A new air flow system — which operates on low pressures — from Atlas Copco Secoroc, Commerce City, Colo., is designed to boost rotary drilling performance by combining the best of down-the-hole (DTH) and rotary drilling technology.

The new Secoroc PARD system combines a high frequency, low impact DTH hammer and a specially designed tricone drill bit that’s mounted onto a standard rotary drill rig and drill string. The result is a combination of percussive power and rotational force that provides up to 50% increases in the rate of penetration.

The Secoroc PARD hammer operates on pressures from 50 to 110 psi, which is low compared to standard DTH hammers. They would normally operate at pressures of 350 psi.

Optimal air flow is achieved with the proprietary Secoroc PARD parallel air flow system, which distributes air proportionately between the hammer and tricone drill bit.

According to Clarence Zink, product specialist — Rotary Drilling Products, “With Atlas Copco Drilling Solution (ADS) drills, drill air compressors can deliver 100% volume at up to 110 psi, although this level of pressure is not needed. Volume still is 100% at the lower pressures on ADS drills. Other manufacturer’s drills deliver a maximum of 100 psi, 80 psi, 65, or 60 psi, depending on manufacturer. The competition product cannot operate on drills that deliver less than 90 psi, which limits their application range. The Atlas Copco PARD system can operate quite effectively at 60 to 80 psi.”

The Secoroc PARD tricone bits can withstand the additional stresses and strains and still retain the same service lives of standard tricone bits. All this adds up to more holes drilled per shift and lower total drilling costs (TDC).

The Secoroc PARD system is ideal for large mines and quarries, where blast hole diameters from 978 to 1214 in. are standard. Two models are currently available – Secoroc PARD 10 and Secoroc PARD 12 – and a comprehensive selection of Secoroc PARD tricone bits are available.

Operation is done hydraulically, says Zink. “Rotation (bit speed) and pulldown (bit loading force, or weight on bit) are applied hydraulically to the drill pipe via multi-pump hydraulic drive gear boxes driven by diesel engines,” he says. “Rotation is driven by one pump, Pulldown by a second pump.”

Visit www.atlascopco.us for information or contact Rob Fournier, Product Line Manager - Rotary Tools, Atlas Copco Construction Mining Technique USA LLC at (303) 253-6903, ext. 12603 or rob.fournier@us.atlascopco.com.