CA2011185A1 - Coating device - Google Patents
Coating deviceInfo
- Publication number
- CA2011185A1 CA2011185A1 CA 2011185 CA2011185A CA2011185A1 CA 2011185 A1 CA2011185 A1 CA 2011185A1 CA 2011185 CA2011185 CA 2011185 CA 2011185 A CA2011185 A CA 2011185A CA 2011185 A1 CA2011185 A1 CA 2011185A1
- Authority
- CA
- Canada
- Prior art keywords
- particulate material
- baffles
- body shell
- fluid coating
- shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01C—PLANTING; SOWING; FERTILISING
- A01C1/00—Apparatus, or methods of use thereof, for testing or treating seed, roots, or the like, prior to sowing or planting
- A01C1/06—Coating or dressing seed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02B—PREPARING GRAIN FOR MILLING; REFINING GRANULAR FRUIT TO COMMERCIAL PRODUCTS BY WORKING THE SURFACE
- B02B1/00—Preparing grain for milling or like processes
- B02B1/04—Wet treatment, e.g. washing, wetting, softening
- B02B1/06—Devices with rotary parts
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Environmental Sciences (AREA)
- Pretreatment Of Seeds And Plants (AREA)
Abstract
ABSTRACT
This invention concerns a device for applying a fluid material to a particulate material. In particular to the device suitable for applying pesticides and the like to agricultural and horticultural seeds.
37,211-F
This invention concerns a device for applying a fluid material to a particulate material. In particular to the device suitable for applying pesticides and the like to agricultural and horticultural seeds.
37,211-F
Description
2 ~ 8 ~
COATING DE~ICE
Thi~ invention concerns a device ~or smoothing out a fluid coatlng applied on particulate material.
Especially preferred ls a device for soothing out a ~luid coating, for example a pesticide, on seeds.
It i~ increasingly attractive to seed suppliers to apply to agricultural seeds, coatings of various materialq, particularly pesticidal materials, which are able to protect the seeds against attack by, ~or example, fungi ~nd insects, while the seed is dormant in the ~oil.
The appllcation o~ coating material~ to large quantities o~ ~eeds ?re3ent substantial problems. It is important that the seed should be uniformly coated, and in order to ensure that this iq achieved, it i9 conventional to apply pesticidal formulations in liquid 2~ form, containing substantial quantities of an inert liquid ~/ehicle (normally water). The inerr liquid vehicle must be -emoved, generally in a separate drying stepl before the treated seed can be bagged and sold.
This procedure normally results in the nee~ for a 37,211-F -1-- 2 0 ~
separate drying ~tep, which increase~ the expense of the overall process. It is. therefore. desirable to be able to apply to the seed the pesticidal substance in a formulation containing very little inert vehicle, so that no separate drying step of the pesticide on the coated product is required, while maintaining substantially even pesticidal distribution.
Surprisingly, such a coating device has now been devised. In accordance with thi~ invention, a device is provided for applying a fluid coating material to a particulate material. said device ha~ing a generally upright circular body, which has an in~ide wall surface defining a flowpath for passage of the particulate material therethrough, which comprises, a device for making uniform a fluid coating material to a particulate material, said device comprising a generally upright circular body shell, having an inside wall ~urface defining a flowpath for passage of the particulate material downwardly therethrough, with a) means for feeding the particulate material to interior of the the upper part of the body shell promptly after fluid coating material has been applied thereto, b) a rotatable sha~t extending upwardly and axially towards the means for feeding and within and generally along the length of the body shell, c) an array of agitator elements spaced along and affixed to the shaft for rotation therewith, ~he agitator elements each having a proximal end attached to the shaft and a distal end directed generally radially towards the said inside wall surface, and d) means for rotating the shaft within the body snell at a controllable predetermined constant rate, wherein successive agitator elements within said array, are so shaped as to provide decreasing agitation 37,211-F -2-2 ~ 5 to the parriculate material~ as ~he material passes downwardly through the body shell.
In particular, the device is preferred for applying a pesticidal material to agricultural seeds, -J although the device is not limited to such application.
The fluid material is preferably a liquid, for example, an aqueous or non-aqueous pesticidal composition which may be of conventional form. The device according to the invention may also be utilized to apply fluid compositions in powder form.
However, as is readily apparent, the device of the present invention is not limited to the use of applying pesticides onto seeds, but may advantageously be employed to apply selec~ed fluid coating onto selected particulate ~aterial.
The de~ice comprises a generally upright circular body shell, having an nside wall surface 2~ defining a flowpath for passage of the particulate material ~herethrough. Mean~ are provided for feeding the particulate material to the lnterior of the upper part of the body, to cause the particulate material to pass downwardly through the body cavity under gravity.
