides which can be pivoted in the manner of a switch, in which case the next following slide must then be arranged laterally next to the previous slide.

Before the waste glass is fed to the crusher 3, it is expediently passed over a classifier similar to the classifier 6 shown and described in FIG. 1, in order to already have small fragments with an edge length of less than 5 mm and fragments with an edge length of 5 to 50 mm Separate the feeder to the crusher from the remaining fragments and thereby sort the fragments with edge lengths of 5 to 50 mm in the same way as was described in connection with the classifier 6. In this way, only those fragments are fed to the crusher 3 that have an edge length greater than 50 mm exhibit. The fragments of the desired edge length for sorting contained in the waste glass are thus obtained directly from the waste glass without being passed through the crusher. In this way, the proportion of small fragments that cannot be sorted is avoided and the crusher is considerably relieved.

The embodiment shown in FIG. 4 relates to a second alternative for a device according to the invention. Not shown in FIG. 4 is the part which corresponds to FIG. 1 and which carries out the initial treatment of the waste glass with crusher 3, conveyor 4, cleaning or washing device 5, collecting containers 7 and 8a to 8c and conveyor device 9.

The glass fragments of a certain fraction of approximately the same size are fed in via the chute 12 shown at the top left in FIG. 4. The bottom of the chute 12 is lined with glass, which reduces the friction of the glass fragments. To separate the fragments, the chute 12 can be vibrated. In addition, baffles (not shown) are provided, which may also transfer individual, still standing glass fragments into a flat position. The glass fragments can be further separated by thresholds.

A light transmitter 33 and a light receiver 34 are provided in the region of the lower end of the slide 12. The light transmitter 33 is located above the slide 12, the light receiver 34 below the bottom of the slide 12. A reverse arrangement of the elements 33, 34 is also possible. The two elements are adjusted to one another in such a way that, in the case of an undisturbed radiation profile, those emitted by the light transmitter 33 Light rays hit the light receiver 34. Since the bottom of the slide 12 is made of glass, preferably colorless glass, such a beam path is readily possible.

A piece of glass sliding on the chute 12 passes the light beam emitted by the light transmitter 33 due to the predetermined dimensions, a certain proportion of the light being absorbed in the piece of glass.

This measurement does not affect the sliding process of the glass fragment. The light receiver outputs a signal corresponding to the quantity of light received to an electronic evaluation unit 22. This thus receives a continuous course of time over the absorption taking place in the chute 12. As long as no glass fragment slides between light transmitter 33 and light receiver 34, a constant, undisturbed normal level is received. This value is not disturbed by the glass bottom of the chute 12 since it has a constant absorption value over the entire time.

If a glass fragment or a ceramic part, porcelain piece or other foreign body now gets between light transmitter 33 and light receiver 34, the emitted light is absorbed. The extent of this absorption depends essentially on the color properties of the passing fragment. With colorless, so-called transparent glass fragments, there is only a slight absorption, with stained glass a stronger absorption and with foreign bodies a practically complete absorption of the light.

After passing the light transmitter 33 and light receiver 34, ie the color recognition unit 14, reach the fragments reach the end of the chute 12 and reach a further no longer vibrating chute or channel 15. This chute 15 and further chutes 16, 17 and 17b arranged underneath lead to sorting or collecting containers 18 to 21. These containers 18 to 21 can 4, in turn, are channels or slides that run perpendicular to the plane of the drawing in FIG. 4, taking up the glass fragments falling from further channels and slides 15 to 17b and finally ending up in larger collecting containers. For the sake of simplicity, only cross sections of these elements 18 to 21 are shown.

The course of the slide 15 is equipped with a transfer device, which is formed here by a swivel part 40. The pivoting part 40 is controlled by the evaluation electronics 20 in its movement sequence. Depending on the absorption value, the swivel part 40 can assume two positions. On the one hand, the fragments falling on the chute 15 can allow unhindered passage into the sorting container 18. In this case, the swivel part 40 assumes the position shown in solid line in FIG. 4. This position can be seen more precisely in FIG. 5.

The second possible position is shown in dashed lines in FIG. 4 and causes fragments sliding along the slide 15 to fall through the opening formed onto the next slide 16.

This slide has a comparable structure and in turn has a swivel part 41 which can be controlled by the evaluation electronics 22 in two positions. In the position shown in broken lines, the glass fragment continues to fall onto the third slide 17, which also is constructed in this way and ultimately has a pivoting part 42 with which the fragments can reach the chute 17b and thus the sorting container 21.

