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WO-2026092870-A1 - METHOD AND DEVICE FOR PEELING CEREAL GRAINS

WO2026092870A1WO 2026092870 A1WO2026092870 A1WO 2026092870A1WO-2026092870-A1

Abstract

The invention relates to a method for peeling cereal grains (100), in particular wheat grains, comprising the following steps: cleaning the cereal grains (100) of contaminants in a cleaning device (10), wetting the cleaned cereal grains (100) in a wetting device (20) for a predefined period of time with water having a predefined temperature, and introducing the wetted cereal grains (100) into a peeling device (30) comprising a housing (32) having a peeling chamber (33) contained therein, in which peeling chamber a rotor (34) rotates with radially outwardly pointing peeling elements (36a) arranged thereon and complementary stationary peeling elements (36b) which originate on the inner side of the housing (32) and interact with the peeling elements (36a) in such a way that the wetted outermost shells (102) of the cereal grains (100) in the peeling chamber (33) are broken open on rotation of the rotor (34) with the generation of a shearing effect, and separating the kernels (104) of the cereal grains (100) from the broken-open outer shells (102) in a classifier (70) by applying heated air to the cereal grains (100) and broken-open shells (102) at a temperature in the range from 35 to 45°C, preferably 40°C. The invention further relates to a device for carrying out said method.

Inventors

  • Ebbecke, Axel

Assignees

  • A. Ebbecke Verfahrenstechnik AG

Dates

Publication Date
20260507
Application Date
20250512
Priority Date
20241029

Claims (20)

  1. Claims
  2. 1. Method for dehulling cereal grains (100), in particular wheat grains, comprising the following process steps:
  3. Cleaning the grain kernels (100) in a cleaning device (10) to remove impurities,
  4. Wetting the cleaned grain kernels (100) in a wetting device (20) with water of a specified temperature for a specified period of time,
  5. Introducing the moistened grain kernels (100) into a dehulling device (30) comprising a housing (32) with a dehulling chamber (33) contained therein, in which a rotor (34) with radially outwardly extending dehulling elements (36a) and complementary stationary dehulling elements (36b) originating on the inside of the housing (32) rotates, which interact with the dehulling elements (36a) in such a way that the moistened outer husks (102) of the grain kernels (100) are broken open in the dehulling chamber (33) when the rotor (34) rotates, generating a shearing effect, and
  6. Separating the kernels (104) of the cereal grains (100) from the broken outer shells (102) in a classifier (70) by applying heated air (72) to the cereal grains (100) and broken shells (102), preferably at a temperature in the range of 35 to 45 °C, particularly preferably 40 °C.
  7. 2. Method according to claim 1,
  8. the ad by marked sign,
  9. that the cleaned grains (100) are moistened with water by conveying them through a water bath (22) by means of an inclined screw conveyor (24) or a sieve drum immersible in a water bath (22), wherein the contact time of the grains (100) with the water is between 4 and 8 minutes, in particular 6 minutes, and the temperature of the water is preferably between 15 and 25 °C, particularly preferably 20 °C. 3. V according to claim 2,
  10. d ad through g ek ennz e i chn et,
  11. that the inclination of the screw conveyor (24) to the horizontal is such that it is arranged with its first inlet end (24a) in the water bath (22) and with its second outlet end (24b) outside the water bath (22).
  12. 4. Method according to claim 3,
  13. d adur ch gekennze i chnet,
  14. that the water-wetted grain kernels (100) are sieved and/or dried in a drying device (50), in particular in a rotary sieve device, before being fed to the hulling device (30), wherein the sieve drum (52) of the rotary sieve device has a mesh size in the range of preferably 300 to 600 pm, particularly preferably 500 pm, and wherein the moisture content of the grain kernels after the drying process is preferably between 4% and 8% and particularly preferably 6%.
  15. 5. Method according to any one of the preceding claims,
  16. then marked,
  17. that the grain kernels (100) are fed to the dehulling device (30) via a buffer storage tank (40) and a sensor-controlled flap arrangement (38) in batches with a substantially constant volume of grain kernels (100), wherein the flap arrangement (38) comprises a first inlet-side flap (38a) associated with the inlet (35) of the dehulling device (30) and a second outlet-side flap (38b) associated with the outlet (37) of the dehulling device (30), which can be opened and closed via a control device such that the first inlet-side flap (38a) is opened for a predetermined, preferably adjustable, duration of time, so that a predetermined volume of moistened grain kernels (100) flows from the buffer storage tank (40) into the dehulling device (30) when the outlet-side flap (38b) is closed, and both flaps (38a, 38b) during the subsequent peeling process, and after completion of the peeling process, the second outlet-side flap (38b) is opened and the peeled material is discharged from the peeling device with the first inlet-side cap (38a) closed. (30)
  18. 6. V experienced according to claim 5,
  19. this has been marked,
  20. that a material sensor (39) is arranged at the outlet (37) of the peeling device (30), with which the presence of peeled wheat kernels (100) in the area of the outlet (37) can be detected, and depending on its signals the second outlet-side flap (38b) is closed and then the first inlet-side flap (38a) is opened by the control device for a predetermined period of time if no wheat kernels are detected by the material sensor (39) in the area of the outlet (37).

