A frangible floating cartridge for fire extinguishers

Abstract

The present invention relates to a cartridge designed for use in a pressurized water-type fire extinguisher activated by perforating a liquid carbon dioxide capsule diaphragm to release pressure through a tube and nozzle. The cartridge features a tubular body made of adhesive with open ends sealed by aluminum foil caps lined with inner adhesive layers, thermally welded to the cartridge body edge. Positioned within the lower portion of the body is an additive of the floating-film-forming agent type, with free space above ensuring positive buoyancy and vertical immersion stability, As pressure increases to approximately 0.4 MPa, the bottom cap ruptures, allowing water to enter and disperse the additive. Subsequently, the upper cap ruptures to complete dispersion from the top, ensuring optimal mixing and performance of the fire extinguisher throughout its operational lifespan during fire extinguishment.

Description

Field of the invention

[0001] The present invention relates to the field of water fire extinguishers, specifically focusing on cartridges designed to enhance the blending of additives with water at times that precede the use of the fire extinguisher. More particularly, the invention aims to improve the extinguishing effectiveness of water by facilitating optimal mixing of additives, thereby enhancing its firefighting capabilities.Background of the invention

[0002] The modern portable fire extinguisher was invented to eject water, water mixed with other substances, or, in general, a chemical solution under compressed gas (CO2, N2 or air) pressure. Some extinguishers are pressurized with gas (CO2, N2 or air), releasing the agent as a steady stream through a hose and nozzle, pushed out by the stored pressure above it. Some others comprise a gas cartridge (e.g. CO2, N2) instead to provide a pressure source. A squeeze-grip handle operates a spring-loaded device causing a pointed spike to pierce the disc that held back the pressure, releasing the gas into the pressure vessel.

[0003] In fire extinguisher technology, the incorporation of frangible cartridges is a well-known practice. These cartridges are designed to break upon activation of the extinguisher, typically in response to pressure from a connected propellant gas source. This rupture releases additives into the water already contained within the extinguisher, ensuring the extinguishing agent is mixed for immediate deployment when required.

[0004] However, due to the rapid and short time frame from activating the extinguisher, breaking the cartridge, releasing the additives into the water, until ejecting the mixture at the intended location, the concentration of the additives in the mixture varies from the beginning to the end of the extinguisher's use. Typically, cartridges in extinguishers break from a button submerged in water, allowing additives to disperse downward. Without mechanisms to ensure thorough mixing of the additives with water, the extinguishing agent may not achieve optimal and consistent effectiveness throughout its use in extinguishing a fire.

[0005] The present invention proposes a new and improved frangible cartridge for a pressurized water fire extinguisher that ameliorates the mixing of additives with water when released into the fire extinguisher by releasing the additives into the water from more than one end of the cartridge. Consequently, the present invention improves the homogeneity of the additive mixture. This advancement ensures consistent and optimal performance throughout the operational lifespan of the extinguisher, thereby enhancing its overall effectiveness in fire suppression.Summary of the invention

[0006] The present invention is related to a frangible cartridge for a fire extinguisher pressurized by releasing a compressed propellant gas inside said fire extinguisher prior to use, said fire extinguisher containing water and said cartridge containing additives capable of enhancing the extinguishing properties of the water of the fire extinguisher comprising: A body configured to partially float on the water (9), inside the fire extinguisher; An upper open end and a bottom open end at two ends of the body; An upper cap for sealing the upper open end and a bottom cap for sealing the bottom open end, wherein the upper cap and the bottom cap are designed to rupture under a specific differential pressure lower than the maximum pressure to which the water is exposed following the release of the propellant gas.

[0007] Preferably, the upper open end is positioned above the water level inside the fire extinguisher.

[0008] Preferably, the bottom open end is submerged in the water within the fire extinguisher.

[0009] Preferably, the upper open end is positioned opposite to the bottom open end.

[0010] Preferably, the body is of sufficient length to prevent the said cartridge from overturning when the upper open end faces upward and the bottom open end faces downward inside the fire extinguisher.

[0011] Preferably, the cartridge is positioned vertically inside the fire extinguisher.

