Is liquid ammonia a flammable medium?
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May I ask if liquid ammonia is a flammable medium? Can that standard be found? This post was last edited by Stone Boy on 2008-8-6 14:14.]
Liquid ammonia is a flammable substance, while ammonia gas is an explosive substance
“ Ignition temperature (°C): 651. Is it flammable as well?
The OP’s question is quite interesting; if liquid ammonia is considered a liquid, then the difference between flammable and combustible substances lies in their flash point! (Liquids with a flash point below 45 degrees Celsius are flammable liquids, while those with a flash point above 45 degrees Celsius are combustible liquids.) ) But what is the flash point of liquid ammonia? The answer is meaningless! Why for meaning? The reason is that liquid ammonia exists under certain temperature and pressure conditions; once these conditions are exceeded, it is no longer liquid ammonia! And as a gas, ammonia is indeed a commonly used flammable gas! So it is generally included in the management of flammable materials! Abroad, ammonia is not considered a flammable substance; its hazard mainly lies in its low toxicity!
For reference: Properties of liquid ammonia: Ammonia is a toxic gas that is colorless and transparent, with an irritating odor. Molecular formula NH3. Molecular weight 17.03. Relative density is 0.7714 g/l. Melting point -77.7°C. Boiling point -33.35°C. Autoignition temperature: 651.11°C. Vapor density is 0.6. Vapor pressure 1013.08 kPa (25.7°C). The explosive limit of the vapor-air mixture is 16–25% (with a concentration at which ignition is most likely to occur at 17%). Liquid ammonia is a compressible, liquefied toxic gas; at certain pressures it appears as a colorless liquid, and it is characterized by high pressure, flammability, and explosiveness. Liquid ammonia transforms into ammonia gas under changes in space, pressure, and temperature; ammonia gas is highly soluble in water. Ammonia has a solubility of 34% in water at 20°C. At 25°C, its solubility in anhydrous ethanol is 10%, and in methanol it is 16%. It is soluble in chloroform and ether, and it serves as a good solvent for many elements and compounds. The aqueous solution is basic; the pH value of a 0.1N solution is 11.1. When ammonia is mixed with water, it forms ammonia water, (NH3.H2O), which is weakly alkaline. It can easily corrode materials such as copper, aluminum, zinc, and tin. When ammonia comes into contact with chlorine, it produces gases that are prone to spontaneous ignition and explosion; (ammonium chloride and nitrogen trichloride are formed), and these mixtures are extremely explosive. It is a colorless liquid at certain pressures, and has the properties of being flammable and explosive under high pressure ? ? What conditions? I don’t know: L
Liquid ammonia is a flammable substance; what those people upstairs were talking about is gaseous ammonia!
The \"Regulations on Safety Inspection of Pressure Vessels\" (version 99) stipulate that \"the classification of the toxicity level of chemical substances in pressure vessels and of flammable substances shall be carried out in accordance with the provisions of HG20660.\" HG20660 defines flammable substances as \"substances whose vapors or mists, when mixed with air, form explosive mixtures, and whose lower explosion limit is less than 10%, or whose difference between the upper and lower explosion limits is 20% or more.\" The explosive limit of liquid ammonia as a medium is “16–25% for vapor-air mixtures (with a concentration of 17% being the most prone to ignition).” ”. Obviously, “liquid ammonia” should not be classified as a “flammable medium”. For the “liquid ammonia” medium, is this where the difference between chemical equipment design and chemical process design lies?
The ignition temperature of gas: 650–700°C. So isn’t gas a flammable substance? The explosive limit of gas is generally 4%–18% (as it is a mixture, and there are no fixed values for the upper and lower limits).
“\"Flammable\" and \"combustible\" are two different concepts! !
Gas meets the definition: A flammable medium is one whose lower limit of the explosion range is less than 10% when mixed with air, or whose difference between the upper and lower limits is greater than 20%! The 4% lower limit is below 10%, so it is considered a flammable substance! But liquid ammonia does not meet the above definition!
“Do “flammable” and “combustible” refer to normal operating conditions? And in normal operating conditions, what state does “ammonia” exist in?