sprayer foam

Abstract

The invention disclosed herein is entitled "Sprayer Bubble". A sprayer bubble (100) for a fire extinguishing system and a method for activating the sprayer bubble (100). The sprayer bubble includes: a sealed, fragile housing (110); a circuit device (120) within the housing (110), wherein the circuit device (120) includes an ultraviolet light source (125); and a photosensitive fluid (130) within the housing, the photosensitive fluid (130) undergoing a chemical reaction when exposed to ultraviolet light from the light source (125) during use.

Description

Technical Field

[0001] This invention relates to a sprayer bulb for fire extinguishing systems, particularly to a sprayer bulb containing a photosensitive fluid, and to a method for activating a fire extinguishing system using a sprayer bulb. Background Technology

[0002] Fire suppression systems typically include sprinkler units arranged to discharge or disperse fluid for fire suppression or prevention. Sprinkler units generally include sprinkler bubbles arranged to rupture at a predetermined temperature indicating a fire (or fire risk), thereby discharging extinguishing fluid from the sprinkler. Thus, sprinkler bubbles operate as a type of mechanical fuse, releasing extinguishing fluid from the associated source when they rupture. For proper functioning, the bubbles in the sprinkler unit must reliably rupture under pre-arranged conditions if a fire occurs. Therefore, the bubble is a critical component of the sprinkler unit.

[0003] Although sprinkler bubbles are designed to burst upon exposure to a predetermined temperature indicating a fire, modern fire suppression systems are often also capable of command-activated sprinkler bubbles (i.e., causing them to burst). This allows sprinkler bubbles to be preemptively activated, for example, in areas where a fire has already been detected by other means (e.g., by user observation). Command-activated sprinkler bubbles can prevent the spread of fire, or extinguish the fire more quickly and / or prevent the fire from reaching temperatures that would otherwise cause the sprinkler bubbles to burst.

[0004] Therefore, fire suppression systems can include heating elements in the form of wire filaments embedded in the sprayer bulbs. The system can then heat and rupture the sprayer bulbs on command. Thus, the system can release extinguishing fluid on command by activating the sprayer bulbs (i.e., rupturing them). However, such activation can require extremely high power, for example, if heating a large number of bulbs simultaneously. Given their critical safety, improvements in sprayer bulb activation are desirable. Summary of the Invention

[0005] According to a first aspect of the invention, a sprayer bubble for a fire extinguishing system is provided, the sprayer bubble comprising: a sealed, fragile housing; an electrical device within the housing, wherein the electrical device includes an ultraviolet light source; and a photosensitive fluid within the housing, the photosensitive fluid undergoing a chemical reaction when exposed to ultraviolet light from the light source during use.

[0006] Therefore, the sprayer bulb can be configured such that activation of the ultraviolet light source causes a chemical reaction in the photosensitive fluid. This chemical reaction can increase the pressure within the housing and may thus facilitate or cause the housing to rupture (e.g., to activate the sprayer unit associated with the sprayer bulb). The housing and photosensitive fluid can be configured such that the chemical reaction causes the sealed, fragile housing to rupture. Thus, during use, activation of the ultraviolet light source inside the housing can cause the sealed, fragile housing to rupture, for example, to release the extinguishing fluid from the sprayer unit.

[0007] The sprayer bubble is suitable for use in conventional sprayer units and / or fire suppression systems or the like. The sprayer can be operated as a conventional sprayer bubble, as well as by exposure to ultraviolet light. The sprayer bubble can be arranged such that the housing cracks, bursts, fragments, or otherwise ruptures under predetermined conditions (e.g., predetermined conditions indicating a fire event, such as a predetermined temperature), allowing the sprayer bubble to activate the sprayer unit and / or fire suppression system when the predetermined conditions are met. Therefore, the sprayer bubble can be operated even without activating the ultraviolet light source and the subsequent chemical reaction of the photosensitive fluid. Thus, the sprayer bubble can act as a failsafe, for example, in the event of a failure of the electrical system and / or the ultraviolet light source.

