Note: Descriptions are shown in the official language in which they were submitted.
. =
Jan Kruyer, P.Eng., Thorsby, AB., CA.
A COMME .CIAL OLEOPHILIC SIEVE SEPARATOR
FIELD OF THE INVENTION
The present application relates generally to devices and methods for
separating
water and hydrophilic particulate mineral matter from viscous hydrocarbon
(e.g. bitumen)
and oleophilic particulate mineral matter. More particularly, the present
invention relates to
apparatus and method for very fast phase separation of a fluid mixture of
oleophilic phase
and hydrophilic phase using oleophilic sieve(s). Accordingly, the present
invention
involves the fields of process engineering, chemistry and chemical
engineering.
PRIORITY
This patent application claims priority to Canadian patent 2,999,466 "AN
OLEOPHILIC SIEVE SEPARATION APPARATUS" of the same inventor, which is
included here by reference. This prior filed patent application had several
deficiencies
which are overcome in the present patent to improve process performance. In
the present
patent, herein described and claimed, the separation apparatus is immersed in
an effluent
tank and oleophilic rods in rotating cage are elevated by and spilled from
bench or benches
inside the rotating cage of the present patent to transfer oleophilic phase
from feed inside
the cage to settling oleophilic rods for subsequent transfer to oleophilic
sieve surfaces. The
oleophilic phase covered sieve surfaces pass through a hot zone where heat
causes
oleophilic phase to leave sieve surfaces as fluid product. In the above
referenced prior
patent, oleophilic rods were not elevated by bench but revolved due to
rotation of the cage
inside the rotating cage which, unlike the present patent application, was not
immersed in
an effluent tank. As a result, the present invention is superior in separating
oleophilic phase
from hydrophilic phase.
BACKGROUND OF THE INVENTION
The present patent application relates to devices and methods for very fast
continuous feed separation of viscous hydrocarbon and oleophilic particulates
from water
and from hydrophilic particulates inside a cage. More particularly, the
present invention
relates to oleophilic sieve(s) surrounding a rotating cage partly immersed in
effluent in a
tank at a temperature preferably below 40 degrees centigrade. Oleophilic rods
spill from
shelf or shelves inside the rotating cage and settle through feed inside the
cage, collect
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_
bitumen and oleophilic mineral particulates from the feed, and roll along cage
bottom
quadrant to transfer collected viscous oleophilic phase from oleophilic rods
to oleophilic
sieve.
The revolving sieve passes through a hot zone above the cage where collected
viscous oleophilic phase on the oleophilic sieve becomes warm liquid product
of separation
due to viscosity reduction by heat. Hydrophilic mineral particulates and water
flow as
effluent from the cage through sieve apertures from the cage into the effluent
tank.
Removal of effluent from the tank is controlled to keep the rotating cage and
its contents
mostly immersed in effluent in the tank with a level difference between cage
and effluent
tank to cause flow of processed feed into the tank.
COMPARISON WITH THE PRIOIR ART
Bitumen froth flotation, currently in commercial use for processing oil sand,
heats
up all water based oil sand slurry feed to 50 degrees C. for processing in
flotation vessels,
and then requires 360 minutes of process residence time inside these vessels
to collect up to
95% of the contained bitumen as aerated froth product to be skimmed off the
top. The
process needs caustic to control pH of the flotation process for optimum
bitumen froth
production and deposits the high pH effluent water with suspended solids of
separation into
tailings pond for many decades of containment. The present patent application
allows but
does not require caustic in the separation process.
Unlike bitumen froth flotation which requires 360 minutes of process residence
time
at 50 degrees C., oleophilic sieve separation requires 15 minutes of process
residence time
at 35 degrees C. to achieve better bitumen product recovery and quality from
oil sand
slurry. It does not need caustic but it is tolerant of caustic. Both short
processing time and
absence of caustic makes oleophilic sieve separation an ideal candidate for
mine face oil
sand extraction. It will eliminate large pipe diameter abrasive transport of
oil sand slurry to
central processing, needing only a small diameter warm bitumen liquid pipeline
to central
upgrading. Not using caustic for commercial oil sand separation will allow
reuse of
process effluent water to process new oil sand after settling out mineral
solids of prior
oleophilic sieve separation for a few months, reducing or eliminating long
duration tailings
ponds.
BACKGROUND
Including prior granted Canadian patents of the instant inventor, the present
invention differs from the prior art. It uses a not-previously patented
separation concept of
oleophilic rods spilling from bench or benches, inside a rotating cage. These
rods settling
through relatively cold feed inside the cage collect, on oleophilic rod
surfaces, oleophilic
phase from the feed, for subsequent transfer in cage bottom quadrant to
oleophilic sieve or
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sieves that cover exterior of the cage and project into cage interior. The
oleophilic phase
covered sieve surfaces then revolve through a hot zone for subsequent removal
of
oleophilic phase by heat from sieve surfaces as warm liquid product of
separation. Unlike
in prior patents of the present inventor, in the present patent application,
hydrophilic phase
of feed separation passes through sieve apertures of the relatively cold cage
into an effluent
tank in which the cage is immersed. Effluent, while passing from the cage
through
oleophilic sieve into the effluent tank also transfers residual bitumen to
sieve surfaces upon
contact, further improving oleophilic phase recovery.
OTHER PRIOR ART
Following are well-known examples of oleophilic phase adhesion, not to
oleophilic
sieves but to air bubbles or printing surfaces.
In 1860, William Hanes invented the separation of oleophilic sulfide from
hydrophilic gangue material by rising air bubbles for froth flotation of oil
wetted sulfide.
Many years later, in 1920, Dr. Karl Clark began his pilot plant study of
separating Alberta
oil sand at the Alberta Research Council in Edmonton, Canada, and subsequently
invented
and patented bitumen adhesion to air bubbles to separate a slurry of bitumen,
water and
sand into a bitumen froth product and a water and sand effluent.
Graphic artists and offset printing press developers, observing that oil based
ink
adheres to oil wet text and graphics but does not adhere to water wet
surfaces, learning to
repeatedly transfer ink wet images of a predominantly water wet master plate
or marble
tablet to many paper sheets in sequence.
None of the above methods used settling oleophilic rods to collect relatively
cold
oleophilic phase from feed inside a cage for transfer to an oleophilic sieve
on cage
circumference for subsequent removal from the sieve by heat as product, whilst
hydrophilic
effluent of separation and water flow through sieve apertures into an effluent
tank
surrounding most of the cage for controlled effluent removal.
OLEOPHILIC SIEVE SEPARATION
The concept of oleophilic sieve separation originated with the present
inventor, who
had operated an offset press, and therefore realized that oleophilic phase
adhesion to
oleophilic surfaces might be adapted to separate mined oil sand. He knew Dr.
Karl Clark,
was familiar with bitumen froth flotation and had access to all the published
and
unpublished reports of Dr. Clark. About 10 years after Dr. Clark had retired
and Suncor
had built the first major commercial oil sands plant in Alberta, using bitumen
froth
flotation, the present inventor conceived and tested his oleophilic sieve
separation concept
for a year at the Alberta Research Council (ARC) while funding was made
available. It
resulted in his first Canadian oil sand separation patent application. When
funding
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CA 3089104 2020-07-31
terminated after a year of oleophilic sieve separation research, he entered
into an agreement
with ARC management to continue his research elsewhere. He assigned his
pending first
Canadian oil sand patent to the ARC and formed his own research establishment,
employing engineers, chemists and technicians. Subsequent oleophilic sieve
research
lasting for decades resulted in many patent applications in progression filed
by him and
granted both in Canada, in the USA. The present Canadian patent application is
his latest.
