WO1988003269A2

WO1988003269A2 - Process and device for collecting measurement samples from a flow of bulk materials

Info

Publication number: WO1988003269A2
Application number: PCT/EP1987/000646
Authority: WO
Inventors: Daniel Brunnschweiler; Emanuel Kummer; Bruno Bischoff; Hans Oetiker
Original assignee: Gebrüder Bühler Ag
Priority date: 1986-10-30
Filing date: 1987-10-30
Publication date: 1988-05-05
Also published as: WO1988003269A3; EP0295290A1

Abstract

A process and device for collecting measurement samples from a flow of bulk materials, in particular foodstuffs and feedstocks, in order to determine one or several characteristic values of the material, such as protein content, moisture, colour, ashes, granulation, etc. At least one first partial flow is derived from the flow of bulk materials and at least this partial flow is reunited with the flow of bulk materials, the first partial flow or a further partial flow derived from the first is at least temporarily dammed, a small percentage of the dammed partial flow is at least in part continuously extracted as measurement sample and this measurement sample is then conveyed through a measuring device, preferably by NMR or NIR, to determine the characteristic values of the material.

Description

Method and device for forming measurement samples from a bulk material flow

The invention relates to a method and a device for forming measurement samples from a bulk material flow, in particular food and feed, for the purpose of determining one or more material parameters, such as protein content, moisture, color, ash, granulation etc., a first of the bulk material flow Partial flow derived and this is combined again with the bulk material flow.

At present, strong trends can be observed, the industrial processing of organic materials, e.g. B. to bring the grinding, screening, sorting out of different fractions etc. into an even higher degree of automation. Both the necessary Processing machines as well as the electronic computer means are available for this. The only problem remaining is the determination of the various material parameters or product parameters in the current product flow.

In practice it is seldom possible that the same measurement method can be used as a single measurement both directly in the production flow and in the laboratory. The best known, also officially approved laboratory method z. B. used for the determination of the water content a laboratory cabinet. The weight loss between the fresh and the dried measurement sample is determined and the moisture of the fresh measurement sample is calculated from this. The entire process takes a period of five minutes to an hour, for example. However, this means that the drying oven method for measurement in the product stream is especially disregarded for quickly effective controls on processing machines.

The measurement of the product moisture on the product stream must therefore be carried out on the basis of other physical laws. However, this is where the first difficulty arises, namely how, based on different physical measurement methods, exactly the same measured values can be obtained from the same sample.

A second key problem lies in the fact that, although it is recognized that very precise measurement results can be obtained in the laboratory, the laboratory itself has almost no influence on whether the measurement sample is representative of the product stream, possibly for an entire product batch.

An often decisive source of error lies in obtaining a representative measurement sample for both the laboratory sample and for measurement on the product stream. The abundance of influencing parameters, for example temperature, segregation, sample size, number of measurement samples, etc., complicates the fact that food and feed are almost exclusively organic. Biological processes take place in these, which can influence the parameters to be measured, so that a systematic or scientific measurement less often leads to the goal than a still frequently used empirical approach.

From GB-PS 597 800 a device is known in which the product stream is run over a weighing system to form the measurement sample, so as to form the size of the sample from the current product stream. If a measurement sample of a few percent is taken from a current division using such a system, e.g. B. from less than 10 or less than 2% of the product stream, strong segregation must be expected, since an edge layer of the free-falling product stream is then preferably detected. Experience has shown that this differs greatly from the average of the bulk material.

The FR-PS 2 345 720 proposes to form the measurement sample by only briefly releasing a by-pass channel. The flap mechanism required for this also results in a disturbance to the product flow, so that segregation and fluctuating product removal time, depending on the size of the current throughput in the main line, also lead to falsified measurement samples and correspondingly falsified measurement values.

The only proposal that has so far been successfully used in practice and cited for the very special purpose of continuous moisture measurement is an on-line measurement with relatively large measurement samples is described in the European patent 43 137 of the applicant. The fluctuations in humidity that occur again and again in practice, for example as a result of a previously mixed together of different raw materials, are smoothed out by the main product flow being jammed, regulated by a certain accumulation height and thus generating a correspondingly delayed product flow in a by-pass channel, the actual measuring channel becomes.

