RU2798754C1 - Pipe for homogeneous foam mixing, foam mixing system for fire extinguishing and its control method and fire engine - Google Patents

Abstract

FIELD: fire extinguishing.

SUBSTANCE: pipe for homogeneous mixing of foam, to a foam mixing system for fire extinguishing, methods for controlling a foam mixing system for fire extinguishing, and to a fire engine. Wherein, the homogeneous foam mixing pipe comprises: a main homogeneous mixing pipe configured to mix the liquid F mixed with the foam and the foaming medium to form the foam F'; and a foaming medium injection pipe configured to inject the foaming medium into the main uniform mixing pipe, the foaming medium injection pipe having an outlet section penetrating into the inner cavity of the main uniform mixing pipe and extending in the extension direction of the main uniform mixing pipe, moreover, the outlet section has a closed end part and a side wall provided with an outlet for the foaming medium. The foaming medium flows out of the foaming medium outlet with complete mixing with the flowing foam-mixed liquid, and the foaming medium outlet on the side wall is not parallel to the flow direction of the foam-mixed liquid, thereby avoiding the foam-mixed liquid from flowing into the foaming outlet.

EFFECT: improving foaming efficiency and foaming stability.

20 cl 5 dwg, 2 tbl

Description

Link to related applications

[0001] The present disclosure and claimed priority are based on China Patent Application No. 201911301215.6, filed December 17, 2019, which is incorporated herein by reference in its entirety.

The field of technology to which the present invention relates

[0002] The present disclosure relates to the field of firefighting engineering, and specifically to a homogeneous foam mixing pipe, a firefighting foam mixing system and method of controlling it, and a fire engine.

Background of the Invention

[0003] When a foam-mixed liquid is used to extinguish a fire in a foam fire engine, the original foam solution must be completely mixed with water in a certain ratio to form a foam-mixed liquid, which is then foamed to extinguish the fire. The liquid mixed with foam is foamed in two ways: one consists in foaming by sucking in external air due to vacuum during the ejection process; and the other is to inject compressed gas as a foaming medium for foaming. Tests and studies have illustrated that, compared with a conventional foaming system that sucks in external air, a foam mixing system that injects pressurized foaming gas not only saves the original foam solution, but also achieves increased water utilization, and in addition, has exceptional advantages. in firefighting, firefighting, fire protection and specific fires.

[0004] Uniform mixing of the compressed gas and foam-mixed liquid is particularly important for fire-fighting efficiency, and the homogeneous foam-mixing pipes known to the inventor still have a non-uniform mixing defect.

[0005] For example, CN105126277B describes a tube for homogeneous mixing of foam, a foam mixing nozzle is located at the center of one end of a cylindrical mixing chamber, a plurality of inlet air ducts are uniformly arranged around the foam mixing nozzle, and in the mixing chamber, at a distance from the foam mixing nozzle, conical flow breaker, the inner wall of the mixing chamber is provided with a plurality of protrusions, the compressed gas and the foam mixture are mixed and enter the conical flow breaker, and the liquid is refracted between the conical flow breaker and the inner side wall of the mixing chamber to form liquid foam. With this structure, it is difficult to achieve uniform mixing because the foam mixing nozzle and the inlet pipe spray the liquid in the same direction.

The essence of the present invention

[0006] Through research, the inventor has found that in the prior art, foam mixing pipes still have a non-uniform mixing defect that affects fire extinguishing efficiency.

[0007] In view of the above problem, in the embodiments of the present disclosure, a pipe for homogeneous foam mixing, a foam mixing system for fire extinguishing and a method for controlling it, and a fire engine are provided so that the foaming medium can be uniformly mixed with the foam mixed liquid to form foam, improving by this fire extinguishing efficiency.

[0008] In an aspect of the present disclosure, there is provided a uniform foam mixing tube comprising:

[0009] a homogeneous mixing main pipe configured to mix the foam-mixed liquid F and the foaming medium to form a foam F'; And

[0010] a foaming medium injection pipe configured to inject the foaming medium into the main homogeneous mixing pipe, wherein the foaming medium injection pipe has an outlet section penetrating into the internal cavity of the main homogeneous mixing pipe and extending in the extension direction of the main homogeneous mixing pipe mixing, and the outlet section has a closed end part and a side wall provided with an outlet for the foaming medium.

[0011] In some embodiments, the foaming medium outlet is perpendicular to the direction of extension of the main pipe for uniform mixing.

[0012] In some embodiments, a plurality of foaming medium outlets are uniformly spaced along the circumferential direction and extension direction of the outlet section of the foaming medium injection pipe.

[0013] In some embodiments, the center line of the outlet section of the pipe for injection of the foaming medium coincides with the center line of the main pipe for uniform mixing.

[0014] In some embodiments, the orientation of the outlet section of the pipe for injection of the foaming medium corresponds to the direction of flow of the liquid F mixed with the foam.

[0015] In some embodiments, the foaming fluid injection conduit is L-shaped and the outlet section of the foaming fluid injection conduit is bent relative to its inlet section.

[0016] In some embodiments, the foaming medium injection pipe comprises a compressed air injection pipe and a liquid foaming medium injection pipe, and the foaming medium outlet includes an air outlet located in the outlet section of the compressed air injection pipe and the outlet for liquid, located in the outlet section of the pipe for injecting a liquid foaming medium.

[0017] In some embodiments, the main homogeneous mixing pipe is L-shaped, the outlet section of the main homogeneous mixing pipe is curved relative to its inlet section, the outlet pipe section for injecting compressed air penetrates the inlet section of the main homogeneous mixing pipe, and the outlet pipe section for injection of liquid foaming medium penetrates into the outlet section of the main pipe for homogeneous mixing.

[0018] In some embodiments, the dimension D of the inner wall of the main pipe for homogeneous mixing is from 125 mm to 200 mm, the dimension D1 of the inner wall of the compressed air injection pipe is from 25 mm to 40 mm, and the dimension D2 of the inner wall of the pipe for injection of liquid foaming medium is from 15 mm to 30 mm.

[0019] In an aspect of the present disclosure, a fire-fighting foam mixing system is provided, comprising the aforementioned pipe for homogeneous foam mixing.

[0020] In some embodiments, the fire extinguishing foam mixing system further comprises:

[0021] a water supply device having a water outlet in communication with the main pipe inlet for homogeneous mixing;

[0022] a foam stock solution supply device having a liquid outlet in communication with a main pipe inlet for homogeneous mixing;

[0023] a fire nozzle having an inlet in communication with the outlet of the main pipe for homogeneous mixing; And

[0024] A foaming medium supply device having an outlet in communication with an inlet of a pipe for injecting a foaming medium.

[0025] In some embodiments, the foaming medium supply device comprises a liquid medium storage tank and a liquid medium supply pump, the liquid medium storage tank is configured to store the liquid foaming medium; and the foaming medium injection pipe comprises a liquid foaming medium injection pipe, wherein the liquid medium storage tank supplies liquid to the liquid foaming medium injection pipe with a liquid medium supply pump.

[0026] In some embodiments, the fire extinguishing foam mixing system further comprises:

[0027] a foam-mixed liquid flow meter configured to detect a foam-mixed liquid flow rate generated by mixing the foam and water; And

[0028] A controller configured to control the number of revolutions of the fluid pump according to the foam-mixed liquid flow rate detected by the foam-mixed liquid flow meter.

[0029] In some embodiments, the fluid pump has a boost pressure of 2.5 MPa to 3.5 MPa and an output flow of 80 L/min to 200 L/min.

[0030] In some embodiments, the liquid storage tank has an operating pressure of 0.4 MPa to 0.8 MPa.

