A CAFS-specific rain shower head

Abstract

This invention relates to a deluge nozzle specifically designed for CAFS (Chemical Air Fever) fires, primarily for hot oil fires and low-boiling-point oil fires. It includes a nozzle body and a deflector plate. The nozzle body comprises a base and a deflector plate mounting seat. The base has a first through-hole, and the deflector plate mounting seat is located above the first through-hole and fixedly connected to the base via a fixing bracket. The deflector plate is fixedly mounted on the deflector plate mounting seat, which has a second through-hole penetrating the deflector plate. In use, compressed air foam is sprayed out through the first through-hole. Most of the foam is broken up by the deflector plate, thus expanding the deluge area. A small portion of the compressed air foam flows out through the second through-hole. This portion of compressed air foam has stronger spray pressure and penetration performance compared to other portions, which not only helps penetrate the fire but also suppresses the fire in cases of reignition or oil vapor flashover, preventing flames from licking and burning the nozzle.

Description

Technical Field

[0001] This invention relates to the field of fire sprinkler technology, and more specifically to a CAFS-specific deluge sprinkler designed for hot oil fires and low-boiling-point oil fires. Background Technology

[0002] CAFS, or Compressed Air Foam System, is a new type of fire extinguishing technology that has gradually developed both domestically and internationally in recent years. The mechanism of foam generation involves introducing a certain proportion of compressed air into a foam mixture, causing impact and mixing to produce foam. Compared to ordinary water spray and foam mist, CAFS is more effective at extinguishing Class A and Class B fires, and is particularly effective against power plants and high-voltage transformer boxes that exhibit both Class A and Class B fire characteristics. However, existing compressed air foam systems lack dedicated sprinkler heads and mostly use ordinary sprinkler heads. When CAFS is applied to extinguish hot oil fires in locations such as high-voltage transformer boxes in power plants, the rapid combustion speed, extreme heat radiation, and the frequent occurrence of oil vapor flashover during combustion make extinguishing difficult. Existing sprinkler heads lack sufficient spray pressure and atomization effect, hindering the full utilization of CAFS's advantages and resulting in poor fire extinguishing performance. Furthermore, sprinkler heads are prone to deformation and thermal melting due to reignition and flashover. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a deluge nozzle specifically designed for CAFS (Compressed Air Foam System) to solve issues such as insufficient spray pressure and atomization effect, poor fire extinguishing effect, and susceptibility to deformation and heat melting in existing compressed air foam system deluge nozzles.

[0004] The present invention adopts the following technical solution:

[0005] A CAFS-specific rain shower head includes a nozzle body and a splash plate. The nozzle body includes a base and a splash plate mounting base. The base has a first through hole for compressed air foam to pass through. The splash plate mounting base is located above the first through hole and is fixedly connected to the base by a fixing bracket. The splash plate is fixedly mounted on the splash plate mounting base. The splash plate mounting base has a second through hole for compressed air foam to pass through, and the second through hole penetrates the splash plate.

[0006] Furthermore, the second through hole is provided with rifling for guiding flow.

[0007] Furthermore, the ratio of the depth of the rifling groove to the radius of the second through hole is 1:4 to 1:2. The groove depth formed by this ratio is significantly greater than the groove depth of a typical firearm barrel, and the groove can form a larger guide groove.

[0008] Furthermore, the second through hole is a funnel-shaped through hole.

[0009] Furthermore, there are two ways to set the flared through hole. One way is to have the end with the larger diameter of the flared through hole facing the first through hole and the end with the smaller diameter facing the object to be burned. The other way is to have the end with the smaller diameter of the flared through hole facing the first through hole and the end with the larger diameter facing the object to be burned.

[0010] Furthermore, the axis of the second through hole and the axis of the splash plate both coincide with the axis of the first through hole.

[0011] Furthermore, the diameter of the second through hole is smaller than the diameter of the first through hole.

[0012] Furthermore, the edge of the splash plate is surrounded by several splashing teeth.

[0013] Furthermore, the splashing teeth are trapezoidal.

