Hot metal6 October 2000
…while a subsidiary has delivered a huge foundry crane
The Mecklenburg Metall Guss foundry at Waren an der Müritz in Germany has now taken delivery of a pair of cranes with a massive open barrel winch trolley system manufactured by Brunnhuber Krantechnik.
The foundry fabricates precision propelling screws for ships of all kinds. The Brunnhuber cranes are designed to handle loads of more than 100t with diameters of up to 11m.
Brunnhuber Krantechnik, celebrating its centenary this year, was taken over by Pfaff-silberblau in July 1999 when it changed its name from Josef Brunnhuber Maschinenfabrik.
The two-rail electric trolley is equipped with a winding mechanism based on open barrel winch construction. It has been designed with all-round accessibility to make servicing easier. The design also uses a special steel construction method in accordance with DIN 15018, H2/B3 and is equipped with a wire rope hoist in accordance with DIN 150202m.
The equipment is capable of lifting molten metals weighing up to 160t at a rate of 4m/min, to a height of 11m. The winding gear and trolley have a combined weight, including the heat shields, of 35t. Track width is 5m and the travel speed is specified at 20m/min.
Drive is provided by two 6.2kW motors (60% ED), continuously variable by means of frequency inverters over the range 1:17. The hoist mechanism is powered by a 132kW system with a continuously variable output (over the range 1:10), using a frequency inverter. The hoist motor is equipped with an impulse transducer for monitoring the direction and speed of rotation, and the over hoist prevention device has an integrated electronic overload protection device with load-sensing pins.
Because of the extreme conditions under which the system has to operate in the Mecklenburg metal foundry, various additional safety features had to be provided. Heat shields protect the electronics and mechanics of the hoist system; there is a second braking system; and the motors are protected by heatsinks.