Low-consumption fire protection system

Abstract

Fire protection system (1) by means of a sprinkler network (4) comprising: - sprinkler pipes (3) configured to carry fluid from a tank (2) configured to store a predefined volume of fluid to the sprinkler network (4), the sprinkler pipes and the tank (2) forming a closed fluid circuit; and - a maintenance device (5) connected to the closed fluid circuit and comprising a filter (7) configured to filter the water in the closed fluid circuit. Figure for the abbreviation: Fig. 1

Description

Title of the invention: Low-consumption fire protection system. Technical field

[0001] This application relates to sprinkler systems for fire protection. More specifically, this application relates to the maintenance of these protection systems. STATE OF THE ART

[0002] A sprinkler system fire protection system comprises one or more tanks configured to store a predetermined volume of fluid, spray lines (or antennas) carrying this fluid under pressure, and sprinklers configured to automatically spray a fire when the ambient air reaches a predetermined temperature and / or when smoke is detected. The fluid generally comprises water.

[0003] These protection systems have proven their worth. However, in order to guarantee the operation of the protection system, actions must be carried out periodically on the protection system.

[0004] Some of these actions, however, result in the waste of a significant volume of water. For example, current national and international regulations require that the tank (with a volume on the order of several hundred cubic meters) and the spray lines be drained periodically (the interval depending on the applicable regulations and generally ranging from three to ten years). Such draining is also necessary for maintenance or part replacement. Another example concerns the pump unit, which circulates water through the spray lines and must undergo weekly tests that also consume water. The same applies to mandatory test visits and bell tests.The Applicant estimates that the volume of drinking water consumed to check and guarantee the operation of protection systems in France amounts to more than three billion litres each year, which corresponds to the annual water consumption of a French city of 55,000 inhabitants.

[0005] Other actions necessary for the operation of the protection system are energy-intensive. Indeed, it is necessary to prevent the water in the tank from freezing, regardless of the ambient temperature. The formation of an ice layer on the surface of the tank can deform the tank when water is drawn in if the protection system is activated (during a (e.g., a fire event). Current tanks therefore include an anti-icing device consisting of a heating element that is immersed in the tank and activated as soon as the ambient temperature becomes too low, generally around 6°C. However, the electrical consumption of such an anti-icing device is on the order of several kilowatt-hours (kWh). EXPOSED

[0006] One objective of this application is to remedy the aforementioned drawbacks by proposing a solution that reduces the volume of water required to verify the operation of the protection systems without impacting their functionality. Secondarily, another objective is to reduce the power consumption of the protection system while ensuring its integrity.

[0007] To this end, a fire protection system using a sprinkler network is proposed according to a first aspect, comprising: - spray lines configured to transport fluid from a tank configured to store a predefined volume of fluid to the sprinkler network, the spray lines and the tank forming a closed fluid circuit; and - a maintenance device connected to the closed fluid circuit and including a filter configured to filter the water in the closed fluid circuit.

[0008] Some preferred but non-limiting features of the protection system according to the first aspect are the following, taken individually or in combination: - the filter includes at least one of a magnetic filter and a sludge trap; - the maintenance device includes an inlet pipe having an upstream end mounted on the tank so as to draw the fluid, for example on a tank drain valve, and a downstream end connected to the filter; - the maintenance device includes an outlet pipe having an upstream end connected to the filter and a downstream end connected to the tank, preferably near a top of the tank, so as to inject the fluid filtered by the filter into the tank; - the protection system further includes a motor-pump unit, configured to draw the fluid from the tank and inject it into the spray lines, and a discharge line having a first end connected to the motor-pump unit and a second end connected to the outlet line or the tank; - the protection system further includes heating means fitted onto the outlet pipe, for example a heating cord wrapped around the outlet pipe; - the protection system also includes a thermal probe configured to measure the temperature of the fluid in the tank; - the tank further includes a convection chamber mounted near one of the tank's peaks, the outlet pipe being configured to open into the convection chamber; and / or - the maintenance device further includes a pump configured to draw fluid from the tank and circulate it through the filter in the maintenance device.

[0009] According to a second aspect, an assembly is proposed comprising a fire protection system by sprinkler network according to the first aspect and a tank fluidly connected to the sprinkler lines, the filter of the maintenance device being configured to filter fluid stored in the tank.

[0010] According to a third aspect, a maintenance method for a fire protection system using a sprinkler network is proposed, conforming to the second aspect and comprising the following steps: - suction of a volume of fluid from the tank; - filtration of the volume of fluid thus aspirated; and - injection of the filtered volume of fluid into the tank.

