Terminal block with autonomous fire-extinguishing device and thermochemical triggering

Abstract

The invention can be used for preventing fires in electrical devices. A terminal block with an autonomous fire-extinguishing device and thermochemical triggering is configured inside a dielectric housing and comprises metal contacts with assemblies for the attachment of wires, said assemblies forming a contact group that forms a closed electric circuit. Inside the dielectric housing there is a module containing an aerosol-forming or gas-forming composition. The closed electric circuit includes a thermal fuse which is connected between the metal contacts and is configured to be capable of breaking the closed electric circuit if the load current passing therethrough exceeds a given threshold or if a maximum bulk temperature is exceeded. A thermochemical igniter is connected to the module. A heat sensitive element is connected to said thermochemical igniter. The dielectric housing contains a nozzle opening for the egress of extinguishants. The terminal block allows the triggering of an autonomous fire-extinguishing device by a thermochemical igniter, as well as the breaking of an electric circuit.

Description

[0001] Terminal block with autonomous fire extinguishing device and thermochemical initiation

[0002] Field of technology

[0003] The invention relates to autonomous fire extinguishing installations based on aerosol-forming or gas-forming compositions and can be used to prevent fires in distribution boxes, socket boxes, computers, electronic equipment (REA), elements of digital and analog modules, and electronic boards.

[0004] When using electrical equipment, fires are not uncommon, the causes of which are: overloading of electrical equipment and wiring at connection points, short circuits, ignition of flammable materials near connected equipment, increased transition resistance in contact groups of electrical wiring or printed circuit boards.

[0005] It is necessary to promptly suppress the sources of such fires with the possibility of removing voltage from the protected device (protected devices), and generating an information signal about the activation of the fire extinguishing device, automatically, without human intervention, eliminating the possibility of electric shock and preserving expensive equipment, protecting automation elements and electronic equipment.

[0006] State of the art

[0007] The following fire extinguishing agents are known from the prior art, intended for suppressing fire in electrical installations.

[0008] Autonomous fire extinguishing system based on a heat-activated agent contained in microcapsules (patent RU 179466), made in the form of a polymer composite plate with a regular surface relief and containing microcapsules with a fire extinguishing agent placed in a special organosilicon compound. The plate substrate on the back has a heat-resistant self-adhesive layer for its attachment to the protected volume. Microcapsules measuring 50-400 μm are used as a fire extinguishing substance (agent), having a core of an ozone-safe fire extinguishing liquid placed inside a spherical polymer shell (patent RU 2469761). Microcapsules are capable of explosive destruction upon reaching a temperature of 90°C. This fire extinguishing system is characterized by low fire extinguishing capacity and a short service life (from practical experience - no more than two years), which is a significant drawback.Autonomous gas fire extinguishing system (patent RU 139678), which contains a cylinder with a gas fire extinguishing agent (for example, freon), communicating with a main line for feeding the fire extinguishing medium into the protected volume, made of a low-melting polymer material. The main line is connected to the cylinder by means of a shut-off and starting device with a pressure gauge and a ball valve, and is also equipped with an elastic outer shell in the form of a metal spiral. This fire extinguishing system is multi-component and highly labor-intensive to install in the protected volume.

[0009] A means for fixing a fire extinguishing cord in an electrical cabinet is known (patent RU 190409). A fire extinguishing cord or pyrocord is an autonomous fire extinguishing installation with a heat-activated microencapsulated fire extinguishing agent, designed to protect against fires in large-sized fire-hazardous objects with electrical equipment, such as switchboards, control cabinets, electrical cabinets, safes, etc. The technical solution according to this patent is a device that holds the fire extinguishing cord in an electrical cabinet, has a support for fixing to the internal walls of the electrical cabinet and is made in the form of a flexible fastener having a groove for holding the cord, and the base of the fastener has an adhesive layer.The disadvantage of this technical solution is the labor-intensive nature of installing the fire extinguishing cord, which is associated with the need to install the proposed fastening device on the inner walls of the electrical cabinet along its perimeter, after which the fire extinguishing cord is fixed into the fastening.

[0010] A self-acting fire extinguishing device is known (patent RU 184841), which contains a housing made of foam plastic, inside which an explosive device and a fire extinguishing agent are placed. The explosive device is connected to a fuse cord coming out through an opening in the housing and placed in a closed recess made on the outside of the housing along its perimeter, and the width of the recess exceeds the width of the fuse cord. To facilitate the rupture of the housing when the explosive device is triggered, grooves are made on the inside of the housing. This device is suspended on a bracket or placed on a flat surface and is triggered independently when the flame touches the fuse cord.The disadvantage of this technical solution is that the fire extinguishing device is placed in a protected room with electrical equipment using a bracket or is installed on a flat surface, which limits its location options and leads to a decrease in the effectiveness of extinguishing fires.

