56results about How to "Stop the fire" patented technology

The invention discloses a switch cabinet capable of automatically cooling and dehumidifying, and belongs to the field of switch cabinets. The switch cabinet comprises a cabinet body provided with an exhaust tube at the top, a cooling device and a dehumidifying device, wherein the dehumidifying device comprises a gas suction pump, a moisture tube, a dry gas tube and a drying tank, the both ends of the drying tank are detachably connected with the moisture tube and the dry gas tube, the other end of each of the moisture tube and the dry gas tube stretches in the cabinet body, and the moisture tube is connected with the gas suction pump; the cooling device comprises a dry ice production device, a dry ice storage box and a circulation tube, the dry ice production device is communicated with the dry ice storage box through a middle tube, the dry ice storage box is communicated with the dry ice production device through the circulation tube, a temperature sensor, a humidity sensor, a smoke sensor and a gas pressure detector are arranged in the cabinet body, and a controller is arranged at the outer side of the cabinet body. According to the switch cabinet disclosed by the invention, a circulation cooling system is formed by virtue of dry ice gasification, the heat dissipation efficiency is high, and moreover, the dehumidifying device is simple in structure and free from generating additional heat during working.

The invention provides a heat preservation demolition-free template and a manufacturing method thereof and relates to a building wall body A-grade heat preservation board. The heat preservation demolition-free template is suitable for a newly-built building wall body, a roof, a basement to serve as the heat preservation board, can take the place of a heat preservation demolition-free template of a building template and is especially suitable for a high-rise building concrete shear wall, a frame structure and inner and outer walls of brick-concrete structure buildings to serve as the heat preservation board and the demolition-free template. The heat preservation demolition-free template comprises a heat preservation board, a resin hardening layer I, alkali resisting glass fiber cloth I, a resin hardening layer II, a resin hardening layer III, alkali resisting glass fiber II, a resin hardening layer IV and a waterproof interface layer, wherein one side of the heat preservation board is provided with the resin hardening layer I, the alkali resisting glass fiber cloth I is arranged outside the resin hardening layer I, the resin hardening layer II is arranged outside the alkali resisting glass fiber cloth I, the other side of the heat preservation board is provided with the resin hardening layer III, the alkali resisting glass fiber II is arranged outside the resin hardening layer III, and the resin hardening layer IV is arranged outside the alkali resisting glass fiber II.

The invention discloses a special fireproof inorganic double-track double-shutter rolling door. The rolling door comprises shutter surfaces, guide rails, a pedestal plate, rollers, a fireproof door roller and a fireproof rolling controller. The rolling door has the following beneficial effects: the shutter surfaces are formed by overlapping multiple layers of materials with corresponding functions, so that the temperature rise can be effectively reduced; the loads of the shutter surfaces are hung by steel wire ropes, so that the service life can be prolonged, and breakages caused by fire can be prevented; the installation cascade structures of the two shutter surfaces can be reversely installed, so that fire coming from different directions can be effectively prevented; the two rollers are controlled by a same shutter rolling machine, so that resources can be saved; reflecting cloth is additionally arranged in the shutter surfaces, so that heat added to the shutter surfaces can be effectively reduced; by arranging smoke control devices in the guide rails, sealing strips are swollen after heated, and gaps between the shutter surfaces and the guide rails can be extruded and eliminated; by additionally arranging expansion spray devices in the guide rails, after water which is contained in cavities of ear channels is swollen after being heated the bottom walls of small holes can be extruded and punched, so that the water in the cavities of the ear channels can be sprayed to the shutter surfaces, the temperatures of the shutter surfaces can be reduced, and the fire-resistant time can be effectively prolonged.

The invention provides a refrigerator and an automatic fire alarm method thereof. The refrigerator is provided with an automatic fire alarm safety device, wherein the automatic fire alarm safety device comprises detection probes, a control unit and an alarm device; the detection probes are arranged on fire prone places of the refrigerator and continuously transmit detection signals to the control unit; and the control unit judges whether a fire breaks out or not according to the detection signals and transmits alarm signals to the alarm device if judging that the fire breaks out. The refrigerator and the automatic fire alarm method thereof have the advantages that: the fire which breaks out outside the refrigerator can be alarmed in time and prevented, that whether a combustible refrigerant is leaked or not can be detected in time, and a fire inside the refrigerator can be prevented.

