What is the difference between ignition temperature and flash point? This temperature is required to supply the activation energy needed for combustion. 10. Explain why, fire caused by electricity should not be extinguished by pouring water.

We modify equipment from industry leading brands: Corresponding Temperature class needed for   explosion safe equipment. Once an oxidation reaction starts, it releases energy increasing the likelihood of another molecular reaction. 1. The temperature class indicates the limitation of the surface temperature your device is designed for. (a) The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value. 32. Ignition of the liquid even without a flame or spark, ignition of the vapour by  a  flame or spark.

Carbon dioxide is heavier than oxygen, covers the fire like a blanket. why diesel self ignition temperature is less than petrol. Fill in the blanks with suitable words (a) A fuel must be heated to its_____ before it starts burning. In a gas explosion, gas is the fuel that mixed with air causes an explosion when ignited. Carbon dioxide used for extinguishing fire can be stored as a liquid at high pressure in cylinders. Name the various zones of a candle flame.

But dry leaves have no moisture content in it, hence its ignition temperature is low. (see: Table 1. 3. Kerosene oil and molten wax are substances that give a flame while burning. 37. The fire caused by electricity extinguished by petrol or by carbon dioxide. What is meant by rapid combustion? All queries related to burning, combustion, fire are focused on in this lesson. No we cannot burn a piece of wood by bringing a lighted matchstick near it. This process is–at the molecular level–easier for diesel than petrol because the chances of an oxygen causing a chemical changes when hitting a hydrocarbon is higher.

4. CO2, being heavier than oxygen, covers the fire like a blanket. The best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol is carbon dioxide. Use of "eben" – does it mean just, also or even? Which zone of a candle flame is the hottest? Job offers - how to negotiate higher salary due to higher costs of living at the new location. 48.

1955: When Marty couldn't use the time circuits anymore was the car still actually driveable? This is the cause that to start a fire in wood or coal paper or kerosene oil is used as the ignition temperature of paper or kerosene oil is lower than that of wood or coal. The added advantage of CO2 is that in most cases it does not harm the electrical equipment. Fuel: Ignition temperature. 25. Therefore it catches fire easily. Please include your technical specifications. What is meant by explosive combustion (or explosion)? Give two examples each of: (a) solid fuels (b) liquid fuels (c) gaseous fuels. (b) Water extinguishes heat by cooling down the burning substance such as wood and paper. (c)Fire produced by burning oil cannot be controlled by water. Category theory and arithmetical identities. Safety guaranteed. Incomplete combustion of fuels produces a very poisonous gas called carbon monoxide. Also be sure to check out our faq on Exproofac.com.

For fires involving electrical equipment and inflammable materials like petrol, carbon dioxide (CO2) is the best extinguisher. [closed], Feature Preview: New Review Suspensions Mod UX, Creating new Help Center documents for Review queues: Project overview, Mechanics behind auto-ignition temperature, Additional Questions Regarding the Auto-Ignition Temperature, Relationship between auto-ignition temperature with pressure and fuel. At standard indoor temperature we try to light both liquids with a burning match.

We also learn about the substances that combust on burning. Why do you have to use paper or kerosene oil to start fire in wood or coal? Various flash points, ignition temperature classes of different substances. B. Minimizes the brake fade.

No, because rusting is an exothermic process as heat is liberated during rusting. Gas ignites, unlike dust explosions, at once. The consequences of gas explosions can be huge.

Incomplete combustion of fuels produces poisonous gas called carbon monoxide. Ethyl acetate is therefore an explosion hazard. Of course there are also other properties of this fluid that potentially cause health hazards. You can also send Gido your specific ATEX question at gt@ex-machinery.com. In typical diesel compound there are simply more opportunities for oxygen to attack the molecule and kick off a reaction because the amount of the molecule exposed to the outside is higher. In other words, only if the immediate environment of the liquid has the same temperature as the flash point, the liquid can be lit. (b)The most common supporter of combustion around us is _________, (c)Fire produced by burning oil cannot be controlled by_________, (d)A liquid fuel used in homes is_________, (e)The amount of heat evolved when 1kg of a fuel is burnt completely is called its_________, (f)The substance which vaporize during, give_________. A.

24. 31. 7. This part of the flame is used because the outermost flame undergoes complete combustion and is considered as the hottest part of the flame.