[0008] Unless the sprayer bubble ruptures, it is adapted to prevent the release of extinguishing agents or the like from the sprayer assembly. For example, the sprayer bubble can be configured to rupture, break apart, or burst when its temperature reaches a predetermined threshold. The sprayer bubble can be arranged such that, when undamaged, it can support predetermined mechanical loads, such as those used to secure seals or plugs of the sprayer assembly to prevent the release of extinguishing agents.

[0009] The photosensitive fluid can be any photoactivated substance. The photosensitive fluid can be any suitable liquid and / or gas, but in one embodiment, it is a liquid (at least initially, for example, before undergoing a chemical reaction). The photosensitive fluid can be sealed within a housing. The housing can be hermetically sealed such that no fluid can enter or leave the housing unless the housing ruptures. The housing can be configured to rupture when the internal pressure reaches a predetermined threshold. Since fluid pressure and temperature are related, the housing can also be configured to rupture when the photosensitive fluid reaches a predetermined temperature. The housing and photosensitive fluid can be arranged such that the housing will rupture under predetermined conditions, and the sprayer bubble will no longer be able to support, for example, the mechanical loads used to prevent the release of extinguishing agent from the sprayer assembly. The housing can be formed of any suitable material and can include or be formed of glass, plastic, crystal, ceramic, quartzoid, or the like. The housing can be formed entirely of glass, plastic, crystal, ceramic, quartzoid, or the like.

[0010] Ultraviolet (UV) light sources can be configured to emit radiation within a predetermined bandwidth of the UV spectrum. UV light sources can emit radiation with wavelengths between approximately 10 nm and approximately 400 nm. Wavelengths can be between approximately 250 nm and approximately 350 nm. Wavelengths can be between approximately 290 nm and 330 nm. Wavelengths can be between approximately 300 nm and 320 nm. Wavelengths can be between approximately 300 nm and 310 nm.

[0011] The photosensitive fluid can be selected and / or configured such that it exhibits significant absorption at wavelengths of light emitted by the ultraviolet light source. The ultraviolet light source can be selected and / or configured such that it emits light at wavelengths to which the photosensitive fluid exhibits significant absorption. Therefore, the ultraviolet light source can be selected based on the photosensitive fluid and / or the photosensitive fluid can be selected based on the ultraviolet light source.

[0012] A chemical reaction can be any suitable type of reaction, and can be any reaction that increases the pressure inside the shell or causes the shell to rupture and / or burst. A chemical reaction can be, for example, chemical corrosion and / or decomposition when ultraviolet radiation is absorbed from a light source. A chemical reaction can be photodissociation, photodecomposition, or photolysis. That is, a photoreaction can be the decomposition or separation of molecules under the influence of light.

[0013] The circuitry may be placed within the photosensitive fluid inside the housing and may be freely positioned within the fluid. The circuitry may not be attached to the housing or otherwise mechanically coupled to it. The circuitry may not be tangibly connected, for example, to wires leading to the outside of the housing. The sprayer bubble may not include any electrical components other than the circuitry. The circuitry may include multiple electronic components. The circuitry may include a printed circuit board or the like. The circuitry may not interfere with or otherwise affect the function of the sprayer bubble in bursting under predetermined conditions. The circuitry may not affect the mechanical properties of the housing. The circuitry may be entirely within the housing and may be entirely integrated with the chambers or openings within the housing. The circuitry may be movable within the housing because it may not be attached to or otherwise coupled to the housing.

[0014] The circuitry may include a wireless module for receiving power. Therefore, the circuitry can wirelessly receive power from a source outside the sprayer bubble. The circuitry can also wirelessly receive power only from a device outside the sprayer bubble. Therefore, the sprayer bubble can be completely sealed, and no connections, wiring, leads, or the like are required to enter or be embedded in the housing. The wireless module can be configured to receive signals, and the circuitry can be controlled via signals received through the wireless module.

[0015] The circuit device can be a passive circuit device, and can be passive in the sense that it cannot operate independently. It may consist only of passive electronic components. The passive circuit device itself may not be able to control the current flow within it. The passive circuit device can be configured to operate only in response to external signals and controls, such as those from the sprinkler device or other devices outside the sprinkler bulb (such as the sprinkler device controller or the fire suppression system controller).

