CH684742A5 - Method for cleaning and sorting bulk material - Google Patents

Abstract

In order to clean foodstuffs taking the form of grains of wheat, grains of rice, soyabeans, sunflower seeds and coffee beans, an optical sorting device (24, 24a, 24a') is deployed following preliminary cleaning (6) and makes it possible to effect a selection by colour and/or size and/or shape. Each particle of the bulk material is assigned to a particle class determined by means of parameters and if necessary is moved from a base transporting the bulk material into a reception area (43, 44, 45) for the corresponding particle class. To clean the bulk material, foreign bodies and defective particles are screened out of the product and the product is divided into classes if necessary. <IMAGE>

Description

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The invention relates to a method for separating and / or cleaning by reading or sorting bulk material in the form of cereal grains, rice grains, soybeans, sunflower seeds, coffee beans, the cleaning and sorting being provided as part of the preparation of these foods for further processing. After pre-cleaning and a first cleaning, grain kernels are wetted, scrubbed and then ground to flour in a mill, preferably with a milling roller. In the case of rice grains, a first cleaning and then a grinding step are provided after a pre-cleaning. The first cleaning includes removing foreign parts, a peeling step and removing shell parts and unwanted rice grains. The rice grains that have been milled and freed of grinding dust are preferably divided into different size classes. Oil seeds such as soybeans and sunflower seeds are subjected to a first cleaning after pre-cleaning, in order to then preferably go through process steps for oil production. In the case of sunflower seeds, the first cleaning is preferably provided after a peeling step, so that foreign matter and shell parts are removed in the process. After pre-cleaning, a first cleaning after a peeling step is also provided for coffee. The coffee beans are then sorted according to size and quality.

Grains, rice, oilseeds, coffee and the like are harvested in large quantities as natural products, and are therefore naturally subject to a certain amount of contamination by foreign substances. The impurities include foreign matter such as metal, glass, wood and plant parts, as well as cords and stones with a much larger or, in the case of dust and sand, a much smaller expansion than the desired product parts. These foreign substances should essentially be removed in the pre-cleaning by using separating sieves such as vibrating or vibrating and / or drum sieves. On the other hand, the contamination also includes stunted or pest-infested particles and / or shells of the product to be processed, as well as seeds or stones which are approximately the same size as the desired product particles. This proportion of the contamination is generally sorted out with several machines in the first cleaning. A selection is made according to criteria that distinguish the product from the contamination. The criteria and devices separating them are essentially the following:

- Size with a sieve

- Density using an air classifier

- Shape using trieure.

A corresponding number of machines are of course assigned to the different reading methods, with several such machines and / or combination machines, which combine screen separation and aspiration or air separation, for example, being provided for each reading criterion. This means not only a large investment, but also a corresponding expenditure in operating energy and space. If the differences in size, density and shape between bad parts and the desired parts are only small, a good separation can not be achieved even with great mechanical effort. For example, small unpeeled or black-colored rice grains cannot be read from the peeled, uncolored rice grains. The invention has for its object to reduce the cost, energy and space and the Auslesebzw. Improve cleaning quality.

This is achieved with the method according to the invention in that the bulk material is subjected to an optical screening during the first cleaning and possibly already during the pre-cleaning. With this optical sighting, at least one of the criteria color, size and shape is recorded.

After evaluating the color, size and / or shape information, the selection of the foreign or Bad parts and / or sorting into different classes. The cleaning of bulk goods and the optical color sorting are known independently of one another. However, it has now been shown that the use of color sorting for cleaning, and in particular the combination of color sorting with optical size and / or shape sorting for cleaning, brings a significant advance over the known methods. In the case of rice, for example, a separation or sorting into rice grains with husk, rice grains without husk, husks, rice grains with black spots, green rice, broken rice and rice grains of various sizes is useful and only possible with the method according to the invention.

The teaching according to the invention is based on the knowledge that the assessment by means of the human eye is very reliable and therefore an optical detection together with an evaluation device which derives size and / or shape and / or color information and compares it with values characterizing the reading classes, or sorting task qualitatively extremely well, but at the same time also with less expenditure on machines, costs, energy and space. In fact, tests have shown that essentially all foreign bodies, product particles affected by pests and, if appropriate, undesired portions of the product, such as shells, can be eliminated by optical sorting.

If all particles of the product stream for reading foreign bodies are optically recorded, the additional effort for sorting the desired product into product classes based on the size and / or shape and / or color is very small. For example, the product can be broken down into different quality classes, such as rice and coffee. The optical sorting has the further advantage that the sharp size sorting can be used for process optimization.

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For example, peeling devices can be optimally set for a partial area of the particle size distribution and can only be fed by the optical sorting device with particles that lie in this partial area.

An optimal separation between desired and undesired particles is achieved if the sorting takes place according to both the color and the size and, if appropriate, the shape. The size is preferably characterized by at least one value that corresponds to a particle expansion or a particle diameter and / or at least one value that corresponds to a particle cut surface or view surface. Shape information includes at least one effective particle contour and / or at least one derived variable, such as the first, the second and / or the third surface moment of a view surface.

The values characterizing the readout classes or the particle classes are preferably acquired in the course of a learning run by evaluating the image information of at least one particle representing the respective particle class or, if appropriate, also entered as standard values with tolerance ranges in the case of size and / or shape parameters.

Since the optical sorting device has a separating device, a support carrying or holding the separated particles and a Auslesebzw. Ejection device includes which elements are designed for a given particle size spectrum, the product must not contain any foreign parts that are outside the specified spectrum. If the product contains foreign substances that are not within the specified range, the product must be pre-cleaned, preferably with vibrating and / or drum screens and / or air classifiers, which removes the too large and / or too small particles and thus the functionality of the optical sorting device granted.

A preferred embodiment of the invention provides that the optical sighting is carried out with at least one optoelectronic sensor, preferably with a line, but possibly a matrix color television camera, the output signal of which, in order to evaluate the quality of the ground material, is carried out using an electronic data processing process which is, in particular, a comparison process between the parameters of at least one sample particle and in each case one particle from the bulk material or possibly a query of a table information and makes a result signal available which is used for the automatic control of the reading device for the product particles. These steps enable an exact evaluation of the criteria or parameters with regard to the required quality of the product or the particles. Radiation sources and / or cameras in the corresponding waveband are to be provided for evaluation criteria that include optical particle properties that are only recognizable when irradiated with and / or when receiving radiation outside the visible range, such as infrared or ultraviolet.

