U.S. patent application number 15/131984 was filed with the patent office on 2016-08-11 for fluid contactor-diffuser tray assembly.
This patent application is currently assigned to GTC Technology US, LLC. The applicant listed for this patent is GTC Technology US, LLC. Invention is credited to Michael J. BINKLEY, Casey F. Bowles, Ian G. Buttridge, SooWoong KIM, David Lin.
Application Number | 20160228788 15/131984 |
Document ID | / |
Family ID | 45525718 |
Filed Date | 2016-08-11 |
United States Patent
Application |
20160228788 |
Kind Code |
A1 |
Buttridge; Ian G. ; et
al. |
August 11, 2016 |
FLUID CONTACTOR-DIFFUSER TRAY ASSEMBLY
Abstract
A separations tray assembly for use in a fluid-fluid exchange
column. The separations tray assembly is of the type where a first
fluid, in a continuous phase, is directed across successive trays
in a serpentine flow path. A second fluid, in a dispersed phase
ascends through apertures in the tray thus inducing interaction and
mass transfer with the first fluid. In accordance with one aspect
of the present invention, the separations tray further includes a
diffuser skirt, having apertures disposed therein, operatively
coupled to a fluid channel. The diffuser skirt is operable to
direct the first fluid to cover substantially an entire volumetric
cross-flow window between successive separations trays and to
induce stirring and mixing of the first fluid and the second fluid
to effect efficient mass transfer.
Inventors: |
Buttridge; Ian G.; (Garland,
TX) ; Lin; David; (Flower Mound, TX) ; Bowles;
Casey F.; (Coppell, TX) ; KIM; SooWoong;
(Flower Mound, TX) ; BINKLEY; Michael J.; (Glenn
Heights, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GTC Technology US, LLC |
Houston |
TX |
US |
|
|
Assignee: |
GTC Technology US, LLC
Houston
TX
|
Family ID: |
45525718 |
Appl. No.: |
15/131984 |
Filed: |
April 18, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14168053 |
Jan 30, 2014 |
9327209 |
|
|
15131984 |
|
|
|
|
13101638 |
May 5, 2011 |
8678357 |
|
|
14168053 |
|
|
|
|
61345439 |
May 17, 2010 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01F 3/04482 20130101;
B01F 3/04078 20130101; B01D 3/20 20130101; B01F 3/04468 20130101;
B01D 3/22 20130101; B01F 3/04496 20130101; B01D 3/324 20130101 |
International
Class: |
B01D 3/32 20060101
B01D003/32; B01F 3/04 20060101 B01F003/04 |
Claims
1. A tray assembly for use in a fluid-fluid exchange column, the
tray assembly comprising: a plurality of trays, each of the
plurality of trays comprising: a tray deck having a plurality of
apertures disposed therein; a fluid conduit depending from at least
one tray of the plurality of trays and fluidly coupling at least
two trays of the plurality of trays; a plurality of apertures
disposed in the fluid conduit; wherein the diffuser skirt
distributes a continuous phase fluid in a desired direction; and
wherein the diffuser skirt reduces recirculation of the continuous
phase fluid.
2. The tray assembly of claim 1 further comprising: a coalescing
element disposed on a side of the tray deck facing a flow of a
dispersed phase fluid; and wherein the coalescing element operable
to promote coalescing of the dispersed phase fluid.
3. The tray assembly of claim 1 comprising a serpentine flow of the
continuous phase fluid.
4. The tray assembly of claim 1 comprising a uni-directional flow
of the continuous phase fluid.
5. The tray assembly of claim 1 comprising an orbital flow of the
continuous phase fluid.
6. The tray assembly of claim 1, wherein the fluid conduit is a
downcomer.
7. The tray assembly of claim 1, wherein the fluid conduit is an
upcomer.
8. The tray assembly of claim 1 further comprising a plurality of
baffles disposed on the tray deck.
9. The tray assembly of claim 8, wherein the plurality of baffles
distribute the continuous phase fluid over a surface of the tray
deck.
10. The tray assembly of claim 1, wherein the plurality of trays
are single-pass trays.
11. The tray assembly of claim 1, wherein the plurality of trays
are multi-pass trays.
12. The tray assembly of claim 1, where in the plurality of trays
are multiple-downcomer trays.
13. A method of diffusing fluid phases in a fluid-fluid exchange
column, the method comprising: providing a fluid-fluid exchange
column comprising: a plurality of trays; at least one fluid conduit
operatively coupled to each of the plurality of trays; flowing a
first fluid across successive trays in a serpentine flow path;
diffusing the first fluid through a fluid conduit thereby
distributing the continuous phase fluid over substantially an
entire surface of the tray; dispersing a second fluid within the
first fluid; and flowing the second fluid through a plurality of
apertures disposed in the plurality of trays.
14. The method of claim 13 further comprising directing the first
fluid, via the diffuser skirt, in a desired direction.
15. The method of claim 13, wherein the first fluid is a heavy
fluid and the second fluid is a light fluid.
16. The method of claim 13, wherein the first fluid is a light
fluid and the second fluid is a heavy fluid.
17. A diffuser skirt for use in a fluid-fluid exchange column
having a plurality of trays associated therewith, the diffuser
skirt comprising: a diffuser body having a plurality of apertures
disposed therein; wherein the diffuser body is operatively coupled
to at least one of the plurality of trays; wherein the diffuser
body distributes a continuous phase fluid over substantially an
entire surface of at least one of the plurality of trays; and
wherein the diffuser body reduces recirculation of the continuous
phase fluid.
18. The diffuser skirt of claim 17, wherein the diffuser body
comprises a conduit.
19. The diffuser skirt of claim 18, wherein the plurality of
apertures are disposed on both an interior face and an exterior
face of the conduit.
20. The diffuser skirt of claim 17, wherein the plurality of
apertures are grouped to create a desired flow pattern.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/168,053, filed on Jan. 30, 2014. U.S.
patent application Ser. No. 14/168,053 is a continuation of U.S.
patent application Ser. No. 13/101,638, filed May 5, 2011. U.S.
patent application Ser. No. 13/101,638 claims priority from U.S.
