Chordal gas flow meter with transducers installed outside the pressure boundary, and method

Patent metadata

Field	Value
Publication number	US-9322689-B2
Application number	US-201314031837-A
Country	US
Kind code	B2
Filing date	Sep 19, 2013
Priority date	Nov 19, 2010
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A flowmeter for detecting gas flow rates in a pipe including a container configured to be attached to the pipe having a channel through which the gas flows, and a plurality of recesses that extend through the container and a plurality of housings. Each recess having one housing of the plurality of housings. Each housing having a pressure containing window. The flowmeter includes a plurality of transducers, with one transducer of the plurality of transducers disposed in each housing in each recess. The transducers transmitting ultrasonic signals through the windows into and receiving ultrasonic signals through the windows from the channel. The flowmeter includes acoustic isolators disposed about the housing along the housing's length and between the housings and the container which acoustically isolate the housings from the container. The flowmeter includes a controller in electrical communication with the plurality of transducers which determines the gas flow rate through the channel by measuring transit times of signals transmitted by and received by the transducers.

First claim

The invention claimed is:

1. A flowmeter for detecting gas flow rates in a pipe comprising:
a container configured to be attached to the pipe having a channel through which the gas flows, and a plurality of recesses that extend through the container and a plurality of housings, each recess having one housing of the plurality of housings, each housing having a pressure containing window which acts as a pressure barier and hermetic seal to gas in the pipe and which is nearly acoustically transparent;
a plurality of transducers, with one transducer of the plurality of transducers disposed in each housing in each recess, the transducers transmitting ultrasonic signals through the windows into and receiving ultrasonic signals through the windows from the channel;
acoustic isolators disposed about the housing along the housing's length and between the housings and the container, each isolator in contact with the housing and the container which acoustically isolate the housings from the container; and
a controller in electrical communication with the plurality of transducers which determines the gas flow rate through the channel by measuring transit times of signals transmitted by and received by the transducers.

2. The flowmeter as described in claim 1 wherein the ultrasonic signals transmitted and received by the transducers define a first path in a first plane and a second path in a second plane which paths cross in the channel.

3. The flowmeter of claim 2 wherein the window is less than 1/10 of a wavelength of the ultrasound of the window material in thickness.

4. The flowmeter of claim 3 wherein the windows are made of titanium.

5. The flowmeter of claim 4 wherein each isolator includes a plurality of discs.

6. The flowmeter of claim 5 wherein each isolator is made of rubber, plastic or foam.

7. The flowmeter of claim 6 wherein there is no metal to metal contact between the housings and the container.

8. A method for detecting gas flow rates in a pipe comprising the steps of:
Transmitting, ultrasonic signals into a channel in which the gas flows, from a plurality of transducers disposed in a plurality of housings that are disposed in recesses in a container attached to the pipe with a plurality of acoustic isolators disposed about each housing along each housing's length and between each housing and the container, each acoustic isolator of each housing disposed in contact with the housing and the container which acoustically isolate the housings from the container, each housing having a pressure containing window which acts as a pressure barrier and hermetically seals gas in the pipe and which is nearly acoustically transparent, the ultrasonic signals transmitted through the windows;
receiving, through the windows, ultrasonic signals from the channel by the transducers in the housings in the recesses; and
determining the gas flow rate through the channel by measuring transit times of the signals transmitted by and received by the transducers with a controller in electrical communication with the plurality of transducers.

9. The method as described in claim 8 wherein the transmitting step includes the step of transmitting ultrasonic signals by the transducers along a first path in a first plane and a second path in a second plane which cross in the channel and the receiving step includes the step of receiving ultrasonic signals by the transducers from the first path and from the second path.

10. The method as described in claim 9 wherein the transmitting step includes the steps of:
generating with an upstream ultrasonic transducer of a first path plane waves that propagate through the channel and are received by a downstream ultrasonic transducer of the first path;
producing a downstream transducer signal with the downstream transducer from the plane waves the downstream transducer receives;
generating with the downstream ultrasonic transducer of the first path plane waves that propagate through the channel and are received by the upstream ultrasonic transducer of the first path;
producing an upstream transducer signal with the upstream transducer from the plane waves the upstream transducer receives; and
determining with the controller the gas flow rate from transit times of the signals generated and received by the upstream transducer and downstream transducer.

11. The method of claim 10 wherein the window is less than 1/10 of a wavelength of the ultrasound of the window material in thickness.

12. The method of claim 11 wherein the windows are made of titanium.

13. The method of claim 12 wherein each isolator includes a plurality of discs.

14. The method of claim 13 wherein each isolator is made of rubber, plastic or foam.

15. The method of claim 14 wherein there is no metal to metal contact between the housings and the container.

Assignees

• Gottlieb Emanuel J
• Augenstein Donald R
• Freund Jr William R
• Zuckerman Richard A
• Estrada Herbert
• Hastings Calvin R
• Cameron Int Corp

Inventors

• Gottlieb Emanuel J
• Augenstein Donald R
• Freund Jr William R
• Zuckerman Richard A
• Estrada Herbert
• Hastings Calvin R

Classifications

• G01F1/665

  of the drag-type · CPC title

• G01F1/667

  Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters · CPC title

• G01F1/662 Primary

  Constructional details · CPC title