KR102707665B1 - Drug for extinguishing metal fires comprising porous ceramics particles, method for manufacturing the same, fire extinguisher and energy storage system containing the same - Google Patents

Abstract

The present invention relates to a metal fire extinguishing agent, a method for manufacturing the same, a metal fire extinguishing agent including the same, and an energy storage device (ESS). The metal fire extinguishing agent according to the present invention is characterized by containing porous ceramic particles that are silicate-based glass and have an average diameter of 50 ㎛ to less than 1,000 ㎛ and a density of 0.4 to 1.5 g/cm3. The extinguishing agent of the present invention absorbs the heat that runs wild when a metal fire occurs, thereby being effective in the initial suppression, and forms a glass film at the point where the metal fire occurs, thereby maximizing the oxygen-blocking suffocation effect. In particular, the extinguishing agent of the present invention is highly environmentally friendly and is completely harmless to the human body, and is a highly ecological and environmentally friendly extinguishing agent that does not generate any toxic substances at the high temperature at which a fire occurs.

Description

{DRUG FOR EXTINGUISHING METAL FIRES COMPRISING POROUS CERAMICS PARTICLES, METHOD FOR MANUFACTURING THE SAME, FIRE EXTINGUISHER AND ENERGY STORAGE SYSTEM CONTAINING THE SAME}

The present invention relates to a fire extinguishing agent for metal fires, a method for producing the same, a fire extinguishing agent including the same, and an energy storage device (ESS).

Metal fires are the most dangerous fires, and they come in many forms and are very difficult to extinguish. Combustible metals that cause metal fires can be classified into alkali metals, alkaline earth metals, transition metals, other alloys, and metal hydrides, and the form of fire varies depending on the type. In the case of alkali metals such as lithium (Li), sodium (Na), and potassium (K), they react violently and catch fire when they come into contact with water regardless of the type of ignition source. When exposed to air, they undergo an oxidation reaction due to moisture and oxygen in the air, and the heat generated during this reaction causes ignition. Alkaline earth metals such as magnesium (Mg), beryllium (Be), and calcium (Ca), transition metals such as titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), and uranium (U), and other aluminum metals are not as dangerous as alkali metals when there is no fire, but when water is used, they are extremely dangerous. Also, even for the same metal, the situation varies depending on the fire scene, such as in the form of castings, chips, powder, fragments, and CHIPS. The smaller the particle size, the stronger the fire, and in the case of powder form, the risk of dust explosion also increases. When a metal fire occurs, the flame temperature ranges from about 2,750℃ to 4,700℃. In this temperature range, water can be decomposed into hydrogen and oxygen, and carbon dioxide can also be decomposed into carbon and oxygen. Therefore, when using aqueous solution-based extinguishing agents and carbon dioxide-based extinguishing agents in fire extinguishers to extinguish metal fires, the fire can spread and even lead to an explosion, so the use of these extinguishing agents is strictly prohibited for metal fires.

Accordingly, in Korea, the Hazardous Materials Safety Management Act and the Fire Service Act require the use of powder fire extinguishing equipment such as bicarbonate as fire extinguishing equipment and materials for metal fires, and require the provision of dry sand, expanded vermiculite, etc. at sites where there is a risk of fire. In fact, in many metal fires that occurred in Korea, it took a long time to extinguish the fire, and dry sand was used to extinguish the fire.

However, the current method of domestic fire departments to extinguish metal fires is to isolate combustible materials around the metal fire and allow the burning combustible metal to be naturally extinguished. This is because fire departments usually do not have dry sand and rely on local governments, and the sand held by local governments is for snow removal and cannot be used for firefighting. In reality, there is no system that can provide rapid support for the supply of dry sand in the event of an actual metal fire, so it takes a long time for dry sand to be supplied to the site of a metal fire, which makes it difficult to extinguish the fire. In addition, even if dry sand is supplied, it is difficult for firefighters and firefighting equipment to access the fire site due to exposure to smoke and high temperatures. In addition, improper storage of chemicals over a long period of time can lead to contamination of the chemicals, and if the contamination is moisture or water, the user can be in great danger when spreading the chemicals to extinguish the fire. In addition, even if the fire is extinguished, in the case of a metal fire, the fire appears to have been extinguished on the surface, but there is a high risk of re-ignition because high temperatures remain inside.

Metal fires are difficult to extinguish and require unique application techniques. Unlike general fires or oil fires, metal fires may not produce a large amount of flame or feel much radiant heat in the early stages of the fire. Magnesium may produce intense light, lithium may produce a large amount of thick smoke, and titanium or zirconium may produce very little smoke. However, even if the fire is small or does not produce many flames, it is by no means easy to extinguish. These are serious fires, and there is a great risk of danger when they are underestimated. Metal fires are like that.

In particular, with the recent increase in the use of various lithium-based energy storage systems (ESS), including lithium batteries for electric vehicles, uninterruptible power supplies (UPS) for data centers, and solar power generation systems, another type of lithium metal fire is occurring frequently, but there is currently no special measure to extinguish it.

Therefore, in the case of these metal fires, early extinguishment is essential. The safest way to extinguish a metal fire early is with a metal fire extinguisher. Extinguishing with a metal fire extinguisher is safer than any other method and will be like stopping what cannot be stopped with a sputum with a hoe. The advantage of a fire extinguisher is early fire suppression and rapid use. An effective extinguishing agent is an absolute element for effective extinguishment with a metal fire extinguisher.

Metal fires are classified as Class D fires in the fire classification system, and as mentioned above, they are completely different from other classes of fires. Agents used for Class A (general fire), Class B (oil fire), Class C (electrical fire), or Class K (kitchen fire) fires have no effect on Class D fires and may even have the opposite effect. Agents used for Class D fires may also have no effect on Class A, B, or C fires.

The KOSHA Guide G-77 of the Occupational Safety and Health Agency suggests the following extinguishing agents for metal fires developed domestically and internationally: sodium chloride (NaCl)-based MET-LX powder, sodium carbonate (Na ₂ CO ₃ )-based Na-X powder, graphite-based G-1 powder or Lith-X, TEC powder, a ternary mixture of potassium chloride (KCI), sodium chloride (NaCl), and barium chloride (BaCl2), and Boralon, a mixture of trimethoxyborane (TMB) and bromochlorodifluoromethane (Hallon 1211), and copper powder.

Most of the suggested extinguishing agents for metal fires are in powder form. According to NFPA 484, the adaptability of extinguishing agents varies depending on the type of combustible metal, centered on these components. Looking at the main components, aluminum, magnesium, thallium, and titanium are not adaptable to graphite and copper powder extinguishing agents, and lithium (Li) is adaptable to graphite extinguishing agents but not to sodium chloride. A notable point of NFPA 484 is that dry sand is suggested to be adaptable to extinguishing all major combustible metal fires, including Al, Li, Mg, Na, K, Ta, Ti, Nb, and Zr.

The present invention aims to develop an extinguishing agent for a metal fire extinguisher that can be applied universally regardless of the type of combustible metal, such as a dryer, and effectively extinguish a metal fire.

