Grain sorting process

Grain sorting process and apparatus (1) includes a grain infeed chute (2) for delivery of bulk cereal grain into the apparatus (1) past an in-line measurement station (3) which analyses selected parameters of grain delivered through the infeed chute (2). The grain infeed chute (2) discharges onto a horizontal grain sorting conveyor (4) which discharges the grain into storage silos (5, 6) in response to one or more measured parameters of the grain determined at the measurement station (3), The measurement station (3) In has a sensor unit (7) which includes a near-infrared light source for emitting light onto grain delivered through the grain infeed chute (2) or through the grain sorting conveyor (4), The light is reflected from the grain and reflected light is detected by the sensor (7) to provide a spectrum of the grain. A spectrometer (8) connected to the sensor unit (7) converts the spectrum into one or more corresponding preselected grain parameter values, The grain parameter values generated by the spectrometer (8) are delivered to a controller (9). The controller (9) then controls operation of the sorting conveyor (4) in response to the measured grain parameter values to deliver the cereal grain into a storage silo (5, 6) having a grain parameter corresponding to the measured grain parameter.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. § 371 of International Patent Application No. PCT/EP2021/065359 filed Jun. 8, 2021, which claims the benefit of priority of British Patent Application No. GB 2008617.9 filed Jun. 8, 2020, both of which are incorporated by reference in their entireties. The International Application was published on Dec. 16, 2021, as International Publication No. WO/2021/250041 A1.

INTRODUCTION

This invention relates to a grain sorting process. In particular, the present invention relates to an apparatus and a process for in-line sorting of cereal grains, at industrial capacity (100t/h), ensuring individual storage based on a selected parameter of the cereal grain considered for sorting.

BACKGROUND OF THE INVENTION

Cereal acceptance criteria for use in different industries require the measurement of a number of parameters of the cereal grains. This allows the identification of the most suitable cereal grain batches as well as the storage and subsequent use of homogenous cereal grain batches.

Some current solutions offered to industries to measure quality parameters for the cereals are based mainly on individual sampling of each bulk load of cereal grains received, followed by its measurement with laboratory equipment. Certain companies have developed methods and devices able to measure higher amounts of cereals, but a limiting factor remains the capacity that is able to be processed with such equipment. Solutions have been offered by different companies for in-line measurement of different cereal parameters which either have a limited capacity of the system, and as such are not suitable for production scale, or the values measured are only collected for information purposes, without any action for separation into different cereal grain batches based on the quality of the cereal grain.

US 2013/168301 A1 discloses an apparatus and method for sorting of particles such as seeds, grains and the like. Patent No. U.S. Pat. No. 4,057,146 A discloses an optical sorting apparatus for beans or grains which provides sorting on the basis of size and colour. U.S. Pat. No. 5,779,058 A discloses a colour sorting apparatus for grains.

A grain sorting process and apparatus is described in our U.S. Pat. No. 8,569,644 for analysing grain in-line and separating grain into batches on the basis on one or more sensed parameter values, such as protein content or moisture content for example. The separation process separates the grain into homogenous batches which is desirable for subsequent processing of the grain. It is an object of the present invention to provide an improved process and apparatus of this type.

SUMMARY OF THE INVENTION

According to the invention, there is provided a process for analysing bulk quantities of grain in-line and separating the grain into batches, each batch corresponding to at least one pre-selected grain parameter value, the processing including:delivering the grain continuously past an in-line measurement station,analysing the grain by emitting light onto the grain passing the in-line measurement station and detecting the light reflected from the grain to provide a spectrum of the grain,converting the spectrum into the or each parameter value, andseparating the grain in-line into batches in response to the or each measured grain parameter value,characterised in that the process includes controlling grain flow through the measurement station for forming an optically dense grain layer at the measurement station for reflecting the light emitted onto the grain.

In one embodiment of the invention, the process includes funnelling the grain for delivering the grain in an optically dense grain layer stream past a sensing head at the measuring station.

In another embodiment the process includes delivering the grain through an infeed chute having a sensor unit mounted in a side wall of the infeed chute at the measurement station, passing grain delivered through the infeed chute to a funnel mounted on the side wall at the sensor unit, forming the optically dense grain layer by means of the funnel and delivering the grain in an optically dense grain layer stream against the side wall past a sensing head of the sensor unit mounted on the side wall.

