Patent Application
20140063228
The present invention generally relates to inspection equipment and methods. More particularly, this invention relates to insertion tube devices configured for inspecting complex hardware, for example, of gas turbines.
Remote inspection of hard to access locations is a growing problem in the power generation industry. Components located within complex machinery, such as gas turbines and other turbomachinery, must be inspected regularly to prevent failure due to the harsh environments in which they operate. Gas turbine components are often visually inspected using a borescope or similar device.
A borescope is generally characterized as an elongated insertion tube which can be flexible with a viewing head at its distal or forward end. The viewing head may be equipped with, for example, a camera head assembly, that provides the operator of the borescope with a remote viewing capability. Borescopes are typically adapted to be maneuvered through narrow tortuous passageways, and therefore their insertion tubes are flexible and must allow corresponding bending and steering. For this purpose, a borescope typically includes a bendable tube steering section or articulation section at or near its distal end adjacent to the viewing head, and a control housing at its proximal end for controlling or steering the viewing head. One or more pairs of control articulation cables typically extend from the articulation section and connect with a steering control at the control housing, with which the cables can be differentially displaced to bend the articulation section. The viewing camera head assembly can thus be remotely oriented to facilitate the visual inspection of an object. As a nonlimiting example,
Borescopes have been found to be particularly useful for visual inspection of large machinery, including gas turbines and other turbomachines whose internal components would be difficult or impossible to directly examine without disassembling the machine. Pathways to internal components of turbomachines can be quite long, and it is often necessary that the insertion tube of a borescope have a length of fifteen meters or more.
In order to perform non-destructive inspect of an internal component within a turbomachine, the surfaces of the component must be relatively clean and free from heavy corrosion and contamination. Unfortunately, internal components of turbomachines are difficult to clean due to their remote locations and the long and tortuous pathways often required to reach the components within the turbomachine.
In view of the above, it can be appreciated that there are certain problems, shortcomings or disadvantages associated with inspecting internal components of complex machinery, and that it would be desirable if equipment and methods were available that enabled remote cleaning and inspection of difficult to access components.
The present invention provides methods and systems suitable for remote cleaning and inspection of difficult to access components within complex machinery, including but not limited to gas turbines and other turbomachinery.
According to a first aspect of the invention, an inspection system is provided that includes a display screen, a video borescope coupled to the display screen, an insertion tube having a distal end relative to the display screen, a camera head disposed on the distal end of the insertion tube, means for capturing an image and/or video with the camera head and displaying the image and/or video on the display screen, and means of remotely steering the distal end of the insertion tube. A feed tube is physically coupled to the insertion tube and is fluidically coupled to a source of a cleaning fluid. The feed tube has a distal end relative to the source and a nozzle disposed at the distal end of the feed tube. The feed tube is adapted to apply the cleaning fluid to a surface to be inspected with the borescope. The feed tube is physically coupled to the insertion tube so that the steering means of the borescope simultaneously steers the distal end of the feed tube.
According to a second aspect of the invention, a method is provided for cleaning and inspecting a surface within a complex machine. The method includes inserting at least one tube into the machine and feeding the at least one tube through a pathway into an interior of the machine. The at least one tube is remotely steered around obstacles in the pathway. A distal end of the at least one tube is positioned at a location near the surface within the machine and the surface is cleaned with a cleaning fluid delivered to the surface via the at least one tube. A non-destructive inspection of the surface is performed with the at least one tube.
A technical effect of the invention is the ability of the inspection system to perform both remote cleaning and inspection of component surfaces that are difficult to access within a machine, and might otherwise require partial disassembly of the machine in order to gain access to the component and its surface.
Other aspects and advantages of this invention will be better appreciated from the following detailed description.
For purposes of this disclosure, the borescope 10 will be described as being similar or equivalent to the borescope 10 represented in
The camera head assembly 14, in addition to having means of capturing images and/or video, can have an illumination system for lighting the surface to be inspected. As known in the art, illumination can be accomplished by including fiber optic bundles or light emitting diodes within the camera head assembly 14, though other illumination techniques are also foreseeable.
According to an aspect of the invention, the insertion tube 12 of the borescope 10 is physically coupled to a small diameter, flexible, low-temperature-capable feed tube 26 that forms part of the cleaning system 24. The feed tube 26 is adapted to transfer a fluid from a source 34 of a cleaning fluid to be applied to surfaces to be inspected with the borescope 10. The feed tube 26 has a distal end 32 equipped with a nozzle 28 that is preferably small and tapered for controlling the flow from the feed tube 26 to the inspected surface. The nozzle 28 of the feed tube 26 can be directly coupled to the camera head assembly 14 of the insertion tube 12. The feed tube 26 may be attached externally to the insertion tube 12, in either a removable or permanent manner, or disposed within the insertion tube 26. Preferably, the feed tube 26 is attached in a removable manner to allow the feed tube 26 to be replaced should another type of cleaning fluid and source 34 be desired.
The source 34 may be of any suitable type or construction capable of supplying the desired cleaning fluid to a surface to be inspected. For example, the source 34 can be an air cylinder, a low pressure compressed air supply, or a compressor (electric or gas). Cleaning fluid that is supplied by the source 34 may be, as used herein, a gas, liquid, solution, solid suspended in a liquid or gas, or any other medium capable of cleaning the surface to be inspected. For example, the cleaning fluid may be a mixture of nitrogen and oxygen (e.g., air), water, nitrogen, carbon dioxide, or inert gases such as helium or argon. In a preferred embodiment, the source 34 is a standard dry ice (CO2) blasting system that is modified to deliver dry ice shavings entrained in a pressurized air stream. Preferably, the cleaning fluid utilized leaves little or no residue and does not require the use of a solvent to clean the surface to be inspected after application of the cleaning fluid.
The insertion tube 12 and feed tube 26 may be inserted through an inspection port or void provided or present in a machine that is intended for or otherwise enables access to surfaces of internal components of the machine that are to be inspected with the inspection system 30. As the insertion tube 12 and feed tube 26 are fed through this port or void, the remote visual and mechanical articulation capability of the borescope 10 and its insertion tube 12 are used to simultaneously direct or steer the camera head assembly 14 and nozzle 28 around any obstacles along the pathway to the surfaces to be inspected. As such, the borescope 10 provides aiming and steering capabilities for the entire inspection system 30, including the means for delivering the nozzle 28 of the feed tube 26 to internal areas of a machine.
Once the distal ends 18 and 32 of the insertion and feed tubes 12 and 26 have reached a location near a surface to be inspected, the inspection system 30 may be used to prepare the surface for various nondestructive inspections. Surface preparation may involve remotely cleaning surface contaminants, for example, deposits, corrosion products and/or residue, from the surface to be inspected by activating the source 34 to transfer the cleaning fluid through the feed tube 26 to the surface, such that the surface is impinged by the cleaning fluid in a manner that will sufficiently remove the surface contaminants to permit visual inspection with the borescope 10.
After surface preparation is complete, the borescope 10 may be used in performing nondestructive inspections of the surface such as remote visual inspection, fluorescent penetrant inspection, or any other type of inspection for which the borescope 10 is adapted to perform.
While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configuration of the inspection system 30 could differ from that shown, and materials and processes other than those noted could be used. Therefore, the scope of the invention is to be limited only by the following claims.
