Howden is looking to re-enter the Australian secondary ventilation market with a bang, coming out with a new product that offers the energy efficiency, durability and smarts to help ‘future proof’ underground mines.

Its Jetstream AX secondary fans were launched across the globe this month, with service centres on the east and west coast of Australia having already received units.

Phil Durham, Global Mining Applications Engineer, said the Jetstream AX secondary fan is the missing piece to complete the full Howden ventilation puzzle.

“Howden, in the past, was heavily involved in the secondary market in Australia, but some years after exiting this space, the new Jetstream AX is filling the gap in our lineup, helping complete our total mine ventilation solution approach,” he told IM. “Howden has the Ventsim™ DESIGN software, the Ventsim CONTROL ventilation on demand software, plus all the required equipment including a comprehensive primary fan offering, mine cooling options and mine heating options.

“A global secondary fan was needed to complete the set, meaning we can now be considered a one-stop shop for miners wanting to go down the full Howden route for ventilation.”

While the Jetsteam AX will be available in all markets – bar USA where Howden already has a secondary fan offering – Howden sees it being particularly relevant for the Australian market where evolving diesel particulate emission regulations are making effective ventilation operations a must.

“These regulations will definitely affect how those mines manage, monitor and control their ventilation network,” Durham said. “The smart move would be to use their secondary fans more efficiently in terms of how and where they are locating them, which ones are operating and tightening up on where the working areas, vehicles and personnel are.

“In this respect, the Australia region is a key one in terms of the secondary fan product rollout.”

Just some of the attributes the region’s miners could benefit from, according to Howden, include:

• The highest fan output at low power consumption, providing high efficiencies across a broad operating range;
• A range of fans from 762-1,600 mm in diameter, with flow rates from 6.5-108 cu.m/sec;
• Single-stage or twin-stage configuration;
• A flexible modular design providing commonality of parts;
• Adjustable pitch aerofoil blades to maximise operational envelope and provide reliable high-efficiency aerodynamic performance across a wide range;
• An anti-stall chamber for continued safe operation during transient high-pressure events, offering a “risk-free process” in parallel fan arrangements; and
• Downstream guide vanes with full inner fairing tube and tail cone in each fan to ensure maximum static pressure regain.

Durham expanded on some of these.

“That main inner fairing tube serves a couple of purposes, with one of the main ones being a reduction in shock losses,” he said. “That same design helps from a maintenance perspective, too, providing protection for the motor. In other ventilation fan designs, the motors are exposed to the dusty mine air. The inner tube provides a good level of protection, without being a totally sealed environment. Some air gets through for motor cooling purposes, but it is much less than your typical exposed fan.”

The option of a dual-speed fan could also be important for gaining sales in Australia given there are limited variable speed drive options in this market than others, according to Durham.

“In Australia, specifically, variable speed control is not a very common option due to the required 1,000 V supply,” he said. “Currently there are no proven reliable variable speed drives at such voltages.”

This dual-speed fan offering provides the mines with high and low speed settings – with high typically employed to, for example, clear blasting gases and low employed when a vehicle leaves the airway, and the ventilation demand reduces.

To get the best out of dual-speed fans, mines will most likely require remote access to easily switch from one setting to the next, according to Durham.

Miners that understand the benefits of using dual-speed fans – reducing energy consumption and costs – will also, most likely, be potential customers for Howden’s ventilation on demand and smart ventilation solutions, namely Ventsim CONTROL.

“We are definitely seeing an increase with the number of mines looking to adopt these new technologies and smarter ventilation control methods,” Durham said. “As they are moving towards digitalisation and automation of mining methods, ventilation is also coming into that equation. This is especially so when you consider that the energy cost coming from ventilation and cooling can be around 50% of the mine’s total expense.”

The use of effective secondary fans is part of that exercise, according to Durham, who said efficiencies of over 85% are possible with these units when used optimally.

“Although the primary fans are generally a much higher kilowatt rating, these mines usually have quite a number of secondary fans in operation,” he said. “Being able to use them in a smarter way on a day-to-day basis means they will be able to make some large savings there.”