Title of Invention

MONITORING DEVICE WITH SCRAPER UNIT

Abstract

In a monitoring device (11) in the wall (3) of a furnace (1), particularly for capturing the image of an incineration process in the furnace (1), having an inner end (I), an outer end (15), at least one housing (13, 17), and an monitoring element (25) arranged inside the housing (13, 17), extending at least between the inner end (I) and the outer end (E), the monitoring device (11) is provided with a scraper unit (31) that keeps the inner end (1) of the monitoring element (25) free from deposits occurring on the wall (3).

Full Text

BACKGROUND OF THE INVENTION The invention relates to a monitoring device with scraper unit. In a well-known monitoring device of this type, compressed air is used to clean the inner end of deposits. If this does not succeed, then either manual cleaning must take place, which requires switching off the furnace, or the regulation of the incineration process must get along with less or - if faults remain undetected - wrong information, in both cases this leads to additional costs. The present invention is based on the object of improving a monitoring device of the initially specified type. Owing to the fact that the monitoring device is provided with a scraper unit which keeps the monitoring element on the inner end free from deposits formed on the wall, the vision of the monitoring element on the inside of the furnace can be automatically kept free. This increases the efficiency of the furnace and reduces operating costs. The terms monitoring device and monitoring element are not limited to the optical range. Rather, they should also be understood as devices and elements for other measuring procedures, including automatic flame detectors and resistance elements. The scraper unit preferably includes a scraper head that is arranged between the internal end and the external end when in the initial position, so that its functionality is protected by the housing. When the scraper unit is activated, the scraper head is moved by means of a drive along the housing, in order to clean the monitoring element. For this, the scraper head is preferably at least partially extendable beyond the internal end, in order to remove the deposits mechanically. The housing provided for a compact type of construction with simultaneous integration of the scraper unit preferably consists of a first housing inside which a second housing is arranged at a distance, the monitoring element preferably being firmly attached in the second housing and the scraper head being movably installed between the first housing and the second housing, in particular being supported on the second housing. It can be alternatively or additionally supported on the first housing. Simple geometrical conditions and a simple mounting option in the wall by drilling result from rotational symmetry, the monitoring element, the first housing, the second housing and the scraper head being arranged preferably coaxially to a common axle. The drive, which is limited to no special drive system, can be act directly on the scraper head, preferably however to extension rods that can be attached to the scraper head for extending it in order to save material. The housing preferably leads compressed air to the internal end, on the one hand in order to rinse and to cool the monitoring device, on the other hand to cool down the deposits, so that these are not flexible, but can be broken off. Preferably, activation of the scraper unit takes place on a regular basis, and, in cases when the image processing downstream from the monitoring element detects a darkening and/or clouding at the internal end, an extraordinary activation of the scraper unit takes place additionally, i.e. in either case automatically. This does not exclude manual cleaning. In addition, the information about the activation can be included into an automatic control loop. The monitoring device according to the invention with a scraper unit is preferably used in a furnace of an incineration plant, in which particularly strong deposits of cinder occur on the wall; however its purpose is not limited to this. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The invention is explained in greater detail below by means of an exemplary embodiment illustrated in the drawing, in which: Fig. 1 is a partial section view of the exemplary embodiment with retracted scraper head, its mobility being indicated by a double arrow, and Fig. 2: is a representation according to Fig. 1 with extended scraper head, in which the wall of the furnace is not indicated. A furnace 1 of a hazardous waste incineration plant has several openings on its wall 3, each of which receiving a monitoring device 11. The portion with the end the monitoring device 11 facing toward the inside of the furnace 1 is referred to as the internal end I, whereas the portion facing away from the inside of the furnace is referred to as the external end E. The monitoring device 11 includes a hollow, circle-cylindrical first housing 13, which defines an axis A by its geometry, and which is firmly (and tightly) connected to the wall 3. The axis A runs at least approximally perpendicularly to the wall 3, and horizontally. A radially projecting first flange 15 is formed onto the first housing 13 at the outer end E. The monitoring device 11 further includes a cylindrical second housing 17 of smaller diameter that is coaxial with the first housing and arranged therein at a radial distance from the wall of the first housing 13. The second housing 17 is has a hollow wall. At the inner end I, the second housing 17 is flush with the first housing 13, whereas at the external end E, there is first a radially extending second flange 19 and followed, in the axial direction, by a clutch 21. The second flange 19 is fitted closely to the first flange 15 and is fastened to it for example by a tie-clip connection of the clutch 21. Inside the second housing 17, the monitoring device 11 includes a substantially rotationally symmetrical monitoring element 25 of smaller diameter that is coaxial to the second housing, in the present case a boroscope. The monitoring element 25 is arranged at a radial distance from the wall of the second housing 17 and is firmly attached at both ends of the second housing 17 by mounting rings or suchlike. The monitoring element 25 can be connected to a camera arrangement which is arranged at a distance from the wall 3 of the furnace 1 either directly or by means of a light conductor. Depending upon the application, various infrared and/or light-sensitive cameras with high space-, time- or frequency resolution or simple diodes are provided in the camera arrangement, for which the monitoring element 25 forms the optical access to the inside of the furnace 1 and which serve to capture the images of the incineration process taking place in the furnace I. In the present connection, the term "optical" also relates to radiation beyond both sides the visible range. For flushing, i.e. for preventing the monitoring element 25, the second housing 17 and the inside of the first housing 13 from getting dirty, and also for cooling these parts of the monitoring device 11, compressed air L is constantly introduced into the monitoring device 11 through a radial drilling in the first flange 15, said compressed air L being led to the inner end I through the gap between second housing 17 and first housing 13 and through the hollow wall of the second housing 17. The difference in pressure to inside the furnace 1 prevents dirt from entering. The monitoring device 11 has an additional scraper unit 31 which prevents the inner end I of the monitoring device 11 from getting clogged by settling cinder due to caking or from losing the view of the inside of the furnace I for any other mechanical reason. For this, the scraper unit 31 comprises a sleeve-like scraper head 33, which is (axially) moveably arranged (sliding) in the gap between the second housing 17 and the first housing 13 and on the second housing 17 parallel to the axle A. The scraper unit 31 furthermore comprises four extension rods 35 which are attached, in particular screwed, in axial extension of the scraper head 33 to that front side of the scraper head 33 that is facing toward the outer end E, and which are guided in supports 37 connected to the second housing 17. In the exemplary embodiment, the extension rods 35 are coupled to piston rods 39 whose ends, shaped as a piston and facing away from the extension rods 35, move in cylinders 41 and can be pneumatically activated. Different drives may also be considered, such as an electric motor or a hydraulic drive. If necessary, the drives can be provided with reset springs. 7 Cinder is produced in the furnace 1 during the incineration process, settling on the wall 3 of the furnace 1 and, being soft, running down due to the force of gravity. It can thus happen that such a cinder deposit running down reaches the inner end I of the monitoring device 11. Then, the compressed air L begins to cool the cinder. When the scraper unit 31 is in the initial position, the scraper head 33 is arranged inside the first housing 13, i.e. at a distance from the inner end of the monitoring device 11. The scraper unit 31 is normally clock operated, i.e. regularly activated, for instance, every 10 seconds or each minute, with the activated extension rods 35 extending the scraper head 33 until the latter reaches beyond the inner end I, and then retracting it again until it reaches the initial position. Any cinder deposit that reaches the the extending range of the scraper head 33 is mechanically broken off by this regular