Device for ejecting bad products from a product stream

Abstract

A device for discharging bad products from a product stream, including a detection unit for detecting the product stream and a computer unit for receiving property data of the product stream from the detection unit and for identifying bad products in the product stream. The device includes a compressed air discharge unit controlled by the computer unit and a deflection element discharge unit for the passive discharge of bad products from the product stream. The computer unit divides the identified bad products into first-order and second-order bad products and controls the compressed air discharge unit so that it will actively discharge the first-order bad products, and also controls the deflection element discharge unit so that it will passively discharge the second-order bad products.

Claims

1. A device for discharging bad products from a product stream made up of good products and bad products and moving in a transport direction (T), comprising; a detection unit designed for detecting the product stream, a computer unit connected to the detection unit and operable to receive property data of the product stream from the detection unit and to identify bad products in the product stream detected by the detection unit from the property data in real time, and a discharge unit controlled by the computer unit and—as seen in the transport direction (T)—arranged at the product stream downstream of the detection unit and operable to discharge bad products from the product stream by at least one burst of compressed air, wherein the device comprises at least one further discharge unit controlled by the computer unit and—as seen in the transport direction—arranged at the product stream downstream of the detection unit on the side of the product stream opposite of the compressed air discharge unit and operable to discharge bad products by partially deflecting the product stream by at least one deflection element and the computer unit is operable to divide the identified bad products into first-order bad products and second-order bad products, wherein the compressed air discharge unit is operable to discharge the first-order bad products while being controlled by the computer unit, and the deflection element discharge unit is operable to discharge the second-order bad products while being controlled by the computer unit, wherein the deflection element discharge unit has at least one actuator which moves the at least one deflection element between a first position and a second position, wherein the deflection element protrudes into the product stream in the first position and is arranged outside of the product stream in the second position, with the good products being deflected in the first position, and wherein the computer unit is operable: to determine the outlines or shapes of the products contained in the product stream and the spectral composition of the products contained in the product stream from the property data of the product stream; to infer the material of the products from the spectral composition of the products contained in the product stream; to infer the volume of the products from the outlines or the shape of the products; to estimate the mass of the products from their material and volume; and to distinguish between good products, first-order bad products, and second-order bad products based on the mass of the products.

2. A device according to claim 1, wherein the deflection element discharge unit is arranged in the transport direction (T) downstream of the compressed air discharge unit.

3. A device according to claim 1, wherein the deflection element discharge unit is arranged in the transport direction upstream of the compressed air discharge unit.

4. A device according to claim 1, wherein the detection unit is operable to detect at least a subrange of a reflection or transmission spectrum when the products are irradiated with electromagnetic waves and for outputting corresponding property data.

5. A device according to claim 4, wherein the detection unit is comprises an optical detection unit operable to detect light in the visible wavelength range and/or outside of the visible wavelength range.

6. A device according to claim 5, wherein the optical detection unit comprises a hyperspectral camera operable to disintegrate frequencies in the near infrared wavelength range and/or in the visible wavelength range.

7. A device according to claim 5, wherein the optical detection unit comprises an RGB camera or a laser system.

8. A device according to claim 4, wherein the detection unit comprises a detection unit operable to detect X-rays or terahertz radiation.

9. A device according to claim 1, wherein the compressed air discharge unit comprises a control valve operable to adjust an intensity of the at least one burst of compressed air.

10. A device according to claim 1, wherein the deflection element deflects the product stream toward a first discharge path in the first position and deflects the product stream toward a second discharge path in the second position.

11. A device according to claim 10, wherein the deflection element is adjustable in further positions for the formation of further discharge paths.

12. A device according to claim 1, wherein the computer unit is operable to determine the colors of the products contained in the product stream from the property data of the product stream, and to distinguish between good products, first-order bad products, and second-order bad products based on the colors of the products.

13. A device according to claim 1, wherein the device comprises a further detection unit.

Description

(1) Advantageous embodiments of the device according to the invention are explained in further detail hereinbelow by way of example with reference to the drawings.

(2) FIGS. 1 to 3 show schematic views of embodiments of a device according to the invention for discharging bad products from a product stream moving in a transport direction.

(3) FIG. 1 shows a schematic view of an embodiment of a device 1 according to the invention for discharging bad products 2a and 2b from a product stream 3 moving in a transport direction T, the product stream 3 being composed of good products 4 and bad products 2a and 2b. A subsection of the product stream 3 is depicted in FIG. 1, wherein the product stream 3 moves through the device 1 along a path 14 and is guided by baffles 9 and 10 in two sections.

