CAFS system and control method of the CAFS system for extinguishing localised fires at high heights

Abstract

CAFS system (1) for extinguishing localised fires at high heights comprising a first pump (2) for pumping water, a second pump (3) for pumping a foaming agent and an air compressor (4) adapted to supply compressed air to the CAFS system (1). Downstream of these elements there are respective flow meters (5). A first injector (6) mixes the foaming agent with water to obtain a first mixture. A second injector (7) mixes compressed air to the first mixture to obtain an extinguishing mixture. A delivery system (8) is configured for the ejection of the extinguishing mixture and a control unit (9) is configured to control the CAFS system (1) itself so as to change flow rate and pressure values as a function of a target height. The CAFS system (1) further comprises a flow rate regulation system (10), interposed between the first injector (6) and the second injector (7), for regulating the flow rate of the first mixture as a function of the target height.

Description

[0001] The present invention relates to a CAFS system and a control method of the aforesaid CAFS system for extinguishing localised fires at high heights.

[0002] In detail, the present invention is included in the field of fire-fighting systems, in particular in the field of CAFS (Compressed Air Foam System) systems.

[0003] As is known, CAFS systems are fire-fighting systems in which an extinguishing mixture composed of water, a foaming agent and compressed air is employed.

[0004] In particular, the CAFS systems are known to be characterized by a higher extinguishing power than the use of water alone or a mixture composed of water and foam.

[0005] In detail, by varying the composition of the CAFS extinguishing mixture, it is possible to obtain a mixture with extinguishing capacity that is modulable depending on the needs.

[0006] Therefore, it is known that the CAFS systems use a foamy solution which, depending on its density and ejection pressure, flows at different speeds compared to the dispensing speed of water alone.

[0007] Depending on the intervention needs, a very dry CAFS mixture will remain at the dispensing point acting as a blanket that covers the fuel for hours and cools it below the combustion temperature. Differently, a very wet CAFS mixture might drain off within minutes.

[0008] Therefore, depending on the ratio between the quantities of water, foaming agent and compressed air a distinction can be made between wet CAFS and dry CAFS.

[0009] As is known, the choice between a wet CAFS system and a dry CAFS system is dictated by the type of fire to be extinguished and the effect to be achieved with the extinguishing mixture.

[0010] In other words, the currently available CAFS systems are part of a type of advanced fire-fighting system that mixes water-foam-air in which the ratio between the amounts of the constituent elements of the extinguishing mixture is modulated as a function of the effects to be obtained by means of the aforesaid mixture. Therefore, currently, the focus is oriented on the choice of a wet CAFS or a dry CAFS only as a function of optimal fire extinguishing.

[0011] Despite the high efficiency of the currently available fire extinguishing systems, including CAFS systems, there is a need to address the emergence of new problems related to the safety of buildings with particularly high heights, such as for example the skyscrapers.

[0012] The increasingly frequent development of vertical construction in urban contexts pushes the fire-fighting sector to provide these buildings with fire-fighting systems integrated into the structure of the building itself. For example, fixed booster systems are used for traditional fire-fighting systems that guarantee adequate pressure and water flow rate to guarantee an effective intervention in the event of fire developing inside large buildings, such as for example skyscrapers or industrial complexes. However, the malfunction or damage of the fixed booster systems for traditional systems would lead to a building totally defenceless in the event of a fire. As a result, a fire on an high floor would be difficult for a traditional fire-fighting system to have access to and, in some cases, such as in a skyscraper or any building at a high height, it might even be impossible to reach with the currently available fire-fighting means.

[0013] The technical task of the present invention is therefore to make available a CAFS system and a control method of the CAFS system for extinguishing localised fires at high heights that are able to overcome the drawbacks that have emerged from the prior art.

[0014] Aim of the present invention is therefore to make available a CAFS system and a control method of the CAFS system that allow extinguishing localised fires at high heights.

[0015] The specified technical task and purpose are substantially achieved by a CAFS system and a control method of the CAFS system comprising the technical features set forth in one or more of the preceding claims. The dependent claims correspond to possible embodiments of the invention.

