Title:
SPEED CHANGEOVER METHOD FOR ARC FURNACE ELECTRODE ELEVATING/SINKING DEVICE
Document Type and Number:
Japanese Patent JP2979816
Kind Code:
B2
Abstract:
PURPOSE: To shorten the operating time of an arc furnace by making automatic operation from the electrode upper limit position without requiring manual intervention of the operator, and letting it to descend until current starts to flow at the maximum value of manual operating speed.
CONSTITUTION: Scrap 40 is put in the furnace body 18 of an AC arc furnace, and three electrodes 10 are fed with three-phase power from a three-phase transformer. The three electrodes 10 are rapidly discended from the upper limit position at the max. speed of manual operation mode. When either of them touches the scrap, the electrode speed is changed over into the automatic operation mode. Even when the two electrodes touch the scrap to cause current flow, they can be pulled up immediately because the electrode speed in the automatic operation mode is sufficiently lower than the speed by the manual operation mode, and can be changed to the constant impedance control without generating hunting phenomenon.
Inventors:
KASUGA TOSHIAKI
TSURUTA MASAMI
TSURUTA MASAMI
Application Number:
JP1614692A
Publication Date:
November 15, 1999
Filing Date:
January 31, 1992
Export Citation:
Assignee:
FUJI DENKI KK
International Classes:
F27D11/08; H05B7/152; (IPC1-7): H05B7/152; F27D11/08
Domestic Patent References:
| JP59891A |
Attorney, Agent or Firm:
Haruo Hamada