U.S. patent application number 11/948816 was filed with the patent office on 2009-06-04 for endless cable system and associated methods.
Invention is credited to Jan Kruyer.
Application Number | 20090139905 11/948816 |
Document ID | / |
Family ID | 40673771 |
Filed Date | 2009-06-04 |
United States Patent
Application |
20090139905 |
Kind Code |
A1 |
Kruyer; Jan |
June 4, 2009 |
ENDLESS CABLE SYSTEM AND ASSOCIATED METHODS
Abstract
A separation apparatus can include at least one endless cable.
The cable can be wrapped around at least two revolvable cylindrical
members a plurality of times. The wraps can form gaps between
adjacent windings, which, along with the endless cable, can be used
to facilitate separations processing. Additionally, the separation
apparatus can optionally include a repositioning guide for each
multiple wrap endless cable that can guide the endless cable in an
endless route and prevent the cable from rolling off or falling off
of the cylindrical members. Separation can be accomplished by
oleophilic adherence to the cable, electrostatic adherence to the
cable, and/or physical retention on the cable. This endless cable
system can be particularly useful for separation of oil sand
slurries, mass transfer operations, and physical separations.
Inventors: |
Kruyer; Jan; (Alberta,
CA) |
Correspondence
Address: |
THORPE NORTH & WESTERN, LLP.
P.O. Box 1219
SANDY
UT
84091-1219
US
|
Family ID: |
40673771 |
Appl. No.: |
11/948816 |
Filed: |
November 30, 2007 |
Current U.S.
Class: |
208/390 |
Current CPC
Class: |
C10G 1/047 20130101;
B01D 17/041 20130101; B01D 17/0202 20130101 |
Class at
Publication: |
208/390 |
International
Class: |
C10G 1/04 20060101
C10G001/04 |
Claims
1. A separation apparatus, comprising: a) at least one endless
cable wrapped a plurality of times around at least two revolvable
cylindrical members to form a first wrap, a plurality of subsequent
wraps, and a final wrap such that the cable is wrapped from one
cylindrical member to another and contacts each of the at least two
cylindrical members a plurality of times to form gaps between
adjacent windings.
2. The separation apparatus of claim 1, further comprising a cable
stripping device operatively associated with the at least one
endless cable, configured to remove material from the endless
cable.
3. The separation apparatus of claim 1, wherein the endless cable
is oleophilic.
4. The separation apparatus of claim 3, further comprising an
agglomerator drum having openings oriented in fluid communication
with the endless cable to allow passage of fluid from an interior
to an exterior of the agglomerator drum and including oleophilic
members for adhering oleophilic material.
5. The separation apparatus of claim 1, further comprising a gas
inlet oriented to direct a gas across a flight of the at least one
endless cable, and a first liquid reservoir wherein the at least
two revolvable cylindrical members includes a feed roller and an
upper roller, said feed roller being oriented within the first
liquid reservoir sufficient to contact liquid therein and said
upper roller being remote from the first liquid reservoir.
6. The separation apparatus of claim 5, further comprising at least
one additional liquid reservoir each including a corresponding
additional feed roller oriented within a corresponding additional
liquid reservoir.
7. The separation apparatus of claim 1, wherein the at least one
endless cable includes a first endless cable configured to be
charged electrically with a high potential direct or alternating
current of a first polarity or phase.
8. The separation apparatus of claim 7, wherein the first endless
cable and the at least two revolvable cylindrical members are
oriented within a containment vessel, said containment vessel being
electrically charged with a high potential direct or alternating
current of a second polarity or phase opposite the first polarity
or phase.
9. The separation apparatus of claim 7, comprising a second endless
cable wrapped a plurality of times around the at least two
cylindrical members such that the second endless cable is wrapped
from one cylindrical member to another and contacts each of the at
least two cylindrical members a plurality of times to form gaps
between adjacent windings of the second endless cable and wherein
said the wraps of said second endless cable are alternating with
and are located within the gaps of the first endless cable, wherein
the wraps of the second endless cable are configured to be charged
electrically with a high potential direct or alternating voltage of
opposing polarity or of opposing phase to the wraps of the first
endless cable.
10. The separation apparatus of claim 1, wherein the at least two
revolvable cylindrical members are oriented to form an upper flight
and a lower flight of the at least one endless cable, the upper
flight being within 45.degree. of horizontal and wherein the gaps
between adjacent windings are configured to be sufficiently narrow
to allow passage of liquid therethrough and retention and
conveyance of particulate solids thereon having a predetermined
particle size and further comprising a liquid collection vessel
oriented below the first flight and configured to receive the
liquid.
11. The separation apparatus of claim 1, wherein the gaps between
adjacent windings are spaced apart a distance sufficient to size
particulate material into at least two separate size ranges and
further comprising at least two particulate collection members
oriented to collect each the at least two separate size ranges.
12. The separation apparatus of claim 11, wherein the adjacent
windings are non-parallel sufficient to form gradually expanding
distances between the adjacent windings from a narrowly spaced end
to a widely spaced end of a top flight of the at least one endless
cable, wherein a particulate feed inlet is oriented to distribute
particulate material over more narrowly spaced portions of the top
flight.
13. The separation apparatus of claim 1, wherein the at least two
revolvable cylindrical members are oriented to form an upper flight
and a lower flight of the at least one endless cable and further
comprising: a) a secondary separation apparatus including a second
endless cable wrapped a plurality of times around at least two
secondary revolvable cylindrical members to form a plurality of
secondary wraps to form secondary gaps between adjacent windings,
said secondary separation apparatus having a secondary upper flight
being oriented at an angle with respect to the upper flight and
being substantially coplanar therewith; and b) a plurality of
directing pins oriented within junction spaces formed between the
gaps and the secondary gaps, said directing pins being elevatable
from a lower position to an upper directing position said lower
position placing an upper end of the respective directing pin below
the secondary upper flight, said plurality of directing pins being
selectively elevatable to direct an object on the upper flight to
move along the secondary upper flight.
14. A method of separating oleophilic material from hydrophilic
material in a flowable material, comprising: passing the flowable
material through at least one continuously moving endless cable,
wherein the hydrophilic material passes through gaps between
adjacent wrappings in said at least one continuously moving endless
cable, said at least one continuously moving endless cable having
been wrapped a plurality of times around at least two cylindrical
members, such that at least a portion of the oleophilic material is
retained on or by the endless cable; and removing at least a
portion of the oleophilic material from the endless cable.
15. The method of claim 14, wherein the step of removing at least a
portion of the oleophilic material from the at least one endless
cable includes passing the endless cable through a means for
removing oleophilic material.
16. The method of claim 14, further comprising passing the flowable
material through an agglomerator sufficient to increase recovery
yields of the second component.
17. The method of claim 14, further comprising: collecting a
bitumen rich sludge from a tailings pond, said tailings pond having
a bitumen rich layer between a top water rich layer and a bottom
silt and sand layer; and directing the bitumen rich sludge to the
at least one continuously moving endless cable, wherein the bitumen
rich sludge forms at least a portion of the flowable material.
18. A multi-phase method of contacting components of a gaseous
flowable material, comprising: passing the gaseous flowable
material through at least one continuously moving endless cable,
wherein a first portion of the flowable material passes through
gaps between adjacent wrappings in said at least one continuously
moving endless cable, said at least one continuously moving endless
cable having been wrapped a plurality of times around at least two
cylindrical members, such that a second portion of the flowable
material contacts the endless cable.
19. The method of claim 18, further comprising the steps of:
contacting a portion of the endless cable with a liquid sufficient
for a portion thereof to coat the endless cable, wherein the
endless cable is oriented to transport the coated liquid upwards to
a contacting region such that the second portion of the flowable
material contacts the coated liquid in the contacting region.
20. The method of claim 19, wherein the step of contacting involves
at least one of crystallization, evaporation, chemical reaction,
humidifying, drying, and gas cleaning.
21. The method of claim 18, further comprising applying a high
potential voltage AC or DC to the at least one endless cable while
the flowable material passes through the gaps and particulate and
droplet material adheres to the wraps of the at least one endless
cable for subsequent removal in the presence of an additional
electrode charged with DC or AC of opposite polarity or opposite
phase than the endless cable.
22. The method of claim 21, further comprising a second
continuously moving endless cable in which the wraps of the second
endless cable are interlaced with the wraps of first endless cable,
and wherein the wrappings create gaps through which material can
flow, wherein the wraps of the second endless cable have opposite
electrical charges or opposite electrical phase from the wraps of
the first endless cable and wherein particulate and droplet
material adheres to the wraps of said endless cables for subsequent
removal.
23. The method of claim 18, wherein the at least one endless cable
is configured to charge passing particles for subsequent
electrostatic separation.
24. A method of physically separating components of a flowable
material containing particulates, comprising: passing the flowable
material through at least one continuously moving endless cable
which is oriented and configured to form an upper flight and a
lower flight allowing at least a portion of the particulates to be
retained on or by the endless cable, wherein a first component of
the flowable material passes through gaps between adjacent
wrappings in said at least one continuously moving endless cable,
said at least one continuously moving endless cable having been
wrapped a plurality of times around at least two cylindrical
members, such that a second component of the flowable material is
retained on or by the endless cable; and removing at least a
portion of the second component from the endless cable.
25. The method of claim 24, wherein said upper flight is within
45.degree. of horizontal, and further comprising depositing a first
coarse slurry onto the upper flight such that at least a portion of
solid particulates are retained on the upper flight while at least
a portion of liquids pass through the upper flight and separately
collecting the portion of liquids and the portion of solid
particulates.
26. The method of claim 24, wherein the flowable material is a
substantially dry particulate having a non-uniform particle size
range, and wherein the method further comprises depositing the
flowable material onto an upper flight of the endless cable such
that a first size portion of the dry particulate passes through the
upper flight while a second size portion of the dry particulate is
retained on the upper flight and separately collecting each of the
first size portion and the second size portion.
27. The method of claim 24, wherein the flowable material is a wet
slurry of a particulate and fluid, wherein the particulate has a
non-uniform particle size range, and wherein the method further
comprises depositing the wet slurry onto an upper flight of the
endless cable such that a first size portion of the particulate
passes through the upper flight while a second size portion of the
particulate is retained on the upper flight and separately
collecting each of the first size portion and the second size
portion.
Description
RELATED APPLICATIONS
[0001] This application is related to U.S. patent application Ser.
Nos. 11/939,978 entitled "Sinusoidal Mixing and Shearing Apparatus
and Associated Methods," filed Nov. 14, 2007 (hereinafter referred
to as "Sinusoidal Mixing Application") and 11/940,099 entitled
"Hydrocyclone and Associated Methods," filed Nov. 14, 2007
(hereinafter referred to as "Hydrocyclone Application"), and
11/unassigned entitled "Isoelectric Separation of Oil Sands" filed
concurrently herewith (hereinafter referred to as "Isoelectric
Application"), which are each incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to devices and methods for
separating materials. Accordingly, the present invention involves
the fields of materials science, chemistry, and chemical
engineering.
BACKGROUND OF THE INVENTION
[0003] According to some estimates, oil sands, also known as tar
sands or bituminous sands, may represent up to two-thirds of the
world's petroleum. Oil sands resources are relatively untapped.