Another advantage of the optical read-out device compared to mechanical screens, for example, or, as in the case of Trieurs, pockets that hold product particles, extensive separating devices is the significantly smaller wear. The separation by means of sieving requires movements of the particles over the sieving surface such that all the particles come to rest directly on a sieve opening at least once. The intensive particle movement over the screen surface leads to undesired screen wear and thus to increased maintenance work and to screen interruptions when changing screens. Corresponding to the sieve wear, product wear and thus an impairment of the product quality, as well as m <f of product dust that has to be removed, can also be expected. The optical separation is a gentle separation of the product and can therefore also be used for sensitive products.

In the case of an optical separating or reading device, it is very easy to change the separating limits, since no machine parts are exchanged, so only the size and / or shape and / or color values characterizing the classes to be read out or tables previously created are given have to. Electronic control measures such as adjustments and automatic corrections can prevent the separation limits from changing during operation. This guarantees constant product quality even over long operating phases. In the case of mechanical separation devices, the adjustment of the separation limits is associated with the replacement of screens and / or interior parts and, in the case of wind classifiers, with the setting of the correct air flow. The correct choice of the variables influencing the separation requires an experienced operator and, if necessary, complex tests. In addition, the separation limits can shift during operation due to increasing contamination of the separation devices by product dust.

Further details of the invention result from the following description of exemplary embodiments schematically shown in the drawings.

Fig. 1a milling plant for Durum according to the prior art

Fig. 1b milling plant for common wheat according to the prior art

Fig. 2 milling plant with optical first cleaning

Fig. 3 rice milling according to the prior art

Fig. 4a rice milling with optical cleaning and sorting sections

Fig. 4b rice milling in which a plan reader and an optical sorting is provided directly after the peeling.

Fig. 5 soybean oil production according to the prior art

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Fig. 6 soybean oil production with an optical cleaning or reading

Fig. 7 sunflower oil production according to the prior art

Fig. 8 sunflower oil production with optical cleaning

Fig. 9 sunflower oil production with optical separation of the crop flow before removing the shells

Fig. 10 coffee treatment according to the prior art

Fig. 11 Coffee treatment with optical cleaning

Fig. 12 coffee treatment with an optical cleaning and classification

FIG. 1 a shows schematically the example of a durum mill equipped with a particularly large number of cleaning machines in order to illustrate the savings which the invention can achieve. However, it is to be understood that the invention is not limited to such mills, but can also be applied to other types of mills, where a smaller number of cleaning machines may be conventionally provided.

Fig. 1a is divided purely optically by four merely indicated elevators 2 to 5 into individual sections. Instead of the elevators 2 to 5, any other suitable means of transport can of course also be used. A group of input silos 1 is provided on the far left for the delivered grain. Treatment steps for removing coarse and fine foreign matter are carried out in a pre-cleaning area 6 between the elevators 2 and 3. The treatment steps of a first cleaning are shown in a first cleaning area 7 or 7a and 7b arranged between the elevators 3 and 4 and between the elevators 4 and 5. To the right of the elevator 5 is a processing area 8 with a second cleaning, preferably in the form of a scouring device 21a, with a wetting and settling device 21b, 21c and with a milling roller mill 22.

The delivered goods from the input silos 1 are first fed to a magnetic separator 9 and then to a scale 10. This is followed by a screening device 11, preferably in the form of a vibration screening screen with a first and a second screen. The first sieve is possibly a so-called roller sieve and separates coarse foreign matter such as earth bulbs, wood and straw parts, as well as stones ect. from grain and small foreign substances. The small foreign matter, such as sand, is at least partially removed from the grain through the second sieve. To remove dust, the grain is then passed through an air stream, preferably through an air classifier 12. This pre-cleaning must be carried out at high bulk material throughputs and therefore cannot separate the contaminants from the cereal grains.

After the pre-cleaning, the pre-cleaned comes

Grain in raw fruit silos 14 and is available there for further processing, separated by grain type. The further processing preferably comprises the first cleaning, a first wetting and settling, a second cleaning and a second wetting and settling as well as the grinding. Different processing methods are used to produce flour mixtures from different types of grain. For example, the desired mixture of different types of grain can be generated directly after the raw fruit silos 14, so that the grain mixture is processed further. If appropriate, the different types of grain arrive separately at the first wetting and are mixed after the first weaning, or it is provided that the different types of grain are also led separately through the second cleaning for the second wetting and settling and preferably before milling, if appropriate but also only be mixed after grinding. To process a certain grain mixture, the types of grain required for this are removed from the silos 14 and mixed with the aid of the raw fruit silos 14 for each assigned quantity regulator 15 and fed via a conveyor 16 to a scale 10a determining the weight of the mixture.

The first cleaning adjoins the scale 10a and optionally includes a further magnetic separator 9a, a further sieve cleaning device 11a with an air classifier 12a, a stone reader 17, at least one chamber 18, a fluidized bed stone reader 19 and a light grain reader 20. The sieve cleaning device 11a preferably also reaches two vibrating sieves a separation into cereal grains and larger and smaller foreign matter. Due to the lower throughput and the narrower separation limits, a better separation than pre-cleaning is achieved. Due to its vibrations, the stone reader 17 enables a separation according to the specific weight on the one hand, and a separation according to the air resistance on the other hand due to the fluidized bed generated therein. At least one round and / or spiral and / or disc interior 18 is separated according to shape and size, in that desired grains are carried on with appropriately shaped pockets. Unwanted particles such as stunted grains, breakage, particles that are too long or too round are excreted. The fluid bed stone reader 19 - similar to the stone reader 17 - carries out a separation according to specific weight, so that heavier components (e.g. stone-sized stones) are separated. The light grain reader 20 is provided for removing poorly developed grains, broken grains etc.

