Doppler flowmeter

Patent · Tue Nov 08 04:00:00 EST 1983

OSTI ID:5248965

Karplus, H H.B.; Raptis, A C

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.

• Assignee: Dept. of Energy
• Patent Number(s): US 4413531
• OSTI ID: 5248965
• Country of Publication: United States
• Language: English

Related Subjects

440105* -- Radiation Instrumentation-- Radiometric Instruments-- (-1987)
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
CONTROL
DESIGN
DISPERSIONS
DOPPLER EFFECT
FLOWMETERS
FREQUENCY CONTROL
MEASURING INSTRUMENTS
METERS
MIXTURES
PIPES
SLURRIES
SOUND WAVES
SUSPENSIONS
ULTRASONIC WAVES
VELOCITY