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Laboratory Management
Basic knowledge of laboratory fire safety

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1. Basic methods of putting out fire

Fire fighting mainly takes measures from three aspects: Control of combustibles,Control the material basis that causes combustion,Reduce the combustion range; isolate the air (combustion aid),Prevent m88 online bettingm88 live casino and sports bettingm88 online bettingcombustion-supporting conditions; eliminate sources of ignition,Eliminate the heat source that triggers combustion。

There are four basic methods of putting out fires:

l, cooling method:Water spray、Sprinkling,Reduce the temperature of burning substances。当其降到着火点The following will extinguish the fire.Because water is the most convenient to use、Cheapest,So extinguishing fire with water is the most common method to put out fire。

2, suffocation method:Use carbon dioxide、Nitrogen、Foam or asbestos cloth,Water-stained bedding、Cover the burning object with non-combustible or refractory materials such as sacks or sand,Keep air and other oxidants from fully contacting combustibles,Reduce the oxygen content of the air in the combustion space to16%The following will extinguish the fire.

3, Isolation Law:Spread flammable materials near the fire away from the fire source,Fire can be limited to the smallest range,Prevent the spread of fire,Can make the fire from big to small,Until extinguished。

4、Suppression method m88 online bettingm88 live casino and sports betting(chemical interruption method): use bromine-containing agent、Alkane halide chemistry。

2. Common knowledge about fire extinguishing agents

Commonly used fire extinguishing agents other than water,There are still bubbles、Alkane halide、Carbon dioxide、Dry powder, etc..Can be used to put out various types of fires。The use of fire extinguishing agents must be equipped with corresponding fire extinguishing equipment and equipment,In order to exert its fire-extinguishing effect,According to the different properties of fire extinguishing agents,Use it correctly in different fire extinguishing situations,In order to put out the fire quickly。

Introduction to commonly used fire extinguishing agents:

(1) Water

1, Fire extinguishing function of water

l) Cooling effect:increase in temperature per kilogram of waterl℃will absorblkCal, the latent heat of evaporation of water is539.9cal/g, that is, every kilogram of water must be absorbed when evaporating and vaporizing539.9kcalof heat。When water comes into contact with m88 sports bettinghot burning objects,During m88 slot machine casinothe process of being heated and cooled,It will absorb a lot of heat,Forcing the temperature of the burning material to greatly reduce and eventually stop burning。

2) Dilution of oxygen: after water encounters hot burning objects,Vaporization produces a large amount of water vapor,Can prevent air from entering the combustion zone,And can dilute the oxygen content in the combustion zone,The combustion zone gradually lacks m88 online bettingm88 live casino and sports bettingm88 online bettingcombustion-supporting oxygen and weakens the combustion intensity。

3) Water-soluble flammable、The dilution effect of flammable liquids: when water-soluble is flammable、In case of fire involving flammable liquids,Under the conditions where water fighting is allowed,Water and flammable、After mixing flammable liquids,Can reduce its concentration and the concentration of flammable vapor in the combustion zone,Reduce the burning intensity。

4) The impact of water: the water sprayed from the water gun has great kinetic energy and impact,m88 online bettingCan rush to the inside of the burning surface,m88 best betting websiteDestroy the products of combustion and decomposition,Isolate the burning zone from the unfired part,Prevent combustible substances from continuing to decompose,Significantly weakens the burning intensity。

2, Issues that should be paid attention to when using water to fight fires

l) When substances that react with water to produce flammable gases or easily explode catch fire, do not use water to put out the fire。such as alkali metal、Light metal、Carbide、Molten iron、Where there is a fire in molten steel, etc.,It is strictly forbidden to use water to fight the fire。

2) Water-insoluble flammable、Flammable liquid

3) Direct flow of water cannot be used to extinguish fires involving electrical equipment,Cannot extinguish combustible dust (such as aluminum powder)、Zinc powder、flour、Fire in a gathering place of coal powder, etc.。

4)Concentrated sulfuric acid、Fires caused by concentrated nitric acid and heated and molten oxidants,Cannot use direct water to save the life.To avoid causing the hot acid to splash and hurt people。Use spray water when necessary。

()Foam fire extinguishing agent

Foam fire extinguishing agent aqueous solution through chemistry、Physical effects、After filling with a large amount of gas (carbon dioxide or air), countless small bubbles (called fire-extinguishing foam) are formed.,When sprayed out,Floating、Covered on flammable liquid surface,On the one hand, it captures the heat of the liquid (endotherm),Reduce the temperature of the liquid,Evaporation speed slows down;On the other hand, it has a certain inherent stickiness,It is not easy for the vapor of flammable liquid to pass through,When the liquid surface gas is capped by foam, an isolation layer is formed,Keep outside air from entering。And because foam is a poor conductor of heat,It can also act as heat insulation。

