U.S. patent application number 12/883789 was filed with the patent office on 2011-01-13 for method and apparatus for forming undulating conduit.
This patent application is currently assigned to UNDULTEC, INC.. Invention is credited to LUBOMYR M. CYMBALISTY, FREDERICK ARTHUR HEMPHILL.
Application Number | 20110005291 12/883789 |
Document ID | / |
Family ID | 39639948 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110005291 |
Kind Code |
A1 |
CYMBALISTY; LUBOMYR M. ; et
al. |
January 13, 2011 |
METHOD AND APPARATUS FOR FORMING UNDULATING CONDUIT
Abstract
Method and apparatus for forming conduit or pipe of various
sizes into undulating, helical pipe by feeding a length of conduit
at a controlled rate through a bending mechanism while also
continuously rotating the pipe at a controlled rate so that bending
occurs in multiple axis directions and the diameter of the helical
path of the conduit centerline of the coil is less than the conduit
diameter, the pitch is greater than the pipe diameter, and a
straight open channel is retained through the pipe coil.
Inventors: |
CYMBALISTY; LUBOMYR M.;
(Edmonton, CA) ; HEMPHILL; FREDERICK ARTHUR;
(Victoria, CA) |
Correspondence
Address: |
BENNETT JONES LLP;C/O MS ROSEANN CALDWELL
4500 BANKERS HALL EAST, 855 - 2ND STREET, SW
CALGARY
AB
T2P 4K7
CA
|
Assignee: |
UNDULTEC, INC.
Edmonton
CA
|
Family ID: |
39639948 |
Appl. No.: |
12/883789 |
Filed: |
September 16, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11956707 |
Dec 14, 2007 |
|
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12883789 |
|
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60874848 |
Dec 14, 2006 |
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Current U.S.
Class: |
72/250 ; 138/122;
138/178; 138/DIG.11; 138/DIG.8; 72/369 |
Current CPC
Class: |
B01F 5/0646 20130101;
B01F 5/0647 20130101; B01F 5/065 20130101; B21D 7/08 20130101; B21D
11/07 20130101 |
Class at
Publication: |
72/250 ; 72/369;
138/122; 138/178; 138/DIG.008; 138/DIG.011 |
International
Class: |
B21B 19/00 20060101
B21B019/00 |
Claims
1. A method of forming an undulating pipe comprising: providing a
substantially straight pipe having a longitudinal axis through the
center of the pipe; providing a bending apparatus including a
system for feeding the pipe through the bending apparatus; moving
the pipe in an axial direction through the bending apparatus, the
bending apparatus asserting a force on the pipe to arcuately bend
the pipe; and simultaneously rotating the pipe about the
longitudinal axis as the pipe is moving in the axial direction such
that the pipe undulates in a generally helical path.
2. The method of claim 1 wherein the bending apparatus includes a
plurality of rollers.
3. The method of claim 2 wherein the bending apparatus comprises a
feed roller and a bending roller.
4. The method of claim 1 wherein the interior of the pipe includes
a continuous smooth interior wall throughout a length of the
pipe.
5. The method of claim 1 wherein the pipe has an interior wall that
is circular in cross-section at every position along a length of
the pipe.
6. The method of claim 1 wherein the pipe is moved and rotated at
rates such that the pitch is substantially greater than one pipe
diameter.
7. The method of claim 6 wherein the pipe is moved and rotated at
rates such that the pitch is a multiple of the pipe diameter.
8. The method of claim 1 wherein the pipe is moved and rotated at
rates such that the radius of the helical path is smaller than the
radius of the interior of the pipe.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a divisional application of U.S.
application Ser. No. 11/956,707 filed Dec. 14, 2007, which is
presently pending. U.S. application Ser. No. 11/956,707 and the
present application claim priority under 35 U.S.C. .sctn.119(e) to
U.S. provisional patent application No. 60/874,848, filed Dec. 14,
2006, which is incorporated by reference in its entirety
herein.
FIELD OF THE INVENTION
[0002] This invention pertains to a method and apparatus for
forming bent conduit or pipe of various sizes that can be used for
a variety of applications, including but not limited to
hydrodynamic mixing with no moving parts, generally known in the
industry as a static mixer. This invention provides a method and
apparatus which can be utilized to form the undulating conduit
disclosed and claimed in my below mentioned applications and U.S.
Pat. No. 6,896,007, which is highly effective for extraction of oil
from oil sands deposits present in many countries throughout the
world.
BACKGROUND OF THE INVENTION
[0003] Various methods and apparatus are employed to bend or form
lengths of pipe. In U.S. Pat. No. 4,317,353, an automated apparatus
is shown for forming helical corrugations in tubing by a twisting
operation. However, such apparatus and methodology creates ridges
and valleys in the interior of the pipe, which when formed as shown
in the reference, can produce undesirable flow properties for fluid
passing through the pipe. Furthermore, such apparatus and
methodology would not likely be practical for large-diameter
conduits or for pipes made of certain materials. A hydraulic pipe
bender is disclosed in Sheen U.S. Pat. No. 5,431,035 issued Jul.