Provisional Patent Application No. 61/345,439, filed May 17, 2010.
U.S. patent application Ser. No. 14/168,053, U.S. patent
application Ser. No. 13/101,638, and U.S. Provisional Patent
Application No. 61/345,439 are incorporated herein by reference.
Additionally, the present application incorporates by reference the
entire disclosure of U.S. patent application Ser. No. 12/408,333,
filed Mar. 20, 2009, U.S. patent application Ser. No. 12/109,781,
filed Apr. 25, 2008, and U.S. Provisional Patent Application No.
61/178,676, filed May 15, 2009.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to mass-transfer trays for
chemical process columns and, more particularly, but not by way of
limitation, to an improved liquid-liquid contactor tray for
facilitating increased mass transfer efficiency.
[0004] 2. History of Related Art
[0005] Distillation columns have been developed and used for many
decades to separate selected components from a multicomponent
stream. The major "separations" process is commonly known in the
art as "fractionation." Successful fractionation in a distillation
column depends upon intimate contact between a heavier fluid and a
lighter fluid. Some contact devices, such as, for example, trays,
are characterized by relatively high pressure drop and relatively
high fluid hold-up. One type of contact apparatus utilizes fluid in
a vapor phase to contact fluid in a liquid phase. Another type of
contact apparatus is structured packing. Structured packing is
energy efficient as it exhibits low pressure drop and low fluid
hold-up. However, these very properties at times make columns
equipped with structured packing difficult to operate in a stable,
consistent manner. Moreover, many applications simply require the
use of trays.
[0006] A particularly effective tray in process columns is a sieve
tray. Typically, the sieve tray is constructed with a plurality of
apertures formed in a deck surface. The plurality of apertures
permit ascending lighter fluid to flow into direct engagement with
heavier fluid that is flowing across the sieve tray. When there is
sufficient lighter-fluid flow upwardly through the sieve tray, the
heavier fluid is prevented from running downwardly through the
plurality of apertures (referred to as "weeping"). A small degree
of weeping is normal in sieve trays while a larger degree of
weeping is detrimental to the capacity and efficiency of the tray.
Such trays may be either single-pass or multi-pass. In addition,
such trays may incorporate serpentine flow, orbital flow, or
uni-directional flow.
[0007] Another type of "separations" process involves mass transfer
between two fluids which are both in a liquid state. This is
commonly referred to as "fluid-fluid exchange." The primary
advantage of fluid-fluid exchange over fluid-vapor exchange is an
amount of process energy required. In the fluid-vapor exchange,
substantial energy must be provided and consumed to boil a fluid
into a vapor state and maintain the fluid in the vapor state for
the duration of the process. In contrast, most fluid-fluid exchange
processes operate at temperatures slightly above ambient
temperature such as, for example, 90.degree. F. resulting in
significant energy savings.
[0008] In cases involving fluid-fluid exchange, there are specific
performance issues that impact efficiency. In typical fluid-fluid
exchange columns, a first fluid is in a continuous phase and a
second fluid is in a dispersed phase. In one arrangement, the
heavier fluid, in a continuous phase, is passed downwardly in a
circuitous path across a series of horizontally disposed trays
spaced in a vertical relationship, one to the other. The heavier
fluid forms a fluid layer on the trays. Droplets of the lighter
fluid, in a dispersed phase, ascend through the plurality of
apertures and interact with the continuous fluid. This arrangement
may be used, for example, in re-capture of an acid where the
heavier fluid is water containing the acid and the lighter fluid is
a selected solvent. In another arrangement, the heavier fluid is
the dispersed phase and the lighter fluid is the continuous phase.
In this arrangement, the heavier fluid forms droplets which fall
downwardly through the plurality of apertures. The heavier fluid
droplets fall through the lighter fluid, in continuous phase,
flowing upwardly in a circuitous path across an underside of the
trays. This arrangement may be used, for example in solvent
recovery of Benzene from aromatics process streams.
[0009] In conventional fluid-fluid contactor trays, velocities of
the continuous-phase fluid are very low relative to fluid-vapor
columns. The low velocities in the continuous-phase fluid result in
the continuous-phase fluid having minimal head pressure thereby
inducing re-circulation and stagnation. Recirculation and
stagnation reduces mass-transfer driving force. Tray areas where no
mass transfer between the continuous-phase fluid and the
dispersed-phase fluid occurs are referred to as "dead zones." Dead
zones form in locations where the continuous-phase fluid stagnates
thus exhausting the solvent absorption capability. Furthermore, the
low velocities of the continuous-phase fluid result in the
continuous-phase fluid tending to not cover an entire surface of a
tray. Such incomplete tray coverage lessens an area of effective
mass transfer and reduces an efficiency of the tray. These problems
are generally present regardless of whether the heavier fluid or
the lighter fluid is used as the continuous phase.
[0010] U.S. Pat. No. 7,556,734, assigned to AMT International Inc.,
teaches an exchange column for contacting liquid in a continuous
phase with liquid in a dispersed phase. Contact between liquid in
the continuous phase and liquid in the dispersed phase is enhanced
by providing upstanding baffles on lower trays interspersed with
depending baffles from trays above. In addition, flow distribution
partitions extend along a flow path, between the baffles, to
distribute liquid flow across the trays.
[0011] U.S. Pat. No. 4,247,521, assigned to Union Carbide
Corporation, teaches a liquid-liquid contacting tray having a
channelized liquid transfer means for transferring continuous phase
liquid from a contacting zone on one side of the tray to a
contacting zone on the other side of the tray. The channelized
liquid transfer means includes a settling section operable to allow
disengagement of the discontinuous phase liquid from the continuous
phase liquid, and a pressure drop section.
