LU87582A1 - DEVICE FOR TREATING SEEDS - Google Patents

Description

PRIORITY REeOICATIQN Filing of the patent application in France of September 13, 1988 UNDER number 8812158

DESCRIPTIVE MEMORY FILED IN SUPPORT OF A PATENT INVENTION APPLICATION IN THE GRAND DUCHY OF LUXEMBOURG by; Ceres Z.I. BP 6 F-91660 Mereville pou r; Seed treatment device

The present invention relates to a device for treating seeds.

By "seed" is meant any plant organ which can lead to the regeneration of a plant and obtained either by the sexual route, in which case we will speak of seed, or by vegetative propagation, in which case we will speak of plant or explant.

By treatment is meant any addition of liquid or solid product to the surface of the seed.

If this contribution results in a change in the form of the seed, for example to allow mechanical sowing of individual seeds, we are dealing with coating techniques. These generally comprise initially the deposition on the seed of an adhesive product then, optionally after partial drying, the deposition of a liquid filler or a powder, of a treatment agent, agrochemical product, dye. , or other adjuvant, fertilizer or improving the germination conditions of the seed.

If this contribution is made without changing the shape of the seed, for example to give protection and possibly a coloration or appearance, we will speak of film coating. This technique includes the deposition on the seed, by spraying, of a liquid, often aqueous composition, of a film-forming product containing a treatment agent without charge, and the simultaneous drying of the deposit obtained.

These coating and film-coating techniques use, among other things, rotary horizontal cylindrical turbines comprising, in addition to the turbine proper, means for its rotation, means for distributing the load and the treatment agent and possibly drying means. To ensure homogenization of the treatment, it is known to adapt mixing elements inside the turbine. However, despite a significant improvement in the quality of the coating, this is often not industrially sufficient, for example when treating seeds of irregular shape of variable density or particle size or when one seeks to carry out a coating, requiring a deposit of high quality, that is to say of great uniformity, over the entire surface of the seed, of protection and / or coloring.

There is therefore a need to have techniques and apparatus which make it possible to carry out these treatments for improved protection and presentation of these seeds, in order to increase the yield during sowing.

The Applicant has now found that this need could be met using devices of the above type and provided with stirring and guiding means allowing each seed to appear a number of times substantially identical before the means of distribution of the treatment agent, throughout the duration of treatment. The invention therefore relates to a device for the treatment of seeds comprising a generally cylindrical turbine, substantially horizontal, rotary, in the lower part of which is the seed bed to be treated, comprising means for distributing the load or of the treatment agent and optionally drying means, means for rotating the turbine and directional elements, fixed inside the container, that is to say the turbine, for stirring of the seedbed during treatment, this device being characterized in that these directional elements consist of at least one pair of vertical rows of blades, in opposite directions, such that: a) each row is located in one of the transverse parts the volume of the turbine, substantially parallel to the transverse walls of the latter, the two rows creating between them a substantially vertical central corridor for the flow of seeds , b) the blades are inclined relative to the axis of rotation of the turbine, c) two adjacent blades belonging respectively to one of the two rows substantially determine an open angle towards the top of the turbine, d) one rows is angularly offset from each other, by pivoting relative to the axis of the turbine, e) the useful part of the blades for stirring and guiding is distant from the cylindrical wall.

The central seed flow corridor is an essential characteristic of the device according to the invention, this corridor is substantially vertical. Its width must be sufficient not to cause a shovel effect on the seeds, that is to say not to drive the seeds towards the upper part of the cylinder and make them fall in rain in an uncontrolled manner, without being too important in which case the mixing or guiding of the seeds is too weak to ensure the homogeneity of the covering of said seeds. Preferably, the width is from 5 to 45% of the width of the row, in particular from 10 to 40%.

For the purposes of the invention, the term “blade” designates a rigid shape having a surface enabling it to push and especially to accompany a packet of seeds from one point to another of the volume of the turbine, that is to say to return seeds effectively. This surface can be flat or twisted, to improve the turning of the seeds from below to the top and vice versa, to avoid raising or projecting the seeds in the turbine.