Perhaps the largest reason for this is the difficulty of extracting
bitumen from the sands. Mineable oil sand is found as an ore in the
Fort McMurray region of Alberta, Canada, and elsewhere. This oil
sand includes sand grains having viscous bitumen trapped between
the grains. The bitumen can be liberated from the sand grains by
slurrying the as-mined oil sand in water so that the bitumen flecks
move into the aqueous phase for separation. For the past 40 years,
bitumen in McMurray oil sand has been commercially recovered using
the original Clark Hot Water Extraction process, along with a
number of improvements. Karl Clark invented the original process at
the University of Alberta and at the Alberta Research Council
around 1930 and improved it for over 30 years before it was
commercialized.
[0004] In general terms, the conventional hot water process
involves mining oil sands by bucket wheel excavators or by
draglines at a remote mine site. The mined oil sands are then
conveyed, via conveyor belts, to a centrally located bitumen
extraction plant. In some cases, the conveyance can be as long as
several kilometers. Once at the bitumen extraction plant, the
conveyed oil sands are conditioned. The conditioning process
includes placing the oil sands in a conditioning tumbler along with
steam, water, and caustic soda in an effort to disengage bitumen
from the sand grains of the mined oil sands. Further, conditioning
is intended to remove oversize material for later disposal.
Conditioning forms a hot, aerated slurry for subsequent separation.
The slurry can be diluted for additional processing, using hot
water. The diluted slurry is then pumped into a primary separation
vessel (PSV). The diluted hot slurry is then separated by flotation
in the PSV. Separation produces three components: an aerated
bitumen froth which rises to the top of the PSV; primary tailings,
including water, sand, silt, and some residual bitumen, which
settles to the bottom of the PSV; and a middlings stream of water,
suspended clay, and suspended bitumen. The bitumen froth can be
skimmed off as the primary bitumen product. The middlings stream
can be pumped from the middle of the PSV to sub-aeration flotation
cells to recover additional aerated bitumen froth, known as a
secondary bitumen product. The primary tailings from the PSV, along
with secondary tailings product from flotation cells are pumped to
a tailings pond, usually adjacent to the extraction plant, for
impounding. The tailings sand can be used to build dykes around the
pond and to allow silt, clay, and residual bitumen to settle for a
decade or more, thus forming non-compacting sludge layers at the
bottom of the pond. Clarified water eventually rises to the top for
reuse in the process.
[0005] The bitumen froth is treated to remove air. The deaerated
bitumen froth is then diluted with naptha and centrifuged to
produce a bitumen product suitable for upgrading. Centrifuging also
creates centrifugal tailings that contain solids, water, residual
bitumen, and naptha, which can be disposed of in the tailings
ponds.
[0006] More than 40 years of research and many millions of dollars
have been devoted to developing and improving the Clark process by
several commercial oil sands operators, and by the Alberta
government. Research has largely been focused on improving the
process and overcoming some of the major pitfalls associated with
the Clark process. Some of the major pitfalls are: [0007] 1. Major
bitumen losses from the conditioning tumbler, from the PSV and from
the subaeration cells. [0008] 2. Reaction of hot caustic soda with
mined oil sands result in the formation of naphthenic acid
detergents, which are extremely toxic to marine and animal life,
and require strict and costly isolation of the tailings ponds from
the environment for at least many decades. [0009] 3. Huge energy
losses due to the need to heat massive amounts of mined oil sands
and massive amounts of water to achieve the required separation,
which energy is then discarded to the ponds. [0010] 4. Loss of
massive amounts of water taken from water sources, such as the
Athabasca river, for the extraction process and permanently
impounded into the tailings ponds that can not be returned to the
water sources on account of its toxicity. For example, to produce
one barrel of oil requires over 2 barrels of water from the
Athabasca River. [0011] 5. The cost of constructing and maintaining
a large separation plant. [0012] 6. The cost of transporting mined
oil sands from a remote mining location to a large central
extraction plant by means of conveyors. Additionally, the conveyors
can be problematic. [0013] 7. The cost of dilution centrifuging.
[0014] 8. The cost of naphtha recovery. [0015] 9. The cost of
maintaining and isolating huge tailings ponds. [0016] 10. The cost
of preventing leakage of toxic liquids from the tailings ponds.
[0017] 11. The cost of government fines when environmental laws are
breached. [0018] 12. The eventual cost of remediation of mined out
oil sands leases and returning these to the environment in a manner
acceptable to both the Alberta and the Canadian government. [0019]
13. The environmental impact of the tailings ponds. Some major
improvements have been made that included lowering the separation
temperature in the tumbler, the PSV, and the flotation cells. This
reduced the energy costs to a degree but may also require the use
of larger tumblers and the addition of more air to enhance bitumen
flotation. Another improvement eliminated the use of bucket wheel
excavators, draglines and conveyor belts to replace these with
large shovels and huge earth moving trucks, and then later to
replace some of these trucks with a slurry pipeline to reduce the
cost of transporting the ore from the mine site to the separation
plant. Slurry pipelines eliminate the need for conditioning
tumblers but require the use of oil sand crushers to prevent pipe
blockage and require cyclo-feeders to aerate the oil sand slurry as
it enters the slurry pipeline, and may also require costly
compressed air injection into the pipeline. Other improvements
included tailings oil recovery units to scavenge additional bitumen
from the tailings, and naptha recovery units for processing the
centrifugal tailings before these enter the tailings ponds.
[0020] More recent research is concentrating on reducing the
separation temperature of the Clark process even further and on
adding gypsum or flocculants to the sludge of the tailings ponds to
compact the fines and release additional water. However, adding
gypsum hardens the water and this can require softening of the
water before it can be recycled to the extraction plant. Most of
these improvements have served to increase the amount of bitumen
recovered and reduce the amount of energy required, but have
increased the complexity and size of the commercial oil sands
plants.
[0021] One particular problem that has vexed commercial mined oil
sands plants is the problem of fine tailings disposal. In the
current commercial process, mined oil sands are mixed and stirred
with hot water, air, and caustic soda to form a slurry that is
subsequently diluted with cooler water and separated in large
separation vessels. In these vessels, air bubbles attach to bitumen
droplets of the diluted slurry and cause bitumen product to float
to the top for removal as froth. Caustic soda serves to disperse
the fines to reduce the viscosity of the diluted slurry and allows
the aerated bitumen droplets to travel to the top of the separation
vessels fast enough to achieve satisfactory bitumen recovery in a
reasonable amount of time. Caustic soda serves to increase the pH
of the slurry and thereby imparts electric charges to the fines,
especially to the clay particles, to repel and disperse these
particles and thereby reduce the viscosity of the diluted slurry.
Without caustic soda, for most oil sands the diluted slurry would
be too viscous for effective bitumen recovery. It can be shown from
theory or in the laboratory that for an average oil sand, it takes
five to ten times as long to recover the same amount of bitumen if
no caustic soda is added to the slurry. Such a long residence time
would make commercial oil sands extraction much more expensive and
impractical.
[0022] While caustic soda is beneficial as a viscosity breaker in
the separation vessels for floating off bitumen, it is
environmentally very detrimental. At the high water temperatures
used during slurry production it reacts with naphthenic acids in
the oil sands to produce detergents that are highly toxic. Not only
are the tailings toxic, but also the tailings fines will not
generally settle. Tailings ponds with a circumference as large as
20 kilometers are required at each large mined oil sands plant to
contain the fine tailings. Coarse sand tailings are used to build
huge and complex dyke structures around these ponds.
[0023] Due to the prior addition of caustic soda, the surfaces of
the fine tailings particles are electrically charged, which in the
ponds, causes the formation of very thick layers of microscopic
card house structures that compact extremely slowly and take
decades or centuries to dewater. Many millions of dollars per year
have been and are being spent in an effort to maintain the tailings
ponds and to find effective ways to dewater these tailings.
Improved mined oil sands processes must be commercialized to
overcome the environmental problems of the current plants. One such
alternate method of oil sands extraction is the Kruyer Oleophilic
Sieve process invented in 1975.
[0024] Like the Clark Hot Water process, the Kruyer Oleophilic
Sieve process originated at the Alberta Research Council and a
number of Canadian and U.S. patents were granted to Kruyer as he
privately developed the process for over 30 years. The first
Canadian patent of the Kruyer process was assigned to the Alberta
Research Council and, and all subsequent patents remain the
property of Kruyer. Unlike the Clark process, which relies on
flotation of bitumen froth, the Kruyer process uses a revolving
apertured oleophilic wall (trade marked as the Oleophilic Sieve)
and passes the oil sand slurry to the wall to allow hydrophilic
solids and water to pass through the wall apertures whilst
capturing bitumen and associated oleophilic solids by adherence to
the surfaces of the revolving oleophilic wall.
[0025] Along the revolving apertured oleophilic wall, there are one
or more separation zones to remove hydrophilic solids and water and
one or more recovery zones where the recovered bitumen and
oleophilic solids are removed from the wall. This product is not an
aerated froth but a viscous liquid bitumen.
[0026] A bitumen-agglomerating step normally is required to
increase the bitumen particle size before the slurry passes to the
apertured oleophilic wall for separation. Attention is drawn to the
fact that in the Hot Water Extraction process the term
"conditioning" is used to describe a process wherein oil sands are
gently mixed with controlled amounts water in such a manner as to
entrain air in the slurry to eventually create a bitumen froth
product from the separation. The Oleophilic Sieve process also
produces a slurry when processing mined oil sands but does not
"condition" it. Air is not required, nor desired, in the Oleophilic
Sieve process. As a result, the slurry produced for the Oleophilic
Sieve, as well as the separation products, are different from those
associated with the conventional Hot Water Extraction process. The
Kruyer process was tested extensively and successfully implemented
in a pilot plant with high grade mined oil sands (12 wt % bitumen),
medium grade mined oil sands (10 wt % bitumen), low grade oil sands
(6 wt % bitumen) and with sludge from commercial oil sands tailings
ponds (down to 2% wt % bitumen), the latter at separation
temperatures as low as 5.degree. C. A large number of patents are
on file for the Kruyer process in the Canadian and U.S. Patent
Offices. These patents include: CA 2,033,742; CA 2,033,217; CA
1,334,584; CA 1,331,359; CA 1,144,498 and related U.S. Pat. No.
4,405,446; CA 1,141,319; CA 1,141,318; CA 1,132,473 and related
U.S. Pat. No. 4,224,138; CA 1,288,058; CA 1,280,075; CA 1,269,064;
CA 1,243,984 and related U.S. Pat. No. 4,511,461; CA 1,241,297; CA
1,167,792 and related U.S. Pat. No. 4,406,793; CA 1,162,899; CA
1,129,363 and related U.S. Pat. No. 4,236,995; and CA
1,085,760.
[0027] While in a pilot plant, the Kruyer process has yielded
higher bitumen recoveries, used lower separation temperatures, was
more energy efficient, required less water, did not produce toxic
tailings, used smaller equipment, and was more movable than the
Clark process. There were a number of drawbacks, though, to the
Kruyer process.
[0028] One drawback to the Kruyer process is related to the art of
scaling up. Scaling up a process from the pilot plant stage to a
full size commercial plant normally uncovers certain engineering
deficiencies of scale such as those identified below.
[0029] Commercial size apertured drums that may be used as
revolving apertured oleophlilic walls require very thick perforated
steel walls to maintain structural integrity. Such thick walls
increase retention of solids by the bitumen and may degrade the
resulting bitumen product. Alternately, apertured mesh belts may be
used as revolving apertured oleophilic walls. These have worked
well in the pilot plant but after much use, have tended to unravel
and fall apart. This problem will likely be exacerbated in a
commercial plant running day and night. Rugged industrial conveyor
belts are available. These are made from pre-punched serpentine
strips of flat metal and then joined into a multitude of hinges by
cross rods to form a rugged industrial conveyor belt. Other
industrial metal conveyor belts are made from flattened coils of
wire and then joined into a multitude of hinges by cross rods to
form the belts. Both types of metal belts were tested and have
stood up well in a pilot plant. However, it was difficult and
energy intensive to remove most of the bitumen product in the
recovery zone from the surfaces of the belts before these revolved
back to the separation zone.
