Groundbreaking top-hammer drilling technology

Sandvik introduce RockPulse drill tool stress monitoring system for use in top-hammer applications

SANDVIK Mining and Rock Technology have introduced RockPulse – a new technology and product that is said to be the first practical solution for real-time tool stress monitoring in top-hammer drilling.

The add-on system integrates directly with the rock drill and its control system, and can be used for drilling process optimization in varying rock conditions.

By helping to reduce drilling tool stress fatigue, RockPulse is said to offer the potential to improve overall drilling performance by as much as 5%.

Profitable rock drilling requires a fine balance between drilling power and cost-efficiency. While the use of high drilling power is required for good performance, excessive power can be counterproductive, due to high stress levels and drilling tool wear.

Optimization of tool stress and, consequently, tool life are essential for cost-efficient drilling operations. Conventional drilling-control technologies have achieved this through indirect performance indicators only, such as percussion or feed pressures.

RockPulse analyzes each piston blow in real time to extract data on the tool stress. This allows operators to optimize drilling power and minimize inefficient use of percussion energy.

Stress waves created by the piston strikes are measured continuously using sensor technology developed and patented by Sandvik. The system consists of a Sandvik shank adapter and rugged contactless sensor inside the rock drill.

Stress wave signals captured by the sensor are analyzed within the drill rig’s Sandvik SICA control system. The system is available for new Ranger DXi drill rigs and RD920-series rock drills.

‘Our tests from real-life conditions show a 5% increase in average penetration rate, even though the percussion power was decreased by 4%,’ commented Jarno Viitaniemi, product manager for surface drilling at Sandvik Mining and Rock Technology.

‘Drill operators have also commented that RockPulse helps them to optimize bit re-grinding intervals and thus boost efficiency and productivity.’

The RockPulse user interface visualizes and provides alerts on three key parameters: drill bit response, tool load and feed level.

Drill bit response helps to minimize the strain on the tool by indicating how much of the impact energy is used for breaking rock and how much is reflected back to the tool string.

Tool load indicator shows the tensile stresses affecting the tool string, which helps to avoid underfeed in weak rock and excessive wear of drilling tools.

Feed level indication shows whether drilling is being done within the specified feed range – a key parameter for excellent hole quality and long tool life.

‘I realize this is a bold statement, but we believe RockPulse is a truly groundbreaking solution that marks the beginning of a new era in top-hammer drilling,’ said Mr Viitaniemi.