KR20000016073A - Endoscopic inspection sensor for coke oven batteries - Google Patents

Abstract

PURPOSE: Disclosed is an endoscope with inspecting head secured at the end of a longitudinally flexible support line which connects it to a control unit provided with means for humidifying the line. CONSTITUTION: The endoscope characterized in that a support line (2) is rigid when axially twisted while an inspecting head (1) is movable in axial rotation and formed by an assembly detachable in two portions; one permanent portion (11) secured at the end of the support line by a rotary joint (10) and housing a miniature camera (26), and an interchangeable portion (12), rigidly fixed to the said permanent portion, in the extension of the latter, by means of a detachable connection (44) and comprising a parietal opening (lateral or axial) provided with a wide angled eyepiece lens (23) followed by an optical line (25) conveying the quantity of light captured by the said lens towards the camera (26), and in that means (32 to 36) are included in the sensor to drive the inspecting head in axial rotation and ensure adjustment of its angular position relative to the support line. This sensor is highly adapted for visually inspecting coke oven flues.

Description

Endoscope Inspection Sensors for Coke Oven Batteries

The present invention relates to the maintenance and maintenance of industrial furnaces, particularly coke oven batteries, and more particularly to the state of refractories forming the walls of the flue of these ovens, even during operation of the oven. It is about monitoring accurately.

During the operation of the oven, the coke oven battery is subjected to thermomechanical stress, which is inherently caused by the circulation of the operation of loading and unloading the material. This, sooner or later, results in permanent deformation of the metal parts and the refractory material, reducing the service life of the battery.

To ensure satisfactory use for more than 30 years, the refractory condition of the oven must be regularly and accurately diagnosed. However, certain areas of the oven, for example areas such as the year, are very difficult to diagnose because their access is very limited, and furthermore, this year is where the greatest thermal stress is. Thus, too late treatment and improper or useless repairs may result.

Endoscopy techniques, which will be widely used in many parts of the industry in the future, are still rarely used in the field of coke at this time, because most of the proposed endoscopy techniques are not suitable for inspecting refractory materials in the year of a coke oven. In particular, there is no doubt in terms of the extreme temperature conditions present in the year.

Schematically, the probes currently used or available for testing the coke oven flue can be classified into two types, which commonly have a test head housing the sensing element suspended within the flue at the end of the support line and said support line The test head is connected to an operating device installed outside of the oven.

In fact, according to a first known kind, including an endoscope, the support line consists of a long rigid metal tube which is cooled by an internal water circulation and operated in vertical translation by a rack and pinion system. This embodiment constitutes a heavy and bulky assembly that is difficult to handle and, in fact, intended to be in place, while inspection requirements are of short duration and relatively long intervals apart.

In a second known type of probe comprising the present invention, the rigid tube is replaced by a longitudinally flexible sleeve wound on a drum, the lower part of the sleeve being submerged in a water tank intended to wet the sleeve and cooled. do. This technique allows a simple and light weight device to be operated quickly, so that if the inspection operation can be carried out quickly by the device without a complicated cooling system, there is virtually no need for cooling by internal water circulation. It comes from the fact that it is possible. Thus, the probes disclosed in document FR-B-84.18822 have been designed and developed. In this probe, the sensing head consists of an optical pyrometer of elongated shape (" pencil "), protected in a sheath made of fibrous refractory material fixed to the base, the top of the head being a flexible support sleeve Attached to an end of the housing, the end housing a steel rope, and at the end of the steel rope a pyrometer is suspended. This probe seems to be completely satisfactory so far. However, the probe is limited to providing the temperature of the gas in the duct, and this amount is only an indicator that is far from indicating the condition of the wall of the refractory material.

It is an object of the present invention to observe these walls directly in sight.

