Doppler flowmeter

Patent · Sat Jan 01 04:00:00 EST 1983

OSTI ID:864766

Karplus, Henry H. B. ^[1]; Raptis, Apostolos C ^[2]

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1. Hinsdale, IL
2. Downers Grove, IL

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.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4413531
• OSTI ID: 864766
• Country of Publication: United States
• Language: English

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compares
control
convertor
cutoff
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determinable
divergence
divider
doppler
doppler flowmeter
doppler frequency
feedback
feedback control
filter
filtered
filtered signal
filters
fixed-frequency
flow
flow rate
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fractional
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frequency
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frequency-controlled
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pipe
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pulsed signal
rate
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ratios
reflected
reflected signal
repetition
scattered
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slurry
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ultrasonic
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whereby