11, 1995. As with all prior bending operations, the pipe is bent
only in one axis direction and it is not undulating in the
interior.
BRIEF SUMMARY OF THE INVENTION
[0004] Accordingly, the present invention provides the methodology
and equipment to form undulating conduit or pipe, which is bent in
multiple axes directions in the nature of a helix, and where the
conduit or pipe diameter is larger than the diameter of the helical
path of the conduit centerline.
[0005] The invention comprises forming conduit of various diameters
including, but not limited to, large size conduit or pipe, into an
undulating helical pipe. The conduit used may be any suitable shape
in its internal diameter (such as round), but preferably relatively
continuous and smooth. The external cross section of the conduit
may be any suitable shape. The coil is formed by feeding the
conduit or pipe at a controlled rate through a bending mechanism
while also rotating it at a controlled rate such that bending
occurs in multiple axis directions through 360 degrees. The
diameter of the resulting helical path of the conduit centerline is
less than the pipe diameter, while the pitch is greater than the
pipe diameter so that a straight open circular channel is retained
through the pipe coil. The combination of the helical shape of the
internal walls of the conduit and the straight open round channel
through the pipe coil imparts hydrodynamic mixing particularly to
slurries flowed through the pipe.
[0006] A method is disclosed of forming an undulating pipe
comprising, providing a substantially straight pipe having a
longitudinal axis through the center of the pipe, providing a
bending apparatus including a system for feeding the pipe through
the bending apparatus, moving the pipe in an axial direction
through the bending apparatus, the bending apparatus asserting a
force on the pipe to arcuately bend the pipe, and simultaneously
rotating the pipe about the longitudinal axis as the pipe is moving
in the axial direction such that the pipe undulates in a generally
helical path.
[0007] The bending apparatus may include a plurality of rollers.
The bending apparatus may comprise a feed roller and a bending
roller. The interior of the pipe may include a continuous smooth
interior wall throughout a length of the pipe. The pipe may have an
interior wall that is circular in cross-section at every position
along a length of the pipe. The pipe may be moved and rotated at
rates such that the pitch is substantially greater than one pipe
diameter. The pipe may be moved and rotated at rates such that the
pitch is a multiple of the pipe diameter. The pipe may be moved and
rotated at rates such that the radius of the helical path is
smaller than the radius of the interior of the pipe.
[0008] An undulating pipe formed by the method is also disclosed.
The undulating pipe may be a hydro-dynamic static mixing apparatus
for flowing fluidized slurries, the pipe having a preselected and
predetermined configuration and length for mixing and/or
transporting various substances including highly abrasive solids
contained in slurries, said pipe being interconnected into a
transportation and processing separation system for such slurries,
said pipe having an internal radius rc and the undulations are
formed by a coil having a radius rh such that the diameter of the
conduit is greater than the coil diameter, means for pumping said
fluidized slurry through an undulating interior of the pipe at some
stage of transportation through the separation system, and said
undulating interior configuration causing dynamic mixing of flowing
slurries as said slurries are pumped through the pipe.
[0009] The undulating pipe may be a hydrodynamic static mixing
apparatus having a preselected and predetermined configuration and
length for mixing and/or transporting various substances, including
fluids and solids contained in slurries, said pipe having an
interior forming a helical coil having a pitch and with the
diameter of the interior being greater than a coil helix diameter,
said pipe including a generally round internal cross-section having
a radius rc and a generally helical undulation having a path radius
rh, said pipe, including an open inner channel along the
longitudinal axis of the conduit, the inner channel having a radius
ri that is substantially equal to rc-rh, the pitch of the helical
coil being greater than one pipe diameter and said pipe is adapted
to be incorporated into systems that perform one or more of the
functions of fluid or slurry transport, processing and
separation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a diagrammatic view of the working principle of
the present invention for straight-feed without rotation;
[0011] FIG. 2 is a diagrammatic view showing the operation of the
bender mechanism with controlled feeding and controlled rotation to
form undulating pipe;
[0012] FIGS. 3a and 3b are two-dimensional illustrative side
sectional views of a formed conduit;
[0013] FIG. 3c is an end view showing the undulating configuration
with desired open channel interior produced by the bending
operation;
[0014] FIG. 4a is an end view of a length of helically undulating
conduit having a circular cross-section and an open center
channel;
[0015] FIG. 4b is a shallow perspective side view of the helically
undulating conduit of FIG. 4a;
[0016] FIG. 4c is a steep perspective side view of the helically
undulating conduit of FIG. 4a;
[0017] FIG. 5 is an illustrative representation of the end views of
several alternative cross-sectional shapes for undulating
conduits;
[0018] FIG. 6a is an illustrative side view of an alternative form
of undulating conduit mixer in which the pitch of the helical
undulation is non-zero and the radius of the helical undulation is
zero, for the case where the undulating conduit has an oval
cross-section and the direction of rotating undulation is abruptly
reversed to provide a short region of intense mixing in the
conduit;
[0019] FIG. 6b is a magnified end view of the conduit in FIG. 6a,
showing the open central channel provided by a spiral-twisted
undulating conduit having an oval cross-section;
[0020] FIG. 6c is an illustrative trimetric view of a short section
of the conduit of FIG. 6b inserted as a flow revitalizer between
two sections of standard cylindrical pipe;
[0021] FIG. 7 is a flow diagram of an oil sands bitumen extraction
method utilizing undulating conduits of the present invention;
[0022] FIG. 8 is a simplified diagram showing various pipe
cross-sections showing a settling of solids to the bottom of the
pipe such as would occur when the flow through the pipe has
stopped; and
[0023] FIG. 9 is a simplified end view of a length of helically
undulating conduit having a circular cross-section and an open
center channel.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The invention provides a method and apparatus for forming an
undulating pipe having a helical interior path. A pipe of this kind
may be used for the transmission of fluids or slurries. The helical
undulating shape may help to transmit slurries in such a manner
that solids disposed within the fluid may travel in a suspended
state to limit the amount of solid material that may collect near
the bottom of the pipe.
