Claims
- 1. Apparatus for monitoring and indicating conditions of flow of steam from a pressurized source thereof, to determine the steam's quality and rate of flow without substantially reducing the pressure of the steam as a result of its passing through said apparatus, which apparatus includes:
- conduit means communicated with said pressurized source of steam for receiving a flow therefrom;
- an orifice plate in said conduit means;
- a venturi in said conduit means spaced downstream from the orifice plate to define an intermediate chamber therebetween;
- said venturi having a multi-segment axial passage for conducting said flow of steam, defined by an inlet segment which opens into a constricted throat, which in turn opens into a diverging wall segment having an internal angle of approximately 3.degree. to 10.degree.;
- said multi-segment passage being contoured to provide the flow of steam passing therethrough with critical flow characteristics;
- first sensing means communicated with said intermediate chamber for indicating steam pressure therein;
- second sensing means communicated with said intermediate chamber and said conduit means upstream of said orifice plate for indicating the steam pressure differential across said orifice plate; and
- third sensing means communicated with said axial passage for indicating steam pressure downstream of said inlet segment.
- 2. In the apparatus as defined in claim 1 wherein the said inlet segment is formed by a progressively converging wall, said outwardly diverging wall segment defines an included angle of between 3.degree. and 10.degree., and the overall length of said venturi is in the range of 6 to 10 inches.
- 3. An apparatus for concurrently determining the mass flow rate and the quality of pressurized steam flowing through a conduit at a sufficient velocity to be at critical flow conditions, which comprises:
- an orifice plate disposed transversely of said conduit;
- a critical flow venturi in said conduit spaced downstream of said orifice plate to define an intermediate chamber therebetween;
- means for measuring the pressure differential across said orifice plate;
- means for measuring the pressure in said intermediate chamber; and
- means for determining mass flow rate and the quality of the steam flowing through said conduit as a function of said indicated pressure differential across said plate and the pressure in said intermediate passage respectively in accordance with the following equations: ##EQU8## wherein a=39.0
- b=0.446
- C.sub.o =0.60
- d=diameter of orifice plate (inches)
- c=Venturi throat diameter
- Y=steam vapor expansion factor
- .phi.=differential pressure across the orifice (inches of water)
- F.sub.a =temperature coefficient factor (in./.degree.F.)
- C.sub.1,C.sub.2 = coefficients
- D=inside diameter of meter
- P=absolute pressure upstream of the venturi (psia)
- X=steam quality
- W=mass flow rate
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
This patent application is a continuation of application Ser. No. 07/995,902 which was filed Dec. 22, 1992, and now is abandoned, and which was in turn a continuation of application Ser. No. 07/699,048, filed May 13, 1991, and now abandoned.
US Referenced Citations (3)
Continuations (2)
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Number |
Date |
Country |
Parent |
995902 |
Dec 1992 |
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Parent |
699048 |
May 1991 |
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