[0011] An automatic fire extinguishing device for telecommunications equipment is known, which is placed in a standard telecommunications rack (STR) of a closed type (patent RU 190222). The device is a single structure containing a housing in which a flame extinguishing agent generator (FEG) is placed, consisting of two tanks that are connected to a system for delivering a flame extinguishing agent to the source of fire, consisting of pipelines and nozzles of the FEG. The initiation unit of the device is made in the form of an external linear-extended sensor, which is laid through the most heat-loaded zones of the STR and is connected to the input of the device, which, in turn, is connected inside the device to a sensor for exceeding the temperature threshold. Additionally, this device includes a trigger signaling device, which is a light and sound indicator indicating the fact that the generator has produced a flame extinguishing agent.This automatic fire extinguishing device offers the use of standard flame extinguishing agents, which are characterized by insufficient fire extinguishing capacity and are unsafe in their chemical composition, which reduces the efficiency of extinguishing, the presence of pipelines and nozzles for supplying the flame extinguishing agent to the protected premises increases the labor intensity of manufacturing the device, and the installation of the device in other types of premises with electrical equipment is characterized by increased labor intensity due to the use of standard methods of fastening to the TKS.

[0012] An autonomous fire extinguishing device with fixation on a DIN rail is known (Patent RU 204767) consisting of a housing, inside which a fire extinguishing aerosol generator (FEAG) with an initiation unit is placed, the FEAG is made in the form of a housing made of a hardly combustible material with an outlet nozzle, in which an aerosol-forming or gas-forming composition (AGC) is placed, wherein nozzle openings are made in the FEAG housing for the outlet of the aerosol-forming or gas-forming composition and a groove for fastening the housing with the FEAG to a DIN rail, and the initiation unit is made in the form of a self-igniting thermal cord, while, in a preferred embodiment, the initiation unit is made in the form of a self-igniting thermal cord with a heat-sensitive element, the activation temperature of which is less than the activation temperature of the thermal cord.The disadvantage of this device is that it uses only a heat-sensitive cord and an element with high response temperatures, namely, it is known that such heat-sensitive elements are triggered by a temperature of at least 1500C - 1800C, which does not allow a prompt response to a temperature increase during a fire and greatly delays the start of the extinguishing cycle. The absence of an electric igniter does not allow the device to be initiated by an external signal. In addition, the device in question does not have thermal fuses, which does not allow disconnecting the load from the supply voltage in the protected device in the event of a fire. It should be noted that the device specified in the patent does not contain a response sensor and is not capable of generating a signal at the start of the extinguishing process.The device presented in the patent is also intended for mounting only on a DIN rail and, based on its dimensions, it cannot be mounted in small spaces, such as wall boxes, power supplies, electronic equipment elements or computers.

[0013] A patent is known (GB 643188, 15.09.1950), which describes improvements relating to means for extinguishing explosions and preventing or extinguishing fires, in which apparatus for detecting and suppressing a fire or explosion includes pressure-sensitive membrane means for detecting an increase in pressure and, if a fire or explosion occurs, the diaphragm is selected with a high level of sensitivity, for example, to respond to a small increase in pressure when the rate of pressure increase exceeds 50 pounds per square inch per second and is capable of closing an electrical contact within 0.02 seconds after the start of the pressure increase to release a substance that suppresses the fire or explosion. Materials for suppressing or extinguishing an explosion or combustion may contain methyl bromide or other substances, including stone dust. The invention can also be applied to processes such as cotton spinning and flour milling.This technical solution can be selected as the closest analogue to the claimed invention and can act as a prototype.

[0014] Disclosure of invention

[0015] The technical problem that the claimed solution is aimed at solving is to expand the functionality of the terminal block.

[0016] The technical result of the claimed invention consists in providing the possibility of using a terminal block with a built-in autonomous fire extinguishing device for connecting wires, providing the possibility of initializing the autonomous fire extinguishing device with a thermochemical igniter and breaking the electrical circuit in the form of wires connected to the terminal block.

[0017] The said technical result is achieved by means of a terminal block housing designed with the possibility of placing contact groups, a module with an aerosol-forming or gas-forming composition, an initiation unit in the form of a thermochemical igniter containing a heat-sensitive element, and in addition, the housing contains a heat-sensitive fuse connected to the contact groups, capable of breaking the electrical circuit when the load current flowing through it is exceeded or the temperature created by the burning aerosol-forming or gas-forming composition is exceeded.

[0018] In an alternative embodiment, the terminal block housing contains fasteners capable of connecting several terminal block housings together into a group.

[0019] In a preferred embodiment, the initiation unit is made in the form of a thermochemical igniter with a heat-sensitive chemical element, the activation temperature of which is less than the activation temperature of the AOS thermochemical igniter.

