Pressure fluctuation flowmeter

A pressure fluctuation flowmeter comprising

• a bluff body having a base surface facing fluid flow, a pair of converging surfaces extending downstream from said base surface and an orifice adjacent each downstream surface,
• means defining a hollow inner chamber,
• a sensor assembly for insertable mounting in said chamber and including
• wall means having an exterior sealing a portion of said chamber and an inner segment defining a hollow interior,
• means bifurcating said interior into a pair of channels, each of said channels having port means at a same end of said interior for admitting and withdrawing pressure fluctuations from separate ones of said orifices,
• a substantially planar vibratory sensor having first and second opposite surfaces,
• means providing an aperture between a first one of said channels and said hollow inner chamber, and
• means mounting said sensor for communication of pressure fluctuations in said first one of said channels through said aperture, said hollow inner chamber with said first sensor surface and for separate communication of pressure fluctuation in a second one of said channels with said second sensor surface and thereby to vibrate said sensor in response to said communicating pressure fluctuations.

A vortex shedding flowmeter comprising

• means for generating streets of pressure fluctuations in a fluid flow through a conduit comprising a bluff body having a base surface, a pair of converging surfaces extending downstream from said base surface, a pair of orifices adjacent said downstream surfaces, and said body having at one end thereof a cavity which extends inwardly along the long axis of said body and communicates with said pair of orifices
• in combination with a flow sensor assembly comprising
• a vibratory sensor,
• a sensor housing means removably disposed in said cavity,
• said sensor housing means having a hollow interior bifurcated into separate channels and insertably disposed in said cavity,
• means mounting said sensor in said housing means for communicating the fluid flow and pressure fluctuations of an individual one of the generated streets of pressure fluctuations from an individual one of said downstream surfaces through an individual one of said orifices and a first one of said channels individually to said first sensor surface and separately communicating the fluid flow and pressure fluctuations of another individual one of the generated streets of pressure fluctuations from another individual one of said downstream surfaces through another individual one of said orifices and a second one of said channels individually to said second sensor surface and thereby to cause said sensor to vibrate in response to the communicating fluid and pressure fluctuations and at a frequency related to the flowrate through said conduit, and
• means in non-fluid-flow communication with said first and second channels for sensing vibrations of said sensor.

A vortex shedding flowmeter comprising

• means for generating streets of pressure fluctuations in a fluid flow through a conduit comprising a bluff body having a base surface, a pair of converging surfaces extending downstream from said base surface and a pair of orifices adjacent said downstream surfaces, in combination with a flow sensor assembly comprising
• means defining a hollow inner chamber;
• means bifurcating said orifices and inner chamber into a pair of channels, each of said channels having port means at the same end of said inner chamber;
• a substantially planar sensor having first and second opposite surfaces;
• means mounting said sensor for cooperating with said bifurcating means for providing non-fluid-flow communication between said channels and for communicating the fluid flow and pressure fluctuations of an individual one of the generated streets of pressure fluctuations from an individual one of said downstream surfaces through an individual one of said orifices and a first one of said channels individually to said first sensor surface and separately communicating the fluid flow and pressure fluctuations from another individual one of said downstream surfaces through another one of said orifices and a second one of said channels individually to said second sensor surface and thereby to cause said sensor to vibrate in response to the communicating fluid and pressure fluctuations and at a frequency related to the flowrate through said conduit;
• means in non-fluid-flow communication with said first and second channels for sensing vibrations of said sensor;
• and
• wherein said sensor comprises a ferromagnetic material, and
• said sensing means comprises a magnetic detector.

A flowmeter comprising

• a bluff body having a base surface facing fluid flow, a pair of converging surfaces extending downstream from said base surface and a pair of orifices adjacent said downstream surfaces and in nonpressure communication with one another,
• means defining a first hollow conduit,
• means defining a second hollow conduit having a longitudinal portion thereof substantially parallel to and in nonpressure communication with said first conduit defining means,
• a substantially planar vibratory sensor having first and second surfaces,
• said first and second conduits having exterior ports substantially parallel to one another for admitting pressure fluctuations from said orifices into said conduits in the same direction toward said sensor, and
• means mounting said sensor with said sensor surfaces substantially normal to said longitudinal portion of said second hollow conduit and for communicating pressure fluctuations in said first conduit with said first sensor surface and for separately communicating pressure fluctuations in said second conduit with said second sensor surface.

Apparatus for measuring the flowrate of fluid in a conduit comprising

• an elongated vortex shedding body spanning substantially the entire inner diameter of said conduit and having a base surface disposed substantially normal to the direction of fluid flow and a pair of downstream surfaces extending downstream from said base surface and meeting said base surface along a pair of edges, said base and downstream surfaces being mutually adapted so that the boundary layers of said fluid separate from said edges and so that vortex shedding is free of intermittency, and
• means responsive to said vortex shedding for producing an electrical signal related to the flowrate of said fluid, CHARACTERIZED IN THAT
• said body has at one end thereof a cavity which extends inwardly along the long axis of said body and forms in each of said downstream surfaces an orifice, and
• said responsive means comprises
• a vibratory sensor,
• a sensor housing means removably disposed in said cavity and vibratorily housing said sensor,
• said sensor housing means having a hollow interior bifurcated into separate channels and insertably disposed in said cavity so that said channels are in fluid flow communication with separate ones of said downstream surface orifices,,
• said housing means having means defining an aperture which places a first one of said channels in fluid flow communication with one side of said sensor and a second one of said channels with an opposite second side of said sensor so that fluid flow in said conduit entering said orifices passes through said channels and thence to said opposite first and second sides of said sensor, and
• detector means responsive to the vibration of said sensor for producing said electrical signal.