A rotatable shaft extends generally axially within the body, and has a plurality of agitator elements spaced along and affixed to it, for rotation with it. The agitator elements each have a proximal end attached to the shaft, and a distal end directed generally radially towards the inside wall surface of the body. Means are provided for supporting and rotating the shaft within the body at a controllable preselected constant rate. A
spray head is provided for applying ~he fluid coating material (typically, a pesticide) to the particulate 37,211-F -3-_4_ 2~ 8~
material ~ or e.Yample seeds), ?rior to contact of the particulate material with the said agitator. The spray head may ce provided within t:~e upper part of the body, or externaily of the ~ody sucn that the particulate material .may be treated prior ~o its entry into the body.
In one aspect of the invention the agitator element~ are so shaped as to provide a decreasing amount of agitation to the ~articulate material as it passe~
downwardly through the body. For example. the agitator elements n the upper ?art of the body may be generally in the form of plates of blades. angled so as to direct the falll-.g particulate material momentarily generally upwardly -gainst the gravitational flow, wnerea~ the agitator elements in the lower part o~ the body may be rodq or bar~ or the like. It is desired to produce decreasing agitation as the particular material passeq downwardly through the body to ensure even distribution over the particulate material. Ihis result is accomplished when the fluid coating material i~ applied to particulate material, either immediately before the coated material enters the body, or within the body itself, such that it is distributed to cover all of the ~5 available surfaces of the par~iculate material as soon as po~sible. For this reason, a relatively large degree of agitat on or shear is initially applied. this amount being pre~erably to provide as high a level of shear as is consis~ent with not damaging the material which is being treated. The ~ower part of the body functionq mainly ~s a drying chamber. A sufficient -mount of drying taKes place (?articularly in the case of agricult~-al seeds) so that ~he material emerging from the coat ng device can be packed and shipped. Left 37,211-F -4-undistur~ed, the fluid coating material distributed in the upper part of the body can tend to cause the material to agglomerate. so that it is not free flowing.
In order to pre~rent ?ossible agglomera~ion agitation is provided in the lower part of the body, but this agitation is of a much lower degree than is provided in the upper part of the body.
In a second aspect of the invertion, which is preferably employed in conjunction with the first aspect, but which may be employed separately, the agitator element~ are tapered towards thelr radially extending distal ends in such a manner as to tend to equalize the shear applied to the particulate material over the length of the agitator elements. It has been found that shaping the agitator elements in this way to equalize the shear applied to the particulate material along the length of the agitator elements gives rise to a particularly advantageous distribution o~ the fluid coating material over the surface of the particulate material.
In a third aspect of the invention, which may be employed with one or the other of the ir~t aspects described above, but which also may be employed alone, a plurality of baffles are mounted on the inside wall of the bod-J. ~he Daffles are so positioned 'hat all of the particulate material pa~sing though the device must necessarily encounter at least one of the baffles, there 3 being no direct downward straight-line path through the body by which the baffleq may be avoided. The baffles preferably extend around substantiallJ the entire circumference of the said inside wall. The baffles haYe a deflecting surface so angled aq to face inwardly, so 37,211-r -5-2 ~ 8 ~
as to deflect downwaraly flowing particulate material in a direction generally towards the shaft.
When baffles re employed which do not extend around the entire circumference of the inside wall, their leading edges are preferably inclined so as to disrupt plug rotation of the particulate material, for example, they may be nclined at an angle of from 30 to 80 to the vertical, ?referably 40 to 70, most preferably 60, and so angled as to face upwardly, and thu~ deflect particulate material generally upwardly.
In thi~ aspect of the invention, the baffleq are somewhat interdigitated with the agitator elements, and the clearance between the distal ends of the agitator elements and the ins de wall including the baffles is Yuch that when the shaft ls rotated at a constant rate, the shear imparted to the particulate material i3 from 5 to 50 sec-1. Shear is defined to be the difference in velocity between two layers, divi.ded by the distance between the layers. r or the present purposes, the velocity of the layer of particular material adjacent the agitator element, may be considered to be the same as that of the agitator element, and the layer of material adjacent the inside wall surface of the body may be considered to oe stationary, and the applied ~hear may, therefore, be calculated in terms of the relative velocity of ~he agitator element tips and the inside wall~ The rate o~ shear is from 5 to 50 sec~1, preferably from 10 to 30 sec-1, more preferably 20 sec-1, although this will depend to some e~tent on the nature of the particul~te material (such as seeds) being treated. Fragile ?articulate material, for example pea seeds, will reauire a low shear rate, for example, 5 sec~ hereas cereal seeds such as wheat or 37,211-F -6--7- 2~ 8~
other cereal crop3 will be more suitably treated with a higher shear rate, for example. 20 sec~1.
The agitators elements may be of any desired shape, for example they may be circular or 3quare in cros~ sect on, but as indicated above in a pre~erred embodiment, are ~haped so as to direct the falling particulate material generally upwardly, again3t the gravitational flow. For example, they may be triangular in cro~ section, or may take the form of an angled plate, pre~erably having a leading surface which ~orms an angle o~ from 20 to 75 from the vertical, preferably 60.
It is preferred that the baffles employed in accordance with the third aspect of the invention ex~end around the entire periphery of inside wall surface of the body, because this configuration results in the best mixing, and allows the shortest possible body length.