The moisture measurement method described in DE-OS 3 441 856 is used for floury goods. In this case, the measured material is guided through a measuring channel via a by-pass channel to determine water content, protein, etc. The measurement itself is carried out using infrared light. The light emitted back from a sample surface is sighted and the respective water content is calculated from it.

The value (accuracy and industrial applicability) of all the measurement methods described above essentially depends on the type of measurement sample obtained.

The invention now encompasses the task of forming samples, preferably very small samples, from a continuous flow of bulk material in such a way that the measurement sample can be used as representatively as possible for the flow of bulk material and can be used directly without great delay, if possible online and in calibration time.

The formation of representative micro-samples from a bulk material flow is already extremely difficult. With increasing reduction of the sample (e.g. reduction of the sample cross-section, the sample amount, and / or the sample volume), the probability decreases to obtain a representative particle cross-section from the bulk material flow.

The formation of small samples becomes particularly difficult when they represent a continuous flow of bulk material should. If time fluctuations in the composition of the bulk material flow are to be expected, then sampling must also take place continuously, since fluctuations in time are usually also reflected in the sampling. The continuous taking of samples, however, poses the problem that sample quantities begin that are beyond the scope of very small samples.

The above object is achieved in the generic method mentioned in the introduction in that the first partial flow or a further partial flow derived therefrom is backed up at least temporarily, a small percentage of the backed up partial stream is at least partially continuously taken as a measurement sample and this measurement sample is then determined by a corresponding one to determine the material parameters Measuring device is guided.

In the generic device also mentioned in the introduction, this object is achieved by one or more flow dividers for dividing the bulk material flow into a main flow and one or more partial flows, by return means for returning at least the first partial flow to the main flow, by a measurement sample flow divider for taking a Measurement sample from the lowest partial flow, and by means of first backflow means for at least temporarily backflow of the smallest partial flow in the area of the measurement sample flow division.

Surprisingly, it was found that the idea on which the measuring device according to EP-PS 43 137 is based gives very advantageous results if the essential part of the corresponding measuring device, instead of being the measuring device itself, is taken as a secondary or partial flow in EP-PS 43 137 and from it a measurement sample is derived. The actual measurement sample occurs with a very small time delay and shows almost no segregation in the case of small samples of a few percent or per thousand. It is particularly important that the measurement sample formation takes place in the backwater. It has been shown that the behavior of a segregation inherent in the bulk goods can be switched off with sufficient certainty. Complicated mechanisms for obtaining many measurement samples and remixing are no longer an imperative. The flow property is influenced in the favorable sense by the jam of the goods; the bulk material behaves similar to a liquid in a traffic jam and is not subject to the air vortex disturbances of free bulk material fall. In the case of free bulk material, different particles move towards each other at different speeds. These relative particle velocities can arise from the difference in the specific weight, the shape, the surface air resistance etc. of the individual particles. The relevant backflow reduces the relative movements of the particles to one another to the extent that they are negligible for the measurement purposes required here. In other words, the different particles move only negligibly against each other. As a result, the segregation effects, more generally the sample falsifications, are reduced to a negligible level.

However, the invention allows a whole series of further advantageous configurations. Thus, particularly in the case of flour-like, less easily pourable products, the measurement sample is preferably removed via a conveyor element, preferably a screw or a pneumatic cylinder, which works from the backflow area of the secondary flow, the product quantity of the measurement sample being able to be adjusted by varying the discharge capacity of the conveyor element; this also gives a quasi a "sample" from the "sample". It is also possible to produce measurement samples in selectable time periods by alternately operating the screw conveyor. However, this made it possible for the first time in a simple manner to measure various product parameters on-line, and for this purpose to continuously carry the test sample through the measuring device. Furthermore, measuring methods such as NMR, (nuclear magnetic resonance) and NIR (near infrared), which due to the special measuring technology allow only the smallest measuring samples. As is known, the size of the measurement sample is a decisive criterion for the accuracy of the measurement result in relation to the entire product quantity. In the older manufacturing processes, the laboratory raw materials are preferred to check the raw materials and then the finished products. Only the ever increasing automation of production made it necessary to examine intermediate products during processing for their ingredients, for example to make the necessary changes to the manufacturing parameters.

As a direct measuring method for determining the various ingredients, e.g. B. the percentage water content of a bulk material is particularly suitable for NMR measurement. With this measuring technique, the signal received is a direct measure of the number of hydrogen nuclei. For sporadic measurements, i.e. H.

