U.S. patent application number 13/954118 was filed with the patent office on 2014-02-06 for methods and assemblies for separating liquid from a gas-liquid stream.
This patent application is currently assigned to Cummins Filtration IP, Inc.. The applicant listed for this patent is Cummins Filtration IP, Inc.. Invention is credited to Shane Connaughton, Lee A. Peck, Kieran J. Richards, Benjamin L. Scheckel, Roger L. Zoch.
Application Number | 20140033922 13/954118 |
Document ID | / |
Family ID | 50024197 |
Filed Date | 2014-02-06 |
United States Patent
Application |
20140033922 |
Kind Code |
A1 |
Peck; Lee A. ; et
al. |
February 6, 2014 |
Methods and Assemblies for Separating Liquid from a Gas-Liquid
Stream
Abstract
A two stage gas-liquid separator assembly includes a housing
having an inlet for receiving a gas-liquid stream and an outlet for
discharging a gas stream. A first plenum chamber includes a
pre-separator that causes liquid to separate from the gas-liquid
stream and to drain to a lower portion of the first plenum chamber.
A second plenum chamber includes a main separator downstream of the
pre-separator that further causes liquid to separate from the
gas-liquid stream and to drain to a lower portion of the second
plenum chamber. A first drain port drains liquid from the lower
portion of the first plenum chamber and a second drain port drains
liquid from the lower portion of the second plenum chamber. Liquid
drains from the first and second plenum chambers regardless of a
pressure difference between a pressure in the first plenum chamber
and a pressure in the second plenum chamber.
Inventors: |
Peck; Lee A.; (Stoughton,
WI) ; Richards; Kieran J.; (Daventry, GB) ;
Connaughton; Shane; (Daventry, GB) ; Scheckel;
Benjamin L.; (Stoughton, WI) ; Zoch; Roger L.;
(McFarland, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cummins Filtration IP, Inc. |
Columbus |
IN |
US |
|
|
Assignee: |
Cummins Filtration IP, Inc.
Columbus
IN
|
Family ID: |
50024197 |
Appl. No.: |
13/954118 |
Filed: |
July 30, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61677525 |
Jul 31, 2012 |
|
|
|
Current U.S.
Class: |
95/272 ; 55/419;
55/430; 55/431; 55/447; 55/462 |
Current CPC
Class: |
F01M 2013/0433 20130101;
F01M 13/04 20130101; F01M 2013/0488 20130101; F01M 2013/0438
20130101 |
Class at
Publication: |
95/272 ; 55/462;
55/430; 55/431; 55/419; 55/447 |
International
Class: |
F01M 13/04 20060101
F01M013/04 |
Claims
1. A two-stage gas-liquid separator assembly comprising: a housing
haying a flowpath therethrough from upstream to downstream, the
housing having an inlet, for receiving a gas-liquid stream and an
outlet fur discharging a gas stream; a first plenum chamber defined
by the housing and comprising a pre-separator that causes liquid to
separate from the gas-liquid stream and to drain to a lower portion
of the first plenum chamber; a second plenum chamber defined by the
housing and comprising a main separator downstream of the
pre-separator that further causes liquid to separate from the
gas-liquid stream and to drain to a lower portion of the second
plenum chamber; a first drain port in the housing draining liquid
from the lower portion of the first plenum chamber; and a second
drain pot in the housing draining liquid from the lower portion of
the second plenum chamber; wherein liquid drains from the lower
portions of the first and second plenum chambers through the first
and second drain ports, respectively, regardless of a pressure
difference between a pressure in the first plenum chamber and a
pressure in the second plenum chamber.
2. The assembly of claim 1, further comprising a conduit in fluid
communication with both the first and second drain ports that
conveys liquid from the lower portions of the first and second
plenum chambers away from the housing.
3. The assembly of claim 2, wherein the conduit comprises a pump
that removes liquid from the lower portions of the first and second
plenum chambers through the first and second drain ports,
respectively.
4. The assembly of claim 3, wherein the pump comprises a jet pump
in fluid communication with both the first and second drain
ports.
5. The assembly of claim 4, wherein the jet pump comprises a first
jet orifice accelerating pressurized fluid so as to pump liquid
from the first drain port and a second jet orifice accelerating
pressurized fluid so as to pump liquid from the second drain
port.
6. The assembly of claim 5, wherein the pressurized fluid is
oil.
7. The assembly of claim 5, wherein the jet pump comprises a feed
bore that supplies the pressurized fluid to both the first and
second jet orifices.