[0016] The wireless module may include inductors and capacitors. The wireless module may be provided solely through capacitors and inductors. Inductors and capacitors may be arranged as resonant circuits, LC circuits, tank circuits, tuning circuits, or the like. Therefore, the circuitry can be arranged to be powered via the wireless module without any tangible, solid connection to anything outside the sprayer bubble.

[0017] The circuitry may include a power storage device (e.g., a battery, battery cell, or the like) for storing power received via the wireless module. Therefore, the circuitry may be charged via the wireless module. The circuitry may be wirelessly powered, for example, from a fire suppression system or a fire suppression system's sprinkler unit.

[0018] The circuitry may include a heating element operable to heat a photosensitive fluid. The circuitry may include a heating element for heating the photosensitive fluid within the housing of a sprayer bubble. The heating element may be operable to heat the photosensitive fluid within the housing of the sprayer bubble, thereby increasing the pressure within the housing. The heating element may be operable to heat the photosensitive fluid, thereby increasing the pressure within the housing of the sprayer bubble and causing the housing to rupture.

[0019] The circuitry can be arranged such that the ultraviolet light source and / or heating element are activated only when predetermined conditions are met (e.g., only when the signal received by the wireless module has an amplitude greater than a predetermined threshold). Therefore, the sprayer bubble can be arranged such that the ultraviolet light source and / or heating element can be activated only when needed by receiving, for example, a signal with a sufficiently large amplitude at the wireless module. The circuitry can be configured such that if the signal received by the wireless module is not a predetermined signal (e.g., has an amplitude less than a predetermined threshold), the ultraviolet light source and / or heating element are not activated.

[0020] The circuitry may include a control unit configured to control the circuitry and its components, for example, to activate a UV light source under predetermined conditions. The circuitry may be operable to activate either the UV light source or a heating element as needed. Compared to conventional sprayer bulbs, the sprayer bulbs are also more reliable because they can still be activated even if the heating element fails.

[0021] The photosensitive fluid can be 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone. The photosensitive fluid can be a fluorinated ketone. The photosensitive fluid can be CF3CF2C(=O)CF(CF3)2. The photosensitive fluid can be C2F5C(O)CF(CF3)2. The photosensitive fluid can be 3M. TM Novec TM 1230 Firefighting Fluid. The photosensitive fluid can be any suitable polymer. The photosensitive fluid can be any suitable organic or inorganic substance. The photosensitive fluid can be any substance that undergoes a chemical reaction in response to the absorption of ultraviolet light. That is, the photosensitive fluid can be any photoactivated substance.

[0022] Photosensitive fluids can themselves be fire extinguishing agents. Photosensitive fluids can be non-conductive, and are therefore suitable for immersing electronic devices (and particularly circuit devices) in them. Thus, even when the electrical connections of a circuit device are in direct contact with the photosensitive fluid and submerged in it, immersion in the photosensitive fluid may not cause the circuit device to malfunction (e.g., due to a short circuit).

[0023] The housing can be opaque to ultraviolet radiation, and thus essentially prevents ultraviolet radiation from being transmitted through it. Therefore, the sprayer bubble can be used in environments containing ultraviolet radiation, because ultraviolet radiation will not be able to penetrate the housing, and therefore will not cause the photosensitive fluid to react, degrade, or corrode.

[0024] The sprayer bulb can be arranged to rupture using less than 1 watt of power. It can also be arranged to rupture using less than 0.5 watts, and even less than 0.1 watts. In other words, the ultraviolet light source can use less than 1 watt, 0.9 watts, 0.8 watts, 0.7 watts, 0.6 watts, 0.5 watts, 0.4 watts, 0.3 watts, 0.2 watts, or 0.1 watts to induce a sufficient chemical reaction in the photosensitive fluid to cause the housing to rupture. Therefore, compared to conventional systems, the sprayer bulb can use significantly less power for activation because relatively high power is not required to heat the wire or similar material.