Description

Method and device for hulling grains The invention relates to a method and a device for dehulling cereal grains, in particular wheat grains, with the features of claims 1 and 10. The processing of wheat into wheat flour has been known for a long time and takes place, for example, in grain mills. In these mills, the wheat kernels, after being cleaned and moistened with water, including the fruit and seed coats surrounding the kernel and germ of the wheat grains, are fed successively to different pairs of rollers in roller mills, and the resulting flour is separated from the rest of the milled material in appropriate sifters. Furthermore, it is known to separate wheat grains from their husk in grain dehulling devices. The husk consists of an outer multilayered fruit husk and an underlying seed coat, which contains a large proportion of the minerals and the main part of the dietary fiber. DE 90 12 355 Ul describes such a device for dehulling grain, which has a driven roller surrounded by a sieve, the surface of which is provided with ridges arranged in rows. When the roller rotates, a gap is formed between the inside of the sieve and the radially outer surfaces of the ribs. This gap is slightly less high than the grain kernels to be dehulled, so that the shearing action exerted by the ribs breaks open the kernels and separates them from the corresponding kernels. The detached kernels and kernels are then discharged through an outlet located on the underside of the device and separated from each other by a transverse airflow. The described device presents the problem that all layers of the fruit and seed coat are broken open and separated, so that the endosperm, i.e., the kernels of the grains, are indeed separated, but the different layers of the fruit and seed coat are contained as a mixture in the dehulled product, which cannot be separated from each other in this form using known separation methods, or only with great difficulty. However, as the applicant has recognized, harmful substances such as pesticides and toxic substances from the air and rainwater often accumulate in the very outermost layer of the fruit peel, the so-called epidermis or upper cell skin layer, which is exposed to the weather and protects the underlying layers. These substances burden the human organism and are considered the main cause of most of the health problems associated with the consumption of wheat products. Accordingly, it is an object of the present invention to provide a method and an arrangement for carrying it out, with which only the outermost layer of the fruit shell of cereal grains, in particular wheat grains, the so-called epidermis, can be separated from the underlying layers of the fruit and seed coats as well as the kernels of the cereal grains. This problem is solved according to the invention by a method and a device having the features of claims 1 and 10. Further features of the invention are contained in the dependent claims. According to the invention, a method for dehulling grains, in particular wheat grains, comprises cleaning the grains of impurities in a cleaning device, wetting the cleaned grains with water of a predetermined temperature in a wetting device for a predetermined period of time, introducing the cleaned and wetted grains into a dehulling device, which includes a rotor rotating in a housing within a dehulling chamber, with radially outwardly projecting dehulling elements arranged thereon and complementary stationary dehulling elements extending from the inside of the housing, which interact with the dehulling elements in such a way that the moistened outer husks of the grains are broken open in the dehulling chamber during rotation of the rotor, generating a shearing effect, and the subsequent separation of the kernels of the grains from the broken outer husks in a classifier using heated air, preferably at a temperature in the range of 35 to 45 °C. Preferably, the temperature of the separating air supplied to the classifier is 40 °C, which to a certain extent also results in an advantageous drying of the surface of adhering water droplets. As the applicant has found in numerous experiments, combining the individual steps of the inventive process yields a final product with a purity level of almost 100%. This means that, for example, 1 kg of the final product contains only a single wheat kernel in which the outer husk, i.e., the epidermis, has not been completely removed, or in which the hulled kernel has been mechanically damaged. In the preferred embodiment of the process, the cleaned grains are wetted with water by conveying them through a water bath using an inclined screw conveyor or, alternatively, a sieve drum that can be pivoted and immersed in the water bath. The contact time of the grains with the water is advantageously between 4 and 8 minutes, and particularly is 6 minutes. As the applicant has found, the maximum achievable purity of the final product can be optimized by the afo