FLOTATION. 



OIL SLICK 



WATER 



COLLECTION RESERVOIR 



SUCTION DISCHARGE HOSE 

 Figure 12. Vertical and lateral views of the components of the weir skimmer. 



The idea behind this device is commonly referred to as the "waterfall" 

 principle. The collecting reservoir is submerged to the level of the oil/ 

 water interface, at which point, gravity forces the oil into the reservoir, 

 creating a "waterfall" effect. The advantages of this type of skimmer include 

 its high mobility and good recovery efficiency in relatively calm water. 

 The weir is susceptible to being clogged with debris, but a screen can be 

 placed around the unit to minimize this problem. 



DYNAMIC INCLINED PLANE SKIMMERS 



Dynamic inclined plane skimmers use an inverted, continuous belt; that 

 is, a belt that runs from high to low, as opposed to normal conveyors which 

 run from low to high (Figure 13). The belt takes the oil below the surface 

 of the water. The oil leaves the belt and floats upward to a reservoir, where 

 it is collected and pumped to a storage container. Like oleophilic skimmers, 

 which are discussed later, dynamic inclined plane skimmers have good recovery 

 efficiency and are available in a variety of sizes. Both types have restrictions 

 on maneuverability and loss of efficiency when trash or debris is present. 



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