Title of Invention

A SYSTEM FOR REAL TIME MONITORING FROM A REMOTE STATION THE BLAST FURNACE BURDEN AND TOP GAS FLOW DISTRIBUTION

Abstract

The invention relates to a system for real-time monitoring from a remote station the blast furnace burden and top gas flow distribution, comprising a camera (3) with an optical system consisting of lenses and optical cylinders for viewing and imaging the blast furnace interior through a hole (2) of about 6 mm in dia; a ball valve (7) for mechanically isolating the system from the inner part of the blast furnace and prevent venting of poisonous blast furnace gas on failure of the optical system through a pyrex window (11); a nitrogen purging system (13) for a clear view of the furnace interior by pressurization of a chamber (12) maintained at a pressure higher than the furnace top pressure to prevent ingress of dusty gases from the furnace top. The ball valve (7) and the optic at system (4) are enabled by a programmable logic controller (PLC) to automatically provide a controlled video signal for monitoring the pressure of purging nitrogen, operation of the ball valve, and location of the optical cylinders to control the blast furnace interior parameters.

Full Text

FIELD OF THE INVENTION The present invention relates to a furnace scope equipment for viewing the blast furnace burden and top gas flow distribution. The furnace scope equipment is a visual aid to continuously monitor the Blast Furnace top gas flows and charged material behaviour in real time. This system provides visual observation of the movement of the blast furnace charge as well as the top gas flow. This enables the operators to identify uneven or irregular distribution, and to determine abnormalities inside the furnace. The operators get confidence and sense of security, as they know in real time the status of the furnace by physically observing the operating conditions. Observations of the rotating chute, and the descent trajectory, is very useful as the operators can take necessary action to modify the charging schedule, for a stabilized furnace operation. Improvement of thermal efficiency can be achieved by observing the intensity of the gas flows at the center and at the periphery. These observations also facilitate balancing the intensity of the peripheral gas flows, to prevent long term damage to the refractories at the furnace wall. There is no system to view the blast furnace burden and top gas flow distribution. Data from the over burden probes, under charge probes and thermograph or profile meter are not adequate to take appropriate remedial action for optimal operation and maintain a normal operation of the blast furnace. The main object of the present invention therefore, is to provide a furnace scope equipment for monitoring from a remote station the status of the blast furnace by physically observing the operating conditions. This object is achieved by using a small opening viewing optics. The system is based on the pinhole imaging principle. The image of the inerior of the Blast Furnace is seen through a small opening. The camera along with special optics and window views the furnace through this small opening. The Pyrex window acts as the shield from the poisonous blast furnace gas and the high temperature dust environment of furnace. This special optical configuration helps in keeping a very small opening in the furnace, at the same time getting a wider field of view of the furnace. The system uses a very high sensitive CCD camera for viewing visible as well as IR radiation from the furnace so that the material at low temperature could be also observed. The window acts as the shield from the blast furnace gas. This special optical configuration helps in keeping a very small opening in the furnace , at the same time getting a wider field of view of the furnace. The camera can be provided with zooming facility which allows the operator to zoom and see a portion of the total image.To view the entire furnace top, two furnace scopes need to be installed at diametrically opposite ends for providing full 360° view of the furnace interior. For maintenance purpose the whole furnace scope equipment can be isolated from the furnace interior by a pneumaticball valve, which can be operted manually, as well as remotely by the operator. The optical system is mounted on a cylinder or lens tube which can be slid down to the furnace for viewing, sliding of the lens tube is operated pneumatically. A programmable logic controller (PLC) is provided for automatically controlling the operation of the lens tube. The PLC also controls the operation of the ball valve. The PLC is provided with programmed interlocks. Manual override operation is also supported. The PLC constantly monitors the pressure of purging nitrogen and the operation of the pneumatic ball valve as well as the location of the optical cylinder and generates an alarm and closes the ball valve in case of an emergency, such as failure of the Nitrogen supply. The system has a dust and water proof case with industrial connectors for the electrical power supply and the output signals. The output video signal can be carried to a convenient place for viewing on a monitor. The signal can also be used for storing the important images. If the distance to the display unit is very high, then a video amplifier can be installed to boost up the signal. Thus the present invention provides a furnace scope equipment for viewing the blast furnace burden and top gas flow distribution, comprising: - a camera with necessary optics for viewing and imaging the blast furnace interior through a hole; a ball valve for mechanically isolating the equipment from the inner part of the blast furnace; a nitrogen purging system for a clear view of the furnace interior; and a programmable logic controller (PLC) for automatic operation of the ball valve and the optics , thereby providing a video signal for monitoring the blast furnace interior. The furnace scope equipment of the present invention will now be described with the help of the accompanying drawings, where Pig. 1 shows in schematic form the furnace scope equipment; Fig. 2 shows the ball valve and actuator of the furnace scope equipment; Fig. 3 shows the nitrogen purging system. As shown in Fig. 1 the furnace scope equipment 1 is installed on the shell plate 9 of the blast furnace. This can be installed at an angle to the vertical to capture the view of the stock line. A camera 3 along with the special optics 4 and a window 5 are used for viewing blast furnace gases through a small opening 2 provided in the equipment. This small opening in the furnace may be of about 6mm in diameter and helps in getting a wider field of view of the furnace. The camera used can be a very high sensitive CCD camera, for viewing both visible as well as IR radiations from the blast fee. The optical system 4 is mounted on a pneumatic cylinder or lens tube 8 so that the optics 4 can slide down to the furnace opening 2 for viewing the blast furnace gases. A programmable logic controller PLC is provided ( not shown) for controlling the sliding operation of the optics 4. The blast furnace shall 9 can be modified for fixing a nitrogen purging line 10 of a nitrogen purging system. The furnace scope nitrogen purging system 11 is provided with a hole 2 through which the optical system images the furnace onto the camera, A pyrex window 11 separates the