Following the successful commissioning of a 10 t pouring furnace in the spring of this year, OTTO JUNKER also received the order for the delivery, installation and commissioning of a 90 t channel induction furnace from the Polish foundry Odlewnia Zeliwa Lisie Katy; this will be used as a storage and holding furnace as part of the company’s cupola melting operations. The furnace should also allow for closer temperature tolerances and improved analysis accuracy.
The furnace has a useful capacity of 75 tonnes and is heated by a watercooled inductor. The power supply (800 kW) is provided by an IGBT frequency converter system, which allows for stepless control of the power input.
This power allows superheating of 14t/h by 100 K, starting from a temperature of 1,400 °C. The furnace design and the selected refractory lining ensure a low holding power consumption of 230 kWh/h.
The furnace will be equipped with a weighing device; in conjunction with the JOKS furnace processor, this ensures exact calculation and input of the necessary heating power. The system also supervises and monitors all units, meaning that refractory erosion of the inductor is also monitored. The program also includes the saving of all data and the acquisition of shift and day protocols.
The water cooling circuit of inductor and switchgear includes an evaporative cooling tower. The furnace’s hydraulic unit is equipped with two pumps, and an emergency air cooling device is de- livered for the inductor. In order to prevent the furnace from freezing should the electrical system fail, the furnace benefits from a 350 kW mains-frequency emergency power supply system which is identical in design with the one already provided for the pouring furnace.
Delivery of the furnace to the polish customer took place in early 2015.