Aciéries Hachette & Driout, the French company based in St. Dizier, has ordered a flexible medium-frequency furnace plant from OTTO JUNKER for its alloyed steel melting operations.
Our solution will incorporate DUO-CONTROL technology, relying on one 4-tonne and one 8-tonne coreless furnace. Power is to be supplied via a converter system rated for a 400 - 500 Hz operating frequency range. The nominal energy consumption of the 4-tonne furnace is 4,000 kW; the 8-tonne unit can be provided with a nominal 4,800 kW. At a 1,550 °C melt temperature this corresponds to a mains power demand of 490 kWh/t for the small furnace and 500 kWh/t for its 8-tonne counterpart.
Melting rates of 8.5 and 10 tonnes/hour, oth coreless furnaces will be equipped with bi-directionally tiltable exhaust hoods and with our stepless back-tilting feature allowing the furnace to be tipped towards the rear by a maximum of 20 deg. The 8-tonne furnace will receive a de-slagging spout to facilitate slag removal. In addition, the furnaces will be equipped with an OCP crucible monitoring system.
The cooling water returning from the furnace and power converter circuits will be recooled in an air-to-water cooler requiring no glycol. The entire system is to be controlled and monitored by an M2F-TouchControl melt processor.
Work is now ongoing on the engineering and production of this equipment which is scheduled to be delivered to the French customer in the summer of this year.
The Otto Junker GmbH received from another steel foundry in France the contract to design, manufacture and installation of a new modern medium frequency melting furnace (MFT).
The new melting system forms part of a project to expand and update production operations for the foundry's line of heavyduty undercarriage parts for railway cars.
The contractual equipment will be of the DUOMELT type, comprising two 6-tonne furnaces as well as a power converter and switchgear system rated for 4,800 kW at a nominal frequency of 250 Hz. For metallurgical treatment purposes both furnaces will be equipped with gas bubbling systems. They will also be provided with the proven OCP crucible monitoring system.
Furthermore, our scope of supply in cludes the water recooling system, two charging chutes, the JOKS process control system and an emergency power generator.
Since the steel casting alloys produced must meet particularly exacting demands in terms of mechanical properties, advance melting trials were conducted at OTTO JUNKER's high-grade steel foundry in order to optimize the furnace technology to be employed. The mechanical property tests carried out on specimen castings yielded results in conformity with the specifications.
At the time of writing, the equipment was about to be shipped to the customer. Commissioning is scheduled to take place in the early summer of this year, following completion of the erection work.