(4) The device 1 comprises a detection unit 5, a computer unit 6, a first discharge unit 7 and a second discharge unit 8, which are interconnected for the exchange of data. In the embodiment shown in FIG. 1, the second discharge unit 8 is arranged at the product stream 3 in the transport direction T downstream of the first discharge unit 7 and the first discharge unit 7 and the second discharge unit 8 are arranged opposite to each other on the product stream 3. However, there is also the possibility that the second discharge unit 8 is arranged at the product stream 3 in the transport direction T upstream of the first discharge unit 7. The arrangement of the first discharge unit 7 and the second discharge unit 8 is advantageously adapted to the installation requirements of the device 1 in higher-level systems and/or of the transport direction T of the product stream 3 and the path 14 resulting therefrom.

(5) The first discharge unit 7 is designed for discharging first-order bad products 2a. The first discharge unit 7 is formed by a compressed air unit which has a nozzle 11 with a valve that can be controlled electrically by the computer unit. The compressed air unit is connected to a compressed air supply via supply lines, which are not illustrated. The first discharge unit 7 thus constitutes a compressed air discharge unit. In the embodiment variant of the device 1 according to the invention as shown in FIG. 1, only a first discharge unit 7 is illustrated, but the device 1 can also have a plurality of first discharge units 7, which may be arranged either consecutively, side by side or offset from each other. There is also the possibility that the compressed air unit comprises a control valve designed for adjusting an intensity of a burst of compressed air emitted from the nozzle 11. The adjustment of the intensity can be effected either manually or via the computer unit 6. If the intensity is adjusted via the computer unit 6, the intensity is advantageously adapted to the first-order bad products 2a to be discharged. For example, the intensity can thus be higher in a first-order bad product 2a with a high mass and a small dimension than in a first-order bad product 2a with a low mass and a small dimension.

(6) The second discharge unit 8 is designed for discharging second-order bad products 2b. The second discharge unit 8 is formed by an actuator, e.g., in the form of an electrically controllable pneumatic cylinder 12, and a deflection element 13, with the pneumatic cylinder 12 acting on the deflection element 13, moving it between a first position and a second position. The second discharge unit 8 thus constitutes a deflection element discharge unit. The pneumatic cylinder 12 is connected to a compressed air supply via supply lines, which are not illustrated. In the first position, the deflection element 13 protrudes into the product stream 3 and deflects it, and in the second position, the deflection element 13 is arranged outside of the product stream 3. In the embodiment variant shown in FIG. 1, the pneumatic cylinder 12 is controlled by the computer unit 6 in such a way that the good products 4 are deflected in the first position and the second-order bad products 2b are discharged in the second position. Such a discharge, which discharges the second-order bad products 2b without touching them, is also referred to as a passive discharge.

(7) As an active discharge, a system is defined in which the bad product is deflected from its trajectory by the discharge units in such a way that it is removed from the product stream and conveyed into a separate path. The good product, however, is not influenced in its trajectory by the discharge units. Such an active discharge takes place only in the first discharge unit 7 by means of compressed air.

(8) During the passive discharge implemented in the second discharge unit 8, the good product is deflected, whereas the bad product is not influenced in its trajectory. This passive system has the advantage that the discharge units and the associated control can be optimized for the good product, which usually is known in terms of shape and weight. The bad product may consist of very different products, which would render an optimization considerably more difficult. Since the trajectory of the bad product is not affected, foreign materials, such as, e.g., rubber balls, are also removed more safely, because, during the deflection in an active system, uncontrolled movements of elastic products, e.g., uncontrolled bouncing of the rubber ball, may easily occur in the plant, whereby the ball can ultimately end up back in the good product. The same applies also to extremely light-weight or, respectively, floating bad products, such as, for example, film or paper. The system provides further advantages, for example, also for glass, as it can be discharged without splinters.

(9) Instead of electrically controllable pneumatic cylinders, other actuators may also be used. Such actuators are known to the person skilled in the art, and he or she knows how to select them according to the intended application. The demands made on the actuators are such they can be used in the system quickly enough, with sufficient accuracy and with great reliability. Examples of such alternative actuators are hydraulic cylinders, solenoids, electric drives, in particular rotary or linear drives.