8. The assembly of claim 7, wherein the jet pump comprises a first
suction port that receives liquid from the first drain port and
pressurized fluid from the first jet orifice, and a second suction
port that receives liquid from the second drain port and
pressurized fluid from the second jet orifice.
9. The assembly of claim 8, wherein the jet pump comprises a mixing
bore that receives liquid from both the first suction port and the
second suction port.
10. The assembly of claim 4, wherein the jet pump is coupled to the
housing.
11. The assembly of claim 10, wherein the second drain port
comprises a tube extending from the lower portion of the second
plenum chamber through the first plenum chamber to the jet
pump.
12. The assembly of claim 1 further comprising a chimney supported
by the housing and extending from the first plenum chamber into the
second plenum chamber and allowing for the gas-liquid stream to
flow therethrough.
13. The assembly of claim 12, wherein the lower portion of the
second plenum chamber comprises a funnel that slopes downwardly
from an inner surface of the housing to an external wall of the
chimney so as to drain liquid to the second drain port.
14. The assembly of claim 12, wherein the main separator is an
impactor separator comprising a nozzle plate coupled to a
downstream end of the chimney and haying a plurality of nozzles
therethrough that accelerate the gas-liquid stream toward an
impaction plate downstream of the nozzle plate.
15. The assembly of claim 14, further comprising a shroud extending
circumferentially and downwardly from the impaction plate and
surrounding at least the downstream end of the chimney.
16. The assembly of claim 12, wherein the main separator is a
coalescer separator comprising a filter media coupled to a
downstream end of the chimney.
17. The assembly of claim I wherein the pre-separator is a cyclone
separator.
18. The assembly of claim 17, further comprising an arched baffle
adjacent the inlet that guides the gas-liquid stream along an inner
surface of the first plenum chamber as the gas-liquid stream enters
the first plenum chamber.
19. A method for separating liquid from a gas-liquid stream, the
method comprising: introducing the gas-liquid stream into a housing
having a flowpath therethrough from upstream to downstream;
separating, liquid from the gas-liquid stream in a first plenum
chamber defined by the housing; draining liquid to a lower portion
of the first plenum chamber and through a first drain port; further
separating liquid from the gas-liquid stream in a second plenum
chamber defined by the housing and downstream of the first plenum
chamber; draining liquid to a lower portion of the second plenum
chamber and through a second drain port; and pumping liquid from
the lower portions of the first and second plenum chambers through
the first and second drain ports, respectively.
20. The method of claim 19, further comprising pumping liquid from
the first and second drain ports into first and second suction
ports, respectively.
21. The method of claim 20, further comprising accelerating
pressurized fluid through first and second jet orifices and into
the first and second suction ports, respectively, so as to pump
liquid from the lower portions of the first and second plenum
chambers, respectively.
22. The method of claim 21, further comprising supplying the
pressurized fluid to the first and second jet orifices from a
common pressurized fluid source.
23. The method of claim 22, further comprising mixing the
pressurized fluid from the first jet orifice and the liquid from
the first drain port with the pressurized fluid from the second jet
orifice and the liquid horn the second drain port in a common
mixing chamber.
24. The assembly of claim 21, wherein the pressurized fluid is
oil.
25. The assembly of claim 24, wherein the oil is provided from an
oil pump coupled to a crankcase of an engine.
26. The assembly of claim 21, wherein the pressurized, fluid is
air.
27. The assembly of claim 26, wherein the air is provided from a
turbocharger.
28. An assembly for removing scavenged liquid from a two-stage
gas-liquid separator, the assembly comprising: a first suction port
receiving scavenged liquid from a first stage of the gas-liquid
separator; a second suction port receiving scavenged liquid from a
second stage of the gas-liquid separator; a first jet orifice
accelerating a pressurized fluid into the first suction port; a
second jet orifice accelerating the pressurized fluid into the
second suction port; a feed bore supplying both the first and
second jet orifices with the pressurized fluid, and a common mixing
bore receiving the pressurized fluid from the first and second jet
orifices and receiving scavenged liquid from the first and second
stages of the gas-liquid separator.
29. The assembly of claim 28, further comprising a first connection
port conveying liquid from an outlet in the first stage of the
gas-liquid separator to the first suction port, and a second
connection port conveying liquid from an outlet in the second stage
of the gas-liquid separator to the second suction port.
30. The assembly of claim 28, wherein the first and second suction
ports extend perpendicularly to a flow of the accelerated,
pressurized fluid from the first and second jet orifices,
respectively.
