Acoustic flow rate meter having a high frequency induction coil mounted directly on the piping without an acoustic coupling

1. An acoustic flow rate meter for the noninvasive determination of the flow or the flow rate in electrically conductive objects through which media flow comprising:

an excitation transducer for generating at least one ultrasonic guided wave in the object, said at least one ultrasonic wave being coupled into the medium as a longitudinal wave on an inner side of the object oriented toward the medium, and

a receiving transducer for the detection of an ultrasonic signal in the object,

wherein the ultrasonic signal at least partially results due to the longitudinal wave,

wherein the excitation transducer is implemented as a high-frequency induction coil, while omitting an acoustic coupling of the excitation transducer with the surface of the object, to generate a varying magnetic field in a surface-proximal region of the object, which is metallic, and the ultrasonic wave is generated by interaction of the varying magnetic field with a static or quasi-static magnetic field in this region.

2. The flow rate meter according to claim 1 , characterized in that the receiving transducer is implemented as a high-frequency induction coil for the detection of the ultrasonic signal while omitting an acoustic coupling with the object.

3. The flow rate meter according to claim 1 , characterized by an implementation to generate a static or quasi-static magnetic field, which is implemented in by at least one of a permanent magnet and an electromagnet, and which is one of aligned along an axial direction of the object and perpendicularly thereto.

4. The flow rate meter according to claim 1 , characterized in that a conductor path of the high-frequency induction coil is aligned perpendicularly to the longitudinal axis of the object for the intended application.

5. The flow rate meter according to claim 4 , characterized in that the conductor path is implemented as meandering.

6. The flow rate meter according to claim 1 , characterized in that the excitation transducer generates guided waves in the form of Lamb waves of the nth order with n being an integer and being greater than or equal to 0.

7. The flow rate meter according to claim 1 , characterized in that at least one of the side of the excitation transducer and receiving transducer to be oriented toward the object is implemented as curved.

8. The flow rate meter according to claim 1 , characterized in that at least one of the excitation transducer and the receiving transducer is implemented to be at least one of applied to the pipe and wrapped around the pipe.

9. The flow rate meter according to claim 8 , characterized in that the excitation and receiving transducers have conductor paths to be wound or laid around the object.

10. The flow rate meter according to claim 9 , characterized in that at least one of excitation and receiving transducers are implemented as at least partially flexible, to be adaptable to different pipe external diameters.

11. The flow rate meter according to claim 9 , characterized in that at least one of the excitation and receiving transducers have a film provided with at least one of an electrical conductor and a flat band cable, which can be wound at least partially around the pipe.

12. The flow rate meter according to claim 9 , characterized in that at least one of the conductor paths is implemented as meandering.

13. The flow rate meter according to claim 8 , characterized in that at least one of the excitation and receiving transducers are implemented as at least partially flexible, to be adaptable to different pipe external diameters.

14. The flow rate meter according to claim 13 , characterized in that at least one of the excitation and receiving transducers have a film provided with at least one of an electrical conductor and a flat band cable, which can be wound at least partially around the pipe.

15. The flow rate meter according to claim 8 , characterized in that at least one of the excitation and receiving transducers have a film provided with at least one of an electrical conductor and a flat band cable, which can be wound at least partially around the pipe.

16. The flow rate meter according to claim 1 , characterized in that at least one of the excitation and receiving transducers are designed for the purpose of detecting the flow rate in a complete cross-section of the pipe.

17. The flow rate meter according to claim 1 , characterized in that an analysis unit is implemented for at least one of the detection and size determination of bubbles in the medium.

18. The flow rate meter according to claim 1 , characterized in that, for optimized alignment of a longitudinal wave to be generated in the medium, the high frequency at which the excitation transducer is to be operated is automatically variable.

19. The flow rate meter according to claim 1 , characterized by an implementation for measuring at least one of the wall thickness and the pressure of the medium on the basis of the ultrasonic signal.

20. The flow rate meter according to claim 1 , characterized in that the excitation and receiving transducers comprise heat resistant materials in such a manner that they are implemented for the contactless measurement of the flow rate in an object hotter than 180° C.

21. The flow rate meter according to claim 1 , characterized by a modular construction wherein that at least one of the excitation and receiving transducers are permanently positionable on the object and are connectable to an activation and analysis unit, which is portable by operators, for measuring the flow rate, wherein the flow rate meter has a device for generating the static or quasi-static magnetic field.

22. The flow rate meter according to claim 1 , characterized in that the high-frequency induction coil for generating the ultrasonic guided wave is operable in a frequency range of 20 kHz to 50 MHz.