SEPARATOR

A separator for separating contaminants from a fluid stream has first and second chambers coupled by an aperture through which fluid can pass. An actuator can adjust the crossectional area of the aperture according to a pressure differential between the first chamber and a pressure reference. An impaction surface can deflect the first fluid stream after it enters the second chamber such that contaminants are separated from the stream. A pump generates a pressure differential across the aperture. It includes a third chamber having a second inlet for receiving a second fluid stream into the third chamber. The second inlet includes a convergent nozzle for accelerating the second fluid stream, and a third inlet for receiving the first fluid to stream downstream of the impaction surface, the third inlet being arranged relative to the second inlet such that the second fluid stream can entrain and accelerate the first fluid stream.