Note: Descriptions are shown in the official language in which they were submitted.
APPARATUS AND METHODS FOR THE COMMINUTION OF BOTANICAL
FEEDSTOCK
FIELD
[0001] This disclosure relates generally to apparatus and methods for the
comminution of botanical feedstock. More specifically, this disclosure relates
to
apparatus and methods for the comminution of cannabis and the collection
and/or separation of cornminuted cannabis.
INTRODUCTION
[0002] The following is not an admission that anything discussed below is
part of the prior art or part of the common general knowledge of a person
skilled
in the art.
[0003] Blade grinders are typically used to chop and mix a material
using a
relatively high speed rotating blade. Typically, with a blade grinder (or
other
similar chopping methods), the particles get smaller and smaller during the
grinding process, which may make it difficult to achieve a consistent grind
from
batch to batch. In addition, may grinders operate on a batch basis as opposed
to
a continuous basis.
SUMMARY
[0004] The following introduction is provided to introduce the
reader to the
more detailed discussion to follow. The introduction is not intended to limit
or
define any claimed or as yet unclaimed invention. One or more inventions may
reside in any combination or sub-combination of the elements or process steps
disclosed in any part of this document including its claims and figures.
[0005] In accordance with one aspect of this disclosure, which may
be
used alone or in combination with any other aspect, an apparatus for the
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comminution of a botanical feedstock, such as cannabis, includes a screen
positioned in a vessel and a rotating blade positioned above the screen. For
example, the screen may be oriented generally horizontally (e.g., 15 from
the
horizontal) and the rotating blade may be on a shaft that is oriented
perpendicularly to the screen. A cutting edge of a leading side of the blade
is
spaced from the screen by a first distance. Accordingly, pieces of botanical
feedstock resting on the screen that are large enough to extend upwardly from
the screen by a distance greater than the first distance will be cut by the
blade as
it rotates above the screen.
[0006] The blade also has a downwardly extending trailing portion. This
trailing portion has a lower edge having a plurality of discontinuities along
its
radial length. An advantage of this design is that, as the blade is rotated at
relatively high speeds, air turbulence generated by these discontinuities may
aerodynamically lift some or all of the pieces of botanical feedstock resting
on the
screen to a position above the screen, where they may then be cut by the
cutting
edge of the blade as it rotates above the screen. Additionally, or
alternatively, the
air turbulence generated by the downwardly extending trailing portion may
aerodynamically suspend some pieces of botanical feedstock in a position above
the screen, where they may then be cut by the cutting edge of the blade.
[0007] By providing a rotating blade with such a downwardly extending
trailing portion, the apparatus may be more efficient at reducing the size of
the
botanical feedstock pieces before they pass through openings in the screen.
Additionally, or alternatively, the apparatus may provide a more consistent
size of
cut botanical feedstock pieces that pass through openings in the screen.
Improving the consistency of the size of cut botanical feedstock (e.g. cut
cannabis particles) may advantageously improve further processing of the
botanical feedstock. For example, a more consistent cut particle size may
increase the packing density of the cut particles, which may improve
throughput
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of subsequent processing of the feedstock (e.g. an extraction process to
obtain a
cannabis extract from cut cannabis feedstock).
[0008]
Another potential advantage of this design is that the rotating blade
may be spaced from the screen during its rotation, which may reduce or
minimize
heat generated by friction. For certain botanical feedstocks, e.g. cannabis,
it may
be desirable to reduce the size of feedstock pieces without unnecessarily
heating
the feedstock (e.g. by crushing or shearing), as such heating may degrade or
otherwise alter the chemical structure of one or more components or compounds
in the feedstock (e.g. trichomes, terpenes).
[0009] In
accordance with this broad aspect, there is provided an
apparatus for the comminution of a botanical feedstock, the apparatus
comprising:
(i) a
vessel having a top and a bottom, the bottom comprising a first
feedstock outlet;
(ii) a screen
positioned in the vessel above the first feedstock outlet
and spaced from the top of the vessel, the screen having an upper surface
and a lower surface; and,
(iii) a
blade rotatably mounted above and generally parallel to the
screen and configured to be rotated in a direction of rotation, the blade
having a leading side, a trailing side in the direction of rotation and a
radial
blade length between an axis of rotation and a blade tip, at least a portion
of the leading side having a cutting edge and at least a portion of the
trailing side having a downwardly extending trailing portion, the
downwardly extending trailing portion having a lower edge having a
plurality of discontinuities along a radial length of the trailing portion,
wherein the cutting edge is spaced from the upper surface of the screen
by a first distance and a lowermost portion of the lower edge is spaced
from the upper surface of the screen by a second distance.
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[0010] In some embodiments, the plurality of discontinuities may
comprise
radially spaced apart downwardly extending sections of the lower edge, each
section having a top and a bottom, wherein the radial extent of each section
may
narrow towards the bottom of the section and a gap between adjacent sections
may increase towards the bottom.
[0011] In some embodiments, the lower edge may be generally saw
toothed in shape.
[0012] In some embodiments, the lower edge may be generally
sinusoidal
in shape.
[0013] In some embodiments, the first distance may be from 31 mm to 54
mm.
[0014] In some embodiments, the second distance may be from 7 mm to
30 mm.
[0015] In some embodiments, the screen may have an aperture size of
between 2 mm and 15 mm.
[0016] In some embodiments, the vessel may define a volume
overlying
the blades and the volume may be uninterrupted.
[0017] In some embodiments, the apparatus may further comprise a
feedstock inlet in communication with the vessel and comprising an openable
feed port.
[0018] In some embodiments, first feedstock outlet may be
connectable in
fluid communication with a source of negative pressure.
[0019] In some embodiments, the blade may have a rate of rotation
and at
the rate of rotation, the downwardly extending trailing portion may be
operable to
draw at least some feedstock positioned on the upper surface of the screen
from
the upper surface of the screen towards a plane of rotation of the cutting
edge.
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[0020] In some
embodiments, the downwardly extending trailing portion
may extend at an angle of between 30 degrees and 60 degrees to the plane of
rotation.
[0021] In some
embodiments, the apparatus may further comprise a
cyclonic separator positioned downstream from the first feedstock outlet, the
cyclonic separator being in flow communication with a separated material
collection region and a fluid outlet.
[0022] In some
embodiments, the apparatus may further comprise a filter
positioned downstream from the fluid outlet.
[0023] In some
embodiments, the blade may comprise a plurality of
blades.
[0024] In
accordance with another aspect of this disclosure, which may be
used alone or in combination with any other aspect, a method of grinding a
botanical feedstock, such as cannabis, comprises rotating one or more cutting
blades wherein the
one or more curring blades are configured to produce lift or
turbulence to raise uncut or partially cut feedstock into a zone in which they
may
be cut by the blade or blades. In one embodiment, the grinding apparatus is
operated under negative pressure which may produce a downwardly flow of air
and feedstock and accordingly, in such a case, the lift may be sufficient to
overcome the downward force and raise uncut or partially cut feedstock into a
zone in which they may be cut by the blade or blades. In accordance with this
aspect, an apparatus for the comminution of a botanical feedstock, such as
cannabis, may include a vessel having a feedstock outlet in fluid
communication
with a source of negative pressure, a screen positioned in the vessel above
the
outlet, and a rotatable blade positioned above the screen. The blade has a
downwardly extending trailing portion. This trailing portion has a lower edge
having a plurality of discontinuities along its radial length. A method for
operating
such an apparatus includes rotating the blade at a rate of rotation sufficient
for
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the trailing portion of the blade to generate an upward force such as by
turbulence that induces upward movement of cut and partially cut feedstock
resting on the screen despite a downward force produced by the negative
pressure.
[0025] An advantage of this method is that, as the blade is rotated, air
turbulence generated by the trailing portion of the blade may aerodynamically
lift
and/or suspend some or all of the pieces of botanical feedstock resting on the
screen to a position above the screen, where they may then be cut by the
cutting
edge of the blade as it rotates above the screen.
[0026] Optionally, the source of negative pressure may be activated to
reduce the pressure in the vessel to below ambient pressure, and draw
botanical
feedstock (including pieces of cut and partially cut feedstock) towards the
feedstock outlet. Preferably, at the rate of rotation, the turbulence
generated by
the blade may overcome a downward force on the pieces of cut and partially cut
feedstock produced by the source of negative pressure.
[0027] Another potential advantage of this method is that pieces of
cut and
partially cut feedstock (including 'dust' and other fine particles) may be
drawn
through the screen and through the feedstock outlet by the source of negative
pressure. Optionally, cut feedstock drawn through the feedstock outlet may be
subjected to separation (e.g. cyclonic separation wherein the source of
negative
pressure is downstream from the cyclone air outlet) and/or filtration and
subsequent collection. This may reduce or minimize any loss of fine
particulate
matter (e.g. trichomes) which may be regarded as valuable.