[0012] Preferably, the cartridge is positioned freely inside the fire extinguisher.

[0013] Preferably, the body is made of translucent polyethylene.

[0014] Preferably, the upper cap and the bottom cap comprise of a sheet of aluminum covered with a layer of adhesive on the side of the body.

[0015] Preferably, the upper cap and the bottom cap are thermally welded onto the body.

[0016] Preferably, the upper cap and the bottom cap are configured to rupture under a differential pressure of approximately between 0.3 and 0.4 MPa.

[0017] Preferably, the bottom cap is configured to rupture under a lower differential pressure compared to the upper cap.

[0018] Preferably, the fire extinguisher comprises at least one cartridge.

[0019] Preferably, the fire extinguisher comprises at least two cartridges comprising additives adapted to different types of fires.Brief description of the drawings

[0020] Figure. 1: An axial section through the upper part of an extinguisher having a cartridge according to the invention. Figure. 2: A cartridge according to the invention with a cross-section A-A and a cap. Detailed description of the invention

[0021] Frangible cartridges are known and used in fire extinguishers. Their principle is based on their breakage to facilitate the release of the holding solution, agents, or additives that are intended to mix with the solution already present within the fire extinguisher.

[0022] Moreover, frangible cartridges are connected to the source of propellant gases so that, upon activation of the fire extinguisher, the pressure from the propellant gas causes a complete or partial break of the cartridge. This rupture facilitates the release and mixing of chemical additives with the solution (primarily water) present in the main compartment of the fire extinguisher.

[0023] The additives and / or solutions employed in water-based fire extinguishers significantly enhance the fire-suppressing capabilities of water when integrated and blended. These additives are designed to create a barrier, such as foam, on the fire's surface, which inhibits oxygen, a critical fuel for fires, thereby extinguishing the flames and suppressing the fire.

[0024] By encapsulating these additives and / or solutions within a dedicated floating container or cartridge integrated into the water-based fire extinguisher, their longevity and protection from environmental influences are assured. This method effectively maintains their stability and effectiveness by isolating them from external factors when the fire extinguisher is idle.

[0025] The operational integrity of the fire extinguisher necessitates periodic verification, which typically leads to replacing the entire unused cartridge in case of expiration.

[0026] Additionally, precise metering and thorough mixing of the additives and / or solutions with water are crucial for enhancing the efficiency of fire extinguishers. Typically, the frangible cartridge containing these additives breaks near the lower end, causing the additives to mix predominantly with the water at the bottom of the fire extinguisher, near the outlet of the tube used to transport the mixture to the outside environment of the fire extinguisher. This uneven mixing results in an inhomogeneous mixture from the beginning to the end of the operation. Therefore, improving the uniformity of the solution (water + additives) is essential to ensure the optimal effectiveness of the fire extinguisher.

[0027] The present invention aims to address or at least mitigate the aforementioned challenges while preserving the benefits associated with fire extinguishers in general and floating, frangible cartridges in particular.

[0028] Figure 1 illustrates a conventional water fire extinguisher 1 equipped with a cartridge 2 containing an extinguishing agent liquid additive positioned freely inside. The fire extinguisher 1 includes a head 3 that seals its body and connects to a capsule 4 housing a liquid carbon dioxide charge. A dip tube 5 runs parallel to the axis of the body of the fire extinguisher 1, extending just beyond the total height of the body and continuing beyond the head 3 with an extension nozzle 6. The head 3 incorporates a percussion system featuring a striker 7 capable of puncturing a diaphragm with a spring and can be activated by depressing a lever 8.

[0029] The cartridge 2 is defined by an elongated, rigid tubular body 11 with two open ends 12 and 13 sealed by a sealing mechanism (e.g., a cap) designed to rupture under a specified differential pressure lower than the maximum pressure experienced by the water 9 upon propellant gas release. It can be freely positioned within the fire extinguisher 1, with one bottom open end 13 facing downwards and one upper open end 12 facing upwards. Ideally, the cartridge 2 is prevented from rotating inside the fire extinguisher 1; however, if it does rotate, it will always have at least one open end facing downwards and another facing upwards.