[0016] In particular, the present invention refers to a CAFS system for extinguishing localised fires at high heights and a control method of the aforesaid CAFS system.

[0017] Below reference will be made to the CAFS system also using the single term "system".

[0018] The CAFS system for extinguishing fires at high heights, subject matter of the present invention, comprises two feed pumps. A first pump is adapted to pump water into the CAFS system while a second pump is adapted to pump a foaming agent into the aforesaid system.

[0019] Additionally, the CAFS system comprises an air compressor adapted to supply compressed air to the system itself.

[0020] Downstream of the two feed pumps and the air compressor there are respective flow meters for measuring the flow rates of water, foaming agent and air.

[0021] A first injector is arranged downstream of the first and second pump and is in use configured to mix the foaming agent with the water and thus obtain a first mixture.

[0022] A second injector is arranged downstream of the air compressor and the first injector and is adapted to mix compressed air to the first mixture to obtain an extinguishing mixture.

[0023] Additionally, the CAFS system comprises a delivery system configured for the ejection of the extinguishing mixture towards a target height where a fire to be extinguished is present.

[0024] The CAFS system is controlled by a control unit that has the task of changing the flow rate and pressure values of water, foaming agent, compressed air, of the first mixture and of the extinguishing mixture as a function of a target height.

[0025] In particular, the CAFS system subject matter of the present invention further comprises a flow rate regulation system interposed between the first injector and the second injector. This flow rate regulation system is adapted to regulate the flow rate of the first mixture as a function of the target height.

[0026] The term "target height" means the arrangement in height of a point of interest that it is to be reached with the extinguishing mixture by ejecting it. In other words, "target height" refers to the height at which a fire to be controlled is identified.

[0027] Advantageously, the CAFS system in question allows to obtain an extinguishing mixture with variable composition. Specifically, the composition of the extinguishing mixture, and therefore the ratio between the amounts of water, foaming agent and compressed air, depends on a target height chosen by the user of the CAFS system.

[0028] Therefore, the CAFS system subject matter of the present invention allows to regulate the flow rate and pressure values of water, foaming agent, compressed air as a function of a target height to obtain an extinguishing mixture capable of reaching the aforesaid desired height and at the same time having an optimal composition of the extinguishing mixture to stop the fire present at the target height.

[0029] In other words, by varying the density of the extinguishing mixture it is possible to eject the aforesaid mixture at different heights.

[0030] The density of the extinguishing mixture is defined as the ratio between the amount of compressed air and the amount of the first mixture, the latter consisting of water and foaming agent.

[0031] "Amount" can be understood as a percentage value of the different components that make up the extinguishing mixture. Therefore, "amount" can be understood as a volume, a mass or another unit that allows to define the composition of the extinguishing mixture.

[0032] In particular, reasoning with the same ejection pressure of the delivery system, an extinguishing mixture containing a greater quantity of compressed air is able to reach higher heights than an extinguishing mixture having a higher density. Thus, by modulating the density of the extinguishing mixture and the delivery pressure it is possible to reach a desired target height.

[0033] Advantageously, the CAFS system can be used to control fires that develop in buildings exceeding 100 metres in height (identifiable as the limiting height of intervention with the traditional fire-fighting systems).

[0034] Additionally, the CAFS system can be used in case of fire developing in historic buildings characterized by a certain height, almost certainly not equipped with fixed fire-fighting systems and / or traditional booster systems.

[0035] Object of the present invention is also a control method of the CAFS system described above.

[0036] In detail, the control method of the CAFS system comprises a first step of selecting a desired target height. Subsequently, there is an automatic variation of the flow rate and pressure values of water, foaming agent, compressed air, of the first mixture and of the extinguishing mixture as a function of a target height. After that, the foaming agent is mixed with water to obtain a first mixture. In particular, the flow rate of the first mixture is regulated on the basis of the target height selected in the initial step.

[0037] Thereafter, there is the step of mixing compressed air to the first mixture to obtain an extinguishing mixture.

[0038] Finally, the extinguishing mixture is ejected towards the target portion selected in the initial step.

