HIGH-EXPANSION FOAM GENERATOR
20230081536 · 2023-03-16
Inventors
- Shawn J. FEENSTRA (Caledonia, MI, US)
- Marc S. FERERE (Grand Rapids, MI, US)
- Derek J. SCHEFFERS (Mattawan, MI, US)
Cpc classification
B05B7/005
PERFORMING OPERATIONS; TRANSPORTING
B05B7/0892
PERFORMING OPERATIONS; TRANSPORTING
B05B7/0075
PERFORMING OPERATIONS; TRANSPORTING
B05B1/3415
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
An apparatus and method directed to aspirated-type high-expansion foam generation having a nozzle manifold configured to receive a foam solution and at least one nozzle assembly. The generator includes a foam generator assembly disposed adjacent the nozzle manifold. The foam generator has a body portion having a first foam generating portion and a second foam generating portion that is connected to the first foam generating portion. The generator is configured with a main header of the nozzle manifold disposed orthogonal to at least one sub-header; less than six nozzle assemblies; a ratio of a diameter of an inlet of a respective nozzle to a distance from an inner wall surface of the header to the inlet of the respective nozzle is 0.8 or less; and a nozzle with a nozzle insert with a crossover path defined by a non-sharp transition member and a cone shaped tip.
Claims
1. An aspirated-type high-expansion foam generator comprising: a nozzle manifold having at least one nozzle housing and at least one header configured to receive a foam solution; at least one nozzle assembly attached to the nozzle manifold, each nozzle assembly having, a nozzle configured to discharge the foam solution, and a nozzle insert disposed within the nozzle; 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 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.
2. The generator of claim 1, wherein each nozzle housing is configured such that the foam solution enters a laminar flow region prior to entering the respective nozzle.
3. The generator of claim 1, wherein the at least one nozzle assembly includes less than six nozzle assemblies.
4. 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, 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.
5. The generator of claim 1, wherein each nozzle insert includes swirl vanes to create a swirl pattern in a flow of the foam solution, the swirl vanes splitting a flow path of the foam solution through the respective nozzle into at least two curvilinear paths that have solid surfaces, and wherein each curvilinear path includes a crossover path that transitions the respective flow path from a downstream side of a swirl vane to an upstream side of another swirl vane, the crossover path defined by a non-sharp transition member in the nozzle insert.
6. The generator of claim 1, wherein a tip of each nozzle is cone shaped.
7. 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.
8. The generator of claim 7, 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.
9. The generator of claim 1, wherein the aspirated-type high-expansion generator generates foam at an expansion ratio that is Underwriter Laboratories compliant.
10. An aspirated-type high-expansion foam generator comprising: a nozzle manifold configured to receive a foam solution and having one or more nozzles to discharge the foam solution; and a foam generator assembly disposed adjacent the nozzle manifold, the foam generator assembly configured 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 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 each nozzle assembly further includes a nozzle housing configured to receive the respective nozzle, the nozzle housing disposed on a header of the nozzle manifold such that a ratio of a diameter of an inlet of the respective nozzle to a distance from an inner wall surface of the header to the inlet of the respective nozzle is 0.8 or less.
11. The generator of claim 10, wherein the high-expansion foam generator generates foam at an expansion ratio that is Underwriter Laboratories compliant.
12. A method for generating high-expansion foam using an aspirated-type high-expansion foam generator, the high-expansion foam generator having one or more nozzles, and including a foam generator assembly having a first foam generator portion and a second foam generator portion disposed in an interior of the first foam generator portion, the method comprising: receiving a foam solution that is a mixture of a foam concentrate and a fire suppression fluid; and generating a foam by spraying the foam solution from the one or more nozzles against the first foam generator portion and the second foam generator 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 each nozzle assembly further includes a nozzle housing configured to receive the respective nozzle, the nozzle housing disposed on a header of a nozzle manifold such that a ratio of a diameter of an inlet of the respective nozzle to a distance from an inner wall surface of the header to the inlet of the respective nozzle is 0.8 or less.
13. The method of claim 12, wherein the foam is generated at a foam expansion ratio of at least 400 at a spray inlet pressure of 40 psi or less.
