High-expansion foam generator

1 . A high-expansion foam generator comprising:

a nozzle manifold having at least one nozzle housing and at least one header to receive a foam solution;

at least one nozzle assembly attached to the nozzle manifold, each nozzle assembly having,

a nozzle having an inlet to receive the foam solution from the nozzle manifold and an outlet configured to discharge the foam solution, and

a nozzle insert disposed within the nozzle and attached to the nozzle in a stationary position; and

a foam generator assembly disposed adjacent the nozzle manifold, the foam generator assembly including,

a body portion having an inlet to receive the foam solution from the at least one nozzle assembly,

a first foam generating portion having a tapered configuration, a base of the first foam generating portion being connected to an outlet of the body portion such that a portion of the foam solution exiting the body portion impinges on an interior surface of the first foam generating portion, and

a second foam generating portion having a tapered configuration, a base of the second foam generating portion being connected to an apex of the first foam generating portion, and wherein the second foam generating portion protrudes into an interior of the first foam generating portion,

wherein a ratio of a largest inlet dimension of the foam generator assembly to a length of the foam generator assembly is 0.50 or less, and

wherein the at least one nozzle housing is configured to receive a respective nozzle assembly and is disposed on the at least one header such that a ratio of a diameter of an inlet of the respective nozzle to a distance from an inner wall surface of the at least one header to the inlet of the respective nozzle is 0.8 or less,

wherein each nozzle insert includes a flow divider positioned in the nozzle at the inlet of the nozzle and swirl vanes between the flow divider and the outlet of the nozzle, the swirl vanes creating a swirl pattern in a flow of the foam solution, the flow divider and the swirl vanes splitting a flow path of the foam solution through the respective nozzle into two flow streams;

wherein the swirl vanes comprise a first swirl vane on one side of the flow divider, the first swirl vane having a first upstream solid surface and a first downstream solid surface, and a second swirl vane on another side of the flow divider, the second swirl vane having a second upstream solid surface and second downstream solid surface,

wherein the first downstream solid surface crossovers the flow divider and connects with the second upstream solid surface,

wherein the second downstream solid surface crossovers the flow divider and connects with the first upstream solid surface,

wherein the flow divider transitions with a first non-sharp transition member to the first upstream solid surface,

wherein the flow divider transitions with a second non-sharp transition member to the second upstream solid surface.

2 . The generator of claim 1 , wherein the at least one nozzle assembly includes less than six nozzle assemblies.

3 . The generator of claim 1 , wherein the at least one header includes at least one main header that receives the foam solution from an external source and at least one sub-header that is connected to the at least one main header, the at least one sub-header configured to receive the foam solution from the at least one main header,

wherein the at least one nozzle housing comprises a plurality of nozzle housings and each of the at least one main header has one or more nozzle housings of the plurality of nozzle housings disposed thereon and each of the at least one sub-header has one or more nozzle housings of the plurality of nozzle housings disposed thereon,

wherein the at least one main header and the at least one sub-header have linear configurations and the at least one sub-header is disposed orthogonal to the at least one main header, and

wherein at least one of the at least one main header or the at least sub-header has a closed end along a centerline of the respective header.

4 . The generator of claim 1 , wherein a tip of each nozzle is cone shaped such that a surface of the tip of the nozzle forms an angle with respect to a base of the nozzle, the angle being in a range of 30 degrees to 60 degrees.

5 . The generator of claim 1 , wherein the diameter of the inlet of the respective nozzle is in a range of 0.5 in. to 1.5 in.

6 . The generator of claim 5 , wherein the distance from the inner wall surface of the at least one header to the inlet of the respective nozzle is in a range of 3.5 in. to 4.5 in.

7 . The generator of claim 1 , wherein one or more of the following provides a means for generating foam at a spray inlet pressure of 40 psi or less:

the at least one nozzle assembly including less than six nozzle assemblies,

the at least one header including at least one main header that receives the foam solution from an external source and at least one sub-header that is connected to the at least one main header, the at least one sub-header configured to receive the foam solution from the at least one main header, the at least one main header and the at least one sub-header having linear configurations and the at least one sub-header being disposed orthogonal to the at least one main header,

a tip of each nozzle having a cone shape,

the nozzle insert including the swirl vanes, or

the ratio of the diameter of the inlet of the respective nozzle to the distance from the inner wall surface of the at least one header to the inlet of the respective nozzle.

8 . A foam generator comprising:

a nozzle manifold having at least one nozzle housing and at least one header to receive a foam solution;

at least one nozzle assembly attached to the nozzle manifold, each nozzle assembly having, a nozzle to discharge the foam solution, and

a nozzle insert disposed within the nozzle and attached to the nozzle in a stationary position; and

a foam generator assembly disposed adjacent the nozzle manifold, the foam generator assembly to receive the foam solution and aspirated air to generate foam, the foam generator assembly including a first foam generator portion and a second foam generator portion disposed in an interior of the first foam generator portion,

wherein each nozzle insert includes a flow divider and intersecting swirl vanes for creating a swirl pattern in a flow of the foam solution, the flow divider and the swirl vanes forming a flow path for the foam solution through the respective nozzle into at least two flow paths that have solid surfaces,

wherein each flow path includes a crossover path that transitions a surface of the flow divider and a downstream surface of a swirl vane to an upstream surface of another swirl vane,

wherein the crossover path includes a non-sharp transition member,

wherein a base of the flow divider is disposed upstream of the crossover path in a flow direction of the foam solution, and

wherein the downstream surface of each swirl vane crosses the surface of the flow divider and contacts the upstream surface of the another swirl vane.