[0039] Advantageously, the composition of the extinguishing mixture is automatically modulated as a function of the target height selected by the user of the CAFS system in order to obtain a mixture with optimal extinguishing power and capable of reaching the desired height.

[0040] Advantageously, by varying the composition of the extinguishing mixture, it is possible to intervene in the suppression of fires located at high heights. For example, it is possible to intervene on fires that develop in skyscrapers where the fixed booster systems for traditional fire-fighting systems are out of order. Additionally, it is possible to intervene in fires that develop in historic buildings characterized by high heights and not equipped with classic fire-fighting systems.

[0041] Further characteristics and advantages of the present invention will become clearer from the indicative, and therefore non-limiting, description of an embodiment of a CAFS system for extinguishing fires at high heights and a method for using the aforesaid CAFS system.

[0042] Such description will be set forth herein below with reference to the accompanying drawings, provided for merely indicative and therefore non-limiting purposes, wherein: figure 1 is a schematic representation of a first possible configuration of the CAFS system; figure 2 is a schematic representation of a second possible configuration of the CAFS system; figure 3 is a schematic representation of a third possible configuration of the CAFS system.

[0043] With reference to the accompanying figures, number 1 denotes a CAFS system for extinguishing localised fires at high heights as a whole which, within the scope of this description, will be referred to as "CAFS system 1". With reference to the accompanying figures, the CAFS system 1 for extinguishing localised fires at high heights comprises a first feed pump 2 adapted to pump water into the CAFS system 1, a second feed pump 3 adapted to pump a foaming agent into the CAFS system 1 and an air compressor 4 adapted to supply compressed air to the CAFS system 1.

[0044] Downstream of the first pump 2, the second pump 3 and the air compressor 4 there are respective flow meters 5 for measuring the flow rates of water, foaming agent and compressed air.

[0045] Downstream of the first pump 2 and the second pump 3 there is a first injector 6 adapted to mix the foaming agent with water to obtain a first mixture.

[0046] A second injector 7 is arranged downstream of the first injector 6 and the air compressor 4 and is configured to mix compressed air in the first mixture to obtain an extinguishing mixture.

[0047] Further, the CAFS system 1 comprises a delivery system 8 configured for the ejection of the extinguishing mixture.

[0048] In the accompanying figures the delivery system 8 has been schematically represented by means of an arrow representative of the outlet of the CAFS system 1.

[0049] A control unit 9 is configured to control the CAFS system 1 so as to change flow rate and pressure values of water, foaming agent, compressed air, the first mixture and the extinguishing mixture as a function of a target height.

[0050] In detail, the CAFS system 1 comprises a flow rate regulation system 10 interposed between the first injector 6 and the second injector 7. The aforesaid flow rate regulation system 10 is adapted to regulate the flow rate of the first mixture, composed of water and foaming agent, as a function of the target height.

[0051] Advantageously, the CAFS system 1 subject matter of the present invention allows to modulate the composition of the extinguishing mixture as a function of a target height in which a fire to be suppressed is located. Therefore, by varying the composition of the extinguishing mixture it is possible to reach different heights by ejecting the extinguishing mixture itself.

[0052] The composition of the extinguishing mixture can be changed by changing the composition of the first mixture, i.e. by varying the ratio between the amount of water and foaming agent, and by varying the quantity of air introduced into the first mixture to obtain the final extinguishing mixture.

[0053] Therefore, based on the needs, it is possible to have an extinguishing mixture having an optimal composition to reach a desired height. Such a mixture is at the same time characterized by an optimal extinguishing capacity.

[0054] In particular, with the same delivery pressure for the ejection of the extinguishing mixture, an extinguishing mixture characterized by the presence of a high content of compressed air (hence low density) will more easily reach high heights. On the other hand, an extinguishing mixture with a higher density, and therefore a lower air content in its inside, requires greater pressure to reach high target heights.

[0055] Advantageously, the composition of the extinguishing mixture is modulable based on the needs of the user.