The invention discloses a safety protection device for a switch of a natural gas pipeline, which comprises a rectangular casing, and gas inlet pipes and gas outlet pipes are respectively arranged on the left and right sides of the upper part of the rectangular casing. The safety protection device for a natural gas pipeline switch has a simple structure and is easy to install , it occupies a small space when used, and can play a good role in safety protection for natural gas users. The use of the display enables the present invention to display the concentration of natural gas in the surrounding environment and the amount of natural gas used in real time, which is convenient for users. When a fire occurs, the flame arrester can effectively prevent the combustion of natural gas in the outlet pipe, the natural gas concentration detector can monitor the content of natural gas in the surrounding gas in real time, and the temperature sensor can monitor the temperature of the surrounding gas. The gas machine can discharge the surrounding air together with the natural gas to the outside, which can effectively prevent the occurrence of fire.

The invention discloses a heat insulation protection cable. The cable comprises an outer protective layer, an inner protective layer and three wire. The outer protective layer is positioned outside the inner protective layer; the three wires are located in the inner protective layer, a flame-retardant layer is fixedly installed on an inner wall of the outer protective layer, a heat insulation layer is fixedly installed on an inner wall of the flame-retardant layer, a waterproof insulation layer is fixedly installed on an inner wall of the heat insulation layer, a fire extinguishing cavity is formed between the waterproof insulation layer and the inner protective layer, and a steel sheet is fixedly installed in the fire extinguishing cavity. By setting the heat insulation layer, a three-layer heat insulation function can be realized outside the wires; the high temperature resistance and the heat insulation performance of a first heat insulation filling layer and a second heat insulationfilling layer are utilized, the high temperature resistance and the heat insulation performance of the cable are greatly improved, the normal work of the cable can be prevented from being influencedby external temperature factors, workers can be prevented from being scalded by too high temperature when the cable works, and the cable has very good safety.

The invention discloses a fireproof transformer which comprises a coil rack with a coil wound on the rack, a magnetic core arranged in a through hole in the center of the coil rack, a closing assembly capable of automatically closing the coil rack, a movable assembly connected with the closing assembly and an air extraction piece fixed on the closing assembly. A closing cover of a closable coil and an air pump capable of extracting air are provided, a sealed environment can be provided for the coil when fire happens, fire is prevented, and accidents are avoided.

The invention provides a flame retardant paper and a production method thereof. According to the method, 35-75 weight parts of aluminum silicate fibers and 5-4 weight parts of adhesives are used as the raw materials; the aluminum silicate fibers are removed dregs, then beaten for 5-30 minutes, mixed with the adhesives, poured into a defibering device with 800-3000rad for defibering, and subsequently made into papers by using a paper making forming device; and the papers are dried by vacuumizing to form paper sheets. The flame retardant packaging paper is produced by using aluminum silicate fiber compound papers instead of plant fibers and traditional flame retardants, is environment-friendly, and has good flame retardant effect, and the problems of using toxic substances, polluting environments, having poor flame retardant effect and the like during production of flame retardant packaging papers are avoided.

The invention discloses an automatic security bottle system comprising one or more bottle bodies. The bottle bodies are provided with bottle valves connected with an electric controlling device; the electric controlling device can achieve signal transmission with a controller; the electric controlling device is started through the controller to enable air in upper cavities to be discharged outward, the air pressure of the upper cavities is decreased, pistons move up, and accordingly automatic opening of valve openings is achieved to enable media in the bottle bodies to be released outward through nozzles; the electric controlling device is shut down through the controller, the pistons move down for retting to achieve automatic closing of the valve openings, and the nozzles are made to stop releasing the media. The automatic security bottle system has the functions of automatic starting and resetting, and accordingly the media can be sprayed and released for multiple times. The invention further discloses an automatic controlling method of the automatic security bottle system.

