Foam generating device, gel foam generating device and gel foam fire rescue device

Abstract

The utility model relates to colloid foam generating equipment, and discloses a foam generating device, a gel foam generating device and a gel foam fire rescue device.The foam generating device comprises the foam generating device, and the foam generating device comprises a first mixer, a second mixer and a primary expander which are sequentially connected; a foaming liquid channel and a compressed gas channel of the first mixer are both communicated with a turbulent flow cavity of the second mixer, so that foaming liquid and compressed gas are mixed to form gas-liquid mixed fluid, and the turbulent flow cavity is communicated with a primary expansion cavity of the primary expander; the cross sectional area of the turbulent flow cavity is smaller than that of the primary expansion cavity, and a foaming assembly used for foaming the gas-liquid mixed fluid is arranged in the primary expansion cavity. According to the foam generation device, the gel foam generation device and the gel foam fire rescue device, gel foam has high foaming times.

Description

Technical Field

[0001] The present application relates to a colloidal foam generating device, and more particularly to a foam generating device, a gel foam generating device and a gel foam fire rescue device. Background Art

[0002] As my country's urbanization level increases, emergency rescue scenes such as high-rise buildings and large fires are gradually increasing, and the rescue situation at fire scenes is becoming increasingly complex and urgent. Therefore, the demand for fire extinguishing agents and emergency rescue equipment that integrate multiple functions such as rapid fire extinguishing, heat insulation and flame retardancy is more urgent.

[0003] Foam fire extinguishing agent is currently the main fire extinguishing material in my country. Conventional water-based foam fire extinguishing agent is a liquid foam. Although it can be quickly deployed for fire extinguishing, its anti-burning performance is poor (1000℃, within 4 minutes), and the foam retention time is short (usually within 20 minutes), making it difficult to achieve the effect of long-term fire isolation. Therefore, gel foam fire extinguishing technology, as a new type of fire prevention and extinguishing technology, can achieve better anti-burning performance and longer-term fire isolation effect, and is widely used. For example, the fire extinguishing agent of inorganic salt gel system is a solid foam, which not only has the good fluidity and covering sealing of ordinary foam, but also has outstanding advantages such as abnormally good anti-burning performance (1000℃, more than 20 minutes) and long foam retention time (more than 24 hours).

[0004] At present, in the field of coal fire fighting, gel foam fire fighting technology is widely used as a new and efficient mine fire prevention and extinguishing technology. However, there is a problem that the gel foam fire extinguishing agent cannot foam. Utility Model Content

[0005] The purpose of the present application is to provide a foam generating device to achieve a higher foaming multiple of gel foam. The second purpose of the present application is to provide a gel foam generating device. The third purpose of the present application is to provide a gel foam fire rescue device.

[0006] In order to achieve the above-mentioned objectives, the first aspect of the present application provides a foam generating device, including a mixer for mixing foaming liquid and compressed gas and a primary expander, the mixer is connected to the primary expander, the foaming liquid and compressed gas are mixed to form a gas-liquid mixed fluid, and a foaming component for foaming the gas-liquid mixed fluid is arranged in the primary expansion chamber of the primary expander.

[0007] In some embodiments, the mixer includes a first mixer and a second mixer, and the first mixer, the second mixer and the primary expander are connected in sequence, and the bubble liquid channel and the compressed gas channel of the first mixer are connected to the turbulence chamber of the second mixer so that the bubble liquid and the compressed gas are mixed to form a gas-liquid mixed fluid, and the turbulence chamber is connected to the primary expansion chamber of the primary expander, and the cross-sectional area of ​​the turbulence chamber is smaller than the cross-sectional area of ​​the primary expansion chamber.

[0008] The second aspect of the present application provides a gel foam generating device, which is provided with the above-mentioned foam generating device, and the primary expansion chamber is connected to the gel mixing reaction device to transport the foam fluid formed after the gas-liquid mixed fluid is foamed to the gel mixing reaction device for gelation.

[0009] In some embodiments, the gel mixing reaction device includes a shrinkage device, which includes a shrinkage chamber connected to the primary expansion chamber, the cross-sectional area of ​​the shrinkage chamber is smaller than the cross-sectional area of ​​the primary expansion chamber, and the shrinkage device is provided with a plurality of coagulant injection holes connected to the shrinkage chamber along its circumference.

[0010] In some embodiments, the gel mixing reaction device further comprises a secondary expander for homogenizing the foam fluid that has passed through the gel, and the shrinkage device and the secondary expander are connected in sequence.

[0011] In some embodiments, a nozzle is installed at one end of the secondary expander away from the contraction device.

[0012] In some embodiments, the secondary expander includes a secondary expansion chamber communicated with the contraction chamber, and a homogenizing component for swirling and stirring the foam fluid passing through the gel is arranged in the secondary expansion chamber.

[0013] In some embodiments, the homogenizing assembly includes a rotating shaft and a plurality of spiral blades, and the spiral blades are sequentially arranged on the rotating shaft to form a spiral blade group.

[0014] In some embodiments, the rotating shaft is alternately provided with the forward-rotating spiral blades and the reverse-rotating spiral blades.

[0015] In some embodiments, the spiral length of the spiral blade is 0.4 to 0.6 times the pitch.

[0016] In some embodiments, the helical blade has a helical angle of 30 to 60°.

[0017] In some embodiments, the length of the spiral blade set is 4 to 8 times the pitch.

[0018] In some embodiments, a secondary conical diffusion region is provided between the contraction chamber and the secondary expansion chamber, and a cone angle β of the secondary conical diffusion region is 7.5-25°.

[0019] In some embodiments, the first mixer, the second mixer, the primary expander, the contraction device and the secondary expander are sequentially connected to form an integrated structure.