[0030] Bitumen agglomerating drums using oleophilic free bodies, in
the form of oleophilic balls that tumbled inside these drums worked
very well in the pilot plant. However commercial size agglomerators
using tumbling free bodies may require much energy and massive drum
structures to contain a revolving bed of freely moving heavy
oleophilic balls with adhering viscous cold bitumen to achieve the
desired agglomeration of dispersed bitumen particles.
SUMMARY OF THE INVENTION
[0031] Accordingly, the present invention relates to apparatuses
and methods for separations. Although the systems and methods have
wide-spread application, in a specific embodiment, the separation
mechanism can be based on the oleophilic and non-oleophilic nature
of components of a flowable material.
[0032] The separation apparatus can include at least one endless
cable. The cable can be wrapped multiple times around at least two
revolvable cylindrical members. The wrapping of the cable can form
gaps between adjacent windings that, along with the endless cable,
can facilitate separation processes.
[0033] In one aspect of the present invention, the at least one
endless cable includes a first multiple wrap endless cable wherein
a first wrap, a plurality of subsequent wraps and a final wrap are
formed by wraps of the first endless cable. In such embodiments,
the endless cable passes over each of the cylindrical members a
plurality of times.
[0034] Alternatively, the at least one endless cable can be formed
of a plurality of single wrap cable loops such that each of the
first wrap, subsequent wraps, and final wrap are formed by a
corresponding single wrap cable loop. Such single wrap cable loops
can be composed of the same materials as the multiple wrap endless
cables where the single wrap cable loops differ from multiple wrap
endless cables primarily in length. Single wrap cable loops are
configured to rotate in a single loop, i.e. directly from one
cylindrical member to another, or possibly between three or more
cylindrical members in a single connected pass. The single wrap
loops do not contact each of the cylindrical members a plurality of
times, but rather follow a single track or path on a cylindrical
member. In these embodiments, there is no need for repositioning
guides.
[0035] The separation apparatus can further include a repositioning
guide or guides when the endless cable is wrapped a plurality of
times around the cylindrical members. As the endless cable moves
along a route, the repositioning guide can ensure continuous
movement by allowing a continuous path for the endless cable and by
preventing the endless cable from rolling off or falling off of the
cylindrical members.
[0036] In one aspect, the separation apparatus can include an
oleophilic endless cable. Such apparatus can be used, e.g., for
oleophilic-based separations such as bitumen recovery from oil
sands. In a further aspect, the apparatus can include an
agglomerator drum. An agglomerator drum can have openings oriented
in fluid communication with the endless cable to allow passage of
fluid from an interior to an exterior of the agglomerator drum. The
agglomerator drum can also include oleophilic members for adhering
oleophilic material. Such oleophilic members can be oleophilic
baffles, tower packing or other suitable structures. A separation
apparatus including an oleophilic endless cable and an agglomerator
drum can have a variety of applications including, but not limited
to, processing of bitumen and oil products.
[0037] In another embodiment, the separation apparatus can include
a gas inlet that is oriented to direct a gas through or across one
or more flights of the endless cable or cables. The apparatus can
further include a first liquid reservoir wherein the revolvable
cylindrical members include a feed roller and an upper roller where
the feed roller is contacted by liquid from the first reservoir. In
still another embodiment, the separation apparatus can include one
or more endless cables configured to be charged electrically with a
high potential direct or alternating current.
[0038] A separation apparatus of the type described herein can also
or alternatively be used as a sand filter. In such embodiment, the
revolvable cylindrical members can be oriented to form an upper
flight and a lower flight of the at least one endless cable. The
gaps between adjacent windings can be configured to be sufficiently
narrow to allow passage of liquid therethrough and retention and
conveyance of particulate solids thereon. In still another
embodiment, the separation apparatus can be configured to size and
sort particulate or other material.
[0039] A method is also presented for separating that can include
using an endless cable. To separate components of a flowable
material, the material can be passed through at least one
continuously moving endless cable. A first component can pass
through gaps between adjacent wrappings of the endless cable. A
second component can be retained on or by the endless cable, which
can then be partially or completely removed from the cable.
[0040] There has thus been outlined, rather broadly, various
features of the invention so that the detailed description thereof
that follows may be better understood, and so that the present
contribution to the art may be better appreciated. Other features
of the present invention will become clearer from the following
detailed description of the invention, taken with the accompanying
claims, or may be learned by the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1a is a perspective view of a separation apparatus
including two revolvable cylindrical members, and repositioning
guide, according to one embodiment of the present invention.
[0042] FIG. 1b is a cross-sectional view along line A-A of FIG. 1a,
illustrating one aspect of the present invention.
[0043] FIG. 1c is an alternate cross-sectional view along line A-A
of FIG. 1a, illustrating one aspect of the present invention.
[0044] FIG. 1d is an alternate cross-sectional view along line A-A
of FIG. 1a, illustrating another aspect of the present
invention.
[0045] FIG. 1e is an alternate cross-sectional view along line A-A
of FIG. 1a, illustrating still another aspect of the present
invention.
[0046] FIG. 2 is a side view of a separation apparatus including an
agglomerator oriented outside the endless cable and above the top
flight, according to one embodiment of the present invention.
[0047] FIG. 3 is a side cross-sectional view of a separation
apparatus including an agglomerator situated between the top and
bottom flights of endless cable, according to one embodiment of the
present invention.
[0048] FIG. 4a is an exploded perspective view of a separation
apparatus including an agglomerator situated between the top and
bottom flights of endless cable, where the agglomerator includes a
plurality of longitudinal baffles according to one embodiment of
the present invention.
[0049] FIG. 4b is a perspective view of the agglomerator and
endless cable of FIG. 4a.
[0050] FIG. 4c is an exploded partial view of the longitudinal
strips and end plate of the agglomerator shown in FIG. 4b.
[0051] FIG. 5a is a side view of an endless cable route where the
endless cable is configured to travel around a revolvable member
and come into close proximity with an adjacent wrap of an endless
cable, according to one embodiment of the present invention.
[0052] FIG. 5b is a side view of a configuration where an endless
cable travels through a comb to remove material therefrom,
according to one embodiment of the present invention.
[0053] FIG. 5c is a front view of a grooved scraper blade
configured adjacent to a grooved roller to remove material from
wraps of an endless cable, according to one embodiment of the
present invention.
[0054] FIG. 5d is a front view of wraps of an endless cable passing
through two complimentary grooved revolvable members, according to
one embodiment of the present invention.
[0055] FIG. 5e is a front view of wraps of an endless cable passing
through two revolvable members, one of which is an impressionable
rubber roller, according to one embodiment of the present
invention.
[0056] FIG. 6 is a side schematic view of a system for removing
hydrophilic solids from bitumen, including separations processing
with an endless cable and a serpentine pipe according to one
embodiment of the present invention.
[0057] FIG. 7 is a side view of an arrangement of an endless cable
configured for mass transfer applications where the endless cable
travels through a fluid reservoir, while gas is directed to travel
past portions of the endless cable according to one embodiment of
the present invention.
[0058] FIG. 8 is a side view of an arrangement of another endless
cable configured for mass transfer applications where the endless
cable travels through four separate fluid reservoirs, according to
one embodiment of the present invention.
[0059] FIG. 9 is a side view of an endless cable configured to
carry a high potential AC or DC electric charge for defogging
separations according to one embodiment of the present
invention.
[0060] FIG. 10a is a side view of another endless cable configured
to carry a high potential AC or DC electric charge for
electrostatic separations according to one embodiment of the
present invention.
[0061] FIG. 10b is a top view of FIG. 10a but not showing the
bottom flight for reasons of simplicity of the Figure.
[0062] FIG. 11a is a side view of an endless cable configured to
act as a suspended moving filter according to one embodiment of the
present invention.
[0063] FIG. 11b is a top view of FIG. 11a but not showing the
bottom flight for reasons of simplicity of the Figure.
[0064] FIG. 12a is a side view of an endless cable arranged to
separate objects based on size according to one embodiment of the
present invention.
[0065] FIG. 12b is a top view of one optional embodiment of FIG.
12a, but not showing the bottom flight for reasons of
simplicity.
[0066] FIG. 13 is a top view of multiple endless cables arranged
together to form a conveyor system according to one embodiment of
the present invention.
[0067] It will be understood that the above figures are merely for
illustrative purposes in furthering an understanding of the
invention. Further, the figures are not drawn to scale, thus
dimensions and other aspects may, and generally are, exaggerated or
changed to make illustrations thereof clearer. Therefore, departure
can be made from the specific dimensions and aspects shown in the
figures in order to produce the separation system using endless
cables of the present invention.
DETAILED DESCRIPTION
[0068] Before the present invention is disclosed and described, it
is to be understood that this invention is not limited to the
particular structures, process steps, or materials disclosed
herein, but is extended to equivalents thereof as would be
recognized by those ordinarily skilled in the relevant arts. It
should also be understood that terminology employed herein is used
for the purpose of describing particular embodiments only and is
not intended to be limiting.
[0069] It must be noted that, as used in this specification and the
appended claims, the singular forms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
Thus, for example, reference to "a splice" includes one or more of
such splices, reference to "an endless cable" includes reference to
one or more of such endless cables, and reference to "the material"
includes reference to one or more of such materials.
DEFINITIONS
[0070] In describing and claiming the present invention, the
following terminology will be used in accordance with the
definitions set forth below.
[0071] As used herein, the term "endless cable" refers to a cable
having no beginning or end, but rather the beginning merges into an
end and vice-versa, to create an endless or continuous cable. The
endless cable can be, e.g., a wire rope, a plastic rope, a single
wire, compound filament (e.g. sea-island) or a monofilament which
is spliced together to form a continuous loop, e.g. by
long-splicing.
[0072] As used herein, "conditioning" in reference to mined oil
sand is consistent with conventional usage and refers to mixing a
mined oil sand with water, air and caustic soda to produce a warm
or hot slurry of oversize material, coarse sand, silt, clay and
aerated bitumen suitable for recovering bitumen froth from said
slurry by means of froth flotation. Such mixing can be done in a
conditioning drum or tumbler or, alternatively, the mixing can be
done as it enters into a slurry pipeline and/or while in transport
in the slurry pipeline. Conditioning aerates the bitumen for
subsequent recovery in separation vessels. Likewise, referring to a
composition as "conditioned" indicates that the composition has
been subjected to such a conditioning process.
[0073] As used herein, "bitumen" refers to a viscous hydrocarbon
that may include maltenes and asphaltenes that is found in oil
sands ore interstitially between sand grains. In a typical oil
sands plant, there are many different streams that may contain
bitumen.
[0074] "Agglomeration drum" refers to a revolving drum containing
oleophilic surfaces that is used to increase the particle size of
bitumen in oil sand slurries prior to separation. Bitumen particles
flowing through said drum come in contact with the oleophilic
surfaces and adhere thereto to form a layer of bitumen of
increasing thickness until the layer becomes so large that shear
from the flowing slurry and from the revolution of the drum causes
a portion of the bitumen layer to slough off, resulting in bitumen
particles that are much larger than the original bitumen particles
of the slurry.