KR 10-1292512 B1 KR 10-2020-0137711 A KR 10-2022-0086725 A

The present invention proposes an extinguishing agent for a metal fire extinguisher that can be applied universally regardless of the type of combustible metal, such as a dryer, and can effectively extinguish a metal fire.

In order to effectively extinguish a metal fire, both oxygen supply blocking (suffocation extinguishing) and flame temperature lowering (cooling extinguishing) must be accomplished simultaneously. Therefore, the extinguishing agent for a metal fire extinguisher must completely surround or coat the combustible metal to block oxygen from the combustible metal, and must also have the ability to absorb heat so that the temperature required to maintain the flame is lowered.

Therefore, in order to satisfy these extinguishing principles, the extinguishing agent for a metal fire extinguisher must have the following characteristics.

① It must be able to withstand high temperatures without chemically reacting with flammable metals.

② It must have a cooling effect (it must be possible to extinguish a fire by rapidly cooling it down to below the ignition point).

③ It can cover burning metal surfaces and uneven metal surfaces to block oxygen. (The fire extinguishing agent forms a tight shell on the burning metal surface, suffocating it and extinguishing the fire.)

④ It should be able to float on the surface of the molten metal during combustion.

(i.e., the specific gravity of the extinguishing agent must be lower than that of the liquid combustible metal)

Therefore, the agent for a metal fire extinguisher is chemically stable at high temperatures and will not react with pyrophoric metals. It has heat absorption properties that lower the fire temperature and is applied over the material causing the fire to block oxygen, thereby enabling the metal fire to be extinguished.

The powder extinguishing agents for metal fires proposed so far are substances with the above-mentioned characteristics, such as graphite, sodium carbonate, sodium chloride, and talc, as main components, and organic substances added as binders. These agents melt the organic substances by heating, turning the main component into a glassy state, covering the metal surface and blocking the supply of oxygen.

In addition, even if it is a material with the above characteristics, it must be possible to fill the fire extinguisher in order to be used as an extinguishing agent for a metal fire extinguisher. Generally, a metal fire of about 0.5 kg requires about 6.5 kg of metal fire extinguishing agent, and a small metal fire extinguisher weighs 30 LB (13.6 kg) and a large metal fire extinguisher weighs 150 LB (68 kg). Therefore, at least 13.6 kg of extinguishing agent must be able to be filled into the volume of a metal extinguisher currently in use. In other words, if the density is too low, it may not be easy to fill the required amount of agent according to regulations.

In this respect, it can be noted that dry sand, expanded vermiculite, and expanded pearlite, which are currently recommended as fire extinguishing equipment and materials for metal fires under the Hazardous Materials Safety Management Act and the Fire Service Act, are stable materials that can withstand high temperatures without chemically reacting with combustible substances, although they have low metal covering properties or cooling effects.

The present invention focuses on the fact that an inorganic glass material having a silicate structure has the basic characteristic of being an extinguishing agent for metal fires. The melting point of glass varies depending on the type of glass, but is 1000 ^o C or less, so that when a metal fire occurs, it will melt and cover the surface of the combustible metal to exhibit the performance of blocking oxygen. Furthermore, when soda-lime glass having a low melting point is selected as the type of glass, it can easily cover the burning metal surface or the uneven metal surface at an even lower temperature, so that the oxygen blocking effect can be achieved more easily.

However, it is difficult to expect the cooling effect, which is a necessary requirement as a metal fire extinguishing agent, from the normal glass itself. In addition, the specific gravity of the glass material is 2.45 g/cm3, which is similar to the specific gravity of sand, which is 2.6 to 2.7 g/cm3, so it cannot be a extinguishing agent filled and used in a metal fire extinguisher by itself. Furthermore, in order to use the glass material as a metal fire extinguishing agent, it must be used in the form of glass powder, and it is not easy to avoid moisture contamination like sand when stored in the form of glass powder for a long time. Therefore, in order to use the glass material as an extinguishing agent for a metal fire extinguisher, how to impart a cooling function to it and how to make it lightweight so that it can float on the liquid surface of the molten metal during combustion are tasks that must be solved in the present invention.

These challenges can be solved by foaming glass.

The foaming process of glass is carried out by finely crushing glass material, adding an appropriate foaming agent, mixing well, and then firing the mixture under temperature conditions of 700 to 1,100 ^o C. During this firing process, the glass particles surrounding the foaming agent are first bonded through melting and sintering, and at the same time, the foaming agent itself surrounded by the glass particles decomposes or the gas generated through the reaction between the foaming agent and the glass components expands, causing the glass to swell overall. As a result, the glass having a certain shape has pores of various shapes formed inside it, and the glass having a density of 2.45 g/cm3 before foaming becomes lightweight when foaming is complete, becoming 0.12 to 0.14 g/cm3.

However, the core process for manufacturing the extinguishing agent for the metal fire extinguisher of the present invention is not to sufficiently foam the spherical ceramic particles formed with fine glass powder having a density of 2.45 g/cm3 to become porous ceramic particles having a density of 0.12 to 0.14 g/cm3 as in a conventional foaming process, but to partially foam them so that the density has a value of 0.4 to 1.5 g/cm3. In addition, the spherical porous ceramic particles are manufactured so that the average diameter of the manufactured spherical ceramic particles does not exceed 1000 ㎛. This is to ensure that the spherical porous ceramic particles have cooling performance and dispersing performance as a metal fire extinguishing agent. The spherical porous ceramic particles manufactured in this way can become an extinguishing agent having all of the necessary characteristics as an extinguishing agent for a metal fire extinguisher.

Based on the principle of this foaming process, the manufacture of extinguishing agents for metal fire extinguishers is carried out more specifically through the following manufacturing process.

(a) a step of pulverizing a glassy material;

(b) a step of preparing raw material powder for manufacturing ceramic particles by mixing a molding binder and a pore control agent into the above-mentioned unpulverized glass powder;

(c) a step of granulating the raw material powder into a molded body having a diameter of less than 1000 ㎛ in a molding machine; and

(d) It is characterized by including a step of foaming the above molded body to produce porous ceramic particles.

And by filling the porous ceramic particles, which are fire extinguishing agents for metal fires, manufactured through the above manufacturing process, together with liquid nitrogen into the fire extinguisher, a fire extinguishing agent for metal fires is manufactured. When filling the agent, ammonium phosphate monobasic (MAP) may also be filled together if necessary. This is because, in cases where organic electrolytes in the battery, such as lithium batteries, combust together and flames are generated, the spherical porous ceramic fire extinguishing agent can be expected to have a preferential effect in extinguishing the flames simultaneously with the spraying of the agent before it is sprayed and sufficiently covers the ignition area.

Additionally, when a certain amount of the fire extinguishing agent of the present invention is added to the contact portion of an adjacent energy storage system and packaged by connecting multiple lithium batteries into one unit, the cooling function of the fire extinguishing agent suppresses thermal runaway when a fire occurs, thereby blocking the spread of fire to the energy storage system of the neighboring adjacent packaging unit, thereby facilitating fire extinguishing of a lithium battery-based energy storage system. The use of such a fire extinguishing agent is similar to installing a fire extinguishing agent for metal fire extinguishing in an energy storage system.

