WO2021043965A1

WO2021043965A1 - Root crop harvesting system

Info

Publication number: WO2021043965A1
Application number: PCT/EP2020/074737
Authority: WO
Inventors: Achiel VANGILBERGEN
Original assignee: Ses Vanderhave
Priority date: 2019-09-04
Filing date: 2020-09-04
Publication date: 2021-03-11

Abstract

A root crop harvester device (1) comprising a double wheeled system (2) mounted on an ax (3), driving the double wheeled system (2) to turn in the direction opposite (18) of the direction of the harvester (19), each wheel (10) of the double wheeled system (2) comprising a plurality of elements (6) assembled so as to form a wheel (10), and each of the said element (6) comprising an internal opening (7), use thereof, and process to harvest roots using such device (1).

Description

ROOT CROP HARVESTING SYSTEM

Field of the invention

The present invention is in the field of the root crop industry and of agronomy. More particularly, the present invention discloses a method for improved harvesting of roots, for instance of sugar beet.

Background of the invention

Sugar beet is an important agricultural crop in temperate and subtropical regions.

However, the harvesting of roots, such as of sugar beet roots, is time -and energy- consuming and may cause major damages to the roots, whereas damaged roots have impaired storage properties.

Regular harvesting systems are based on spikes or disks, that rotate in the same direction of the harvester, and that enters deep enough into the soil to extract the roots, such as sugar beet roots.

SE25268 discloses a variation of such system with a kind of clamping device in an attempt to more gently harvest the beet. Here, again, the rotational direction of the harvesting device is the same as the harvester.

Vibrating systems can be added to improve the yield and/or to reduce the soil tare.

Besides sugar beet, several root crops, such as chicory or fodder beet are in a long need of a better harvesting machine .

Indeed, a disadvantage of current harvesters is that they may miss a proportion of the roots in the soil due to breakage of the tip of the root. Also, especially in too dry or too wet conditions, the harvester performances are impaired, for instance due to a significant amount of soil material that is extracted together with the roots, or sticks to the harvesting device. This means unnecessary amounts to load and carry and, later, to separate.

This also means that significant quantities of water and energy will be needed to clean the roots and the harvesting device.

The current harvesting systems are complex and expensive to construct. Consequently, any damage to one single element requires time-consuming reparations. This is not convenient: quick reparations are needed, since the harvest season is often limited by weather conditions, and an immobilized harvester represents a significant immobilized capital .

A lot of efforts have been achieved in downstream processing, for instance to remove soil or to efficiently deliver the roots to a container; however, there have been only few improvements in the system to extract the roots from the soil.

There is thus a clear need to improve the system to extract the roots.

However, any new system must meet several requirements, such as efficiency of harvesting (low amount of remaining roots in the soil), reduced damages to the roots, robustness, flexibility so as to be able to work in different conditions and type of soils, or capacity to work in high throughputs such as in a multi-row system and at an acceptable speed of several kilometers per hours. Summary of the invention

The present invention discloses a root crop harvester device 1 comprising a double wheeled system 2 mounted on an ax (axle) 3, this ax (axle) 3 driving this double wheeled system 2 to turn in the direction opposite 18 of the direction of the harvester 13, each wheel 10 of this double wheeled system 2 being made of a core 24' and comprising protrusions in the form of a plurality of (planar) elements

6 assembled to this core 24' so as to form a wheel, and each of this (planar) element 6 comprising an internal opening

7.

Preferably, the (planar) elements 6 of the present device 1 are all identical.

Preferably each wheel 10 of the double wheeled system 2 is concave.

Preferably, the angle 14 between the (planar) elements 6 of the double wheeled system 2 present on one wheel and the (planar) elements 6 of the double wheeled system 2 present on other wheel is comprised between 10° and 40°, preferably between 15° and 35°, more preferably between 20° and 30°, still more preferably between 22º and 23° (about 22.5°), and/or the angle(s) 23 between the core 24 of the wheel 10 and the (planar) element(s) 6 is (are) lower than 180° (i.e. comprised between 100º and 160°, preferably between 120° and 150°) and/or the angle(s) 25 between the core 24 of the wheel 10 and the (planar) element(s) 6 is (are) lower than

90°, preferably comprised between 30° and 60°.