MODERN OLEOPHILIC SIEVE SEPARATION TECHNOLOGY
The present application for patent claims the unique use of a large number of
long
oleophilic rods inside a relatively cold rotating cage filled with feed for
separation, which
cage is covered with oleophilic sieve(s) that project into cage interior and
with cage
provided with ,one or more shelves inside the cage. During cage rotation,
these shelf or
shelves inside the cage assemble the oleophilic rods inside the cage, and
subsequently spill
from shelf or shelves the rods to settle through feed inside the cage during
each cage
complete revolution. During settling through feed, the rods collect from feed
inside the age
-- relatively cold viscous oleophilic phase on surface of the settling rods.
After settling
through feed, the oleophilic phase coated rods roll along cage bottom quadrant
and transfer,
upon contact, viscous oleophilic phase from oleophilic rod surfaces to
relatively cold
oleophilic sieve, also transferring oleophilic phase between oleophilic rods
for transfer to
oleophilic sieve surfaces. After that, during each cage rotation, shelf or
shelves again
-- assemble oleophilic rods from along the cage bottom for subsequent spillage
through feed
as the cage continues to rotate.
More than one oleophilic sieve may cover side by side the cage exterior. Each
oleophilic sieve contacting the cage has the shape of an incomplete polygon in
which
corners of each polygon are located at the longitudinal structural members of
the cage and
sides of each polygon project into the cage interior between adjacent
longitudinal structural
members to allow contact between oleophilic rods and oleophilic sieve. The
polygon shape
of each oleophilic sieve is incomplete since the oleophilic sieve leaves the
cage near the top
of the cage to pass through a hot zone above and/or beside the cage. In the
hot zone, heat
causes oleophilic phase to flow from the oleophilic sieve(s) as liquid product
of separation.
Tension is provided in oleophilic sieve(s) to cause sieve movement as a result
of cage
rotation. After passing through the hot zone the oleophilic sieve, continue to
revolve and
return to the rotating cage.
The cage is immersed in effluent of oleophilic sieve separation in an effluent
tank
that surrounds bottom and sides of the cage. This immersion slows down liquid
flow
-- through oleophilic sieve from the cage into the tank by controlling level
difference of feed
inside the cage and of effluent in the effluent tank. Hydrophilic effluent of
separation
passes through apertures in oleophilic sieve and flows into the effluent tank,
surrounding
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most of the cage, whilst uncollected residual oleophilic phase of the feed
leaving the cage
for the effluent tank is largely collected by oleophilic sieve surfaces.
Oleophilic phase sieving is a single stage continuous two temperature process
which
achieves very fast phase separations and is now ready for commercial
development to
reduce the cost of separating oil sands, tar sands, tailings pond fluid fine
tailings, weathered
oil spills, mine minerals and wet marine minerals. For processing mine, or
sediment
minerals, containing both hydrophilic and oleophilic mineral particulates, a
viscous
hydrocarbon such as petroleum jelly or bitumen, is added to the feed for
collecting on
oleophilic mineral particles for subsequent adhesion to oleophilic sieve
surfaces as
hydrophilic mineral particulates and water flow into the effluent tnak.
If needed, two oleophilic sieve separators may be used in series but normally
this is
not required to improve recovery of oleophilic phase. Fifteen minutes of
residence time
inside the rotating cage using a large number of settling oleophilic rods from
shelf or
shelves will recover most of the oleophilic phase present in a feed on
oleophilic sieve.
Since feed for oleophilic sieve separation can be pH neutral (pH close to 7.0)
the
hydrophilic minerals in water effluent of oleophilic sieve separation, removed
from the
process, can settle relatively fast to the bottom of a tailings pond. This
will allow, within a
few weeks or a few months, recycle of a very high percentage of tailings pond
water for
reuse, in oleophilic sieve separation, to reduce demand for fresh water for
oil sand or
minerals separation. This serves to reduce the current negative environmental
impact of oil
sand development and tailings ponds expansion.
In some cases, water from existing old oil sand tailings pond fluid fine
tailings
(FFT), in large quantity may be considered as an optional source of process
water to use for
mined oil sand extraction by oleophilic sieve. Oleophilic sieve separation is
tolerant of
mineral fines and is generally not impacted much by process water pH, at least
between 6
and 8. This could lead to the simultaneous recovery of new bitumen from mined
oil sand
and old bitumen from pond FFT. It is an option that should be considered as a
future means
to empty existing tailings ponds, thereby producing bitumen from both new
mined oil sand
ore and from old pond FFT, while benefitting from reduced fresh separation
water demand.
Oleophilic sieve slurry separation of oil sand slurry as disclosed in the
present
patent requires about 15 minutes of process residence time and does not need
caustic. The
hydrophilic minerals in the effluent of oleophilic sieve separation, using
fresh water, settle
relatively quickly and the resulting effluent water of separation can then be
reused as
process water for separating fresh oil sand after first settling the effluent
water for a few
months. Recycling process water in that manner will reduce in a major way the
environmental impact of oil sand processing.
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Unlike froth flotation, which requires all feed at 50 degrees C, oleophilic
sieve
separation temperature inside its cage normally is around 40 degrees C. or
lower,
depending on feed composition. Product leaving the hot zone of oleophilic
sieve separation
may be at a much higher temperature beneficial for further processing. Since
the relatively
cold cage handles the bulk of the feed for processing, and the hot zone only
heats the
product, commercial oleophilic sieve separation energy demand will be
relatively low.
Because of caustic use, current effluent of commercial oil sand separation by
froth
flotation cannot be safely discarded but requires permanent impounding of its
fluid fine
tailings (FFT) in large tailings ponds to prevent toxic release to the
environment. After
years of minerals settling, only the upper layers of oil sand tailings pond
are currently
reused as part of water make up for froth flotation of oil sand slurry. The
oil sand tailings
ponds are very large and are considered an environmental problem. When
oleophilic sieve
separation of mined oil sand is implemented commercially, the negative
environmental
impact of oil sand tailings will be reduced.
The oleophilic sieve was very effective for processing existing tailings ponds
fluid
fine tailings (FFT) to recover discarded bitumen in a two year field pilot
project costing
well over $1 million. Removing bitumen from tailings pond effluent (FFT) is
expected to
result in cleaner tailings ponds that represent less of an environmental
hazard, and
recovering in the process a substantial amount of valuable bitumen. An episode
of a large
number of migrating ducks landing on and dying in an oil sand tailings pond is
still
remembered by many.
TYPES OF OLEOPHILIC SIEVES
There are at least three types of conveyor belts suitable for use as
oleophilic sieves.
These include conventional metal belts formed from strips of metal shaped in
the form of
an almost square square wave with holes punched in the metal strips to accept
rods to pass
through the holes to join the metal strips and form a flexible endless belt.
The square wave
shape is lightly tapered to allow the formed strips to mesh into adjacent
formed strips and
thus form a long belt of hinges that can be made endless by joining belt end
to belt
beginning. Another type of belt is formed from flattened metal coils that are
joined by rods
passing through adjacent flat coils to form a multitude of interconnected flat
coils with the
starting coil connected to the last coil by rod.
A more preferred belt for use as an oleophilic sieve comprises multiple wraps
of a
rope made endless by joining the end of the rope to the beginning of the same
rope. This
type of oleophilic sieve is shown in the drawing of Figure 1 and especially in
Figure 11 and
may be made from plastic rope, from metal rope or from carbon fiber rope.
