Siemens awarded winder contract

A consortium consisting of the

Industrial Solutions and Services Group (I&S) and Siemag, Netphen, has received an order from Xinji Energy to supply two electric winders for the Liuzhuang coal mine.

Siemens said in a statement that it would be responsible for the electrical equipment, which includes motors with converters, as well as the associated power supply, the closed-loop control system and the safety equipment. The new winders are to start operating in April 2006.

The production shaft of the Liuzhuang mine to the north of Hefei in Anhui province has a production capacity of around eight million metric tons of coal per year. The main shaft is eight metres in diameter and is being equipped with two dual-compartment skip hoisting systems, each with a payload of 40 metric tons. The winding speed is 12 metres per second, which is just under 50 kilometres an hour. The winding tower in which the winders are to be accommodated is around 70 metres high and the haulage distance is 775 metres.

The two six-rope winders have a diameter of 4650 mm. The motors are integrated in the rope drums. This enables symmetric loading of the winder, a factor which in turn makes the machine very stable in respect of a constant air gap between the stator and rotor. The two winders can be mounted next to each other on one machine platform in the winding tower.

Siemens is supplying the external-rotor synchronous motors, each with an output of 5.5 megawatts, including the associated Simovert D 12-pulse cyclo-converters. The motors and converters are air-cooled. The drives are controlled (Winder Technological Control, WTC) via the FM458 Simatic application module.

In order to improve safety, the control system has a two-channel structure, whereby the signals of the two channels are compared with each other continuously. An error triggers a “watchdog” module, which then immediately stops the drives and applies the safety brakes. For purposes of operator control and visualisation, there are two operator control consoles with a visualisation system.

The scope of supply also includes high-voltage transformers, the low-voltage switchgear as well as fans for the motors. Siemens will also be responsible for in situ commissioning.