Improved cab air inlet location reduces dust levels and air filter loading rates

"Enclosed operator cabs are widely used on mobile excavation equipment in the mining and construction industries. They protect the operator from bad weather, noise, and airborne dusts. The inside cab environment usually must be kept at very low dust concentrations because of quartz dust generated from the excavation of silica-bearing rock. Most cab designs achieve heating and air conditioning effectiveness by recirculating most of the interior cabin airflow, with a smaller portion of the outside air added to the cab as makeup air. Both the recirculated cab airflow and exterior makeup air added to the cabin should be efficiently filtered, with the makeup air positively pressurizing the cab interior. Ideally, operator cab air filters should provide at least 99% capture efficiency for dust particles as small as 0.3microm aerodynamic diameters. These higher efficiency air filters provide good dust control for the equipment operator, but tend to accumulate dust more quickly than lower efficiency air filters." - NIOSTHTIC-2NIOSHTIC no. 2000098