Vortex swirl flowmeter sensor probe

Claim 2

In a fluid flow system, a probe for measuring the rate of fluid flow said probe comprising: a housing having a cavity open at one end thereof to one broadside of said housing; means substantially parallel to said one broadside of said housing dividing said cavity into an outer cavity open to said one broadside and an inner cavity, said means having first and second spaced apart apertures therein for fluid communication between said outer and inner cavities; a first open-ended tubular member axially in line with said first aperture and having a cross sectional area less than the cross sectional area of said outer cavity and equal to or less than the cross sectional area of said first aperture, said tubular member extending longitudinally beyond said one broadside of said housing; a solid state sensing means mounted on low thermal conductive substrate means and positioned in said inner cavity and having control leads extending outside of said housing, said sensing means axially in line with and spaced from said second aperture on said dividing means and responsive to variations of fluid flowing through said second aperture impinging thereon and exhausting through said first aperture and said tubular member for generating an electrical signal indicating the rate of fluid flow.

Claim 3

The probe according to claim 1 wherein said second tubular member is flush with the one broadside of said housing means.

Claim 4

The probe according to claim 1 wherein said sensor means is a positive temperature co-efficient silicon chip supported on a low thermal conductivity substrate.

Claim 5

In a swirl fLowmeter having a conical converging inlet section with fluid swirl means positioned therein, a cylindrical measuring section having an aperture in the cylindrical wall thereof and a diverging output section, a fluid flow measuring probe comprising: a housing member having a pair of spaced broadsides and secured to the outside of the cylindrical wall of the measuring section along one of said broadsides overlying the aperture, said housing member having first and second parallel cylindrical cavities opened to and extending from the broadside adjacent the aperture to a plane intermediate the broadsides and an enlarged cylindrical cavity extending from said plane and opening to the other broadside, said parallel cavities open for fluid communication with said enlarged cavity; an elongated tubular member open at each end and having one end inserted in said first parallel cylindrical cavity and the other end for extending through the aperture of the measuring section of the flowmeter and into the fluid flowing through the meter; an orifice member positioned at the end of said second parallel cylindrical cavity adjacent said enlarged cavity, an orifice in said member being in axial alignment with said second parallel cavity; and a thermal-electric sensor member supported in said enlarged cavity aligned with said orifice, said sensor changing its electrical resistance in response to flow fluctuations in the fluid flowing in said first and second parallel cavities as a result of the pressure differential between said other end of said tubular member and the end of said second parallel cavity adjacent to the aperture in the measuring section of the flowmeter for generating an electrical signal indicating the rate of fluid flow through the flowmeter.

Claim 6

In a swirl fLowmeter having a conical converging inlet section with fluid swirl means positioned therein, a cylindrical measuring section having an aperture in the cylindrical wall thereof and a diverging output section, a fluid flow measuring probe comprising: a housing member having a pair of spaced broadsides and secured to the outside of the cylindrical wall of the measuring section along one of said broadsides overlying the aperture, said housing member having first and second parallel cylindrical cavities opened to and extending from the broadside adjacent the aperture to a plane intermediate the broadsides and an enlarged cylindrical cavity extending from said plane and opening to the other broadside, said parallel cavities open for fluid communication with said enlarged cavity; an elongated tubular member open at each end and having one end inserted in said first parallel cylindrical cavity and the other end for extending through the aperture of the measuring section of the flowmeter and into the fluid flowing through the meter; an orifice member positioned at the end of said second parallel cylindrical cavity adjacent said enlarged cavity, an orifice in said member being in axial alignment with said second parallel cavity; and a thermal-electric sensor member supported in said enlarged cavity aligned with said orifice, said sensor changing its electrical resistance in response to flow fluctuations in the fluid flowing in said first and second parallel cavities as a result of the pressure differential between said other end of said tubular member and the end of said second parallel cavity adjacent to the aperture in the measuring section of the flowmeter for generating an electrical signal indicating the rate of fluid flow through the flowmeter.

Claim 7

A fluid flow measuring probe according to claim 4 wherein said thermal-electric sensor is a silicon chip supported on a low thermal conductivity substrate.

Claim 8

A fluid flow measuring probe according to claim 5 wherein said silicon chip is a rectangular shaped chip having one broadside surface normal to and centrally located about the axis of said second parallel cavity and spaced from said orifice member a distance proportional to the size of said orifice.

Claim 9

A fluid flow measuring probe according to claim 6 wherein said silicon chip has at least two strip leads each bonded at one end to said one broadside surface in a spaced apart relationship and bonded at the other end to said substrate.

Claim 10

A fluid flow measuring probe according to claim 5 wherein said substrate has a thermal conductivity characteristic equal to or less than .01 calorie/second/degree Centigrade/square centimeter/centimeter.

Claim 11

A fluid flow measuring probe according to claim 4 wherein said probe is positioned in the flowmeter so as to have said tubular member positioned downstream as respects the flow of the fluid in the meter from said other parallel cavity.

Claim 12

A fluid flow measuring probe according to claim 4 further including a second tubular member positioned in said other parallel cavity and extending through the aperture in the flowmeter into the flow of fluid through said meter a distance substantially less than said first tubular member.