System and process for break detection in porous elements for screening or filtering

• US 20070101802A1
• Filed: 11/08/2005
• Published: 05/10/2007
• Est. Priority Date: 11/08/2005
• Status: Active Grant

• Current Assignee: M-I LLC (Schlumberger NV)
• Original Assignee: M-I LLC (Schlumberger NV)
• Inventors: Biggs, Michael
• Granted Patent: US 7,343,827 B2
• Time in Patent Office: Days
• US Class Current: 73/38
• CPC Class Codes: G01N 15/08 Investigating permeability, pore-volume, or surface area of porous materials
• CPC Class Codes: G01N 2015/084 Testing filters
• CPC Class Codes: G01N 22/02 Investigating the presence of flaws
• CPC Class Codes: G01N 9/24 by observing the transmission of wave or particle radiation through the material

Abstract

A method of detecting breaks in a porous element in a material separator is disclosed. A shielding is created in the material separator to form a barrier to RF energy. The shielding is formed with a path through the barrier capable of allowing RF energy and material to flow therethrough. The electrically conductive porous element is positioned fully across the path. An RF signal is transmitted on one side of the porous element, and signal levels of the RF signal are detected on the other side of the porous element, such that the detected RF signal crosses the porous element. A baseline signal strength indicator is established from the detected signal levels using an unbroken porous element. An operative signal strength indicator is generated from the detected signal levels. Breaks in the porous element are detected by comparing the operative signal strength indicator against the baseline signal strength indicator.

Claims

1. A method of detecting breaks in a porous element in a material separator, the method comprising:

creating shielding in the material separator forming a barrier to RF energy with a path through the barrier capable of allowing RF energy and material to flow therethrough;

positioning the porous element fully across the path, wherein the porous element is electrically conductive;

transmitting an RF signal on one side of the porous element;

detecting signal levels of the RF signal on the other side of the porous element at a plurality of discreet frequencies, wherein the detected RF signal crosses the porous element;

establishing a baseline signal strength indicator from the detected signal levels using an unbroken porous element;

generating an operative signal strength indicator from the detected signal levels; and

comparing the operative signal strength indicator against the baseline signal strength indicator to detect a break in the porous element.

2. The method of claim 1, wherein transmitting the RF signal includes transmitting the RF signal in the microwave range of electromagnetic energy.

3. The method of claim 1, wherein transmitting the RF signal includes sweeping the transmitted RF signal through the plurality of discrete frequencies.

4. The method of claim 1, wherein establishing the baseline signal strength indicator includes averaging two or more detected signal levels.

5. The method of claim 4, wherein establishing the baseline signal strength indicator includes averaging the three highest detected signal levels.

6. The method of claim 1, wherein generating the operative signal strength indicator includes averaging two or more detected signal levels.

7. The method of claim 6, wherein generating the operative signal strength indicator includes averaging the three highest detected signal levels.

8. The method of claim 1, wherein the electrically conductive porous element comprises a screen including metal screen cloth.

9. A method of detecting breaks in a porous element in a material separator, the method comprising:

creating shielding in the material separator forming a barrier to RF energy with a path through the barrier capable of allowing RF energy and material to flow therethrough;

positioning the porous element fully across the path, wherein the porous element is electrically conductive;

positioning an RF signal generator on one side of the porous element;

sweeping transmission of an RF signal through a plurality of discrete frequencies, the RF signal being in the microwave range of electromagnetic energy;

detecting signal levels of the RF signal on the other side of the porous element at the plurality of discreet frequencies, wherein the detected RF signal crosses the porous element;

establishing a baseline signal strength indicator from the detected signal levels using an unbroken porous element;

generating an operative signal strength indicator from the detected signal levels; and

comparing the operative signal strength indicator against the baseline signal strength indicator to detect a break in the porous element.

10. The method of claim 9, wherein establishing the baseline signal strength indicator includes averaging two or more detected signal levels.

11. The method of claim 10, wherein establishing the baseline signal strength indicator includes averaging the three highest detected signal levels.

12. The method of claim 9, wherein generating the operative signal strength indicator includes averaging two or more detected signal levels.

13. The method of claim 12, wherein generating the operative signal strength indicator includes averaging the three highest detected signal levels.

14. The method of claim 9, wherein the electrically conductive porous element comprises a screen including metal screen cloth.

15. A method of detecting breaks in a porous element in a material separator, the method comprising:

creating shielding in the material separator forming a barrier to RF energy with a path through the barrier capable of allowing RF energy and material to flow therethrough;

positioning the porous element fully across the path, wherein the porous element is electrically conductive;

positioning an RF signal generator on one side of the porous element;

sweeping transmission of an RF signal through a plurality of discrete frequencies, the RF signal being in the microwave range of electromagnetic energy;

detecting signal levels of the RF signal on the other side of the porous element at the plurality of discreet frequencies, wherein the detected RF signal crosses the porous element;

averaging two or more of the highest detected signal levels to establish a baseline signal strength indicator using an unbroken porous element;

averaging two or more of the highest detected signal levels to generate an operative signal strength indicator; and

comparing the operative signal strength indicator against the baseline signal strength indicator to detect a break in the porous element.

16. The method of claim 15, wherein the electrically conductive porous element comprises a screen including metal screen cloth.