[0025] Sprayer bubbles can be operated to burst upon exposure to ultraviolet light without special heating, such as by a heating element or a nearby fire. That is, the sprayer bubble can be activated without heating by a dedicated heating element or the like. Therefore, the sprayer bubble can be activated at a lower temperature compared to conventional sprayer bubbles. Simultaneously, the sprayer bubble can still be activated if and when heated to a sufficient temperature. Sprayer bubbles can be operated to burst at temperatures below 260°C, below 240°C, below 220°C, below 200°C, below 180°C, below 160°C, below 140°C, below 120°C, below 100°C, below 80°C, below 60°C, and / or below 40°C. Typical sprayer bubbles are often configured to activate at industry-standard temperature ratings and can be color-coded to indicate their temperature ratings. For example, the following table shows the industrial standard temperature rating and the corresponding sprayer bubble color.

[0026]

[0027] The sprayer bubble can be configured according to the industry standards shown above, and therefore can have an industry standard temperature rating (i.e., a predetermined temperature at which the housing ruptures beneath it). The sprayer bubble also changes color according to the industry standards shown above. The sprayer bubble can also be configured to rupture at a temperature below its temperature rating by using an ultraviolet light source for activation, rather than by heating. In particular, the sprayer bubble can be activated at a temperature below 57 degrees Celsius using an ultraviolet light source. Therefore, the sprayer bubble can be activated at temperatures lower than those required to activate conventional sprayer bubbles. Thus, the sprayer bubble can be used in temperature-sensitive environments or environments where high temperatures pose a risk (e.g., computer server rooms, environments with flammable or explosive chemicals, etc.).

[0028] A sealed, fragile housing, an ultraviolet light source, and / or a photosensitive fluid can be configured such that the housing will rupture when the pressure inside reaches a predetermined threshold. Therefore, the size, thickness, characteristics, and / or mechanical properties of the housing can be selected based on the ultraviolet light source and / or based on the photosensitive fluid and its chemical properties. Similarly, the ultraviolet light source and / or photosensitive fluid can be selected based on the properties of the housing to ensure that the housing will rupture under predetermined conditions.

[0029] Sprinkler bulbs may have a diameter of less than about 12 mm, less than about 8 mm, or less than about 4 mm. Sprinkler bulbs may be of conventional sizes and may be any size suitable for a fire suppression system. However, sprinkler bulbs may be relatively small. Sprinkler bulbs may have sizes according to, for example, the Day-Impex Range of Standard Glass Bulbs, and may be of type 826, 817, 933, 937, 984, 941, 942, or 989.

[0030] According to a second aspect of the invention, a fire extinguishing system is provided, the fire extinguishing system comprising a sprayer device and a sprayer bubble as described herein with reference to a first aspect of the invention.

[0031] Sprinkler bulbs can be arranged to prevent the extinguishing fluid from spreading from the sprinkler assembly, and the sprinkler assembly can be arranged such that, in the event of a mechanical failure of the sprinkler bulb, the extinguishing fluid is released for fire suppression. In this respect, sprinkler bulbs and sprinkler assemblies can be arranged in a conventional manner and can be installed, for example, in buildings, aircraft, vehicles, ships, or other suitable structures in which fire suppression capabilities may be required. Fire suppression systems can be installed in buildings, aircraft, vehicles, ships, or the like.

[0032] A sprayer bubble can be arranged in a sprayer assembly such that when it is undamaged, it prevents the extinguishing fluid from being released from the sprayer assembly, and when it ruptures, it allows the extinguishing fluid to be released from the sprayer assembly.

[0033] The system may include multiple sprayer devices, each sprayer device having associated sprayer bubbles as described herein with reference to a first aspect of the invention. The system may be configured to activate multiple sprayer bubbles simultaneously. The system may also be configured to activate all sprayer bubbles simultaneously.

[0034] The sprinkler unit can be arranged to wirelessly power the circuitry of the sprinkler bulb. The sprinkler unit can be arranged to power the circuitry via a wireless module. Therefore, the ultraviolet light source can be wirelessly powered by the sprinkler unit. The fire suppression system may not include any tangible, solid wires (e.g., heating wires or electrical connections for power or signals) connected to or embedded in the sprinkler bulb.

