Note: Descriptions are shown in the official language in which they were submitted.
SHEARING AND SPARGING OF BITUMEN FROTH TREATMENT TAILINGS
BACKGROUND
Field of Disclosure
[0001] The disclosure relates generally to the field of oil sand
processing, and more
particularly to bitumen tailings separation.
Description of Related Art
[0002] This section is intended to introduce various aspects of the
art, which may be
associated with the present disclosure. This discussion is believed to assist
in providing a
framework to facilitate a better understanding of particular aspects of the
present disclosure.
Accordingly, it should be understood that this section should be read in this
light, and not
necessarily as admissions of prior art.
[0003] Modern society is greatly dependent on the use of hydrocarbon
resources for
fuels and chemical feedstocks. Hydrocarbons are generally found in subsurface
formations
that can be termed "reservoirs". Removing hydrocarbons from the reservoirs
depends on
numerous physical properties of the subsurface formations, such as the
permeability of the
rock containing the hydrocarbons, the ability of the hydrocarbons to flow
through the
subsurface formations, and the proportion of hydrocarbons present, among other
things. Easily
harvested sources of hydrocarbons are dwindling, leaving less accessible
sources to satisfy
future energy needs. As the costs of hydrocarbons increase, the less
accessible sources become
more economically attractive.
[0004] Recently, the harvesting of oil sand to remove heavy oil has
become more
economical. Hydrocarbon removal from oil sand may be performed by several
techniques.
For example, a well can be drilled to an oil sand reservoir and steam, hot
air, solvents, or a
combination thereof, can be injected to release the hydrocarbons. The released
hydrocarbons
may be collected by wells and brought to the surface. In another technique,
strip or surface
- 1 -
Date Recue/Date Received 2021-04-28
mining may be performed to access the oil sand, which can be treated with
water, steam or
solvents to extract the heavy oil.
[0005] Oil sand extraction processes are used to liberate and separate
bitumen from
oil sand so that the bitumen can be further processed to produce synthetic
crude oil or mixed
with diluent to form "dilbit" and be transported to a refinery plant. Numerous
oil sand
extraction processes have been developed and commercialized, many of which
involve the
use of water as a processing medium. Where the oil sand is treated with water,
the technique
may be referred to as water-based extraction (WBE) or as a water-based oil
sand extraction
process. WBE is a commonly used process to extract bitumen from mined oil
sand.
[0006] One WBE process is the Clark hot water extraction process (the
"Clark
Process"). This process typically requires that mined oil sand be conditioned
for extraction by
being crushed to a desired lump size and then combined with hot water and
perhaps other
agents to form a conditioned slurry of water and crushed oil sand. In the
Clark Process, an
amount of sodium hydroxide (caustic) may be added to the slurry to increase
the slurry pH,
which enhances the liberation and separation of bitumen from the oil sand.
Other WBE
processes may use other temperatures and may include other conditioning
agents, which are
added to the oil sand slurry, or may operate without conditioning agents. This
slurry is first
processed in a Primary Separation Cell (PSC), also known as a Primary
Separation Vessel
(PSV), to extract the bitumen from the slurry.
[0007] In one WBE process, a water and oil sand slurry is separated into
three major
streams in the PSC: bitumen froth, middlings, and a PSC underflow (also
referred to as coarse
sand tailings (CST)).
[0008] Regardless of the type of WBE process employed, the process will
typically
result in the production of a bitumen froth that requires treatment with a
solvent. For example,
in the Clark Process, a bitumen froth stream comprises bitumen, solids, and
water. Certain
processes use naphtha to dilute bitumen froth before separating the product
bitumen by
centrifugati6n. These processes are called naphtha froth treatment (NFT)
processes. Other
- 2 -
CA 3067314 2020-01-09
processes use a paraffinic solvent, and are called paraffinic froth treatment
(PFT) processes,
to produce pipelineable bitumen with low levels of solids and water. In the
PFT process, a
paraffinic solvent is used to dilute the froth before separating the product,
diluted bitumen, by
gravity. A portion of the asphaltenes in the bitumen is also rejected by
design in the PFT
process and this rejection is used to achieve reduced solids and water levels.
In both the NFT
and the PFT processes, the diluted tailings (comprising water, solids and some
hydrocarbon)
are separated from the diluted product bitumen.
[0009] Solvent is typically recovered from the diluted product bitumen
component
before the bitumen is delivered to a refining facility for further processing.
