Approximately 70 kilometers south of Katowice in Upper Silesia is located the Pniowek coal mine. This mine, which belongs to the Jastrzebska Wolka Weglowa Group, does not only deliver the “black gold” much in demand, but also methane gas on a large scale.

It is common practice to burn off the pit gas in the surface area, which just means wasting it. This has changed now: Since May 2000, Pniowek is the first mine in Poland using the methane gas for pit cooling. The gas is collected and fed to a gas turbine on surface. As a result, electrical energy of more than 5MW is produced, which Pniowek themselves are using for operating their machines and facilities. Nearly the same amount of energy is fed via a compressor into the mine for cooling the galleries and faces.

In this process, SIEMAG’s PES three-chamber pipe feeder takes the function of a pressure exchanger. It uses the principle of “communicating pipes” and is controlled such that a cooling power of approximately 5MW is exchanged with very little energy expenditure. The PES is installed underground and transfers the high pressure of the chilled water coming from the surface cooling plant to the return water that goes back to surface – while the cooling circuit underground runs at low pressure.

Thanks to the inside insulation of the pipe chambers, the cooling water leaves the pipe feeder underground after a temperature rise of 0.5°C only, which means low energy loss and operating costs. The sound construction of the PES and it’s insensibility to soiling in the cooling medium grants a high availability.

The complete control system of the PES, the monitoring as well as the visualization were planned and realized by SIEMAG. This offers the customer the possibility of having maintenance and inspection jobs done by SIEMAG’s specialists in Netphen with the aid of remote diagnostics.

16 PES three-chamber pipe feeder systems built by SIEMAG are in operation at different mining companies in the world and prove the advantages of this solution and the excellent performance of our equipment.