In the following, the inclination of the blades means the inclination of the mean plane of the latter, that is to say the plane tangent to the surface at the center of symmetry of this surface. The inclination of the blades, as defined above, relative to the axis of rotation of the turbine determines the speed of flow of seeds in the central flow corridor.

It has been observed that results of great uniformity are obtained when the width of the central corridor is approximately one third of the width of the turbine. Similarly, an inclination of 30 to 60 °, preferably 40 to 50 ° is preferred.

In addition, the blades in the device according to the invention are such that two neighboring blades, one belonging to one row and the other belonging to the other row in opposite directions, which therefore have a different inclination, form a angle facing the top of the turbine, so that the seeds from the top of the seed bed are brought back towards the central flow corridor. This angle is generally between 30 and 60 ° and preferably between 40 and 50 °.

Furthermore, the blades of a row are not opposite those of the other row but offset angularly, by pivoting relative to the axis of the turbine. This is important to ensure both a fluidity of the flow of seeds from top to bottom (no blocking of seeds between the lower part of the blades) at the same time as a mixing of the seeds coming from an upper blade with those lying on a pale opposite lower.

Finally and unlike many known devices, the part of the blades useful for stirring must end at a certain distance from the neighboring transverse walls of the turbine. This distance is generally small but must be sufficient for the lateral seeds to slide down and fall back into the cycle of general movement towards the center.

Thus, the orthogonal projection of the blades on the axis of the turbine is, taking into account this condition and the dimensions of the central flow corridor, always less than half the width of the turbine and preferably approximately close to one third of this width.

All the above parameters can be modified according to the species, the form and quantity of the seeds to be treated, the type of technique applied to the desired effect for the seed. In all cases, a brewing of a quality is obtained such that, on average, the seeds pass the same number of times under the projection of the treatment product.

The blades described above may be solid or hollow or perforated and of any material provided that it is sufficiently abrasion resistant, non-adherent with respect to the loads brought to the seeds and inert with regard to the treatment products. .

Likewise, the turbine can be full or perforated, in particular if an external suction or blowing device is provided, in particular for drying the seeds.

The above description relates to a pair of rows of blades, but it is obvious that the device according to the invention can comprise, to increase the capacity and / or the throughput of the installation, several pairs of rows of blades in series, that is to say, coaxial with the first row and which may be of identical or different dimension and inclination from the first.

According to a preferred form, the device according to the invention can be improved, mainly in the case where it is intended for the film coating of seeds, by the fact that in each pair of rows, one of the rows is offset vertically with respect to the 'Other so that the central corridor, substantially vertical gives the flow of the falling seeds a substantially sinuous appearance. This characteristic further increases the degree of homogeneity in seed treatment.

In a particularly advantageous manner, one of the rows of each pair is offset vertically with respect to the other row, by an equal distance, approximately half the common pitch of the blades in each row of the pair.

Another improvement to the device according to the invention applied to lamination lies in that the width of the central corridor represents 5 to 20% of the total width of the pair of rows of blades.

According to another important improvement of the device according to the invention for all of these applications, each pair of rows defines, in projection on the axis of the turbine, a zero or negative spacing of a value at most equal to half of the width of each row. This arrangement has the advantage that in projection the blade row pairs overlap so that a greater blade density is obtained per unit of turbine volume, which increases the quality of the processing and the productivity of the device.

In addition, still for the sake of productivity, it is advantageous that, against each transverse wall of the turbine, the arrangement of the rows of blades begins or ends with a half pair, that is to say a row of blades oriented towards the transverse wall co-considered and therefore towards the outside of the turbine in order to create a flow corridor between this row and the transverse wall considered. The invention is explained in more detail with the aid of Figures (1) to (4) and the description which follows by way of illustration of preferred embodiments of the device according to the invention. In these figures are represented:

Figure 1: an axial cross-sectional view of a device according to the invention.

Figure 2: a cross-sectional view, along a diametrical plane, of the device of Figure (1)

Figure 3: a sectional view of a device according to the invention comprising five coaxial pairs of rows of blades

Figure 4: a sectional view of a device according to the invention, more particularly suitable for lamination, comprising pairs of blades offset vertically.

