Rockmore International, the global manufacturer of rock drilling tools for DTH and top-hammer drill rigs, is to introduce the ROK 250 – a new 2 inch class DTH hammer – at the upcoming CONEXPO-CON/AGG exhibition in Las Vegas in March 2014. This new addition to the broad range of Rockmore’s high performance DTH hammer line is described as “a breakthrough for DTH drilling technology.”
The ROK 250 model is considered to be the first 2 in class DTH hammer ever developed to operate under high air pressure levels up to 350 psi (24 bar) and beyond. With a 2.6 in (66 mm) wear sleeve diameter, the ROK 250 is designed to drill 3 in to 3.5 in (76 mm to 89 mm) diameter holes at high penetration rates. “We recognised a niche market segment in the DTH drilling sector that could utilise higher air pressure input levels to improve hammer penetration rates and drilling performance for hole requirements as small as 3 inches (76 mm),” said Pejman Eghdami, Executive Vice President of Rockmore.
Traditional 2 in DTH hammers suited to drilling 3 in (76 mm) holes are not designed to withstand higher operating air pressures and are often limited to 145 psi (10 bar). The low energy values at such pressure levels result in poor hammer performance and low penetration rates, thus increasing overall drilling costs and adversely affecting hole diameter selection. “Our design team faced the arduous challenge of developing a compact 2 in class DTH hammer to withstand the technical demands of utilising higher input air pressure to produce exceptional hammer performance levels similar to larger high pressure rated models,” commented Eghdami.
The ROK 250 exhibits excellent drilling performance in DTH applications for smaller diameter blast holes and construction projects that demand high drilling efficiencies and faster drilling rates by utilizing larger compressors rated up to 350 psi (24 bar) and beyond. The new ROK 250 model offers exceptional performance by incorporating the patented Rockmore SonicFlow technology, which optimises airflow in the hammer. This is achieved by simplifying and streamlining the air paths to minimise detrimental back flow and turbulence, resulting in maximum energy to the piston. This optimised energy level is transferred to the bit and rock formation to promote ultra high performance hammer characteristics.