14. The method of claim 12, wherein the foam is generated at a rate of at least 2000 CFM at the spray inlet pressure of 40 psi or less.
15. The method of claim 12, wherein the foam is generated at a ratio that is Underwriters Laboratories compliant for the spray inlet pressure that is in a range of 29 psi to 101 psi.
16-77. (canceled)
Description
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention, and, together with the description given above, serve to explain the features of the invention.
[0015]
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[0020]
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[0024]
DETAILED DESCRIPTION
[0025] Embodiments of the present invention are directed to an aspirated-type high-expansion foam generator. As used herein, an “aspirated-type high-expansion foam generator” means a foam generator that has no moving parts and uses aspirated air as the primary means to generate foam. For example, rather than forcing air into the foam generators by using motor-operated or water-operated fans, the foam generator draws in the surrounding air into the foam generator.
[0026] With reference to
[0027] The HEF generator 10 preferably includes a solution discharge assembly 200 and a foam generator assembly 100. In some embodiments, the solution discharge assembly 200 includes a nozzle manifold 220 and one or more nozzle assemblies 240. The nozzle manifold 200 preferably includes one or more headers (e.g., a main header 224 and sub-headers 230a,b—see
[0028] The foam generator assembly 100 preferably receives the foam solution sprayed from the discharge assembly 200 and the aspirated air to generate a fire suppression foam that can be discharged into an enclosure to be protected. In some embodiments, the overall length L1 of the foam generator assembly 100 can be in a range of 50 in. (1270 mm) to 85 in. (2159 mm). In some embodiments, the length L1 can be in a range of 50 in. (1270 mm) to 55 in. (1397 mm), and more preferably 53 in.±1 in. (1346 mm±25 mm). In other embodiments, the length L1 can be in a range of 72 in. (1829 mm) to 85 in. (2159 mm), and more preferably 79 in.±1 in. (2007 mm±25 mm). In some embodiments, a ratio of the gap G to the length L1 is 0.125 or greater, more preferably in a range of 0.125 to 0.132, and even more preferably 0.127±1.
[0029] In some embodiments, the foam generator assembly 100 can be segmented into two or more portions. For example, the foam generator assembly 100 can include a main body portion 110 and a foam generator portion 120, which preferably attaches to the body portion 110. The body portion 110 preferably defines a passageway in which the foam solution travels prior to impinging on a surface of the foam generator portion 120. The body portion 110 can include an inlet end 112 that receives the foam solution from the nozzle assemblies 240 and the aspirated air. The body portion 110 can also include a distal end 114 that is proximate to the foam generator portion 120. In some embodiments, the body portion 110 attaches to the foam generator portion 120 at the distal end 114 (e.g., via soldering, welding, fasteners, bonding, and/or some other attachment means). In some embodiments, the discharge assembly 200 is preferably disposed such that the outlet of the one or more nozzles 250 is at a predetermined distance from the inlet 112 of the foam generator assembly 100. Preferably, the body portion 110 has a length L2 that is in a range of 25 in. (635 mm) to 45 in. (1143 mm). In some embodiments, the length L2 can be 25 in. (635 mm) to 30 in. (762 mm), and more preferably 27.5±1 in. (699 mm±25 mm). In other embodiments, the length L2 can be 40 in. (1016 mm) to 43 in (1092 mm), and more preferably 41.75 in.±1 in. (1060 mm±25 mm). In some embodiments, the body portion 110 can include one or more expansion joints (not shown) near the inlet 112 and/or the distal end 114 to mitigate stresses in the interfaces between the body portion 110 and the manifold assembly 220 and/or between the body portion 110 and the foam generator portion 120. In some embodiments, the body portion 110 is a tube that directs the foam solution towards the foam generator portion 120. For example, in some embodiments, the body portion 110 can have a cylindrical shape with a diameter D1 that is in a range of 21 in. (533 mm) to 38 in (965 mm). In some embodiments, the diameter D1 can be in a range of 23 in (584 mm) to 25 in (635 mm), and even more preferably 24 in.±0.1 in. (610 mm±2.5 mm). In other embodiments, the diameter D1 can be in a range of 35 in. (889 mm) to 37 in. (940 mm), and even more preferably 36±0.5 in. (914 mm±13 mm). Preferably a length of the foam generator assembly is dependent on the inlet dimension. In some embodiments, a ratio of the largest inlet dimension of the foam generator assembly to a length of the foam generator assembly (also referred to herein as “generator ratio”) is 0.5 or less. In some embodiments, the generator ratio can be in a range of 0.40 to 0.50, more preferably in a range of 0.42 to 0.48 and even more preferably a ratio of 0.46±0.01. For example, in the exemplary embodiments, the generator ratio is a ratio of diameter D1 to length L1. In some embodiments, the body portion 110 can have other shapes such as, for example, rectangular (e.g., square), triangular, trapezoidal, or some other polygonal shape that allows for the foam solution spray to pass through to the foam generator portion 120 while bounding the spray within the interior of the body portion 110. In embodiments that have non-circular inlet configurations, the largest inlet dimension can be used in the numerator of the generator ratio equation. For example, if the inlet to the foam generator is rectangular in shape, the largest length dimension is used.
