Foam generating apparatus

Claim 2

A foam generating nozzle assembly comprising: in combination: an inlet section through which a liquid can pass and including orifice-forming means through which liquid passes; and a foamproducing section having an inlet end which receives a stream issuing from said orifice-forming means, a pressure reducing passageway with a low pressure portion communicating with said inlet end, air inlet port-forming means in communication between the exterior of the nozzle assembly and said pressure reducing passageway, said pressure reducing passageway when said stream passes therethrough causing the aspiration of air through said air inlet port-forming means and the mixing thereof into the liquid stream passing through the nozzle assembly, the shape and dimension of said pressure reducing passageway being such that foam-producing turbulence is produced in the aerated stream passing therethrough, and a foam thickness enhancing expansion chamber beyond said pressure reducing passageway which expansion chamber has a width at least about two times that of the low pressure portion of said pressure reducing passageway, the length to diameter ratio of said expansion chamber being in the range from about 7 to 20 so that the foamed material issuing from the end of said pressure reducing passageway is thickened substantially without substantially reducing the velocity thereof.

Claim 3

The foam-generating nozzle assembly of claim 1 wherein the length to diameter ratio of said expansion chamber is in the range from about 10 to 16.

Claim 4

The foam-generating nozzle assembly of claim 1 wherein said pressure reducing passageway includes an outwardly tapering portion merging with a throat portion which is said low pressure portion thereof.

Claim 5

The foam generating nozzle assembly of claim 1 wherein said inlet section of said nozzle assembly is adapted to pass an unaerated liquid stream through said orifice-forming means.

Claim 6

In an adjustable foam-generating nozzle assembly comprising, in combination: an inlet section through which liquid can pass and including an orifice-forming means through which liquid passes with an outwardly diverging shape; a foam-producing section including an inlet end which receives the stream issuing from said outlet orifice-forming means, a pressure reducing passageway communicating with said inlet end, said pressure reducing passageway including an outwardly tapering portion merging with a throat portion, and air inlet port-forming means in communication between the exterior of the nozzle assembly and said pressure reducing passageway, said pressure-reducing passageway when said stream passes therethrough causing the aspiration of air through said air inlet port-forming means and the mixing thereof into the liquid stream passing through the nozzle assembly, and manually adjustable means for progressively varying the portions of said pressure reducing passageway initially struck by the diverging stream issuing from said outlet orifice-forming means so the widest portion of said diverging stream selectively can be made to strike at least one part of said outwardly tapering portion thereof and other portions of said passageway which vary the thickness of the foam stream discharged from said assembly substantially from a relatively thin to a relatively thick foam, the improvement wherein said foam-producing section includes a foam thickness enhancing expansion chamber beyond said pressure reducing passageway which expansion chamber has a width at least about twice that of the forward end portion of said pressure reducing passageway, and the length of said expansion chamber being sufficiently great that the foamed material issuing from the end of said pressure reducing passageway is thickened substantially without substantially reducing the velocity thereof.

Claim 7

In an adjustable foam-generating nozzle assembly comprising, in combination: an inlet section through which liquid can pass and including an orifice-forming means through which liquid passes with an outwardly diverging shape; a foam-producing section including an inlet end which receives the stream issuing from said outlet orifice-forming means, a pressure reducing passageway communicating with said inlet end, said pressure reducing passageway including an outwardly tapering portion merging with a throat portion, and air inlet port-forming means in communication between the exterior of the nozzle assembly and said pressure reducing passageway, said pressure-reducing passageway when said stream passes therethrough causing the aspiration of air through said air inlet port-forming means and the mixing thereof into the liquid stream passing through the nozzle assembly, and manually adjustable means for progressively varying the portions of said pressure reducing passageway initially struck by the diverging stream issuing from said outlet orifice-forming means so the widest portion of said diverging stream selectively can be made to strike at least one part of said outwardly tapering portion thereof and other portions of said passageway which vary the thickness of the foam stream discharged from said assembly substantially from a relatively thin to a relatively thick foam, the improvement wherein said foam-producing section includes a foam thickness enhancing expansion chamber beyond said pressure reducing passageway which expansion chamber has a width at least about twice that of the forward end portion of said pressure reducing passageway, and the length of said expansion chamber being sufficiently great that the foamed material issuing from the end of said pressure reducing passageway is thickened substantially without substantially reducing the velocity thereof.

Claim 8

The foam-generating nozzle assembly of claim 5 wherein the length to diameter ratio of said expansion chamber is in the range from about 7 to 20.

Claim 9

The foam-generating nozzle assembly of claim 5 wherein the length to diameter ratio of said expansion chamber is in the range from about 10 to 16.

Claim 10

An attachment for a non-foaming liquid spray nozzle unit including an outlet section through which unaerated liquid can pass and including an adjustable portion with manually adjustable means and orifice-forming means through which unaerated liquid passes so the portion of a passageway located beyond said orifice-forming means struck by the stream issuing therefrom will vary as the manually adjustable means is varied; the attachment comprising a body portion attachable to the non-foaming liquid spray nozzle and having an inlet for receiving the variably shaped stream issuing from said orifice-forming means of said non-foaming spray nozzle unit, a foam producing pressure reducing passageway communicating with said inlet and positioned to receive the stream issuing from said orifice-forming means so different portions thereof are struck thereby as said manually adjustable means is varied, air inlet port-forming means in communication between the exterior of the attachment and said pressure reducing passageway, said pressure reducing passageway when said stream passes therethrough causing the aspiration of air through said air inlet port-forming means and the mixing thereof into the liquid stream passing through the attachment, the position, shape and dimension of said pressure reducing passageway being such that foam-producing turbulence is produced in the aerated stream passing therethrough to a degree which varies with the points thereof struck by the stream issuing from said orifice-forming means so the thickness of the foam is substantially variable, and a foam enhancing chamber beyond said pressure reducing passageway which expansion chamber has a width much greater than that of the forward end portion of said pressure reducing passageway, the length to diameter ratio of said expansion chamber being in the range from about 7 to 20 so that the foamed material issuing from the end of said pressure reducing passageway is thickened substantially without substantially reducing the velocity thereof.

Claim 11

An attachment for a non-foaming liquid spray nozzle unit including an outlet section through which unaerated liquid can pass and including an adjustable portion with manually adjustable means and orifice-forming means through which unaerated liquid passes so the portion of a passageway located beyond said orifice-forming means struck by the stream issuing therefrom will vary as the manually adjustable means is varied; the attachment comprising a body portion attachable to the non-foaming liquid spray nozzle and having an inlet for receiving the variably shaped stream issuing from said orifice-forming means of said non-foaming spray nozzle unit, a foam producing pressure reducing passageway communicating with said inlet and positioned to receive the stream issuing from said orifice-forming means so different portions thereof are struck thereby as said manually adjustable means is varied, air inlet port-forming means in communication between the exterior of the attachment and said pressure reducing passageway, said pressure reducing passageway when said stream passes therethrough causing the aspiration of air through said air inlet port-forming means and the mixing thereof into the liquid stream passing through the attachment, the position, shape and dimension of said pressure reducing passageway being such that foam-producing turbulence is produced in the aerated stream passing therethrough to a degree which varies with the points thereof struck by the stream issuing from said orifice-forming means so the thickness of the foam is substantially variable, and a foam enhancing chamber beyond said pressure reducing passageway which expansion chamber has a width much greater than that of the forward end portion of said pressure reducing passageway, the length to diameter ratio of said expansion chamber being in the range from about 7 to 20 so that the foamed material issuing from the end of said pressure reducing passageway is thickened substantially without substantially reducing the velocity thereof.