[0035] The system can be configured to activate the sprayer bubbles using less than 1 watt of power. The system can also be configured to activate the sprayer bubbles using less than 0.9 watts, 0.8 watts, 0.7 watts, 0.6 watts, 0.5 watts, 0.4 watts, 0.3 watts, 0.2 watts, or less than 0.1 watts.

[0036] The system may include the features described herein with reference to the first aspect of the invention. In the case where the system includes multiple sprayer bubbles, each sprayer bubble may be as described herein with reference to the first aspect of the invention.

[0037] According to a third aspect of the invention, a method for activating a fire extinguishing system is provided, the fire extinguishing system comprising a sprayer bubble, the sprayer bubble comprising a sealed, brittle housing containing a photosensitive fluid, the method comprising: irradiating the photosensitive fluid with ultraviolet light to cause it to undergo a chemical reaction and thereby rupture the housing.

[0038] The method may include activating the sprayer bubble using less than 1 watt of power. The method may also include activating the sprayer bubble using less than 0.9 watts, 0.8 watts, 0.7 watts, 0.6 watts, 0.5 watts, 0.4 watts, 0.3 watts, 0.2 watts, or less than 0.1 watts.

[0039] The method may include activating the sprayer bubbles at temperatures below 260 degrees Celsius, below 240 degrees Celsius, below 220 degrees Celsius, below 200 degrees Celsius, below 180 degrees Celsius, below 160 degrees Celsius, below 140 degrees Celsius, below 120 degrees Celsius, below 100 degrees Celsius, below 80 degrees Celsius, below 60 degrees Celsius, and below 40 degrees Celsius. The method may also include activating the sprayer bubbles at temperatures below 57 degrees Celsius.

[0040] The method may include using sprayer bubbles as described herein with reference to a first aspect of the invention, and / or using a fire extinguishing system as described herein with reference to a second aspect of the invention.

[0041] According to another aspect of the invention, a sprayer bubble containing a photoactivated substance (e.g., a photosensitive fluid) is provided, said substance being configured to undergo a chemical reaction upon exposure to ultraviolet light during use to cause the sprayer bubble to rupture. According to another aspect of the invention, a method for rupturing a sprayer bubble containing a photoactivated substance (e.g., a photosensitive fluid) is provided, comprising irradiating the photoactivated substance with ultraviolet light to cause the sprayer bubble to rupture. Attached Figure Description

[0042] The following describes certain embodiments of the invention by way of example only and with reference to the figures, in which:

[0043] Figure 1 A sprayer bubble is shown, comprising a housing and an internal circuitry device, wherein the circuitry device includes an ultraviolet light source; and

[0044] Figure 2 Show Figure 1 A schematic diagram of the circuit device. Detailed Implementation

[0045] Figure 1 A sprayer bubble 100 is shown, comprising a sealed, fragile housing 110 and a circuit device 120 disposed within the housing 110. Thus, the circuit device 120 is sealed inside the housing 110. The housing 110 also contains a photosensitive fluid 130 (in a liquid phase) and a bubble 140.

[0046] In use, Foam 100 is located in the sprayer device 200 of the fire extinguishing system (not shown). Figure 1 (As shown in the middle part) and is arranged to secure the sealing device 210, plug, or similar in place to prevent the extinguishing fluid from leaving the sprayer assembly 200. The sealing device 210 of the sprayer assembly 200 is in Figure 1 As shown in the diagram, the sprayer bubble 100 is arranged such that it prevents the extinguishing fluid from dispersing from the sprayer assembly 200 unless it ruptures. If a fire occurs near the sprayer assembly, the liquid 130 in the housing 110 will be heated, and thus the pressure within the housing 110 will increase. Once the liquid 130 reaches a predetermined temperature (e.g., indicating proximity to a fire), the resulting pressure from the heated liquid 130 will cause the fragile housing 110 to rupture and the sealing device 210 of the sprayer assembly 200 will no longer be secured in place. The extinguishing fluid will then be released from the sprayer assembly 200. The housing 110, liquid 130, and bubble 140 can be configured such that the housing 110 will rupture under predetermined conditions (e.g., when the liquid 130 reaches a predetermined temperature, and therefore when the housing 110 is thus exposed to a predetermined pressure). The housing 110 can be formed of any suitable material, such as glass, plastic, crystal, ceramic, quartz-like material, or the like. Quartz-like materials may be preferred due to their popularity in the art.