[0030] In some embodiments, the body portion 110 can be made of sheet metal and have an appropriate thickness for the material being used and can be, for example, a standard thickness such as, e.g., 1/32 in. (0.8 mm). The sheet metal can be stainless steel and/or another appropriate metal. Of course, the body portion 110 is not limited to a metal construction and other materials can be used (e.g., composites, plastics, ceramics, and/or another appropriate material) and the thickness will vary as appropriate. Preferably, the body portion 110 is configured to attach to a fixed structure such as, for example, a wall, ceiling, roof, floor, platform, or other fixed structure using means of attachments such as, for example, brackets, bolts, screws, welding, soldering, bonding, or other means of attachment.
[0031] Preferably, the foam generator portion 120 receives the foam solution from the body portion 110 and is configured to generate a fire suppression foam that is discharged into the enclosure to be protected. In some embodiments, the foam generator portion 120 is generally tube shaped. For example, in some embodiments, the foam generator portion 120 can preferably have a conical shape and even more preferably in the shape of a frustum cone. In some embodiments, the foam generator portion 120 can be segmented into two or more parts. For example, the foam generator portion 120 can include an exterior segment 122 and an interior segment 124. The exterior segment 122 and/or the interior segment 124 can have a tapered shape in some embodiments. For example, the exterior segment 122 can have a conical shape such as, for example, a frustum cone with an inlet end 126 that is attached and/or otherwise secured to the body portion 110 and a distal end 127. Preferably, the wall of the exterior segment 122 defines an interior 125. The interior segment 124 preferably has a conical shape and, in some embodiments, can be a frustum cone. In some embodiments, the segments 122 and 124 are arranged such that interior segment 124 is disposed in the interior 125 of the exterior segment 122 and a base 128 of the interior segment 124 is attached to the distal end 127 of the exterior segment 122 (e.g., by soldering, welding, bonding, fastening via screws or bolts, or attaching by some other means). By segmenting the foam generator portion 120 into two or more parts, the surface area on which the foam solution impinges can be increased while minimizing the overall dimensions of the HEF generator 10. Of course, exemplary embodiments of the present disclosure are not limited to foam generator portions that are segmented into parts and/or limited to conical shapes or frustum shapes. For example, the foam generator portion 120 can be a single part (e.g., made from a single piece of sheet metal) and/or have other shapes such as, for example, rectangular (e.g., square), triangular, trapezoidal, and/or some other polygonal shape (with or without a frustrum).