[0020] In some embodiments, the axis of the contraction cavity is perpendicular to the axis of the coagulant injection hole, the distance between the coagulant injection hole and one end of the contraction cavity away from the primary expansion cavity is x, the diameter of the contraction cavity is d, and x and d satisfy the following formula:

[0021]

[0022] Among them, u p is the average flow velocity of the foam fluid in the contraction cavity, u c is the average injection rate of the coagulant, and c is the coefficient.

[0023] In some embodiments, a primary conical diffusion region is provided between the turbulence chamber and the primary expansion chamber, a cone angle α of the primary conical diffusion region is less than or equal to 30°, and a length L1 of the turbulence chamber is 3 to 10 times a diameter D1 of the turbulence chamber.

[0024] In some embodiments, the foaming component is a baffle alternately arranged at the bottom and the top of the primary expansion chamber.

[0025] In some embodiments, a plurality of through holes are disposed on the baffle.

[0026] In some embodiments, the baffle is a semicircular plate.

[0027] In some embodiments, the diameter D2 of the primary expansion cavity is 2 to 5 times the diameter D1 of the turbulent cavity, and the length L2 of the primary expansion cavity is 2 to 10 times the diameter D2 of the primary expansion cavity.

[0028] In some embodiments, the first mixer includes a first body and a second body, the second body is sleeved on the first body, the end of the first body facing the second mixer is a tapered end with a gradually decreasing cross-sectional area, and the second body of the second mixer has a tapered groove with a gradually decreasing cross-sectional area at one end facing the first mixer of the second mixer, the tapered groove is connected to the turbulent chamber, and the compressed gas channel is formed between the tapered end and the tapered groove, the compressed gas channel is an annular channel, and the foaming liquid channel is a hollow channel that penetrates the first body along the axial direction of the first mixer.

[0029] In some embodiments, the distance s between the outlet position of the foaming liquid channel and the starting position of the turbulent chamber is 0.5 to 1.5 times the diameter d1 of the outlet position of the foaming liquid channel, and the contraction cone angle of the compressed gas channel is 60 to 90°.

[0030] A third aspect of the present application provides a gel foam fire rescue device, which is provided with the above-mentioned gel foam generating device.

[0031] Through the above technical scheme, a mixer and a primary expander are used in combination, the foaming liquid and the compressed gas are mixed in the mixer, and then a foaming component is arranged in the primary expansion chamber of the primary expander, so that the foaming liquid with higher viscosity can have a higher foaming multiple.

[0032] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0034] Figure 1 This is a schematic diagram of the gel foam generation principle in a specific embodiment of the present application;

[0035] Figure 2 It is a schematic diagram of the pressure state during the gel foam generation process in a specific embodiment of the present application;

[0036] Figure 3 This is one of the structural schematic diagrams of the gel foam generating device in the specific embodiment of the present application;

[0037] Figure 4 This is the second structural schematic diagram of the gel foam generating device in the specific embodiment of the present application.

[0038] Description of Reference Numerals

[0039] DETAILED DESCRIPTION

[0040] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0041] All terms used in this application have the same meaning as those understood by those of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0042] It should be noted that in the description of this application, unless otherwise stated, the directional words used, such as "front" and "rear", generally refer to the direction of flow of the fluid, with the upstream being the front and the downstream being the rear. For example, the rear end of the contraction chamber 41 refers to the end facing the secondary expansion chamber 51, and the front end of the contraction chamber 41 refers to the end opposite thereto. Unless otherwise stated, the indicated orientation or positional relationship is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0043] Spontaneous combustion of coal is one of the main disasters that directly threatens the safe production of mines. Traditional coal mine fire prevention and extinguishing technologies have obvious shortcomings. For example, when using water injection and grouting technology, water and slurry only flow along the low-lying areas in the goaf, and cannot evenly cover the goaf, and cannot accumulate at high places; inert gas easily escapes with air leakage, reducing the fire extinguishing ability. In response to these problems, gel foam fire prevention and extinguishing technology was proposed, but the existing gel foam fire prevention and extinguishing equipment still has the problem of low foaming multiples or even inability to foam.

[0044] In view of the above-mentioned deficiencies in the prior art, the basic embodiment of the present application provides a foam generating device, such as Figure 3 and Figure 4 As shown, it includes a mixer for mixing foaming liquid and compressed gas and a primary expander 3, the mixer is connected to the primary expander 3, the foaming liquid is mixed with the compressed gas to form a gas-liquid mixed fluid, and a foaming component for foaming the gas-liquid mixed fluid is arranged in the primary expansion chamber 31 of the primary expander 3.

[0045] Furthermore, the mixer includes a first mixer 1 and a second mixer 2, the first mixer 1, the second mixer 2 and the primary expander 3 are connected in sequence, the first mixer 1, the second mixer 2 and the primary expander 3 are connected in sequence, the foaming liquid channel 11 and the compressed gas channel 12 of the first mixer 1 are connected to the turbulence chamber 21 of the second mixer 2, so that the foaming liquid and the compressed gas are mixed to form a gas-liquid mixed fluid, the turbulence chamber 21 is connected to the primary expansion chamber 31 of the primary expander 3, the cross-sectional area of ​​the turbulence chamber 21 is smaller than the cross-sectional area of ​​the primary expansion chamber 31, and a foaming component is arranged in the primary expansion chamber 31, and the foaming component is used to foam the gas-liquid mixed fluid.