[0025] For example, in the application of oil field drilling, it is
common that the oil slurry removed from the earth would contain a
mixture of liquid and solid particles, such as oil sands. This
mixture is commonly transported from the drilling site to a remote
location for separation of the slurry. In straight pipes, the solid
material in the slurry tends to collect near the bottom of the
pipe, thus obstructing transport. In pipes having undulation in a
single plane, the solid material tends to collect in the valleys of
the undulating pipe and the abrasiveness of the slurry wears down
the pipe. The invention provides a method of forming a pipe having
an interior that undulates in a helical path such that the solid
material is substantially transported in a suspended state in the
fluid.
[0026] An example of a machine capable of bending conduit is shown
for example in U.S. Pat. No. 5,431,035, incorporated herein by
reference. The bending machine may comprise frame elements,
rollers, gears, a clutch, mechanisms for lifting, guiding, feeding
and bending, and operating systems including, for example,
electronic controls and hydraulics. Referring to FIG. 1, a system
of rollers 102 is shown with a pipe 100 progressing thereby in a
single direction for accomplishing single-axis bending of the pipe
100. As shown, roller 104 imparts the bending force on the pipe
100, while rollers 102 serve as feed rollers for directing the pipe
toward the roller 104. The roller 104 is offset with the rollers
102 to bend the pipe. The resulting pipe formed by such a process
is curved into a coil having a relatively large radius of
curvature. It will be appreciated that any suitable number of
rollers may be utilized to form a pipe having an undulating helical
interior pathway.
[0027] Turning to FIG. 2, a mechanism is provided to impart a
rotation to the pipe 100 as it progresses through the system of
rollers 102. The rotation mechanism may continuously and
controllably rotate the pipe 100 along with a controlled feed rate.
The revolving rate determines the diameter of the helix of the coil
and the feed rate controls the pitch or length of a single
undulation imparted to the pipe. Examples of undulating pipe having
various pitches are shown, for example, in FIGS. 3a and 3c. The
desired relationships for a pipe suitable in transportation,
conditioning and separating oil sands, or for the transportation of
oilsands tailings, for example, include having the diameter of the
helical path of the conduit centerline which is less than the pipe
diameter, a pitch that is a substantially greater than the pipe
diameter (and in some embodiments, approximately a multiple of the
diameter) and an open channel through the pipe. The properties of
the undulating helical pipe as specified herein may be useful in
the transportation of slurries containing abrasive solids in order
to create a mixing effect to suspend the solid material in the
slurry and also to reduce the amount of wear experienced in the
interior of the pipe.
[0028] In some embodiments, the interior wall of the pipe has a
continuous smooth surface, although it will be appreciated that the
interior surface may have any suitable surface property.
Furthermore, in some embodiments, the interior wall may be round in
cross-section throughout the length of the pipe, although it will
be appreciated that the pipe interior may have any suitable shape.
A representative set of example cross-sectional shapes is shown in
FIGS. 5a-5d. It will also be appreciated that the exterior of the
pipe may be any suitable shape. For example, the exterior of the
pipe may be generally circular as shown in FIG. 2. In other
embodiments, the exterior of the pipe may be non-circular. In some
non-circular embodiments, the feeding and/or bending mechanisms may
need adjustment to accommodate the non-circular shape, and/or a
framing mechanism may be utilized around the pipe.
[0029] The diameter and pitch of the undulating pipe may be
tailored, within the defined parameters, to best suit the
particular application for the pipe whether it is for maximizing
the effectiveness of static mixing, conditioning of oilsands
slurries for maximum oil recovery, or for maximum reduction of
pumping horsepower and wear for tailings transport. Moreover, by
varying the feed rate of smaller diameter conduit through the
machine, along with the rate and direction in which it is rotated,
a wide variety of pitch and helix diameters, with either left
handed or right handed rotational direction, can be interspersed in
the same length of conduit in order to achieve multiple hydraulic
objectives. It will be appreciated that the pipe used in oil filed
applications is typically large diameter pipe, such as described
further below, however, it will be appreciated that an undulating
helical pipe of any suitable diameter may be formed as described
herein.