Apparatus for measuring the flowrate of fluid in a conduit comprising

• an elongated vortex shedding body spanning substantially the entire inner diameter of said conduit and having a base surface disposed substantially normal to the direction of fluid flow and a pair of downstream surfaces extending downstream from said base surface and meeting said base surface along a pair of edges, said base and downstream surfaces being mutually adapted so that the boundary layers of said fluid separate from said body at said edges and so that vortex shedding is free of intermittency, and
• means responsive to said vortex shedding for producing an electrical signal related to the flowrate of said fluid, CHARACTERIZED IN THAT
• said body includes a support member at one end thereof for mounting said body in said conduit, said support member having a sensor chamber therein,
• said responsive means includes a substantially planar vibratory sensor disposed within said chamber, and detector means exterior to said chamber but proximate thereto for producing said electrical signal when said sensor vibrates,
• said body having a pair of orifices, each of said orifices located in an individual one of said downstream surfaces near to said one end, and
• means disposed within said member forming a pair of channels in non-fluid-flow communication with one another, said channels connecting said orifices in fluid flow communication with opposite sides of said sensor, thereby to cause said sensor to vibrate in response to said vortex shedding,
• said forming means comprising
• a cylindrical housing having a hollow interior,
• said sensor being mounted at one end of said housing,
• a partition within said housing which bifurcates said interior and forms said pair of channels so that only one said channel is in fluid flow communication with the side of said sensor interior to said housing,
• said housing having a first aperture which places the other of said channels in fluid flow communication with said chamber and the side of said sensor exterior to said housing.

Apparatus for measuring the flowrate of steam in a conduit comprising

• an elongated vortex shedding body having a planar base surface disposed substantially normal to the direction of fluid flow and a pair of downstream surfaces extending downstream from said base surface and meeting said base surface along a pair of edges, said base and downstream surfaces being mutually adapted so that the boundary layers of said fluid separate from said body at said edges and so that vortex shedding is free of intermittency, and
• means responsive to said vortex shedding for producing an electrical signal related to the flowrate of said fluid, CHARACTERIZED IN THAT,
• said body has at one end thereof a cavity which extends inwardly along the long axis of said body and forms in each of said downstream surfaces an orifice,
• said responsive means comprises
• a support member for mounting said one end of said body in said conduit, said member including a sensor chamber,
• a substantially planar vibratory sensor,
• a sensor housing having said sensor mounted at one end thereof which is disposed in said chamber,
• said sensor housing having a hollow interior bifurcated into separate channels in non-fluid-flow communication with one another and opening to the other end of said housing,
• said housing having said other end thereof disposed in said cavity of said body so that said channels are in fluid flow communication with separate ones of said orifices,
• said housing having therein an aperture which places one of said channels in fluid flow communication with said chamber so that fluid in said conduit entering said orifices passes through said channels and thence to opposite sides of said sensor, and
• detector means responsive to the vibration of said sensor for producing said electrical signal.

Apparatus for measuring the flowrate of steam in a conduit comprising

• an elongated vortex shedding body having a planar base surface disposed substantially normal to the direction of fluid flow and a pair of downstream planar surfaces extending downstream from said base surface and meeting said base surface along a pair of edges, said base and downstream surfaces being mutually adapted so that the boundary layers of fluid separate from said body at said edges and so that vortex shedding is free of intermittency, and
• means responsive to said vortex shedding for producing an electrical signal related to the flowrate of said fluid, CHARACTERIZED IN THAT,
• said body includes a support member at one end thereof for mounting said body in said conduit, said support member comprising a cylindrical portion connected to said body and having a bore therein and being insertable through a hole in the wall of said conduit,
• a sensor chamber located in said portion,
• a removable head cap engaging said portion and arranged so that when removed said chamber is exposed,
• said responsive means includes a ferromagnetic substantially planar vibratory sensor disposed within said chamber and a magnetic detector incorporated in said head cap,
• said body has a cavity in one end face thereof and a pair of rectangular orifices located in said downstream surfaces and in fluid flow communication with said cavity, and
• means disposed within said support member forming a pair of channels in non-fluid-flow communication with one another, said channels connecting said orifices in fluid flow communication with opposite sides of said sensor, thereby to cause said sensor to vibrate in response to said vortex shedding, said forming means comprising
• a cylindrical housing having a hollow interior, said housing being situated in said bore of said portion of said support member,
• said sensor being mounted at one end of said housing, the other end of said housing being removably situated in said cavity and having a pair of rectangular cut-outs in substantial registration with said rectangular orifices of said body,
• an L-shaped partition within said housing which bifurcates said interior and forms said pair of channels,
• said housing having a first aperture near to said sensor which places one of said channels in fluid-flow communication with said chamber and the side of said sensor exterior to said housing,
• the foot of said L-shaped partition being affixed near to said sensor so that said first aperture and said one channel are separated from the side of said sensor interior to said housing,
• the leg of said L-shaped partition extending parallel to the walls of said housing and extending flush with said other end of said housing and abutting the bottom of said cavity.

Pressure fluctuation sensor means comprising

• means defining a hollow inner chamber,
• a sensor assembly for insertable mounting in said chamber and including
• wall means having an exterior sealing a portion of said chamber and an inner segment defining a hollow interior,
• means bifurcating said interior into a pair of channels, each of said channels having port means at a same end of said interior for admitting and withdrawing pressure fluctuations therethrough,
• a substantially planar vibratory sensor having first and second opposite surfaces,
• means providing an aperture between a first one of said channels and said hollow inner chamber, and
• means mounting said sensor for communication of pressure fluctuations in said first one of said channels through said aperture, said hollow inner chamber with said first sensor surface and for separate communication of pressure fluctuation in a second one of said channels with said second sensor surface and thereby to vibrate said sensor in response to said communicating pressure fluctuations.