Foaming device and foam fire extinguishing system equipped with the same

Abstract

To provide a foaming device capable of achieving 25% reduction time for one minute or more, and a foam expansion ratio of 6 times or more of fire extinguishing foam even when a protein foam fire extinguishing agent is used.SOLUTION: There is provided a foaming device 1 used for a foam fire extinguishing system for extinguishing a fire occurring in a storage tank for storing flammable liquid. A ratio of a diameter d3 at least of an outlet 42 of a foam discharge pipe 40 to a diameter d2 of an outlet 12 of a foam maker pipe 10A is in a range of 0.64-1.15, and a ratio of a cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 to a cross-sectional area c1 of a space of a foam chamber 30 is in a range of 0.050-0.170. When a fire extinguishing foam solution is supplied to an inlet 11 of the foam maker pipe 10A with a pressure in a range of 0.25-0.7 MPA, it is possible to achieve 25% reduction time for one minute or more, and a foam expansion ratio of 6 times or more of the fire extinguishing foam discharged from the outlet 42 of the foam discharge pipe 40.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a foaming device used in a foam fire extinguishing system for extinguishing a fire that has broken out in a storage tank that stores a flammable liquid, and a foam fire extinguishing system equipped with the foaming device. [Background technology]

[0002] A fixed foaming device has been conventionally installed in a storage tank for flammable liquids such as petroleum. The conventional foaming device mainly comprises a foam maker pipe, an air intake pipe, a foam chamber, and a foam discharge pipe. The foam maker pipe is a vertically arranged metal pipe having an inlet opening at the lower end and an outlet opening at the upper end. The air intake pipe is a horizontally arranged metal pipe having an inlet opening in the atmosphere and an outlet communicating with the lower part of the foam maker pipe. The foam chamber is a metal container that covers the upper part of the foam maker pipe and forms a space surrounding the outlet of the foam maker pipe. The foam discharge pipe is a horizontally arranged metal pipe having an inlet communicating with the foam chamber and an outlet through which foam generated in the foam chamber is discharged.

[0003] Such a foaming device is installed at the upper part of the side wall of the storage tank. A fire-extinguishing foam solution, which is a mixture of water and a foam extinguishing agent, is supplied to the inlet at the lower end of the foam maker pipe. As the fire-extinguishing foam solution passes through the foam maker pipe, it is agitated and mixed with air flowing in from the air intake pipe. As a result, fire-extinguishing foam is generated by foaming the fire-extinguishing foam solution. The fire-extinguishing foam discharged from the outlet at the upper end of the foam maker pipe is further foamed in the foam chamber and discharged from the outlet of the foam discharge pipe onto the burning surface of the flammable liquid. The burning surface of the flammable liquid is extinguished by the suffocating effect of being covered with the fire-extinguishing foam and the cooling effect of the moisture contained in the fire-extinguishing foam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-206232 A [Patent Document 2] JP 2016-067948 A [Patent Document 3] JP 2016-158748 A Summary of the Invention [Problem to be solved by the invention]

[0005] Foam fire extinguishing agents have surfactants as their active ingredient. Conventional foam fire extinguishing agents have widely used fluorosurfactants that contain trace amounts of organic fluorine compounds such as PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid). Fluorosurfactants that contain trace amounts of organic fluorine compounds such as PFOS and PFOA have high water repellency, oil repellency, chemical resistance, solvent resistance, and heat resistance, and enable the generation of foam that is suitable for extinguishing flammable liquids.

[0006] However, due to their high chemical stability, PFOS and PFOA tend to remain in the environment and are known to have the potential for bioaccumulation and long-distance mobility, and as such are now regulated by law as environmental pollutants. Under the Act on the Examination and Regulation of Manufacture, etc. of Chemical Substances (Chemical Substances Control Act), PFOS and its salts were designated as Class I Specified Chemical Substances on April 1, 2010, and PFOA and its salts were designated as Class I Specified Chemical Substances on October 22, 2021. Currently, fluorosurfactants that contain trace amounts of organic fluorine compounds such as PFOS and PFOA cannot be used in foam fire extinguishing agents in principle.

[0007] Therefore, the inventors have produced a prototype fluoroprotein foam fire extinguishing agent mainly composed of a fluorosurfactant that does not contain organic fluorine compounds such as PFOS and PFOA, and hydrolyzed protein, and conducted a foaming test using the conventional foaming device described above. As a result, the extinguishing foam generated by the conventional foaming device could not achieve a 25% reduction time of 1 minute or more and a foaming ratio of 6 times or more, which are necessary for extinguishing a fire in a storage tank of a flammable liquid.

[0008] In addition, a 25% reduction time of 1 minute or more means the time (minutes) required for 25% of the total volume (ml) of the extinguishing foam solution before foaming to be reduced from the extinguishing foam to the extinguishing foam solution. In addition, a foaming ratio of 6 times or more means that the volume ratio of the extinguishing foam solution to the extinguishing foam generated by it is 6 times or more.

[0009] As described above, when a fluorosurfactant that does not contain organic fluorine compounds such as PFOS and PFOA is used in a foam fire extinguishing agent, there is a problem that conventional foaming devices cannot achieve a 25% reduction time of 1 minute or more and a foaming ratio of 6 times or more, which are necessary for extinguishing a fire in a storage tank of a flammable liquid, and further improvements in the foaming device are desired.