Measurements at comparatively large intervals are brought to a standstill in the measuring device. If, on the other hand, the time interval between the individual measurements is short or even negligible compared to the dwell time of the sample in the measuring device, it is not necessary to stop the measuring sample, the measuring sample is preferably carried out continuously by the measuring device.

Grain and flour products are usually still living in the mill area. Most of the grains are germinable. Many essential life processes still take place in the flour or within the individual protein bodies, e.g. B. breathing. As a result, the detection of the Water is faced with the entire microbiological and physical processes within the product mass, the water being known to form very different bonds.

In practice, it has been shown that the NMR method can be used to determine representative values after only a short calibration. In particular, the same calibration could be used for all average wheat varieties without measuring deviations being ascertainable, the measuring accuracy being plus / minus 0.2% even for personnel not trained in NMR technology; therefore all types of products can be measured with the same basic measuring method.

The NMR method has also proven to be insensitive to changes in bulk density, since the mass of the material to be measured can also be recorded using the resonance method and the calculation of the percentage of moisture can be included.

In the case of a very particularly advantageous design option, in particular in the case of NMR and NIR methods, a calibration sample can be entered into the measuring device and the device can be designed for self-calibration by means of appropriate electronic evaluation and computing means. This means that the standard method for flour control, namely the direct comparison of a sample with a sample from the production process can now be used analogously for the measurement of moisture. At the start of the work process, a pattern for reading in the calibration values is entered, on which the entire production is then based.

Furthermore, the percentage water content of the grain is preferably determined twice using the same device, namely before and after wetting, preferably using the NMR or NIR method. For this purpose, be for a first measurement Dry grains are conveyed through the measuring device for a few seconds without water. Using the dry wheat and an approximate hourly output, the water addition is calculated, adjusted and a few seconds later the wetting is checked in the same way.

The solution according to the invention also includes that a further partial flow can be derived from the first partial flow and the measurement sample is then taken from this. The further partial flow is preferably formed from the backflow section of the partial flow immediately preceding it. This principle can be continued when further partial flows are formed.

Preferably, if the further partial flow taken from a partial flow contains only the smallest quantities of bulk material, the further partial flow is fed to a mixer, mixed there and the measurement sample "is taken from the partial flow homogenized thereby. This measuring method makes it possible to extract the smallest quantities of bulk material over a long period of time Bulk material flow or a preceding partial flow continuously and then in the mixer to produce a representative cross-section of the bulk material flow and its possible fluctuations in time, including different particle occupations during the time Mixer can be controlled to the measuring device.

The first partial flow is preferably also taken from the bulk material flow in a storage area, preferably according to the overflow principle. For this purpose, the bulk material stream for forming the first partial stream and the remaining bulk material stream, hereinafter also called the main stream, is preferably referred to the loading led the first part of the stream. The result of this is that the bulk material flow fraction, ie the main flow, not taken up by the first partial flow overflows, so to speak, from the vessel or the area of the first partial flow.

A flow scale based on the Buhler principle is preferably used to form one or more or even all of the partial flows. The backflow for partial flow formation can also be carried out with this balance. Furthermore, the throughput of the partial stream or streams is also recorded with it. Such a scale is described, for example, in European patent applications 84 111 967.0; 86 902 385.3 and 86 901 871. To avoid repetition, we hereby expressly refer to the content of the European patent applications.

When using the aforementioned Buhler flow weigher, the formation and the backflow of the partial flow or flows on the one hand and its flow rate detection on the other hand is preferably carried out at least partially simultaneously; preferably synchronous and continuous. According to a further preferred embodiment, the partial flow or flows are continuously formed and backed up by means of the balance and the throughput of the partial flows is determined in batch operation.

Finally, the invention also encompasses a method for monitoring the production of foodstuffs, preferably from cereals, in which the material parameters for food production are determined at process-critical points, and material parameters determined in this way are prepared for simultaneous display and comparison with a setpoint value scheme.