It is, however, possible to provide short gaps in the baffles, provided that such gaps are not aligned with each other in adjacent baffles so as to provide a direct flow path for the particulate material9 without deflection towards the shaft. The deflecting surface of the baffles is preferably at an angle of from 30 to 80 from the vertical, preferably from 40 to 70, more preferably 60~.
The device in accordance with the invention will generally also include measuring means for ensuring that the appropriate dosage of the fluid material is applied. Such measuring means may include means for measuring the flow rate of the incoming particulate material (e.g., seed) and fluid coating material (e.g., pesticide), and may preferably also include means for 37,211-F _7_ 2 0 ~
weighing t eated particulate material, and means for indicating the level of material in the body, for example, a proximity sensor. The device may also include means for indicating the dosage rate applied, in dependence upon the said measuring a~d sensing means.
The invention includes -~ithin its scope a method for the application of a fluid coating material (e~g., pesticidal material) to particulate material te.g., seeds), employing a device as described above.
0 Also included are particulate material thus treated.
A preferred embodiment of the invention will now be described with reference to the accompanying drawings.
Figure lA is a schematic elevation, partially in section and partially in full, of a first embodiment of a device in accordance with the invention.
Figure lB is a schematic elevation, partially in section and partially in full, of an alternate first embodiment o a device in accordarlce with the invention, Figure 2A is an in section view of the device of Figure lA, taken along the line 2-2.
Figure 2B is an in section view of the device of Figure lB, taken along the line ~ ~, Figure 3 is a schematic elevation, partially in section and partially in full, of a second embodiment of a device employing the invention.
Referring to Figure lA, a coating device for applying a fluid coating material (e.g., pesticide~ to particulate material (e.g., seeds) is shown, which 37,211-F -8-2011 ~18~
devlce co~prlses a generally upright circular body shelL
1~ having an inside wall surface 2, defining a flow path for passage of ~he particulate material. Means not shown are provided for feeding the particulate material to the upper part of the body through the feed opening 3, in direction of arrows 4.
Before entering body 1, fluid coating material is applied to the particulate material, using a spray head (not shown) of the conventional "rolling cone"
0 type. The particulate material throughput through opening 3 is such as to maintain the body 1 substantially full of particulate material through the coating process. Thus 9 the particulate material is allowed to pass the spray head at a convenient rate so that the fluid coating is selectively metered onto it.
Centrally located within body 1 is a rotatable shaft 5, extending generally axially within body 1, and journalled for rotation in a bearing (not shown) in the direction of arrow 6. Agitator elements 7 and 8 provided in the upper and lower part of body 1, respectively, are affixed to the shaft 5 for rotation t~erewith, and have their proximal ends attached to shaft 5, and their distal ends directed generally radially towards surface 2. An electric motor (not shown) is provided for rotating shaft 5 in the direction of arrow 6, at a controllable constant rate.
Agitator elements 7 are in the form of angled blades, and are so shaped as to have a maximum cord line or width a, shown in Figure 2A, and to taper from the said maximum chord a both towards shaft 5, and (by 37,211~F -9-2 0 ~
, o--virtue of tapered edges 9) towards their distally-directed tips.
The tapering edges 9 of agitators 7 tend to equalize the shear applied to the particulate material, over the length of the agitators (i.e. over the radius of body l).
The agitator elements 7 are angled so as to direct the alling particulate material generally upwardly, against their gravitational flow through the body, and serve to distribute the fluid coating material evenly over the surface of the descending particulate ma~erial.
In the lower part of body l, paddle-like agitator elements 7 are replaced by smaller agitators 8, in the form of rods tha~ are More or less circular in section. The function of rods 8 is not primarily to further distribute the fluid coating material over the particulate ~aterial, but instead to agitate the particulate ~aterial continuously, so the agglomerations or clumping of the particulate material does not occur.
It has been found that an excess of agi~atio~ to the particulate material once the drying process has begun is likely to result in the fluid coating materials being mechanically removed from the particulate material, leading to the formation of dust. The agitator elements 8 are thus shaped to provide a gentle agitation, to minimize such removal.
After traversing downwardly through passage through body l, the treated particulate ma~erial emerges passes over a skirt lO at the bottom of shaft 5, and to 37,211-F -10-2~17 ~
a discharge hopper indicated generallJ at 11, but not shown.
Referring now to Figures lB and 2B~ a coating device generally similar in form to that of the device of Figures lA and 2A, respec~ively is shown, which device has stationary baffles 61 which are similar to the agitator elements 7 of ~igures lA and 2A~ except that the baffles 61 are fixed to the wall of the body shell, not to the shaft. The leading edge 60 (Figure 2B) is the edge which first contacts the particulate material if the shaft is rotated in the direction of arrow 6, and the agita~or elements 62 form an angle to the horizon~al.
Referring to Figure 3 or the drawings, a coating device, generally similar in form to that of the device of Figures lA and 2A, is shown, which device has a body 31, with an inside r~all surface 32 defining a flowpath for particulate material 28.
