AU637322B2 - Device for the treatment of seeds - Google Patents

Description

637322 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: Ceres Zone Industrielle BP 6 Mereville 91660 France NAME(S) OF INVENTOR(S): Michelle BAZIN Michel TARON Etiemie PILTE ADDRESS FOR SERVICE: DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Device for the treatment of seeds The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1A- The present invention relates to a device for the treatment of seeds.

"Seed" is understood to mean any vegetable organ which can lead to the regeneration of a plant and which is obtained either sexually, in which case reference will be made to a grain, or by vegetative multiplication, in which case reference will be made to a plant or an explant.

Treatment is understood to mean any contribution of a liquid or solid product to the surface of the seed.

If this contribution is reflected in a change in the form of the seed, for example to permit mechanical sowings of individual seeds, it involves coating -techniques. The latter generally comprise, in a first stage, the deposition on the seed of an adhesive product then, possibly after partial drying, the deposition of a liquid charge or of a powder, of a treatment agent, agrochemical product, colorant, or other adjuvant, to fertilize or improve the conditions of germination of the seed.

If this contribution is made without a change in form of the seed, for example in order to give protection and possibly a coloration or an appearance, reference will be made to covering with a film. This technique comprises 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 deposition obtained.

-2- These techniques of coating and of covering with a film make use, inter alia, of rotating horizontal cylindrical turbines comprising, in addition to the actual turbine, means for placing it in rotation, means for distributing the charge and the treatment agent and possibly drying means. In order to ensure homogenisation of the treatment, it is known to fit, inside the turbine, mixing elements. Howvever, despite a considerable improvement in the quality of the covering, the latter is often insufficient in industrial terms when, for example, treating seeds of irregular form, of variable particle size or density, or if it is desired to perform a covering with a film requiring a high-quality deposition, that is to say with a great uniformity, over the entire surface of the seed, of the protection and/or of the coloration.

The requirement therefore exists for having available techniques and apparatuses which make it possible to carry out these treatments for a protection and an improved presentation of these seeds in order to increase the sowing yield.

According to a first aspect of the present invention there is provided a device for the treatment of seeds comprising a rotating, substantially horizontal turbine of generally cylindrical form arranged to receive a bed of seeds to be treated and having a substantially cylindrical wall portion and a pair of end wall portions, means for distributing a charge or a treatment agent or a drying means, means for rotating the turbine and directional elements fixed inside the turbine for mixing and guiding the bed of seeds during the treatment, said directional elements comprising at least one pair of vertical rows of blades positioned such that: a) each vertical row of blades is attached to said substantially cylindrical wall portion substantially parallel to the end wall portions, the pair of vertical rows together creating a substantially vertical central corridor for the flow of seeds; b) the blades being inclined with respect to the axis of rotation of the turbine; c) two adjacent blades belonging respectively to one of the two vertical rows being incined substantially to determine an angle which is 92082,kayspe.001,39993-89.cla,2 4 -3open towards an upper part of the turbine; d) one of the vertical rows being angularly offset with respect to the other, by pivoting the blades with respect to the axis of the turbine; and e) a portion of the blades arranged for mixing and guiding of the seeds to be treated being positioned distant from the substantially cylindrical wall portion and in each pair of vertical rows, one of the vertical rows is offset vertically with respect to the other vertical row such that the vertical corridor causes the flow of seeds to follow a substantially sinuous path.

In the terms of the invention, blade denotes a rigid form having a surface which makes it possible to push and above all to accompany a mass of seeds from one point to another of the volume of the turbine, that is to say to turn the seeds over effectively. This surface may be plane, or, alternatively, twisted in order to improve turning over of the seeds from the bottom towards the top and vice versa in order to avoid having to move the seeds up or to project the seeds into the turbine.

Inclination of the blades will hereinafter denote the inclination of the mean plane of the latter, that is to say the plane tangent to the surface at the centre of symmetry of this surface.

The inclination of the blades as defined above, with respect to the axis of rotation of the turbine, determines the speed of flow of the seeds in the c. ntral flow corridor.