31. The assembly of claim 28, further comprising a drain line
coupled to the common mixing bore that drains the scavenged liquid
from the common mixing bore to a crankcase of an engine.
32. The assembly of claim 28, wherein the pressurized fluid is
oil.
33. The assembly of claim 28, wherein the pressurized fluid is
air.
34. The assembly of claim 28, wherein the assembly is integrally
molded to a lower portion of a housing of the gas-liquid
separator.
35. The assembly of claim 28, wherein the assembly is bolted to a
lower portion of a housing of the gas-liquid separator.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of and priority to U.S.
Provisional Application Ser. No. 61/677,525, filed Jul. 31, 2012,
the disclosure of which is hereby incorporated by reference in its
entirety.
FIELD
[0002] The present disclosure relates to two-stage gas-liquid
separators and methods for separating liquids from a gas-liquid
stream.
BACKGROUND
[0003] U.S. Pat. No. 7,870,850, which is hereby incorporated by
reference in its entirety, discloses a crankcase ventilation system
for an internal combustion engine that has a jet pump suctioning
scavenged separated oil from the oil outlet of an air/oil separator
and pumping same to the crankcase.
[0004] U.S. Pat. No. 7,614,390, which is hereby incorporated by
reference in its entirety, discloses a two stage drainage
gas-liquid separator assembly including an inertial gas-liquid
impactor separator haying one or more nozzles accelerating a
gas-liquid stream therethrough, and an inertial impactor in the
path of the accelerated gas-liquid stream and causing liquid
particle separation from the gas-liquid stream. The separator
assembly further includes a coalescer filter downstream of the
inertial gas-liquid impactor separator and effecting further liquid
particle separation, and coalescing separated liquid particles.
[0005] U.S. Pat. No. 6,290,738, which is hereby incorporated by
reference in its entirety, discloses an inertial gas-liquid
separator. A housing has an inlet for receiving a gas-liquid stream
and an outlet for discharging a gas stream. A nozzle structure in
the housing has a plurality of nozzles receiving the gas-liquid
stream from the inlet, and accelerating the gas-liquid stream
through the nozzles. An inertial collector in the housing in the
path of the accelerated gas-liquid stream causes a sharp
directional change thereof and in preferred form has a rough porous
collection surface causing liquid particle separation from the
gas-liquid stream of smaller size liquid particles than a smooth
non-porous impactor impingement surface and without the sharp
cut-off size of the latter, to improve over all separation
efficiency including for smaller liquid particles. Various housing
configurations and geometries are provided.
SUMMARY
[0006] This Summary is provided to introduce a selection of
concepts that are further described below in the Detailed
Description. This Summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used as an aid in limiting the scope of the claimed
subject matter.
[0007] The present disclosure is directed to a two-stage gas-liquid
separator assembly comprising a housing having a flowpath
therethrough from upstream to downstream, the housing having an
inlet for receiving a gas-liquid stream and an outlet for
discharging a gas stream. A first plenum chamber is defined by the
housing and comprises a pre-separator that causes liquid to
separate from the gas-liquid stream and to drain to a lower portion
of the first plenum chamber. A second plenum chamber is defined by
the housing and comprises a main separator downstream of the
pre-separator that further causes liquid to separate from the
gas-liquid stream and to drain to a lower portion of the second
plenum chamber. A first drain port in the housing drains liquid
from the lower portion of the first plenum chamber and a second
drain port in the housing drains liquid from the lower portion of
the second plenum chamber. Liquid drains from the lower portions of
the first and second plenum chambers through the first and second
drain ports, respectively, regardless of a pressure difference
between a pressure in the first plenum chamber and a pressure in
the second plenum chamber.
[0008] Also disclosed is a method for separating liquid from a
gas-liquid stream. The method comprises: introducing the gas-liquid
stream into a housing having a flowpath therethrough from upstream
to downstream. The method further comprises separating liquid from
the gas-liquid stream in a first plenum chamber defined by the
housing and draining liquid to a lower portion of the first plenum
chamber and through a first drain port. The method further
comprises further separating liquid from the gas-liquid stream in a
second plenum chamber defined by the housing and downstream of the
first plenum chamber and draining liquid to a lower portion of the
second plenum chamber and through a second drain port. The method
further comprises pumping liquid from the lower portions of the
first and second plenum chambers through the first and second drain
ports, respectively.