Figure 11
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shows two such sieves made endless by joining the start of each rope to the
end of the same
rope. As shown in Figure 11 two rope wrap redirecting guide rollers are needed
to keep
each sieve of equally spaced sieve wraps on cage from rolling off a drum or
cage.
A nice feature of an endless oleophilic sieve of parallel rope wraps is that,
at the
rakes the space between adjacent wraps is fixed by rake tine and valley
spacing but,
between rakes on a cage, two adjacent wraps can spread to allow passage of
hydrophilic
particles much larger in size than distance between adjacent rake valleys.
When this
happens, space between the spread wraps is increased locally and space between
each
spread wrap and adjacent neighbor wraps is reduced. It allows oversize mineral
particles
much larger than distance between rake valleys to spread sieve wraps for such
particles to
leave the cage and enter the effluent tank. Rake valley spacing prevents wrap
spacing at
the rakes but allows, between rakes, local wrap spreading and corresponding
adjacent local
wrap crowding between rakes for oversize mineral particles to leave the cage.
As shown in Figure 11, two pulleys on each oleophilic sieve of rope wraps
redirect
sieve wraps so that those wraps never roll off the cage nor off the rollers
that guide the
sieve wraps between cage and hot zone. When conventional endless conveyor
aperture
metal belts are used for oleophilic sieves, such pulleys are not needed.
ROPE WRAP COMMERCIAL OLEOPHILIC SIEVE SEPARATORS
Three sizes of commercial oleophilic separators are detailed in Table Figure 8
with
cages respectively 2, 4 and 8 meters in diameter each using endless oleophilic
ropes for the
sieve(s) similar to Figure 11 on cages detailed in Figures 1, 2, 3 and 12
instead of on
aperture drums. The cages are immersed in an effluent tank as detailed in
Figures 3 and 12.
All three cages feature a strong central shaft for cage construction, two
strong end walls and
a number of longitudinal structural members equally spaced along the periphery
of the cage
end walls provided with rakes to space the rope wraps. The diameter of the
longitudinal
structural members of the cage should be small enough to allow oleophilic rods
to roll and
tumble in cage bottom quadrant for directly or indirectly transferring
oleophilic phase to the
oleophilic sieve(s); but are sufficiently strong to support without observable
bending
oleophilic sieve wraps in tension that take the form of incomplete polygons
supported on
the structural longitudinal members. The central shaft prevents bending of the
cage. The
weight of settled oleophilic rods inside the cage is mainly carried by the
central shaft of the
cage in bearings, since hoops or flat bar welded to the cage end walls
transfer weight of
settled oleophilic rods inside the cage to the central shaft via the end
walls.
When more than one oleophilic sieves is used on a cage, a hoop or an assembly
of
flat bars also is located between adjacent sieves to space the sieves, to give
room for
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bearings and bearing mounts of sieves and to prevent spillage of feed into the
effluent tank
between adjacent sieves. Hence, when two oleophilic sieves are used on a cage,
three sets
of hoops or three assemblies of flat bars are needed. When three oleophilic
sieves are used
on a cage, four sets of hoops or four assemblies of flat bars are needed, etc.
MINE FACE OLEOPHILIC SIEVE SEPARATION
Oleophilic sieve separation appears thus far to be the only hot water process
replacement technology suitable for mine face oil sand extraction because of
its simplicity
and its very short processing residence time. As detailed in Table Figure 8,
each
commercial 8 meter diameter, 24 meter long oleophilic sieve separator is
designed to
process 83,000 cubic meters of oil sand slurry per day. When three such
separators are
used, one at each mine face, total oil sand slurry for mine site extraction
will amount to
about 250,000 cubic meters of slurry per day, each separator producing good
quality
bitumen product for shipment by liquid pipeline to central upgrading. Using
skid mounted
units at the mine face, and enclosing each unit as needed, will allow
oleophilic sieve
separation equipment to move with an advancing mine face. An important feature
of
oleophilic sieve separation is that slurry production for oleophilic sieve
separation is
simpler and faster than slurry production for bitumen froth flotation.
In pilot plant studies of the present inventor, separating mined oil sand
slurries by
oleophilic sieve, the presence or absence of caustic in the feed made little
difference. It
indicated that for commercial oleophilic sieve separation of mined oil sand
slurry, caustic
will not be needed either. When caustic is not needed for commercial
oleophilic sieve
separation of mined oil sand, mineral particulates in the water effluent of
oleophilic
separation at neutral pH will settle rapidly and will allow tailings pond
water to be reused
in commercial oil sand extraction after settling for a few months. This
reduces in a major
way the need for fresh water in commercial mined oil sand separation by
oleophilic sieve.
In pilot plant studies, not 360 minutes, but less than 15 minutes of
oleophilic sieve
separation of oil sand slurry yielded a very acceptable bitumen product and
clean tailings.
Field piloting by oleophilic sieve separation of tailings pond FFT also
retrieved in a few
minutes a high percentage of prior discarded bitumen from froth flotation
extraction. All
this indicates that existing tailings pond fluid fine tailings (FFT) may be
considered a
potential source of useful water to process mined oil sand to recover new
bitumen from
mined oil sand and old bitumen from FFT at the same time.
Water washing the bitumen product with clean water, optionally including a
chemical reagent, may thereafter remove hydrophilic mineral from the resulting
bitumen
product, as was achieved in our pilot plant when cleaning up bitumen produced
from pond
FFT.
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OTHER USES
The cages described above may also, instead of sieves of endless rope, use
endless
conventional open area (i.e. aperture) metal conveyor belts, of the type
described in this
patent, on cage longitudinal structural members and projecting into cage
interior similar to
sieves of endless rope. In that case rope guide pulleys, (73a and 73b) shown
in Fig. 11, are
not needed. These conveyor belts have a selected constant opening size which
prevents
hydrophilic particulates beyond a given particle size age. In some cases a
punched metal
sheet conveyor may be used or an open area woven plastic belt. However, an
oleophilic
sieve of multiple wraps of oleophilic rope is more versatile and long lasting,
especially
when the oleophilic rope comprises twisted metal wire to which bitumen will
adhere.
An oleophilic sieve separator designed for processing oil sand slurry may be
used to
recover bitumen from tailings pond FFT without the need for a slurry tumbler.
In side by
side field testing to separate 120 metric tons of tailings pond FFT, the
bitumen froth
flotation pilot plant had a process residence time of 26 minutes and the
oleophilic sieve
pilot plant had a process residence time of 2 minutes. The product of froth
flotation
contained 25% bitumen and the product of oleophilic sieving contained 58%
bitumen. In
other words, oleophilic sieve separation was 13 times as fast, irrespective of
equipment size
and the bitumen product was twice as pure. Process residence time is a process
parameter
independent of equipment size and is used for evaluating process performance.
Oleophilic sieve separation may also be used to clean up oil spills but that
is not its
current development objective. For separating mine minerals, bitumen or
viscous other
hydrocarbon is added to a water wet slurry of mine minerals for oleophilic
sieve separation.
Such oleophilic phase addition will coat the oleophilic mine minerals in the
slurry for
subsequence adherence to oleophilic rods and to oleophilic sieve surfaces
whilst
hydrophilic minerals remain water wetted and flow with water as effluent of
separation
through apertures of the oleophilic sieve into the effluent tank.