[0028] In accordance with this broad aspect, there is provided a
method of
operating an apparatus for the comminution of a botanical feedstock, wherein
the
apparatus comprises:
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(i) a vessel having a top and a bottom, the bottom comprising a first
feedstock outlet connected in fluid communication with a source of
negative pressure;
(ii) a screen positioned in the vessel above the first feedstock outlet
and spaced from the top of the vessel, the screen having an upper surface
and a lower surface; and,
(iii) a blade rotatably mounted above and generally parallel to the
screen and configured to be rotated in a direction of rotation, the blade
having a leading side, a trailing side in the direction of rotation and a
radial
blade length between an axis of rotation and a blade tip, at least a portion
of the leading side having a cutting edge and at least a portion of the
trailing side having a downwardly extending trailing portion, the
downwardly extending trailing portion having a lower edge having a
plurality of discontinuities along a radial length of the trailing portion;
the method comprising:
rotating the blade in the direction of rotation at a rate of rotation, wherein
the trailing portion generates turbulence that induces upward movement of
cut and partially cut feedstock from the upper surface of the screen to a
plane of rotation of the cutting edge of the blade.
[0029] In some
embodiments, the method may further comprise activating
the source of negative pressure to reduce the pressure in the vessel to below
ambient pressure, wherein at the rate of rotation, the turbulence generated by
the
rotation of the blade may overcome a downward force on the cut and partially
cut
feedstock that is produced by the source of negative pressure.
[0030] In some
embodiments, at the rate of rotation, the plurality of
discontinuities may produce eddy currents that draw cut and partially cut
feedstock upwardly to a plane of rotation of the cutting edge of the blade.
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[0031] In some embodiments, at the rate of rotation, the rotation of
the
blade may neutralize a downward force on the cut and partially cut feedstock
that
is produced by the negative pressure in the vessel and may provide lift to the
cut
and partially cut feedstock.
[0032] In some embodiments, the lower edge of the downwardly extending
trailing portion may be generally saw toothed in shape and at the rate of
rotation,
the rotation of the blade may provide lift to the cut and partially cut
feedstock.
[0033] In some embodiments, the rate of rotation may be between 750
and 1400 revolutions per minute.
[0034] In some embodiments, the vessel may define a volume positioned
above the blade and the negative pressure may draw fine particulate matter
from
the volume and through the screen.
[0035] In some embodiments, the negative pressure may draw at least
75% of the fine particulate matter from the volume and through the screen.
[0036] In some embodiments, the method may further comprise
withdrawing cut feedstock from the first feedstock outlet and conveying the
treated feedstock to a cyclonic separator.
[0037] In some embodiments, the method may further comprise
subjecting
a fluid stream drawn from the vessel through the first feedstock outlet to
cyclonic
separation thereby separating some of the cut feedstock from the fluid stream
and collecting the separated feedstock in a separated material collection
region.
[0038] In some embodiments, the method may further comprise
obtaining
a fluid steam having a reduced level of cut feedstock from the cyclonic
separator
and subjecting the fluid stream to physical filtration to remove fine
particulate
matter from the fluid steam having a reduced level of cut feedstock.
[0039] Typically, a batch grinder may be operated by loading the
grinder
with a botanical feedstock through a feed port, closing the feed port,
operating
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the grinder with the feed port closed until the feedstock has been ground, and
then deactivating the grinder prior to re-opening the feed port and
introducing
additional botanical feedstock to be ground. Grinding a feedstock in such
'batches' may have one or more disadvantages. For example, the grinder is idle
(i.e. not grinding feedstock) while additional batches of feedstock are being
loaded into the grinder, which may reduce overall throughput.
[0040] In accordance with another aspect of this disclosure, which
may be
used alone or in combination with any other aspect, a method of continuously
operating a batch grinder is provided. First, botanical feedstock is loaded
into a
vessel of the grinder. The vessel is closed and the grinder is operated under
negative pressure and a fluid stream containing treated feedstock is removed
from the grinder. While continuing to draw air from the vessel, and while
continuing to operate the grinder, a feed port of the vessel is opened and
additional botanical feedstock is introduced into the grinder.
[0041] An advantage of this method is that, by continuing to draw air from
the vessel, pieces of feedstock (including dust and other fine particulate)
may be
inhibited or prevented from exiting the vessel via the feed port of the
vessel.
Additionally, or alternatively, by loading additional feedstock into the
grinder
without stopping and restarting the grinder, overall throughput and the
uniformity
of the treated feedstock may be increased.
[0042] Another advantage is that, for cannabis, dust produced by
the
grinding process includes a fine dry resin that has been detached from the
plant
material, which is typically considered valuable. Further, government or
health
regulations may limit the amount of such material that may be in a work
environment (e.g., parts per million). By operating the grinder under negative
pressure, such dust may tend to be drawn away from a feed inlet in an upper
portion of the vessel thereby enabling a feed inlet port to be opened during
the
grinding process and untreated feedstock to be introduced. Accordingly, the
grinder may be operated on a continuous basis.
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[0043] Another potential advantage of this method is that pieces of
cut and
partially cut feedstock (including 'dust' and other fine particles) may be
withdrawn
from the grinder using the source of negative pressure. Optionally, cut
feedstock
drawn through the feedstock outlet may be subjected to separation (e.g.
cyclonic
separation) and/or filtration and subsequent collection. This may reduce or
minimize any loss of fine particulate matter (e.g. trichomes) which may be
regarded as valuable.
[0044] In accordance with this broad aspect, there is provided a
method of
continuously operating a batch grinder comprising:
(a) introducing a botanical feedstock into a vessel of the grinder;
(b) closing the vessel and operating the grinder as a closed vessel
under negative pressure and withdrawing a fluid steam containing treated
feedstock from the grinder; and,
(c) while continuing to operate the grinder under negative pressure,
opening a feed port of the vessel and introducing additional botanical
feedstock into the grinder while continuing to draw air from the vessel
using a source of negative pressure.
[0045] In some embodiments, the grinder may comprise a rotating
blade
and the method may further comprise rotating the blade at a rate to counter a
downward force applied to the feedstock in the grinder due to the negative
pressure.
[0046] In some embodiments, the grinder may comprise a rotating
blade
having an eddy producing trailing edge and the method may further comprise
rotating the blade to produce eddy currents to draw cut and partially cut
feedstock upwardly from a screen to a level of a leading edge of the blade.
[0047] In some embodiments, the method may further comprise
conveying
the fluid steam containing the treated feedstock to a cyclonic separator.
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[0048] In some embodiments, the method may further comprise
subjecting
the fluid stream containing the treated feedstock to cyclonic separation using
a
cyclonic separator thereby separating some of the treated feedstock from the
fluid stream and collecting the separated treated feedstock in a separated
material collection region.
[0049] In some embodiments, the method may further comprise
obtaining
a secondary fluid steam having a reduced level of treated feedstock from the
cyclonic separator and subjecting the secondary fluid stream to physical
filtration
to remove fine particulate matter from the secondary fluid steam.
[0050] In accordance with another aspect of this disclosure, which may be
used alone or in combination with any other aspect, an apparatus for the
treatment of cannabis is provided. The apparatus includes a grinder having a
feedstock outlet and a source of negative pressure downstream of the feedstock
outlet. A cyclonic separator downstream of the feedstock outlet has an inlet
for
receiving comminuted cannabis from the grinder and a comminuted cannabis
outlet.
[0051] An advantage of this design is that, as a cannabis feedstock
is
reduced to comminuted cannabis by the grinder, the comminuted cannabis may
be withdrawn from the grinder entrained in an airflow and subsequently
separated from the airflow using the cyclonic separator. This may increase the
total volume of comminuted cannabis collected from the grinding process. For
example, dust and other fine cannabis particles (including e.g. trichomes,
terpenes) may be drawn from the grinder and collected following cyclonic
separation. Such fine cannabis particles may escape to the atmosphere and/or
otherwise be lost when processed in a typical 'batch' grinder (e.g. without a
source of negative pressure and/or without a cyclonic separator).
[0052] In accordance with this broad aspect, there is provided an
apparatus for the treatment of cannabis comprising:
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(i) a grinder having a feedstock inlet and a feedstock outlet;
(ii) a first cyclonic separator positioned downstream from the feedstock
outlet, the first cyclonic separator having a cyclone inlet receiving
comminuted cannabis from the grinder, a comminuted cannabis outlet,
and a cyclone air outlet; and,
(iii) a source of negative pressure downstream from the feedstock
outlet of the grinder.
