Longwall shearers have been designed to combat coal dust and battle black lung.
As an eighth miner is identified with black lung in Australia this year, and fears rise of at least 12 potential cases being confirmed by the end of 2016, the industry is turning to new technology and methods to cut the potential for workers’ exposure.
The University of Kentucky’s Alliance Coal chair in the Department of Mining Engineering’s Thomas Novak and assistant professor Chad Wedding have developed functional, full-scale models of longwall shearers featuring scrubber systems that can reduce operators’ exposure and cut the potential for Coal Workers’ Pneumoconiosis
“Scrubbers aren’t new to underground mining,” explained Novak.
“Continuous mining operations — which are different from longwall mining operations — have used what are called flooded bed scrubbers successfully for quite some time; basically, we are trying to bring what we know works for one method of mining to another method that suffers from more difficult dust control.”
As longwall shearers face height restrictions, it is not simply a case of retrofitting scrubbers on to existing machines; due to this Novak and Wedding have incorporated their scrubber into a new shearer design.
The University of Kentucky explained that the placement of the scrubber is crucial.
“Because the dust must be captured before it is dispersed into the air and diluted, the scrubber inlet needs to be near the cutting drum, which cuts into the longwall face; however, if it is too close, large coal particles may clog the scrubber bed. Computational fluid dynamics (CFD) modelling played a critical role in helping the team place the scrubber’s large centrifugal fan and ductwork.”
Based on the CFD modelling, Novak and Wedding 3D printed a small-scale version of the shearer design, after which they began building a working 20 metre model, which will be transported to the Pittsburgh Research Lab of the National Institute for Occupational Safety and Health (NIOSH), where they can test the scrubber’s capabilities in NIOSH’s longwall dust gallery.
“There wouldn’t be any way to test this prototype due to its size and the disruption it would cause to a mining operation,” Wedding said.
“That is why it is important that we are able to use the longwall gallery at NIOSH, which closely simulates a longwall face. Currently, we are working on building a similar gallery for continuous mining in Georgetown, Kentucky [in the US].”
The project was supported by Joy Global and Alliance Coal, and funded by the Alpha Foundation for the Improvement of Mine Safety and Health.