In Figures (1) and (2) are shown a horizontal cylindrical turbine (1), rotating around its axis (2) by drive means not shown, in which are arranged means (3) for distributing a treatment product, for example nozzles for spraying an aqueous dispersion of a film-forming product or powder dispensers. Inside the turbine (1), in each of the parts of the volume adjacent respectively to the transverse walls (4) (5), two rows (6) and (7) of blades (6a, 6b, 6c and 7a) are fixed. , 7b, 7c) using the fasteners (61, 62, 63 and 71, 72, 73), respectively, on the cylindrical wall of the turbine (1).

These blades are inclined at 45 ° relative to the axis of the turbine, are distributed symmetrically relative to the diametral plane of the turbine (see FIG. 2), that is to say with an angle of 120 ° relative to one another. to others in this plan. Finally the row (7) is offset by 60 ° relative to the row (6). These two rows of blades create a central flow corridor (8), the width of which advantageously represents one third of the width (1) of the turbine.

The seed bed is designated by (9) when the turbine is at rest and by (10) when it is operating. It is clearly seen that, due to the arrangement of the blades, the seeds are brewed in a particularly homogeneous manner.

Figure (3) schematically shows a turbine (11) according to the invention comprising five pairs of rows, (12, 13, 14, 15, 16, of blades 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b , 16a, 16b), of the type described in Figures (1) and (2).

Figure (4) schematically shows a turbine (17) with a horizontal axis (18). comprising three pairs (20, 21, 22) of vertical rows (20a, 20b, 21a, 21b, 22a, 22b) of blades, each pair having a width 1, as well as two rows (19, 23) one at each end against the corresponding transverse wall (24, 25). Inside each pair of blades (20, 21, 22), the two rows are vertically offset from each other by a distance equal to half the pitch of each pair and define between them a vertical central corridor of width C equal to approximately 9% of the width 1 and which allows a sinusoidal flow.

The pairs (20, 21, 22) between them have, in projection on the axis (18) of the turbine (17), a spacing e zero, as the pairs (20 and 22) respectively with the extreme rows ( 19 and 23).

Claims (10)

1) Device for treating seeds comprising a generally cylindrical turbine, substantially horizontal, rotary, in the lower part of which is the seed bed to be treated, comprising means for distributing the load or the agent treatment and possibly drying means, means for rotating the turbine and directional elements, fixed inside the turbine, for stirring and guiding the seed bed during the treatment, characterized in that these directional elements consist of at least one pair of vertical rows of opposite direction blades such as: a) each row is located in one of the transverse parts of the volume of the turbine substantially parallel to the transverse walls, the two rows creating between them a substantially vertical central corridor for the flow of seeds. b) the blades are inclined relative to the axis of rotation of the turbine. c) two neighboring blades belonging respectively to one of the two rows substantially determine an open angle towards the top of the turbine. d) one of the rows is angularly offset relative to the other, by pivoting relative to the axis of the turbine. e) the useful part of the blades for stirring and guiding is distant from the cylindrical wall. 2) Device according to claim 1 characterized in that the angle of inclination of the blades is 30 to 60 ° and preferably 40 to 50 °. 3) Device according to claim 2 characterized in that the angle of inclination of the blades is 45 °. 4) Device according to one of claims 1 and 3 characterized in that the central seed flow corridor has a width substantially equal to one third of the width of the row of blades considered. 5) Device according to one of claims 1 to 4 characterized in that one of the rows is offset from the other by an angle of 60 °. 6) Device according to one of claims 1 to 5 characterized in that: in each pair of rows one of the rows is offset vertically relative to the other so that the vertical central corridor gives the flow of seeds drooping a noticeably sinuous look. 7) Device according to one of claims 1 to 6 characterized in that one of the rows of the pair is offset from the other row by a distance equal to half the common pitch of the blades in each row of the pair. 8) Device according to one of claims from 1 to 7 characterized in that the central corridor at a width equal to 5 to 20% of the total width of the pair of rows of blades. 9) Device according to one of claims 1 to 8 characterized in that it comprises at least two pairs of rows defining in projection on the axis of the turbine a zero or negative spacing of a value at most equal to half the width of each row. 10) Device according to one of claims 1 to 9 characterized in that against each transverse wall of the turbine the row arrangement begins with a row whose blades are oriented towards the transverse wall considered of the turbine and which creates a corridor with the corresponding transverse wall.