[0012] U.S. Pat. No. 2,752,229 assigned to Universal Oil Products
Company, teaches a tower for effecting countercurrent contacting of
fluid streams, particularly liquid-liquid contacting. The tower
includes a plurality of vertically spaced perforated liquid
distributing decks extending across a confined chamber. Sloping
liquid downpipe assemblies extend from a liquid receiving well on
one deck to a liquid seal reservoir of the next lower deck. Use of
the sloping downpipe ensures that the continuous-phase liquid moves
in the same direction across successive trays thus creating a
uni-directional flow path.
SUMMARY OF THE INVENTION
[0013] The present invention relates to a separations tray assembly
for use in a fluid-fluid exchange column. The separations tray
assembly is of the type where a first fluid, in a continuous phase,
is directed across the tray in a cross-flow path. A second fluid,
in a dispersed phase, ascends through apertures in the tray thus
inducing interaction and mass transfer with the first fluid. In
accordance with one aspect of the present invention, the
separations tray further includes a diffuser skirt, having
apertures disposed therein, operatively coupled to a fluid channel.
The diffuser skirt is operable to direct the first fluid to cover
substantially an entire surface of the separations tray and to
induce stirring and mixing of the first fluid and the second fluid
to effect efficient mass transfer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A more complete understanding of the method and system of
the present invention may be obtained by reference to the following
Detailed Description when taken in conjunction with the
accompanying drawings wherein:
[0015] FIG. 1 is a side-elevational cross-sectional view of a prior
art fluid-fluid exchange column;
[0016] FIG. 2 is a side-elevational cross-sectional view of a
prior-art fluid-fluid exchange column;
[0017] FIG. 3 is a diagrammatic, side-elevational, cross-sectional
view of a fluid-fluid exchange column according to an exemplary
embodiment;
[0018] FIG. 4 is a top-plan, diagrammatic view of a tray according
to an exemplary embodiment;
[0019] FIG. 5 is a diagrammatic, side-elevational, cross-sectional
view of a fluid-fluid exchange column according to an exemplary
embodiment;
[0020] FIG. 6 is a top-plan, diagrammatic view of a tray according
to an exemplary embodiment;
[0021] FIG. 7A is a perspective view of a diffuser skirt according
to an exemplary embodiment;
[0022] FIGS. 7B-7E are top-plan views of diffuser skirts according
to exemplary embodiments;
[0023] FIG. 7F is a top-plan, diagrammatic view of a tray according
to an exemplary embodiment;
[0024] FIG. 8 is a diagrammatic, side-elevational, cross-sectional
view of a fluid-fluid exchange column according to an exemplary
embodiment;
[0025] FIG. 9A is a top-plan, diagrammatic view of a tray according
to an exemplary embodiment;
[0026] FIG. 9B is a top-plan, diagrammatic view of a tray according
to an exemplary embodiment; and
[0027] FIG. 10 is a is a diagrammatic, side-elevational,
cross-sectional view of a fluid-fluid exchange column according to
an exemplary embodiment.
DETAILED DESCRIPTION
[0028] Various embodiments of the present invention will now be
described more fully with reference to the accompanying drawings.
The invention may, however, be embodied in many different forms and
should not be construed as limited to the embodiments set forth
herein; rather, the embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art.
[0029] Referring now to FIG. 1, there is shown a side-elevational
cross-sectional view of a prior-art fluid-fluid exchange column. A
fluid-fluid exchange column 10 includes a continuous-fluid-feeder
line 12 and a first draw-off line 14. Also included are a
dispersed-fluid feeder line 16 and a second draw-off line 18. A
plurality of trays 20(1)-20(7) are disposed within the fluid-fluid
exchange column 10. Typically, the fluid-fluid exchange column 10
is used in extraction processes such as, for example, extraction of
an acid from water using a solvent.
[0030] Still referring to FIG. 1, the plurality of trays
20(1)-20(7) generally comprise a solid tray or deck having a
plurality of apertures 22 disposed therein. The plurality of
apertures 22 may include, for example, holes, slots, floating
valves, or any other appropriate type of aperture. Separation trays
such as, for example, the plurality of trays 20(1)-20(7) comprise
at least one of cross-flow trays with downcomers and counter-flow
trays without downcomers. In cross-flow trays, a lighter fluid 30
ascends through the plurality of apertures 22 and contacts a
heavier fluid 24 moving across the plurality of trays 20(1)-20(7).
In an active area, the heavier fluid 24 and the lighter fluid 30
mix and fractionation occurs. In counter-flow trays, both the
lighter fluid 30 and the heavier fluid 24 pass through the
plurality of apertures 22.
[0031] Still Referring to FIG. 1, in cross-flow operation, the
heavier fluid 24, in a continuous phase, is introduced to, and
substantially fills, the fluid-fluid exchange column 10 via the
continuous-fluid-feeder line 12. The heavier fluid 24 is directed
onto one of the plurality of trays 20(1)-20(7) such as, for
example, the tray 20(2) by means of a fluid channel 26 from the
tray 20(1) above. The fluid channel 26 is referred to as a
"downcomer." The heavier fluid 24 moves across the tray 20(1) and
enters the fluid channel 26 through a downcomer entrance 28(a) and
then leaves through a downcomer exit 28(b). At the same time, the
lighter fluid 30 in a dispersed phase is introduced to the
fluid-fluid exchange column 10 via the dispersed-fluid feeder line
16. The lighter fluid 30 forms bubbles that rise through the
heavier fluid 24. Typically, the bubbles of the lighter fluid 30
are approximately 1/4 of an inch or smaller. The lighter fluid 30
rises through the fluid-fluid exchange column 10 and forms a
coalesced layer on an underside of each of the plurality of trays
20(1)-20(7). The plurality of apertures 22 facilitate passage of
the lighter fluid 30 through each of the plurality of trays
20(1)-20(7) allowing interaction with the heavier fluid 24.
Remaining heaver fluid 24 is removed from the fluid-fluid exchange
column 10 via the first draw-off line 14. Likewise, remaining
lighter fluid 30 is removed from the fluid-fluid exchange column 10
via the second draw-off line 18.
