| 摘要 |
An enhanced map width compressor comprises an impeller wheel 2 having blades 5 which sweep across the surface of a chamber 8. A passageway 20, with a venturi inlet 24, communicates with a slot (or circumferentially-spaced openings) 12. The pressure within the passageway is controlled, for example as a function of flow rate through the compressor. The slots may be radial with respect to the wheel axis, a pressure differential being established between the compressor inlet and the passageway in low flow conditions to produce an improved surge line position. Alternatively, the slots may be axial, the pressure in the passageway being higher than that in the compressor inlet in high flow conditions. Other embodiments include a closable flap valve (25, Fig.10) in the passageway, two passageways opening at respective slots (Fig.11), and a butterfly valve (33, Fig.12) in the compressor inlet. |
