Microwave probe for furnace refractory material

• US 9,255,794 B2
• Filed: 12/06/2012
• Issued: 02/09/2016
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Paneratech, Inc.
• Original Assignee: Paneratech, Inc.
• Inventors: Walton, Eric, Bayram, Yakup
• Primary Examiner(s): Charioui, Mohamed
• Assistant Examiner(s): KUAN, JOHN CHUNYANG
• Application Number:
  US13/706,787
• Publication Number:
  US 20130144554A1
• Time in Patent Office: 1,160 Days
• US Class Current: 1/1
• CPC Class Codes: F27D 21/0021 Devices for monitoring linings for wear
• CPC Class Codes: G01B 15/02 for measuring thickness
• CPC Class Codes: G01N 22/02 Investigating the presence of flaws
• CPC Class Codes: G06F 15/00 Digital computers in general details G06F1/00 – G06F13/00; Data processing equipment in general

Abstract

Disclosed is a system and method to aid in these inspections that avoid the disadvantages of the prior art. The system and method are operative to take thickness measurements of, and thus evaluate the condition of, materials including but not limited to refractory materials, operating in frequency bands that result in less loss than previously known technologies, and utilizing a system configuration and signal processing techniques that isolate the reflected signal of interest from other spurious antenna reflections, particularly by creating (through the configuration of the antenna assembly) a time delay between such spurious reflections and the actual reflected signal of interest, thus enabling better isolation of the signal of interest. Still further, the antenna assembly is intrinsically matched to the material to be probed, such as by impedance matching the antenna to the particular material (through knowledge of the dielectric and magnetic properties of the material to be evaluated) to even further suppress spurious reflections.

Claims

1. A method for evaluating a condition of a remote surface of a material, comprising the steps of:

providing a wide band coherent radar antenna that is selected based upon an impedance match with the material to be evaluated, wherein said antenna is provided a physical configuration adapted to delay receipt of a signal of interest reflected from said remote surface of said material by a time period sufficient to distinguish between said reflected signal of interest and reflected spurious signals from a near surface of said material;

placing said antenna adjacent said near surface of said material;

irradiating said material with coherent microwave radiation tuned over a frequency range;

detecting reflected microwave radiation from said remote surface of said material; and

determining a thickness of the material based upon a determined distance traveled by said signal of interest.

2. The method of claim 1, wherein said distance traveled by said signal of interest is determined based upon a time of travel of said signal of interest.

3. The method of claim 2, wherein the time of travel of said signal of interest is greater than a time of travel of said spurious signals by a sufficient extent so as to enable temporal isolation of said signal of interest from said spurious signals.

4. The method of claim 1, wherein said step of determining the thickness of the material further comprises the steps of:

measuring coherent radar scattering from said reflected microwave radiation to produce frequency domain data;

transforming said frequency domain data to time domain data;

calibrating said time domain data to a distance domain profile;

identifying a peak in said distance domain profile associated with said reflected microwave radiation from said remote surface of said material;

determining a distance traveled by said reflected microwave radiation from said remote surface of said material; and

displaying a thickness measurement of said material based upon said distance traveled by said reflected microwave radiation from said remote surface of said material.

5. The method of claim 4, wherein said step of calibrating said time domain data to a distance domain profile is performed based upon a known velocity of a radio frequency signal travelling through said material.

6. The method of claim 4, further comprising the step of subtracting a delay time attributable to said antenna and cables extending from said antenna to processing equipment.

7. The method of claim 1, wherein said antenna is formed as a single hand-held unit.

8. The method of claim 1, further comprising the step of generating a 3-dimensional image of said remote surface of said material.

9. The method of claim 1, further comprising the step of scanning one or more of said antenna in a pattern over said material.

10. The method of claim 1, wherein said frequency range is between 1 and 30 GHz.

11. The method of claim 10, wherein said frequency range is between 1 and 8 GHz.

12. The method of claim 11, wherein said frequency range is between 1 and 5 GHz.

13. A system for evaluating the condition of a remote surface of a material, comprising:

a wide band coherent radar antenna that is selected based upon an impedance match with the material to be evaluated, wherein said antenna is provided a physical configuration adapted to delay receipt of a signal of interest reflected from said remote surface of said material by a time period sufficient to distinguish between said reflected signal of interest and reflected spurious signals from a near surface of said material; and

a computer processor having executable computer code configured to;

measure coherent radar scattering from reflected microwave radiation to produce frequency domain data;

transform said frequency domain data to time domain data;

calibrate said time domain data to a distance domain profile;

identify a peak in said distance domain profile associated with said reflected microwave radiation from said remote surface of said material;

determine a distance traveled by said reflected microwave radiation from said remote surface of said material; and

display a thickness measurement of said material based upon said distance traveled by said reflected microwave radiation from said remote surface of said material.

14. The system of claim 13, wherein calibrating said time domain data to a distance domain profile is performed by said computer executable code based upon a known velocity of a radio frequency signal travelling through said material.

15. The system of claim 13, wherein said antenna is formed as a single hand-held unit.

16. The system of claim 13, wherein said executable computer code is further configured to generate a 3-dimensional image of said remote surface of said material.

17. The system of claim 13, wherein the system is adapted to operate over a frequency range of between 1 and 30 GHz.

18. The system of claim 17, wherein the system is adapted to operate over a frequency range of between 1 and 8 GHz.

19. The system of claim 18, wherein the system is adapted to operate over a frequency range of between 1 and 5 GHz.