A continuous wave laser light beam is directed at the refractory lining within a furnace vessel, and the displacement as measured by a self-scanned linear array of the scattered light beam from a nominal or reference position measured to provide an indication of lining wear or damage. The video signal received by the linear array receiver provides information for mapping the worn or damaged areas of the vessel lining so that such areas may be repaired by a gunning spray nozzle. The inspection apparatus includes an optical filter which is temperature controlled to prevent wavelength shifts away from the nominal laser wavelength. The electronic processing circuitry includes a voltage controlled oscillator responsive to the average background level for modifying the scan rate of the linear array to compensate for changes in background level. The threshold against which the reflected laser beam video signal is compared is also a function of background level. Consequently, the system is self-compensating for changes in background radiation temperature. The apparatus may be lowered into a hot furnace vessel following each heat without the need to cool the furnace vessel. The inspection apparatus is mechanically scanned vertically and angularly within the vessel to provide a large number of inspection data points.
This is a continuation of application Ser. No. 560,915, filed Dec. 13, 1983 (and issued Nov. 24, 1987 as U.S. Pat. No. 4,708,482), which was a continuation-in-part of Ser. No. 351,316, filed Feb. 22, 1982, now abandoned.
A machine for inspecting the surface conditions of structural members within a furnace, particularly within a furnace operating at a high temperature or with a highly radioactive environment, such as a melting furnace for processing radioactive wastes. The machine comprises a laser-transmission optical fiber incorporated with a laser projector at one end thereof inserted into the furnace and being connected to a laser beam source outside the furnace; a fiberscope incorporated with the objective portion at one end thereof inserted into the furnace and being connected to an image sensor located outside the furnace; means for calculating the distance to a structural wall surface on which the laser beam from a tip portion of the inspection machine has fallen, by subjecting an image from the image sensor to image processing; a double-walled tube of a structure such that the laser-transmission optical fiber is incorporated through an inner tube thereof, and a coolant introduced into a passageway within the inner tube returns in the vicinity of the laser projector at the tip portion; and a double-walled tube of a structure such that the fiberscope is incorporated through an inner tube thereof, and a coolant introduced into a passageway within the inner tube returns in the vicinity of the objective portion at the tip portion.
A method for positioning a device emitting and receiving optical radiation for measuring wear in the lining of a container involves fixing the coordinate systems of the device and the container to each other by measuring the position of specific fixing points (P1, P2, P3) in the coordinate system (16) of the device (1). The fixing points have a regular shape. The position of each fixing point is measured by deflecting optical radiation in two intersecting directions across the fixing point, by measuring the optical radiation reflected from the fixing point, by determining on the basis of the optical radiation reflected to the measuring device at least two intersections, in both deflection directions, between the fixing point and the optical radiation emitted, and by calculating, on the basis of these at least four intersections, a directing point, to which the optical radiation emitted by the device is directed for determining the coordinates of the fixing point.
A removable reference laser target for detachable installation at identified target positions on the exterior of a refractory lined high temperature molten metal vessel. The target includes a generally rectangular target plate with an elongated slot generally paralleling the long dimension of the rectangle. On the same side of the plate but on opposite sides of the slot are two mounting and adjusting bolts for detachably affixing the target at an identified position on the exterior surface of the vessel. Extending essentially at right angles to the major rectangular surface of the plate is an extension, the free end of which contacts an external reinforcing member and assures precise re-location of the target to be used with laser equipment to provide a reference for determining thickness and/or condition of a refractory lining of the vessel.
An inspection device and method determines the accuracy of an irregular shaped elongate slot disposed through a piece part supported on an indexable turntable. The inspection device includes a movable illumination device for directing backlighting towards the piece part and illuminating the elongate slot, and a camera for taking a picture of the illuminated irregular shaped elongate slot and delivering an image of the irregular elongate slot. A vision system determines actual key characteristics (center coordinate value, angle value, area value, and true position value) of an image of the actual elongate slot and a monitor displays information corresponding to the actual and target values. The inspection device and method is primarily used to inspect slotted rings used in stators for gas turbine engines.
The disclosed methods and systems for inspecting and repairing vessels include a laser used to project a laser beam into a hot furnace or vessel, a laser reader to measure a point cloud formed when the laser light reflects from the wall of the furnace, means for selecting those points in the cloud that are more relevant, and using the points to produce a 3D image that corresponds to the geometry of the interior of the furnace or vessel. The disclosed systems and methods further include means for comparing the 3D geometric data corresponding to the interior of the vessel with 3D geometric data provided as a reference, generating a 3D repair trace based on the comparison, and controlling a spray gun for applying refractory material according to the trace by taking into account a set of physical variables related to the vessel and the refractory material.
