PLANNING THE INSTALLATION
- WARNING -
The M66O source capture Media Air Cleaner is
not explosion-proof. It must not be installed where
there is danger of vapor, gas or dust explosion.
INTRODUCTION
Clean air is the subject of numerous laws and
regulations. Typical requirements in the United
States are those put out by the Occupational
Safety and Health Administration (OSHA). Private
groups, such as the American Society of Heating,
Refrigeration and Air Conditioning Engineers
(ASHRAE), have also published numerous
recommendations.
Normally, clean air is defined in regulations and
recommendations as air having a limited amount
of contaminant in it, commonly expressed as parts
per million or milligrams per cubic meter.
Approved counteractions are intended to lower or
eliminate the amount of contaminants in the air.
One of the more common methods of achieving
this goal is through the use of media air cleaners.
At no time should a media air cleaner be placed
where there is a potential for explosion due to the
presence of explosive dusts, gases or vapors.
Contact the nearest Air Quality Engineering, Inc.,
representative for assistance in determining the
correct application of a media air cleaner.
SIZING
Sizing is the process of determining the amount of
air cleaning necessary in any given application.
Since the M66O is a source capture air cleaner,
the sizing process is relatively simple
—provide
one source capture hood per contaminant source.
If air contaminants are generated from fixed
stations where hoods and hoses can be
acceptably installed, cleaning the air by capturing
the contaminant at the source is strongly
recommended. For source capture air cleaning, a
hood (not provided) is installed where the
contaminants are generated and an attached hose
feeds the contaminants to a source capture
plenum. The plenum transfers the contaminants
from up to two hoses directly into the media air
cleaner (hoses are ordered as accessories).
The composition, quantity and rate of generation
of the contaminants determines the air velocity in
turn not only affects the hood design and location
but it also sets limits on how much hose can be
used before the air pressure drop becomes too
great for effective contaminant capture.
Therefore, when sizing an application for source
capture air cleaning, it is necessary to keep in
mind how the specific contaminants, the hood and
the needed velocity all combine to affect the
number of stations which can be attached to a
single unit and the number of units which will be
needed for a particular application.
SOURCE CAPTURE CLEANING
When selecting a location for a media air cleaner
that uses a hood and hose to capture the
contaminants at the source choose the location
that will keep the air pressure drop caused by the
length of the hose within an acceptable range. Do
not mount the outlet of the air cleaner so close to a
wall that it inhibits the airflow. Also, the outlet of
an air cleaner should not be located such that it
interferes with the source capture process of
another air cleaner hood.
To effectively control atmospheric contamination
at its source, proper hood design is necessary.
Minimum airflow and power consumption are also
important factors in designing an effective local
exhaust system to control contamination.
Capturing air contaminants at their source requires
the creation of sufficient airflow past the
contaminant source to remove the contaminated
air and draw it into an exhaust hood. Fine
airborne dust particles, mist, vapors, gases and
fumes follow air currents. Airflow alone is
sufficient to capture these contaminants.
Basic knowledge of the contaminated airflow to be
controlled is necessary before an effective hood or
enclosure can be designed. The more complete
and effective the design, the more economical and
efficient the installation will be.
A complete enclosure is often the best way to
start. Once a source is ideally enclosed, provide
access and working openings as required. This
concept can be used to develop booths, side- or
downdraft hoods and side shields.
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Summary of Contents for M660
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