The invention relates to a steel heat insulation fireproof door. Each door leaf of the fireproof door comprises a framework and a door leaf panel; each of the frameworks and the door leaf panels is formed by cold rolled galvanized steel plates through rolling; each door leaf panel covers the outer side of the corresponding framework to form a two-layer flat box body; composite fireproof door core materials are injected into each two-layer flat box body; main bodies of two-layer door leaves are formed; the main bodies of the two-layer door leaves form an integral door leaf; a gap exists between the main bodies of the two-layer door leaves; the door leaves with the hollow middles are formed; an air inlet hole is formed in the lower end, corresponding to the hollow part, of each door leaf; the upper end and the side end of each door leaf are provided with exhaust holes; and the inner side surface and the outer side surface of each door leaf are provided with seam covering plates corresponding to door seams of the two door leaves. The steel heat insulation fireproof door has the advantages that the problem that the existing fireproof door cannot prevent fire and smoke from overflowing through the door seams; the integral flame-resistant or high-temperature-resistant performance of the fireproof door is poor; and the door can easily deform. The steel heat insulation fireproof door has the advantages that the all-around fireproof function is realized; the heated deformation of the door body after the fire catching can be prevented; and the flame and smoke overflowing can also be effectively prevented.

The invention discloses a fireproof transformer which comprises a coil rack with a coil wound on the rack, a magnetic core arranged in a through hole in the center of the coil rack, a closing assembly capable of automatically closing the coil rack, a movable assembly connected with the closing assembly and an air extraction piece fixed on the closing assembly. A closing cover of a closable coil and an air pump capable of extracting air are provided, a sealed environment can be provided for the coil when fire happens, fire is prevented, and accidents are avoided.

The invention discloses a fireproof rolling door with a locking mechanism, which comprises a transmission mechanism, a reel, a track, a fireproof rolling door body, a socket and a locking mechanism, rails are arranged on both sides of the fireproof rolling door body, and the fireproof rolling door body The upper end is wound on the outer circumferential surface of the reel, and a transmission mechanism is fixed at one end of the reel. The fireproof rolling door body includes a small curtain surface, and a solid part is fixed in the middle of the lowermost one of the small curtain surfaces, and the lowermost end The inner two sides of a small curtain surface are all set as hollow parts, and there are two locking mechanisms in total. The present invention provides a locking mechanism, which can lock the fire-proof rolling door body on the track when the fire-proof rolling door body falls to the ground. On the one hand, it avoids the opening of the lower rolling door caused by the fire-proof rolling door body due to the negative pressure generated by the fire, so that the fire-proof rolling door can be tightly closed to block the fire.

The invention discloses phase-changing heat-absorption expansive flame-retardant fireproof water-based paint. The phase-changing heat absorption expansive flame-retardant fireproof water-based paint is prepared from the following components in parts by weight: 35 to 75 parts of polyethylene glycol phase-changing self-cross-linked acrylate film forming emulsion, 5 to 25 parts of galactose expansionflame-retardant system and 5 to 35 parts of expandable filler. The phase-changing energy-storage material such as the polyethylene glycol and the galactose are used for absorbing the potential heat in a fire environment to resist the temperature rising, the expansive flame-retardant system formed by the ammonium polyphosphate and galactose is used for resisting the combustion of the material, sothat the high-efficiency flame retardance and fire resistance are realized, and the phase-changing absorbed heat is vast, the cooling and fireproof effect is significant, and the phase-changing heat-absorption expansive flame-retardant fireproof water-based paint is suitable for the flame retardance and fire resistance of furniture, walls, steel structures, cars, ships and tunnels; and the paint is carbonized and expanded at 250 DEG C to form an expansive foam carbon layer, so that the heat and oxygen can be effectively insulated, the release of the combustible gas can be prevented, the low fire can be prevented from forming big fire, the fire occurrence probability can be reduced, and the fire loss can be reduced.

The invention provides a fire gun of a high-rising building outer wall, which comprises a handle pipe and a sparge pipe, wherein the sparge pipe is installed at one end of the handle pipe, and a blow hole is arranged on the sparge pipe. The fire gun is characterized in that: the fire gun has a simple structure, is low in cost, and adopts the telescopic spray extinguishment, so the extinguishment scope is increased, the vertical spreading fire of an outer wall surface can be effectively stopped, the functions of cooling and extinguishment are obtained, during the initial fire period, personnel in a high-rising building connect the fire gun through a water hose in a wall fire hydrant for initial arrangement, so precious time for successful fire suppression is obtained, because the fire gun is provided with the handle pipe, an operator does not need to lean out of a window to operate, so the personnel safety of the operator is ensured, a switch which is arranged on the handle pipe brings more convenience to the operation, and only one person can complete the operation.

