1
25-020
Computational Fluid Dynamics (CFD) Study of the
Impact of Powered Air-Purifying Respirators (PAPR) in
Underground Mining Operations
Luis Sanchez Gonzalez
The Pennsylvania State University,
University Park, PA
Ashish Ranjan Kumar
The Pennsylvania State University,
University Park, PA
Barbara Arnold
The Pennsylvania State University,
University Park, PA
ABSTRACT
Mining operations adopt a variety of measures to combat
dust underground. These include ventilation systems, water
sprays, physical barriers, and personal protective equipment
(PPE). Respirators are a class of PPE that can provide clean
particulate- free air to the users. Powered Air-Purifying
Respirators (PAPRs), used commonly in medical and other
sectors, are not prevalent in the mining industry. PAPRs
use P100 filters that have 99.97% dust capture efficiency.
We present our results from computational fluid dynamics
(CFD) simulations performed to understand the impact of
a PAPR on airflow and dust particle concentration in the
vicinity of a miner. These results show that donning PAPRs
can lower the miners’ exposure to respirable coal dust in
their workplace.
INTRODUCTION
Several processes in a mining facility generate dust particles.
These include mechanical excavation of minerals, attrition
during transportation, crushing, grinding, and others.
Many of these particles have aerodynamic diameters of less
than 10.0 µm. Most of them could be smaller than 4.0 µm
in size. These particles are considered respirable [1]. They
can travel deep inside the human respiratory system and
cause irreversible illnesses in the affected persons. Mining
operations, therefore, adopt several measures, such as artifi-
cial ventilation systems to dilute the particulate concentra-
tion under permissible limits. Water sprays are mounted at
strategic locations within the mine. The sprays not only cool
the cutting bits but also move the particles away from the
miners using the higher airflow momentum. Flooded-bed
dust scrubbers are installed on mining machines such as
continuous miners. They capture dust particles on fibrous-
type dust filters and are efficient under several conditions
[2]. Recent research has also investigated the performance
of novel non-clogging dust scrubbers, such as Vortecone
and impingement-type dust filters. Unlike fibrous filters,
these direct the motion of dust particles preferentially using
their momentum and capture them on engineered surfaces.
Their mechanical availability is much higher compared to
traditional scrubbers [3 4].
The scrubbers alleviate dust over a known flow domain.
However, they are also attached to the major equipment
and cannot protect the equipment operators or the min-
ers who move continuously close to the active mining face.
Therefore, personal protective devices (PPEs) are used to
capture the dust particles and lower their exposure to respi-
rable particulate matter. Powered Air-Purifying Respirators
(PAPRs) are an important class of PPEs that have been
demonstrated to capture 99.97% of airborne particles
using P100-rated filters [5]. Therefore, they are used in hos-
pitals and other settings where particulate exposure is criti-
cal to employee health. However, the mining industry has
not adopted them on a large scale. This manuscript pres-
ents the operations of a PAPR using numerical modeling
techniques. We developed computational fluid dynamics
(CFD) models to show the steady-state airflow in the vicin-
ity of the PAPR when placed in a controlled volume. We
also present our findings from transient-state simulations
that demonstrate particle transportation. We investigated
particles of 1.0, 2.5, 4.0, and 10.0 µm. We used Reynold’s-
Averaged Navier-Stokes (RANS) turbulence models to
develop these computer models.
25-020
Computational Fluid Dynamics (CFD) Study of the
Impact of Powered Air-Purifying Respirators (PAPR) in
Underground Mining Operations
Luis Sanchez Gonzalez
The Pennsylvania State University,
University Park, PA
Ashish Ranjan Kumar
The Pennsylvania State University,
University Park, PA
Barbara Arnold
The Pennsylvania State University,
University Park, PA
ABSTRACT
Mining operations adopt a variety of measures to combat
dust underground. These include ventilation systems, water
sprays, physical barriers, and personal protective equipment
(PPE). Respirators are a class of PPE that can provide clean
particulate- free air to the users. Powered Air-Purifying
Respirators (PAPRs), used commonly in medical and other
sectors, are not prevalent in the mining industry. PAPRs
use P100 filters that have 99.97% dust capture efficiency.
We present our results from computational fluid dynamics
(CFD) simulations performed to understand the impact of
a PAPR on airflow and dust particle concentration in the
vicinity of a miner. These results show that donning PAPRs
can lower the miners’ exposure to respirable coal dust in
their workplace.
INTRODUCTION
Several processes in a mining facility generate dust particles.
These include mechanical excavation of minerals, attrition
during transportation, crushing, grinding, and others.
Many of these particles have aerodynamic diameters of less
than 10.0 µm. Most of them could be smaller than 4.0 µm
in size. These particles are considered respirable [1]. They
can travel deep inside the human respiratory system and
cause irreversible illnesses in the affected persons. Mining
operations, therefore, adopt several measures, such as artifi-
cial ventilation systems to dilute the particulate concentra-
tion under permissible limits. Water sprays are mounted at
strategic locations within the mine. The sprays not only cool
the cutting bits but also move the particles away from the
miners using the higher airflow momentum. Flooded-bed
dust scrubbers are installed on mining machines such as
continuous miners. They capture dust particles on fibrous-
type dust filters and are efficient under several conditions
[2]. Recent research has also investigated the performance
of novel non-clogging dust scrubbers, such as Vortecone
and impingement-type dust filters. Unlike fibrous filters,
these direct the motion of dust particles preferentially using
their momentum and capture them on engineered surfaces.
Their mechanical availability is much higher compared to
traditional scrubbers [3 4].
The scrubbers alleviate dust over a known flow domain.
However, they are also attached to the major equipment
and cannot protect the equipment operators or the min-
ers who move continuously close to the active mining face.
Therefore, personal protective devices (PPEs) are used to
capture the dust particles and lower their exposure to respi-
rable particulate matter. Powered Air-Purifying Respirators
(PAPRs) are an important class of PPEs that have been
demonstrated to capture 99.97% of airborne particles
using P100-rated filters [5]. Therefore, they are used in hos-
pitals and other settings where particulate exposure is criti-
cal to employee health. However, the mining industry has
not adopted them on a large scale. This manuscript pres-
ents the operations of a PAPR using numerical modeling
techniques. We developed computational fluid dynamics
(CFD) models to show the steady-state airflow in the vicin-
ity of the PAPR when placed in a controlled volume. We
also present our findings from transient-state simulations
that demonstrate particle transportation. We investigated
particles of 1.0, 2.5, 4.0, and 10.0 µm. We used Reynold’s-
Averaged Navier-Stokes (RANS) turbulence models to
develop these computer models.