Embodiments of the invention are shown in the drawing and are described in more detail below. Show it

Fig. 1 sampling with screw discharge

Fig. 2 a double application of power division in traffic jams

Fig. 3 schematically shows a device according to the invention for flour-like goods, FIG. 4 shows a section I-I of FIG. 3

Fig. 5 shows an embodiment of an application of the invention in the acceptance control for silo delivery

Fig. 6 shows an example of the course of measured values of air-dry wheat

7 shows an example of the course of measured values of freshly wetted wheat

8 shows an application of the invention as a delivery control for the mill delivery and for controlling the wetting of flour-like goods,

Fig. 9 shows the application of the invention for the control of the wetting for the whole grain and the control of the ingredients of the grains before grinding

10 shows a further exemplary embodiment of the invention, using a mixer in one of the partial streams;

Fig. 11 further embodiments of the invention using one and 12 sets of a continuous scale on the one hand for granular material (Fig. 11) and on the other hand for floury material (Fig. 12).

There follows the explanation of the invention with reference to the drawings according to structure and possibly also according to the mode of operation of the invention shown.

In Fig. 1, a device for the continuous formation of smallest measurement samples is shown schematically. A bulk or product stream 1 is divided into a main stream 3 and a first partial or secondary stream 4 in the region of a first division, also called a coarse division. The side stream 4 is by a Storage space 5 and via a return channel 6 back into the main stream 3, so that the product stream 1 can be continued again after the main stream and the secondary stream have been combined. The proposed solution has the particular advantage that regardless of the current throughput of the product stream 1 there is always an approximately constant ratio between the current throughput of main stream 3 and secondary stream 4. This is achieved in that both the main flow 3 and the secondary flow 4 are stowed by a damming valve 7 which specifies a cross section "X" through which the entire bulk material flow must flow. The main stream 3 is passed through a level control path 8, in which an electro-capacitive level measuring plate 9 is arranged in time and, depending on the setting, for. B. is constantly maintained about a level line 10. The baffle valve 7 releases a certain cross section "X" so that the level control path 8 does not empty, but always remains filled up to the level line 10. The corresponding electrical signal is processed via electronics 11 with an electropneumatic converter 12 and used as an actuating signal via a membrane 13 for setting the baffle slide 7. The build-up in cross section "X" has the result that a backed-up product stream also arises in the return channel 6, so that both the main stream 3 and the secondary stream 4 are actually stowed via the damming valve 7. It is now important for the implementation of the invention that a further flow divider and fine flow divider 14 is arranged in the area of the storage space 5, because in any case in the storage space 5 there is undisturbed settling (practically no relative movement of the particles against one another) of the product. The storage space 5 is, of course, flowed through by a still considerable current product throughput of the secondary flow. At least previous experiments have shown that the product composition of the secondary stream 4 corresponds very precisely to the product composition of the product stream 1. But this can be done in one step the sample formation z. B. 1:10 or 1: 5 can be reduced. The storage space 5 is opposite the return channel 6 z. B. 1: 5 or 1:10 expanded, so that there is a delayed flow of the product accordingly in the storage space.

However, in order to achieve a percentage relationship between the main and secondary flow, the fine flow divider, as can be seen in FIG. 2, must represent an essentially identical repetition of the coarse flow divider 2. For this purpose, a sample collector 30 is arranged in the storage space 5. The ratio of the flow rate in the storage space 5 and the P-robes collector 30 is determined by double stowage of the product flow on the one hand and a narrowing of the cross section 31 from the sample collector 30 on the other hand.

In the variant according to FIG. 2, it is necessary, by means of appropriate level control 32, to ensure double the congestion, analogously to the flow control with the pusher slide 7.

1 further shows how the fine flow divider 14 is formed by a screw discharge driven by an electric motor 15. The measurement sample is fed via a test channel 16 to a measuring device 17. It is indicated in broken lines how the measurement samples can be fed back into the product stream 1 either directly into the measuring device 17 or via an overflow 18 and a connecting line 18 '.