[0032] In some embodiments, the inlet 126 of the foam generator portion 120 can have a diameter that is approximately the same as the diameter at the distal end 114 of the body portion 110. For example, the diameter D2 at the inlet 126 can be in a range of 21 in. (533 mm) to 38 in (965 mm). In some embodiments, the diameter D2 can be in a range of 23 in (584 mm) to 25 in (635 mm), and even more preferably 24 in.±0.1 in. (610 mm±2.5 mm). In other embodiments, the diameter D2 can be in a range of 36 in. (914 mm) to 37 in. (940 mm), and even more preferably 36.5±0.1 in. (927 mm±2.5 mm). Preferably, the length L3 of the exterior segment 122 (and, in some embodiments, the overall length of the foam generator portion 120) along the axis F1 is in a range of 23 in. (584 mm) to 40 in. (1016 mm). In some embodiments, the length L3 can be in a range of 24.5 in. (622 mm) to 26.5 in. (673 mm), and more preferably 25.5 in.±0.1 in. (648 mm±2.5 mm). In other embodiments, the length L3 can be in a range of 35 in. (889 mm) to 37 in. (940 mm), and more preferably 36 in.±0.1 in. (914 mm±2.5 mm). In some embodiments, to facilitate attachment to the body portion 110, the length of body portion 110 and/or the exterior segment 122 can include an extension E (see
[0033] In some embodiments, the base 128 of the interior segment 124 can have a diameter that is approximately the same as the diameter at the distal end 127 of the main segment 122. For example, the diameter D4 at the base 128 can be in a range of 13 in. (330 mm) to 26 in. (660 mm). In some embodiments, the diameter D4 can be in a range of 14 in. (356 mm) to 16 in. (406 mm), and even more preferably 15 in.±0.1 in. (381 mm±2.5 mm). In other embodiments, the diameter D4 can be in a range of 22.5 in. (572 mm) to 24.5 in. (622 mm), and even more preferably 23.5 in (597 mm±2.5 mm). Preferably, the length L4 of the interior segment 124 along the axis F1 is in a range of 19.5 in. (495 mm) to 33.5 (851 mm). In some embodiments, the length L4 can be in a range of 20.5 in. (521 mm) to 22.5 in. (572 mm), and more preferably 21.25±0.1 in. (540 mm±2.5 mm). In other embodiments, the length L4 can be in a range of 30.5 in. (775 mm) to 32.5 in. (826 mm), and more preferably 31.5 in.±0.1 in (800 mm±2.5 mm). In some embodiments, when the interior segment 124 has a cone shape or a frustum cone shape, the slope of the cone portion forms an angle β with the axis F1 that is in a range of 12 degrees to 20 degrees. In some embodiments, the angle β can be in a range of 15 degrees to 19 degrees, and more preferably 17 degrees±0.5 degree. When the interior segment 124 has a frustum cone shape, the distal end 129 of the interior segment 124 (e.g., the apex of the frustum cone shape of the interior segment 124) can have a diameter D5 in a range of 1 in. (25 mm) to 6 in. (152 mm). In some embodiments, the diameter D5 can be in a range of 1.5 in. (38 mm) to 2.5 in. (63.5 mm), and more preferably 2.0 in.±0.1 in. (51 mm±2.5 mm). In other embodiments, the diameter D5 can be in a range of 3 in. (76 mm) to 5 in. (127 mm), and more preferably 4 in. (102 mm±2.5 mm).
[0034] Preferably, the interior 125 of the foam generator portion 120 includes a surface (e.g., surface 122a of exterior segment 122 and/or surface 124a of interior segment 124) that facilitates the generation of the foam. For example, in some embodiments, the surface 122a and/or the surface 124a of the foam generator portion 120 can have a plurality of openings that go through the wall(s) of the foam generator portion 120. For example, the walls(s) of the foam generator portion 120 (e.g., exterior segment 122 and/or interior segment 124) can be constructed from a perforated sheet, a mesh screen, and/or some other material with a plurality of holes (e.g., metal wires, or similar structures, in a web-like pattern with evenly spaced openings) having a mesh size of about 1/8 in. (3.2 mm). The foam solution from the body portion 110 preferably impinges on the surface 122a and/or surface 124a at a velocity that will cause the foam solution to become a foam. More specifically, as the foam solution impinges on the surface 122a and/or surface 124a and passes through the mesh openings, air is encapsulated or entrained by the foam solution to form bubbles and generate the foam. Once the foam solution passes through the surface openings of the foam generator portion 120, the foam enters the enclosure to suppress the fire. In some embodiments, depending on the inlet pressure, an expansion ratio of the HEF generator 10 can be in a range of 400 to 1100, preferably in a range of 400 to 1000, more preferably in a range of 400 to 900, and even more preferably in a range of 400 to 800. In some embodiments, all or a portion of the foam generator portion 120 (e.g., the exterior segment 122 and/or the interior segment 124) can be made of sheet metal (e.g., a perforated sheet metal) that has a standard thickness for the material such as, for example, 1/32 in. (0.8 mm). The sheet metal can be stainless steel and/or another appropriate metal. Of course, the foam generator portion 120 is not limited to a metal construction and other materials can be used (e.g., composites, plastics, ceramics, and/or another appropriate material.