9 . The generator of claim 8 , wherein the at least one nozzle assembly receives a respective nozzle and is disposed on the at least one header such that a ratio of a diameter of an inlet of the respective nozzle to a distance from an inner wall surface of the at least one header to the inlet of the respective nozzle is 0.8 or less.

10 . The generator of claim 8 , wherein a number of the swirl vanes in each nozzle insert is two.

11 . The generator of claim 8 , wherein the non-sharp transition member includes one of a chamfered edge or a rounded edge.

12 . The generator of claim 11 , wherein the non-sharp transition member includes the rounded edge.

13 . The generator of claim 11 , wherein the non-sharp transition member includes the chamfered edge.

14 . The generator of claim 8 , wherein the at least one nozzle assembly includes less than six nozzle assemblies.

15 . The generator of claim 8 , wherein the at least one nozzle assembly includes four nozzle assemblies or less.

16 . The generator of claim 8 , wherein the at least one header includes at least one main header that receives the foam solution from an external source and at least one sub-header that is connected to the at least one main header, the at least one sub-header configured to receive the foam solution from the at least one main header,

wherein the at least one nozzle housing comprises a plurality of nozzle housings and each of the at least one main header has one or more nozzle housings of the plurality of nozzle housings disposed thereon and each of the at least one sub-header has one or more nozzle housings of the plurality of nozzle housings disposed thereon,

wherein the at least one main header and the at least one sub-header have linear configurations and the at least one sub-header is disposed orthogonal to the at least one main header, and

wherein at least one of the at least one main header or the at least sub-header has a closed end.

17 . The generator of claim 8 , wherein a tip of each nozzle is cone shaped.

18 . The generator of claim 17 , wherein a surface of the tip of the respective nozzle forms an angle with respect to a base of the nozzle, the angle being in a range of 30 degrees to 60 degrees.

19 . The generator of claim 18 , wherein the angle is in a range of 40 degrees to 50 degrees.

20 . The generator of claim 8 , wherein a diameter of an inlet of the respective nozzle is in a range of 0.5 in. to 1.5 in.

21 . The generator of claim 8 , wherein a distance from an inner wall surface of the at least one header to an inlet of the respective nozzle is in a range of 3.5 in. to 4.5 in.

22 . The generator of claim 8 , wherein the foam generator assembly further includes a body portion having an inlet to receive the foam solution from the at least one nozzle assembly,

wherein the first foam generator portion has a tapered configuration, a base of the first foam generator portion being connected to an outlet of the body portion such that a portion of the foam solution exiting the body portion impinges on an interior surface of the first foam generator portion, and

wherein the second foam generator portion has a tapered configuration, a base of the second foam generator portion being connected to an apex of the first foam generator portion, and wherein the second foam generator portion protrudes into an interior of the first foam generator portion.

23 . The generator of claim 8 , wherein the at least one header includes at least one main header that receives the foam solution from an external source and at least one sub-header that is connected to the at least one main header, the at least one sub-header receives the foam solution from the at least one main header, and

wherein the at least one main header and the at least one sub-header have linear configurations and the at least one sub-header is disposed orthogonal to the at least one main header.

24 . The generator of claim 23 , wherein the at least one sub-header includes two sub-headers disposed colinear to each other and orthogonal to a main header of the at least one main header to form a plus shape.

25 . The generator of claim 8 , wherein a ratio between a gap between an outlet of each nozzle and an inlet to the foam generator assembly and a length of the foam generator assembly is 0.125 or greater.

26 . The generator of claim 8 , wherein a length of the foam generator assembly is in a range of 72 in. to 85 in.

27 . The generator of claim 8 , wherein each nozzle includes one or more internal chambers including a main chamber for receiving the respective nozzle insert and a reduction chamber disposed downstream on the main chamber, the reduction chamber configured to funnel and direct the foam solution to an outlet of the respective nozzle, and

wherein an angle between an inner surface of the reduction chamber and a base of the respective nozzle is in a range of 40 degrees to 50 degrees.

28 . The generator of claim 27 , wherein each nozzle includes an intermediate chamber between the main chamber and the reduction chamber, and

wherein each nozzle includes a land area between the main chamber and the intermediate chamber, the land area being formed by a difference in a diameter of the main chamber and a diameter of the intermediate chamber.

29 . The generator of claim 8 , wherein each nozzle housing is configured such that the foam solution enters a laminar flow region prior to entering the respective nozzle.

30 . The generator of claim 8 , wherein a largest inlet dimension of the foam generator assembly is an inlet diameter that is in a range of 35 in. to 37 in.

31 . The generator of claim 8 , wherein one or more of the following provides a means for generating foam at a spray inlet pressure of 40 psi or less:

the at least one nozzle assembly including less than six nozzle assemblies,

the at least one header including at least one main header that receives the foam solution from an external source and at least one sub-header that is connected to the at least one main header, the at least one sub-header configured to receive the foam solution from the at least one main header, the at least one main header and the at least one sub-header having linear configurations and the at least one sub-header being disposed orthogonal to the at least one main header,

a tip of each nozzle having a cone shape,

the nozzle insert including the swirl vanes, or

the at least one nozzle housing receiving a respective nozzle and being disposed on the at least one header such that a ratio of a diameter of an inlet of the respective nozzle to a distance from an inner wall surface of the at least one header to the inlet of the respective nozzle is 0.8 or less.

32 . The generator of claim 8 , wherein a ratio of a largest inlet dimension of the foam generator assembly to a length of the foam generator assembly is 0.50 or less.

33 . The generator of claim 8 , wherein an entirety of the downstream surface of each swirl vane is solid.