[0009] An assembly for removing scavenged liquid from a two-stage
gas-liquid separator is also disclosed. The assembly comprises a
first suction port receiving scavenged liquid from a first stage of
the gas-liquid separator and a second suction port receiving
scavenged liquid from a second stage of the gas-liquid separator. A
first jet orifice accelerates a pressurized fluid into the first
suction port. A second jet orifice accelerates the pressurized
fluid into the second suction port. A feed bore supplies both the
first and second jet orifices with the pressurized fluid. A common
mixing bore receives the pressurized fluid from the first and
second jet orifices and receives scavenged liquid from the first
and second stages of the gas-liquid separator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Examples of assemblies and methods for use with a crankcase
ventilation unit are described with reference to the following
Figures. The same numbers are used throughout the Figures to
reference like features and like components.
[0011] FIG. 1 is a schematic representation of one embodiment of a
crankcase ventilation system;
[0012] FIG. 2 illustrates one embodiment of a two-stage gas-liquid
separator, in one embodiment, for use in a crankcase ventilation
system;
[0013] FIG. 3 illustrates a flowpath through the gas-liquid
separator of FIG. 2 when viewed from an opposite side than in FIG.
2;
[0014] FIGS. 4 and S show sectional views through the gas-liquid
separator of FIGS. 2 and 3, wherein FIG. 4 is a top view and FIG. 5
is a bottom view;
[0015] FIG. 6 illustrates a detail view of a lower portion of the
gas-liquid separator;
[0016] FIG. 7 illustrates a sectional detail view of the lower
portion of the gas-liquid separator and one embodiment of a jet
pump for use with the gas-liquid separator;
[0017] FIG. 8 illustrates a top sectional view of the jet pump;
[0018] FIG. 9 is a schematic representation of flow through a jet
pump;
[0019] FIG. 10 illustrates another embodiment of a two-stage
gas-liquid separator; and
[0020] FIG. 11 is a schematic representation of another embodiment
of a crankcase ventilation system.
[0021] FIG. 12 depicts one embodiment of a method for separating
liquid from a gas-liquid stream according to the present
disclosure.
DETAILED DESCRIPTION
[0022] Crankcase ventilation systems are used in conjunction with
internal combustion engines that generate blowby gas in a crankcase
containing engine oil and oil aerosol. A gas-liquid separator, or
an aerosol-oil or air-oil separator, has an inlet receiving blowby
gas and oil aerosol from the crankcase. An air outlet discharges
clean blowby gas to the atmosphere or back to the engine air
intake. An oil outlet discharges scavenged separated oil back to
the crankcase. The gas-liquid separator has a pressure drop
thereacross such that the pressure at its inlet and in the
crankcase is higher than the pressure at its air outlet and oil
outlet. The pressure differential between the crankcase and the oil
outlet of the separator can cause back flow of oil from the higher
pressure crankcase to the lower pressure oil outlet. Further,
depending on the location of venting of the crankcase ventilation
system, a high volume of liquid entering the gas-liquid separator
may be present.
[0023] According to the present disclosure, FIG. 1 illustrates a
crankcase ventilation system .10 for an internal combustion engine
12 generating blowby gas in a crankcase 14 containing engine oil 16
and oil aerosol. The system 10 includes a gas-liquid separator 18,
such as an air-oil separator, having an inlet 20 receiving blowby
gas and oil aerosol from the crankcase 14 (shown by arrow 21) and
having an air outlet 22 discharging clean blowby gas to the
atmosphere (shown by arrow 23) or returning clean blowby gas to the
engine air intake (see FIG. 11). The gas-liquid separator 18
further includes an oil outlet 24 discharging scavenged separated
oil back to the crankcase 14, as will be further described herein
below.
[0024] The system 10 further includes a jet pump 26 pumping
scavenged separated oil from oil outlet 24 back to crankcase 14.
The engine 12 includes an oil circulation system 28 circulating
engine oil 16 from crankcase 14 through an oil pump 30. The oil
pump 30 delivers pressurized oil through filter 32 to selected
engine components such as a piston 34 and a crankshaft 36, and then
back to crankcase 14. Pressurized oil is also delivered through
filter 32 to jet pump 26.
[0025] Now with reference to FIG. 2, one embodiment of a gas-liquid
separator 18 will be described, The gas-liquid separator 18
comprises a housing 38 haying a flowpath therethrough from upstream
(at inlet 20) to downstream (at outlet 22). The housing has an
inlet 20 for receiving a gas-liquid stream and an outlet 22 for
discharging a gas stream. The housing 38 comprises a first plenum
chamber 40 defined by the housing 38 and comprising a pre-separator
41 that causes liquid to separate from the gas-liquid stream and to
drain to a lower portion 42 of the first plenum chamber 40. The
gas-liquid separator 18 further comprises a second plenum chamber
44 defined by the housing 38 and comprising a main separator 43
downstream of the pre-separator 41 that further causes liquid to
separate from the vas-liquid stream and to drain to a lower portion
46 of the second plenum chamber 44.