THE PRESENT PATENT APPLICATION
The present patent application describes the construction and operation of
oleophilic
sieve(s) wrapped around part of a rotating cage, and passing through a hot
zone; including
an effluent tank in which the cage is immersed. The present claims are
specific to a
rotating cage in part filled with feed and in part filled with oleophilic
rods. Shelf or shelves
supported inside the cage collect the oleophilic rods on shelf for subsequent
spillage from
bench into cage interior due to cage rotation. The spilled oleophilic rods
settle through feed
inside the cage and collect oleophilic phase on rod surfaces from the feed. At
least half of
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the cage circumference is void of shelf or shelves, which allows the rods to
roll and tumble
along bottom quadrant of the cage for transfer of oleophilic phase between
oleophilic rods
and from oleophilic rods to oleophilic sieves, for conveyance of the sieve and
contents
through a hot zone to yield warm good quality oleophilic product flowing from
the sieve.
This further results in a relatively clean hydrophilic effluent of water and
hydrophilic
minerals, which after the minerals have settled may be used to process more
feed since
caustic is not needed for oleophilic sieve separation. Minerals settle
reasonably fast in
aqueous effluent of separation when its pH is close to 7Ø
In the hot zone, heat removes the oleophilic phase as product of separation
from the
sieve. The cage is immersed well over half in a tank containing the
hydrophilic effluent of
oleophilic sieve separation.
Immersion of a rotating cage in effluent, combined with oleophilic sieve(s) on
an
immersed cage exterior and with sieve projecting into cage interior to improve
bitumen
collection, and combined with collection of bitumen from processed feed
entering the
effluent tank, while passing through oleophilic sieve, was not disclosed in
any other
currently pending or granted patents of the present inventor.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a drawing of an oleophilic sieve cage. It consists of two circular
disc
types end walls with eight longitudinal structural members equally spaced
along cage
circumference and attached to each end wall inside face. Five of the eight
structural
members are shown. The other three are hidden by the shown structural members.
The
cage has a central shaft, to mount the cage in secured bearings and to drive
slow cage
rotation, using a gear box and motor (not shown). A manhole with cover is
provided in at
least one of the end walls for inserting and removing long oleophilic rods to
and from the
cage. One and preferably two or more oleophilic sieves surround most of the
cage in the
form of either multiple wraps of endless oleophilic rope that are supported by
longitudinal
structural members and are equally spaced by rakes on the longitudinal
structural members,
or in the form of aperture metal conveyor belts. The oleophilic rope may be
made from
plastic or from metal. Two oleophilic sieves of equal length on a separator
simplify
construction and keep the hot zone parallel with the cage in this Figure.
Figure 2A is a drawing of the cage viewed from inside the cage with oleophilic
sieve wraps at least covering the cage bottom and sides, showing a metal hoop
surrounding
the longitudinal structural members. This metal hoop is shown as a thin line
to allow
showing the thick dashed line sieve. The cage contains some oleophilic rods in
the cage to
show curvature of sieve due to oleophilic rod weight but constrained by the
hoop.
CA 3089104 2020-07-31
Figure 2B is the same drawing as Figure 2 except that the metal hoop is
replaced by
eight straight flat bars mounted between longitudinal structural members and
projecting for
a short distance beyond the inside face of each end wall to support the weight
of oleophilic
rods on the flat bars between longitudinal structural members due to contact
between
oleophilic rod ends with the straight flat bars. It shows a single oleophilic
sieve which hides
the straight metal bars except near the top of the cage. The circles with a
cross in each
represent oleophilic rods inside the cage.
Figure 3 shows the cage immersed in an effluent tank and shows a hot zone
above
and beside the cage. The cage also shows a single shelf that, due to cage
rotation, has
collected all the oleophilic rods in the cage ahead of shelf inside the cage.
As the cage
rotates slowly, all the oleophilic rods will gradually spill from the shelf to
collect relatively
cold oleophilic phase from the feed. After each spill, settled oleophilic rods
directly or
indirectly transfer collected oleophilic phase to the sieve as a result of
transfer of oleophilic
phase between rolling oleophilic rods in cage bottom quadrant. This sequence
is repeated
with every cage rotation. Oleophilic sieve(s) convey viscous oleophilic phase
into a hot
zone where heat converts the viscous oleophilic phase into warm liquid product
of
separation.
Figure 4A illustrates a cage with a curved single bench connected between the
cage
central shaft and one of the longitudinal structural members. This bench, in
its simplest
form consists of two or three curved bars attached to the central shaft and to
one of the
longitudinal structural members. The bench has collected all oleophilic rods
due to cage
rotation.
Figure 4B illustrates gradual spilling of the oleophilic rods from the curved
bench
inside the cage due to cage rotation. The use of a curved shelf allows for
longer duration of
spillage of rods from the shelf during each rotation of the cage.
Figure 5 illustrates the use of four curved benches inside the cage. Enough
rods are
provided in the cage to fill almost all four benches with rods. During about
half of each
cage rotation, each bench in sequence spills rods inside the cage interior to
settle through
feed and collect oleophilic phase from the feed, and then allows, during the
other half of
each cage rotation, transfer of collected viscous oleophilic phase between
oleophilic rods
rolling along cage bottom quadrant and from rods to oleophilic polygon shaped
sieve
projecting into cage interior.
Figure 6 illustrates a typical rake to space the rope wraps of an oleophilic
sieve.
Such a rake is normally inserted and fastened in a groove of every, or
alternate longitudinal
structural member of a cage, with depth of insertion into the longitudinal
structural
member, indicated by the dashed line. A rake with tines of sloping sides tends
to provide
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extra friction between tines and rope wraps. When a conveyor is used for the
oleophilic
sieve, the rake is adapted to accept surfaces of such a conveyor.
Figure 7 illustrates a longitudinal structural member of the cage in the form
of a
round bar or half round bar (above dashed line at bar center). A rake is shown
inserted in
the longitudinal structural member and the heavier dashed line shows a sieve
wrap in the
rake.
Figure 8 is a table of recommended commercial separator sizes with details and
estimated separation capacities.
Figure 9 provides details of a typical oleophilic sieve separator effluent
tank end
wall to allow immersion of the cage into effluent of separation.
Figure 10 provides details of mounting a rotary seal and a shaft bearing in
the end
wall of the effluent tank.
Figure 11 provides details of prior patented art of the inventor to prevent
oleophilic
sieve from rolling off an aperture drum. Only two pulleys in total keep the
wraps of a sieve
from rolling off rotating drum and associate rollers. This concept of using
only two wrap
directing pulleys or sheaves is also used in the present patent by the
inventor to prevent
oleophilic sieve wraps from rolling off an immersed cage.
Figure 12 is similar to Figure 3 except that in Figure 12 the cage rotates in
opposite
direction (counter clockwise), resulting in bitumen loaded sieve entering the
hot zone as the
top flight for product removal, whereas in Figure 3 the cage rotates
clockwise, resulting in
the bitumen loaded sieve entering the hot zone as the bottom flight for
product removal. In
most cases the more effective method is illustrated in Figure 12, since it
reduces heating of
the empty sieve prior to returning from the hot zone to the cold cage.
DETAILED DESCRIPTION OF THE FIGURES
Figure 1 is a drawing of one of the smallest of the three oleophilic sieve
cages
detailed in Table Figure 8. It consists of two circular disc type end walls
(10,11), two
meters in diameter and six meters long with eight longitudinal structural
members
(1,2,3,4,5,6,7.8) equally spaced along cage circumference and attached to each
end wall
(10,11) inside faces (10a, 11a). Five of the eight structural members
(1,2,3,4,5) are shown.