Another possibility for taking samples is shown in FIGS. 3 and 4 (in cross section). A shell 102, in which a conveyor screw 103 is arranged, leads across and in the middle through the main power shaft 3 in its upper half. Shortly after the exit from the main power shaft 3 in the direction of an NMR measuring device 6, the screw conveyor tapers to a closed channel, which means less Bulk goods, when received in the open tray 102, are transported further. The screw conveyor 103 is driven by a motor 104, which is connected to the NMR measuring device 6 via control electronics 105. The NMR measuring device has the structure known per se. A magnetic field 108, which includes a measuring channel 110, is formed between two opposing magnets 107. The measuring channel 110 is connected directly to the bowl 102 by a transition piece 109, so that the flour collecting in the bowl 102 is conveyed through the transition piece by means of the screw conveyor 103

109 is conveyed into the measuring channel 110. The tray 102 continuously fills with the falling product stream. The product is compressed by the screw conveyor 103 in the measuring channel 110. At the end of the measuring channel 110 there is a stand element 111 which, due to its backflow effect, ensures that the product is easily accumulated in the measuring channel 110. From the end of the measuring channel

110 the material leaving the NMR measuring device falls back into the secondary power shaft 4 via a by-pass 112.

6 and 7 show the typical course of the NMR signal obtained over time from practical experiments.

6 shows the measurement of the moisture of air-dry

Wheat with the help of the pulsed magnetic nuclear magnetic resonance (NMR).

The signal curve shown was generated with a pulse sequence of 90 degrees to 180 degrees.

The signals S ₁ to S _{4 are} sampled at the appropriate times. These provide the following information:

S ₁ - mass of the sample

S ₂ - mass of the liquid phase (water and oil)

S ₃ - mass of the oil

S ₄ - noise. The proportion of water in the product can be determined by linking these signals. Example:

% Humidity =

The constant a, b depend on the product and must be determined in a calibration. The oil content of the product can be determined with an analog link. Example:

Here too, the constant a, b must be determined with a calibration depending on the product.

FIG. 7 shows the measurement of the moisture of freshly wetted wheat with the aid of the pulsed magnetic resonance (NMR).

Here, with a 90 ° - 180 ° - 180 ° pulse sequence, the signal curve shown was generated qualitatively and to the appropriate ones

Times the signals S ₁ to S ₅ sampled. These provide the following information:

S ₁ - mass of the sample S ₂ - mass of the liquid phase: bound water plus oil-free water

S ₃ - mass of oil and free water

S ₄ - mass of free water

S ₅ - noise.

The proportion of water in the product can be determined by appropriately linking these signals. Example:

% Humidity =

The constants depend on the product and must be determined in a calibration.

The proportions of the individual components bound and free water, oil can be determined with similar linkages.

It may be convenient to use other Kontanteπ. Example:

% Humidity =

In general it can be said:

With suitable pulse sequences it is possible to determine both the total proportion of liquid in a product and the individual components of a possible mixture of liquids. In the figures that follow, the application of the new invention is shown in various process stages of grain processing, from the acceptance of the grain to the delivery.

Fig. 5 shows the grain acceptance. The grain is weighed continuously via a supply conveyor 130 into a receiving scale 131. In a by-pass line 112, which is guided parallel to the balance 131, the test sample is passed through an NMR measuring device, for example according to FIGS. 3 and 4. The determined values are transferred simultaneously with the measured values of the balance 131 to a central computer 132 via signal lines 133. B. passed over a rough cleaning 135 or a drying 136 and then stored by means of a conveyor 137 in the storage cell 38 ... 42 provided for the special grain.

8 shows the end of the process of a mill. Flour and / or semolina are each stored in the storage cells 50 ... 53 corresponding to the quality. Depending on how freely flowing the product is, it is passed via an NMR measuring device 6 according to FIGS. 3 or 5, which is arranged in a by-pass line 112 parallel to a balance 131. In this case, the NMR measuring device is used as an online control of the contents of the finished products. However, several types of flour or flours with different proteins and / or water content in a mixer 54 and again the weight and the various ingredients can also be determined in the on-line measuring method by means of the NMR measuring device 6.

Another possibility is to moisten the flour for a certain water content. For this purpose, the product is fed into a network screw 55 with metered addition of water 56, then sieved and again closed back to the scale 131 and passed through the NMR measuring device 6. The NMR measuring device 6 works here as an actual value detector for the water content of the flour or for the corresponding control of the water addition 56 for wetting to a predetermined setpoint.