Recently, the number of fires has increased due to social and environmental factors such as the increase in high-rise buildings, diversification of construction methods and materials, lack of management of fire facilities, and abnormally high temperatures in summer. In addition, the use of combustible metals has increased due to the development of industries such as fuel cells and semiconductors. Accordingly, the possibility of fatal metal fires has increased, and it will be very effective in the early extinguishment of such fires.

It will work effectively for extinguishing fires in lithium batteries and energy storage devices including the same. It is possible to extinguish a lithium fire itself, but it will be difficult to extinguish thermal runaway of a lithium battery. However, the method of the present invention has an excellent cooling effect for suppressing thermal runaway, so it is effective for extinguishing fires in lithium batteries and energy storage devices including the same. In particular, the fire extinguishing agent of the present invention has a cooling effect, so when filled in a packaging that surrounds a battery in an energy storage system, it will have the effect of directly suppressing thermal runaway when a fire occurs and delaying the spread of the fire.

As electric vehicles are developed and popularized, electric vehicle charging facilities will inevitably be installed in underground parking lots of apartments or homes, and accordingly, the possibility of a battery fire occurring during charging will increase. In this case, the fire will become very large, and by deploying a fire extinguisher containing the extinguishing agent of the present invention, it will be possible to extinguish the battery fire in the early stage of the fire and prevent it from spreading to a large fire.

Figure 1 is a photograph of a metal fire extinguishing agent according to the present invention, showing cross-sections of the manufactured extinguishing agent and fine particle grains in sequence.
Figure 2 is a photograph showing the process and results of a Mg fire extinguishing performance test in sequence, in which a burning magnesium rod was immersed in the agent and tested.
Figure 3 is a photograph showing the process and results of a test of the extinguishing performance of a Mg fire in sequence. The test was conducted by covering a burning magnesium rod with the agent.
Figure 4 is a photograph showing the process and result of evolving combustion of 5 kg of ignited titanium powder.
Figure 5 is a photograph showing the process and result of extinguishing combustion of 5 kg of ignited metal scrap.
The upper photos in Figure 6 show the form of a plate formed by the dispersed glassy extinguishing agent melting at high temperature and flowing down onto the burning metal, and the lower photo shows that there are traces of numerous pores bursting in the upper form of the plate.
Figure 7 is a photograph showing the process and result of re-igniting the residual metal of the first evolved portion.
Figure 8 is a photograph showing the process and results of extinguishing a lithium battery fire.

Hereinafter, preferred embodiments of the present invention will be described in detail. First, in describing the present invention, specific descriptions of related known functions or configurations have been omitted so as not to obscure the gist of the present invention. The terms "about", "substantially", etc. used in this specification are used in the meaning of a numerical value or a meaning close to a numerical value when manufacturing and material tolerances inherent to the mentioned meaning are presented, and are used to prevent unscrupulous infringers from unfairly using the contents in which exact or absolute values are mentioned to help understanding of the present invention.

The present invention proposes an extinguishing agent for a metal fire extinguisher and a manufacturing method thereof, which can be applied universally without being restricted by the type of combustible metal such as a dryer, using a glassy material as a raw material, and can effectively extinguish a metal fire.

According to one aspect of the present invention, a metal fire extinguishing agent is provided, which contains porous ceramic particles that are silicate-based glass and have an average diameter of 50 ㎛ or more to less than 1,000 ㎛ and a density of 0.4 to 1.5 g/cm3.

According to one embodiment of the present invention, the porous ceramic particles may have a density of 0.4 to 1.3 g/cm3, for example, 0.4 to 1.25 g/cm3 or 0.8 to 1.3 g/cm3 or 0.9 to 1.25 g/cm3.

According to another embodiment of the present invention, the porous ceramic particles may have closed pores or a mixture of closed pores and open pores.

According to another embodiment of the present invention, the porous ceramic particles may be made of soda-lime glass or borosilicate glass.

According to another embodiment of the present invention, the porous ceramic particles may have a spherical shape.

According to another embodiment of the present invention, the extinguishing agent may be used to extinguish combustion of a lithium battery or combustion of a lithium-based energy storage system.

According to another aspect of the present invention, a metal fire extinguisher comprising the above-described extinguishing agent is provided.

According to one embodiment of the present invention, the fire extinguisher may further include ammonium phosphate monobasic (NH ₄ H ₂ PO ₄ ) as an extinguishing agent.

According to another aspect of the present invention, an energy storage device including the aforementioned digestive agent and a lithium battery is provided.

According to another aspect of the present invention, there is provided a method for manufacturing a fire extinguishing agent for a metal fire,

(a) a step of pulverizing a glassy material;

(b) a step of mixing a molding binder and a pore control agent into the above-mentioned unpulverized glass powder to create a raw material powder for manufacturing porous ceramic particles;

(c) a step of granulating the raw material powder for manufacturing the porous ceramic particles into a molded body having an average diameter of less than 1000 ㎛ in a molding machine; and

(d) a manufacturing method is provided, comprising a step of foaming the molded body to manufacture porous ceramic particles.

According to one embodiment of the present invention, the step (a) may be to pulverize the glassy material into a size having an average diameter of less than 44 ㎛.

According to another embodiment of the present invention, the step (d) is performed by introducing the molded body into a reactor whose temperature is controlled between 150 and 1100°C; the manufacturing method may further include the step (e) of slowly cooling the porous ceramic particles to room temperature.

According to another embodiment of the present invention, the reactor may be an upright kiln or a fluidized bed reactor divided into sections such that the drying and preheating steps, the foaming calcination step, the stabilization step, and the slow cooling storage step are sequentially performed.

According to another embodiment of the present invention, the molded body can be placed on top of the upright kiln and allowed to fall freely to undergo the steps in the upright kiln.

According to another embodiment of the present invention, the drying and preheating steps may be performed in a region controlled to a temperature range of 150 to 600°C, the foaming firing step may be performed in a region controlled to a temperature range of 700 to 1,100°C, and the stabilization step may be performed in a region controlled to a temperature range of 450 to 550°C.

According to another embodiment of the present invention, the upright kiln may be an upright kiln equipped with an electric field to prevent the porous ceramic foam from being attached to the high-temperature furnace wall due to electrical repulsion after the foaming kiln step.

According to another embodiment of the present invention, in step (a), the glassy material may be waste glass.

According to another embodiment of the present invention, the molding binder may be water glass, PVA (Poly(vinyl alcohol)), or a combination thereof.

According to another embodiment of the present invention, the pore control agent is at least one selected from carbon, carbonate, and glycerin. It could be strange.

In order to be an extinguishing agent for a metal fire extinguisher, it must have the following characteristics:

① It must be able to withstand high temperatures without chemically reacting with flammable metals.

② It will have a cooling effect (extinguishes the fire by rapidly cooling it down to below the ignition point.)

