Title:
HEAT TREATMENT OF METAL WORK PIECES
Document Type and Number:
WIPO Patent Application WO2006111252
Kind Code:
A8
Abstract:
The invention relates to a method for heat-treating metal work pieces, whereby a cooling gas flow is produced in a vacuum furnace by means of a fan, driven by a three-phase AC motor, in order to quench the work pieces. The aim of the invention is to improve the heat treatment of metal work pieces in such a manner as to improve the quenching in a simple and inexpensive manner. For this purpose, the three-phase AC motor comprises first three-phase windings designed for a lower supply voltage and second three-phase windings designed for a higher supply voltage. The three-phase AC motor is operated with the first three-phase windings until a minimum pressure defined in terms of the motor output is reached in the vacuum furnace and with the second three-phase windings until a minimum pressure defined in terms of the motor output is reached or exceeded in the vacuum furnace.
Inventors:
JURACK MARIO (DE)
Application Number:
PCT/EP2006/002842
Publication Date:
November 15, 2007
Filing Date:
March 29, 2006
Export Citation:
Assignee:
IPSEN INT GMBH (DE)
JURACK MARIO (DE)
JURACK MARIO (DE)
International Classes:
H02P1/26; F27B5/06; F27B5/18; H02P25/18; H02P25/22
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