[0046] The foaming liquid flows into the turbulent chamber 21 from the foaming liquid channel 11, and the compressed gas also flows into the turbulent chamber 21 from the compressed gas channel 12. In the turbulent chamber 21, under the flow velocity difference, turbulent disturbance and high and low pressure fluctuations, the surface of the foaming liquid is accelerated, broken and mixed with the compressed gas to form a gas-liquid mixed fluid. Then, the gas-liquid mixed fluid enters the primary expansion chamber 31 and collides with the foaming component to form foam. Since the cross-sectional area of ​​the turbulent chamber 21 is smaller than the cross-sectional area of ​​the primary expansion chamber 31, the flow velocity decreases and the pressure rises under the action of the viscosity force and the foaming component, so that the foams with large size differences are aggregated (aggregation refers to the process of two or more dispersed phase particles merging into a large particle) to form a more uniform foam, so that the foaming liquid with higher viscosity has a higher foaming multiple (foaming multiple ≥ 6).

[0047] Furthermore, a gel mixing reaction device may be provided, which is connected to the primary expansion chamber 31 of the foam generating device to form a gel foam generating device, so as to transport the foam fluid formed after the gas-liquid mixed fluid is foamed to the gel mixing reaction device for gelation.

[0048] It should be noted that the application of the gel foam generating device of the present application is not limited to the fire prevention and extinguishing effect of coal spontaneous combustion in the field of coal mines, and can also be applied to other fields or places that require fire prevention and extinguishing, such as forest fires, grassland isolation belts, chemical raw material fires, high-rise building fires and other complex fire scenes. It can be an inorganic salt mixed foaming liquid, for example, the inorganic salt mixed foaming liquid can be a mixture of various solutions such as inorganic salt sol solution, composite foaming agent, foam stabilizer, flame retardant, antifreeze agent, etc., among which, inorganic salt sol solution, composite foaming agent, foam stabilizer, flame retardant, antifreeze agent, etc. are well known to those skilled in the art, and do not belong to the core improvement part of the present application, so they will not be repeated here. Among them, fire rescue can be directly facing the fire source, using the method of covering the fire source to extinguish the fire source, or it can be surrounding the fire source, making an isolation belt, isolating the fire source to achieve the purpose of extinguishing the fire.

[0049] In some embodiments, Figure 4As shown, the first mixer 1 includes a first body and a second body, a cavity is formed in the second body for installing the first body, a first gap is formed between the second body and the first body, one end of the first body facing the second mixer 2 is a tapered end with a gradually smaller cross-sectional area, that is, the rear end of the first body is a tapered end with a gradually smaller cross-sectional area, and the first gap between the second body and the first body can be an annular groove surrounding the tapered end, and the second body of the second mixer has a tapered groove with a gradually smaller cross-sectional area at one end facing the first mixer 2, that is, the rear end of the second body of the second mixer has a tapered groove with a gradually smaller cross-sectional area, and the tapered groove is connected to the turbulent cavity. The conical end is inserted into the conical groove, and a second gap is formed between the conical end and the conical groove. The second gap is the compressed gas channel 12. The compressed gas channel 12 is an annular channel. The first gap can be used as an air inlet for passing compressed air into the first mixer of the compressed gas channel 1, and then used to fill the turbulent cavity 21 with compressed air (pressure 0.3MPa~1.0MPa). The foaming liquid channel 11 is a hollow channel that runs through the first body along the axial direction of the first mixer 1, and is used to fill the turbulent cavity 21 with foaming liquid. The diameter of the inlet end of the cavity in the second body is D0, and the diameter of the inlet end of the foaming liquid channel 11 is d0, and D0 is greater than d0. Since the compressed gas channel 12 is relatively narrow, it can form a high-speed and low-pressure annular airflow. The gas flow rate U of the high-speed and low-pressure annular airflow g The flow rate U of the foaming liquid l There is a large difference (the typical flow velocity difference is greater than 20m / s), so it is easy to accelerate, break and mix the foaming liquid surface with compressed air under the flow velocity difference, turbulent disturbance and high and low pressure fluctuations to form a gas-liquid mixed fluid.

[0050] In some embodiments, the length of the outlet of the foaming liquid channel 11 is L0, and the distance between the end of the outlet of the foaming liquid channel 11 and the starting position of the turbulent chamber 21 is s, which is 0.5 to 1.5 times the diameter d1 at the outlet of the foaming liquid channel 11, so that the foaming liquid and the compressed gas have a better contact area at the outlet of the foaming liquid channel 11, thereby enhancing the mixing effect. Furthermore, the contraction cone angle of the compressed gas channel 12 before the compressed air enters the turbulent chamber 21 is 60 to 90 degrees, which reduces the pressure loss. This ensures the impact force of the high-speed low-pressure annular airflow on the outflow of the foam fluid, wherein, with reference to Figure 1 and Figure 2, high-speed low-pressure annular airflow refers to the fact that according to the fluid principle, the flow velocity of the fluid will increase while the pressure of the fluid decreases, so that the compressed gas channel 12 forms a high-speed low-pressure annular airflow before the compressed air enters the turbulent chamber 21. Among them, the turbulent contraction chamber of the turbulent chamber 21 refers to the conical contraction groove at the front end of the turbulent chamber 21, and the compressed gas channel 12 is formed between the conical contraction groove and the rear end of the first main body. The turbulent chamber 21 also includes a turbulent direct flow chamber connected to the turbulent contraction chamber, and a turbulent diffusion chamber connected to the turbulent direct flow chamber. The turbulent diffusion chamber is formed as a primary conical diffusion area between the turbulent chamber 21 and the primary expansion chamber 31. The cross-sectional area S of the compressed gas channel 12 at the outlet of the bubble liquid channel 11 (diameter d1) needs to be g The diameter D1 of the turbulent cavity 21 is designed to ensure the gas flow rate U g The fluid flow rate U is much higher than that of the foaming liquid l To ensure that the foam fluid is fully mixed with the compressed gas, the specific flow rate is determined according to the following design method:

[0051] (1) The design airflow Reynolds number must be greater than the critical turbulence Reynolds number:

[0052]

[0053] in, is the gas density, is the gas dynamic viscosity, is the characteristic diameter of the airflow (the actual calculation takes the diameter of the turbulent cavity 21), the critical Reynolds number Generally, it is 2500.