Preferably, the minimal distance 8 between the (planar) elements 6 of the first and of the second wheel 10 of the double wheeled system 2 is comprised between 30 mm and 100 mm, preferably between 35 mm and 50 mm, and/or the maximal distance 15 between the (planar) elements 6 of the first and of the second wheel 10 of the double wheeled system 2 is comprised between 170 mm and 250 mm, preferably between 175 min and 210 mm.

Preferably, the ax (axle) 3 has a polygonal section, such as a square section or an hexagonal section.

Advantageously, the wheels 10 of the doubled wheeled 2 system rotate at a speed comprised between 40 rpm and 170 rpm, preferably between 50 rpm and 150 rpm, more preferably, between 60 rpm and 120 rpm (e.g. about 77 rpm).

Preferably, the opening 7 of the (planar) elements 6 of the wheels of the doubled wheeled system 2 represents between 10 % and 70 % of the surface of the said element 6, preferably between 20% and 60% of the surface, more preferably between 30% and 50% of the surface.

Preferably, the (planar) elements 6 of the wheels of the doubled wheeled system 2 have a substantially rectangular shape and/or a trapezoidal shape, so that no right angle enters first into (attacks) the ground 9.

Preferably the wheels 10, the ax (axle) 3 and the (planar) elements 6 are arranged so that the (planar) elements 6 enter into the soil 9 at a depth of less than 10 cm, preferably less than 5 cm.

A related aspect of the present invention is an harvester for root crops comprising at least one root crop harvester device 1 depicted here above, and preferably a plurality of such devices 1 (all identical); in this case, more preferably, the ax (axle) 3 is tilted so that the (planar) elements 6 of the different devices 1 do not enter into the ground 9 in the same time.

Preferably, the harvester further comprises a mechanical transport system 13 to drive the harvested root crop to a predefined location, more preferably, this mechanical transport system 13 is a rubber belt, mounted on wheels 16 and/or more preferably, this mechanical transport system 13 turns in the opposite direction 20 than that 18 of the device 1.

The preferred root crops are selected from the group consisting of sugar beet, fodder beet and chicory.

A related aspect of the present invention is an intermediate product in the form of an half-wheel 21 comprising at least one attaching means 22 on its core 24 and two or three (planar) elements 6 comprising an opening 7 for forming the root crop harvesting system depicted here above.

Preferably, the (planar) elements 6 of this intermediate product are all identical.

Preferably, the angle 23 between the core 24 of the half wheel 21 and the (planar) element(s) 6 is lower than 180⁰

(i.e. comprised between 100° and 160°, preferably between 120° and 150°) and/or the angle 25 between the core 24 of the half-wheel 21 and the element(s) (6) is lower than 90°, preferably comprised between 30° and 60°.

Another related aspect of the present invention is the use of this device, or of this half-wheel for harvesting root crops, preferably wherein the root crops are selected from the group consisting of sugar beet, fodder beet and chicory.

Another related aspect of the present invention is a process to harvest root crops comprising the steps of - obtaining an harvester comprising at least one device 1 depicted here above; i.e. being a double wheeled system 2 mounted on an ax 3, each wheel 10 of this double wheeled system 2 comprising a plurality of (planar) elements 6 assembled so as to form a wheel 10, and each (planar) element 6 comprising an internal opening 7, - performing the rotation 18 of the device 1 in the opposite direction as the movement 19 of the harvester so that the (planar) elements 6 of the device enter into the ground 9. Advantageously, the root crops harvested by this process are selected from the group consisting of sugar beet, fodder beet and chicory.

Preferably, in this process, the opening 7 of the (planar) elements 6 of the wheels of the doubled wheeled system 2 represents between 10 % and 70 % of the surface of the said (planar) element 6, preferably between 20% and 60% of the surface, more preferably between 30% and 50% of the surface. Preferably, in this process, the (planar) elements 6 of the wheels of the doubled wheeled system 2 have a substantially rectangular shape and/or a trapezoidal shape, so that no right angle enters first into (attacks) the ground 9.

Preferably, the (planar) elements 6 of this process are all identical.

Preferably, in this process, the wheels 10, the ax 3 and the (planar) elements 6 are arranged so that the (planar) elements 6 enter into the soil 9 at a depth of less than 10 cm, preferably less than 5 cm.