[0031] In some embodiments, the fluid pump is a gear pump, a vane pump, or a plunger pump.

[0032] In some embodiments, the fire extinguishing foam mixing system further comprises a controller, wherein the foaming medium supply apparatus further comprises a purge valve, and a first temperature sensor, and a fluid control valve located in the fluid channel of the fluid pump, purge valve inlet communicates with an outlet of the fluid pump, and the controller is configured to control the on-off states of the purge valve and the on-off states of the fluid control valve in accordance with the temperature of the fluid supply detected by the first temperature sensor.

[0033] In some embodiments, the fire extinguishing foam mixing system further comprises:

[0034] an in-line heater disposed in a confluence passage for a liquid outlet of the foam stock solution supply device and a water outlet of the water supply device;

[0035] a second temperature sensor located in the liquid outlet of the pipe for homogeneous mixing of the foam; And

[0036] a controller configured to control on-off states of the linear heater in accordance with the liquid supply temperature detected by the second temperature sensor.

[0037] In some embodiments, the foam stock solution supply device comprises a foam stock solution reservoir and a foam stock solution pump; the liquid outlet of the foam stock solution pump communicates with the inlet of the main pipe for homogeneous mixing; The foam stock solution tank comprises a class A foam stock solution tank and a class B stock stock solution tank that share a common foam stock solution pump.

[0038] In some embodiments, the blowing medium supply device further comprises an air compressor, the blowing medium injection pipe comprises a compressed air injection pipe, and the air compressor is configured to supply air to the compressed air injection pipe.

[0039] In an aspect of the present disclosure, a method for controlling the aforementioned fire-fighting foam mixing system is provided, comprising:

[0040] Controlling the speed of the fluid pump by the controller by invoking a predetermined program command in accordance with the foam-mixed liquid flow rate determined by the foam-mixed liquid flow meter and the type of foaming required at the site.

[0041] In an aspect of the present disclosure, a method for controlling the aforementioned fire-fighting foam mixing system is provided, comprising:

[0042] when the ambient temperature Ta is not lower than 0°C, and the liquid supply temperature T detected by the second temperature sensor (18) is not lower than 5°C, turning off the linear heater (16) by the controller (13) and starting the liquid medium filling operation;

[0043] when the ambient temperature Ta is not lower than 0°C, and the liquid supply temperature T detected by the second temperature sensor (18) is below 5°C, the controller (13) starts the linear heater (16) to maintain the liquid supply temperature T from 5 °C to 10°C, and then start the operation of filling the liquid medium;

[0044] when the ambient temperature Ta is lower than 0°C, the controller (13) starts the linear heater (16) to maintain the liquid supply temperature T detected by the second temperature sensor (18) from 30°C to 35°C, and then starts the operation filling the liquid medium.

[0045] In an aspect of the present disclosure, a fire engine is provided, comprising the aforementioned fire-fighting foam mixing system.

[0046] Therefore, according to embodiments of the present disclosure, the outlet section of the pipe for injection of the foaming medium penetrates into the inner cavity of the main pipe for uniform mixing and corresponds to the direction of extension of the main pipe for homogeneous mixing, and the outlet section has a closed end portion and a side wall provided with an outlet for a foaming medium. The foaming medium flows out of the foaming medium outlet with complete mixing with the flowing foam-mixed liquid, and the foaming medium outlet on the side wall is not parallel to the direction of flow of the foam-mixed liquid, thereby avoiding the foam-mixed liquid from flowing into the foaming outlet. foaming medium, and improving the foaming efficiency and foaming stability.

Brief description of the drawings

[0047] The drawings, which form part of the description, illustrate embodiments of the present disclosure and, together with the description, explain the principle of the present disclosure.

[0048] The present disclosure can be more clearly understood in accordance with the following detailed description with reference to the drawings, in which

[0049] in FIG. 1 is a cross-sectional view of some embodiments of a uniform foam mixing tube according to the present disclosure;

[0050] in FIG. 2 and 3 are cross-sectional views of a liquid foam injection tube and a compressed air injection tube, respectively, in some embodiments of the uniform foam mixing tube of the present disclosure;

[0051] in FIG. 4 is a schematic representation of the hydraulic system of some embodiments of a fire-fighting foam mixing system according to the present disclosure;

[0052] in FIG. 5 is a structural diagram of some embodiments of a fire truck according to the present disclosure.

[0053] Reference numbers:

[0054] 1, water tank; 2, foam stock solution tank; 2-1, class A foam stock solution tank; 2-2, class B foam stock solution tank; 3, water pump; 3-1, water tank supply valve; 3-2, water tank injection valve; 4, foam initial solution pump; 4-1, Class A foam stock solution tank supply valve; 4-2, foam mixed liquid line purge valve; 4-3, Class B foam stock solution tank supply valve; 5-1, upper fire barrel of the tank; 5-2, fire barrel boom; 6, air compressor; 6-1, compressed air outlet valve; 6-2, pressure equalization valve; 7, foam homogeneous mixing pipe; 71, main pipe for homogeneous mixing; 72, compressed air injection pipe; 73, pipe for injection of liquid foaming medium; 74, liquid outlet; 75, air outlet; 8, operating water fire extinguishing valve; 9, maintenance foam fire extinguishing valve; 10, top platform fire hydrant supply valve; 11, foam-mixed flow control valve; 12-1, foam-mixed liquid flow meter; 12-2, foam stock solution flow meter; 13, controller; 14, liquid medium storage tank; 14-1 liquid medium storage tank supply valve; 14-2, self-pressure service valve; 14-3, liquid medium storage tank filling valve; 15, liquid medium pump; 15-1, purge valve; 15-2, fluid control valve; 15-3, high pressure relief valve; 15-4, impulse suppression device; 16, line heater; 17, the first temperature sensor; 18, the second temperature sensor; 100, chassis; 200, front stabilizer; 300, the first interface device; 400, subframe; 500, the second first interface device; 600, rear stabilizer; 700, central drum; 800, turntable; 900, arrow.

Detailed description

[0055] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the drawings. the description of any illustrative embodiment is illustrative only and is in no way intended to limit the present disclosure, its application, or its use. The disclosed disclosure may take many different forms and should not be limited to the embodiments set forth herein. These embodiments are presented so that the present disclosure may be exhaustive and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless specifically noted otherwise, the relative arrangement of components and steps, compositions of materials, numerical expressions, and values set forth in these embodiments should be interpreted as illustrative only and not restrictive.

[0056] The term "first", "second", and the like, as used herein, does not indicate any sequence, quantity, or importance, but rather is used to distinguish one part from another. The term "include", "comprising" and the like means that the element before the term covers the elements listed after the term, and does not exclude the possibility of covering other elements. "Upper", "lower", "left", "right" and the like are used simply to indicate the relative relative position, which can also change accordingly when the absolute positions of the described objects change.

[0057] In the present disclosure, when a particular device is described as being between a first device and a second device, there may or may not be an intermediate device between the particular device and the first device or the second device. When a particular device is described as being connected to another device, the particular device may be directly connected to another device without any intermediate device, or indirectly connected to another device using an intermediate device.

[0058] Unless specifically stated otherwise, all terms (including technical terms or scientific terms) used herein have the same meanings as would be commonly understood by one of ordinary skill in the art to which the present disclosure pertains. In addition, it should be understood that terms, such as those defined in general dictionaries, are to be interpreted as having meanings corresponding to those in the context of the relevant technical field, and are not to be interpreted in an ideal or overly formal sense, unless explicitly defined. in this document.

[0059] Methods, methods and devices known to the ordinary person in the prior art may not be discussed in detail, but, if necessary, they should be considered as part of the description.