[0054] (2) The design flow Weber number is greater than the critical Weber number:

[0055]

[0056] in, is the foam fluid density, is the surface tension coefficient of the gas and foam fluid interface, is the characteristic diameter of the foam fluid (the diameter of the pipe before the foam fluid enters the turbulent chamber 21, that is, the diameter of the end of the foaming liquid channel 11 facing the turbulent chamber 21), and the critical Weber number is generally 10 5 .

[0057] In a specific embodiment, the diameter of the foaming liquid channel 11 is set at 5-30 mm, the flow rate is set at 3-40 L / min, and the channel length of the foaming liquid channel 11 is 2.5-5 times the diameter to ensure that the fluid flow rate U l Stable, compressed gas flow Q g Set at 12~400L / min, compressed gas flow Q g Equal to the cross-sectional area S of the compressed gas channel 12 at the outlet of the foaming liquid channel 11g and the gas flow rate U at that location g Further, the gas flow rate U g With the fluid flow rate U l The difference is greater than 20m / s.

[0058] In some embodiments, Figure 1 As shown, the foaming component can be a baffle 32, and a plurality of baffles 32 are alternately arranged at the bottom and top of the primary expansion chamber 31. The gas-liquid mixed fluid enters the primary expansion chamber 31 and forms foam with the baffles 32. At the same time, under the action of the viscosity of the fluid and the baffles 32, the fluid flow rate decreases and the fluid pressure rises, so that the foams with large differences in size gather and form relatively uniform foams to form foam fluid. Figure 1 and Figure 4 As shown, a primary conical diffusion area is provided between the turbulent chamber 21 and the primary expansion chamber 31, the cone angle α of the primary conical diffusion area is less than or equal to 30°, and the length L1 of the turbulent chamber 21 is 3 to 10 times the diameter D1 of the turbulent chamber 21, so as to reduce the pressure loss under the condition of ensuring a good turbulent effect. Among them, the primary conical diffusion area refers to the transition area between the turbulent chamber 21 and the primary expansion chamber 31, such as Figure 4 As shown, in terms of specific structural form, a conical groove facing the primary expansion chamber 31 is provided at the rear end of the second mixer 2, and the cross-sectional area of ​​the conical groove gradually increases from the turbulence chamber 21 to the primary expansion chamber 31, and the area covered by the conical groove is the primary conical diffusion area.

[0059] Alternatively, a plurality of spiral blades are arranged in the primary expansion chamber 31 as foaming components, and the spiral blades rotate to stir the gas-liquid mixed fluid, causing turbulent flow disturbance of the gas-liquid mixed fluid to form a foam fluid.

[0060] Furthermore, the diameter D2 of the primary expansion chamber 31 is 2 to 5 times the diameter D1 of the turbulent chamber 21, and the length L2 of the primary expansion chamber 31 is 2 to 10 times the diameter D2 of the primary expansion chamber 31. In the process of the gas-liquid mixed fluid entering the primary expansion chamber 31, the pressure is maximized and the pressure loss is small, and the pressure can remain stable before entering the contraction chamber 41 of the contractor 4.

[0061] In some embodiments, the baffle 32 may be a grid-type blocking block, such as a plurality of through holes provided on the baffle 32, or the baffle 32 may be a mesh structure to improve the passing capacity and mixing effect of the baffle 32. Alternatively, the baffle 32 may be a semicircular plate or other shaped plate, and each baffle 32 may be staggered.

[0062] In addition to the problem that the gel fire extinguishing agent cannot foam, the existing gel foam fire extinguishing technology also has the problem of long gel time. Figure 3 As shown, the present application also provides a gel mixing reaction device, so that the primary expansion chamber 31 is connected to the gel mixing reaction device to transport the foam fluid formed after the gas-liquid mixed fluid is foamed to the gel mixing reaction device for gelation. Specifically, as Figure 4 As shown, the gel mixing reaction device includes a shrinker 4, the shrinker 4 includes a shrinkage chamber 41, the shrinkage chamber 41 includes a shrinkage cone chamber and a shrinkage straight tube chamber connected in sequence, the shrinkage cone chamber is connected to the primary expansion chamber 31, the cross-sectional area of ​​the shrinkage cone chamber gradually decreases from the primary expansion chamber 31 to the shrinker 4, the shrinkage cone chamber or the shrinkage straight tube chamber is connected to the coagulant injection hole 42, in the case where the shrinkage cone chamber is connected to the coagulant injection hole 42, the shrinkage cone chamber has a lower pressure than the primary expansion chamber 31, when the coagulant is injected into the shrinkage chamber 41 through the coagulant injection hole 42, under the action of the low pressure and the injection positive pressure of the coagulant injection hole 42, the coagulant injection flow rate can be guaranteed to be stable at the set flow rate. In the case where the shrinkage straight tube chamber is connected to the coagulant injection hole 42, the cross-sectional area of ​​the shrinkage straight tube chamber is smaller than the cross-sectional area of ​​the primary expansion chamber 31, and a negative pressure is formed in the shrinkage straight tube chamber. Under the action of the negative pressure and the injection positive pressure of the coagulant injection hole 42, the coagulant injection flow rate can be guaranteed to be stable at the set flow rate. The contraction-diffusion chamber refers to the secondary conical diffusion region between the contraction chamber 41 and the secondary expansion chamber 51 .