[0035]
[0036] In some embodiments, each of the main headers can include one or more sub-headers that are fluidly connected to the respective main header. As used herein, “sub-header” means a header receiving foam solution from a main header. For example, sub-headers 230a,b can be fluidly connected to the main header 224 such that the foam solution in the main header 224 flows to the sub-headers 230a,b. Preferably, the main header 224 and/or the sub-headers 230a,b have a substantially linear configuration such as, for example, a linear tube-shaped configuration. For example, the main header 224 can have a linear tube-shaped configuration with an inlet 226 and a closed end 228 disposed opposite the inlet 226. The tube-shaped configuration for the main header 224 is preferably a cylindrical configuration, but other configurations are possible such as rectangular (e.g., square), triangular and/or another polygonal shape. Similarly, one or both of the sub-headers 230a,b preferably have a linear tube-shaped configuration. The tube-shaped configuration for the sub-headers 230a,b is preferably a cylindrical configuration, but other configurations are possible such as rectangular (e.g., square), triangular and/or another polygonal shape. In some embodiments, the main header 224 and the respective sub-headers 230a,b are disposed crosswise to each other such as, for example, orthogonal to each other. For example, as best seen in
[0037] In some embodiments, the inside diameter D9 of the main header 224 and/or the inside diameter D10 of one or both of the sub-headers 230a,b is in a range of 1 in. (25 mm) to 4 in. (102 mm), and more preferably, 2 in. (51 mm) to 3.5 in. (89 mm). For example, in some embodiments, the diameter D9 of the main header 224 can be 2.5 in.±0.1 in. (64 mm±2.5 mm), and in other embodiments, the diameter D9 can be 3.0 in.±0.1 in. (76 mm±2.5 mm). In some embodiments, the diameter D10 of one or both of the sub-headers 230a,b can be 2.0 in.±0.1 in. (51 mm±2.5 mm), and in other embodiments, the diameter D10 can be 2.5 in.±0.1 in. (64 mm±2.5 mm). In some embodiments, main header 224 and/or the sub-headers 230a,b conform to known pipe standards such as, for example, British standard pipe (BSP), national pipe thread taper (NPT), and/or some other pipe standard. The main header 224 and/or one or both of the sub-headers 230a,b can be made of carbon steel, stainless steel, and/or some other appropriate material.
[0038] The nozzle manifold 220 is preferably configured to have one or more nozzle housings, such as, for example, nozzle housings 234, that are each configured to accept a nozzle 250. Preferably, the nozzle 250 can be fixedly attached (e.g., by soldering, welding, bonding) or detachably attached (e.g., by screwing the nozzle into the nozzle housing). For example, the nozzle housing 234 and the nozzle 250 can be configured with corresponding thread patterns (e.g., patterns that meet BSP and NPT standards) as shown by interface 236 in
[0039] Preferably, a length L5 corresponding to a distance from the centerline of the main header 224 (shown in
[0040]
[0041] Preferably, the diameter D8 of the outlet 258 of the nozzle 250 is in a range from 0.10 in. (2.5 mm) to 0.5 in. (13 mm), and more preferably 0.12 in. (3 mm) to 0.4 in. (10 mm). For example, in some embodiments, the diameter D8 can be 0.15 in.±0.01 in. (3.8 mm±0.25 mm) and in other embodiments, the diameter D8 can be 0.375 in.±0.01 in. (9.5 mm±0.25 mm). Between the inlet 248 and outlet 258, the nozzle 250 can include one or more internal chambers. For example, as best seen in
[0042] In some embodiments, the tip 257 of nozzle 250 is cone shaped. For example, in some embodiments, the surface of tip 257 forms an angle θ2 with respect to a base of the nozzle 250 that is in a range of 30 degrees to 60 degrees, and more preferably 40 degrees to 50 degrees, and even more preferably 45 degrees±1 degree. It is believed that the cone-shaped tip 257 aids the jet spray from each nozzle in drawing in the surrounding air. Thus, in contrast to some related art nozzles that have a flat tip, the nozzles 250 of the present disclosure are more efficient with respect to aspirating the air into the HEF generator 10.
