Junction box with independent fire extinguishing equipment and thermochemical trigger

Abstract

The invention relates to an autonomous fire extinguishing device based on aerosol-forming or gas-forming components. The device can be used for preventing fire disasters of switchboards, sub-sockets, computers, electronic equipment (REA), digital and analog module elements and electronic boards. A junction box with autonomous fire extinguishing equipment and thermochemical triggering is provided in a dielectric housing (1) and comprises a metal contact (3) with wire attachment points. The metal contacts (3) with attachment points are contact groups forming a closed circuit. A module (2) having an aerosol-forming or gas-forming component is located within the dielectric housing. A thermal fuse (4) connected to the closed circuit between the metal contacts (3) having the attachment points of the contact group, designed to have the possibility of opening the closed circuit by exceeding the load current flowing therethrough or exceeding the maximum average volume temperature. A thermochemical igniter is connected to the module (2). The thermo-sensitive element (8) is connected to the thermochemical igniter. The dielectric housing includes an opening that is also a nozzle opening for the fire extinguishing product outlet. It provides the possibility of connecting wires using a junction box with a built-in autonomous fire extinguishing device, the possibility of initializing the autonomous fire extinguishing device using a thermochemical igniter, and the possibility of disconnecting a circuit in the form of wires connected to the junction box.

Description

Technical Field

[0001] The invention relates to an autonomous fire extinguishing device based on aerosol-forming or gas-forming components, which can be used to prevent fires in switchboards, interface extensions and sub-sockets, computers, radio electronic equipment (REA), digital and analog module components, electronic boards. Background Art

[0002] Fires often occur when operating electrical equipment due to: overloading of electrical equipment and wiring at the connection point, short circuits, ignition of flammable materials near connected equipment, excessive transient resistance of wires or printed circuit board contact groups.

[0003] It is necessary to suppress fires appropriately and automatically at an early stage, with the possibility of removing the voltage from the protected device (protected devices) and automatically forming information signals about the operation of fire extinguishing equipment without human intervention, eliminating the possibility of electric shock and saving expensive equipment, protection elements of automation and REA.

[0004] From the background of the invention fire extinguishing devices are known which are intended to suppress fires in electrical installations as follows.

[0005] An autonomous fire extinguishing device based on a heat-activated agent contained in microcapsules (patent RU 179466), comprising a polymer composite plate with a regular surface relief and containing microcapsules with an extinguishing agent placed in a special organosilicon compound. The substrate on the back of the plate has a heat-resistant self-adhesive layer for fixing it in the protected volume. Microcapsules of 50-400 microns are used as extinguishing agent, which have a core of a fire-extinguishing ozone-safe liquid, which is placed in a spherical polymer shell (patent RU 2469761). The microcapsules are capable of explosive destruction at temperatures reaching 90°C. This fire extinguishing system is characterized by low fire extinguishing capacity and a short service life (no more than two years, as shown in application practice), which is a significant disadvantage.

[0006] An autonomous gas fire-extinguishing device (patent RU 139678), which consists of a cylinder with a gaseous extinguishing agent (for example, Halon), communicating with a main device for supplying the extinguishing medium to the protected volume designed using fusible polymer materials. The main device is connected to the cylinder by a closing and starting device with a pressure gauge and a ball valve, and is also equipped with an elastic casing in the form of a metal spiral. This fire-extinguishing device is characterized by its plurality and highly complex installation in the protected volume.

[0007] A device for fixing a fire extinguishing wire in an electrical cabinet is known (patent RU 190409). A fire extinguishing wire or fire burn wire is an autonomous fire extinguishing device with a heat-activated microcapsule extinguishing agent, intended to prevent fires in large fire-hazardous installations, including electrical equipment such as switchboards, control cabinets, electrical cabinets, safes, etc. The technology according to this patent is a device for fixing a fire extinguishing wire in an electrical cabinet, the electrical cabinet having a bracket for fixing to the inner wall of the electrical cabinet and designed in the form of a curved chassis having grooves for fixing the wires and the bottom of the chassis having an adhesive layer. The disadvantage of this technology is the complexity of the installation of the fire extinguishing wire, which is associated with the need to install the required device for fixing to the inner wall of the electrical cabinet along its periphery and then fix the fire extinguishing wire in the chassis.

[0008] A self-operating fire extinguishing device is known (patent RU 184841), which comprises a foam housing consisting of an explosive device and an extinguishing agent. The explosive device is connected to a fuse extending outward through a hole in the housing and is placed in a closed groove designed from the outside of the housing along its periphery, the width of the groove exceeding the width of the fuse. In order to facilitate the rupture of the housing when the explosive device is triggered, a groove is designed on the inside of the housing. The device is suspended on a bracket or placed on a flat surface and is automatically activated when the flame contacts the fuse. The disadvantage of this technology is that the fire extinguishing device is placed in a guarded room and the electrical equipment uses a bracket or is mounted on a flat surface, which limits its location options and reduces the effectiveness of the fire extinguishing.

