Fluid handling – Systems – Multiple inlet with multiple outlet
Reexamination Certificate
2001-07-09
2003-03-25
Hepperle, Stephen M. (Department: 3753)
Fluid handling
Systems
Multiple inlet with multiple outlet
C137S371000
Reexamination Certificate
active
06536471
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a sampling system. Preferably, the invention relates to a stream switching system for fluid analysis.
2. Description of the Related Art
It is often very important to know what fluids are flowing through a conduit such as a pipeline. For example, a buyer and seller of gas may agree upon a price for the fluid flowing through a process pipeline based upon the content of the fluid stream. Thus, the fluid content must be measured. Where multiple pipelines are positioned near one another, it may be economical to use a single meter or measurement device to monitor all of the fluid flows. The device used to extract and deliver the fluid to the measurement device is traditionally referred to as a sampling system. The sampling system provides fluid sample to a measurement device such as a gas chromatograph.
FIG. 6
shows a “double block and double bleed” stream switching system for selectively supplying various fluid samples to downstream devices such as sample valves. The stream switching system
600
includes four streams
601
-
604
upstream of a stream-handling portion
691
. The four streams include a calibration sample
601
, stream
1
602
corresponding to a first fluid sample, stream
2
603
corresponding to a second fluid sample, and stream
3
604
corresponding to a third fluid sample.
Streams
601
-
604
supply various fluid samples and connect respectively to actuatable calibration port
611
and actuatable stream ports
612
-
614
. Actuatable ports
615
-
616
and
632
-
633
, as well as ports
631
and
634
, are also part of the sample-handling portion
691
. Each actuatable port may be actuated into either an open or closed state as controlled by eight connected solenoids
650
-
657
(also labeled SV
1
-SV
8
) which correspond respectively to ports
611
-
616
,
632
-
633
. When a port is in an open state, fluid may pass freely through the port. When a port is in a closed state, fluid is prevented from flowing through that port. Also shown in
FIG. 6
are solenoid pressure line
658
and solenoid vent line
659
, as well as gas path
642
extending from port
615
to ports
633
and
632
.
Each actuatable stream port
612
-
614
, as well as actuatable calibration port
611
, is positioned in an area
620
that creates a common sample path. Also positioned in the common sample path
620
are an actuatable “blocking” port
615
and an actuatable “bleed” port
616
. In addition, area
621
creates a first sample shut off that contains two “blocking” ports
632
and port
631
. Area
622
creates a second sample shut off that contains two “blocking” ports
633
and port
634
. As shown, ports
632
and
633
are actuatable, while ports
631
and
634
are not.
Two channels, channel
1
640
and channel
2
645
, are output tubing that direct fluid sample away from the stream switching system. The channels connect to, for example, downstream gas chromatographs including valve, heating, and measurement devices. Each channel thus may be separately analyzed by a gas chromatograph. Each channel can also be used as a flow path to “bleed” the system when switching from sample point to sample point.
As can also be appreciated, first and second sample shut offs correspond to first and second channels
640
,
645
. Consequently each channel is associated with two solenoids
650
and
657
, either one of which can be actuated to prevent the flow of any fluid through the channel. In the illustration, the flow of fluid through channel
1
may be prevented by closing either actuatable blocking port
615
or actuatable port
632
in the first sample shut off. Similarly, the flow of fluid through channel
2
may be prevented by closing either actuatable blocking port
615
or the actuatable port
633
in the second sample shut off. Thus, because the flow of fluid may be prevented through a channel at either of two locations, this is a “double block” design. In addition, the system may be bled through sample bleed port
616
. Thus, because the system may be bled either through a channel or through the sample bleed port
616
the embodiment is a “double bleed” design.
Referring now to
FIG. 7
, a side exploded view of the stream switching portion
691
is shown. The stream switching portion constitutes upper, middle, and lower plates aligned and connected together by dowel pins
770
and torque screws
771
-
775
. The lower plate, referred to as a manifold plate
710
, includes eight actuation ports
711
-
718
connected by tubing to solenoids
650
-
657
(not explicitly shown in FIG.
7
). The middle plate, also called a piston plate
720
, includes eight locations
721
-
728
designed to receive respective pistons
750
-
757
. Middle plate
720
also includes shallow channels, chambers, or grooves that form areas
620
-
622
, as described with reference to FIG.
6
. The upper plate, referred to as the primary plate
730
, includes screw holes corresponding to the torque screws, as well as three exemplary fluid ports
616
,
632
, and
631
. Eight pistons
750
-
757
(corresponding to ports
611
-
616
,
632
-
633
) as well as a pair of actuating diaphragms
740
lie between manifold plate
710
and middle plate
720
. Sealing diaphragm
765
and cushion diaphragm
760
lie between the primary plate
730
and middle plate
720
. The sealing and actuating diaphragms may be made from KAPTON polyimide film.
Each solenoid is placed in a closed position by the application of actuation gas from connected tubing. The application of the actuation gas for each individual solenoid is, in turn, controlled by a processor and associated software.
Although this stream switching system has significant advantages over previous designs, the use of actuating diaphragms, plates, and numerous pistons makes the system more expensive than is desirable. In addition, in the unlikely event that the electrical power to the solenoids is turned off and the carrier gas stream fails, sample leaks through the system. Although such a circumstance is uncommon, any leakage of the sample is undesirable.
A stream sampling system is needed that is less expensive than those previously in existence. This stream sampling system should be more resistant to operational failure than previous stream sampling systems is needed. Ideally, such a novel system could be compatible with the processor and software used with previous systems to enable single substitution of the novel system for the old.
SUMMARY OF THE INVENTION
One embodiment of the invention features a housing with an exterior, and a common stream path with connected first port, second port, and third port. Flow switches connect to the three ports and to three fluid sources, each flow switch being actuatable between an open position that allows flow of fluid from said the corresponding fluid source through said flow switch and a closed position that prevents the flow of fluid from the fluid source. Advantageously, each switch is in a closed position in the absence of electrical power applied to the switch.
Tubing is attached to the housing and may connect the common stream path to additional stream shut off solenoids. The housing is preferably a one-piece housing made from stainless steel. It also preferably includes a heating channel for warming fluid sample to a desired temperature.
Thus, the, present invention comprises a combination of features and advantages that enable it to overcome various problems of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
REFERENCES:
patent: 5325889 (1994-07-01), Paul et al.
patent: 5368062 (1994-11-01), Okumura et al.
patent: 5765591 (1998-06-01), Wasson et al.
patent: 6363966 (2002-04-01), Browne
Lechner-Fish Teresa
Mancha Henry
Conley & Rose, P.C.
Daniel Industries Inc.
Hepperle Stephen M.
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