Spray nozzle assembly with impingement post-diffuser

An internal mix air atomizing spray nozzle assembly comprising:

• a nozzle body having a central liquid flow passage for coupling to a pressurized liquid supply, said liquid flow passage having a discharge orifice from which pressurized liquid is directed along a central axis of the nozzle assembly;
• an air cap mounted at a downstream end of said nozzle body having an upstanding impingement post against which a pressurized liquid flow stream from said liquid discharge orifice impinges and is transversely directed;
• an air guide for coupling to a pressurized air supply for directing pressurized air into said air cap about said impingement post for interaction with and atomizing liquid transversely directed by the impingement post;
• said air cap having an expansion chamber about said impingement post and a plurality of discharge orifice defining passages communicating with the expansion chamber disposed in circumferentially spaced relation about the impingement post;
• said air cap passages extending at a compound angle to said central axis such that in a downstream direction the passages proceed both radially outwardly and transversely to the central axis for discharging atomized liquid in a conical spray pattern swirling in a predetermined rotative direction about the central axis;
• and
• said impingement post having a diffuser cap fixedly mounted on an end thereof that defines a flat central impingement surface in aligned relation to said liquid discharge orifice and an outer annular array of non radial diffuser veins about the periphery of the impingement surface extending outwardly of the impingement surface and in a similar transverse direction relative to the central axis as said air cap passages for directing the atomized liquid and pressurized air in a swirling fashion about the impingement post in the same rotative direction as the spray pattern discharge from the air cap passages.

An internal mix air atomizing spray nozzle assembly comprising:

• a nozzle body having a central liquid flow passage for coupling to a pressurized liquid supply, said liquid flow passage having a discharge orifice from which pressurized liquid is directed along a central axis of said spray nozzle assembly;
• an air cap mounted at a downstream end of said nozzle body having an upstanding impingement post against which a pressurized liquid flow stream from said liquid discharge orifice impinges and is transversely directed;
• an air guide for coupling to a pressurized air supply for directing pressurized air into said air cap and about said impingement post for interaction with and atomizing liquid transversely directed by the impingement post;
• said air cap having an expansion chamber about said impingement post and a plurality of discharge orifices defining passages communicating with the expansion chamber disposed in circumferentially spaced relation about the impingement post;
• said air cap passages being angled with respect to said central axis for discharging atomized liquid flow streams outwardly of the air cap in a conical spray pattern swirling in a predetermined rotative direction about the central axis;
• and
• said impingement post having a diffuser at an end thereof that defines a flat central impingement surface in aligned relation to said liquid discharge orifice and an outer annular array of non radial diffuser veins about the periphery of the impingement surface extending outwardly of the impingement surface for directing the atomized liquid and pressurized air in a swirling fashion about the impingement post in the same rotative direction as the rotative direction of the swirling spray pattern from the air cap passages.