The other three (6,7,8 ) are hidden by the five shown structural members, The
cage has a
central shaft (9). The central shaft (9) is securely mounted in bearings and
bearing mounts
(not shown) to be slowly driven to rotate, using a gear box and a motor (not
shown). A
manhole with cover (12) is provided in at least one of the end walls (10, 11)
for inserting
and removing long oleophilic rods to and from the cage. One such rod (15) is
shown inside
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CA 3089104 2020-07-31
the cage. It is long enough to be prevented by hoop (13) or eight flat bars
(See Fig 2) from
leaving the cage. A hoop (14) or eight flat bars at cage mid length provides
for spacing the
two sieves (18, 19) for mounting of components to position two sieves. The two
oleophilic
sieves (18, 19) surround most of the cage circumference. The sieves (18,19)
are illustrated
in the form of dashed lines that are supported by the longitudinal structural
members (1 to
8) and, when in the form of endless rope are equally spaced by rakes (not
shown) on the
longitudinal structural members. Hoop or eight straight bars (13) of limited
width are used
between the longitudinal structural members (1,2,3,4,5,6,7,8) as detailed in
Figures 2A and
2B, These flat bars are welded to the inside face (10a, 1 1 a) of each end
wall (10,11), and/or
are welded to the longitudinal structural members (1,2,3,4,5,6,7,8) for a
short distance on
each of those members near cage end walls inside surfaces (10a, 11 a) to
prevent oleophilic
rods from putting excess stress on the oleophilic sieve and to prevent rods
from getting
caught between sieve(s) and cage end wall circumference. Similar hoop or eight
straight
bars (14) indicated in black on Figure 1 are shown at cage mid length to
separate the two
sieves (18,19). The hoops or bars (13) at cage end walls prevent weight of
oleophilic rods
from putting excess stress on sieve(s) (18, 19) when the cage rotates. The
single hoop or
eight straight flat bars (14) at cage midpoint allow for mounting roller
supports at sieve
edges and to prevent spillage of unprocessed feed into the effluent tank. The
hoops or flat
bars at midpoint also provide rigidity to the cage by connecting to all
longitudinal structural
members at cage midpoint. More detail is provided with Figures 2A and 2B. The
longitudinal structural members (1,2,3,4,5,6,7,8,) normally are of small
diameter, using
high tensile steel, and provide support for the oleophilic sieves (18,19) on
the cage to
encourage contact between settled oleophilic rods and oleophilic sieve wraps
mainly in the
bottom quadrant of the cage, while minimizing obstruction to oleophilic rods
rolling along
cage bottom quadrant. The central shaft and the two end walls provide most of
the
structural integrity of the cage. For large diameter cages the number of
longitudinal
structural members may be increased, still allowing oleophilic sieve to
project into cage
interior. For example, a four meter diameter cage could have 12 longitudinal
structural
members, still allowing the oleophilic sieve(s) (18, 19) to suitably project
into cage interior.
Each sieve thereby takes on the form of an incomplete polygon with straight
polygon sides
between the longitudinal structural members, with the structural members (1 to
8) forming
the corners of each incomplete polygon, as illustrated in the next Figures.
The polygon of
each sieve wrap is incomplete since each sieve wrap leaves the cage to pass
through a hot
zone and back to the cage.
Figure 2A is a drawing of the cage viewed from inside the cage showing one
oleophilic sieve (18). It shows a central shaft (9) and circumference of end
wall (10). It
shows eight longitudinal structural members (1,2,3,4,5,6,7,8) and shows a hoop
(61) of
metal, which is attached to each end wall (10) and attached over a short
distance from cage
end wall along each longitudinal structural member (1 to 8) to said members.
These hoops
(61) support the oleophilic rods (15) near oleophilic rod ends and prevent
rods from
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misaligning and attempting to leave the cage. Oleophilic rods (15) are
illustrated in Figure
2A by circles, each with a cross inside. Noteworthy is that along cage bottom
the sieve(s)
(18) deflects and conforms to the hoop (61) along cage bottom due to weight of
oleophilic
rods (15).
Figure 2B is similar to Figure 2A except that the hoop of Figure 2A is
replaced by
eight straight flat bars (13) of limited width, welded to the end wall and
welded for a short
distance to the longitudinal structural members (1,2,3,4,5,6,7,8) of the cage.
A single
oleophilic sieve (18) is added to the Figure to show the location and shape of
each
incomplete polygon of sieve along the cage. Figure 2B uses eight flat bars
instead of a
hoop. Each sieve (18) in the Figure hides the metal flat bars (13), except
along the top of
the cage where the wraps leave the cage to move to and from the hot zone above
the cage.
As in Fig. 2A, in Fig. 2B, each sieve (18) forms a polygon with straight sides
between
longitudinal structural members (1 to 8) but aligns with the metal flat bars
(13) in Fig. 2B
which are welded to the end wall inside faces (10a, 11 a) and for a short
distance to the
longitudinal structural members. Noteworthy in Figure 2B is that the
oleophilic rods do not
put pressure on the sieve since the oleophilic rods are supported by the flat
bars (13). Only
near the top of the cage are two flat bars (13) clearly visible, not hidden
behind the sieve
(18). In both Figures, the oleophilic rods can roll along the cage bottom
quadrant of the
rotating cage. Less stress is imposed on the oleophilic in Figure 2B but more
contact is
achieved between oleophilic rods and oleophilic sieve in Figure 2A. Both
methods (Figure
2A and Figure 2B) may be used in the cages of the present invention to keep
oleophilic
rods inside the cage and provide contact between rods and sieve for oleophilic
phase
transfer.
Figure 3 shows the cage immersed in an effluent tank (30) and a hot zone (37)
above and beside the cage (68). The cage also shows a single bench (20) that,
due to
clockwise cage rotation, has collected together all the oleophilic rods (23)
in the cage. As
the cage (68) rotates further and the bench (20) approaches a horizontal
position and
beyond, all the oleophilic rods (23) will in sequence spill from the bench
(20) to settle
through feed inside the cage (68) to collect oleophilic phase from the feed
inside the cage
on the rod (23) surfaces. A typical bench (20) comprises two or three widely
spaced
straight parallel bars between the cage central shaft (9) and one of the
longitudinal
structural members, member (1) in this case. The hot zone (37) in this figure
uses heat
radiators (38) above the sieve (18) entering the hot zone (37) as the bottom
flight, after
passing over a guide roller (33). A heat reflecting surface (39) covered by
insulation (40)
above the heat radiators (38) in the hot zone limits further heating in the
hot zone of
oleophilic sieve surface returning to the cage before passing over guide
roller (34). The
oleophilic phase depleted sieve passing over guide roller (34) may next be pre-
coated with
oleophilic phase supplied by a slip stream (21) of feed controlled by a valve
(22). The long
distance between roller (34) and cage (68) provides time for pre-coating of
the warm,
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oleophilic phase depleted, oleophilic sieve with cold fresh oleophilic phase
from a slip
stream of feed. Pre-coating the sieve surfaces with bitumen reduces the flow
of oleophilic
phase through sieve apertures after these return to the cage along the right
quadrant of the
cage, especially when a curved optional containment baffle (17) along cage
exterior
restricts the flow of feed through the sieve returning to the cage along the
cage right cage
quadrant.
All the feed (24) for separation, except for the slip stream (21), enters
through a
control valve (25) and a feed distributor (26) to fill the cage to a desired
level (27) and
initially also fills the effluent tank to that level, depositing some
oleophilic phase (bitumen
and bitumen coated particulates) to the sieve (18) as it enters the effluent
tank (29). A
tension roller (35) provides tension (45) to the sieve, which enters the hot
zone by passing
over guide roller (33) and returns to the cold cage by passing over guide
roller (34). Warm
oleophilic product (43) leaves the hot zone for collecting through a chute
(44) for further
processing or upgrading. When the hot zone contains flammable gasses, an inert
gas (41) is
introduced into the hot zone to remove flammable gasses from the hot zone
through a stack
(42)
Once the separator is operating, the contents of the effluent in the tank (29
is
dropped to a desired level (28) that is lower than the level (27) of feed
being processed
inside the cage, so as to encourage outflow of effluent from the cage into the
effluent tank.