[0053] In some embodiments, the source of negative pressure may be
downstream from the cyclone air outlet.
[0054] In some embodiments, the apparatus may further comprise a first
separated material collection chamber downstream from the comminuted
cannabis outlet.
[0055] In some embodiments, the apparatus may further comprise an
extractor having an inlet that receives at least some of the comminuted
cannabis
exiting the comminuted cannabis outlet, the extractor producing a cannabis
extract.
[0056] In some embodiments, the apparatus may further comprise an
extractor having an inlet that receives at least some of the comminuted
cannabis
from the separated material collection chamber, the extractor producing a
cannabis extract.
[0057] In some embodiments, the grinder may further comprise:
(a) a screen positioned in a vessel above the feedstock outlet, the
screen having an upper surface and a lower surface; and,
(b) at least one blade rotatably mounted above the screen and
rotatable in a direction of rotation, a first blade of the at least one blade
having a leading edge comprising a cutting portion, wherein the cutting
portion is spaced from the upper surface of the screen by a first distance.
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[0058] In some embodiments, the at least one blade may have a
trailing
edge comprising a downwardly extending trailing portion, the downwardly
extending trailing portion may have a lower edge having a plurality of
discontinuities along a radial length of the trailing portion, wherein a
lowermost
portion of the lower edge may be spaced from the upper surface of the screen
by
a second distance.
[0059] In some embodiments, the first blade may have the trailing
edge.
[0060] In some embodiments, the apparatus may further comprise a
filtration member positioned downstream of the cyclone air outlet.
[0061] In some embodiments, the filtration member may comprise a
second cyclonic separator.
[0062] In some embodiments, the filtration member may comprise a
physical filtration member.
[0063] In accordance with another aspect of this disclosure, which
may be
used alone or in combination with any other aspect, a method of treating
cannabis is provided. First, a feedstock of cannabis is treated to obtain
comminuted cannabis. The treated feedstock is conveyed to a cyclonic separator
to obtain a stream of treated feedstock and a fluid stream having a reduced
level
of treated feedstock.
[0064] An advantage of this method is that, by pneumatically conveying
the comminuted cannabis to the cyclonic separator, any loss of fine
particulate
matter (e.g. trichomes) during transfer from the treatment stage to the
cyclonic
separation stage may be reduced or preferably minimized.
[0065] Another potential advantage of this method is that the fluid
stream
having a reduced level of treated feedstock may be subjected to further
treatment
(e.g. cyclonic separation or physical filtration) to increase the overall
recovery of
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the comminuted cannabis, including in particular the recovery of fine
particulate
matter (e.g. trichomes).
[0066]
Another potential advantage of this method is that comminuted
cannabis obtained by cyclonic separation may be subjected to extraction to
obtain a cannabis extract. Additionally, multiple cyclonic separation stages
may
be arranged in series and used to obtain treated cannabis feedstock with
different average particle sizes.
[0067]
In accordance with this broad aspect, there is provided a method
for treating cannabis comprising:
(a) treating a
feedstock of cannabis and obtaining treated feedstock
comprising comminuted cannabis;
(b) pneumatically conveying the treated feedstock to a cyclonic
separator; and,
(c) subjecting the treated feedstock to a first cyclonic separation stage
and obtaining a first stream of treated feedstock separated out of a fluid
stream by the first cyclonic separation stage and a first fluid stream having
a reduced level of treated feedstock.
[0068]
In some embodiments, step (a) may comprise comminuting at least
a portion of the feedstock of cannabis.
[0069] In some
embodiments, the method may further comprise subjecting
at least a portion of the first stream of treated feedstock to extraction and
obtaining a cannabis extract.
[0070]
In some embodiments, the method may further comprise collecting
the first stream of treated feedstock exiting the cyclonic separator and
subsequently subjecting at least a portion of the collected first stream of
treated
feedstock to extraction and obtaining a cannabis extract.
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[0071] In some embodiments, step (c) may further comprise
subjecting the
treated feedstock to at least one subsequent cyclonic separation stage in
series
with the first cyclonic separation stage, wherein each subsequent cyclonic
separation stage may separate treated cannabis having a smaller particle size
than the immediately previous cyclonic separation stage.
[0072] In some embodiments, the method may further comprise
subjecting
the first fluid stream having a reduced level of treated feedstock to a second
cyclonic separation stage and obtaining a second fluid stream having a further
reduced level of treated feedstock and treated feedstock separated out of a
fluid
stream by the second cyclonic separation stage wherein the treated feedstock
separated out of a fluid stream by the second cyclonic separation stage may
have a smaller average particle size than an average particle size of the
treated
feedstock separated out of a fluid stream by the first cyclonic separation
stage.
[0073] In some embodiments, the method may further comprise
subjecting
the first fluid stream having a reduced level of treated feedstock to a
physical
filtration stage.
[0074] In some embodiments, step (a) may comprise comminuting at
least
a portion of the feedstock of cannabis, and the method may further comprise
collecting the first stream of treated feedstock exiting the cyclonic
separator and
subsequently subjecting at least a portion of the collected first stream of
treated
feedstock to extraction and obtaining a cannabis extract.
[0075] In some embodiments, the method may further comprise
subjecting
the first fluid stream having a reduced level of treated feedstock to a
physical
filtration stage.
[0076] It will be appreciated by a person skilled in the art that an
apparatus
or method disclosed herein may embody any one or more of the features
contained herein and that the features may be used in any particular
combination
or sub-combination.
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[0077] These and other aspects and features of various embodiments
will
be described in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0078] For a better understanding of the described embodiments and
to
show more clearly how they may be carried into effect, reference will now be
made, by way of example, to the accompanying drawings in which:
[0079] Figure 1 is a perspective view of an apparatus for the
comminution
of a botanical feedstock in accordance with one embodiment, with portions of
the
vessel wall shown as translucent for ease of understanding;
[0080] Figure 2 is a top perspective view of the interior of the upper
portion
of the vessel of the apparatus of Figure 1;
[0081] Figure 3 is a top view of a cutting edge insert and a main
blade
body of a blade of the apparatus of Figure 1 during manufacture, prior to
bending
the main blade body to create a downwardly extending trailing portion;
[0082] Figure 4 is a radial section view of the main blade body of Figure
3
after bending to create the downwardly extending trailing portion;
[0083] Figure 5 is a top view of the main blade body and downwardly
extending trailing portion of Figure 4;
[0084] Figure 6 is a schematic elevation view of a screen and
rotating
blade of the apparatus of Figure 1, with botanical feedstock being swept up as
the blade is rotated;
[0085] Figure 7 is a schematic view of an apparatus for the
treatment of
cannabis or other botanical feedstock in accordance with another embodiment,
including a source of negative pressure, a cyclonic separator, and an optional
physical filtration member;
[0086] Figure 8 is a schematic view of an apparatus for the
treatment of
cannabis or other botanical feedstock in accordance with another embodiment,
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including a source of negative pressure, and two cyclonic separators arranged
in
series;
[0087] Figure 9 is a simplified process flow diagram for a method
of
operating an apparatus for the comminution of a botanical feedstock in
accordance with one embodiment;
[0088] Figure 10 is a simplified process flow diagram for a method
of
continuously operating a batch grinder in accordance with one embodiment;
[0089] Figure 11 is a simplified process flow diagram for a method
for
treating cannabis in accordance with one embodiment;
[0090] Figure 12 is a top perspective view of a lower end of a vessel in
accordance with another embodiment;
[0091] Figure 13 is a top view of the lower end of a vessel of
Figure 12;
and
[0092] Figure 14 is a side view of the lower end of a vessel of
Figure 12.
[0093] The drawings included herewith are for illustrating various
examples of articles, methods, and apparatuses of the teaching of the present
specification and are not intended to limit the scope of what is taught in any
way.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0094] Various apparatuses, methods and compositions are described
below to provide an example of an embodiment of each claimed invention. No
embodiment described below limits any claimed invention and any claimed
invention may cover apparatuses and methods that differ from those described
below. The claimed inventions are not limited to apparatuses, methods and
compositions having all of the features of any one apparatus, method or
composition described below or to features common to multiple or all of the
apparatuses, methods or compositions described below. It is possible that an
apparatus, method or composition described below is not an embodiment of any
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claimed invention. Any invention disclosed in an apparatus, method or
composition described below that is not claimed in this document may be the
subject matter of another protective instrument, for example, a continuing
patent
application, and the applicant(s), inventor(s) and/or owner(s) do not intend
to
abandon, disclaim, or dedicate to the public any such invention by its
disclosure
in this document.
