MXPA00003000A - Furnace video camera apparatus - Google Patents

Abstract

A high temperature camera apparatus (10) has an elongated steel camera housing tube (12) and an elongated camera support member (20) which supports a video camera (22) at the furnace interior end of the camera housing tube (12). A ceramic heat shield tube (42) telescopically surrounds the camera (22). The ceramic heat shield tube (42) is separated from the camera housing tube (12) by a plurality of spacers (44).

Description

VIDEO CAMERA DEVICE FOR OVEN FIELD OF THE INVENTION This application relates, in general, to an apparatus for inspecting industrial processes, and more particularly refers to a video camera and associated thermal protection apparatus, for observing the inside of a hot chamber.

BACKGROUND OF THE INVENTION Video cameras are commonly used in CCTV systems associated with the operation and control of industrial processes. The prior art describes a variety of video camera systems for observing the interior of a hot, hostile environment, such as the chamber of a high-temperature furnace, through an aperture provided in a laboratory wall. Because a furnace can typically reach temperatures of the order of 1094 'C to 1650' C (2000 'F to 3000 * F), but video cameras can not tolerate temperatures well above 38 * C (100"F), it is necessary to provide thermal insulation and cooling to prevent damage to the video camera.In the usual approach, the prior art uses an elongated steel tube, which extends through the opening of the wall. The camera contains a series of separate optical elements, including lenses, to form a relay tube.The camera is placed outside or near the outside of the camera wall and the series of optical elements transmit the image and They focus on the camera, away from the hot, hostile environment.List relay tubes or relay tubes of this type can have a length that varies from 0.6-6.1 m (2 to 20 ft.). Prior art is that high temperatures and variations in temperature make it extremely difficult to maintain the narrow tolerances that are necessary to accurately transmit the image through the relay tube These thermal stresses cause the relative movement of the components of the relay tube, whereby distortion is introduced into the image. Additionally, each lens or optical element introduces some distortions as a result of its imperfections. Consequently, the video systems using these lens tubes have limited operating characteristics, and are expensive, and demand high quality lenses, in order to obtain and maintain the formation of an image of acceptable quality. Another difficulty with these prior art systems arises from the fact that there is a variety of different furnaces, and consequently these systems require the availability of numerous lens tubes, so that they adjust to the variabilities of the different installations. The need to design and build a variety of lens tubes increases the cost additionally. Therefore, an object and feature of the present invention is to eliminate the typical lens tube and its relay optical elements, and to place the camera at the inner end of a thermally protective tube structure, to eliminate costs and problems. associated with a lens relay tube, and improve the quality of the image, and at the same time provide a cooling and thermal insulation system capable of maintaining the chamber environment at a temperature of 38 'C (100' F) or less . The elimination of the relay tube with lenses not only improves the quality of the available image, but also eliminates the requirement, and therefore the cost, of the design and maintenance of a wide variety of lens relay tubes, for different installations.

SUMMARY OF THE INVENTION In the present invention, the camera is mounted on a support member of the camera, and is positioned at the inner end of the surrounding protective tubes. One of the tubes is a thermal ceramic screen, extending from the inner end of the furnace, from the video camera apparatus, to the outside of the furnace, a distance that surrounds, at least partially, the axial, linear interval, which contains the camera. The term "camera," unless otherwise indicated, is used to include both the portion of the camera that converts an optical image into an electronic signal and the portion of the lens attached to the portion of the camera, to focus the image on the photosensitive surface of the camera. More particularly, the camera apparatus of the present invention has an elongated chamber housing tube, located in the innermost part, which extends through the wall opening of the hot chamber and a collector for the air inlet at the outer end of the tube accommodating the chamber, for transporting the cooling fluid towards the outer end, through the tube accommodating the chamber and into the oven. The thermal ceramic screen surrounds telescopically, and is separated from at least a portion of the housing tube containing the chamber. The housing tube of the chamber may have a reflective outer surface, formed by a chrome plating and a plurality of radially outwardly tapered spacers, projecting from the outer surface of the chamber housing tube, to retain the thermal screen ceramic, in a concentric position, while making minimal contact with it. The invention may also have a tubular, outer, steel sleeve, which telescopically surrounds the ceramic heat shield tube, a first steel end plate, at the inner end of the chamber housing tube, and a second end plate of steel. ceramic, at the inner end of the ceramic ceramic screen tube.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of one embodiment of the invention, having a segment removed from the inner end of the oven, to reveal the end plates and a portion of the chamber mounted at the inner end. Figure 2 is a cross-sectional view, taken substantially along line 2-2 of Figure 1, showing the embodiment illustrated in Figure 1. Figure 3 is a side elevational view of the accommodation tube. of the chamber, and of the associated air inlet manifold, of the embodiment illustrated in figure 1. Figure 4 is an end view, on the left side, of the structure illustrated in figure 3. Figure 5 is a view extreme, on the right side, of the structure illustrated in Figure 3. Figure 6 is a cross section of the embodiment of Figure 1, also taken substantially along line 2-2 of Figure 1, but illustrating the thermal ceramic screen, in side view. Figure 7 is an axial sectional view, similar to the sectional view of Figure 2, and illustrating an alternative embodiment of the invention. Figure 8 is an axial sectional view, similar to the sectional view of Figure 2, illustrating yet another alternative embodiment of the invention, which has cooling water. Figure 9 is an axial sectional view, illustrating a portion of yet another alternative embodiment of the invention. In describing the preferred embodiment of the invention, which is illustrated in the drawings, certain specific terminology will be used for reasons of clarity. However, the invention is not intended to be limited to the specific terms selected, and it should be understood that each specific term includes all technical equivalents that function in a similar manner to achieve a similar purpose.