③ It can cover burning metal surfaces and uneven metal surfaces to block oxygen. (The fire extinguishing agent forms a tight shell on the burning metal surface, suffocating it and putting out the fire.)

④ It should be able to float on the surface of the molten metal during combustion.

(i.e., the specific gravity of the extinguishing agent must be lower than that of the liquid combustible metal)

In other words, the agent for a metal fire extinguisher must be chemically stable at high temperatures and not react with pyrophoric metals, have heat absorption properties to lower the fire temperature, and be applied over the material causing the fire to block oxygen, thereby extinguishing the metal fire.

In the present invention, the glass, which is a raw material for manufacturing the fire extinguishing agent, is a ceramic material having a silicate structure, which does not chemically react with combustible metals at high temperatures and can stably withstand high temperatures. In addition, the melting point of the glass varies depending on the type of glass, but is 1000 ^o C or lower, so that it can melt when a metal fire occurs and cover the surface of the combustible metal to block oxygen, and can also exhibit the performance of blocking oxygen. If soda-lime glass with a low melting point is selected and used, it can more easily cover the burning metal surface or the uneven metal surface, so that an effective oxygen blocking effect can be expected.

However, the cooling effect, which is a necessary requirement as a metal fire extinguishing agent, the property to float on the surface of molten metal during a metal fire, and the performance to release and disperse the extinguishing agent at the time of a metal fire after being charged into a metal fire extinguisher are performances that cannot be achieved by themselves due to the specific gravity of glass, which is 2.45 g/cm3, and the material engineering characteristics of ceramic material. The way to solve these problems is the foaming process of glass.

The foaming process of glass is carried out by finely crushing glass material, adding an appropriate foaming agent to it, mixing well, and then firing the mixture under temperature conditions of 700 to 1100 ^o C. During this firing process, the glass particles surrounding the pore-controlling agent (foaming agent) are first bonded through melting and sintering, and at the same time, the glass substance swells due to the expansion of gas generated through the decomposition of the foaming agent itself surrounded by the glass particles or the reaction between the foaming agent and the glass components, ultimately causing the glass substance to expand overall. As a result, the glass substance with a certain shape has pores of various shapes formed inside it, and the glass substance with a density of 2.45 g/cm3 before foaming can have its density lowered to 0.12 to 0.14 g/cm3 when foaming is complete, and it becomes lighter.

However, in the present invention, the foaming of the glass material for manufacturing the fire extinguishing agent for a metal fire extinguisher does not sufficiently progress to foam the manufactured porous ceramic particles so that the density reaches 0.12 to 0.14 g/cm3, and the key manufacturing process requirement is to partially foam the manufactured porous ceramic particles so that the density is limited to 0.4 to 1.5 g/cm3.

The reason for this partial foaming is to ensure that the manufactured spherical ceramic porous body has cooling performance as a metal fire extinguishing agent. The foaming process involves finely pulverizing a glass material, adding an appropriate foaming agent and a molding binder, and mixing the finely powdered glass powder into a size that can be used as a fire extinguishing agent. This is then foamed at a certain optimal temperature for a certain period of time. The finely spherical glass powder molded body becomes lightweight and its density is reduced to 0.4 to 1.5 g/cm3 through the foaming process, and it can be discharged through a fire extinguisher. Since only partial foaming is performed, the fine powder spherical molded body spontaneously foams until its density reaches 0.12 to 0.14 g/cm3 through the high heat generated by the fire during the metal fire extinguishing process, and this process is a very strong endothermic reaction, which causes a cooling function that lowers the temperature of the metal fire.

This cooling effect is particularly effective in extinguishing lithium battery fires. It is not easy to extinguish a fire of lithium metal itself, but in the case of lithium batteries, thermal runaway occurs, making extinguishing very difficult. However, the extinguishing agent of the present invention has an excellent cooling effect for suppressing thermal runaway, and is therefore effective in extinguishing lithium battery fires. In particular, an energy storage system is packaged by connecting multiple lithium batteries into one unit, and if the extinguishing agent is included in the packaging, when a fire occurs, the cooling function of these extinguishing agents suppresses thermal runaway, thereby blocking the spread of fire to the energy storage system of the neighboring packaging unit, making it easy to extinguish a fire in a lithium battery-based energy storage system.

The spherical fine powder molded body discharged from the fire extinguisher has an appropriate density of 0.4 to 1.5 g/cm3, so that in the event of a metal fire, it will not fly away due to the high temperature buoyancy but will fall to the ignited area, and also will be able to float on the molten metal. Finally, this glassy foam molded body will melt and cover all metal parts including the uneven parts of the metal, completely blocking oxygen, so that the metal fire will be effectively extinguished.

Therefore, in the present invention, the production of a fire extinguishing agent for metal fires using a glassy material as a raw material is specifically carried out through the following production process.

(a) a step of pulverizing a glassy material into a size having an average diameter of less than 44 ㎛;

(b) a step of mixing a molding binder and a pore control agent into the above-mentioned unpulverized glass powder to prepare a raw material powder for manufacturing a fire extinguishing agent;

(c) The raw material powder for manufacturing the above digestive agent is molded into a diameter of 1000㎛ in a molding machine. A step of forming into spherical particles of less than 100 micrometers;

(d) a step of introducing the above spherical particles into the upper part of an upright kiln controlled at 150 to 1100 ^o C and allowing them to fall freely, thereby firing and stabilizing them to be partially foamed into spherical porous ceramic particles having a density of 0.4 to 1.5 g/cm3;

(e) It is characterized by comprising a step of obtaining a fire extinguishing agent for extinguishing metal fires by slowly cooling and heat-treating stabilized spherical porous ceramic particles to room temperature.

Below, we will look at each step in detail.

The step of (a) pulverizing the glassy material into a size having an average diameter of less than 44 ㎛;

In the present invention, the raw glass for manufacturing the extinguishing agent for a metal fire extinguisher uses various bottle glasses, plate glasses, solar glass, and soda-lime glasses as starting materials. However, soda-lime glass is not limited to the starting material. Various glasses including borosilicate glasses for display glass and automobile glass can also be starting materials. In other words, the manufacturing process for the extinguishing agent for a metal fire extinguisher can be applied to all types of glass without limitation on the type of glass, and when borosilicate glass is used, the extinguishing agent manufactured can be expected to have an extinguishing power that can be more effective in extinguishing metal fires that proceed at higher temperatures. When borosilicate glass is used as the starting material, the foaming firing temperature requires high temperature firing of 800 to 1050 ^o C, which is higher than the foaming temperature of 700 to 900 ^o C in the case of soda-lime glass due to the high melting point of borosilicate glass. Although it may affect the increase in manufacturing cost due to additional energy requirement for high-temperature firing and restrictions on installation of high-temperature firing equipment, the manufactured fire extinguishing agent may have the great advantage of being a specialized fire extinguishing agent that can be applied to extinguishing high-temperature fires.