[0011] Some preferred but non-limiting features of the maintenance process according to the third aspect are the following, taken individually or in combination: - the maintenance process further includes a step of heating the filtered fluid before the injection step; - the heating stage is implemented when the fluid temperature is below a predefined threshold temperature; and / or - the protection system further includes a motor-pump unit configured to draw fluid from the tank and inject it into the spray lines of the protection system and the maintenance process further includes the filtration of a cooling fluid from the motor-pump unit. DESCRIPTION OF THE FIGURES

[0012] Other features, purposes and advantages will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0013] Fig. 1 schematically illustrates an example of a fire protection system using a sprinkler network according to an embodiment;

[0014] Fig. 2 is a flowchart of steps of an example of a maintenance process for a sprinkler network fire protection system.

[0015] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0016] A fire protection system 1 for an installation using a sprinkler network 4 comprises: - spray pipes 3 configured to transport fluid from a tank 2 configured to store a predefined volume of fluid to the sprinkler network 4; and - a maintenance device 5.

[0017] In what follows, the invention will be described in the case where the fluid comprises water. This is not, however, limiting; the present description is applicable when another fluid is used by the protection system 1.

[0018] The spray pipes 3 are in fluidic communication with the tank 2. The spray pipes 3 and the tank 2 form a closed water circuit, so that the protection system 1 is independent of the public sewage network, thus ensuring its operation even in the event of a public network failure. The protection system 1 further includes a motor-pump unit 6 configured to draw water from the tank 2 and circulate it under pressure through the spray pipes 3.

[0019] The volume of tank 2 depends on the size of the installation to be protected. Depending on the installation, the protection system 1 may include several tanks 2 connected to the spray lines 3.

[0020] The sprinkler lines 3 contain water, generally under pressure, and are configured to automatically spray a fire when the ambient air reaches a predetermined temperature and / or when smoke is detected. Since the operation of the sprinkler lines 3 is conventional, it will not be described in further detail here.

[0021] In order to reduce, or even eliminate, water losses induced by the maintenance of the protection systems 1, the maintenance device 5 includes a filter 7 configured to filter the water from the closed fluid circuit of the protection system 1. The water filtration makes it possible to remove particles present in the fluid circuit, and in particular in the tank 2, and thus avoid the need to periodically drain and clean the tank 2.

[0022] The filter 7 may, for example, include a magnetic filter 8 configured to filter ferromagnetic particles present in the water. The magnetic filter 8 may, in particular, include a settling tank, which is mounted on the closed water circuit, a magnetic core mounted in the settling tank and configured to attract and extract the ferromagnetic particles present in the water circulating through the magnetic filter 8, and a drain valve configured to allow the discharge of the ferromagnetic particles extracted by the magnetic core. An example of a magnetic filter 8 that may be used is the DIRTMAG# flanged settling tank with magnet and insulating shell marketed by the Caleffi brand. The capacity of the The effectiveness of magnetic filter 8 in filtering ferromagnetic particles depends on the type of magnetic core chosen, the water flow rate in filter 7, the duration and frequency of filtration of the magnetic filter 8, and the particle size. For example, the magnetic core may include a neodymium magnet; the flow rate in magnetic filter 8 may be greater than or equal to 5 m³ and may reach several tens of m³, for example, on the order of 8 to 10 m³; the water filtration in tank 2 may be carried out daily for 12 hours; and the size of the ferromagnetic particles is generally less than or equal to 5 µm.

[0023] The filter 7 may also include a sludge trap 9, which may be mounted in series with the magnetic filter 8 or integrated directly into the magnetic filter 8. The sludge trap may, in particular, include a sieve whose mesh size is chosen according to the type of impurities likely to be present in the tank 2 and the frequency of cleaning the filter 7 in order to prevent its saturation. For example, the mesh size may be between 5 µm and 100 µm. Weekly cleaning of the filter 7 is then sufficient to prevent clogging by impurities while ensuring effective filtration of the closed-circuit water.

[0024] The maintenance device 5 further includes a pump 10 configured to draw water from the tank 2, circulate it through the filter 7, and return it to the tank 2. The pump 10 is thus fluidly connected to the tank 2 and the filter 7 via dedicated pipes. The pump 10 may be a single-unit centrifugal pump adapted to the volume of the tank 2. The pump 10 may, for example, have a flow rate between 5 m³ / h and 15 m³ / h, for example, on the order of 10 m³ / h for a tank 2 of 750 m³, and a pressure between 0.5 bar and 1.5 bar, for example, on the order of 1 bar for a tank 2 of 750 m³.