[0009] An automatic fire extinguishing device for telecommunication equipment is known, which is placed in a standard closed telecommunication rack (TCR) (patent RU 190222). The device is a unitary structure containing a housing that includes a generator of extinguishing agent (FEAG); the generator of extinguishing agent consists of two containers connected to the extinguishing agent delivery system and to the ignition source, consisting of pipes and FEAG nozzles. The device triggering unit is designed in the form of an external linear expansion sensor that passes through the area of ​​the strongest thermal load of the TCR and is connected to the input of the device, which in turn is connected inside the device to a sensor of the exceeded temperature threshold. In addition, the device includes an alarm device (light and sound indicator) indicating the fact that the generator has produced extinguishing agent. In this automatic fire extinguishing device, standard extinguishing agents are provided for use; they are characterized by insufficient extinguishing capacity and unsafe chemical composition. It reduces the extinguishing effect, and the presence of pipes and nozzles for supplying extinguishing agent to the guarded room increases the complexity of manufacturing the device, as well as the characteristics of installing the device in other types of rooms with electrical equipment due to the increased complexity of manufacturing due to the use of standard methods for fixing to the TCR.

[0010] An automatic fire extinguishing device fixed to a DIN rail is known (patent RU 204767), comprising a housing having a fire extinguishing aerosol generator (FAG) with a trigger unit; the structure of the FAG is a housing designed from non-flammable material with an outlet nozzle in which an aerosol-forming or gas-forming component (AFC) is placed, the housing of the automatic fire extinguishing system comprises a nozzle opening for outputting the aerosol-forming or gas-forming component and a slot for attaching the housing from the FAG to the DIN rail, the trigger unit comprising the form of a self-igniting hot wire. Preferably, the trigger unit comprises the form of a self-igniting hot wire with a thermosensitive element; the activation temperature is lower than the activation temperature of the hot wire. The device has the disadvantage of using only a thermosensitive wire and an element with a high operating temperature, i.e. such thermosensitive elements are known to operate at a temperature of at least 150°C–180°C, which does not allow a rapid response to a temperature increase during a fire and significantly delays the start of the fire extinguishing cycle. The absence of an electronic igniter results in the device not being able to be triggered by an external signal. Furthermore, there is no thermal fuse in the device, which does not allow disconnection of the load from the mains voltage in the event of a fire in the protected device. It should be noted that the device claimed in the patent does not include a trigger sensor and cannot signal the start of the fire extinguishing process. Furthermore, the device claimed in the patent is designed to be mounted only on a DIN rail and, due to its size, it cannot be installed in small volumes, such as sub-sockets, power supplies, REA elements or computers.

[0011] A patent is known (GB 643188, September 15, 1950), which describes improvements related to explosion prevention and fire prevention or fire extinguishing, in which the equipment for detecting and suppressing fire and or explosion includes a pressure-sensitive membrane device for detecting pressure increase. If a fire or explosion occurs, a diaphragm with high sensitivity is selected, for example, when the rate of pressure increase exceeds 50psi per second, it responds to a slight increase in pressure and is able to close the electrical contacts within 0.02 seconds after the pressure increase begins, releasing a substance that suppresses the fire or explosion. The material used to suppress or extinguish the explosion or combustion may include methyl bromide or other substances, namely rock dust. The invention can also be applied to processes such as cotton spinning and milling. The technical solution can be selected as the closest analog to the claimed invention and can be used as a prototype. Summary of the invention

[0012] The technical problem of the claimed solution is aimed at solving the functional expansion of the junction box.

[0013] The technical result of the claimed invention is the possibility of connecting electrical wires using a junction box with a built-in autonomous fire extinguishing device, the possibility of initializing the autonomous fire extinguishing device using a thermochemical igniter and disconnecting the circuit connected to the junction box in the form of electrical wires.

[0014] This technical achievement is achieved thanks to: a housing of a terminal box, in which a contact group can be placed, a module with an aerosol-forming or gas-forming component, a trigger unit in the form of a thermochemical igniter containing a heat-sensitive element; and, in addition, a thermal fuse connected to the contact group in the housing, which is able to open the circuit by exceeding the current flowing through the fuse, exceeding the load current or excessive temperature generated by the burning aerosol-forming or gas-forming component.

[0015] Alternatively, the junction box housing comprises fasteners which are capable of connecting several junction box housings to each other in groups.