The most important characteristic for manufacturing the extinguishing agent for a metal fire extinguisher is that the spherical porous ceramic particles, which are the extinguishing agent, have an average diameter of less than 1000 ㎛ and a density of 0.4 to 1.5 g/cm3. In order to manufacture spherical porous ceramic particles having the characteristics of such density and average diameter from a glassy material having a density of 2.45 g/cm3 as a starting material, the particle size of the crushed fine glass is a very important key manufacturing condition.

Basically, in order to obtain the lowest possible density, the particle size of the raw glass is very important. During the foaming process, pores are created, and it is desirable that each pore be formed as an independent pore. At this time, the thickness of the wall between each pore is directly affected by the diameter of the raw glass particles. In other words, as the diameter of the glass particles increases, the pore walls become thicker, which directly leads to an increase in weight and an increase in the density of the porous ceramic particles. Therefore, in order to control the pores and obtain a low density, it is desirable to make it as fine as possible, and in order to control the target density of the porous ceramic beads to 0.4 to 1.5 g/cm3, it is desirable to finely powder the glass particles to a size as small as possible, less than 44 ㎛ in average diameter. However, the finer the powder, the more grinding energy is required, which can also cause an increase in manufacturing costs due to a decrease in productivity.

(b) a step of preparing a raw material powder for manufacturing a fire extinguishing agent by mixing a molding binder and a pore control agent into the above-mentioned unpulverized glass powder;

The most important characteristic for manufacturing the fire extinguishing agent of the fire extinguishing agent for the metal fire extinguishing device of the present invention is to make the spherical porous ceramic particles, which are the fire extinguishing agent, have an average diameter of less than 1000 ㎛ and a density of 0.4 to 1.5 g/cm3. To this end, glass having a density of 2.45 g/cm3 as a starting material is finely ground to a size of less than 44 ㎛, and a molding binder and a pore regulator are added and mixed into the glass powder, and then this fine glass powder mixture is made into a powder having an average diameter of 1000 ㎛. It must be molded into a spherical bead shape having an average diameter of less than 1000㎛. The molding binder is a binder for molding a fine glass powder mixture into a spherical bead shape having an average diameter of less than 1000㎛.

The above molding binder can be used alone or in combination with liquid binders such as water glass, CMC, and PVA. There may be slight differences in the mixing method depending on the form used, but it is appropriate to use 2 to 20 parts by weight per 100 parts by weight of raw glass powder. If the molding binder is used in an amount of less than 2 parts by weight, the bonding force is insufficient, making molding difficult. Excessive addition of more than 20 parts by weight not only makes molding difficult, but also causes an increase in the density of porous ceramic particles, which is not desirable.

The above pore regulator directly affects the foaming of glass and the pore shape. The primary goal of the pore regulator in the glass material is to control the density of the extinguishing agent for metal fires. More specifically, it is to make the glass with a density of 2.45 g/cm3 have a density of 0.4 to 1.5 g/cm3. In addition, this pore regulator plays a role in promoting additional foaming when the metal fire agent is injected as an extinguishing agent.

Any material that generates gas by itself or reacts with components in the glass at the time of foaming can be used as a pore-controlling agent. Therefore, the optimal pore-controlling agent should be selected and determined according to the type of glass used.

In addition, another function of the pore control agent is to control the shape of the internal pores of the finished fire extinguishing agent, the spherical porous ceramic particles. The porous characteristics formed in the glass through the foaming process of the glassy material are achieved by the bubbles formed in the glass. The bubbles formed in the glass are composed of open bubbles and independently closed bubbles. There is no significant difference in the fire extinguishing performance regardless of the shape of the bubbles formed. However, in terms of the long-term storage of the fire extinguishing agent, the pore characteristics formed by independently closed bubbles are more preferable than the open bubbles. Since the pores formed by independently closed bubbles have greater resistance to moisture penetration than the open pores, porous ceramic particles formed by closed pores are more preferable as a metal fire extinguishing agent where the presence of moisture is absolutely prohibited.

When soda-lime glass is used, the pore regulator can be a solid pore regulator such as various forms of carbonates such as sodium carbonate, calcium carbonate, carbon, and a liquid pore regulator such as glycerin or PVA. The mixing method can be different depending on the type used, and it is effective for the formation of pores or foaming to use it alone or in combination in an amount of 0.1 to 4.5 parts by weight per 100 parts by weight of fine glass powder. Basically, the appropriate amount of carbon pore regulator to be added is 0.1 to 0.5 parts by weight per 100 parts by weight of glass powder. The amount of carbon for foaming should be at least 0.1 part by weight or more, and adding more than 0.5 parts by weight causes overfoaming and is not suitable. When a carbon pore regulator is used, the formation of closed pores is advantageous. When using a carbonate such as CaCO ₃ or Na ₂ CO ₃ as a pore regulator, 1.5 to 4.5 parts by weight can be added per 100 parts by weight of glass powder, and in this case, open pores and closed pores are created together. Therefore, carbon and carbonate can also be used in combination for pore control. When using glycerin or PVA, which are liquid pore regulators, 0.5 to 4.5 parts by weight can be added per 100 parts by weight of glass powder. When using less than 0.5 parts by weight, the pore creation effect is low due to self-decomposition before foaming, and when using 4.5 or more, excessive foaming occurs or the independent pore formation of the spherical formation of the porous ceramic beads is inhibited, which causes an increase in the density of the porous ceramic beads. When using glycerin or PVA, which are liquid pore regulators, independent pore creation takes the lead.

(c) a step of molding the raw material powder for manufacturing the above digestive agent into spherical particles with an average diameter of less than 1000㎛ in a molding machine;

This is a step of adding a molding binder and a pore regulator to finely ground glass powder to a size of less than 44 ㎛, mixing the mixture, and then feeding the glass powder mixture into various types of molding machines to mold into spherical particles having an average diameter of less than 1000 ㎛. It is preferable to process the molding into spherical particles in large quantities using a flat plate molding machine, and if necessary, various granulating devices such as cone drums can be used, and the use of special devices is not limited to the use of such devices. The size of the molded body directly affects the future foaming and sintering process. In the foaming and sintering process, the speed of heat conduction is fast in the high-temperature plastic foaming region, so it is desirable to maintain a uniform size with little deviation in the size of the spherical particle molded body.