[0010] The present invention has been made in consideration of the above problems, and aims to provide a foaming device and a foam fire extinguishing system equipped with the same that can achieve a 25% reduction time of 1 minute or more and a foaming ratio of 6 times or more, even when using a protein foam fire extinguishing agent that does not contain organic fluorine compounds such as PFOS and PFOA. [Means for solving the problem]

[0011] (1) In order to achieve the above-mentioned object, the foaming device of the present invention is a foaming device used in a foam extinguishing system for extinguishing a fire that occurs in a storage tank that stores flammable liquid, and comprises a foam maker pipe which is a vertically arranged metal pipe having an inlet opening at the lower end and an outlet opening at the upper end, an air intake pipe which is a horizontally arranged metal pipe having an inlet opening in the atmosphere and an outlet communicating with the lower part of the foam maker pipe, a foam chamber which is a metal container that covers the upper part of the foam maker pipe and forms a space surrounding the outlet of the foam maker pipe, and a horizontally arranged metal pipe. and a foam discharge pipe having an inlet communicating with the foam chamber and an outlet through which foam generated in the foam chamber is discharged, wherein the ratio of at least the diameter of the outlet of the foam discharge pipe to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.15, and the ratio of the cross-sectional area of ​​the outlet of the foam discharge pipe to the cross-sectional area of ​​the space of the foam chamber is within the range of 0.050 to 0.170, and when a fire-extinguishing foam solution is supplied to the inlet of the foam maker pipe at a pressure within the range of 0.25 MPa to 0.7 MPa, the foam expansion ratio of the fire-extinguishing foam discharged from the outlet of the foam discharge pipe can be made 6 times or more.

[0012] (2) Preferably, in the foaming device of (1) above, the foam maker pipe has an inner diameter in a portion above the air intake pipe that is larger than the inner diameter in a portion below the air intake pipe that communicates with the air intake pipe.

[0013] (3) Preferably, in the foaming device of (1) above, the foam discharge pipe is composed of a cylindrical metal pipe, and the ratio of the inner diameter of the cylinder of the metal pipe to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.15.

[0014] (4) Preferably, in the foaming device of (1) above, a metal plate having a circular hole formed therein is attached to the outlet of the foam discharge pipe, and the ratio of the diameter of the circular hole in the metal plate to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.15.

[0015] (5) Preferably, in the foaming device of (1) above, a metal or synthetic resin cylinder having an outer diameter approximately the same as the inner diameter of the foam discharge pipe is inserted inside the foam discharge pipe, and the ratio of the inner diameter of the metal or synthetic resin cylinder to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.15.

[0016] (6) Preferably, in the foaming device of (1) above, a dam plate is provided in the foam chamber to block approximately half of the inlet of the foam discharge pipe.

[0017] (7) Preferably, in the foaming device of (6) above, the dam is fixed to the upper end of the foam maker pipe and has an upper dam part protruding upward than the upper end of the foam maker pipe and a lower dam part protruding downward than the upper end of the foam maker pipe, and the lower dam part blocks approximately 1 / 2 of the entrance of the foam discharge pipe.

[0018] (8) Preferably, in the foaming device of (1) above, a gap is provided between the upper end of the foam maker pipe and the inner ceiling surface of the foam chamber, and the ratio of the vertical length of the gap to the diameter of the outlet of the foam maker pipe is 0.2 to 1.3.

[0019] (9) In order to achieve the above object, the foam extinguishing system of the present invention is a foam extinguishing system for extinguishing a fire that has occurred in a storage tank that stores a flammable liquid, and includes a water tank for storing water for producing a fire-extinguishing foam / water solution, a pump provided on the secondary side of the water tank for sucking and discharging the water from the water tank, a concentrate tank provided on the secondary side of the pump for storing a foam extinguishing agent for producing the fire-extinguishing foam / water solution, a mixer provided on the secondary side of the pump and the concentrate tank for mixing the foam extinguishing agent supplied from the concentrate tank with the water discharged by the pump to produce the fire-extinguishing foam / water solution, and a foaming device described in any one of (1) to (8) above, provided on the secondary side of the mixer and at the upper part of the side wall of the storage tank, for mixing the fire-extinguishing foam / water solution produced by the mixer with air taken in from the air intake pipe to produce the fire-extinguishing foam, and discharging the fire-extinguishing foam from the outlet of the foam discharge pipe onto the surface of the flammable liquid. Effect of the Invention

[0020] With the foaming device of the present invention and the foam fire extinguishing system equipped with it, it is possible to achieve a 25% reduction time of the fire extinguishing foam of more than one minute and a foaming ratio of more than six times, even when using a protein foam fire extinguishing agent. [Brief description of the drawings]

[0021] [Figure 1] Fig. 1(a) is a side view showing the whole foaming device according to the first embodiment of the present invention. Fig. 1(b) is a bottom view showing the inlet of a foam maker pipe constituting the foaming device of Fig. 1(a). Fig. 1(c) is a front view showing the outlet of a foam discharge pipe constituting the foaming device of Fig. 1(a). [Diagram 2] Fig. 2(a) is a side view showing the whole foaming device according to the second embodiment of the present invention. Fig. 2(b) is a bottom view showing the inlet of a foam maker pipe constituting the foaming device of Fig. 2(a). Fig. 2(c) is a front view showing the outlet of a foam discharge pipe constituting the foaming device of Fig. 2(a). [Diagram 3]FIG. 3(a) is a front view showing the outlet of the first foam discharge pipe constituting the foaming device of this embodiment. FIG. 3(b) is a front view showing the outlet of the second foam discharge pipe. FIG. 3(c) is a front view showing the outlet of the third foam discharge pipe. FIG. 3(d) is a front view showing the outlet of the first foam discharge pipe, which is the same as FIG. 3(a). FIG. 3(e) is a front view showing a first metal plate having a circular hole formed therein. FIG. 3(f) is a front view showing a second metal plate having a circular hole formed therein. FIG. 3(g) is a front view showing a state in which the first metal plate is attached to the outlet of the first foam discharge pipe. FIG. 3(h) is a front view showing a state in which the second metal plate is attached to the outlet of the first foam discharge pipe. FIG. 3(i) is a front view showing the outlet of the first foam discharge pipe, which is the same as FIG. 3(a). FIG. 3(j) is a perspective view showing a first cylinder having an outer diameter that is approximately the same as the inner diameter of the first foam discharge pipe. Fig. 3(k) is a perspective view showing a second cylinder having an outer diameter substantially the same as the inner diameter of the first foam discharge pipe. Fig. 3(l) is a front view showing the first cylinder inserted into the first foam discharge pipe. Fig. 3(m) is a front view showing the second cylinder inserted into the first foam discharge pipe. [Figure 4] Fig. 4(a) is a side view showing a dam plate attached to the foaming device of this embodiment, Fig. 4(b) is a plan view showing the dam plate of Fig. 4(a), and Fig. 4(c) is a partial side view showing the dam plate attached to the outlet of the foam maker pipe of the foaming device. [Diagram 5] FIG. 5 is a schematic diagram showing a foam fire extinguishing system equipped with the foaming device of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of a foaming device and a foam fire extinguishing system equipped with the foaming device of the present invention will be described with reference to the drawings.