[0032] For example, in the case of an extraction column, heavier
fluid 24 such as, for example, water containing acetic acid is
pumped into the fluid-fluid exchange column 10 in a continuous
phase, via continuous-fluid feeder-line 12. The heavier fluid 24
comprising the water-acid mixture descends through the fluid-fluid
exchange column 10 in a circuitous route passing over each of the
plurality of trays 20(1)-20(7) in alternating directions.
Simultaneously, lighter fluid 30 such as, for example, a solvent
containing an alkyl acetate is introduced via the dispersed-fluid
feeder line 16. The lighter fluid 30 comprising the solvent-alkyl
acetate mixture bubbles up through the water-acid mixture and
coalesces on the underside of each of the plurality of trays
20(1)-20(7). The solvent interacts with the water-acid mixture and
gradually absorbs the acetic acid. Thus, the concentration of
acetic acid is greatest in water-acid mixture moving across the
tray 20(1). The concentration of acetic acid in the water decreases
as the water-acid mixture moves across each successive tray of the
plurality of trays 20(1)-20(7) until, finally, residual water (also
referred to as "raffinate") is removed from the fluid-fluid
exchange column 10 via the first draw-off line 14. In similar
fashion, the concentration of acetic acid in the solvent increases
with each successive tray until acetic acid extract is removed from
the fluid-fluid exchange column 10 via the second draw-off line
18.
[0033] Referring now to FIG. 2, there is shown a side-elevational
cross-sectional view of a prior-art fluid-fluid exchange column. A
fluid-fluid exchange column 32 includes a continuous-fluid-feeder
line 34 and a first draw-off line 36. Also included are a
dispersed-fluid feeder line 38 and a second draw-off-line 40. A
plurality of trays 42(1)-42(7) are disposed within the fluid-fluid
exchange column 32. A fluid-fluid exchange column such as, for
example, the fluid-fluid exchange column 32 may be used in a
process such as, for example, extraction of benzene from water.
[0034] Still referring to FIG. 2, the plurality of trays
42(1)-42(7) generally comprise a solid tray or deck having a
plurality of apertures 44 disposed therein. The plurality of
apertures 44 may include, for example, holes, slots, floating
valves, and other appropriate types of apertures. In operation, a
lighter fluid 46, in a continuous phase, is introduced to, and
substantially fills, the fluid-fluid exchange column 32 via the
continuous-fluid-feeder line 34. The lighter fluid 46 is directed
onto a tray such as, for example, the tray 42(6) by means of a
fluid channel 48 from the 42(7) tray below. The fluid channel 48 is
referred to as an "upcomer." The lighter fluid 46 moves across the
tray 42(7) and enters an upcomer entrance 50(a). The lighter fluid
46 then exits the fluid channel 48 via an upcomer exit 50(b). A
heavier fluid 52, in a dispersed phase, is simultaneously
introduced to the fluid-fluid exchange column 32 via the
dispersed-fluid feeder line 38. The heavier fluid 52 forms bubbles
that descend through the lighter fluid 46. Typically, the bubbles
of the heavier fluid 52 are approximately 1/4 of an inch or
smaller. The heavier fluid 52 descends through the fluid-fluid
exchange column 32 and forms a coalesced layer on a top surface of
each of the plurality of trays 42(1)-42(7). The plurality of
apertures 44 facilitate passage of the heavier fluid 52 through
each of the plurality of trays 42(1)-42(7) allowing interaction
with the lighter fluid 46. Residual lighter fluid 46 is removed
from the fluid-fluid exchange column 32 via the first draw-off line
36. Likewise, residual heavier fluid 52 is removed from the
fluid-fluid exchange column 32 via the second draw-off line 40.
[0035] FIG. 2 is included herein to demonstrate that either a
heavier fluid or a lighter fluid may be used in operation as the
continuous phase with appropriate modifications to a structure of
the fluid-fluid exchange column. For ease and clarity of
discussion, the following exemplary embodiments will be described
by way of example as having a heavier fluid in the continuous
phase. However, one skilled in the art will recognize that,
alternatively, each of the embodiments below could function with a
lighter fluid as the continuous phase and flow redirected in
accordance therewith.
[0036] Referring now to FIG. 3, there is shown a diagrammatic,
side-elevational, cross-sectional view of a fluid-fluid exchange
column according to an exemplary embodiment In various embodiments,
a fluid-fluid exchange column 300 includes a plurality of trays
302(1)-302(5) and a plurality of fluid channels 304. In various
embodiments, the plurality of fluid channels 304 may include, for
example, a downcomer or an upcomer as described hereinabove. In a
typical embodiment, a tray such as, for example, the tray 302(2),
allows fluid to enter and exit via the fluid channels 304. In a
typical embodiment, the fluid channels 304 include a plurality of
orifice constrictions 306(a)-306(c) disposed therein. The plurality
of orifice constrictions 306(a)-306(c) may utilize a variety of
pressure-drop control devices such as, for example, an
envelope-pipe reducer 306(a), a perforated plate 306(b), a
plurality of baffles 306(c), and the like. In a typical embodiment,
plurality of the orifice constrictions 306(a)-306(c) restrict the
flow of fluid moving through the fluid channels 304 and prevent
backflow of either a continuous-phase fluid 308 or a
dispersed-phase fluid 310 therethrough. In a typical embodiment,
the plurality of trays 302(1)-302(5) include a diffuser skirt
312(a). The diffuser skirt 312(a) includes a diffuser body and
plurality of apertures 314 therein. The diffuser skirt 312(a)
depends from an underside of the fluid channel 304. As shown by way
of example in FIG. 3, the diffuser skirt 312(a) extends entirely
between two trays such as, for example, the trays 302(1) and the
tray 302(2); however, one skilled in the art will recognize that
the diffuser skirt 312(a) may not extend entirely between the two
trays 302(1) and 302(2) leaving a clearance space. Although the
plurality of apertures 314 are shown by way of example in FIG. 3 as
perforations, one skilled in the art will recognize that, in
alternative embodiments, the plurality of apertures 314 may include
slots, louvers, and the like. The plurality of apertures 314 are
illustrated by way of example in FIG. 3 as being evenly spaced
around the diffuser skirt 312(a); however, the plurality of
apertures 314 may alternatively be grouped to direct the
continuous-phase fluid 308 in a desired direction. By way of
example, the fluid-fluid exchange column 300 is shown in FIG. 3 as
containing five trays 302(1)-302(5); however, one skilled in the
art will recognize that, in alternative embodiments, any number of
trays may be utilized.