9 shows the cleaning and grinding preparation of the grain. The grain is stored in raw fruit cells 60, 61, 62, 63 etc. depending on the quality and type of grain. All values measured from the raw material are stored in a computer 132. The mixture desired for grinding is put together on the computer 132 and drawn off from the raw fruit cells 60... To 63 etc. by metering units 64 and fed into a cleaning unit 66 via a conveyor 65. The mixture is detected by a balance 131 and the various constituents of the mixture are measured by the NMR measuring device 6 and, if necessary, corrections are made to the proportions of the individual components by means of the metering units 64 in order to ensure a specific mixture desired for the grinding. The cleaned mixture is passed via a further conveyor 67 via a network device 55. At the output of the network device 55 there is an NMR measuring device 6 which detects the water content of the mixture and controls the addition of the network water (for example 3 to 4%) to a certain preselected setpoint. It is the main wetting. The wetted grain is stored in standing boxes 68 to 71. For grinding, the moistened grain is fed to a second wetting 74 via metering devices 72 and a transport pneumatics 73. At this point, however, only a quantity of water of e.g. B. 0.1 to 0.2% added. After a very short dwell time in a stand-off box 75, the mixture which is now ready for grinding is weighed again as the mill input (before B ₁ ) and as a control the Ingredients, especially the exact amount of water measured in the grain. The measured values can be used for a further correction of the previous work steps or for controlling the grinding.

Of course, it is possible to use the NMR measuring device 6 only at one point in the entire mill diagram. The economically optimal use, however, can be seen at least for the main wetting, in front of the stand-up boxes 68 to 71 etc. and for checking the finished flour according to FIG. 9. In larger automatic mills, the third most important measuring point, the incoming mill check before B must also be carried out using the NMR measurement method. The remaining measuring inserts are more a question of the degree of automation that should be sought in a mill.

FIG. 10 shows a further exemplary embodiment of the invention, which essentially corresponds to the exemplary embodiment described in FIG. 1. In this regard, reference is made to FIG. 1.

In a departure from the example described in FIG. 1, the fine flow divider 14 designed as a screw feeds into a mixer 70 whose agitator is driven by a drive motor m. This exemplary embodiment is particularly suitable for the case in which a very small proportion of bulk goods is to be continuously withdrawn from the storage space 5 over a comparatively long period of time. The mixer room serves as a store in which the material supplied is homogenized. The material homogenized in the mixer space is conveyed into the conveying line 16 leading to the measuring device 17 by means of a further positive conveyor 72, for example, again a check. The positive conveyor 72 is driven by a drive motor AM. The positive conveyor is used for a controlled discharge of the homogenized bulk part from the mixer 70. This can prevent the mixer 70 from running empty.

In the exemplary embodiment shown in FIG. 11, the bulk material is first fed into the conveyor scale 75, which works according to the Buhler principle. Such a continuous scale is described, for example, in the EP applications mentioned at the beginning.

The flow scale 75 is supported with its supports 75 electronic weight detection elements. It is arranged to be movable relative to the supply and discharge lines by means of sleeves 80, 81. Via a measurement value processing circuit connected downstream of the electronic weight detection means, the slide device 78 is set in such a way that a constant level of the conveyor scale 75 is set.

Insofar as the same reference numerals have been used in FIG. 11 as in the preceding figures, they also mean the same functional unit. In this respect, reference can be made to the corresponding explanations in the preceding figures.

The discharge from the measuring device 17 and thus the speed of the measuring sample is set by the measuring device 17 to a constant value and held there by means of a screw conveyor 76 connected downstream of the measuring device 17. The ratio of the quantity of bulk material that is discharged from the positive conveyor 76 to the quantity of bulk material that is supplied to the storage space 5 determines the quantity of bulk material that is supplied to the main stream via the bypass channel 6.

This embodiment has made it possible to simultaneously detect the throughput of the bulk material flow 1 and the parameters of this bulk material flow. At the same time The flow scales are used to divide the current according to the overflow principle in the area of the flow divider 2. The flow scales based on the Buhler principle ensure that a mass flow - in contrast to the core flow - moves through them. This means that the particles of the bulk material flow have practically no relative velocity to one another, or at least a negligible relative velocity. This avoids the undesired segregation effects.

In principle, FIG. 12 corresponds to the exemplary embodiment according to FIG. 11 for floury material. In contrast to FIG. 11, in FIG. 12 the floury material is conveyed out of the storage space of the conveyor scale 75 by means of a positive conveyor 90. The positive conveyor 90 is connected to the storage space 5 via a bellows 92. The line 16 leads from the storage space 5 to the measuring device 17, from which the positive conveyor 76 conveys the measuring sample back into the main stream.

