Title of Invention | LADLE TILTING STAND FOR LADLE WITH BALE ARMS. |
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Abstract | Accordingly, there is provided an electro-mechanically operated Tilting device for a ladle with bale arms. The ladle tilting device takes care of all the ladle manipulatious required during the ladle preparation and release the E 0 T crane for other shop operation. The device is so configured that the ladle can be caused to rotate from 0° - 360° in forward and reverse direction and eliminates the additional engagement of the E.O.T. The ladle tilting device comprising, a ring-type frame with a trunion pin shrunk fitted on either side. The frame is supported on spherical roller bearings on either side. An epicyclic gearing device is mounted on either side of the ring frame and a sun gear is mounted on a drive shaft with a sleeve-bearing in between. The drive shaft and the trunion pin for drive mechanism are fitted in the blocks. The ladle sits on a bale arm support frames. Two such frames are hinged to the tilting frame. The entire assembly is driven through a four stage heavy-duty gear box and driven through a squiral cage induction motor through a VWF drive. The VWF drive system has been envisaged in order to have precise speed control of the ladle tilter rotation. Two numbers shunt- wound electromagnetic brakes have been provided to stop the ladle in position during operation. The various positions of the ladle are tracked by proximity of sensors . |
Full Text | -2- FIELP OF THE INVENTION: The invention generally relates to a ladle mounted with bale arms adaptable to continous casting machine such as billet/slab casters for steel plants. More particularly the invention relates to an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle for cleaning and minor repair work on the ladle for its uses for molten material there from. BACKGROUND OF THE INVENTION In a typical Slab or Billet Casting shop of a steel plant, - after pouring of the liquid metal in slab or Billet mould, a small quantity of steel and slag is left out at the bottom of the teeming ladles. This gets solidified and blocks the teeming nozzle. The operations as described here in below are generally performed before the teeming ladle is returned to the original location to receive the next heat:- - cleaning the blocked nozzle; - replacing the nozzle plate of slide gate and the disposing of porus plugs at certain interval; - performing refractory repair work around the teeming nozzle wall; -3- dislodging and dumping out skull and the solidified slag and steel in ladle bottom; and dislodging the slag hot metal deposition at the lip of the ladle. For carrying out the above operations, the ladle is required to be manipulated and held in various positions, for example, the ladle requires to be held with its axis at horizontal position to perform a specific operation, and the ladle has to be turned up-side down for dumping. In a conventional steel melting shop,such operations are normally carried out manipulating the ladle by an E.O.T. crane. Manipulation of the ladle by E.O.T. crane is cumbersome, time consuming and unsafe. Further, the availability of the E.O.T. crane for ladle manipulation becomes a bottle-neck in the other operations of the steel melting shop. A prior Art discloses an Electro Hydraulic Ladle tilter for the ladles without bale arms. During commissioning of these tilters, a number of operational problems were faced, particularly with the locking mechanism. The problems generally arose due to mal functioning of limit switches, indicator lamps and operator's mistake. Such Electro hydraulic tilters were designed with three pairs of hydraulic cylinders. The first pair of the cylinders were -4- used for locking the ladle with the tilting frame. The second pair was for tilting the ladle along with the frame upto 90 degrees and the third pair was for further tilting the ladle to 180 degree. Two service cars are generally provided, one on either side of the tilting stands for the operators to do necessary repair work. This mechanism is suitable for the ladle without bale arms and rotation less than 180 degrees. Similar mechanism cannot be used for the ladle with bale arms and 360 degree rotation. To overcome the disadvantages of prior art and considering safety and easy access for manipulation of the ladle tilting device, an improved electro mechanically operated ladle tilting device is developed adaptable to rotate a teeming ladle at 0°- 360° degree both in clockwise and anti-clockwise direction for cleaning therein after completion of a teeming operation and further for preparing the teeming ladle for next use. OBJECTS OF THE INVENTION It is an object of the invention to propose an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle with bale arms. -5- It is an object of the invention to propose an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle for cleaning molten metal therefrom for reuse which eliminates disadvantages of the prior art. Another object of the present invention is to propose an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle for cleaning molten metal therefrom for reuse which ensures faster operation