[0014] Furthermore, it also includes a back plate, which is integrally formed with the splash plate.

[0015] As can be seen from the above description of the structure of the present invention, compared with the prior art, the present invention has the following advantages:

[0016] 1. During use, compressed air foam is sprayed out through the first through hole. Most of the sprayed compressed air foam is broken up by the splash plate, thereby expanding the rain area. At the same time, some of the compressed air foam will gush out through the second through hole when it hits the splash plate mounting base and splash plate. This part of the compressed air foam has stronger spray pressure and penetration performance than the other part of the compressed air foam that is broken up by the splash plate. It is not only conducive to penetrating the fire, but also can suppress the fire in the case of reignition of hot oil fire or flashover of oil vapor, and prevent the flames from licking and burning the nozzle.

[0017] 2. The second through hole of this invention imitates a firearm and is equipped with rifling. When compressed air foam passes through the second through hole at high speed, it will be accelerated by spiraling through the rifling, making the compressed air foam ejected from the second through hole more penetrating and further enhancing its ability to penetrate fire.

[0018] 3. The ratio of the depth of the rifling groove to the radius of the second through hole is 1:4 to 1:2. The groove depth formed by this ratio is significantly greater than that of the groove in a typical firearm barrel. The groove can form a deeper guide groove, which is more suitable for driving the high-speed flow of compressed air foam to rotate. The guide groove in this ratio range can ensure strong rotational force when compressed air foam passes through at high speed, without losing too much of the impact force of the compressed air foam.

[0019] 4. The second through-hole of the present invention is funnel-shaped. There are two ways to set the funnel-shaped through-hole. One way is to have the larger diameter end of the funnel-shaped through-hole facing the first through-hole and the smaller diameter end facing the burning object. In this way, when the compressed air foam passes through the second through-hole, the contraction effect of the funnel-shaped through-hole can further increase the spray pressure and greatly enhance the penetration of the fire. The other way is to have the smaller diameter end of the funnel-shaped through-hole facing the first through-hole and the larger diameter end facing the burning object. In this way, when the compressed air foam is sprayed out through the second through-hole, although the penetration force of the compressed air foam flow is reduced, it still has a strong spray pressure. Moreover, the compressed air foam flow will be diffused. When facing the flames licking at the flames during deflagration or oil vapor flashover, the diffused spray can more comprehensively and effectively suppress the flames and provide stronger protection for the rain shower head. Attached Figure Description

[0020] Figure 1 This is a front view of Embodiment 1 of the present invention;

[0021] Figure 2 for Figure 1 Sectional view along the AA direction;

[0022] Figure 3 This is a schematic diagram of the splash plate structure according to Embodiment 1 of the present invention;

[0023] Figure 4 This is a bottom view of the splash plate mounting base according to Embodiment 2 of the present invention;

[0024] Figure 5 This is a cross-sectional view of the splash plate mounting base according to Embodiment 2 of the present invention;

[0025] Figure 6 This is a cross-sectional view of the splash plate mounting base with the default rifling in Embodiment 3 of the present invention;

[0026] Figure 7 This is a schematic diagram of the structure used in the fire extinguishing experiment simulating actual fire accident conditions using the present invention.

[0027] Figure 8 To demonstrate the field effect of the fire extinguishing experiment using this invention Figure 1 ;

[0028] Figure 9 To demonstrate the field effect of the fire extinguishing experiment using this invention Figure 2 .

[0029] The nozzle body 1, base 11, splash plate mounting base 12, fixed bracket 13, splash plate 2, splash teeth 21, back plate 3, first through hole 4, second through hole 5, and rifling 6. Detailed Implementation

[0030] The specific implementation of the embodiments of the present invention will now be described with reference to the accompanying drawings.

