Extinguishing Agents

Water. Water is primarily a cooling agent. It absorbs heat and cools burning materials more effectively than any other of the commonly used extinguishing agents. It is most effective when it absorbs enough heat to raise the temperature to 100°C (212° F). At that temperature water absorbing still more heat turns to steam, and moves the absorbed heat away from the burning material. This quickly reduces the temperature of the burning material below its ignition temperature, and the fire goes out.

Water has an important secondary effect: when it turns to steam, it is converted from the liquid state to the gaseous state, and expands about 1700 times in volume. This great cloud of steam surrounds the fire, displacing the air that supplies oxygen for the combustion process. Thus, water provides a smothering action as well as cooling.

Seawater is just as effective in fighting fires as fresh water. In fact, hard water, soft water, seawater, and distilled water are equally effective against Class "A" fires.

Carbon dioxide. Carbon dioxide, C02, has a number of properties making it useful for extinguishing fires. It is non- combustible and does not react with most substances. Since it is a gas, it can generate and spread to all parts of a fire area. It is a non- conductor of electricity and does not damage electronic equipment.

Carbon dioxide is especially effective and safe for all confined fires. It acts as an inert blanket and being heavier than air it excludes oxygen very efficiently from a fire on the floor of a building. It is not effective in an elevated location or outdoors where the wind can blow the gas away.

Foam. Protein foam compounds are the most widely used agents, extinguishing flammable liquid fires. Protein foam of good quality is resistant to the effects of heat and fuels and is capable to flow over the fuel surface to form a cohesive blanket. This blanket of foam extinguishes the fire by excluding air and suppressing the release of flammable vapour from the fuel surface. Its water content also provides cooling the fuel and adjacent surface.

Fluoroprotein foam has the excellent stability and heat resistance as protein foam but it is more effective in suppressing the release of volatile fuel vapours.

In addition to its primary use in extinguishing flammable liquid fires, foam can be used in other ways, such as extinguishing fires in enclosed spaces.

Active Vocabulary

Words

absorb v поглощать

adjacent a соседний, смежный

as well as adv в такой же мере, так же

blanket n покрытие

convert v превращать

displace v вытеснять, перемешать

enclosed a ограниченный

exclude v исключать

expand v расширяться, увеличиваться

gо out v погаснуть

outdoors adv на открытом воздухе

release n освобождение

resistance n сопротивление

smother v тушить (пожар)

volatile а летучий, быстро испаряющийся

I. Practise the following for pronunciation:

primary, extinguish, smother, dioxide, exclude, cohesive, release, adjacent, surface, volatile, enclosed.

II. Read the international words:

agent, absorb, material, effectively, temperature, convert, gaseous, process, action, fact, carbon dioxide, gas, electricity, electronic, safe, location, elevated, protein, quality, resistant, effect, suppress, stability, primary.

III. Read and translate the pairs of nouns and verbs:

water- to water, heat - to heat, use - to use, turn - to turn, act - to act, cloud - to cloud, supply - to supply, process- to process, release - to release, part- to part, spread - to spread, damage - to damage.

IV. Give three forms of the verbs:

absorb, burn, use, extinguish, raise, go out, expand, have, react, can, blow, flow, suppress, release.

V. Read and translate words of the same root:

prime - primary - primarily, effect - effective, second - secondary -

secondly, generate - generation - generative, elevate - elevation - elevated, resist - resistance - resistant, part - participate – participation.

VI. Put the adjectives in the comparative and superlative degrees:

effective, important, fresh, hard, soft, useful, safe, inert, heavy, flammable

VII. Choose the translation of the underlined words and word combinations:

1. Water cools burning materials.

2. Sea water is also effective in fighting fires.

3. Carbon dioxide has a number of properties.

4. Carbon dioxide is useful for extinguishing fires.

5. Protein foam can be used in extinguishing fires.

(ряд, в тушении пожаров, охлаждает, полезен, морская вода).

VIII. Match the synonyms:

a) primarily, enough, important, steam, supply, extinguish, effectively, use,

flammable, state, widely, turn to (into), area, quickly, expand, go out, since, enclosed

b) sufficient, vapour, as, significant, convert (into), broadly, condition, broaden,

provide, die out, rapidly, combustible, employ, efficiency, originally, space, put out, confined.

IX. Match the antonyms:

a) quickly, lower, burn, equally, conductor, include, indoors, place, flammable,

great, important, useful, good, resistant, effectively

b)displace, useless, outdoors, bad, little, ineffectively, raise, slowly,

unimportant, unequally, non - conductor, exclude, go out, non - resistant, non –flammable.

X. Read and translate the noun groups:

ignition temperature, combustion process, class "A" fires, protein foam

compounds, fuel surface, water content, fluoroprotein foam, heat resistance.

XI. Read and translate the text "Extinguishing Agents"

XII. Fill in the blanks with the following words:

cloud, widely, flammable, reduces, liquid, damage, enclosed, excludes, spaces, primarily, properties, blanket, the release, substances, stability

1. Water is... a cooling agent.

2. This quickly... the temperature of the burning material.

3. When water turns to steam it converts from the... state to the gaseous state.

4. This great... of steam surrounds the fire.

5. Carbon dioxide has a number of...

6. It does not react with many...

7. It does not... electric equipment.

8. Carbon dioxide is effective for all... fires.

9. It acts as an inert...

10. Carbon dioxide... oxygen very efficiently.

11. Protein foam compounds are most... used agents.

12. Protein foam extinguishes... liquid fires.

13. Fluoroprotein foam has the excellent...

14. It is more effective in suppressing... of volatile fuel vapours.

15. Foam can be used in extinguishing fires in enclosed...

XIII. Match the nouns from the right column with the adjectives from the left column in accordance with the text:

XIV. Put general questions to the following sentences:

1. Water is primarily a cooling agent.

2. Water has an important secondary effect.

3. Great cloud of steam surrounds the fire.

4. Carbon dioxide acts as inert blanket.

5. Protein foam compounds are the most widely used agents.

6. Fluoroprotein foam has the excellent stability.

7. Foam can be used in extinguishing fires in enclosed spaces.

XV. Choose the proper variant:

1. Water absorbs heat

a) more effectively than any other extinguishing agents

b) lеss effectively than any other extinguishing agents

2. Water provides

a) smothering action

b) smoldering action

3.Carbon dioxide is

a) combustible

b) non - combustible

4. Carbon dioxide is

a) non - conductor of electricity

b) conductor of electricity

5. Carbon dioxide is especially safe for

a) confined fires

b) open air fires

6. Protein foam compounds are

a) the most widely used agents

b) rarely used agents

7. Fluoroprotein foam is characterized with

a) absolute unsuitability

b) excellent stability

XVI. Answer the following questions:

1. What is a primary water effect?

2. What does water absorb?

3. What does water cool?

4. How does water absorb heat and cool burning materials?

5. When is it most effective?

6. What temperature does water turn to steam at?

7. What is water secondary effect?

8. What does water provide?

9. What types of water are as effective as fresh water?

10. What properties has carbon dioxide as extinguishing agent?

11. When is carbon dioxide especially effective and safe?

12. How does it act?

13. Where is carbon dioxide ineffective?

14. What agent is the most widely used?

15. What kind of fire does it extinguish?

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