[0037] Referring still to FIG. 3, in various embodiments, the
fluid-fluid exchange column 300 includes a first conduit 312(b). In
a typical embodiment, the first conduit 312(b) includes a plurality
of apertures 315 disposed therein. In various embodiments, the
first conduit 312(b) depends from an underside of the fluid channel
304. As shown by way of example in FIG. 3, the first conduit 312(b)
does not extend entirely between two trays such as, for example,
the tray 302(3) and the tray 302(4); however, one skilled in the
art will recognize that, in alternative embodiments, the first
conduit 312(b) may extend entirely between the two trays 302(3) and
302(4). Although, the plurality of apertures 315 are shown by way
of example in FIG. 3 as perforations; one skilled in the art will
recognize that, in alternative embodiments, the plurality of
apertures 315 may include slots, louvers, or the like. The
plurality of apertures 315 are illustrated by way of example in
FIG. 3 as being evenly spaced around the first conduit 312(b);
however, the plurality of apertures 315 may alternatively be
grouped to direct the continuous-phase fluid 308 in a desired
direction.
[0038] Referring still to FIG. 3, in certain embodiments, the
plurality of apertures 315 are disposed on both an interior face
and an exterior face of a second conduit 312(c). Such an
arrangement facilitates mixing of the continuous-phase fluid 308
and the dispersed-phase fluid 310 on the exterior side of the
second conduit 312(c). Additionally, this arrangement allows an
active area, where mixing of the continuous-phase fluid 308 and the
dispersed-phase fluid 310 occurs, to extend entirely to the outer
wall 301 of the fluid-fluid exchange column 300.
[0039] Referring still to FIG. 3, in certain embodiments, a
coalescing element 316 may be included on any of the plurality of
trays 302(1)-302(5) to facilitate coalescing of the dispersed-phase
fluid 310. Although the coalescing element 316 is shown in FIG. 3
as being disposed on an underside of the plurality of trays
302(1)-302(2), one skilled in the art will recognize that the, in
alternative embodiments, coalescing element 316 may be located on a
top surface of the plurality of trays 302(1)-302(2) in cases where
the dispersed-phase fluid 310 is heavier than the continuous-phase
fluid 308.
[0040] Still referring to FIG. 3, during operation, the
continuous-phase fluid 308 moves across a tray such as, for
example, the tray 302(1), into the fluid channel 304, and through
at least one of the plurality of orifice constrictions
306(a)-306(c). As the continuous-phase fluid 308 moves through at
least one of the plurality of orifice constrictions 306(a)-306(c),
flow of the continuous-phase fluid 308 is restricted resulting in
increased velocity of the continuous-phase fluid 308. The added
velocity further facilitates stirring and mixing of the
continuous-phase fluid 308 and the dispersed-phase fluid 310
forcing the continuous-phase fluid 308 to be spread entirely across
a cross-flow volumetric window between successive trays such as,
for example, the trays 302(1) and 302(2) preventing stagnation and
reducing recirculation (also referred to as "eddy current") in the
continuous-phase fluid 308. Additionally, according to an exemplary
embodiment, thrust tabs (not explicitly shown in FIG. 3) may be
incorporated in conjunction with the plurality of apertures 314 or
315 to direct the continuous-phase fluid 308 to cover the entire
volumetric cross-flow window between each of the plurality of trays
302(1)-302(5).
[0041] Referring now to FIG. 4, there is shown a top-plane,
diagrammatic view of a tray according to an exemplary embodiment.
In a typical embodiment, a tray such as, for example, the tray
302(2) includes a diffuser skirt 312(a), a plurality of baffles
408, and a plurality of vanes 412. In a typical embodiment, the
diffuser skirt 312(a) forms a chord across a surface of a tray such
as, for example, the tray 302(2). As illustrated in FIG. 4, a
plurality of tabs 404 may be incorporated with the plurality of
apertures 314 (shown in FIG. 3) to direct the continuous-phase
fluid 308 in a desired direction thus further inducing the
continuous-phase fluid 308 to cover the entire volumetric
cross-flow window of a tray such as, for example, the tray 302(2).
The plurality of baffles 408 may be incorporated within the fluid
channel 304 to direct the continuous-phase fluid 308 to cover the
entire volumetric cross-flow window of a tray such as, for example,
the tray 302(2). Additionally, the plurality of vanes 412 may be
incorporated to impart additional velocity to the continuous-phase
fluid 308 and to further direct the continuous-phase fluid 308 to
cover the entire volumetric cross-flow window of a tray such as,
for example, the tray 302(2).
[0042] Referring now to FIG. 5, there is shown a diagrammatic,
side-elevational, cross-sectional view of a fluid-fluid exchange
column according to an exemplary embodiment. In a typical
embodiment, a fluid-fluid exchange column 500 includes a plurality
of trays 502(1)-502(5). By way of example, the fluid-fluid exchange
column 500 is illustrated in FIG. 5 as having five trays
502(1)-502(5); however, one skilled in the art will recognize that,
in alternative embodiments, any number of trays could be utilized.
