AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Modeling and Optimization of Wearable Personal Dust Exposure Monitor (WPDEM) for Underground Mines
MANDANA HAJIZADEHMOTLAGH, Omid Mahdavipour, Igor Paprotny, University of Illinois at Chicago
Abstract Number: 653 Working Group: Instrumentation and Methods
Abstract Lung disease in underground mining has been a long-standing health problem due to excessive exposure to respirable coal mine or silica dust. Consequently, underground mining operations must be controlled so that levels of respirable particles remain below regulatory standards set by Mine Safety and Health Administration (MSHA). Federal law stated that coal mine respirable particle dust concentrations in the work environment could not exceed 1 mg/m3 for 10 hour work shift. Current exposure limits to silica dust are set at 100 µg/m3. Lung damage due to chronic silicosis is irreversible, thus it is important to determine the miners exposure to silica dust, in addition to coal mass fraction.
In this work, we present a comprehensive numerical, analytical, and computational fluid dynamic modeling for a novel miniaturized wearable personal dust monitor, which can be used for continuous monitoring of respirable (ISO respirable convention) dust concentrations. Highly variable ambient operating conditions, including high dust concentration (up to 10 mg/m3), and high humidity are some of the challenges facing dust monitors being used in underground mining environment. To overcome those issues, we developed comprehensive design of a miniaturized direct read respirable PM mass sensing system consisting of a pre-dryer (elutriator), dryer, respirable fractionator and direct read Particulate Matter (PM) mass sensing element. This design allows for significant removal of the moisture water content of particles before they reach the fractionator and the mass-sensing resonator. Trade-off between flow rate, power consumption and design of the system were evaluated, and the design trade-offs are analyzed. The presented comprehensive numerical model can further be used to evaluate design trade-offs for other types of direct-read PM mass sensors.