[0030] FIG. 8 shows a variety of cross-sectional positions along
the pipe length. As shown, when the flow of slurry is stopped, the
solid material 106 in the slurry may settle toward the bottom of
the pipe and the liquid portion 108 of the slurry will generally
occupy the remainder of the pipe interior. Specifically, this
figure estimates the level of settled sand in a pipe (in horizontal
position), when slurry flow of about 65 wt. % solids is suddenly
interrupted. When flow restarts, resuspension of settled solids is
aided by transverse secondary flows in the liquid moving through
the open pipe cross-section above the settled solids.
[0031] FIG. 9 is a simplified end view of a undulating helical pipe
showing the open pathway through the pipe, the radius of which is
represented by r.sub.i. The radius of the conduit is represented as
r.sub.c. The radius of the helical path of the conduit centerline
is represented by r.sub.h.
[0032] The Undulating Conduit Hydrodynamic Mixer--The undulating
conduit hydrodynamic mixer is the physical plant that provides
controlled continuous positive dynamic interaction within the
transported slurry. The undulating conduit creates the optimum
environment for mixing of the oil sands slurry. The action may be
described as directional flow changes, accelerating and
decelerating, twirling, spiraling, gyrating, folding the slurry
over on itself and stretching the mixture as it is transported.
[0033] The above pattern of dynamic flow provides several
advantages usually not available in present mixing systems.
[0034] Referring to FIGS. 3a and 3b, the undulating conduit
hydrodynamic mixer is a static mixing apparatus of a preselected
and predetermined length of elongated tubular conduit. It allows
for mixing and transporting various substances including highly
abrasive solids-containing slurries. As further discussed herein,
the conduit member can be interconnected into a transportation and
processing separation system.
[0035] In accordance with the present invention, the undulations
may take a variety of serpentine paths or shapes with various
pitches (FIG. 3a-3c), repetitive or varying waves and differing
cross sections, FIGS. 4, 4a, 5, 6. The undulations can be, of a
helical type formation (i.e., coil spring configuration) such as
could be advantageously used for round pipe cross-sections, or a
spiraled screw type shape for pipes of oval, polygonal, or other
geometric cross-sections or combinations thereof, or the
undulations can be sinusoidal when the conduit is not free to
undulate in three dimensions.
[0036] It is not necessary that the conduit walls be of uniform
thickness. For example, the exterior surface of the conduit could
have a cylindrical pipe shape, while the interior surface of the
conduit could have an undulating shape, thereby forming an
undulating passage inside an externally cylindrical pipe of varying
wall thickness. Such a design is particularly appropriate for small
diameter undulating conduits or for relatively short `revitalize`
sections of undulating conduit. It will be appreciated that the use
of other than round conduit, or other than a mathematically precise
helix for the path of undulation, is also permissible as well
without deviating from the intent of this invention.
[0037] Helical type undulations are defined by geometry, having
parameters such as conduit radius, radius and pitch of the helical
path of the conduit centerline, the offset between the centerline
of the conduit cross-section and the centerline of the helical
path, and the inner and outer radii of the resulting conduit
undulations.
[0038] Spiraled screw-shaped undulations are a special case of
helical undulation in which the radius of the helical path
undulation is zero but the pitch of undulation is non-zero.
Spiraled screw undulations can be defined by parameters such as the
spiral screw pitch, the offset between the conduit cross-section
centerline and the centerline of the spiral path, and the
cross-sectional shape of the conduit, for instance, oval,
elliptical, semicircular, polygonal, or a combination thereof, or
other non-circular shape.
[0039] Undulations can be formed by indenting the outside of a
conduit in a spiraled screw type manner. The indentations can be
grouped and placed at predetermined intervals. In an example for
conduits containing slurried solids, the indentations may be
limited to the upper portion of the conduit only and do not extend
around the full circumference. Upper-surface indentations leave a
straight conduit bottom that offers less resistance to sliding
solids, is less prone to wear, and has no pockets to capture
settled solids and impede resuspension during startup after a
shutdown. During restart, the upper-surface undulations create
currents angled down toward the conduit bottom, which disturb the
settled solids and revitalize the flow.
[0040] Resuspension of Settled Solids. --In yet another embodiment
of the Undulating Conduit Hydrodynamic Mixer, it is particularly
advantageous for the conduit to follow a helical path whose radius
r.sub.h is less than the conduit hydraulic radius r.sub.c. This
configuration provides an open inner channel of radius
r.sub.i=r.sub.c-r.sub.h along the longitudinal axis of the
undulating conduit, through which it is possible for fluid to flow
in a straight line without undulation. With this configuration,
even if the lower undulations of the conduit are almost completely
plugged with settled solids after an unplanned shutdown, this
center channel allows fluid to be pumped through the unplugged
upper undulations of the conduit. The flow follows the conduit's
upper undulations and develops primary and secondary motions that
aid resuspension of settled solids in the conduit's lower
undulations, thereby returning the entire conduit to the fluidized
flow condition.