[0030] The invention proposes a dedicated frangible cartridge 2 for a pressurized water fire extinguisher 1 that is capable of releasing a compressed propellant gas at the times that precede the use of the fire extinguisher 1. The said frangible cartridge 2 may include additives 10 that enhance the firefighting capabilities of the water 9. It is characterized by an elongated, rigid tubular body 11 with two open ends 12 and 13, each sealed by a cap 12' and 13', respectively, intended to rupture either simultaneously or sequentially under a predetermined differential pressure lower than the maximum pressure experienced by the water 9 after the release of the propellant gas. The volume of additives 10 within the cartridge 2 does not exceed 90 percent, preferably 80 percent of its internal body volume.

[0031] Since the caps 12' and 13' may break due to the effect of excess pressure external to the cartridge 2, the cartridge 2 does not necessitate any connection or manipulation by another component of the fire extinguisher 1. Moreover, the cartridge 2 remains in its original state until the fire extinguisher 1 is activated for firefighting. During routine inspections of the fire extinguisher 1, it is sufficient to take out the cartridge 2, and replacement is only considered if its integrity is doubtful.

[0032] The cartridge 2 is made, preferably, of a translucent polyethylene tube body 11 sealed at the upper open end 12 with an upper cap 12' and at the bottom open end 13 with a bottom end 13'. These caps 12' and 13' are made preferably of aluminum foil lined with adhesive on the interior face facing the inside of the body 11, facilitating thermal welding to the edge. This design may ensure that the additives 10 do not react with the adhesive, thereby maximizing the cartridge's longevity. Furthermore, the translucent nature of the tube allows for visual inspection and control of the additive level within the cartridge 2.

[0033] In another embodiment, each open end 12, 13 of the cartridge 2 may be closed or sealed with a film made of aluminum foil lined with adhesive on the inner surface facing the inside of the body 11 of the cartridge 2. The film may be affixed by thermal welding or adhesive bonding to the edge of the cartridge 2.

[0034] The upper cap 12' and the bottom cap 13' are designed to rupture at a differential pressure ranging approximately between 0.1 and 0.6 MPa, preferably between 0.2 and 0.5 MPa, and more preferably between 0.3 and 0.4 MPa. This range of pressure is chosen to ensure effective dispersion of the contained additives 10 immediately following rupture, which occurs just after the activation of the fire extinguisher 1 but before the use of the fire extinguisher 1. This range of pressure may be sufficiently low relative to the maximum pressure within the fire extinguisher 1 to ensure effective dispersal, yet high enough to prevent premature accidental rupture, thereby ensuring proper flushing of the cartridge 2 under normal operating conditions.

[0035] To activate the fire extinguisher 1, the lever 8 may be folded down after removing its safety mechanism, causing it to depress the striker 7 into the diaphragm that seals the capsule 4. As the lever 8 reaches the end of its depression, the part of the striker 7, on which the lever 8 penetrates, disengages from the diaphragm due to the spring force, allowing the carbon dioxide to expand into the space above the water level 9 under the head 3. The lever 8 may remain locked in the folded-down position, indicating that the fire extinguisher 1 has been discharged.

[0036] Preferably, the bottom cap 13' ruptures in close proximity to the tube 5 that transfers the mixture from within the fire extinguisher 1 to the external environment before the upper cap 12' of the cartridge 2 ruptures. This sequence may ensure that the additives 10 are first released into the water 9 at the bottom and subsequently at the top. Once the bottom cap 13' breaks and releases the additives 10, the tube 5 can promptly begin delivering the additive-water mixture.

[0037] Typically, the additives 10 are introduced into the water 9 to enhance its fire-extinguishing effectiveness, such as surfactants or substances capable of forming thin surface layers at the surfaces to be extinguished. The selection of additives 10 may be tailored to the specific class of fire, such as Class A, B, C, D, E, or F fires. These additives 10 may not have sufficient stability when in direct contact with water. Therefore, a common approach involves encapsulating the additives 10 within a cartridge 2 designed to rupture or break under a certain internal pressure. When the capsule 4 releases the carbon dioxide propellant, it impacts the cartridge 2, causing it to rupture and release its contents into the water 9.