Thereafter, most of residual oleophilic phase that leaves the cage with
effluent is captured
by the oleophilic sieve before it enters the tank. A control valve (32)
controls the outflow
of effluent (31) from the tank. Normally a computer is used to control the
flow of feed into
the cage by valve (25) and the flow of effluent (30) out of the tank
controlled by a valve
(32) to become the effluent (31) of oleophilic sieve separation. These flow
monitors
control the difference in level (27) inside the cage and level (28) in the
tank. When large
hydrophilic mineral particles are present in the effluent, a conveyor may be
used to remove
these from the tank (29). Alternately, the effluent exit valve may be
controlled to cycle
from fully open to fully closed, under computer control to allow mineral
particles with
effluent to pass through the effluent exit valve (32). Similarly the feed
distributor (26) may
be adapted to accommodate entry of hydrophilic particulates into the cage by
cycling the
feed entry valve (25) from the fully open to the fully closed position, using
suitable valves
for that purpose. Alternately the feed (24) is pre-screened to remove particle
of a given size
before feed enters the cage.
During operation the rotating cage spills all the contained oleophilic rods
from
bench during each cage rotation to collect oleophilic phase from feed inside
the cage as the
rods settle though feed inside the cage. The rods (23), after reaching the
bottom of the cage
roll along the bottom quadrant of the cage to transfer oleophilic phase
collected from the
feed to the sieve upon contact, including the transfer of oleophilic phase
between oleophilic
CA 3089104 2020-07-31
rods for transfer to the sieve. As shown in the Table Fig. 8, it is estimated
that during every
15 minutes of operation the 2 meter diameter, 6 meter long cage, rotating at
10 RPM, spills
460 cubic meters of oleophilic rods inside the cage (during 150 cage
rotations) and, as a
result, captures nearly all the bitumen or oleophilic phase from the feed for
transfer to the
sieve which conveys it into the hot zone (37) to produce warm oleophilic phase
product.
The effluent of separation, when it still contains oleophilic phase transfers
oleophilic phase
to the sieve upon contact whilst the effluent flows into the effluent tank.
Large cages of Table Figure 8 rotate at a slower rate than small cages since
the
oleophilic rods need to settle for a longer distance in the large cages but
spill more
oleophilic rods every 15 minutes because of the larger cage volume.
Circumference surface
speed of all cages is initially set at 1 meter per second to minimize effluent
turbulence in
the tank. This speed may be increased if shorter residence of feed in the cage
is desired, or
may be decreased if longer residence of feed in the cage is desired. During
some pilot plant
tests, only a few minutes of residence time was needed in small diameter cages
to achieve
good product recovery and effluent that contained very little product.
Figure 4A illustrates the cage provided with a curved single shelf (58)
connected
between the cage central shaft (9) and one of the longitudinal structural
members (2). This
shelf (58), in its simplest form consists of two or three spaced bars, each in
the form of a
half circle attached to the central shaft (9) and to the same longitudinal
structural member
(2) which may be increased in diameter as needed for strength. In the Figure
the shelf (58)
has collected all the oleophilic rods in the cage due to cage rotation. Again,
the dashed line,
representing a sieve, hides the bars (13) between the longitudinal structural
members,
which bars support the oleophilic rods (23). Near the top of the cage, where
the sieve (18)
leaves for or returns from the hot zone, are the flat bars (13) clearly
visible
Figure 4B illustrates gradual spilling of oleophilic rods (65) from the curved
bench.
The curved bench (58), instead of being a straight shelf allows for more
gradual rod
spillage inside the cage during cage rotation. A dashed line (64) illustrates
how large a
percentage of the rods (23) on shelf (58) have spilled from the shelf and
settle as settling
rods (65) through feed to collect oleophilic phase from feed inside the
rotating cage after
the cage has rotated one eight of a turn to transfer collected oleophilic
phase from settled
rods to sieve (18).
Figure 5 illustrates the use of four curved short shelves (58) inside the cage
to allow
during each cage rotation gradual spillage of rods inside the cage interior
that contains feed
for separation to collect on their surfaces oleophilic phase from feed inside
the cage. In this
case, the number of oleophilic rods inserted in the cage does not exceed a
volume of rods
that can be contained on the four shelves in total. Each of the four benches
in sequence
then collect its allotted number of oleophilic rods during each single cage
rotation and spill
these in sequence into the feed contained in the rotating cage. As with other
types of shelf
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CA 3089104 2020-07-31
or shelves in the cages of the present invention, the spilled oleophilic rods,
after collecting
oleophilic phase from the feed inside the cage roll along the cage bottom
quadrant to
transfer oleophilic phase between the rods and from the rods to a metal
oleophilic sieve or
to oleophilic sieve rope wraps. Oleophilic phase not captured by the
oleophilic rods is
collected by oleophilic sieve as effluent of processed feed flows into the
effluent tank.
Multiple shelves in a cage tend to extend the time of total rod spillage
inside a cage during
each 360 degrees of revolution of the cage.
Figure 6 illustrates a typical rake with tines (49) and valleys (50) to space
wraps
(51) of oleophilic sieve when wraps instead of aperture conveyor belts are
used. Such a
rake is normally inserted in the groove of every, or alternate longitudinal
structural
members of a cage, with depth of insertion indicated by the dashed line (59).
Valleys
between rake tines may taper to put pressure on sieve wraps for friction
between rakes and
wraps for sustained movement of wraps with cage circumference.
Figure 7 illustrates a longitudinal structural member of the cage in the form
of a
round bar (52) or a half round bar (53 above the dashed line). A rake (48) for
a sieve of
rope wraps, shown inserted in the longitudinal structural member is normally
contained
therein by friction, by an adhesive bond, by silver or brass solder or by spot
welding.
Figure 8 is a table of proposed commercial oleophilic sieve separation cages.
The
table provides structural dimensions, cage sizes and capacities, predictions
of cage
performance and number of rod spills from shelf during 15 minutes of
oleophilic sieve
separation residence time in each cage. The larger the cage, for a given cage
surface speed,
the slower the rotation RPM, and the longer the settling time of rods in a
cage and the
larger the volume of rods spilled from each shelf. The foot note in the table
identifies
yellow jacket pipe as the preferred source for producing oleophilic rods.
Yellow jacket
pipe has a very strong bond between the parent steel pipe and its yellow
plastic cover for
long lasting use as oleophilic rods and is readily available. Threading each
steel pipe end
and putting a threaded pipe cap or threaded or inserting a pipe plug at each
end closes each
yellow jacket pipe to form an oleophilic rod for the present invention.
Oleophilic rod
density is then controlled by the selection of yellow jacket pipe diameter for
Schedule 40
pipe, which is the common type of yellow jacket pipe. Normally the yellow
jacket pipe is
dense enough not to require added weight inside the pipe, but filling each
pipe with some
weight is an option. For Schedule 40 empty yellow jacket pipe the capped pipe
density will
tend to be determined by the pipe outside diameter. As the need arises, yellow
jacket pipe
or tube may yet be produced in schedules 5, 10 and 20 grades to allow the use
of smaller
diameter pipes for a desired empty pipe density at a given pipe diameter,
Fiber glass pipe, sandblasted on the outside to increase adhesion of
oleophilic phase
to its outside surface, is another source for fabricating oleophilic rods. In
that case, the
17
CA 3089104 2020-07-31
fiber glass pipe normally needs inside loading to achieve a desired oleophilic
rod density
for settling through feed inside a rotating cage at a desired rate.