[0063] Furthermore, the shrinkage device 4 is provided with a plurality of coagulant injection holes 42 along its circumference, and the coagulant injection holes 42 are connected to the shrinkage chamber 41. Since the shrinkage chamber 41 has a smaller cross-section, it is beneficial for the coagulant and the foam fluid to be mixed evenly (under the action of diffusion and convection), and according to the fluid principle (Bernoulli principle, viscous force mitigation effect), there is a relatively low pressure and stable area (less affected by foam pressure fluctuations) at the rear end of the shrinkage chamber 41, which can ensure that the coagulant injection flow rate is stable at the set flow rate. Among them, the coagulant is well known to those skilled in the art, and does not belong to the core improvement part of the present application, so it will not be repeated here. Moreover, the cross-sectional area of ​​the contraction straight tube cavity of the contraction chamber 41 is smaller than the cross-sectional area of ​​the primary expansion chamber 31, and at the same time, the cross-sectional area of ​​the contraction straight tube cavity of the contraction chamber 41 is smaller than the cross-sectional area of ​​the secondary expansion chamber 51, so that the contraction chamber 41 forms a structure similar to a Venturi tube, such as Figure 2 As shown, the foam fluid forms negative pressure in the contraction chamber 41, and the coagulant is injected into the coagulant injection hole 42 under positive pressure, which can ensure that the coagulant injection flow rate is stable at the set flow rate; the foam fluid coagulant can be efficiently and evenly mixed.

[0064] In some embodiments, the size of the contraction chamber 41 needs to comprehensively consider the flow channel pressure loss and the uniformity of the coagulant mixing. To this end, the axis of the contraction chamber 41 can be designed to be perpendicular to the axis of the coagulant injection hole 42, that is, the coagulant can be injected into the contraction chamber 41 in a manner perpendicular to the flow direction of the foam fluid. Figure 4 As shown, the distance between the axis of the coagulant injection hole 42 and the end of the contraction cavity 41 away from the primary expansion cavity 31 is x, the diameter of the contraction cavity 41 is d, and x and d satisfy the following formula:

[0065]

[0066] Among them, u p is the average flow velocity of the foam fluid in the contraction chamber 41, u c is the average injection velocity of the coagulant, and c is the coefficient (ranging from 1 to 3).

[0067] Furthermore, the gel mixing reaction device further comprises a secondary expander 5, the shrinkage device 4 and the secondary expander 5 are connected in sequence, and the secondary expander 5 is used to homogenize the foam fluid passing through the gel. Figure 3 and Figure 4 As shown, the secondary expander 5 includes a secondary expansion chamber 51, which is connected to the contraction chamber 41. The length of the secondary expansion chamber 51 is L3. A homogenizing component is arranged in the secondary expansion chamber 51. After the coagulant and the foam fluid are preliminarily mixed in the contraction chamber 41, they enter the secondary expansion chamber 51 for further homogenization. Under the action of the homogenizing component, swirl stirring and path extension are generated, so that the coagulant and the foam fluid are uniformly mixed and preliminarily gelled, which can make the coagulant and the foam fluid efficiently and uniformly mixed, shorten the gel time of the foaming liquid, and prevent the coagulant injection hole 42 from being blocked. Among them, the coagulant injection hole 42 is set on the side wall of the contraction device 4 and is connected to the contraction chamber 41. In a preferred case, a number of through holes can be evenly arranged along the circumference in the annular groove as coagulant injection holes 42 for connecting to the contraction chamber 41. Alternatively, the homogenizing component may be installed with baffles alternately arranged at the bottom and top of the secondary expansion chamber 51. After the coagulant and the foam fluid are evenly mixed and initially gelled, the foam fluid that has undergone initial gelling collides with the baffles, thereby achieving homogenization of the gel foam by means of collision.

[0068] In some embodiments, Figure 3 and Figure 4 As shown, a nozzle 6 is installed at one end of the secondary expander 5 away from the shrinker 4. After the gel foam is initially gelled in the shrinkage chamber 41, it can continue to gel after being ejected from the nozzle 6.

[0069] In some embodiments, Figure 1 and Figure 4As shown, a secondary conical diffusion area is provided between the contraction cavity 41 and the secondary expansion cavity 51. The cone angle β of the secondary conical diffusion area is 7.5-25°, and the pressure is recovered to reduce the pressure loss. The secondary conical diffusion area refers to the transition area between the contraction cavity 41 and the secondary expansion cavity 51. Figure 3 and Figure 4 As shown, in terms of specific structural form, a conical groove facing the secondary expansion chamber 51 is provided at the rear end of the contraction device 4, and the cross-sectional area of ​​the conical groove gradually increases from the contraction chamber 41 to the secondary expansion chamber 51, and the area covered by the conical groove is the secondary conical diffusion area.

[0070] Among them, in the secondary conical diffusion area, the pressure is recovered to reduce the pressure loss; at the same time, a homogenization component is arranged in the secondary expansion chamber 51, which has the function of buffering the back pressure, so that the coagulant and the foam fluid can be evenly mixed and initially gelled, and finally sprayed out at a high speed from the nozzle 6 for preventing and extinguishing fire.

[0071] In some embodiments, Figure 3 and Figure 4 As shown, the homogenizing assembly includes a rotating shaft 71 and a plurality of spiral blades 72, and each spiral blade 72 is sequentially arranged on the rotating shaft 71 to form a spiral blade group.