[0038] The cartridge 2 may offer benefits for end-of life collection, processing and recycling, allowing for the reuse of one or more components after the replacement of an expired cartridge 2. This approach may eliminate the need to replace the entire fire extinguisher 1 or its solution when maintenance or expiration occurs.

[0039] In a preferred embodiment, the cartridge 2 comprises an upper open end 12 sealed by a cap 12' and a bottom open end 13 sealed with a bottom cap 13'. The cap 13' is designed to break first, allowing the additives 10 to disperse and mix with the water 9 located at the bottom, ensuring a well-mixed solution near dip tube 5 for effective fire extinguishing. Subsequently, the upper cap 12' breaks, releasing the remaining additives 10 to blend with the water 9 at the top. This ensures thorough mixing throughout the fire extinguisher 1 (bottom and top), optimizing efficiency for extinguishing fires when the solution from the bottom reaches dip tube 5 and is dispensed into the environment. This design guarantees homogeneous distribution throughout use, maximizing the effectiveness of the fire extinguisher 1.

[0040] To ensure the sequential breakage of the bottom cap 13' at the bottom open end 13 before the upper cap 12' at the upper open end 12, several approaches can be employed. One method involves designing the bottom cap 13' with a thinner thickness compared to the upper cap 12'. Alternatively, the bottom cap 13' can be made from a material with lower resistance than the material of the upper cap 12', ensuring a sequential breakage. Adjusting the type of sealing used can also be considered to achieve differential resistance between the caps 12' and 13', serving the same purpose. Those skilled in the art may devise other solutions to achieve this objective. Crucially, the cartridge 2 comprises more than one open end capable of releasing the additives 10 into the water 9 to achieve optimal homogeneity. Preferably, the additives 10 are released from both the upper and bottom ends, ensuring thorough mixing near dip tube 5. When utilized, the resulting mixture at dip tube 5 is uniformly mixed with consistent proportions of additives throughout use, thereby optimizing extinguishing performance.

[0041] The thickness of the caps 12' and 13' is calibrated to rupture under an outer pressure ranging approximately from 0.1 to 0.6 MPa, preferably between 0.2 and 0.5 MPa, and more preferably between 0.3 and 0.4 MPa. The thickness of each cap 12' and 13' may be determined based on specific criteria: ensuring the bottom cap 13' breaks shortly after activation of fire extinguisher 1, and allowing an appropriate delay for the upper cap 12' to rupture relative to the pressure increase inside the fire extinguisher 1. Upon discharge of the propellant gas (e.g., carbon dioxide), the pressure within the fire extinguisher 1 rises gradually, reaching up to 1.5 MPa after percussion of the capsule 4, and stabilizing between 0.3 and 0.4 MPa within approximately 1 second.

[0042] The upper cap 12' and the bottom cap 13' may break at the junction with the end edge of the tubular body 11 of the cartridge 2. As some additives 10 may disperse into the water 9, the water 9 may enter the cartridge 2, reducing the empty volume 14. This reduction may aid in breaking the upper cap 12' and dispersing the remaining additives 10 from the top. This process ensures the upper cap 12' breaks after the bottom cap 13', minimizing pressure impact, especially considering the anticipated pressure increase when the bottom cap 13' breaks.

[0043] In an alternative embodiment, the upper and bottom caps 12' and 13' of the upper open end 12 and the bottom open end 13 may break simultaneously, enabling the additives 10 to release both from the top and bottom. This ensures efficient mixing with the water 9, promoting optimal homogeneity throughout the use of the fire extinguisher 1 from activation to fire extinguishment.

[0044] In an alternative embodiment, additional open ends may be incorporated on one or more sides of the cartridge 2, enabling the additives 10 to disperse not only from the top and / or bottom but also from the sides. These ends may break sequentially or simultaneously based on the geometry of the cartridge 2, properties of the additives 10, specific application requirements, or other considerations. This design enhances flexibility in dispersal dynamics, accommodating various operational needs effectively.

