AAF International SAAF:DBA - Manual (Page 7)

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• Remove the cap on the filling port on the top of the DBA. Acquire
adequate chemical media, based on sales drawing, and gradually
pour it in a controlled manner into the DBA. Avoid causing
significant impact loading by gradually metering the media into
the DBA. When the media level is close to the top of the DBA,
make sure the media is level in order to achieve the design media
volume capacity. It is important to prevent over filling of the media.
There must be enough empty space between the top of the media
to the inlet collar inside the DBA for air distribution. Respirator
Masks are required to be worn by all personnel during the media
installation process. After the chemical media has been installed,
bolt the cap back onto the filling port.
The collector is now ready to be started. Review the instructions thus
far in this bulletin and inspect the DBA to ensure everything
is assembled correctly. Ensure that bolted connections are
properly tightened.
4.0 Start-up Instructions
When the fan system is started up ensure that the airflow volume
is controlled so that the fan motor is not overloaded. This may be
achieved by partially blanking off the inlet or outlet. The fan damper or
duct blast gates shall be partially opened when starting the fan. At the
same time, observe the pressure gauge, which indicates the pressure
drop across the chemical media. Adjust the damper or blast gate until
the pressure drop is stabilized at the design level, the fan damper or
duct blast gates shall be fixed in position.
Immediately on start-up examine the filter system for any apparent air
leaks or other anomalies. Air leaks may be detected by noise or by
use of a synthetic smoke puffing device at the duct joints, sample
ports and opening port of the DBA installation. Correct or repair any
discrepancies, as necessary. Repeat this examination after 24 hours
of operation and again after one week of operation.
5.0 Gas Monitoring, Operation, and Maintenance
A discussion of sophisticated gas phase monitoring is beyond the
scope of this manual. Suffice it to say that when the system is a
safety system designed to protect human health and life appropriate
automatic gas monitoring instrumentation, isolation, alarm, and filter
system start-up controls shall be provided and installed. All such
automatic safety control systems shall have built-in redundancy, be
fail-safe, and be rigorously maintained and routinely tested.
Following a release of gas up to the amount for which the system has
been designed (see the approved product drawing specific to this
installation) all potentially hazardous materials shall be secured and
the gas phase media shall be immediately replaced. If a partial
release has occurred and an oxidizing media is being used, samples
can be taken at different depth locations within the bed and tested to
determine the remaining capacity of the bed. AAF can provide the
appropriate testing services. Contact your local AAF representative for
more information. Based on the condition of the media after a partial
release a number of options are available. The unused portion of the
bed may be retained, the portion of the bed that has been neutralized
by the release should be removed, and fresh media may be added to
make up for the removed material. If the media supplied is an
adsorbent only and does not have an oxidizing capability all of the
media must be replaced as there is no practical way to determine the
remaining life of the media.
AAF International advises that the user develop written procedures
defining the purpose, operation and use of the DBA safety system,
provide personnel training, and conduct periodic drills to ensure that
the system is used properly and operates optimally. This should be
done under the guidance of a suitably qualified and licensed
professional. Complete written records shall be maintained to
document all training, drills, system use, and maintenance.
5.1 Disposal of Used Media
Used chemical media shall be packaged and disposed of in full
accordance with all required and applicable laws and regulations.
Consult with local environmental control authorities such as local,
state and federal EPA & OSHA authorities for direction. Material
Safety Data Sheets (MSDS) are available on all products supplied
by AAF. Contact your AAF representative for further information.
5.2 General System Maintenance
Ducts joints, bolted on components, pressure gauge with tubing
and other system infrastructure should be checked at least every
6 months. Internal DBA surfaces and media support grating shall
be examined whenever media is replaced.
The system should be completely dry at all times. The presence of
standing water, condensation or dampness is detrimental to the
performance and life of the system. If water does penetrate the filter
system, determine and remove the cause for the presence of water
in the system, dry the system and examine all components for the
presence of mould and other biological growth. Remove all
contamination, clean and sterilize as necessary.