MARINESHELF publishes articles contributed by seafarers and other marine related sites solely for the benefit of seafarers .All copyright materials are owned by its respective authors or publishers.
The free oil-and oil emulsified Bilge Water in the Holding Tank have to
be pre heated to about +50°. For direct bilge
operation a full flow pre heater can be installed.
The pre-heated Bilge Water will be fed by the feed pump to the oil
descaler where all “free oil” is separated. The oil sensor activates the oil
release valve draining of the free oil to the Sludge Holding Tank.
The effulent is led from the oil descaler to the Flocculation Tanks during
which it is dosed with a
flocculation chemical. The dosage will be in the range of 200 –300 PPM
depending on the quality
and pH value of the Bilge
water.
When the level in the Flock Tanks reaches the High Level switch the Feed
pump stops and the flocculation process starts. The flocculation process goes
on for about 25-50 minutes, depending on the quality of the Bilge Water.
After this period of time the emulsions are broken and the major parts
of the “flocks” have settled
to the bottom of the Flock Tanks. However since it is a marine
application on a ship, which moves in
the sea, some of the flocks will be in suspension. These flocks also
have to be trapped and not to
be discharged into the open sea. When the flocculation sequence is
completed the discharge
pump will start. The Bilge Water is now fed through the filter stages.
In these filters the remaining flocks and all other types of impurities will be
trapped. The BWa leaving the fine filter stage is monitored and controlled by a
PPM monitor
If during the discharge cycle, the pressure drop (PD) across the filter
stages will exceed a
certain pre set value, a back-flushing sequence automatically starts and
the flock tanks are emptied until the low level switch is activated.
A discharge oil level of less than 3ppm is claimed and the ability to
break emulsions.
2 comments:
Marifloc is a reliable equipment at the time of commissioning. Unfortunately, this reliable equipment is found not in a satisfactory condition while joining all the vessels where it is in use. Reason for this is only because of lack of sufficient operating knowledge. Basic knowledge is not sufficient. We need real training sessions from an experienced Marine engineer who has wide knowledge of this equipment. Otherwise, Marinfloc will loose its good name. Recently our Owners replaced Marinfloc by Wartssila OWS, thinking that Marinfloc is not reliable.
Nice article about Oily Water Seperator
Post a Comment