Title: DPM Dispersion Study Using CFD for Underground Metal/Nonmetal Mines
1DPM Dispersion Study Using CFD for Underground
Metal/Nonmetal Mines
12th Mine Ventilation Symposium Reno, Nevada USA
- Yi Zheng yzz59_at_mst.edu
- Jerry C. Tien tien_at_mst.edu
- Mining Nuclear Engineering Department
- Missouri University of Science Technology
2OUTLINE
- DPM Regulation for U/G M/NM Mines
- DPM Situation and Control Strategies
- Simulation Method and Assumption
- Main Airflow Simulation
- Single Heading Airflow-Blowing Exhausting
- Results and Discussion
- Summary and Conclusions
3DPM Regulation for U/G M/NM Mines
- Diesel-powered equipments are widely used in U.S.
U/G M/NM mines for the power, reliability, easy
to operate and repair, fuel efficiency,
durability, etc. - However, it can cause health problems.
- Therefore, beginning May 20, 2008, 160 µg/m3 of
TC or less is required by MSHA.
4DPM Situation
- 2001 - 2002, MSHA 358 valid samples from 30
mines - 488 µg/m3 of TC for metal mines, 372 µg/m3 of
TC for stone mines - 2002 - 2003, MSHA 1,194 valid DPM from 183 mines
- 354 µg/m3 of TC for metal mines, 235 µg/m3 for
stone mines - 2003 2006, MSHA 1,798 valid samples from all
mines covered by the regulation - 64 (1,151) exceeded 160 µg/m3 of TC
5DPM Control Strategies
- MSHA six available DPM control strategies
- Modern low-DPM emission diesel engines
upgrade ventilation system environmental cabs
work practices alternative fuels DPM filters. - Ventilation is a critical one
- 1 gram of DPM can pollute 6,250 m3 of space to
final limit if without ventilation. -
6Simulation Method and Assumption
- Simulation Method Computational Fluid Dynamics
- Program FLUENT
- Assumption
- DPM movement will be entirely dictated by the
airflow patterns -
7Main Airflow Simulation
South section of an underground metal mine
8Main Airflow Simulationwithout Stoppings
Path of small particles without stoppings
9Main Airflow Simulationwith Stoppings
Stoppings to guide the air
10Main Airflow Simulationwith Stoppings
Path of small particles with stoppings
11Main Airflow Simulationwith Stoppings
Three types of working face with ventilation
problems
12Main Airflow Simulationwith Stoppings
Main airflow velocity near the dead end opening
13Single Heading Airflow Simulation
Single heading
Main entry
Layout of a single heading with blower fan and
tubing
14Single Heading Airflow Simulation
Layout of a single heading with exhaust fan and
tubing
15Single Heading Airflow Simulation
CAT 725 articulated truck
CAT 980H wheel loader
16Results and DiscussionBlowing System
Airflow velocity of the main entry and single
heading
17Results and DiscussionBlowing System
Airflow velocity in the face area
18Results and DiscussionBlowing System
Exhaust airflow pattern in the face area
19Results and DiscussionBlowing System
DPM concentration dispersion in the face
20Results and DiscussionExhausting System
Airflow velocity of the main entry and single
heading
21Results and DiscussionExhausting System
Airflow velocity in the face area
22Results and DiscussionExhausting System
Exhaust airflow pattern in the face area
23Results and DiscussionExhausting System
DPM concentration dispersion in the face
24Summary and Conclusions
- 1. CFD method can be used to simulate the
airflow patterns for the entire mine or for a
part of it. Areas with poor ventilation can be
identified and local ventilation control measures
designed and evaluated. - 2. Single heading face usually has the worst
working condition in underground mines. Local
ventilation facility is needed to improve the
situation. - 3. In a single heading face, loader driver is
working in a higher DPM environment for both
blowing and exhausting systems. More work need to
be done to meet the regulation.
25Summary and Conclusions
- 4. DPM is distributed in a much smaller space in
a blowing face ventilation system than in an
exhausting face system, which means high air
velocity is more effective than quantity to
control DPM. - 5. In the near future, a validation experiment is
planed to take out. After that, a single
measurement in the face (near the exhaust pipe)
can give the DPM concentration distribution for
the whole face area.
26Thank You!