[0056] Advantageously, a plurality of different heights can be reached through the same CAFS system 1 by modulating the density of the extinguishing mixture.

[0057] Advantageously, the CAFS system 1 automatically varies the composition of the extinguishing mixture to reach the desired target height and at the same time maximise the extinguishing potential.

[0058] Advantageously, the CAFS system 1 can be used not only for extinguishing fires at high heights but also for controlling fires spaced out on the level. In other words, the range of the CAFS 1 can be exploited to reach a fire that is localised horizontally farther away from the fire-fighting operators. This functionality can be exploited in cases where the fire-fighting operators are unable to approach the fire with the common fire-fighting systems, for example due to the presence of natural and / or artificial obstacles or for safety reasons, such as in the case of a fire in a nuclear power plant or in a place with potentially risky characteristics for the health of the fire-fighting operators.

[0059] In accordance with a possible embodiment of the present invention, the flow rate regulation system 10 comprises a position control valve 11, controlled by the control unit 9, for regulating the flow rate of the first mixture in input to the second injector 7.

[0060] In other words, the first step for the regulation of the composition of the extinguishing mixture lies in the regulation of the flow rate of the first mixture by means of the flow rate regulation system 10.

[0061] Advantageously, by means of the position control valve 11, controlled by the control unit 9, it is possible to modulate the flow rate of the first mixture composed of water and foam as a function of a desired target height.

[0062] In accordance with a second embodiment of the CAFS system 1, the flow rate regulation system 10 comprises a plurality of calibrated valves 12, controlled in opening and / or closing by the control unit 9, for regulating the flow rate of the first mixture in input to the second injector 7.

[0063] Advantageously, the flow control of the first mixture, composed of water and foaming agent, can be carried out by means of a plurality of calibrated valves 12. Therefore, the control unit 9 will control one or more of the calibrated valves 12 in opening or closing, enabling the flow of the first mixture only in certain calibrated valves 12 on the basis of the final composition desired for the extinguishing mixture to reach a certain target height.

[0064] In accordance with a third embodiment of the CAFS system 1, the flow rate regulation system 10 comprises a plurality of calibrated orifices 13 adapted to regulate the flow rate of the first mixture in input to the second injector 7.

[0065] Analogously to what has been said above for the other two possible embodiments, a flow rate regulation system 10 comprising a plurality of calibrated orifices 13 allows to regulate the flow rate of the mixture composed of water and foaming agent in input to the second injector 7.

[0066] Also in this third embodiment, the regulation of the flow rate of the first mixture takes place with the aim of having an extinguishing mixture with the optimal composition to be ejected at a certain target height and at the same time be endowed with a maximized extinguishing power.

[0067] According to a further possible embodiment, the flow rate regulation system 10 can be composed of a combination of position control valves 11, calibrated valves 12 and / or calibrated orifices 13. In other words, the flow rate regulation system 10 may comprise a combination of two or more of the above-mentioned elements.

[0068] Thus, the flow rate regulation system 10 may comprise one or more position control valves 11, one or more calibrated valves 12 and one or more calibrated orifices 13.

[0069] According to one aspect of the present invention, upstream of each calibrated orifice 13 of the plurality of calibrated orifices 13 comprised in the flow rate regulation system 10, there is a valve, controlled in opening and / or closing by the control unit 9, for controlling the flow of the first mixture in each calibrated orifice 13.

[0070] It is specified that in the accompanying figures no valves have been represented upstream of the calibrated orifices 13.

[0071] Furthermore, it should be noted that the type of valve upstream of the calibrated orifice does not belong to a specific type. In fact, it is at the discretion of the manufacturer to choose a particular type of valve with a view to optimising the operation of the CAFS system 1.

[0072] Advantageously, by controlling in opening and / or closing the valves upstream of the calibrated orifices 13 through the control unit 9 it is possible to direct the flow of the first mixture towards the accessible calibrated orifices 13 and therefore modulate the flow rate of the first mixture in input to the second injector 7.