DESCRIPTION OF THE PREFERRED MODALITY Simultaneously referring to Figures 1-6, the invention consists of a high-temperature camera apparatus 10, for observing the interior of a high-temperature chamber, such as an oven, through an opening in a wall, which encloses the chamber in the same manner as the conventional lens relay tube, of the prior art. The camera apparatus 10 has an elongated tube of steel 12 housing the chamber, which is cylindrical and has an inner passage 14. The accommodation tube 12 has an outer end 16 for mounting in a relatively closer position, in the exterior of the chamber wall, and an inner end 18 for mounting near the interior of the chamber wall. Inside the elongated tube 12 housing the chamber, there is an elongated member 20 supporting the chamber, which, in the preferred embodiment, is a tubular tube that forms a rod for supporting the chamber. A video camera 22 is mounted near the inner end 24 of the camera support member 20, by means of a pair of support brackets 26, attached to the camera support member 20, by welding. The camera support member 20 supports the camera near the inner end of the camera housing tube 12, by circular brackets 28, and extends outwardly from the outer end. An electrical cable 30 passes through the interior of the camera support member 20, to make connection with the camera 22 in order to power the electrical signals. The support member 20 of the chamber is clamped within a sleeve 32, by a radial bolt 34, to allow axial adjustment and the sleeve 32 itself is welded to a circular plate 36. The plate 36 is attached to a manifold 38 of air intake, by means of a pair of fastening clips 39 (only one is visible) manually releasable, diametrically opposed, connected between the plate 36 and a latching assembly block 41, formed as a protrusion on the outside of the manifold 38 This allows the plate 36 to be manually removed from the manifold 38 such that the entire support member 20 of the camera, and the camera 22 mounted thereto, can be removed from the housing tube 12 of the chamber, and easily accessible thereto for service or replacement. The air inlet manifold 38, includes an air inlet 40 in fluid communication, through the interior of the manifold 38, with the inner duct 14 of the tube 12 housing the chamber. This allows cooling air to be blown into the air inlet 40, and to be transported from the outer end to the inner end, along the inner passage 14 to cool the chamber and exit towards the furnace. A vortex cooler, for cooling the air entering through the air inlet from 4.5'C (40'F), to approximately -1.7'C (29 * F) has been found particularly desirable for use with the preferred of the invention. Additionally, air is preferably blown through the furnace chamber apparatus, at a ratio of the order of 4720 to 23600 cm3 / s (10 to 50 cubic feet per minute). A ceramic, cylindrical ceramic heat shield tube 42 telescopically surrounds the housing tube 12 of the chamber and is spaced apart therefrom. It extends from the inner end of the chamber housing tube 12, towards the outer end of the tube housing the chamber, a distance that is at least sufficient to surround the video camera 22 and preferably further in extension. For example, in one embodiment of the invention, the chamber housing tube is approximately 91.44 cm (36 inches) in length, and the ceramic ceramic screen tube is approximately 45.72 (18 inches) in length. The preferred ceramic material consists of a mixture of alumina and silicon oxide, of large pore size, marketed under the trade name of Mullite. The ceramic thermal screen tube 42 is located in a surrounding relationship, spaced apart from the housing tube 12 of the chamber, by a plurality of spacers 44, which are distributed around and projecting outward from the surface outside of the housing tube 12 of the chamber. These separators 44 are preferably tapered radially outwardly and to a point, for example in a conical or pyramidal configuration, in order to minimize thermal, conductive contact between the housing tube 12 of the chamber and the thermal screen tube 42, of ceramic The reflector steel tube 12 and the ceramic tube 42 function as a multilayer radiation shield, which minimizes the thermal radiation incident on the camera lens. The reflecting surface on the steel tube 112 reflects the thermal radiation coming from the ceramic tube 42, causing the ceramic tube to reach a high temperature, decreasing the thermal radiation potential of the furnace to the ceramic tube. Since the ceramic tube 42 can be heated to a much higher temperature than the steel tube, the resulting