Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
Method and system for palletizing peat moss
FIELD OF THE INVENTION
[0001] The present invention relates to improvements in the field of peat
moss bulk
shipping. More particularly, the invention pertains to a method and apparatus
for palletizing peat
moss in bulk compressed form.
SUMMARY OF THE INVENTION
[0002] More specifically, in accordance with the present invention, there
is provided a
system for palletizing peat moss in bulk form, comprising a dosing and feeding
unit; a filling and
compaction unit, receiving an amount of peat moss determined by the dosing and
feeding unit, and
compressing each determined amount of peat moss into a compressed bloc of peat
moss on a pallet;
a stabilization unit, receiving, from the filling and compaction unit,
pallets, each pallet supporting a
compressed bloc of peat moss, and wrapping the compressed bloc for
stabilization thereof; a
weighing and height measuring unit, measuring each compressed bloc received
from the stabilization
unit; and a wrapping unit, finally wrapping each measured compressed bloc.
[0003] There is further provided a method for palletizing peat moss in
bulk form,
comprising a) determining an amount of peat moss corresponding to a target
bloc; b) feeding the
determined amount to a compaction box and compacting into a compacted bloc
supported by a
pallet; c) stabilizing the compacted bloc; d) measuring the compacted bloc;
and e) wrapping the
pallet with the compacted bloc thereon.
[0004] Other objects, advantages and features of the present invention
will become
more apparent upon reading of the following non-restrictive description of
specific embodiments
thereof, given by way of example only with reference to the accompanying
drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0005] In the appended drawings:
[0006] Figure la is a schematical perspective view; Figure lb is a
schematical top
view; and Figure lc is a schematical side view; of a system according to an
embodiment of an aspect
of the present invention;
[0007] Figure 2a is a schematical view of a doser in the system of Figure 1,
and
Figure ibis a detail of Figure 2a;
[0008] Figure 3 is a schematical view of a sampler in the system of Figure
1;
[0009] Figure 4a is a first perspective schematical view; Figure 4b is a
side
schematical view; and Figure 4c is a second perspective schematical view, of a
compaction box
according to an embodiment of an aspect of the present invention;
[0010] Figure 5a is a side schematical view of Figure 4a, Figures 5b, 5c
show details
of Figure 4a;
[0011] Figure 6 shows details of Figure 4a;
[0012] Figure 7 a) is a perspective partial schematical view and b) is a top
view, of a
compaction box according to an embodiment of an aspect of the present
invention;
[0013] Figure 8 shows a conveyer according to an embodiment of an aspect of
the
present invention;
[0014] Figures 9 show a pallet feeder a) in down and b) up positions
according to an
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embodiment of an aspect of the present invention;
[0015] Figures 10 show a) a top view of a compaction box according to an
embodiment of an aspect of the present invention b) a top view of a vent in a
wall of the compaction
box according to an embodiment of an aspect of the present invention and c) a
perspective view of a
palletized bloc according to an embodiment of an aspect of the present
invention;
[0016] Figure 11 is a) a side view and b) a top view of units of the
system of Figures
1; and
[0017] Figure 12 is a block diagram schematically illustrating a method of
palletizing
peat moss according to an embodiment of an object of the present invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0018] As illustrated for example in Figures 1, a system according to an
embodiment
of an aspect of the present invention comprises a dosing and feeding unit 12,
a filling and
compaction unit 14, a stabilization unit 16, a weighing and height measuring
unit 18, a wrapping unit
20 and an output unit 22.
[0019] The illustrated dosing and feeding unit 12 comprises two feeding
lines (I) and
(II), each line comprising a doser 30 (Figure 1a).
[0020] The doser 30 is essentially a supply of peat moss, fed with peat
moss from the
back. As illustrated in Figure 2a, a doser 30 comprises a conveyor 310 and an
equalizer 320, the
equalizer 320 pushing the material towards the front (see arrow A in Figure
2a). The equalizer 320
comprises rotating aluminum bats 322 that gradually push the material
forwards, ensuring constancy
in volumes by using a number of sensors positioned at intervals, each one
corresponding to a
predetermined volume, and monitored through a panel view 330 (see Figure 2b).