[0031] Example 1

[0032] Reference Figures 1 to 3 A CAFS-specific rain shower head includes a nozzle body 1, a splash plate 2, and a back plate 3, with the back plate 3 integrally formed with the splash plate 2. The nozzle body 1 includes a base 11 and a splash plate mounting base 12. The base 11 is used to connect to the piping network of the compressed air foam system, and has a first through hole 4 for the passage of compressed air foam. The splash plate mounting base 12 is located above the first through hole 4 and is fixedly welded to the base 11 by a heart-shaped fixing bracket 13. The splash plate 2 is fixedly welded to the splash plate mounting base 12, and a plurality of splashing teeth 21 are arranged around the edge of the splash plate 2, preferably trapezoidal teeth. A second through hole 5 for the passage of compressed air foam is formed inside the splash plate mounting base 12, the second through hole 5 penetrating the splash plate 2. The diameter of the second through hole 5 is smaller than the diameter of the first through hole 4, and the axis of the second through hole 5 and the axis of the splash plate 2 coincide with the axis of the first through hole 4.

[0033] Reference Figures 1 to 3 In use, the base 11 of the nozzle body 1 is connected to the piping network of the compressed air foam fire extinguishing system. When a fire occurs, the compressed air foam fire extinguishing system is activated, and compressed air foam flows into the base 11 of the invention from the piping network and is sprayed out through the first through hole 4. Most of the sprayed compressed air foam is broken up by the splash plate 2, thereby expanding the rain area. When some of the compressed air foam hits the splash plate mounting base 12 and the splash plate 2, it will flow out through the second through hole 5. This part of the compressed air foam has a stronger spray pressure and penetration performance than other compressed air foam. It is not only conducive to penetrating the fire, but also can suppress the fire and prevent the flames from burning the nozzle in the event of reignition or flashover of oil vapor in hot oil fires.

[0034] Example 2

[0035] Reference Figure 4 and Figure 5This embodiment is basically the same in structure as Embodiment 1, and will not be described in detail here. The difference is that the second through hole 5 is provided with rifling 6. That is, the second through hole 5 of this invention imitates a firearm and is provided with rifling 6. When compressed air foam passes through the second through hole 5 at high speed, it will be spirally accelerated by the rifling 6, making the compressed air foam ejected from the second through hole 5 more penetrating and further enhancing its ability to penetrate fire. The ratio of the depth of the rifling 6 to the radius of the second through hole 5 is 1:4 to 1:2, and is preferably 1:4 in this embodiment. The depth of the rifling formed by this ratio range is significantly greater than the depth of the rifling in a typical firearm barrel. The rifling can form a deeper guide groove, which is more suitable for driving the high-speed flowing compressed air foam to rotate. The guide groove in this ratio range can ensure strong rotational force when the compressed air foam passes through at high speed, without losing too much of the impact force of the compressed air foam.

[0036] Example 3

[0037] Reference Figure 6 This embodiment is basically the same in structure as Embodiment 2, and will not be described in detail here. The difference is that the second through hole 5 not only has rifling 6, but also has a trumpet-shaped through hole. In this invention, there are two ways to set the trumpet-shaped through hole. One way is to have the larger diameter end of the trumpet-shaped through hole facing the first through hole 4 and the smaller diameter end facing the burning object. Thus, when the compressed air foam passes through the second through hole 5, it is not only accelerated by the spiral of the rifling 6, but also further enhanced by the contraction of the trumpet-shaped through hole, thus greatly increasing the spray pressure and significantly enhancing the penetration of the fire. The other way is to have the smaller diameter end of the trumpet-shaped through hole facing the first through hole 5 and the larger diameter end facing the burning object. Thus, when the compressed air foam is sprayed out through the second through hole 5, although the penetration of the compressed air foam flow is reduced, it still has a strong spray pressure. Moreover, the compressed air foam flow will be spirally diffused and sprayed. When facing the flames licking at the flames during deflagration or oil vapor flashover, the spiral diffusion and spray can more comprehensively and effectively suppress the flames, providing stronger protection for the rain sprinkler head. In this embodiment, the second design method is preferred.

[0038] The following is a fire extinguishing experiment conducted in Zhangzhou Hua'an to simulate the actual fire accident conditions of the fixed compressed air foam fire extinguishing system using the rain sprinkler head of this invention, in order to effectively grasp the fire extinguishing effect of the +-800KV UHVDC transmission project.

