Jet pump diffuser for a separator

A diffuser for a jet pump of a separator for separating contaminants from a first fluid stream in which the contaminants are entrained, the diffuser comprising:

• an inlet portion having a diffuser inlet which is adapted to receive the first fluid stream including the entrained contaminants, the inlet defining a first flow area;
• an outlet portion in fluid communication with the inlet portion and having a diffuser outlet through which the first fluid stream can exit the diffuser,
• a flow path for the first fluid stream is defined which extends from the diffuser inlet to the diffuser outlet, and the diffuser outlet defines a second flow area which is greater than the first flow area so that a velocity of the first fluid stream flowing through the diffuser inlet is greater than a velocity of the first fluid stream flowing through the diffuser outlet, the diffuser outlet defining a first maximum internal dimension;
• a transition portion disposed between the inlet portion and the outlet portion, the transition portion defining a third flow area which is greater than the first flow area but less than the second flow area, and an opening defining a second maximum internal dimension;
• and
• a communication port extending through a wall of the diffuser and having a port inlet which communicates with an interior of the diffuser and a port outlet which communicates with an exterior of the diffuser, the port inlet of the communication port is located at a position along the flow path which is between the diffuser inlet and the diffuser outlet and with at least a portion of the port inlet located below a longitudinal center axis of the diffuser during use, so that the entrained contaminants which have become separated from the first fluid stream during flow along the flow path can be removed from the diffuser through the communication port;
• the second maximum internal dimension defined by the opening of the transition portion is less than the corresponding first maximum internal dimension defined by the diffuser outlet;
• and
• the transition portion comprises a lip which defines a third maximum internal dimension of an opening at least partially defined by the lip, the lip being disposed in the flow path, an internal bore of the diffuser increasing from the third maximum internal dimension described by the lip to the first maximum internal dimension defined by the outlet of the outlet portion, with at least a portion of the communication port overlapping the lip in a radial direction perpendicular to the longitudinal center axis of the diffuser.