[0041] Premature Separation/Stratification. --The transportation of
slurries of various compositions particularly in large diameter
straight pipes (10''+) tends to give rise to premature separation
and/or stratification of elements.
[0042] By choosing appropriate geometry parameters, the undulating
conduit hydrodynamic mixer lends itself to precise control and
therefore management of the flow, while the alternating primary and
secondary flow patterns create a mixing effect which prevents
premature separation and stratification of fluid components
transported within the pipeline.
[0043] Flow Velocity. The swirling action in the undulating conduit
hydrodynamic mixer keeps solids in constant suspension, which means
that deposition of solids along the base of the pipe is
considerably less than in a straight pipe; ergo, lower velocities
of slurry travel are feasible without causing deposition. The lower
velocity significantly reduces the abrasive effect of the
solids.
[0044] Slurry Conditioning. The entry of screened slurry into the
undulating conduit hydrodynamic mixer, brings with it lumps of oil
sand reduced in size for additional digestion.
[0045] The swirling flow pattern in the undulating conduit
hydrodynamic mixer is conducive to better abrading and digestion of
lumps.
[0046] The "folding-over" mixing action of the undulating conduit
hydrodynamic mixer enhances the contact and attachment of air to
the oil droplets thus enhancing the conditioning of the slurry.
[0047] Economy of Development of the Invention Prototype. Since the
undulating conduit hydrodynamic mixer system is based on principles
of hydraulic flow, most of its parameters can be established
theoretically and a numerical model developed and proven
experimentally within a relatively short time and at a reasonable
cost.
[0048] The Undulating Conduit Hydrodynamic Mixer Can Be Utilized in
Several Phases of Mixing, Transport and Separation. The undulating
conduit hydrodynamic mixer lends itself to use in at least three
stages of mixing, transport and extraction, as illustrated in FIG.
7. A description of the oil sand extraction process shown in this
Figure is provided in the following sections.
[0049] Stage #1--Undulating conduit hydrodynamic mixer (B) inserted
as a hydro-dynamic mixer between contactor (A) and sand settler
(D). The oil sand slurry is preconditioned in the contactor (A) as
dense media. Contactor (A) is shown as a pug mill in FIG. 7.
However, this function could also be provided by an undulating
conduit hydrodynamic mixer.
[0050] After one or two minutes of mixing, the slurry is diluted
and pumped through the undulating conduit hydrodynamic mixer (B)
where it is further conditioned before entering the sand settler
(D) and cyclo distributor (C). The diluted dense media slurry
stream (8) will have a typical weight composition of approximately
65% solids, 10% bitumen and the remainder water. The components of
the diluted dense media must stay in suspension between (A) and (D)
to prevent conglomerates forming from the solids, bitumen and
fines. The swirling flow of the undulating conduit hydrodynamic
mixer keeps these components in suspension until the slurry reaches
the flotation stage. This also prevents rapid conduit wear that
would otherwise be caused by settled solids sliding between (A) and
(D).
[0051] In Stage #2, the introduction of the undulating conduit
hydrodynamic mixer (E) in transportation of the oil-laden middlings
from the sand settler (D) to the froth separator (F) prevents
premature coalescence of aerated oil globules and solids. The
undulating conduit hydrodynamic mixer maintains the contents as a
well-mixed suspension so that they can be evenly distributed across
the Froth Separator area to yield optimum product.
[0052] In stage #3, the undulating conduit hydrodynamic mixer (H)
will transfer middlings from the froth separator (F) to the
contactor (A), to be used as a slurry dilution stream. The function
of the undulating conduit hydrodynamic mixer between (F) and (A) is
to maintain a homogeneous fluid suspension and thereby prevent
formation of viscous amalgams that could restrict the flow. The
working of this system enhances oil recovery by bringing the
unaerated oil droplets back into the system, and also recycles
fines that enhance transport of the slurry.
[0053] In stage #4, the undulating conduit hydrodynamic mixer (T)
will transfer tailings from the sand separator (D) to the tailings
disposal area. The tailings stream (16) will have a typical weight
composition of approximately 65% coarse and fine solids, less than
2% bitumen and the remainder water. The function of the undulating
hydrodynamic mixing conduit (T) is to maintain a well-fluidized
tailings slurry that can be pumped at high density without causing
rapid localized abrasive wear due to settled solids sliding along
the conduit bottom. The undulating hydrodynamic mixing conduit will
also be resistant to plugging with settled solids during a tailings
line shutdown.
[0054] Mobility of the Undulating Conduit Hydrodynamic Mixer. The
undulating conduit hydrodynamic mixer can be structured to be
compact and mobile, so that it can be moved about in the mining
sites if necessary.