[0026] FIG. 3 shows flow through the gas-liquid separator 18. The
gas-liquid stream enters the housing 38 at the inlet .20 as shown
at arrow 48. The gas-liquid stream is then routed through the
pre-separator 41, for example a cyclone separator as shown herein
and further described herein below, that causes liquid to separate
from the gas-liquid stream as it is guided through the housing 38
as shown at arrows 50. Some liquid is separated from the gas-liquid
stream in the pre-separator, and the pre-separated gas-liquid
stream then enters the second plenum chamber 44 as shown at the
arrow 52. The second plenum chamber 44 comprises a main separator
43, for example an impactor separator as shown herein, and further
described herein below. The gas-liquid stream is accelerated
through the impactor separator as shown at arrows 54 and then exits
the impactor separator as shown at arrows 56. The gas stream then
exits the housing 38 via the outlet 22 as shown at arrow 58.
According to the present disclosure, separated liquid drains from
the housing 38 as shown at arrows 60 and 62, and further described
herein below. A first drain port 64 in the housing 38 drains liquid
from the lower portion 42 of the first plenum chamber 40. A second
drain port 66 in the housing 38 drains liquid from the lower
portion 46 of the second plenum chamber 44. Liquid drains from the
lower portions 42, 46 of the first and second plenum chambers 40,
44, respectively, through the first and second drain ports 64, 66
regardless of a pressure difference between a pressure in the first
plenum chamber 40 and a pressure in the second plenum chamber 44,
as further described herein below.
[0027] With respect to each of FIGS. 2-6, in the embodiment shown
therein, the pre-separator 41 is a cyclone separator, but the
pre-separator 41 could comprise various other types of gas-liquid
separators. Air enters the inlet 20 tangentially as shown at arrow
48, is directed around a baffle 94, and is guided around a curve
defined by the inner surface 110 of the housing 38 as shown by
arrows 50. The baffle 94 minimizes pressure drop as air enters the
housing 38. Air is somewhat guided by a chimney 96 supported by the
housing 38 and extending from the first plenum chamber 40 into the
second plenum chamber 44 that allows for the gas-liquid stream to
flow therethrough. As the gas-liquid stream is circulated as shown
by the arrows 50, heavier liquid particles drop to the lower
portion 42 of the first plenum chamber 40. Additionally, heavier
liquid particles collect along the inner surface 110 of the housing
38 and drain to the lower portion 42 of the first plenum chamber
40. Liquid that collects in the lower portion 42 of the first
plenum chamber 40 thereafter drains from the housing 38 via the
first drain port 64. Upon completing the cyclonic flow and
separating heavier oil particles, flow exits directly through the
chimney 96 into the impactor separator or coalescer separator. The
chimney 96 includes the second drain port 66, in the example shown
comprising a tube 114 that extends down to the jet pump 26. The
downstream end 100 of the chimney 96 is directly molded to the main
separator 43 (FIG. 2).
[0028] In the embodiment shown in FIGS. 2-5, the main separator 43
comprises an impactor separator comprising a nozzle plate 98
coupled to a downstream end 100 of the chimney 96 and having a
plurality of nozzles 102 therethrough that accelerate the
gas-liquid stream toward an impaction plate 104 downstream of the
nozzle plate 98. This acceleration is shown by the arrows 54 in
FIG. 3. in the embodiment shown, the main separator 43 is a
variable impactor separator that further comprises a valve
comprising a spring 150 and disc 152 assembled into a cup 153 with
the nozzle plate 98 sonic welded, or in an alternative embodiment
spin welded, threaded in, glued, or the like, to the downstream end
100 of the chimney 96. In the configuration shown in FIG. 2, the
spring 150 and disc 152 are in a closed-disc valve configuration.
However, when the pressure produced by flow through the chimney 96
is great enough to overcome the force of the spring 150, the disc
152 is unseated from the cup 153 and the gas-liquid stream flows
into the cup 153 and then through the nozzle plate 98. Different
numbers and sizes of nozzles 102 and different springs 150 may be
used depending on the engine 12. The variable impactor separator
and related components can be modified to accommodate a variety of
flow ranges, restriction, and efficiency requirements.