After this first cleaning in the areas 7a, 7b, the grain passes through a scrubbing device 21a and a network device 21b with automatic moisture regulation into stand-off silos 21c with outlet quantity regulators 21d. Scouring 21a, wetting 21b and conditioning in the storage silos 21c is preferred

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Provided twice in succession before the grain is finally fed to a milling roller mill 22, preferably via a balance. The roller mill 22 stands for a whole series of such chairs, the first roller mill 22, in a known manner, opening the grain of grain by driving its rollers 23, which are provided with corrugations and are at a predetermined distance from one another, at different speeds in such a way that the one the side of the respective grain of grain facing the rollers 23 is removed from the side of the grain of grain facing the other roller of the pair of rollers 23 and thus the content of the grain of grain, ie on the whole the flour is exposed. This portion of flour is then separated from the shells in the further passages or ground according to the desired degree of fineness.

The invention is based on the knowledge that the machines required for the first cleaning, in particular the screen cleaning device 11a with air classifier 12a, the stone reader 17, at least one door 18, the fluidized bed stone reader 19 and the light grain reader 20 are at least partially replaced can, if an optical sorting device is used instead. Such an arrangement can be seen, for example, in FIG. 2.

Since the durum processing shown in FIG. 1a provides an extremely complex first cleaning, the processing of common wheat according to the prior art is described in a second example in FIG. 1b. A comparison of FIGS. 1a and 1b shows that neither a fluidized bed stone reader 19 nor a light grain reader 20 is provided for the first cleaning of soft wheat. In addition, circular and spiral drives 18a, 18b are preferably used for cleaning soft wheat. A further difference between FIGS. 1a and 1b is that the two passes of the scrubbing, wetting and conditioning with the devices 21a to 21d and 21a 'to 21d' are shown twice.

As can be seen from a comparison of FIGS. 1a and 1b with FIG. 2, the elevator 4, the screen 11a with the air classifier 12a, and the machines 17 to 20 or 17 and 18 are missing in the latter individually shown, specially equipped optical sorting apparatus 24 is provided, which takes over the work of the omitted machines. However, it should be remembered that FIG. 2 only illustrates an example, and that in the case of mill diagrams which differ from FIG. 1a, the machines conventionally provided there, in particular the first cleaning 7, can be replaced by the device 24. Although it would be possible per se to also replace other machines of the pre-cleaning stage 6 by the optical device 24, this will generally not be possible.

Accordingly, material to be sorted out, which is supplied via the magnetic separator 9a, arrives, for example, via an inlet shaft 25, which expediently has a metering element, e.g. in the form of a flap 26 which changes the shaft cross-section, to a distribution device 27. The arrangement can be made in a manner similar to that in FIGS. 10 to 13 of US Pat. No. 4,905,917 using the device 30 and a feed roller connected downstream 8 is shown, wherein in the case of the present FIG. 2 the feed roller 28 is connected directly downstream of the distribution rotor 27.

In order to avoid the accumulation of grains, a vibration conveyor 29 with a vibration drive 30 is expediently provided for preparation of the separation, it being advantageous if the vibration conveyor 87 has individual, suitably parallel feed channels 31 in the longitudinal direction of the conveyor, which already have individual rows of successive ones Separate particles from one another in that the feed channels 31 each have a width which corresponds to a grain width. In this way, the grains are not only distributed over the width of the vibration conveyor 29, but are also arranged one behind the other, so that only the process of arranging the individual grains in a position that is precisely prescribed relative to one another then has to be carried out.

This process now takes place in such a way that individual grains reach the end of the vibrating conveyor 29 at open intervals 31, which are not predetermined, from one another. In the area of this end, namely here directly at the end of the vibration conveyor 29, but possibly also on a separate part, there is expediently an acceleration device 32 in the form of a brush roller (or at least one blowing nozzle) in order to bring the grains at least to that speed, which has a downstream drum 33. The grains are held at suction openings on the drum 33. If necessary, the suction openings are arranged in depressions in the drum surface. Instead of the drum 33, an at least partially air-permeable conveyor belt can also be provided.

The acceleration device 32 avoids that after the vibration conveyor 29 there is again an uneven distribution of the grains with individual grain accumulations. Rather, the grains are expediently brought to such a speed that they are distributed over the surface of the drum and remain on suction openings. The grains thus arrive in the positions shown relative to one another in front of a monitoring device, which expediently has, if appropriate, also more than one television camera 34 with lighting device 35, where appropriate it could also be formed by individual light-electric walls. This device is preferably located in a light-tight housing 36 in order to eliminate the influence of extraneous light. Any video camera, in particular a solid-state camera, such as a diode array or a CCD camera, can be used as the television camera 34.

It should be mentioned that such a vibration conveyor 27 with feed channels 29 has numerous modifications.

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NEN can be subjected, for example, by omitting the vibration drive, or by the feed channels 31 instead of parallel to each other, are formed slightly diverging in the conveying direction. A further separation effect can also be achieved in that the feed channels 31 have individual strips of material of different friction which run transversely to the direction of the feed channels 31 and which are either uniformly wide or also have an increasing width in the conveying direction. Likewise, the acceleration can be carried out in various ways, for example also by means of at least one acceleration drum passing through a partial area through an acceleration drum or a centrifugal disc already provided at the beginning of the vibration conveyor 29 and accelerating the grains tangentially onto the vibration conveyor 29, etc.

As soon as the grains are brought against the drum 33 by the brush roller 32, a negative pressure applied inside the drum 33 begins to act in the area of depressions and only sucks the grains in the area of the depression.

The circumference of the drum can be provided with separating ribs or channels, similar to the feed channels 31 of the vibration conveyor 29, with suction holes being provided at intervals. The grains are then held at these suction holes, are thus in a predetermined mutual position and are fed to the checking device 34 within the housing 36. To achieve the corresponding negative pressure, an opening 38 is again provided which passes through a hollow stub shaft 37. A corresponding negative pressure prevails above a sealing wall 39 inside the drum 33, which secures the contact of the grains on the drum 33 even at high speeds, a further housing 40 being designed such that the negative pressure can also act there, for example, and grains only are then thrown out when the negative pressure is overcome by the blowing pressure of nozzles 41, 42 arranged therein, one of which throws the parts to be sorted out into a trough 43, the other into a trough or a channel 44, whereas a seal on the cover wall 39 ensures that the suction pressure does not come into effect in the area below this wall 39 and therefore the parts which are found to be good fall into a trough or a channel 45. If only a distinction is made between good and bad particles, the nozzle 42 can be omitted, for example. On the other hand, further nozzles can be provided for sorting into several particle classes. Preferably, the most extensive class of particles enters the channel 45 without blowing out effect.

