U.S. patent application number 11/390917 was filed with the patent office on 2007-09-27 for omni-directional pressure pickup probe.
This patent application is currently assigned to Honeywell International, Inc.. Invention is credited to Paul W. Banta, James G. Clifton, Richard R. Hopkins, Dori M. Marshall, Justin A. Tanner, David B. Tornquist.
Application Number | 20070220987 11/390917 |
Document ID | / |
Family ID | 38531933 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070220987 |
Kind Code |
A1 |
Clifton; James G. ; et
al. |
September 27, 2007 |
OMNI-DIRECTIONAL PRESSURE PICKUP PROBE
Abstract
A pressure pickup probe assembly includes a probe housing, a
plurality of openings, and a pickup probe. The probe housing is
configured to be mounted within, and extend at least substantially
across, a flow passage. The probe housing further includes at least
an inner surface and an outer surface. The probe housing inner
surface defines at least a plenum therein. The plurality of
openings is formed in the probe housing, and each opening extends
between the probe housing inner and outer surfaces and is in fluid
communication with the probe housing plenum. The pickup probe is
disposed at least partially within the probe housing, and has at
least a first end, a second end, and a bore extending between the
first and second ends and that is in fluid communication with the
probe housing plenum.
Inventors: |
Clifton; James G.;
(Chandler, AZ) ; Marshall; Dori M.; (Mesa, AZ)
; Tornquist; David B.; (Chandler, AZ) ; Hopkins;
Richard R.; (Apache Junction, AZ) ; Banta; Paul
W.; (Phoenix, AZ) ; Tanner; Justin A.;
(Chandler, AZ) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.
101 COLUMBIA ROAD
P O BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Assignee: |
Honeywell International,
Inc.
|
Family ID: |
38531933 |
Appl. No.: |
11/390917 |
Filed: |
March 27, 2006 |
Current U.S.
Class: |
73/736 |
Current CPC
Class: |
G01F 1/44 20130101 |
Class at
Publication: |
073/736 |
International
Class: |
G01L 15/00 20060101
G01L015/00 |
Claims
1. A pressure pickup probe assembly, comprising: a probe housing
configured to be mounted within, and extend at least substantially
across, a flow passage, the probe housing having at least an inner
surface and an outer surface, the probe housing inner surface
defining at least a plenum therein; a plurality of openings formed
in the probe housing, each opening extending between the probe
housing inner and outer surfaces and in fluid communication with
the probe housing plenum; and a pickup probe disposed at least
partially within the probe housing, the pickup probe having at
least a first end, a second end, and a bore extending between the
first and second ends and in fluid communication with the probe
housing plenum.
2. The assembly of claim 1, wherein: the probe housing further
includes a first end and a second end, each having an opening
formed therein; and the pickup probe first end extends through the
opening in the probe housing first end.
3. The assembly of claim 2, further comprising: a plug disposed
within, and configured to fluidly seal, the opening in the probe
housing second end.
4. The assembly of claim 3, wherein the plug is formed at least
partially of a substantially compliant material.
5. The assembly of claim 1, wherein the plurality of openings are
spaced evenly about a perimeter of the probe housing.
6. The assembly of claim 1, further comprising: a spring disposed
between the probe housing inner surface and the pickup probe, the
spring configured to bias the probe housing and the pickup probe
away from each other.
7. The assembly of claim 6, wherein: the probe housing inner
surface further defines a spring mount projection; the pickup probe
further includes a flange extending from an outer surface thereof;
and the spring is disposed between the probe housing spring mount
projection and the pickup probe flange.
8. The assembly of claim 1, further comprising: a seal surrounding
the pickup probe and engaging the probe housing inner surface.
9. The assembly of claim 8, wherein: the pickup probe further
includes a seal groove formed in an outer surface thereof; and the
seal is disposed at least partially within the pickup probe seal
groove.
10. The assembly of claim 1, wherein: the probe housing plenum has
a first inner diameter; the probe housing inner surface further
defines a pickup probe receptacle, the pickup probe receptacle in
fluid communication with the probe housing plenum and having a
second inner diameter at least a portion of which is less than the
first inner diameter; and the pickup probe is disposed at least
partially within the probe housing pickup probe receptacle.