[0047] The circuit device 120 is housed within the housing 110. For proper operation of the sprayer bubble 100, it is necessary to seal the housing 110 to prevent any and all leaks (e.g., to prevent any fluid from entering the housing 110 and / or to prevent any fluid from escaping the housing 110), which would otherwise be vulnerable to rupture in the event of an emergency as described above. Therefore, the circuit device 120 is sealed within the housing 110 and cannot simply be provided with external connections (e.g., for power supply and / or communication). The sprayer bubble 100 does not include any wires or solid electrical connections connected to the circuit device 120. Thus, the housing 110 does not have any wires (e.g., heating wires or electrical connections) embedded within it.

[0048] Therefore, the circuit device 120 is provided with a wireless unit 160, such as... Figure 2The LC circuit shown is an inductor 164 and a capacitor 162, used to generate and / or receive signals at a predetermined frequency (e.g., the resonant frequency of the LC circuit) and / or amplitude. Therefore, the circuit device 120 can receive signals from outside the housing 110 of the bubble 100 via a broadband connection. The circuit device 120 also includes a power storage device 190, which can receive and store power for its operation as needed via the wireless unit 160, although it is sealed within the bubble housing 110. The circuit device 120 can also transmit and receive communication signals via the wireless unit 160, thereby being configured to communicate with other components of the fire suppression system or sprinkler device 200 outside the housing 110.

[0049] The circuit device 120 includes a control unit 180 configured to control the operation of the circuit device 120 and its components. The control unit 180 can autonomously control the operation of the circuit device 120, and / or can control the operation of the circuit device 120 under the control of a remote system controller located outside the housing 110, configured to control, for example, multiple sprayer devices and sprayer bubbles. The control unit 180 can communicate with components outside the bubble 100 via a wireless unit 160, and / or can be controlled by the remote system controller.

[0050] The circuit device 120 includes a printed circuit board (PCB) and multiple electronic components. It includes a capacitor 300, a capacitor 162 forming part of the wireless unit 160, and a capacitor configured as a pressure sensor 150. The circuit device also includes a temperature sensor 172 for sensing the temperature of the fluid 130 in the housing 110.

[0051] The circuit device 120 also includes an ultraviolet (UV) light source 125, such as a UV bulb, UV LED, or the like. The UV light source 125 can be activated to emit UV radiation. Since the circuit device 120 is in, surrounded by, and exposed to the photosensitive fluid 130, when the UV light source 125 is activated, the fluid 130 will be exposed to UV radiation from the UV light source 125. Therefore, the UV light source 125 is arranged to irradiate the photosensitive fluid 130 when activated.

[0052] The photosensitive fluid 130 has a chemical structure that makes it sensitive to ultraviolet radiation. In use, ultraviolet radiation from the UV light source 125 causes the fluid 130 to undergo a chemical reaction, which subsequently increases the pressure in the housing 110. The fluid 130 and the housing 110 can be selected and configured such that when the UV light source 125 is activated, the pressure in the housing 110 will exceed a predetermined threshold required to rupture the housing 110. Therefore, the sprayer bubble 100 can be activated by activating the UV light source 125 (i.e., the housing 110 ruptures to release the extinguishing fluid through the sprayer device 200). Thus, the sprayer device 200 can be activated, and the extinguishing fluid can be dispensed.