Advantageously, in this process, the wheels 10 of the doubled wheeled 2 system rotate at a speed comprised between 40 rpm and 170 rpm, preferably between 50 rpm and 150 rpm, more preferably, between 60 rpm and 120 rpm (e.g. about 77 rpm) . Detailed description of the invention

The inventor has developed an harvesting device 1 for root crops (sugar beet and/or chicory and/or fodder beet), with a system rotating in the opposite direction of the movement of the harvester. The harvesting device is made of a double (concave) wheel 10. Each wheel 10 comprises a plurality of (planar) elements 6, which have an internal opening 7,

This unique combination unexpectedly allows a gentle removing of the roots from the soil (thus less damages), and allows to reduce the quantity of soil taken together with the roots.

In addition, the overall harvested yield is increased, whereas the energy consumption is reduced. The system is, furthermore, particularly robust; moreover, any damaged element can easily be replaced, usually on-site with no need of external help.

Therefore, a first object of the present invention is a root crop harvester device 1 comprising a double wheeled system

2 mounted on an ax (axle) 3, the ax (axle) 3 driving the double wheeled system to turn in the direction opposite 18 of the harvester movement direction 19, each part (wheel) of the said double wheeled system 2 comprising a plurality of elements 6 assembled so that to form a wheel 10, the elements 6 comprising an internal opening 7.

A corresponding element is an half-wheel 21 comprising at least one attaching means 22 and two or three elements 6 comprising an opening 7.

Preferably, the angle 23 between the core 24 of the wheel 10, or of the half-wheel 21 and the element 6 is lower than 180º (i.e. comprised between 100° and 160°, preferably between 120º and 150°) and/or the angle 25 between the core 24 of the wheel 10, or of the half-wheel 21 and the element 6 is lower than 90°, preferably comprised between 30º and 60°.

This half-wheel 21 is for harvesting the root crops as above. This half-wheel 21 is particularly useful because this element can easily be replaced if damaged, and this element can be stored in the harvester or close to the harvester, to allow rapid replacement after damages (see below).

In this system, soil is taken by the rotating wheel; from which a part acts as a protective cushion between the root (sugar beet) and the elements 6, yet almost all of the extracted soil rapidly falls on the ground, including through the holes 7.

This system has been shown to be very efficient in dry soils, but also in wet soils. Stones did not damage it.

The elements 6 preferably comprise extra strong alloys or materials, such iron and/or titanium and/or kevlar, and it is preferred to rely on strong alloys, for instance on alloys comprising iron, as well as on a protecting layer, which may comprise tungsten-based alloys.

Simple fixing means 22 are enough to perform the present invention.

The ax (axle) 3 has preferably a polygonal section, such as a square section (as shown in Fig. lb) or an hexagonal section; this polygonal section allows a better fastening of the wheel to the rotating ax (axle).

As mentioned, even if the wheel 10 is very robust, for instance by comparison to a spike system, the elements of the wheel 10 can easily be replaced, if needed. For instance, the wheel mounted on the ax is advantageously formed by two parts 21 (the assembly showing the separation is depicted by a double nearly vertical bar, one above and one below the ax 3 in Fig. lb), each part having the same number of elements 6 (usually 2 or 3). Even a whole wheel can easily be replaced, if needed; there is thus no absolute need for a wheel 10 made of two parts (half-wheels) 21. The rotating direction 18 opposite of the direction of the harvester 19) is essential in the present invention: the inventor has noticed that, under normal field conditions, where rows are not totally linear, or where there are some variation of the soil surface, a system rotating in the same direction as the harvester direction results into a lot of broken roots, which is unacceptable.

Preferably, this root crop harvesting system is for harvesting "true roots", such as roots from Beta vulgaris, carrot, celeriac, chicory, salsify, radish, turnip, but also tuber (potato, manioc) or rhizomes (curcuma, ginseng, ginger). Most preferably, the root crop harvesting system is for harvesting "true roots", such as sugar beet roots, fodder beet roots or chicory roots.

Advantageously, the elements 6 of the double wheeled system

2 present on one wheel are shifted by between 10º and 40°, preferably between 15º and 35°, more preferably between 20° and 30°, still more preferably between 22° and 23° (about 22.5°) by comparison to the corresponding elements 6 present on the second wheel of the double wheeled system 2. This equates to the angle 14 ranging from 15° and 35°, more preferably from 20º and 30°, still more preferably from 22° and 23º (or being of about 22.5°).