[0023] 1. First embodiment of the foaming device First, a foaming device according to a first embodiment of the present invention will be described with reference to Figs. 1(a) to (c). In Fig. 1(a), the foaming device 1 of this embodiment is composed of a foam maker pipe 10A, an air intake pipe 20, a foam chamber 30, a foam discharge pipe 40, and a dam plate 50. The foaming device 1 of this embodiment is larger than the foaming device 2 according to the second embodiment shown in Fig. 2(a). The size of the foaming device 1 is not particularly limited, but for example, the total height H1 of the foaming device 1 is within a range of about 730 mm to 935 mm. Also, for example, the height H2 from the lower end of the foam maker pipe 10A to the center of the foam discharge pipe 40 is within a range of about 470 mm to 600 mm.

[0024] 1.1 Formmaker Pipe As shown in FIG. 1(a), the formmaker pipe 10A is a vertically arranged metal pipe, and is configured by welding a small diameter pipe and a large diameter pipe via a connecting pipe. The small diameter pipe constitutes a lower part including an inlet 11 of the formmaker pipe 10A. The large diameter pipe constitutes an upper part including an outlet 12 of the formmaker pipe 10A. The connecting pipe has a lower end having the same outer diameter as the small diameter pipe and an upper end having the same outer diameter as the large diameter pipe. Both the small diameter pipe and the large diameter pipe are straight pipes and have constant outer and inner diameters. The inner diameter d1 of the small diameter pipe is equal to the diameter d1 of the inlet 11 of the formmaker pipe 10A. The inner diameter d2 of the large diameter pipe is equal to the diameter d2 of the outlet 12 of the formmaker pipe 10A.

[0025] The dimensions of the small diameter pipe, the large diameter pipe, and the connecting pipe are not particularly limited, provided that the inner diameter d2 of the large diameter pipe is larger than the inner diameter d1 of the small diameter pipe. For example, the inner diameter d1 of the small diameter pipe is within the range of about 49 mm to 106 mm, the inner diameter d2 of the large diameter pipe is within the range of about 80 mm to 156 mm, and the inner diameter d2 of the large diameter pipe is larger than the inner diameter d1 of the small diameter pipe. For example, the small diameter pipe is preferably made of STPG370 (carbon steel pipe for pressure piping). The connecting pipe and the large diameter pipe are preferably made of SGP (carbon steel pipe for piping).

[0026] As shown in Fig. 1(b), a flange for connecting to a pipe 150 (see Fig. 5) is welded to the outer periphery of the inlet 11 of the foam maker pipe 10A. A fire-extinguishing foam solution is supplied from the inlet 11 to the inside of the foam maker pipe 10A through this pipe 150. For example, the flange is preferably made of SS400 (general structural rolled steel).

[0027] Meanwhile, a flange for clamping a sealing glass and sealing gasket (not shown) is welded to the outer periphery of the outlet 12 of the foammaker pipe 10A. The outlet 12 of the foammaker pipe 10A is sealed by the sealing glass and sealing gasket. For example, a storage tank for a flammable liquid such as petroleum has an internal pressure equal to or higher than atmospheric pressure. The sealing glass and sealing gasket prevent the vaporized gas of the flammable liquid from flowing into the outlet 12 of the foammaker pipe 10A. In the event of a fire in the storage tank, the sealing glass is shattered by the fire-extinguishing foam solution that flows into the inside of the foammaker pipe 10A from the inlet 11.

[0028] 1.2 Air intake pipe As shown in Fig. 1(a), the air intake pipe 20 is a horizontally disposed metal pipe having an inlet 21 that opens into the atmosphere and an outlet 22 that communicates with the lower portion of the formmaker pipe 10A. The outlet of the air intake pipe 20 is covered with a wire mesh (not shown). For example, the air intake pipe 20 is preferably made of CAC203 (brass casting). The wire mesh is preferably made of SUS304 (austenitic stainless steel).

[0029] Here, an orifice (not shown) for spraying the extinguishing foam and water solution supplied from piping 150 is built in near the inlet 11 inside the foam maker pipe 10A. When the orifice sprays the extinguishing foam and water solution, negative pressure is created near the inlet 11 of the foam maker pipe 10A, and air is sucked into the foam maker pipe 10A from the air intake pipe 20. Inside the foam maker pipe 10A, the extinguishing foam and water solution sprayed from the orifice is stirred and mixed with the air sucked in from the air intake pipe 20. As a result, extinguishing foam is generated inside the foam maker pipe 10A.

[0030] 1.3 Foam chamber 1(a), the foam chamber 30 is a metal container with a circular cross section, and has a bottom surface that slopes downward toward the foam discharge pipe 40. The bottom surface of the foam chamber 30 is provided with a circular opening into which the large diameter pipe that constitutes the foam maker pipe 10A can be inserted. The circular opening provided in the bottom surface of the foam chamber 30 is welded to the large diameter pipe that constitutes the foam maker pipe 10A.