[0053] Although any suitable photoactivator can be used, the photofluid 130 is preferably 3M. TM Novec TM The fire-fighting fluid 1230 is 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone. That is, the photosensitive fluid is CF3CF2C(=O)CF(CF3)2 or C2F5C(O)CF(CF3)2. When exposed to UV radiation, fluid 130 undergoes photodecomposition and essentially corrodes. It has a suitable UV cross-section with a maximum absorption wavelength of 306 nanometers (nm) and exhibits significant absorption above 300 nm. Therefore, the UV light source 125 is configured to emit UV radiation above 300 nm and is configured to emit radiation in the range of 300 nm to 320 nm or 300 nm to 310 nm.

[0054] The photosensitive fluid 130 is itself a fire extinguishing fluid and is non-conductive, and is safe for immersion in electronic equipment (sometimes referred to as "dry water"). Therefore, the circuit device 120 can be immersed in the fluid 130 without affecting its operability.

[0055] In use, the sprayer bulb 100 can be activated (e.g., via a remote system controller of the fire extinguishing system). The wireless unit 160 can receive the activation signal, and the control unit 180 can activate the ultraviolet light source 125 in response to the activation signal. The ultraviolet light source 125 can then irradiate the photosensitive fluid 130, causing it to undergo a chemical reaction, thereby increasing the pressure within the housing 110 until the housing 110 ruptures. As a result of the rupture of the housing 110, the extinguishing fluid can be released from the sprayer assembly 200. The fire extinguishing system can simultaneously command the activation of multiple sprayer bulbs 100. The sprayer bulbs 100 can be activated at temperatures lower than those required to activate the sprayer bulbs by heating.

Claims

1. A sprinkler bulb for a fire suppression system, comprising: a sealed frangible housing (110); a circuit arrangement (120) within the sealed frangible housing (110), wherein the circuit arrangement (120) comprises an ultraviolet light source (125); and a photosensitive fluid (130) within the sealed frangible housing, the photosensitive fluid (130) undergoing a chemical reaction in use when exposed to ultraviolet light from the ultraviolet light source (125) such that the sealed frangible housing ruptures.

2. The sparger blister of claim 1 wherein, the circuit arrangement (120) comprises a wireless module (160) for receiving power.

3. The sparger blister of claim 1 wherein, the circuit arrangement (120) comprises a heating element operable to heat the photosensitive fluid (130).

4. The sparger blister of claim 1 wherein, the photosensitive fluid (130) is 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3- pentanone.

5. The sparger blister of any of claims 1-4, wherein, the sealed frangible housing (110) is opaque to ultraviolet radiation.

6. The sparger blister of any one of claims 1-4 wherein, the sprinkler bulb is arranged to rupture by using less than 1 watt of power.

7. The sparger blister of any one of claims 1-4 wherein, the sprinkler bulb is operable to rupture at a temperature of less than 57 degrees Celsius.

8. The sparger blister of any one of claims 1-4 wherein, the sealed frangible housing (110), the ultraviolet light source (125) and the photosensitive fluid (130) are configured such that the sealed frangible housing (110) will rupture when a pressure within the sealed frangible housing (110) reaches a predetermined threshold.

9. A fire suppression system comprising a sprinkler device (200) and a sprinkler bulb (100) as claimed in any of claims 1-8.

10. The fire extinguishing system of claim 9, wherein, the sprinkler device (200) is arranged to wirelessly provide power to the circuit arrangement (120).

11. A method of activating a fire suppression system, the fire suppression system comprising a sprinkler bulb (100), the sprinkler bulb (100) comprising a sealed frangible housing (110) containing a photosensitive fluid (130), the method comprising: irradiating the photosensitive fluid (130) with ultraviolet light to cause it to undergo a chemical reaction and thereby cause the sealed frangible housing (110) to rupture, wherein the ultraviolet light is from an ultraviolet light source comprised in a circuit arrangement within the sealed frangible housing.

12. The method of claim 11, comprising activating the sprinkler bulb (100) using less than 1 watt of power.

13. The method of claim 11, comprising activating the sprinkler bulb (100) at a temperature of less than 57 degrees Celsius.

14. The method of claim 11, 12 or 13, comprising using a sprinkler bulb (100) as claimed in any of claims 1 to 8 and / or a fire suppression system as claimed in claim 9 or 10.

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