This allows to locally apply upward pressure on the root (beet, chicory) sequentially on one side, then on the other side; usually every root (beet, chicory) is pushed 4-5 times by the elements 6 of the rotating wheel 10: this reduces the risks of damaging the root (beet) and speeds up the harvesting, even without the addition of vibrating forces.

Preferably, the minimal distance 8 between the elements 6 of the first and second wheel 10 of the double wheeled system 2 is comprised between 30 mm and 50 mm, especially when the root crop is sugar beet or chicory.

The maximal distance 25 between the elements 6 of the first and second wheel of the double wheeled system 2 is preferably comprised between 170 mm and 210 mm, especially when the root crop is sugar beet (or chicory).

The wheels of the doubled wheeled 2 system rotate at a speed comprised between 40 rpm (revolution per minute; rotational speed) and 170 rpm, preferably between 50 rpm and 150 rpm, more preferably, between 60 rpm and 120 rpm (e.g. about 77 rpm). The speed can be adapted, for instance to ensure that there are enough occurrences for (indirect; soil cushion between the element 6 and the root) contact between the elements 6 and the roots 26; hence the number of (indirect) contacts is a function of the speed of the harvesting machine and of the number of the elements 6. A correct speed also allows to remove enough soil, and even to propel the harvested roots 26 to the container part of the harvester, and/or far from the harvesting device. On the other hand, a too rapid speed results into lost energy and into risks of damages to the roots 26.

Advantageously, the wheels of the doubled wheeled system 2 each comprise 4 (or 5) or 6 elements 6; these elements 6 are preferably all identical. In view of the above, a too low number of elements 6 will force a too rapid speed of the wheels, whereas wheels with too many elements 6 are no longer able to push away (extract) the roots 26 from the soil 9.

The elements 6 are evenly distributed around the wheel 10, for instance, if four elements 6 form the wheel 10, the four angles between two consecutive elements 6 of the same wheel are of 90°; if six elements 6 form the wheel 10, the six angles between two consecutive elements 6 of the same wheel are of 60°.

Preferably, the internal opening 7 of the elements 6 of the wheels 10, or of the half-wheels 21, of the doubled wheeled system 2 represents between 10 % and 70 % of the surface of this element 6, preferably between 20% and 60% of the surface, more preferably between 30% and 50% of the surface. Preferably, the internal opening is the same in all the elements 6 of the wheel 10 and/or of the double wheeled system 2.

The size of the internal opening 7 is chosen and/or optimized to allow for a correct removal of the soil.

Preferably, the elements 6 of the wheels 10, or of the half- wheels 21, of the doubled wheeled system 2 (substantially) have a rectangular shape and/or are planar. This allows for a part of the element to enter for some centimeters into the soil, so as to push the root and to extract it.

Preferably (in addition to the substantially rectangular shape), the elements 6 of the wheels of the doubled wheeled system 2 have a trapezoidal shape, so that no right angle enters first into (attacks) the soil 9. This allows a smoother entry into the soil; hence a lower energy consumption, as well as reduced damages to the root to harvest .

Preferably, when observed in a planar view such as in Fig. 3, no space remains in the projected base of the elements 6 of the wheel 10 of the doubled wheeled system 2. This allows a continuous presence of elements 6 of the harvesting device into the soil 9.

Advantageously, the planar surfaces of two elements 6 of the two wheels 10 of the doubled wheeled system cross when prolonged from the bottom 11 of the elements 6 of the doubled wheeled system 2 and/or the planar surfaces of two elements of the two wheels 10 of the doubled wheeled system cross when prolonged from the basis 12 of the elements 6 closest to the ax (axle) of the doubled wheeled system. In other words, the elements 6 of the two wheels of the wheeled system 2 are oriented in two directions, making an opening (in two dimensions) to first gently push the root, then being more closed, in two dimensions, for a gentle extraction of the root. Still in other words, the angle 23 between the core 24 of the wheel 10, or of the half-wheel 21 and the element 6 is lower than 180° (i.e. comprised between 100º and 160°, preferably between 120º and 150°) and/or the angle 25 between the core 24of the wheel, or of the half-wheel 21, and the element 6 is lower than 90°, preferably comprised between 30° and 60°.

Preferably, the wheels 10, the ax (axle) 3 and the elements 6 are arranged so that the elements 6 enter into the soil at a depth of less than 10 cm, more preferably of less than 5 cm.

