Feature 4
Victor separates the spoils
Strong uptake is reported for new generation oily water separators that
meet the latest IMO strictures on protecting the environment.
W
ith over 130 million gallons of Using the system, suction is taken from
oil every year released into our the bilges through a pump strainer and foot-
oceans via bilge water, oily water valve into an integral slow-revving positive
separators have rightly been at the centre displacement feed pump to minimise the
of recent industry discussion on pollution. mechanical emulsification of the bilge
After all, the amount is substantially more water. The oily bilge water is then fed into
than the 37 million gallons per year traceable the first stage High Viscosity Oil Removal
to oil spills and accidents. (Hi-VOR) system and initial oil separation
Since 1983, discharge of untreated
The Victor MiniSep - VM Series, specifically
takes place. Free oils are removed via a
bilge water has been strictly prohibited
designed for the marine envirnoment.
high matrix oleophilic coalescing mesh
by international law and subject to heavy which draws oil to its surface, creating large
fines. International legislation stipulates globules of oil. These globules are allowed to
that separated or treated bilge water chemicals and other onboard organic lift to the top of the vessel for collection and
containing 15ppm or below oil in water can substances, they form stable droplets that discharge. The equipment is pre-set (via the
be discharged into international waters as no longer coalesce. pressure regulating water valve) to operate
written in MARPOL 73/78. Victor Marine Ltd has been producing at 20psi (1.38bar) and can effectively
Most vessels currently in operation separators for over 80 years and Victor operate in the region of 20psi-40psi with a
are fitted with MEPC 60(33) standard MiniSep MS Series oily water separators pressure relief valve set at 50psi (3.45bar).
separators but the International Maritime for 35 years. Development by the company When oil is detected at the oil capacitance
Organization (IMO) issued a resolution of a new product to meet then impending probe, it activates the oil discharge valve
for new ships in 2005, resolution MEPC regulations began in 2004 and, by working for dumping of oils to the slopes tank. This
107(49), which specified a more stringent with the marine engineering department at discharge causes the water valve to shut and
test procedure for bilge water separators the University of Plymouth, the team came the feed pump continuously runs to drive
capable of removing heavy fuel oils, marine up with a completely new separator for bilge the fluid out to the oil outlet. The advantage
diesels, and stable oily emulsions from bilge water treatment. Taking the design principles of this is that the heavy fuel oil is pumped
water. This change in regulation has been from the gravity type Victor MiniSep MS to dump, allowing the most viscous of oil
implemented to ensure that the separators Series, two specific design processes were to move easily. This oil dump continues
could manage the modern problems that developed: the Hi-VOR (High Viscosity until the probe senses clean water, and then
cause many failures to happen. Oil Removal) system to handle high density waits for a preset time before shutting the
The separators certified to MEPC 60(33) and viscosity oils and the AGM (Advanced dump valve. The pressure in the Hi-VOR
regulation that are mostly in operation Granular Media) filtration to remove oils increases back to 20psi (1.38bar) and the
nowadays are only tested with diesel fuel. from emulsified bilge water. water valve then reopens and sends the
However, the newer regulation imposes two The Victor MiniSep VM Series was effluent of the Hi-VOR unit to the second
new challenges onto these old style gravity- introduced to the marketplace in 2005. Fully stage.
based separators: heavy fuel oil and oily type approved by Bureau Veritas and the In the second stage, a coalescing cartridge
emulsions. Heavy fuel oils are now regularly US Coast Guard, the unit consists of three at 20micron traps and coalesces any
used by ships as they have become cheaper. stages (four tanks) of separation. Each stage remaining fine oil droplets, which are also
They are extremely viscous, which means is designed to deal with the different types collected at the top of the vessel, due to their
they do not flow easily and their specific of fuels that may be encountered in the bilge raised buoyancy, and discharged to the bilge
gravity is close to water, which makes tanks. tank to be retreated. The effluent at this stage
traditional gravity separation extremely Since that time, the company reports rapid would have been reduced of all its free oils
difficult. uptake of the new system, with a reference and enters the emulsion treatment stage.
Novel designs are needed to counter these list now including The Indian Coast This extra fine coalescer is important during
physical properties. Bilge water can also Guard, Acergy Group, Diamond Offshore, normal shipboard operation, as it offers
contain countless tiny droplets of emulsified Mercator Lines, Lotus Shipping, the Omani a simple protection against contaminants
oil, which are not readily separated in Navy, Mercy Ships, and Tidewater Offshore, for the more expensive consumables
conventional gravity separators where among others. China’s Yangzhou Kejin Yard, downstream.
these droplets would normally coalesce and for example, is reported to be taking two The third vessel acts as a buffer tank for
separate out. When combined with cleaning systems per month on an ongoing basis. the emulsion treatment unit. A three point
The Naval Architect January 2008 83
NA Jan - p83+
85.indd 83 04/01/2008 15:58:19
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