(d) The above spherical particle molded body is 150 to 1,100 ^o A step of introducing into the upper part of an upright sintering furnace controlled by C and allowing it to fall freely, sintering and stabilizing it so that it is partially foamed into spherical porous ceramic particles having a density of 0.4 to 1.5 g/cm3;

The spherical particle molded body having an average diameter of less than 1000㎛ formed in the molding machine is introduced into the sintering step for foaming. In order for these spherical particles to foam, they must first become glassy by melting and sintering between the glass particles around the pore-control agent in the foaming reaction mechanism, thereby enclosing the pore-control agent. At the same time, the pore-control agent surrounded by the glass particles swells due to the expansion of gas generated through self-decomposition or reaction between the pore-control agent and the components of the glass, and the foaming process in which the glass material expands as a whole proceeds. Therefore, in order for the foaming to proceed efficiently and easily, the glass material must be maintained in a nearly molten state. The glass powder molded body with the surface melted sticks to each other or adheres to the wall of the sintering furnace, making it impossible to manufacture normal spherical particles without using a release agent. In order to foam the glassy spherical particle molded body in this state, it may be possible to manufacture it by introducing the release agent and the spherical particle molded body to be sintered together using a rotary kiln. However, in the present invention, the particles to be foamed by plasticization are fire extinguishing agents for metal fire extinguishers and have a particle size of less than 1000㎛ in diameter, so it is not easy to select an appropriate release agent, and even if an appropriate release agent is used, it is impossible to avoid the inconvenience of having to separate the fire extinguishing agent and the release agent obtained after the foaming firing process. Therefore, in the present invention, in order to foam and fire spherical ceramic particles without using a release agent, the spherical particle molded body to be foamed is introduced and dropped from the top of an upright firing furnace controlled at 150 to 1100 ^o C to carry out foaming by plasticization.

The upright kiln into which the spherical particle molded body is introduced consists of four sections: a drying section, a preheating section, a foaming firing section, and a subsequent stabilization section, and is operated so that the temperature of each section can be controlled. The temperature range of each section should be controlled according to the type of raw glass. In the case of soda-lime glass, the temperature of the foaming firing step is controlled in the temperature range of 700 to 900 ^o C, and the target density of 0.4 to 1.5 g/cm3 of the spherical porous ceramic particles obtained after the firing is obtained by controlling this temperature. After the firing foaming section, the spherical porous foam body passes through the stabilization section controlled at 450 to 550 ^o C and falls into the storage section on the bottom.

And since the foam firing process is carried out without the use of a release agent, in the foam firing area, if the foam fired spherical porous foam is attached in a molten state to the high-temperature wall of the upright firing furnace, production of normal porous ceramic particles is impossible, so an electric field is used to suppress attachment by electrical repulsion.

(e) a step of obtaining a fire extinguishing agent for extinguishing metal fires by slowly cooling and heat-treating the stabilized spherical porous ceramic particles to room temperature;

The spherical porous foam that has passed through the stabilization zone falls as spherical porous ceramic particles into a storage space installed at the lowest floor of the upright kiln. The spherical porous ceramic particles are cooled by air sucked in from the outside, and the cooled spherical porous ceramic particles are pressurized and discharged to an external storage, and finally, a fire extinguishing agent for extinguishing metal fires is obtained. These fire extinguishing agents were directly used or filled into fire extinguishers to carry out the following examples.

[ Example 1 ]

12 kg of waste glass bottles, which are soda-lime glass, are placed in a ball mill and crushed to an average diameter of glass particles of less than 44 ㎛. For 10 kg of this finely divided glass powder, 1.9 kg of water glass as a molding binder and 0.2 kg of glycerin as a pore regulator are added and mixed well. This mixture is molded into a disk-type spherical molding granulator with an average diameter of 1000 ㎛. The spherical porous ceramic particles are formed into particles less than 100 μm in diameter. After drying at room temperature, they are introduced into the upper part of an upright kiln where the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature to 750 to 800 ^o C, and the stabilization zone to 450 to 500 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to cool the spherical porous ceramic particles, which are then pressurized and transferred to an external container to obtain an extinguishing agent for a metal fire. The manufactured spherical porous ceramic particles had a density of 1.12 g/cm ³ , and it was confirmed that the pore structure was formed almost entirely of closed pores, as shown in Fig. 1. Fig. 1(a) shows the form of the manufactured extinguishing agent, and Fig. 1(b) is a cross-sectional photograph of fine particle grains. It was confirmed that the pore structure was formed into the most preferable structure in which moisture penetration was suppressed for long-term storage of the extinguishing agent in an independent closed tank, and that foaming was performed.

[ Example 2 ]

12 kg of waste glass bottles made of soda-lime glass are placed in a ball mill and crushed so that the average diameter of the glass particles is less than 44 μm. For 10 kg of this finely divided glass powder, 2 kg of water glass as a molding binder and 0.3 kg of calcium carbonate as a pore regulator are added and mixed well. This is molded into spherical particles having an average diameter of less than 1000 μm in a disk-type spherical molding granulator. After drying at room temperature, this is introduced into the upper part of an upright kiln where the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is adjusted to 780 to 820 ^o C, and the stabilization zone is adjusted to 450 to 500 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to pressure-transport the cooled spherical porous ceramic particles to obtain an extinguishing agent for a metal fire in an external container. The manufactured spherical porous ceramic particles had a density of 0.98 g/cm ³ and the pore structure was confirmed to be a structure formed by closed pores and open pores.

[ Example 3 ]

12 kg of waste glass bottles made of soda-lime glass are placed in a ball mill and crushed so that the average diameter of the glass particles is less than 44 μm. For 10 kg of this finely divided glass powder, 2 kg of water glass as a molding binder and 0.03 kg of carbon as a pore regulator are added and mixed well. This is molded into spherical particles having an average diameter of less than 1000 μm in a disk-type spherical molding granulator. After drying at room temperature, this is introduced into the upper part of an upright kiln in which the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is adjusted to 750 to 800 ^o C, and the stabilization zone is adjusted to 450 to 500 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to pressure-feed the cooled spherical porous ceramic particles to obtain an extinguishing agent for a metal fire in an external container. The manufactured spherical porous ceramic particles had a density of 1.13 g/cm ³ , and the pore structure was confirmed to be a structure in which closed pores and open pores were mainly developed.

[ Example 4 ]

12 kg of waste solar glass, which is soda-lime tempered glass, is put into a ball mill and crushed to a glass particle size of 44 ㎛ or less. For 10 kg of this finely divided glass powder, 2.0 kg of water glass as a molding binder and 0.3 kg of calcium carbonate as a pore regulator are added and mixed well. This is molded into a disk-type spherical molding granulator with an average diameter of 1000 ㎛. The spherical porous ceramic particles are formed into particles of less than 100 μm. After drying at room temperature, they are introduced into the upper part of an upright kiln, where the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is adjusted to 750 to 800 ^o C, and the stabilization zone is adjusted to 450 to 500 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to cool the spherical porous ceramic particles, thereby obtaining an extinguishing agent for a metal fire extinguisher in an external container. The manufactured spherical porous ceramic particles had a density of 1.01 g/cm ³ , and it was confirmed that the pore structure was a structure in which mainly open pores were developed.

[ Example 5 ]

12 kg of borosilicate glass for LCD display is put into a ball mill and crushed so that all glass particles are 44 ㎛ or less in size. 2.0 kg of water glass as a molding binder and 0.3 kg of calcium carbonate as a pore control agent are added to 10 kg of this finely divided glass powder and mixed well. This is molded into a disk-shaped spherical molding granulator with an average diameter of 1000 ㎛. The spherical porous ceramic particles are formed into particles less than 10 μm in diameter. After drying at room temperature, they are introduced into the upper part of an upright kiln, where the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is 950 to 1050 ^o C, and the stabilization zone is 550 to 650 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to cool the spherical porous ceramic particles, thereby obtaining an extinguishing agent for a metal fire extinguisher in an external container. The manufactured spherical porous ceramic particles had a density of 1.21 g/cm ³ , and it was confirmed that the pore structure was mainly developed with closed pores and open pores.