[0031] Such a foam chamber 30 covers the upper part of the foam maker pipe 10A and forms a space with a circular cross section surrounding the outlet 12 of the foam maker pipe 10A. For example, the diameter d4 of the space of the foam chamber 30 is within a range of about 205 mm to 305 mm. In this case, the cross-sectional area c1 of the space of the foam chamber 30 is about 330 cm. 2 ~730cm 2 For example, the vertical length L of the space from the upper end of the form maker pipe 10A to the inner surface of the ceiling of the form chamber 30 is within a range of about 20 mm to 100 mm. For example, the main body portion forming the circular cross-sectional space of the form chamber 30 is preferably made of SGP (carbon steel pipe for piping). Meanwhile, the flange provided on the ceiling of the form chamber 30 is preferably made of SS400 (general structural rolled steel).

[0032] 1.4 Foam discharge tube As shown in FIG. 1(a), the foam discharge pipe 40 is a metal pipe arranged in the horizontal direction, and has an inlet 41 communicating with the foam chamber 30, and an outlet 42 from which the fire-extinguishing foam generated in the foam chamber 30 is discharged. The foam discharge pipe 40 is a straight pipe, and has a constant outer diameter and inner diameter. The inner diameter d3 of the foam discharge pipe 40 is equal to the diameter d3 of the inlet 41 and the outlet 42 of the foam discharge pipe 40. For example, the diameter d3 of the outlet 42 of the foam discharge pipe 40 is within a range of about 20 mm to 156 mm. In this case, the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is about 3 cm 2 ~191cm 2 As shown in Fig. 1(c), a flange for installing the foaming device 1 is welded to the outer periphery of the outlet 42 of the foam discharge pipe 40 on the upper part of the side wall of the storage tank 200 (see Fig. 5). For example, the foam discharge pipe 40 is preferably made of SGP (carbon steel pipe for piping). The flange is preferably made of SS400 (general structural rolled steel).

[0033] The extinguishing foam discharged from the outlet 42 of the foam discharge pipe 40 is discharged onto the burning surface of the flammable liquid stored in the storage tank 200. The burning surface of the flammable liquid is extinguished by the smothering effect of being covered with the extinguishing foam and the cooling effect of the moisture contained in the extinguishing foam.

[0034] 1.5 Weir plate As shown in FIG. 1(a), a dam plate 50 made of a rectangular metal plate is fixed to the upper end of the form maker pipe 10A. FIGS. 4(a) to 4(c) show the detailed configuration of the dam plate 50. As shown in FIGS. 4(a) and 4(b), the dam plate 50 is curved so as to follow the arc of a flange provided at the outlet 12 of the form maker pipe 10A. A semicircular ring-shaped mounting portion 51 is provided on the back surface of the dam plate 50. The mounting portion 51 has a shape and dimensions that correspond to approximately half of the flange provided at the outlet 12 of the form maker pipe 10A. Furthermore, the mounting portion 51 is provided with a second circular hole that corresponds to a first circular hole provided in the flange. As shown in Figures 4(a) and (c), the dam plate 50 is fixed to the upper end of the formmaker pipe 10A by overlapping the mounting portion 51 with approximately half of the flange provided at the outlet 12 of the formmaker pipe 10A and screwing the butterfly screw 52 inserted into the first and second circular holes into a nut (not shown).

[0035] The means for attaching the dam plate 50 to the mounting portion 51 is not limited to the thumbscrew 52, ​​and for example, a mechanical element other than the thumbscrew 52, ​​such as a bolt, may be used. Furthermore, the dam plate 50 may be welded to the mounting portion 51.

[0036] 4(c), the dam plate 50 has an upper dam plate portion 50a that protrudes upward from the upper end of the foam maker pipe 10A and a lower dam plate portion 50b that protrudes downward from the upper end of the foam maker pipe 10A, based on the mounting portion 51. When the dam plate 50 is fixed to the upper end of the foam maker pipe 10A, approximately 1 / 2 of the inlet 41 of the foam discharge pipe 40 is blocked by the lower dam plate portion 50b.

[0037] Such a dam plate 50 blocks the flow of extinguishing foam toward the inlet 41 of the foam discharge pipe 40 along the downwardly inclined bottom surface of the foam chamber 30, and causes the extinguishing foam to flow into the inlet 41 of the foam discharge pipe 40 by bypassing it. The extinguishing foam generated in the foam chamber 30 collides with the dam plate 50, and the travel distance and travel time within the foam chamber 30 are extended. This promotes mixing of the extinguishing foam solution with the air, making it possible to generate bubbles with smaller diameters. As a result, the reduction time and foaming ratio of the extinguishing foam discharged from the outlet 42 of the foam discharge pipe 40 are improved.

[0038] 1.6 Configuration for further improving reduction time and foaming ratio of fire extinguishing foam As already mentioned, when a fluorosurfactant that does not contain organic fluorine compounds such as PFOS and PFOA is used as a foam extinguishing agent, there is a problem that a 25% reduction time of 1 minute or more and a foaming ratio of 6 times or more, which are necessary for extinguishing a flammable liquid storage tank, cannot be obtained with a conventional foaming device. As a result of intensive research, the present inventors have found that the reduction time and foaming ratio of the extinguishing foam can be further improved by making the components of the foaming device 1 satisfy the following parameters.

[0039] 1.6.1 Ratio of foam discharge pipe outlet diameter to foam maker pipe outlet diameter The ratio of the diameter d3 of at least the outlet 42 of the foam discharge pipe 40 to the diameter d2 of the outlet 12 of the foam maker pipe 10A is set within the range of 0.64 to 1.15. As already exemplified, the diameter d3 of the outlet 42 of the foam discharge pipe 40 is within the range of about 20 mm to 156 mm. On the other hand, the diameter d2 of the outlet 12 of the foam maker pipe 10A is within the range of about 80 mm to 156 mm. Figures 3(a) to (m) show a configuration for matching the diameter d3 of at least the outlet 42 of the foam discharge pipe 40 to the diameter d2 of the outlet 12 of the foam maker pipe 10A to satisfy d3:d2 = 0.64 to 1.15.