In a typical embodiment, a tray such as, for example, the tray
502(2) allows fluid to enter and exit via fluid channels 504. In
various embodiments, the plurality of fluid channels 504 may
include, for example, a downcomer or an upcomer as described
hereinabove. In various embodiments, the fluid channels 504 include
at least one of the plurality of orifice constrictions
306(a)-306(c) (shown in FIG. 3) disposed therein. The plurality of
orifice constrictions 306(a)-306(c) are described above with
respect to FIG. 3. In a typical embodiment, a plurality of diffuser
skirts 506(a)-506(c), each having a diffuser body and a plurality
of apertures 508 disposed therein, depends from an underside of the
fluid channels 504. As shown by way of example in FIG. 5, the
plurality of diffuser skirts 506(a)-506(c) extends substantially
between two trays such as, for example, the tray 502(1) and the
tray 502(2); however, one skilled in the art will recognize that,
in alternative embodiments, the plurality of diffuser skirts
506(a)-506(c) may not extend entirely to, for example, the tray
502(2) leaving a clearance space between the plurality of diffuser
skirts 506(a)-506(c) and the tray 502(2) for additional flow.
[0043] Still Referring to FIG. 5, in contrast to FIG. 3, the
plurality of diffuser skirts 506(a)-506(c) are, in a typical
embodiment, angled towards an outer wall 510 of the fluid-fluid
exchange column 500 thereby inducing turbulence in the
continuous-phase fluid 308. Although, the plurality of apertures
508 are shown by way of example in FIG. 5 as perforations; one
skilled in the art will recognize that the plurality of apertures
508 could include slots, louvers, and other configurations. The
plurality of apertures 508 are illustrated by way of example in
FIG. 5 as being evenly spaced around the plurality of diffuser
skirts 506(a)-506(c); however, the plurality of apertures 508 may
alternatively be grouped to create a specific fluid flow
Additionally, in various embodiments, at least one of inlet weirs
512(a)-512(c) may be disposed on a top surface of a tray such as,
for example, the trays 502(2)-20(4) medially of the plurality of
diffuser skirts 506(a)-506(c). In some embodiments, a diffuser
skirt such as, for example, the plurality of diffuser skirts 506(b)
may extend entirely to the outer wall 510 of the fluid-fluid
exchange column 500. In this arrangement, the plurality of diffuser
skirts 506(b) also performs the function of at least one of the
orifice constrictions 306(a)-306(c). Such an arrangement also
allows an active area associated with a tray such as, for example,
the tray 502(4) to extend entirely to the outer wall 510 of the
fluid-fluid exchange column 500. In addition, in some embodiments,
a diffuser skirt 506(c) may seal upon a floor of an adjacent tray
such as, for example, the tray 502(5).
[0044] Still Referring to FIG. 5, in certain embodiments, the
coalescing element 316 may be included on any of the plurality of
trays 502(1)-502(5) to facilitate coalescing of the dispersed-phase
fluid 310. Although the coalescing element 316 is shown in FIG. 5
as being disposed on an underside of a tray such as, for example,
the trays 502(1)-502(2), one skilled in the art will recognize
that, in alternative embodiments, the coalescing element 316 could
be located on a top surface of a tray such as, for example, the
trays 502(1)-502(2) in those flow configurations where the
dispersed-phase fluid 310 is heavier than the continuous-phase
fluid 308 and the flow is redirected in accordance therewith.
[0045] Still referring to FIG. 5, during operation, the
continuous-phase fluid 308 moves across a tray such as, for
example, the tray 502(1), into the fluid channel 504, and through
at least one of the plurality of orifice constrictions
306(a)-306(c). As the continuous-phase fluid 308 moves through the
plurality of diffuser skirts 506(a)-506(c). In a typical
embodiment, the diffuser skirts 506(a)-506(c) are angled towards an
outer wall 510 of the fluid-fluid exchange column 500. In a typical
embodiment, flow restriction imposed by the plurality of apertures
508 results in additional velocity being imparted to the
continuous-phase fluid 308. The added velocity further facilitates
stirring and mixing of the continuous-phase fluid 308 and the
dispersed-phase fluid 310. Such added velocity also forces the
continuous-phase fluid 308 to be spread entirely across a
volumetric cross-flow window between successive trays such as, for
example, the trays 502(1)-502(2) thus preventing stagnation and
reducing recirculation of the continuous-phase fluid 308. In
addition, the continuous-phase fluid 308 passes through the
plurality of apertures 508 at right angles to the plurality of
diffuser skirts 506(a)-506(c). In various embodiments, some of the
continuous-phase fluid 308 will pass over, for example, a solid
inlet weir 512(a). In an alternative embodiments, some of the
continuous-phase fluid 308 could pass through a perforated inlet
weir 512(b). The interaction of the plurality of diffuser skirts
506(a)-506(c) and the perforated inlet weir 512(b) introduce
turbulence to the continuous-phase fluid 308. The directional
turbulence causes stirring of the continuous-phase fluid 308 thus
facilitating interaction with the dispersed-phase fluid 310.
Additionally, thrust tabs (not explicitly shown in FIG. 5) may be
incorporated in conjunction with the plurality of apertures 508 of
the plurality of diffuser skirts 506(a)-506(c) or the perforated
inlet weir 512(b) to direct the continuous-phase fluid 308 to cover
an entire volumetric cross-flow window of the plurality of trays
502(1)-502(5).
[0046] Referring now to FIG. 6, there is shown a top-plane,
diagrammatic view of a tray according to an exemplary embodiment.
In a typical embodiment a tray such as, for example, the tray
502(2) includes a diffuser skirt 506(a) and a plurality of vanes
602. The diffuser skirt 506(a) forms a chord across a surface of
the tray 502(2). As illustrated in FIG. 6, thrust tabs (not
explicitly shown in FIG. 6) may be incorporated with the plurality
of apertures 508 to direct to the continuous-phase fluid 308 (not
shown in FIG. 6) in a desired direction thereby inducing the
continuous-phase fluid 308 to cover an entire volumetric cross-flow
window of a tray such as, for example the tray 502(2).