heat radiation flow from the furnace to the steel tube 12 or chamber is significantly reduced, compared to the use of the tube. of reflector steel 12 without the ceramic tube 42. Preferably the housing tube 12 of the chamber, of this embodiment, is a steel tube which is provided with an outer, reflecting surface, such as a chromium plating, which is preferably polished The reflecting surface intensifies the reflection radially outward of the incident thermal radiation, which radiates inwardly, from the inner surface of the ceramic heat shield tube 42. An outer, tubular, steel sleeve 46 is welded to a circular flange 48 and telescopically surrounds the ceramic heat shield tube 42 or can be omitted and the remaining components can be slid into an existing hole through the refractory wall, of a hot chamber. The flange 48 of the outer sleeve 46 is bolted to the circular flange 50 which is a part of the air inlet manifold 38. The flange 50 also has a central hole into which the tube 12 accommodating the chamber is inserted and fastened by welding. The function of the carbon steel outer tube 46 is to provide a method of attachment to the furnace wall. The end of the carbon steel tube, in the oven, it will be welded to the oven wall. The chamber assembly is then attached to the flange of the carbon steel tube, through the bolts 49. Mounted on the inner end 18 of the chamber housing tube 12, is an end plate 52 of steel. The end plate 52 of steel, has a hole for images 54 that has a conical shape in a direction that expands from the inside of the furnace towards the outside, in order to receive the conical end of the chamber 22 in alignment with the axis of images , of the chamber 22. A plurality of separate ventilation holes 56 circumferentially surrounds the image hole 54. These ventilation holes 56 are inclined inwards in the direction from the outside towards the inside of the hot chamber, to allow the exhausting the cooling air towards the furnace chamber, and directing the air flow from inside the chamber accommodating tube 12, towards the interior of the furnace. By placing the ventilation holes 56 in this orientation and arrangement, the cooling of the end plate 52, where it makes contact with the chamber 22, is maximized, and additionally the exhaust air maintains the inner end of the apparatus, without slag or other contaminants that could otherwise block the vision of the chamber 22. The orientation and arrangement of the cooling hole minimizes the degree of contact of the cooling air on the hot ceramic disk 60, which could cause a great thermal stress on the ceramic disk 60, frontal, possibly breaking it. The inner end 58 of the ceramic heat shield tube 42 is directed inwardly with a frusto-heterospherical shape. A ceramic end plate 60 is seated against, and preferably cemented to, the interior of the inwardly directed end 58, and has a hole 62 concentric with the image hole 54 of the steel end plate 52. The wall The annular defining hole 62 of the ceramic end plate 60 is inclined, so that the hole tapers inwardly, from the outside to the inside of the oven. This minimizes the cooling of the ceramic end plate 60 to minimize stress on the ceramic. This also helps keep it free and clean of slag or other contaminants. A plurality of spacers 64 are mounted and project towards the interior of the furnace, from the inner end of the steel end plate 52. These spacers 64 are seated against the ceramic end plate 60. They are also tapered outwards, to minimize the contact with the ceramic end plate 60. The ceramic heat shield tube 42 carrying its ceramic end plate 60 is spring-biased by spiral springs 63 under tension. These springs 63 are circumferentially spaced at 120 'intervals around and out of the chamber housing tube 12, and are subjected to tension between a set of three similarly spaced holes 70, drilled radially through the outer end of the screen tube. 42 and a set of three similarly spaced holes 72 drilled radially through the outer end of the outer sleeve 46. The springs 63 pull the ceramic, thermal screen tube 42 out of the furnace, thereby seating the plate. ceramic end 60 against the spacers 64, to secure the thermal screen tube 42 in its position against the inner end of the spacers projecting from the steel end plate 52. This spring loading prevents the application of too much force on the ceramic, when heated, which would increase, otherwise, the probability of fracture. When the ceramic tube 42 heats up and expands, it can expand forward, and the ceramic end plate 60 could block the view of the chamber, if it were not pulled towards the