For this purpose, the subject of the present invention is an endoscope probe of the kind having an inspection head for inspecting an industrial furnace, in particular a fireproof wall of the corridor of a coke oven, the inspection head receiving a sensing element Attached to an end of a flexible support line, the support line connects the test head to an operating device provided with means for wetting the support line, wherein the endoscope probe is configured such that the support line is rigid under axial torsion, The inspection head is axially movable and is formed of a two part detachable assembly, the two parts being interchangeable with the permanent part, the permanent part being attached to the end of the support line by a rotatable joint, (Preferably a micro video camera), said interchangeable part being positioned in the direction of extension of said permanent part; An orifice on the wall side (front or side) mounted with the objective lens fixed by the permanent portion and followed by optical means for carrying the optical energy captured by the objective lens toward the photography device, the means being provided in the probe Mounted to ensure the motorization of the axial rotation of the test head and the adjustment of each position of the test head relative to the support line.

According to one embodiment, the support line consists of a tubular metal reinforcement made of braided wires and covered with a flexible sheath made of fiber reinforcement.

According to a preferred arrangement, the mounting means for rotating the inspection head to reliably position it at the desired respective positions consists of a motor having a transmission shaft having end pinions fixed to the support line and engaged with the inner wall of the support line.

In the case of interchangeable parts with side wall orifices, the optical transport means has a prism that reflects the light energy captured by the lens towards the camera, the prism being located in the vicinity of the lens.

As will be appreciated, the present invention provides a means for visually observing flue walls that are naturally indicated in the red range by heat radiation from an oven in operation, at a support line that is flexible in the " portrait " direction and at the free end of the support line. Composed essentially of a combination, the support line can be wound, but in other respects it is hard to prevent unexpected bitrim movement about the axis of the support line. The means is movably mounted in axial rotation by a mounting actuator remotely controlled by an operator of the control station, the observation means providing the operator with a real and instant image of the flue wall.

The invention can be understood from the embodiments with reference to the accompanying drawings and other aspects and advantages are also apparent.

1 is a vertical cross-sectional view of a portion of a tube of a coke oven battery and an endoscope according to the invention operating in the tube;

Figure 2 is an axial longitudinal cross-sectional view detailing the sensing head mounted at the end of the endoscope line according to the present invention;

FIG. 3 is a cross-sectional view similar to FIG. 2 showing another embodiment with respect to the viewing direction. FIG.

Like elements in the figures are designated by like reference numerals.

First, referring to FIG. 1, the test head 1 is suspended by a flexible support line 2 and penetrates into the tube 3 through the upper orifice 4 of the tube 3 by gravity. . The flexible support line 2 is wound over the drum 6 via a return pulley 5, and the drum is provided with means for setting it to the rotation indicated by the crank handle 7. In the semi-cylindrical tank 8 filled with water, the lower portion of the winding drum 6 is locked so that the support line 2 is wetted. The screen console 9 is mounted at the chest height on the frame of the drum and the operator performs all the operations by permanent visual control provided by the display screen indicating what the inspection head 1 has captured. can do.

The test head 1 is externally composed of an elongated shaped metal capsule (about 50 cm in length with a diameter of several cm) and is made of a rigid shell (not shown) made of refractory materials for thermal and impact protection. Is housed within. The test head 1 consists of two continuous parts of approximately the same length and is fixed to each other by an assembling flange formed of a knurled ring 44 which can be screwed by hand. Here, the two continuous parts are the "upstream" part 11 and the interchangeable "downstream" part 12 attached to the support line 2 by the rotatable joint 10. This rotatable joint 10 may typically be made of a ball bearing 13, the inner ring of the ball bearing having an inlet annular bearing surface 14 of a connector 49 forming an end of the support line 2. Mounted around and the outer ring of the ball bearing is coupled to the inner wall of the " downstream " These arrangements may, of course, be reversed. However, in order to ensure a seal against the outside as far as possible, it is always necessary to size the rotary joint 10 to provide only a simple functional play 15 between the rotary "downstream" and the fixed "upstream". Be careful. A collar 50 formed at the end of the bearing surface 14 ensures that the translation of the head 1 with respect to the support line is blocked.

As shown, the connector 49 is fixed to the rest of the support line 2 by clamp straps 16 in two parts that are screwed together, the free end of the two parts being the end of the connector 49. And at the end of the flange 18, for this purpose, a flexible sleeve forming a pusher against each other formed collars 17 and 17 ′ against each other and forming a support line 2 on the flange. (19) is combined.

