Title of Invention

INSITU TURNING MACHINE FOR ROLLS IN COKE CRUSHER SYSTEM

Abstract

TITLE: MACHINE FOR ROLLS IN COKE CRUSHER SYSTEM. THE PRESENT INVENTION RELATES TO INSITU TURNING MACHIEN FOR ROLLS IN COKE CRUSHER SYSTEM. THE IN SITU TURNING MACHINE COMPRISES PEDESTAL FORMED OF MATERIAL WITH HIGH ELASTIC LIMIT AND MECHANICAL PROPERTIES BEARING THE TURNING MACHINE; STATIONARY CYLINDRICAL SHAFT; MEANS LOCATED ALONG THE LENGTH OF THE SAID SHAFT AND ADAPTED TO GUIDE RECIPROCATION MOVEMENT OF A CARRIAGE; MEANS ADAPTED TO ACHIEVE STEPLESS VARIOABLE SPEED FEED; PLURALITY OF SLIDER MEANS AND MEANS FOR PROVIDING ROTATION TO THE ROLLS AND LEAD SCREW.

Full Text

Field of invention The present invention relates to in situ turning machine for rolls in coke crusher system. More particularly it relates to the in situ turning machine comprising plurality of means including means for providing stepless variable speed feed such that the turning machine is adapted to maintain the evenness of the surfaces of rolls, improve the crushing index of coke involving much lesser time and to prevent loss of manpower thus improving the availability of operation and thereby tonnage crushed. Background of invention In the raw material handling plant lumped size of cokes are crushed in the conventional twin roll crushers. The crusher consists of steel welded frame for mounting fixed and floating rolls, two hydraulic cylinders for roll setting, cover and an integrated out feed chute for further guiding of the material. One stationary roll and one floating roll are located on the crusher frame with spherical bearings in bearing housings. The hydraulic adjustment of the floating roll is done through two horizontally arranged cylinders and the guide slide makes the movement between the frame and bearing housings of floating rolls possible. The two movable 45 KW drive units consisting of the shifting frame with eye type bearing, driving seesaw, driving frame, three phase AC motor and pulley are bedded in the building construction. Maintaining rolls exactly cylindrical in shape and mark free is precondition for ensuring uniform roll gap over the entire roll width on which ultimately quality of the material prepared at roll crusher depends. The shells of the rolls wear out during crushing with the wear being non-uniform along the width of the rolls i.e. more in the center and less at the periphery. For machining worn out shells of the rolls, the practice at raw material handling plant is sending the rolls to central machine shop for turning them on lathe. The shape of the slide ways used for guiding carriage in the conventional lathe machine is flat. No cylindrical slide ways or guides are found in the conventional lathe or turning machines. There is no arrangement for step less variable speed drive, in lathe, which would ensure high precision in the movement of the tool. Also beds of the conventional lathe machines are not made of steel plates. The pedestal of the conventional lathe or turning machine being made of cast iron is heavy and has inferior elastic limit. Drawbacks of known art The main disadvantage of the present practice is that the rolls wear out faster than they can be replaced producing inferior quality of crushed coke. Another disadvantage of the present practice is that for machining worn out shells of the rolls are being sent to the central machine shop for turning them on lathe which is both time consuming and also involves a lot of manpower and logistic support. One further disadvantage of the present practice is that during dismantling and removal or re-fixing of rolls the equipment may be damaged. Thus there is a need to provide for a highly precise in situ turning machine for twin- roll of coke crusher which would improve the crushing index of coke as well as prevent frequent dismantling and removal for machining of worn out shells of the rolls thus making the crushing operation both cost-effective and less time consuming. Object of invention The basic object of the present invention is to provide a high precision in situ turning machine for twin-roll of coke crusher for improving the crushing index of coke to a product size of 90% less than 3 mm. Another object of the present invention is to provide for an in situ turning machine, adapted for decreasing downtime of the crusher due to roll turning/roll replacement. One further object of the present invention is to provide for an in situ turning machine adapted for improved availability of operation leading to increased tonnage of coke crushed. Another object of the present invention is to provide for an in situ turning machine adapted to prevent the damage of the equipment by reducing the chance of frequent dismantling and removal or re-fixing of the shells of the rolls. One more object of the present invention is to provide an in situ turning machine adapted to maintain the rolls in proper shape and mark free having roller material with hardness of about 350-400 Brinell Hardness Number (BHN). Yet further object of the present invention is to provide for an in situ turning machine adapted to provide a high precision turning operation with a tool feed as low as 0.1 mm per revolution. The other object of the present invention is to provide for an in situ turning machine adapted to provide minimum vibration of the machine during turning operation. Summary of invention Thus according to the main aspect of the present invention there is provided an improved in situ turning machine for rolls in coke crusher system adapted to increase the crushing index of the crushed material; the said in situ turning machine comprising: i) pedestal formed of material with high elastic limit and mechanical properties bearing the turning machine; ii) stationary cylindrical shaft; iii) means located along the length of the said shaft and adapted to guide reciprocation movement of a carriage; iv) means adapted to achieve stepless variable speed feed; v) plurality of slider means; vi) means for providing rotation to the rolls and lead screw. Detailed description of the invention The turning machine comprises of auxiliaries like roll drive and feed drive, turning mechanism and the torsion free pedestal fastened to the frame of the coke crusher system. The turning machine of the present invention is bolted on pedestal made of steel, which is welded of carbon steel plates. Since, the elastic limit and mechanical properties of carbon steel are much higher than those of ordinary cast iron the pedestal provided in the present invention is much lighter and able to withstand greater amount of force and torque without changing its original configuration. Sufficient large number of stiffening ribs and partitions are provided in the pedestal dividing it into number of compartments. This provides rigidity that is required to sustain the cutting forces arising due to the turning operation. The rigidity of the aforesaid parts ensures precision in turning operation achieved by the in situ turning machine of the present invention. During turning as achieved by the machine of present invention, the belt pulley mechanically coupled to the dedicated geared motor drives the roll. Cutting speed is maintained at 10 rpm. The center-to-center distance of roll pulley and motor pulley is such that the same belts are used during crushing and machining by simple change over. The means for providing rotation to the rolls of diameters 1000 and length 1000 mm comprises auxiliary drive adapted to rotate the roller at desired speeds according to need of turning operation. Another geared motor is provided which serves as feed drive. This geared motor in conjunction with variable-voltage-variable-frequency drive (VVVF) and lead screw-nut comprises means adapted to achieve stepless variable speed feed. This stepless variable speed feed drive is compact and allows easy and smooth speed changing without stopping the machine. The variable-voltage-variable- frequency (VVVF) drive provides tool feed as low as 0.1 mm/rev. Limit switches are provided on two ends of the bearing blocks to protect over travel of the carriage. The limit switches are interlocked with VVVF drive, which stops after the striker arm hits the limit switches. The turning machine comprises a number of precisely machined parts. The stationary cylindrical shaft of diameter 190 mm. is provided in the turning machine. The shaft is supported by bearing blocks and serves as guide for the carriage holding the cutting tool. The means located along the length of the said shaft and adapted to guide reciprocation movement of the carriage comprises prismatic key in the key groove along the length of the shaft. The key on bearing housing prevents the shaft from rotation. The lead screw is nested in another groove and supported by bearings fastened to the flat ends of the guiding shaft. The geared motor with power rating of 2 hp (horsepower) in electrical combination with variable-voltage-variable- frequency (VVVF) drives the lead screw. The hand wheel drives the lead screw manually. The plurality of sliders comprise cross feed slide. This in conjunction with the hand operated crank is adapted to move the cross rest along with the tool holder. Cutting feed is adjusted manually by the hand operated crank with lead screw nut arrangement. The cross feed slide comprises lower slide and the upper slide, both machined as dove tail. The upper slide with tool holder is moved along the lower slide with the help of the crank handle. The nut provided in the lead screw nut arrangement is fastened to upper sliding carriage allows adjustable feed for the cutting tool. Wedge is adapted for providing clearance between the slides. Cutting tool is clamped to the carriage by pressure plate. Brief Description of Accompanying Figures Figure 1 illustrates in situ roll turning machine installed in coke crusher system. Figure 2 illustrates elevation of the turning machine. Figure 3 illustrates end view (A) of the turning machine as marked in figure 1. Figure 4 illustrates sectional view B-B of the turning machine as marked in figure 1. Figure 5 illustrates sectional view A-A of the turning mechanism. In figure 1 two existing movable 45 kilowatt drive units (17) consisting of the shifting frame with eye type bearing, driving seesaw, driving frame, three phase AC motor and pulley are bedded in the building construction. Dedicated 1.5 kilowatt geared motor (6) with variable-voltage-variable-frequency drive is shown in figure 1. 11 kilowatt geared motor (29) is coupled with the belt pulley (2) (figure 4) drives the roll during turning operation. In Fig. 1 it is found that gear pair (7) is mounted on the end shaft of the geared motor (6) and end of lead screw (16) (Figure 5). Figure 2 illustrates the elevation of the turning machine. In figure 2 the front view of the pulley (2) has been illustrated. The pulley (2) is connected to the rolls via V belt (3) and pulley (2) (shown in figure 4). It is also found that in figure 2 the turning mechanism (4) (illustrated in figure 5) is mounted on the pedestal (5), which is fastened to the crusher"s frame (18). Crusher cover (10) encapsulates the rolls of the crusher. Figure 5 illustrates turning mechanism arrangement. In figure 5 lead screw (16) is supported by pair or bearings (8) and driven by 2HP or 1.5 x w geared motor (6) (Fig.1). The gear shifting mechanism (9) (illustrated in Fig.3), is used for engaging and disengaging lead screw (16) with geared motor (6) during idle movement of carriage. In figure 5 carriage assembly (19) consists of lower sliding carriage (1), upper sliding carriage (13), lead screw (27), nut (14), wedge (15) and support (25). In figure 5 turning mechanism is provided with shaft (11) supported on a pair of bearings (8) and restricted from rotation by key (12). The shaft has two longitudinal grooves - one for key (21), which guides carriage (19) along the shaft (11) during machining and other for nesting lead screw (16), which is by mating with nut (22) makes a lead screw-nut arrangement transmitting power from geared motor (6) (fig. 1) and gear pair (7) (fig. 1) to carriage (19) and ultimately to cutting tool (23) (shown in figure 2). Lead screw (16) is supported by pair of bearings (24), which are fastened to machined flat surfaces at both ends of shaft (11). Lead screw (16) and nut (22) have trapezoidal thread. In figure 5 carriage assembly (19) consists of a cast iron support (25) which when assembled with other parts makes mechanisms allowing movement of carriage (19) parallel to roll axis and movement of cutting tool in direction radial to roll. Cutting feed is adjusted manually by crank (26) through lead screw nut arrangement (lead screw 27, nut 14). Nut (22) which meets with lead screw (16) is fastened to machined surface of support (25) an one side and to lower sliding carriage (1) on its other side. Upper sliding carriage (13) and lower sliding carriage (1) are machined as dove tail on their mating surfaces. Upper sliding carriage (13) meets with lower sliding carriage (1) and can thus slide on it when crank (26) is turned. Nut (14) is fastened to upper sliding carriage to allow adjust feed for cutting tool (23) required for turning operation. Clearance between dove tail slides is adjusted by wedge (15). There is provision for manual movement of carriage by hand wheel (30). Cutting tool (23) is clamped to carriage with pressure plate (28) and tightened with screws. We claim 1) An improved in situ turning machine for rolls in coke crusher system adapted to increase the crushing index of the crushed material; the said in situ turning machine comprising: i) pedestal formed of material with high elastic limit and mechanical properties for bearing the turning machine; ii) stationary cylindrical shaft; iii) means located along the length of the said shaft and adapted to guide reciprocation movement of a carriage; iv) means adapted to achieve stepless variable speed feed; v) plurality of slider means; vi) means for providing rotation to the rolls and lead screw. 2) A turning machine as claimed in claim 1 wherein means adapted to achieve stepless variable speed feed comprises variable-voltage-variable-frequency drive (VVVF) connected electrically to a geared motor. 3) A turning machine as claimed in claims 1 and 2 adapted for smooth speed changing ensuring tool feed as low as 0.1 mm/revolution by means of said variable-voltage-variable-frequency drive (VWF). 4) A turning machine as claimed in claims 1 to 3 wherein said variable-voltage- variable-frequency drive is provided with a limit switch adapted to restrict the over travel of the carriage. 5) A turning machine as claimed in claims 1 to 4 wherein said pedestal is provided with a large number of stiffening ribs and partitions dividing the pedestal into a number of compartments making the total system rigid. 6) A turning machine as claimed in claims 1 to 5 wherein the said pedestal is made up of steel having high elasticity and mechanical strength. 7) A turning machine as claimed in claims 1 to 6 wherein the stationary cylindrical shaft is supported by bearing blocks and is adapted for guiding a carriage with the cutting tool in a limited space constraint without obstructing the working of the crusher. 8) A turning machine as claimed in claims 1 to 7 wherein means located along the length of the said shaft and adapted to guide reciprocation movement of the carriage comprises prismatic key in the key groove along the length of the shaft. 9) A turning machine as claimed in claims 1 to 8 wherein the plurality of slides comprises cross feed slide and are fastened on the carriage. 10) A turning machine as claimed in claim 9 wherein the cross feed slide comprises lower slide and upper slide both machined as dove tail. 11) A turning machine as claimed in claim 10 wherein the lower slide is mechanically coupled with hand-operated crank. 12) A turning machine as claimed in claim 10 wherein the upper slide is provided with tool holder. 13) A turning machine as claimed in claims 11 and 12 wherein the hand operated crank is adapted to move the cross feed slide with the tool holder. 14) A turning machine as claimed in any preceding claim wherein means for providing rotation to the rolls comprises an auxiliary drive adapted to rotate the rolls at desired speeds according to need of turning operation. 15) A turning machine as claimed in any preceding claim adapted to machine rolls made up of materials having Brinell Hardness Number (BHN) ranging between 350 and 400 BHN. 16) An improved in situ turning machine for rolls in coke crusher system adapted to increase the crushing index of the crushed material substantially as herein described with reference to accompanying drawings. The present invention relates to in situ turning machine for rolls in coke crusher system. The in situ turning machine comprises pedestal (5) formed of material with high elastic limit and mechanical properties bearing the turning machine; stationary cylindrical shaft (11); means located along the length of the said shaft (11) and adapted to guide reciprocation movement of a carriage (19); means adapted to achieve stepless variable speed feed; plurality of slider means (1 and 13) and means for providing rotation to the rolls and lead screw.

Documents:

623-kol-2004-granted-abstract.pdf

623-kol-2004-granted-claims.pdf

623-kol-2004-granted-correspondence.pdf

623-kol-2004-granted-description (complete).pdf

623-kol-2004-granted-drawings.pdf

623-kol-2004-granted-form 1.pdf

623-kol-2004-granted-form 18.pdf

623-kol-2004-granted-form 2.pdf

623-kol-2004-granted-form 3.pdf

623-kol-2004-granted-letter patent.pdf

623-kol-2004-granted-pa.pdf

623-kol-2004-granted-reply to examination report.pdf

623-kol-2004-granted-specification.pdf