Toshkent davlat agrar universiteti meva-sabzavotchilik va uzumchilik fakulteti



Download 0.9 Mb.
bet18/26
Sana28.08.2021
Hajmi0.9 Mb.
1   ...   14   15   16   17   18   19   20   21   ...   26
Fire considerations

Water is used for fighting wildfires.

Water has a high heat of vaporization and is relatively inert, which makes it a good fire extinguishing fluid. The evaporation of water carries heat away from the fire. It is dangerous to use water on fires involving oils and organic solvents, because many organic materials float on water and the water tends to spread the burning liquid.

Use of water in fire fighting should also take into account the hazards of a steam explosion, which may occur when water is used on very hot fires in confined spaces, and of a hydrogen explosion, when substances which react with water, such as certain metals or hot carbon such as coal, charcoal, or coke graphite, decompose the water, producing water gas.

The power of such explosions was seen in the Chernobyl disaster, although the water involved did not come from fire-fighting at that time but the reactor's own water cooling system. A steam explosion occurred when the extreme overheating of the core caused water to flash into steam. A hydrogen explosion may have occurred as a result of reaction between steam and hot zirconium.

Some metallic oxides, most notably those of alkali metals and alkaline earth metals, produce so much heat on reaction with water that a fire hazard can develop. The alkaline earth oxide quicklime is a mass-produced substance which is often transported in paper bags. If these are soaked through, they may ignite as their contents react with water.[99]




Download 0.9 Mb.

Do'stlaringiz bilan baham:
1   ...   14   15   16   17   18   19   20   21   ...   26




Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©hozir.org 2020
ma'muriyatiga murojaat qiling

    Bosh sahifa
davlat universiteti
ta’lim vazirligi
maxsus ta’lim
O’zbekiston respublikasi
zbekiston respublikasi
axborot texnologiyalari
o’rta maxsus
guruh talabasi
nomidagi toshkent
davlat pedagogika
texnologiyalari universiteti
xorazmiy nomidagi
toshkent axborot
pedagogika instituti
haqida tushuncha
rivojlantirish vazirligi
toshkent davlat
Toshkent davlat
vazirligi toshkent
tashkil etish
matematika fakulteti
ta’limi vazirligi
samarqand davlat
kommunikatsiyalarini rivojlantirish
bilan ishlash
pedagogika universiteti
vazirligi muhammad
fanining predmeti
Darsning maqsadi
o’rta ta’lim
navoiy nomidagi
haqida umumiy
Ishdan maqsad
fizika matematika
nomidagi samarqand
fanlar fakulteti
moliya instituti
sinflar uchun
maxsus ta'lim
Nizomiy nomidagi
ta'lim vazirligi
Ўзбекистон республикаси
universiteti fizika
umumiy o’rta
Referat mavzu
таълим вазирлиги
respublikasi axborot
Toshkent axborot
Alisher navoiy
махсус таълим
Buxoro davlat