Transcript Cyclones - SKC, Inc

RESPIRABLE DUST
SAMPLERS
Presented by
www.skcinc.com
THE HAZARD POTENTIAL
OF AIRBORNE PARTICULATES
Determined by:
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Chemical composition
Concentration in air
Size characteristics
SIZE CHARACTERISTICS
OF AIRBORNE PARTICULATES
Determine the
deposition site in
the respiratory
system and the
ultimate health
effects for exposed
individuals.
SIZE-SELECTIVE EXPOSURE
LIMITS AND GUIDELINES
To more appropriately assess the possible
health effects of airborne particulate
matter, occupational exposure limits and
guidelines including the Threshold Limit
Values (TLVs®) have been issued for
different sizes of particles.
RESPIRABLE DUST
DEFINED
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The TLV booklet defines respirable
particulate matter as those materials that are
hazardous when deposited in the gasexchange region of the lung.
Samplers designed to collect only the
respirable fraction of airborne particulate
matter should be used when the target
compound has an established limit issued as
respirable dust.
WHY USE A RESPIRABLE
DUST SAMPLER?
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Size-selective respirable dust samplers
enable separation and collection of this
specific size fraction from all the suspended
particulates in air.
Collecting larger, non-respirable particulates
would inflate results of the sample,
overestimating exposure.
SPECIFICATIONS FOR
RESPIRABLE DUST SAMPLERS
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Performance specifications for respirable
dust samplers have been issued by various
scientific organizations and standard setting
bodies throughout the world.
The performance specifications are issued as
collection efficiency curves that specify the
efficiency of a dust sampler for particles of
designated sizes.
50% CUT-POINT:
A PERFORMANCE SPECIFICATION
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The 50% cut-point is
often used to describe
the performance of
respirable dust
samplers.
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It is the particle size
that the sampler can
collect with 50%
efficiency.
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Particles smaller than
the 50% cut-point of
the cyclone are
collected with an
efficiency greater than
50%.
Larger particles are
collected with an
efficiency less than
50%.
CURRENT SPECIFICATIONS
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Most organizations involved in occupational
hygiene now recommend the use of respirable
samplers designed to meet the specifications in
ISO Standard 7708:1995.
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This ISO standard has already been adopted
by ACGIH, CEN, and NIOSH. U.S. OSHA
has proposed adoption of this ISO Standard
in their 2013 notice of proposed rulemaking
for respirable crystalline silica.
CURRENT SPECIFICATIONS
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The ISO standard for respirable dust samplers
specifies the collection efficiency curve for
respirable dust samplers.
This curve includes a 50% cut-point of 4 um.
This is a more conservative curve than the
existing U.S. OSHA/MSHA regulations that
specify a collection efficiency curve with a 50%
cut-point of 3.5 um.
TRADITIONAL RESPIRABLE
DUST SAMPLERS: CYCLONES
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Named for the
rotation of air within
the chamber
Function on the same
principle as a
centrifuge
Use rapid circulation
of air to separate
particles according to
their aerodynamic
diameter
CYCLONE OPERATION
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Air enters through a slit
on the side of the sampler
which creates cyclonic
action.
Large particles fall into
the cap (grit pot) and are
discarded.
Small particles are thrown
up onto the filter for
analysis.
Cap must
be in
place.
CYCLONES AVAILABLE
FROM SKC
Aluminum Cyclone
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SKC 225-01-01/02
Meets ISO/CEN criteria at
flows of 2. 5 L/min
Eliminates adverse
electrostatic effects
Specified in NIOSH
Methods for respirable
dust and respirable
crystalline silica
CYCLONES AVAILABLE
FROM SKC
GS-3 Cyclone
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Conductive plastic
Suitable for underground
mine use
Eliminates adverse
electrostatic effects
Multi-inlet design
overcomes orientation bias
Listed in OSHA proposed
rulemaking on silica
Meets ISO/CEN criteria at
flows of 2.75 L/min
CYCLONES AVAILABLE
FROM SKC
GS-1 Cyclone
Constructed of same
conductive plastic
material as GS-3
 Single inlet design serves
as a Dorr-Oliver
equivalent for existing
U.S. OSHA/MSHA
requirements
• Meets ISO/CEN criteria at
flows of 2.0 L/min
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SKC 225-100/103
CYCLONES AVAILABLE
FROM SKC IN UK
Conductive Plastic
Cyclone
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SKC 225-69/-37
Meets ISO/CEN criteria at
flows of 2.2 L/min
Features a snap together
cassette
Static dissipating
IMPORTANT NOTE ON
FLOWRATE
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All cyclones are not
created equal!