The video camera 34 is shown with its preferred circuit. Such a conventional solid-state or tube camera for the delivery of color signals generally has six outputs, namely an output 57 for the horizontal deflection signal (this expression should also include the corresponding signal from a solid-state camera) and an output 58 for the vertical deflection signal (if it is is not just a line scan camera), an output 59 for the red signal, an output 60 for the blue signal, and an output 61 for the green signal. There is also an output 62 for the Y signal (brightness). It is now easier for processing if a converter stage 63 is connected to these outputs, which converts these signals into the so-called I HS system, so that there is a line 64 for the brightness signal and a line 65 for the color saturation signal at their output and results in a line 66 for the hue signal. Of course, the converter stage 63 can be omitted if the camera 34 is already designed in such a way that it has outputs 64 to 66 corresponding to it, or if the signal evaluation essentially requires the red, blue and green signals.

In the area of the edges of the drum 33 there is preferably a color reference pattern and on the drum itself clock markings are arranged at predetermined positions, so that during a deflection period the signal sections corresponding to these references will appear at a specific point within the video signal, the clock markings being used to determine the Particle speed is determined or a line is read out with each clock pulse in order to define the triggering of the image point in the direction of movement and to facilitate the measurement of the particles. Therefore, if the lines 57, 58 are fed to a switching stage 67, the latter can use these deflection signals to determine whether the incoming signal comes from such a reference point or a clock mark or from another point. Accordingly, the signals are divided by the switching stage, namely the reference signal originating from the color reference pattern is emitted into a reference storage stage 68, the signal originating from the drum surface, with the exception of the clock mark signals, to a stage 69, whereas the clock mark signals reach an output line 70.

The inputs of a comparison stage 71 are connected to the outputs of stages 68, 69 and compensate for any irregularities or changes in the brightness of the background by forming differences, so that readjustment of the lighting devices 35 is not absolutely necessary. It is advantageous if a further difference is formed which is based on the learning ability of the circuit.

If a specific color or brightness is required for the bulk material particles, there are different ways to proceed. The simplest way is to specify a threshold value for a desired brightness and, if this desired brightness threshold is not reached, to remove the particle in question by actuating a blow-out nozzle or another sorting device. However, if you want to sort by color, you could analogously provide several color channels (for example corresponding to lines 59 to 62 or 64 to 66) and provide appropriate threshold value transmitters in these channels. On digital

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This can be achieved by entering the respective color parameters in a keypad, which is tedious on the one hand and unreliable on the other hand due to the many error possibilities. Here, too, another path is expediently followed.

If one starts a learning run before sorting out a quantity of bulk material to be checked, at the beginning of the operation, a number of grains (in themselves a single one) run past the video camera 34 or - in the case of a matrix or tube camera - are left standing, so the color of this reference grain can be saved in order to later serve as a reference value for the desired color. For this purpose, a switchover stage 72 may be provided at the output of the comparison circuit 71 (or, if this is not provided because a background control according to the prior art is preferred, at the output of the camera 34 or stage 69). In the present exemplary embodiment, this switchover stage (but not necessarily) has a switchable control input 73, so that its switchover can be controlled via a selector switch S1 by a timing element 74, which automatically switches the switchover device to normal operation after a time corresponding to the passage of the reference sample, or, depending on the position of the selector switch S1, the changeover can also be carried out manually by means of a manual switch S2, the opening or closing of which causes the changeover of the stage 72. Such a manual control is particularly advantageous if the time for the, preferably adjustable, timer 74 cannot be determined exactly from the start (e.g. a sample of grains is sent a few days in advance so that it can be sorted out later).

Depending on the position of the switching stage 72, a learning operation or normal operation is carried out, with at least one memory 75 being connected in the former case, which is preferably designed as a non-volatile memory (e.g. floppy disk). In the learning mode, at least one particle and the background, but possibly several particles representing different particle classes, are subjected to a color recognition and the resulting values are stored. For this purpose, several memory locations 75 with optional access, i.e. either several separate memories or a single, correspondingly larger memory 75 with addressable memory locations can be connected to the output signal of the camera 34 or the comparison stage 71. It is expedient if the memory 75 is connected to the memory 68 in order to be able to correct its content as a function of the illumination color of the color reference pattern and to avoid reading errors. Although it would alternatively also be conceivable to assign such a control device to the lighting that its color values are always kept constant, the connecting line drawn in broken lines between the two memories 68 and 75 forms the simpler way of a corresponding correction.

When the switching stage 72 - controlled by the timer 74 or the switch S2 - switches to normal operation, it delivers the signals received to a buffer stage 76 lying parallel to the memory 75 or directly to one input of a comparison and control stage 77, the other input of which is connected to the outputs of the reference signal memory 75. This allows a constant comparison between a reference signal and the actual signal from the grains being checked. In the case of several defined particle classes, the comparison is carried out with the corresponding stored particle and background values. The comparison stage 77 will have adjustable and expediently predetermined threshold values, so that it does not provide any output signal in the event that the signal lies within the tolerance range for the particles not to be ejected or the background. The particles which are not to be ejected are preferably those which are the most frequent in number, that is to say the good particles in the normal case. However, the comparison stage 77 will deliver a signal via an output 80 to a switchover stage 78 in accordance with the particle class recognized. The supplied signal is used to control one of preferably two, but possibly also more than two, control stages 81 or 82, each with a corresponding valve as an actuator for actuating one of the preferably two, but possibly also more than two, nozzles 41 or 42 to control. To synchronize this actuation, the clock signal line 70 is connected to the comparison and control stage 77. If necessary, an ejection nozzle is controlled in such a way that it ejects everything that was not recognized as a background or as belonging to a particle class as a foreign part by means of an ejection nozzle.

