【Daily Question】Chemical Engineering Principles 316: Explosion Limit (February 5)
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This post was last edited by “Back to Cambridge” on February 19, 2016, at 15:53. Starting today, the Chemical Engineering Theory section is launching the “Question of the Day” activity, aimed at helping everyone reinforce their basic knowledge of chemical engineering. Subsequently, series such as “Fundamentals of Chemical Engineering”, “Mass Transfer and Separation”, “Chemical Thermodynamics”, and “Chemical Process Technology” will also be introduced. We hope for your active participation! Wishing you all a Merry Christmas~~ For replies to the “Question of the Day” activity, answers can be viewed directly; however, the thread will be closed after one day! ! To encourage everyone’s continued participation this year! You get 3 wealth rewards just for participating, and an additional 4 wealth points for correct answers~~~ Short answer question: What is the explosion limit of flammable materials? Answer: When combustible gases or combustible dusts mix with air, and the concentration of these combustible substances reaches a certain level, they will explode immediately upon contact with an open flame. The lowest concentration at which ignition occurs is called the ignition lower limit, while the highest concentration is called the ignition upper limit.
Combustible materials (combustible gases, vapors, and dusts) must be evenly mixed with air (or oxygen) within a certain concentration range to form a premixed gas; only when this mixture comes into contact with a fire source will an explosion occur. This concentration range is known as the explosion limit, or explosive concentration limit. For example, the explosion limit of a mixture of carbon monoxide and air is 12.5% to 80%. The lowest and highest concentrations at which a flammable mixture can explode are referred to as the lower explosive limit and the upper explosive limit, respectively; these are sometimes also called the lower ignition limit and the upper ignition limit. It does not explode or catch fire when the temperature is below the explosion threshold ； Above the explosion limit, no explosion will occur, but ignition will take place. This is because the combustible material concentration in the former is insufficient, and the cooling effect of the excess air prevents the flame from spreading ； The latter is due to a lack of air, which prevents the flame from spreading. The greatest explosive power is achieved when the concentration of the combustible material is roughly equivalent to the stoichiometric concentration for the reaction (i.e., the concentration ratio calculated based on the complete combustion reaction equation). The explosion limit and the hazards of combustible materials: The wider the explosion limit range of a flammable mixture, the lower its lower explosion limit, and the higher its upper explosion limit, the greater its explosion risk. This is because the wider the explosion limit, the greater the chances of conditions for an explosion occurring ； The lower the explosion threshold, the more likely it is that even a slight leakage of flammable materials will create conditions for an explosion ； The higher the explosion limit, the more air can penetrate into the container, where it can mix with the flammable substances inside to create conditions for an explosion. It should be noted that when the concentration of a flammable mixture exceeds the upper limit for explosion, no ignition or explosion occurs; however, if it escapes from a container or pipeline and comes into contact with air again, it can burn, and there is still a risk of fire.
What is the explosion limit of flammable materials? Answer: Combustible substances (combustible gases, vapors, and dusts) must be evenly mixed with air (or oxygen) within a certain concentration range to form a premixed gas; only when this premixed gas comes into contact with a source of ignition will an explosion occur. This concentration range is known as the explosion limit, or explosive concentration limit. For example, the explosion limit of a mixture of carbon monoxide and air is 12.5% to 80%. The lowest and highest concentrations at which a flammable mixture can explode are referred to as the lower explosive limit and the upper explosive limit, respectively; these are sometimes also called the lower ignition limit and the upper ignition limit. It does not explode or catch fire when the temperature is below the explosion threshold ； Above the explosion limit, no explosion will occur, but ignition will take place. This is because the combustible material concentration in the former is insufficient, and the cooling effect of the excess air prevents the flame from spreading ； The latter is due to a lack of air, which prevents the flame from spreading. The greatest explosive power is achieved when the concentration of the combustible material is roughly equivalent to the stoichiometric concentration for the reaction (i.e., the concentration ratio calculated based on the complete combustion reaction equation). The explosion limit and the hazards of combustible materials: The wider the explosion limit range of a flammable mixture, the lower its lower explosion limit, and the higher its upper explosion limit, the greater its explosion risk. This is because the wider the explosion limit, the greater the chances of conditions for an explosion occurring ； The lower the explosion threshold, the more likely it is that even a slight leakage of flammable materials will create conditions for an explosion ； The higher the explosion limit, the more air can penetrate into the container, where it can mix with the flammable substances inside to create conditions for an explosion. It should be noted that when the concentration of a flammable mixture exceeds the upper limit for explosion, no ignition or explosion occurs; however, if it escapes from a container or pipeline and comes into contact with air again, it can burn, and there is still a risk of fire.
When combustible gases or combustible dusts mix with air, and the concentration of these combustible substances reaches a certain level, they will explode immediately upon contact with an open flame. The lowest concentration at which ignition occurs is called the ignition lower limit, while the highest concentration is called the ignition upper limit.
When combustible gases or combustible dusts mix with air, and the concentration of these combustible substances reaches a certain level, they will explode immediately upon contact with an open flame. The lowest concentration at which ignition occurs is called the ignition lower limit, while the highest concentration is called the ignition upper limit.
Combustible materials (combustible gases, vapors, and dusts) must be evenly mixed with air (or oxygen) within a certain concentration range to form a premixed gas; only when this mixture comes into contact with a fire source will an explosion occur. This concentration range is known as the explosion limit, or explosive concentration limit.
There are upper and lower limits for reaching the explosion concentration
The best and lowest percentages at which combustibles and oxides can cause explosions
What is the explosion limit of flammable materials? Combustible materials (combustible gases, vapors, and dusts) must be uniformly mixed with air (or oxygen) within a certain concentration range to form a premixed gas; only when this mixture comes into contact with a fire source will an explosion occur. This concentration range is known as the explosion limit.
When combustible gases or combustible dusts mix with air, and the concentration of these combustible substances reaches a certain level, they will explode immediately upon contact with an open flame. The lowest concentration at which detonation occurs is called the lower limit for detonation, while the highest concentration is called the upper limit for detonation
What is the explosion limit of flammable materials? Answer: When combustible gases or combustible dusts mix with air, and the concentration of these combustible substances reaches a certain level, they will explode immediately upon contact with an open flame. The lowest concentration at which ignition occurs is called the ignition lower limit, while the highest concentration is called the ignition upper limit.