New fluid coupling doubles productivity in Chinese coal mine

An additional 350,000 tpm of coal production has been made possible at the Chinese Sandaogou coal mine in the Shaanxi province, largely because of CPC 1600 AFC (armoured face conveyor) couplings installed at the mine. This fluid coupling can continuously transmit up to 1600 kW, roughly 60% more power than standard fluid couplings of comparable installation space. The XL profile design turbine wheel helps the fluid coupling achieve these statistics.

To be able to efficiently mine a coal face measuring 7 m high, 350 m wide and more than 3 km long, the operator of the Sandaogou coal mine required powerful equipment. Existing drive systems were not able to transfer the necessary power to the conveyor. The CPC 1600 couplings combine maximum power transmission and small size. Orders for three CPC 1600s have been delivered and are currently in use in the Chinese Sandaogou coal mine.

Motors and drive components

Tong Xiangyang, team leader of a coal face in the Sandaogou coal mine, said a benefit of the CPC 1600 was that there is no mechanical connection between the input side and the output side of the coupling. “We can run our motors up to speed without load. We switch the motors on one after another to avoid high current demands that would place an unnecessary load on our grid power system," Tong said. The fluid coupling protects the motors against overload. This overload protection is possible since the fill-controlled fluid couplings simply slip because of the hydrodynamic principle. This slip protects the drive components and the chain of the AFC against damage. Consequently, the fluid coupling maximises the availability of the entire system and its productivity.

"With the CPC 1600, users in Sandaogou can perform as many startups in a row as they wish," explained Tang Min, general manager of startup components at Voith in China. “This is important, for example, in order to break free a heavily loaded conveyor. In this way, the personnel avoid needing to manually clear the overloaded system, which is time-consuming and results in costly, unplanned downtime."

There have been no unplanned downtimes and production is running at considerably higher efficiency since the new AFC was commissioned in May 2012

Service life and production output

The Voith CPC 1600 hydrodynamic fluid coupling uses water as the operating medium. As a result, users avoid expensive explosion protection measures. Moreover, water is environmentally friendly and almost always available underground in coal mines. The fluid coupling power transmission is wear-free and requires little maintenance. The fluid couplings are resistant to environmental effects, such as dust, dirt and moisture and are ideally suited for rough use in the underground coal mining industry These features result in long life cycles.

The Sandaogou coal mine is located in Shaanxi province, roughly 700 kilometers west of Beijing. The mine has a current output of ten million tpa from two longwall coal faces. Before using Voith fluid couplings at one of the coal faces, the mine produced 5.8 million tpa. Thanks to the new couplings on one AFC, output has now risen by 4.2 million t.

Adapted from press release by Sam Dodson

Read the article online at: https://www.worldcoal.com/coal/16092013/new_mining_technology_at_chinese_coal_mine_50/