Coal Age Magazine - For more than 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/718122
68 www.coalage.com August 2016 product news Fletcher Offers Dry Scrubber to Improve Operator Environment J.H. Fletcher & Co. recently released a new product to improve the roof bolter opera- tor environment. The machine, known as a dry scrubber, is supported by field testing, and backed by a long history in dust sup- pression. The dry scrubber is permissible and has the ability to operate in a variety of applications, making it a complement to the Fletcher roof bolting product line. The need for this product is evident, as dust concentrations downwind of the continuous miner can exceed regulatory standards and overexpose roof bolter op- erators. In underground mining, onboard flooded bed scrubbers are used on con- tinuous mining machines for respirable dust collection. Though these systems are proven, dust bypassing the continuous miner scrubber may expose roof bolter operators to high levels of respirable dust when working downwind of the continu- ous miner. J.H. Fletcher & Co. was a pioneer in dust collection, receiving patents as early as the 1950s. When maintained, Fletcher's Mine Safety and Health Administration (MSHA)-approved onboard dry dust col- lectors are proven to remove the respi- rable dust generated from roof bolting. With this background, Fletcher's research and development department developed the MSHA-approved Fletcher dry air scrubber. The machine is a stand-alone, self-propelled, electrically powered venti- lation fan. The machine has two operating modes: tram and ventilation. While in tram mode, the fan cannot be operated. The dry air scrubber is engineered to be positioned between the rib and vent curtain. The unit then works to clean contaminated air be- fore it enters the roof bolter work space, working to provide roof bolter operators with a cleaner air supply and lowering their exposure to respirable dust. The design reflects Fletcher's diversity in the underground mining sector, with the ability to fit into a variety of mines. The dry scrubber is 16.5 ft long and 4.5 ft wide, equipped with 12-in. crawler pads. The dry scrubber pulls a portion (up to 9,000 cfm) of the air flowing between the rib and the vent curtain into the filters on the inlet side of the fan. Filtered air is directed out of the machine and back into the main air stream. A pressure sensor ar- rangement is used to monitor filter condi- tions to alert the operator when the filters need to be replaced. A hydraulically oper- ated hood and pivoting electrical control- ler allows access to the air filters. The fan speed and resulting airflow is controlled by a variable frequency drive (VFD). This allows the mine to select an airflow controlled with a feedback loop to automatically adjust the fan speed to maintain a constant airflow output as the filters are loaded with dust. NIOSH laboratory tests found that the dry scrubber averaged greater than 95% re- spirable coal dust removal while being oper- ated at two different fan airflow speed quanti- ties of 3,000-9,000 cfm. Underground studies found a collection efficiency of 99.2%. Other potential applications for the dry scrubber include belt conveyor trans- fers, underground truck dumps, single entry air cleaning, and diesel particulate matter removal. www.jhfletcher.com Hilliard Unveils New Braking System At MINExpo 2016, The Hilliard Corp. will unveil new braking systems that use cali- per brakes that it has developed, tested and certified. For more than 30 years, the com- pany has been supplying braking systems for draglines, electric shovels, conveyors, mine hoists and mills. The new systems, according to Rick Kallenborn, regional sales manager for Hilliard, will replace existing systems with a more standardized product that is more user-friendly and will allow miners to reduce their parts inventories. "We have made a lot of modifications to improve longevity and the ease of oper- ation, using what we have learned over the years to correct the problems that these systems sometimes encountered while operating," said Ben Heater, engineering product manager for Hilliard. "The Hilliard engineers that developed these braking systems are the same engineers that spent years servicing them in the field." Since the early 1980s, Hilliard has been distributing brakes for Twiflex Ltd. and now the company is designing and manufacturing its own brand of brakes, explained Mark Rose, marketing manag- er for Hilliard. "In 2007, Hilliard started to consider new designs and improvements for brakes that no other manufacturer This permissible unit from Fletcher scrubs dry up to 9,000 cfm of air.