In another embodiment, the process includes funnelling the grain for delivering the grain in an optically dense grain layer stream past a sensor unit at the measuring station, delivering the grain through an infeed chute having the sensor unit mounted at a side wall of the infeed chute at the measurement station, passing grain delivered through the infeed chute through a funnel mounted on the side wall at the sensor unit, forming the optically dense grain layer by means of the funnel and delivering the grain in an optically dense grain layer stream against the side wall past a sensing head of the sensor unit mounted on the side wall, channelling the grain between tapered funnel side walls projecting outwardly from the side wall of the grain infeed chute at which the sensor unit is mounted and between an angled guide flap and the chute side wall, the angled guide flap extending between the funnel side walls and spaced-apart from the chute side wall at which the sensor unit is mounted, said angled guide flap tapering inwardly from an inlet of the funnel towards the chute side wall on which the sensor unit is mounted.

In another embodiment, the process includes conveying the grain through the measuring station on a grain feed conveyor having a number of spaced-apart paddles mounted within and movable through an associated trough by moving the paddles through the associated trough of the conveyor and forming the optically dense grain layer in the trough between each adjacent pair of paddles.

In another embodiment, the process includes conveying the grain through the measuring station on a grain feed conveyor enclosed within a housing and having a number of spaced-apart paddles mounted within and movable through an associated trough by moving the paddles through the associated trough of the conveyor and forming the optically dense grain layer in the trough between each adjacent pair of paddles, the measuring station being mounted on a side wall of the housing and having a sensor unit mounted at the side wall of the housing at a side of the grain feed conveyor for sensing the optically dense grain layer formed between each adjacent pair of paddles.

In another embodiment the process includes forming an optically dense grain layer having a thickness of at least 5 cm.

In another embodiment the process includes emitting near-infrared light onto the optically dense grain layer for generating a near-infrared spectrum of the grain.

In another aspect the invention provides apparatus for analysing bulk quantities of grain in-line and separating the grain into two or more batches in response to at least one sensed grain parameter value, the apparatus comprising:a measurement station having a sensor unit;means for delivering grain past the sensor unit in an optically dense grain layer;a light emitter at the measurement station operable to emit light onto the optically dense grain layer for reflection back to the sensor unit;the sensor unit for detecting light reflected from the grain to provide a spectrum;means for converting the spectrum into at least one grain parameter value; andmeans for separating the grain into two or more batches in response to the measured parameter value.

In another embodiment the means for delivering the grain past the sensor unit in an optically dense grain layer comprises a funnel having tapered sidewalls leading to a narrowed neck portion, a sensing head of the sensor unit being mounted at a side of the neck portion for streaming the grain in an optically dense grain layer in front of the sensing head.

In another embodiment, the measurement station is mounted on a grain infeed chute, the measuring station having a sensor unit mounted at a side wall of the grain infeed chute, a funnel mounted within the grain infeed chute, the funnel comprising tapered funnel side walls projecting outwardly from the side wall of the grain infeed chute at which the sensor unit is mounted, an angled guide flap extending between the funnel side walls and spaced-apart from the chute side wall at which the sensor unit is mounted, said angled guide flap tapering inwardly from an inlet of the funnel towards the chute side wall on which the sensor unit is mounted.

In another embodiment, the angled guide flap is curved between an inlet end and an outlet end of the angled guide flap.

In another embodiment, the outlet ends of the tapered funnel side walls connect to a funnel neck portion having parallel neck walls extending outwardly from each funnel side wall.

In another embodiment, an outlet end of the angled guide flap extends partially into the funnel neck portion between the neck walls.

In a further embodiment the means for delivering the grain in an optically dense grain layer comprises a grain feed conveyor having a number of spaced-apart paddles which are movable along an associated trough to form an optically dense grain layer in the trough between adjacent pairs of paddles, the sensor unit being mounted at a side of the trough.