[0029] In the embodiment shown, a shroud 106 extends
circumferentially and downwardly from the impaction plate 104 and
surrounds at least the downstream end 100 of the chimney 96, The
shroud 106 causes the gas stream to flow as shown by arrows 56.
Liquid particles that are separated by a sharp directional change
in flow caused by the gas-liquid stream hitting the impaction plate
104 drip from the shroud 106 and fall to the lower portion 46 of
the second plenum chamber 44. Separation with an impactor separator
is described in U.S. Pat. No. 6,290,738, which was incorporated by
reference in its entirety herein above, and will thus not be
explained in more detail herein.
[0030] As shown in FIGS. 2, 3, and 6, the lower portion 46 of the
second plenum chamber 44 comprises a funnel 108 that slopes
downwardly from an inner surface 110 of the housing 38 to an
external wall 112 of the chimney 96 so as to drain liquid to the
second drain port 66. In the embodiment shown, the second drain
port 66 comprises a tube 114 extending from the lower portion 46 of
the second plenum chamber 44, specifically from the lowest portion
of the funnel 108, through the first plenum chamber 40 to the jet
pump 26. The tube 114 is hermetically sealed from the first plenum
chamber 40, such that the pressure in the first plenum chamber 40
does not affect drainage of oil through the tube 114. In the
embodiment shown herein, the tube 114 is coupled to the jet pump 26
via a cylindrical projection 115 extending from the lower portion
42 of the first plenum chamber 40.
[0031] The gas-liquid separator 18 further comprises a conduit 68,
FIG. 3, coupled to the housing 38 and in fluid communication with
both the first and second drain ports 64, 66 that conveys liquid
from the lower portions 42, 46 of the first and second plenum
chambers 40, 44 away from the housing 38, as shown by arrows 60 and
62. In the embodiment shown herein, the conduit 68 comprises a pump
that removes liquid from the lower portions 42, 46 of the first and
second plenum chambers 40, 44 through the first and second drain
ports 64, 66, respectively. In one embodiment, the pump comprises a
jet pump 26 (see FIGS. 7-9) in fluid communication with both the
first and second drain ports. 66 In the embodiment shown herein,
the jet pump 26 is bolted to a lower portion 140 of the housing 38
of the gas-liquid separator 18. Alternatively, the jet pump 26
could be integrally molded to the lower portion 140, FIGS. 2 and 3,
of the housing 38 of the gas-liquid separator 18 or coupled to the
housing in some other manner.
[0032] Now with reference to FIGS. 7-9, the jet pump 26 will be
described in more detail. As shown schematically in FIG. 9, a jet
pump 26 is operated by a motive fluid directed through a reduced
diameter jet orifice 72 into a larger diameter mixing bore 74
having a suction chamber 76 there around. The momentum exchange
between the high velocity motive jet flow from motive jet orifice
72 and the lower velocity surrounding fluid in mixing bore 74
creates a pumping effect which pumps fluid from suction chamber 76,
for example as shown in the flow diagram. Examples of jet pumps are
described in "The Design of Jet Pumps", Gustav Flugel, National
Advisory Committee for Aeronautics, Technical Memorandum No. 982,
1939; "Jet-Pump Theory and Performance with Fluids of High
Viscosity", R. G. Cunningham, Transactions of the ASME, November
1957, pages 1807-1820. In the embodiment of FIG. 9, jet pump 26 is
a fluid-driven jet pump having. a pressurized jet orifice at 72
receiving pressurized motive fluid from a source of pressurized
fluid, such as oil pump 30, a suction chamber at 76 receiving
separated oil from oil outlet 24 of gas-liquid separator 18, and an
output at mixing bore 74 delivering jet-pumped oil to crankcase 14,
as shown in FIG. 1.
[0033] Referring now to FIGS. 7 and 8, in the embodiment shown
therein, the jet pump 26 comprises a first jet orifice 78
accelerating pressurized fluid so as to pump liquid from the first
drain port 64 and a second jet orifice 80 accelerating pressurized
fluid so as to pump liquid from the second drain port 66. First and
second jet orifices 78, 80 correspond to jet orifice 72 shown in
the schematic of FIG. 9. The jet pump 26 also comprises a feed bore
82 that supplies the pressurized fluid to both the first and second
jet orifices 78, 80. The feed bore 82 is supplied with pressurized
fluid via motive line 125 as shown in FIGS. 1 and 8, or motive line
13$ as shown in FIG. 11. The jet pump 26 further comprises a first
suction port 84 that receives liquid from the first drain port 64
and pressurized fluid from the first jet orifice 78, and a second
suction port 86 that receives liquid from the second drain port 66
and pressurized fluid from the second jet orifice 80. Suction ports
84, 86 correspond to suction chamber 76 in the schematic of FIG. 9.