If the different particle classes differ primarily in shape and not in color, it is preferably provided that particles of all particle classes are treated as good particles in the color recognition step and that the vectorial difference generator 77 does not provide any output signal for good particles or grains. However, it can now be seen that the line 80 does not directly control the switchover stage 78, but that a form processor Fp is also linked to the line 80. This form processor Fp receives the output signal of the difference generator 77, expediently via an inverting stage Iv. If only good and bad particles are differentiated, the shape processor Fp is activated via the inverter iv only in the case of grains of good color and thus in the case of a vanishing output signal of the vectorial difference former 77, which makes its operation (in comparison to a possible one as well) Parai lei operation of difference generator and form processor) simplified.

At the exit of stages 77 and Fp there is a logical link log, which is shown here simply as an OR operation, and which actuates the switching stage 78 as a function of the signals from both stages 77 and Fp. In such an embodiment, generally more than just two ejection nozzles 41, 42 are then arranged one behind the other.

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be net, in order to be able to carry out a sorting out according to colors and sizes and / or shapes or qualities, under certain circumstances a sorting out only by color or only by size and / or shape is sufficient. Shape information includes at least one effective particle contour and / or at least one derived variable, such as the first, the second and / or the third surface moment. In the learning process, at least one particle contour and an associated tolerance range can be determined as a characteristic of a particle class, so that the shape processor can compare the current particle contour with the possible contours of this particle class.

It goes without saying that numerous variants are conceivable within the scope of the invention; for example, all conventional optical sorting devices can be used, provided they are equipped with color and / or size and / or shape recognition devices.

Unnecessary blowing out is avoided if the color of the background formed by the drum 33 is recorded, as already mentioned above. A particle to be separated out is only present if no “good” grain or a grain belonging to a defined particle class and also the background are not scanned.

If necessary, the background could also be calculated using the deflection signals, since the openings next to one another for receiving the grains will probably always pass successively at the same location, and the presence of a number of grains can also be determined using clock signals, but this is due to excessive imprecisions connected, especially since it can also happen that a drum opening is not occupied at all (and then probably gives off a background color).

If the above-mentioned, dashed-line connection exists between the memories 68 and 75, then within the axis system of the color signals IHS, which practically reproduces a three-dimensional order within the memory 75, the reference signal for red, the reference signal for blue and the reference signal for Store green. These reference signals can then be checked, expediently at least at the start of operation, but possibly also at periodic time intervals, by calling up the output signal of the memory 68, in which the respective color signal taken from the standard color pattern is present, and with the stored value for red, Blue and green are compared. If there is a deviation as a result of a change in the color tone of the lighting, all color values are corrected to the same extent (corresponds to a rotation of the three-dimensional axis cross), so that the reference values and also with changed lighting are adjusted accordingly.

3 schematically shows a rice processing in which paddy or parboiled rice is transported from input silos 101 by means of elevators 102, 103, 104 to further treatment sections. Instead of the elevators 102, 103, 104, any other suitable means of transport can be used and the arrangement of the means of transport and the

The division into treatment sections separated by these can vary depending on the respective circumstances.

In the example shown, the pre-cleaning directly following the input silos 101 essentially comprises a screen cleaning machine 105, for example a drum screen, for removing coarse foreign matter and an air classifier 106 for removing dust. If necessary, a magnetic separator is also provided. The pre-cleaned product is kept ready in rice silos 107 for further processing in an area of the first cleaning 7 or 7a and 7b and reaches a sieving device 11a, preferably a vibrating sieve machine with a first and. Via quantity regulator 15, a conveyor 16 and a balance 10a a second sieve. The screening device 11a separates from the bulk material in particular two fractions, namely larger and smaller foreign substances. A wind sifter 12a directly adjoining the screening device 11a essentially removes the dust in the bulk material. Foreign matter with densities and shapes that differ from the rice grains or air attack surfaces are read out of the remaining bulk material with a dry stone reader. If appropriate, a further magnetic separator is provided after the dry stone reader 17.

In the part of the first cleaning 7a or 11a, 12a, 17, 9a described above, weed or foreign seeds, lumps of sand, stones and small pieces of iron are excreted. In addition to these foreign parts, the peel is now detached from the grain of rice in area 7b with a peeling device 108 and excreted in the air flow by table separators 109. Since, in addition to husked rice grains and husks, unhulled rice also emerges from the hulling device 108, the table separators 109 must also separate unhulled rice from hulled rice. Due to the small difference, this separation can only be achieved with great effort and then only insufficiently. In order to ensure that essentially no unhulled rice kernels are carried on with the hulled hulls, it must be accepted that a large proportion of the hulled kernels with the unhulled kernels can be returned to the peeling device 108 via a return line 110 and the elevator 103.

To remove immature grains or green rice, a complex sorting device must be used to carry out a thickness sorting. For this purpose, drum sorters 111 are used in the system according to FIG. 3. Both the machine effort and the stress on the good rice grains are high, which leads to a particularly inefficient treatment step with a small proportion of green rice. At the end of the first cleaning, the rice may pass through a magnetic separator 9b.

In a second cleaning, the rice is ground, for example, by means of ring grinding machines 112 and polished by means of polishing machines 113, and dust is removed by means of aspiration.

In a treatment area 8 following the elevator 104, the product is conveyed through a

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Distributing device 114 distributed to plansifter 115. The plan sifter removes lumps and fine fragments, so that essentially only rice grains with a predetermined minimum size reach trieure 117 via a further distribution device 116. The trieure sort the rice into predefined size classes. A division into 3/4 to 1/1, 1/2 to 3/4 and 1/4 to 1/2 grains is preferably carried out. The sorted rice comes into the corresponding size class Si'os 117. The sorted rice grains may also be subjected to a color check in order to separate grains with black spots.