[0060] In an aspect of the present disclosure, a tube for uniform foam mixing is shown, and FIG. 1 is a cross-sectional view of some embodiments of a uniform foam mixing tube according to the present disclosure. As shown in FIG. 1, the foam homogeneous mixing pipe 7 of this embodiment comprises: a main homogeneous mixing pipe 71 configured to mix the foam-mixed liquid F with a foaming medium to form a foam F'; and a foaming medium injection pipe configured to inject the foaming medium into the main pipe 71 for uniform mixing, the foaming medium injection pipe having an outlet section penetrating into the inner cavity of the main pipe 71 for uniform mixing and extending in the extension direction of the main pipe 71 for homogeneous mixing, and the outlet section has a closed end part and a side wall provided with an outlet for the foaming medium.

[0061] As shown in FIG. 1, foam-mixed liquid F formed by mixing water and foam stock solution in a certain ratio is supplied from the inlet of the main pipe 71 for homogeneous mixing. The foaming medium is injected into the main uniform mixing pipe 71 through the foaming medium injection pipe completely mixed with the foam-mixed liquid F to form foam F', and then it flows out from the outlet of the main uniform mixing pipe 71. The foaming medium comprises compressed air A and/or a liquid foaming medium N, wherein the liquid foaming medium N may be liquid nitrogen or any other suitable liquid medium, provided that the medium is rapidly evaporating, suitable for foaming, suitable for firefighting, non-toxic and has a coefficient more than 300 gas volumes.

[0062] Specifically, as shown in FIG. 1, the foaming medium injection pipe comprises a compressed air injection pipe 72 configured to inject compressed air A into the main mixing pipe 71 and/or a liquid foaming medium injection pipe 73 configured to inject liquid foaming medium N into main pipe 71 for homogeneous mixing. As shown in FIG. 1-3, the foaming medium outlet includes an air outlet 75 located in the outlet section of the compressed air injection pipe 72 and/or a liquid outlet 74 located in the outlet section of the liquid foaming fluid injection pipe 73. The compressed air A enters the inner cavity of the main pipe 71 for homogeneous mixing through the air outlet 75 of the pipe 72 for injection of compressed air, and the liquid foaming medium N enters the inner cavity of the main pipe 71 for homogeneous mixing through the liquid outlet 74 of the pipe 73 for injection of a liquid foaming medium.

[0063] As shown in FIG. 1, the outlet section of the compressed air injection pipe 72 penetrates into the inner cavity of the main homogeneous mixing pipe 71 and extends in the extension direction of the main homogeneous mixing pipe 71, and the outlet section has a closed end portion and a side wall provided with an air outlet 75; the outlet section of the foaming liquid injection pipe 73 penetrates into the inner cavity of the main homogeneous mixing pipe 71 and extends in the extension direction of the main homogeneous mixing pipe 71, and the outlet section has a closed end portion and a side wall provided with a liquid outlet 74; the compressed air A flows out of the air outlet 75 fully mixing with the flowing foam-mixed liquid F, the foaming liquid N flows out fully mixing with the flowing foam-mixed liquid F, and the flow direction of the compressed air A or the foaming liquid N is not parallel direction of flow of the foam-mixed liquid, thereby preventing the foam-mixed liquid F from flowing into the foaming medium outlet, and improving the foaming efficiency and foaming stability.

[0064] In order to increase the mixing contact area, in some embodiments, a plurality of foaming medium outlets are evenly spaced along the circumferential direction and extension direction of the foaming medium injection pipe outlet section. As shown in FIG. 1-3, a plurality of air outlets 75 are evenly spaced along the circumferential direction and the extension direction of the outlet section of the compressed air injection pipe 72, and a plurality of liquid outlets 74 are arranged along the circumferential direction and the extension direction of the outlet section of the pipe 73 for injection of liquid foaming agent. environment.

[0065] In order to further improve the foaming efficiency and formation of stability, in some embodiments, the foaming medium outlet is perpendicular to the extension direction of the main pipe 71 for uniform mixing. As shown in FIG. 1, both the air outlet 75 and the liquid outlet 74 are perpendicular to the extension direction of the main uniform mixing pipe 71, thereby avoiding the foam-mixed liquid F from flowing into the air outlet 75 and the liquid outlet 74 to the maximum. as far as possible, and this form of construction can further improve the efficiency of mixing with foaming.

[0066] In some embodiments, the center line of the outlet section of the pipe for injection of the foaming medium coincides with the center line of the main pipe 71 for uniform mixing. As shown in FIG. 1, the center line of the outlet section of the compressed air injection pipe 72 coincides with the center line of the main pipe 71 for uniform mixing, the center line of the outlet section of the pipe 73 for injection of liquid foaming medium coincides with the center line of the main pipe 71 for uniform mixing, and this form of structure can to increase the mixing area of the foaming medium and the liquid F mixed with the foam, thereby improving the efficiency of the mixed foam.

[0067] In some embodiments, the orientation of the end portion of the outlet section of the pipe for injection of the foaming medium corresponds to the direction of flow of the liquid mixed with the foam F. As shown in FIG. 1, the orientation of the outlet section of the outlet section of the compressed air injection pipe 72 corresponds to the direction of flow of the liquid mixed with foam F, the orientation of the end of the outlet section of the pipe 73 for injection of liquid foaming medium also corresponds to the direction of flow of the liquid mixed with foam F, which facilitates the discharge of the foaming medium, while the design is reasonable with convincing practicality.

[0068] In order for the outlet section of the foaming medium injection pipe to match the extension direction of the main pipe 71 for uniform mixing, in some embodiments, the foaming medium injection pipe is L-shaped, and the outlet section of the foaming medium injection pipe is bent relative to its inlet section, so that machining is easy and the design is reasonable. Specifically, as shown in FIG. 1, the compressed air injection pipe 72 has an L shape, the outlet section of the compressed air injection pipe 72 is bent with respect to its inlet section; the liquid foaming medium injection pipe 73 is L-shaped, and the outlet section of the liquid foaming medium injection pipe 73 is bent with respect to its inlet section.

[0069] Considering that compressed air A is more difficult to mix uniformly for foaming than liquid foaming medium N, in some embodiments, as shown in FIG. 1, the main homogeneous mixing pipe 71 is L-shaped, the outlet section of the main homogeneous mixing pipe 71 is curved relative to its inlet section, the outlet section of the compressed air injection pipe 72 penetrates the inlet section of the main homogeneous mixing pipe 71, and the outlet pipe section 73 for injection of liquid foaming medium penetrates into the outlet section of the main pipe 71 for homogeneous mixing. This ensures that the foam-mixed liquid F and the compressed air A are pulsed agitated and re-mixed by hitting the curved surface of the elbow of the main pipe 71 for uniform mixing, and the L-shaped main pipe 71 for uniform mixing has a compact structure that facilitates layout with little resistance. flow and high practicality.

[0070] In some embodiments, the dimension D of the inner wall of the main pipe 71 for homogeneous mixing is from 125 mm to 200 mm, the dimension D1 of the inner wall of the pipe 72 for injection of compressed air is from 25 mm to 40 mm, and the dimension D2 of the inner wall of the pipe 73 for injection of a liquid foaming medium is from 15 mm to 30 mm. Within the above size range, the uniform foam mixing tube 7 can achieve good foaming efficiency and foaming stability.

[0071] The above embodiments of the uniform foam mixing pipe according to the present disclosure can be applied to a foam mixing system for fire extinguishing. Accordingly, the present disclosure provides a foam mixing system for fire suppression that includes any of the above embodiments of pipes for homogeneous foam mixing.