[0020] The proposed device is an assembly unit made in a single housing and has functional and structural unity, therefore it can be claimed as a patent.

[0021] The possibility of installing the proposed device, which includes an AOS with a solid-fuel aerosol-forming or gas-forming composition, and a heat-sensitive fuse inside limited volumes with electrical or electronic equipment, allows for high fire-extinguishing efficiency in suppressing fire sources at installation sites and disconnecting the load that is the source of the fire.

[0022] Taking into account that the aerosol-forming composition, in comparison with powder, carbon dioxide and foam compositions, has no restrictions on application (in terms of the power of the protected electrical equipment and the presence of voltage) and does not have a negative impact on electrical equipment or electronic equipment, the proposed device can be installed in any place of the protected devices.

[0023] The presence of an initiation unit in the form of a thermochemical igniter AOS, which is launched using an initiating heat-sensitive device, allows for the possibility of initiating the device at relatively lower response temperatures, for example 1730C, which provides greater versatility and allows the use of a terminal block as an element that expands the extinguishing capabilities of electrical devices.

[0024] The use of a terminal block housing of the smallest possible size makes it possible to install the terminal block without special fastening in any type of wall boxes, distribution boxes, power supplies, electronic equipment housings, digital or electronic modules, on printed circuit boards and reduces the labor intensity in manufacturing the device.

[0025] The aerosol-forming or gas-forming composition is a low-temperature solid fuel composition.

[0026] Implementation of the invention

[0027] (Fig. 1) shows a diagram of the proposed terminal block, where 1 is the housing, 2 is the module with an aerosol-forming or gas-forming composition, 3 is the contact block, 4 is a thermal fuse with conductors (7), 5 is a thermochemical igniter with a heat-sensitive element (8), 6 is the housing mount, 7 is the conductors, 8 is the heat-sensitive element.

[0028] The terminal block contains 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 side open part of the housing, which is also a nozzle opening. Also, a thermal fuse (4) is placed in the housing (1) before placing the module with the aerosol-forming or gas-forming composition (2), connected by its conductors (7) to the contact blocks (3) in a closed electric circuit.

[0029] The terminal block can be placed in the housing of any electrical device, being connected to the load through contact blocks (3), conductors (7) and a thermal fuse (4).

[0030] The AOS initiation unit is a thermochemical igniter (5) with a heat-sensitive element (8).

[0031] In a preferred embodiment of the terminal block, the thermochemical igniter (5) is made in the form of a housing element and is provided with a heat-sensitive element (8) located, for example, at the end of the thermochemical igniter (5), which allows for a reduction in the autoignition temperature, for example, to 173°C and below. The activation temperature of the heat-sensitive element (8) is lower than the activation temperature of the thermochemical igniter (5).

[0032] In the preferred embodiment of the terminal block, fasteners (6) are located on the outer part of the housing (1), allowing the terminal blocks to be connected to each other in groups to connect two or more pairs of wires.

[0033] In a preferred embodiment of the terminal block, the contact groups (3) are made in the form of screw contacts, where the input cable is fixed with a screw or a screw and a pressure pad.

[0034] In an alternative version of the terminal block, the contact groups (3) are made in the form of non-detachable crimping sleeves, where the input cable is fixed in the form of crimping by the contact group (3).

[0035] In an alternative embodiment of the terminal block, the contact groups (3) are made in the form of a spring contact, capable of independently pressing the input cable to the contact group (3) when the cable is inserted into the contact group (3).

[0036] In an alternative embodiment of the terminal block, the contact groups (3) are made in the form of a movable contact-clamp, which can be opened by a lever clamp and then clamped, returning the lever clamp to its original position, thereby clamping the input cable in the contact group (3).

[0037] In the initial working condition, the load wires are connected to the contact group (3) of the terminal block. Further, the contact group (3) is connected to a closed circuit via conductors (7) and a thermal fuse (4), into which, for example, a voltage of 220 volts is supplied and in which a current of, for example, up to 16 amperes flows. The thermal fuse is selected, for example, for the nominal operating voltage of 230 volts and a maximum load current of 16 amperes, as well as a tripping temperature of 90 °C. In the event of a sharp increase in the load current in the terminal block above, for example, 16 amperes (short circuit), the thermal fuse (4) burns out and opens the line: contact group (3) - conductor (7) - thermal fuse (4) - conductor (7) - contact group (3). In this case, the contact block acts simultaneously as a fuse element of the electrical circuit and a connecting element of two wires.