[0072] In order to ensure uniform initial gelation of the foam, the secondary expansion chamber 51 needs to have a larger space, and the built-in spiral blades 72 can be arranged alternately in forward and reverse rotation. A number of forward and reverse spiral blades 72 are alternately arranged on the rotating shaft 71. The spiral length of the spiral blade 72 is designed to be 0.4~0.6 times the pitch (favorable for stirring and mixing), the spiral angle of the spiral blade 72 can be 30~60° (balance pressure loss and mixing degree), and the length of the spiral blade group is 4~8 times the pitch (to ensure uniform mixing, while controlling the length so that it is not too long to cause too low pressure at the nozzle 6). Among them, the spiral length of the spiral blade 72 refers to the distance between the starting end and the corresponding position on the end of the spiral blade 72 in the direction of the rotating shaft 71; the length of the spiral blade group refers to the sum of the spiral lengths of the individual spiral blades 72.

[0073] In some embodiments, the first mixer 1, the second mixer 2, the primary expander 3, the contraction device 4 and the secondary expander 5 are sequentially connected to form a Figure 3 and Figure 4 The one-piece structure shown.

[0074] In order to better understand the technical concept of the present application, the following description will be continued in combination with relatively comprehensive technical features.

[0075] like Figure 3 and Figure 4As shown, a preferred embodiment of the present application provides a gel foam generating device, including a foam generating device and a gel mixing reaction device, the foam generating device includes a first mixer 1, a second mixer 2 and a primary expander 3, the first mixer 1, the second mixer 2 and the primary expander 3 are connected in sequence, the first mixer 1 includes a first body and a second body, a cavity is formed in the second body for installing the first body, a first gap is formed between the second body and the first body, the second body and the first body can be an integral structure, the first body has a hollow channel, the hollow channel penetrates the first body along the axial direction of the first mixer 1, and forms a foaming liquid channel 11, which is used to fill the turbulent cavity 21 of the second mixer 2 with foaming liquid, and the rear end of the first body is a cone with a gradually smaller cross-sectional area. end, and the first gap between the second body and the first body can be an annular groove around the tapered end. The rear end of the second mixer of the second body has a tapered groove with a gradually smaller cross-sectional area. The tapered groove is connected to the turbulent chamber 21 of the second mixer 2, and the tapered end is inserted into the tapered groove. A second gap is formed between the tapered end and the tapered groove. The second gap is a compressed gas channel 12. The compressed gas channel 12 is an annular channel for filling compressed air (pressure 0.3MPa~1.0MPa) into the turbulent chamber 21. The annular channel can be a channel inclined toward the turbulent chamber 21. The contraction cone angle of the compressed gas channel 12 is 60~90°. Since the compressed gas channel 12 is relatively narrow, a high-speed and low-pressure annular airflow can be formed. The gas flow rate U of the high-speed and low-pressure annular airflow is g The flow rate U of the foaming liquid lThere is a large difference (typical flow velocity difference is greater than 20m / s), so it is easy to accelerate, break and mix the foaming liquid surface with compressed air under flow velocity difference, turbulent disturbance and high and low pressure fluctuations to form a gas-liquid mixed fluid. The primary expander 3 has a primary expansion chamber 31, and a plurality of baffles 32 are alternately arranged at the bottom and top of the primary expansion chamber 31. The baffles 32 can be grid-type blocking blocks. A primary conical diffusion area is arranged between the turbulent chamber 21 and the primary expansion chamber 31. The cone angle α of the primary conical diffusion area is less than or equal to 30°, and the length L2 of the turbulent chamber 21 is 3 to 10 times the diameter D1 of the turbulent chamber 21 to ensure a better turbulent effect and reduce pressure loss. The rear end of the second mixer 2 is provided with a conical groove facing the primary expansion chamber 31. The cross-sectional area of ​​the conical groove gradually increases from the turbulent chamber 21 to the primary expansion chamber 31. The area covered by the conical groove is the primary conical diffusion area. The diameter of the primary expansion chamber 31 is 2 to 5 times the diameter of the turbulent chamber 21, and the length L2 of the primary expansion chamber 31 is 2 to 10 times the diameter D2 of the primary expansion chamber 31. In the process of the gas-liquid mixed fluid entering the primary expansion chamber 31, the pressure is maximized, the pressure loss is small, and the pressure can be kept stable before entering the contraction chamber 41 of the contraction device 4. The gel mixing reaction device includes a contraction device 4 and a secondary expander 5, and a nozzle 6 is installed at one end of the secondary expander 5 away from the contraction device 4. The contraction device 4 includes a contraction chamber 41, which is connected to the primary expansion chamber 31. The secondary expander 5 includes a secondary expansion chamber 51, which is connected to the contraction chamber 41. A homogenizing component is arranged in the secondary expansion chamber 51. The homogenizing component includes a rotating shaft 71 and a plurality of spiral blades 72. A plurality of positive-rotating spiral blades 72 and counter-rotating spiral blades 72 are alternately arranged on the rotating shaft 71. The spiral length of the spiral blade 72 is designed to be 0.4 to 0.6 times the pitch (favorable for stirring and mixing), the spiral angle of the spiral blade 72 can be 30 to 60° (balancing the pressure loss and the degree of mixing), and the length of the spiral blade group is 4 to 8 times the pitch (to ensure uniform mixing, while controlling the length so as not to be too long to cause too low pressure at the nozzle 6). A mounting cavity is formed at the rear end of the primary expander 3, and the contraction device 4 is mounted in the mounting cavity. The coagulant injection hole 42 is arranged on the side wall of the contraction device 4 and is connected to the contraction cavity 41. Further, a plurality of coagulant injection holes 42 can be evenly arranged along the circumference in the annular groove to connect the contraction cavity 41. A secondary conical diffusion area is arranged between the contraction cavity 41 and the secondary expansion cavity 51. The cone angle β of the secondary conical diffusion area is 7.5~25°, and the pressure is recovered to reduce the pressure loss. A conical groove facing the secondary expansion cavity 51 is arranged at the rear end of the contraction device 4. The cross-sectional area of ​​the conical groove gradually increases from the contraction cavity 41 to the secondary expansion cavity 51. The area covered by the conical groove is the secondary conical diffusion area.Since the contraction chamber 41 has a smaller cross-section, it is beneficial for the coagulant and the foam fluid to be mixed evenly (under the action of diffusion and convection), and according to the fluid principle (Bernoulli principle, viscous force mitigation effect), there is a low-pressure and stable area (less affected by foam pressure fluctuations) at the rear end of the contraction chamber 41, which can ensure that the coagulant injection flow rate is stable at the set flow rate.