[0075] As used herein, "fluid" refers to flowable matter. Fluids,
as used in the present invention typically include a liquid, gas,
and/or flowable particulate solids, and may optionally further
include amounts of solids and/or gases dispersed therein. As such,
fluid specifically includes slurries (liquid with solid
particulate), flowable dry solids, aerated liquids, gases, and
combinations of two or more fluids. In describing certain
embodiments, the term slurry and fluid may be used interchangeably,
unless explicitly stated to the contrary.
[0076] The term, "central location" refers to a location that is
not at the periphery. In the case of a pipe, a central location is
a location that is neither at the beginning of the pipe nor the end
point of the pipe and is sufficiently remote from either end to
achieve a desired effect, e.g. washing, disruption of agglomerated
materials, etc.
[0077] As used herein, "velocity" is used consistent with a
physics-based definition; specifically, velocity is speed having a
particular direction. As such, the magnitude of velocity is speed.
Velocity further includes a direction. When the velocity component
is said to alter, that indicates that the bulk directional vector
of velocity acting on an object in the fluid stream (liquid
particle, solid particle, etc.) is not constant. Spiraling or
helical flow-patterns are specifically defined to have
substantially constant or gradually changing bulk directional
velocity.
[0078] The term, "multiple wrap endless cable" as used in reference
to separations processing refers to an endless cable that is
wrapped around two or more drums and/orrollers a multitude of times
to form an endless belt having spaced cables. Movement of the
endless cable belt can be facilitated by at least two guide rollers
or guides that prevent said cable from rolling off an edge of the
drum and guide the cable back to the opposite end of the same or
other drum. The spacing in the endless belt is formed by the slits
or gaps between sequential wraps. The endless cable can be a wire
rope, a plastic rope, a single wire, compound filament (e.g.
sea-island) or a monofilament which is spliced together to form a
continuous loop, e.g. by splicing. As a general guideline, the
diameter of the endless cable can be as large as 3 cm and as small
as 0.001 cm, although other sizes might be suitable for some
applications. An oleophilic endless cable belt is a cable belt made
from a material that is oleophilic under the conditions at which it
operates.
[0079] As used herein, "single wrap endless cable" refers to an
endless cable which is wrapped around two or more cylindrical
members in a single pass, i.e. contacting each roller or drum only
once.
[0080] The term "cylindrical" indicates a generally elongated shape
having a circular cross-section. Therefore, cylindrical includes
cylinders, conical shapes, and combinations thereof. The elongated
shape has a length referred herein also as a depth as calculated
from one of two points--the open vessel inlet, or the defined top
or side wall nearest the open vessel inlet.
[0081] As used herein, "recovery yield" refers to the percentage of
material removed from an original mixture or composition.
Therefore, in a simplified example, a 100 kg mixture containing 45
kg of water and 40 kg of bitumen where 38 kg of bitumen out of the
40 kg is removed would be a 95% recovery yield.
[0082] As used herein, the term "confined" refers to a state of
substantial enclosure. A path of fluid may be confined if the path
is, e.g., walled or blocked on a plurality of sides, such that
there is an inlet and an outlet and direction of the flow is
directed by the shape and direction of the confining material.
[0083] As used herein, "retained on" refers to association
primarily via simple mechanical forces, e.g. a particle lying on a
gap between two or more cables. In contrast, the term "retained by"
refers to association primarily via active adherence of one item to
another, e.g. retaining of bitumen by an oleophilic cable. In some
cases, a material may be both retained on and retained by one or
more cables.
[0084] The term "roller" indicates a revolvable cylindrical member
or drum, and such terms are used interchangeably herein.
[0085] As used herein, "wrapped" or "wrap" in relation to a cable
wrapping around an object indicates an extended amount of contact.
Wrapping does not necessarily indicate full or near-full
encompassing of the object.
[0086] The term "metallic" refers to both metals and metalloids.
Metals include those compounds typically considered metals found
within the transition metals, alkali and alkali earth metals.
Examples of metals are Ag, Au, Cu, Al, and Fe. Metalloids include
specifically Si, B, Ge, Sb, As, and Te. Metallic materials also
include alloys or mixtures that include metallic materials. Such
alloys or mixtures may further include additional additives.
[0087] As used herein, the term "substantially" refers to the
complete or nearly complete extent or degree of an action,
characteristic, property, state, structure, item, or result. For
example, an object that is "substantially" enclosed would mean that
the object is either completely enclosed or nearly completely
enclosed. The exact allowable degree of deviation from absolute
completeness may in some cases depend on the specific context.
However, generally speaking the nearness of completion will be so
as to have the same overall result as if absolute and total
completion were obtained. The use of "substantially" is equally
applicable when used in a negative connotation to refer to the
complete or near complete lack of an action, characteristic,
property, state, structure, item, or result.
[0088] As used herein, a plurality of components may be presented
in a common list for convenience. However, these lists should be
construed as though each member of the list is individually
identified as a separate and unique member. Thus, no individual
member of such list should be construed as a de facto equivalent of
any other member of the same list solely based on their
presentation in a common group without indications to the
contrary.
[0089] Concentrations, amounts, volumes, and other numerical data
may be expressed or presented herein in a range format. It is to be
understood that such a range format is used merely for convenience
and brevity and thus should be interpreted flexibly to include not
only the numerical values explicitly recited as the limits of the
range, but also to include all the individual numerical values or
sub-ranges encompassed within that range as if each numerical value
and sub-range is explicitly recited. As an illustration, a
numerical range of "about 1 inch to about 5 inches" should be
interpreted to include not only the explicitly recited values of
about 1 inch to about 5 inches, but also include individual values
and sub-ranges within the indicated range. Thus, included in this
numerical range are individual values such as 2, 3, and 4 and
sub-ranges such as from 1-3, from 2-4, and from 3-5, etc. This same
principle applies to ranges reciting only one numerical value.
Furthermore, such an interpretation should apply regardless of the
breadth of the range or the characteristics being described.
EMBODIMENTS OF THE INVENTION
[0090] It has been found that a separation apparatus that is both
versatile and effective can be created using one or more endless
cables. The cable or cables can be wrapped a plurality of times
around at least two revolvable cylindrical members. Such wrapping
can form a first wrap, a plurality of subsequent wraps, and a final
wrap for each endless cable. The wrapping can be from one
cylindrical member to another, so that the one or more endless
cables contacts each of the at least two cylindrical members
multiple times to form gaps between adjacent windings.
[0091] In one aspect of the present invention, the at least one
endless cable includes a first multiple wrap endless cable wherein
the first wrap, the plurality of subsequent wraps and the final
wrap are formed by wraps of the first endless cable. In such
embodiments, the endless cable passes over each of the cylindrical
members a plurality of times. This is the embodiment illustrated in
FIGS. 1a, 4 and others as discussed in more detail below. In order
to avoid an unacceptable amount of cable twisting as the cable is
wrapped around the cylinders, the endless cable can be formed, e.g.
by long splice, having a twist opposite to that created when
wrapping. In this way the wrapped endless cable can avoid excessive
twist or bending.
[0092] Alternatively, the at least one endless cable can be formed
of a plurality of single wrap cable loops such that each of the
first wrap, subsequent wraps, and final wrap are formed by a
corresponding single wrap cable loop. Such single wrap cable loops
can, in one embodiment, be composed of the same materials as the
multiple wrap endless cables. Single wrap cable loops typically
differ from multiple wrap endless cables primarily in size. Cable
loops are configured to rotate in a single loop, i.e. from one
cylindrical member to another, or possibly between three or more
cylindrical members. The single wrap loops do not contact each of
the cylindrical members a plurality of times, but rather follow a
single track or path on a cylindrical member. In this embodiment,
there is no need for repositioning guides.
[0093] A separation apparatus can further include a repositioning
guide or guides for each of the multiple wrap endless cables. As
the endless cable moves along a route, the repositioning guide can
be oriented to continuously allow guidance of the final wrap of a
multiple wrap endless cable to roll into and assume the position of
the first wrap, thus preventing the endless cable from rolling off
or falling off the cylindrical members.
[0094] General
[0095] FIG. 1 is a perspective view of a single multiple wrap
endless cable 2 wrapped between two revolvable cylindrical members
4, 6 multiple times. As illustrated, the wrapping forms a first
wrap 8, a plurality of subsequent wraps 10, and a final wrap 12. A
repositioning guide support 14 is shown including two guide rollers
16, 18. The final wrap 12 travels from the revolvable cylindrical
member 6 to the first guide roller 16, and then to a second guide
roller 18, where it is repositioned as the first wrap 8. Shown is a
basic concept of an endless cable belt wrapped, in this case,
around two rollers in a large number of wraps using a single
endless cable. A number of different configurations are possible by
variations in number of endless belts, number, size and position of
revolvable members, and various repositioning guides.
[0096] In FIG. 1a, a drive roller 6 and tension roller 4 are used.
The drive roller initiates and maintains rotation of the roller,
which, in turn, causes the endless cable 2 to rotate along the
endless path. The drive roller can be rotated via a drive belt 7
and motor, not shown, or other suitable mechanism. The tension
roller can be maintained an adjustable distance from the drive
roller that maintains the endless cable at a tension that allows
for use in separations processing and keeping the cable in track.
For example, cables may stretch during use requiring periodic
tension adjustment. The desirable tension can vary greatly and will
depend on the anticipated application and type and size of endless
cable. Tension adjustment may alternately be provided by a guide or
guide rollers or one or more tension rollers.
[0097] The endless cable can be configured in a variety of ways.
FIG. 1a shows line A-A, along the path of the endless cable along
the top flight of the endless cable. FIGS. 1b through 1e illustrate
various embodiments of endless cable arrangements as seen across
the line A-A. FIG. 1b is a cross-sectional view of a single,
multiwrap endless cable wrapped around two revolvable members, as
illustrated in FIG. 1a. FIG. 1c shows two multiwrap endless cables
which are wrapped on the rollers in alternating wraps. The empty
circles refer to the first cable and the filled-in circles refer to
the second cable. In this case two repositioning guides are
required instead of one. FIG. 1d is a cross-section of an
embodiment of FIG. 1a where one endless cable is wrapped around the
main rollers of FIG. 1a, with the addition of grizzly bars situated
in gaps between adjacent wraps. The grizzly bars (indicated by
triangles in the Figure) can be stationary or vibrate in a vertical
or orbital plane. These grizzly bars, in conjunction with the
revolving wraps create shear or vibration that, in some cases, may
enhance the operation of the endless cable belt, and may provide
support to the upper flight of the endless cable so that it will
not sag or deflect unacceptably under the weight of material on top
of the flight or by the movement of material through the gaps.
Although the grizzly bars are shown having a triangular
cross-section with one flat edge upward, other cross-sectional
shapes can be suitable such as, but not limited to, rectangular,
circular, trapezoidal, or the like. FIG. 1e is similar to FIG. 1c
in that two multiple wrap endless cables are used, but in this
case, the wraps are grouped together per endless cable and not
intertwined. Again, a repositioning guide is used for each endless
cable in this case. If four endless cables are used, then four
repositioning guides may be required. Each of the configurations
shown in FIG. 1b through 1e can also be applied to the lower or
bottom flight as an alternative to the upper flight or in
combination with the same or different configurations on the top
flight.
[0098] When more than one endless cable is used, it is preferred
that the repositioning guides, or another element other than a
revolvable member jointly used by the multiple endless cables, be
used to provide the desired tension for each cable individually.