The maximal depth is not really limiting, yet limiting the depth allows to reduce the energy costs, and the damages to the roots. On the other hand, a dept of few centimeters (e.g. at least 3 cm; about 5 cm) is needed to ensure the penetration of the elements 6 into the soil, especially for uneven soils.

The ax (axle) 3, when it drives several harvester devices 1 (i.e. double-wheeled systems 2), thus in a multi row harvester, can be tilted over its length, so as to impart a constant force over one full rotation: only a fraction of the doubled wheeled system 2 mounted on the ax (axle) 3 will firstly attack the soil 9, then, a second (or the remaining) fraction of the doubled wheeled system 2 will attack the soil 9, when the force needed to move the first fraction of the doubled wheeled system 2 is reduced, since there is no longer the need to attack the soil for this fraction. In other words, along the ax (axle) 3, the elements 6 of one wheel 10 of a first double wheeled system 2 are preferably not at the same height that the corresponding elements 6 of the corresponding wheel 10 of a second (or of a further) double wheeled system 2 mounted on the same ax (axle) 3.

A corresponding aspect of the present invention is the use of the device 1 (i.e. the double wheeled system 2) or of the wheel 10, or of the half-wheel 24, for harvesting root crops (as mentioned above, preferably, sugar beet, fodder beet and/or chicory).

Another related aspect of the present invention is a process to harvest root crops comprising the step of obtaining an harvester comprising at least one device 1 (doubled wheeled system 2), of performing the rotation 18 of the device 1 in the opposite direction as the movement 19 of the harvester so that the elements 6 of the device enter into the ground 9 and extract the root 26. Preferably, a mechanical transport system 13 drives the harvested root crop to the predefined location.

Preferably, the mechanical transport system 13 is a rubber belt, mounted on wheels 16.

Advantageously, the mechanical transport system 13 turns in the opposite direction 20 than that 18 of the device 1. In this process, the preferred root crops are as above, more preferably, sugar beet, fodder beet and/or chicory. Brief description of the figures.

Figure 1. Shows a frontal view (Fig, la) of the double wheeled system and a lateral view (Fig. lb) of the double wheeled system.

Figure 2. Is a real 3D view of the double wheeled system. Figure 3 is a planar view of one wheel of the double wheeled system.

Figure 4 is a schematic side view of the device according to the invention together with elements of the harvester. Figure 5 depicts three enlarged views of an half-wheel.

In operations, as shown in Figure 4, the harvester is moving in one direction 19 to harvest the roots 26, here sugar beet roots.

The dimensions shown in the figures have been validated for sugar beet, but should not be considered as limiting; one skilled person, on the basis of the present disclosure, can easily adapt these dimensions either for the harvest of the roots of sugar beet, or for the harvest of other root crops. Usually, several harvesting devices 1 (double wheeled systems 2) according to the invention are mounted on one ax (axle), for instance for a 6-row, a 8-rows or a 12-rows harvester (one device per row). The number of rows to harvest (thus of devices to mount on one ax; axle) is not critical in the present invention, and the skilled person is able to adapt the number of the devices 1 of the present invention to existing harvesters, meaning that a 6-row root crop harvester with systems of the prior art can easily be converted into a 6-rows root crop harvester by plugging 6 devices 1 of the present invention.

In the example shown in Figure 4, a mechanical transport unit 13, here a rubber belt mounted on wheels 16 and comprising additional rubber elements 17 is turning in the opposite direction 20 with regard to the direction 18 of the harvesting device 1 of the present invention, so as to better drive the harvested roots 26 (here sugar beet) in the desired direction, for instance in a container.

Claims

1. A root crop harvester device (1) comprising a double wheeled system (2) mounted on an ax (3), the said ax (3) driving the said double wheeled system (2) to turn in the direction opposite (18) of the direction of the harvester (19), each wheel (10) of the said double wheeled system (2) being made of a core (24') and comprising protrusions in the form of a plurality of substantially planar elements (6) assembled to the said core (24') so as to form a wheel, and each of the said substantially planar element (6) comprising an internal opening (7).

2. The root crop harvester device (1) of claim 1, wherein the angle (14) between the substantially planar elements (6) of the double wheeled system (2) present on one wheel and the substantially planar elements (6) of the double wheeled system (2) present on other wheel is comprised between 10° and 40°, preferably between 15° and 35°, more preferably between 20° and 30°, still more preferably between 22° and 23° (about 22.5°), and/or wherein the angle(s) (23) between the core (24) of the wheel (10) and the substantially planar element(s) (6) is (are) lower than 180° (i.e. comprised between 100° and 160°, preferably between 120° and 150°) and/or wherein the angle(s) (25) between the core (24) of the wheel (10) and the substantially planar element(s) (6) is (are) lower than 30°, preferably comprised between 30° and 60°.

