Flow meter with protruding transducers

• US 9,182,260 B2
• Filed: 09/19/2012
• Issued: 11/10/2015
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Kamstrup A/S (OK AmbA)
• Original Assignee: Kamstrup A/S (OK AmbA)
• Inventors: Nielsen, Sren Tnnes, Laursen, Peter Schmidt, Srensen, Jens Lykke
• Primary Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US14/346,177
• Publication Number:
  US 20140216167A1
• Time in Patent Office: 1,147 Days
• Field of Search: 738/612.8, 738/612.7
• US Class Current: 1/1
• CPC Class Codes: G01F 1/66 by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
• CPC Class Codes: G01F 1/662 Constructional details
• CPC Class Codes: G01F 1/667 Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters

Abstract

The invention relates to an ultrasonic flow meter arranged to measure a flow rate of a liquid, the flow meter comprises a flow tube 2, optionally a measurement insert, and two or more ultrasonic transducers 8 which are arranged in transducer inserts 20 to be inserted into the flow tube through openings in the flow tube. The transducer inserts are formed monolithically with the housing as a part of the bottom of the housing. The transducer inserts are in a mount position inserted through the openings in the flow tube to extend into the flow passage so that the surface 15 of the transducer inserts protrude into the flow passage. In this manner, gas bubbles, such as air bubbles, released from the flowing liquid will not rest in front of the transducer insert irrespectively of the orientation of the flow meter in the pipe installation.

Claims

1. An ultrasonic flow meter arranged to measure a flow rate of a liquid, the flow meter comprises:

a through-going flow tube arranged for passage of a liquid between an inlet and an outlet, the flow tube defines a centre axis between the inlet and the outlet, the flow tube defines a flow passage either by an inner wall of the flow tube itself, by an inner wall of a measurement insert inserted into the flow tube or by a combination of the inner wall of the flow tube and a measurement insert;

a housing for liquid tight mounting on the flow tube, the housing comprises two or more ultrasonic transducers and a control circuit arranged for operating the transducers and for generating a signal or value indicative of the flow rate of the liquid;

each transducer comprises a surface for emission and receipt of ultrasonic signals, the surface defines a surface normal, and wherein the transducer is arranged so that the surface normal is perpendicular to the centre axis;

wherein the housing further comprises two or more separate transducer inserts formed monolithically with the housing as a part of the bottom of the housing, the two or more transducers being arranged in the transducer inserts, and wherein each transducer insert comprises a coupling surface formed monolithically with the transducer insert arranged in a plane parallel manner to cover the surface of the transducer; and

wherein the housing is mounted on the flow tube so that the transducer inserts are inserted through separate matching openings in the flow tube to extend into the flow passage in a manner so that a distance between the centre axis and the coupling surface is smaller than a distance between the centre axis and a corresponding point on the inside cross-section of the inner wall so that gas bubbles in a liquid in the flow tube will not rest at the coupling surface.

2. The ultrasonic flow meter according to claim 1, wherein the distance between the centre axis and the coupling surface is at least 1 mm smaller than the distance between the centre axis and the corresponding point on the inside cross-section of the inner wall.

3. The ultrasonic flow meter according to claim 1, wherein the distance between the centre axis and the coupling surface is smaller than the distance between the centre axis and the inner wall in an extended region abutting and surrounding the edge of the openings in the flow tube, the extended region being at least 0.5 mm broad.

4. The ultrasonic flow meter according to claim 1, wherein the flow meter comprises a measurement insert for directing the ultrasonic signal from an emitting transducer through the flow tube to a receiving transducer, and wherein with the transducer insert mounted on the flow tube, the edge of at least one of the transducer inserts lock the measurement insert in at least one direction parallel with the centre axis.

5. The ultrasonic flow meter according to claim 1, wherein the cross-sectional shape of the transducer insert in a plane parallel with the surface of the transducer for emission and receipt of ultrasonic signals is a closed convex curve with at least one axis of symmetry.

6. The ultrasonic flow meter according to claim 1, wherein the cross-sectional shape of the coupling surface in a plane perpendicular to the surface of the transducer for emission and receipt of ultrasonic signals is parallel with the centre axis or is slightly convex.

7. The ultrasonic flow meter according to claim 1, wherein the cross-sectional shape of the transducer insert in a plane perpendicular to the surface of the transducer for emission and receipt of ultrasonic signals changes along the depth of the transducer insert.

8. The ultrasonic flow meter according to claim 1, wherein the housing is made from a polymer material.

9. The ultrasonic flow meter according to claim 1, wherein the housing is cast in a single process.

10. The ultrasonic flow meter according to claim 1, wherein the housing forms an enclosure with only a single opening.

11. The ultrasonic flow meter according to claim 10, wherein the housing together with a cover forms a water-tight enclosure with only a single seal positioned in the area between the housing and the cover.

12. The ultrasonic flow meter according to claim 1, where the flow meter is a water meter, a heat meter and/or a cooling meter.