The invention relates to an adsorber (1a, 1b) for cleaning exhaust gas containing at least SOx and NOx, having: a gas distributor floor (2) for supplying the exhaust gas; a bulk material region (4) which is arranged above the gas distributor floor (2) and which is filled with adsorption and / or absorption medium, wherein the bulk material region (4) has a lower portion (9) and an upper portion (10), wherein the lower portion (9) is arranged above the gas distributor floor (2) and the upper portion (10) is arranged above the lower portion (9); - an extraction device (5) arranged above the bulk material region (4) for the purpose of extracting the exhaust gas which flows upwards from below; - a removal device (3) for removing the adsorption and / or absorption medium; - a hopper (6), arranged above the extraction device (5), for supplying the adsorption and / or absorption medium which travels through the bulk material region (4) from top to bottom; - a lance (7) which, in a transition regionbetween the upper (9) and the lower (10) portion of the bulk material region (4), projects into the bulk material region (4) and has at least one opening (25) for the direct injection of an ammonia-containing gas into the bulk material region (4). Also disclosed is a method for cleaning the exhaust gas.

The invention provides a fireproof door comprising a door frame, a door plank, a fire control alarm, a roller blind switch and a fire-proof roller blind. The door plank is located in the middle of the door frame and is fixedly connected to the door frame. The fire control alarm and the roller blind switch are located on one side of the door frame and are fixedly connected to the door frame. The left inner side and the right inner side of the door frame are provided with sliding grooves. The door frame is internally provided with an electric rolling shaft and a UPS, wherein the electric rolling shaft is movably connected with the door frame and the UPS is fixedly connected with the door frame. The upper end of the fireproof roller blind is fixed to the electric rolling shaft and the fireproof roller blind is movably connected with the door frame through the electric rolling shaft and the sliding grooves. The roller blind switch and the electric rolling shaft are electrically connected with the UPS and the fire control alarm is electrically connected with the UPS. The fireproof door can effectively prevent fire and smoke from spreading into houses, protect the safety of lives and property, can emit messages for help to the outside immediately and reduce the casualty rate of accidents.

The invention discloses a special fireproof inorganic double-track double-shutter rolling door. The rolling door comprises shutter surfaces, guide rails, a pedestal plate, rollers, a fireproof door roller and a fireproof rolling controller. The rolling door has the following beneficial effects: the shutter surfaces are formed by overlapping multiple layers of materials with corresponding functions, so that the temperature rise can be effectively reduced; the loads of the shutter surfaces are hung by steel wire ropes, so that the service life can be prolonged, and breakages caused by fire can be prevented; the installation cascade structures of the two shutter surfaces can be reversely installed, so that fire coming from different directions can be effectively prevented; the two rollers are controlled by a same shutter rolling machine, so that resources can be saved; reflecting cloth is additionally arranged in the shutter surfaces, so that heat added to the shutter surfaces can be effectively reduced; by arranging smoke control devices in the guide rails, sealing strips are swollen after heated, and gaps between the shutter surfaces and the guide rails can be extruded and eliminated; by additionally arranging expansion spray devices in the guide rails, after water which is contained in cavities of ear channels is swollen after being heated the bottom walls of small holes can be extruded and punched, so that the water in the cavities of the ear channels can be sprayed to the shutter surfaces, the temperatures of the shutter surfaces can be reduced, and the fire-resistant time can be effectively prolonged.

The invention discloses a fire-retardant heat preservation external wall and belongs to the technical field of buildings. The fire-retardant heat preservation external wall comprises a wall body. A heat preservation layer, a middle layer and a thermal insulation layer are arranged on the outer side of the wall body in sequence. The heat preservation layer is formed through mortise-tenon joint of a plurality of heat preservation plates. The heat preservation plates are connected with the wall body through expansion bolts. The thermal insulation layer is formed through mortise-tenon joint of a plurality of thermal insulation plates. The middle layer comprises a plurality of tin pieces, and the space between every two adjacent tin pieces is filled with an expansion block. One end of each tin piece is welded to the corresponding thermal insulation plate, and the other end of each tin piece is in threaded connection with the corresponding heat preservation plate. According to the scheme, through the arrangement of the middle layer, the heat preservation layer connected with the wall body is separated from the outside thermal insulation layer, when the thermal insulation layer burns in case of a fire, the state of matter in the middle layer is changed, separation of the heat preservation layer from the thermal insulation layer is achieved automatically, therefore the fire is prevented from spreading to the heat preservation layer fundamentally, and the purpose of thorough control over the fire is achieved.