[0073] According to one aspect of the present invention, the control unit 9 is configured to vary a composition of the extinguishing mixture as a function of a ratio of the flow rates of water and foaming agent in the first mixture and as a function of the flow rate of compressed air introduced into the first mixture by means of the second injector 7.

[0074] Advantageously, an extinguishing mixture is obtained with a maximized extinguishing capacity capable of reaching high heights to suppress localised fires in points difficult to reach or not reachable by the common fire-fighting systems.

[0075] According to one aspect of the present invention, the control unit 9 is configured to obtain a delivery pressure of the extinguishing mixture as a function of the desired target height.

[0076] In accordance with a preferred, and therefore non-limiting, embodiment, the control unit 9 is configured to obtain a delivery pressure of the extinguishing mixture comprised between 1 bar and 10 bar, as a function of the desired target height.

[0077] In other words, the CAFS system 1 is a non-stationary pressure system in which the control unit 9 adapts the delivery pressure of the extinguishing mixture on the basis of the target height desired by the user of the CAFS system 1. At the same time, the control unit 9 modulates the composition of the extinguishing mixture. Therefore, by regulating the delivery pressure and the composition of the extinguishing mixture, it is possible to intervene precisely and optimally in extinguishing the fire identified at a high height. As mentioned above, the control unit 9 is configured to perform an ejection of the extinguishing mixture as a function of an arbitrary target height.

[0078] According to a preferred, and therefore non-limiting embodiment, the control unit 9 is configured to perform an ejection of the extinguishing mixture comprised between 0 metres and 550 m.

[0079] In other words, by varying the delivery pressure and the composition of the extinguishing mixture, it is possible to intervene in extinguishing localised fires up to 550 metres in height, remaining in a delivery pressure range comprised between 1 bar and 10 bar.

[0080] As a result, by increasing the delivery pressure value, target heights greater than 550 metres in height can be reached.

[0081] Advantageously, the CAFS system 1 is able to reach heights above 100 m with pressures generally below 10 bar.

[0082] In accordance with an aspect of the present invention, the CAFS system 1 comprises a user interface 14 configured to send a control signal to the control unit 9, wherein said control signal identifies the desired target height.

[0083] In other words, a user of the CAFS system 1 may manually enter a target height via the user interface 14. Specifically, the user of the CAFS system 1 can choose a target height among the predefined heights established by the manufacturer or can manually enter the desired height at which to eject the extinguishing mixture. Based on this signal, the control unit 9 modulates the composition of the extinguishing mixture by controlling the elements comprised in the CAFS system 1.

[0084] Advantageously, the CAFS system 1 adapts to the needs of the user and allows targeted interventions to be performed thanks to the possibility of choosing a specific target height set by the user.

[0085] According to an alternative embodiment of the present invention, the control unit 9 is configured to receive signals from an automatic fire detection system present in a controlled environment. In other words, the control unit 9 receives signals from smoke, heat, gas and / or flame detectors installed in a protected area. Based on the location of the sensor, the control unit 9 automatically establishes the target height and defines the composition of the optimal extinguishing mixture for reaching the aforesaid height.

[0086] In accordance with an aspect of the present invention, the CAFS system 1, integrated in a fire-fighting vehicle, provides for connection with a water source and a foaming agent source. As far as the foaming agent is concerned, this is typically stored in a tank present in the fire-fighting vehicle itself. In the same way, the water can be stored in a tank present in the fire-fighting vehicle. Alternatively, the CAFS system 1 can be connected to the urban water network, to a natural water reservoir or to the fixed pipes of the building in which it is necessary to intervene, or of an adjacent one.

[0087] The present invention further concerns a control method of a CAFS system 1 having the features described above.

[0088] In particular, the control method of the CAFS system 1 provides for a first step of selecting a target height. If the user interface 14 is present, the fire-fighting operator is prompted to select a target height among predefined heights or manually enter an arbitrary target height.

[0089] The control method therefore intervenes in the definition of the flow rate and pressure values of water, foaming agent, compressed air, of the first mixture and of the extinguishing mixture as a function of the target portion chosen in the initial step.

[0090] Subsequently, the foaming agent is mixed with water to obtain a first mixture.

