Leak detection in storage tank bottoms by pneumatic enhancement of acoustic emissions

• US 5,052,215 A
• Filed: 10/18/1990
• Issued: 10/01/1991
• Est. Priority Date: 10/18/1990
• Status: Expired due to Fees

• Current Assignee: Lewis, Donald E.
• Original Assignee: Lewis, Donald E.
• Inventors: Lewis, Donald E.
• Primary Examiner(s): Williams, Hezron E.
• Application Number:
  US07/599,890
• Time in Patent Office: 348 Days
• Field of Search: 73/40.5 A, 73/49.2, 73/40.7, 73/592
• US Class Current: 73/40.50A
• CPC Class Codes: G01M 3/24 using infrasonic, sonic, or ultrasonic vibrations
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00

Abstract

A system and method for injecting gas or fluid in the base beneath an above ground storage tank to enhance the rate of any leakage in the bottom of the tank, and detecting and locating the leak by acoustic sensors placed about the tank. The leak may then be sealed by injecting sealant through a probe placed beneath the tank in the area of the leak.

Claims

1. A system for detecting leaks in the bottom of a storage tank which sits on a base, comprising:

at least one perforated conduit inserted in said base beneath said tank;

means of injecting gas under positive pressure into said conduit; and

at least one acoustical sensor placed about said tank in a position so that the sensor can detect any acoustic event created by passage of said gas through said leaks in said tank bottom.

2. The system as defined in claim 1 which further comprises:

means for amplifying any signals detected by said acoustical sensors;

means for analyzing said amplified signals; and

means for displaying said analysis results such as to show the area of leakage.

3. The system as defined in claim 1 in which at least one acoustic sensor is suspended within the tank, and at least one acoustic sensor is in direct contact with the wall of said tank.

4. The system as defined in claim 1 in which at least three acoustic sensors are spaced apart on the wall of said tank.

5. The system as defined in claim 2 further comprising:

a probe inserted in the base beneath said tank in the area of leakage through which sealant may be injected to plug said leak.

6. A system for detecting leaks in the bottom of a storage tank which sits on a base, comprising:

at least one perforated conduit inserted in the base beneath said tank;

means of injecting fluid under pressure into said conduit;

means of sealing the periphery of said base to retain pressure therein;

a plurality of acoustic sensors mounted about said tank capable of detecting any acoustical events created by said fluid under pressure passing through a leak in the bottom of said tank;

means of amplifying signals derived from said acoustic sensors;

means of analyzing and displaying said signals; and

a probe placed within said base to inject sealant in the area of leakage.

7. A method for pneumatically enhancing the acoustical emissions from leaks in the bottom of a storage tank which sits on a base, and for detecting said emissions, comprising:

installing at least one perforated test conduit in said base beneath said storage tank;

injecting fluid under positive pressure into said conduit;

placing a plurality of acoustic sensors about said tank so as to detect any acoustic signal generated by the passing of material through said leak in the bottom of said tank; and

amplifying, analyzing and displaying any output of said sensors.

8. The method of claim 7 further comprising the step of sealing the periphery of the base to prevent escape of injected fluid.

9. The method of claim 7 further comprising the steps of:

inserting a perforated probe beneath said tank in the area of said leak; and

forcing a settable sealant through said probe such that the sealant exits the perforation in said probe and forms a seal over the leak in said tank bottom.