[ Example 6 ]

12 kg of waste plate glass, which is soda-lime glass, is put into a ball mill and crushed to a glass particle size of less than 44 ㎛. For 10 kg of this finely divided glass powder, 2 kg of water glass as a molding binder and 0.2 kg of glycerin as a pore regulator are added and mixed well. This is molded into a disk-type spherical molding granulator with an average diameter of 1000 ㎛. The spherical porous ceramic particles are formed into particles less than 100 μm in diameter. After drying at room temperature, they are introduced into the upper part of an upright kiln, where the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is adjusted to 750 to 800 ^o C, and the stabilization zone is adjusted to 450 to 500 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to cool the spherical porous ceramic particles, thereby obtaining an extinguishing agent for a metal fire extinguisher in an external container. The manufactured spherical porous ceramic particles had a density of 0.97 g/cm ³ , and it was confirmed that the pore structure was a structure in which closed pores were mainly developed.

[ Example 7 ]

12 kg of scrap automobile glass, which is borosilicate glass, is placed in a ball mill and crushed so that the glass particles have a size of less than 44 μm. For 10 kg of this finely divided glass powder, 2 kg of water glass as a molding binder and 0.2 kg of glycerin as a pore regulator are added and mixed well. This is molded into spherical particles with an average diameter of less than 1000 μm in a disk-type spherical molding granulator. After drying at room temperature, this is introduced into the upper part of an upright kiln in which the additional drying and preheating zone is adjusted to 200 to 600 ^o C, the firing and foaming temperature is adjusted to 950 to 1000 ^o C, and the stabilization zone is adjusted to 450 ^o C, and dropped. Then, room temperature air is injected into the lower part of the upright kiln to pressure-transport the cooled spherical porous ceramic particles to obtain an extinguishing agent for a metal fire in an external container. The manufactured spherical porous ceramic particles had a density of 1.03 g/cm ³ and the pore structure was confirmed to be a structure in which closed pores were mainly developed.

[ Example 8 ]

The performance test of the extinguishing agent for metal fires manufactured through an embodiment of the present invention was conducted in a manner similar to the principle of the test standard of ISO 7165, which is an experimental method conducted in the United States for the certification of extinguishing agents for metal fires. The extinguishing ability test of the extinguishing agent for metal fires according to the ISO 7165 standard is a extinguishing ability unit experiment, in which a combustible (2 kg of magnesium) is placed on the bottom of an iron tray measuring 600×600×300㎜ in size, and then the central part of the combustible is heated with a gas torch for about 25 to 30 seconds to ignite it, and then the performance of applying the extinguishing agent is tested when the surface of the combustible is burned by about 25%.

Accordingly, in the present invention, the first test method for verifying the extinguishing performance of the manufactured extinguishing agent was conducted by burning a magnesium rod with a gas torch and applying the extinguishing agent thereto when combustion was actively progressing. The application method was conducted in a way such as a way of putting the combustion part of the magnesium rod that was burning strongly into the extinguishing agent into the agent as shown in Fig. 2, and a way of covering the combustion part of the magnesium rod that was burning strongly with the extinguishing agent as shown in Fig. 3. In all examples of Examples 1, 2, 3, 4, 5, 6, and 7 of the present invention, the spherical porous ceramic particles, i.e., the extinguishing agents for extinguishing metal fires, commonly completely extinguished the magnesium combustion on the magnesium rod that was burning strongly as soon as the agent was introduced and applied.

[ Example 9 ]

In the present invention, the second test method for confirming the extinguishing performance of the manufactured extinguishing agent is to confirm it through the combustion of titanium powder. In the case of titanium powder, the extinguishing performance of the agent was applied according to the extinguishing performance test of a metal fire extinguisher according to the ISO 7165 standard. As shown in Fig. 3, 10 kg of titanium powder was placed in a steel plate capable of holding a certain amount of titanium powder or scrap, and then the center of the combustible was heated with a gas torch for about 25 to 30 seconds to ignite, and when the surface of the combustible was burned by about 25%, the extinguishing agent filled in the extinguishing agent was applied to test the fire extinguishing performance. As a result, as shown in FIG. 4, the spherical porous ceramic particles, i.e., the fire extinguishing agent for extinguishing metal fires, manufactured in all examples of Examples 1, 2, 3, 4, 5, 6, and 7 of the present invention commonly caused the combustion of titanium powder to be strongly combusted and, within about 10 minutes after application, the combustion of the titanium powder was stopped, and upon checking the titanium metal powder that was burning, it was confirmed that the combustion was completely extinguished.

[ Example 10 ]

In the present invention, the third test method for confirming the extinguishing performance of the manufactured extinguishing agent was conducted through combustion of metal scrap, and the method was confirmed in the same way as in the case of titanium powder. As shown in Fig. 5, 10 kg of metal scrap was placed on an iron plate, and the central part of the combustible was heated and ignited with a gas torch for about 25 to 30 seconds. When the surface of the combustible was burned by about 25%, the extinguishing agent filled in the fire extinguisher was applied to test the fire performance. As a result, in all examples of the present invention, including Examples 1, 2, 3, 4, 5, 6, and 7, the spherical porous ceramic particles, i.e., the extinguishing agent for extinguishing metal fires, were commonly introduced into the combustion of the metal scrap that was burning strongly, and the combustion of the metal scrap that was burning fiercely stopped within about 10 minutes, and the result of checking the metal scrap that was burning confirmed that the combustion was completely extinguished.

In the above-described extinguishing performance verification test of the extinguishing agent of the present invention, all the extinguishing agents manufactured in the examples of the present invention showed excellent metal fire extinguishing ability without exception. This result is obtained because the extinguishing agent for metal fire of the present invention blocks the oxygen supply by suffocation and rapidly cools the runaway heat generated during metal combustion. And this rapid cooling effect is based on the foaming, which is a strong endothermic reaction, of the extinguishing agent, porous ceramic particles during the combustion process. To confirm this, the surface of the agent formed by applying it to the surface of the metal after the combusted metal is extinguished can be confirmed. As shown in Fig. 6, the extinguishing agent covered after the metal combustion is extinguished is glassy, so it melts and forms a thin plate-like piece, and traces of numerous pores expanding on this surface can be confirmed with the naked eye. This porous trace is the result of the additional foaming of the porous ceramic particles continuing and the bubbles generated bursting by absorbing the runaway heat during the combustion reaction. In other words, it is a trace showing that the rapid cooling effect has been in progress.