activation of the scraper unit 31. The image of the inside of the furnace 1 taken by the camera arrangement of the monitoring device 11 is subjected to an image processing by an electronic analysis and control device, which takes actions for controlling the incineration process in the furnace 1 depending on the control targets, if necessary, i.e. controlling the feeding of the furnace I. If a darkening from the (upper) edge is detected from the image, the scraper unit 31 is driven in a specific manner, i.e. the growing cinder deposit is cleared by an extraordinary activation of the scraper unit 31. If necessary, the intervals for regular activation of the scraper unit 31 can then be shortened. If there is no improvement, an alarm is triggered in order to request manual cleaning, particularly if repeated extraordinary activation of the scraper unit 31 remains fruitless. The information about the frequency of the activation of the scraper unit 31 is also preferably used for controlling the incineration process. WE CLAIM: 1. Monitoring device (11) in the wall (3) of a furnace (1), particularly for capturing the image of an incineration process in the furnace (1), having an inner end (I), an outer end (E), at least one housing (13, 17) and a monitoring element (25) arranged inside the housing (13, 17), extending at least between the inner end (I) and the outer end (E), characterized in that the monitoring device (11) is provided with a scraper unit (31) that keeps the inner end (I) of the monitoring element (25) free from deposits occurring at the wall (3). 2. Monitoring device as claimed in Claim 1, wherein the scraper unit (31) has a scraper head (33) that, in the initial position, is arranged, in a retracted state, between the inner end (I) and the outer end (E), and is conceived to move along the housing (13, 17) by means of a drive in case of an activation of the scraper unit (31). 3. Monitoring device as claimed in Claim 2, wherein the scraper head (33) is conceived to extend outward, at least partially beyond the inner end (I), in case of an activation of the scraper unit (31). 4. Monitoring device as claimed in Claim 2 or 3, wherein the housing (13, 17) consist of a first housing (13), inside which a second housing (17) is arranged at a distance. 5. Monitoring device as claimed in Claim 4, wherein the monitoring element (25) is fixed in the second housing (17) and that the scraper head (33) is guided movably between the first housing (13) and the second housing (17). 6. Monitoring device as claimed in Claim 5, wherein the monitoring element (25), the first housing (13), the second housing (17) and the scraper head (33) are coaxially arranged around a common axle (A). 7. Monitoring device as claimed in any of Claims 2 to 6, wherein the extension rods (35) are attached to the scraper head (33) which are engaged by the drive. 8. Monitoring device as claimed in any of Claims 1 to 7, wherein the housing (13, 17) leads compressed air (L) to the inner end (I). 9. Monitoring device as claimed in any of Claims 1 to 8, wherein the regular activation of the scraper unit (31) takes place and that, in such cases when the image processing downstream from the monitoring element (25) detects a darkening and/or clouding at the inner end, an extraordinary activation of the scraper unit (31) takes place. 10. Incineration plant, particularly a hazardous waste incineration plant with a furnace (1), having at least one monitoring device as claimed in any of Claims 1 to 9. In a monitoring device (11) in the wall (3) of a furnace (1), particularly for capturing the image of an incineration process in the furnace (1), having an inner end (I), an outer end (15), at least one housing (13, 17), and an monitoring element (25) arranged inside the housing (13, 17), extending at least between the inner end (I) and the outer end (E), the monitoring device (11) is provided with a scraper unit (31) that keeps the inner end (1) of the monitoring element (25) free from deposits occurring on the wall (3).

Documents:

367-KOL-2005-CORRESPONDENCE.pdf

367-KOL-2005-FORM 27.pdf

367-KOL-2005-FORM-27.pdf

367-kol-2005-granted-abstract.pdf

367-kol-2005-granted-assignment.pdf

367-kol-2005-granted-claims.pdf

367-kol-2005-granted-correspondence.pdf

367-kol-2005-granted-description (complete).pdf

367-kol-2005-granted-drawings.pdf

367-kol-2005-granted-examination report.pdf

367-kol-2005-granted-form 1.pdf

367-kol-2005-granted-form 18.pdf

367-kol-2005-granted-form 2.pdf

367-kol-2005-granted-form 26.pdf

367-kol-2005-granted-form 3.pdf

367-kol-2005-granted-form 5.pdf

367-kol-2005-granted-priority document.pdf

367-kol-2005-granted-reply to examination report.pdf

367-kol-2005-granted-specification.pdf

367-kol-2005-granted-translated copy of priority document.pdf

367-KOL-2005-OTHERS PATENT DOCUMENTS.pdf