[0072] In some embodiments, as shown in FIG. 4, the fire-fighting foam mixing system further comprises: a water supply device having a water outlet in communication with the inlet of the main pipe 71 for homogeneous mixing; a foam stock solution supply device having a liquid outlet in communication with an inlet of the main pipe 71 for homogeneous mixing; a fire nozzle having an inlet communicating with an outlet of the main pipe 71 for homogeneous mixing; and a foaming medium supply device having an outlet in communication with an inlet of the pipe for injecting the foaming medium.

[0073] Specifically, as shown in FIG. 1 and 4, the water supply device includes a water tank 1, a water tank supply valve 3-1, a water tank injection valve 3-2, and a water pump 3; the foam stock solution supply device comprises a foam stock solution reservoir 2 and a foam stock solution pump 4, wherein the liquid outlet of the foam stock solution pump 4 communicates with the inlet of the main pipe 71 for homogeneous mixing, the foam stock solution reservoir 2 comprises a reservoir 2- 1 for class A foam stock solution, equipped with a class A foam stock solution tank supply valve 4-1, and a class B foam stock solution tank 2-2, equipped with a class B foam stock solution tank supply valve 4-3, and a tank 2-1 for class A foam stock solution and class B stock stock solution tank 2-2 have a common foam stock pump 4 . In this embodiment, as an actuator for ejecting the fire extinguishing medium, the fire nozzle comprises an upper tank fire nozzle 5-1 located on the lower platform, a boom fire nozzle 5-2 located on the upper platform, and a supply valve 10 of the upper platform fire hydrant, wherein the fluid inlets of the two fire nozzles are arranged in parallel, they both communicate with the foam outlet pipe of the system, and can be switched by means of valves; the foaming medium supply device comprises a liquid medium storage tank 14, a liquid medium storage tank supply valve 14-1, a liquid medium supply pump 15, an air compressor 6, and a compressed air outlet valve 6-1, wherein the liquid medium storage tank 14 environment is configured to store liquid nitrogen or other liquid foaming media, the air compressor 6 supplies air to the compressed air injection pipe 72, and the liquid storage tank 14 supplies liquid to the liquid foam injection pipe 73 by means of the pump 15 to supply liquid environment.

[0074] It should be noted that the basic functions and principles associated with proportional mixing of the foam-mixed liquid in various parts set forth above are essentially the same as in the prior art, and the technical solution for changing the types of foaming medium and the type of source liquid for foam in different fire fighting scenarios are described below with an example where a foaming medium that consists of compressed air A and liquid nitrogen N and a foam stock solution that consists of a class A foam stock solution and a class B foam stock solution are used in a fire truck with lifting platform, thereby mixing and combining compressed gas and liquid mixed with foam, providing foaming.

[0075] (I) For extinguishing a fire in an occupied building, a foam fire extinguishing mode with an initial solution of foam class A+compressed air A+water is preferable.

[0076] As shown in FIG. 4, when performing fire extinguishing with water, the service valve 8 for fire extinguishing with water is opened, and the service valve for fire extinguishing with foam is closed. The liquid outlet of the water pump 3 can communicate with the top fire barrel 5-1 of the tank and the fire barrel 5-2 of the boom through the service water fire extinguishing valve 8 . When performing fire extinguishing with foam, the service valve 8 for fire extinguishing with water is closed, and the service valve 9 for fire extinguishing with foam is opened. The liquid outlet of the water pump 3 can communicate with the top fire nozzle 5-1 of the tank and the fire nozzle 5-2 of the boom in order through the foam fire extinguishing service valve 9, the foam-mixed liquid flow meter 12-1, the foam-mixed liquid flow control valve 11, and pipe 7 for homogeneous foam mixing.

[0077] When class A foam stock solution is preferred for foam agent mixing, the class A foam stock solution tank supply valve 4-1 is opened, and the class B foam stock solution supply tank supply valve 4-3 and the mixed line purge valve 4-2 liquid foam close; the foam stock solution pump 4 sucks the class A foam stock solution from the class A foam stock solution tank 2-1 to pressurize the discharge line; after passing through the foam stock solution flow meter 12-2, the pressurized foam stock solution is combined and mixed with the pressurized water from the fire extinguishing service valve 9, and then the mixture flows in order through the foam mixed liquid flow meter 12-1 valve 11 the foam-mixed flow control and the in-line heater 16, and it is injected into the inlet end of the main uniform mixing pipe 71 of the foam uniform mixing pipe 7.

[0078] It should be noted that the class A foam stock solution is preferable in this case, because the class A foam fire extinguishing agent is environmentally friendly, while the generated foam has strong adhesion and good heat insulation and heat radiation prevention effect, which can effectively fight the re-ignition of solid combustible materials and is suitable for class A fire fighting scenarios. If class B foam source solution is selected for foam agent mixing, class A foam source solution tank supply valve 4-1 and foam mixed liquid line purge valve 4-2 are closed , and the supply valve 4-3 of the class B foam stock solution tank is opened; the foam stock solution pump 4 sucks the class B foam stock solution from the class B stock stock solution tank 2-2 to pressurize the discharge line; just as after passing through the foam stock solution flow meter 12-2, the pressurized foam stock solution is combined and mixed with the pressurized water from the fire extinguishing service valve 9, and then the mixture flows in order through the foam mixed liquid flow meter 12-1, valve 11 adjusting the flow rate of the foam-mixed liquid and the in-line heater 16, and it is injected into the inlet end of the main uniform mixing pipe 71 of the foam uniform mixing pipe 7.

[0079] To control the precise proportionality between foam feed solution and water, in some embodiments of the present disclosure, flow feedback is used to control the flow of foam feed solution to provide proportional mixing. In some embodiments, as shown in FIG. 4, the fire extinguishing foam mixing system further comprises a controller 13, a foam mixed liquid flow meter 12-1 configured to detect the flow rate of the mixed water and foam stock solution, and a foam stock solution flow meter 12-2 configured to detect the foam stock solution flow rate, where the controller 13 adjusts the speed of the foam stock solution pump 4 by calling a predetermined program command (i.e., determining the use of different mixing ratios according to different descriptions of the foam fire extinguishing agent and different types of foaming) according to the input signals of the two flow meters, such as information such as identification of the open state of the outlet foam stock solution reservoir valve, and the type of foam required at the site, thereby ensuring that the exact proportion of foam stock solution and water is obtained by controlling the flow of foam stock solution.

[0080] In addition, different types of blowing agents will corrode the piping system and associated components, and then affect the operating efficiency and service life of the system. Thus, in some embodiments of the present disclosure, a flushing function is provided to avoid corrosion due to long-term adherence of residual blowing agent. As shown in FIG. 4, a foam mixed liquid line purge valve 4-2 is provided in line between the outlet of the foam fire extinguishing service valve 9 and the inlet of the foam stock solution pump 4. In non-flushing operation, the foam-mixed line purge valve 4-2 is always closed to ensure the foam-mixed liquid function. Only when the foam ejection operation is completed, the foam mixed liquid line purge valve 4-2 can be opened each time, and the foam stock solution pump 4 can be started to purge the foam line system after the foam stock solution tank supply valve 4-1 class A and the feed valve 4-3 of the class B foam stock solution tank is closed.

[0081] As the driving element supplying the compressed air A, the air compressor 6 supplies the compressed air A to the homogeneous foam mixing pipe 7, the construction of which is shown in FIG. 1. While the foam-mixed liquid after mixing flows into the inlet end of the main pipe 71 for homogeneous mixing, compressed air A is also injected into the inlet end of the compressed air injection pipe 72. It should be noted that there is no liquid nitrogen flowing into the liquid foaming medium injection pipe 73, so that the liquid mixed with the foam is in sufficient contact only with the air inside the main pipe 71 for uniform mixing to form the foam F', and the foam F' after pre-foaming flows into the foam outlet pipe of the system through the outlet end of the main pipe 71 for homogeneous mixing. In order to avoid interference between the compressed air injection line and the liquid nitrogen injection line, one-way check valves are respectively provided at the injection ends of the two lines.