including easy handling of the ladle. A further object of the present invention is to propose an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle for cleaning molten metal therefrom for reuse thereby eliminating longer engagement of the E.O.T. crane. An yet further object of the present invention is to propose an electro-mechanically operated ladle tilting device adaptable to rotate a teeming ladle for cleaning molten metal therefrom for reuse which ensures safer, environmental friendly and operator friendly operations of the ladle in a melting shop. SUMMARY OF THE INVENTION Accordingly, there is provided an electro-mechanically operated Tilting device for a ladle with bale arms. The ladle tilting device takes care of all the ladle manipulatious required during the ladle -6- preparation and release the E 0 T crane for other shop operation. The device is so configured that the ladle can be caused to rotate from 0° - 360° in forward and reverse direction and eliminates the additional engagement of the E.O.T. The ladle tilting device comprising, a ring-type frame with a trunion pin shrunk fitted on either side. The frame is supported on spherical roller bearings on either side. An epicyclic gearing device is mounted on either side of the ring frame and a sun gear is mounted on a drive shaft with a sleeve-bearing in between. The drive shaft and the trunion pin for drive mechanism are fitted in the blocks. The ladle sits on a bale arm support frames. Two such frames are hinged to the tilting frame. The entire assembly is driven through a four stage heavy-duty gear box and driven through a squiral cage induction motor through a VWF drive. The VWF drive system has been envisaged in order to have precise speed control of the ladle tilter rotation. Two numbers shunt- wound electromagnetic brakes have been provided to stop the ladle in position during operation. The various positions of the ladle are tracked by proximity of sensors . The improved tilting device has suitable safety arrangement. The folowing interlocks and safety devices have been provided. -7- • Electrical interlocks have been provided between tilter and the service cars in such a way that the service cars can come to their working position when the ladle is tilted to 90°. The ladle can be further tilted only when the service cars are taken away to their working position when the ladle is tilted to 90°. The ladle can be further tilted only when the service cars are taken away to their home position. • Two brakes have been provided in the system with 100% back up. In the case of failure of one brake, the other caters to the operation. • Proximity sensors are provided to ensure the positioning of the ladle at various inclinations vis a vis, 90° & 180°. The Operator can tilt the frame as desired by him through joystick controller. • The drive motor is of heavy-duty type, suitable for continuous operation. Thermistors have been provided in the motor to protect the motor from over heating. • The drive panel is provided with open loop vector control (VWF) system. The designed speed is 10% at 1st step, 50% at 2nd step and 100% at final step. The advantages of the invented tilting device are (1) Time for ladle preparation work is reduced, (2) A substantial reduction in tap to tap cycle time in steel making operation, -8- (3) Substantial increase of productivity, (4) Implementing a safer, faster and economic operation through the ladle, (5) Providing an environmental friendly and operator friendly tilting device. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING Figure -1- Shows a schematic diagram of a ladle tilting device according to the present invention. Figure-2- Shows a plan view of the ladle tilting device of Fig-1 Figure -3- Shows a schematic diagram of a ring-frame of the tilting device according to the invention. Figure-4- Shows a schematic diagram of tilter rotational Position at various angles of Fig-1. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Figure-1 shows a Ring-frame (1) having trunion pin shrunk fitted on either side. The ring frame (1) is supported on spherical roller bearings (4). Two bale arm support frame (3) are hinged to the -9- tilting frame (1), one epicyclic gear train (5) on both sides of tilting ring-frame (1) are mounted and a sun gear is mounted on a drive shift with a sleeve bearing in between. A ladle (6) is placed with a bale Arm (2) resting on the bale arm support frame (3). The ladle is tilted by four brackets (10a 10b 10c lOd) which are integral part of the ring frame. The entire assembly (1,6,2) is tilted by means of tilting drive consisting of a four stage heavy duty gear box through a squiral cage induction motor via a VWF drive (7). The device is so configured that the ladle can rotate from 0°-360° in clockwise or anti clockwise direction as shown in fig 4. The following sequence of operations have been envisaged. • To start with, the tilter ring frame (1) is at its home position i.e. 0°, i.e., the tilter frame (1) is horizontal (Fig.4a). The indication is received in the PLC through the proximity sensor. • The ladle (6) is kept on the tilting frame (1) with the help of EOT Crane. At this point, both the Service Cars are in