[0025] The maintenance device 5 can be mounted on an existing protection system 1 which is already in place in a given installation, or integrated directly into a new protection system 1.

[0026] For this purpose, the maintenance device 5 includes an inlet pipe 11 mounted on the tank 2 in order to take water from the tank 2 and circulate it through the filter 7, and an outlet pipe 12 which receives the water filtered by the filter 7 and is configured to inject it into the tank 2.

[0027] The inlet pipe 11 is preferably mounted near the bottom 13 of the tank 2 so that the pump 10 draws water from the bottom of the tank 2. The water at the bottom 13 of the tank 2 is indeed at a higher pressure than the water at its surface, which reduces the power required for the pump 10 to circulate the water through the filter 7 and also allows it to draw in any particles that may be at the bottom 13 of the tank 2. For example, the inlet pipe 11 can be mounted on the drain valve of tank 2: such a drain valve is indeed pre-existing on most tanks 2 to allow for their periodic draining.

[0028] The outlet pipe 12 is preferably mounted near the top 14 of tank 2 so as to inject the filtered water close to the surface of the water contained in tank 2. Injection at the top of tank 2 has several advantages. The water at the surface is generally colder than the water at the bottom 13 of tank 2: injecting the filtered water at the top of tank 2 thus warms the surface water and reduces the risk of freezing. Furthermore, the suction at the bottom 13 of tank 2 combined with the injection at the top of tank 2 has the effect of circulating the water in tank 2, thus creating water movement that can further reduce the risk of the water surface freezing.This configuration of the inlet pipes 11 and outlet pipes 12 of the maintenance device 5 thus reduces the risk of freezing of the surface water and, consequently, reduces the heating requirements of the water in tank 2.

[0029] If the tank 2 is buried (basin), the maintenance device 5 can be placed on the surface. In this case, the inlet pipe 11 and the outlet pipe 12 can be connected near the top 14 of the buried tank 2. Furthermore, the pump 10 can be of the self-priming type, as the water pressure at the top 14 of the tank 2 is lower than at its bottom 13.

[0030] To further limit the risk of freezing, the maintenance device 5 may also include heating means 15 for the outlet pipe 12 and / or the inlet pipe 11. The heating means 15 may, in particular, include a conduction heater fitted onto the pipe(s) 11, 12, such as a heating cable. The heating cable may, for example, be wrapped around the inlet pipe 11 and the outlet pipe 12. The heating means 15 thus allow, when necessary, the water treated by the maintenance device 10 to be heated.

[0031] When the outlet pipe 12 is mounted near the top 14 of the tank 2, the length of the pipes 11, 12 of the maintenance device 5 is sufficient to allow the filtered water to be heated. For example, for a 750 m³ tank 2, the height of the tank 2 is generally around 9 m. The length of the pipes can therefore be around ten meters, while the length of the heating cable (before winding) can be, for example, around fifteen meters, which makes it possible to raise the temperature of the filtered water by at least 0.1 °C between its collection at the bottom of the tank 2 and its injection into the tank 2 (for a heating cable power of around 10 W / m).

[0032] Where appropriate, the assembly formed by the outlet pipe 12 and / or the inlet pipe 11 and the heating means 15 can be insulated in order to improve heat transfer to the filtered water.

[0033] Preferably, the heating means 15 are only activated in the event of a risk of freezing. To this end, in a first embodiment, the maintenance device 5 includes a thermal probe 16 configured to measure the water temperature in the tank 2. The heating means 15 are then only activated when the water temperature is below a predefined temperature, for example, less than or equal to 1°C. In this embodiment, it is therefore the water temperature in the tank 2, and not the ambient temperature, that serves as the setpoint for activating the heating means 15. The thermal probe 16 may, for example, include an immersion heater submerged in the tank 2, preferably near or at the surface of the water, as the surface water is generally colder and therefore more likely to freeze than the water at the bottom 13 of the tank 2.

[0034] Optionally, the tank 2 further comprises a convection chamber 17 mounted near the top 14 of the tank 2. The convection chamber 17 may, in particular, comprise one or more walls, for example, metal sheets, fixed to the walls of the tank 2 at the water surface so as to contain water from the tank 2. The sheet(s) are connected to each other so as to form a sleeve open at two opposite ends (one end facing the bottom 13 of the tank 2 while the other end faces the top 14, near the water surface). The sleeve may therefore have a generally cylindrical shape of any cross-section (for example, parallelepiped or ovoid). The water contained in the convection chamber 17 is thus in fluidic communication with the water contained in the rest of the tank 2.