[0095] The terms "an embodiment," "embodiment," "embodiments," "the
embodiment," "the embodiments," "one or more embodiments," "some
embodiments," and "one embodiment" mean "one or more (but not all)
.. embodiments of the present invention(s)," unless expressly specified
otherwise.
[0096] The terms "including," "comprising" and variations thereof
mean
"including but not limited to," unless expressly specified otherwise. A
listing of
items does not imply that any or all of the items are mutually exclusive,
unless
expressly specified otherwise. The terms "a," "an" and "the" mean "one or
more,"
unless expressly specified otherwise.
[0097] As used herein and in the claims, two or more parts are said
to be
"coupled", "connected", "attached", or "fastened" where the parts are joined
or
operate together either directly or indirectly (i.e., through one or more
intermediate parts), so long as a link occurs. As used herein and in the
claims,
two or more parts are said to be "directly coupled", "directly connected",
"directly
attached", or "directly fastened" where the parts are connected in physical
contact with each other. None of the terms "coupled", "connected", "attached",
and "fastened" distinguish the manner in which two or more parts are joined
together.
[0098] Furthermore, it will be appreciated that for simplicity and clarity
of
illustration, where considered appropriate, reference numerals may be repeated
among the figures to indicate corresponding or analogous elements. In
addition,
numerous specific details are set forth in order to provide a thorough
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CA 2983838 2017-10-26
understanding of the example embodiments described herein. However, it will be
understood by those of ordinary skill in the art that the example embodiments
described herein may be practiced without these specific details. In other
instances, well-known methods, procedures, and components have not been
described in detail so as not to obscure the example embodiments described
herein. Also, the description is not to be considered as limiting the scope of
the
example embodiments described herein.
General description of an apparatus for comminution of a botanical
feedstock
[0099] Referring to Figures 1 to 8, an exemplary embodiment of an
apparatus for comminution of a botanical feedstock is shown generally as 1000.
The following is a general discussion of this embodiment which provides a
basis
for understanding several of the features which are discussed herein. As
discussed subsequently, each of the features may be used individually or in
any
particular combination or sub-combination in this or in other embodiments
disclosed herein.
[00100] In the illustrated embodiment, the apparatus breaks up a
botanical
feedstock (e.g. cannabis) into smaller pieces using one or more rotating
cutting
blades. The apparatus may also be characterized as a 'blade grinder' or simply
as a 'grinder'.
[00101] As exemplified in Figures 1 to 6, apparatus 1000 includes a
vessel
100 having an upper end 102, a lower end 104, and a screen 120 positioned in
the vessel 100 between the upper end 102 and the lower end 104.
[00102] In the illustrated example, vessel 100 is generally
cylindrical.
Preferably, vessel 100 is generally round at the position of the screen 120
and
blade 200 (discussed further below), although it may have any suitable shape.
For example, vessel 100 may have a diameter of about 22 inches.
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CA 2983838 2017-10-26
[00103] Screen 120 has an upper surface 122, a lower surface 124, and
includes a plurality of holes or other apertures 125 extending through the
screen
from the upper surface 122 to the lower surface 124. Preferably, at least the
majority of apertures 125 have the same or similar dimensions. Accordingly,
particles of botanical material introduced into the vessel above the screen
(e.g.
via an inlet provided in the upper end 102) that are larger than the screen
apertures will be retained by and remain above the screen, while particles of
botanical material that are smaller than the apertures 125 are able to travel
through the screen into the lower end 104 of vessel 100. Thus, the 'grind
size' or
average size of the particles of botanical feedstock that reach the lower end
104
of vessel 100 is based on the size of the screen apertures 125. Accordingly,
the
size of the screen apertures may be selected based on a desired 'grind size'
for
the comminuted botanical feedstock. In some embodiments, the screen 120 may
be a 0.25 inch square mesh screen. In some embodiments, the screen may have
a Tyler mesh size in the range spanning 7 to 2.5. Alternatively, mesh sizes
with
larger openings may be used depending on e.g. an intended use for the
comminuted botanical feedstock.
[00104] In the illustrated example, two feedstock inlets 112 are
provided at
the upper end 102 of vessel 100. Each feedstock inlet 112 is openable to allow
a
botanical feedstock to be introduced into the upper end 102 of vessel 100. It
will
be appreciated that in alternative embodiments, a single feedstock inlet 112
may
be provided, or three or more inlets 112 may be provided. Further, the inlets
may
be placed elsewhere (e.g., on an upper portion of the sidewall 110 of vessel
100).
[00105] In the illustrated example, a feedstock outlet 114 is provided in
the
lower end 104. It will be appreciated that in alternative embodiments, two or
more
feedstock outlets may be provided. Further, the one or more outlets may be
located at any position below screen 120 and need not be in a lower portion of
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CA 2983838 2017-10-26
the sidewall of vessel 100. For example, an outlet may be provided in the
lower
surface of vessel 100.
[00106] Figures 12 to 14 (and Figures 7 and 8) illustrate an example
of a
conical lower end 104 of vessel 100 in which the sidewall 110 tapers inwardly
at
an angle 111 towards a feedstock outlet 114. In the illustrated example, the
angle
111 of the sidewall taper is about 70 , although it may be larger or smaller
in
alternative embodiments. Also, in the illustrated example the lower end 104
has
an overall height 109 of about 11.4 inches, an upper portion 107 of about 2.1
inches that is not tapered, and a distance 108 of about 10.1 inches from the
top
of lower end 104 to the top of feedstock outlet 114. Upper portion 107 has an
inner diameter of about 22 inches. It will be appreciated that other suitable
designs and/or dimensions of lower end 104 may be used in alternative
embodiments.
[00107] In example illustrated in Figure 1, feedstock outlet 114 is
provided
with an optional openable door 115 to allow particles of comminuted feedstock
to
be removed from the lower end of the vessel at selected times (i.e., when the
door 115 is opened). Also, in the illustrated example an optional deflector
plate
105 is provided to direct comminuted feedstock towards feedstock outlet 114
and
openable door 115. Deflector Plate 105 may be of any configuration which
directs comminuted feedstock to door 115. Alternatively, a door may not be
provided. For example, as discussed further below, feedstock outlet 114 may be
an opening in the sidewall that is coupled to a conduit or otherwise in fluid
communication with a source of negative pressure.
[00108] Apparatus 1000 also includes at least one blade 200
rotatably
mounted above screen 120. As will be discussed further below, when blade 200
is rotated, botanical material in the path of a cutting edge of the blade will
be cut
by the blade, thereby reducing the particle size of the botanical material. As
noted above, once botanical material has been reduced to a particle that is
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CA 2983838 2017-10-26
smaller than an aperture in the screen, that particle of comminuted material
may
travel through the screen into the lower end 104 of vessel 100.
[00109] In the illustrated example, blade 200 is coupled to a motor
140 via a
drive shaft 150. In use, motor 140 rotates the drive shaft 150, thereby
rotating the
blade 200. In alternative embodiments, a gearbox or the like may be provided
between the motor 140 and blade 200 to control e.g. the speed and/or torque of
the blade during rotation. The motor is preferably positioned above the blade
200, as shown in the illustrated embodiment, although it may be positioned
below
the blade 200 in alternative embodiments.
[00110] As exemplified, vessel 100 is shown as being vertically oriented.
Accordingly, as exemplified drive shaft 150 extends vertically or generally
vertically. It will be appreciated that vessel may be oriented such that drive
shaft
150 is at an angle (e.g., 5 , 10 , 15 , 20 ) to the vertical. It will be
appreciated
that drive shaft 150 is preferably perpendicular or generally perpendicular to
screen 120. Accordingly, as the blade rotates, it remains a relatively
constant
distance from the upper surface of screen 120.
[00111] As exemplified in Figure 2, three blades 200 may be provided
for
cutting botanical feedstock. In alternative embodiments, a single blade 200,
two
blades 200, or four or more blades 200 may be provided. The blades may be
equally spaced around motor shaft 150. Therefore, if three blades 200 are
provided, they may be spaced 120 around the motor shaft. In alternate
embodiments, they need not be equally spaced apart.
Configuration of the cutting blades
[00112] The flowing is a description of the configuration of blades
200 which
may be used by itself or in combination with one or more of the other features
disclosed herein including having the feedstock outlet in communication with a
source of negative pressure, the use of one or more cyclone separators and any
of the methods disclosed herein.
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[00113] In accordance with this aspect, blades 200 are configured to
cut the
feedstock and also to draw feedstock (which may or not have been cut) upwardly
from the upper surface of screen 120 and into a zone in which it will be cut
by
blades 200. For example, blades 200 may be configured to entrain or 'sweep up'
feedstock and direct the feedstock upwardly towards a plane of rotation of the
cutting edge 210 of blade 200.