[0055] Cost Effectiveness. The undulating conduit hydrodynamic
mixer can displace some of the mixing equipment which is in current
use at a considerably lower capital cost, lower operational and
maintenance cost, and reduced down time to repair and/or replace
worn out equipment.
[0056] The Process Described in the Application of this Invention.
Oil sands contain sharp, various sized grains of sand particles,
bitumen (a high viscosity oil) and connate water containing various
amounts of corrosive chlorides. Conditioning starts in contactor
(A) with the addition of fresh water, middlings from froth
separator and chemicals if required.
[0057] The next step in preparation of slurry is accomplished in
the hydrodynamic mixer, where it will be gently conditioned by
thoroughly mixing while air, chemicals, predetermined energy and
set time will be applied.
[0058] The next function is accomplished in the sand settler (D).
Here, the slurry is diluted, mixed with recycled middlings in the
cyclodistributor (C) followed by settling of the sand and floating
of oil and middlings.
[0059] Settled sand, diluted by tailings from secondary oil
recovery is removed for disposal while oil and floating middlings
are transported by undulating conduit hydrodynamic mixer, to
prevent coalescence of aerated oil droplets with high solids
middlings, to the Froth Separator ("F"). In this stage of process,
oil is floated off and removed as final froth while middlings
containing liquid, some oil and fines (solid particles usually less
than 44 microns), are recycled to the Contactor.
[0060] Static Undulating Conduit Hydrodynamic Mixer Management of
Settling and Flotation Problems. The transport of slurry in
straight pipes is subject to the problem of blockage caused by
solids. At times of reduced velocities and/or stoppage,
heterogeneous slurries, such as oil sand slurry, settle rapidly to
form a sandy or hard deposit.
[0061] Similarly, in particular when processing high oil content
ore (+12%), the spontaneous rise of aerated oil droplets forms a
viscous amalgam at the top of the conduit, which increases in size
with time of travel, building up system pressure and restricting
the flow of slurry.
[0062] Solids suspended in the aerated viscous amalgam layer also
cause high conduit wear where this layer slides along the conduit
walls. The viscous amalgam layer is dispersed, or is prevented from
forming, by the low-shear mixing action of slurry flow within the
undulating conduit hydrodynamic mixer.
[0063] The undulating conduit hydrodynamic mixer will overcome the
above deteriorating conditions, even at the low fluid velocities of
laminar flow, by keeping the slurry in a state of gentle swirling
flow. The slurry is subjected to continuous flow direction changes,
vortexing and rotation, and as a result the elements are kept in
motion.
[0064] Undulating Conduit Hydrodynamic Mixer Management of Abrasion
Problem. By keeping solids in suspension the abrasive aspect of
moving sand will be reduced. The velocity can be reduced without
loss of mixing benefit; the sands are evenly distributed within the
slurry, which also minimizes the abrasive effect on the walls of
the conduit. With the sands in continuous suspension there is no
settlement to the bottom of the conduit to create uneven wear on
its base. In other words, the total wear factor is both reduced and
spread out evenly within the pipe.
[0065] Applications. This invention offers a great range of
potential applications. It is a mixer and can also serve as a
materials transporter that incorporates a controlled mixing
function.
[0066] Some uses are oil extraction from Alberta oil sands (water
wet sand grains); U.S. oil sands (oil coated sand grains); and oil
sands deposits in other parts of the world.
[0067] Various utilities such as water treatment plants and sewage
treatment plants.
[0068] Industrial uses such as petrochemical industries, various
solids transport industries such as transport of potash ore, coal
and other mined minerals, dredging of harbors and rivers, paint
manufacturing, and the food preparation industry. It can enhance
and improve existing systems by the principle of the undulating
conduit apparatus.
[0069] One particular use to which this invention is suited is in
the extraction of oil from the Fort McMurray oil sands deposits in
the vicinity of the Athabasca River in northeastern Alberta,
Canada. Because of the smaller size of the apparatus, its low
capital cost, lower operating expenses and portability, this
invention has potential to allow the development of marginal oil
sands deposits by small-scale operators.
[0070] This capability may be of benefit to less prosperous
countries and smaller regional economies that have oil sands
deposits.
[0071] Explanation of Flow Diagram (FIG. 7) Showing Utilization of
Static Undulating Conduit Hydrodynamic Mixer in the Proposed Oil
Extraction Process.
[0072] FIG. 7 is an example flow sheet for a method of separating
oil from oil sands.
[0073] Contactor (A). The contactor is a sturdy mixing device for
preconditioning of the oil sand slurry. The Contactor accomplishes
oil sand lump digestion efficiently with a minimum of
emulsification of the bitumen. A Pug Mill contactor can perform the
required oil sand lump digestion and slurry preconditioning, or
alternatively an Undulating Conduit Hydrodynamic Mixing contactor
can be used for this purpose.
[0074] The contactor can be mounted and operated on mobile
trailers, thus increasing mining flexibility. Retention time at
this stage should preferably be short (a minute or two) while
holding slurry consistency around 25% liquid by weight (including
connate water).