According to FIG. 4a, a solution according to the invention provides that an optical sorting device 24 is provided instead of the dry stone reader 17 provided in the area 7a of the first cleaning and optionally also the magnetic separator 9a (cf. FIG. 3). As already described above, the particles fed to the sorting device can be assigned to different predetermined particle classes and then sorted into corresponding partial bulk material streams. An evaluation and control electronics 114 connected to the video camera 34 and to at least one ejecting device 42, 41 ensures that all the bad particles are ejected into the trough 43 or into the trough 44 when divided into good and bad particles. The good particles fall from the drum 33 into the groove 45 in the drum area formed by the cover 39 without suction. In addition to the possibility of separating everything that is not recognized as good particles, it can also be provided that all foreign particles have a predefined coloring and / or size and / or shape class can be read out separately from the other bad particles by an appropriate ejection device 41. This can be of interest if bulk material with a high proportion of foreign seeds is to be discharged from the non-biological material, possibly for further use.

The optical sorting device enables an extremely sharp separation of good and bad particles, so that only a few good particles can be found in the separated particles and only a few bad particles in the particles found to be good. The separation limit can be easily adjusted, for example, by simply specifying a different set of values representing the good particles and possibly previously stored. Since the optical sorting device 24 also includes a learning mode, the desired product for recording the class-determining parameters of the optical sorting device can be presented, for example, for a new rice variety before the start of the processing process. Since the cleaning according to the invention is essentially a sorting process, possibilities open up by which the first cleaning becomes significantly more efficient. For example, in addition to foreign parts, not enough fully grown or deformed rice grains can be read out in front of the peeling device 108. Optionally, good part classes of different grain sizes can also be separated in order to then be peeled in optimally set peeling devices 108.

In the area 7b of the first cleaning that follows the peeling device, there is a further advantageous area of application for an optical sorting device 24a. There, it can replace the table separators 109 and the drum sorters 111 provided according to the prior art. The table readers 109 are large and are based on the reciprocal stroke movement principle, so that great demands are made on the construction volume and the building thickness. These claims disappear with the use of the optical sorting device 24a. In addition to the reduction in machine * and building expenditure, the return of unpeeled rice grains is optimized. With the table readers 109, peeled and unshelled rice grains are separated according to their specific weight, impact behavior and seeping capacity, the selectivity being poor due to the small differences. In order to keep the proportion of unhulled rice in the hulled small, it must be accepted that the fraction returned to the hulling device 108 is composed in equal parts of hulled and unshelled rice and results in a return of about 20% in the known hulling devices.

Since the unshelled (paddy) and the peeled rice (brown rice) differ in size (approx. 5%) and in color, the optical sorting device 24a can ensure a much sharper separation than the known table reader 109, so that the portion for The peeling device 108 of the returned husked rice becomes minimal. In addition to the classes of good and unhulled rice, the optical sorting device preferably reads at least one further class, such as green rice, discolored and / or deformed rice or, if appropriate, foreign parts. For this purpose, a number of ejection devices 41, 41 ', 42 corresponding to the number of classes to be ejected is controlled by the controller 114. By reading out green rice with the optical sorting device 24a, the expensive drum sorter 111 is also superfluous. It again shows that cleaning, which functions as a sorting into different color and / or size and / or shape classes, has significant advantages over a conventional separating device.

Instead of the plan sifter 115 and the trieure 117, an optical sorting device 24b can be used to sort the desired size classes and, if necessary, breakage or foreign parts. At the same time as the size classification, a color classification can be carried out, for example to read black rice, so that no additional color classification is necessary. Combined selection criteria open up separation options that were previously not possible or that were not sensible due to excessive effort. For example, black-colored rice broken can be separated from uncolored rice without additional effort. Due to the separate readout,

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various impurities, they can be reused optimally and do not have to be completely removed as waste. A major advantage of the optical sorting device 24, 24a, 24 'is its universal applicability due to the possibility of separating particle classes with any size and / or shape and / or color features. The cleaning and sorting requirements of different rice milling plants can thus be satisfied by the same device.

An embodiment according to FIG. 4b provides a combination of a plan reader 118 with an optical sorting device 24a 'after the peeling device 108 to increase the throughput. The plan reader 118 separates the product stream into the following three fractions, unpeeled paddy rice, mixture of unpeeled and peeled rice and peeled rice. The optical sorting device 24a 'then only separates the mixed fraction into unhulled and hulled rice and possibly into bad particles such as green rice.

Fig. 5 shows a conventional processing of soybeans for oil production. Different processing areas are separated from one another by elevators 202, 203 and 204. From the input silos 1, the soybeans preferably pass via an elevator 202 into a pre-cleaning area 6 with a balance 10, a sieving device 11, a wind sifter 12 and possibly a metal separator 9. The pre-cleaning process removes both coarse foreign matter such as earth bulbs, wood and straw parts and Stones, etc., as well as fine particles. To remove dust, the grain is then passed through an air stream, preferably through an air classifier 12. This pre-cleaning must be carried out at high bulk material throughputs and therefore cannot remove the impurities in the size range of the grain kernels.

The pre-cleaned product passes through elevator 203 for the first cleaning into an area 7 with a further screen cleaning device 11a with wind sifter 12a and a stone reader 17. If necessary, a bias tape is provided for separating half or split soybeans so that the bean parts that remain remain whole soybeans but fall down. The fragments of soybeans should be separated because they have an increased bacterial infestation. The soybeans reach the area 8 via the elevator 204, where they are treated with hot steam in a steam treatment device 205 and then reach an oil extractor 209 through a shot rolling mill 206, a vibrating screen 207 and a flaking roller 208.

6 an optical sorting device 24 is provided according to the invention when processing soybeans for the first cleaning. It replaces the screen cleaning device 11a and the stone reader 17 and, if necessary, the bias tape. Foreign matter and pieces of soybean are recognized on the basis of color and / or sizes and / or shape features and are preferably ejected separately. In addition, there is the possibility with the optical sorting device 24 to remove the green and unripe soybeans, the bacterial content of which is high, on the basis of the color and possibly the shape. This gives white flakes after flocculation, which can also be used to produce TVP (textured vegetable protein) for human consumption.