The invention discloses a high flame-retardant intelligent distribution box. The distribution box comprises a shell with high flame-retardant performance, a door is arranged on the shell, an electric component is arranged in the shell, a camera is embedded outwards into the door of the shell, an image processing device is embedded into the door of the shell, and a communication device is embedded into the inner wall of the shell. The high flame-retardant intelligent distribution box has the functions of monitoring on the safety of the power utilization condition and the surrounding environment of the distribution box, communication transmission on power utilization information and safety information, and can meet the intelligent requirement of power distribution; and because the shell of the distribution box is made of a high flame-retardant material, the distribution box has good flame-retardant and fireproof performance, and the safety of power distribution is improved.

The invention discloses a packaging plastic thin film with a flame retardant effect, which comprises the following components in parts by weight: 100 to 110 parts of polyvinyl chloride, 7 to 10 parts of epoxidized soybean oil, 1 to 4 parts of barium cadmium stearate, 1 to 4 parts of a stabilizer, 3 to 5 parts of brominated polystyrene and 0.5 to 1 part of acrylate copolymer. In the mode, according to the packaging plastic thin film with the flame retardant effect, which is disclosed by the invention, in the case of a fire, the plastic thin film has low probability of burning, flame, dense smoke, toxic gas and the like cannot be generated, the fire can be prevented, lives and properties of people are protected, and the use safety is improved.

The invention discloses a garden landscape fire protection flowerpot based on air compression power. The flowerpot includes a base, a through hole is formed in the top of the base; a reaction cavity is formed in the base; a liquid storage tank is fixedly connected to the bottom of the inner wall of the reaction cavity; one side of the liquid storage tank communicates with a water outlet pipe; an electronic valve is arranged on the water outlet pipe; the part, located on one side of the liquid storage tank, of the bottom of the inner wall of the reaction cavity is fixedly connected with a solidtank; and the bottoms of the two sides of the reaction cavity communicate with air outlet pipes, the ends, away from the reaction cavity, of the air outlet pipes penetrate through the base and extendout of the base, the ends, located outside the base, of the air outlet pipes communicate with air pressure control valves, and air outlets of the air pressure control valves communicate with flow dividing air pipes. The invention relates to the technical field of garden fire protection. According to the garden landscape fire protection flowerpot based on the air compression power, fire spreadingcan be prevented, plants can be isolated from flames, and the portability is good.

A ballistic panel system is disclosed and claimed. In particular, the ballistic panel system includes a plurality of panels, each of which includes a frame comprises of a plurality of vertical and horizontal beams connected together. An armor layer is disposed over the frame; the armor layer could be ceramic armor plates, graphene, Kevlar, or some other ballistic material. The ballistic panel system is intended for use in schools and other locations where hostile actors are known to operate.

The invention discloses a multifunctional monitor for monitoring electrical fires and a method. The method comprises monitoring and control. The multifunctional monitor comprises a monitoring protection circuit, a PCB plate and a power incoming and outgoing wire electrode, wherein the monitoring protection circuit comprises an over-current switch, a temperature switch, a temperature fuse, varistors, a gas discharge tube and the like; the multifunctional monitor is installed at a power incoming wire end of an electrical appliance and directly monitors the current going into the power supply, the surge voltage and the temperature in the shell body directly; when an over-current or a surge overvoltage invades or the temperature is too high, control is carried out instantly, the power supply is intercepted or turned off immediately to remove hidden troubles, the electrical appliance is protected, and a fire is prevented from happening. The multifunctional monitor of the invention which integrates a thunder protection (containing surge and electrostatic protection), an over-current protection circuit and an overheating protection circuit is provided. The multifunctional monitor is advantaged by compact structure, small size, integrated detection and control, and convenient use. The series products of the monitor can construct a flexible and multifunctional electrical fire monitoring system and a vast electrical fire hazard prevention network.