Each cyclone has
different operating
specifications and
performance criteria.
Be sure you know the
flow rate specified to
achieve the desired cutpoint before using any
cyclone.
TIPS FOR SAMPLING
WITH SKC AL OR GS CYCLONES
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Load filter into a 3-piece filter cassette.
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Place cyclone into middle ring.
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Calibrate the pump with sampler in line.
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Take sample at specified flow rate.
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Remove filter & cyclone from sample train.
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Recap and send filter to lab.
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Clean cyclone before reuse.
TIPS FOR CALIBRATION
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SKC Aluminum Cyclone
Has a handy calibration adapter that
fits over the cyclone and allows
standard tubing to be attached for
connection to the pump calibrator.
The chamber fits both the 25-mm and
the 37-mm aluminum cyclones.
SKC
225-01/2
SKC
225-01-03
TIPS FOR CALIBRATION
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Calibration Jar
SKC 225-111/112
Very large jars are not
recommended when
calibrating with the pistonstyle primary calibrators
like the Defender. The
dead volume in the jar can
affect the rise/fall of the
piston causing the
readings to be erroneously
low!
TIPS FOR CALIBRATION
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Calibration Jar
SKC 225-111/112
Use the smallest jar
possible to contain the
cyclone/filter assembly.
SKC offers a calibration jar
suitable for the SKC GS or
other samplers of similar
size.
TIPS FOR CALIBRATION
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Another option is the socalled “jarless” calibration
method when using pistonstyle primary calibrators.
Attach the pump only to the
suction port and the
cyclone/filter assembly to
the other port on the
calibrator. This will create
the same pressure drop as
the sampling train
assembled in the field.
POST-SAMPLE CLEANING
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After sampling, clean all parts of the cyclone, with mild
soapy water
Don’t forget to clean the grit pot.
Dry the cyclone. (Air-dry or blow-dry)
Wipe with a dust-free tissue or wipe with an isopropyl
alcohol moistened pad.
Caution: Do not use strong solvents to clean plastic
cyclones
A NEW RESPIRABLE DUST
SAMPLER FROM SKC
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SKC has developed a new
impactor based sampler for
respirable dust called the
Parallel Particle Impactor
or PPI.
The PPI was designed to
improve performance
characteristics evidenced
with older traditional
cyclones.
PPI SAMPLERS FROM SKC
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Specifically designed to
precisely match the
new criteria for
respirable samplers
specified in the ISO
7708 standard that is
followed by most
occupational hygiene
organizations around
the globe.
PPI SAMPLER PERFORMANCE
COMPARED TO CRITERIA
100
Penetration, P, %
75
Respirable PPI, 2.0 L/min
50
Respirable PPI, 4.0 L/min
Respirable PPI, 8.0 L/min
ISO/CEN Respirable Criteria
25
0
1
5
Aerodynamic Particle Diameter, da, mm
10
SKC RESPIRABLE PPI:
FUNCTIONALITY
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The disposable models of
the PPI look and function
very much like a traditional
37-mm cassette.
But the inlet comes preloaded with size-selective
impactor plates that scrub
out non-respirable dust.
PPI samplers are smaller
than traditional cyclones and
can fit under a welder’s
helmet or other PPE.
SKC RESPIRABLE PPI:
FLOWRATES
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Single-use, disposable
PPI models are
available for use at
either 2, 4, or 8 L/min.
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This provides flexibility
in pump options,
sample duration, and
concentration.
2 L/min: 225-385
8 L/min: 225-384
4 L/min: 225-387
IMPORTANT NOTES ON THE
PPI
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Disposable PPI samplers are available from
SKC pre-loaded with designated filters or
your lab can load the filters into the PPI.
Reusable PPI samplers made of aluminum
are also available for those that want to
assemble, clean, and reuse.
A calibration adapter is available for the PPI
as SKC 225-389.
THANK YOU FOR YOUR
INTEREST
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Please visit the SKC website for more
training options and details on SKC samplers.
Email [email protected] with questions or
contact your local SKC representative.
www.skcinc.com