Doppler flowmeter
Abstract
A Doppler flowmeter impulses an ultrasonic fixed-frequency signal obliquely into a slurry flowing in a pipe and a reflected signal is detected after having been scattered off of the slurry particles, whereby the shift in frequencies between the signals is proportional to the slurry velocity and hence slurry flow rate. This flowmeter filters the Doppler frequency-shift signal, compares the filtered and unfiltered shift signals in a divider to obtain a ratio, and then further compares this ratio against a preset fractional ratio. The flowmeter utilizes a voltage-to-frequency convertor to generate a pulsed signal having a determinable rate of repetition precisely proportional to the divergence of the ratios. The pulsed signal serves as the input control for a frequency-controlled low-pass filter, which provides thereby that the cutoff frequency of the filtered signal is known. The flowmeter provides a feedback control by minimizing the divergence. With the cutoff frequency and preset fractional ratio known, the slurry velocity and hence flow will also be determinable.
- Inventors:
- Issue Date:
- OSTI Identifier:
- 5087445
- Application Number:
- ON: DE82020889
- Assignee:
- Dept. of Energy
- DOE Contract Number:
- W-31-109-ENG-38
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 42 ENGINEERING; FLOWMETERS; DESIGN; OPERATION; SLURRIES; FLOW RATE; DOPPLER EFFECT; PIPES; TRANSDUCERS; ULTRASONIC WAVES; DISPERSIONS; MEASURING INSTRUMENTS; METERS; MIXTURES; SOUND WAVES; SUSPENSIONS; 420200* - Engineering- Facilities, Equipment, & Techniques; 420400 - Engineering- Heat Transfer & Fluid Flow
Citation Formats
Karplus, H H.B., and Raptis, A C. Doppler flowmeter. United States: N. p., 1981.
Web.
Karplus, H H.B., & Raptis, A C. Doppler flowmeter. United States.
Karplus, H H.B., and Raptis, A C. Fri .
"Doppler flowmeter". United States.
@article{osti_5087445,
title = {Doppler flowmeter},
author = {Karplus, H H.B. and Raptis, A C},
abstractNote = {A Doppler flowmeter impulses an ultrasonic fixed-frequency signal obliquely into a slurry flowing in a pipe and a reflected signal is detected after having been scattered off of the slurry particles, whereby the shift in frequencies between the signals is proportional to the slurry velocity and hence slurry flow rate. This flowmeter filters the Doppler frequency-shift signal, compares the filtered and unfiltered shift signals in a divider to obtain a ratio, and then further compares this ratio against a preset fractional ratio. The flowmeter utilizes a voltage-to-frequency convertor to generate a pulsed signal having a determinable rate of repetition precisely proportional to the divergence of the ratios. The pulsed signal serves as the input control for a frequency-controlled low-pass filter, which provides thereby that the cutoff frequency of the filtered signal is known. The flowmeter provides a feedback control by minimizing the divergence. With the cutoff frequency and preset fractional ratio known, the slurry velocity and hence flow will also be determinable.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1981},
month = {11}
}