[0045] The length of the cartridge 2 in relation to the diameter of the body of the extinguisher 1 may prevent the cartridge 2 from turning over or floating horizontally on the surface of the water 9. Specifically, because the cartridge 2 is longer than the body diameter of the extinguisher 1, it eliminates any risk or potential for the cartridge 2 to invert. Additionally, the free space or volume 14 above the additives 10 in the cartridge 2 may ensure its positive buoyancy and vertical immersion stability.

[0046] In an alternative embodiment where the upper open end 12 and the bottom open end 13 may break simultaneously, there are no restrictions on the length of the cartridge 2 relative to the diameter of the body of the fire extinguisher 1, allowing the cartridge 2 to potentially turn over. In practical terms, whether one end faces upwards or downwards does not affect the functionality of the cartridge 2 because the additives 10 will disperse in both directions (top and bottom) simultaneously upon the breakage of the caps 12' and 13'. This flexibility in design reduces dimensional constraints and eliminates the risk of incorrect orientation when inserting the cartridge 2 into the fire extinguisher 1. Moreover, the cartridge 2 is not confined to an elongated tubular shape and may adopt other configurations as needed.

[0047] The cartridge 2 is inserted into the fire extinguisher 1 by placing and orienting the bottom cap 13' downwards and the upper cap 12' upwards within the body of the fire extinguisher 1, partially filled with water, before adjusting the head 3. To facilitate correct placement, the upper cap 12' and / or the bottom cap 13' may feature different colors, shapes, signs, or symbols to distinguish between orientations. This may ensure that the cartridge 2 is inserted in the correct orientation into the fire extinguisher 1.

[0048] During routine inspections of the fire extinguisher 1, the cartridge 2 may require replacement if, for example, the volume of the additives 10 is inadequate or if the additives 10 appear abnormal. The present invention may simplify, speed up, and secure the process of replacing or inspecting the cartridge 2 requiring no specific knowledge or experience.

[0049] One or more rings, hooks, knobs, or similar mechanisms may be incorporated onto one or more caps or any surface of the cartridge 2 to facilitate its placement or removal from the fire extinguisher 1 without requiring an operation to insert a hand or finger. This design allows a hooked tool to be used to grasp the cartridge 2 inside the body of the extinguisher fire 1, eliminating any risk of operator contact with the solution or mixture inside before or after use.

[0050] The additives 10 and / or solutions are introduced into the water 9 to enhance its extinguishing effectiveness, forming thin surface layers when applied to a fire surface. However, these additives 10 and / or solutions may lack stability when directly exposed to water. Therefore, encapsulating them within a cartridge capable of rupturing or breaking due to an internal pressure increase for mixing and propulsion proves to be an ideal solution.

[0051] Thanks to the dispersion of the additives 10 throughout the solution such as the water 9 within the fire extinguisher 1, from both top and bottom, the effectiveness of the mixture may be enhanced through improved homogeneity.

[0052] Figure 2 illustrates the cartridge 2 according to one embodiment of the invention with a cross-section A-A and a cap. The inner and outer diameters of the cartridge 2 as well as the length are not restricted to specific dimensions, allowing the cartridge 2 to be used in various types and sizes of extinguishers. In this embodiment, the inner and outer diameters are 50 mm and 53 mm, respectively, with a total length of approximately 330 mm. The upper cap 12' and the bottom cap 13' each have a thickness of approximately 6 mm as per the present design.

[0053] The design and shape of the cartridge 2 presented in this invention may offer manufacturing advantages in terms of cost and process efficiency. It features an elongated tubular body with two similar caps or seals, enhancing production feasibility.

[0054] In an alternative embodiment, the inner body of the cartridge 2 may feature multiple compartments separated by partitions. Each compartment can house the same type or different types of additives, allowing for separate dispersion and mixing within the fire extinguisher environment. This setup is advantageous, especially when storing incompatible additives or when preferring different compositions at the start and end of extinguishing operations.