Means 29, for example a conveyor belt, are provided for feeding the particulate material ta the upper part of the body through the feed opening 33, in direction of arrows 4. The particulate material is ~ed into the hopper head 46, in either a batch or continuous process.
The fluid coating is fed to the spray head 38, and contacts the particulate material within the hopper head (i.e., prior to the particulate material entering the body).
Particulate material enters body 31 via opening 33O A shaft 35 is journalled in bearing 36 for rotation about a vertical axis, driven by an electric motor 42.
37,211-F -ll--l2- 2 ~
A spray head 45 or the rolling cone t-rpe applies fluid coating ma~erial 30 to particulate ma~erial falling througn the hopper 46, in which the spray head 45 is ~ounted or suspended.
A plurality of agitator elements 37 of generally eriangular cross-section extend from shaft 35 towards the wall 32. A plurality of baffles 48 are mounted on wall 32, and each extends around the entire circumference of the inside wall. Baf fles 48 have a 0 deflecting surface 49 which is angled so as to deflect the particulate material generally inwardly toward the shaft 35. ~he baffles 48 are interdigitated with agitators 37, and have a clearance such as to provide shear of from ~ to 50 seC~l when the device is in use.
As an example, in a device in which the diameter of body 31 is 0.3 meters, and the gap between the tips of agitators 37 and surface 49 is 50 mm, a shear rate of 20 sec~l will be achieved at a rotational speed of 64 rpml Generally, it is preferred that the clearance between the agitators and the inside wall surfaces is from 25 to 50 mm and the speed of rotation is such that the distal ends of the agitators have a velocity of from 1 to 2 ~/s.
Treated particulate material leaves the body 31 via a discharge hopper 41, and is caused to discharge through a gate valve 50a or 50b into a sock 51, which rests on a weighing device 52. A pair of capascitative 3 proximity sensors 53 and 54 detect upper and lower permissible limits of particulate material in body 31~
and meter~g pumps (not shown) are provided for metering the flow of particulate material and fluid material to hopper 46 and spray head 45. Means (not shown) are also provided or producing a visual display of the said flow 37,211-F -12-2 ~ 5 rate, weight of material removed, a~d levels to enable the dosage applied to the particulate material to be accurately moni~ored and controlled.
r~hen the particulate material is seeds, the seeds may then be planted in soil or ?otting medium, e.g., in a greenhouse or in the field and under ambient normal growth conditions the seeds develop into plants which flower and develop seeds.
As used herein the term "plant" include~ seed capable of being germinated into a whole fertile plant;
plant cells; plant protoplasts; plant cell or tisque cultures from which a plant can be regenerated; plant calli; plant clumps: and plant cells that are intact in a plant or parts of a plant, 3uch as flowers, kernels, ear~, cob~, lea~e~, husks, 3talks, and similar parts or tissues.
37,211-F -13-
COATING DE~ICE
Thi~ invention concerns a device ~or smoothing out a fluid coatlng applied on particulate material.
Especially preferred ls a device for soothing out a ~luid coating, for example a pesticide, on seeds.
It i~ increasingly attractive to seed suppliers to apply to agricultural seeds, coatings of various materialq, particularly pesticidal materials, which are able to protect the seeds against attack by, ~or example, fungi ~nd insects, while the seed is dormant in the ~oil.
The appllcation o~ coating material~ to large quantities o~ ~eeds ?re3ent substantial problems. It is important that the seed should be uniformly coated, and in order to ensure that this iq achieved, it i9 conventional to apply pesticidal formulations in liquid 2~ form, containing substantial quantities of an inert liquid ~/ehicle (normally water). The inerr liquid vehicle must be -emoved, generally in a separate drying stepl before the treated seed can be bagged and sold.
This procedure normally results in the nee~ for a 37,211-F -1-- 2 0 ~
separate drying ~tep, which increase~ the expense of the overall process. It is. therefore. desirable to be able to apply to the seed the pesticidal substance in a formulation containing very little inert vehicle, so that no separate drying step of the pesticide on the coated product is required, while maintaining substantially even pesticidal distribution.
Surprisingly, such a coating device has now been devised. In accordance with thi~ invention, a device is provided for applying a fluid coating material to a particulate material. said device ha~ing a generally upright circular body, which has an in~ide wall surface defining a flowpath for passage of the particulate material therethrough, which comprises, a device for making uniform a fluid coating material to a particulate material, said device comprising a generally upright circular body shell, having an inside wall ~urface defining a flowpath for passage of the particulate material downwardly therethrough, with a) means for feeding the particulate material to interior of the the upper part of the body shell promptly after fluid coating material has been applied thereto, b) a rotatable sha~t extending upwardly and axially towards the means for feeding and within and generally along the length of the body shell, c) an array of agitator elements spaced along and affixed to the shaft for rotation therewith, ~he agitator elements each having a proximal end attached to the shaft and a distal end directed generally radially towards the said inside wall surface, and d) means for rotating the shaft within the body snell at a controllable predetermined constant rate, wherein successive agitator elements within said array, are so shaped as to provide decreasing agitation 37,211-F -2-2 ~ 5 to the parriculate material~ as ~he material passes downwardly through the body shell.