It has been observed that highly uniform results 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 o, preferably of 40 to 50 o, is preferred.

Moreover, the blades in the device according to the invention are preferably such that two adjacent blades, one belonging to one row and the other belonging to the other row in the opposite direction, and which are therefore of different inclination, together form an angle turned towards the top of the turbine such that the seeds leaving the top of the bed of seeds are brought back towards the central flow corridor. This angle is generally 2'.

920825,kayspe.001,39993-89.cla,5 -4between 30 and 60 and preferably between 40 and 50 0.

Moreover, the blades in one row are not opposite those in the other row but offset angularly by pivoting with respect to the axis of the turbine.

This is important to ensure both a fluidity in the flow of the seeds from top to bottom (no blockage 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 located on an opposite lower blade.

Finally, and unlike several known devices, a portion of the blades arranged for mixing and guiding of the seeds to be treated are positioned distant from the substantially cylindrical wall portion of said device. This distance is generally small but should be sufficient for the lateral seeds to be able to slide downwards and to fall back into the general cycle of movement towards the centre.

Therefore, the orthogonal projection of the blades on the axis of the turbine is, bearing in mind this condition and the r'imensions of the central flow corridor, are preferably always less than half the width of the turbine and preferably approximately close to one third of this width.

All the above parameters may be modified as a function of the type, of the form and of the quantity of seeds to be treated, of the type of technique applied and of the effect desired for the seed. In each case, a mixing is obtained of a quality 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 mae from any material provided that it is sufficiently resistant to abrasion, non-adhesive with respect to the charges provided on the seeds and inert with E respect to the treatment products.

Similarly, the turbine may be solid or perforated, in particular if a suction or exterior blowing device is provided, in particular for drying the seeds.

The above description relates to a pair of rows of blades but, obviously, the device according to the invention may comprise, in order to increase the capacity and/or the throlughput of the installation, several pairs of rows of z1 920825,kayspeO01,39993-89.cla,4 blades in series, that is to say coaxial to the first row and which may be of a size and inclination which are identical to or different from the first.

Preferably, the central corridor for the flow of seeds has a width equal to 5 to 20% of the total width of the pair of vertical rows of blades.

Preferably, the device further comprises at least two pairs of rows defining, in a direction parallel to the axis of the turbine, a zero or negative spacing between adjacent vertical rows of a value which is at most equal to half the width of each row. This arrangement affords the advantage that, in projection, the pairs of rows of blades overlap such that a greater density of blade per unit of volume of turbine is obtained which increases the quality of the treatment and the productivity of the device.

Preferably, substantially adjacent each end wall portion there is positioned a vertical row of blades adjacent each end wall portion being such that they together create a flow corridor.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:- Figure 1 is a view of an axial transverse section of a device according to an embodiment of the invention.

Figure 2 is a view of a transverse section of the device of Figure along a diametral plane.

Figure 3 is a view in section of a device according to an embodiment of the invention comprising five coaxial pairs of rows of blades.

Figure 4 is a view in section of a device according to an embodiment of the invention, more particularly adapted for 92082,kayspe.001,39993-89.c,5 covering with a film, comprising pairs of blades which are vertically offset.

Figures and show a horizontal cylindrical turbine rotating about its axis via drive means which are not shown, in which turbine are arranged means for distributing a treatment product, for example nozzles for spraying an aqueous dispersion of a filmforming product or powder dispensers. Inside the turbine in each of the parts of the volume adjacent respectively to the transverse walls are fixed two rows and of blades (6a, 6b, 6c and 7a, 7b, 7c) by means of fastenings (61, 62, 63 and 71, 72, 73), respectively, on the cylindrical wall of the turbine These blades are inclined at 45° with respect to the axis of the turbine, are distributed symmetrically with respect to the diametral plane of the turbine (cf.

