Ship Hull Antifouling
US Patent 7,390,560 & Patents Pending
The present technology comprises a practical system for
cleaning the ship hull from fouling on command at any time.
The method is particularly useful for energy conservation
and reduction of carbon footprint since drag is reduced and
power saved with a cleaner hull. The method based on
Hull/Hydrodynamics is currently entering small scale
manufacturing and can be rapidly transitioned to ship
operation within twelve
months.
PEL’s patented Smart Coating Systems US 7,390,560 technology
supports this ship application. Array layers composed of
selected polymeric sheet material and are readily mounted to
the ship hull and activated on command. Suitable array
prototypes can be prepared, tested, and transitioned to most
vessels including recreational, military, and later the
larger cruise ships, and cargo vessels. The method should be
suited to modification of existing vessels and inclusion on
new ones as well. A simple schematic is shown in Figure I
below.
The mechanism involves energetic input across a coating
array which releases the fouled layer. A number of
prototypes for smaller vessels have been prepared (Figures 1
and 2) and tailoring for selected application should
directly follow. The method will allow ships to save fuel,
reduce the introduction of dangerous species to our waters,
keep our environment cleaner, reduce the laborious need to
clean the hull every few months, and no longer require
antifouling paint which contains as active ingredients
environmentally unfriendly heavy metals such as copper or
tributyl tin compounds, and the ships will be easier to
handle and maneuver. We estimate about 5-10% fuel and carbon
savings translating into millions of dollars saved.
Layer shedding and the accompanying antifouling can be done
at will, for example every six months (three times over 1 ½
year period) where fouling would go to zero at six, twelve,
and eighteen months. The level of fouling would then never
pass the six month accumulation level compared to an
eighteen month accumulation level with current methods.
Assuming a linear fouling rate, median fouling would be at
about the three month level, and maximum fouling would be at
the six month level over the 1 ½ years.
Note that typical layer materials selected will have very
low surface free energy and therefore be in the range of
fouling prevention as most antifouling paints. Also the
release interlayer can be conductive as depicted in Figure I
or insulative depending on the materials selected.
PEL Associates has vast experience with materials and
processing of polymeric film and sheet materials. We have
worked on projects for DARPA, NAVAIR, and ONR on detection,
surveillance, and upgrading of ships. Our experience has led
to a survey of appropriate coating materials, and
preparation of prototype coating arrays (Figures 1 and 2).
Patent US 7,390,560
Figure 1
Technology Demonstration on Ship Hull in Marine
Environment
Fouled top layer is removed leaving clean layer
exposed. This process is readily done on dry dock or
by divers at sea. Energy input facilitates removal.
Fouled layer is readily collected and disposed of in
an environmentally safe manner. Later we plan
in-water service station facilities where a ship can
enter and fouled layer automatically removed,
collected, and disposed of. |
Patent US 7,390,560
Figure 2
Technology Demonstration on Ship Hull in Marine
Environment
On removal of the top fouled layer shown above a
clean layer is exposed as depicted here. This boat
had been in the water about two weeks. It had been
moving slowly for over two miles with no adverse
effect.
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During
Coating Removal
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After Top
Coat Removal
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