The jet pump 26 comprises a common mixing bore 88 that receives
liquid from both the first suction port 84 and the second suction
port 86. Between the common mixing bore 8$ and the first and
second. suction ports 84, 86, are intermediate mixing bores 90, 92,
respectively. Mixing bores 88, 90. and 92 correspond to mixing bore
74 in the schematic of FIG. 9.
[0034] With continued reference to FIGS. 7 and 8, an assembly for
removing scavenged liquid from a two-stage gas-liquid separator
will be described. The assembly comprises a first suction port 84
receiving scavenged liquid from a first stage, such as
pre-separator 41, of the gas-liquid separator 18. The assembly
comprises a second suction port 86 receiving scavenged liquid from
a second stage, such as a main separator 43, of the gas-liquid
separator 18. A first jet orifice 78 accelerates a pressurized
fluid into the first suction port 84. A second jet orifice 80
accelerates the pressurized fluid into the second suction port 86.
A feed bore 82 supplies both the first and second jet orifices 78,
80 with the pressurized fluid. A common mixing bore 88 receives the
pressurized fluid from the first and second jet orifices 78, 80 and
receives scavenged liquid from the first and second stages of the
gas-liquid separator. The assembly further comprises a first
connection port 120 conveying liquid from an outlet, such as first
drain port 64 in the first stage of the gas-liquid separator 18 to
the first suction port 84, and a second connection port 122
conveying liquid from an outlet, such as second drain port 66 in
the second stage of the gas-liquid separator 18 to the second
suction port 86. In the embodiment shown, the first and second
suction ports 84, 86 extend perpendicularly to a flow of the
accelerated pressurized fluid flowing from the first and second jet
orifices 78, 80, respectively. (See also FIG. 9) As shown in FIGS.
1 and 8, the assembly can further comprise a drain line 124 coupled
to the mixing bore 88 that drains the scavenged liquid from the
mixing bore 88 to the crankcase 14 of the engine 12.
[0035] Now with reference to FIG. 10, a second embodiment of a
gas-liquid separator 18' will be described. The gas-liquid
separator 18' comprises an inlet 20 for receiving a gas-liquid
stream and an outlet 22 for discharging a gas stream. As in the
first embodiment, the second embodiment of the gas-liquid separator
18' comprises a pre-separator 41 that is a cyclone separator having
an arched baffle 94 that guides the gas-liquid stream around the
inner surface 110 of the housing 38 within the first plenum chamber
40. The gas-liquid stream is then directed upward through the
chimney 96. Here, the gas-liquid stream is directed through a main
separator 43, which in this embodiment is a coalescer separator
comprising a filter media 116 coupled to the downstream end 100 of
the chimney 96. Air flows in an inward-out (inside-out) direction
through the filter media 116, as shown by the arrows 118. The
filter media 116 has properties that cause oil to coalesce
within/on the filter media 116 and thereby to separate from the
gas-liquid stream.
[0036] While in the embodiment shown in FIG. 1 the pressurized
fluid is oil, in the embodiment shown in FIG. 11, the pressurized
fluid is air. As shown in FIG. 11, the air is provided to the jet
pump 26 via motive line 138. A turbocharger 126, in the example
shown, fed with gas exiting, the outlet 22 of the gas-liquid
separator 18, provides the pressurized air to the jet pump 26 as
shown by arrows 128. Alternatively, an air compressor, for example
as shown in dashed lines at 130, or a tank of compressed air, for
example as shown in dashed lines at 132, can provide the
pressurized air to the jet pump 26. One or more optional check
valves 134, 136 can be provided in the motive line 138 and/or the
drain line 124 to prevent backflow in a condition of low or
negative air supply pressure.
[0037] One result of the assembly described herein is an integrated
product that separates coarse liquid oil challenge before the main
separator 43, for example with a pre-separator 41, such as a
cyclone separator, which coarse liquid oil challenge is drained
back to the engine 12 via a first drain port 64, in order to
achieve high efficiency. The air-oil mixture is then separated in a
main separator 43, such as an impactor separator (FIG. 1) or a
coalescer separator FIG. 10) and is drained via a second drain port
66 from the housing 38.
