US researchers create longwall shearers to combat coal dust in mines
Researchers from the University of Kentucky in the US have developed full-scale models of longwall shearers featuring scrubber systems that can help reduce operators' exposure to coal.
The longwall shearer helps combat dust emissions, and was created by the University of Kentucky Department of Mining Engineering Alliance Coal chair Thomas Novak and assistant professor Chad Wedding.
Novak said that around 50% of all coal produced underground comes from longwall mines.
Although these mines are productive, they are not effective at reducing the amount of dust generated by longwall shearers, which extract the coal.
Novak said: "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."
The electrical and computer-control system for the scrubber has been designed by Novak, while Wedding fabricated all of the components with the help of the college's machine shop.
Wedding also used a 3D printer to create a mold for the scrubber's 32 cutting picks.
Novak and Wedding have incorporated their scrubber into a new shearer design. This is because longwall shearers face vertical height restrictions and it is not possible to attach a scrubber onto an existing machine.
The team was able to place the scrubber's large centrifugal fan and ductwork with the help of computational fluid dynamics (CFD) modelling.
Based on CFD, Novak and Wedding 3D printed a small-scale version of the new shearer design and later on worked on producing the 65ft full-scale model.
The team plans to transport the shearer to Pittsburgh Research Lab of the National Institute for Occupational Safety and Health (NIOSH) to test its capabilities in the lab's longwall dust gallery.
The project received support from Joy Global and Alliance Coal, and was funded by the Alpha Foundation for the Improvement of Mine Safety and Health.
Image: Novak and Wedding created a full-scale model of a longwall shearer to combat dust emissions. Photo: courtesy of UK College of Engineering.