[0055] In an alternative embodiment, the fire extinguisher 1 may comprise more than one cartridge 2. The said more than one cartridge 2 may be housed within the same body 11 or in separated bodies 11 if the fire extinguisher 1 comprises more than one body 11. This configuration allows the fire extinguisher 1 to be used for different fire classes. The more than one cartridge 2 may break simultaneously or sequentially, depending on the application. Additionally, the fire extinguisher 1 may feature multiple strikers 7, with each body 11 equipped with one striker 7. When a specific cartridge 2 needs to be broken, the corresponding striker 7 is manipulated, causing the cartridge 2 to break and release its additives 10 into the water, creating the appropriate mixture for the fire class to be extinguished. If another cartridge 2, comprising the same or different additives 10 needs to be braked, another striker 7 or similar mechanism is engaged, either manually or automatically, to form a new mixture, thereby extinguishing a different fire class or continuing to extinguish the same fire class if it is not fully extinguished. This design is economically and environmentally advantageous as it allows partial use of the fire extinguisher 1 for small fires, with only the used cartridge 2 needing to be refilled or replaced. Unused cartridge 2 can remain in the body 11 until the next maintenance date.

[0056] In an alternative embodiment, the fire extinguisher 1 may comprise at least two cartridges 2. The said at least two cartridges 2 may comprise additives 10 tailored to different types of fires. For example, one cartridge 2 may comprise additives 10 suitable for extinguishing fire class A (combustible materials), while another cartridge 2 may comprise additives 10 suitable for extinguishing fire class F (cooking oil and fats).

[0057] The present invention is not restricted by the dimensions of the cartridge 2 or the nature of the additives 10, filling liquid, or propellant gas.

Claims

1. A frangible cartridge (2) for a fire extinguisher (1) pressurized by releasing a compressed propellant gas inside said fire extinguisher (1) prior to use, said fire extinguisher (1) containing water (9) and said cartridge (2) containing additives (10) capable of enhancing the extinguishing properties of the water (9) of the fire extinguisher (1) comprising: - A body (11) configured to partially float on the water (9), inside the fire extinguisher (1); - An upper open end (12) and a bottom open end (13) at two ends of the body (11); - An upper cap (12') for sealing the upper open end (12) and a bottom cap (13') for sealing the bottom open end (13), wherein the upper cap (12') and the bottom cap (13') are designed to rupture under a specific differential pressure lower than the maximum pressure to which the water (9) is exposed following the release of the propellant gas.

2. The cartridge (2) according to claim 1, wherein the upper open end (12) is positioned above the water (9) level inside the fire extinguisher (1).

3. The cartridge (2) according to claim 1, wherein the bottom open end (13) is submerged in the water (9) within the fire extinguisher (1).

4. The cartridge (2) according to any one of the preceding claims, wherein the upper open end (12) is positioned opposite to the bottom open end (13).

5. The cartridge (2) according to claim 1, wherein the body (11) is of sufficient length to prevent the said cartridge (2) from overturning when the upper open end (12) faces upward and the bottom open end (13) faces downward inside the fire extinguisher (1).

6. The cartridge (2) according to claim 1, wherein the said cartridge (2) is positioned vertically inside the fire extinguisher (1).

7. The cartridge (2) according to claim 6, wherein the said cartridge (2) is positioned freely inside the fire extinguisher (1).

8. The cartridge (2) according to any one of the preceding claims, wherein the body (11) is made of translucent polyethylene.

9. The cartridge (2) according to claim 1, wherein the upper cap (12') and the bottom cap (13') comprise of a sheet of aluminum covered with a layer of adhesive on the side of the body (11).

10. The cartridge (2) according to claim 9, wherein the upper cap (12') and the bottom cap (13') are thermally welded onto the body (11).

11. The cartridge (2) according to any one of the preceding claims, wherein the upper cap (12') and the bottom cap (13') are configured to rupture under a differential pressure of approximately between 0.3 and 0.4 MPa.

12. The cartridge (2) according to claim 11, wherein the bottom cap (13') is configured to rupture under a lower differential pressure compared to the upper cap (12').

13. A fire extinguisher (1) comprising at least one cartridge (2) according to any of the previous claims.

14. A fire extinguisher (1) according to claim 13 comprising at least two cartridges (2) comprising additives (10) adapted to different types of fires.

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