If the continuous scale 75 operates in batch mode, the following change in the exemplary embodiment shown in FIG. 12 is preferably provided. The bellows 92 is omitted. Instead, the measuring device 17 directly adjoins the positive conveyor 90. The measuring device 70 is then connected to the discharge tube of the measuring device via a bellows. The latter opens into the main stream below the flow scale 75.

The principle "sample from the sample" is also observed in this exemplary embodiment. The measuring or the first partial flow is formed by the bulk material stowed over time in the closed flow weigher. The forced conveyor 90 now conveys a partial flow from the jammed measuring flow, the measuring sample into the measuring device.

INTERNATIONAL PATENT COOPERATION (PCT)

(51) International Patent Classification 4 (11) International Publication Number: WO 88/03 G01N 33/10; 1/20 A3 (43) International

RELEASE DATE: May 5, 1988 (May 5,

(21) International file number: PCT / EP87 / 00646 (74) Lawyers: VON SAMSON-HIMMELSTJERNA, F., etc .; Widen ayerstr. 5, D-8000 Munich 22 (D

(22) International filing date:

October 30, 1987 (10/30/87)

(81) Destination countries: AT (European patent), BE European patent), CH (European patent),

(31) Priority number: 4290 / 86-3 (European patent), FR (European patent), (European patent), HU, IT (European patent

(32) Priority date: October 30, 1986 (October 30, 1986) JP, KR, LU (European patent), NL (European patent), SE (European patent), SU, US.

(33) Country of priority: CH

Released

(71) Applicant (for all destination countries except US): GEM with international search report.

BRÜDER BÜHLER AG [CH / CH]; CH-9240 Uzwü Prior to the expiry of the changes to the claims (CH). Deadline. Publication will be repeated if changes occur.

(72) inventor; and

(75) Inventor / applicant (only for US): BRUNNSCHWEI- LER, Daniel [CH / CH]; Lindengarten 1, CH-9242 (88) Date of publication of the international research Oberuzwil (CH). KUMMER, Emanuel [CH / CH]; richfc- ^' July 28, 1988 (July 28, Neueggstrasse 8, CH-9212 Arnegg (CH). BISCHOFF, Bruno [CH / CH]; Sturzeneggerstrasse 19, CH-9015 St. Gallen (CH). OETIKER, Hans [CH / CH ]; Salisstrasse 4, CH-9000 St. Gallen (CH).

(54) Title: PROCESS AND DEVICE FOR COLLECTING MEASUREMENT SAMPLES FROM A FLOW OF BU MATERIALS

(54) Designation: METHOD AND DEVICE FOR FORMING MEASURING SAMPLES FROM A BULK FLOW

(57) Abstract

A process and device for collecting measurement samples from a flow of bulk materials, in particular foodstuffs and feedstocks, in order to determine one or several characteristic values of the material, such as protein content, moisture, color, ashes, granulation, etc. At least one first partial flow is derived from the flow of bulk materials and at least this partial flow is reunited with the flow of bulk materials, the first partial flow or a further partial flow derived from the first is at least temporarily dammed, a small percentage of the dammed partial flow is at least in part continuously extracted as measurement sample and this measurement sample is then conveyed through a measuring device, preferably by NMR or NIR, to determine the characteristic values of the material.

(57) Summary

Method and device for forming measurement samples from a bulk material flow, in particular from food and feed, for the purpose of determining one or more material parameters such as protein content, moisture, color, ash, granulation etc., at least one first partial flow being derived from the bulk material flow and at least this partial flow is reunited with the bulk material flow, the first partial flow or a further partial flow derived from it is backed up at least temporarily, a small percentage of the backed up partial flow is at least partially continuously taken as a measurement sample and this measurement sample is then used to determine the material parameters by a measuring device, preferably for NMR or NIR is performed.

ONLY FOR INFORMAΗON

Code used to identify PCT contracting states on the headers of publications that publish international applications in accordance with the PCT.

