US 5,732,885 A · Internal mix air atomizing spray nozzle

Abstract

The nozzle effects three stages of liquid atomization. The first stage is carried out by means of a single liquid orifice and an expansion chamber containing an impingement pin. A high velocity stream of liquid is discharged through the liquid orifice and is broken-up upon striking the flat end of the impingement pin. The second stage is produced by an air guide which reduces in area to form jets of air into a high velocity annular air curtain, the curtain passing through the liquid orifice in surrounding relation with the liquid stream and striking the broken-up flow of the first stage to atomize the particles. The mixture is then allowed to expand in the expansion chamber to reduce the tendency of the liquid particles in the atomized mixture from commingling together and reforming into larger particles. The third stage is effected by the expansion chamber and by multiple discharge orifices. The mixture is sprayed from the expansion chamber through the multiple orifices and, upon being discharged into the atmosphere, the particles are atomized further due to the release of pressure formed inside the expansion chamber.

Claims32

Dependent claims

A nozzle for atomizing and spraying liquid into the atmosphere, said nozzle comprising a body having a liquid passage which terminates in a single discharge orifice, an impingement pin having a generally flat end disposed in spaced opposing relation with said orifice whereby a jet of pressurized liquid discharged through said orifice strikes the end of said pin and breaks up into a dispersed flow of the liquid, an air supply for discharging air around said discharge orifice whereby pressurized air discharged therefrom forms an annular curtain of air around said liquid jet, an air guide located between said air supply and said impingement pin for contracting said air curtain and increasing the velocity thereof whereby said curtain of air will strike and further atomize such a dispersed flow of the liquid into atomized particles, said air guide having a discharge opening through which said stream and said curtain pass before said stream strikes said pin, an expansion chamber located downstream of and communicating with said discharge opening, said chamber extending around said end of said impingement pin and having a cross-sectional area substantially greater than the cross-sectional area of said discharge opening and said pin whereby the fluid discharged through said opening expands in said chamber to restrict such atomized particles from commingling together and reforming into larger particles, and angularly spaced orifices located about said pin and communicating directly between said chamber and ambient atmosphere to discharge such particles from said chamber and effect further atomization thereof.

An internal mix pneumatic atomizer for atomizing and spraying liquids, said atomizer including

a supply member having a liquid flow passage which terminates in a liquid discharge orifice for high velocity discharge of a stream of liquid along a predetermined axis,
an impingement element having an impingement surface spaced from said discharge orifice and disposed across said axis for breaking up such a stream of liquid impinging thereon into a laterally spreading dispersion of such liquid which thereby is dispersed laterally of said axis from the impingement of such stream on said impingement surface,
one or more air outlet orifices disposed around said axis upstream of said impingement surface and oriented to discharge air in a downstream direction at high velocity around said axis to strike the liquid while in such a laterally spreading dispersion to atomize such dispersed liquid;
and
a housing which defines an expansion chamber of substantial volume extending around said impingement surface for expansion therein of the mixture of air and atomized liquid resulting from the impingement of such stream on said impingement surface and the striking of such dispersed liquid by such high velocity air, said housing having a plurality of discharge orifices disposed circumferentially about said impingement surface and communicating directly between said expansion chamber and ambient atmosphere through which such expanded mixture is discharged from said chamber and thereby further atomized.

2 more elements

An internal mix pneumatic atomizer for atomizing and spraying liquids into the atmosphere, said atomizer including

a supply member having a liquid flow passage which terminates in a liquid discharge orifice for high velocity discharge of a stream of liquid along a predetermined axis,
an impingement element having an impingement surface spaced from said discharge orifice and disposed across said axis for breaking up such a stream of liquid impinging thereon into a laterally spreading dispersion of such liquid which thereby is dispersed laterally of said axis from the impingement of such stream on said impingement surface,
one or more air outlet orifices disposed around said axis upstream of said impingement surface and oriented to discharge a substantially continuous annulus of air around said liquid discharge orifice in a downstream direction substantially parallel to said axis at high velocity to surround such stream from said liquid discharge orifice to said impingement surface and to strike the liquid while in such a laterally spreading dispersion to further atomize such liquid;
and
a housing which defines a chamber extending around and downstream of said impingement surface, said housing having a plurality of discharge orifices disposed circumferentially about said impingement surface and communicating directly between said expansion chamber and ambient atmosphere through which the mixture of air and atomized liquid particles resulting from the impingement of such stream on said impingement surface and the striking of such liquid dispersion by such high velocity air is discharged from said chamber.

2 more elements

An internal mix pneumatic atomizer for atomizing and spraying liquids into the atmosphere, said atomizer including

a supply member having a liquid flow passage which terminates in a liquid discharge orifice for high velocity discharge of a stream of liquid along a predetermined axis,
an impingement element having an impingement surface spaced from said discharge orifice and disposed across said axis for breaking up of a stream of liquid impinging thereon into a laterally spreading dispersion of liquid which is thereby dispersed laterally of said axis from the impingement of the stream on said impingement surface,
an air guide which defines an internal surface around said axis and which extends downstream from said supply member,
an air supply disposed around said supply member upstream of said air guide and communicating with the upstream end of said air guide to supply air thereinto at high velocity,
said internal surface defining a flow area which decreases in cross-section from said liquid discharge orifice toward said impingement surface for enhancing the velocity of such air and discharging such air in a downstream direction substantially parallel to said axis to strike the liquid while in a laterally spreading dispersion to further atomize such liquid particles,
a nozzle tip defining an expansion chamber about said impingement element for expansion therein of the mixture of air and atomized liquid particles resulting from the impingement of such stream on said impingement surface and the striking of such dispersed liquid by such high velocity air, said nozzle top having a plurality of discharge orifices disposed circumferentially about said impingement element through which said expanded mixture is discharged from said chamber directly to the atmosphere.

3 more elements

Dependencies are inferred from the claim text.

Internal mix air atomizing spray nozzle

Life of this patent

Internal mix air atomizing spray nozzle

Life of this patent

Abstract

Claims32