Australian company improves secondary mine ventilation

Minetek’s secondary mine ventilation system, based on a high output axial fan system, uses the company’s patented Mine Air Control (MAC) system to maximise return from its performance-on-demand (POD) units, which automatically sense how much air is needed in any one heading at any time. Each solution is engineered and manufactured in Australia specific for the end user.

While these secondary underground fans strategically optimise air flow, they eliminate much of the power traditionally wasted in such applications while performing across a very large operating range and meeting broad regulatory compliance parameters.

Compared to the common standard twin stage axial fan ventilation systems, the Minetek High Output axial fan system is modular and provides:

• reduced energy costs
• adequate air at the face
• high levels of control
• sensor tracking to automatically adjust to real-time demand
• high volume compliance
• rapid blast dust removal
• reduced noise output.
   

According to Minetek’s Engineering Manager, Remy Bourcier, the company’s high output axial fan has been designed and manufactured in Australia completely with the underground mining industry in mind and the MAC control system brings the mine’s fan system together with complete automation.

“Until now, the market has to a certain limit used high-maintenance variable speed drives to provide some level of control to the air flow in secondary ventilation systems,” Bourcier said. “But our patented system works on high-pressure, steel fabricated impeller technology allowing operation at temperatures and conditions previously thought impractical for an axial fan — and we achieve this in seriously harsh environments.

“It’s in the area of energy costs where the real savings are found, and this is very tangible too. Various studies point out that between 42% and 49% of a mine’s energy costs are consumed by mine ventilation, with the figure of about 27% attributed to the cost of secondary ventilation alone.

“Typically, a fan consuming 190 kW with an electricity price of 15c per kW will cost $249,660 per year to run and may not even be properly compliant. Considering the average mine uses about 15 secondary fans, the total annual consumption costs around $3,744,900.”

Key to its high cost efficiency is the POD system — an electronic controller on the fan which allows the fan to be regulated from very low flow requirements right through to more than double the duty point of a traditional vane axial fan.

With the use of the MAC System RFID trackers, it constantly remains aware what items of underground mining equipment are moving into the heading, so the POD controller will automatically adjust the air volumetric flow required to provide sufficient air volume to disperse the gases and ventilate the area.

It will sense what specific truck has entered the tunnel and it will be aware of the size of its engine and the number of people it will be carrying, so it will automatically adjust to meet the demand for sufficient ventilation for the people in accordance with industry regulation.

Considering temperatures at the rock face can be up to 50°C, it is critical to ensure adequate ventilation is providing fresh and cool air reliably.

Being a modular solution, mine managers can add or take away things such as silencers or adapters, booster fans or even boost the system further through control options.

In normal underground mining conditions, the Minetek systems will operate significantly quieter, providing a noise level 8 dB less than a twin 110 kW system for the same volume flow.