In particular, the device is preferred for applying a pesticidal material to agricultural seeds, -J although the device is not limited to such application.
The fluid material is preferably a liquid, for example, an aqueous or non-aqueous pesticidal composition which may be of conventional form. The device according to the invention may also be utilized to apply fluid compositions in powder form.
However, as is readily apparent, the device of the present invention is not limited to the use of applying pesticides onto seeds, but may advantageously be employed to apply selec~ed fluid coating onto selected particulate ~aterial.
The de~ice comprises a generally upright circular body shell, having an nside wall surface 2~ defining a flowpath for passage of the particulate material ~herethrough. Mean~ are provided for feeding the particulate material to the lnterior of the upper part of the body, to cause the particulate material to pass downwardly through the body cavity under gravity.
A rotatable shaft extends generally axially within the body, and has a plurality of agitator elements spaced along and affixed to it, for rotation with it. The agitator elements each have a proximal end attached to the shaft, and a distal end directed generally radially towards the inside wall surface of the body. Means are provided for supporting and rotating the shaft within the body at a controllable preselected constant rate. A
spray head is provided for applying ~he fluid coating material (typically, a pesticide) to the particulate 37,211-F -3-_4_ 2~ 8~
material ~ or e.Yample seeds), ?rior to contact of the particulate material with the said agitator. The spray head may ce provided within t:~e upper part of the body, or externaily of the ~ody sucn that the particulate material .may be treated prior ~o its entry into the body.
In one aspect of the invention the agitator element~ are so shaped as to provide a decreasing amount of agitation to the ~articulate material as it passe~
downwardly through the body. For example. the agitator elements n the upper ?art of the body may be generally in the form of plates of blades. angled so as to direct the falll-.g particulate material momentarily generally upwardly -gainst the gravitational flow, wnerea~ the agitator elements in the lower part o~ the body may be rodq or bar~ or the like. It is desired to produce decreasing agitation as the particular material passeq downwardly through the body to ensure even distribution over the particulate material. Ihis result is accomplished when the fluid coating material i~ applied to particulate material, either immediately before the coated material enters the body, or within the body itself, such that it is distributed to cover all of the ~5 available surfaces of the par~iculate material as soon as po~sible. For this reason, a relatively large degree of agitat on or shear is initially applied. this amount being pre~erably to provide as high a level of shear as is consis~ent with not damaging the material which is being treated. The ~ower part of the body functionq mainly ~s a drying chamber. A sufficient -mount of drying taKes place (?articularly in the case of agricult~-al seeds) so that ~he material emerging from the coat ng device can be packed and shipped. Left 37,211-F -4-undistur~ed, the fluid coating material distributed in the upper part of the body can tend to cause the material to agglomerate. so that it is not free flowing.
In order to pre~rent ?ossible agglomera~ion agitation is provided in the lower part of the body, but this agitation is of a much lower degree than is provided in the upper part of the body.
In a second aspect of the invertion, which is preferably employed in conjunction with the first aspect, but which may be employed separately, the agitator element~ are tapered towards thelr radially extending distal ends in such a manner as to tend to equalize the shear applied to the particulate material over the length of the agitator elements. It has been found that shaping the agitator elements in this way to equalize the shear applied to the particulate material along the length of the agitator elements gives rise to a particularly advantageous distribution o~ the fluid coating material over the surface of the particulate material.
In a third aspect of the invention, which may be employed with one or the other of the ir~t aspects described above, but which also may be employed alone, a plurality of baffles are mounted on the inside wall of the bod-J. ~he Daffles are so positioned 'hat all of the particulate material pa~sing though the device must necessarily encounter at least one of the baffles, there 3 being no direct downward straight-line path through the body by which the baffleq may be avoided. The baffles preferably extend around substantiallJ the entire circumference of the said inside wall. The baffles haYe a deflecting surface so angled aq to face inwardly, so 37,211-r -5-2 ~ 8 ~
as to deflect downwaraly flowing particulate material in a direction generally towards the shaft.
When baffles re employed which do not extend around the entire circumference of the inside wall, their leading edges are preferably inclined so as to disrupt plug rotation of the particulate material, for example, they may be nclined at an angle of from 30 to 80 to the vertical, ?referably 40 to 70, most preferably 60, and so angled as to face upwardly, and thu~ deflect particulate material generally upwardly.
