Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
W 0 92/0~08fi 1 PCTtF191/00335
; A METHOD AND DEVICE FOR DRYING CONES 2 0 9 ~
The object of th~ invantion is a method and device for drying
cones, in which the cone mass is treated by blowing warm air
through the mass ard is necessary wetting the cone mass. The
invention is also directed to a cone drying and treatment
apparatus intended to implement the method in which there is a
bin allowing air penetration and a warm air device for blowing
warmed air through the cone mass located in the bin.
An important stage in the production chain of conifer seeds is
the drying of the cones, so that the scales of the cones open
and the seeds separate from the interior o~ the cone. At
present extraction stations use tower-like groups of silos, in
which the cones are placed on shelves one on top of the other
and drying aix blown from below is directed vertically through
the silo and the rone mass in it. Due to the drier model it is
impossible to direct drying air evenly through the entire layer
of cones, even though some degree of evening out takes place
between the various layers. As the drying progresses the volume
of the cones increases, the space between them diminishes, and
evening out is less.
As the drying air travels through the cone mass it becomes damp
and thus the last cones in the direction of travel of the air
are subject to the dampness removed from the first layers. Due
to this these last cones do not always dry before the first
cones have dried to a considerable degree. When using a drier
of this type it is not possible to simulate other variables
that appear in nature. Wetting has, however, been added to this
type of drier, when particularly the cones in the lower part
are subject to a back a~d forwards treatment, in which the
scales open by drying, close by wetting, and open again by
drying. This kind of back and forwards treatment has been shown
to be beneficial.
The main purpose of the treatment of the cone mass is to
produce as many germinable seeds as possible per unit of weight
of cone mass. Thus purely quantitative production is not
sufficient, but rather the seeds obtained must be germinable
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re to b~ benefit from large production. In present type~
of driers more efficient dr~ing e.g. by heating the air or
lengthening the haating period generally cause a reduction in
germinability.
The intention of this invention is to remove the aforementioned
defects and to create a naw kind oE efficient method and device
for the treatment and drying of cones, by means of which it is
possible to produce seed~ with a ,great germinability substan-
tially more efficiently than previously. The characteristicfeatures of the method in accordance with the invention are
presented in Patent Claim 1 and the characteristic features of
a device implementing a corresponding method are presented in
Patent Claim 6. The invention is to a great extent based on the
observation that homogenous drying is only possible up to an
ahsolutely determinable mass limit in the same way that it is
possible to absolutely determine the maximum layer thickness of
the cone mass being treated. Because of this the cone mass must
be divided into sufficiently small batches and the drying and
treatment stage must be carried out separately ~or each b~tch
of cones. It is then possible to copy the phenomena taking
place in nature better. Phenomena of this kind are variations
in temperature, moisture content, atmospheric pressure, and
amount of light. Other advantageous forms of application and
advantages of the invention appear in the examples of ap-
plication shown later.
In what follows the invention is illustrated by reference to
the accompanying ~igures, which show one kind of cone drying
and treatment apparatus in accordance with the invention.
Figure 1 shows the treatment apparatus seen from the side.
Figure 2 shows a cross-section of the apparatus in Figure 1 a
point II - II.
Figure 3 shows a corresponding cross-section to that in Figure
2, but with the bins in the transfer position.
The device in accordance with the invention is formed of a kind
of conveyor, in which the cone drying bins 2 are sequentially
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W~92/OB086 2 0 9 ~ ~ 0 8 P c3/Fl~1ton335
connected -to on8 another be means of intermediate pieces 5, and
the corners of the bins have`wheels ~ to transport them along
the desired track. Here the bins are trans~erred to the device
in the transfer position in the upper circulation 9 along track
6 and in the lower circulation 8 along track 7, which tracks
are formed of beams set in the sides of the device. The uppe~
track 6 is formed at the transfer stage, as is described later.
