By Edited by Laura Carrabine, Senior Editor
Software plays critical role in drill bit design that widened escape route for the trapped Chilean minors.
As the world watched the rescue of 33 Chilean miners who were trapped 2,000 ft underground for two months, few knew that a redesigned drill from Center Rock Inc. made the rescue possible. Center Rock is a manufacturer of drilling supply equipment. The company’s pneumatic bits use wear-resistant carbide and diamond tips on a series of rotating hammers. Unlike the bits in conventional rotary drills, Center Rock’s percussive hammer bits can tunnel through even the hardest, most abrasive rock, as was the case at the San José Mine in Chile.
With the results of a SolidWorks Flow Simulation study, Center Rock customized its percussive rock bit design to let cuttings fall by gravity, accelerating the rescue of the miners.
Developing its industry-leading technology demands 3D design and simulation tools,according to Rudy Lyon, Center Rock’s senior engineer and product development manager. “Designing an effective percussion rock bit is challenging,” Lyon explained. “You have to visualize how the hammers will function underground, analyze the structural stresses involved, and understand the impact of air flow on cuttings removal. We usually perform these simulations concurrent with the design process, but, at critical times, we need to conduct simulations and redesign bits during an actual deployment. That was the scenario during the Chilean mine rescue.”
Center Rock also relies on 3D technology to meet its product expansion goals. “Not every bit satisfies every situation,” Lyon added. “There are different sizes of drill holes, several types of drilling rigs, and rock of varying density, hardness, and thickness. To meet the full range of customer demands, we need to design and manufacture an extended line of products.”
To meet its product development objectives, Center Rock acquired SolidWorks 3D design and simulation software products, including SolidWorks Professional and SolidWorks Premium design software, and the SolidWorks Simulation Premium and SolidWorks Flow Simulation applications for nonlinear structural and CFD analysis. Center Rock chose SolidWorks software because it is easy to use for multidisciplinary engineering and provides an integrated suite of design visualization and simulation solutions.
A race against time
During the Chilean mine rescue, expanding the 5½-in. probe hole – first to 12 in. and then to 28 in.– using a Center Rock CR120 hammer and hole opener and then a 28 in. Low Profile multi-hammer, was one of three simultaneous rescue attempts. Most estimates projected that the rescue would take at least four months. Using Center Rock drill bits and drilling rigs from Schramm, Inc., “We believed we could drill the hole faster than that,” Lyon said.
Center Rock used the software tools to expand its drilling supply equipment.
Center Rock’s assertion proved to be right when the rescue team pulled the 33 miners to safety inside a 28-in. wide escape capsule on October 9, 2010. Many watched the miraculous event unfold on television. However, only the Center Rock team knew about the important contribution of SolidWorks Simulation in the redesign of the bit that enabled the miners to return to the surface two months ahead of schedule.
Simulation crucial to redesign
Using SolidWorks Flow Simulation, Center Rock designed the bit to let drill cuttings fall into the mine. “The SolidWorks Flow Simulation studies helped us customize the tool by putting a band around the bit, so that two-thirds or more of the air went down the shaft,” Lyon recalled. “We needed an adequate split of air to let the cuttings fall by gravity, where the trapped miners kept busy clearing about eight dump-truck loads of spoil. SolidWorks Flow Simulation allowed us to reconfigure the tool and reach the miners faster.”
When the drilling slowed because the bit hit a metal rock-bolt support, Center Rock used SolidWorks nonlinear analysis studies to redesign the bit, resolve the snag, and continue drilling. “SolidWorks Simulation Premium helped us tweak the bit by thickening the space between the carbide buttons,” Lyon explained. “We ran the analysis, did the redesign, manufactured the new design, and delivered the bit in just three days. The ease of use and integration of SolidWorks Simulation analysis tools helped the process go much faster and provided reassurance that we had done the best we could.”
Efficiency expands product offering
SolidWorks solutions also have helped Center Rock develop new products more efficiently. In fact, the company has quadrupled its product offering while cutting design cycles by 66%.
“Many of our products come in different sizes,” said Lyon. “Using SolidWorks design configurations we can develop product families three times faster, taking advantage of standardization and design reuse. We also use eDrawings as our standard file format for document control. SolidWorks solutions support high-end engineering and manufacturing and give us the ability to quickly turn on a dime when necessary.”