The evaluation electronics 22 can work, for example, in such a way that colorless glass passes undisturbed via the chute 15 into the container 18, while brown glass via the chute 16 into the container 19, green glass via the chute 17 into the container 20 and foreign parts, such as ceramic, get into the container 21 via the chute 17b.

If the evaluation electronics 22 detects with such a setting that a colorless glass fragment has passed the light transmitter 33 or the light receiver 34, it controls the pivoting part 40 in such a way that the bottom opening 23 of the slide 15 is closed and the glass fragment reaches the container 18 unhindered can.

If it detects a stained glass or ceramic part instead, it ensures that the swivel parts 40, 41 and, if necessary, 42 are positioned appropriately in order to transfer the fragments into the intended container

The control can be carried out in such a way that a switching takes place only when the swiveling parts 40, 41, 42 need to be changed. This extends the service life of the drives connected to the swivel parts 40, 41, 42 compared to a respective return to a normal position.

In the example described above, only then must the swivel part 40 be switched to its open position Position if a fragment that is not identified as a colorless glass appears. As long as only colorless glass fragments are recognized by the evaluation electronics 22, the position of the swivel parts 41 and 42 is irrelevant and a change in position is therefore unnecessary.

The control of the swivel parts 40, 41, 42 can also be set such that, in the event of defects in the drives, a predetermined position of the swivel parts is carried out in such a way that an enrichment of the container for colorless glass with stained glass or foreign parts is avoided in any case. As a result, the quality of the colorless glass is kept constant even in the event of defects. In this case, feeding colorless glass into a stained glass container leads to a lower yield of colorless glass, but is less important for the quality of the stained glass.

5 and 6 details are shown again. The swivel part 40 is connected at its end lying in the conveying direction of the glass fragments in a rotationally secure manner to a two-armed lever 43, which in turn is mounted in a stationary manner in the swivel axis 44. The two-armed lever 43 is connected to an electromagnet 44 as a drive.

In Fig. 6 it can be seen that the slide 15 is covered with glass on its bottom and on the side walls. The glass layers 48 consist of flat glass. The slides 12, 16, 17 and 17b have a similar structure.

Instead of the swivel parts 40, 41, 42, a construction would also be conceivable which transfers the glass fragments from a predetermined path to other paths via air nozzles with a beam which is adjustable in strength and influenced by the measurement.

Claims (18)