[0010] The PFT process may comprise at least three units: Froth
Separation Unit
(FSU), Solvent Recovery Unit (SRU) and Tailings Solvent Recovery Unit (TSRU).
Mixing
of the solvent with the feed bitumen froth may be carried out counter-
currently in two stages
in separate froth separation units. The bitumen froth comprises bitumen,
water, and solids. A
typical composition of bitumen froth is about 60 wt. % bitumen, 30 wt. %
water, and 10 wt.
% solids. The paraffinic solvent is used to dilute the froth before separating
the product
bitumen by gravity. The foregoing is only an example of a PFT process and the
values are
provided by way of example only. An example of a PFT process is described in
Canadian
Patent No. 2,587,166 to Sury.
[0011] From the PSC, the middlings, which may comprise bitumen and
about 10-30
wt. % solids, or about 20-25 wt. % solids, based on the total wt. % of the
middlings, is
withdrawn and sent to the flotation cells to further recover bitumen. The
middlings are
processed by bubbling air through the slurry and creating a bitumen froth,
which is recycled
back to the PSC. Flotation tailings (FT) from the flotation cells, comprising
mostly solids and
water, are sent for further treatment or disposed in an external tailings area
(ETA).
SUMMARY
[0012] A disclosed method comprises providing tailings from a bitumen
froth
treatment using solvent, introducing the tailings into a flotation column,
using a shearing
- 3 -
CA 3067314 2020-01-09
device to break asphaltenes flocs in the tailings, introducing water and gas
into the flotation
column through sparging; and removing an overflow and an underflow from the
flotation
column.
[0013] The foregoing has broadly outlined the features of the present
disclosure so
that the detailed description that follows may be better understood.
Additional features will
also be described herein.
BRIEF DESCRIPTION OF THE DRAWING
[0014] These and other features, aspects and advantages of the
disclosure will become
apparent from the following description, appending claims and the accompanying
drawing,
which is briefly described below.
[0015] Fig. 1 is a schematic of a process configuration utilizing a
flotation column for
separating bitumen tailings herein.
[0016] Fig. 2 is a schematic of a process configuration utilizing a
flotation column for
separating bitumen tailings herein.
[0017] Fig. 3 is a schematic of a process configuration for processing
bitumen froth
herein.
[0018] It should be noted that these figures are merely examples and no
limitations
on the scope of the present disclosure is intended thereby. Further, the
figures are generally
not drawn to scale, but are drafted for purposes of convenience and clarity in
illustrating
various aspects of the disclosure.
DETAILED DESCRIPTION
[0019] For the purpose of promoting an understanding of the principles
of the
disclosure, reference will now be made to the features illustrated in the
drawings and specific
language will be used to describe the same. It will nevertheless be understood
that no
limitation of the scope of the disclosure is thereby intended. Any alterations
and further
- 4 -
CA 3067314 2020-01-09
modifications, and any further applications of the principles of the
disclosure as described
herein are contemplated as would normally occur to one skilled in the art to
which the
disclosure relates. It will be apparent to those skilled in the relevant art
that some features that
are not relevant to the present disclosure may not be shown in the drawings
for the sake of
clarity.
[0020] At the outset, for ease of reference, certain terms used in this
application and
their meaning as used in this context are set forth below. To the extent a
term used herein is
not defined below, it should be given the broadest definition persons in the
pertinent art have
given that term as reflected in at least one printed publication or issued
patent. Further, the
present processes are not limited by the usage of the terms shown below, as
all equivalents,
synonyms, new developments and terms or processes that serve the same or a
similar purpose
are considered to be within the scope of the present disclosure.
[0021] Throughout this disclosure, where a range is used, any number
between or
inclusive of the range is implied.
[0022] A "hydrocarbon" is an organic compound that primarily includes
the elements
of hydrogen and carbon, although nitrogen, sulfur, oxygen, metals, or any
number of other
elements may be present in small amounts. Hydrocarbons generally refer to
components found
in heavy oil or in oil sand. However, the techniques described are not limited
to heavy oils but
may also be used with any number of other reservoirs to improve gravity
drainage of liquids.
Hydrocarbon compounds may be aliphatic or aromatic, and may be straight
chained,
branched, or partially or fully cyclic.
[0023] "Bitumen" is a naturally occurring heavy oil material.