(10) For certain applications, in particular if the shapes, dimensions and weights of bad products are within narrow tolerances, there is also the possibility that the second discharge unit 8, depending on the nature of the products, is designed as a switch point which actively deflects the good products 4 toward a first discharge path and actively deflects the second-order bad products 2b toward a second discharge path, thus discharging them. Furthermore, there is the possibility that the second discharge unit has more than two positions and, hence, a multiway sorting can be performed with this discharge unit alone. (For example: subdivision of good products into several classes by deflection into different discharge paths and passive discharge of bad products).

(11) In this embodiment, the detection unit 5 is designed as an optical detection unit and comprises a hyperspectral camera and, optionally, an RGB camera or a laser system. However, instead of optical detection units, the above-mentioned alternative detection units are also usable.

(12) When the device 1 according to the invention is used, the product stream 3 is guided through the device 1 in the transport direction T along the path 14. In doing so, the product stream 3 is detected with the optical detection unit 5, wherein the optical property data resulting therefrom are continuously transmitted to the computer unit 6.

(13) The optical properties include the spectral composition, the size, the shape and the colour of the products contained in the product stream 3, the computer unit 6 being designed for classifying the products according to their different chemical compositions, based on the spectral composition of the products. Based on the detected size, shape and colour, the computer unit is able to refine the classification and, for example, to differentiate wood residues from skin residues. On the basis of this classification, the computer unit 6 identifies good products 4 as well as bad products 2a and 2b in the product stream 3 in real time, wherein the computer unit 6 divides the bad products 2a and 2b into first-order bad products 2a and second-order bad products 2b, in accordance with the better discharge method.

(14) Based on the ascertained good products 4, first-order bad products 2a and second-order bad products 2b, the computer unit 6 controls the first discharge unit 7 in a further step so that it will actively discharge the first-order bad products 2a, and controls the second discharge unit 8 so that it will passively discharge the second-order bad products 2b, whereby only the good products 4 will remain at the end of the path 14.

(15) FIG. 2 shows a schematic view of a further embodiment of a device 15 according to the invention for discharging bad products 2a and 2b from a product stream 3 moving in a transport direction T. In contrast to the device 1 according to FIG. 1, in the device 15, the detection unit 5 is split into two housings, with, for example, a hyperspectral camera and an RGB camera being accommodated in the housing 5a and a laser system being accommodated in the housing 5b. Furthermore, the device 15 has an additional detection unit 16 in comparison to the device 1 according to FIG. 1, which is arranged on the side of the product stream 3 opposite to the detection unit 5 and which is also split into two housings, with, for example, a hyperspectral camera and an RGB camera being accommodated in the housing 16a and a laser system being accommodated in the housing 5b. It should be mentioned that, instead of or in addition to optical sensors, the detection units 5, 16 may also have other sensors, in particular sensors for detecting electromagnetic waves outside of the wavelength range of light, e.g., for the detection of X-rays or terahertz radiation. Due to the additional detection unit 16, the advantage is obtained that the product stream 3 can be detected even more precisely, as a result of which the computer unit 6 is able to differentiate even better between the good product 4, the first-order bad product 2a and the second-order bad product 2b, and thus the quality of the discharge is enhanced even further. Elements which are the same as in the device 1 according to FIG. 1 are provided with the same reference symbols. Furthermore, it should be pointed out that, in other embodiments of the invention, the above-described arrangement of the detection units 5, 16 can be varied in different housings on different sides of the product stream. For example, adjacent arrangements or an arrangement surrounding the product stream may also be chosen, or, respectively, more than two bad product streams may also be chosen in an unlimited manner.

(16) It should be mentioned that, in the device 15, the discharge of the second-order bad products 2b by means of the second discharge unit 8 is a passive discharge. This means that the good products 4 are deflected in the first position of the deflection element 13, whereas, in the second position of the deflection element 13, the second-order bad products 2b are discharged from the product stream 3.

(17) FIG. 3 shows a schematic view of a further embodiment of a device 17 according to the invention for discharging bad products 2a and 2b from a product stream 3 moving in the transport direction T. In contrast to the device 15 according to FIG. 2, the position of the discharge units 7 and 8 relative to the product stream 3 is reversed in the device 17.

(18) Elements of the device 17 which are the same as in the device 15 according to FIG. 2 are provided with the same reference symbols.