Continuous sonic wave analyzer
AssigneeEvoqua Water Technologies LLC
InventorPhilip Tinsley Dempster
Life of this patent
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Abstract
A gas analyzer uses continuous sonic signals through a conduit to determine the composition of a gas in the conduit. A transmitting transducer drives sonic signals at a fixed frequency and a second transducer receives the sonic signals. The phase shift between two signals corresponds to the speed of sound through the gas and is related to the composition of the gas. The electronic versions of these signals are processed by lowering, or dividing, the fixed frequency which expands the range of phase shift measurement and allows the determination of an expanded range for the gas composition. In an ozone generation system, the gas analyzer is highly suitable for determining the composition of gases derived from air as a gas of known composition and a calibration point.
Claims43
An analyzer for one or more gases derived from a first gas of known composition and speed of sound, each derived gas having a concentration of a component changed, the analyzer comprising:
- a first transducer, the first transducer driving continuous sound waves responsive to a fixed frequency signal source;
- a conduit acoustically connected to the first transducer, the conduit selectively receiving and holding samples of the first gas and one or more derived gases;
- a second transducer acoustically connected to the conduit opposite the first transducer, the second transducer receiving sound waves from the first transducer through the conduit and generating second transducer signals responsive to the received sound waves;
- a processing unit receiving fixed frequency signal source signals and the second transducer signals, the processing unit determining a relative phase shift between the frequency source signals and second transducer signals for a gas sample in the conduit, the relative phase shift corresponding to a difference of speed of sound in one gas sample relative to another gas sample, the processing unit including circuitry lowering the frequency of the received fixed frequency source signals and second transducer signals to expand the range of measurement of the relative phase shift;
- and
- a calculating unit determining from the first gas of known composition the speed of sound of the one or more gases derived from the first gas, and calculating the composition of a sample of one or more derived gases from the first gas as a reference.
A method of operating an analyzer for one or more gases derived from a first gas of known composition and speed of sound, each derived gas having a concentration of a component changed, the method comprising:
- driving continuous sound waves with a first transducer in response to fixed frequency electrical signals through a conduit holding a sample of the first gas or one or more derived gases at a time;
- receiving the sound waves driven through the conduit by a second transducer and generating electrical signals in response to the received sound waves, a phase shift between the received sound wave signals and the driven sound wave signals corresponding to a speed of sound in the gas sample;
- processing the fixed frequency electrical signals and the electrical signals generated signals in response to the received sound waves at a lowered frequency to expand the range of measurement of the phase shift to determine a relative phase shift between the frequency source signals and second transducer signals for a gas sample in the conduit, the relative phase shift corresponding to a difference of speed of sound in one gas sample relative to another gas sample;
- determining a speed of sound of one or more gases derived from the first gas from the known speed of sound of the first gas and from the relative phase shift of gas samples of the first gas and one or more gases derived from the first gas in the conduit, and
- calculating a composition of a gas sample of one or more gases derived from the first gas as a reference.
A method of determining the composition of one or more gases derived from a first gas of known composition and speed of sound, the method comprising:
- driving continuous sonic waves through the conduit at a fixed frequency, a phase difference between sonic waves entering a conduit and leaving the conduit corresponding to a speed of sound of a gas in the conduit;
- processing electronic signals corresponding to the continuous sonic waves entering the conduit and leaving the conduit at a lowered frequency to expand the range of measurement of the phase shift;
- changing the gas in the conduit among the first gas and the one or more derived gases;
- determining the speed of sound of the first gas of known composition and the one or more gases derived from the first gas in the expanded range from a relative phase shift of gases of the first gas of known composition and the one or more derived gases, the relative phase shift corresponding to a difference of speed of sound in one gas sample relative to another gas sample;
- and
- calculating a composition of the one or more derived gases from the first gas as a reference.
Dependencies are inferred from the claim text.