Existing load cells paired with SIWAREX DB junction box and SIWAREX WP231 weighing module mean increased the reliability and diagnostics in steel manufacturer Cogne Acciai Speciali’s (CAS’s) system. This combination solved the company’s ongoing maintenance issues while ensuring quality measurement of casting speeds during production. 

Drive across Hong Kong’s Stonecutter Bridge—the third longest cable stay bridge in the world—and you will see massive cargo ships cruising the channel along with city lights from the busy urban centers.   

What you won’t see—but will fully appreciate—are the kilometers of strong, stainless-steel bar used to reinforce the bridge’s concrete below your vehicle.

A world leader in the production of long stainless steels like wire rods and round bars as well as nickel alloys, Cogne Acciai Speciali in northwestern Italy has been supplying quality metal products for projects like this since 1911.   
With market sectors that include automotive, aerospace, architectural and construction, the company’s more than 1,000 employees are dedicated to consistently expanding into new opportunities.   
But before new markets can be tapped, product quality in CAS’s manufacturing plant is critical.

Casting reliable measurements   
In the production facility’s steel and forging shops, an electric arc furnace heats raw materials to temperatures of 2,800 °F, melting steel and then casting it using presses weighing in the thousands of tons.   
During this process, a casting crane tips a massive ‘ladle’, pouring molten steel into the casting equipment. Accurate measurements during this spill phase are critical to product quality:

• If flow rates are too fast, casting won’t be able to keep up;
• If the flow is too slow, product could cool too quickly or the company might not be able to meet production quotas.

CAS had been experiencing some difficulties with its weighing system in this application—instruments didn’t have the reliability technicians required, maintenance was becoming a regular occurrence, and parts of the system had reached obsolescence from instrument vendors.    
Enter SIWAREX weighing technology.

Retrofitting with ease   
To tackle these issues on the casting cranes, CAS maintenance staff designed a small plant, connecting the existing load cells installed on the casting crane to a SIWAREX DB digital junction box. The junction box allows for targeted monitoring of weighing processes as well as enhanced diagnosis—and is then connected to a SIWAREX WP231 weighing module.   
Finally, operators integrate the weighing solution into the SIMATIC S7-1200 control system, delivering readings directly to the control room.   
The aim? To calculate the flow rate (Delta W / Delta Time) of the steel more accurately during the spill phase, reaching a reliable casting speed measurement while also saving retrofitting time and costs by keeping crane casting mechanics unchanged using the existing load cells. ` 
Diagnostics and the possibility of preventive maintenance to reduce downtime were also goals, as staff hoped to integrate reporting into the system, thereby increasing diagnostic information and preventive maintenance programs.