[0040] 3(a)-(c) show three foam discharge pipes 40 with different inner diameters. When designing the foaming device 1, the total length of the foam maker pipe 10A, the ratio of the small diameter pipe to the large diameter pipe, the diameter d1 of the inlet 11, and the diameter d2 of the outlet 12 are determined according to the required foaming performance. Then, a foam discharge pipe 40 with an inner diameter that satisfies d3:d2=0.64-1.15 is selected for the diameter d2 of the outlet 12 of the foam maker pipe 10A. For example, FIG. 3(a) shows a foam discharge pipe 40 with an inner diameter d3 of about 80.7 mm. FIG. 3(b) shows a foam discharge pipe 40 with an inner diameter d31 of 67.9 mm. FIG. 3(c) shows a foam discharge pipe 40 with an inner diameter d32 of 51.6 mm. Depending on the predetermined diameter d2 of the outlet 12 of the foam maker pipe 10A, any one of the foam discharge pipes 40 having an inner diameter d3, d31 or d32 that satisfies d3:d2=0.64 to 1.15 and provides the best reduction time and foaming ratio of the fire-extinguishing foam is selected.

[0041] Next, Figures 3(d) to (h) show a foam discharge pipe 40 and two circular metal plates 43, 44 for reducing the diameter d3 of the outlet 42 of the foam discharge pipe 40. The inlet 41 of the foam discharge pipe 40 shown in Figure 3(d) is welded to the foam chamber 30. The foam discharge pipe 40 is a straight pipe, and the inner diameter d3 of the foam discharge pipe 40 is equal to the diameters d3 of the inlet 41 and the outlet 42 of the foam discharge pipe 40. For example, the inner diameter d3 of the foam discharge pipe 40 is about 80.7 mm.

[0042] On the other hand, the two circular metal plates 43, 44 shown in Figures 3(e) and (f) each have an outer diameter larger than the diameter d3 of the outlet 42 of the foam discharge pipe 40 and large enough not to interfere with the circular hole provided in the flange of the foam discharge pipe 40. A circular hole smaller than the diameter d3 of the outlet 42 of the foam discharge pipe 40 is formed in the center of each of the metal plates 43, 44. For example, the diameter d31 of the circular hole of the metal plate 43 shown in Figure 3(e) is about 67.9 mm. The diameter d32 of the circular hole of the metal plate 44 shown in Figure 3(f) is about 51.6 mm.

[0043] As shown in Fig. 3(g) and (h), the metal plates 43, 44 are selectively attached to the outlet 42 of the foam discharge pipe 40. The ratio of the diameter d31 of the circular hole of the metal plate 43 to the diameter d2 of the outlet 12 of the foam maker pipe 10A satisfies 0.64 to 1.15. The ratio of the diameter d32 of the circular hole of the metal plate 44 to the diameter d2 of the outlet 12 of the foam maker pipe 10A also satisfies 0.64 to 1.15. In this way, multiple metal plates 43, 44... are prepared that satisfy d3n:d2 = 0.64 to 1.15 according to the diameter d2 of the outlet 12 of the foam maker pipe 10A, and the diameters d31, d32...d3n of the circular holes that provide the best reduction time and foaming ratio of the fire-extinguishing foam are selected.

[0044] Next, Figures 3(i) to (m) show a foam discharge pipe 40 and two cylinders 45, 46 for reducing the diameter d3 of the outlet 42 of the foam discharge pipe 40. The inlet 41 of the foam discharge pipe 40 shown in Figure 3(i) is welded to the foam chamber 30. The foam discharge pipe 40 is a straight pipe, and the inner diameter d3 of the foam discharge pipe 40 is equal to the diameters d3 of the inlet 41 and the outlet 42 of the foam discharge pipe 40. For example, the inner diameter d3 of the foam discharge pipe 40 is about 80.7 mm.

[0045] On the other hand, two cylinders 45, 46 shown in Figures 3(j) and (k) are made of metal or synthetic resin. Both cylinders 45, 46 have an outer diameter that is approximately the same as the inner diameter d3 of the foam discharge pipe 40. Both inner diameters d31, d32 of the cylinders 45, 46 are smaller than the diameter d3 of the outlet 42 of the foam discharge pipe 40. For example, the inner diameter d31 of the cylinder 45 shown in Figure 3(j) is approximately 67.9 mm. The inner diameter d32 of the cylinder 46 shown in Figure 3(k) is approximately 52.9 mm.

[0046] As shown in Fig. 3(l) and (m), the cylinders 45, 46 are selectively inserted into the foam discharge pipe 40. The ratio of the inner diameter d31 of the cylinder 42 to the diameter d2 of the outlet 12 of the foam maker pipe 10A satisfies 0.64 to 1.15. The ratio of the inner diameter d32 of the cylinder 46 to the diameter d2 of the outlet 12 of the foam maker pipe 10A also satisfies 0.64 to 1.15. In this way, a plurality of cylinders 45, 46... that satisfy d3n:d2 = 0.64 to 1.15 are prepared according to the diameter d2 of the outlet 12 of the foam maker pipe 10A, and the inner diameters d31, d32... that provide the best reduction time and foaming ratio of the fire-extinguishing foam are selected.