[0016] Preferably, the trigger unit is in the form of a thermochemical igniter having a heat-sensitive chemical element, the trigger temperature of which is lower than the trigger temperature of the thermochemical igniter of the AFC.

[0017] The claimed device is an assembled unit made in a single housing and has functional and structural unity, so it can be patented as claimed.

[0018] Possibilities for installing the required equipment include: AFC with solid fuel aerosol-forming or gas-forming components, and thermal fuses within a limited volume with electrical or electronic equipment, allowing fires at the installation site to be suppressed with high extinguishing efficiency and disconnecting the loads that are the source of the fire.

[0019] Considering that aerosol-forming ingredients, in contrast to powders, carbon dioxide and foam compositions, have no restrictions on use (with respect to the presence of power and voltage of the protected electrical equipment) and do not have adverse effects on electrical or electronic equipment, the claimed device can be installed at any location in the protected equipment.

[0020] The presence of a trigger unit in the form of a thermochemical AFC igniter triggered using a triggering thermal device makes it possible to trigger the device at relatively low operating temperatures (e.g. 1730C), which provides greater versatility and allows the use of junction boxes as elements to expand the fire extinguishing capabilities of electrical equipment.

[0021] Using the smallest size terminal block housing, the terminal block can be installed in any type of sub-socket, distribution board, power supply, REA housing, digital or electronic module on the printed circuit board without special installation and reduces the complexity of equipment manufacturing.

[0022] The aerosol-forming or gas-forming component is a cryogenic solid fuel composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram showing the required junction box;

[0024] Figure 2A schematic diagram showing the required autonomous fire extinguishing equipment. DETAILED DESCRIPTION

[0025] Figure 1 A schematic diagram of the required junction box is shown, wherein 1 is a housing, 2 is a module with an aerosol-forming or gas-forming component, 3 is a contact block, 4 is a thermal fuse with a conductor (7), 5 is a thermochemical igniter with a thermistor (8), 6 is a housing base, 7 is a conductor, and 8 is a thermistor.

[0026] The junction box comprises an aerosol-forming or gas-forming composition (2) and a compact dielectric housing (1). The module (2) is placed in the housing (1) through the open side of the housing, which is also a nozzle opening. In addition, before placing the module with the aerosol-forming or gas-forming composition (2), a thermal fuse (4) is placed in the housing (1) and connected to the contact block (3) in a closed circuit through its conductor (7).

[0027] The junction box can be placed in the housing of any electrical equipment and is connected to the load through the contact block (3), the conductor (7) and the thermal fuse (4).

[0028] The AFC trigger unit is a thermochemical igniter (5) with a heat sensitive element (8).

[0029] Preferably, the thermochemical igniter (5) is made in the form of a housing element and is provided with a thermosensitive element (8), for example, located at the end of the thermochemical igniter (5), which reduces the autoignition temperature to, for example, 173° C. and below. The triggering temperature of the thermosensitive element (8) is lower than the triggering temperature of the thermochemical igniter (5).

[0030] Preferably, the fasteners (6) are located outside the housing (1) to allow the junction boxes to be interconnected in groups to connect two or more pairs of wires.

[0031] Preferably, the contact set (3) is made in the form of a screw contact, wherein the input line is fixed with screws or screws and clamping pads.

[0032] Alternatively, the contact group (3) is made in the form of a non-detachable crimp sleeve, wherein the input line is fixed in a compressed form by the contact group (3).

[0033] Alternatively, the contact group (3) is made in the form of a spring contact, and when the wire is inserted into the contact group (3), the input wire can be pressed into the contact group (3) independently.

[0034] Alternatively, the contact group (3) is made in the form of a movable contact clamp, which can be opened by a lever clamp and then clamped by returning the lever clamp to its original position, thereby clamping the input line in the contact group (3).

[0035] Initially, the load line is connected to the contact group (3) of the junction box. Furthermore, the contact group (3) is connected to a closed circuit via a conductor (7) and a thermal fuse (4), in which a voltage of, for example, 220 V is applied and a current flows through the circuit, for example, up to 16 amperes. The nominal operating voltage of the thermal fuse is selected to be, for example, 230 V, the maximum load current is 16 amperes, and the opening temperature is 90°C. If the load current in the upper junction box increases sharply, for example, to 16 amperes (short circuit), the thermal fuse (4) burns out and disconnects the line: contact group (3) - conductor (7) - thermal fuse (4) - conductor (7) - contact group (3). In this case, the contact block acts as both a safety element of the circuit and a connecting element of the two wires.