11. A pressure pickup probe assembly, comprising: a probe housing
configured to be mounted within, and extend at least substantially
across, a flow passage, the probe housing having at least, a first
end, a second end, an inner surface, and an outer surface, the
probe housing first and second ends each having an opening formed
therein, the probe housing inner surface defining at least a plenum
in the probe housing; a plurality of openings formed in the probe
housing, each opening extending between the probe housing inner and
outer surfaces and in fluid communication with the probe housing
plenum; a pickup probe disposed at least partially within the probe
housing, the probe having at least a first end, a second end, and a
bore extending between the first and second ends thereof, the
pickup probe first end extending through the opening in the probe
housing first end, the pickup probe bore in fluid communication
with the probe housing plenum; and a plug disposed within, and
configured to fluidly seal, the opening in the probe housing second
end.
12. The assembly of claim 11, further comprising: a spring disposed
between the probe housing inner surface and the pickup probe, the
spring configured to bias the probe housing and the pickup probe
away from each other.
13. The assembly of claim 12, wherein: the probe housing inner
surface further defines a projection; the plurality of openings are
spaced evenly about a perimeter of the probe housing; the pickup
probe further includes a flange extending from an outer surface
thereof; and the spring is disposed between the probe housing
projection and the pickup probe flange.
14. The assembly of claim 11, further comprising: a seal groove
formed in an outer surface of the pickup probe; and a seal disposed
at least partially within the pickup probe seal groove and engaging
the probe housing inner surface.
15. The assembly of claim 11, wherein: the probe housing plenum has
a first inner diameter; the probe housing inner surface further
defines a pickup probe receptacle, the pickup probe receptacle in
fluid communication with the probe housing plenum and having a
second inner diameter at least a portion of which is less than the
first inner diameter; and the pickup probe is disposed at least
partially within the probe housing pickup probe receptacle.
16. A valve assembly, comprising: a duct having an inlet port, an
outlet port, and inner wall that defines a flow venturi between the
inlet and outlet ports, the flow venturi having an upstream
convergent section, a downstream divergent section, and a flow
constricting throat disposed therebetween; a valve element mounted
in the duct downstream of the flow venturi; and a pressure pickup
probe assembly coupled to the duct, the pressure pickup probe
assembly including: a probe housing disposed within, and extending
at least substantially across, the flow constricting throat, the
probe housing having at least an inner surface and an outer
surface, the probe housing inner surface defining at least a plenum
therein, a plurality of openings spaced evenly about a perimeter of
the probe housing, each opening extending between the probe housing
inner and outer surfaces and in fluid communication with the probe
housing plenum, and a pickup probe disposed at least partially
within the probe housing, the probe having at least a first end, a
second end, and a bore extending between the first and second ends
and in fluid communication with the probe housing plenum.
17. The valve assembly of claim 16, wherein: the duct further
includes an outer wall, and a probe opening extending between the
duct inner and outer wall and in fluid communication with the flow
constricting throat; the plurality of openings are spaced evenly
about a perimeter of the probe housing; the probe housing further
includes a first end and a second end, each having an opening
formed therein; and the pickup probe first end extends through the
opening in the probe housing first end.
18. The valve assembly of claim 17, further comprising: a plug
formed at least partially of a substantially compliant material,
the plug engaging the duct inner wall and disposed at least
partially within, and configured to fluidly seal, the opening in
the probe housing second end.
19. The valve assembly of claim 16, further comprising: a spring
disposed between the probe housing inner surface and the pickup
probe, the spring configured to bias the probe housing and the
pickup probe away from each other.
20. The valve assembly of claim 16, further comprising: a seal
surrounding the pickup probe and engaging the probe housing inner
surface.
Description
TECHNICAL FIELD
[0001] The present invention relates to pressure measurement and,
more particularly, to an improved pressure pickup probe
assembly.
BACKGROUND
[0002] Systems and methods for measuring and controlling fluid flow
in a system are found in various industries. For example, various
air distribution systems in commercial aircraft include various
devices for measuring and controlling the flow of air through
numerous branch lines that feed different portions of the aircraft.
The flow of air through these branch lines is, in many instances
controlled by a control valve, in response to a flowrate
measurement.
