RU2034585C1 - Device preventing spreading of fire along current-carrying cable - Google Patents

Abstract

FIELD: electrical engineering; maintenance of electric systems. SUBSTANCE: device has cable cutting mechanism, fire obstructing belt and fire partition. Fixed and movable blades of cutting mechanism are installed relative to cable. In case of fire, flame kindles flexible thread passing over system of sheaves which burns out and releases striker. The latter, acted upon by spring, strikes against powder charge. Movable blade, acted upon by powder gases, moves downwards and cuts burning cable. Simultaneously, boss throws burning part of cable downwards, and plane of movable blade prevents access of fire to nonburning cable at side of fire obstructing belt. Thus, fire is localized. EFFECT: enhanced quality of localization of fire in current-carrying cables. 2 cl, 2 dwg

Description

 The invention relates to fire fighting equipment, in particular to devices for localizing a fire and preventing the possibility of a fire spreading in cable channels, tunnels and other rooms.

 A device is also known to prevent the spread of fire along an electric cable, including a fire barrier, a fire barrier, a mechanism for chopping a cable with an explosive in the form of a sleeve.

 The disadvantage of this device is that the clutch with explosive is a danger to people who may be in this area when extinguishing a fire, if it has not yet exploded. Such a coupling is also dangerous if installed in rooms where people are located (even periodically). In addition, when the coupling explodes, the possibility of damage to the fire-retarding belt is not excluded, since the direction of the explosion significantly depends on the accuracy of the tolerances of the end walls of the coupling and cable, which is very difficult to accomplish.

 It should also be noted that after cutting the cable (after the explosion of the coupling), the possibility of re-ignition of the cable from the side of the fire-retardant belt is not excluded, since the cable being cut (the end part) is in the zone of fire.

 The aim of the invention is to increase the safety of personnel in the fire zone from injury due to the explosion of the clutch, eliminating damage to the fire-retardant belt, and completely eliminating the spread of fire through the cable after being chopped when the fire continues into the neighboring room.

 This is achieved by the fact that in the device for preventing the spread of fire along the electric cable, including the fire barrier, the fire barrier, the cable cutting mechanism, the cable cutting mechanism is made in the form of a fixed and movable knife, covering the cable and mounted in a housing fixed to the firewall with the opposite sides of the fire-retardant belt, and in which on the side of the movable knife there is a bolt with a spring-loaded striker acting on the powder aryad (chuck) disposed in the chamber, at break of the flexible member (thread) having one end secured to the striker, and the other units through the system is fixed directly on the cable from the opposite side of the fire wall.

 In addition, on the movable knife on the opposite side of the burning cable there is a protrusion that deflects the chopped cable to the side, and the knife plane is made from the condition of overlapping the cross section of the chopped cable at its extreme position, which completely eliminates the penetration of fire into the adjacent room.

 The proposed design reliably works when a cable ignites, since a flexible thread easily burns out, freeing a hammer that strikes the cartridge’s capsule and moves a downward knife from the action of powder gases, cuts the cold part of the cable located in an adjacent room. In the combustion zone, a fire-retardant belt contributes to the retention of fire. However, if, nevertheless, the cable burns from a high temperature, then this can only be carried out to the plane of the movable knife located in the adjacent room, since it not only blocks the path to the fire, but, cutting the cable, rejects it to the side. At the same time, the design does not pose a danger to people around, since the device is located in an adjacent room and, in addition, the action of the powder gases of the cartridge occurs in a limited volume of the powder chamber of the housing.

 In FIG. 1 shows a device, a General view; in FIG. 2, section AA in FIG. 1.

 The device consists of a fire barrier 1 with a fire-retardant belt 2 of an asbestos cord at the passage of the electric cable 3 through the partition. On the opposite side of the partition 1 from the fire-retardant belt 2, a housing 5 is fixed on the bracket 4, in which a fixed 6 and movable 7 knives are installed that cover the cable 3. In the upper part of the housing 5 there is a chamber 8 with a powder charge (cartridge) 9, as well as a shutter 10 with a striker 11 and a spring 12. In the upper part of the striker 11 a flexible thread 13 is fixed, thrown through a system of blocks 14 fixed on the partition 1, and through the hole 15 fixed on the cable 3 from the side of the fire-retardant belt 2.

 On the movable knife 7 there is a protrusion 16, which discards the cold part of the cable after cutting to the side. The movement of the knife 7 down is limited by the depreciation unit 17.

 The device operates as follows.

 The housing 5 is fixed on the bracket 4 of the wall 1 on the opposite side from the fire-retardant belt 2. Install the movable 7 and fixed 6 knives relative to the cable 3.

 The chamber 8 is charged with a powder charge (cartridge) 9 and with the help of a flexible thread 13 thrown through a system of blocks 14, and the hole 15 compresses the spring 12, setting the hammer 11 in its highest position. The other end of the thread is fixed to the cable 3 from the side of the fire-retardant belt 2. When the cable 3 is ignited, the flame ignites the flexible thread 13, which burns out and releases the hammer 11. The hammer under the action of the spring 12 strikes the cartridge 9, which ignites. Under the influence of powder gases, the movable knife 7 moves down and cuts the cold part of the cable, while the protrusion 16 throws it down, and the plane of the knife blocks the fire access to the cold part of the cable, even if the fire from the burning section passes through the fire-retardant belt 2. There is a complete localization fire access from the side of the burning cable.

 The invention improves the safety of people who find themselves in the combustion zone (when extinguishing a fire), and also to eliminate damage to the fire barrier belt. The device is simple in design, easily accessible for inspection, during routine inspections and does not require special dangerous explosives.

Claims (2)

 1. A DEVICE FOR PREVENTING FIRE DISTRIBUTION ON AN ELECTRICAL CABLE, comprising a fire barrier, a fire barrier and a cable cutting mechanism, characterized in that, in order to increase reliability by eliminating damage to the fire barrier belt and to increase personnel safety in the event of a fire, the mechanism placed on the side of the partition opposite the side of the wall with a refractory belt, and has a housing mounted on it from different sides of the cable the first and movable knives, placed under the movable knife, the cartridge in the chamber and the bolt with a spring-loaded striker interacting with the cartridge, a system of blocks and a flexible element covering them, one end of which is fixed to the hammer, and the other on the cable from the side of placement of the flame retardant belt.  2. The device according to claim 1, characterized in that on the movable knife from the side opposite the partition, a protrusion is made to discard the end of the cable.

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