Taking heat treatment to the next level

Refrattari Brebbia has over forty years’ experience building industrial furnaces and heat treatment plants. As well as producing facilities for steel it has built furnaces for the light alloys used in aircraft and aerospace applications and for structural elements for civil engineering, resin polymerisation furnaces, vulcanising systems for thermopolymers and tunnel kilns for brick firing.

Technological development has always been vital to Refrattari Brebbia, with one of its greatest innovations being a ‘sliding transporter’, which is protected by international, European and American patents. This moves the steel from one process stage to another on a cushion of inert gas, a concept that allows compact layouts in both linear and round formats, provides unrivalled flexibility of use and enables the production of high quality steel products.

This system can be fitted with a series of standalone workstations, each one assigned specific tasks within the whole automated heat treatment process cycle. These workstations communicate to provide overall control whilst allowing a modular design that brings flexibility for the system to be adapted and reconfigured as needs change.

Refrattari Brebbia’s heating treatment chambers are gas tight cylinders with giant impellers that ensure even temperature and atmosphere distribution. Similarly, powerful mixing systems are fitted inside the quenching tanks to ensure perfectly even cooling.

Achieving 24hr process reliability
Overall the system has been designed to work 24/7 non-stop in a completely automatic mode. Each station is independent and controlled by a supervisory controller, whose architecture is based on an Industrial PC with the Movicon SCADA (supervisory control and data acquisition) system. The Movicon control system ensures constant supervision of all the process, temperatures, atmosphere composition, gas flows and loading movements’ synchronisation.

Originally Refrattari Brebbia engineers had used another SCADA system, but this could not satisfy the company’s rather ambitious development plans. They took the opportunity to fundamentally re-assess the system requirements and realised that the system needed to have a fully integrated control system that could not only control each workstation but also co-ordinate them. This meant the system could combine increased productivity with improved product quality.

The key requirements for any heat treatment process include accurate temperature control, precise composition of the atmosphere (or cooling liquid) and exact timings. The Movicon SCADA was able to ensure these and also had the power to allow various products to pass through the workstations in different cycle sequences, whilst guaranteeing total reliability.

Movicon applications
Movicon is produced in Italy by Progea Srl and used around the world on a wide variety of applications. For example, in the UK Products4Automation has installed it in steel mills, dairies, distilleries, oil and gas refineries, car factories and biomass power plants. It is designed to collect real-time data from sensors spread across a plant, and automatically adjust the controllers to constantly optimise and re-optimise production. It also drives HMIs, produces production reports and archives traceability information.

Movicon’s exclusive ‘XML-Inside’ technology offers an all-in-one development environment for managing HMI, SCADA and statistical production data analysis applications. It provides unrivalled openness, simplicity and can interface with web services, SVG graphics, OPC, SQL, ODBC, .Net and the java technology. In short, Movicon is a truly universal SCADA/HMI platform, independent from hardware, adaptable and deployable anywhere.

Operator benefits
Movicon proved suitable for Refrattari Brebbia because it allows the operator to select which treatments are to be used, their sequence and duration. Movicon then does all the necessary calculations and control settings and monitors each product through its production sequence, including initial loading and final unloading. The work cycle plans allow work times to be scheduled so that pieces are not kept waiting in each station, improving production efficiency, quality and reproducibility of results.

Each workstation is controlled by a dedicated PLC which interfaces with the Movicon SCADA network. The PLCs at the heat treatment stations control temperature settings, fan speeds, dwell times etc, while those at the load and unload station control the motors and hydraulic cylinders of the handling equipment.

From an HMI, the operator can constantly view the status of each station, and the progress of each product - and can intervene manually if required. Movicon’s visualisation capability presents the heat treatment plant as a clear and simple graphic, while its zoom function can focus-in on individual workstations for extra detail.

Through the SCADA the operator is assisted in running the plant system with simple, very comprehensible and intuitive commands and menus. Diagnostics are ensured with accurate alarms management through which the operator or maintenance worker can immediately single out any anomaly and intervene straightaway to quickly and safely restore normal operations. Movicon also facilitates remote control of the plant both in-network or via a modem, a feature highly valued in systems working 24/7.

The system archives all the values of each station in an ODBC standard database (being treatments which need time and care to carry out, data is gathered every minute). This data is available in production reports for quality approval and traceability records.