Alternately oleophilic rods that may be used in cages of the present invention
are
capped steel tubes or steel pipes covered with a plastic (PVC, urethane,
polypropylene or
other plastic) pipe slid over the steel pipe or tube OD. Painting an
oleophilic coating on a
steel pipe or tube tends to wear too fast for use in commercial oleophilic
sieve cages unless
applied in a thick abrasion resistant layer.
Figures 9 and 10 provide details that may be used for mounting the cage in an
effluent tank. Figure 9A shows one of the two end walls (66) cut with cut-out
to accept a
bearing and rotary seal plate (Fig. 9B). "Figure 9B enlarged" shows the same
seal plate
and Figure 10 shows side view of the seal plate provided with a rotary seal
(71) at one face
and a flange mount bearing on the other face. During construction a seal
plate, complete
with rotary seal and flange mount bearing is inserted over each projecting
central shaft end,
such that the seal faces inward into the tank near the cage end wall. Then,
the separator
cage, with hot zone and oleophilic sieves attached, is lowered into the tank
and seal plates
are bolted to both tank end walls. Then, motor and gear box(es) are attached
to drive
rotation of the cage. If desired, a heavy shaft mount gear box may be mounted
on the shaft
of the cage external to the tank, with additional gearing and/or belt or
roller chain to drive
slow rotation of the cage to achieve a desired cage surface speed without
creating too much
turbulence in the effluent tank. Other ways of mounting the rotatable cage
inside a
stationary effluent tank may be used without invalidating the present patent.
Figure 11 illustrates prior art of the present inventor for preventing
oleophilic sieve
wraps (18 or 19) from rolling off drum, cage or roller, using two pulleys or
sheaves (73a
and 73b) for each sieve (18 or 19) to redirect a wrap about to roll off the
end of a cage.
Figure 12 is similar to Figure 3 except that the cage rotates counter
clockwise, such
that each oleophilic phase loaded sieve enters the hot zone as the top flight
by passing over
top guide roller (34) to travel under heat generators (38) covered with a heat
reflector (39)
mounted along the top of the hot zone enclosure (37). Warm product (46)
leaving sieve top
flight(s) flows over enclosed insulation (40) and thereafter sideways out of
the hot zone
ahead of the sieve tension roller (35) to be collected in the product exit
(44) for leaving the
hot zone as product (43) of separation. As a result, each bottom flight in the
hot zone of
Figure 12 is colder than each top flight in the hot zone of Figure 3, which
enhances
subsequent adhesion of oleophilic phase to sieve surfaces leaving the hot zone
for the cold
cage. An optional slip stream (21) of feed with control valve (22) impacts the
sieve
surfaces leaving the hot zone returning to the cage. Similar to Figure 3, an
optional baffle
(17) along sieve (18) returning to the cage prepares the returning sieve for
optimum
collection of oleophilic phase from effluent leaving the cage for the effluent
tank, slowing
by baffle (17) the flow between cage (68) and tank (29). Since the cage (68)
of Figure 12
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rotates counter-clockwise, the oleophilic rods collect to the right of the
bench (20) during
cage rotation. Noteworthy is that in Figure 3 the sieve hotter wraps returning
from the hot
zone to the cage have a longer distance of travel for cooling than the cooler
wraps in Figure
12. Each of the two separators (Fig 3 and Fig 12) may be adapted for use with
a specific
feed.
THE HOT ZONE
Various types of hot zones were described in previous patents of the inventor,
which used internally heated drums and guided oleophilic sieves differently
than in the hot
zones shown in Figures 3 and 12 of the present patent. Many such prior types
of hot zones
are suitable for use with the present invention. In Figures 3 and 12 the hot
zones use non
contacting heating elements to warm the oleophilic sieve and its adhering
product by
radiant heat. This new design allows for more effective release of oleophilic
product from
sieve surfaces, with less wear and tear on oleophilic sieve(s). Compared with
previous
patents, for example Canadian 2,999,466 or US 10,399,008, the present
invention allows
more sieve coverage of cage circumference, using a shorter distance of
uncovered cage for
feed to enter the cage. More sieve coverage on a cage allows for higher feed
levels inside
the cage for feed processing. Unlike the above quoted patents, having an
effluent tank,
with effluent of oleophilic separation surrounding most of the cage, improves
efficiency of
the separation process, as compared with a cage not surrounded by effluent and
also allows
for simpler cage construction. The cage of the present invention, being
immersed in
effluent of separation, provides buoyancy and slows the outflow of effluent
from the cage
for more efficient feed separation. Unlike the above quoted patents, the use
of bench or
benches in the present invention to elevate oleophilic rods for settling
through feed, for
subsequent rolling along cage bottom quadrant to transfer oleophilic phase
between rods
and from rods to sieve, also provides for major improvements in cage
separation
performance.
SHORT CAGES
Oleophilic rods in short cages do not work well when the inside cage length is
shorter than the cage end wall diameter. Oleophilic rods may misalign in such
short
rotating cages. Only round balls or other types of short bitumen agglomerating
instruments
work successfully in short drums or cages. Weighted golf balls worked well in
pilot plant
studies using short drums. For feed separation tests in such drums, each golf
ball was
provided with a drilled central hole and tapped with a thread for inserting
added weight to
each ball and thereby achieve a desired ball density inside the cage or
perforated drum to
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CA 3089104 2020-07-31
collect oleophilic phase for the oleophilic sieve. A short piece of threaded
steel rod was
screwed into each golf ball to increase its density to a desired amount. Each
threaded rod
was slightly shorter than the golf ball diameter. Steel threaded rods of
various diameters
were used to achieve a desired mix of modified golf ball densities. This
worked well to
collect oleophilic phase from feed to oleophilic sieve surfaces in initial
pilot plant studies.
Similar ball densities may be achieved by casting balls from plastic, using
hollow metal
balls or metal particulates to add weight to balls in the casting process.
PASSAGE OF HYDROPHILIC PARTICULATES
When oleophilic sieves of adjacent wraps of endless rope are used to separate
a feed
that contains hydrophilic gravel, and all sieve wrap surfaces, are spaced by
rake 0.5
centimeter apart, fine gravel not much larger than 1.0 centimeter in maximum
dimension
can pass out of the cage by locally spreading two adjacent sieve wraps to
allow for such
passage. As a result of locally spreading space between two adjacent wraps,
the space
between each spread wrap and its non-spread adjacent neighbour wrap is locally
narrowed.
The same applies for sieve wraps that are spaced by rake 1.5 centimeters apart
to allow fine
gravel not exceeding 3 centimeters in maximum dimension to pass out of the
cage by
locally spreading adjacent wraps, etc. Consequently, oleophilic sieve aperture
size or wrap
spacing is a sieve and cage design parameter that may vary for each feed to be
processed by
oleophilic sieve separation. Compared with prior art of the inventor, such as
is detailed, for
example, in US granted patent 10,399,008, B2 and Canadian pending patent
2.999,466 that
did not use an effluent tank, the fact that the cage of the present invention
is immersed in
effluent allows for the use of oleophilic sieves of larger aperture size or
for sieve wraps that
can spread to allow larger size hydrophilic surface gravel to flow into the
effluent tank
while yet achieving high oleophilic phase recovery from the feed by the
oleophilic sieve(s).