Generally, it is the
hydrocarbon component found in oil sand. Bitumen can vary in composition
depending upon
the degree of loss of more volatile components. It can vary from a very
viscous, tar-like,
semi-solid material to solid forms. The hydrocarbon types found in bitumen can
include
aliphatics, aromatics, resins, and asphaltenes. A typical bitumen might be
composed of:
19 weight (wt.) % aliphatics (which can range from 5 wt. % - 30 wt. %, or
higher);
- 5 -
CA 3067314 2020-01-09
19 wt. % asphaltenes (which can range from 5 wt. % - 30 wt. %, or higher);
30 wt. % aromatics (which can range from 15 wt. % - 50 wt. %, or higher);
32 wt. % resins (which can range from 15 wt. % - 50 wt. %, or higher); and
some amount of sulfur (which can range in excess of 7 wt. %), the weight %
based
upon total weight of the bitumen.
In addition, bitumen can contain some water and nitrogen compounds ranging
from less than
0.4 wt. % to in excess of 0.7 wt. %. The percentage of the hydrocarbon found
in bitumen can
vary. The term "heavy oil" includes bitumen as well as lighter materials that
may be found in
a sand or carbonate reservoir.
[0024] "Heavy oil" includes oils which are classified by the American
Petroleum
Institute ("API"), as heavy oils, extra heavy oils, or bitumens. The term
"heavy oil" includes
bitumen. Heavy oil may have a viscosity of about 1,000 centipoise (cP) or
more, 10,000 cP or
more, 100,000 cP or more, or 1,000,000 cP or more. In general, a heavy oil has
an API gravity
between 22.3 API (density of 920 kilograms per meter cubed (kg/m3) or 0.920
grams per
centimeter cubed (g/cm3)) and 10.00 API (density of 1,000 kg/m3 or 1 g/cm3).
An extra heavy
oil, in general, has an API gravity of less than 10.00 API (density greater
than 1,000 kg/m3 or
1 g/cm3). For example, a source of heavy oil includes oil sand or bituminous
sand, which is a
combination of clay, sand, water and bitumen.
[0025] "Fine particles" or "fines" are generally defined as those
solids having a size
of less than 44 microns (.), as determined by laser diffraction particle size
measurement.
[0026] "Coarse particles" are generally defined as those solids having
a size of greater
than 44 microns (im).
[0027] The term "solvent" as used in the present disclosure should be
understood to
mean either a single solvent, or a combination of solvents.
[0028] The terms "approximately," "about," "substantially," and similar
terms are
intended to have a broad meaning in harmony with the common and accepted usage
by those
of ordinary skill in the art to which the subject matter of this disclosure
pertains. It should be
- 6 -
CA 3067314 2020-01-09
understood by those of skill in the art who review this disclosure that these
terms are intended
to allow a description of certain features described and claimed without
restricting the scope
of these features to the precise numeral ranges provided. Accordingly, these
terms should be
interpreted as indicating that insubstantial or inconsequential modifications
or alterations of
the subject matter described and are considered to be within the scope of the
disclosure.
[0029] The articles "the", "a" and "an" are not necessarily limited to
mean only one,
but rather are inclusive and open ended so as to include, optionally, multiple
such elements.
[0030] The term "paraffinic solvent" (also known as aliphatic) as used
herein means
solvents comprising normal paraffins, isoparaffins or blends thereof in
amounts greater than
50 wt. %. Presence of other components such as olefins, aromatics or
naphthenes may
counteract the function of the paraffinic solvent and hence may be present in
an amount of
only 1 to 20 wt. % combined, for instance no more than 3 wt. %. The paraffinic
solvent may
be a C4 to C20 or C4 to C6 paraffinic hydrocarbon solvent or a combination of
iso and normal
components thereof. The paraffinic solvent may comprise pentane, iso-pentane,
or a
combination thereof..
[0031] TSRU tailings are generated from bitumen froth treatment using
solvents (i.e.
paraffinic or naphthenic). In the case of paraffinic processes, the tailings
may be rich in
asphaltenes (rejected by design) and may have some maltenes (considered a
loss). TSRU
tailings include valuable thermal energy as they may be at a temperature of
about 80-90
degrees C.