[0082] As shown in FIG. 4, in order to ensure smooth injection of compressed air, in some embodiments, the fire extinguishing foam mixing system further comprises a compressed air outlet valve 6-1 and a pressure equalization valve 6-2, the pressure equalization valve 6-2 is configured to compare water pressure with air pressure. , and supplying a pressure adjustment signal to adjust the air flow from the air compressor 6 to provide a combination of pressure. to control obtaining the exact proportion of the ratio between the compressed air and the foam-mixed liquid, the controller 13 adjusts the speed of the air compressor 6 by calling a given program command (i.e., determining the use of different mixing ratios according to different descriptions of the foam extinguishing agent and different types of foaming) according to the input signal of the flow meter 12-1 of the liquid mixed with the foam and the type of foaming required on site, thereby ensuring that the exact proportion is obtained by adjusting the output flow of the air compressor 6. In addition, the compressed air outlet valve 6-1 is configured to adjust the compressed air flow according to such factors like actual fire dynamics, foam type and so on. To avoid backflow of compressed air, a one-way check valve is provided in the corresponding line.

[0083] Of course, it should also be noted that, in some cases, it is also possible to use a fixed air compressor output to adjust the capacity of the fire pump and foam pump to provide a proportional mixture of foam-mixed liquid and compressed air.

[0084] The outlet of the homogeneous foam mixing pipe 7 communicates with the inlet of the two fire nozzles through the foam outlet pipe so that the resulting foam can be even more homogeneously mixed in the outlet pipe before being ejected from the ejector. To avoid backflow of foam, a one-way check valve is provided in the foam outlet pipe.

[0085] (II) For automatically controlled extinguishing of industrial fires, a foam fire extinguishing mode with an initial solution of foam class B + compressed nitrogen based on liquid nitrogen + water filling is preferable.

[0086] When a class B foam stock solution is preferred for foam agent mixing, the class A foam stock solution tank supply valve 4-1 and the foam mixed liquid line purge valve 4-2 are closed, and the foam stock solution tank supply valve 4-3 class B open; to pressurize the discharge line, the foam stock solution pump 4 sucks the class B foam stock solution from the class B foam stock solution tank 2-2. For the principle of mixing, formation and flow direction of the liquid mixed with foam, see the previous description.

[0087] It should be noted that a class B foam stock solution is preferred because a class B foam extinguishing agent is suitable for class B fire fighting scenarios, especially for various petroleum products, flammable and combustible liquids, and so on in industrial fires. Class B foam fire extinguishing agent can be classified into water-insoluble foam fire extinguishing agent (such as protein foam fire extinguishing agent, fluoroprotein foam fire extinguishing agent and water film-forming foam fire extinguishing agent), and insoluble foam fire extinguishing agent, and the specific description and model of class B foam fire extinguishing agent should be determined according to the material properties of the salvage object. Also, if class A foam stock solution is selected for foam agent mixing, refer to the previous description for manipulation of Class A foam stock solution tank supply valve 4-1, Class B foam stock solution tank supply valve 4-3, valve 4-2 purging the line of liquid mixed with foam and pump 4 for the initial foam solution, as well as the principle of mixing, formation and direction of the flow of liquid mixed with foam.

[0088] The liquid medium supply pump 15 is a driving member for sucking and forcing liquid nitrogen into the liquid medium storage tank 14, and discharging the liquid nitrogen into the pipe 7 to uniformly mix the foam. As shown in FIG. 1, while the liquid mixed with foam after mixing flows into the inlet end of the main pipe 71 for uniform mixing, liquid nitrogen N is also injected into the inlet end of the pipe 73 for injection of liquid foaming medium. It should be noted that at this time, the air compressor system is inactive and no compressed air enters the compressed air injection pipe 72, so that the foam-mixed liquid is in sufficient contact only with liquid nitrogen N inside the main pipe 71 for homogeneous mixing, and liquid nitrogen N absorbs heat from the liquid mixed with the foam with rapid evaporation and boiling to form foam F'. In order to ensure sufficient contact between the liquid nitrogen N and the foam-mixed liquid F, in some embodiments, as shown in FIG. 1, the outlet section of the pipe 73 for injection of liquid foaming medium should be coaxial with the axis of the outlet section of the main pipe 71 for uniform mixing and have a closed end part, and a plurality of liquid outlets 74 are provided along the axial direction and the circumferential direction of the outlet section of the pipe 73 for injection of the liquid foaming medium, so that the liquid nitrogen N can be rapidly pulsed and mixed with the foam-mixed liquid F after ejected into the main pipe 71 for homogeneous mixing. Thus, the foam F' after pre-foaming flows into the foam outlet pipe of the system through the outlet end of the main pipe 71 for homogeneous mixing. Also, the resulting foam can be further homogeneously mixed in the exhaust pipe before being ejected by the fire nozzle.

[0089] In some embodiments, as shown in FIG. 4, the liquid storage tank 14 may be a self-pressurized liquid nitrogen tank with a design pressure of not more than 1.6 MPa and a design temperature of -196° C. for storing liquid nitrogen, and provided with a safety valve and a pressure detection device. In some embodiments, the liquid storage tank 14 has an operating pressure of 0.4 MPa to 0.8 MPa when used on a platform fire truck. When the liquid medium storage tank is in a normal storage state, the filling valve of the liquid medium storage tank 14-3 and the supply valve 14-1 of the liquid medium storage tank are closed; when the liquid medium storage tank is in the discharge operation state, the filling valve of the liquid medium storage tank 14-3 is closed, and the supply valve 14-1 of the liquid medium storage tank is opened; when the medium in the liquid medium storage tank is used up and needs to be filled, the filling valve 14-1 of the liquid medium storage tank is closed, and after the external liquid nitrogen filling port is connected, the filling valve of the liquid medium storage tank 14-3 is opened, and the liquid medium supply pump 15 is started to suck and fill from outside. When the liquid storage tank is in the state of normal storage and operation, the self-pressure operating valve 14-2 is used to adaptively adjust the pressure in the tank, that is, the control system opens the self-pressure operating valve 14-2 as soon as the pressure in the tank drops to 0.4 MPa. , so that part of the liquid nitrogen in the tank flows out with evaporation into nitrogen by means of an evaporator at ambient air temperature in the line, and then enters the tank to pressurize; as soon as the pressure in the tank exceeds 0.8 MPa, the on-board control system closes the self-pressurization service valve 14-2. It should be noted that the pressure in the liquid medium storage tank 14 is required to achieve the above range mainly in order to supply liquid at a stable pressure to the liquid medium supply pump 15, and not directly to pressurize the injection into the pipe 7 for homogeneous mixing of the foam (the pressure must not be lower than that of the liquid mixed with the foam). In fact, the injection pressure of liquid nitrogen is provided by increasing the pressure of the pump 15 for supplying a liquid medium.