For the reaction to kick off some of the molecules in the mix have to have enough thermal energy to react when they meet. What is the first thing you should do if a fire caused by burning wood or paper? It goes without saying that the risk of explosion decreases when the liquid temperature is kept below the flash point or the ambient temperature is kept lower than the liquid temperature. It only takes a minute to sign up. Therefore it does not catch fire easily. Now about the flash point: gasoline placed in an open bin has a flammable vapour above the surface when temperature of the liquid is – 23 °C. (b) Describe one method of putting out a fire caused by burning wood or paper. The added advantage of CO2 is that in most cases it does not harm the electrical equipment. 42. The ignition temperature of wood or coal is higher and it requires more heat to start burning. Is it possible Alpha Zero will eventually solve chess? What are recommended ways to connect fridge ice maker? Give a reason for your answer. The goldsmith mainly uses a non-luminous flame which is termed to be the outermost part of the flame. Explain how the use of CNG in automobiles has reduced pollution in cities. Substances having low ignition temperature: LPG and Petrol, Substances having high ignition temperature: Coal and wood, 20. Related Questions on Automobile Engineering. 2.

The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg). Example – coal and charcoal.

Relatively little energy is needed to ignite gas. 19. Table 1. Without oxygen, combustion will not take place. (e)The amount of heat evolved when 1kg of a fuel is burnt completely is called its calorific value.

We can get a crude (and probably oversimplistic) understanding by looking at the typical components of the two fuels. And oxygen has to hit the hydrocarbon hard enough or there is no reaction. Give reason for the following: LPG is a better domestic fuel than wood. Autoignition temperature = kindling point; is the temperature at which a material spontaneously ignites in a normal atmosphere without an external source of ignition. Since the contact between the fuel and oxygen is cut off, the fire is controlled.

(b) Characteristics of an ideal fuel (or good fuel) are: 22. The burning of fuels like wood as fuel releases unburnt carbon particles in the air which causes respiratory problems. Water is heavier than oil.

Kerosene has a higher ignition temperature due to which it burns smoothly in kerosene stove.

Name the term which is used to express the efficiency of a fuel.

The 6 fuels were chosen to span AIT ranges of approximately 210-425°C and boiling points of approximately 30-185°C. Give a reason for your answer. There are three zones in a flame.

When the temperature goes down below the ignition temperature of the burning substance the fire extinguishes. C. Maintains directional control during braking by preventing the wheels from locking. A low flash point is more dangerous. (b) State any four characteristics of an ideal fuel (or good fuel). A goldsmith blows air into the kerosene lamp flame with a blow-pipe to ensure that the combustion of fuel takes place and the temperature of the flame increases. Substances having low ignition temperature: LPG and Petrol. Name one fuel which burns without producing a flame. The fuel efficiency of LPG is more than that of wood. The answer to this question is dealt with in this chapter. Air contains about twenty-one percent of oxygen and this oxygen present in the air helps in the process of combustion. Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. Which is the best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol? When water is thrown on these substances, it gets cooled below its ignition temperature and also stops burning.

Since the 1970s, there have been regulations regarding industrial locations where there are risks of gas explosions. Coal- Is used to produce electricity through steam engines. The fires caused by the burning of inflammable materials like oil or petrol are also extinguished by using carbon dioxide fire extinguishers. Auto Ignition Temperature The Auto-Ignition Temperature - or the minimum temperature required to ignite a gas or vapor in air without a spark or flame being present - are indicated for some common fuels below: Coke- Coke is used as a reducing agent in the extraction of metals. The combustion of fuels like petroleum causes many unburnt carbon particles along with carbon monoxide which leads to respiratory diseases.

5. Why is the auto ignition temperature of petrol higher than that of diesel? Name the unit in which the calorific value is expressed. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2020.11.12.37996, Sorry, we no longer support Internet Explorer, The best answers are voted up and rise to the top, Chemistry Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. How does pouring water extinguished a fire?

The calorific value of LPG is 55000 kJ/kg. Your email address will not be published. In a flat building the automatic switch on of a central heater unit in the basement was enough to cause an explosion. Can the process of rusting be called combustion? (g)Burning of wood and coal causes_________ of air. All properties of liquids are found in the so-called safety data sheet, which are prepared by the manufacturer. 35.


The most common fire extinguisher is water. For fires involving electrical equipment and inflammable materials like petrol, carbon dioxide (CO2) is the best extinguisher.