Controlling tension of multiple endless cables using a common
tensioner or tension roller is possible, but can be difficult in
some embodiments. One method of providing satisfactory tension
along the top flight of a group of a large number of single wrap
endless cables is to allow slack along the bottom flight. For
example, both main rollers in FIG. 1a could be driven counter
clockwise. When each main roller is provided with a squeeze roller
and the left main roller is driven at a slightly higher surface
speed than the right main roller, the top flight would be in
tension and the bottom flight could be slack. The slackness of the
bottom flight would accommodate any small changes in the lengths of
the individual single wrap endless cables while allowing the top
flight to remain tight and serve the desired separating function.
When more than two main rollers are used to support the single wrap
endless cables, then two sets of squeeze rollers can be dedicated
to provide the desired cable slack over a section of the apparatus
whilst maintaining the desired cable tension for the rest of the
apparatus. In this case, the set of squeeze roller feeding the
cables into the slack section can be driven at a slightly higher
surface speed than the surface speed of the other main rollers; and
the slack section could be anywhere along the endless cables as
desired, and would not necessarily have to form the bottom
flight.
[0099] The endless cable or cables can comprise or consist
essentially of a member selected from the group consisting of
metal, plastic, fiber, and combinations thereof. All of the endless
cables can be of the same composition, or, each can independently
comprise or consist essentially of a member selected from the group
consisting of metal, plastic, fiber, and combinations thereof. In
one embodiment, at least one endless cable can comprise or consist
essentially of single strand or multi strand steel, galvanized
steel, tin coated steel, clad steel, plastic coated steel cable,
copper, stainless steel, titanium, wire rope, twisted plastic rope,
braided polymeric rope, carbon fiber rope, single monofilament
rope, and combinations thereof. The desirability of a particular
material for use as the cable can depend on a variety of factors,
not limited to, strength, availability, cost, electrical
conductivity, hydrophobicity, particular application, and the
like.
[0100] The endless cable can be of any size that allows for
arranging the endless cable to wrap around at least two revolvable
cylindrical members in a manner that facilitates separations
processing. As such, appropriate endless cable sizes are dependent
on the type of separation, the weight and size of material to be
separated, the endless pathway through which the endless cable
travels, the gap size, etc. In a specific embodiment, one or more
of the endless cables can have a diameter ranging from about 0.02
cm to about 3 cm. In a further embodiment, one or more of the
endless cables has a diameter ranging from about 0.1 cm to about
1.0 cm.
[0101] Separations or gaps between windings at least partially
result from the winding route of the endless cable. The gaps can be
configured to allow material to flow through in the desired manner,
e.g. increasing surface contact with fluids without hindering flow
through gaps, retaining larger materials above while allowing
smaller materials to pass through the gaps, etc. As illustrated in
FIG. 1a, the gaps between adjacent windings can be substantially
uniform. Alternatively, the gaps can be non-uniform or variable. In
one aspect, the gaps between adjacent windings are from about 1% to
about 10% or in some cases 50% of a diameter of the endless cable.
In some embodiments, the gaps between adjacent windings range from
about 50% to about 600% of the cable diameter, or more. The
specific size of the gaps may vary greatly due to the application,
type of separation desired, type of endless cable, etc. As a
non-limiting example, and in one embodiment, the gaps can range in
size from about 0.02 cm to about 5 cm, or from about 0.1 cm to
about 2.0 cm.
[0102] Endless cables are continuous and include no recognizable
beginning or ending. Such endless cables can be created by joining
the ends of a single cable. The joining mechanism can be any type
for which the separation apparatus and separations process allows.
A basic example that could be used in a very forgiving system is a
simple knot or crimped sleeve. Preferably, the cable is joined in a
manner that leaves no noticeable area, but allows for a seamless
transition from beginning to end of the cable. A long splice can be
used in such situations. Such cables can, in some instances,
include multiple cables joined together to form a single endless
cable. In one aspect, an endless cable can include more than one
standard long splice to join cable ends and to make one cable
endless. A "long splice" is a well known method of joining cables
in a manner which does not significantly increase the cable
diameter at the splice but results in a splice that has almost the
same strength as the cable itself.
[0103] There are a wide variety of arrangements of at least one
endless cable wrapped between at least two cylindrical members.
More than one endless cable could be used. More than two
cylindrical members can be used, in which case, the route of the
endless cable may not be directly from one cylindrical member to
another, but may include a more intricate or circuitous route. An
endless cable can be wrapped any number of times around some or all
cylindrical members. For example, at least one endless cable of a
separation apparatus can wrap around at least two of the
cylindrical members of the separation apparatus from about 10 to
about 1000 times. In a relatively simple variation of the single
endless cable wrapped around two cylindrical members design, a
second endless cable can be wrapped a plurality of times around the
same two cylindrical members. Furthermore, the second endless cable
can be wrapped around any number of cylindrical members, associated
with the first endless cable or following a different path. In one
embodiment including a second endless cable, the wraps of the
second endless cable can be grouped together and located adjacent
to the group of wraps of the first endless cable. Alternatively,
the wraps of the second endless cable can alternate with the wraps
of the first endless cable, or rather each succeeding wrap of the
second endless cable individually can be located adjacent to each
succeeding wrap of the first endless cable.
[0104] In another design variation, the cylindrical members can
number more than two. For example, the cylindrical members in one
embodiment can range from 3 to 10. Multiple cylindrical members can
be oriented to also contact the at least one endless cable a
plurality of times to form the gaps between adjacent windings. Such
orientation may cause the same number of wraps or contacts with
more than one of the cylindrical members, or may leave one or more
rollers with more or fewer contacting cable passes. The two or more
cylindrical members may have substantially the same diameter, or
may have differing diameters depending the particular application
and system design. In one embodiment, at least one of the
cylindrical members has a diameter from about 10 cm to about 1000
cm.
[0105] In order to facilitate proper or improved flow of the fluid
or solids, various parts of the separation apparatus can vibrate.
Vibration can help to prevent clustering and agglomeration of
material and break up previously agglomerated materials. In one
aspect, one or more of the cylindrical members can be configured to
vibrate. Alternatively, or in addition, the endless cable can be
configured to vibrate. Material separation may be further improved
by including an optional material distributor. Such material
distributor can be configured to distribute material over at least
a portion of the gaps between adjacent windings of an endless
cable. Non-limiting examples of material distributors include
screens, perforated sheets, parallel support grizzly bars, and
combinations thereof. Such material distributors can be configured
to vibrate to better improve the desired separation.
[0106] Once components of the fluid are separated, each component
can be collected in a separate collection apparatus. The separation
apparatus can, therefore, include a pass-through outlet oriented to
collect material which passes through the gaps of the endless
cable. The separation apparatus can also include a retained outlet
oriented to collect material retained on the at least one endless
cable. In one aspect, such pass-through outlet or outlets are
positioned under a generally horizontally-oriented endless cable.
Similarly, a corresponding retained outlet can be positioned near a
cylindrical member, and often near a stripping device which removes
material retained on or by the endless cable. In some embodiments,
a portion of the fluid is retained by the endless cable by a manner
of adhering or sticking to the cable rather than temporarily
resting on the cable. In such cases, it may be necessary to strip
the material from the cable. Such stripping can occur at regular or
semi-regular intervals, and can continuously occur during
processing and operation of the separation apparatus. Non-limiting
examples of cable stripping devices include rubber squeeze rollers,
complimentary grooved rollers, combs, grooved knife, cross-cables,
steam heat zones, inductive heat zones, microwave heat zones, and
combinations thereof. In one aspect, a separation apparatus
including an endless cable can include one or more wash water
sources oriented to wash material adhered to an endless cable.
Additionally or alternatively, a separation apparatus can include
one or more dryers configured and oriented to dry material adhered
to an endless cable.
[0107] As discussed, a repositioning guide can include a plurality
of guides configured to guide an endless cable along a continuous
or endless path. Such repositioning guide or guides can be spaced
apart from the at least two revolvable cylindrical members. A
repositioning guide or guides can, in addition to moving the
endless cable from the last wrap to the first wrap, be configured
to control location and spacing of gaps. The revolvable cylindrical
members can include a variety of surfaces. In one aspect, the
surface of at least one cylindrical member can be smooth.
Alternatively, the surface can be treated to have an abrasive
surface. In one aspect, the surface can include a mild adhesive. In
still another aspect, at least one of the revolvable cylindrical
members can be a grooved cylindrical member including grooves on an
exterior surface of the grooved cylindrical member. The grooves can
be configured to control location and spacing of the gaps.
Generally, any approach which can be used to maintain adjacent
wraps or windings of the endless cables can be used in the present
invention.
Oleophilic Separations
[0108] In one embodiment, one or more of the endless cables of a
separation apparatus can be oleophilic. One or more oleophilic
endless cables can be wrapped a multitude of times around two main
rollers to form an endless cable belt. When such wrapping are
between two or more rollers or cylindrical members that are
horizontally spaced apart, the wraps can form a top flight and a
bottom flight. Such is the case with FIG. 2 which illustrates two
cylindrical members 22, 24 or rollers of different sizes. With at
least one endless cable 26 traveling between the cylindrical
members in a continuous path facilitated by the repositioning guide
28. In one aspect, one roller can be a driving roller, while the
other roller is adjustable to maintain the desired tension in the
wraps to prevent these wraps from sagging. The repositioning guide
can optionally include two or more guide rollers that are spring
loaded to maintain approximately equal tension in the wraps when
one or more than one oleophilic cable is used.
[0109] In one aspect of using an oleophilic endless cable, oil sand
slurry or desanded oil sand slurry forms the feed. As shown in FIG.
2, the feed 29 is directed into an agglomerator 30 positioned above
the top flight 32 of the endless cable 26. The agglomerator can be
configured to revolve. Although a variety of agglomerator
configurations could work with the design presented, in one aspect,
the agglomerator can have a central cylindrical apertured screen 33
and an outer cylindrical apertured screen 35 to allow the flow of
slurry from the centre of the agglomerator, out through the outer
screen and onto the top flight of the oleophilic endless belt.
[0110] The annular volume between the inner screen 33 and the outer
screen 35 of the agglomerator 30 can optionally be filled with
oleophilic tower packings or other suitable agglomerating members,
e.g. fixed baffles, etc. As slurry flows through this volume,
bitumen from the slurry temporarily adheres to the surfaces of the
agglomerating members and then sloughs off in the form of enlarged
bitumen particles. The enlarged bitumen particles are captured more
readily by the oleophilic endless cable belt than small bitumen
particles.
[0111] As shown in FIG. 2, bitumen is captured and retained by the
endless cable 26 as the slurry from the agglomerator 30 passes
through the top flight 32. A bitumen-reduced slurry passes through
the top flight. The retained bitumen is conveyed towards and along
the main roller 24 at the right until it encounters the squeeze
roller 36 mounted along this main roller. The squeeze roller
removes bitumen from the belt as it revolves with this main roller
by preventing bitumen from passing between the two rollers. Bitumen
accumulates on the underside of the two rollers and sloughs off.
The thus removed bitumen can be collected as a primary product in a
first product collector 38. At least a portion of residual bitumen
in the bitumen-reduced slurry can be captured as slurry passes from
the top flight through the bottom flight 34. Slurry which passes
through the bottom flight can be primarily non-oleophilic and can
be collected and directed to the tailings reservoir 40. Residual
bitumen retained by the bottom flight can be collected with a
squeeze roller 42 along the left main roller 22 in a similar manner
as with squeeze roller 36. Bitumen removed from the bottom flight
can be collected in a second product collector 44. The first and
second bitumen products can be combined for further processing or
treated independently.