In another embodiment, the means for delivering the grain in an optically dense grain layer comprises a grain feed conveyor having a number of spaced-apart paddles which are movable along an associated trough in a position extending vertically upwardly form a bottom wall of the trough to form an optically dense grain layer in the trough between adjacent pairs of paddles, the grain feed conveyor being mounted within a housing having a grain inlet end connected to a grain infeed chute and a grain outlet end having at least one discharge chute, the grain feed conveyor communicating between the grain inlet end and the grain outlet end of the housing, the measuring station being mounted at a side wall of the housing and having a sensor unit mounted at the side wall of the housing at a side of the grain feed conveyor for sensing an optically dense grain layer formed between each adjacent pair of paddles on the grain feed conveyor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, and initially toFIGS.1to4thereof, there is illustrated grain sorting apparatus according to the invention, indicated generally by the reference numeral1. The apparatus1includes a grain infeed chute2for delivery of bulk cereal grain into the apparatus1. An in-line measurement station3analyses selected parameters of grain delivered through the infeed chute2into the apparatus1. The grain infeed chute2discharges onto a horizontal grain sorting conveyor4which discharges the grain into storage silos5,6in response to one or more measured parameters of the grain determined at the measurement station3.

The measurement station3has a sensor unit7which includes a near-infrared (NIR) light source for emitting light onto grain delivered through the grain infeed chute2. The light is reflected from the grain and reflected light is detected by the sensor7to provide a spectrum of the grain. A spectrometer8connected to the sensor unit7converts the spectrum into one or more corresponding preselected grain parameter values. The grain parameter values generated by the spectrometer8are delivered to a controller9. The controller9then controls operation of the sorting conveyor4in response to the measured grain parameter values to deliver the cereal grain into a storage silo5,6having a grain parameter corresponding to the measured grain parameter.

Two storage silos5,6are shown inFIG.1andFIG.2by way of illustration, although it will be appreciated that any desired number of storage silos may be provided. Discharge chutes10,11communicate between the sorting conveyor4and each silo5,6. An inlet12of the first discharge chute10has a slide plate14moveable by means of a pneumatic ram15between a closed position across the inlet12, closing the inlet12, and an open position to allow discharge of cereal grain from the sorting conveyor4through the discharge chute10and into the silo5.

The second discharge chute11, which is downstream of the first discharge chute10, may be fitted with a similar slide plate or may be open as shown inFIG.2. Thus, when the slide plate14at the inlet12of the first discharge chute10is open, cereal grain is delivered to the first silo5and when the slide plate14is closed the cereal grain is delivered into the second silo6. The controller9regulates operation of the slide plate14in response to sensed grain parameters to deliver the cereal grain into the required silo5,6for collecting homogenous cereal grain in each silo5,6.

The sorting conveyor4has a box-section housing16with an inlet end17and an outlet end18. A grain feed conveyor19is mounted within the housing16for delivery of grain through the housing16between the inlet end17and outlet end18of the housing16. Grain is discharged from the infeed chute2onto the grain feed conveyor19at the inlet end17of the housing16and is transported by the grain feed conveyor19to the outlet end18of the housing16for discharge through one of the discharge chutes10,11.

Referring in particular toFIG.3andFIG.4, the in-line measurement station3is shown in more detail. In this case the sensor unit7is mounted on a bottom side wall20of the grain infeed chute2. A funnel21is mounted within the infeed chute2in alignment with the sensor unit7to deliver a portion of the grain passing through the infeed chute2in an optically dense grain layer stream past the sensor unit7. The optically dense grain layer stream is about 5 cm deep against an inside face22of the bottom side wall20of the infeed chute2.

The funnel21has an upper tapered portion26with inwardly tapered side walls23,24leading to a lower narrowed neck portion25within which a sensing head of the sensor unit7is mounted. The funnel side walls23,24and neck portion25project outwardly from the inside face22of the bottom side wall20of the chute2. The neck portion25is formed by two spaced-apart substantially parallel neck walls33,34extending outwardly and downwardly from each funnel side wall23,24and forming extensions thereof.