[0003] For example, one or more of the branch lines in an aircraft
air distribution system may include a duct having a flow venturi
disposed therein. A flow venturi, as is generally known, may be
used to sense fluid flowrate, and typically includes an upstream
convergent section, a downstream divergent section, and an
interposed flow constricting throat. The change in cross-sectional
flow area in the flow venturi causes a pressure change between the
convergent section and the flow constricting throat. This change in
pressure is sensed and is used to measure fluid flowrate through
the duct. In response to the measured flowrate, a control valve,
which may be mounted on the duct downstream of the flow venturi,
may then be positioned to control the fluid flowrate to a commanded
magnitude.
[0004] In some systems, including various ones of the aircraft air
distribution systems mentioned above, increased flowrate
measurement accuracy and controllability is being demanded. In some
systems such demands may be realized by reducing the cross
sectional flow area of the interposed constricting throat in the
existing flow venturi. However, many conventional techniques for
reducing the cross sectional flow area a sufficient amount to meet
the increased flowrate measurement accuracy and controllability
demands may rely on significant redesign of the flow duct, which
can be relatively costly and time consuming.
[0005] Hence, there is a need for a method of reducing the cross
sectional flow area of a venturi flow constricting throat a
sufficient amount to meet increased flowrate measurement accuracy
and controllability demands that does not rely on a relatively
costly and/or time consuming redesign. The present invention
addresses at least this need.
BRIEF SUMMARY
[0006] The present invention provides a pressure pickup probe
assembly that sufficiently reduces the cross sectional flow area of
a venturi flow constricting throat to meet increased flowrate
measurement accuracy and controllability demands.
[0007] In one embodiment, and by way of example only, a pressure
pickup probe assembly includes a probe housing, a plurality of
openings, and a pickup probe. The probe housing is configured to be
mounted within, and extend at least substantially across, a flow
passage. The probe housing further includes at least an inner
surface and an outer surface. The probe housing inner surface
defines at least a plenum therein. The plurality of openings is
formed in the probe housing, and each opening extends between the
probe housing inner and outer surfaces and is in fluid
communication with the probe housing plenum. The pickup probe is
disposed at least partially within the probe housing, and has at
least a first end, a second end, and a bore extending between the
first and second ends and that is in fluid communication with the
probe housing plenum.
[0008] In another exemplary embodiment, a valve assembly includes a
duct, a valve element, and a pressure pickup probe assembly. The
duct has an inlet port, an outlet port, and an inner wall that
defines a flow venturi between the inlet and outlet ports. The flow
venturi has an upstream convergent end, a downstream divergent end,
and a flow constricting throat disposed therebetween. The valve
element is mounted in the duct downstream of the flow venturi. The
pressure pickup probe assembly is coupled to the duct and includes
a probe housing, a plurality of openings, and a pickup probe. The
probe housing is disposed within, and extends at least
substantially across, the flow constricting throat, and has at
least an inner surface, which defines at least a plenum therein,
and an outer surface. The plurality of openings is formed in the
probe housing, and each opening extends between the probe housing
inner and outer surfaces and is in fluid communication with the
probe housing plenum. The pickup probe is disposed at least
partially within the probe housing, and has at least a first end, a
second end, and a bore extending between the first and second ends
and that is in fluid communication with the probe housing
plenum.
[0009] Other independent features and advantages of the preferred
pressure pickup probe will become apparent from the following
detailed description, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a simplified schematic representation of a flow
control valve assembly according to an embodiment of the present
invention;
[0011] FIG. 2 is a perspective view of a pressure pickup probe
assembly according to an exemplary embodiment of the present
invention that may be used in the flow control valve assembly of
FIG. 1, depicting the pressure pickup probe assembly installed in a
venturi flow constricting throat; and
[0012] FIG. 3 is a cross section view of the pressure pickup probe
assembly taken along line 3-3 of FIG. 2.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0013] The following detailed description is merely exemplary in
nature and is not intended to limit the invention or the
application and uses of the invention. Furthermore, there is no
intention to be bound by any theory presented in the preceding
background or the following detailed description. Thus, although
the present embodiment is, for convenience of explanation, depicted
and described as a flow control valve with a system that is used to
determine and control mass flow rate, it will be appreciated that
it can be used to determine and control other fluid flow
properties, such as volumetric flow rate and heat flow rate.
[0014] Turning now to FIG. 1, a schematic representation of a flow
control valve assembly 100 is depicted. The flow control valve
assembly 100 includes a duct 102 that has an inlet port 104, an
outlet port 106, and an inner wall 108 that defines a flow venturi
110 between the inlet 104 and outlet 106 ports. The fluid whose
flowrate is being controlled flows into the inlet port 104, through
the flow venturi 110, and exits the outlet port 106. It will be
appreciated that the valve assembly 100 could be configured to
measure and control the flowrate of various types of fluid,
including both liquids and gasses. In a preferred embodiment,
however, the fluid is a gas, such as air.
