Net cleaning

MEOX has developed its own unique patented washing system where air is oscillated into the water jet, also called cavitation cleaning.

We supply equipment for washing nets, canvas and several other special applications.

Cavitation washing is possible with both low and high pressure. On seines, Sintef has tested that even with 200 bar, this type of washing is far more effective and gentle than washing with 80 bar conventional washing. Others have tested that with cavitation washing at 60-80 bar, hulls can be washed without separating copper waste from the bottom lining.

The washing system is basically gentle on everything as the jet consists of large amounts of air.

With a combination of reduced pressure and little water, you can still wash cleanly and gently and reduce diesel consumption by up to 80% compared to regular high-pressure washing. We also have machines that collect dirt from washing.

See below for more details.

Cavitation cleaning

New and patented for cleaning rigs, with many times more effect.

Cavitation is for most people known for damages to propellers and pump housings. If you have ever seen a propeller completely eaten up by cavitation you know the power of it.

It is air bubbles that form on the propeller blades and then collapse that eat away at the metal. We use the same principle for washing. We add air to the water flow and transport the bubbles out to the net wall.

There, it is the air bubbles that do most of the washing work by knocking loose the weeds on the nets.

Laboratory tests have shown that washing with cavitation provides many (typically 5-10) times greater effect than regular high-pressure washing at the same pressure.

Air bubbles

Very gentle cleaning with air bubbles

Sintef has recently tested wear and tear during high pressure, low pressure and cavitation.

Quote from Sintef report:

…After 35 cleaning events, on average 82% and 90% of the Notorius A and Notorius 3 coating, respectively, were damaged (Figure 7). Low-pressure cleaning damaged on average up to 9% after a single cleaning event and up to 46% after 35 cleaning events. In contrast, a single cavitation cleaning event had no measurable effect on the coatings (average damage 0%, maximum 2%)…

This means, after 35 cleanings, with impregnation Notorius A:

  • High pressure, 220 bar, 220L, 82% wear
  • Low pressure, 80 bar, 120L, 46% wear (increases with more water)
  • Cavitation cleaning 200 bar 2% wear

It was so majorly to cavitation cleaning that even we were surprised.

With a washing interval of every 10 days, 35 washes will last for a whole year.

This is nothing when it typically disappears about 50% without washing over the same period.

ASC requirement 4.7

Satisfies “Gentle cleaning” under ASC 4.7

The ASC states the following: In ASC, paragraph 4.7, about impregnated nets, note 91 states the following:

…Light cleaning of nets is allowed. Intent of the standard is that, for example, the high-pressure underwater washers could not be used on copper treated nets under this standard. …

If there are any cleaning methods covering the phrase ‘Light cleaning’ it’s cavitation cleaning, also see ‘wery gentle as cleaning is done using air bubbles’.

All experiments that Sintef ran were with high pressure and cavitation.

With our patented washing system, we have washed many impregnated nets with low pressure (typically 80-100 bar) and cavitation throughout 2019.

It has proven that it washes well and is very gentle.