optics 4 and the furnace opening 2. The aim of the purging system 13 is to keep this window clean so that the camera can view the furnace clearly. Nitrogen comes into this chamber through multiple jets of the purging system. The discharge velocity of the nitrogen flow is supersonic through the pinhole aperture. This ensures that no dust settles over the window. The furnace scope optical system is mechanically isolated from the inner part of the blast furnace by a ball valve 7. This acts as the safety valve as this calve can be closed in case of emergency. This ball valve is pneumatically operated. The operator can open or close the valve remotely from the control room or manually at the site. The Nitrogen Purging system is below the ball valve. The PLC also controls the opening and closing of the ball valve 7. Interlocks of the PLC ensure that the ball valve 7 can be opened only when the purging is on. The cylinder 8 carrying the optical system 4 can be slid down through the ball valve 7 only when both the nitrogen purging system is functioning and the ball valve 7 is open. The special pinhole viewing optics 4 is mounted on a sliding cylinder lens tube 8. The lens tube 8 is slid down into the nitrogen purging chamber 12 after the ball valve is opened. Similarly before closing the valve the lens tube is brought up. The sequence of extraction operation is done by the PLC automatically. The camera 3 is a highly sensitive CCD camera and is provided with a zoom lens 6. This allows the operator to zoom and see portions of the total image. The lens 4 sees through the hole 2 in the nitrogen chamber. The lens 4 and the zoom lens 6 together form an image of the blast furnace interior with a field of view of 80 degrees onto the CCD camera 3. When the lens tube 8 is slid down into the nitrogen chamber through the ball valve 7, the stopper present in the nitrogen chamber maintains the distance between the lens 4 and the hole 2. As the optical system has an 80-degree field of view, a conical opening of the same apex angle has to be formed in the furnace wall refractory. The image by the objective lens 4 and zoom lens 6 combination is formed on a monochrome CCD camera. The camera can function in extremely low light condition (0.031ux) and is sensitive to infra red light as well. By adjusting the amount of light to the CCD camera 3 an image with satisfactory clarity of all corners of the blast furnace interior can be achieved. In addition because of its sensitive in the infra red spectrum, views of the hot gas flows (300degC) in the furnace are also provided. The camera 3 sends the image signal through a co-axial cable to the video monitor in the control room. The operator remotely from the control room can control all the operation of ball valves 7 and camera 3. The controls like ball valve OPEN, CLOSE and lens tube IN/OUT controls are terminated at the desk of the operator for ease of operation. The operator can select from the manual or auto operation modes. The operator views the image on a video monitor. With the use of zoom, focus and aperture controls the operator can adjust for the better image. If the pressure of the nitrogen purging fails visual and audio alarms are provided to the operator for attention. The whole operation of ball valve 7 and cylinder 8 is controlled by the PLC in auto mode. The PLC system will not open the valve if the purging is not present and close the valve automatically if the purging pressure drops. The PLC checks for fully opened condition of ball valve before inserting the cylinder. Also, while closing the ball valve, a particular extraction sequence is programmed, which involves sliding up the cylinder and closing the valve after the cylinder has retracted fully. System Specifications: CAMERA (CCIR Camera) Sensitivity 0.031ux Interlace 1/3 inch Black & White Video Output IV p-p /75 ohm composite S/N ratio -50dB Zoom Lens Focal Length 5.8-121.8mm Max Aperture Ratio 1:1.6 Max Image Format 4.8 x 3.6 x 6mm Iris F1.6-560 Focus 1.5m-infinite Supply voltage DC 8.5-16V Current 40mA or less Lenses Diameter 75mm Focal length 40mm combined Opening to the furnace-Pinhole 6mm Nitrogen Pressure 6 bar Supply Voltage 230V,50Hz Ball Valve Material Stainless Steel Diameter 6" Cylinder Material Stainless Steel Length 26" We Claim: 1. A system for real-time monitoring from a remote station the blast furnace burden and top gas flow distribution, comprising: a camera (3) with an optical system consisting of lenses and optical cylinders for viewing and imaging the blast furnace interior through a hole (2) of about 6 mm in dia; a ball valve (7) for mechanically isolating the system from the inner part of the blast furnace and prevent venting of poisonous blast furnace gas on failure of the optical system through a pyrex window (11); a nitrogen purging system (13) for a clear view of the furnace interior by pressurization of a chamber (12) maintained at a pressure higher than the furnace top pressure to prevent ingress of dusty gases from the furnace top; characterized in that the ball valve (7) and the optic at system (4) are enabled by a programmable logic controller (PLC) to automatically provide a controlled video signal for monitoring the pressure of purging nitrogen, operation of the ball valve, and location of the optical cylinders to control the blast furnace interior parameters. 2. The system as claimed in claim 1 wherein said camera is a highly sensitive CCD camera for viewing visible as well as infra red radiation from the blast furnace. 3. The system as claimed in claim 2 wherein said CCD camera (3) is provided with a zoom lens (6) allowing the operator to zoom and see portions of the total image. 4. The system as claimed in claim 1 , wherein said ball valve (7) is pneumatically operated and controlled by said PLC. 5. The system as claimed in claim 4, wherein said optics (4) are mounted on a lens tube (8); operation of said lens tube (8) and of said ball valve (7) being controlled by said PLC. 6. The system as claimed in preceding claims wherein a monitor is provided at a remote location for viewing the images using the output video signals. 7. A system for real-time monitoring from a remote station the blast furnace burden and top gas flow distribution as substantially described and illustrated herein with reference to the accompanying drawings. The invention relates to a system for real-time monitoring from a remote station the blast furnace burden and top gas flow distribution, comprising a camera (3) with an optical system consisting of lenses and optical cylinders for viewing and imaging the blast furnace interior through a hole (2) of about 6 mm in dia; a ball valve (7) for mechanically isolating the system from the inner part of the blast furnace and prevent venting of poisonous blast furnace gas on failure of the optical system through a pyrex window (11); a nitrogen purging system (13) for a clear view of the furnace interior by pressurization of a chamber (12) maintained at a pressure higher than the furnace top pressure to prevent ingress of dusty gases from the furnace top. The ball valve (7) and the optic at system (4) are enabled by a programmable logic controller (PLC) to automatically provide a controlled video signal for monitoring the pressure of purging nitrogen, operation of the ball valve, and location of the optical cylinders to control the blast furnace interior parameters.