Fig. 7 shows schematically the processing of sunflower seeds according to the prior art. The silos and pre-cleaning in area 6 are the same as for processing soybeans. The subsequent first cleaning for removing foreign parts and shell parts is preferably provided in an impact peeler 210 after a peeling process. In the impact peeler 210, a mixture of shells and peeled and unshelled cores is formed. A first vibrating sieve device 211 and an aspiration device 113 are used to attempt to split into unshelled grains, peeled grains and shells. A first fraction with the unpeeled kernels makes up approx. 17% of the total amount of bulk material and is composed of around 40% unpeeled and 60% peeled kernels. This fraction reaches the impact mill 210 via the elevator 203. The poor selectivity leads to a high load on the impact peeler 210 with returned peeled cores. A part of the shells is excreted as a second fraction via the aspiration device 213. A third fraction consisting of peeled cores and shells is fed to a second vibrating sieve device 212 with a second aspiration device 214. The core parts, which get into the aspiration device with the shells, are then separated as best as possible from the shells with plan sifters 215. The cores from the second screening device 212 and the core parts from the plan sifters 215 enter a processing device 216, which preferably comprises flaking rollers and a pressing device.

8 provides that a method according to the invention for processing sunflower seeds for the first cleaning comprises an optical sorting by means of an optical sorting device 24. A device for removing peels, preferably a vibrating sieve device 211 with an aspiration device 213, is provided next to the impact peeler 210. The optical sorting device separates the bulk material freed from part of the shells by means of color and / or size and / or shape information into unshelled cores, peeled cores and core parts and shells. The sorting device 24 optionally includes a video camera system 34 with two or more cameras that provide information from different perspectives. The evaluation of this image information provides three-dimensional size and / or shape information for each particle, so that, for example, shells and cores can be distinguished on the basis of different thicknesses. If the sorting device 24 has a very high ejection capacity, there may be 5

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if the preclassification by the vibrating sieve device 211 is dispensed with. A key advantage of optical sorting is the sharp separation into the desired classes. The fraction with the unshelled cores essentially comprises neither shells nor peeled cores, so that the impact peeler 210 is not unnecessarily loaded by peeled cores and achieves a higher product throughput with the same performance.

In order to optimize the first cleaning when processing sunflower seeds, the embodiment according to FIG. 9 already provides a first optical sorting device 24a in front of the impact peelers 210. With this sorting device, essentially definable size characteristics, such as length and / or width and / or size of the cross-sectional or viewing area, are used to essentially divide the product stream into two partial streams with cores of different sizes. These partial flows are peeled in the impact peelers 210 set to the respective particle size. Due to the individual setting, the smashing into too small particles as well as a large proportion of unshelled cores can be avoided. The subsequent aspiration device 213 separates a large proportion of the shells, so that the classification in a second optical sorter 24 does not have to throw out unnecessarily many shell parts. The unshelled cores are fed back to the first sorting device via the elevator 203. In addition to the optimized peeling process, the first optical sorting device 24a has the further advantage that it is also possible to read out foreign parts such as stones, light grains, weed seeds and the like.

10 shows a known system for cleaning, peeling and classifying coffee beans. In a first area 7a of the first cleaning of product silos 14, dried coffee cherries or pergamino coffee reach a sieve separating device 11a with an aspiration device 12a via quantity regulator 15, a conveyor 16 and a balance 10a. Coarse, very fine and light foreign parts are read out of the coffee in the separating device 11a, 12a. In the adjoining dry stone reader 17, foreign parts of the size of the coffee beans are separated out with a larger and possibly also with a smaller weight. The dried coffee cherries enter a peeling device 305 and the pergamino coffee into a polishing device 306 via a magnetic separator 9 and an elevator 302. The peeling or polished bulk goods are separated into three fractions, namely essentially bowls, peeled and unshelled coffee a vibrating sieve 307 and in air classifiers 308. The fraction with unpeeled coffee can be brought back to the peeling device 305 via the elevator 303. In the case of a small unshelled portion, preferably when processing pergamino coffee, a class of pergamino coffee is already guided into a container in a drum sieve 309 and the rest is fed to a classification area (8 ') via an elevator 310. In the case of coffee cherries, a fraction with unpeeled coffee beans is optionally led to the peeling device 305 via the elevator 303.

The peeled or polished coffee beans pass through an elevator 304 into a sorting area in which the beans are 3-separated into different size classes and cleaned of breakage by means of vibration sieve devices 310 and aspiration separating device 311 in different size classes. In a further treatment step, 312 infected, deformed, overgrown beans, as well as small cherry beans and small glassine coffee are read out using light grain readers. In a last step, color sorting devices 313 remove color-undesirable, mainly black beans.

11 shows how the first cleaning according to the invention is optimized by using an optical sorting device 24, which takes the place of the dry stone reader 17. Due to the color and / or size and / or shape features that clearly distinguish the coffee beans from possible contamination, the optical sorting device can not only read out foreign parts with greater density and size different from the coffee beans, but essentially all foreign parts.

If necessary, the coffee cherries are additionally divided into two size classes for cleaning, which go separately into optimally set peeling devices 305. To enable this optimization of the peeling process, two peeling lines or intermediate storage cells must be provided.

According to FIG. 12, at least one second, possibly also a third optical sorting device 24a is provided in order to discolor (eg black), infected, deformed, broken, from the peeled or polished coffee beans by means of color and / or size and / or shape features. Read out overgrown, small cherry and small glassine beans, as well as to divide the good coffee beans into different size classes. A third sorting device is necessary if the second cannot separate all the desired bean classes. Reading out the unwanted coffee portion is the second part of the first cleaning. According to the state of the art, this cleaning step was essentially carried out only after the bean classification and therefore had to be carried out separately for different product classes with a large amount of light grain readers 312 and color sorting devices 313. By using the second and possibly third optical sorting device 24a, the cleaning step and the classification can be carried out functionally in an optimal manner. The optical bean classification replaces the vibrating sieve devices 310 used according to the prior art, the aspiration separating devices 311, the light grain readers 312 and the color sorting devices 313, which corresponds to a significantly smaller device *, space and energy expenditure.

It goes without saying that method steps according to the invention for the first cleaning of all Nah5

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means in the form of bulk goods can be provided analogously to the examples shown. The respective pre-cleaning or further processing are different depending on the input or. designed according to the starting product.