[0047] 1.6.2 Ratio of cross-sectional area of ​​foam outlet pipe to cross-sectional area of ​​foam chamber space The ratio of the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 to the cross-sectional area c1 of the space of the foam chamber 30 is set within a range of 0.050 to 0.170. As already exemplified, the diameter d3 of the outlet 42 of the foam discharge pipe 40 is within a range of about 20 mm to 156 mm. In this case, the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is set within a range of about 3 cm 2 ~191cm 2 On the other hand, the diameter d4 of the space of the foam chamber 30 is within a range of about 205 mm to 305 mm. In this case, the cross-sectional area c1 of the space of the foam chamber 30 is about 330 cm 2 ~730cm 2 3(a)-(c), (d)-(h), or (i)-(m) is adopted, the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is adjusted to the cross-sectional area c1 of the space of the foam chamber 30, so that c2:c3=0.050-0.170 is satisfied.

[0048] 1.6.3 The ratio of the vertical distance from the top of the foam maker pipe to the inner surface of the ceiling of the foam chamber to the diameter of the foam maker pipe outlet. The ratio of the vertical length L of the distance from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30 to the diameter d2 of the outlet 42 of the foam maker pipe 10A is within a range of 0.2 to 1.3. As already exemplified, when the diameter d2 of the outlet 12 of the foam maker pipe 10A is approximately 80.7 mm, the vertical length L of the distance from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30 is within a range of approximately 20 mm to 100 mm. On the other hand, the diameter d2 of the outlet 12 of the foam maker pipe 10A is within a range of approximately 80 mm to 156 mm.

[0049] For example, by changing the welding position of the foam chamber 30 to the foam maker pipe 10A, it is possible to adjust the vertical length L of the interval from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30. Also, for example, by changing the overall length of the foam maker pipe 10A, it is possible to adjust the vertical length L of the interval from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30. By these methods, it is possible to select a length L that satisfies L:d2=0.2 to 1.3 and provides the best reduction time and foaming ratio of the fire-extinguishing foam according to the predetermined diameter d2 of the outlet 12 of the foam maker pipe 10A.

[0050] Also, for example, it is possible to reduce the diameter d2 of the outlet 12 of the foam maker pipe 10A by using metal plates 43 and 44 shown in Figures 3(e) and (f) or cylinders 45 and 46 shown in Figures 3(j) and (k). Therefore, depending on the predetermined vertical length L of the distance from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30, it is possible to select the diameter d2 of the outlet 12 of the foam maker pipe 10A that satisfies L:d2=0.2 to 1.3 and provides the best reduction time and foaming ratio of the fire-extinguishing foam.

[0051] 2. Second embodiment of foaming device 2(a)-(c) show a foaming device 2 according to a second embodiment of the present invention. In FIG. 2(a), the foaming device 2 of this embodiment is composed of a foam maker pipe 10B, an air intake pipe 20, a foam chamber 30, a foam discharge pipe 40, and a dam plate 50. The foaming device 2 of this embodiment is smaller than the foaming device 1 according to the first embodiment shown in FIG. 1(a). The size of the foaming device 2 is not particularly limited, but for example, the total height H1 of the foaming device 2 is within a range of about 530 mm to 1085 mm. The height H2 from the lower end of the foam maker pipe 10A to the center of the foam discharge pipe 40 is within a range of about 350 mm to 700 mm. The foam maker pipe 10B of the foaming device 2 is a single straight pipe and has a constant outer diameter and inner diameter. The inner diameter of the foam maker pipe 10B, the diameter d1 of the inlet 11, and the diameter d2 of the outlet 12 are equal to each other. When the components of the foaming device 2 shown in Figs. 2(a) to (c) satisfy the parameters of the first embodiment described above, the reduction time and foaming ratio of the fire-extinguishing foam can be further improved.

[0052] 3. Example of foaming device Next, examples of the foaming device of the present invention will be described. Table 1 below shows the diameters d1 to d4 (mm) and cross-sectional areas c1 and c2 (cm 2 ), length L (mm) and whether or not a barrier plate is included.

[0053] [Table 1]

[0054] 3.1 Commonalities between Examples 1 to 8 All of Examples 1 to 8 are based on the foaming device 1 of the first embodiment shown in Fig. 1. Therefore, all of Examples 1 to 8 have the same foam maker pipe 10A and foam chamber 30. The diameter d1 of the inlet 11 of the foam maker pipe 10A is 49.62 mm. The diameter d2 of the outlet 12 of the foam maker pipe 10A is 80.7 mm. The diameter d4 of the space of the foam chamber 30 is 204.7 mm. The cross-sectional area c1 of the space of the foam chamber 30 is 329.1 cm 2 It is.

[0055] 3.2 Description of Examples 1 and 2 The foam discharge pipe 40 in Examples 1 and 2 is a straight pipe with an inner diameter of 80.7 mm. The diameter d3 of the outlet 42 of the foam discharge pipe 40 is 80.7 mm. The cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is 51.15 cm 2 In Examples 1 and 2, the vertical length L of the interval from the upper end of the foam maker pipe 10A to the ceiling inner surface of the foam chamber 30 is 100 mm. Example 1 does not have a dam plate 50. Example 2 has a dam plate 50 configured as shown in Figures 4(a) to (c). The dam plate 50 is a rectangular metal plate with a total length of 190 mm, and is curved to follow the arc of the flange provided at the outlet 12 of the foam maker pipe 10A. The dam plate upper part 50a protrudes 60 mm upward from the upper end of the foam maker pipe 10A. The dam plate lower part 50b protrudes 130 mm downward from the upper end of the foam maker pipe 10A. The dam plate lower part 50b blocks approximately 1 / 2 of the inlet 41 of the foam discharge pipe 40.

[0056] 3.3 Description of Examples 3 and 4 Examples 3 and 4 have the same foam discharge pipe 40 as Examples 1 and 2, but a circular metal plate 43 shown in Figures 3(e) and (g) is attached to the outlet 42 of the foam discharge pipe 40. A circular hole with a diameter of 67.9 mm is formed in this metal plate 43. With such a metal plate 43, the diameter d3 of the outlet 42 of the foam discharge pipe 40 in Examples 3 and 4 is 67.9 mm, and the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is 36.21 cm 2Other configurations of Examples 3 and 4 are the same as those of Examples 1 and 2. Example 3 does not have the dam plate 50. Example 4 has the same dam plate 50 as Example 2.