[0039] Experimental framework such as Figure 7As shown, a 1:1 full-size UHV toroidal transformer model was constructed based on the actual conditions of the UHV converter station. A sprinkler network was arranged around the firewall to fully cover the converter transformer and oil tank. The sprinkler pipes and fire monitors were connected to the compressed air foam generator via a DN250 main delivery pipeline. Four sprinkler pipe sections were installed on both sides of the firewall, with the sprinkler pipes installed at two different heights: one group at 6 meters above the ground and another group at 4 meters above the ground. The sprinkler heads on the 6-meter-high sprinkler pipes used in this embodiment had one end of the larger funnel-shaped through-hole facing the first through-hole 4, and the other end facing the object of combustion. The sprinkler heads on the 4-meter-high sprinkler pipes used the same method, with one end of the smaller funnel-shaped through-hole facing the first through-hole 5, and the other end facing the object of combustion.

[0040] Add 10.2 tons of experimental fuel (approximately 270 mm thick, overflowing from both sides) to the main oil tank, add 2.6 tons of experimental fuel (approximately 100 mm thick) to each of the two emergency oil pools, and add 0.5 tons of experimental fuel to the oil conservator. Heat the transformers in the main oil tank and the two emergency oil pools to 155°C or higher, and heat the oil temperature in the oil conservator to approximately 90°C. Simultaneously ignite the transformer oil at all three locations remotely, and simultaneously open the oil conservator valves to inject oil into the main oil tank, creating an oil spill fire. The pre-ignition time should be no less than 180 seconds. Then, activate the compressed air foam fire extinguishing system to extinguish the fire, observing and recording the extinguishing time.

[0041] Reference Figure 8 and Figure 9 The deluge nozzle of this invention has an excellent fire extinguishing effect. It is currently the only nozzle in China and abroad capable of extinguishing large hot oil fires with a deluge nozzle, and can extinguish open flames within 1 minute (58 seconds). The compressed air foam has a large diffusion area and strong self-protection ability. After being burned by "high-temperature oil fire", the deluge nozzle did not deform or melt. Even under continuous reignition and "classic oil vapor flashover", where the temperature is much higher than the oil fire temperature, the deluge nozzle can still maintain and stabilize the jet. During the re-inspection, there was still no shape change. Existing deluge nozzles cannot achieve this level of industrial-grade experimental verification.

[0042] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A rain shower head specifically for CAFS, characterized in that: The device includes a nozzle body and a splash plate. The nozzle body includes a base and a splash plate mounting base. The base has a first through hole. The splash plate mounting base is located above the first through hole and is fixedly connected to the base by a fixing bracket. The splash plate is fixedly mounted on the splash plate mounting base. The splash plate mounting base has a second through hole that penetrates the splash plate. The second through hole has rifling for guiding the flow. The ratio of the depth of the rifling groove to the radius of the second through hole is 1:4 to 1:

2.

2. The CAFS-specific rain shower head according to claim 1, characterized in that: The second through hole is a funnel-shaped through hole.

3. A CAFS-specific rain shower head according to claim 2, characterized in that: The larger end of the trumpet-shaped through hole faces the first through hole.

4. A CAFS-specific rain shower head according to claim 2, characterized in that: The smaller end of the trumpet-shaped through hole faces the first through hole.

5. A CAFS-specific rain shower head according to claim 1, characterized in that: The axis of the second through hole and the axis of the splash plate both coincide with the axis of the first through hole.

6. A CAFS-specific rain shower head according to claim 1, characterized in that: The diameter of the second through hole is smaller than the diameter of the first through hole.

7. A CAFS-specific rain shower head according to claim 1, characterized in that: The edge of the splash plate is surrounded by several splashing teeth, which are trapezoidal in shape.

8. A CAFS-specific rain shower head according to claim 1, characterized in that: It also includes a back plate, which is integrally formed with the splash plate.

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