[ Example 11 ]

In the present invention, the fourth test method for verifying the extinguishing performance of the manufactured extinguishing agent is an example for verifying the cooling effect through re-ignition of metal scrap remaining after a metal fire is extinguished. As verified in the above [Example 10], an additional experiment was conducted to verify the cooling effect of the extinguishing agent of the present invention. Fig. 7 shows an attempt to ignite the metal scrap remaining after Example 10 using a gas torch in the same manner as in [Example 10]. The metal scrap that was attempted to be ignited using a gas torch in this Example 11 is the metal scrap remaining after the fire was extinguished using the extinguishing agent in [Example 10], and the extinguishing agent is still attached to the metal. Although ignition of the metal scrap using a gas torch was attempted several times, the metal scrap that was attached to the extinguishing agent was not ignited. This is thought to be because, due to the cooling effect of the extinguishing agent, the temperature required for ignition was not raised even when ignition was attempted using a gas torch. The results of these examples demonstrate that the fire extinguishing agent of the present invention has the ability to prevent the risk of secondary fire.

In addition, this example is the basis for showing that when a certain amount of the fire extinguishing agent of the present invention is added to the contact portion of an adjacent energy storage system and packaged by connecting multiple lithium batteries as a single unit, the cooling function of the fire extinguishing agent suppresses thermal runaway in the event of a fire, thereby blocking the spread of fire to the energy storage system of the neighboring adjacent packaging unit, and this shows that the fire extinguishing agent has an effective performance in extinguishing fires in batteries and energy storage systems where the ignition portion does not protrude to the outside, as if a metal fire extinguishing fire extinguishing device is installed in the energy storage system.

[ Example 12 ]

In the present invention, the fifth test method for verifying the extinguishing performance of the manufactured extinguishing agent was conducted through the combustion of a lithium battery. As shown in Fig. 7, the extinguishing ability test for lithium battery combustion was conducted by placing two batteries, each of which is a lithium battery installed in an electric vehicle (Volt), with a voltage of 3.63 V, 60 Ah, and a charge of approximately 80%, in an iron box from the top and bottom, igniting the lithium battery with a torch, and spraying the extinguishing agent filled in the extinguishing agent into the extinguishing agent to measure the extinguishing ability. In this case, the extinguishing agent of the present invention and ammonium phosphate monobasic (MAP) were filled into the extinguishing agent together. This is simply to suppress the flame, not the metal fire, at the same time, since the organic matter in the battery is also burned together with the lithium metal. In this case, in order to verify the thermal runaway state during the combustion of the lithium battery, two thermocouples were installed near the negative electrode and the positive electrode of the lithium battery on the upper side, respectively, to measure the temperature change during the combustion and extinguishing process.

As can be seen in Fig. 8, the evolution of the initial flame was evolved by the effectiveness of ammonium phosphate. Normally, during combustion of lithium batteries, no matter what extinguishing agent, including water, is sprayed, the battery experiences thermal runaway accompanied by flames, but in this case, only flammable gas without flames ran away. This is because thermal runaway is suppressed by the cooling effect, so it is judged that rapid temperature increases are suppressed and propagation to the stage of generating flames is suppressed. This phenomenon is evidence that the fire has been extinguished. It is also a very positive result that the second cell at the bottom of the iron box only emitted gas without flames. This is because, in terms of fire science, the fire, i.e. the fire, has been extinguished. The suppression of thermal runaway was also confirmed by the measurement results of the four installed thermocouples. The temperature at which the first thermal runaway appeared, 90 seconds after ignition, was 890 to 925 ^o C, which was shown at one thermocouple for 5 to 8 seconds, but after 8 seconds, the temperature immediately dropped below 750 ^o C, and the temperatures of the other three thermal conductions did not show any thermal runaway phenomenon, and the highest measured temperature was only below 750 ^o C. In other words, the thermal runaway was suppressed. In addition, at 20 minutes after ignition, the temperatures of all thermocouples were below 600 ^o C, and at 50 minutes, no thermal conduction point showed more than 200 ^o C. Therefore, it is judged that these results show that the extinguishing agent of the present invention is effective in extinguishing lithium ion battery fires.

Claims (19)

As a fire extinguishing agent containing porous ceramic particles and used in fire extinguishers for metal fires,
The above porous ceramic particles are silicate-based glass, have an average diameter of 50 ㎛ or more and less than 1,000 ㎛ and a density of 0.4 to 1.5 g/cm3, and have closed pores or a mixture of closed pores and open pores.
Digestive enzyme. In paragraph 1,
The above porous ceramic particles are fire extinguishing agents having a density of 0.4 to 1.3 g/cm3. delete In paragraph 1,
A fire extinguishing agent wherein the porous ceramic particles are made of soda-lime glass or borosilicate glass. In paragraph 1,
The above porous ceramic particles are spherical in shape, a fire extinguishing agent. In the first paragraph,
The above extinguishing agent is an extinguishing agent used for the purpose of extinguishing combustion of lithium batteries or combustion of lithium-based energy storage systems. A metal fire extinguisher comprising an extinguishing agent as described in any one of claims 1, 2, and 4 to 6. delete delete A method for producing a digestive agent according to any one of claims 1, 2, and 4 to 6,
(a) a step of pulverizing a glassy material;
(b) a step of mixing a molding binder and a pore regulator into the above-mentioned unpulverized glass powder to create a raw material powder for manufacturing porous ceramic particles;
(c) a step of granulating the raw material powder for manufacturing the porous ceramic particles into a molded body having an average diameter of less than 1000 ㎛ in a molding machine; and
(d) A manufacturing method comprising a step of foaming the molded body to manufacture porous ceramic particles. In Article 10,
A manufacturing method, wherein the step (a) above is to pulverize a glassy material into a size having an average diameter of less than 44 ㎛. In Article 10,
A manufacturing method, wherein the step (d) is performed by introducing the molded body into a reactor whose temperature is controlled between 150 and 1100°C; and further comprising the step (e) of slowly cooling the porous ceramic particles to room temperature. In Article 10,
A manufacturing method, wherein the step (d) is performed by introducing the molded body into an upright kiln or a fluidized bed reactor. In Article 12,
The above reactor is an upright kiln divided into sections so that a drying and preheating step, a foaming kiln step, a stabilization step, and a slow cooling storage step are sequentially performed, and the molded body is placed at the top of the upright kiln and allowed to fall freely to go through the steps in the upright kiln. A manufacturing method. In Article 14,
A manufacturing method wherein the drying and preheating steps are performed in a region controlled to a temperature range of 150 to 600°C, the foaming firing step is performed in a region controlled to a temperature range of 700 to 1,100°C, and the stabilization step is performed in a region controlled to a temperature range of 450 to 550°C. In Article 14,
The above-mentioned upright kiln is a manufacturing method in which an electric field is installed in the upright kiln to prevent the porous ceramic foam from being attached to the high-temperature kiln wall by electrical repulsion after the above-mentioned foaming kiln step. In Article 10,
A manufacturing method wherein the glassy material in step (a) is waste glass. In Article 10,
A manufacturing method wherein the above molding binder is water glass, PVA (Poly(vinyl alcohol)), or a combination thereof. In Article 10,
A manufacturing method, wherein the pore control agent is at least one selected from carbon, carbonate, and glycerin.