A Trawl System for the Removal of Oil Pollution

Oil spills usually originate from offshore oil pipeline leaks, platform blowouts, sea vessel collisions or tank loading procedures when the vessels anchor. Trawl systems are used extensively in the fishing industry and can also be used to remove oil pollution, particularly small spills in shallow water.

Trawl Systems

• A number of commercial trawl systems are designed for the purpose of collecting oil pollutants. These allow the user to recover oil spills and other pollutants without specialized training. They are generally economical and contain no mechanical instruments. The average system consists of a net or guide, a wave pump and a storage tank. Trawl systems vary in size and are used according to the space available on the sea vessel.

Nets

• The net functions by gathering the oil spill toward the wave pump. Nets are available in different sizes and some can be connected together to cover a larger surface area. Nets are usually fitted with both a weight and a floatation device, to ensure the entire depth and spread of the spill is reached. Nets are designed for a range of water bodies including estuaries, coastal waters and deep sea.

Wave Pumps

• The wave pump pumps the gathered waste into the storage tank. It consists of a channel fixed with a valve that allows only the one-way passage of oil pollutants, even when the pump is off. The pump itself is particularly useful as it enables the trawl system to be used in water bodies with heavy currents such as rivers.

Storage Tank

• Storage tanks range in size anywhere from 5-to-25 cubic meters. Some tanks are also designed as a water separator, which removes water and concentrates the oil spill. The tanks are detachable and can either be carried ashore for emptying or emptied while at still at sea. The option is also available to use detached tanks as a temporary storage vessel while a new storage bag is attached to the system.