Claims (1)

Claims 1. A method for separating and / or cleaning by selecting or sorting bulk material in the form of cereal grains, rice grains, soybeans, sunflower seeds, coffee beans, cleaning being provided as the first cleaning after pre-cleaning and before processing and at least one selection of the bulk material particles characterized in that an optical screening (24) is provided, wherein at least one of the criteria color, size and shape of the bulk material particles is recorded, and that after evaluating this criterion or these criteria, the sorting or selection of Particle is made. 2. The method according to claim 1, characterized in that the optical sighting (24) is carried out with at least one optoelectronic sensor, preferably with at least one color television camera (34), the output signal of which or the classification of each bulk material particle is subjected to an electronic data processing process, in particular is a comparison process between the parameters characterizing a particle class and a bulk particle to be classified in each case and makes a result signal available which is used for the automatic control of the sorting device (24, 41, 42) for the classified particles. 3. The method according to claim 1 or 2, characterized in that the parameters characterizing the particle classes are acquired in the course of a learning run by evaluating the image information of at least one particle representing the respective particle class or, if appropriate, preferably also as standard values in the case of size and / or shape parameters with tolerance ranges can be entered. 4. The method according to claim 1, 2 or 3, characterized in that the size information of a bulk particle preferably comprises at least one value that corresponds to a particle expansion or a particle diameter and / or at least one value that corresponds to a particle cut surface or view surface ; and that the shape information comprises at least one effective particle contour and / or at least one derived variable, such as the first, the second and / or the third surface moment of a visible surface. 5. Plant for carrying out the method according to one of claims 1 to 4 for the processing of grain, with a pre-cleaning area (6), with raw fruit silos (14) for receiving pre-cleaned regrind selected by types and / or qualities with a first cleaning area ( 7) for cleaning the regrind coming from the raw fruit silos, with at least one network device (21b) with stand-off silos (21c) for conditioning the regrind and at least one scrubbing device (21a) for the cleaned good, as well as with at least one milling drum roller that conditions the conditioned regrind (22), characterized in that an optical sorting device (24) is provided in the area of the first cleaning (7), which sorts out foreign parts and / or stunted or deformed grains and / or breakage. 6. Plant for carrying out the method according to one of claims 1 to 4 for processing rice, with a pre-cleaning area (6), with at least one rice silo (107), with a first and a second area of the first cleaning (7a, 7b) A peeling device (108) and then a separating device for separating peeled rice grains, unpeeled rice grains and peels that can be returned to the peeling device (108) and foreign bodies are provided in the second area (7b) with a grinding and / or polishing device (112 , 113) and with a classifying device for dividing the rice grains into fragments and different size classes, characterized in that at least one of the following features is provided, a) in the first area of the first cleaning (7a) there is an optical sorting device (24) and this is preceded by a screen cleaning device (11a), which reads significantly larger and significantly smaller foreign parts compared to the rice grains, and a dust-extracting aspiration device (12a), whereby the optical sorting device (24) sorts out foreign parts and / or stunted or deformed grains and / or breakage; b) the separating device adjoining the peeling device (108) comprises an optical sorting device (24a); and c) the classifying device is an optical sorting device (24b) which, in addition to the size classification, also carries out a color classification. 7. Plant according to claim 6, characterized in that the separating device adjoining the peeling device (108) comprises a plan reader (118) upstream of the optical sorting device (24a '), which separates the product into three fractions, namely unpeeled rice grains, peeled rice grains and one Splits the mixed fraction, the mixed fraction being fed via a connecting line from the plan sifter (118) to the optical sorting device (24a ') and the optical sorting device (24a') thus only sorting part of the product coming from the peeling device (108). 8. Plant for carrying out the method according to one of claims 1 to 4 for the processing of soybeans, with a pre-cleaning area (6), an area of the first cleaning (7) and a processing area (8) each with at least one device for hot steam treatment (205 ), a shot rolling mill (206), a vibrating screen (207), a flaking roller (208) and an oil extractor (209), characterized in that in 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 12th 23 CH 684 742 A5 24th In the area of the first cleaning (7) an optical sorting device (24) is provided for reading out foreign matter, pieces of soybean and green, unripe soybeans. 9. Plant for carrying out the method according to one of claims 1 to 4 for processing sunflower seeds, with a pre-cleaning area (6), then an area of the first cleaning (7), which area at least one peeling device (210) and at least one separating device for separation into peeled, unshelled cores and shells, wherein a return device for unshelled cores connects to the separating device and leads to the beginning of the first cleaning area (7), and a processing area (216) for the cores separated in the first cleaning of foreign parts and shells , characterized in that a) in the area of the first cleaning (7) after the at least one peeling device, an optical sorting device (24) and directly upstream of this a mechanical separating device (211) and / or an aspiration device (213), and b) in the area the first cleaning (7) before the at least one peeling device ( 108) an optical sorting device (24a) is provided, which separates the unshelled sunflower seeds into at least two size classes and feeds these separate peeling devices (210) and reads out foreign parts. 10. Plant for carrying out the method according to one of claims 1 to 4 for processing coffee cherries or glassine coffee, with a first and a second area of the first cleaning (7a, 7b), wherein in the first area a first separating device for reading out foreign parts and in the second a peeling device (305) or a polishing device (306), as well as a second separating device is provided, which separates the product into peeled coffee beans, unshelled coffee beans, for their return to the peeling device, a return device is used, and shells, and with a classification area (8 ') for separating the coffee beans into different size or quality classes, characterized in that a) in the first area of the first cleaning (7a) a first optical sorting device (24) and a mechanical separating device fHa) and / or connected directly upstream thereof an aspiration device (12a); and b) a second optical sorting device (24a) is provided in the classifying area (8 '). 11 Plant according to one of claims 5 to 10, characterized in that the optical sorting device (24, 24a, 24a '), a separating device (28 to 32) for the pre-cleaned bulk material, a support (33) transporting the separated bulk material, at least one the individual bulk material-monitoring video device (34), the output signals of which are fed to an electronic computing device (114) which, at least one storage device (68) for color classes and / or sizes and / or defining particle classes Form information and a comparison device (71) for the parameter values derived from the storage device (68) and from the video device (34), the result signal of which is fed to a sorting device (41, 42), the particles which are assigned to a particle class to be read, throws into a receiving area (43, 44) assigned to the particle class, the non-ejected particles coming from the base into a further receiving area (45). 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 13