In thi~ aspect of the invention, the baffleq are somewhat interdigitated with the agitator elements, and the clearance between the distal ends of the agitator elements and the ins de wall including the baffles is Yuch that when the shaft ls rotated at a constant rate, the shear imparted to the particulate material i3 from 5 to 50 sec-1. Shear is defined to be the difference in velocity between two layers, divi.ded by the distance between the layers. r or the present purposes, the velocity of the layer of particular material adjacent the agitator element, may be considered to be the same as that of the agitator element, and the layer of material adjacent the inside wall surface of the body may be considered to oe stationary, and the applied ~hear may, therefore, be calculated in terms of the relative velocity of ~he agitator element tips and the inside wall~ The rate o~ shear is from 5 to 50 sec~1, preferably from 10 to 30 sec-1, more preferably 20 sec-1, although this will depend to some e~tent on the nature of the particul~te material (such as seeds) being treated. Fragile ?articulate material, for example pea seeds, will reauire a low shear rate, for example, 5 sec~ hereas cereal seeds such as wheat or 37,211-F -6--7- 2~ 8~
other cereal crop3 will be more suitably treated with a higher shear rate, for example. 20 sec~1.
The agitators elements may be of any desired shape, for example they may be circular or 3quare in cros~ sect on, but as indicated above in a pre~erred embodiment, are ~haped so as to direct the falling particulate material generally upwardly, again3t the gravitational flow. For example, they may be triangular in cro~ section, or may take the form of an angled plate, pre~erably having a leading surface which ~orms an angle o~ from 20 to 75 from the vertical, preferably 60.
It is preferred that the baffles employed in accordance with the third aspect of the invention ex~end around the entire periphery of inside wall surface of the body, because this configuration results in the best mixing, and allows the shortest possible body length.
It is, however, possible to provide short gaps in the baffles, provided that such gaps are not aligned with each other in adjacent baffles so as to provide a direct flow path for the particulate material9 without deflection towards the shaft. The deflecting surface of the baffles is preferably at an angle of from 30 to 80 from the vertical, preferably from 40 to 70, more preferably 60~.
The device in accordance with the invention will generally also include measuring means for ensuring that the appropriate dosage of the fluid material is applied. Such measuring means may include means for measuring the flow rate of the incoming particulate material (e.g., seed) and fluid coating material (e.g., pesticide), and may preferably also include means for 37,211-F _7_ 2 0 ~
weighing t eated particulate material, and means for indicating the level of material in the body, for example, a proximity sensor. The device may also include means for indicating the dosage rate applied, in dependence upon the said measuring a~d sensing means.
The invention includes -~ithin its scope a method for the application of a fluid coating material (e~g., pesticidal material) to particulate material te.g., seeds), employing a device as described above.
0 Also included are particulate material thus treated.
A preferred embodiment of the invention will now be described with reference to the accompanying drawings.
Figure lA is a schematic elevation, partially in section and partially in full, of a first embodiment of a device in accordance with the invention.
Figure lB is a schematic elevation, partially in section and partially in full, of an alternate first embodiment o a device in accordarlce with the invention, Figure 2A is an in section view of the device of Figure lA, taken along the line 2-2.
Figure 2B is an in section view of the device of Figure lB, taken along the line ~ ~, Figure 3 is a schematic elevation, partially in section and partially in full, of a second embodiment of a device employing the invention.
Referring to Figure lA, a coating device for applying a fluid coating material (e.g., pesticide~ to particulate material (e.g., seeds) is shown, which 37,211-F -8-2011 ~18~
devlce co~prlses a generally upright circular body shelL
1~ having an inside wall surface 2, defining a flow path for passage of ~he particulate material. Means not shown are provided for feeding the particulate material to the upper part of the body through the feed opening 3, in direction of arrows 4.
Before entering body 1, fluid coating material is applied to the particulate material, using a spray head (not shown) of the conventional "rolling cone"
0 type. The particulate material throughput through opening 3 is such as to maintain the body 1 substantially full of particulate material through the coating process. Thus 9 the particulate material is allowed to pass the spray head at a convenient rate so that the fluid coating is selectively metered onto it.
Centrally located within body 1 is a rotatable shaft 5, extending generally axially within body 1, and journalled for rotation in a bearing (not shown) in the direction of arrow 6. Agitator elements 7 and 8 provided in the upper and lower part of body 1, respectively, are affixed to the shaft 5 for rotation t~erewith, and have their proximal ends attached to shaft 5, and their distal ends directed generally radially towards surface 2. An electric motor (not shown) is provided for rotating shaft 5 in the direction of arrow 6, at a controllable constant rate.
Agitator elements 7 are in the form of angled blades, and are so shaped as to have a maximum cord line or width a, shown in Figure 2A, and to taper from the said maximum chord a both towards shaft 5, and (by 37,211~F -9-2 0 ~
, o--virtue of tapered edges 9) towards their distally-directed tips.
The tapering edges 9 of agitators 7 tend to equalize the shear applied to the particulate material, over the length of the agitators (i.e. over the radius of body l).
The agitator elements 7 are angled so as to direct the alling particulate material generally upwardly, against their gravitational flow through the body, and serve to distribute the fluid coating material evenly over the surface of the descending particulate ma~erial.
In the lower part of body l, paddle-like agitator elements 7 are replaced by smaller agitators 8, in the form of rods tha~ are More or less circular in section. The function of rods 8 is not primarily to further distribute the fluid coating material over the particulate ~aterial, but instead to agitate the particulate ~aterial continuously, so the agglomerations or clumping of the particulate material does not occur.