Documents:

567-KOL-2003-(07-10-2011)-ABSTRACT.pdf

567-KOL-2003-(07-10-2011)-AMANDED CLAIMS.pdf

567-KOL-2003-(07-10-2011)-CORRESPONDENCE.pdf

567-kol-2003-abstract 1.1.pdf

567-kol-2003-abstract.pdf

567-KOL-2003-ASSIGNMENT.pdf

567-kol-2003-claims 1.1.pdf

567-kol-2003-claims.pdf

567-KOL-2003-CORRESPONDENCE 1.2.pdf

567-KOL-2003-CORRESPONDENCE-1.1.pdf

567-kol-2003-correspondence.pdf

567-kol-2003-description (complete) 1.1.pdf

567-kol-2003-description (complete).pdf

567-kol-2003-drawings 1.1.pdf

567-kol-2003-drawings.pdf

567-kol-2003-examination report reply recieved.pdf

567-KOL-2003-EXAMINATION REPORT.pdf

567-kol-2003-form 1 1.1.pdf

567-kol-2003-form 1.pdf

567-KOL-2003-FORM 13 1.1.pdf

567-kol-2003-form 13.pdf

567-KOL-2003-FORM 18 1.1.pdf

567-kol-2003-form 18.pdf

567-kol-2003-form 2 1.1.pdf

567-kol-2003-form 2.pdf

567-KOL-2003-FORM 3 1.1.pdf

567-kol-2003-form 3.pdf

567-KOL-2003-GPA 1.1.pdf

567-KOL-2003-GRANTED-ABSTRACT.pdf

567-KOL-2003-GRANTED-CLAIMS.pdf

567-KOL-2003-GRANTED-DESCRIPTION (COMPLETE).pdf

567-KOL-2003-GRANTED-DRAWINGS.pdf

567-KOL-2003-GRANTED-FORM 1.pdf

567-KOL-2003-GRANTED-FORM 2.pdf

567-KOL-2003-GRANTED-SPECIFICATION.pdf

567-kol-2003-others 1.1.pdf

567-KOL-2003-OTHERS 1.2.pdf

567-kol-2003-pa 1.1.pdf

567-kol-2003-prtition under rule 137.pdf

567-KOL-2003-REPLY TO EXAMINATION REPORT 1.1.pdf

567-kol-2003-specification.pdf