Additionally, at least one or a plurality of vanes 602 may be
disposed on a tray such as, for example, the tray 502(2) to impart
additional velocity to the continuous-phase fluid 308 and to
further direct the continuous-phase fluid 308 to cover the entire
volumetric cross-flow window of a tray such as, for example, the
tray 502(2). According to exemplary embodiments, the vanes 602 may
be curved, angled, or straight to reduce eddy currents in the
continuous-phase fluid 308 and the dispersed-phase fluid 310 (not
shown in FIG. 6). Reducing eddy currents prevents recirculation of
either the continuous-phase fluid 308 or the dispersed-phase fluid
310 and improves efficiency of the plurality of trays
502(1)-502(5). The plurality of apertures 508 are illustrated by
way of example in FIG. 6 as being evenly spaced around the diffuser
skirt 506(a)-506(c); however, the plurality of apertures 508 may
alternatively be grouped to create a specific fluid flow.
[0047] Referring now to FIG. 7A, there is shown a perspective view
of a diffuser skirt according to an exemplary embodiment. In a
typical embodiment, a diffuser skirt 700 comprises a plurality of
apertures 702. The plurality of apertures 702 are illustrated by
way of example in FIG. 7A as being evenly spaced around the
diffuser skirt 700; however, the plurality of apertures 702 may, in
alternative embodiments, be grouped to create a specific fluid
flow. In a typical embodiment the diffuser skirt 700 is
substantially convex shaped. The diffuser skirt 700 may be, for
example, roughly infundibular or quasi-frustoconical in shape.
[0048] FIGS. 7B-7E illustrate various exemplary shapes of the
diffuser skirt 700. FIG. 7B illustrates the diffuser skirt 700 as
chevron shaped. FIG. 7C illustrates the diffuser skirt 700 as
pentagon-shaped, FIG. 7D illustrates the diffuser skirt 700 as open
hexagon-shaped. FIG. 7E illustrates the diffuser skirt 700 as an
open polygon or any other appropriate shape.
[0049] Referring specifically to FIG. 7F, there is shown a
top-plane, diagrammatic view of a tray according to an exemplary
embodiment. In a typical embodiment, a tray 704 includes a diffuser
skirt 700 having a plurality of apertures 702 therein. In a typical
embodiment, the diffuser skirt 700 is substantially arc-shaped. In
a typical embodiment, the diffuser skirt 700 may be, for example,
roughly infundibular or quasi-frustoconical in shape. During
operation, the continuous-phase fluid 308 moves through the
plurality of apertures 702 at an approximate right angle to the
diffuser skirt 700. The roughly arcuate profile of the diffuser
skirt 700 facilitates directing the continuous-phase fluid 308 over
the entire volumetric cross-flow window between successive trays
such as, for example, the tray 704. In various embodiments, tabs 64
(shown in FIG. 4) may be incorporated with the plurality of
apertures 702 to direct the continuous-phase fluid 308 in a desired
direction thereby inducing the continuous-phase fluid 308 to cover
the entire volumetric cross-flow window between the successive
trays such as, for example, the trays 502(1)-502(2) (shown in FIG.
5). Additionally, at least one or a plurality of vanes 706 may be
incorporated to impart additional velocity to the continuous-phase
fluid 308 and to further direct the continuous-phase fluid 308 to
cover the entire volumetric cross-flow window of a tray such as,
for example, the tray 704. The vanes 706 may be curved, angled, or
straight to reduce eddy currents in the continuous-phase fluid 308
and the dispersed-phase fluid 310 (not explicitly shown in FIG. 7).
The plurality of apertures 702 are illustrated by way of example in
FIG. 7F as being evenly spaced around the diffuser skirt 700;
however, the plurality of apertures 702 may, in alternative
embodiments, be grouped to direct the continuous-phase fluid 308 to
cover an entire volumetric cross-flow window of the tray 704.
[0050] Referring now to FIG. 8, there is shown a diagrammatic,
side-elevational, cross-sectional view of a fluid-fluid exchange
column according to an exemplary embodiment. A fluid-fluid exchange
column 800 includes a plurality of trays 802(1)-802(4). In a
typical embodiment, a tray such as, for example, the tray 802(2)
allows fluid to enter and exit via fluid channels 804. In various
embodiments, the plurality of fluid channels 804 may include, for
example, a downcomer or an upcomer as described hereinabove. In a
various embodiments, the fluid channels 804 include at least one of
the plurality of orifice constrictions 306(a)-306(c) (shown in FIG.
3) discussed above with respect to FIG. 3 disposed therein. A
downspout 806, having a plurality of apertures 808 therein, depends
from an underside of the fluid channel 804. As shown by way of
example in FIG. 8, the downspout 806 extends substantially between
two successive trays such as, for example, the tray 802(1) and the
tray 802(2) leaving a clearance gap 810 between the downspout 806
and the tray 802(2); however, one skilled in the art will recognize
that, in alternative embodiments, the downspout 806 may extend
entirely to the tray 802(2) leaving no clearance space. Although,
the plurality of apertures 808 are shown by way of example in FIG.
8 as perforations; one skilled in the art will recognize that, in
alternative embodiments, the plurality of apertures 808 could
include slots, louvers, or the like. The plurality of apertures 808
are illustrated by way of example in FIG. 8 as being evenly spaced
around the downspout 806; however, the plurality of apertures 808
may alternatively be grouped to create a specific fluid flow. By
way of example, the fluid-fluid exchange column 800 is illustrated
as including four trays 802(1)-802(4); however, one skilled in the
art will recognize that, in alternative embodiments, any number of
trays could be utilized.
[0051] Still Referring to FIG. 8, in certain embodiments, the
coalescing element 316 may be included on the any of the plurality
of trays 802(1)-802(4) to facilitate coalescing of the
dispersed-phase fluid 310. Although the coalescing element 316 is
shown in FIG. 8 as being disposed on an underside of the plurality
of trays 802(1)-802(4), one skilled in the art will recognize that,
in alternative embodiments, the coalescing element 316 could be
located on a top surface of the plurality of trays 802(1)-802(4) in
cases where the dispersed-phase fluid 310 is heavier than the
continuous-phase fluid 308.
