Coal Age Magazine - For nearly 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.
Issue link: https://coal.epubxp.com/i/347546
Joy Global's Wethead cutter system, a popular solution for coal mines, incorpo- rates a fine spray behind each cutting bit of the cutter drums to reduce the potential for frictional ignitions and to reduce respirable dust levels. The water spray acts as both a cooling and wetting agent in order to address both issues, and also provides bit life-extending lubrication for the machine — all while consuming less water. Regardless of a mine's size, Joy officials are fast to note that they have a solution that will fit the operation's needs and budget. "Base- level models like the 14CM15 and 12CM12 are standard across the industry," according to Director of Marketing and Application Engineering Brian Thompson. "They offer exceptional reliability and longevity in an entry-level package, [while] the 14CM27 and 12CM27 are also available in high-voltage configurations." In addition to its work on remote controls that incorporate operator assistance tools, automated sequences, advanced diagnos- tics and performance monitoring analysis, Joy Global's Faceboss control platform also allows for outby communications and advanced diagnostics in a user-friendly interface. Also, the SmartZone proximity detection system is now available on all Joy continu- ous miner models. The system's zones can be varied within limits to suit specific oper- ational designs, and are automatically adjusted in the cut mode and tram mode to provide both warning and shutdown zones. Joy Global's SmartConveyor technology encompasses sound abatement technology for mines that have returned noise level improvements of 45-65% in underground testing (versus standard machines). SmartConveyor, an option on all of Joy Global's current CM models, combines multiple technologies such as Joy's Dual Sprocket Conveyor Chain and auto-ten- sioning features. Overall, Joy Global CMs possess ele- ments that reduce noise levels. The first is the dual-sprocket continuous miner con- veyor chain and two parallel eight-tooth sprockets for increased torsional rigidity; together, they reduce the likelihood of abrupt chain breakage. Finally, using Joy polymer-coated con- veyor chains can provide an additional 3 dB reduction for the miner. "Utilizing the coat- ed conveyor chain along with previously proven controls for the CM chain conveyor will provide operators with the opportunity to be within the Mine Safety and Health Administration (MSHA) permissible expo- sure limit," Thompson said. Friends in Low Places Caterpillar has placed a sizable level of atten- tion to the low- to mid-seam mines of the U.S. over the last few years, and its newest available model for those applications, the CM235, was unveiled at MINExpo 2012. At 135,000 lb, it is among the most com- pact designs available from any OEM, and it has power all tied up with 2 x 205 kW/2 x 275 horsepower cutterhead motors. The CM235's motors are parallel to the cutter- heads, and they are perpendicular in the CM235T. Both have a variable frequency drive (VFD) traction system and have the same — and numerous other — features as other models in the CM200 series. Cat recommends the CM235 for seam heights of 43 to 116 in. (1,092 to 2,946 mm), with a minimum clearance of 27 in.; maximum cutting height on the unit is 128 in. (3251 mm) and has a total power of 940 hp, as well as a balanced power-to-weight ratio and loading rates of 15 to 32 tons per minute (tpm). The Machine Control Unit (MCU) is based on a mine-duty PLC and is designed to maximize coal production and operator safety while minimizing downtime, and traction motors are controlled by a micro- processor-based system, which minimizes electrical connections and enhances relia- bility. The MCU provides data logging, fast diagnostics and advanced troubleshooting capabilities. The control system is proximi- ty-detection system ready, and a radio remote control unit with self-diagnostics is available. The CM235 also has a graphic display to provide the condition of all motors and VFD components and the condition and position of hydraulic control valves and solenoids. Both standard and compact remotes are available to suit operator preference. Easy, simplified maintenance and access also can be found on the unit, with central- ized grease ports and fill points and easy- to-locate diagnostic ports and panels and a split cutterhead gear case for easier repairs as needed. Safety and health are another point of concentration for Cat, and on the CM235 and 235T, enhancements to both are found via a quieter dual-sprocket conveyor chain that permits lower ambient noise, and a hydraulic temperature and spool position monitoring (over CAN bus) herald a new level of safety in which the machine can determine points of failure and recognize valve malfunction. Looking ahead, the company said that electronic controls and technology are offer- ing good opportunities for mines' improved performance and simplified diagnostics. While rebuild orders are up versus new machine requests, the U.S. still is largely the leader in room-and-pillar innovation. The OEM is also planning to announce further enhancements to the CM235 later this year. On a related note, Caterpillar is also putting much effort into its scoop scene. Over four decades later in scoop engineer- ing and manufacturing, and more than 6,500 battery-powered units produced, the manufacturer and its predecessors have r o o m - a n d - p i l l a r m i n i n g c o n t i n u e d July 2014 www.coalage.com 29 Caterpillar recommends its CM235 for seam heights of 43 to 116 in. (1,092 to 2,946 mm).