Ultrasonic void fraction detector

Claim 2

A void fraction detector for measuring the fraction of gas in a gas liquid mixture, comprising, a transmission line capable of supporting a stress wave therein positioned in contact with the gas liquid mixture, said stress wave travelling through said transmission line in a predetermined time interval, generating means for developing a driving signal having an ultrasonic frequency and a particular time duration, a trigger circuit coupled to said generating means and acting to develop a first gating signal and a second gating signal said predetermined time interval after said first gating signal said generating means being responsive to said first gating signal to develop said driving signal, a generating transducer coupled to said generating means and to one end of said transmission line, said generating transducer being responsive to said driving signal to develop said stress wave with said stress wave having said particular time duration at said ultrasonic frequency, a receiving transducer coupled to the other end of said transmission line and responsive to said stress wave to develop an output signal, having a magnitude proportional to the magnitude of said stress wave at said receiving transducer measuring means, and gating means coupled to said trigger circuit and coupling said receiving transducer to said measuring means, said gating means being responsive to said second gating signal to permit the passage for said particular time duration of said output signal from said receiving transducer to said measuring means, said measuring means acting to measure the magnitude of said output signal.

Claim 3

The void fraction detector of claim 1 wherein said transmission line is a wire in the form of a helical coil positioned in the gas-liquid mixture with said generating and receiving transducers being coupled to the ends of said wire.

Claim 4

The void fraction detector of claim 1 wherein said transmission line is in the form of a bar with said stress wave being a shear wave, said generating and said receiving transducers being coupled to the ends of said bar.

Claim 5

The void fraction detector of claim 1, further including a container for containing said gas-liquid mixture and having side walls, said generating and receiving transducers being mechanically coupled to said side walls with the portion of said side walls extending between said transducers being said transmission line.

Claim 6

A void fraction detector for measuring the fraction of gas in a gas liquid mixture, comprising, a transmission line capable of supporting a stress wave therein positioned in contact with the gas liquid mixture, said transmission line having a plurality of sections, a plurality of generating transducers and a plurality of receiving transducers, one of said generating and receiving transducers being positioned at one end of said transmission line and coupled thereto, the remaining ones of said generating and receiving transducers being positioned alternately from said one end of said transmission line to the other end of said transmission line with the transducer positioned at said other end of said transmission line being coupled thereto, the transducers intermediate said one end of said transmission line and said other end of said transmission line being positioned at the boundaries between said transmission line sections with each intermediate transducer being coupled to both transmission line sections at the boundary, a plurality of generating means each coupled to a separate one of said generating transducers, a trigger circuit coupled to each of said generating means and acting to develop a plurality of first gating signals and a plurality of second gating signals, each of said generating means being selectively energized by a first gating signal applied thereto to develop a driving signal having an ultrasonic frequency and a particular time duration, each of said generating transducers being responsive to said driving signal applied thereto to develop said stress wave In each transmission line section coupled thereto with said stress wave having said particular time duration and said ultrasonic frequency, measuring means, a plurality of gating means each coupling a separate one of said receiving transducers to said measuring means, each of said receiving transducers being responsive to a stress wave burst in a section of said transmission line coupled thereto to develop an output signal having a magnitude proportional to the magnitude of said stress wave, circuit means coupling each of said gating means to said trigger circuit, each of said gating means being selectively responsive to one of said plurality of second gating signals to couple selectively particular ones of said output signals to said measuring means, said measuring means acting to measure the magnitude of each of said output signals coupled thereto.

Claim 7

A void fraction detector for measuring the fraction of gas in a gas liquid mixture, comprising, a transmission line capable of supporting a stress wave therein positioned in contact with the gas liquid mixture, said transmission line having a plurality of sections, a plurality of generating transducers and a plurality of receiving transducers, one of said generating and receiving transducers being positioned at one end of said transmission line and coupled thereto, the remaining ones of said generating and receiving transducers being positioned alternately from said one end of said transmission line to the other end of said transmission line with the transducer positioned at said other end of said transmission line being coupled thereto, the transducers intermediate said one end of said transmission line and said other end of said transmission line being positioned at the boundaries between said transmission line sections with each intermediate transducer being coupled to both transmission line sections at the boundary, a plurality of generating means each coupled to a separate one of said generating transducers, a trigger circuit coupled to each of said generating means and acting to develop a plurality of first gating signals and a plurality of second gating signals, each of said generating means being selectively energized by a first gating signal applied thereto to develop a driving signal having an ultrasonic frequency and a particular time duration, each of said generating transducers being responsive to said driving signal applied thereto to develop said stress wave In each transmission line section coupled thereto with said stress wave having said particular time duration and said ultrasonic frequency, measuring means, a plurality of gating means each coupling a separate one of said receiving transducers to said measuring means, each of said receiving transducers being responsive to a stress wave burst in a section of said transmission line coupled thereto to develop an output signal having a magnitude proportional to the magnitude of said stress wave, circuit means coupling each of said gating means to said trigger circuit, each of said gating means being selectively responsive to one of said plurality of second gating signals to couple selectively particular ones of said output signals to said measuring means, said measuring means acting to measure the magnitude of each of said output signals coupled thereto.