[0112] Baffles 46 can optionally be mounted between the top flight
32 and the bottom flight 34 to direct bitumen-reduced slurry from
the top flight to the bottom flight and to keep it away from the
main rollers 22, 24. In some cases, a mesh screen 48 or several
mesh screens can be placed above the bottom flight between the
baffles to slow down the flow of slurry impacting onto the bottom
flight. This is done to minimize dispersion of residual bitumen
droplets that fall from the top flight to the bottom flight and to
improve contact between the bottom flight of endless cable and the
slurry.
[0113] FIG. 3 illustrates another embodiment of a separation
apparatus including an oleophilic endless cable 60. This
configuration can be used to separate oil sand slurry or desanded
oil sand slurry in two stages, although other materials may also be
effectively separated in this manner. One or more endless cables 60
are wrapped a multitude of wraps around rollers 62, 64, 66 and
agglomerator drum 68 to form an endless belt. Guides or guide
rollers are used as in the previous embodiments and previous
figures, but these are not shown for reasons of clarity. Stage 1
separation occurs along the top flight 70 and stage 2 separation
occurs along the bottom flight 72 in conjunction with an
agglomerator 68 optionally filled with oleophilic tower packings.
Oleophilic tower packings are used extensively in the refining
industry for distillation columns and in extraction columns and are
often made from polypropylene, polyethylene or from other plastics,
although metal packings could also be used.
[0114] Slurry feed flows onto the top flight 70 from a dispenser 74
that spreads it evenly over the endless belt. A screen 76 or
several screens may optionally be used under the dispenser to
better distribute and slow down the flow of slurry onto the top
flight. Bitumen captured from the slurry by the top flight is
conveyed to the set of squeeze rollers 64, 66 where the bitumen is
squeezed off the belt by these two rollers and then flows into a
pipe 78 or other receiver as a primary bitumen product. Tailings 86
from stage 1, primarily including water, solids and some bitumen,
pass through the gaps of the top flight and flow into a reservoir
80 connected with a pipe to a central inlet of the agglomerator 68.
A pump, not shown, may optionally be used to convey these tailings
to the agglomerator. In the agglomerator bitumen particles of these
tailings are further agglomerated by the oleophilic tower packings.
These bitumen particles temporarily adhere to the oleophilic
surfaces of the tower packings and form a layer of bitumen on the
surfaces of these packings. This layer of bitumen increases in
thickness until shear from water and solids, flowing through the
packings, sloughs off bitumen in the form of enlarged bitumen
particles, which are then captured by the bottom flight 72 as these
leave the agglomerator. Bitumen thus captured by the bottom flight
is conveyed to another set of rollers 81, 62, where it is squeezed
off the belt and flows into a pipe 82 or other receiver as a
bitumen product. Tailings from stage 2 drop into a tank 84 under
the agglomerator and bottom flight and are sent to dewatering and
disposal. These tailings are preferably substantially free of
bitumen, although some residual bitumen is sometimes present.
[0115] Optionally, wash water may be used to wash adhering solids
from bitumen on the top flight and air may be used to blow dry this
bitumen. However such washing or drying may only be used as needed
or desired.
[0116] Free bodies, such as 1 or 2 inch grinding balls or balls
similar to golf balls or a mixture thereof may be used as the
agglomerating medium in an agglomerator of the instant invention.
Such balls tumble with the bitumen and tend to kneed the bitumen
and, in many cases, assist in the agglomerating process by
stripping fine solids from the surface of the bitumen and thereby
encourage bitumen to agglomerate more readily. However care must be
taken to prevent the charge of balls from becoming so heavy that
the agglomerator drum becomes like a ball mill requiring a very
heavy drum with a resulting heavy support structure. Alternative to
the tower packings or other free bodies, the agglomerator 68 can
include a plurality of internal baffles. In this case, tailings
that have passed through the gaps of the top flight 70 fall onto a
baffle, which directs these tailings into the volumes between
oleophilic baffles of the agglomerator. The velocity of these
tailings is such, and the angle of the oleophilic baffles is such,
that the tailings are scooped up by the baffles and flow towards
the centre of the agglomerator. Bitumen particles remaining in the
tailings of the top flight come in contact with oleophilic baffles
of the agglomerator and temporarily adhere thereto until the layer
of bitumen on the baffles becomes thick enough that shear from the
flowing tailings sloughs off the bitumen in the form of enlarged
bitumen particles. Then, as the agglomerator revolves, these
tailings containing residual bitumen reverse direction with respect
to the agglomerator centre and flow outward past the baffles of the
agglomerator, and towards the bottom flight 72 for capture of
bitumen by the bottom flight. Bitumen product from the bottom
flight is removed by means of squeeze rollers 81, 62, or is removed
by other means. Wash water and air (not shown) may be used along
the bottom flight as well, but only as needed or desired, to wash
solids from the bottom flight and dry the contents of the bottom
flight.
[0117] It should be noted that the agglomerator can have endwalls
to contain the tailings from the top flight, but these are not
shown in FIG. 3 for the sake of clarity. In one embodiment, the
oleophilic baffles are attached to and are supported by steel bars
or strips that connect to the endwalls of the agglomerator. FIG. 4a
shows an exploded perspective view of such an agglomerator 69
incorporated into a separation apparatus similar to that of FIG. 3.
In particular, an endless cable 61 is wrapped around the
agglomerator and between two separate sets of squeeze rollers 63
and 65 using two tension rollers 67 and 71. A dispenser 73 can be
used to distribute slurry across the top flight of the endless
cable system, either with or without additional screening or
distributors. As described previously, oleophilic materials within
the slurry tend to adhere to the endless cable while other
non-adhered portions pass through the top flight and onto a
collection pan 75. The collection pan can direct the partially
separated slurry onto the agglomerator 69 through the gaps between
the oleophilic baffles. Bitumen removed from each of the sets of
squeeze rollers can be collected in hoppers 77 and 79,
respectively. Similarly, material and fluids which pass through the
agglomerator are collected in vessel 85 and drained via line
83.
[0118] As shown in FIG. 4b, the agglomerator has an endwall 95
(shown removed) which includes slanted notches 97 for receiving
notched longitudinal strips 99 (in this case 26 such strips). These
strips are notched or grooved to keep the wraps of the endless
cable belt in alignment and to maintain the gaps or apertures
between these wraps at constant width. FIG. 4c illustrates an
exploded view where each single strip 99 has a plurality of
alignment grooves 101 which are oriented facing outward of the drum
as can be seen in FIGS. 4b and 4c. Retaining holes 103 can be used
to attach suitable oleophilic baffles 105. Referring again to FIG.
4b, as slurry flows across the longitudinal strips 99 and
oleophilic baffles 105 additional bitumen is adhered to and
agglomerates along these structures. The rotational speed of the
agglomerator is sufficient to allow agglomerated bitumen to collect
and flow towards the lower flight of the endless cable where it is
collected and carried towards squeeze rollers 63.
[0119] In one aspect of the present invention, the endless cable
can separate a first component that is a hydrophilic material and
the second component that is an oleophilic material. It is
understood that recovery yields may not, and usually will not,
reach 100% such that some minor amount of hydrophilic material may
be present in the oleophilic product and visa-versa. In another
aspect, a first separation product or component can primarily
include water and a second component can primarily include bitumen.
In one embodiment, the flowable material further includes a member
selected from the group consisting of clay, silt, sand, and
mixtures thereof. Various yield recoveries can be achieved by
varying different aspects of the separation apparatus and can
depend on the characteristics of the slurry or fluid. However, in
one specific embodiment with bitumen separations, the bitumen can
be separated from the slurry at a bitumen recovery yield of greater
than about 95 wt %, although actual recovery yields can vary
depending on the grade of oil sand used as a feed. As an
illustration, for a poor quality beach sand containing 6% bitumen,
recovery may be as high as 60%. For a medium grade oil sand
containing 10% bitumen, recovery can exceed 92%, and for high grade
oil sand ore containing 12% bitumen recovery may exceed 95%.
[0120] As previously mentioned, various methods for mechanically
removing bitumen from the oleophilic endless cable belt are shown
in FIGS. 5a through 5e. The temperature of bitumen adhering to the
cable belt can be left unaltered and the bitumen can be recovered
by the methods shown in, e.g., FIGS. 5a-5e and alternatively or
additionally, the cable wraps and the bitumen may be heated in the
recovery zone using steam, heated gas, microwaves, electricity, or
other heat source to reduce the bitumen viscosity. The more fluid
bitumen can then be scraped or squeezed off more effectively by
methods similar to the mechanical methods shown in FIGS. 5a-5e.
Bitumen may also be heated by internally heating the main rollers
and/or the recovery rollers with steam or other means.
[0121] In FIG. 5a, cable 110 is wrapped around a roller 112 such
that throughout the endless belt, each cable wrap before contacting
this roller, and following its contour, is scraped on either side
by two adjacent cable wraps at the location 113 where the cable
wraps cross. When the slits or gaps between adjacent cable wraps
are equal to the diameter of the cable, such crossing of the cable
wraps serves to comb bitumen from each cable wrap approaching the
roller. This method is particularly useful when the slits are equal
to or only slightly larger than the cable diameter. A blade (not
shown) under and in contact or near contact with the cable cross
can facilitate removing bitumen from the cable wraps at the
crossing location. Bitumen thus removed from the wraps falls or
flows into a suitable receiver.
[0122] FIG. 5b uses a comb 118 to remove bitumen from the cable
116. Tines of the comb are shaped and placed between the cable
wraps and the back of the comb can either be above the wraps or
below the wraps. Bitumen combed from the wraps falls or flows away
from the comb into a receiver. The comb can be shaped to have
complimentary grooves with the cable wraps. Further, the comb can
be formed of any suitable material such as, but not limited to,
ultra-high density polyethylene, stainless steel, Teflon-coated
materials, polycarbonate, and the like.
[0123] FIG. 5c uses a scraper blade 122, e.g. of ultra high density
polyethylene, machined to follow the contour of the cable wraps 120
on a main roller 124, which is grooved and made of wear resistant
material or surface such as those listed above. While scraping,
this blade will slowly wear and form itself to fit closely around
the contour of the individual wraps as it scrapes bitumen from the
roller and from the cable wraps.
[0124] FIG. 5d uses a main roller 130 and a recovery roller 132
having complimentary grooves which allow the cable to pass through.
Both rollers are grooved and made from wear resistant metal and/or
are hard surfaced. The grooves are machined to tolerances that will
force most of the bitumen to be squeezed off the wraps 134 before
the wraps pass between the rollers. Bitumen thus forced from the
wraps is collected in a receiver below the wraps or rollers.
[0125] FIG. 5e is similar to FIG. 5d except that the recovery
roller 140 is a rubber or impressionable roller pressing against
the main roller 138, the rubber being deformed to the contour of
the cable wraps on the main roller in order to squeeze bitumen off
the wraps 142. The recovery roller may be made from rubber,
urethane or any flexible wear resistant material commonly used for
the fabrication of flexible long lasting rollers.
[0126] Another method for removing at least a portion of a second
component, such as bitumen, from the endless cable includes heating
the endless cable. Since the specific heat of water may be
approximately ten times as great as the specific heat of the
endless cable, the endless cable rapidly cools down when again
coming into contact with the aqueous mixture it separates and thus
continues to serve well in capturing bitumen at the mixture
temperature of the instant invention. Optionally, the heated
endless cable can be cooled or washed by rinsing with water and/or
cooled gas. Regardless, excessive heating of the endless cable can
be avoided which might otherwise reduce adherence of bitumen during
subsequent passes or cause carbon formation on the cable
surface.