The invention provides an emergency system for a liquid reservoir and an over-ground oil depot. The liquid reservoir comprises at least one storage tank located on the ground. The emergency system comprises at least one emergency storage tank and at least one liquid conveying pipe, wherein the two ends of the liquid conveying pipe communicate with the emergency storage tank and the storage tank, and each storage tank is at least connected with one emergency storage tank. According to the emergency system for the liquid reservoir and the over-ground oil depot, when fire disasters or other damage risk events happen to the storage tank, oil products in the accident storage tank is transferred into the emergency storage tank in time, so that the damage risk events such as the fire disasters are effectively controlled, further expansion of disaster risks is reduced, the probability of environmental pollution is reduced, and the security of reservoir areas can be ensured. In addition, a large amount of burning loss or draining of liquid in the accident storage tank is avoided, thereby facilitating asset storage.

The invention provides an intelligent linked fire extinguishing method for a pipeline. The intelligent linked fire extinguishing method comprises the following steps: detecting the dust concentrationin the pipeline by a dust detector, and transmitting a dust concentration signal in a control module; detecting the spark concentration in the pipeline by a spark detector, and transmitting a spark concentration signal in the control module; detecting the temperature in a dust remover by a temperature sensor, and transmitting a temperature signal in the control module; and controlling a first fireextinguishing device, a second fire extinguishing device, an alarming device and an image acquisition instrument according to the dust concentration, the spark concentration and the temperature by the control module. The intelligent linked fire extinguishing method has the advantages that a fire hazard can be effectively prevented, and intelligent linked alarming for fire extinguishing can be realized.

The invention provides a cable fireproof protection method and related equipment, and the method comprises the steps: S1, enabling a to-be-monitored cable to be divided into N feature cable segments,and enabling a temperature measurement optical fiber to be divided into M optical fiber temperature measurement points; S2, detecting the temperature of the N sections of characteristic cable sectionsin real time through M optical fiber temperature measuring points, and when the i optical fiber temperature measuring point detects that the N sections of characteristic cable sections have firehazard points and gives an alarm, automatically calculating the positioning information of the i optical fiber temperature measuring point by related equipment; and S3, according to the positioning information, the related equipment tripping off the circuit breaker of the fault cable section. Compared with the prior art, the cable fireproof protection method and the related equipment thereof fully utilize the optical fiber temperature measurement positioning information, analyze the distribution condition of the positioning information in the network, realize segmented protection, and adopt an energy blocking mode to realize active prevention and prevent fire disasters.

The invention discloses a lithium battery non-conductive charging device capable of preventing fire, which comprises a box body with a box cover and an electric control system, wherein the upper part of the box body is a battery compartment, and the lower part of the box body is an instrument compartment; an aerosol vehicle-mounted fire extinguishing device is mounted in the battery compartment; the electric control system comprises a current sampler, a current lead, a microprocessor, an alarm and a charging power supply; and the microprocessor is connected with the charging power supply, the alarm and the current sampler, and when the charging is finished or the current signal is abnormal, the microprocessor sends an instruction to control the alarm to send an alarm signal. The innovation point of the invention is that the source and range of battery fire can be controlled in the battery compartment, and the aerosol vehicle-mounted fire extinguishing device is used for extinguishing fire, so that the possibility of fire caused by battery combustion is thoroughly prevented. The device adopts a sealed charging space, oxygen is isolated firstly, and combustion is avoided at high temperature; and high-temperature substances of the second injection are limited in a tank body, so that external inflammable substances cannot be ignited.

The invention provides an integrated fireproof roller shutter door which comprises a door frame. A winding roller is arranged on the upper portion of the door frame, a fireproof roller shutter is wound on the surface of the winding roller, a first driving component is arranged at one end of the winding roller and drives the winding roller to rotate, sliding grooves are formed in the two sides of the door frame correspondingly, and a first mounting groove is formed in the bottom of the door frame. A rotating shaft is arranged in the first mounting groove, inhaul cables are arranged at the two ends of the rotating shaft correspondingly, the other opposite ends of the inhaul cables are connected to the fireproof roller shutter, the inhaul cables are arranged in the sliding grooves, a second driving component is arranged at one end of the rotating shaft and drives the rotating shaft to move, and the inhaul cables are driven by the rotating shaft to wind the bottom of the fireproof roller shutter around the rotating shaft. Compared with the prior art, the situation that in the prior art, a roller shutter door below is opened due to negative pressure generated by the fire behavior of thefireproof roller shutter door is avoided, the fireproof roller shutter door can be tightly closed, and the fire behavior is blocked.