US3614978A - Computerized continuous casting system control responsive to strand position - Google Patents

Computerized continuous casting system control responsive to strand position Download PDF

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Publication number
US3614978A
US3614978A US741567A US3614978DA US3614978A US 3614978 A US3614978 A US 3614978A US 741567 A US741567 A US 741567A US 3614978D A US3614978D A US 3614978DA US 3614978 A US3614978 A US 3614978A
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computer
strand
line
cutting
casting
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Michael A Kosco
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/16—Controlling or regulating processes or operations

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  • the computer keeps tracks of the position of the moving cast strand of each of a plurality of casting lines from the time it emerges from the mold and, in response to position of the strand, controls various elements at the proper time along the casting line, such as coolant flow, pinch rolls, straightening roller, dummy bar head separation, table or conveyor rolls, and slab cutting machine.
  • the computer keeps track of the slab cutting machine and the position of its cutting elements, and controls the cutting operation in syuchronism with movement of the strand.
  • the computer at appropriate times begins to monitor and compare against stored references such conditions as coolant and strand temperatures, coolant flow rates, pinch roll drive current, and pinch roll pressure.
  • the computer also performs a pre-pour diagnostic check-up on various elements of the casting line to determine if a malfunction exists. Additionally as the casting progresses, the computer gathers and outputs information as a function of position and time with respect to each strand.
  • the computer controls a plurality of casting lines in parallel by suitable multiplexing.
  • This invention relates to the operation of systems wherein metal is cast in a continuous billet by pouring molten metal into a fluid-cooled mold and continuously withdrawing the metal as it solidifies from an opening in the mold by means of withdrawal devices.
  • the billet commonly referred to as strand
  • strand As the billet (commonly referred to as strand) emerges from the mold, it is characterized by a solid exterior enclosing a molten interior, and as the strand progresses it passes through an auxiliary cooling area to further solidify the strand.
  • the billet is cut in suitable slab lengths by a cutting mechanism for example a torch cutting machine.
  • the strand is generally separated from the dummy bar.
  • the withdrawal mechanism usually includes pinch rolls that drive the dummy bar and later drive the strand after it reaches the pinch rolls.
  • human operators control various elements of the system and also check gauges and other sensors detecting various conditions such as fluid coolant temperatures and flow rates, strand skin temperatures, pinch roll pressure, etc.
  • the invention is directed to improved computer controlled methods of and apparatus for controlling a continuous casting system.
  • One of the objects is to provide such control in a simple but effective and accurate manner without resorting to complex formulation.
  • Another object of the invention is to enhance the capabilities of the system whereby a high throughput consistent with acceptable quality is achieved.
  • pulses generated as the cast strand advances are accumulated in a computer whereby the computer knowns the position of the advancing strand and in response to arrival of the strand at successive points along the line applies control functions to devices along the line in the order of succession of the devices.
  • Each device affects in some manner the cast product.
  • the devices may for example be water spray control, pinch roll control, slab cutter control, and others.
  • the traverse of the cutting members is controlled by the computer to be in timed relation with the moving strand so that the cut is finished at a predetermined point along the line.
  • FIGS. la and 1b taken together side-by-side with FIG. 1a to the left form a composite block diagram of a continuous casting system incorporating computer control in accordance with the invention
  • FIG. 2 is a block diagram illustrating details of the torch machine shown in FIG. 1b.
  • FIGS. 1a and 1b two similar continuous casting lines A and B are shown with elements thereof monitored and controlled by control apparatus including an operators control console 9 and a digital computer 10. Since the casting lines A and B are similar, only one, casting line is shown in detail, casting line B being shown only as a single box. It may be noted that casting line A extends across the FIGS. 1a and lb, taken together.
  • Molten material for example steel
  • a ladle 12 to tundishes TD1 and TD2 that in turn supply the molten steel at controlled rates to the molds of the respective casting lines A and B.
  • the mold at the head of casting line A is indicated at 14 and typically is provided with an open top to receive the molten steel from tundish TD1, and a bottom opening from which the cast product for example a strand 16 is withdrawn.
  • the strand 16 is shown diagrammatically as a thin line, it in fact may be of considerable cross-section, for example forty inches wide and seven inches thick.
  • the withdrawal drive is provided by pinch roll sets 18 and 20 and to some extent by a dummy bar winch 22, all in a manner as later described.
  • mold 14 may be lined with copper and provided with means for lubricating the mold and for oscillating the mold.
  • Lubrication of the mold liner is provided by a suitable lubrication control LC controlled from the operators console 9 via a control line 24, and the lubrication rate is sensed by a suitable sensor ML that transmits signals representing lube rate to the computer through a multi-conductor cable AN, a scanner 26 and an A/D (analog-to-digital) converter 27.
  • Cable AN is so labeled because its conductors carry analog signals.
  • Control line 24 passes through a multi-conductor cable that is labeled OCO because its conductors carry the various outputs from the operators control console 9.
  • Diagnostic status (for example operative or inoperative) of the control LC is communicated to the computer as a CCI (contact closure input) through a signal line 28 and a multiplexer 29.
  • Signal line 28 passes through a multiconductor cable that is labeled CCI because its conductors carry signals from contact closure inputs (CCIs).
  • Oscillation of the mold is controlled by a suitable oscillator drive regulator OR controlled from the operators console through a line 30, and the oscillations are sensed by a suitable oscillator sensor OS whose output is transmitted to the computer through cable AN, scanner 26 and the converter 27. Diagnostic status of the control OR is transmitted as a CCI to the computer through a line 32 and scanner 29.
  • the flow of molten metal from tundish TD1 to the mold 14 is regulated by a flow regulator FR in accordance with the withdrawal rate from the mold as evidenced by the level of the metal in the mold.
  • Suitable weight sensors TW1 and TW2 supply to the computer, output signals representing the weights of tundishes TD1 and TD2 respectively.
  • a suitable slag binder, sensor SB supplies to the computer (through scanner 26), signals indicating the slag binder speed in the mold 14.
  • ON and OFF pour control for the tundishes is provided by signals from the operators console 9 via lines 34 and 36.
  • cooling zone Z1 Adjacent to and surrounding at least a portion of the mold is a cooling zone Z1 followed in consecutive order, downstream along the casting line, by cooling zones Z2, Z3 and Z4. These zones are defined by suitable enclosures so that coolant, for example water, may be applied to the mold in zone Z1 in liquid form, and to the cast strand 16 as it passes through zones Z2, Z3 and Z4 in a spray form.
  • coolant for example water
  • Cooling zones Z1, Z2, Z3 and Z4 are provided with coolant inlets I1, I2, I3 and I4, respectively, each connected through its own fiow control FC to a source of coolant not shown.
  • Coolant inlet 11 also has coupled thereto a temperature sensor TS1 for supplying to the computer signals representing the temperature of the coolant at the inlet.
  • Each of the inlets has also coupled thereto a How meter FM for generating and transmitting to the computer (through scanner 26), signals indicating the rate of coolant flow to the respective inlets. More specifically, inlet I1 has coupled to it flow control FCl, flow meter FMl and temperature sensor TSl.
  • Inlet I2 has coupled thereto flow control FC2 and flow meter FM2.
  • inlet I3 the flow control and flow meter are at PCS and FM3 respectively, and for inlet I4 these instruments are at FC4 and FM4 respectively.
  • inlets I2, I3 and I4 is also connected to a spray head S extending into its associated zone for spraying coolant onto the strand 16 as it passes through that zone.
  • zone Z1 associated with the mold has a separate closed cooling system whereby inlet I1 and outlet 01 are coupled to a separate source of coolant, while the inlets of the other zones are connected to another source of coolant. Coupled to the coolant outlet 01 is a temperature sensor T52 for transmitting to the computer a signal representing the temperature of the outgoing coolant from zone Z1.
  • Each of the flow controls FCl, FCZ, FC3 and FC4 is operable to ON or OFF as desired in response to commands from the computer via lines 40, 42, 44 and 46, respectively, passing through a multi-conductor cable that is labeled CCO because its conductors carry contact closure outputs (CCOs).
  • These flow controls are also adjustable via lines 48, 50, 52 and 54 from the operators console 9 to change the rate of coolant flow. Diagnostic status 4 information of these flow controls is supplied to the computer 10 along lines 56, 58, 60 and 62 and scanner 29.
  • suitable temperature sensors TS3, T54 and T55 are placed in the zones along the course of the strand to generate and transmit to the computer signals representing these temperatures.
  • the mold 14 it is shown as a curved mold whereby the cast product is curved to the right as it is drawn downward. It will be noted that the defining means for the respective cooling zones also form an arcuate course along which the advancing strand 16 is guided.
  • zone Z4 Downstream of zone Z4 is the set of pinch rolls 18 which includes driving rolls 66 and 68 and a downwardly forced pressure roll 70, the strand 16 being pinched between the pressure roll 70 and the bottom drive rolls 66 and 68.
  • rolls 68 and 66 may be driven separately if desired.
  • Drive unit RDl is controllable to ON and OFF by computer command along an input line 72 to be run at a preset speed selected by the operator through signal line 74.
  • Pinch roll set 18 is opened or closed by a controller C1 in response to computer commands via line 76.
  • Roll pressure for the set 18 is controlled by a pressure control unit PR1, which on command from the computer along line 78 operates to compress or decompress the roll set, and selectively calls for high or low pressure on the rolls on command from the computer via line 80.
  • Pressure on the rolls 18 may be adjusted from the operators console 24 through a line 82. Diagnostic status of the roll pressure control system is transmitted to the computer via line 84 (passing through cable CCI) and scanner 29.
  • the roll set 18 may be locked in closed position on command of the computer through a line 86 applied to a pinch lock control PL. Pressure of the roll set 18 is monitored by the computer through a pressure sensor PS1 outputed through scanner 26.
  • Pinch roll set 20 includes a bottom drive roll 88 and an upper pressure roll 90.
  • Roll 88 is driven by a roll drive unit DR2 which is controlled to ON and OFF by computer command along signal line 92, and which operates roll 88 at a preset speed selected from the operators console 9 through line 94.
  • the drive current is monitored by the computer through a current sensor CS outputed through scanner 26.
  • Pinch roll set 20 is provided with a controller CO2 for opening and closing the pinch rolls on command from the computer through a line 96.
  • Roll set 20 is also provided with a pressure control unit PR2. High or low pressure is selected on computer command via line 98 and compress and decompress status of the rolls is selected by computer command through line 100. Diagnostic status of the pressure control unit PR2 is transmitted to the computer via line 102 and scanner 29.
  • the roll pressure of pinch roll set 20 may be adjusted from the operators console 24 through a line 104.
  • Pressure of the roll set 20 is monitored by the computer through a pressure sensor PS2.
  • a pulse generator PGl coupled to the drive roll 88 generates a pulse for each successive equal predetermined increment of angular travel of the drive roll, and thereby for each successive equal predetermined increment of travel of the cast strand being worked on with the aid of the roll set 20.
  • These pulses are transmitted along a line 106 to the computer as CPIs (computer process interrupts) passing through a cable that is labeled CPI because it carries process interrupts.
  • the frequency of these pulses is used by the computer to calculate the casting speed of the strand, and the accumulation of the pulses is used to calculate the location of the front end of the strand and the total length of the stand.
  • Diagnostic statuses of roll drive units RD1 and RD2 are transmitted to the computer through lines 103 and 105 and scanner 29.
  • Downstream of the pinch roll set 20 are a plurality of motor-driven conveyor rolls R spaced along the normal course of travel of the cast strand and cut slabs, which course is indicated by the dashed line 107 running along the tops of the conveyor rolls R.
  • the drive unit for only one of the rolls is shown at RD3.
  • Drive unit RD3 is operated ON or OFF by computer command along a line 108 at a preselected speed set by the operators console 9 via line 109. It will be understood that each of rolls R has a similar controlled drive unit coupled thereto.
  • a rocker arm 110 Downstream of the pinch rolls 20 is a rocker arm 110 for guiding a dummy bar 112, the latter comprising a dummy bar head 114 coupled to a dummy bar chain 116.
  • the dummy bar chain passes around a pulley 117, and its other end or a cable attached thereto is wound around the drum of the winch 22 which is controlled for wind-up or pay-out under command of the computer through a line 118 applied to a winch controller WC.
  • a drive unit LRl coupled to the rocker arm 110 operates to selectively lower or raise the rocker arm in response to computer command through a line 124.
  • the dummy bar head is detachably coupled to the dummy bar chain by an arrangement wherein a pin 120 fixed to the end of the dummy bar chain is disposed in the upwardly directed open jaws of a hookshaped end of the dummy bar head.
  • the fit is tight enough so that they do not normally fall apart, but will be forced apart in response to a downward push on the dummy bar head by a straightener roll 126.
  • Roll 126 Disposed between the pinch roll set 20 and rocker arm 110 is the roll 126 which has the dual function of uncoupling the dummy bar head from the dummy bar chain and straightening the cast strand 16 along the horizontal path 107 as it emerges from the pinch roll set 20.
  • Roll push-off mechanism 140 (FIG. 1b), operable under control of the computer through a line 142.
  • a push-off sensor POS for example, a limit switch is actuated if the dummy bar head is in fact successfully pushed off, thereby to transmit a signal to the computer through scanner 29.
  • a slab cutter in the form of a torch cutting machine 144 which is provided with an inside torch 146 and an outside torch 148, and which machine is shown in greater detail, although still in diagrammatic form, in FIG. 2. It will be noted that although the torches are shown one after the other along the casting line in FIG. 117, they are in fact laterally displaced from each other relative to the casting line as more clearly shown in FIG. 2. It should be noted that while in FIG. 1b the cast strand 16 has not yet reached the torch machine, the illustration in FIG. 2 shows the strand 16 under the torch machine.
  • the torch machine is shown as having a frame 150, including members 152, 154, 156, 158, 160 and 162, cantilevered over the casting line from a side carriage 164 that rolls on a rail 166.
  • the torch machine is prevented from falling across the course of the strand by means of a roller 168 attached to the torch 172 and 174.
  • a traverse mechanism 176 secured to frame member 162, is coupled through a mechanical linkage 178 to that torch.
  • Traverse mechanism 176 is controlled by the computer through a line 180. It should be understood that line 180 is symbolic of whatever number of lines connected to separate contact closure outputs of the computer are necessary to effect lateral movement of the torch 146 in either direction and at selected speeds (high or low).
  • a pulse generator PG2 secured to the frame 150 and driven by a wheel 184 in engagement with the mechanical linkage 178, generates a pulse for every unit of distance traversed by torch 146.
  • the pulses are transmitted as process interrupts (CPIs) to the computer along a line 186.
  • CPIs process interrupts
  • lateral movement in either direction is imparted to torch 148 through a link 188 by a traverse mechanism 190 attached to frame member 154, and controlled by the computer through a line 192 which line is symbolic of the necessary number of lines connected to separate contact closure outputs of the computer to effect computer control of lateral movement for torch 148 in either direction at a selected speed (high or low).
  • a pulse generator PG3 secured to frame 150 generates a pulse for every unit of torch distance traversed and transmits the pulses as process interrupts (CPIs) along a line 196 to the computer.
  • CPIs process interrupts
  • torches 146 and 148 under control of the computer is effected by vertical drive units 200 and 202 respectively.
  • Vertical drive unit 200 is controlled by the computer through a line 204
  • drive unit 202 is controlled by the computer through a line 206.
  • lines 204 and 206 is of course symbolic of the necessary number of lines to separate contact closure outputs of the computer to effect up and down control for the torches.
  • control unit 208 is controlled by the computer for oxygen through a line 212, and for iron powder through a line 213, while control unit 210 is controlled by the computer for oxygen through a line 214, and for iron powder through a line 215.
  • a limit switch LS2 transmits a signal along a line 220 and through scanner 29 to the computer when the torch 146 reaches the edge 222 of the strand 16 during lateral traverse of the torch.
  • a limit switch LS3 sends a signal to the computer along a line 224 through scanner 29 when torch 148 reaches the edge 226 of the strand 16 while the torch is executing a lateral traverse.
  • Switches LS2 and LS3 are secured to frame member 158.
  • the torch machine 144 is provided with a pair of tongs 228 for clamping it to the strand 16 whereby the torch machine is moved by and along with the strand.
  • the tongs 228 are operated ON (clamped) or OFF (released) by a clamp control 230 in response to command by the computer along a line 232.
  • Clamp control 230 is secured to frame member 158.
  • the torch machine 144 is moved downstream by the strand 16 when it is clamped to the strand.
  • a return drive mechanism 240 including an endless chain 242 coupled to the torch machine carriage 164 and passing at opposite ends thereof over pulleys. Only one of the pulleys, a drive pulley 244, is shown.
  • the drive pulley 244 is driven by a drive mechanism TMR controlled by the computer along a line 246.
  • a pulse is trans- 7 mitted to the computer for every unit distance traveled by the torch machine relative to the strand 16.
  • These pulses are generated by a pulse generator PG4 driven by a measuring roll 250 which, when in a lowered position, engages the top of the strand 16.
  • the measuring roll 250 is raised or lowered by a suitable vertical drive mechanism 252 in response to computer command along a line 254.
  • Drive mechanism 252 is secured to frame member 158.
  • Pulses from the generator PG4 are transmitted as process interrupts (CPIs) to the computer via a line 256.
  • Downstream overtravel by the torch machine is registered by a limit switch LS5 (FIG. lb) which transmits a signal (CCI) to the computer.
  • a diagnostic line 259 connected to traverse driver 190 of the torch machine is symbolic of a line connected to all control elements and drive units of the torch machine to communicate a diagnostic check (machine operable or inoperable) of the torch machine to the computer.
  • a crop chute 260 for receiving the crop separated from the strand is located between two of the rolls R.
  • Each is driven by a separate roll drive unit controlled ON or OFF and speedup by the computer, at speeds which may be preselected at the operators console 9. Since all the drive units are similar only one is shown at RD4 coupled to roll R02.
  • Drive unit RD4 is controlled ON or OFF by teh computer through a line 262. Speedup control by the computer is through a line 264, and speed selection at the operators console 9 is through a line 266.
  • a sensor LS6 for example a limit switch which sends an interrupt signal to the computer to read the weight of the slab at that point which weight is sensed by a weight sensor SBW that generates signals representing weight and transmits them to the computer through scanner 26 and converter 27.
  • the computer 10 (FIG. lb) conventionally includes an I/O unit (input-output unit) 270, a memory unit 272 an arithmetic unit 274, and a control unit 276.
  • the outputs of various sensors are analog in nature and before they are applied to the computer they are converted to digital form by the analog digital converter 27, to which the analog signals are sequentially applied by scanner 26 under control of the computer. More specifically, the output line of each of sensors TWl, TWZ, ML, 05, SB, T51, T82, T83, T54, T85, FMl, FM2, FMS, FM4, PS1, PS2 and SBW of each casting line A and B is connected as a separate input line to the scanner 26.
  • the scanner under command of the computer, periodically, for example every /2 second, and at a predetermined scan rate sequentially scans the lines from the various sensors.
  • the scan rate may for example be 14 points in 10 ms. (milliseconds).
  • the converted signals from the sensors are compared by the computer to reference values stored in the computer, and if they deviate beyond acceptable limits stored in the computer, the computer prints out and displays an alarm, so that the operator can make the necessary corrections at the operators control console 9.
  • the outputs of the diagnostic lines from various controllers are CCI (contact closure inputs) to the computer and provide a diagnostic check for malfunction, for example: is the controller OFF or ON? These outputs are multiplexed before being applied to the computer. More specifically, each of the diagnostic lines 28, 32, 56, 58, 60, '62, 84, 102, 103, 105 and 259 is applied as a separate unit to the scanner 29 which periodically for example every /2 second, scans these lines at a predetermined scan rate under command of the computer to sequentially connect these lines to the computer. The scan rate 8 may for example be 14 points in 10 ms. Also connected as separate inputs to scanner 29 are the output lines of the switches and controllers POS, LS2, LS3.
  • Certain contact closure outputs from the operators console 9 are also connected as separate inputs to the scanner 29 to be included in the scan routine.
  • the contact closure outputs of switches LS1, LS4, LS5, LS6 are applied directly as separate interrupts to the computer along CCI line 280.
  • the outputs of the pulse generators PGl, PG2, PG3 and PG4 are each applied as a separate interrupt to the computer via the CPI cable.
  • Other outputs from the operators control console are applied as necessary to the computer either as direct interrupts on a line 284 or multiplexed through a scanner 286 as necessary.
  • the computer has display and print out outputs 288 and 290 connected to suitable display elements and a printer located for example at the operators control console 9.
  • the computer is provided with a plurality of contact closure outputs (CCOs) connected to all the controllers and drive units (except LC and OR) so that the control functions of these various units commanded by the computer can be executed.
  • COs contact closure outputs
  • Each of these contact closure outputs is connected to a different one of control lines 40, 42, 44, 46, 72, 76, 78, 80, 86, 92, 96, 98, 100, 108, 118, 124, 128, 142, 143, 180, 192, 204, 206, 212, 213, 214, 215, 232, 246, 254, 262 and 264 (all passing through the cable CCO). It is to be understood that in any case where any of the above lines represents a plurality of lines, each line of the plurality is connected to a different CCO.
  • the control console includes the previously mentioned printer, display and reader.
  • the console 9 also includes adjustable controls for entering slab width, thickness and desired length into the computer. Also located at the operators console 9 are separate controls for adjusting each of the flow controls FCl, FC2, FC3 and FC4 whereby the operator can adjust the coolant flow rates at the different cooling zones.
  • The. console 9 further includes a separate control for adjusting each of the pressure controllers PR1, PR2 and PR3. Controls for adjusting the mold oscillator control OR and the mold lubricant rate control LC through lines 30 and 24 are also located in the operators console 9.
  • the control console is further provided with controls for adjusting the output stoppers of tundishes TDI and TD2 over lines 34 and 36.
  • Speed selection controls for all the roll drive units in the system are located in the operators console 9 to provide speed selection signals over lines 74, 94, 109 and 266. Additionally there is a control in the operators console for operating the pinch roll set 20 in a reverse direction during the MOVE-IN mode.
  • the control console is provided with mutually exclusive switches for selecting MOVE-IN, POUR, and MOVE-OUT modes, and for selecting either the outside torch or the inside torch or both torches of the torch machine. Each of these switches, in addition to providing control functions, also provides signals to the computer. Each mode switch when operated communicates with the computer as an interrupt, while each torch selector switch, when operated, transmits a signal to the computer through scanner 29.
  • the computer 14 is suitably programmed to execute the various monitoring and operating procedures described herein.
  • the initial mode of the line is MOVE-IN mode during which the dummy bar is drawn to the mold from the dummy bars home position so that the dummy bar head can be inserted into the bottom opening of the mold.
  • MOVE-IN mode selector switch in the operators control console 9.
  • Operation of the MOVE-IN mode switch transmits an interrupt CCI to the computer which responds by closing the contact closure outputs (CCOs) for effecting the following operations: close pinch roll sets 18 and 20; start the dummy bar winch 22 to pay out the dummy bar chain; turn off the coolant in zones Z1, Z2, Z3 and Z4; start the main drives in reverse.
  • CCOs contact closure outputs
  • the computer closes the contact closure outputs (CCOs), if not closed before, for effecting the following operations: (a) lower the dummy bar rocker arm to the conveyor roll level, (b) deenergize the straightener roll 126, (c) unlock the pinch roll set 18, ((1) set pinch roll pressures to low, (e) deenergize dummy bar push off mechanism 140.
  • CCOs contact closure outputs
  • a redundant set of controls by-passing the computer is operated in response to the MOVE-IN mode switch to effect parallel control of the same operations and in the same manner.
  • READY TO POUR switch When the above described sealing operation is completed, the operator depresses READY TO POUR switch at the operators console 9. Operation of the READY T O POUR switch transmits a signal to the computer, which in response thereto runs a diagnostic checkup program that checks whether or not the following controls are operative or non-operative: lube control LC through line 28; oscillator control OR through line 32; coolant system through lines 56, 58, 60 and 62; pinch roll drives through lines 103 and 105; pinch roll pressure system through lines 84 and 102; torch machine operations through line 259. If these devices and areas are functioning properly the computer will cause a READY TO POUR light to light up at the operators console, signifying to the operator that he can start his casting operation.
  • the computer will print out a diagnostic message telling the operator that he should not start his cast because certain elements are malfunctioning.
  • the operator will move the speed controls on the operators console 9 to the position which will provide, when the roll drivers are turned on, the desired withdrawal speed of the cast strand.
  • the computer effects the following: (1) calculates the front crop cut initiate point for the sequence control program, (2) clears the total strand length display on the operators control console, (3) displays the preset slab length on the operators control console, (4) turns on the roll drive units RD1, RD2, RDS, RD4 in the normal direction, (5) sets the pressure of pinch rolls 18 and 20 to HIGH through lines 78 and 100, and (6) turns on the cooling water for zone Z1.
  • the pinch roll set 20 drives the dummy bar chain 116 in the downstream direction to begin withdrawing the dummy bar head 1 14 from the mold, while the slack in the dummy bar chain is taken up by winch 22 under command of the computer through line 118.
  • the pulse generator PG1 coupled to the pinch rolls 20 transmits an interrupt for every unit distance of strand cast, for eX ample for every inch of strand cast.
  • a program in the computer which may be identified as the PG1 program runs each time an interrupt is received from the pulse generator PG1 and recognized by a main control program in the computer.
  • the computer starts to monitor the mold water temperature through sensors T81 and T52, starts to monitor the tundish weight through sensor TWl, initiates a data gathering program, and stores the start of cast time for a heat information sheet to be printed out.
  • the torch control program in the computer includes the front crop cut program and utilizes the process interrupt inputs associated with the pulse generators P62 and PG3.
  • the control program receives a process interrupt from these pulse generators for every unit distance traversed by the torches, for example for every A inch. By accumulating these interrupts the program knows exactly where the torches are during the cutting of the strand. It may be noted, that for the sake of simplicity the rollers R on which strand 16 travels, are not shown in FIG. 2, and that the torch machine carriage and rails are not shown in FIG. 1b.
  • the following described crop cut and subsequent slab cuts and associated routines of the torch machine are effected under computer command.
  • the torches are initially at respective reference outward positions (home bases of the torches).
  • the torch machine clamps to the strand and the torches start lowering and traversing toward each other inwards to the opposite edges 222 and 226 of the strand.
  • the computer in response to the signals from the limit switches stops the movement of the torches, and the torches preheat the strand edges 222 and 226 with their heating gases for a predetermined length of time previously programmed into the computer. Then, when the preheat time has expired, the cutting oxygen is turned on and the torches begin notching the strand. For the crop cut, the iron powder is turned on with the oxygen. The notching operation is done at a slow traverse speed for a programmed period of time and when this time has expired, the torches start cutting the strand at high traverse speed.
  • the inside torch 146 When both torches are used, and when the torches come within a predetermined distance, for example two inches, of each other, the inside torch 146 will raise and return to its initial base. When the inside torch 146 completes its cutting, raises and returns, the outside torch 148 stops cutting and stays in position with only its heating gases on. The control program in the computer then calculates the point along the casting line at which the outside torch should restart and complete the final two inches of cut by the time the crop end reaches the crop chute 260 so that the cropped end will fall into the crop chute. When the calculated restart point is reached, computer commands restart the cutting action (oxygen on traverse) of the torch 14-8.
  • a predetermined distance for example two inches
  • the operator signals the computer through the console 9, and under computer command, the remaining torch cuts to within a predetermined distance for example six inches of the point where the malfunction occurred. This six inches will then be cut by hand at the end of the casting line at a piler located thereat. If the dummy bar head had not separated from the strand 16 at the dummy bar push-off station, the computer is so notified by lack of signal from POS, and the front crop cut would not have been completed, since the crop with the dummy bar head attached could not drop into the chute 260. In that case the front crop cut would have stopped six inches before completion, and the balance of the cut finished by hand at the end of the casting line.
  • the torches are returned to their respective home bases, and the computer knowing the positions of the torches and the strand at all times, commands the drive unit 252 to lower the measuring roller 250 to the surface of the strand and, again under computer command, the tongs 228 are released by the clamp control 230, and, when relative motion between the strand 16 and the torch machine 144 is not zero, the torch machine starts returning under command of the computer to the point on the strand where the next slab out should occur in accordance with the instructions on slab length programmed into the computer.
  • the position of the torch cutting machine relative to the strand 16 is known by the computer by reason of the interrupts supplied by the pulse generator PG4 to the computer.
  • interrupts are generated for every unit distance of relative travel, for example for every one eighth of an inch of travel.
  • the tongs 228 are operated to clamp the torch machine to the strand 15, and the torches start lowering and traversing inwards to the edges of the strand.
  • the torches hit the limit switches LS2 and LS3, the torches under computer command stop and preheat the slab edges with their heating gases for the programmed time.
  • the preheat time expires, the cutting oxygen is turned on and the torches begin notching the slab.
  • the notching operation is done at slow traverse speed for a programmed time period and when this time expires, the torches start cutting the strand at high traverse speed.
  • the torch 146 will raise and return to its initial base, a predetermined distance for example two inches prior to meeting the outside torch 14S, and the latter torch will complete the slab cut.
  • the computer increases the speed of the runout rolls R01, R02, R03 and R04 through control line 264 to pull the slab away from the strand when the final inch is cut.
  • the operator designates which torch is operable by manipulating the torch selector switches at the operators control console 9.
  • the computer receives the information that only one torch is operable, it calculates a new cut-complete-point for the remaining torch, utilizing the distance that the malfunctioning torch had traversed, and the good torch will then traverse the remaining distance required to cut the slab.
  • the computer is programmed to begin the cutting of the strand at a point along the casting line such that the cutting operation will be completed before the torch machine engages the overtravel limit switch LS5, and the last one inch of cut will be made with the end of the strand on at least one of the runout rolls R01, R02, R03 and R04 whereby the runout rolls can be speeded up by the computer to pull the severed slab away from the strand.
  • the operator is always aware of the amount of molten metal left in the tundish TD1.
  • the operator selects the MOVE OUT mode switch on the operators console 24 to place the system in the MOVE OUT mode.
  • the casting line is stopped for a predetermined period of time, for example five minutes, to allow the tail end of the strand to cool and solidify before it is withdrawn from the mold (under command of the computer).
  • the solidifying time period five minutes
  • mold coolant temperature zone Z1
  • mold oscillation mold lube rate
  • slab binder rate slab binder rate
  • strand temperature for zone Z1 are deleted.
  • Pinch roll set 18 is locked before the tail reaches this roll set in order to keep the tail from curling.
  • pinch roll set 18 After strand tail passes through pinch roll set 18, this roll set is opened; monitors for pinch roll set 20 current and pressure of pinch roll sets 18 and 20 are deleted.
  • pinch roll set 18 is unlocked; pinch roll set 20 is opened; straightener roll 126 is raised, and pinch roll drives RDl and RD2 are stopped.
  • the computer compares the sensed values of the various parameters, being monitored and determines whether they are within or without predetermined stored limits. When a sample parameter is outside permissible limits, the computer through the printer at the operators console prints out alarms so that the operator can correct particular out of limits area by adjusting the proper con. trols at console 9. This is applicable to the mold oscillation rate, the mold lube rate, the slab binder speed, the coolant temperature in zone Z1, the coolant flow rates in zones Z1, Z2, Z3 and Z4, the strand temperatures in zones Z1, Z2 and Z3, the low pressure of pinch roll sets 18 14 and 20, the current of roll drive RD2, and the slab weights at the end of the casting line.
  • an INFORMATION SHEET program in the computer is responsible for gathering information relative to the strand being cast and the computer will retain this data in its memory until the casting is complete. After the cast is finished the information obtained is printed out.
  • the INFORMA- TION SHEET program obtains information as a function of position and time with respect to the strand. Position of the strand is reflected by information retained in the memory for the information sheet until the cast reaches a predetermined point on the strand. Time is reflected as a variable to position, so that each piece of information can be stored a given period of time after the cast reaches the specified point.
  • the program starts gathering data at some time after the strand reaches zone Z3. The information obtained at this time is pinch roll current, pinch roll pressure (high) and time.
  • the computer As a cast is progressing, and slabs are being cut and weighed, the computer is storing the slab length and weight for every slab to be recorded in the information sheet. When all strands cast have been cut and weighed, the information sheet is printed out, although the operator may at any time on demand order a printout.
  • the computer is programmed to display to the operator at the console 9 how many slabs of predetermined length have been poured from the ladle into the tundish.
  • This program computes the number of slabs cast from the tundish and adds to this the number of slabs represented by the metal now in the tundish, and updates the display to the value when another predetermined fraction of a length of a slab has been poured.
  • the computer maintains in storage a record of the length of the strand cast and from this it calculates the number of predetermined length slabs in the already cast strand.
  • the predetermined length of the slabs has been previously preset into the computer by the operator.
  • the computer maintains a periodic check of the metal weight in the tundish and from this it calculates the number of slabs represented by the weight noted, utilizing preset constants and information regarding weight per unit length of strand preset or programmed into the computer by the operator.
  • the computer is programmed to allow the operator to obtain the information associated with the next strand to be cast on a demand basis, except during MOVE OUT mode.
  • the data groups gathered for such a demand log are:
  • Zone Z1 coolant flow rate and temperatures (in and out).
  • the operators control console 9 includes a duplicate set of controls and adjustments for casting line B, and that there is a duplicate set of interconnections between the various elements of the casting line, the computer and the operators control console, for casting line B, whereby computer 10 controls both casting lines A and B simultaneously in the manner heretofore described for casting line A.
  • the computer executes on a first-come first-served" basis, equal priority bids from casting lines A and B.
  • control apparatus comprising means for generating digital information while the cast product is advancing each of successive predetermined increments of the length cast, a computer, a control circuit connected between each device and the computer for controlling the device in response to control signals from the computer, means for feeding said digital information to said computer, the computer being operable to accumulate said digital information as it is recelved and to keep track of the linear position of the cast product as it progresses along the casting line, said computer being responsive to accumulations of said digital information signifying the arrival of said cast product at each of successive positions along said line to apply a control signal to a different one of said control circuits in predetermined order, at least one of said devices being a pinch roll set that is adjustable for at least tending to change roll position.
  • clamping means operable under command of the computer for clamping the cutting means to the strand whereby the cutting means moves downstream along with the strand;
  • said computer is arranged to effect control of said cutting means to perform the following operations:
  • cutting means disposed along said line and movable therealong in either direction, said cutting means comprising (a) means operable under command of the computer for moving said cutting means upstream;
  • clamping means operable under command of the computer for clamping the cutting means to the strand whereby the cutting means moves downstream along with the strand;
  • one of said devices is cutting means for cutting the the cast product while in motion along the casting line, which cutting means is disposed along said line and movable therealong in either direction, said cutting means comprising (a) clamping means operable under command of the computer for clamping the cutting means to the cast product whereby the cutting means moves downstream along with the cast product;
  • (0) means responsive to movement of the cutting elements for transmitting to the computer information relating to position of the cutting elements

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
US741567A 1968-07-01 1968-07-01 Computerized continuous casting system control responsive to strand position Expired - Lifetime US3614978A (en)

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AT (1) AT301778B (de)
BE (1) BE735501A (de)
CA (1) CA937022A (de)
DE (1) DE1932884A1 (de)
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Cited By (13)

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Publication number Priority date Publication date Assignee Title
US3785427A (en) * 1972-08-15 1974-01-15 Metallurg Hoboken Overpett Casting of deoxidized copper
JPS4915104U (de) * 1972-05-12 1974-02-08
US3938584A (en) * 1971-06-09 1976-02-17 Meylan Jean Luc Charles Apparatus for cooling continuous castings
US4009750A (en) * 1972-09-06 1977-03-01 Concast Ag Apparatus for controlling the cooling of a strand emanating from a continuous casting mold
US4149580A (en) * 1976-12-14 1979-04-17 Mannesmann Aktiengesellschaft Method of ascertaining the effectiveness of cooling rollers in continuous casting machines
US4523624A (en) * 1981-10-22 1985-06-18 International Telephone And Telegraph Corporation Cast ingot position control process and apparatus
US4619306A (en) * 1982-10-13 1986-10-28 Mannesmann Aktiengesellschaft Quality control in multiple continuous casting plants
US4625787A (en) * 1985-01-22 1986-12-02 National Steel Corporation Method and apparatus for controlling the level of liquid metal in a continuous casting mold
US4735399A (en) * 1985-03-16 1988-04-05 Aute Gesellschaft Fuer Autogene Technik Mbh Method of operating a continuous casting apparatus and a casting flame cutting machine for carrying out the method
US5267604A (en) * 1989-11-03 1993-12-07 Steel Casting Engineering, Ltd. Motion control system for horizontal continuous caster
CN107817752A (zh) * 2017-09-19 2018-03-20 芜湖安普机器人产业技术研究院有限公司 一种铜板水平连铸的自动化上料装置电气控制系统
CN114625055A (zh) * 2022-04-15 2022-06-14 山东莱钢永锋钢铁有限公司 一种连铸机火焰切割系统的冗余控制方法
US20250135528A1 (en) * 2022-03-24 2025-05-01 Novelis Inc. Systems and methods for controlling vertical folds during direct chill casting

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JPS5124753B1 (de) * 1971-03-03 1976-07-26
BE787812A (fr) * 1971-08-24 1973-02-21 Uss Eng & Consult Procede et mecanisme pour maitriser les forces exercees sur unebarre coulee en continu a mesure qu'elle se solidifie
JPS522370B2 (de) * 1971-08-28 1977-01-21
IT1021775B (it) * 1974-10-11 1978-02-20 Centro Speriment Metallurg Processo e dispositivo per il controllo della fusione di metalli sotto scoria elettrofusa
DE2714338C3 (de) 1977-03-31 1984-08-02 Mannesmann AG, 4000 Düsseldorf Anfahrstrang-Transportvorrichtung
DE2759660B2 (de) * 1977-03-31 1981-07-16 Mannesmann Demag Ag, 4100 Duisburg Stranggießvorrichtung mit einer Anfahrstrang-Aufnahme für einen kurzen Anfahrstrang
AT378707B (de) * 1983-01-11 1985-09-25 Voest Alpine Ag Verfahren zum ueberwachen einer bogenstranggiessanlage
US4580614A (en) * 1983-01-31 1986-04-08 Vereinigte Edelstahlwerke Aktiengesellschaft Cooling apparatus for horizontal continuous casting of metals and alloys, particularly steels
US4570230A (en) * 1983-03-28 1986-02-11 United States Steel Corporation Method of measuring and controlling the level of liquid in a container
AT381049B (de) * 1985-01-21 1986-08-11 Voest Alpine Ag Verfahren zum ablaengen eines kontinuierlich in einer stranggiessanlage gegossenen stranges sowie einrichtung zur durchfuehrung des verfahrens
AT381050B (de) * 1985-01-21 1986-08-11 Voest Alpine Ag Verfahren zum stranggiessen sowie einrichtung zur durchfuehrung des verfahrens
DE3531041A1 (de) * 1985-08-30 1987-03-05 Aute Autogene Tech Strangbrennschneidmaschine
CN113083906B (zh) * 2021-02-22 2022-06-14 阳春新钢铁有限责任公司 一种减少螺纹钢检废的生产控制方法
EP4494782A1 (de) * 2023-07-19 2025-01-22 Primetals Technologies Austria GmbH Strangführung einer stranggiessanlage mit verfahrbarer trenneinrichtung

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FR1392427A (fr) * 1964-05-11 1965-03-12 Davy & United Eng Co Ltd Procédé et appareil pour sectionner une matière horizontalement mobile, telle qu'un lingot continu
US3358743A (en) * 1964-10-08 1967-12-19 Bunker Ramo Continuous casting system
FR1421059A (fr) * 1965-01-18 1965-12-10 Schloemann Ag Installation de coulée continue, à coquille et guide à rouleaux de forme courbe

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938584A (en) * 1971-06-09 1976-02-17 Meylan Jean Luc Charles Apparatus for cooling continuous castings
JPS4915104U (de) * 1972-05-12 1974-02-08
US3785427A (en) * 1972-08-15 1974-01-15 Metallurg Hoboken Overpett Casting of deoxidized copper
US4009750A (en) * 1972-09-06 1977-03-01 Concast Ag Apparatus for controlling the cooling of a strand emanating from a continuous casting mold
US4149580A (en) * 1976-12-14 1979-04-17 Mannesmann Aktiengesellschaft Method of ascertaining the effectiveness of cooling rollers in continuous casting machines
US4523624A (en) * 1981-10-22 1985-06-18 International Telephone And Telegraph Corporation Cast ingot position control process and apparatus
US4619306A (en) * 1982-10-13 1986-10-28 Mannesmann Aktiengesellschaft Quality control in multiple continuous casting plants
US4625787A (en) * 1985-01-22 1986-12-02 National Steel Corporation Method and apparatus for controlling the level of liquid metal in a continuous casting mold
US4735399A (en) * 1985-03-16 1988-04-05 Aute Gesellschaft Fuer Autogene Technik Mbh Method of operating a continuous casting apparatus and a casting flame cutting machine for carrying out the method
US5267604A (en) * 1989-11-03 1993-12-07 Steel Casting Engineering, Ltd. Motion control system for horizontal continuous caster
CN107817752A (zh) * 2017-09-19 2018-03-20 芜湖安普机器人产业技术研究院有限公司 一种铜板水平连铸的自动化上料装置电气控制系统
CN107817752B (zh) * 2017-09-19 2024-01-30 芜湖安普机器人产业技术研究院有限公司 一种铜板水平连铸的自动化上料装置电气控制系统
US20250135528A1 (en) * 2022-03-24 2025-05-01 Novelis Inc. Systems and methods for controlling vertical folds during direct chill casting
CN114625055A (zh) * 2022-04-15 2022-06-14 山东莱钢永锋钢铁有限公司 一种连铸机火焰切割系统的冗余控制方法
CN114625055B (zh) * 2022-04-15 2024-03-12 山东莱钢永锋钢铁有限公司 一种连铸机火焰切割系统的冗余控制方法

Also Published As

Publication number Publication date
DE1932884A1 (de) 1970-01-15
GB1269563A (en) 1972-04-06
AT301778B (de) 1972-09-25
BE735501A (de) 1969-12-16
CA937022A (en) 1973-11-20
FR2012094A1 (de) 1970-03-13

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