At the feed end the conveyor has a normal pulley wheel 10 to
transfer the bins ~rom the lower circulation B to the upper
circulation 9. At the discharge end on the other hand the
arrangement is more complicated. The wheels 4 of the bins are
permitted to drop onto the cable 16 at the end of the track 6,
which leads them to the lower circulation 8. In this way a
rapid emptying movement is achieved, in which the bins turn
quickly into a downwards sloping position to drop the cones
into the hopper 19, which is shown in Figure 1 with broken
lines~
The upper funnels 1 are connected to the output channel 12 by
means of a flexible connection 11. The flexible connection il
permits the funnels to be raised by about 10 cm..
In Figures 1 and 2 the device is shown in the drying and treat-
ment position, when the bins 2 ha~e pressed with their low2r
flanges 21 tightly against the input connections 23 of the
fixed lower funnels 3 and further the output connection 20 of
each upper funn~l is pressed against the upper flange 22 of the-
corresponding bin. The flanges of both the bins 2 and the
connections 23, 20 are 40 mm. wide. There is a rubber seal in
the input and output connection flanges 23, 20. When they are
pressed together these simple connections are tight and in
addition a reasonable tolerance is permitted in the positioning
of the bins.
In the experimental apparatus depicted the size of the bins is
1200 mm. x 500 mm. x 300 mm.. In this case about 40 kg. of
fresh cones will fit each bin (in a layer of about 10 cm.),
when it is taken into consideration that the volume of the
cones will increase as much as 2,5 times in drying. In an
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WO92/OXOX6 ~ 9 ~ P~r/F~ /00335 -
apparatus intended ~or proper production operation the size of
the bins is greater ~capacit~ about 65 kg.) being, however,
su~iciently small that the homogenou~ treatment of the entire
batch is possible. In principle the size of the batch may be 10
- 100 kg, with an optimum size of batch of 50 - 70 kg, when a
suitable flow resistance over the cone layer is achieved with
a practical fan output. In the experimental apparatus each
lower funnel 3 had its own fan, with an output of 0,15 - 0,20
m3/s at a counterpressure of 250 Pascals.
1~
Figures 2 and 3 show how the transfer of the bins 2 is carried
out. Figure 2 corresponds to the situation in Figure 1 and
there the input connection 23 of the lower ~unnel 3 and the
output connection 20 of the upper funnel 1 are attached to bin
2. The bins 2 of the upper circulation 9 lie on top of the
fixed lower funnels 3 and the carrying wheels 4 are in the air.
Upper funnel 1 is correspondingly set by its own weight on top
of bin 2. Figure 2 shows that at this stage the track 6 is at
a distance to the carrying wheels 4. The lifting cylinder 13
first lifts the upper funnels l clear of the bins 2 by means of
beam 14, but beam 6 should come upwards by a pre-set amount
until it contacts carrying wheel 4. After this the upper
circulation bins 2 rise along with the upper funnel l, when
gaps 17 and 18 are created between input and output connections
23, 20 are the flanges 21, 22 of bin 2. After this stepped
hydraulic cylinder 15 can be used to move the bins forward by
one unit.
The solution in accvrdance with the invention makes possible a
simple but reliable seal construction, which does not come
under any stress during the movement of the bins.
The upper funnels 1 include wetting nozzles and the lower
funnels drain cormections (not shown). In addition the upper
funnels include ultra violet lamps for lighting the cone mass
(not shown).
Independent units include control automation, by means of which
among other things the heat blowing is controlled on the basis
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W092/080~C 2 0 9 '1:) 0 8 pc~r/Flsl/oo33s
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of tha temperature of the incoming air and data based on
experience. For more accurate'cont:rol the system would include
measurement of the moisture content of the outgoing air.
ThP apparatus can either be used in such a way that all the
bins are filled and all the stages are carried out for each bin
with the same unit, or each unil: can specialize to provide
heating, wetting, or other treatmlent, in which case the bins
are moved one step at a tima.
Naturally the apparatus is applicable to the drying of other
materials than cones. For example when drying batches o~ gun-
powder it is important that the opposing seals never rub
against one another.
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