[0032] Disclosed herein is a process to recover hydrocarbons (in the
form of
maltenes). In the processes herein, a flotation column equipped with a
shearing device and/or
gas spargers is used. The role of the shearing device (e.g., cavitation tubes,
cavitation pumps,
jet pumps, etc.) is to use an extensive shear in order to break the structure
of asphaltene flocs
in the tailings. After the breakage of asphaltene flocs, the dispersed
particles get exposed to a
microbubbles stream, generated through gas spargers. In this way, a greater
amount of
- 7 -
CA 3067314 2020-01-09
hydrocarbons (in the form of maltenes) and heat can be retained rather than
being lost to
tailings.
[0033] A disclosed method comprises providing tailings from a bitumen
froth
treatment using solvent, introducing the tailings into a flotation column,
using a shearing
device to break asphaltenes flocs in the tailings, introducing water and gas
into the flotation
column through sparging; and removing an overflow and an underflow from the
flotation
column. While shearing and sparging are generally described herein in this
order, the method
is not limited by any particular order as between the shearing and sparging.
In fact, since the
method is generally a continuous method, all steps are happening at once. The
methods herein
are directed at improved recovery of valuable hydrocarbons from the flotation
column as a
result of the process configurations disclosed herein. In particular, the
processes herein are
directed to improved maltenes recovery (valuable hydrocarbons that are
normally rejected
with the tailings in conventional froth treatment separation processes).
[0034] The flotation column may be a generally vertical cylindrical
vessel with a high
length to diameter ratio. The flotation column may have a cone bottom to
mitigate solids build
up. An external sparging system may inject gas or a gas/water mixture into a
lower portion of
the flotation column. In embodiments, the gas utilized may be air or a gas
mixture comprised
of air. The flotation column may operate with a deep froth layer to improve
drainage of
entrained mineral particles. Froth washing, a water spray over the collected
froth layer at the
top of the column, may be incorporated to mitigate clays and minerals from
reporting to the
froth product (overflow). The spargers may be designed or controlled to
provide the
appropriate amount and size of bubbles to provide the required surface area
for bitumen
recovery, for instance by controlling gas and water pressures or by selecting
the size of the
spargers. The spargers may be (evenly) distributed around the column to
provide an even
distribution of gas across the cross-section of the column. After, the
breakage of the flocs, the
smallbubbles will attach to the hydrocarbon molecules due to the
hydrophobicity of both
surfaces (i.e. gas bubble and hydrocarbon) and float to the top of flotation
cell. Any suitable
industrial, commercially available spargers may be used.
- 8 -
CA 3067314 2020-01-09
[0035] The bitumen froth treatment may comprise any suitable bitumen
froth
treatment and may be a paraffinic froth treatment. The tailings may comprise
any suitable
tailings from a bitumen froth treatment and may comprise tailings solvent
recovery unit
(TSRU) tailings. TSRU tailings are tailings exiting a TSRU following solvent
recovery.
[0036] The gas may be any suitable gas and may comprise air, N2, CO2,
CI-14, or a
combination thereof. In view of the presence of residual solvent, an air-free
operation may
be selected in which the spargers use gases such as CO2, N2 or CI-14.
[0037] The method may further comprise spraying water onto the top of a
froth layer
in the flotation column for mitigating minerals from reporting to the
overflow.
[0038] Depending on the severity and conditions of flotation, the
underflow may be a
high water, low fines content stream. The underflow may be used as dilution
water or process
water in the bitumen froth treatment process. The underflow may be used as
primary
separation cell (PSC) dilution water, froth separation cell (FSU) cone
dilution water, TSRU
underflow dilution water, or a combination thereof. Where two FSUs are used in
series
(commonly referred to as FSU-1 and FSU-2), the underflow may be used in either
or both
FSUs. Using the underflow in these ways may significantly reduce PFT water
usage and may
significantly reduce heating requirements.
[0039] The method may further comprise removing solids from the
overflow.
[0040] The method may comprise recycling the overflow to an FSU (e.g.
FSU-1).
Such recycling may lower the amount of required asphaltene rejection to meet
pipeline
specification by acting as a seed for asphaltene precipitation. Asphaltene
seeding results in
the formation of asphaltenes flocs with a lower porosity and a higher density.
These flocs will
entrain less hydrocarbon (solvent and maltenes) as they settle through the FSU
units, which
ultimately reduces bitumen and solvent loss. By tuning the process variables
(e.g., gas
injection rate, shear, etc.) or using chemicals, it is possible to selectively
recover the maltenes
fraction. These additional hydrocarbons would go to FSU product upon recycling
to FSU.