[0043]
[0044] In some embodiments, the nozzle insert 260 can have a configuration in which one or more twisting flow paths are created in order to enhance the exit velocity of the foam solution jet spray. For example, the nozzle insert 260 can include a swirl-type insert to create a swirl pattern on the foam solution jet spray that is exiting the nozzle 250. Preferably, all of the foam solution flowing through the nozzle 250 follows one or more curvilinear flow paths. In some embodiments, the nozzle insert 260 can have a multi-swirl vane configuration which splits the foam solution flow path into two or more curvilinear paths through the nozzle 250. In some prior art inserts, only a portion of the flow solution may follow a curvilinear path. That is, some prior art inserts can have slots or gaps that can allow a portion of the foam solution to pass through the nozzle along a substantially linear flow path while a portion follows a curvilinear path. It is believed that such an arrangement is less efficient with respect to aspirating the surrounding air as the foam solution exits the nozzle 250 and/or the foam expansion ratio of the generated foam.
[0045] In some embodiments, the nozzle insert 260 includes a dual swirl vane configuration with a flow divider 262 and swirl vanes 266 and 276. The nozzle insert 260 can be a single integrated unit or assembled from separate parts. For example, one or more of the swirl vane 266, the swirl vane 276, and/or the divider 262 can be a separate part that is attached (e.g., by soldering or other known means) to the insert assembly. Preferably, the swirl vanes 266 and 276 are angled and twisted with respect to a base of the nozzle 250 so as to provide a swirling motion as the foam solution flows through the nozzle 250. In some embodiments, the twist of each swirl vane 266, 276 extends approximate 180 degrees around the main chamber 251. However, in other embodiments, the twist of the swirl vanes can extend more than 180 degrees or less than 180 degrees. The slopes of the swirl vanes 266 and 276 are preferably opposite to each other so as to form an “X” shape when viewed from the side (e.g., see
[0046] In operation, as the foam solution enters the nozzle 250 through the nozzle inlet 248, the flow divider 262 splits the inlet flow into two streams (e.g., a first stream S1 and a second stream S2). As the first stream S1 flows up through the insert 260, the first stream S1 is bounded by the upstream surface 276b of vane 276 (see
[0047] In some exemplary embodiments, depending on the inlet pressure, the velocity of the foam solution at the outlet 258 of nozzle can be in a range of 248 in/min (630 cm/min) to 432 in/min (1007 cm/min) and the flow rate from each nozzle can be in a range of 16.5 gpm (62.5 1 pm) to 30 gpm (113.6 1 pm). Preferably, in some embodiments, the nozzle 250 includes a nozzle insert 260 that is configured to achieve desired flow characteristics for the foam solution as the foam solution impinges on the surface 122a and 124a of the foam generator portion 120. For example, the insert 260 can provide a flow pattern, velocity, and/or flow rate that achieves a desired foam expansion ratio. Exemplary embodiments of the nozzle 250 and/or the nozzle insert 260 described herein are not limited to aspirated-type foam generators and can be used in other applications such as, for example, other types of foam generators.
[0048] In some exemplary embodiments of the present disclosure, the nozzles 250 can have a K-factor in a range 0.4 to 3.2 GPM/(psi).sup.1/2. In some embodiments, the HEF generator 10 can include nozzles 250 having a K-factor in a range of 0.5 to 0.6 GPM/(psi).sup.1/2. For example, exemplary embodiments of the HEF generator 10 with nozzles in a range of 0.5 to 0.6 GPM/(psi).sup.1/2 K-factor can meet or exceed the expansion ratios of related art foam generators with nozzles in a range of 1.25 to 1.35 GPM/(psi).sup.1/2. By using lower K-factor nozzles, for the same number of nozzles, some exemplary embodiments of the HEF generator 10 can meet the performance of related art HEF foam generators while using less foam solution.