The volumes are
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thus automatically selected, without manual manpower, by selecting a sensor
from the panel view
330. Filling of the doser, equalizing and dumping from the doser, at the front
end of the doser 30, into
the compaction box of the filling and compaction unit 14 are all controlled by
an automate (PLC) and
fully automatic.
[0021] As best seen in Figure 3, a sampler 324 is provided at the back of
the doser
30, for collecting a reference volume, i.e. a cubic foot box for example, of
material of each amount
determined by the doser 30. A cubic foot box (12 in x 12 in x 12 in) is fed by
a sampler screw 325 in
a cubic box (not shown), and the weight of the cubic foot is measured by the
PLC and stored as a
reference. The cubic box is then emptied for a next sampling and measurement.
This is done twice
for each amount determined by the doser 30 for a given bloc of predetermined
volume, for example
240 cubic foot, since it is found that an average over two reference
measurements provides a
reasonable accuracy for the bloc. This sampling is controlled by a
programmable logic controller
(PLC) and fully automatic. Another sampler (not shown) may be provided to
collect material
sampling, for humidity content testing for example.
[0022] The doser 30 thus determines the amount of material to be fed into
the
compaction box 40 of the filling and compaction unit 14 for a specific bloc.
[0023] As people in the art will appreciate, in the present system, the
volumes are
determined upstream of the filling and compaction unit 14. Moreover, by
providing two feeding lines
(I) and (II), as best seen in Figure la, typically one feeding line for coarse
peat moss and one feeding
line for fine peat moss, the system allows production of two different
products, using the same
wrapping units, by allowing compaction of a bloc of a first type, for example
coarse peat moss, at the
filling and compaction unit 14 while wrapping of a bloc of a second type, for
example fine peat moss,
at the wrapping units, in a continuous process. As a result, the speed and
production rate are
increased since different types and qualities of peat moss can be processed
concurrently with the
same system.
[0024] The amount of peat moss determined by the doser 30 is dumped from
the front
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end of the doser 30 into the compaction box 40 of the filling and compaction
unit 14, positioned
below the dosing and feeding unit 12 in Figure la. This discharge of the
material at the front of the
doser 30 into the compaction box takes barely 12 to 15 sec. Thus, the
compaction box 40 receives
the amount of material as determined in the doser 30 for a bloc, as described
hereinabove.
[0025] As shown in Figure 4, the compaction box 40 comprises a top part 510
and a
mobile bottom part 520. A flange 530, i.e. a ring part, mobile on rails and
bearings and hydraulically
driven for example, is adapted to be lifted from the bottom part 520 to
disengage the bottom part 520
from the top part 510 to allow the bottom part with a compacted bloc therein
to leave the filling and
compaction unit 14 for the stabilization unit 16, and to engage the bottom
part 520 for connection
with the top part 510 at the filling and compaction unit 14 for receiving the
peat moss from the doser
30 for compaction. When the bottom part 520 is below the top part 510 for
receiving the peat moss
from the doser, the flange 530 in position therebetween ensures continuity
between the two parts,
thereby preventing dust or material leaks between the two parts 510 and 520.
Those actions are
monitored by the PLC and are all automatic. In Figures 7, the bottom part 520
of the compaction box
40 is shown with its doors open.
[0026] As shown in Figures 4 and 5, the bottom part 520 is mobile on tracks
540
provided below the box 40, which allows saving space above the box 40. A first
track 540a may have
a V shape so as to guide the box 40 and ensure it does not move sideways and a
second track 540b
may be provided with a flat wheel to give a sideways play to the box 40,
thereby avoiding that the
box 40 gets jammed on the tracks.
