1
25-093
Three-Dimensional Ventilation Modeling of a Large-Opening
Stone Mine Using COMSOL Multiphysics
K.V. Raj
CDC NIOSH Pittsburgh Mining Research Division,
Pittsburgh PA
Vasu Gangrade
CDC NIOSH Pittsburgh Mining Research Division,
Pittsburgh PA
ABSTRACT
Airflow in large-opening stone mines is largely dependent
on the natural ventilation due to the large cross- section
area of the opening. The openings of such stone mines are
typically twice or thrice the size of typical underground coal
or metal/nonmetal mines. Due to the influence of natural
ventilation, air velocities as well as the static pressure drop
in the mines are low. Mines rely on auxiliary fans to ven-
tilate active faces to reduce contaminant exposure to mine
workers. The National Institute for Occupational Safety
and Health (NIOSH) is conducting research on ventilation
of large-opening stone mines to reduce worker exposure
to dust and other contaminants such as diesel particulate
matter (DPM). In order to reduce worker exposure to dust
and DPM, an understanding of the airflow pattern due to
auxiliary fans in the mine is needed. Under this research,
NIOSH researchers are exploring the computational fluid
dynamics (CFD) modeling to understand the airflow
behavior in large-opening mines. In this paper, the team is
presenting the results from three-dimensional CFD model-
ing of airflow in a large-opening stone mine and investigat-
ing the effect of a fan placement with the movement of
trucks.
INTRODUCTION
Underground stone mines produce a wide range of material
such as limestone, marble, sandstone, etc. for the construc-
tion industry that is needed for infrastructure development.
As of 2020, there are 4,248 stone mining operations with
110 underground operations in the United States [1]. The
majority of the underground stone mines produce broken
limestone according to the standard industrial classification
(SIC) system. These underground limestone mines are
characterized by mine openings which are larger than the
openings as compared to those of coal and metal/nonmetal
mines. The mining method for large-opening limestone
mines is room-and-pillar which is similar to coal mines.
However, the dimensions of these underground mines are
twice or thrice of the typical coal mines. The large openings
and the inner dimension of the limestone mines creates a
unique challenge to ventilate these mines. Due to the large
dimensions, airflow in the mine is mainly influenced by
natural ventilation with little differential pressure change at
two locations in the mine. Due to the relatively small num-
ber of large opening mines not much attention was given
to understand and address unique ventilation issue related
to large-opening mines.
In the early 2000s, the National Institute for
Occupational Safety and Health (NIOSH) started conduct-
ing research to improve air quality by reducing contaminants
such as diesel particulate matter (DPM) in large-opening
mines. These studies looked into ventilation, fan selection,
stoppings, and mine planning to reduce the contaminants’
level in large-opening mines [2]. The research suggested that
large-opening mines face three primary ventilation chal-
lenges: moving adequate volumes of ventilation air, con-
trolling and directing the airflow, and planning ventilation
systems that work well with production requirements [3].
Multiple studies were also conducted that showed increased
suitability of propeller fans for low-resistance ventilation
systems present in stone mines compared to the vane axial
fans commonly applied in coal mines [4, 5]. Studies on the
effectiveness of different large- opening stone mine venti-
lation stoppings showed steel stoppings were effective for
25-093
Three-Dimensional Ventilation Modeling of a Large-Opening
Stone Mine Using COMSOL Multiphysics
K.V. Raj
CDC NIOSH Pittsburgh Mining Research Division,
Pittsburgh PA
Vasu Gangrade
CDC NIOSH Pittsburgh Mining Research Division,
Pittsburgh PA
ABSTRACT
Airflow in large-opening stone mines is largely dependent
on the natural ventilation due to the large cross- section
area of the opening. The openings of such stone mines are
typically twice or thrice the size of typical underground coal
or metal/nonmetal mines. Due to the influence of natural
ventilation, air velocities as well as the static pressure drop
in the mines are low. Mines rely on auxiliary fans to ven-
tilate active faces to reduce contaminant exposure to mine
workers. The National Institute for Occupational Safety
and Health (NIOSH) is conducting research on ventilation
of large-opening stone mines to reduce worker exposure
to dust and other contaminants such as diesel particulate
matter (DPM). In order to reduce worker exposure to dust
and DPM, an understanding of the airflow pattern due to
auxiliary fans in the mine is needed. Under this research,
NIOSH researchers are exploring the computational fluid
dynamics (CFD) modeling to understand the airflow
behavior in large-opening mines. In this paper, the team is
presenting the results from three-dimensional CFD model-
ing of airflow in a large-opening stone mine and investigat-
ing the effect of a fan placement with the movement of
trucks.
INTRODUCTION
Underground stone mines produce a wide range of material
such as limestone, marble, sandstone, etc. for the construc-
tion industry that is needed for infrastructure development.
As of 2020, there are 4,248 stone mining operations with
110 underground operations in the United States [1]. The
majority of the underground stone mines produce broken
limestone according to the standard industrial classification
(SIC) system. These underground limestone mines are
characterized by mine openings which are larger than the
openings as compared to those of coal and metal/nonmetal
mines. The mining method for large-opening limestone
mines is room-and-pillar which is similar to coal mines.
However, the dimensions of these underground mines are
twice or thrice of the typical coal mines. The large openings
and the inner dimension of the limestone mines creates a
unique challenge to ventilate these mines. Due to the large
dimensions, airflow in the mine is mainly influenced by
natural ventilation with little differential pressure change at
two locations in the mine. Due to the relatively small num-
ber of large opening mines not much attention was given
to understand and address unique ventilation issue related
to large-opening mines.
In the early 2000s, the National Institute for
Occupational Safety and Health (NIOSH) started conduct-
ing research to improve air quality by reducing contaminants
such as diesel particulate matter (DPM) in large-opening
mines. These studies looked into ventilation, fan selection,
stoppings, and mine planning to reduce the contaminants’
level in large-opening mines [2]. The research suggested that
large-opening mines face three primary ventilation chal-
lenges: moving adequate volumes of ventilation air, con-
trolling and directing the airflow, and planning ventilation
systems that work well with production requirements [3].
Multiple studies were also conducted that showed increased
suitability of propeller fans for low-resistance ventilation
systems present in stone mines compared to the vane axial
fans commonly applied in coal mines [4, 5]. Studies on the
effectiveness of different large- opening stone mine venti-
lation stoppings showed steel stoppings were effective for