outer end by the springs 63. This combination of a tube housing for the camera, inside, through which the air is passed, and a thermal, ceramic, surround tube, allows the camera 22 to be mounted at the inner end of this structure, thereby eliminating the need for a relay tube. glasses. This is particularly effective when the outer surface of the tube accommodating the chamber becomes a reflector, and is further intensified by the use of a tubular outer sleeve of steel, which telescopically surrounds the ceramic thermal screen tube. It is believed that this combination of structures provides the first video camera vision system, which provides sufficient thermal insulation, so that the camera can be mounted at the inner end of the assembly, and remove the relay tube with lenses. Figure 7 illustrates an alternative embodiment of the invention, which has minor variations of the embodiment illustrated in Figures 1-6. In Figure 7, the springs 80 extend from the outer end 82 of the ceramic heat shield tube 84 to establish connection with the holes in the end of a steel tube 86, connected to an annular flange 88, compressed between the flanges 90 and 92. Additionally, the support member 94 of the chamber is provided with three outwardly extending spacer flaps, welded to the support member 94 of the chamber, to radially secure the support member 94 of the chamber. , and to the chamber 97 mounted thereto, in its position, within the housing tube 98 of the chamber. Figure 8 illustrates yet another alternative embodiment of the invention. In the embodiment of Figure 8, a pair of tubes 100 and 102 with jacket for cooling liquid, are sealed, in a sealed manner, to the tube 104 housing the chamber, at each of its opposite ends. This forms a pair of coolant jacket chambers, 106 and 108, one on each radial side of the chamber housing tube 104. The pair of jacket chambers for refrigerant, 106 and 108, is connected, in fluid communication, by a plurality of holes 110, through and distributed around the inner end of the tube housing 104 of the chamber. A pair of fluid conduits 112 and 114 are each connected in fluid communication to a different jacket with refrigerant jacket 106 and 108, such that a conduit can function as an inlet for the liquid refrigerant, and the other as an outlet for the liquid refrigerant. In this way, the liquid refrigerant, preferably water, can be circulated towards the inlet, preferably towards the duct 112 of the refrigerant jacket chamber, radially inward, and passes parallel to the central axis of the tubes, towards the inner end of the chamber housing tube 106, and then passes outwardly through the holes 110 and circulates in a reverse direction away from the tube 114. A wire separator 113 is wound in a helical configuration, in the cavity 106. of external flow. The wire separator 113 reduces the available flow area, creating a spiral flow pattern. By reducing the available flow area, the flow becomes turbulent at lower coolant flows, increasing the heat transfer coefficient, between the refrigerant and the outer flow tube 100. This allows the outer tube of stainless steel (with plating) of chromium) 100 remain at a temperature below the boiling point of the refrigerant, with much lower coolant flows, for example, of 0.06308 liters / second (1 gallon per minute), instead of 0.3154 liters / second (5 gallons per The cooling jacket feature of the present invention can be used with any of the embodiments of the present invention, and preferably provides additional cooling, complementing air cooling through the air intake manifold 116 in the manner Figure 9 illustrates still another alternative embodiment of the invention In Figure 9 the camera 120 highlights interior of the tube 122 housing the chamber. An end plate 124 is mounted on the inner end of the tube 122 housing the chamber, such that a portion of the chamber 120 extends through a central opening 126 through the end plate 124. The ceramic heat shield 128 is mounted to the end plate 124, and extends internally therein. Additionally, a tubular cover 136 with chrome plate and polished, is also mounted on the end plate 124, radially inwardly of the ceramic screen 128. Consequently, both the ceramic screen 128 and the cover 136 surround at least the portion from the internal chamber 120 to the inner wall of the chamber at high temperature. Although certain preferred embodiments of the present invention have been described in detail, it should be understood that various modifications can be made without departing from the spirit of the invention or the scope of the following claims.