According to an important feature of the present invention, the sleeve is flexible enough to be wound, for example, on a drum of about 50 cm diameter, and in the unwinded state it should be possible to simply recover the straight shape by the weight of the inspection head 1. . At the same time, this sleeve should be sufficiently rigid against axial torsion to avoid the addition of random rotation to the rotation of the "downstream" portion of the inspection head controlled by the operator. For this purpose, the flexible sleeve 19 is preferably made of a reinforcement made of flat stainless steel braid, similar to the metal sleeve used for protecting the electrical cable.

The sleeve is encased in a layer of flexible fiber insulator 20, such as rock wool in strip form, which can be wetted by being immersed in a water tank, thereby thermally protecting the sleeve and the various cables and wires it receives. Can be. Assembly is assured by clamp straps. In this kind of sleeve, the flexible rod fits perfectly over the entire length, allowing the cooling air to be circulated if desired.

Referring to Fig. 2 in more detail, inside the side observation inspection head 1, starting from the bottom, a predetermined number of members are provided as follows.

First, the optical line 22 which visually acquires the image observed by the probe forms a first component of the optical chain which functions to transmit an image formed by the lens 23 in the direction of the photography device. It has a " wide angle " objective 23 coupled to a regression prism 24 associated with the adaptive bilens 42. The rest consists of an optical tube 25 mounted to the front of the photography device 26. The objective lens 23 is fitted to an orifice 27 made on the side wall of the inspection head 1 for this purpose. The field of view of the objective lens determines the range of observable areas on the ductal wall. The prism 23 reflects light received from the objective lens 23 at right angles and is directed in the direction of the optical tube 25 along the longitudinal axis of the probe. At the end of the optical tube, an inlet bilens 28 and an outlet bilens 29 are provided, and the optical tube 25 having a spectral attenuation or correction filter 43 and a luminance adaptive diaphragm 30 is photographed. An image is directed towards device 26, which preferably comprises a microcamera having a photodiode matrix. In this way, the image of the inspection area, captured by the camera, is transmitted to the display screen 9 by the flexible cable 31.

The inspection head 1 further comprises an incremental encoder 32 which allows, at any moment, to know the angular position of the lens 23 (and therefore in the viewing direction) with respect to the "zero" reference point. Thus, a complete rotational scan of the year can be performed under the operator's permanent control, or the previously observed area can be easily found again.

The inspection head 1 is also provided with a reversible synchronous DC motor 33, which is associated with the transmission member of the DC motor, ie the drive shaft 34, and at the end of the drive shaft a pinion ( 35 is engaged with the gear wheel 36, which is fixed against the inner wall of the "downstream" part which is movable with the rotation of the probe.

Of all the items of the device described above, only the motor 33, together with the pinion shaft 34 of the motor, is not fixed to the rotary head 1. The motor is fastened in the connector by fastening 48.

The encoder 32 and the motor 33 are connected to the outside by the electric cables 37 and 38.

All items of these devices are fixed in the probe by retainers which connect them firmly to the inner wall. The retainer holding the prism 24 and the adaptive bilens 42 associated with the prism is accessible from the front of the probe after the probe nose 40 has been removed.

The accessibility of this essential part of the probe is characterized by a flange having a cylindrical bearing surface 52 screwed at the end of the tube 11, on the one hand and a radial ring 53 on the other hand with an internal thread. 51), on the cylindrical bearing surface a tube forming the interchangeable portion 12 slips and is centered on its own at the same time, with a clamp screw inside the inner thread. Is combined. Likewise, the clamp screw 54 accessible after the nose 40 has been removed pushes the retainer 39 through which the clamp screw penetrates at their ends, so that the interchangeable portion 12 is clamped to the tube (by clamping). 11) is firmly fixed.

The retainer 41 holding the optical tube 25 is accessible from the removable ring 44 and also the filter 43 is accessible. The retainer 45, which holds the photography device 26, is accessible by a screw connection 46, which joins two adjacent portions that form the permanent portion 11. In addition, after the camera 26 is removed, the retainer 45 can access the retainer 47 holding the incremental encoder 32.