3. The root crop harvester device (1) of claim 1 or 2, wherein the minimal distance (8) between the substantially planar elements (6) of the first and of the second wheel (10) of the double wheeled system (2) is comprised between 30 mm and 100 mm, preferably between 35 mm and 50 mm, and/or wherein the maximal distance (15) between the substantially planar elements (6) of the first and of the second wheel 10 of the double wheeled system (2) is comprised between 170 mm and 250 mm, preferably between 175 mm and 210 mm.

4. The root crop harvester device (1) according to any one of the preceding claims 1 to 3, wherein the ax (3) has a polygonal section, such as a square section or an hexagonal section.

5. The root crop harvester device (1) according to any one of the preceding claims 1 to 4, wherein the opening (7) of the substantially planar elements (6) of the wheels of the doubled wheeled system (2) represents between 10 % and 70 % of the surface of the said substantially planar element (6), preferably between 20% and 60% of the surface, more preferably between 30% and 50% of the surface.

6. The root crop harvester device (1) according to any one of the preceding claims, wherein the substantially planar elements (6) of the wheels of the doubled wheeled system (2) have a substantially rectangular shape and/or a trapezoidal shape, so that no right angle enters first into the ground (9).

7. The root crop harvester device (1) according to any one of the preceding claims, wherein the wheels (10), the ax (3) and the substantially planar elements (6) are arranged so that the substantially planar elements (6) enter into the soil (9) at a depth of less than 10 cm, preferably less than 5 cm.

8. An harvester for root crops comprising at least one root crop harvester device (1) according to any one of the preceding claims 1-7 and preferably a plurality of the devices (1) according to any one of the preceding claims 1-7, more preferably, wherein the ax (3) is tilted so that the substantially planar elements (6) of the different devices (1) do not enter into the ground (9) in the same time.

9. The harvester of claim 8, wherein the root crops are selected from the group consisting of sugar beet, fodder beet and chicory.

10. The harvester of claim 8 or 9 further comprising a mechanical transport system (13) to drive the harvested root crop to a predefined location, wherein preferably the mechanical transport system (13) is a rubber belt, mounted on wheels (16) and preferably, wherein mechanical transport system (13) turns in the opposite direction (20) than that (18) of the device (1).

11 . An half-wheel (21) comprising at least one attaching means (22) on its core (24) and two or three substantially planar elements (6) comprising an opening (7) for forming the root crop harvesting system according to any one of the preceding claims.

12 . The half wheel of claim 11, wherein the angle (23) between the core (24) of the half wheel (21) and the substantially planar element(s) (6) is (are) lower than 180° (i.e. comprised between 100º and 160°, preferably between 120° and 150°) and/or the angle (25) between the core (24) of the half-wheel (21) and the substantially planar element(s) (6) is (are) lower than 90°, preferably comprised between 30° and 60°.

13 . Use of the device according to any one of the preceding claims 1 to 7 , or of the half-wheel according to claims 11-12 or of the harvester according to any one of the preceding claims 8 to 10 for harvesting root crops, preferably wherein the root crops are selected from the group consisting of sugar beet, fodder beet and chicory.

14 . A process to harvest root crops comprising the steps of

- obtaining an harvester comprising at least one device (1) being a double wheeled system (2) mounted on an ax (3), each wheel (10) of the said double wheeled system (2) comprising a plurality of substantially planar elements (6) assembled so as to form a wheel (10), and each of the said substantially planar element (6) comprising an internal opening (7), - performing the rotation (18) of the device (1) in the opposite direction as the movement (19) of the harvester so that the substantially planar elements (6) of the device enter into the ground (9) and extract the root (26).

15. The process of claim 14, wherein the root crops are selected from the group consisting of sugar beet, fodder beet and chicory.

16. The process according to any one of the preceding claims 14 to 15, wherein the wheels (10) of the doubled wheeled (2) system rotate at a speed comprised between 40 rpm and 170 rpm, preferably between 50 rpm and 150 rpm, more preferably, between 60 rpm and 120 rpm (e.g. about 77 rpm).