[0090] In the existing technical solutions (fire engine+corresponding skid devices=combined and complete fire extinguishing installation), liquid nitrogen injection pressure is provided directly by self-pressurization of the liquid medium storage tank 14. It is known that there are basically two types of evaporators: one is an evaporator at ambient temperature, and the other is an evaporator at water temperature (water is taken as a heat carrier, and heat is provided by electric or gas heating). Both types of self-boosting are hysteretic for pressure feedback, so the disadvantage is that it is impossible to quickly increase the pressure to the desired one when the pressure in the tank is insufficient, and the pressure increase cannot be immediately stopped when the desired pressure is reached, and the disadvantage is especially obvious when the capacity of the tank for liquid medium storage is great. Thus, it is difficult to ensure timely self-inflating of the liquid medium storage tank. In addition, since the liquid storage tank usually has a design pressure of 1.6 MPa, the pressurization capacity is also limited. During the operation of a fire engine with a lifting platform, the pressure at the outlet of the fire pump varies depending on the extended or retracted state and the amplitude-changed state of the boom (or ladder) and the ejected flow of the system, and, accordingly, the pressure of the liquid mixed with foam in the pipe 7 for homogeneous mixing foam also varies significantly from 1 to 1.6 MPa, or at least 1.6 MPa for a fire truck with a higher lifting platform. Therefore, in real engineering practice, liquid nitrogen filling of a fire truck with a lifting platform is fully ensured by automatic adjustment of the self-pressure of the liquid medium storage tank 14, while it is impossible to reliably ensure that the liquid nitrogen injection pressure is not lower than the pressure of the liquid mixed with foam in the pipe 7 for homogeneous mixing. foam.

[0091] On the other hand, in order to achieve different fire fighting purposes, the foam-mixed liquid needs to be mixed with different proportions of pressurized gas depending on the use, ensuring the foam expansion coefficient and foam quality of the blowing agent. Thus, liquid nitrogen is filled in different flow proportions according to the volumetric ratio (typically 640) of nitrogen gas and liquid nitrogen after the liquid nitrogen has evaporated. the existing solution, which fills liquid nitrogen by self-pressurizing the liquid medium storage tank 14, adjusts the filling flow of liquid nitrogen proportionally by measuring the flow of liquid mixed with foam in real time, and adjusting the filling flow of liquid nitrogen, finally, depends on the degree of opening of the flow control valve in line. Obviously, since the flow in the line is highly correlated with the pressure drop of the flow control valve, even if the flow rate of the foam-mixed liquid is constant, the operating pressure of the foam-mixed liquid in the pipe for homogeneous foam mixing is still influenced because the position of the boom ( or stairs) of aerial platform fire truck is changed, and then affects the filling flow of liquid nitrogen, so that the expansion coefficient of the foam liquid mixed with the foam is changed, and the quality of the foam cannot be ensured. In addition, since the self-pressurization of the liquid medium storage tank 14 is hysteretic, the above-described feedback adjustment process of the flow control valve also makes it difficult to perform regular compensation correction.

[0092] Thus, it is difficult to match between injection pressure and flow by self-pressurizing a liquid storage tank in engineering practice.

[0093] In order to effectively solve this problem, in some embodiments, as shown in FIG. 4, the fluid pump 15 has a boost pressure of 2.5 MPa to 3.5 MPa and an output flow of 80 L/min to 200 L/min. The foam flow obtained in the system can be 500 l / s or more, and for ease of use and compact arrangement of the on-board system, the liquid medium pump 15 is a gear pump, a vane pump, or a plunger pump. The hydraulic motor is preferably connected directly to the clutch drive. Of course, a variable frequency motor can also be used to directly connect to a clutch to drive a gear pump, or a variable frequency motor can be connected in series to a gearbox to drive a gear pump. It is known that the output flow of a gear pump, vane pump or plunger pump depends only on the speed, and the output pressure depends on the load. Thus, the pressure and proportional flow matching between the blowing agent and pressurized nitrogen charged by a pressurized gear pump, vane pump, or plunger pump can be simplified to a single proportional flow matching.

[0094] To control obtaining an accurate proportion of the ratio between liquid nitrogen and foam-mixed liquid, in some embodiments, the fire-fighting foam mixing system further comprises: a foam-mixed liquid flow meter 12-1, configured to determine the flow rate of the foam-mixed liquid after the foam has been mixed, and water, and a controller 13 configured to control the rotation number of the liquid medium supply pump 15 in accordance with the flow rate of the foam-mixed liquid detected by the foam-mixed liquid flow meter 12-1. The controller 13 adjusts the speed of the liquid pump 15 by calling a predetermined program command (that is, determining the use of different mixing ratios according to different descriptions of the foam extinguishing agent and different types of foaming) according to the input signal of the foam mixed liquid flow meter 12-1 and the type of foaming, required on site, thereby ensuring that the exact proportion is obtained by adjusting the output flow of the liquid pump.

[0095] Accordingly, in an aspect of the present disclosure, a method for controlling a fire-fighting foam mixing system is provided, comprising:

[0096] The controller 13 adjusts the speed of the fluid pump 15 by invoking a predetermined program command in accordance with the foam-mixed liquid flow rate detected by the foam-mixed liquid flow meter 12-1 and the type of foaming required at the site.

[0097] The method effectively ensures that the exact proportion between the liquid foaming medium and the liquid mixed with the foam is obtained, and is quite feasible.

[0098] At the initial operation of the liquid medium pump 15, due to the relatively high initial temperature of the liquid nitrogen inlet line and the gear pump housing, the liquid nitrogen partially vaporizes during flow. In order to avoid cavitation of the fluid pump 15 during operation, in some embodiments, the foaming media delivery device further comprises a purge valve 15-1, and a first temperature sensor 17 and a fluid control valve 15-2 located in the fluid channel of the pump 15 for supplying a liquid medium, wherein the inlet of the purge valve 15-1 is in communication with the outlet of the pump 15 for supplying the liquid medium, and the controller 13 is configured to control the on-off states of the purge valve 15-1 and the on-off states of the liquid control valve 15-2 in accordance with the liquid supply temperature detected by the first temperature sensor 17 . In this embodiment, the line and pump casing are cooled, that is, the first temperature sensor 17 detects the temperature in the liquid nitrogen outlet pipe in real time, and when the detected temperature is not lower than -175°C (liquid nitrogen has a standard boiling point of -195.8°C , while under pressure conditions of 0.4 MPa to 0.8 MPa, it has a boiling point of -173°C to -180°C; thus, by comprehensively considering the causes of thermal conductivity, the response temperature can be set to -175 °C), the controller 13 controls the closing of the liquid control valve 15-2 and the opening of the purge valve 15-1; and when the temperature is lower than -175°C, the controller 13 controls the closing of the purge valve 15-1 and the opening of the liquid control valve 15-2.

[0099] When added from the outlet section of the pipe 73 for injection of liquid foaming medium into the outlet section of the main pipe 71 for homogeneous mixing, liquid nitrogen will absorb a large amount of heat from the liquid mixed with the foam, which leads to a decrease in the temperature of the outlet section of the pipe 7 for homogeneous foam mixing . As is commonly believed, when low expansion wet foam (foam expansion coefficient is approximately 8) is used to extinguish a fire, it can be seen by calculation that the foam temperature can be at least 3°C after injection, evaporation and mixing of liquid nitrogen, provided that the temperature liquid mixed with foam is not lower than 5°С, and the flow rate is not less than 80 l/s. But in application, if high expansion dry foam (foam expansion coefficient of at least 15) is used for fire protection and extinguishing, it can be calculated by calculation that at low ambient temperature, injection of liquid nitrogen can lead to the fact that the temperature of the outlet section of the pipe 7 for a homogeneous mixing foam will be below 0°C.