In addition, an angled guide flap27narrows a grain passage28through the funnel21between an inlet29and an outlet30of the funnel21. This provides a consistent depth of grain at the sensor unit7throughout delivery of cereal grain through the grain infeed chute2to promote sensor accuracy. The angled guide flap27extends between the funnel side wall23,24and is spaced-apart from the bottom side wall20of the infeed chute2. The angled guide flap27tapers inwardly from the inlet29of the funnel21towards the bottom side wall20of the infeed chute2. An outlet end32of the flap27is spaced apart from the inside face22of the bottom side wall20of the grain infeed chute2by a required distance to produce a desired grain layer stream depth at the sensor unit7, which in this case is about 5 cm. The angled guide flap27may be straight or curved between an inlet end31and the outlet end32of the angled guide flap27.

In use, grain is delivered through the infeed chute2past the in-line measurement station3. The sensor unit7emits NIR light onto the grain delivered through the grain infeed chute2. The light is reflected from the grain and reflected light is detected by the sensor7to provide a spectrum of the grain. The spectrometer8connected to the sensor unit7converts the spectrum into one or more corresponding preselected grain parameter values. The grain parameter values generated by the spectrometer8are delivered to the controller9. The controller9then controls operation of the sorting conveyor4in response to the measured grain parameter values to deliver the cereal grain into a storage silo5,6having a grain parameter corresponding to the measured grain parameter.

Referring now toFIGS.5to8, there is shown another grain sorting apparatus according to a second embodiment of the invention, indicated generally by the reference numeral40. Parts similar to those described previously are assigned the same reference numerals. The apparatus40has a grain infeed chute42discharging to an inlet end50of a grain sorting conveyor44. The grain sorting conveyor44has a box-section housing46at a bottom of which is mounted an elongate trough47. A grain feed conveyor48is mounted within the housing46such that a lower pass49of the grain feed conveyor48is located in and travels along the trough47between the inlet end50and an outlet end51of the housing46for delivery of grain received from the infeed chute42at the inlet end50to the discharge chutes10,11at the outlet end51of the housing46.

The grain feed conveyor48has two spaced-apart parallel endless drive chains52,53mounted on drive sprockets54,55at the outlet end51of the housing46. A drive mechanism56rotates the drive sprockets54,55which are mounted on a drive shaft58drivably connected to the drive mechanism56. Opposite ends of each drive chain52,53are carried on associated rotatable sprockets (not shown) mounted on a rotatable shaft59at the inlet end50of the housing46.

A plurality of spaced-apart scraper paddles60are mounted between the drive chains52,53. Each scraper paddle60extends substantially perpendicular to the direction of travel of the drive chains52,53. Grain delivered from the grain infeed chute42into the housing46collects in the trough47between scraper paddles60on the lower pass49of the grain feed conveyor48which project vertically upwardly from a bottom wall45of the trough47and is delivered along the trough47between the inlet end50and the outlet end51of the housing46by movement of the scraper paddles60along the trough47.

In this case the sensor unit7is positioned on a side wall62of the housing46. The depth of the scraper paddles60is such that the sensing head of the sensor unit7is fully covered by the depth of grain retained in the trough47between each adjacent pair of scraper paddles60.

The process and apparatus of the invention is able to measure any desired grain parameter, such as protein content, moisture content, etc., of the cereal grain during intake of bulk cereal grain material. The intake of cereal grain is separated into quality groups based on the different measured levels of the parameter or parameters under consideration and each quality group is separated out in-line and stored in its own silo5,6by the process and apparatus of the invention. Thus, the cereal grain is separated in-line into homogenous batches of cereal grain which ensures consistently high quality when the cereal grain is later processed.

It will be appreciated that the invention provides a process and apparatus for high-speed, non-destructive measurement in real time and providing a high level of measurement accuracy.

The sensor head of the sensor unit3is in direct contact with the cereal grain product and measures the required parameters using NIR technology. To ensure that the NIR sensor produces correct measured values, the measurements are taken in the compact product flow in which the cereal grains are closely packed together. The compact product flow is permanently illuminated with NIR light. The absorption behaviour and hence the spectrum of the reflected light changes depending on the concentration of the parameters in the passing cereal grain. Through comparison of the reflected light with a calibration database created with the help of a laboratory, the respective properties such as the protein content can be determined.

The terms “comprise” and “include”, and any variations thereof required for grammatical reasons, are to be considered as interchangeable and accorded the widest possible interpretation.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.