Waveguides for non-invasive measurement of flow in a high temperature pipe and apparatuses, systems, and methods of use thereof

1. An apparatus, comprising:

first and second waveguides adapted to be connected to a pipe; and

first and second transducers adapted to be connected to the first and second waveguides, respectively, and to exchange ultrasonic wave signals through the first and second waveguides, the pipe, and a fluid flowing in the pipe;

wherein a temperature of the fluid flowing in the pipe exceeds 600° C.; and

wherein

the first and second waveguides are configured to, and each have a shape to: (i) insulate the first and second transducers from the pipe, and (ii) permit propagation of the ultrasonic wave signals between the pipe and the first and second transducers, respectively, while maintaining an acoustic attenuation through the first and second waveguides at an acceptable level that is small enough to permit ultrasonic wave signals from one of the transducers to pass through the waveguides and be detected by the other of the transducers, so that the ability of the first and second transducers to exchange the ultrasonic wave signals is not adversely affected by the temperature of the fluid flowing in the pipe.

2. The apparatus of claim 1 , further comprising a control unit adapted to be in communication with the first and second transducers;

wherein, when the control unit is in communication with the first and second transducers, the control unit is further adapted to send control signals to the first and second transducers, said control signals effecting the exchange of the ultrasonic wave signals between the first and second transducers, to receive data from the first and second transducers based on the exchange of the ultrasonic wave signals between the first and second transducers, and to determine a flow rate of the fluid flowing in the pipe based on the data received from the first and second transducers.

3. The apparatus of claim 1 , wherein at least respective portions of the first and second waveguides are made of a high-temperature ceramic material.

4. The apparatus of claim 3 , wherein at least respective portions of the first and second waveguides are made of a calcium silicate technical ceramic.

5. The apparatus of claim 1 , wherein, when the first and second transducers are connected to the first and second waveguides, respectively, and the first and second waveguides are connected to the pipe, the first and second waveguides support the first and second transducers in a manner that permits propagation of the ultrasonic wave signals through the first and second waveguides at an angle greater than or equal to about 40 degrees and less than or equal to about 70 degrees with respect to a longitudinal axis of the pipe.

6. The apparatus of claim 1 , wherein the first and second waveguides are each formed in the shape of a prism.

7. The apparatus of claim 6 , wherein the first and second waveguides are each tapered so that contact areas between each of the first and second waveguides and the pipe are smaller than contact areas between the first and second waveguides and the first and second transducers, respectively.

8. The apparatus of claim 1 , wherein the first and second waveguides are each machined to include a surface configured to matingly engage an external surface of the pipe.

9. The apparatus of claim 1 , further comprising the pipe, wherein either:

an external surface of the pipe is machined to include surfaces configured to matingly engage the first and second waveguides; or

material is added to an external surface of the pipe to form surfaces configured to matingly engage the first and second waveguides.

10. The apparatus of claim 1 , wherein the first transducer is connected to the first waveguide via a connector ring;

wherein a recess in which the connector ring extends is formed in a portion of the first waveguide; and

wherein the connector ring:

is made of a material more ductile and/or less brittle than a material of which the portion of the first waveguide is made; and/or

includes an internal threaded connection threadably engaged by the first transducer.

11. The apparatus of claim 1 , further comprising:

the pipe, wherein the pipe includes a U-bend defining opposing first and second corners at which the first and second waveguides, respectively, are connected to the pipe;

wherein the ultrasonic wave signals pass through the fluid flowing in the pipe directly from a first interior wall of the pipe at the first corner to a second interior wall of the pipe at the second corner.

12. The apparatus of claim 11 , wherein the ultrasonic wave signals travel in a parallel relation to the fluid flowing in the pipe during at least a portion of their passage between the first interior wall of the pipe at the first corner and the second interior wall of the pipe at the second corner.

13. A system, comprising:

the apparatus of claim 1 ; and

a control unit adapted to be in wireless communication with the first and second transducers, the control unit comprising:

one or more processors;

a non-transitory computer readable medium; and

a plurality of instructions stored on the non-transitory computer readable medium and executable by the one or more processors, the plurality of instructions comprising:

instructions that cause the one or more processors to send control signals to the first and second transducers, said control signals effecting an exchange of ultrasonic wave signals between the first and second transducers, and said ultrasonic wave signals passing through the first and second waveguides, the pipe, and the fluid flowing in the pipe;

instructions that cause the one or more processors to receive data from the first and second transducers based on the exchange of the ultrasonic wave signals between the first and second transducers; and

instructions that cause the one or more processors to determine a flow rate of the fluid flowing in the pipe based at least in part on the data received from the first and second transducers.

14. A method, comprising:

connecting first and second transducers to first and second waveguides, respectively;

connecting the first and second waveguides to a pipe; and

exchanging ultrasonic wave signals between the first and second transducers, said ultrasonic wave signals passing through the first and second waveguides, the pipe, and a fluid flowing in the pipe;

wherein a temperature of the fluid flowing in the pipe exceeds 600° C.; and

wherein the first and second waveguides are configured to, and each have a shape to: (i) insulate the first and second transducers from the pipe, and (ii) permit propagation of the ultrasonic wave signals between the pipe and the first and second transducers, respectively, while maintaining an acoustic attenuation through the first and second waveguides at an acceptable level that is small enough to permit ultrasonic wave signals from one of the transducers to pass through the waveguides and be detected by the other of the transducers, so that the ability of the first and second transducers to exchange the ultrasonic wave signals is not adversely affected by the temperature of the fluid flowing in the pipe;

insulating, using the first and second waveguides, the first and second transducers from the pipe; and

maintaining, using the first and second waveguides, an acoustic attenuation of the ultrasonic wave signals.

15. The method of claim 14 , further comprising:

placing a control unit in communication with the first and second transducers;

sending, using the control unit, control signals to the first and second transducers, said control signals effecting the exchange of the ultrasonic wave signals between the first and second transducers;

receiving, using the control unit, data from the first and second transducers based on the exchange of the ultrasonic wave signals between the first and second transducers; and

determining, using the control unit, a flow rate of the fluid flowing in the pipe based on the data received from the first and second transducers.

16. The method of claim 14 , wherein at least respective portions of the first and second waveguides are made of a high-temperature ceramic material.

17. The method of claim 16 , wherein at least respective portions of the first and second waveguides are made of a calcium silicate technical ceramic.

18. The method of claim 14 , further comprising supporting the first and second transducers in a manner that permits propagation of the ultrasonic wave signals through the first and second waveguides at an angle greater than or equal to about 40 degrees and less than or equal to about 70 degrees with respect to a longitudinal axis of the pipe.

19. The method of claim 14 , wherein the first and second waveguides are each formed in the shape of a prism.