1. Apparatus for sorting waste glass, comprising a breaking device (3) for reducing waste glass to fragments with an edge length of 5 - 50 mm, a fragment sorting means for removing slivers and small pieces with edge lengths of less than 5 mm, a conveyor (9) which transfers the fragments to a separator (11), a colour identifying unit to distinguish between clear and coloured glass, and sorting receptacles (18-21) to receive the glass fragments of different colours,
   characterised in that
   the breaking device (3) is followed by a grading means (6), and collecting vessels (7 and 8a-8c) are provided for a plurality of fractions of different-sized fragments,
   that the fragments are fed continuously and without deceleration from the separator (11) along channel-shaped chutes (12) to the colour identifying unit and pass through the unit,
   that other channel-shaped chutes (15-17) lead from the colour identifying unit to the sorting receptacles (18-21), and
   that transfer means are provided downstream of the colour identifying unit, whereby the fragments are transferred from the first chute (12) to one of the other channel-shaped chutes (15-17) dependent on values metered by the colour identifying unit.
2. Apparatus for sorting waste glass, comprising a breaking device (3) for reducing waste glass to fragments with an edge length of 5 - 50 mm, a fragment sorting means for removing slivers and small pieces with edge lengths of less than 5 mm, a conveyor (9) which transfers the fragments to a separator (11), a colour identifying unit to distinguish between clear and coloured glass, and sorting receptacles (18-21) to receive the glass fragments of different colours,
   characterised in that
   the breaking device (3) is followed by a grading means (6), and collecting vessels (7 and 8a-8c) are provided for a plurality of fractions of different-sized fragments,
   that the fragments run from the separator (11) along channel-shaped chutes (12),
   that the channel-shaped chutes (12) are equipped with two arresting means (13, 13a) which can be shifted into the path of movement of the fragments, identifying units (14, 14a) each effective in two different planes being provided immediately upstream of the arresting means (13 and 13a), and
   that transfer means are provided downstream of the colour identifying unit, whereby the fragments are released on the same channel-shaped chute or transferred to a different chute, dependent on values metered by the colour identifying unit, and passed on into the respective sorting receptacles for the different types of glass.
3. Apparatus according to claim 1 or 2,
   characterised in that
   the colour identifying units have at least one opto-transmitter and one opto-receiver, for red light in particular.
4. Apparatus according to claim 3,
   characterised in that
   all the opto-transmitters (33, 35) are connected to a common light source by fibre optic light guides.
5. Apparatus according to any of the preceding claims,
   characterised in that
   a cleaning unit (5) is provided between the breaking device (3) and the grading means (6).
6. Apparatus according to any of claims 3 to 5,
   characterised in that
   the chutes (12; 15-17) each have a U-shaped cross-section of a width corresponding to 1.3 to 1.4 times the maximum edge length of the fragments in that particular fraction, and that opto-transmitters and receivers (33-35) are arranged respectively above and below the base of the chutes (15-17).
7. Apparatus according to any of the preceding claims,
   characterised in that
   the base of the chutes (12; 15-17) is made of glass.
8. Apparatus according to any of the preceding claims,
   characterised in that
   the conveyor (9) leads from the collecting vessels (7 and 8a-8c) to at least one storage container (10) for the transfer of fragments of the individual fractions,
   that the separator (11) is associated with the or each storage container,
   that each separator (11) associated with the storage container (10) is linked with a plurality of chutes, and
   that each chute (12) extending from the separator has other, similarly constructed chutes (15-17) associated with it, to which the individual fragments are successively transferable.
9. Apparatus according to claims 2 and 8,
   characterised in that
   the associated chutes are superimposed and have base apertures (23) which can be closed and freed by the arresting means (13; 13a), the base apertures being offset in the conveying direction from the upper to the lower chute and the bottom chute (17) being in the form of a continuous channel.
10. Apparatus according to claim 9,
    characterised in that
    the arresting means (13, 13a) are in the form of electromagnetically or pneumatically operable swivelling members which are held in and can be moved through the base aperture (23), and which close the plane of the base in a base aperture.
11. Apparatus according to claim 10,
    characterised in that
    the swivelling members are in the form of flaps or swivelling members with tapering pointing in the conveying direction, and that each swivelling member is mounted, at its end pointing in the conveying direction, on a two-armed lever (26) by means of a swivel pin (27), the lever being held between springs (28, 29) which work in opposite directions, with its two arms each being acted on by an electromagnet (30, 31).
12. Apparatus according to any of claims 9 to 11,
    characterised in that
    an opto-transmitter and receiver are arranged in front of each base aperture (23) of each chute (12; 15; 16) perpendicularly thereto, and openings (36, 37) for the passage of light are provided in the region of the centre longitudinal line of the base and in the side walls of the chute close above the base.
13. Apparatus according to any of claims 3 to 12,
    characterised in that
    the opto-receiver (34) is connected to an electronic evaluator (22), to which it continuously transmits a signal characterising the luminous intensity received, and that the evaluator (22) is connected to the transfer means and supplies a control signal to them dependent on the signal.
14. A method of sorting waste glass, the waste glass being reduced to fragments with an edge length of 5 to 50 mm and fragments with edge lengths of less than 5 mm being collected as mixed glass, while the remaining fragments are separated, the separated fragments are fed to a colour identifying unit, and the colour-identified fragments are then fed to sorting receptacles which are assigned according to the colour identified,
    characterised in that
    the fragments are divided into a plurality of fractions according to size, and that the fragments slide along channel-shaped chutes while colour identification is carried out, and are fed along other channel-shaped chutes to the respective sorting receptacles for the different types of glass.
15. A method of sorting waste glass, the waste glass being reduced to fragments with an edge length of 5 to 50 mm and fragments with edge lengths of less than 5 mm being collected as mixed glass, while the remaining fragments are separated, the separated fragments are fed to a colour identifying unit, and the colour-identified fragments are then fed to sorting receptacles which are assigned according to the colour identified,
    characterised in that
    the fragments are divided into a plurality of fractions according to size,
    the fragments in each fraction are stopped moving along a channel-shaped trough, exposed one or more times, separately in an immobile position, to opto-transmitters and receivers each acting in two different planes to identify the colour and light transmission, and are then either released on the same channel-shaped chute or transferred to another chute, dependent on the central light transmission value, and passed on into the relevant sorting receptacles for the different types of glass.
16. A method according to claim 14,
    characterised in that
    only the central part of the time lapse of the absorption curve for a fragment is used to determine the colour of the fragment.
17. A method according to any of claims 14 to 16,
    characterised in that
    the fragments are exposed to the action of coloured, particularly red light beams in order to identify their colour.
18. A method according to any of claims 14 to 17,
    characterised in that
    the fragments are cleaned before being fed to the colour identifying unit and particularly before being divided into a plurality of fractions.

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