[00100] In order to enable normal vehicle use in the environment and high expansion foam application scenarios, in some embodiments, as shown in FIG. 4, the fire extinguishing foam mixing system further comprises an in-line heater 16 located in the liquid outlet of the foam stock solution supply device; and a second temperature sensor 18 located in the liquid outlet of the pipe 7 for homogeneous foam mixing; wherein the second temperature sensor 18 detects the liquid supply temperature of the homogeneous foam mixing pipe 7 in real time, the controller 13 calculates and compares the heat balance according to the input flow of the foam-mixed liquid flowmeter 12-1, the input speed of the liquid supply pump 15 , the liquid supply temperature of pipe 7 for homogeneous mixing of the foam, and the ambient temperature at the fire site (assuming that the liquid nitrogen temperature is -196°C, and the temperature of the foam after mixing can be calculated according to the determined temperature and flow of the foam agent, as well as the inlet flow of liquid nitrogen). In accordance with the calculation result and the predetermined control strategy, the controller outputs a control signal to control the start and stop of the linear heater 16 and the start of the liquid nitrogen filling system. Control strategy: (1) When the ambient temperature is not lower than 0°C, if the temperature of the liquid supply at the outlet end of the pipe for homogeneous foam mixing is not lower than 5°C, the in-line heater 16 should not start heating, and the liquid nitrogen filling system can start working normally ; if the liquid supply temperature at the outlet end of the homogeneous foam mixing pipe 7 is lower than 5°C, the in-line heater 16 will automatically start heating to maintain the liquid supply temperature at the outlet end of the homogeneous foam mixing pipe 7 between 5°C and 10°C, so that the liquid nitrogen filling system can start working normally. (2) When the ambient temperature is lower than 0°C, the in-line heater 16 will automatically start heating to maintain the liquid supply temperature at the outlet end of the pipe 7 for homogeneous foam mixing between 30°C and 35°C, so that the liquid nitrogen filling system can normally start work. Although the linear heater 16 can automatically start and stop according to the temperature detected by the second temperature sensor 18, a manual emergency on/off function must also be provided.

[00101] In addition, in some embodiments, as shown in FIG. 4, the fire extinguishing foam mixing system further comprises a high pressure safety valve 15-3 located in the liquid supply line to protect the line from overpressure, and a pulse suppression device 15-4 configured to eliminate fluctuations in the outlet pressure of the liquid medium supply pump 15 . The liquid supply control valve 15-2 is also configured to control the filling flow of liquid nitrogen according to factors such as the actual fire situation and the type of foam. To avoid backflow of liquid nitrogen, a one-way check valve is also provided in the respective line.

[00102] Based on the above control strategy, in an aspect of the present disclosure, a method for controlling a fire extinguishing foam mixing system is provided, including:

[00103] when the ambient temperature Ta is not lower than 0°C and the liquid supply temperature T detected by the second temperature sensor 18 is not lower than 5°C, the controller 13 turns off the in-line heater 16 and starts the liquid medium filling operation;

[00104] when the ambient temperature Ta is not lower than 0°C and the liquid supply temperature T detected by the second temperature sensor 18 is lower than 5°C, the controller 13 starts the in-line heater 16 to maintain the liquid supply temperature T from 5°C to 10°C , and then starts the liquid medium filling operation;

[00105] When the ambient temperature Ta is lower than 0°C, the controller 13 starts the line heater 16 to maintain the liquid supply temperature T detected by the second temperature sensor 18 from 30°C to 35°C, and then starts the liquid medium filling operation.

[00106] Embodiments of the foam mixing system for fire suppression of the present disclosure can be applied to a fire engine, and in particular to a fire engine with a lifting platform. Accordingly, the present disclosure provides a fire engine comprising a fire-fighting foam mixing system.

[00107] In some embodiments, as shown in FIG. 4 and 5, the fire truck is a multifunctional foam positive pressure lifting platform fire truck, comprising a chassis 100, a subframe 400, a front stabilizer 200, a rear stabilizer 600, a center drum 700, a fire extinguishing foam mixing system, a first interface device 300, a second device 500, the turntable 800, and the boom 900. There are four types of extinguishing agent tanks, that is, a water tank, a class A foam stock solution tank, a class B foam stock solution tank, and a liquid nitrogen tank. The water pump 3 is driven from the chassis engine by means of a power take-off shaft, with an estimated pressure increase potential of 1.3 to 1.7 MPa and an estimated flow of 50 to 120 l/s. The foam stock pump 4 is driven by a pump motor with a design pressure rise potential of 1.3 to 1.7 MPa and a design flow of 5 to 200 l/min; The calculated pre-set range for proportional mixing of foam stock solution and water is: Class A foam stock solution (0.1 to 1%) and Class B foam stock solution (water-based film-forming foam) 3%. Both the air compressor 6 and the fluid pump 15 are driven by a hydraulic motor, with the chassis motor providing hydraulic power through the side PTO, which drives the hydraulic main oil pump; since the air compressor 6 and the fluid pump 15 are operated separately at different times, the two types of gas source devices can be operated economically and compactly by switching the flow direction of the hydraulic oil supply line; the pressure boosting potential of the air compressor 6 and the estimated supply of the amount of compressed air are the same as in the existing system and will not be re-described; the fluid pump 15 has a design pressure rise potential of 1.3 to 1.7 MPa and a design flow of 50 to 200 l/min.

[00108] The multifunctional foam positive pressure lifting platform fire truck not only throws out water, compressed air and foaming agent, but also throws out a large flow of compressed nitrogen foam for fire fighting at height and rescue of personnel, with the principle of operation of the fire system described above, providing due to this, the universal and efficient operation of one machine.

[00109] Performance indicators and corresponding machine design parameters are shown in Tables 1 and 2 below, respectively.

[00110] Table 1

Estimated flow of liquid mixed with foam (l/s) Target 1:80 Target 2: 120 Notes Required water flow (l/s) 77.6 116.4 Calculated as 97% flow of liquid mixed with foam Required foam stock solution flow class A (l/s) 0.8 1.2 Calculated as 1% foam-mixed liquid flow Required flow of aqueous film-forming foam stock solution (l/s) 2.4 3.6 Calculated as 3% foam-mixed liquid flow Required liquid nitrogen flow (l/s) 0.87 1.31 The expansion coefficient of liquid nitrogen during evaporation is considered to be 640, and the ratio of nitrogen and solution is 1: 7 Liquid nitrogen flow (l/s): foam expansion coefficient 15 1.75 2.63 The expansion coefficient of liquid nitrogen during evaporation is considered to be 640, and the ratio of nitrogen and solution is 1: 14

[00111] Table 2

Estimated capacity of liquid storage tank Continuous work time (min) Estimated flow of liquid mixed with foam Target 1:80 Target 2: 120 Notes Water tank volume (m ³ ) 1 4.8 7.2 Estimated and rounded according to the flow of water in table 1 Liquid nitrogen tank volume (m ³ ) 10 0.525 0.7875 Calculated and rounded according to the flow of liquid nitrogen, which corresponds to a foam expansion coefficient of 8 in table 1 5 0.525 0.7875 Calculated and rounded according to the flow of liquid nitrogen, which corresponds to a foam expansion coefficient of 15 in table 1 The volume of the tank for the initial solution of foam class A (m ³ ) 10 0.48 0.72 Calculated and rounded according to the flow of the initial solution of foam class A 1% in table 1 The volume of the tank for the initial solution of foam class B (m ³ ) 10 1.44 2.16 Calculated and rounded according to the flow rate of the aqueous film-forming stock solution of 3% foam in Table 1 Flow rate of theoretically produced foam with nitrogen class A or class B (l/s) ≥640~960 Calculated by multiplying target values 1 and 2 of the flow rate of the liquid mixed with foam by the expansion factor of the foam 8

[00112] Various embodiments of the present disclosure are described in detail herein. To avoid confusion in the concept of the present disclosure, some details well known in the art are not described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the description above.

[00113] While some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art will appreciate that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. Those skilled in the art will appreciate that the above embodiments may be modified, or some technical features may be equivalently substituted without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined in the appended claims.