[00114] As exemplified in Figure 6, blade 200 has a leading side 202
that
precedes a trailing side 204 when blade 200 is rotated in its forward
direction of
rotation 30. A cutting edge 210 is provided along at least a portion of, and
preferably along most or substantially all of, the leading side 202, so that
botanical feedstock impacted by the blade will be cut or otherwise reduced in
size. Cutting edge 210 preferably has a sharpened surface 211 positioned at
the
forward extent of leading side 202, such that when blade 200 is rotated in its
forward direction of rotation, cutting edge 210 will likely be the initial
point of
contact between blade 200 and botanical feedstock positioned in the path of
blade 200.
[00115] In the illustrated example, cutting edge 210 is formed on
separate
cutting edge insert 215 that is mechanically fastened to a main body portion
250
of blade 200 using bolts inserted through apertures 216 in cutting edge insert
215
and apertures 218 in main body portion 250. Alternatively, cutting edge insert
215 may be secured to blade 200 in another suitable manner, such as by welding
or through the use of an adhesive.
[00116] Alternatively, cutting edge 210 may be formed by sharpening,
grinding, or otherwise machining the leading side of main body portion 250 of
blade 200.
[00117] As exemplified in Figure 2, cutting edge 210 of blade 200
may
extend to or proximate to the inner surface of the sidewall of vessel 100. An
advantage of this design is that feedstock may be inhibited of falling down
the
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CA 2983838 2017-10-26
sidewall of the vessel to the upper surface of screen 120. Therefore the
radial
length 219 (see Figure 3) of blade 200 may be based on the diameter of vessel
100. For example, the radial length 219 may be equal to the radius of vessel
100
less an allowance for the hub to which blade 200 is attached and less an
amount
to position the radial outer end of blade 200 spaced from the inner surface of
the
sidewall of vessel 100. As exemplified, vessel 100 has a diameter of 22 inches
and a radial length 219 of about 8.5 inches, although the cutting edge may be
longer or shorter in alternative embodiments. Also, cutting edge insert 215
may
have a width 217 in the direction of rotation of about 0.87 inches, although
the
insert 215 may be wider or narrower in alternative embodiments.
[00118] Blade 200 also has a downwardly extending trailing portion
240
provided along at least a portion of, and preferably along most or
substantially all
of or all of, the trailing side 204. When blade 200 is rotated in its forward
direction
of rotation, downwardly extending trailing portion 240 may generate air
turbulence (e.g. localized areas of lower pressure) sufficient to impart an
upward
force on botanical feedstock positioned on or above screen 120. For example,
downwardly extending trailing portion 240 may be configured to produce eddy
currents that draw cut and partially cut feedstock upwardly towards a plane of
rotation of the cutting edge 210 of blade 200.
[00119] Preferably, downwardly extending trailing portion 240 has a
plurality
of discontinuities along a radial length of the trailing portion. In the
example
illustrated in Figures 4 and 5, the lower edge 244 of downwardly extending
trailing portion 240 is generally saw toothed in shape, with four triangular
notches
245 provided along the lower edge 244. In alternative embodiments, more or
fewer notches may be provided. Also, the discontinuities need not be
triangular
notches, and lower edge 244 may have any other suitable shape or profile. For
example, lower edge 244 may have a profile that is generally sinusoidal in
shape.
[00120] By providing downwardly extending trailing portion 240 at an
angle
to the direction of rotation of blade 200, as the blade is rotated energy
imparted
- 24 -
CA 2983838 2017-10-26
to the air can be characterized as a downward 'pushing' force. Further, as the
downwardly extending trailing portion 240 has a plurality of discontinuities
(e.g. a
saw toothed or sinusoidal profile), as the blade 200 is rotated the
discontinuities
generate alternating regions of higher pressure (proximate the lowermost edge
or
'peaks' of the discontinuities) which may be characterized as 'higher
compression areas', and of lower pressure (proximate the uppermost edge or
'troughs' of the discontinuities) which may be characterized as 'lower
compression areas'. An effect of these alternating pressure regions is that
botanical feedstock positioned between blade 200 and screen 120 may be
entrained or 'swept up' and directed upwardly as air is forced from the higher
compression areas towards the lower compression areas.
[00121] For example, as shown schematically in Figure 6, as blade
200 is
rotated so that the leading side 202 precedes trailing side 204, botanical
feedstock 10 positioned in the rotational plane 201 of cutting edge 210 may be
impacted (and cut) by the cutting edge, while botanical feedstock 10
positioned
above screen 120 and entirely below the plane 201 of cutting edge 210 may not
be impacted by the cutting edge. However, as blade 200 is rotated, air
turbulence
or a lifting force 20 generated by downwardly extending trailing portion 240
may
impart upward movement on at least some botanical feedstock particles 10
positioned above screen 120 that were below the plane 201 of cutting edge 210,
such they move to a position in or above the plane 201 of cutting edge 210 and
may therefore be impacted (and cut) by subsequent rotations of blade 200 (or,
if
more than one blade is provided, by another blade 200). Comminuted feedstock
particles 12 may pass through apertures 125 in screen 120 and be directed
towards feedstock outlet 114 by gravity and/or an induced air flow (as
discussed
further below).
[00122] In the illustrated example, the depth and width of each
notch is
similar, with each notch 245 having a depth 221, a width 224, and a notch
angle
225. For example, each notch 245 may have a depth 221 of about 0.63 inches, a
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CA 2983838 2017-10-26
width 224 of about 1.26 inches, and a notch angle 225 of about 90 degrees. In
alternative embodiments, downwardly extending trailing portion 240 may have
notches with dissimilar depths, widths, and/or notch angles.
[00123] Preferably, downwardly extending trailing portion 240
extends at an
angle 230 of between 1200 and 150 to the plane of rotation of cutting edge
210.
In the illustrated example, downwardly extending trailing portion 240 extends
at
an angle 230 of about 135 .
[00124] Downwardly extending trailing portion 240 may be secured to
blade
200 in any suitable manner. For example, a main body portion 250 and
downwardly extending trailing portion 240 may be cut or otherwise formed as a
flat sheet and subsequently bent at fold line 241 to form angle 230. Main body
portion 250 may then be mechanically fastened, welded, or otherwise secured to
a separately formed cutting edge 210 to form blade 200. In alternative
embodiments, downwardly extending trailing portion 240 may be formed
separately and mechanically fastened, welded, or otherwise secured to blade
200.
[00125] In the illustrated example, main body portion 250 has a
radial
length 220 of about 8 inches, although main body portion 250 may be longer or
shorter in alternative embodiments. Also, main body portion 250 has a width
222
of about 1.97 inches prior to folding (see Figure 3), although main body
portion
250 may be wider or narrower in alternative embodiments.
[00126] After folding, (e.g. as shown in Figure 4), main body
portion 250
has an overall width 233, which may be about 1.71 inches, or wider or narrower
in alternative embodiments. Also, downwardly extending trailing portion 240
may
have a height 236 of about 0.56 inches.
[00127] Also, in the illustrated example main body portion 250 has a
thickness 231 of about 0.06 inches (e.g. it may be cut from a sheet of 16
gauge
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CA 2983838 2017-10-26
SAE 304 stainless steel), although main body portion 250 may be thicker or
thinner in alternative embodiments.
[00128] As exemplified in Figure 6, blade 200 is mounted above
screen
120. In this arrangement, cutting edge 210 is spaced from screen 120 by a
first
distance 262. Preferably, distance 262 is from about 31 mm to about 54 mm. In
a
preferred embodiment, distance 262 is about 24 mm.
[00129] Also, the lowermost portion of lower edge 244 of downwardly
extending trailing portion 240 is spaced from screen 120 by a second distance
264. Preferably, distance 264 is from about 7 mm to about 30 mm. In a
preferred
embodiment, distance 264 is about 20 mm.
[00130] An advantage of this spacing is that it may reduce crushing
and/or
shearing of botanical feedstock by the downwardly extending trailing portion
240
as the blade is rotated. Alternatively, or additionally, it may reduce
frictional heat
generated in and/or transferred to botanical feedstock during comminution. For
some feedstocks (e.g. cannabis), this may be particularly desirable, as one or
more components of the feedstock may be susceptible to thermal degradation
and/or volatilization (e.g. aliphatic aldehydes (nerol, geraniol, octanal,
decanal),
and/or monoterpenes (limonene, pinenes, ocimenes)).