[0027] As shown in Figures 4c, 5 and 6, the filling and compaction unit 14
comprises a
pallet feeder 570 comprising arms 550 and a frame 560, which handles a bundle
of pallets and
deposits one pallet at a time at the back of the box 40. In Figures 4c, 5b or
6, a pallet (P) is shown,
waiting to be deposited behind the compaction box 40 on the tracks 540 by
opening of the arms 550
so that the frame 560 moves down. When the bottom part 520 of the compaction
box 40 is back at
the filling and compaction unit 14 from the stabilization unit 16, the pallet
feeder 570 thus deposits a
pallet behind the box and slides the pallet inside the box for receiving a
next load of material. The
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frame 560 can move up and down to lift the bundle of pallets as shown in
Figure 5b. In previous
systems, the pallets had to be manually positioned, which was dangerous and,
although efficient for
a production of 10 blocs/hour, could not allow a production of up to 32
blocs/hour. In the present
system, the pallet feeder 570 is provided at the back of the machine, with
hydraulic arms 550 that
take pallet bundles to leave only one pallet on the conveyor 310, just behind
the compaction box 40.
It is a two action system: open/close arm 550 on the pallet bundle and up/down
the pallet bundle. As
a result, a pallet is left behind the box 40 when the bottom part 520 of the
compaction box 40 leaves
a compressed bloc at the stabilization unit. When the bottom part 520 of the
compaction box 40
returns to the filling and compaction unit 14, the pallet enters in the box 40
by an opening of the size
of the pallet in the bottom part 520. All those actions are monitored by the
PLC and fully automatic.
[0028] The filling and compaction unit 14 comprises a piston and cylinder
arrangement 15, supported by a frame 17 (best seen in Figure 1c), for
compaction of the amount of
peat moss determined by the doser, within the compaction box 40. A digital
encoder is used to
monitor the course of the piston so as to control the compaction ratio and the
height of the bloc
formed. The height of the bloc is thus precisely and automatically controlled,
and uniform. The peat
moss is compressed at a pressure between 3 and 5 kg/cm2, for example at about
3.85 kg/cm2, to a
volume ratio of non-compressed peat moss to compressed peat moss between 2:1
and 3:1.
[0029] The compaction box 40 may be provided with vents (see for example
figures
4a, 4b, 4c, 7a), allowing air expulsion during compaction. In order to prevent
such vents from being
obstructed by the peat moss, the vents are formed by tapered bores in the
doors of the compaction
box 40, as shown in Figure 10b for example, the tapering resulting in any
material entering the bores
to slide on the tapered surfaces of the bores, without obstructing them.
[0030] As shown in Figure 10a, the compaction box 40 is provided with inner
round
corners 600, so as to produce peat blocs 700, shown in Figure 10b on a pallet
(P) for example,
having round corners 710, which are found to be more resistant to breaking.
Back inner corners 600b
of the compaction box 40 may have an angle of 90 degrees, and the front inner
corners 600a of the
compaction box 40 may have an angle of 92 degrees, thereby reducing the risks
that the bloc
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corners break upon opening of the front doors of the box.
[0031] Figure 8 shows a conveyor, driven by a motor 546, and the tracks 540
that
guide the mobile part of the compaction box 40 from the filling and compaction
unit 14 to the
stabilization unit 16. Forks 542, actuated by cylinders 544 for example,
support the pallet during
compression of the peat moss within the compaction box 40, at the filling and
compaction unit 14.
[0032] At the stabilization unit 16, a top platen 311, best seen in Figure
11a, driven by
a piston for example, is moved to contact the top surface of the bloc upon
arrival of the bottom part
520 of the compaction box 40, thereby stabilizing the bloc, before the doors
of the bottom part 520
open to release the bloc. The bottom part 520 of the compaction box 40 leaves
the pallet with the
bloc thereon and withdraws to the filling and compaction unit 14. An elevator
548, actuated by a
cylinder 541 for example, is used to lift the pallet (P), placed on a plate
543 (see Figures 8 and 9),
and a layer of film is wrapped about the loaded pallet for stabilization of
its expansion, as fast as
possible, i.e. within between 45 to 60 s from its output from the compaction
box 40, so that the bloc
remains straight and integral, i.e. so that the bloc does not collapse, the
conveyer remaining in
position, as best seen in Figure 9.
[0033] As shown in Figures 11, the stabilization unit 16 may comprise a
rotary arm
stretch wrapper. The wrapper needs not be mobile or moved away to allow the
box 40 to deliver the
bloc, since the tracks 540 allow moving the compaction box 40 with the loaded
pallet forward, as
mentioned hereinabove. Those entire steps are fully automated by the PLC and
need no manpower.
