Til innholdet

Ultrasonic antifouling

Ultrasonic antifouling is meant to reduce fouling on underwater structures, through using small-scale acoustic cavitation to destroy and discourage attachment of algae and other single-celled organisms.

Principle

Ultrasonic antifouling is based on destroying the micro fouling at the cellular level. By rupturing the cell walls of the organisms the system is supposed to prevent the basic elements of fouling from attaching to the hull.

Basically, the system generates gas bubbles in water. When the bubbles collapse, the local pressure should prevent marine growth.

Main components

POWER CONTROL: Provides specific low powered ultrasonic frequencies.
TRANSDUCERS: Emitting the ultrasonic waves.

Ultrasonic antifouling equipment
Ultrasonic antifouling equipment. Photo: Courtesy of Harsonic (C)

Methods

HARD CAVITATION: High intensity (>50 W). High and local pressure.
SOFT CAVITATION: Lower intensity. Generates conditions which prevent marine growth.

How well does it work?

Perhaps you have seen the adds, where the maker claims this scientifically named system contains a breakthrough combination of ultrasonic waves and multiple frequencies that result in a micro jet action that creates a cleaning effect on the hulls surface below the waterline.

Ultrasonic treatment is a well proven technique for antifouling and cleaning for certain industrial applications. The challenge of avoiding marin fouling is, however, very complex. To our experience, ultrasonic systems are not yet proven to be efficient enough in sea chests, at least when installed singularily – with no support from other active sysems. The best effect comes in conjunction with electrolytic copper based antifouling systems. We still encourage ship owners to take part in testing projects in a quest to optimise these systems for future application.