Feedstock outlet in communication with a source of negative pressure
[00131] The flowing is a description of the use of negative pressure which
may be used by itself or in combination with one or more of the other features
disclosed herein including the configuration of the cutting blades, the use of
one
or more cyclone separators and any of the methods disclosed herein.
[00132] In accordance with this aspect, feedstock outlet 114 is
coupled to a
conduit or otherwise in fluid communication with a source of negative
pressure.
[00133] In accordance with this aspect, the source of negative
pressure
may be used to reduce the air pressure within vessel 100 to below ambient.
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CA 2983838 2017-10-26
Reducing the air pressure within the vessel may have a number of advantages.
For example, pieces of cut and partially cut feedstock ¨ including dust and
other
fine particulate matter generated during comminution ¨ may be drawn through
the screen and towards and through feedstock outlet 114, which may increase
the collection efficiency of the comminution apparatus. Additionally, reducing
the
air pressure within the vessel may reduce or minimize any loss of fine
particulate
matter (e.g. trichomes, terpenes) during comminution. For example, dust and
other fine particulate matter may be inhibited from collecting on interior
surfaces
of vessel 100. Additionally, or alternatively, dust and other fine particulate
matter
may be inhibited from exiting vessel 100 through feed port 113 of In addition,
comminuted feedstock may be drawn to downstream equipment for, e.g.,
separation or further processing, without mechanically contacting the
feedstock.
[00134] Another advantage of feedstock outlet 114 being in fluid
communication with a source of negative pressure is that botanical feedstock
(including pieces of cut and partially cut feedstock) may be drawn downwardly
towards the cutting zone or the screen 120.
[00135] It will be appreciated that if the blades are configured to
cause the
feedstock to rise upwardly from the screen into the cutting zone, then
trailing
portion 240 of the rotating blade may be configured to impart an upward force
on
botanical feedstock positioned between blade 200 and screen 120 sufficient to
overcome the negative pressure and cause the feedstock to rise.
[00136] Directing botanical feedstock towards the rotating blade 200
may
improve the efficiency and/or throughput of the comminution apparatus. For
example, the apparatus may be able to process a greater amount of botanical
feedstock per unit time. Also, the apparatus may be able to process a given
volume of botanical feedstock in less time, which may be particularly
desirable
for some feedstocks (e.g. cannabis), one or more components of the feedstock
(e.g. aliphatic aldehydes, monoterpenes) may be susceptible to thermal
degradation.
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CA 2983838 2017-10-26
[00137] Referring to Figure 7, an apparatus for comminution of a
botanical
feedstock 1000 is shown with a feedstock outlet 114 in fluid communication
with
a source of negative pressure 300. In the illustrated example, a separation
member 400 is positioned downstream of feedstock outlet 114 and upstream of
the source of negative pressure 300. As discussed further below, in the
illustrated example separation member 400 is a cyclonic separator. The
separation member may be any separation member which uses changes in the
direction of flow of air (e.g., a momentum separator) or changes in an air
flow
pattern or speed (e.g., a cyclone separator) or the like to disentrain
feedstock
from an air stream.
[00138] In the illustrated example, a conduit 502 extends between
feedstock outlet 114 and a fluid inlet 402 of separation member 400, and a
conduit 504 extends between a fluid outlet 404 of separation member 400 and
the source of negative pressure 300. It will be appreciated that any suitable
conduit may be used, such as a flexible plastic conduit, a rigid plastic
conduit, a
rigid metal conduit, and the like.
[00139] The source of negative pressure may comprise any suitable
device
or apparatus capable of inducing a fluid flow out of feedstock outlet 114. For
example, the source of negative pressure 300 may comprise a powered airflow
fan capable of inducing an airflow from an air inlet of the source of negative
pressure 300 to an air outlet of the source of negative pressure 300. In such
an
example, by placing the air inlet of the source of negative pressure 300 in
fluid
communication with feedstock outlet 114, the source of negative pressure 300
may thereby induce an airflow out of vessel 100, thereby reducing the pressure
within vessel below ambient.
[00140] In some embodiments, the negative pressure may be from 15 to
29
inHg, 20 to 27 inHg, or 22 to 25 inHg.
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CA 2983838 2017-10-26
Feedstock outlet in communication with a cyclonic separator
[00141] The flowing is a description of the use of one or more
cyclone
separators which may be used by itself or in combination with one or more of
the
other features disclosed herein including the configuration of the cutting
blades,
having the feedstock outlet in communication with a source of negative
pressure
and any of the methods disclosed herein.
[00142] In accordance with this aspect, one or more cyclone
separators
may be provided to separate the feedstock from the air stream.
[00143] Another advantage of this aspect is that botanical feedstock
(including pieces of cut and partially cut feedstock and dust) may be
separated
from an air stream used to convey the feedstock from the vessel 100 without
further damage to the feedstock. A further advantage is that more than one
cyclonic separator may be positioned in series in the fluid flow path between
the
feedstock outlet of the vessel and the source of negative pressure. Each such
cyclone separator may be configured to remove different sized particulate
matter.
For example, a first stage cyclonic separator may be configured to remove
larger
or heavier portions of the feedstock and a downstream second stage cyclonic
separator may be configured to remove lighter or finer portions of the
feedstock.
Accordingly, the cyclonic separators may be used to produce treated feedstocks
having different particle size profiles.
[00144] In the example illustrated in Figure 7, the source of
negative
pressure 300 induces fluid flow from the vessel 100, into and through the
cyclonic separator 400. Cyclonic separator 400 may be of any design. As air
travels in the cyclonic separator 400, particulate matter is separated and an
air
stream having a reduced level of particulate matter exits the cyclonic
separator
400 via a cyclonic separator air outlet. The separated particulate matter may
exit
the cyclonic separator 400 via a comminuted particle outlet 406.
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CA 2983838 2017-10-26
[00145] As exemplified in Figure 7, a separated material collection
chamber
450 is shown in communication with the comminuted particle outlet 406 of
cyclonic separator 400 to receive particles of comminuted botanical feedstock
(e.g. particles of comminuted cannabis) dis-entrained from a fluid stream
(e.g. an
air stream) entering fluid inlet 402 of the cyclonic separator 400.
[00146] Preferably, the separated material collection chamber 450 is
removable from the cyclonic separator 400. Providing a detachable separated
material collection chamber 450 may allow a user to transport (e.g. carry) the
collected comminuted feedstock (e.g. comminuted cannabis) to another location
for emptying and/or further processing, without needing to carry or move the
cyclonic separator 400. Preferably, the separated material collection chamber
450 is removable as a closed module, which may help prevent the comminuted
feedstock from spilling out of the separated material collection chamber 450
during transport.
[00147] Alternately, comminuted particle outlet 406 may be in flow
communication with a conduit which transports the separated particulate matter
to, e.g., another piece of equipment for further processing.
[00148] Optionally, an additional filter may be provided downstream
of
cyclonic separator 400. The additional filter may remove particulate matter
from
the airstream exiting the cyclonic separator 400 that was not removed from the
incoming airstream to the cyclonic separator 400. For example, as illustrated
in
Figure 7, a physical or electrostatic filtration member 490 may be provided
downstream of the cyclonic separator 400 and upstream of the source of
negative pressure 300. Filtration member 490 may incorporate a bag, a porous
physical filter media (such as foam or felt), or other physical air treating
means.
[00149] It will be appreciated that two or more cyclonic separation
stages
may be used, each of which uses one or more cyclonic separators 400. The
cyclonic separators 400 of each stage may be the same or different. The
cyclonic
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CA 2983838 2017-10-26
separators 400 of one stage may be different to the cyclonic separators of
another stage, although in some embodiments, they may be the same. As
exemplified in Figure 8, a second cyclonic separator 400b is provided
downstream of a first cyclonic separator 400a. A second separated material
collection chamber 450b is shown in communication with a comminuted particle
outlet 406b of second cyclonic separator 400b to receive particles of
comminuted
botanical feedstock (e.g. particles of comminuted cannabis) dis-entrained from
the fluid stream exiting the first cyclonic separator 400a.
[00150] For example, the fluid stream that exits first cyclonic
separator 400a
via fluid outlet 404a and that is conveyed to fluid inlet 402b of second
cyclonic
separator 400b by conduit 506 has a reduced level of comminuted feedstock
relative to the fluid stream entering the first cyclonic separator 400a via
inlet
402a, due the separation of comminuted botanical feedstock (e.g. particles of
comminuted cannabis) by first cyclonic separator 400a, with the separated
particles being collected in separated material collection chamber 450. Also,
the
fluid stream exiting second cyclonic separator 400b via conduit 504 has a
further
reduced level of comminuted feedstock relative to the fluid stream entering
the
second cyclonic separator 400b via fluid inlet 402b, due the separation of
comminuted botanical feedstock (e.g. particles of comminuted cannabis) by
second cyclonic separator 400b, with the separated particles being collected
in
second separated material collection chamber 450b.