[0127] An endless cable separation apparatus can be a portion of a
process for removing hydrophilic solids from bitumen froth or from
bitumen product. Bitumen product or bitumen froth from an oil sand
extraction process normally contains water and solids which
conventionally are removed by means of dilution centrifuging. This
entails deaerating the froth with steam after which the deaerated
froth or the bitumen product are mixed with a light hydrocarbon,
such as naphtha, heated and centrifuged. The products of dilution
centrifuging are clean diluted bitumen, which after naptha removal,
is suitable for long distance pipelining or upgrading to synthetic
crude oil, and centrifugal tailings which contain water, solids,
some naphtha and some bitumen. Dilution centrifuging is a costly
operation and any pretreatment which will remove even a portion of
the solids and/or water from bitumen froth or from bitumen product
is beneficial in reducing the cost of subsequent dilution
centrifuging. Alternatively, a cleaner bitumen product may
eliminate dilution centrifuging and allow the use of cheaper
processing and upgrading. Thus, the separation apparatuses of the
present invention can be advantageously used to treat bitumen or
bitumen froth prior to dilution centrifuging.
[0128] One alternative embodiment of an overall bitumen clean up
process is shown in FIG. 6. Bitumen product or bitumen froth, water
and a suitable chemical (for example a demulsifier) can be
introduced into the pump 150 and from there flow through a
serpentine pipe 152 described in the Isoelectric Application. The
serpentine pipe can act to dislodge hydrophilic solids from bitumen
and thus improve bitumen quality. High pressure water may
optionally be injected through a side inlet 154 of the serpentine
pipe if so desired to further dislodge or disengage hydrophilic
solids from bitumen. Initially, in the bitumen product feed or in
the bitumen froth, bitumen forms the continuous phase and water
forms the dispersed phase. In the serpentine pipe, water and
chemicals thoroughly mix with the bitumen product or the bitumen
froth to such a degree that bitumen becomes the dispersed phase and
water becomes the continuous phase. Hydrophilic particulates
previously trapped in the bitumen phase or in the dispersed water
phase are released and report to the now continuous aqueous
phase.
[0129] This dispersion then flows into an agglomerator 156
surrounded by an oleophilic endless cable belt 158 with the
agglomerator as one of the revolvable cylindrical members in the
assembly, as described in detail previously. Dispersed bitumen
droplets adhere to the tower packings of the agglomerator and grow
in size due to adherence to the oleophilic surfaces of the tower
packings and subsequently sloughing off in the form of enlarged
bitumen droplets. From the agglomerator, the mixture flows to the
oleophilic endless cable belt where bitumen is captured by the
wraps of the cable belt whilst water and hydrophilic particulates
pass through the gaps of the endless cable belt to a receiver 160
and from there to dewatering and disposal. Bitumen is recovered
from the belt by methods described in the instant invention and
collected in a bitumen product collector 162.
[0130] Non-limiting examples of suitable chemicals that may be used
in the processing may include demulsifiers, acids, buffers or
divalent salts to reduce emulsification of the mixture in the
serpentine pipe. For example, an acid or buffer may be used if the
bitumen froth contains water having a high pH which tends to
encourage the formation of tight bitumen in water emulsions in the
serpentine pipe. A divalent salt, such as gypsum may be used if the
bitumen froth contains natural detergents which also tend to
encourage the formation of hard-to-break bitumen in water emulsions
in the serpentine pipe. The gypsum would tend to counteract the
emulsion formation tendency of the natural detergent by hardening
the water.
[0131] In an alternate design, the tower packings in the
agglomerator can be replaced by other oleophilic members for
adhering oleophilic material. The agglomerator drum in this
embodiment, as well as other embodiments, can be situated adjacent
to the gaps of the endless cable between adjacent windings and
sufficient to allow material to flow from an interior volume of the
agglomerator drum through the gaps of the endless cable wraps.
[0132] In another embodiment, the agglomerator drum can be one or
more of the revolvable cylindrical members between the endless
cable wraps. The agglomerator drum in this case can be positioned
between the top flight and the bottom flight of the endless cable,
and can be adjacent to the gaps between adjacent windings
sufficient to allow material to flow through the gaps of the top
flight, or a direct feed, and into the interior volume of the
agglomerator drum and from the interior volume of the agglomerator
through the gaps of the bottom flight of said endless cable wraps.
Alternatively, the revolving agglomerator drum can be spaced from
and oriented either between the top flight and the bottom flight or
above the top flight. Much discussion has been directed to
revolving or moving agglomerators, however, in one aspect, an
agglomerator drum can be a stationary vessel.
[0133] One method of assembling an agglomerator drum for use in the
present application includes assembling a plurality of longitudinal
strips oriented substantially parallel to one another, spaced
apart, and oriented to form a cylindrical shape. The strips can be
attached at ends to two end discs, one end disc at each end. In one
aspect, the longitudinal strips can include notches spaced and
oriented to maintain the gaps between adjacent windings of the at
least one endless cable, as described in connection with FIGS.
4a-4c.
[0134] As may be necessary, the separation apparatus disclosed
herein can be located in a variety of locations. A non-limiting
example of a location is underground or inside a mine shaft. Such
placement can allow for more efficient removal of materials from
mining-type operations of a deeply buried oil sand deposit in situ
and prior to transport of bitumen product to the surface. In this
case some or all the tailings may need to be transported to the
surface as well. Oil sand ore normally is very tightly packed and
when this ore is disturbed and separated it will tend to fluff up
and create more volume than the ore originally in place.
[0135] In yet another embodiment of the present invention, the
endless cable device can be used to recover bitumen from
conventional caustic tailings found in tailings ponds associated
with the Clark process or other similar processes. Current
commercial developers of the Clark process see a tailings pond as a
means for storing toxic tailings and recovering water for reuse in
the commercial process but generally do not use a pond as part of
the process for recovering bitumen. As a result, the current
commercial plants go to great lengths and expense recover bitumen
from the warm tailings before they flow into the ponds and loose
their elevated temperatures. However, in accordance with the
present invention, a large amount of additional bitumen may be
recovered as such a tailings pond is incorporated into a bitumen
recovery process utilizing the endless cable devices of the present
invention. At current commercial tailings ponds, sand and silt
settle out of the tailings and water floats to the top, leaving a
sludge containing bitumen, clay fines and water present in a
bitumen-rich middlings portion of the pond (e.g. below the water
rich layer and above the sand and silt layer). The percent bitumen
content of this sludge can be an order of magnitude greater than
the bitumen content of the tailings flowing into the pond. In some
cases, on a dry basis percentage, sludge may contain as much
bitumen as mined oil sand ore. As long as the ponds are not
abandoned, this bitumen is not lost but collects in the ponds and
may be recovered by oleophilic devices described in this or in the
Endless Cable application. Such separation may be carried out at
very low temperatures, even approaching zero degrees centigrade
when centrifugal tailings (or tailings from other types of
hydrocarbon bitumen clean up) are blended with primary and
secondary tailings flowing into the pond thereby reducing the
viscosity of bitumen of primary and secondary tailings by residual
solvent contained in the centrifugal tailings. Without such
blending, the separation of sludge from primary and secondary
tailings may be carried out by oleophilic means around 10.degree.
C. to 20.degree. C. The bitumen rich sludge can be collected using
a suitable mechanism, such as but not limited to, pumping with an
intake set at the appropriate depth. The collected sludge can then
be directed to the endless cable as either the sole feed
(optionally mixed with water or other additives to control
flowability) or in combination with a crushed sands slurry or other
materials as discussed previously.
[0136] When a tailings pond becomes part of the bitumen recovery
process of a commercial oil sands plant, and oleophilic means can
be used to recover this bitumen. Allowing bitumen to accumulate and
concentrate in tailings ponds and then recovering this bitumen at a
later date can effectively increase overall annual commercial plant
bitumen recovery after the commercial plant has been in operation
for some time. Since caustic process aid is used in the current
commercial plants, the debitumenized sludge left after recovering
bitumen from a current commercial tailings pond (e.g. using the
Clark process or its equivalent) remains toxic.
[0137] Mass Transfer
[0138] The endless cable belt of the present invention may be used
for a range of chemical engineering mass transfer applications.
These may include among others: drying, freeze drying, evaporating,
humidifying, gas cleaning, reacting of components in a gas with a
liquid, etc. In the application illustrated in FIG. 7, a gas 170 is
passed through slits between sequential wraps of the endless cable
172. Although not shown in this figure, a plurality of wraps can
optionally be oriented substantially parallel as described
previously. A feed reservoir 174 and a product reservoir 176 are
also shown. As the endless cable passes through liquid in the feed
reservoir, some liquid adheres to the endless cable and is drawn
upward into a contact region where gases are directed. The
gas-liquid contacting can result in a wide variety of mass
transfer, chemical reactions or other processes. For example, the
feed liquid may be a liquid reactant and the gas may contain or
consist essentially of a corresponding gas reactant. Gaseous
products or components can be reacted with or be collected and
liquid products can be formed and retained on or by the endless
cable. Product reservoirs are not required for simple drying, for
example, and only one reservoir may be used for humidifying or
evaporating, unless the process of humidifying or evaporating
results in the production of salts or more concentrated liquids. An
optional scraper or a comb may be used to remove crystals from the
cable or to remove concentrated liquids and/or liquid products.
Furthermore the two rollers 178, 180 above the product reservoir
can serve to squeeze liquid from the cable or to break crystals
from the cable. In gas cleaning or in reacting a liquid with the
components or impurities in a gas stream, one or several more
reservoirs may be required, depending upon the complexity of the
unit operation. It should be noted that enclosures, drives, gas
inlets and outlets and other auxiliary components are not shown for
clarity but are well within the skill of those in the art.
[0139] FIG. 8 illustrates a more complex mass transfer unit than
FIG. 7, and includes four liquid reservoirs 188, 190, 192, and 194.
This embodiment includes an enclosure 196, a gas inlet 198, a gas
outlet 200, one or more endless cable belts 202, nineteen main
cylindrical members 204, and repositioning guides 206 to keep the
endless cable or cables on the cylindrical members in the same
manner as previously described. In one aspect, two or more of the
separate reservoirs can include a distinct liquid composition
therein or may contain a common liquid which is recoated over the
endless cable upon each pass into the corresponding liquid
reservoir. As with other embodiments, when more than one endless
cable is used, a guide or set of guide rollers is required for each
endless cable, unless single wrap endless cables are used. Such
individual repositioning guides may also provide proper tension to
the cables. Note that the cable or cables run from main roller to
main roller in sequence and return along the top of the figure. In
one aspect, one or more of the main rollers can be grooved to
accept the cable and maintain predetermined gap distances. The
concepts disclosed with FIG. 7 will apply to FIG. 8 in many
instances, and visa versa.
[0140] Generally speaking, an apparatus of this type, when dealing
with gas-liquid, can include a gas inlet oriented to direct a gas
across a flight of the at least one endless cable, and a first
liquid reservoir. In one aspect, the revolvable cylindrical members
can include a feed roller and an upper roller, where the feed
roller is oriented within the first liquid reservoir to contact
liquid therein, and the upper roller is remote from the first
liquid reservoir. Optionally, alternating upper rollers or
respective grooves can be offset from adjacent upper rollers such
that adjacent flights of the endless cables are offset in order to
allow incoming gases to be more fully exposed to each flight and
reduce channeling through unobstructed gas flow paths. The
apparatus can optionally include a cable stripping device for use
in removing a product material and/or excess liquid adhered to the
endless cable.