[0035] The walls of the convection chamber 17 delimit a volume of water which is very small compared to the total volume of the tank 2. For example, the volume of water delimited by the convection chamber 17 is less than 5% of the total volume of the tank 2.

[0036] The outlet pipe 12 preferably opens into the convection chamber 17 so that the filtered water is injected into the convection chamber 17. Since the filtered water is warmer than the water on the surface of the tank 2 (because it has been drawn from the bottom 13 of tank 2 and, if necessary, heated by the heating means 15), the filtered water heats the water contained in the convection chamber 17. As the volume of water delimited by the convection chamber 17 is very small compared to the total volume of water in the tank 2, the temperature of the water in the convection chamber 17 necessarily increases more rapidly than if the filtered water were injected directly into the tank 2, which reduces the heating requirements of the filtered water.It is sufficient that the water in the convection chamber 17 be sufficiently warm so as not to freeze in order to avoid the risk of damage to the tank 2: indeed, even if the surface water in the rest of the tank 2 were to freeze, the water present on the surface in the convection chamber 17 would remain liquid, which would allow the water to be drawn up. by the motor-pump group 6 of the protection system 1 without risking damage to the tank 2.

[0037] When the tank 2 includes a convection chamber 17, the thermal probe 16 is preferably placed in the convection chamber 17, or even immersed in the water contained in the convection chamber 17, preferably near the surface, so as to heat the filtered water only when the volume of water delimited by the convection chamber 17 is likely to freeze.

[0038] Note that the activation of the heating means 15 only when the water temperature is below the threshold temperature (and rather than when the ambient temperature becomes too low), combined with the movement of the water by means of the maintenance device 5 and the injection of filtered water into the convection chamber 17, makes it possible to divide by at least three the electrical power required to prevent the water from freezing on the surface of the tank 2.

[0039] The protection system 1 further includes a cooling system for the pump unit 6, comprising a supply line configured to supply cooling water to the motor of the pump unit 6 for cooling purposes, and a discharge line 19 configured to discharge the water after the motor has cooled. The discharge line 19 can be connected to the outlet line 12 of the maintenance device 5, so that the water used to cool the pump unit 6 is injected into the tank 2 along with the filtered water. This water is, in fact, at a higher temperature than the water drawn from the bottom 13 of the tank 2, since it has been heated by the motor of the pump unit 6, which further heats the water contained in the tank 2.Furthermore, the connection to the outlet pipe 12 (rather than the inlet pipe 11) of the maintenance device 5 ensures the cooling, and therefore the operation, of the motor-pump unit 6, even in the event of a malfunction of the maintenance device 5.

[0040] Injecting the water used to cool the motor-pump unit 6 into the tank 2 also allows it to be filtered and thus avoids sending it to the sewer, since it is mixed with the water in the tank 2 on which the maintenance device 5, and therefore the filter 7, is mounted.

[0041] When the protection system 1 includes several tanks 2, the protection system 1 may include a maintenance device 5 per tank 2.

[0042] Alternatively, the protection system 1 may include a single maintenance device 5 connected to several tanks 2. The maintenance device 5 then includes as many secondary inlet pipes and secondary outlet pipes as there are tanks 2 to be maintained, the secondary inlet and secondary outlet pipes then being able to be connected to the inlet pipe 11 and the outlet pipe 12, respectively, of the maintenance device 5. Preferably, a maintenance device 5 is connected to at most two tanks 2.

[0043] Maintenance of tank 2 can be carried out periodically, for example, over a period of 8 to 15 hours. For a 750 m³ tank 2, with the magnetic filter 8 and pump 10 described above, a 12-hour period allows the entire volume of tank 2 to be filtered in one week. However, when the protection system 1 also includes a thermal probe 16 and, where applicable, heating means 15, maintenance of tank 2 can also be carried out when the water temperature falls below the predefined temperature to allow water circulation in tank 2 and in the outlet pipe 12.

[0044] For this purpose, the maintenance device 5 may include an automaton 20 configured to execute operating cycles of the maintenance device 5, and a switch to allow an operator to modify the operating cycle executed by the automaton.

[0045] A first operating cycle of the automaton is an automatic cycle corresponding to the periodic maintenance of the tank 2, the period and duration of which can be adjusted according to the number of tanks 2, the location of the protection system 1 (type of installation (and therefore volume of impurities and particles likely to be generated), geographical position (weather conditions), etc.) and the type of installation to be protected.