Foam fire extinguishing agents are divided into two categories: chemical foam fire extinguishing agents and air foam (or mechanical foam) fire extinguishing agents。The foam fire extinguishing agent used in our laboratory is a chemical foam fire extinguishing agent。Chemical foam is a group of membranous body bubbles formed by the interaction between an aqueous solution of an acidic substance (aluminum sulfate) and an alkaline substance (sodium bicarbonate) and a foaming agent (foam liquid)。Foam liquid is produced by hydrolyzing animal or plant protein substances。Foam fire extinguishing agent is generally used to extinguish various petroleum products、Grease and other fires,Can also be used to put out fires caused by general combustible solids such as wood。

(3) Dry powder fire extinguishing agent

Principles of fire extinguishingDry powder fire extinguishing agent is a kind of dry、Easy-flowing fine solid powder。Usually stored in dry powder fire extinguishers or equipment。When putting out a fire,By pressurized gasCarbon dioxide or nitrogenThe dry powder is ejected from the nozzle,Form a mist powder flow sandwiched with pressurized gas,shoot at burning objects。Dry powder particles can react with a large number of active groups generated by fuel at high temperatures,Make it an inactive substance。When a large amount of powder particles are sprayed into the flame in the form of mist,Can absorb a large amount of active genes in flames,Deeply reduce its number,And interrupt the burning chain reaction。thus extinguishing the flame。Dry powder fire extinguishing agent is suitable for extinguishing flammable liquids、Fires caused by combustible gas and electrical equipment。

(4) Carbon dioxide fire extinguishing agent

Fire extinguishing principle: Carbon dioxide fire extinguishing agent is pressurized and filled in the fire extinguisher in liquid form,When sprayed from the spray can,Liquid carbon dioxide vaporizes rapidly,Can absorb a large amount of heat from itself 13kcal〉,Resulting in a sharp drop in the temperature of the liquid itself,When its temperature drops to one78℃hour,Fine snowflake-like carbon dioxide solids appear,Has a certain cooling effect on burning materials。Its fire-extinguishing function is mainly to increase the components in the air that do not burn and do not support combustion,Relatively reduce the oxygen content of the air,Can inhibit the spread of flame。But this effect is far from enough to extinguish the flames。

Carbon dioxide has no destructive effect on most substances。After extinguishing the fire,No poison,No poison,It is best for fighting various liquids and those affected by water,Bubble,Dry powder and other fire extinguishing agents are easily damaged by contamination (such as precision instruments)、Important documents, files, etc.)Fires of solid materials。Carbon dioxide is a non-conductive substance,Use it to save the life600VFires in the following various live equipment。It still has a certain degree of penetration、Surround ability。Can reach places that ordinary direct sunlight cannot reach。

3. Introduction to commonly used fire extinguishers in laboratories

(1) Foam fire extinguisher

1, model, specification: use letters for model number"MP"Indicates that the specifications are in6.5-130LThere are many kinds of internal points, commonly used in laboratories10L's.

2、Medicine to use: The cartridge contains sodium bicarbonate、Foaming agent and aluminum sulfate solution。

3, Scope of application: Suitable for fighting oil fires.

4, Performance:10LThe fire extinguisher spray time is60S, range is8-l0m. For other specifications, please refer to the corresponding instructions(such as15Lis170s, effective range13.5m

5、How to use: Invert the cylinder and shake it slightly or turn on the switch,The agent can be mixed and react to spray foam。

6、Storage and inspection: Fire extinguishers should be kept in a safe place、Easy to access:Prevent nozzle clogging;Pay attention to the use period; take measures to insulate the cylinder body in winter、Prevent freezing。Foam fire extinguisher foam generation multiple is5.5-8Times. Storage period is less than4The dressing should be changed in time when the dosage is doubledThe second method is to use a weight meter to test internal and external medicines and internal medicines30Degree, foreign medicine is10If the temperature is lower than the regulations, the dressing should be changed in time.

(2) Acid-base fire extinguisher

1、Model、Specification: It is also a kind of foam fire extinguisher、Model numbers also use letters"MP"means that the commonly used specifications in laboratories are10L

2、Medicine to use: The cylinder contains sodium bicarbonate aqueous solution and a bottle of sulfuric acid。

3、Scope of use: suitable for firefighting wood、Cotton、Paper fire。Do not use it to fight electrical and oil fires。

4, Performance:10LThe fire extinguisher spray time is50s, range is10M.

5、How to use: turn the barrel upside down,Solution can be sprayed out。

6, Storage and Inspection:The storage method is the same as that of a foam fire extinguisher,The inspection method is the same as the second inspection method for foam fire extinguishers。 

(3) Portable dry powder fire extinguisher

1, model, specification: use letters for model number“MF" means, the specifications are in1-8kgThere are many ranges, commonly used in laboratories3kg4kg5ltgand8kgFour specifications.

