A newly patented video camera-and-software system allows remote, safe inspection and analysis of corrosion in tank liners and other caustic environments, the inventors say.
U.S. Patent 7822273, approved Oct. 26 after a 3 ½-year review, covers both the method and apparatus for automatic corrosion detection via video capture. The goal, inventors say, is to increase safety of tank and other inspections by minimizing direct human involvement.
“Corrosion needs to be detected as early as possible and should be corrected in a timely fashion,” the inventors note in records filed with the U.S. Patent Office. “This is particularly true with any caustic material, which produces corrosion but is also harmful to humans.
“Containers and other vessels carrying caustic materials are often transported by truck or train. Some of these materials are extremely caustic to humans and can even prove to be deadly. Caustic material, in addition to potentially being harmful to humans, produces corrosion on tanks, particularly metal tanks.”
The system consists of:
• A portal-mounted camera that captures images of a tank surface as it passes through the portal, then displays the images at a remote facility;
• Software with a list of preset corrosion characteristics that analyzes the camera images of surface characteristics of the tank and produces a detection result;
• A histogram that is compiled from the analysis performed by the video image and software and viewed by an operator at a remote facility; and
• A grid overlay superimposed on the tank surface that is also viewed at a remote facility.
Colorful Surface Profiles
In the system, the camera captures a color image of the tank surface and compiles a histogram of the surface orientation. Several surface characteristics or parameters of the tank surface are measured; these, indicating the presence of corrosion, are put into a histogram. The histogram provides a format by which the area of the tank's surface can be analyzed in a readable form.
For instance, the inventors say, “an area of corrosion will typically have a different surface color. The software will discriminate between the different surface colors of the tank and will differentiate between healthy color and healthy lining surfaces and areas of corrosion. The information about the discoloration of the tank surface is incorporated into the histogram.”
Jagged edges, slightly irregular shapes or other characteristics of erosion are also measured and incorporated into the histogram. The software can analyze the general surface contour of the tank lining and determine whether the area is corrosion or simply surface irregularities of the vessel.
Once the information is compiled, it can be transmitted and viewed by the human operator in a readable format in a remote facility.
The inventors are four Jacksonville, FL, men. No company name was listed on the patent documents.
Other devices have used electrodes, ultrasonic waves, refracted light or other technology to detect corrosion, but this is the first to use camera imaging, the inventors say.