[0015] The flow rate of the gas through the duct 102 is controlled
by a valve element 112, which, in the depicted embodiment, is a
butterfly valve gate 112. The butterfly valve gate 112 includes a
valve disk 114 that is mounted on a shaft 116, which is in turn
rotationally mounted within the duct 102. The flow rate of the gas
through the duct 102 may be varied by changing the angular position
of the butterfly valve gate 112. Specifically, the butterfly valve
gate 112 may be moved between a closed position and a fully-open
position. In the closed position the disk 114 is oriented
substantially perpendicular to the gas flow path, thus blocking gas
flow through the duct 102. In the fully-open position the disk 114
is oriented substantially parallel to the gas flow path, thus
presenting less resistance to gas flow through the duct 102. It
will be appreciated that other types of valve elements may be used
including, but not limited to, poppet valves, ball valves, and
sleeve valves.
[0016] The position of the valve gate 112 is controlled by a valve
actuator 118 that receives a position control signal from a control
unit 122. The valve actuator 118 may be any one of numerous types
of valve actuation devices known in the art including an electric,
pneumatic, or hydraulic actuator, which may be directly coupled to
the shaft 116 or coupled to the shaft 116 via one or more gears or
linkages. The control unit 122 determines the flowrate of gas
through the duct 102 based on differential pressure that is sensed
in the duct 102. The control unit 122 compares the determined
flowrate to a desired or commanded flowrate, and positions the
butterfly valve gate 112, via the valve actuator 118, as needed to
achieve the desired or commanded flowrate. For completeness, the
device used to sense differential pressure will now be briefly
described.
[0017] Differential pressure in the duct 102 is sensed using the
flow venturi 110 and a differential pressure sensor 126. The flow
venturi 110, as is generally known, includes an upstream convergent
section 128, a downstream divergent section 132, and an interposed
flow constricting throat 134. The differential pressure 126 is
coupled to the flow venturi via two conduits, an upstream pressure
pickup conduit 136 and a downstream pressure pickup conduit 138.
The upstream pressure pickup conduit 136 extends into the duct 102
preferably upstream of the flow venturi convergent section 128, and
the downstream pressure pickup conduit 132 is coupled to a pressure
pickup probe assembly 200 that is disposed in the flow venturi flow
constricting throat 134. It will be appreciated that the
differential pressure sensor 126 may be any one of numerous devices
known in the art for sensing differential pressure, and may also be
comprised of a single sensor or dual pressure sensors. Some
non-limiting examples of a suitable differential pressure sensor
include a capacitance sensor, a strain gauge sensor, and a thermal
sensor.
[0018] The pressure pickup probe assembly 200 that was mentioned
above enhances flowrate measurement accuracy and controllability
for the valve assembly 100 by providing increased blockage through
the flow venturi 110, without having to redesign the duct 102. In
addition, and as will be now described in more detail, the pressure
pickup probe assembly 200 is configured to withstand vibration, to
accommodate manufacturing tolerances and differential thermal
expansion, and is insensitive to installation orientation relative
to gas flow. With reference now to FIGS. 2 and 3, a detailed
description of the pressure pickup probe assembly 200 will now be
described.
[0019] The pressure pickup probe assembly 200, in both FIGS. 2 and
3, is depicted installed in the venturi flow constricting throat
134. In particular, and with reference first to FIG. 2, it is seen
that the probe assembly 200 extends across the venturi flow
constricting throat 134 and is at least partially held in place via
a non-illustrated threaded fitting that is threaded into a boss 202
formed on the venturi flow constricting throat 134. In the depicted
embodiment, the pressure pickup probe assembly 200 is at least
substantially cylindrical in shape, and has an outside diameter
that is sized to provide the proper blockage. It will be
appreciated, however, that the pressure pickup probe assembly 200
could have any one of numerous other shapes. For example, it could
have a shape similar to the cross section of an aircraft wing, or
any one of numerous other aerodynamic shapes, just to name a few.
As is shown most clearly in FIG. 3, the pressure pickup probe
assembly 200 includes a probe housing 302, a probe 304, a probe
housing plug 306, a seal 308, and a spring 312. With continued
reference to FIG. 3, a detailed description of each of these
components will now be described.