[0076] Based on the above technical solution, Figure 1 and Figure 2 As shown, the foaming and gelling process of the foaming liquid is as follows:

[0077] Foam generation process

[0078] The foaming liquid is introduced from the foaming liquid channel 11 to make the foaming liquid flow into the turbulent cavity 21; at the same time, compressed air (pressure 0.3MPa~1.0MPa) is introduced from the compressed gas channel 12. Since the compressed gas channel 12 is relatively narrow, a high-speed and low-pressure annular airflow can be formed. Under the flow velocity difference, turbulent disturbance and high and low pressure fluctuations, the foaming liquid surface is accelerated, broken and mixed with the compressed air to form a gas-liquid mixed fluid. Figure 2 The 1atm here refers to a standard atmospheric pressure, and the inlet channel refers to the foaming liquid channel 11. Inside the foaming liquid channel 11, there is a relatively high pressure.

[0079] In the turbulent chamber 21 , the foaming liquid is mixed with the compressed air to form a gas-liquid mixed fluid. The turbulent chamber 21 is similar to a Venturi tube. The flow velocity of the gas-liquid mixed fluid in the turbulent chamber 21 increases, while the pressure decreases.

[0080] The gas-liquid mixed fluid continues to flow into the primary expansion chamber 31. A primary conical diffusion area is arranged between the turbulent chamber 21 and the primary expansion chamber 31. The cone angle of the primary conical diffusion area is less than or equal to 30°. At the same time, under the action of the viscosity of the fluid and the baffle 32, the fluid flow rate decreases and the fluid pressure rises, so that bubbles with large differences in size are aggregated to form more uniform bubbles to form a foam fluid.

[0081] The reaction process of coagulant and foam mixing

[0082] Under the action of pressure, the foam fluid continues to flow into the contraction chamber 41, and the coagulant injection holes 42 are arranged at multiple angles around the contraction chamber 41, and the coagulant is injected into the contraction chamber 41 through the coagulant injection holes 42 at multiple angles. Under the action of diffusion and convection, the coagulant and the foam fluid are mixed evenly. The foam fluid forms a negative pressure in the contraction chamber 41, and the coagulant is injected into the coagulant injection holes 42 at a positive pressure, which can ensure that the coagulant injection flow rate is stable at the set flow rate.

[0083] The foam fluid initially gels under the action of the coagulant and continues to flow into the secondary expansion chamber 51. A secondary conical diffusion area is provided between the contraction chamber 41 and the secondary expansion chamber 51. The cone angle of the secondary conical diffusion area is 7.5-25°. The fluid flow rate is reduced, the pressure is recovered, and the pressure loss is reduced. A plurality of spiral blades 72 are arranged alternately in positive and negative rotations in the secondary expansion chamber 51. Under the action of the spiral blades 72, swirl stirring and path extension are generated to uniformly mix the coagulant and the foam fluid and initially gel. Finally, the gel foam is ejected at a high speed from the nozzle 6. The gel foam can continue to gel.

[0084] The present application utilizes a high-speed annular airflow type first mixer 1 in combination with a turbulent chamber 21 and a baffle 32, so that the foaming liquid with a higher viscosity also has a higher foaming multiple (foaming multiple ≥ 6). For the coagulant, the negative pressure adsorption + positive pressure injection method is used to inject it into the contraction chamber 41, and combined with the several spiral blades 72 arranged alternately in positive and reverse rotation in the secondary expansion chamber 51 and the secondary expansion chamber 51, the coagulant and the foam fluid can be efficiently and evenly mixed, and the blockage of the coagulant injection hole 42 can also be prevented. The gel foam generating device of the present application can be an integrated injection mechanism that foams first and then gels, which can quickly form fire-extinguishing gel foam, and at the same time has a compact structure, and can effectively avoid the reduction of the foaming multiple caused by the extrusion of foam in the long-distance pipeline, which is efficient and reliable. Moreover, compared with the gel fire extinguishing agent commonly used in the existing coal fire extinguishing field, the overall structure of the gel foam generating device of the present application occupies a smaller space and is convenient to carry. It can be applied to complex fire scenes such as high-rise building fires, forest fires, chemical raw material fires, and the development of forest isolation belts.

[0085] The present application also provides a gel foam fire rescue device, which is provided with the gel foam generating device described in the above embodiments.

[0086] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0087] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0089] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A foam generating device, characterized in that: The invention comprises a mixer for mixing a foaming liquid and a compressed gas and a primary expander (3), wherein the mixer is connected to the primary expander (3), the foaming liquid and the compressed gas are mixed to form a gas-liquid mixed fluid, and a foaming component for foaming the gas-liquid mixed fluid is arranged in a primary expansion chamber (31) of the primary expander (3).