AT Austria ES France MR Mauritania

AU Australia GA Gabon MW Malawi

BB Barbados GB United Kingdom NL Netherlands

BE Belgium HU Hungary NO Norway

BG Bulgaria ir Italy RO Romania

BJ Benin JP Japan SD Sudan

BR Brazil KP Democratic People's Republic of Korea SE Sweden

CF Central African Republic KR Republic of Korea SN Senegal

CG Congo u Liechtenstein SU Soviet Union

CH Switzerland LK Sri Lanka TD Chad

CM Cameroon LU Luxembourg TG Togo

DE Germany, Federal Republic of MC Monaco US United States

DK Denmark MG Madagascar π Finland ML Mali

Claims

1. Method for forming measurement samples from a bulk material flow, in particular of food and feed, for the purpose of determining one or more material parameters, such as protein content, moisture kit, color, ash, granulation, etc., at least one first partial flow being derived from the bulk material flow and at least this partial flow is combined again with the bulk material flow, characterized in that the first partial flow or a further partial flow derived therefrom is backed up at least temporarily, a small percentage of the backed up partial flow is at least partially continuously taken as a measurement sample and this measurement sample is then determined by a measuring device to determine the material parameter to be led.

2. The method according to claim 1, characterized in that the further partial flow is formed from the backwater section of the partial flow immediately preceding it.

3. The method according to claim 1 or 2, characterized in that the partial stream is mixed and the measuring sample thus homogenized is removed.

4. The method according to at least one of the preceding claims, characterized in that the first partial flow and the remaining part of the bulk material flow (also main flow) are formed according to the overflow principle.

5. The method according to claim 4, characterized in that the bulk material flow is carried out for formation carried out according to the overflow principle, at least predominantly from the first partial flow and main flow to the region of the first partial flow.

6. The method according to at least one of the preceding claims, characterized in that the measurement sample is taken via a mechanical conveying element working in the backflow area of the partial flow (for example a screw conveyor or pneumatic cylinder).

7. The method according to claim 6, characterized in that the measuring sample is obtained by varying the discharge rate of the mechanical conveying element and / or choosing the working time periods of the mechanical conveying element.

8. The method according to at least one of the preceding claims, characterized in that the measurement sample is passed continuously through the measuring device.

9. The method according to at least one of the preceding claims, characterized in that the percentage water content is determined with the same measuring method before and after wetting, preferably by the NMR or NIR method.

10. The method according to claim 9, characterized in that at the start of the working process a known laboratory pattern of Bulk material for reading in calibration values for the measuring method used is entered and the measuring device uses this to calibrate itself using appropriate evaluation and computing means.

11. The method according to at least one of the preceding claims, characterized in that a conveyor scale is used to form at least one of the partial streams, to its / its backwater and to detect its / its backwater and to detect its / its throughput.

12. The method according to claim 11, characterized in that the formation and the backflow of the partial streams on the one hand and its / its throughput detection on the other hand are carried out at least partially simultaneously.

13. The method according to claim 12, characterized in that the formation and the backflow of the partial streams on the one hand and its / its throughput detection on the other hand are carried out synchronously and continuously.

14. The method according to claim 13, characterized in that the formation and the backflow of the partial streams on the one hand continuously and its / its throughput detection on the other hand are carried out in batch operation.

15. Device for carrying out the method according to at least one of the preceding claims, characterized by:

a) one or more flow dividers for dividing the bulk material flow into a main flow and one or more partial flows, b) return means for returning at least the first partial stream into the main stream,

c) a measuring sample flow divider for taking a measuring sample from the smallest partial flow, and

d) first backflow means for the least temporary backflow of the smallest partial flow in the area of the measurement sample flow division.

16. The apparatus according to claim 15, characterized by second backflow means for a backflow of the bulk material flow which has an effect in the region of the first flow division.

17. The apparatus of claim 15 or 16, characterized in that at least the first flow divider is designed as a scale, esp.

18. The apparatus according to claim 17, characterized in that the scale is also the first backflow means.

19. The apparatus according to claim 17 or 18, characterized in that the balance is the second backflow means.

20. Device according to one of claims 15 to 19, characterized in that at least one downstream of the first flow divider flow divider is designed as a conveying element, esp. Screw or pneumatic cylinder.

21. The apparatus according to claim 20, characterized in that the conveying element feeds into a mixer, and the measuring sample divider takes the measuring sample as a partial amount from the mixing area.

22. A method for monitoring the production of foodstuffs, preferably from cereals, in particular according to one of claims 1 to 14, characterized in that the material parameters for food production are determined at points which are critical from a procedural point of view, and the material parameters thus determined for simultaneous reproduction and comparison be prepared with a setpoint scheme.