THE ELECTRICAL CATHODE PREHEATER

To prevent carbon cracking during the cathode rodding process, carbon blocks must be carefully preheated. Traditionally, this has been achieved using gas heating.

Instead of relying on traditional gas burners, the ALMEQ system uses electrical currents to heat the cathode bars which in turn heats the carbon blocks. This results in a more controlled and efficient method of preheating that minimizes the risk of cracking.

Operation and monitoring

The system is designed for effortless operation and requires minimal maintenance. The operators only need to initiate the startup after which the system automatically monitors the heating process and makes necessary adjustments as required.

The solution

The system operates on a 400VAC three-phase power supply. A multi-winding transformer steps down the voltage from 400VAC on the primary side to a lower, three-phase voltage on the secondary side. Water-cooled copper contacts securely clamp the secondary windings to the steel bars, allowing electrical current to flow through them.

Fully automated and monitored by an advanced PLC system, the solution ensures seamless operation and protects against any potential damage.

Increased capacity

As the electrical resistance increases during heat-up, the current will drop accordingly and the heating time will increase. By introducing a second or third step on the primary side, it is possible to step-up the voltage and shorten the heating time. All step-ups are fully automated as the system monitors all temperatures and electrical currents.

Benefits

• High power factor
• No supervision needed during procedure
• No hazard to personnel or facilities
• Low energy consumption (1:5)
• Negligible carbon oxidation
• No exhaust fumes