[0052] Still referring to FIG. 8, during operation, a
continuous-phase fluid 308 moves across a tray such as, for
example, the tray 802(1), into the fluid channel 804, and through
at least one of the orifice constrictions 306(a)-306(c). As the
continuous-phase fluid 308 moves through the downspout 806, the
flow restriction imposed by the plurality of apertures 808 results
in velocity being imparted to the continuous-phase fluid 308. The
added velocity also facilitates stirring and mixing of the
continuous-phase fluid 308 and the dispersed-phase fluid 310. Such
added velocity also forces the continuous-phase fluid 308 to be
dispersed across an entire volumetric cross-flow window between
successive trays such as, for example, the tray 802(1) and the tray
802(2) thus preventing stagnation and recirculation. Additionally,
thrust tabs (not explicitly shown in FIG. 8) may be incorporated in
conjunction with the plurality of apertures 808 to direct the
continuous-phase fluid 308 to cover the entire volumetric
cross-flow window of the plurality of trays 802(1)-802(4).
[0053] Referring now to FIGS. 9A and 9B, there is shown a
top-plane, diagrammatic view of a tray according to an exemplary
embodiment. In a typical embodiment a tray such as, for example,
the tray 802(2) includes the fluid channel 804 and the downspout
806. In a typical embodiment, the downspout 806 can be seen
disposed within the fluid channel 804. As shown in FIG. 9A, in
certain embodiments, a single downspout 806 may be included in the
fluid channel 804. However, as illustrated in FIG. 9B, in certain
alternative embodiments, multiple downspouts 807(1)-807(5) may be
included in the fluid channel 804. As previously illustrated in
FIG. 4, thrust tabs (not explicitly shown in FIGS. 9A and 9B) may
be incorporated with the plurality of apertures (not explicitly
shown in FIGS. 9A and 9B) to direct the continuous-phase fluid 308
in a desired direction thereby inducing the continuous-phase fluid
308 to cover the entire volumetric cross-flow area of a tray such
as, for example, the tray 802(2). Additionally, at least one or a
plurality of vanes 902 may be incorporated to impart additional
velocity to the continuous-phase fluid 308 and to further direct
the continuous-phase fluid 308 to cover the entire volumetric
cross-flow window of a tray such as, for example, the tray 802(2).
The vanes 902 may be curved, angled, or straight to reduce eddy
currents in the continuous-phase fluid 308 and the dispersed-phase
fluid 310 (not explicitly shown in FIG. 9).
[0054] It is thus believed that the operation and construction of
the present invention will be apparent from the foregoing
description. Although the method and apparatus shown or described
has been characterized as being preferred it will be obvious that
various changes and modifications may be made therein without
departing from the spirit and scope of the invention as defined in
the following claims. For example, most embodiments are described
herein as having a heavier fluid in a continuous phase; however,
one skilled in the art will recognize that a lighter fluid could
comprise the continuous phase with minimal change to the structure
of the fluid-fluid exchange column. By way of further example, the
principles disclosed herein are applicable to various types of
separations trays including, for example, valve trays, sieve trays,
and the like. Furthermore, the features discussed above with
respect to FIGS. 1-9 may be combined and rearranged in numerous
advantageous ways that will be apparent to one of ordinary skill in
the art. For example, although specific embodiments are discussed
herein that have various features such as lighter fluid slots,
ridges, and thrust tabs, it is fully contemplated that other
advantageous embodiments may have any combination of or even
multiple instances of these features. Finally, specific embodiments
are illustrated herein as pertaining to single-pass trays with a
serpentine flow path; however, one skilled in the art will
recognize that the principles disclosed herein could be applicable
to separations trays having numerous types of flow paths including,
for example, dual-pass, multiple pass, orbital flow, and
uni-directional flow.
[0055] FIG. 10 is a is a diagrammatic, side-elevational,
cross-sectional view of a fluid-fluid exchange column according to
an exemplary embodiment. In a typical embodiment, a fluid-fluid
exchange column 1000 is constructed similar to any of, for example,
the fluid-fluid exchange columns 300, 500, or 800 shown in FIGS. 3,
5, and 8. In a typical embodiment, a continuous-phase fluid 1008 is
a light fluid and thus flows from a bottom portion to a top portion
of the fluid-fluid exchange column 1000. Likewise, a
dispersed-phase fluid 1010 is a heavy fluid and thus flows from a
top portion to a bottom portion of the fluid-fluid exchange column
1000. In a typical embodiment, during operation, the
continuous-phase fluid 1008 moves across a tray such as, for
example, the tray 1002(1), into a fluid channel 1004, and through
at least one of the plurality of orifice constrictions
306(a)-306(c). As the continuous-phase fluid 1008 moves through at
least one of the plurality of orifice constrictions 306(a)-306(c),
flow of the continuous-phase fluid 1008 is restricted resulting in
increased velocity of the continuous-phase fluid 1008. The added
velocity further facilitates stirring and mixing of the
continuous-phase fluid 1008 and the dispersed-phase fluid 1010
forcing the continuous-phase fluid 1008 to be spread entirely
across a cross-flow volumetric window between successive trays such
as, for example, the trays 1002(1) and 1002(2) preventing
stagnation and reducing recirculation (also referred to as "eddy
current") in the continuous-phase fluid 1008. Additionally,
according to an exemplary embodiment, thrust tabs (not explicitly
shown in FIG. 10) may be incorporated in conjunction with a
plurality of apertures 1014 or 1015 to direct the continuous-phase
fluid 1008 to cover the entire volumetric cross-flow window between
each of the plurality of trays 1002(1)-1002(5). FIG. 10 is included
herein to demonstrate that either a heavier fluid or a lighter
fluid may be used in operation as the continuous phase with
appropriate modifications to a structure of the fluid-fluid
exchange column.
[0056] Although various embodiments of the method and apparatus of
the present invention have been illustrated in the accompanying
Drawings and described in the foregoing Detailed Description, it
will be understood that the invention is not limited to the
embodiments disclosed, but is capable of numerous rearrangements,
modifications and substitutions without departing from the spirit
of the invention as set forth herein.
* * * * *