[0034] From the stabilization unit 16, once stabilized as described
hereinabove, the
bloc is moved to a scale and a linear resistance at the weighing and height
measuring unit 18, to
have its height and weight measured. These pieces of data are processed in a
PC with the weight of
the reference volume as determined before by sampling at the dosing and
feeding unit 12 as
described hereinabove so as to confirm the volume of the bloc, and an
identifying sticker is
generated for that bloc. All those steps are completely automated. The
identifying sticker typically
indicates the time of production of the bloc, the kind (coarse/fine) of the
product, the weight, the
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volume, the height of the bloc, the weight of the reference volume. The
sticker is printed with a
unique ITN # and is put it on the bloc itself. Simultaneously, quality tests
may be performed on the
bloc.
[0035] The wrapping station 20 is provided after the weighing and height
measuring
unit 18. In Figures 11, the wrapping station is shown as comprising a turn
table, lower in speed that
the first wrapper.
[0036] At the output unit 22, an arrangement of conveyors moves the
pallets away
where a forklift takes the loads. All the movements on the conveyors are
automated by a PLC and
require no manpower.
[0037] Determination of a volume for a first bloc at the dosing and
feeding unit 12 is
done concurrently with compaction of a second bloc at the filling and
compaction unit 14, stabilization
of a third bloc at the stabilization unit 16, measuring of a fourth bloc at
the weighing and height
measuring unit 18, and wrapping of a fifth bloc at the wrapping unit 20.
[0038] Sphagnum peat moss optionally in admixture with mineral or organic
aggregates, having a water-content ranging from about 25 to about 50 weight
`)/0 and a density
ranging from about 0.05 to about 0.15 gm/cc on dry basis, is used as
feedstock. If the water-content
is too low, i.e., less than 25 weight /0, it may be adjusted by adding water
by means of water sprays
for example. If, on the other hand, the water-content of the peat moss is too
high, i.e., higher than 50
weight %, the compactions modes need be adjusted to provide a desired density
bloc.
[0039] As shown in Figure 12, in a method according to an embodiment of an
aspect
of the present invention, after determining an amount of peat moss
corresponding to a target bloc
(step A), the determined amount is feed to a compaction box (step B) for
compaction into a
compacted bloc supported by a pallet (step C). The formed bloc is quickly
stabilized (step D) and
measured (step E), then finally wrapped (step F).
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[0040] In step A, a volume of peat moss is automatically determined
according to a
target peat moss bloc. Sample amounts of peat moss are collected as a
reference for calculating the
volume in the bloc.
[0041] In step C, according to a first mode, typically for high quality
peat moss, for
example peat moss with a water-content ranging from about 25 to about 50
weight %, high fiber
content, recently cropped etc.., the peat moss is compressed once fed within
the compaction box by
a piston and cylinder arrangement. According to a second mode, the peat moss
is twice compressed
once fed within the compaction box. According to a third mode, typically in
case of poorer quality
peat moss or for providing higher quality blocs for example, a first portion
of the amount determined
by the doser, for example 60%, is first fed within the compaction box, first
compressed, then the
remaining portion of the amount determined by the doser, for example 40% is
fed within the
compaction box and compressed on top of the first amount.
[0042] The compaction time in step C, between 2 and 30s, is reduced by
about half,
compared to conventional methods, by provision of the stabilizing step D.
[0043] The present method allows forming up to 32 palletized blocs per
hour, i.e. a
cycle time between about 2 and 3 minutes.
[0044] The obtained palletized peat moss comprises a body of compressed
peat
moss upstanding from a pallet and wrapped with a plastic film, the plastic
film retaining the peat
moss in compressed form on the pallet. Typically, the palletized peat moss has
a rectangular cross-
section with a width of about 1.0 meter and a length of 1.2 meters, the height
ranging from about 2.0
to about 2.5 meters. The volume of compressed peat moss retained on the pallet
generally ranges
from about 6 cubic meters.
[0045] The scope of the claims should not be limited by the preferred
embodiments
set forth in the examples, but should be given the broadest interpretation
consistent with the
description as a whole.