[0141] Electrically Charged Devices
[0142] One or more endless cables can be electrically charged to
achieve specific separation results as explained in more detail
below. However, when an oleophilic cable is electrically charged it
tends to become less oleophilic due to the mechanism of
electrowetting. This means that oil adhering to a cable may become
coated with a continuous film of water instead of with water
droplets when an electric potential is applied to the cable.
Alternately, water may seek to wet part of the cable itself under
certain conditions when the cable is electrically charged. This
mechanism of electrowetting can be used to advantage for removing
bitumen or oil from such a cable in a recovery zone.
[0143] FIG. 9 illustrates another embodiment of an endless cable
separation apparatus. This application uses an endless cable 220
that is configured to be charged electrically with a high potential
direct or alternating current of a first polarity or phase via a
suitable electrical source. In one aspect, the endless cable and
two or more revolvable cylindrical members 222, 224 can be oriented
within a containment vessel 226. The containment vessel can
optionally be electrically charged with a high potential direct or
alternating current of a second polarity or phase opposite the
first polarity or phase.
[0144] The endless cable can be configured to use high voltage AC
or DC to separate mixtures. High voltage can be used along with low
current flow. In one aspect, one polarity or phase of the high
voltage may be attached to the wraps of an endless cable belt and
the other polarity or phase may be attached to an external
electrode or an adjacent wrap of another endless cable belt such
that the wraps of one endless cable are intertwined with the wraps
of another endless cable and are of opposite polarity or phase.
FIG. 9 may use the second polarity or phase attached to an external
electrode 228 surrounding the insulated enclosure 230 of the
apparatus.
[0145] This embodiment was tested to condense a petroleum fog
resulting from the rapid cooling of a hydrocarbon gas in the
presence of finely dispersed particulate matter. The particulate
matter formed the nucleus of oil droplets upon condensing of the
hydrocarbon gas, resulting in a fog that was very difficult to
break. When the electricity was turned off, a dense fog formed in
the apparatus. However, in about a second, after 15,000 volts of AC
was turned on, the fog broke and produced a clear gas with liquid
flowing down the walls of the glass enclosure and along the cable.
Particulate matter tended to collect on the cable, which was then
wiped clean with a scraper.
[0146] Another embodiment is illustrated in FIG. 10a and FIG. 10b.
The main rollers 244, 246 are insulated. The endless cable belt 248
can be used as an electrostatic precipitator or coalescer of
aqueous phase dispersed in a continuous hydrocarbon phase. A high
voltage DC imparts a charge to the dispersed phase as the fluid
passes through the gaps of the top flight 250. Then, as these
charged droplets pass the bottom flight 252, they are attracted to
the cables that are of the opposite polarity. When a high voltage
AC is used, the dispersed phase droplets vibrate due to the
alternating field and some of these droplets coalesce as they come
in contact with each other while passing through the top or bottom
flight.
[0147] Alternately, this apparatus of FIG. 10a-10b can be used as a
multi cable separation apparatus to break a hydrocarbon fog or mist
as described with FIG. 9. FIG. 10a-10b provides a different view or
embodiment of such a device which differs in one main aspect. The
device of FIG. 9 uses a single endless cable belt whilst the device
of FIG. 10a-10b uses two endless cable belts, although additional
endless cables can be used. Thus, the device of FIG. 10a-10b uses
at least two endless cable belts which are wrapped alternately upon
the main rollers 244, 246 to make an intertwined cable device. One
cable is charged with a high voltage DC potential or high voltage
AC phase. The other cable is charged with a high voltage DC of
opposite polarity or with a high voltage AC of the opposite phase.
This results in the presence of a high electric potential between
adjacent wraps on the insulated rollers. The high voltage DC or AC
is applied to the cables by means of the repositioning guides 254,
256 for each endless cable.
[0148] When a comb or scraper 258 is used to remove water or solids
from the cables, it often is more convenient to use four rollers in
order to have a region where the cables of opposite polarity are
not close to each other. In those spaced regions a comb or a knife
can be used to remove solids or water from the cables without
danger of bridging the gap between cables of opposite polarity with
water or wet solids which might create electrical discharge in view
of the high potential electricity used. A four roller device
therefore, would prevent or reduce electrical shorts or
sparking.
[0149] Slurry Filter
[0150] A moving bed filter can be created by the use of one or more
endless cables wrapped a plurality of times with very small gaps
around two or more rollers. The sequential wraps can be close
enough to form only very narrow gaps or slits through which liquid
can flow readily but which prevent the undesirable passage of
particulates of the medium to be filtered or dewatered. Undesirable
passage of particulates would be any amount that can be
substantially reduced without substantially blocking passage of
liquids therethrough.
[0151] A two level filter is shown as FIGS. 11a-11b, which uses one
endless cable 270. The endless cable acts as a wet or dry sieving
sifter or as a slurry dewatering device for a liquid slurry, e.g.,
desanded tailings from an oil sands process. For example, a
screened underflow 272 of a hydrocyclone mainly containing coarse
sand can be deposited first onto an upper flight of the filter. The
underflow can be distributed onto almost the full width of the
filter to form a moving bed of coarse particulates. For simplicity
in the drawing, the distributor is here shown as a pipe only. It is
to be understood that other distributors can be used which more
fully spread the slurry of the upper flight. The wraps of the
endless cable are close enough together to prevent coarse sand from
passing through the apertures. Again, for sake of illustration
clarity, the wraps are shown here much wider apart. The small
rollers 274 in FIG. 11b indicate that the wraps are kept close
together. Generally, gaps between wraps can be distanced apart from
about 0.5 mm to about 3 mm, although other gap spacings may be
suitable for particular embodiments and slurries. In this case, it
may not be as useful to have grooves in the rollers. The twist of a
conventional wire rope will normally provide voids adequate for
passage of water between the wraps, even when the extremities of
the individual wraps are touching. The useful size of gaps depends
on many variables of the apparatus, including intended application,
intended separation, composition and size of endless cable,
composition and particle sizes in the slurry, etc. However, in a
specific embodiment, the average gaps between adjacent windings are
about 0.01 cm to about 0.1 cm.
[0152] After the coarse sand bed is established, desanded tailings
276 can be deposited on top of the bed created by the coarse sand
272. The coarse sand then acts as a filtering medium for the
desanded tailings which contain water and fines, including fine
sand, silt and clay, as well as a small amount of bitumen. These
fines would normally pass through the gaps between the cable wraps,
but the coarse sand bed underneath prevents or reduces such
passage. Dewatered particulates and coarse sand leave the top
flight 278 of the filter as a bottom layer and dewatered desanded
tailings leave the filter as a top layer. The bottom flight 280 of
the filter may be shaken, washed, or blasted with air when it
becomes necessary to continuously remove from the bottom flight
sticking particulates or bitumen. As with any other embodiment, the
main rollers do not have to be the same size. Additional materials
can be added to the top flight, and the general concept may be used
for other filtering purposes, either as a single stage moving
filter or as a multi stage moving filter. In this case the liquid
may be water or any other liquid from which particulates are to be
recovered.
[0153] Generally, a filter can be formed of the apparatus where at
least two of the revolvable cylindrical members are oriented to
form an upper flight and a lower flight of the endless cable or
cables. The upper flight can be within 45.degree. of horizontal,
and the gaps between adjacent windings can be configured to be
sufficiently narrow to allow passage of liquid therethrough and
retention and conveyance of particulate solids thereon having a
predetermined particle size. The apparatus can further include a
liquid collection vessel oriented below the first flight and
configured to receive the liquid. Additionally, a first slurry
outlet can be included, which can be configured or oriented to
deposit a first coarse slurry onto the upper flight. Similarly, a
second slurry outlet can be included that is oriented to deposit a
second slurry onto the upper flight subsequent to the first coarse
slurry. Further, the separation apparatus can optionally include a
cleaning mechanism operatively associated with the bottom flight to
remove debris and material from one or more of the endless
cables.
[0154] Physical Separations
[0155] The endless cable belt of the instant invention provides for
a large range of apparatus options. In one aspect, it may be used
as a particle sizing device which moves various fractions to the
appropriate bins in a separation process. FIG. 12a illustrates a
simple configuration designed to separate a particulate feed into
two fractions. Feed is introduced via hopper 300 to the top flight
302 and one larger fraction 304 is removed from the top flight and
a second smaller fraction 306 passes through both flights and
leaves from the bottom flight 308. Thus, the flight gaps between
wraps can be adjusted to screen varying particle sizes from one
another to achieve the desired wet or dry sieving.
[0156] Alternative embodiments include a receiving bin for the
third, fourth and fifth fraction, for example, which may be placed
under the top flight or flights. This is accomplished when the gaps
or apertures between sequential cable wraps increase from one side
to another, as in FIG. 12b. This is shown for a simple
non-vibrating sizing apparatus in FIG. 12b. In this case, guides
310 may be useful to keep the endless cable 312 in the grooves of
the appropriate roller. Alternatively, additional rollers can be
oriented parallel to the outer rollers over which wraps are wound
or past over in order to produce multiple zones where gap distances
vary in each zone. For example, four size ranges can be produced
using four rollers (first through fourth parallel rollers oriented
in a plane in numerical order left to right) where the first and
second rollers have x wraps, the third roller has x/2 wraps, and
the fourth roller has x/4 wraps. In such a case, each subsequent
zone, i.e. from left to right, will have a gap distance which is
double that of the previous zone. Similarly, multiple separation
apparatuses can be oriented in series and/or parallel to further
separate the particulate material into additional size ranges. In
such cases, each separation apparatus can have gap spacings
designed and optimized for separation of a particular size
fraction.
[0157] FIG. 13 illustrates still another separation application
wherein the endless cable is used as a conveyor system for
separating objects which are retained on the endless cable. A
package 320 moves along an endless cable belt 322 main conveyor in
the direction shown by the arrow. One or a plurality of endless
cable belt secondary conveyors 324, 326 revolve under the main
conveyor. Two such secondary conveyors are shown, although
additional secondary conveyors can be added. Sets of pins 328 and
330 are located at the gaps between the cables of the overlapping
conveyors in a diagonal arrangement. These are pins or rollers, and
the elevation of these pins is electronically or otherwise
controlled using conventional mechanisms, e.g. hydraulic,
electronic motor, spring, etc. When the package is to be directed
to the left, onto the first secondary conveyor 324, the
corresponding pins 328 are raised, i.e., by computer. When the
package is to be directed to the right onto the second secondary
conveyor 326, the corresponding pins 330 are raised. The processing
can be fully automated by including sensors to detect bar codes on
packages. These bar codes can be read by the computer which can
then control onto which secondary conveyor the package is directed
using conventional sorting and inventory software. In this manner a
large number of packages, objects, parts, parcels or letters may be
directed rapidly and automatically to their respective desired
destinations. The use of pins or rollers 328 and 330 are possible
because the endless belt of the instant invention does not contain
cross members or cross wraps which in a conventional conveyor belt
would interfere with such pins or rollers located or rising up
between the cable wraps or between longitudinal members of the
belt.
[0158] Of course, it is to be understood that the above-described
arrangements, and specific examples and uses, are only illustrative
of the application of the principles of the present invention.
Numerous modifications and alternative arrangements may be devised
by those skilled in the art without departing from the spirit and
scope of the present invention and the appended claims are intended
to cover such modifications and arrangements. Thus, while the
present invention has been described above with particularity and
detail in connection with what is presently deemed to be the most
practical and preferred embodiments of the invention, it will be
apparent to those of ordinary skill in the art that numerous
modifications, including, but not limited to, variations in size,
materials, shape, form, function and manner of operation, assembly
and use may be made without departing from the principles and
concepts set forth herein.
* * * * *