Claims (21)

NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty, and therefore, the content of the following is claimed as a priority: CLAIMS

1. A high-temperature camera apparatus, including a video camera for observing the interior of a high-temperature chamber, through a hole in a wall of the chamber, the apparatus is characterized in that it comprises: (a) a tube of elongated chamber housing, which includes an inner conduit, for extending through the hole, and having an outer end for mounting relatively close to the exterior of the chamber wall, and an outer end for the chamber. mounting near the inside of the chamber wall; (b) an elongated camera support member having the camera mounted near an inner end of the support member, and extending toward the outer end, the support member supports the camera at the inner end of the tube of camera housing; (c) a ceramic heat shield tube, telescopically surrounding, and spaced apart from, at least a portion of the chamber; and (d) a manifold for air inlet, which includes an air inlet in fluid communication with the inner conduit of the tube for housing the chamber, for transporting the cooling fluid, along the inner conduit and for cooling the camera.

An apparatus according to claim 1, characterized in that the ceramic thermal shield tube, telescopically surrounds, and is spaced out from, the tube housing the chamber, and extends from the inner end of the tube. housing the camera, towards the outer end of the tube housing the camera, at least a distance such that surrounds the entire video camera.

3. An apparatus according to claim 2, characterized in that the tube housing the chamber has a reflective outer surface.

4. An apparatus according to claim 3, characterized in that the tube for housing the chamber is a steel tube that is plated and polished to form a reflecting surface.

An apparatus according to claim 2 or claim 3 or 4, characterized in that a plurality of spacers project outwardly from the outer surface of the tube housing the chamber, to separate the thermal screen tube, from the tube of camera housing.

6. An apparatus according to claim 5, characterized in that a tubular outer sleeve made of steel telescopically surrounds the ceramic thermal screen tube.

7. An apparatus according to claim 5, characterized in that it further comprises a steel end plate, mounted on the inner end of the tube housing the chamber, the steel end plate has a hole for images, aligned with an axis of images, of the camera, and a plurality of separate ventilation holes, which surround the hole for images.

8. An apparatus according to claim 7, characterized in that the ceramic thermal screen tube has an interior facing inwards, and a ceramic end plate is seated against the interior of the inwardly facing end of the screen tube. Thermal ceramic, and has a concentric hole with the hole for images, of the steel end plate.

9. An apparatus according to claim 7, characterized in that it further comprises a plurality of spacers projecting from the inner end of the steel end plate and which are seated against the ceramic end plate.

10. An apparatus according to claim 9, characterized in that the spacers are tapered outwards to minimize contact with the ceramic end plate and with the ceramic heat shield tube.

11. An apparatus according to claim 5, characterized in that the ceramic heat shield tube has an inner end, oriented inward, and a spring is connected to an outer end of the ceramic heat shield tube, to deflect the inner end of the screen tube with springs. thermal, ceramic, against the inner end of the camera housing tube.

12. An apparatus according to claim 11, characterized in that an outer tubular sleeve of carbon steel telescopically surrounds the ceramic thermal screen tube.

13. An apparatus according to claim 12, characterized in that it also comprises a steel end plate, at the inner end of the tube housing the chamber, the steel end plate has an image hole aligned with an image axis, of the chamber, and a plurality of ventilation holes, separated, that surround the hole for images.

14. An apparatus according to claim 13, characterized in that the ventilation holes are inclined inwardly from the inner conduit of the tube housing the chamber.

15. An apparatus according to claim 14, characterized in that it also comprises a ceramic end plate, seated against the inside of the end, oriented inwardly of the ceramic heat shield tube, and having a hole concentric with the hole for images of the steel end plate.

16. An apparatus according to claim 15, characterized in that it further comprises a plurality of separators projecting from the inner end of the steel end plate and which are seated against the ceramic end plate.

17. An apparatus according to claim 16, characterized in that the spacers are tapered outwards, to minimize contact with the ceramic end plate and with the ceramic heat shield tube.

18. An apparatus according to claim 5, characterized in that it also comprises a pair of tubes with jacket for liquid refrigerant, is coupled, in a sealed manner, to the housing tube of the chamber, a tube with jacket for refrigerant, radially outwardly , and a jacket with refrigerant jacket, radially inward, of the tube housing the chamber, to form a jacket chamber for liquid refrigerant, on each radial side of the tube housing the chamber, and a conduit for refrigerant inlet , is connected to a first of the refrigerant jacket chambers, and a refrigerant outlet conduit, is connected to a second of the refrigerant jacket chambers, and wherein a plurality of holes is formed through the refrigerant tube. chamber housing, to provide communication of the liquid refrigerant, between the jacket chambers for the refrigerant.

19. An apparatus according to claim 1, characterized in that it further comprises a pair of jacket tubes for liquid refrigerant, which is sealedly attached to the tube housing the chamber, a jacket tube for refrigerant, radially towards outside, and a refrigerant jacket tube, radially inwardly of the housing tube chamber, to form a jacket chamber for liquid refrigerant, on each radial side of the chamber housing tube, and a conduit for refrigerant inlet it is connected to a first of the jacket tubes for refrigerant, and a conduit for the outlet of the refrigerant is connected to a second of the jacket tubes for refrigerant, and where a plurality of holes is formed through the tube. chamber housing, to provide communication of the liquid refrigerant, between the jacket chambers for refrigerant.

20. An apparatus according to claim 1, characterized in that it also comprises an end plate mounted to the inner end of the tube housing the chamber, and where the thermal screen tube, ceramic, is mounted to the end plate.

21. An apparatus according to claim 20, characterized in that a tubular cover is also mounted to the end plate, radially inwardly of the ceramic thermal shield.