their respective home positions. • The tilting frame (1) along with the ladle (6) is rotated to 90° to make the ladle axis horizontal through elector-mechanical drive system. • The bale arm support frame (3) with the bale arm (2) will always be vertical at any point of time. The proximity sensor gives indication when the ladle is at 90°. -10- • Both the service cars are brought on either side of the ladle (6) for ladle preparing. Operations like lancing of the nozzle, changing.the porous plug, replacing the slide gate etc. are done by the operator while standing on the service cars. • After the ladle (6) preparation work is over, the service cars are taken back to their home positions. • The tilting frame (1) along with ladle (6) is further tilted to 180° to dump the muck or loose materials inside the pit under the ladle (6). The rotation is achieved through the electro-mechanical drive (7). The proximity sensor gives indication when the ladle (6) is at 180°. Ladle tilter (1) along with the ladle (6) is further tilted to bring it back to its normal/home position (0°). The ladle (6) is now ready to be taken back for use, by the EOT crane. This completes one cycle of operation. -11- KEY TO FIGURES Reference Characters FEATURE FIGURE (1) Ring Frame 1,2 (2) Bale Arm 1 (3) Bale Arm Support 1 (4) Support bearing 1 (5) Epicydic Gear 1 (6) Ladle i-i (7) DRIVING MEANS 1,2 (8) ELLIPTICAL EMBLEM 1 (9) Coupling 1 (10) Ladle Support 2 (11) Cradle 3 (12) Trunion pin 3 • Ladle filter (1) along with the ladle (6) is further tilted to bring it back to its normal/home position (0°). * The ladle (6) is now ready to be taken back for use, by the EOT crane. This completes one cycle of operation. -12-WE CLAIM: 1. An electro-mechanically operated tilting device adaptable to„ rotate a teeming ladle for cleaning residual slag therefrom and preparing the ladle for re-use, comprising:- - a ring frame (1) having trunion pin shrunk on both end, supported on spherical roller bearings, - two bale arm support frame (3) hingedly attached with the ring frame (1), - teeming ladle (6) mounted with a bale arm (2) disposed on the atleast two bale arm support frame (3), - a bale arm support (3) for regulating the positioning of the ladle (6) at a central location in respect of atleast four supporting brackets (10a,10b,10c,10d) provided with the ring frame (1); -13- - atleast two numbers shunt-wound electromagnetic brakes for controlling the device, one of the atleast two brakes being provided to caterjbr the failure of the other; - an electro mechanically operated driving means (7) causing the ring -frame (1) to rotate at a regulated speed via an 4 stage gearbox thereby rotating the ladle (6) from 0° to 360° including imparting forward and/or reverse movement corresponding to the signals acquired via proximity sensors; and a logic-controller receiving the signals from the proximity sensor and transmitting command signals enabling an operator to operate the device by means of a joy-stick controller. 2.The device as claimed in claim 1, comprising electrical interlocks provided between the tilter and service cars in such a way that the service cars can move to their working position when the ladle is tilted to 90°, the ladle being further tiltable only when the service cars are taken away to their home position. 3. The device as claimed in claim 1, wherein the driving means (7) is driven by a squirrel cage induction motor. -14- 4. The device as claimed in claim 1 or 3, wherein the induction motor is provided with thermistors to protect the motor from over-heating. 5. The device as claimed in any of the preceding claims wherein the motor is driven via VWF drive system, and wherein a drive panel is provided to the VWFtlrive system. 6. An electro-mechanically operated tilting device adaptable to rotate a teeming ladle for cleaning residual slag therefrom and preparing for re-use, as substantially described and illustrated herein with reference to the accompanying drawing. |
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00993-kol-2006-correspondence others-1.1.pdf
00993-kol-2006-correspondence others.pdf
00993-kol-2006-description(complete).pdf
993-KOL-2006-AMANDED CLAIMS.pdf
993-KOL-2006-AMANDED PAGES OF SPECIFICATION.pdf
993-KOL-2006-CANCELLED PAGES.pdf
993-KOL-2006-DESCRIPTION (COMPLETE) 1.1.pdf
993-KOL-2006-DESCRIPTION (COMPLETE) 1.2.pdf
993-KOL-2006-EXAMINATION REPORT REPLY RECIEVED 1.1.pdf
993-KOL-2006-PETITION UNDER RULE 137.pdf
993-KOL-2006-REPLY TO EXAMINATION REPORT.pdf
Patent Number | 244789 | ||||||||
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Indian Patent Application Number | 993/KOL/2006 | ||||||||
PG Journal Number | 52/2010 | ||||||||
Publication Date | 24-Dec-2010 | ||||||||
Grant Date | 20-Dec-2010 | ||||||||
Date of Filing | 27-Sep-2006 | ||||||||
Name of Patentee | TATA STEEL LIMITED, | ||||||||
Applicant Address | JAMSHEDPUR 831001 | ||||||||
Inventors:
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PCT International Classification Number | A47J47/16 | ||||||||
PCT International Application Number | N/A | ||||||||
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PCT Conventions:
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