[0020] The probe housing 302 is configured to be mounted within,
and extend at least substantially across, the venturi flow
constricting throat 134, and has a first end 314, a second end 316,
an inner surface 318, and an outer surface 322. The probe housing
first and second ends 314 and 316 each have an opening 324 and 326,
respectively, formed therein. The probe 304, which is described in
more detail further below, extends from the probe housing first end
opening 324, and the plug 306 is disposed in the probe housing
second end opening 326. The probe housing inner surface 318 defines
various features therein, which include a plenum 328 and a spring
mount projection 332.
[0021] The probe housing 302 further includes a plurality of
openings 334 that, at least in the depicted embodiment, are spaced
evenly about the perimeter (e.g., the circumference) of the probe
housing 302. It will be appreciated, however, that the openings 334
need not be evenly spaced. Each of the openings 334 extends between
the probe housing inner and outer surfaces 318 and 322, and each is
in fluid communication with the plenum 328 that is defined therein.
It will be appreciated that the specific number of openings 334 may
vary. Preferably, however, the number of openings 334 is selected
so that that the openings 334, in combination with the plenum 328
that each of the openings 334 feeds, makes the pickup probe
assembly 200 relatively insensitive to its orientation relative to
the direction of gas flowing past the pickup probe assembly
200.
[0022] The pickup probe 304 is disposed within the probe housing
302 and includes a first end 336, a second end 338, and a bore 342.
The pickup probe first end 336, as alluded to above, extends
through the probe housing first end opening 324, into the boss 202,
and is held therein via a non-illustrated fitting that threads into
the boss 202. The pickup probe bore 342 extends between the pickup
probe first and second ends 336 and 338, and is in fluid
communication with the probe housing plenum 328. The pickup probe
bore 342 is also configured to be fluidly coupled, via the boss 202
and the non-illustrated fitting, to a sensor, such as the
previously described differential pressure sensor 126. Thus, the
gas pressure in the probe housing plenum 328 is transmitted to the
differential pressure sensor 126 via the pickup probe bore 342.
[0023] The pickup probe 304 is sized and contoured to slide into
the probe housing 302, and to allow for thermally induced
expansions and contractions as well as any dimensional mismatches
that may be occur during manufacturing. The pickup probe 304 has
both a seal groove 344 and a flange 346 formed therein. The seal
groove 344 is formed in an outer surface 348 of the pickup probe
304. The seal 308 is disposed within the seal groove 344 and
engages the probe housing inner surface 318. The seal 308 provides
not only a sealing function between the pickup probe 304 and the
probe housing 302, but also supplies vibration dampening that may
occur during vibration of the pressure pickup probe assembly 200,
to thereby prevent component chafing. It will be appreciated that
the seal 308 may be any one of numerous suitable sealing devices,
but in the preferred embodiment it is a conventional rubber or
silicone o-ring seal.
[0024] The spring 312 surrounds the pickup probe 304 and is
disposed between the pickup probe housing spring mount projection
332 and the pickup probe flange 346. The spring 312 is preferably a
coil spring, though it could be implemented as any one of numerous
other types of springs. No matter the particular type of spring
that is used, the spring 312 is configured to be in compression
when it is installed, thereby biasing the probe housing 302 and
pickup probe 304 away from each other.
[0025] The spring 312 and the plug 306 together provide various
advantages for the pressure pickup probe assembly 200. The plug
306, as was noted above, is disposed within the probe housing
second end opening 326. The plug 306, which is preferably formed at
least partially of a substantially compliant material, such as
rubber, also extends away from the probe housing 302 and engages
the venturi flow constricting throat 134. Thus, the plug 306 and
the spring 312 together restrict the movement of the pressure
pickup probe assembly 200 due to vibration to acceptable levels,
yet accommodate differential thermal expansion and contraction, and
variations in manufacturing tolerances.
[0026] The pressure pickup probe assembly 200 described herein
enhances flowrate measurement accuracy and controllability by
providing increased blockage through the flow venturi 110, without
having to redesign the duct 102. The pressure pickup probe assembly
200 is additionally configured to withstand vibration, to
accommodate manufacturing tolerances and differential thermal
expansion, and is insensitive to installation orientation relative
to gas flow.
[0027] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt to a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *