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CASE HISTORY

Best Practices to Implement Complete Revamping of Obsolete Plants

A common problem for many steel producers is howto modernize and improve their production plantsand schedules without impacting the mechanical layoutand the bottom line. This work details AutomazioniIndustriali Capitanio’s (AIC) strategy to perform acomplete electric revamping of ORI Martin – CepranoRolling Mill (Frosinone, Italy), carried out in two phasesduring planned shutdowns (August and December). Inthe first phase, all activities concerning auxiliary serviceswere implemented, while all tasks related to the rollingmill area and safety system were performed during thesecond phase, thus preserving the existing mechanicalequipment.


This work examines the revamp of ORIMartin – Ceprano Rolling Mill, and describeshow a state-of-the-art automation systemcan modernize an existing plant, ensurea reduction of costs and increase safety,efficiency and reliability.


ORI Martin is a primary group, specializing in highqualitylong product steel production, and its core businessis the long product special steels (SQB) for usein the automotive industry. ORI Martin headquartersare situated in Brescia and house a melting and rollingplant for the hot production of long product steels formechanical applications, while the factory in Ceprano isfocused on construction steels (SQB).
Founded in 1974, the revamped plant specializesin the hot rolling of billets (mainly produced in themeltshop of Brescia) for the production of straight bars(from Ø 8 mm to Ø 32 mm), wire rods (from Ø 8 mm toØ 17 mm) and coiler bars (from Ø 18 mm to Ø 32 mm).AIC is a global system integrator and supplier of electricaland automation systems for the metals industry.
Figure 1 shows the main characteristics of the layoutconfiguration (rolling mill area): two alternate strands,with 20 rolling stands, four intermediate shears (twoshears for both lines) and two finishing blocks (foursteps).
After the first shared line, differentfinishes can be scheduled as follows:
• Single-strand apron line, with optimizing shear andcut-length shear and 50-meter start/stop coolingbed.
• Two-strand high-speed line, with two dividing shearsand optimizing shear, two double-twin channel start/stop, 50-meter start/stop cooling bed and cold shear.
• Wire rod line with two head/tail shears, two layingforming heads and related cooling conveyor.

Fig.1: Continuous rolling mill layout and related productive options.


The Revamping Project
This electrical revamping project, which began in thesummer of 2009, was successfully accomplished in thefirst months of 2010 and comprises a complete on-siteupgrade of all stand drives through new drive controlcards, as well as new electrical equipment for auxiliaryservices, main and local desks, and new PLC platformfor a complete process automation and optimization ofthe steel plant.
The electrical and automation scope of supplyincluded:
• Electrical engineering.
• Upgrade of all drives.
• Twelve automation PLCs with more than 7,000 I/O.
• Safety system based on safety PLCs, totally integratedin the main automation architecture.
• SCADA control system in client-server configuration.
• Main desks.
• Local desks and control stations.
• Hydraulic control.
• Closed-circuit video equipment (CCVE) system.
• Spare part management.

The goal of the project was to increase the productivity— while at the same time reducing direct costs; allowingthe customer to calibrate the production rate forevery range according to the reheating furnace capacity;and optimizing productivity with a great improvementof efficacy, efficiency and rolling performances — withoutany investment in new mechanical equipment.



Basic Steps to Upgrade an ObsoletePlant to State-of-the-Art Level
The prerequisite to defining a successful strategy forthe modernization of the equipment was a deep understandingof the process and its peculiarities: startingfrom the structure of the plant, the hardware (HW) engineering team analyzed all different areas, eachrelating to a homogeneous phase of the productionline, aiming to identify possible bottlenecks and criticalconfigurations/situations.
1. The first step was a meticulous survey of all machinesthat have been in operation for more than 35 years,including several extension programs. Differentsuppliers and various criteria for the items in questionhad caused, year by year, a total lack of uniformity;so the revamping project needed to establish homogeneity and to identify clearly the items tomanage (while at the same time, providing a preciousservice to the customer).
2. The next step was to repeat the process describedabove for motors and sensors. A detailed motor andsensor list, together with technical data, is a greatresource to organize the technical documentationand to establish a good relationship between motorsand machines.
3. The next step is to detail the bottlenecks and toestablish the priorities of action. For this project, the most critical zone was the delivery area (coolingbed entry system as well as compactors, stackers,tying machines and bundlers), which was unable tosupport any possible increase in productivity, andwas operated through manual control of operatorsby pulpit or in the field (which was a source of inefficiencyand danger for the workers).
4. The last preliminary step was the HW design of newelectrical equipment and the revamping of existingones, in order to implement the re-allocation ofall machines, motors and sensors to command andcontrol. Automazioni Industriali Capitanio’s (AIC)staff rationalized the criteria and logics of controlfor the steel plant through the redesign of the electricalfunctions and identification system.

Fig.2: Collecting of technical data of the plant.


Fig.3: Part of the motor list for the project.


"Bottom-Up" Strategy for Improving the ProductionPerformances - Following the baseline analysis, thekey for a successful project is developing a strategy forresolving the most critical productive limits of the plant.The idea that characterized this job was a “bottom-up”approach: the revamping needed to start from thelast phases of the line, allowing the plant to manageand handle final products with a rate appropriate tosuperior rolling and productive performances. Thus,new command logic for the delivery area was designed,including electrical panels, main and local desks, PLCsand SCADA software designed to implement new tasksas follows:
• Increase of packing performance through automaticcycles.
• Increase of quality and uniformity of bundles.
• New control for binding cycles.
• Complete automation and securing of delivery area(safety operating activities).
• Data and alarms interchange with rolling mill andcut lines software.

Fig.4-5: Bundles moving through the binding process and view of the binding cycle.


A Single Brand for Power Control Upgrade (Drives) - Upgraded rolling mill drives with new digital drivecontrol cards, which preserved the existing power section,were also needed to complete this major plantmodernization. Making Ansaldo the single brand forall power control components grants the customer aneasier and more effective integration and maintenanceprogram. Furthermore, the integration and connectionof updated drives in the Profibus network allowsall power parameters (tension, current, alarms control,etc.) to interface, as well as to manage and set properconfigurations. The operators on the command pulpitcan thus monitor continuously the state of all DC drives,thanks to a manageable and user-friendly HMI system.
This step also included new auxiliary service controllogic (stands handling, lubrication and cooling), as wellas high-speed and cut apron lines automation with cutlengthoptimization and complete automation of therolling mill area, which included intermediate shears,loopers and cropping shear.

Fig. 6-7: Sample of DC drives before and after revamping


Fig.8: Auxiliary services panel with safety CPU, shown in redcircle.


A Single Brand for Automation Control (PLC Platform,SCADA, Safety System) - The complete electricalequipment revamping was followed by a new RACSsystem: a completely integrated rolling mill automationcontrol system implemented by AIC through PLCs andSCADA platforms. The previous logic system for thecontrol of the plant was based on outdated componentsthat had no spare parts; the job thus included supply of12 new, state-of-the-art Allen Bradley ControlLogix5000PLCs (including one safety CPU), suited to commandand control all tasks of different production lines, starting from reheating furnace automation up to thefinishing and delivery area, including PLCs safety system.A new HMI system in client-server configurationhas been also implemented.
The PLC software designed by AIC’s engineeringteam allows for the following improvements and results:
• Reheating furnace movement and combustion automation,with consumption analysis and optimizationand production statistics.
• Cascade speed control, used to change the speed ofa particular machine and all the upstream stands inthe production line.
• Tension and loop control, designed to adjust thespeed references of the stands in order to form theloop between them, or to carry out precise regulationof the speed reference of the stands in order tomaintain constant tension or to push the materialforward between two stands.
• Continuity rolling control, in order to automaticallydetect possible cobbles.
• Ghost billet: the system can simulate the rolling processwith no material at a given line speed (parameterin the HMI system), also including the shearcutting; this function is used to save material at thebeginning of the hot test and can also be used tocontinue the rolling process even in case of failureof the encoder used for the cut-to-length calculation.
• High cutting accuracy and repeatability as well as cuttingoptimization strategy: the system automatically calculates an optimal cutting strategy to minimizematerial scrapping. This system can also take advantageof a pre-optimization shear to scrap the materialin the middle of the rolling process.
• Cut cycle simulation: RACS system allows the operatorto simulate the presence of a billet, with a prearrangedlength, in transit in the rolling mill at theselected line speed. Through the simulation it is possibleto verify the correct operation of every machineinvolved in the cutting cycle and the unloading.
• Motor load control: the stands’ motor load is constantlycontrolled to detect anomalous variationsdue to, for example, the stand bearing breakup orexcessive stand cylinder deterioration.
• Complete process optimization, including shearcontrol, cooling bed, finishing and delivery area optimization for aprons, high-speed twin channeland wire rod line.
• Head-forming layer control system for wire rod linewith head positioning on coil conveyor.
• Series of functions to save the rolling parametersand the machine parameters in a database. Theyare collected in a recipe containing the values ofthe parameters related to a specific rolling mill configuration.The recipes are then collected in various“recipe books,” one for each mill area or automationfunction.
• Production control and instant productivity: onrequest of the customer, it’s possible to build graphicpages that show instant snapshots of productivity ofthe plant.
• System deeply integrated with CCVE.


Fig. 9-10: Main control room (rolling mill area) before and after revamping.



Fig. 11-12: Main desk, HMI system and Reheating furnace automation.



Fig. 13-14:Rolling mill automation and delivery area automation.


Revamping of Network Configuration:Ethernet, ControlNet and Profibus
The panels and desks designed and installed to upgradeperformances and productivity of the plant are not wellsupported on the existing power supply and network.
A complete automation system needs a state-of-the-art network configuration in order to properly interlacethe hardware and software solutions and exploit theirpotential. Figure 15 shows the final layout configuration,which includes the following:
• Automation CPUs (reheating furnace, rolling milland services, coiler lines and finishing area) areinterconnected through a dedicated ControlNetnetwork.
• Automation and safety CPUs are connected to theSCADA system through an Ethernet network.
• Safety CPU and safety remote I/O are interconnectedthrough a dedicated ethernet network.
• AC and DC drives are connected to PLCs throughProfibus networks.
• CCVE is integrated on plant Ethernet networks aswell as printers and labeling machines.

All communication networks are interconnected andcan be easily reached and managed through remotecontrol, not only by the maintenance operators, butalso by AIC engineers, thanks to a secure remote devicemanagement. This efficient tool allows the supplier of the automation system to assist the customer in startupactivities and production management, thanks toremote data analyzers and troubleshooting tools. Thesafety system is also exclusively based on the AllenBradley PLC ControlLogix system and does not requiretraditional cable pulling.
Previous traditional safety systems were based onstandard hardware/electromechanical modules thatneeded to be wired; thus, the main problem was thedifficult integration with the command system. The integrationin the main automation system was extremelydifficult, except against additional wirings that complicatethe hardware structure. In this case, the designedPLCs’ safety system is totally integrated in the mainautomation system and can be very easily modified,expanded or reduced both in the construction phaseand in commissioning or after startup.
To implement the automation and safety system,the engineering team handled 37 remote I/O units(automation) and six safety remote I/O units, withabout 7,000 I/O signals.

Fig. 15: General automation layout with network communications.



Fig. 16-17: New local boxes for auxiliary services control.


Rolling Mill Auxiliary Services: Hydraulic and OilControl Units - To complete the revamping of thepower and logic control system for the main productionlines, auxiliary services management and controlhas been integrated in the general automation system,mantaining the existing oil and hydraulic unit as wellas local sensors. By adding a remote I/O unit for eachfluid unit, a complete integration of services has beenreached, giving the operator several advantages, such as:• Easy and user-friendly interface for services managementintegrated in the main HMI system.
• Management and control of reports and alarms.
• SCADA screens dedicated to oil and hydraulic units.


Fig. 18-19: New local stations suited to control oil circuit.


Real-Time Diagnostic and SCADA System - The implemented client-server HMI system is based on a certified package (Allen Bradley Factory Talk View) that enablesreal-time control of plant conditions as well as quick andeasy visualization through SCADA screens showing:
• Reheating furnace movement and combustionparameters.
• Plant synopsis and state of the machines.
• Selected stand of the rolling mill with a bar graph ofthe speed and current.
• Tension and loop regulator gauge.
• Management of rolling recipes and related parametersas well as alarms and auxiliary device parameters(without stopping the mill).

The SCADA screenshots allow continuous monitoringof the state of the production line and the state ofthe machines controlled. The supervision station alsoallows a sophisticated management of a temporal graphdedicated to simplifying the operation of detailed configurationof the plant and preventing breakdowns. Thetemporal graphs, besides allowing the real-time visualization(i.e., armature currents and voltage, speed andsignals feedback), allow the visualization of data previouslystored in the database. This function is very usefulfor analyzing any random anomalies. If necessary, therecorded data could be extracted and sent to after-salesservice for further investigation. A fast data recordingand acquisition IBA system for maintenance, productionoptimization and historical analysis has also beeninstalled; the standalone IBA system is designed to easilyinterface with PLCs for high-performance data acquisition,trend registration and database organization.


Fig. 20-21: Screenshot showing management and control of air/gasflow and pressure in the reheating furnace; screenshot showing parameters of reheating furnacemovement.


Conclusions
ORI Martin – Ceprano obtained the following results:
• Revamping tasks concluded in two phasesplanned during yearly maintenance shutdowns,ensuring a very minimal impact onthe production schedule.
• After only few months, a line speed increaseof 20% in rolling performance for Ø 8–12(rolling speed from 18 m/second to22 m/second) was achieved.
• Increase of reliability and yield optimization.
• Standardized product range in quality andreduction of scrapped material due to thepre-optimization and optimization shearcutting strategy.
• Data analyzer system helps the operators towork efficiently with quick troubleshooting.
• Secure remote device management allowsthe customer to be helped “on-demand” bythe system integrator.
• CCVE and safety system allows the operatorsto work safely.

The target of the project was achieved withinthe first year of production; this project confirmsthat a state-of-the-art automation system,based on long-time experience and know-how, can modernize an existing plant, ensuringreduction of production costs and increasingsafety, efficiency and reliability.


Fig. 22-23: Screenshot showing process control interface and rolling mill synopsis with the stands selected.



Fig. 23-24: PC panel with client/server IT machines with CCVEdigital recorder and SCADA screenshot showing production statistics in different shifts.


Acknowledgments
The authors wish to thank ORI Martin managementfor the cooperation and the supplyof necessary pictures and information. Theywould also like to thank all AIC’s staff for theirsupport.