[0057] 3.4 Description of Examples 5 and 6 Examples 5 and 6 have the same foam discharge pipe 40 as Examples 1 and 2, but a circular metal plate 44 shown in Figures 3(f) and (h) is attached to the outlet 42 of the foam discharge pipe 40. A circular hole having a diameter of 52.9 mm is formed in this metal plate 44. Due to such a metal plate 44, the diameter d3 of the outlet 42 of the foam discharge pipe 40 in Examples 5 and 6 is 52.9 mm, and the cross-sectional area c2 of the outlet 42 of the foam discharge pipe 40 is 21.98 cm 2 Other configurations of the fifth and sixth embodiments are the same as those of the first and second embodiments. The fifth embodiment does not have the dam plate 50. The sixth embodiment has the same dam plate 50 as the second embodiment.

[0058] 3.5 Explanation of Examples 7 and 8 In Examples 7 and 8, the vertical length L of the distance from the upper end of the foam maker pipe 10A to the inner ceiling surface of the foam chamber 30 was set to 20 mm. Other configurations of Examples 7 and 8 are the same as those of Examples 1 and 2. Example 7 does not have a dam plate 50. Example 8 has the same dam plate 50 as Example 2.

[0059] 3.6 Supply pressure of foam and foam solution As the foam extinguishing agent used in Examples 1 to 8, a 3% type fluoroprotein foam extinguishing agent was prototyped, the main components of which were a fluorosurfactant that did not contain organic fluorine compounds such as PFOS and PFOA, and hydrolyzed protein. This 3% type fluoroprotein foam extinguishing agent was mixed with water to prepare a foam aqueous solution for extinguishing. This foam aqueous solution for extinguishing was supplied to the inlet 11 of the foam maker pipe 10A of Examples 1 to 8 at a pressure of 0.35 MPa.

[0060] 3.7 25% reduction time, foaming ratio The foaming tests of Examples 1 to 8 were carried out under the above-mentioned conditions, and the 25% reduction time (seconds) and foaming ratio were measured for the fire-extinguishing foams produced by each of Examples 1 to 8. The measurement results of the 25% reduction time (seconds) and foaming ratio for the fire-extinguishing foams are shown in Table 2 below.

[0061] [Table 2]

[0062] As shown in Table 2 above, all of Examples 1 to 8 satisfy the characteristic parameters found by the present inventors, that is, d3:d2 is within the range of 0.64 to 1.15, c2:c1 is within the range of 0.050 to 0.170, and L:d2 is within the range of 0.2 to 1.3 in Table 2. As a result, all of Examples 1 to 8 were able to achieve a 25% reduction time of more than 1 minute and a foaming ratio of 6 times or more for the extinguishing foam, even when a protein foam extinguishing agent was used.

[0063] 4. Embodiment of foam extinguishing system equipped with foaming device of the present invention Next, an embodiment of a foam extinguishing system equipped with a foaming device of the present invention will be described with reference to Fig. 5. As shown in Fig. 5, the foam extinguishing system 100 of this embodiment is for extinguishing a fire that occurs in a storage tank 200 that stores a flammable liquid such as oil. The foam extinguishing system 100 is mainly composed of a water tank 110, a pump 120, a concentrate tank 130, a mixer 140, the foaming device 1 of the first embodiment, and a plurality of pipes 150 that connect these components.

[0064] 5, water for producing a fire extinguishing foam solution is stored in a water tank 110. A pump 120 is connected to the secondary side of the water tank 110 via a pipe 150. The pump 120 sucks in and discharges the water stored in the water tank 110.

[0065] The concentrate tank 130 is connected to the secondary side of the pump 120 via piping 150. A foam extinguishing agent (e.g., a 3% protein foam extinguishing agent) for producing a fire-extinguishing foam solution is stored in the concentrate tank 130. A diaphragm is provided inside the concentrate tank 130 of this embodiment. The diaphragm is compressed according to the pressure of water supplied from the piping 150 to the inside of the concentrate tank 130. As a result, an amount of foam extinguishing agent according to the water pressure is pressure-fed from the concentrate tank 130.

[0066] The mixer 140 is connected to the secondary side of the pump 120 and the concentrate tank 130 via two pipes 150. The mixer 140 in this embodiment is, for example, an orifice-type proportional mixer, and mixes the foam extinguishing agent pumped from the concentrate tank 130 with the water discharged from the pump 120 at a certain ratio (for example, a mixture ratio with water of 3%) to generate a fire-extinguishing foam aqueous solution. The amount of foam extinguishing agent mixed with the water is determined by the hole diameter of the orifice built into the mixer 140.

[0067] The foaming device 1 is provided on the secondary side of the mixer 140 and on the upper part of the side wall of the storage tank 200. The inlet 11 of the foam maker pipe 10A of the foaming device 1 is connected to the mixer 140 via the piping 150. The outlet 42 of the foam discharge pipe 40 of the foaming device 1 is fixed to the upper part of the side wall of the storage tank 200 and communicates with the inside of the storage tank 200, which has an internal pressure equal to or higher than atmospheric pressure.

[0068] When a fire breaks out in the storage tank 200, the foaming device 1 mixes the extinguishing foam aqueous solution produced by the mixer 140 with air taken in from the air intake pipe 20 to produce extinguishing foam. This extinguishing foam is discharged from the outlet 42 of the foam discharge pipe 40 onto the burning surface of the flammable liquid. The burning surface of the flammable liquid is extinguished by the suffocating effect of being covered with the extinguishing foam and the cooling effect of the moisture contained in the extinguishing foam. As described above, the extinguishing foam produced by the foaming device 1 can achieve a 25% reduction time of more than 1 minute and a foaming ratio of 6 times or more of the extinguishing foam, even when a fluorine-based surfactant that does not contain any PFOS or PFOA is used as a 3% protein foam extinguishing agent.