[0075] The temperature of slurry at this stage, should be
maintained around 30-55.degree. C., to enhance diminution of tar
sand lumps, thus liberating bitumen matrix intact.
[0076] To control the density of the above slurry, a stream (4)
containing recycled middlings from the froth separator (F),
chemicals and possibly fresh water is added.
[0077] After mixing is completed, this slurry (5) overflows the lip
of the contactor and then falls through the screen into the pump
hopper.
[0078] Fresh hot water (6) or a recycle stream (11) can be applied
to dilute and propel this slurry through the screen openings, as
well as to wash attached oil off the rejected oversize lumps
(7).
[0079] The size of rejects (7) is dictated by the handling
capability of the downstream equipment, in this case, the diameter
of Undulating Conduit Hydrodynamic Mixer (B). During cold winter
months, rejects containing frozen lumps of undigested oil sand
might be recycled back to the Contactor (A).
[0080] Process Additives. The final adjustment of slurry density,
the slurry pH, as well as addition of dissolved air, can be made
via stream (17), before it enters the Undulating Conduit
Hydrodynamic Mixer. Using the undulating conduit (in contrast to a
straight pipe), the addition of dissolved air could be tolerated
without increasing the flow stratification and possible pipe wear
by aerated viscous amalgam.
[0081] The screened preconditioned slurry with additives (17) is
pumped through the Undulating Conduit Hydrodynamic Mixer. For
effective mixing, one to two minutes of retention time should be
adequate.
[0082] Static Hydrodynamic Mixer Undulating Conduit. The static
hydrodynamic mixer undulating conduit can be used in various
configurations to fulfill different functions. In FIG. 7, five
static hydrodynamic mixer undulating conduits are utilized (shown
as B, E, H, T and W). The hydrodynamic mixer can be utilized
firstly as a pure mixer to blend fluid components together.
Secondly, it can be utilized as a transporter mixer to
simultaneously mix and transport the conduit contents. Thirdly, it
can serve as inserts in a transportation pipe system to revitalize
the contents in transit.
[0083] The static hydrodynamic mixer undulating conduit can be used
as a mixer only, by applying a small length of conduit having
undulations of a short pitch configuration. This static
hydrodynamic mixer undulating conduit unit could be mounted on
mobile equipment and operated close to the mining area.
[0084] The static hydrodynamic mixer undulating conduit could also
consist of a combined mixing and transport system having continuous
long-pitch undulations or a combination of straight pipes with
insertions of undulating pipes. The correct design of this unit,
establishing length and diameter of conduit, and diameter and pitch
of the undulation, could positively influence the product quality
and reduce related expenses.
[0085] Sand Settler (D). Sand accounts for around 80% of the oil
sand weight. As much sand as possible should be removed from the
slurry as early as possible to avoid abrasive wear on downstream
equipment. The sand settler should therefore be installed as near
as possible to the mine to reduce the need to transport large
volumes of solids out of the mine area.
[0086] Conditioned slurry (8) is introduced into the sand settler
(D) by means of the cyclodistributor (C). Here it is dispersed and
diluted by recycled middlings stream (9), which also induces
additional rotational momentum. The resulting motion enhances
turbulence within the middlings in the lower section of the vessel,
thus preventing the formation of gels (pseudo-plastic
behavior).
[0087] The cyclonic action within the cyclodistributor enhances the
separation of sand and aerated oil droplets by means of turbulence
and density differential.
[0088] After exiting the cyclodistributor, rising aerated oil
droplets and some middlings are floated to the top of the vessel
and then leave the sand separator by means of a stream (10) which
passes through an Undulating Conduit Hydrodynamic Mixer (E)
functioning as a transporter/mixer that prevents conglomeration and
stratification of aerated oil droplets.
[0089] The sand-laden portion of the slurry is discharged onto the
conical deflector where it fans and spreads out. This allows any
oil carried by the outflowing stream to escape. The released oil
rises to the top, while the descending sand is uniformly
distributed across the lower portion of the sand settler.
[0090] As the sand slides down the walls and settles towards the
bottom of the settler, it densifies and releases middlings fluid
and bitumen. The build-up of densified sand on the bottom creates a
sand-middlings interface that acts as a seal to exclude oil-bearing
middlings from the tailings stream (16).
[0091] The flux of released middlings and bitumen creates an upward
flow current towards the cone under the cyclone distributor, where
the released middlings and bitumen join stream (9).
[0092] The density of tailings stream (16) drawn from the bottom of
the vessel, is controlled by injection of secondary oil recovery
tailings (15).
[0093] Froth Separator (F). Oil-enriched middlings stream (10) is
transported from the sand settler to the froth separator by means
of the Undulating Conduit Hydrodynamic Mixer, which prevents
coagulation of aerated oil droplets. The stream enters the froth
separator via the rotary distributor (K) and is laid down unifoimly
across the vessel.
[0094] Streams exiting the rotating distributor (K) are mixed with
surrounding liquid and, thus diluted, are the first step of the
actual process of separation.