[0038] The jet pump 26 provides a way to drain the housing 38 from
scavenged oil regardless of the pressure difference between a
pressure in the first plenum chamber 40 and a pressure in the
second plenum chamber 44. The two chambers 40, 44 are hermetically
sealed from one another everywhere except for at nozzles 102.
Hermetic seals are provided at first and second drain ports 64, 66
so as to prevent flow from leaking from the first plenum chamber
40, which is at a higher pressure, to the second plenum chamber 44,
which is at a lower pressure, for example via the second drain port
66. If flow leaked in this manner, it would not be possible to
drain the second plenum chamber 44 due to increased pressure in the
second drain port 66. A high pressure due to oil build up from the
second plenum chamber 44 is not required to overcome a pressure
within the first plenum chamber 40 in order for the housing 38 to
be drained of scavenged oil because the jet pump 26 actively drains
both plenum chambers 40, 44 instead of relying on an oil column
head to overcome the pressure difference. This eliminates the need
for a check valve between the chambers 40, 44. This further
eliminates the need to design the gas-liquid separator 18 so as to
limit pressure difference to enable a check valve to operate at
certain engine conditions. This also allows the gas-liquid
separator 18 to function in a wide range of engine conditions
without concern for restriction affecting oil return
capability.
[0039] The jet orifices 78, 80 within the jet pump 26 can be fed
off of a single feed, such as through feed bore 82, and evacuated
into a single drain line 124, such as through common mixing bore
88. The high pressure fluid jetting through the first and second
jet orifices 78, 80 allows oil to be drained from the housing 38
independent of the pressure within the housing 38. Such drainage is
independent of both the relative pressures between the pressure
within the first and second plenum chambers 40,44 and independent,
of the pressure within the crankcase 14.
[0040] Now referring to FIG. 12, in another example, a method for
separating a liquid from a gas-liquid stream is provided. The
method comprises introducing the gas-liquid stream into a housing
38 having a flowpath therethrough from upstream to downstream, as
shown at box 201. The method further comprises separating liquid
from the gas-liquid stream in a first plenum chamber 40 defined by
the housing 38, as shown at box 202. The method further comprises
draining liquid to a lower portion 42 of the first plenum chamber
40 and through a first drain port 64, as shown at box 203. The
method further comprises further separating liquid from the
gas-liquid stream in a second plenum chamber 44 defined by the
housing 38 and downstream of the first plenum chamber 40, as shown
at box 204. The method further comprises draining liquid to a lower
portion 46 of the second plenum chamber 44 and through a second
drain port 66, as shown at box 205. The method further comprises
pumping liquid from the lower portions 42, 46 of the first and
second plenum chambers 40, 44 through the first and second drain
ports 64, 66, respectively, as shown at box 206.
[0041] The method may further comprise pumping liquid from the
first and second drain ports 64, 66 into first and second suction
ports 84, 86, respectively. The method may further comprise
accelerating pressurized fluid through first and second jet
orifices 78, 80 and into the first and second suction ports 84, 86,
respectively, so as to pump liquid from the lower portions 42, 46
of the first and second plenum chambers 40, 44, respectively. The
method may further comprise supplying the pressurized fluid to the
first and second jet orifices 78, 80 from a common pressurized
fluid source. The method may further comprise mixing the
pressurized fluid from the first jet orifice 78 and the liquid from
the first drain port 64 with the pressurized fluid from the second
jet orifice 80 and the liquid from the second drain port 66 in a
common mixing bore 88. In one embodiment, as shown in FIG. 1, the
pressurized fluid is oil and the oil is provided from an oil pump
30 coupled to a crankcase 14. In another example, as shown in FIG.
11, the pressurized fluid is air and the air is provided from a
turbocharger 126.
[0042] In the above description certain terms have been used for
brevity, clarity and understanding. No unnecessary limitations are
to be inferred therefrom beyond the requirement of the prior art
because such terms are used fur descriptive purposes and are
intended to be broadly construed. The different assemblies and
methods described herein above may be used alone or in combination
with other assemblies and methods. Various equivalents,
alternatives and modifications are possible within the scope of the
appended claims. Each limitation in the appended claims is intended
to invoke interpretation under 35 USC .sctn.112(f) only if the
terms "means for" or "step for" are explicitly recited in the
respective limitation. While each of the method claims includes a
specific series of steps for accomplishing certain functions, the
scope of this disclosure is not intended to be bound by the literal
order or literal content of steps described herein, and
non-substantial differences or changes still fall within the scope
of the disclosure.
* * * * *