[0091] The next step provides for regulating the flow rate of the first mixture as a function of the target height.

[0092] Thereafter, the control method provides for the step of mixing the compressed air in the first mixture to obtain an extinguishing mixture. Finally, there is a step of ejecting the extinguishing mixture towards the target height initially set.

[0093] Thus, the control method is at least in part performed by the control unit 9 of the CAFS system 1. In other words, the different steps of the control method are to be identified as instructions executed by the control unit 9 of the CAFS system 1 to control the different components of the CAFS system 1.

[0094] Advantageously, the CAFS system 1 and the control method of the CAFS system 1, subject matter of the present invention, allow to overcome the drawbacks that emerged from the prior art.

[0095] Advantageously, the CAFS system 1 allows to intervene on localised fires at high heights by modulating the composition of the extinguishing mixture as a function of a target height set by a user of the aforesaid system.

[0096] Advantageously, by varying the density of the extinguishing mixture, it is possible to reach with the aforesaid mixture a target height comprised between 0 metres and 550 metres by exploiting a delivery pressure equal to or less than 10 bar.

Claims

1. CAFS system (1) for extinguishing localised fires at high heights comprising: - a first feed pump (2) adapted to pump water into said CAFS system (1); - a second feed pump (3) adapted to pump a foaming agent into said CAFS system (1); - an air compressor (4) adapted to supply compressed air to said CAFS system (1); - respective flow meters (5) arranged downstream of said first pump (2), said second pump (3) and said air compressor (4); - a first injector (6), arranged downstream of said first pump (2) and said second pump (3), adapted to mix said foaming agent with said water to obtain a first mixture; - a second injector (7), arranged downstream of said air compressor (4) and said first injector (6), adapted to mix said compressed air in said first mixture to obtain an extinguishing mixture; - a delivery system (8) configured for the ejection of said extinguishing mixture; - a control unit (9) configured to control the CAFS system (1) itself so as to change flow rate and pressure values of water, foaming agent, compressed air, of said first mixture and of said extinguishing mixture as a function of a target height; characterised in that it further comprises a flow rate regulation system (10), interposed between said first injector (6) and said second injector (7), adapted to regulate the flow rate of said first mixture as a function of said target height.

2. CAFS system (1) according to claim 1, wherein said flow rate control system (10) comprises a position control valve (11), controlled by said control unit (9), for regulating the flow rate of said first mixture in input to said second injector (7).

3. CAFS system (1) according to claim 1 or 2, wherein said flow rate regulation system (10) comprises a plurality of calibrated valves (12), controlled in opening and / or closing by said control unit (9), for regulating the flow rate of said first mixture in input to said second injector (7).

4. CAFS system (1) according to one or more of the preceding claims, wherein said flow rate regulation system (10) comprises a plurality of calibrated orifices (13) adapted to regulate the flow rate of said first mixture in input to said second injector (7).

5. CAFS system (1) according to claim 4, wherein upstream of each calibrated orifice (13) of the plurality of calibrated orifices (13) there is a valve, controlled in opening and / or closing by said control unit (9), for controlling the flow of said first mixture in each calibrated orifice (13).

6. CAFS system (1) according to one or more of claims 1 to 5, wherein said control unit (9) is configured to vary a composition of said extinguishing mixture as a function of the variation of a ratio of the flow rates of water and foaming agent in said first mixture and the flow rate of compressed air introduced into said first mixture by means of said second injector (7).

7. CAFS system (1) according to one or more of the preceding claims, comprising a user interface (14) configured to send a command signal to said control unit (9) identifying said target height.

8. Control method of a CAFS system (1) according to one or more of the preceding claims, comprising the steps of: - selecting a target height; - changing flow rate and pressure values of water, foaming agent, compressed air, of said first mixture and of said extinguishing mixture as a function of said target height; - mixing said foaming agent with said water to obtain a first mixture; - regulating a flow rate of said first mixture as a function of said target height; - mixing said compressed air in said first mixture to obtain an extinguishing mixture; - ejecting said extinguishing mixture towards said target height.

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