[0095] The released aerated oil globules rise to the top of the
vessel, where they form a bituminous froth (13), while coarse and
fine sand particles, and some unaerated bitumen, settle to the
bottom of the froth separator.
[0096] Underwash. Fresh (pretreated) underwash water is introduced
preferably by way of underwash rotary distributor (J) beneath the
froth layer, but above the oil enriched middlings distributor (K).
In this way, a highly diluted zone is provided, through which the
ascending bitumen passes immediately before joining the froth. This
step contributes to formation of higher froth quality by washing
rising aerated bitumen droplets and maintaining a mild downward
current that depresses the fines to the middlings withdrawal pipe
(11). There is usually more underwash water than middlings water in
the froth product, suggesting that only excess underwash water is
involved in the downward flow. The dilute underwash zone leads not
only to clean froth, but also maintains stable operation even when
high fines oil sands are being processed.
[0097] Primary Froth. Rising to the surface, aerated oil globules
form a froth (13), on average containing 60-70% oil, 6-10% solids
and 20-30% water, which overflows into launders and is pumped to
froth treatment facilities. An Undulating Conduit Hydrodynamic
Mixer (W) may be a suitable apparatus for washing the froth. Froth
washing gently shears and stretches conglomerated droplets of
aerated bitumen that have trapped solids and water in the
interstices between the clumped droplets. The gentle low-shear
scrubbing action of fluid motion inside the undulating conduit (W)
liberates the trapped solids and water in the froth without
creating an emulsion and moving solids towards and close to walls
of the conduit by centrifugal force, to be removed, shortly before
discharging a product.
[0098] Middlings Recycle. The middlings for recycle to the
contactor (11) are taken from the froth separator via a collector
pipe. By this means a certain percentage of solids (mostly as
fines) are removed from the center of the froth separator (F). The
withdrawal of stream (11) creates gentle shear within the center
zone of the froth separator, which helps prevent the remaining
fines from coalescing or gelling. Stream (11) should be transferred
to the contactor (A) via Undulating Conduit Hydrodynamic Mixer to
prevent formation of viscous amalgams that could restrict the
flow.
[0099] Secondary Oil Recovery. Froth separator tailings (12) are
withdrawn and introduced into the secondary oil recovery system
(G).
[0100] Secondary Oil Recovery Froth. The product of secondary oil
recovery system (14), a froth high in solids, which is introduced
into middlings recycle stream (9) and forwarded to the
cyclodistributor.
[0101] Secondary Oil Recovery Tailings. A low oil content discharge
stream (15) from the secondary oil recovery circuit enters the sand
settler (D) as a sand tailings dilution and fluidizing stream.
[0102] Sand Separator (D) Tailings. A high-solids, low oil content
discharge stream (16) leaves the Sand Settler (D) and is pumped to
the Sand Tailings disposal area via an Undulating Hydrodynamic
Mixing Conduit (T). The function of this undulating mixer conduit
is to maintain a well-fluidized tailings slurry that can be
efficiently pumped at high density without excessive wear of the
conduit due to sliding stratified solids. The undulating conduit is
also resistant to plugging with settled solids during a tailings
line shutdown.
[0103] It will be appreciated that the terms conduit and pipe are
used interchangeably herein.
[0104] Although the invention has been described with respect to
bending pipes for application in oil field slurry transport, it
will be appreciated that the undulating helical pipe may be
utilized for any suitable application.
[0105] For further discussion of undulating helical pipe, please
see Applicant's U.S. patent application Ser. No. 11/525,668, filed
on Sep. 22, 2006; U.S. patent application Ser. No. 10/736,485,
filed on Dec. 15, 2003, now abandoned; and U.S. provisional patent
application No. 60/392,281, filed on Jun. 28, 2002, as well as U.S.
Pat. No. 6,896,007, all of which are incorporated herein by
reference.
[0106] All references, including publications, patent applications,
and patents, cited herein are hereby incorporated by reference to
the same extent as if each reference were individually and
specifically indicated to be incorporated by reference and were set
forth in its entirety herein.
[0107] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. The terms "comprising,"
"having," "including," and "containing" are to be construed as
open-ended terms (i.e., meaning "including, but not limited to,")
unless otherwise noted. Recitation of ranges of values herein are
merely intended to serve as a shorthand method of referring
individually to each separate value falling within the range,
unless otherwise indicated herein, and each separate value is
incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the invention and does not
pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element as essential to the practice of
the invention.
[0108] Preferred embodiments of this invention are described
herein, including the best mode known to the inventor for carrying
out the invention. Variations of these preferred embodiments may
become apparent to those of ordinary skill in the art upon reading
the foregoing description. The inventor expects skilled artisans to
employ such variations as appropriate, and the inventor intends for
the invention to be practiced otherwise than as specifically
described herein. Accordingly, this invention includes all
modifications and equivalents of the subject matter recited in the
claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible
variations thereof is encompassed by the invention unless otherwise
indicated herein or otherwise clearly contradicted by context.
* * * * *