Abstract A vortex-type mass flowmeter for measuring the mass of fluid passing through a flow tube as well as the density thereof. A bluff body, swirl blades or other means disposed within the tube acts to create a pulsatory fluidic vortex therein whose frequency varies as a function of the volumetric flow rate of the fluid being measured. Placed within the flow tube is a pressureresponsive transducer adapted to generate an electrical signal whose frequency is proportional to the fluidic pulse rate and whose amplitude is a function of the kinetic energy contained in the vortex. The transducer signal is processed by an operational amplifier, the gain of which is inversely proportional to frequency, thereby effectively dividing the transducer signal by frequency throuhgout the operating range of the meter to yield an output signal whose amplitude is indicative of mass flow. By additionally dividing this output signal by frequency with a second amplifier having a gain which is inversely proportional to frequency, a signal indicative of the fluid density is produced.
Apparatus for measuring the mass flow of a fluid, said apparatus comprising: A. a vortex meter having a flow tube in which a fluid to be measured is caused by obstacle means in the flow path to produce a pulsatory fluidic vortex at a frequency which is a function of flow rate, and a pressure-responsive sensor for detecting said fluidic pulses to produce an electrical signal at the same frequency, the amplitude of said signal being a function of the kinetic energy contained in said vortex, and B. an operational amplifier coupled to said sensor and directly responsive to said electrical signal whose frequency is a function of the fluid flow rate and whose amplitude is a function of said kinetic energy, said amplifier having a gain which is inversely proportional to frequency to divide the sensor signal by frequency to produce an output signal whose amplitude is indicative of mass flow.
Claim 2
Dependent Claim
152 words
Apparatus for measuring the mass flow of a fluid, said apparatus comprising: A. a vortex meter having a flow tube in which a fluid to be measured is caused by obstacle means in the flow path to produce a pulsatory fluidic vortex at a frequency which is a function of flow rate, and a pressure-responsive sensor for detecting said fluidic pulses to produce an electrical signal at the same frequency, the amplitude of said signal being a function of the kinetic energy contained in said vortex, and B. an operational amplifier coupled to said sensor and directly responsive to said electrical signal whose frequency is a function of the fluid flow rate and whose amplitude is a function of said kinetic energy, said amplifier having a gain which is inversely proportional to frequency to divide the sensor signal by frequency to produce an output signal whose amplitude is indicative of mass flow.
Claim 3
Dependent Claim
16 words
Apparatus as set forth in claim 1, wherein said obstacle means is constituted by swirl blades.
Claim 4
Dependent Claim
17 words
Apparatus as set forth in claim 1, wherein said obstacle means is constituted by a bluff body.
Claim 5
Dependent Claim
17 words
Apparatus as set forth in claim 1, wherein said sensor is constituted by a piezo-electric crystal transducer.
Claim 6
Dependent Claim
24 words
Apparatus as set forth in claim 1, further including means to divide said output signal by frequency to produce an indication of fluid density.
Claim 7
Dependent Claim
20 words
Apparatus as set forth in claim 1, further including means to integrate said output signal to totalize said mass flow.