Centrifuge coalescer for separating oil from water in shipboard applications. Final report

A centrifuge was conceived and tested especially for the separation of oil as it is usually dispersed in the bilge and ballast water of ships. The centrifuge is unusual in having predominantly axial flow allowing comparatively high throughput and low speed. It has both primary and secondary stages of separation incorporated into the design and is thus capable of operating with high input concentrations. The device was tested in the laboratory using mixers in a storage tank and a centrifugal pump to disperse up to 8 percent oil in water. The input and output oil droplet size distributions were measured using the Coulter particle counter. This permitted an evaluation of separator performance as a function of the drop size content of the oil dispersion and a rational assessment of the design method and its application to the development of future prototypes.