- 9 -
CA 3067314 2020-01-09
[0041] The method may further comprise recycling the overflow to the
flotation
column together with the tailings that are fed into the flotation column.
[0042] The method may further comprise using the overflow as a
feedstock for
producing advanced materials. The advanced materials may comprise carbon
fiber, graphene
oxide, or a combination thereof The method may also further comprise sending
the overflow
as a feedstock to an upgrader unit, or to road paving or construction
materials.
[0043] The method may further comprise adding a chemical additive or a
gas additive
to selectively separate maltenes during the flotation so that more maltenes
report to the
overflow and more asphaltenes report to the underflow as compared to without
the chemical
additive or the gas additive. The method may further comprise effecting a two-
stage process
to selectively recover maltenes, comprising: i) liberating maltenes from
asphaltenes using a
collector additive, gas injection, and an asphaltene flocculant; and ii)
selective flotation of
maltenes from asphaltenes using a chemical additive. The collector additive
may comprise
light hydrocarbons (e.g., pentane or kerosene). The asphaltene flocculant may
comprise
sulfonated polystyrene. The chemical additive may comprise a depressant, which
may
comprise a humic acid. The chemical additive may comprise a pH variation
additive, which
may comprise a multivalent metal ion.
[0044] The tailings may comprise, for example, water, 0.5 to 7 wt. %
hydrocarbon,
and 5 to 20 wt. % solids; or water, 10 to 20 wt. % hydrocarbon, and 10 to 20
wt. % solids; or
water, 0 to 0.5 wt. % bitumen, and 1 to 5 wt. % solids.
[0045] The method may be operated at any suitable temperature and may
be operated
at a temperature of 20 to 90 degrees C.
[0046] The shearing device may comprise a cavitation pump, a cavitation
tube, a jet
pump, or a combination thereof The shearing device may comprise a cavitation
pump
through which the tailings are passed prior to introduction into the flotation
column (as
described below with reference to Fig. 1). The shearing device may comprise a
cavitation
pump and subsequent cavitation tube and/or jet pump, arranged in series,
through which a
- 10 -
CA 3067314 2020-01-09
portion of the underflow from the flotation column are passed prior to
recycling into the
flotation cell (as described below with reference to Fig. 2). The shearing
device may comprise
a cavitation pump through which the water and gas are passed prior to
introduction into the
flotation column (as described below).
[0047] The sparging may be provided by one or more spargers
preferentially
distributed around the flotation column.
[0048] Fig. 1 is a schematic of a process herein utilizing a flotation
column. With
reference to Fig. 1, a hydrocarbon-containing stream (102) is passed through a
cavitation
pump (103) and introduced into a flotation column (104) comprising a froth
launder (105).
Water and gas are introduced into the flotation column (104) through spargers
(106) to provide
bubbles for attaching to bitumen. Flotation separation in the flotation column
(104) produces
an overflow (112) and an underflow (114). Water (not shown) may be sprayed
onto the froth
layer in the flotation column (104) for mitigating minerals from reporting to
the overflow
(112).
[0049] Fig. 2 is a schematic of a process herein utilizing a flotation
column. With
reference to Fig. 2, a hydrocarbon-containing stream (202) is introduced into
a flotation
column (204) comprising a froth launder (205). Water and gas are introduced
into the flotation
column (204) through spargers (206) to provide bubbles for attaching to
hydrocarbon.
Hydrocarbon separation in the flotation column (204) produces an overflow
(212) and an
underflow (214), a portion (214a) which is sent for additional tailings
processing. Water (not
shown) may be sprayed onto the froth layer in the flotation column (204) for
mitigating
minerals from reporting to the overflow (212). A portion (214b) of the
underflow (214) may
be passed through a cavitation pump (216) and a cavitation tube and/or jet
pump (218) and
recycled to the flotation column (204) to shear flocs in the bitumen-
containing stream (202).
The water and gas may be added before the cavitation pump (216) or after the
jet pump (218).
