aus Südafrika
refurbishment at Finsch mine
In September 2004 De Beers Consolidated Mines awarded ALSTOM Industry the second phase contract for upgrading the armature thyristor converter for its Koepe rock winder at Finsch diamond mine near Danielskuil in the Northern Cape.
This rock winder and all the equipment driving and controlling it are mounted on top of the headgear at a height of 83 m. The electric portion of this winder consists of two DC power loops, with each loop driving a 2700 kW motor. The two DC motors are mechanically coupled via their shafts that connect to either side of the Koepe drum. The winder is designed to hoist 29,2 tonnes from a depth of 978 m at a speed of 15,24 m/sec, but the shaft is at present only sunk to a depth of 802 m, with the loading arrangement of 70 Level.
A previous R3m first phase contract, comprising supply and installation of a Logidyn D2 digital regulator and field converter, to replace the old analogue system, was awarded to ALSTOM in September 2003 and completed during a three-and-a-half day shutdown in April 2004. This contract included supply and installation of a tele-service facility that provides for monitoring and trouble-shooting of the new electrics by the owner and remote monitoring and trouble-shooting by the supplier.
The mine has now awarded the follow-up second phase contract to ALSTOM Industry for completion in April 2005. This R3,8m contract involves supply and installation of four new PA100 converter cubicles to form two 12/24 pulse, single ended armature converters, one for each of the two 2700 kW DC motors used to drive the winder. A six-day shutdown has been allowed for installation and commissioning of this equipment, which also includes two new DC circuit breakers.
The new equipment in both contracts replaces the old power feed and regulation equipment first supplied and installed by AEG (now ALSTOM together with its other founder companies GEC and Alsthom) when the winder was erected in 1979.
The scope of the two contracts awarded to ALSTOM Industry to date encompasses in both cases design, manufacture, supply, installation and commissioning. ALSTOM Power Conversion of Germany manufactures all the equipment, which is part of a standard product range and customised for specific applications and the equipment will be installed by ALSTOM Industry.
ALSTOM Industry is part of black economic empowerment (BEE) group ALSTOM SA (Pty) Ltd, in which the BEE equity currently stands at 38 per cent. The group’s BEE shareholders are Tiso Private Equity (Pty) Ltd, Kagiso Ventures Private Equity, Kgorong Investment Holdings (Pty) Ltd, Sibilant Investments (Pty) Ltd and Management.
ALSTOM SA (Pty) Ltd employs 4 500 people and has an annual turnover in excess of R2bn. It has 25 operating units, including 2 empowerment subsidiaries, 20 production facilities and 21 distribution centres throughout Southern Africa.
ALSTOM SA has exclusive distribution, technology and representation rights for ALSTOM and AREVA in Southern Africa and maintains management and commercial links to the ALSTOM and AREVA business units in Europe.
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