As soon as an oversize article has passed out of the cage by spreading
adjacent wraps the
wraps snap back to re-establish parallel adjacent wraps. This is not possible
with metal
belts that have a fixed opening size.
TEMPERATURE
Process temperature inside the cage is describes as cold and in the hot zone
is
described as warm or hot. It means that oleophilic sieve separation is a two
temperature
process with cage temperature influenced by the viscosity of oleophilic phase
inside the
cage and inside the hot zone for optimum separation efficiency. For example,
when
successfully processing tailings pond fluid fine tailings (FFT) by oleophilic
sieve
separation, the available feed year round temperature often was close to 12
degrees
centigrade due to the depth of the ponds in spite of a thin ice covering at
the top in winter
time. The temperature in the hot zone was about 80 degrees C. for effective
flow of
oleophilic phase product from the sieve. For processing mined oil sand slurry
the feed
CA 3089104 2020-07-31
temperature during separation averaged close to 35 degrees centigrade. When
processing
FFT that contained centrifuge naphtha, oleophilic sieve separation of FFT
supplied by
highway tankers improved in winter when feed temperature could be dropped
close to 2 or
4 degrees centigrade above freezing to make the naphtha diluted bitumen adhere
well in a
thick layer to oleophilic rods or balls and oleophilic sieves. Naphtha diluted
FFT became a
thing of the past after naphtha recovery at centrifuge plants improved.
SUITABLE OLEOPHILIC SIEVES
When the oleophilic sieve is comprised of wraps of endless rope, the rope may
be of
twisted plastic strands, twisted carbon fiber strands or twisted metal
strands, including steel
wire strands when these have permanent oleophilic surfaces or when voids in
the cable
surface due to strand wrap are oleophilic. Braided ropes may be used but are
not as suitable
as twisted rope, since splices of braided ropes are larger in diameter than
splices of twisted
rope. When braided rope is used, the rakes that space the wraps of endless
rope normally
must be made to accept spliced braided rope. Twisted steel strand and plastic
strand rope
will tend to collect bitumen between its outside strands and on top of the
strands to make it
suitable to form oleophilic sieves of endless rope for use in the present
invention.
Alternately, each external steel strand may be made to have an oleophilic
surface. This
oleophilic surface on each strand may wear off during operation but most will
stay on the
strand surfaces that do not contact abrading surfaces. Such strand surfaces
also work well to
collect oleophilic phase.
As many oil sand workers have discovered, pushing a steel shovel blade in room
temperature oilsand ore will result in a bitumen coating on the shovel metal
surface.
Similar adhesion of bitumen for metal surface cable tends to occur with metal
conveyor
belts and with steel cable, especially when some bitumen already is present in
the valleys
between strands of twisted cable.
Conventional open face metal conveyor belts, such as hinge oven belts or belts
made with interlocking steel wire coils to form a conveyor may be used as
oleophilic
sieves. However, twisted endless plastic or metal rope sieves usually are
preferred for
optimum phase separation, since sieve wraps can be spaced closely to form a
sieve of long
narrow apertures for efficient collection of dispersed oleophilic phase
leaving the cage for
the effluent tank while allowing hydrophilic mineral particles to spread the
wraps on their
way to the effluent tank to prevent hydrophilic particulates from filling the
cage and
reducing separation efficiency. Such spreading is not possible with metal
conveyer belts of
fixed opening size.
FIELD ASSEMBLY
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The cages and tanks detailed in Table Fig. 8 are very large in size to meet
commercial equipment demand and will present some difficulty for highway or
railway
transport. For that reason the separator parts and pieces may be shop
fabricated separately
and assembled in the field. For example, the longitudinal structural members
may be shop
fabricated, cut to desired length, grooved, provided by rake, threaded for
nuts on outside
ends to accept nuts or drilled and tapped to accept bolts to mount to the cage
end walls, or
are welded on site to the end walls.
Similarly, the central shaft may be provided with keyway at both ends to
accept a
flange similar to a pipe flange but provided with a keyway to fit on the
shaft, with both
holes in the flange to be bolted to the cage end plates in the field. A
similar break down of
tank parts fabricated in a shop may be used for assembly in the field for
accepting the cage.
The 2 meter diameter cage and its effluent tank likely is the smallest useful
commercial separator. It will likely be fabricated, assembled and offered for
look/see
demonstration purposes and time limited use by several oil sand operators or
mineral mine
owners.
PROCESSING FEED MIXTURES
Oleophilic sieve separation lends itself to separating mixtures of more than
one
feed. For example, screened mined oil sand, from which gravel has been
removed, may be
mixed for separation with water effluent of prior oleophilic sieve oil sand
extraction, which
has settled for months or even weeks to allow most mineral particulates to
settle. Such use
of prior used process water will reduce fresh water demand in a major way.
Mined, screened to remove hydrophilic oversize, oil sand may be mixed with
existing old tailings pond fluid fine tailings to recover both fresh bitumen
and old bitumen,
reducing in a major way the need for fresh water and increasing total bitumen
production.
Mined, screened to remove oversize, oil sand may be mixed with pH neutral (pH
between 6.8 and 7.2) settled process water of recent oil sand extractions
after settling for a
few weeks or months to prepare a feed for oleophilic sieve separation. This
also reduces
fresh water demand for separations.
Mine minerals may be separated using a mix of mine tailings pond water and
fresh
water using more pond water than fresh water for the mix when caustic is not
used in the
separations. In this case viscous oil is added to the feed to coat oleophilic
mineral particles
=
for cold adhesion the sieve surfaces.
Oleophilic sieve separation is tolerant of feed pH and hydrophilic minerals
content
of small size. Using neutral pH feed, where possible, simplifies separation
and can reduce
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separation costs by allowing major reuse of process water after a period of
minerals
settling.
CLAIMS
What is claimed is:
1. An oleophilic sieve separation apparatus immersed in a cold effluent of
separation
tank suitable for separating: 1. mined oil sand slurries, 2. oil sand tailings
pond fluid
fine tailings, or 3. a mix of mined oil sand and tailings pond fluid fine
tailings, in
each case yielding a relatively cold water and hydrophilic minerals effluent
and a
relatively warm bitumen phase product, wherein
a. the immersed in tank apparatus comprises a rotatable metal cage of two
spaced disc type cage end walls, a central shaft projecting outward from
both cage end walls and at least eight longitudinal structural members
between end walls spaced equidistantly near cage wall circumference,
b. distance between cage end walls inside faces is greater than cage end wall
diameter,
c. the cage central shaft is mounted in bearings supported at both ends by the
tank and is provided with shaft seals to prevent liquid spillage out of the
tank,
d. at least one central shaft end of the cage extends well beyond end wall
of the
tank to allow slow driven rotation of the cage by gear box and motor,
e. at least one endless oleophilic sieve comprising multiple wraps of
oleophilic
surface endless rope surrounds most of the cage circumference and is
prevented from rolling off the cage by two pulleys which redirect a wrap
about to roll off the end of the cage to the beginning of the cage,
f. each rope wrap of oleophilic sieve is supported on the longitudinal
structural
members to form an incomplete polygon with corners at the longitudinal
structural members and with sides that project into cage interior,
g. during cage rotation the incomplete polygon rope wraps leave the cage to
pass through a hot zone above and/or beside the tank to thereafter cool and
return to the cage,
h. rakes on at least alternate longitudinal structural members equally space
the
oleophilic wraps and provide friction for movement to the wraps due to cage
rotation,
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