[0049] In some embodiments of the disclosure, nozzles having a preferred K-factor and/or preferred nozzle inserts can be used to reduce the number of nozzles in a foam generator while still maintaining predetermined foam expansion ratios. For example, some embodiments of the present disclosure, the HEF generator 120 can include nozzles 250 that have K-Factors in a range of 2.85 to 2.95 GPM/(psi).sup.1/2. In some known commercial foam generators, the nozzles can have K-factors in the range of 1.25 to 1.35 GPM/(psi).sup.1/2, which means that 6 to 9 nozzles are needed for these known commercial foam generators to generate foam in a range of 7800 to 11,200 CFM at approximately 101 psi (7 bar). In contrast, in embodiments of the present disclosure, the HEF generator 10 can have less than 6 nozzles, and more preferably 4 nozzles or less, and even more preferably 3 nozzles or less. In some embodiments, the HEF generator 10 can generate foam at a flow rate of about 10,000 CFM or more, and more preferably, 12,000 CFM or more, at about 101 psi, using less than 6 nozzles. For example, for a 4-nozzle configuration having K-factors in a range of 2.85 to 2.95 GPM/(psi).sup.1/2, the foam flow rate is about 9,970 CFM for an inlet pressure of 72 psi (5 bar) and about 12, 574 CFM for an inlet pressure of 101 psi (7 bar). In some exemplary embodiments, two or more HEF generators 10 can be attached to provide a generator system that provides a predetermined CFM that is greater than 12,500 CFM. For example, two HEF generators 10 that can each generate 12,500 CFM or more can be aligned and/or connected to each other to form a paired twin HEF generator unit that functions as a single HEF generator. The paired twin HEF generator unit can generate 25,000 CFM or more. In known commercial systems, a HEF generator unit capable of producing 25,000 CFM or more uses a forced-air type HEF generator having fans. In contrast, the paired twin HEF generator unit of the present disclosure, which generates foam at 25,000 CFM or more, does not use fans and thus is easier to install. Embodiments of the present disclosure are not limited to HEF generators that generate 10,000 CFM or more, and, in some embodiments, the HEF generator 10 can generate less than 10,000 CFM.
[0050] In addition to allowing foam generators to have fewer nozzles and being lighter, the high-efficiency nozzles allow the HEF generator 10 to have a larger inlet pressure range than related art aspirated-type foam generators. For example, in some embodiments, the HEF generator 10 can generate a foam expansion ratio of 400 or more for a nozzle inlet pressure (e.g., pressure in the nozzle manifold 220) at 40 psi (2.76 bar) or less, more preferably 29 psi (2.0 bar) or less, and even more preferably 21.8 psi (1.5 bar) or less. In some embodiments, the HEF generator 10 can generate a foam expansion ratio in a range of 800 to 1100, and more preferably 800 to 1000, for an inlet pressure of 116 psi (8 bar) or less, and more preferably 101 psi (7 bar) or less. In some embodiments, the HEF generator 10 is configured to operate at a nozzle inlet pressure (e.g., pressure in the nozzle manifold 220) that is in range of 21.8 psi (1.5 bar) to 116 psi (8 bar), and more preferably 29 psi (2 bar) to 101 psi (7 bar) while keeping the foam expansion ratio within a predetermined range. Preferably, the predetermined foam expansion ratio can be a ratio based on the foam solution concentrate being used. Preferably, in some embodiments, the predetermined expansion ratio can be in a range of 400 to 1100, preferably in a range of 400 to 1000, more preferably in a range of 400 to 900, and even more preferably in a range of 400 to 800. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 1200 CFM or greater for inlet pressures that are 50 psi (3.44 bar) or less and more preferably 46 psi (3.17 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 2000 CFM or greater for inlet pressures that are 75 psi (5.17 bar) or less, more preferably 40 psi (2.76 bar) or less, and even more preferably 29 psi (2 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 2900 CFM or greater for inlet pressures that are 103 psi (7.1 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 4000 CFM or greater for inlet pressures that are 40 psi (2.76 bar) or less and more preferably 29 psi (2 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 9000 CFM or greater for inlet pressures that are 72.5 psi (5 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 10,000 CFM or greater for an inlet pressure that is 101 psi (7 bar) or less. In some embodiments, the HEF generator 10 can generate foam at a volumetric foam flow rate of 12,500 CFM or greater for an inlet pressure that is 101 psi (7 bar) or less.
[0051] While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.