Claims (42)

1. Pipe (7) for homogeneous foam mixing, containing: a main pipe (71) for uniform mixing, configured to mix the foam-mixed liquid (F) and the foaming medium to form a foam (F'); And a foaming medium injection pipe configured to inject the foaming medium into the main pipe (71) for uniform mixing, the foaming medium injection pipe having an outlet section penetrating into the internal cavity of the main pipe (71) for uniform mixing and extending in the extension direction of the main pipes (71) for homogeneous mixing, and the outlet section has a closed end part and a side wall provided with an outlet for the foaming medium; moreover, the foaming medium injection pipe comprises a compressed air injection pipe (72) and a liquid foaming medium injection pipe (73), and the foaming medium outlet contains an air outlet (75) located on the outlet section of the pipe (72) for compressed air injection, and a liquid outlet (74) located on the outlet pipe section (73) for injecting a liquid foaming medium; moreover, the main pipe (71) for homogeneous mixing is L-shaped, the outlet section of the main pipe (71) for homogeneous mixing is bent relative to its inlet section, the outlet section of the pipe (72) for injection of compressed air penetrates into the inlet section of the main pipe (71) for homogeneous mixing, and the outlet section of the pipe (73) for injecting liquid foaming medium penetrates the outlet section of the main pipe (71) for uniform mixing. 2. Pipe (7) for homogeneous mixing of the foam according to p. 1, and the outlet for the foaming medium is perpendicular to the direction of extension of the main pipe (71) for homogeneous mixing. 3. Pipe (7) for homogeneous foam mixing according to claim 1, and along the circumferential direction and the direction of extension of the outlet section of the pipe for injection of the foaming medium, a plurality of outlet holes for the foaming medium are uniformly located. 4. Pipe (7) for uniform foam mixing according to claim. 1, and the axial line of the outlet section of the pipe for injection of the foaming medium coincides with the axial line of the main pipe (71) for homogeneous mixing. 5. Pipe (7) for homogeneous mixing of the foam according to claim 1, and the orientation of the end part of the outlet section of the pipe for injection of the foaming medium corresponds to the direction of flow of the liquid mixed with the foam (F). 6. The pipe (7) for uniform foam mixing according to claim 1, wherein the pipe for injection of foaming medium has the shape of L, and the outlet section of the pipe for injection of foaming medium is bent relative to its inlet section. 7. Pipe (7) for homogeneous foam mixing according to claim 1, wherein the width (D) of the main pipe (71) for homogeneous mixing is from 125 mm to 200 mm, the width (D1) of the pipe (72) for injection of compressed air is from 25 mm to 40 mm, and the width (D2) of the pipe (73) for injection of liquid foaming medium is from 15 mm to 30 mm. 8. A foam mixing system for fire extinguishing, comprising: pipe (7) for homogeneous mixing of the foam according to any one of paragraphs. 1-7; a water supply device having a water outlet in communication with the inlet of the main pipe (71) for homogeneous mixing; a foam stock solution supply device having a liquid outlet in communication with an inlet of the main pipe (71) for homogeneous mixing; a fire nozzle having an inlet in communication with the outlet of the main pipe (71) for homogeneous mixing; And a foaming medium supply device having an outlet communicating with an inlet of a pipe for injecting the foaming medium. 9. Foam mixing system for fire extinguishing according to claim 8, wherein the foaming medium supply device comprises a reservoir (14) for storing a liquid medium and a pump (15) for supplying a liquid medium, the reservoir (14) for storing a liquid medium is configured to store a liquid foaming medium wherein the liquid medium storage tank (14) supplies liquid to the liquid foaming medium injection pipe (73) by means of the liquid medium supply pump (15). 10. A foam mixing system for fire extinguishing according to claim 9, further comprising: a foam-mixed liquid flow meter (12-1) configured to detect a foam-mixed liquid flow rate generated by mixing the foam and water; And a controller (13) configured to control the number of revolutions of the pump (15) for supplying liquid medium in accordance with the flow rate of the mixed liquid with foam determined by the flow meter (12-1) mixed with foam liquid. 11. Foam mixing system for fire extinguishing according to claim 9, wherein the pump (15) for supplying liquid medium has a boost pressure of 2.5 MPa to 3.5 MPa and an output flow of 80 l/min to 200 l/min. 12. Foam mixing system for fire extinguishing according to claim 9, wherein the tank (14) for storing liquid medium has an operating pressure of 0.4 MPa to 0.8 MPa. 13. Foam mixing system for fire extinguishing according to claim 9, wherein the pump (15) for supplying the liquid medium is a gear pump, a vane pump or a plunger pump. 14. Foam mixing system for fire extinguishing according to claim 9, additionally containing a controller (13), moreover, the foaming medium supply device additionally contains a purge valve (15-1), as well as a first temperature sensor (17) and a supply control valve (15-2) located in the liquid supply channel of the pump (15) for supplying liquid medium, the inlet of the purge valve (15-1) communicates with the outlet of the pump (15) for supplying liquid medium, and the controller (13) is configured to control the on-off states of the purge valve (15-1) and on/off states of the liquid supply control valve (15-2) according to the liquid supply temperature detected by the first temperature sensor (17). 15. The foam mixing system for fire extinguishing according to claim 9, further comprising: a line heater (16) disposed in a confluence passage for a liquid outlet of the foam stock solution supply device and a water outlet of the water supply device; a second temperature sensor (18) located in the liquid outlet of the pipe (7) for homogeneous foam mixing; And a controller (13) configured to control the on-off states of the linear heater (16) in accordance with the liquid supply temperature detected by the second temperature sensor (18). 16. Foam mixing system for fire extinguishing according to claim 8, wherein the source foam solution supply device comprises a reservoir (2) for the initial foam solution and a pump (4) for the initial foam solution; the liquid outlet of the pump (4) for the original foam solution communicates with the inlet of the main pipe (71) for homogeneous mixing; the foam stock solution tank (2) comprises a class A foam stock solution tank (2-1) and a class B stock stock solution tank (2-2), which have a common foam stock pump (4). 17. The foam mixing system for fire extinguishing according to claim 9 or 16, wherein the foaming medium supply device further comprises an air compressor (6), the foaming medium injection pipe comprises a compressed air injection pipe (72), and the air compressor (6) is configured to supply air to the pipe (72) for the injection of compressed air. 18. A method for controlling a foam mixing system for fire extinguishing according to claim 10, including the steps of: determine the flow meter (12-1) the flow rate of the liquid mixed with foam; determine the type of foaming required on site; the controller (13) regulates the number of revolutions of the pump (15) for supplying the liquid medium by calling the program command in accordance with the flow rate of the liquid mixed with foam and the required type of foam formation. 19. A method for controlling a foam mixing system for fire extinguishing according to claim 15, including the steps of: determining whether the ambient temperature is below 0°C; determine whether the liquid supply temperature is below 5°C using the second temperature sensor (18); when the ambient temperature is not lower than 0°C, and the liquid supply temperature is not lower than 5°C, the linear heater (16) is turned off by the controller (13) and the operation of filling the liquid medium is started; when the ambient temperature is not lower than 0°C and the liquid supply temperature is lower than 5°C, the controller (13) starts the linear heater (16) to maintain the liquid supply temperature from 5°C to 10°C, and then starts the liquid medium filling operation; when the ambient temperature is lower than 0°C, the linear heater (16) is started by the controller (13) to maintain the liquid supply temperature from 30°C to 35°C, and then the liquid medium filling operation is started. 20. Fire engine containing a foam mixing system for fire fighting according to any one of paragraphs. 8-17.

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