[00151] Preferably, feedstock particles separated by the second
cyclonic
separator 400b and collected in second separated material collection chamber
450b have a smaller average particle size than feedstock particles separated
by
the first cyclonic separator 400a and collected in separated material
collection
chamber 450a. This may be achieved by, for example, providing a second
cyclonic separator having a cyclone chamber with a smaller radius than the
cyclone chamber of the first cyclonic separator 400a. In such a case,
particles
entrained in the airflow in the second cyclonic separator 400b will experience
a
- 32 -
CA 2983838 2017-10-26
greater centrifugal force than they experienced in the first cyclonic
separator
400a, which may promote the dis-entrainment of smaller particles from the
airflow in the second cyclonic separator 400b. Advantageously, collecting
finer
particles may reduce or eliminate the loss of structures (e.g. trichomes) that
contain one or more compounds of interest.
[00152] Separating (and collecting) comminuted feedstock particles
having
different average particle sizes may have one or more advantages. For example,
for cannabis, the smaller particles separated and using second cyclonic
separator may include a greater proportion of trichomes that have been
detached
from the plant material fed into the grinder 1000. These trichomes contain
resin
with a relatively high concentration of certain compounds (e.g. cannabinoids)
that
are typically considered valuable. Accordingly, particles collected in second
separated material collection chamber 450b may have a relatively higher
concentration of these compounds than particles collected in first separated
material collection chamber 450a. Separating and collecting particles with
different relative cannabinoid concentrations may improve e.g. the efficiency
of
subsequent processing steps (e.g. compound extraction). Alternatively, or
additionally, particles with a larger average particle size (e.g. those
separated by
first cyclonic separator 400a) may be used for a first type of further
processing
(e.g. to produce a 'hashish'-type product of compressed trichomes) and
particles
with a smaller average particle size (e.g. those separated by second cyclonic
separator 400b) may be used for a second type of further processing (e.g. a
solvent extraction).
General description of method of operating an apparatus for the
comminution of a botanical feedstock
[00153] The flowing is a description of a method of operation which
may be
used by itself or in combination with one or more of the other features
disclosed
herein including the configuration of the cutting blades, having the feedstock
- 33 -
CA 2983838 2017-10-26
outlet in communication with a source of negative pressure, the use of one or
more cyclone separators and any of the methods disclosed herein.
[00154] Referring to Figure 9, there is illustrated a method 700 for
operating
an apparatus for the comminution of a botanical feedstock, the apparatus
having
a vessel, a first feedstock outlet connected in fluid communication with a
source
of negative pressure, and a screen positioned above the first feedstock
outlet.
Also, the apparatus has a blade rotatably mounted above the screen and
configured to be rotated in a direction of rotation, where at least a portion
of a
leading side of the blade has a cutting edge, and at least a portion of a
trailing
side of the blade has a downwardly extending trailing portion with a lower
edge
having a plurality of discontinuities. Method 700 may be used to operate
apparatus 1000 or any other suitable apparatus for the comminution of a
botanical feedstock.
[00155] At 705, a botanical feedstock is introduced into the
treatment
apparatus. For example, cannabis may be fed into vessel 100 through a
feedstock inlet 112 provided at the upper end 102 of vessel 100.
[00156] At 710, the blade of the apparatus is rotated at a rate of
rotation in
order to cut the botanical feedstock. Also, at the rate of rotation, the
trailing
portion generates turbulence that induces upward movement of cut and partially
cut feedstock from an upper surface of the screen to a plane of rotation of
the
cutting edge of the blade. For example, the blade may be rotated from between
about 750 rotations per minute (RPM) to about 1400 RPM (measured at the drive
shaft of the blade), and preferably at about 900 RPM. Generally speaking, at
higher rates of rotation the turbulence generated by the rotating blade is
greater,
which may cause cut and partially cut feedstock to be raised into the path of
the
cutting edge more frequently, which may improve the efficiency and/or rate of
reduction in the size of the feedstock.
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[00157] Optionally, at 715, the source of negative pressure is
activated to
reduce the pressure in the vessel to below ambient pressure. Activation of the
source of negative pressure also results in a downward force being applied to
the
cut and partially cut feedstock, as air is drawn towards the feedstock outlet.
However, at the rate of rotation, the turbulence generated by the rotation of
the
blade overcomes the downward force, resulting in upward movement of cut and
partially cut feedstock to the plane of rotation of the cutting edge of the
blade.
[00158] For example, the lower edge of the downwardly extending
trailing
portion of the blade may be generally saw toothed in shape, and at the rate of
rotation, the rotation of the blade may provide lift to the cut and partially
cut
feedstock.
[00159] Additionally, or alternatively, by rotating the blade at the
rate of
rotation, the plurality of discontinuities may produce eddy currents that draw
cut
and partially cut feedstock upwardly to a plane of rotation of the cutting
edge of
the blade.
[00160] Put another way, the blade may be rotated at a rate of
rotation
sufficient to effectively 'neutralize' a downward force on the cut and
partially cut
feedstock that is produced by the negative pressure in the vessel, and provide
lift
so that the feedstock moves upwardly to a zone in which it is cut or further
cut.
[00161] As noted above, at the rate of rotation, the trailing portion may
generate turbulence that induces upward movement of cut and partially cut
feedstock from an upper surface of the screen to a plane of rotation of the
cutting
edge of the blade. However, as illustrated schematically in Figure 6, despite
the
induction of upward movement of at least some cut and partially cut feedstock
10
from an upper surface of the screen, the source of negative pressure may
nevertheless draw fine particulate matter (e.g. cut or otherwise comminuted
feedstock particles 12) through the screen and towards a feedstock outlet of
the
vessel.
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CA 2983838 2017-10-26
[00162] Using the source of negative pressure to draw fine
particulate
matter through the screen may have one or more advantages. For example,
inducing or encouraging fine particulate matter towards a feedstock outlet may
increase the collection efficiency of the comminution process. Additionally,
it may
reduce or minimize any loss of fine particulate matter (e.g. trichomes,
terpenes)
during comminution.
[00163] For example, particles of feedstock that have been cut or
otherwise
reduced to a size that allows them to pass through apertures of the screen may
be encouraged to pass through the screen by the airflow generated by the
source of negative pressure. For example, the negative pressure may be
sufficient to draw at least 75% of the fine particulate matter from a volume
defined above the blade and through the screen. Advantageously, this may
reduce or minimize any loss of fine particulate matter (e.g. trichomes,
terpenes)
during comminution. For example, dust and other fine particulate matter may be
inhibited from collecting interior surfaces of vessel 100, and/or be inhibited
from
exiting vessel 100 through an openable feed port 113 of feedstock inlet 112.
[00164] Optionally, at 720, cut feedstock may be withdrawn from the
first
feedstock outlet and the treated (cut) feedstock may be conveyed to a cyclonic
separator 400. For example, a cyclonic separator 400 may be provided
downstream of the first feedstock outlet and upstream of the source of
negative
pressure.
[00165] Optionally, at 725, the fluid stream drawn from the vessel
through
the first feedstock outlet may be subjected to cyclonic separation. During
cyclonic
separation, cut feedstock (e.g. particles of comminuted cannabis) entrained in
the fluid stream is separated from the fluid stream, and the separated
feedstock
is collected in a separated material collection region.
[00166] Optionally, the cyclonic separation may consist of a single
cyclonic
separation stage, e.g. a single cyclone chamber, or two or more cyclone
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CA 2983838 2017-10-26
chambers arranged in parallel. Alternatively, a second cyclonic separation
stage
may be provided in series with (downstream of) the first cyclonic separation
stage.
[00167] During cyclonic separation, at least some, preferably most,
and
most preferably substantially all of the cut feedstock entrained in the fluid
stream
is separated from the fluid stream. Where not all of the cut feedstock is dis-
entrained from the fluid stream by the cyclonic separator, fluid exiting the
cyclonic
separator will still contain at least some entrained cut feedstock.
Optionally, at
730, a fluid steam having a reduced level of cut feedstock obtained from the
cyclonic separator is subjected to further filtration to remove fine
particulate
matter from the fluid steam having a reduced level of cut feedstock. This
further
filtration may be a physical filter media to reduce the particulate level to a
level
suitable for introduction to the ambient.