It has been found that an excess of agi~atio~ to the particulate material once the drying process has begun is likely to result in the fluid coating materials being mechanically removed from the particulate material, leading to the formation of dust. The agitator elements 8 are thus shaped to provide a gentle agitation, to minimize such removal.
After traversing downwardly through passage through body l, the treated particulate ma~erial emerges passes over a skirt lO at the bottom of shaft 5, and to 37,211-F -10-2~17 ~
a discharge hopper indicated generallJ at 11, but not shown.
Referring now to Figures lB and 2B~ a coating device generally similar in form to that of the device of Figures lA and 2A, respec~ively is shown, which device has stationary baffles 61 which are similar to the agitator elements 7 of ~igures lA and 2A~ except that the baffles 61 are fixed to the wall of the body shell, not to the shaft. The leading edge 60 (Figure 2B) is the edge which first contacts the particulate material if the shaft is rotated in the direction of arrow 6, and the agita~or elements 62 form an angle to the horizon~al.
Referring to Figure 3 or the drawings, a coating device, generally similar in form to that of the device of Figures lA and 2A, is shown, which device has a body 31, with an inside r~all surface 32 defining a flowpath for particulate material 28.
Means 29, for example a conveyor belt, are provided for feeding the particulate material ta the upper part of the body through the feed opening 33, in direction of arrows 4. The particulate material is ~ed into the hopper head 46, in either a batch or continuous process.
The fluid coating is fed to the spray head 38, and contacts the particulate material within the hopper head (i.e., prior to the particulate material entering the body).
Particulate material enters body 31 via opening 33O A shaft 35 is journalled in bearing 36 for rotation about a vertical axis, driven by an electric motor 42.
37,211-F -ll--l2- 2 ~
A spray head 45 or the rolling cone t-rpe applies fluid coating ma~erial 30 to particulate ma~erial falling througn the hopper 46, in which the spray head 45 is ~ounted or suspended.
A plurality of agitator elements 37 of generally eriangular cross-section extend from shaft 35 towards the wall 32. A plurality of baffles 48 are mounted on wall 32, and each extends around the entire circumference of the inside wall. Baf fles 48 have a 0 deflecting surface 49 which is angled so as to deflect the particulate material generally inwardly toward the shaft 35. ~he baffles 48 are interdigitated with agitators 37, and have a clearance such as to provide shear of from ~ to 50 seC~l when the device is in use.
As an example, in a device in which the diameter of body 31 is 0.3 meters, and the gap between the tips of agitators 37 and surface 49 is 50 mm, a shear rate of 20 sec~l will be achieved at a rotational speed of 64 rpml Generally, it is preferred that the clearance between the agitators and the inside wall surfaces is from 25 to 50 mm and the speed of rotation is such that the distal ends of the agitators have a velocity of from 1 to 2 ~/s.
Treated particulate material leaves the body 31 via a discharge hopper 41, and is caused to discharge through a gate valve 50a or 50b into a sock 51, which rests on a weighing device 52. A pair of capascitative 3 proximity sensors 53 and 54 detect upper and lower permissible limits of particulate material in body 31~
and meter~g pumps (not shown) are provided for metering the flow of particulate material and fluid material to hopper 46 and spray head 45. Means (not shown) are also provided or producing a visual display of the said flow 37,211-F -12-2 ~ 5 rate, weight of material removed, a~d levels to enable the dosage applied to the particulate material to be accurately moni~ored and controlled.
r~hen the particulate material is seeds, the seeds may then be planted in soil or ?otting medium, e.g., in a greenhouse or in the field and under ambient normal growth conditions the seeds develop into plants which flower and develop seeds.
As used herein the term "plant" include~ seed capable of being germinated into a whole fertile plant;
plant cells; plant protoplasts; plant cell or tisque cultures from which a plant can be regenerated; plant calli; plant clumps: and plant cells that are intact in a plant or parts of a plant, 3uch as flowers, kernels, ear~, cob~, lea~e~, husks, 3talks, and similar parts or tissues.
37,211-F -13-
Claims (16)
1. A device for smoothing out a fluid coating material applied to a particulate material, said device comprising a generally upright circular body shell, having an inside wall surface defining a flowpath for passage of the particulate material downwardly therethrough, with a) means for feeding the particulate material to interior of the the upper part of the body shell promptly after fluid coating material has been applied thereto, b) a rotatable shaft extending upwardly and axially towards the means for feeding and within and generally along the length of the body shell, c) an array of agitator elements spaced along and affixed to the shaft for rotation therewith, the agitator element each having a proximal end attached to the shaft and a distal end directed generally radially towards the said inside wall surface, and d) means for rotating the shaft within the body shell at a controllable predetermined constant rate, 37,211-F
wherein successive agitator elements within said array, are so shaped as to provide decreasing agitation to the particulate material. as the material passes downwardly through the body shell.
wherein successive agitator elements within said array, are so shaped as to provide decreasing agitation to the particulate material. as the material passes downwardly through the body shell.
