Alfa Laval PureBallast 135 Compact USCG, System Manual

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In USCG mode, the flow is regulated to be as high as possible to fully treat the
water. Between UVI value
a and b , the flow is regulated be between 50 % and
100 % of full flow capacity. The higher UVI value (cleaner water) the the higher
flow.
In IMO mode, the flow is always 100 % above compliant limit. But when UVI
falls below the compliant limit, the flow is decreased to maximum 50 %
2.2.2.2 Power optimization
The purpose is to save power by dimming the lamps to minimum power
required to fully treat the water. Power is regulated when the UVI in the water
is between
c and d (see graph above). The power output is regulated between
50 % and 100 % of full power.
2.2.2.3 Power optimization during special conditions
• Start-up and the first two minutes of ballast/deballast: The UV lamps are lit
to 100 % to ensure treatment before values from the UV sensor are stable.
• Stop: UV lamps are lit to 100 % for 10 seconds before they are stopped.
This will prolong the life of the lamps
• Stripping: The lamps are lit to 100 % during the complete stripping process.
This to have an efficient treatment of the deballast water when it is mixed
with the driving water, which has not been treated at ballast.
• Low UV intensity: See Flow control above.
• Broken UV lamp: See Operation with broken UV lamp below.
2.2.2.4 Operation with broken UV lamp
If a UV lamp breaks during operation, the ongoing process continues but is not
compliant. A warning and an additional common alarm is issued and a log is
written to the event log. The operator should act according to the ballast water
management plan. After process is finished, it will not be possible to start a
new process until the broken lamp has been changed.
The flow is decreased to 65% of max flow and the UV lamps are lit to 100 %.
This is done so that the treatment shall correspond to the type approval
requirements.
If a UV lamp breaks during operation, the ongoing process continues but is not
compliant. A warning and an additional common alarm is issued and a log is
written to the event log. The operator should act according to the ballast water
management plan. After process is finished, it will not be possible to start a
new process until the broken lamp has been changed.
The flow is decreased to 65 % in IMO mode and 50 % in USCG mode of max
flow and the UV lamps are lit to 100 %. This is done so that the treatment shall
correspond to the type approval requirements.
If a lamp breaks in standby mode, it is not possible to start a process.
2.2.3 Start-up
Ballasting and deballasting begins with a start-up phase. During start-up, the
UV lamps are warmed up for 90 seconds.
200000695-1-EN-GB 21
System description 2 EN