In the region of the orifice 27 a small conduit 55 is made into the tube 12 and distributed around the lens 23. According to a preferred embodiment of the present invention, if the flow of cooling air passes through the inside of the probe, the front lens of the objective lens is connected by these conduits connecting the inside of the probe to the space formed in front of the objective lens 23. A protective air curtain can be formed in front.

In Fig. 2 an inspection head designed for viewing the axial direction is again shown identically in a particular arrangement with all these components, except in this case the useless prism 24. The difference here is that the side orifices 27 have been replaced with axial orifices 27 'made in the end pieces 40' forming the probe nose. This orifice receives a wide-angle lens 23 and transmits the captured image to the optical tube 25.

All others remain unchanged. Thus, by simply replacing the interchangeable " downstream " portion 12, which can be easily removed by hand by the ring 44, from the side view configuration (FIG. 1) to the axial viewing configuration (FIG. 2), Conversely, it can be easily changed by the same basic device. Likewise, for a given configuration, objective lenses 23 with progressive optical angles in the range of 30 to 105 ° are altered to panoramic observations for more detailed areas of the surface being inspected by a fixed set of interchangeable parts. Can be.

The present invention is, of course, not limited to the described embodiments, and there are many variations and equivalents are reproduced as long as they have the essential characteristics of the endoscope, as defined by the appended claims.

Claims (10)

An endoscope probe of a type having an inspection head for inspecting a fire barrier of an industrial furnace, wherein the inspection head is attached to an end of a longitudinally flexible support line for receiving a sensing element, wherein the support line is attached to the inspection head. In the endoscope probe, connecting the to the operating device provided with the means for wetting the support line, The support line 2 is rigid under axial torsion, the inspection head is movable in axial rotation and is formed of a two part detachable assembly, the two parts being interchangeable with the permanent part 11. 12, the permanent portion is attached to the end of the support line by a rotatable joint 10 and houses a photography device 26, wherein the interchangeable portion 12 is removable by a removable joint 44. On the wall side where the objective lens is firmly fixed to the permanent portion in the extending direction of the permanent portion and followed by the optical line 22 which transfers the image captured by the objective lens 23 toward the photography device 26. With orifice, Means (32 to 36) mounted in the probe to ensure driving of the axial rotation of the test head and adjustment of each position of the test head relative to the support line. The endoscope probe according to claim 1, wherein the support line (2) is made of a tubular metal reinforcing material (19) made of braided wire and covered with a flexible casing (20) made of a refractory material. An endoscope probe according to claim 1, wherein the photography device (26) is a camera having a photodiode matrix. The drive shaft (34) according to claim 1, wherein said means mounted to ensure axial rotation of said test head has a drive shaft (34) having a pinion (35) engaged with an inner wall of said permanent portion (11) of said test head. Endoscope probe, characterized in that consisting of a motor (33) acting on. 5. An endoscope probe according to claim 1 or 4, wherein said means for reliably adjusting each position of said test head comprises an incremental encoder (32) mounted to said permanent portion (11). 2. The interchangeable portion (12) according to claim 1, wherein said interchangeable portion (12) has a side wall orifice (27) provided with a lens (23) associated with a prism (24), said prism having an optical line arranged in the vicinity of said prism. An endoscope probe, characterized by reflecting the captured image along the axis of the inspection head in the direction of (22). 2. The interchangeable portion (12) according to claim 1, wherein the interchangeable portion (12) has an axial wall side orifice (27 ') made in a probe nose (40'), wherein the orifice arranges the captured image in the vicinity of the orifice. An endoscope probe, characterized in that a lens 23 for transmitting directly toward the optical line 22 '. The end of the support line (2) having the function of attaching the inspection head (1) has a bearing surface (14) for the rotary joint (10) at one end and a rigid connection joint at the other end (1). 16, 17) endoscope probe, characterized in that consisting of a connector (49) with the rest of the support line. The endoscope probe according to claim 1, wherein the detachable joint connecting the permanent part (11) to the interchangeable part (12) consists of a threaded ring (44). The endoscope probe according to claim 1, wherein means for internal circulation of cooling air is provided.