2. The device of Claim 1, wherein the agitator elements are tapered towards their distal ends in such a manner as to tend to equalize the shear applied to the particulate material over the length of the agitator elements.
3. The device of Claim 1, further comprising a spray head for applying the fluid coating material to the particulate material prior to contact of the particulate material with the said agitators and baffles.
4. The device of Claim 2, having a plurality of baffles mounted on the inside wall surface of the body shell, the said baffles being so positioned that there is no direct straight-line downward flowpath for the particulate material through the body shell by which contact with at least one baffle or agitator elements may be avoided and each baffle having a deflecting surface so angled as to deflect downwardly flowing particulate material generally inwardly towards the said shaft.
5. The device of Claim 4, having a spray head for applying the fluid coating material to the particulate material prior to contact of the particulate material with the said agitators and baffles, wherein the baffles are interdigitated with the agitator elements, and wherein the clearance between the distal ends of the said agitator elements and the said 37,211-F
\
inside wall including said baffles is such as to provide shear of from 5 to 50 sec-1 when the shaft is rotated at the said predetermined constant rate.
\
inside wall including said baffles is such as to provide shear of from 5 to 50 sec-1 when the shaft is rotated at the said predetermined constant rate.
6. The device of Claim 5, wherein the baffles have an upper deflecting surface, said deflecting surfaces being positioned at an angle of from 30° to 80°
to the horizontal.
to the horizontal.
7. The device of Claim 6, wherein the deflecting surfaces of the baffles are positioned at an angle of from 40° to 70° to the horizontal.
8. The device of Claim 1, wherein the device is adapted to apply to the said particulate material shear from 10 to 30 sec-1.
9. The device of Claim 1, wherein at least in the upper part of the said body shell, the said agitator elements are so shaped as to direct the falling particulate material generally upwardly against the gravitational flow.
10.The device of Claim 9, wherein the leading surface of the agitators form an angle of from 20° to 75°
with the vertical.
with the vertical.
11.The device of Claim 10, wherein the leading surface of the agitators form an angle of 60° with the vertical.
12. A method of applying a fluid coating material onto a particulate material, which method comprises feeding the particulate material to the upper part of the body shell of the device as claimed in any one of the preceding claims, feeding the fluid coating 37,211-F
material to the said spray head to apply the fluid coating material to the particulate material, and allowing the particulate material to flow through the body shell under gravity while rotating the shaft at a rate such as to impart to the particulate material a shear of from 5 to 50 sec-1, to relatively uniformly distribute the fluid coating material onto the particulate material.
material to the said spray head to apply the fluid coating material to the particulate material, and allowing the particulate material to flow through the body shell under gravity while rotating the shaft at a rate such as to impart to the particulate material a shear of from 5 to 50 sec-1, to relatively uniformly distribute the fluid coating material onto the particulate material.
13. A method as claimed in Claim 12, wherein the clearance between the distal ends of the agitators and the said inside wall surface is from 25 to 50 mm, and wherein the speed of rotating and the rotatable shaft is such that the distal ends of the agitators have a linear velocity of from l to 2 m/s.
14. The method of Claim 12, wherein the particulate material is an agricultural seed material, and the fluid coating material is a pesticide.
15. Seeds treated by a method as claimed in Claim 12.
16. A plant or plant part derived from the seed of Claim 15.
37,211-F
37,211-F
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8904542.1 | 1989-02-28 | ||
| GB898904542A GB8904542D0 (en) | 1989-02-28 | 1989-02-28 | Coating device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2011185A1 true CA2011185A1 (en) | 1990-08-31 |
Family
ID=10652451
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2011185 Abandoned CA2011185A1 (en) | 1989-02-28 | 1990-02-28 | Coating device |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0461173A1 (en) |
| CA (1) | CA2011185A1 (en) |
| GB (1) | GB8904542D0 (en) |
| WO (1) | WO1990009733A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108738494A (en) * | 2018-06-23 | 2018-11-06 | 吴永凤 | A kind of agricultural with seed mixes medicine device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3155542A (en) * | 1960-09-22 | 1964-11-03 | Ben Gustason & Son Mfg Company | Cottonseed-treating machine |
| HU177350B (en) * | 1978-01-02 | 1981-09-28 | Mezoegaz Gepgyar Szolgalt Vall | Seed dressing machine |
-
1989
- 1989-02-28 GB GB898904542A patent/GB8904542D0/en active Pending
-
1990
- 1990-02-26 WO PCT/GB1990/000300 patent/WO1990009733A1/en not_active Application Discontinuation
- 1990-02-26 EP EP19900904397 patent/EP0461173A1/en not_active Withdrawn
- 1990-02-28 CA CA 2011185 patent/CA2011185A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0461173A1 (en) | 1991-12-18 |
| GB8904542D0 (en) | 1989-04-12 |
| WO1990009733A1 (en) | 1990-09-07 |
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| Date | Code | Title | Description |
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| FZDE | Dead |