[0038] In case of fire in the protected volume (location of the terminal block), when the maximum average volume temperature is reached, for example, 173°C, the temperature-sensitive element (8) is triggered by the heating temperature, igniting the thermochemical igniter (5), which in turn ignites the aerosol-forming or gas-forming composition (2). When burning, the aerosol-forming or gas-forming composition (2) releases a fire-extinguishing aerosol, which suppresses the fire in the protected volume as quickly as possible. Fire-extinguishing aerosol is a well-known fire-extinguishing agent (FEA), which is a product of the combustion reaction of the original pyrotechnic components. For example, the FEA can be potassium chloride (KC1) or sodium chloride (NaCl). The released solid particles have a size of 1-5 microns, which allows creating a large FEA area. Particles of fire extinguishing aerosol participate in the ion exchange process to suppress the combustion reaction, which is the main effect in extinguishing fires.

[0039] Also, when burning, the aerosol-forming or gas-forming composition (2) affects the thermal fuse (4) with the heat released, heating it above the operating temperature, for example, 90 °C, which allows the power line to be opened: contact group (3) - conductor (7) - thermal fuse (4) - conductor

[0040] (7) - contact group (3). Thus, if a fire occurs in the protected volume, the terminal block is capable of not only extinguishing the fire, but also simultaneously disconnecting the load, thereby eliminating the source of the fire itself.

[0041] In the event of a fire in the wire connection in the contact block itself, when the maximum heating temperature of the contact block elements is reached, for example, 173 °C, the temperature-sensitive element is triggered by the heating temperature.

[0042] (8), igniting the thermochemical igniter (5), which in turn ignites the aerosol-forming or gas-forming composition (2). Also, the initiation of the module with the aerosol-forming or gas-forming composition (2) can occur independently, for example, at a temperature above 220 °C. It should be noted that the terminal block housing is made of difficult-to-combust materials with a melting or combustion temperature above 250 °C. When burning, the aerosol-forming or gas-forming composition (2) releases a fire-extinguishing aerosol, which suppresses the fire in the protected volume as quickly as possible. Fire-extinguishing aerosol is a well-known fire-extinguishing agent (FEA), which is a product of the combustion reaction of the original pyrotechnic components.

[0043] Also, when burning, the aerosol-forming or gas-forming composition (2) affects the thermal fuse (4) with the released heat, heating it above the response temperature, for example, 90 °C, which allows to open the power line: contact group (3) - conductor (7) - thermal fuse (4) - conductor (7) - contact group (3). Thus, when a fire occurs in the contact group (3), the terminal block is able not only to extinguish the fire of its own contact group (3), but also simultaneously disconnect the load, thereby eliminating the source of ignition itself. The tests have shown that the mass of the aerosol-forming or gas-forming composition (2) in the amount of 0.7 grams is sufficient to stably suppress a fire in a volume of up to 10 liters, while affecting the thermal fuse (4) with the combustion products of the aerosol-forming or gas-forming composition (2) and disconnecting it.A series of tests demonstrated the complete autonomy of the device and stable operation over a wide range of operating temperatures.

Claims

Invention formula 1. A terminal block with an autonomous fire extinguishing device and thermochemical initiation, made in a dielectric housing (1) and containing metal contacts (3) with assemblies for attaching wires to them, the metal contacts (3) with the assemblies representing a contact group that forms a closed electrical circuit, additionally contains a module (2) with an aerosol-forming or gas-forming composition located inside the dielectric housing, and a thermal fuse (4) included in the closed electrical circuit between the metal contacts (3) with the assemblies of the contact group, made with the possibility of breaking the closed electrical network upon exceeding the load current flowing through it or exceeding the maximum average volume temperature, as well as a thermochemical igniter (5) connected to the module (2), a heat-sensitive element (8) connected to the thermochemical igniter, wherein the dielectric housing contains an open part,which also serves as a nozzle opening for the release of extinguishing products.

2. The block according to item 1, characterized in that the activation temperature of the heat-sensitive element (8) is less than the activation temperature of the thermochemical igniter (5).

3. The terminal block according to paragraph 1, characterized in that on the outer part of the housing (1) there are fasteners (6) that allow the terminal blocks to be connected to each other in groups for connecting two or more pairs of wires.

4. The block according to item 1, characterized in that the contact groups (3) are made in the form of screw contacts, where the input cable is fixed with a screw or a screw and a pressure pad.

5. The block according to item 1, characterized in that the contact groups (3) are made in the form of non-detachable crimping sleeves, where the input cable is fixed in the form of crimping by the contact group (3).

6. The block according to item 1, characterized in that the contact groups (3) are made in the form of a spring contact, capable of independently pressing the input cable to the contact group (3) when the cable is inserted into the contact group (3).

7. The block according to item 1, characterized in that the contact groups (3) are made in the form of a movable contact-clamp, which can be opened by a lever clamp, and then clamp it, returning the lever clamp to its original position, thereby clamping the input cable in the contact group (3). and

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