Existing means

SWEEPING ARMS

The boats are equipped with skimmer pumps. They move forward into the hydrocarbons layer to increase its thickness.

Consequences

1- Working speed is limited to 1 knot

Above this speed, the water in front of the arms acts like a weight and diverts the flow, creating an acceleration at the ends of the arms.

This creates a venturi effect, which sucks the water and the surface hydrocarbons to the outside.

The vacuum and overpressure created by the movement of the arms creates suction, which evacuates the hydrocarbons from the footprint of the arms.

  > At a speed of 1 knot, a vessel’s helm does not work, which limits the use of the arms to a maximum of Force 3.

2- Emulsion

Pumping causes an emulsion (like mayonnaise) between the water and the hydrocarbons.
The recovered emulsion must be treated, either:

• Before storage, which limits the sweeping to less than 5m3/hour.
• In the tanker’s tanks, which involves a high heat output and reduces storage capacity by ¾.

> The boats cannot sweep continuously, and their sweeping capacity is less than 5 m3/h, regardless of the power of their pumps.

Other techniques used:

• Dispersants: Accelerate the biodegradability of oil by dispersing it in the water column into a multitude of droplets, but do not eliminate the pollution
• Floating barrages: Effective for protections such as bays, ports, estuaries, etc...

> N.B.: A 500 m straight run of barrages encloses an area of 20,000 m², which our boats clean in approximately 1/2 hour

• Carpets and brushes: use in calm waters.
• Nets and absorbents: effective for small quantities.
• Burning the layers: on light fuel oil, very polluting for the atmosphere.

[Result: Very few hydrocarbons are recovered in the sea (less than 5 m3/h )]