2、Medicine to use: The bottle contains baking soda or potassium salt dry powder,And filled with high-pressure carbon dioxide gas。

3、Scope of use: suitable for fighting oil、Petroleum products、Combustible gas、Fires caused by organic solvents in paint and electrical equipment。

4,Performance:The injection time is8-20Seconds, range2-5mFire extinguishing area0.8-2.5m2, insulation performance is 10,000 volts.

5、Usage: When using,Open the safety pin,Aim the nozzle of the nozzle at the fire source,Pull the tab,Ready to spray dry powder。

6, Storage and Inspection:Dry powder fire extinguishers should be stored in a dry and ventilated place,Prevent moisture、Sun exposure。Check once a year,If the dry powder is found to be damp and lumpy,CO2 weight,When the pressure does not meet the specifications,The dressing should be changed in time。

(4) Carbon dioxide fire extinguisher

1, model specifications: use letters for model number"MT" means, the commonly used specifications in laboratories are3kg

2、Use potion: The bottle contains carbon dioxide compressed into liquid state。

3、Scope of application: Suitable for saving valuable instruments、Equipment fire。Cannot save potassium metal、sodium、Magnesium、Fires of aluminum, etc. and their hydrides。

4, How to use. To approach the fire site, keep3mlong distanceFirst remove the lead seal and carry the handle to make the speaker simplerSpray tubeAim at the fire source and turn the handwheel with the other handSwitch,Rotate counterclockwise,You can turn on the switch,Make high-pressure carbon dioxide gas eject on its own。Be careful not to use it against the wind

5. Storage and Inspection:Store the same foam fire extinguisher。Inspection of carbon dioxide fire extinguisher,The weight should be measured every three months,Compare the measured weight with the body weight and carbon dioxide net weight indicated by the body。When the net weight of carbon dioxide is reduced to the original net weight10%When the temperature exceeds 83492_83502

()Fire hydrant

Fire hydrant is a water supply for fire extinguishingExtinguish the fire with waterOne of the devices,There are two types of indoor fire hydrants and outdoor fire hydrants。When in use,Connect one end of the hose to the outlet of the fire hydrant,Turn the handwheel of the fire hydrant in the opening direction,The water will be sprayed out,Aim at the fire source and shoot。

1, indoor fire hydrantUse letters for model numberSNmeans, the type is internal buckle pipe thread, divided50MM65Two calibers in mm, pressure isl0kg/cm2

2, outdoor fire hydrant:Use letters for model numberSXExpress, share100MM150Two calibers in mm, pressure is8-16kg/cm2

(Six)Water belt 

The hose is connected to the fire pump、Water pipelines for fire hydrants or spray devices such as water guns。The length of the hose is20m。For convenience of connection,Both ends of the hose are equipped with quick-connect interfaces。The hose should be prevented from bending after being filled with water;Prevent contact and friction with hard objects; prevent contamination by various oils。Usual safekeeping,Standing water should be dried、Flat and rolled into a disk、Store in a cool and dry place。 

IV. Laboratory Fire Prevention Instructions 

1, persistPrevention is the main thing, elimination is the supplement’s policy,Improving fire prevention system,Develop fire prevention measures,And appoint the person to the post,Implement item by item。 

2、The use of electric furnaces for non-experimental work is strictly prohibited、Electric ovens and other electric heating appliances; any approved for use in experimental work,Must determine location、Fixed point use,No flammable items of any kind should be kept around。 

3、Soldering iron used,To be placed on a non-combustible bracket,No flammable materials should be piled around,Complete use,The power supply should be cut off immediately。 

4、Where there is a transformer、Inductor coil equipment,Must be placed on a non-combustible base。Electrical equipment started simultaneously during experimental work,The total electricity consumption must not exceed the rated load of the electrical facilities distributed in the room。No random connection or pulling of wires。 

5. When starting various types of equipment, strict operating procedures must be followed;Strictly flammable、Storage of explosive chemicals、Usage system,Don’t be careless。 

6、All kinds of experimental raw materials and other items should be properly kept、Store neatly;Discarded sundries and objects should be cleaned up in time and are not allowed to be thrown around. 

7、All fire extinguishers and other fire-fighting facilities must be in good condition,Keep it safe,It is strictly prohibited to use it for other purposes or to move it casually。 

8、All personnel in the laboratory must be familiar with the effectiveness of various fire extinguishing equipment in the laboratory、Knowledge of applicable scope and usage。Understand the fire hazards of this position,Understand preventive measures,Know how to save the life;You should also be able to call the police,Know how to use various fire extinguishing equipment,Emergency evacuation measures will be taken。

 

 

 

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