fire fight part 2

7/23/2019 Fire Fight Part 2

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IRE BEHAVIOR

AND

CHEMISTRY

Effective fire controland extingi!"#ent



re$ire! a %a!ic

nder!tanding oft"e

c"e#ical and

&"'!ical natre

of fire(



T"i! inclde!

infor #ation de!cri%ing !orce!

of

"eat energ'*



environ#ental

condition!nece!!ar' to

!!tain t"eco#%!tion

roce!!(



car%on +t"e #ain !%!tance

in t"e &a&er,

and ox en fro# t"e air (

-"en &a&er %rn! in a fire*

t"e reactant! are #o!tl'



ire i! t"e

ra&id oxidation of a#aterial in t"e

exot"er#ic

c"e#ical &roce!!of co#%!tion*



relea!ing

"eat*

lig"t*



and vario!

reaction

&rodct!



A te#&eratre .

/"ic" a #aterial

oxide $ic0l' 1

!tart! to%rn i! called

co#%!tion



Slo/er

oxidative

&roce!!e!li0e

r!ting



or dige!tion

are not inclded

%' t"i! definition(



T"e fla#e i! t"e

vi!i%le &ortion of

t"e fire( If "ot enog"*



t"e ga!e! #a' %eco#e

ioni2ed to&rodce &la!#a(



+a "ig"l' ioni2ed

ga! containa&&roxi#atel'

e$al n#%er of

&o!itive ion! andelectron!,



Oxidation i! a

&roce!! t"at

occr! /"en ano%3ect i! ex&o!ed

to ox en for a



Brning !o#et"ing

i! a ra&id oxidation



r!ting i! t"e &erfect

exa#&le of !lo/oxidation



T"i! /ill ca!e t"e

!%!tance! in t"eo%3ect to

!tart

%rea0ingdo/n(



Ox'gen "a! to %e

&re!ent for oxidation tota0e &lace(



Slo/ oxidation of /ood*

T"e addition of

ox'gen to an'

ele#ent i! /"atca!ed oxidation(



a! in rotten of

/ood



oxing i! a ter#

de!cri%ing t"e age4related !&ot! and

%r o/ning !een on vintage

&a&er doc#ent! !c"

a! %oo0!* &o!tage

!ta#&!* certificate!* and

!o fort"(



t"eor' i! t"atfoxing i! ca!ed

%' t"e effect on

certain &a&er! oft"e oxidation



fa!t oxidation*

!c" a!

detonation!



and ex&lo!ion!(



567 fire &oint

587 fla!" &oint597 no fire



For #an' 'ear!*

t"e :fire triangle; +ox'gen* fel* and

"eat, /a! !ed

to teac" t"eco#&onent! of

fire



-"ile t"i!

!i#&le exa#&le

i! !efl*it i! not

tec"nicall'

correct



T"e fire

tetra"edron

re&re!ent! t"e

addition of a



t"e c"e#ical c"ain

reaction*

to t"e t"ree alread'

&re!ent in t"e fire

triangle(



Re#ove an' one of

t"e for co#&onent!and co#%!tion /ill

not occr(

If i iti " l d



If ignition "a! alread'

occrred*t"e fire i!

extingi!"ed/"en one of t"e

co#&onent! i!re#oved fro#

t"e reaction(



Extingi!"#ent Con!idering

t"e Fire Tetra"edron

f



A fire can %e

extingi!"ed%'

re#oving

it! ox'gen(



Starvation i!

ac"ieved %'

re#oval of t"efel %rning in

t"e

fire



So#eti#e!

co#%!ti%le#aterial can

%e re#oved %'!"tting off

ga!valve! or

fel flo/!



T"e re#oval of "eat

or t"e

coolingof a fire i! t"e

#o!t co##onfor# of

!&&re!!ion(

I t t



In #o!t ca!e! /ater

i! !ed to

e!!entiall'!oa0 &

t"e "eatgenerated %' t"e

T"i " t t t"



T"i! "eat trn! t"e

/ater in to !tea#*

t"ere%' ro%%ing t"e

fire of t"e "eat

!ed



If /e loo0 at fel

t'&e! and va&or&rodction* /e find

t"at !olid fel! andli$id fel! /it" "ig"

fla!" &oint! can %eextingi!"ed %'

coolin

Fat <alit' S#o0e =oint

Cocont

oil

ExtraVirgin

+>nrefined,

?@F 5C

Cocont

oilRefined 8@F 9?9C

Corn oil >nrefined ?@9F 5DC

Corn oil Refined 8@F 9?9C

o/ fla!"&oint li$id!



o/ fla!"&oint li$id!

and fla##a%le ga!e!cannot %e

extingi!"ed %'cooling /it" /ater a!

va&or &rodctioncannot %e !fficientl'

redced

Interference i! t"e



Interference i! t"e

&roce!! of a&&l'ing

extingi!"ing agent!

to t"e fire

t"at in"i%it c"e#ical

c"ain reaction

at t"e#oleclar level



STO= CHAIN REACTION

Sto&&ing or interr&ting t"ec"ain reaction %et/een t"e

fel* "eat* and ox'gen /ill

extingi!" t"e fire( S&ecific#et"od! of extingi!"ing fire!

often involve a co#%ination of

#ore t"an one of t"e for

&rinci&le!(



M t fi i l f l



Mo!t fire! involve a fel

t"at i! c"e#icall'

co#%ined /it" t"e ox'gen

nor#all' fond in

at#o!&"eric air(At#o!&"eric air contain!

95 &ercent ox'gen* D&ercent nitrogen and 5

&ercent of ot"er ga!e!(



A ra&id oxidation



A ra&id oxidation

/"ere %rning!%!tance! co#%ine!

/it" Ox'gen t"enenerg' i! given off in

t"e for# of "eat andlig"t( fire

Mo!t co##on



Mo!t co##on

fel! containcar%on along

/it"

co#%ination! of"'drogen and

fire fight part 2

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