[0069] 5.Other The foaming device of the present invention and the foam extinguishing system equipped with the foaming device are not limited to the above-mentioned embodiment. For example, the foaming device of the present invention is not limited to the numerical ranges of H1, H2, d1 to d4, L, c1, and c1 exemplified in the first and second embodiments. Even if the numerical ranges of H1, H2, d1 to d4, L, c1, and c1 exemplified in the first and second embodiments are out of the ranges, the constituent requirements of the foaming device of the present invention can be satisfied as long as d3:d2 is within the range of 0.64 to 1.15, c2:c1 is within the range of 0.050 to 0.170, and optionally L:d2 is within the range of 0.2 to 1.3. [Explanation of symbols]

[0070] 1, 2 Foaming device 10A, 10B Form Maker Pipe 11 Entrance 12 Exit 20 Air intake pipe 21 Entrance 22 Exit 30 Foam Chamber 40, 40A, 40B foam discharge tube 41 Entrance 42 Exit 43, 44 Metal plate 45, 46 Cylinder 50 Weir plate 50a Upper part of the dam 50b Lower part of the dam 51 Mounting part 52 Thumb screw 100 Foam fire extinguishing equipment 110 Water Tank 120 Pump 130 Concentrate tank 140 Mixer 150 Piping 200 Storage Tank H1 Total height of foaming device H2 Height from the bottom of the foam maker pipe to the center of the foam discharge pipe d1 Formmaker pipe inlet diameter d2 Formmaker pipe outlet diameter d3 Diameter of the outlet of the foam discharge pipe d4 Diameter of the foam chamber space c1 Cross-sectional area of ​​the foam chamber space c2 Cross-sectional area of ​​the outlet of the foam discharge pipe L Vertical distance between the top of the foam maker pipe and the inner ceiling surface of the foam chamber

Claims

1. A foaming device used in a foam fire extinguishing system for extinguishing a fire that has occurred in a storage tank that stores flammable liquid, a formmaker pipe, which is a vertically disposed metal tube having an inlet opening at a lower end and an outlet opening at an upper end; an air intake pipe, a laterally disposed metal tube having an inlet opening into the atmosphere and an outlet communicating with a lower portion of said foammaker pipe; a foam chamber, which is a metal container that covers an upper portion of the foam maker pipe and forms a space surrounding the outlet of the foam maker pipe; a foam discharge tube, a laterally disposed metal tube having an inlet communicating with the foam chamber and an outlet through which foam generated within the foam chamber is discharged; The ratio of the diameter of at least the outlet of the foam discharge pipe to the diameter of the outlet of the foam maker pipe is in the range of 0.64 to 1.15; The ratio of the cross-sectional area of ​​the outlet of the foam discharge pipe to the cross-sectional area of ​​the space of the foam chamber is in the range of 0.050 to 0.170; This foaming device is capable of increasing the foaming ratio of the fire-extinguishing foam discharged from the outlet of the foam discharge pipe to 6 times or more when a fire-extinguishing foam solution is supplied to the inlet of the foam maker pipe at a pressure within the range of 0.25 MPa to 0.7 MPa.

2. 2. The foaming device according to claim 1, wherein the inner diameter of the foam maker pipe at a portion above the air intake pipe is larger than the inner diameter of the portion below the air intake pipe.

3. The foaming device according to claim 1, wherein the foam discharge pipe is made of a cylindrical metal pipe, and the ratio of the cylindrical inner diameter of the metal pipe to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.

15.

4. The foaming device according to claim 1, wherein a metal plate having a circular hole is attached to the outlet of the foam discharge pipe, and the ratio of the diameter of the circular hole of the metal plate to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.

15.

5. The foaming device according to claim 1, wherein a metal or synthetic resin cylinder having an outer diameter approximately the same as the inner diameter of the foam discharge pipe is inserted into the inside of the foam discharge pipe, and the ratio of the inner diameter of the metal or synthetic resin cylinder to the diameter of the outlet of the foam maker pipe is within the range of 0.64 to 1.

15.

6. 2. The foaming device according to claim 1, further comprising a dam plate disposed within said foam chamber and blocking approximately one-half of the inlet of said foam discharge pipe.

7. The foaming device described in claim 6, wherein the dam is fixed to the upper end of the foam maker pipe and has an upper dam portion protruding above the upper end of the foam maker pipe and a lower dam portion protruding below the upper end of the foam maker pipe, and the lower dam portion blocks approximately 1 / 2 of the entrance of the foam discharge pipe.

8. The foaming device of claim 1, wherein a gap is provided between the upper end of the foam maker pipe and the inner ceiling surface of the foam chamber, and the ratio of the vertical length of the gap to the diameter of the outlet of the foam maker pipe is 0.2 to 1.

3.

9. A foam fire extinguishing system for extinguishing a fire that occurs in a storage tank that stores flammable liquid, A water tank for storing water for generating a fire extinguishing foam solution; A pump provided on a secondary side of the water tank for sucking and discharging the water from the water tank; A concentrate tank provided on a secondary side of the pump and configured to store a foam extinguishing agent for producing the fire extinguishing foam solution; a mixer provided on the secondary side of the pump and the concentrate tank, for mixing the foam extinguishing agent supplied from the concentrate tank with the water discharged by the pump to generate a fire-extinguishing foam solution; A foaming device described in any one of claims 1 to 8, which is provided on the secondary side of the mixer and on the upper part of the side wall of the storage tank, mixes the fire-extinguishing foam aqueous solution produced by the mixer with air taken in from the air intake pipe to produce the fire-extinguishing foam, and discharges the fire-extinguishing foam onto the surface of the flammable liquid from the outlet of the foam discharge pipe.

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