Figure that is to say with an angle of 120° with respect to one another in this plane. Finally, the row is offset by 600 with respect to the row These 29 two rows of blades create a central flow corridor (a) whose width advantageously represents one third of the -4 width of the turbine. The bed of seeds is denoted by when the turbine is at rest and by (10) when it is in operation. It is clearly seen that, due to the arrangement of the blades, the seeds are mixed in a particularly homogeneous manner.

Figure represents diagrammatically a turbine (11) according toAthe 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 and Figure represents diagrammatically a turbine (17) with a horizontal axis (18) comprising three pairs 21, 22) of vertical rows (20a, 20b, 21a, 21b, 22a, 22b) of blades, each pair having a width 1, as well as 1i) two rows (19, 23), one at each end against the corresponding transverse wall (24, Inside each pair of blades (20, 21, 22), the two rows are offset vertically with respect to one another by a distance equal to half the pitch of each pair and together they define a vertical central corridor of width C equal to approximately 9% of the width 1 and which permits a flow with a sinusoidal path.

The pairs (20, 21, 22), in projection on the axis (18) of the turbine together have a zero spacing e, similar to the pairs (20 and 22) respectively with the end rows (19 and 23).

1,

Claims (9)

1. A device for the treatment of seeds comprising a rotating, substantially horizontal turbine of generally cylindrical form arranged to receive a bed of seeds to be treated and having a substantially cylindrical wall portion and a pair of end wall portions, means for distributing a charge or a treatment agent or a drying means, means for rotating the turbine and directional elements fixed inside the turbine for mixing and guiding the bed of seeds during the treatment, said directional elements comprising at least one pair of vertical rows of blades positioned such that: a) each vertical row of blades is attached to said substantially cylindrical wall portion substantially parallel to the end wall portions, the pair of vertical rows together creating a substantially vertical central corridor for the flow of seeds; b) the blades being inclined with respect to the axis of rotation of the turbine; c) two adjacent blades belonging respectively to one of the two vertical rows being inclined substantially to determine an angle which is open towards an upper part of the turbine; d) one of the vertical rows being angularly offset with respect to the other, by pivoting the blades with respect to the axis of the turbine; and e) a portion of the blades arranged for mixing and guiding of the seeds to be treated being positioned distant from the substantially cylindrical wall portion and in each pair of vertical rows, one of the vertical ronws is offset vertically with respect to the other vertical row such that the vertical corridor causes the flow of seeds to follow a substantially sinuous path.

2. A device according to claim 1, wherein the angle of inclination of the blades with respect to the axis of the turbine is 30 to 60 0. 920825,kayspe.O01,39993-89.ca,8 -9-

3. A device according to cl-:m 1, wherein the angle of inclination of the blades with respect to the axis of the turbine is 40 to

4. A device according to claim 2, wherein the angle of inclination of the blades with respect to the axis of the turbine is 45 0. A device according to any one of claims 1 to 4, wherein the central corridor for the flow of the seeds has a width which is substantially equal to one third of the width of the row of blades in question.

6. A device according to any one of claims 1 to 5, wherein one of the vertical rows is offset with respect to the other by an angle of 60

7. A device according to any one of claims 1 to 6, wherein one of the vertical rows of the pair is offset with respect to the other vertical row by a distance equal to half of the common pitch of the blades in each row of the pair.

8. A device according to any one of claims 1 to 7, wherein the central corridor has a width equal to 5 to 20% of the total width of the pair of vertical rows of blades.

9. A device according to any one of claims 1 to 8, further comprising at least two pairs of rows defining, in a direction parallel to the axis of the turbine, a zero or negative spacing between adjacent vertical rows of a value which is at most equal to half the width of each row. A device according to any one of claims 1 to 9, wherein substantially adjacent each end wall portion there is positioned a vertical row of blades adjacent each end wall portion being such that they together create a flow corridor. '4 c' 920825,kayspe.oo001,39993-89.cla,9 T I II

11. A device according to claim 1, substantially as hereinbefore described with reference to the drawings. Dated this 26th day of August, 1992 Establissements Ceres S.A. by Davies Collison Cave Patent Attorneys for the applicant 920826,kayspe.00 1,39993-89.cad10