Netherlands oil recovery equipment

The practical value of the mechanical oil recovery system was proved during various oil control operations and further improvements were made to the system. The experience thus gained resulted in the final design of the type-8 ‘sweeping arm’ and more recently in a new mechanical recovery system for highly viscous oils — the ‘oil crab’.

The sweeping arm system consists of a fixed sweeping boom with a built-in weir-type skimmer and pumping equipment. The oil crab is also based on a weir-type skimmer system towards which the oil is concentrated by a V-shaped arrangement. The main difference between the two systems is that the oil crab has an integrated storage and oil-water separation facility, while with the sweeping arm system these facilities should be on board the towing vessel.

The advantages of the sweeping arm system are that the whole system is very flexible and can therefore be adapted to changing circumstances, it is mobile, easily transported and can be used from any vessel or barge. The system is, however, limited by its inability to handle very high viscosity oils and debris and the safety requirements of the towing vessel in the case of lighter oils.

To overcome these problems and to have an alternative system the oil crab has been developed. The efficiency of the oil crab is unaffected by the viscosity of the oil and the presence of debris. The whole process is non-mechanical and takes place without the aid of pumps or other moving parts.

The performance of both systems can be improved by using booms to concentrate the oil.