| Abstract | Da bi lakše razumjeli gašenje požara potrebno je analizirati kako dolazi do gorenja, koje kasnije može prerasti u požar s katastrofalnim posljedicama. Svako gorenje zapravo je primjer oksidacijskog procesa kada se goriva tvar spaja s kisikom iz zraka oksidansom, te dolazi do oslobađanja topline i produkata gorenja. Za gorenje je potrebno da su ispunjena 4 uvjeta, a to su: prisustvo gorive tvari, prisustvo kisika iz zraka, dovoljna količina topline te nesmetano odvijanje lančane reakcije gorenja. Iz svakog takvog gorenja koje postaje nekontrolirano nastaje požar. Njih dijelimo prema: mjestu nastanka, obujmu i veličini, fazama razvoja te prema vrsti gorive stvari. Te podjele su nam važne da bi znali kako prema određenom požaru reagirati . Koliko nam je ljudstva potrebno, koliko vozila i opreme, a u konačnici s kojim sredstvom za gašenje gasiti požar. U naftnoj industriji zaštita od požara je jako važan segment iz razloga što je nafta lako zapaljiva tekućina. U postrojenjima gdje su naftne bušotine, rafinerije i skladišta propisano je puno preventivnih mjera zaštite od požara. Za svako tako postrojenje donose se planovi zaštite od požara u kojima su sadržane i druge protupožarne mjere i postupci kojima bi se smanjila mogućnost nastanka požara, a ako do požara dođe da se što prije može ugasiti. Za gašenje požara u naftnoj industriji upotrebljava se pjena i prah. Pjena je mješavina pjenila, vode i zraka, a na požar djeluje ugušujuće te stvara prekrivač na površini zapaljive tekućine i razdvaja pare tekućine i kisik iz zraka. Prisutan je efekt hlađenja zbog prisustva vode u pjeni. Prahovi za gašenje požara su čestice određenih intertnih i neotrovnih anorganskih soli, koje se pod tlakom izbacuju iz aparata za gašenje u požaru. Prahovi koji se koriste za gašenje zapaljivih tekućina gase samo plamen, gase inhibirajućim učinkom tj. u plamenu prekidaju lančanu reakciju gorenja. |
| Abstract (english) | In order to understand better fire-fighting it is necessary to analyse the process of combustion, that can later lead to fire with the catastrophic consequences. Each combustion is actually an example of process of oxidation when a combustible substance comes into a contact with oxygen from air which is called oxidant, and temperature and products of combustion are being extricated. In order for the combustion to happen, 4 conditions have to be fulfilled and these are: presence of the combustible substance, presence of the oxygen in the air, sufficient amount of the heat and unhindered developing of chain reaction of combustion. Fire is created from each combustion of that type, that becomes unhingered. We divide them by: place of emergence, volume, size, phases of development and by the type of combustible substance. These divisions are very important to us in order to know how to react to the specific type of fire. How many people we need, how many vehicles, how much equipment, and ultimately what kind of extinguishing media is used for firefighting. In petroleum industry, protection from fire is a very important segment because petroleum is very flammable fluid. In facilities where there are oil wells, refineries and warehouses, a lot of preventive measures for fire are being prescribed. For each of these facilities, protection plans are being adopted in which other fire prevention measures and procuderes are listed in order to decrease the possibility of emergence of fire, and if it comes to fire, that they can put out a fire as soon as possible. Foam and powder are being used in the petroleum industry to put out a fire. The foam is a mixture of foam concentrares, water and air, and it suffocates fire and it creates a sort of cover on the surface of flammable liquid, and it separates steam from the liquid and oxygen from the air. The effect of cooling is present in this situation because of the presence of water in the foam. Powders for fire-fighting are particles of certain inactive and non-toxic inorganic salts, that are being thrown under pressure from fire extinguisher. Powders that are being used for fire-fighting of flammable liquids put out only a flame, and they put out this flame by inhibiting effect, i. e. they stop the chain reaction of combustion in the flame. |