[0046] A second operating cycle of the automated system is a manual cycle in which the maintenance device 5 is forced to start in order to verify its operation (maintenance, checking the pump 10, etc.). The manual operating cycle can have a predetermined duration, for example twenty minutes.

[0047] A third operating cycle of the automaton corresponds to the shutdown of the maintenance device 5.

[0048] The protection system 1 may further include conventional safety means. Typically, the alarm cable normally connected to the heating pin may be connected to the thermal probe 16.

[0049] It should be noted that the presence of the maintenance device 5 does not affect the operation of the protection system 1. In the event of a fire, the sprinklers 4 continue to automatically spray the fire source as soon as the ambient air reaches a predetermined temperature and / or smoke is detected, regardless of the operation of the maintenance device 5.

[0050] The maintenance device 5 can be placed in an enclosure 21 to protect it from its environment. The tanks 2 are generally stored outside the installations.

[0051] The enclosure 21 may, for example, comprise a steel frame on which cladding panels are mounted, which may be made of a UV-resistant material and comprise, for example, two layers of aluminum alloy skin and a central layer of polyethylene (typically Dibond#). The frame and panels then have the advantage of being recyclable.

[0052] Optionally, the enclosure 12 may also include solar panels in order to reduce the electrical consumption of the maintenance device 5.

Claims

Demands

1. Fire protection system (1) by means of a sprinkler network (4) comprising: - sprinkler pipes (3) configured to carry fluid from a tank (2) configured to store a predefined volume of fluid to the sprinkler network (4), the sprinkler pipes and the tank (2) forming a closed fluid circuit; and - a maintenance device (5) connected to the closed fluid circuit and comprising a filter (7) configured to filter the water from the closed fluid circuit.

2. Protection system (1) according to claim 1, wherein the filter (7) comprises at least one of a magnetic filter (8) and a sludge trap (9).

3. A protection system (1) according to any one of claims 1 and 2, wherein the maintenance device (5) comprises an inlet pipe (11) having an upstream end mounted on the tank (2) so as to draw the fluid, for example on a drain valve of the tank (2), and a downstream end connected to the filter (7).

4. A protection system (1) according to any one of claims 1 to 3, wherein the maintenance device (5) comprises an outlet pipe (12) having an upstream end connected to the filter (7) and a downstream end connected to the tank (2), preferably near a top of the tank (2), so as to inject the fluid filtered by the filter (7) into the tank (2).

5. A protection system (1) according to claim 4, further comprising a motor-pump unit (6), configured to draw fluid from the tank (2) and inject it into the spray lines (3), and a discharge line (19) having a first end connected to the motor-pump unit (6) and a second end connected to the outlet line (12) or to the tank (2).

6. Protection system (1) according to any one of claims 4 and 5, further comprising heating means (15) fitted onto the outlet pipe (12), for example a heating cord wound around the outlet pipe (12).

7. Protection system (1) according to claim 6, further comprising a thermal probe (16) configured to measure a temperature of the fluid in the tank (2).

8. A protection system (1) according to any one of claims 5 to 7, wherein the tank (2) further comprises a convection chamber (17) mounted near a top of the tank (2), the outlet pipe (12) being configured to open into the convection chamber (17).

9. A protection system (1) according to any one of claims 1 to 8, wherein the maintenance device (5) further comprises a pump (10) configured to draw fluid from the tank (2) and circulate it in the maintenance device through the filter (7).

10. Assembly comprising a sprinkler network fire protection system (4) according to any one of claims 1 to 9 and a tank (2) fluidly connected to the sprinkler lines, the filter of the maintenance device (5) being configured to filter fluid stored in the tank (2).

11. Method of maintaining a fire protection system (1) by means of a sprinkler network (4) according to claim 10 comprising the following steps: - aspiration (S1) of a volume of fluid from the tank (2); - filtration (S2) of the volume of fluid thus aspirated; and - injection (S5) of the filtered volume of fluid into the tank (2).

12. Maintenance method according to claim 11, further comprising a heating step (S4) of the filtered fluid before the injection step (S5).

13. Maintenance method according to claim 12, wherein the heating step (S4) is implemented when the fluid temperature is below a predefined threshold temperature.

14. Maintenance method according to any one of claims 11 to 13, wherein the protection system (1) further comprises a motor-pump unit (6) configured to draw fluid from the tank (2) and inject it into spray lines (3) of the protection system (1) and the maintenance method further comprises the filtration of a cooling fluid from the motor-pump unit (6).

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