[0036] If a fire occurs in the protected volume (where the junction box is installed), when the maximum average volume temperature is reached (e.g. 173°C), the thermosensitive element (8) is triggered at the heating temperature, igniting the thermochemical igniter (5) and thus igniting the aerosol-forming or gas-forming component (2). During the combustion process, the aerosol-forming or gas-forming component (2) releases a fire-extinguishing aerosol, which suppresses the fire as quickly as possible in the protected volume. Fire-extinguishing aerosol is a well-known fire-extinguishing agent (FEA), which is a product of the combustion reaction of the initial pyrotechnic component. For example, FEA can be potassium chloride (KCl) or sodium chloride (NaCl). The size of the released solid particles is 1-5 microns, which makes it possible to produce a larger FEA surface area. The particles of the fire-extinguishing aerosol participate in ion exchange processes when suppressing the combustion reaction, playing a major role in extinguishing the fire.

[0037] When burning, the aerosol-forming or gas-forming component (2) also acts together with the heat released on the thermal fuse (4) to heat it above the operating temperature, for example, 90° C., to allow opening of the power supply line: contact group (3) - conductor (7) - thermal fuse (4) - conductor (7) - contact group (3). Thus, if a fire occurs in the protected volume, the terminal box can not only extinguish the fire, but also simultaneously shut down the load, thereby eliminating the fire source itself.

[0038] If a fire occurs between the wires of the contact block itself, when the maximum heating temperature of the contact block elements is reached (e.g. 173° C.), the heating temperature triggers the thermosensitive element (8), ignites the thermochemical igniter (5) and thus ignites the aerosol-forming or gas-forming component (2). Likewise, the triggering of the module with the aerosol-forming or gas-forming component (2) can occur independently, for example, at temperatures above 220° C. It should be noted that the terminal box housing is made of a difficult-to-burn material whose melting temperature is above 250° C. During the combustion process, the aerosol-forming or gas-forming component (2) releases a fire-extinguishing aerosol, which suppresses the fire as quickly as possible within the protected volume. Fire-extinguishing aerosols are a well-known fire-extinguishing agent (FEA) that is a product of the combustion reaction of the initial pyrotechnic component.

[0039] During combustion, the aerosol-forming or gas-forming component (2) also acts together with the heat released on the thermal fuse (4) to heat it above the operating temperature, for example, 90° C., to allow opening of the power line: contact group (3) - conductor (7) - thermal fuse (4) - conductor (7) - contact group (3). Therefore, if a fire occurs in the contact group (3), the terminal box is not only able to extinguish the fire in its own contact group (3), but can also simultaneously shut down the load, thereby eliminating the fire source itself.

[0040] Tests carried out have shown that a mass of 0.7 grams of an aerosol-forming or gas-forming component (2) is sufficient to stably suppress a flame of up to a volume of 10 liters, while simultaneously acting on the combustion products of the aerosol-forming or gas-forming component (2) on the thermal fuse (4) and shutting it off.

[0041] A series of tests showed that the device is fully autonomous and operates stably over a wide operating temperature range.

Claims

1. A junction box with an autonomous fire extinguishing device and a thermochemical trigger, arranged in a dielectric housing (1) and comprising metal contacts (3) with wire attachment points. The metal contacts (3) with attachment points are a set of contacts that form a closed circuit, Also included is a module (2) with an aerosol-forming or gas-forming component, which is located in a dielectric housing, and a thermal fuse (4) connected to the closed circuit between the metal contacts (3) with the contact set attachment points, with the possibility of opening the closed circuit by exceeding the load current flowing through the thermal fuse or exceeding the maximum average volume temperature, and a thermochemical igniter (5), connected to the module (2), A heat sensitive element (8) is connected to a thermochemical igniter, the dielectric housing comprising an opening which is also the nozzle opening for the outlet of the fire extinguishing product.

2. The junction box according to claim 1, characterized in that: Compared to the triggering temperature of the thermochemical igniter (5), the triggering temperature of the heat sensitive element (8) is lower.

3. The junction box according to claim 1, characterized in that: Fasteners (6), located outside the housing (1), allow the junction boxes to be connected to each other in groups to connect two or more pairs of wires.

4. The junction box according to claim 1, characterized in that: The contact group (3) is made in the form of a screw contact, wherein the input line is fixed with a screw, or with a screw and a clamping pad.

5. The junction box according to claim 1, characterized in that: The contact group (3) is made in the form of a non-detachable crimp sleeve, wherein the input line is fixed in a compressed form by the contact group (3).

6. The junction box according to claim 1, characterized in that: The contact group (3) is made in the form of a spring contact, and when the wire is inserted into the contact group (3), the input wire can be pressed into the contact group (3) independently.

7. The junction box according to claim 1, characterized in that: The contact group (3) is made in the form of a movable contact clamp, which can be opened by a lever clamp and then clamped by returning the lever clamp to its original position, thereby clamping the input line in the contact group (3).

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