[0050] Fig. 3 is a schematic of a process herein utilizing a flotation
column as used in
the context of a larger system of froth treatment. With reference to Fig. 3,
bitumen froth (302)
- 11 -
CA 3067314 2020-01-09
is added to a first froth separation unit ("FSU-1") (304) which separates the
bitumen froth into
an FSU-1 overflow product (306) and FSU-1 underflow (308). The FSU-1 underflow
(308)
is passed to a second froth separation unit ("FSU-2") (310) which produces an
FSU-2
overflow (312), which is passed to FSU-1 (304), and FSU-2 underflow (314)
which is passed
to a first tailings solvent recovery unit ("TSRU-1") (316). The TSRU-1
tailings (318) are
passed to a second TSRU ("TSRU-2") (320). Solvent (322 and 324) from the TSRUs
is
recovered and combined with a makeup solvent (326) which is recycled as
recycle solvent
(328) to the FSU-2 (310). TSRU-2 tailings (330), comprising solids, maltenes,
asphaltenes,
solvent and water, are passed to a primary flotation column (332) as described
herein. The
primary flotation column (332) comprises spargers, cavitation pumps, and/or
jet pumps (334)
(shown collectively here, but as described in more detail in Fig. 2). TSRU-2
tailings (330)
are passed through and cavitation means (336) prior to entering the primary
flotation column
(332). A
primary flotation column overflow (338) containing valuable recovered
hydrocarbons is combined with the bitumen froth (302). The primary flotation
column
underflow (340) is passed to an asphaltene flotation column (342) which
produces an
asphaltene flotation column overflow (344) comprising asphaltenes, and an
asphaltene
flotation column underflow (346). In preferred embodiments, heat and water
from the
asphaltene flotation column underflow (346) is recovered by utilizing the
stream in the froth
treatment process.
[0051] A
small scale pilot test was conducted. Oil sands tailings were fully
homogenized and their temperature was adjusted to process temperature (about
60 C). The
oil sands tailings were then pumped in a small flow rate to the feed section
of a flotation
column with a 4 inch diameter and a height of about 2 meters. Air was injected
from the
bottom of column through an air sparger which created micron size bubbles.
While air
bubbles were rising through the column in a plug flow regime, they collided
with bitumen
droplets in the tailings and generated aerated droplets. Due to their small
density, the aerated
droplets rose in the column and collected in the column launder. The
experimental conditions
and measurements for the test were as follows: feed hydrocarbon content: 3 to
4 weight %,
experimental temperature: 55 to 60 C, feed solid content: 6 to 8 weight %,
asphaltenes % (out
- 12 -
CA 3067314 2020-01-09
of total hydrocarbon) in feed: about 72 weight %, asphaltenes % (out of total
hydrocarbons)
in froth: about 73%, froth hydrocarbon content: 13 to 17 weight %, froth solid
content: 16 to
17.5 weight %, hydrocarbon recovery: 84 to 99 weight %. In Table 1, 'Feed l'
represents one
feed introduced into the flotation column as described above, and producing
'Froth 1' and
"Underflow 1'. The 'Recovery' represents the amount of hydrocarbons which
reports to the
froth, as opposed to being lost to the underflow. Similarly, 'Feed 2' produces
'Froth 2' and
`Underflow 2', 'Feed 3' produces 'Froth 3' and Underflow 3', and 'Feed 4'
produces 'Froth
4' and `Underflow 4. As can be seen from the experimental data in Table 1, the
tailings
(underflow) appeared to contain almost no hydrocarbons after leaving the
column which is
aligned with the high recovery observed during the test.
Table 1
Feed Froth Underflow Feed Froth Underflow Feed Froth Underflow Feed Froth
Underflow
1 1 1 2 2 2 3 3 3 4 4 4
Mass %
2.96 16.45 0.02 2.84 12.97 0.15 3.75 12.58 0.11
4.42 12.66 0.97
HC
Mass % 5.58 17.22 1.43 6.00 15.61 1.77 8.24 15.86 2.11
9.41 15.18 2.23
Solids
Mass %
89.5564.37 97.46 89.94 69.91 97.73 87.28 70.84 97.96 84.76 71.55 97.11
Water
Recovery 99.50 96.14 97.88 84.28
[0052] It should be understood that numerous changes, modifications,
and alternatives
to the preceding disclosure can be made without departing from the scope of
the disclosure.
The preceding description, therefore, is not meant to limit the scope of the
disclosure. Rather,
the scope of the disclosure is to be determined only by the appended claims
and their
equivalents. It is also contemplated that structures and features in the
present examples can be
altered, rearranged, substituted, deleted, duplicated, combined, or added to
each other. The
scope of the claims should not be limited by particular embodiments set forth
herein, but
should be construed in a manner consistent with the specification as a whole.
- 13 -
CA 3067314 2020-01-09
