| 摘要 |
PROBLEM TO BE SOLVED: To provide a metered dose inhaler 10 for use with a pressurized aerosol canister 18, in which the respirable fraction of the metered dose (i.e., fraction in the form of dry particles of the optimum size) is maximized at the exit of the apparatus. SOLUTION: In the metered dose inhaler, an air tube 34 is arranged within a conduit with an inlet 38 of the air tube formed in a conduit wall 74 and an outlet 36 of the air tube in opposing relationship with a nozzle orifice. Inhalation through a mouthpiece causes air to be drawn into the inlet and flow out of the outlet of the air tube to form an air jet which impinges on an oppositely moving aerosol plume from the orifice. Auxiliary air inlets 46 in the closed end 24 of the conduit provide a boundary layer flow along the inner wall 44 of the conduit. Vortex generators 54 on the inner wall of the conduit add vorticity and turbulence to the boundary layer flow. COPYRIGHT: (C)2011,JPO&INPIT |