General description of method of operating continuously operating a batch
grinder
[00168] The flowing is a description of a method of operation which
may be
used by itself or in combination with one or more of the other features
disclosed
herein including the configuration of the cutting blades, having the feedstock
outlet in communication with a source of negative pressure, the use of one or
more cyclone separators and any of the methods disclosed herein.
[00169] Typically, a batch grinder may be loaded with a first
quantity of
material to be ground or otherwise comminuted (e.g. a botanical feedstock such
as cannabis) through an inlet port that is closed after the material is
loaded. Once
loaded, the grinder is operated until all or substantially all of the loaded
material
is ground. The grinder is then de-activated to allow a second quantity or
'batch' of
material to be ground, and optionally for the ground material from the first
batch
to be removed.
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[00170] Referring to Figure 10, there is illustrated a method 800
for
continuously operating a batch grinder. Method 800 may be used to operate
grinder 1000 or any other suitable botanical feedstock grinder.
[00171] At 805, a botanical feedstock is introduced into a vessel of
the
grinder. For example, cannabis may be fed into vessel 100 through a feedstock
inlet 112 provided at the upper end 102 of vessel 100.
[00172] At 810, the vessel is closed and the grinder is operated as
a closed
vessel under negative pressure. While the grinder is operational, a fluid
steam
containing treated (e.g. comminuted) feedstock is withdrawn from the grinder.
For example, a source of negative pressure in fluid communication with a
feedstock outlet may draw particles of feedstock that have been cut or
otherwise
reduced in size by the grinder through a feedstock outlet of the grinder. It
will be
appreciated that the grinder may be any apparatus suitable for comminuting the
feedstock.
[00173] At 815, while continuing to operate the grinder under negative
pressure, a feed port of the vessel may be opened and additional botanical
feedstock may be introduced into the grinder via the feed port while
continuing to
draw air from the vessel using a source of negative pressure. Since air is
being
continuously drawn from the vessel, particles of ground (or unground)
feedstock
may be inhibited or prevented from exiting the grinder via the feed port.
Accordingly, valuable feedstock may not be lost to the ambient while fresh
feedstock is added to the grinder with the grinder operating.
[00174] Optionally, at 820, the fluid stream drawn from the vessel
may be
conveyed to a cyclonic separator. For example, a cyclonic separator may be
provided downstream of a feedstock outlet of the grinder and upstream of the
source of negative pressure.
[00175] Optionally, at 825, the fluid stream drawn from the vessel
may be
subjected to cyclonic separation. During cyclonic separation, cut feedstock
(e.g.
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CA 2983838 2017-10-26
particles of comminuted cannabis) entrained in the fluid stream is separated
from
the fluid stream, and the separated feedstock is collected in a separated
material
collection region. Optionally, the cyclonic separation may consist of a single
cyclonic separation stage, e.g. a single cyclone chamber, or two or more
cyclone
chambers arranged in parallel. Alternatively, a second cyclonic separation
stage
may be provided in series with the first cyclonic separation stage.
Accordingly, a
first treated feedstock (e.g., the larger comminuted feedstock) may be
collected
that is suitable for a particular subsequent treatment operation (e.g.,
compressed
resin glands (hashish)) and a second treated feedstock (e.g., the finer
comminuted material) may be collected that is suitable for an alternate
subsequent treatment operation (e.g., extraction).
[00176] Optionally, at 830, a fluid steam having a reduced level of
cut
feedstock obtained from the cyclonic separator is subjected to further
filtration to
remove fine particulate matter from the fluid steam having a reduced level of
cut
feedstock. This further filtration may be a physical filter media to reduce
the
particulate level to a level suitable for introduction to the ambient.
General description of method for treating cannabis
[00177] The flowing is a description of a method of operation which
may be
used by itself or in combination with one or more of the other features
disclosed
herein including the configuration of the cutting blades, having the feedstock
outlet in communication with a source of negative pressure, the use of one or
more cyclone separators and any of the methods disclosed herein.
[00178] While the apparatus and methods discussed herein may be
suitable for use with a variety of botanical feedstock, they may be
particularly well
suited for use with a feedstock of cannabis. Referring to Figure 11, there is
illustrated a method 900 for treating cannabis. Method 900 may be used with
any
apparatus disclosed herein or any other suitable apparatus for treating
cannabis.
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CA 2983838 2017-10-26
[00179] At 905, a feedstock of cannabis is treated and a treated
feedstock
comprising comminuted cannabis is obtained. For example, a cannabis
feedstock may be comminuted using apparatus 1000.
[00180] At 910, the treated feedstock is pneumatically conveyed to a
cyclonic separator. For example, a source of negative pressure in fluid
communication with a feedstock outlet of apparatus 1000 may draw particles of
comminuted cannabis to a cyclonic separator. For example, a cyclonic separator
may be provided downstream of a feedstock outlet of the grinder and upstream
of the source of negative pressure.
[00181] At 915, the air stream drawn from the vessel containing the
comminuted cannabis may be subjected to a first cyclonic separation stage. As
a
result of the cyclonic separation, a first stream of treated feedstock (i.e.
particles
of comminuted cannabis) separated out of the air stream is obtained, along
with
a first fluid stream having a reduced level of treated feedstock.
[00182] Optionally, at 920, the treated feedstock may be subjected to at
least one subsequent cyclonic separation stage in series with the first
cyclonic
separation stage. Preferably, each subsequent cyclonic separation stage
separates treated cannabis having a smaller particle size than the immediately
previous cyclonic separation stage.
[00183] Additionally, or alternatively, the first fluid stream having a
reduced
level of treated feedstock may be subjected to a second cyclonic separation
stage and a second fluid stream having a further reduced level of treated
feedstock and treated feedstock separated out of a fluid stream by the second
cyclonic separation stage may be obtained. Preferably, the treated feedstock
separated out of a fluid stream by the second cyclonic separation stage has a
smaller average particle size than an average particle size of the treated
feedstock separated out of a fluid stream by the first cyclonic separation
stage.
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CA 2983838 2017-10-26
[00184] Optionally, at 925, first stream of treated feedstock
exiting the
cyclonic separator may be collected. For example, the treated feedstock may be
collected in a separated material collection region of the cyclonic separator.
[00185] Optionally, at 930, at least a portion of the first stream
of treated
feedstock may be subjected to extraction to obtain a cannabis extract. For
example, treated feedstock collected at 925 may subsequently be subjected to
an extraction process (e.g. using a botanical extractor) to obtain a cannabis
extract.
[00186] For example, as illustrated in Figure 8, an extractor 600
may be
provided to extract one or more compounds (e.g., waxes, heavy oils, or light
oils)
from cannabis that has been comminuted using apparatus 1000. In the
illustrated
example, extractor 600 is separate from the cyclonic separators 400a, 400b.
Accordingly, the treated cannabis collected in one or both separated material
collection regions 450a, 450b may be transferred to the extractor As discussed
above, comminuted cannabis collected in chamber 450b may be transferred to
the extractor, and comminuted cannabis collected in chamber 450a may be
transferred to another location). For example, where separated material
collection chambers 450a, 450b are detachable from their respective cyclonic
separators, a user may transport (e.g. carry) the collected comminuted
cannabis
in one or both of the detached chambers 450a, 450b to the extractor 600.
Alternatively, an inlet to the extractor may be in communication with a
feedstock
outlet 406 of a cyclonic separator 400, e.g. using a conduit (not shown), such
that
cannabis removed from an air stream by the cyclonic separator is transferred
directly to the extractor.
[00187] Returning to Figure 11, optionally, at 935, a fluid steam having a
reduced level of cut feedstock obtained from the cyclonic separator is
subjected
to further filtration to remove fine particulate matter from the fluid steam
having a
reduced level of cut feedstock. This further filtration may be a physical
filter
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CA 2983838 2017-10-26
media to reduce the particulate level to a level suitable for introduction to
the
ambient.
[00188] As used herein, the wording "and/or" is intended to
represent an
inclusive - or. That is, "X and/or Y" is intended to mean X or Y or both, for
example. As a further example, "X, Y, and/or Z" is intended to mean X or Y or
Z
or any combination thereof.
[00189] While the above description describes features of example
embodiments, it will be appreciated that some features and/or functions of the
described embodiments are susceptible to modification without departing from
the spirit and principles of operation of the described embodiments. For
example,
the various characteristics which are described by means of the represented
embodiments or examples may be selectively combined with each other.
Accordingly, what has been described above is intended to be illustrative of
the
claimed concept and non-limiting. It will be understood by persons skilled in
the
art that other variants and modifications may be made without departing from
the
scope of the invention as defined in the claims appended hereto. The scope of
the claims should not be limited by the preferred embodiments and examples,
but should be given the broadest interpretation consistent with the
description as
a whole.
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