Pressured air oil barriers

Protection against the spreading of leaking oil on water with pressured air.

A rising demand for mineral oil products creates greater danger of oil spills. Several catastrophes have shown us the grave consequences for the ecological system “water”.

AGO Hydroair uses pressured air barriers since many years, among other things, to enrich water with oxygen and mix water layers. The use of air bubble veils as oil barriers is known since the 1930s. Though, back then, the focus lay on thin oil layers. AGO Hdyroair has extensive experience in computer based dimensioning of oil barriers. This know-how enables us to optimize the barriers, taking into account external influences such as wind, waves, currents and the amount of spilled oil. All these can be simulated. AGO Hydroair can lead the project from planning to commissioning.

Functional principle

A pressured air oil barrier consists in principle of a perforated hose/pipe, into which pressured air is blown, that is anchored on the ground of a waterbody. The hose can be installed on the ground or in a trench with gravel bed, depending on the local situation. Air bubbles leave the perforations and rise to the surface. Diameter and distance of the holes and diameter of the hose are calculated so that a regular or varying airstream along the barrier is created. The water that rises with the air bubbles creates a reverse flow that moves towards the barrier at the bottom, and away from it at the surface.

Prinzipskizze zum Funktionsprinzip der Druckluft-Ölsperre

It is this surface flow that keeps oil from spreading. Wind, waves and currents influence an oil layer to a great extent. These factors and their physical properties have to be considered in the design of the oil barrier.

Instrumentation

Die für eine Druckluft-Ölsperre erforderliche Geräteausstattung umfasst:

  • A compressor (oil-free)
  • An aftercooler with condensate separator. This is necessary since the hose consists of plastics, and, therefore, can´t be exposed to hot compressed air
  • Galvanized steel or PE compressed air supply lines from compressor to ground of waterbody
  • Bubbler hoses, weights and anchors
  • Shut-off devices and actuators
  • Oil sensors for automatic surveillance of waterbodies
  • Telecommunication for alarms, control and maintenance

Advantages of pressured air oil barriers

  • Pneumatic oil barriers secure a port or dock within 30 – 60 seconds upon activation.
  • Once active, they work independently. No personnel is required. An activation signal through oil sensors or a button is sufficient to commission the system. This has to be taken into account when tankers are also cleared at night.
  • Pressured air barriers also work on burning oil layers or when ice formed on the surface.
  • Ship traffic is not interrupted. Threatened ships can leave the area and auxiliary ships can enter.
  • An oil layer cannot slip through under the barrier.
  • The cost for installation is very low at a long lifetime. Further costs are avoided since the polyethylene pipes are not equipped with separate nozzles. A special procedure for drilling nozzle holes is used.
  • A pressured air oil barrier is effective against oils, benzene and other floating products like styrene.
  • Possibility of sectorization, i.e. through the use of a multi-hose procedure, highly endangered areas can be further secured taking into account main wind direction and current.

Anwendungsbeispiele

oelBild 1_35

Activated oil barrier at Neckenport, the Netherlands


Druckluft-Ölsperren

Oil barriers can be installed before water inlets to drinking water plants, power plants and so on. The bubble process protects from oil and other dross.

Ein Ölteppich wird an einer Druckluft-Ölsperre zurückgehalten.

An oil layer is held back by a compressed air oil barrier


Stromabwärts treibendes Öl wird aufgehalten

In flowing waters like rivers or canals, a pressured air barrier can act as oil trap. Oil that flows downstream is stopped and collected at one end of the barrier. There it is removed by a skimmer.