2. The foam generating device according to claim 1, characterized in that: The mixer comprises a first mixer (1) and a second mixer (2); the first mixer (1), the second mixer (2) and a primary expander (3) are connected in sequence; the foaming liquid channel (11) and the compressed gas channel (12) of the first mixer (1) are both connected to the turbulence chamber (21) of the second mixer (2) so that the foaming liquid and the compressed gas are mixed to form a gas-liquid mixed fluid; the turbulence chamber (21) is connected to the primary expansion chamber (31) of the primary expander (3); and the cross-sectional area of ​​the turbulence chamber (21) is smaller than the cross-sectional area of ​​the primary expansion chamber (31).

3. A gel foam generating device, characterized in that: The foam generating device according to claim 2 is provided, and the primary expansion chamber (31) is connected to a gel mixing reaction device so as to transport the foam fluid formed after the gas-liquid mixed fluid is foamed to the gel mixing reaction device for gelation.

4. The gel foam generating device according to claim 3, characterized in that: The gel mixing reaction device comprises a shrinkage device (4), the shrinkage device (4) comprising a shrinkage cavity (41) connected to the primary expansion cavity (31), the cross-sectional area of ​​the shrinkage cavity (41) being smaller than the cross-sectional area of ​​the primary expansion cavity (31), and the shrinkage device (4) is provided with a plurality of coagulant injection holes (42) connected to the shrinkage cavity (41) along its circumference.

5. The gel foam generating device according to claim 4, characterized in that: The gel mixing reaction device further comprises a secondary expander (5) for homogenizing the foam fluid that has passed through the gel, and the shrinkage device (4) and the secondary expander (5) are connected in sequence.

6. The gel foam generating device according to claim 5, characterized in that: A nozzle (6) is installed at one end of the secondary expander (5) away from the contraction device (4).

7. The gel foam generating device according to claim 5, characterized in that: The secondary expander (5) comprises a secondary expansion chamber (51) connected to the contraction chamber (41), and a homogenizing component for swirling and stirring the foam fluid passing through the gel is arranged in the secondary expansion chamber (51).

8. The gel foam generating device according to claim 7, characterized in that: The homogenizing component comprises a rotating shaft (71) and a plurality of spiral blades (72), wherein the spiral blades (72) are arranged in sequence on the rotating shaft (71) to form a spiral blade group.

9. The gel foam generating device according to claim 8, characterized in that: The rotating shaft (71) is alternately provided with the forward-rotating spiral blades (72) and the reverse-rotating spiral blades (72).

10. The gel foam generating device according to claim 8, characterized in that: The spiral length of the spiral blade (72) is 0.4 to 0.6 times the spiral pitch.

11. The gel foam generating device according to claim 8, characterized in that: The helical blade (72) has a helical angle of 30 to 60 degrees.

12. The gel foam generating device according to claim 8, characterized in that: The length of the spiral blade group is 4 to 8 times the pitch.

13. The gel foam generating device according to claim 7, characterized in that: A secondary conical diffusion region is provided between the contraction chamber (41) and the secondary expansion chamber (51), and a cone angle β of the secondary conical diffusion region is 7.5-25°.

14. The gel foam generating device according to claim 5, characterized in that: The first mixer (1), the second mixer (2), the primary expander (3), the contraction device (4) and the secondary expander (5) are sequentially connected to form an integrated structure.

15. The gel foam generating device according to claim 4, characterized in that: The axis of the contraction cavity (41) is perpendicular to the axis of the coagulant injection hole (42), the distance between the coagulant injection hole (42) and one end of the contraction cavity (41) away from the primary expansion cavity (31) is x, the diameter of the contraction cavity (41) is d, and x and d satisfy the following formula: Among them, u p is the average flow velocity of the foam fluid in the contraction cavity, u c is the average injection rate of the coagulant, and c is the coefficient.

16. The gel foam generating device according to any one of claims 2 to 15, characterized in that: A primary conical diffusion region is provided between the turbulent chamber (21) and the primary expansion chamber (31); a cone angle α of the primary conical diffusion region is less than or equal to 30°; and a length L1 of the turbulent chamber (21) is 3 to 10 times a diameter D1 of the turbulent chamber (21).

17. The gel foam generating device according to any one of claims 1 to 15, characterized in that: The foaming component is a baffle (32) arranged alternately at the bottom and the top of the primary expansion chamber (31).

18. The gel foam generating device according to claim 17, characterized in that: The baffle (32) is provided with a plurality of through holes.

19. The gel foam generating device according to claim 17, characterized in that: The baffle (32) is a semicircular plate.

20. The gel foam generating device according to any one of claims 2 to 15, characterized in that: The diameter D2 of the primary expansion cavity (31) is 2 to 5 times the diameter D1 of the turbulent cavity (21), and the length L2 of the primary expansion cavity (31) is 2 to 10 times the diameter D2 of the primary expansion cavity (31).

21. The gel foam generating device according to any one of claims 2 to 15, characterized in that: The first mixer (1) comprises a first body and a second body, the second body being sleeved on the first body, the end of the first body facing the second mixer (2) being a tapered end with a gradually decreasing cross-sectional area, the end of the second body (the second mixer) facing the first mixer of the second mixer (2) having a tapered groove with a gradually decreasing cross-sectional area, the tapered groove being connected to the turbulent chamber, the compressed gas channel (12) being formed between the tapered end and the tapered groove, the compressed gas channel (12) being an annular channel, and the foaming liquid channel (11) being a hollow channel penetrating the first body along the axial direction of the first mixer (1).

22. The gel foam generating device according to claim 21, characterized in that: The distance s between the outlet position of the foaming liquid channel (11) and the starting position of the turbulent chamber (21) is 0.5 to 1.5 times the diameter d1 of the outlet position of the foaming liquid channel (11), and the contraction cone angle of the compressed gas channel (12) is 60 to 90 degrees.

23. A gel foam fire rescue device, characterized in that: A gel foam generating device according to any one of claims 1 to 22 is provided.

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