【Daily Question】10.25 Short Answer Question: The necessary conditions for a distillation process are
Thread Content
This post was last edited by Adventure Wang on 2015-10-25 at 10:26. Short answer question: The conditions that must be met for a distillation process are (1) there must be a place where the vapor and liquid phases can come into full contact, namely trays or packing. (2) Vapor reflux and liquid reflux must be provided to the distillation column. (3) There must be a temperature difference and a concentration difference between the contacting vapor and liquid phases. That is, the liquid phase must have a low temperature and a high content of light components ； The vapor phase must have a high temperature and a high content of heavy components. (4) On each tray, both the vapor and liquid phases must be present simultaneously and in full contact. Reply +2 wealth (already set to automatic); correct answer +5 wealth; explanation and sharing of work experience +10 wealth
1. The gas and liquid phases must be in full contact. 2. When the gas and liquid phases come into contact, the concentration of light components in the rising high-temperature gas phase is higher than the equilibrium concentration, whereas the concentration of light components in the descending low-temperature liquid phase is lower than the equilibrium concentration. Heat and mass transfer can occur due to the imbalance between the gas and liquid phases, as well as the presence of a temperature difference, thereby enabling distillation.
Collect the subsidy at the Petrochemical Events section after posting the post. A suggestion: use one question per day, focusing mainly on judgment questions with selection questions as a supplement, so as to increase member engagement! You can find some question banks online!
1. There must be trays or packing that ensure thorough contact between gas and liquid, thereby enabling interphase mass and heat transfer. 2. On each tray, an unbalanced gas-liquid two-phase mixture must be present simultaneously, and a reflux system is required. 3. There must be a certain number of trays (and packing), as well as an appropriate reflux rate.
There must be a place that allows for thorough contact between gas and liquid, enabling heat and mass transfer between the phases, namely the tray (or packing). On each tray, both phases – the gas with an unbalanced composition (rising oil and gas) and the liquid (descending reflux) – must be present simultaneously. To ensure that there is rising vapor and oil on each tray in the distillation column, a heat source is required ； To achieve descending reflux on the trays, external reflux must be introduced below the top of the tower and at each full extraction hopper, so as to create internal reflux on the other trays. To achieve distillation, not only are trays necessary, but a certain number of trays is also required ； Not only must there be a return flow, but also an appropriate amount of it.
A necessary condition for the distillation process is the presence of a location where gas and liquid can come into full contact, enabling heat and mass transfer between the phases; this is namely the tray (or packing). On each tray, both phases – the gas with an unbalanced composition (rising oil and gas) and the liquid (descending reflux) – must be present simultaneously. To ensure that there is rising vapor and oil on each tray in the distillation column, a heat source is required ； To achieve descending reflux on the trays, external reflux must be introduced below the top of the tower and at each full extraction hopper, so as to create internal reflux on the other trays. To achieve distillation, not only are trays necessary, but a certain number of trays is also required ； Not only must there be a return flow, but also an appropriate amount of it.
1) There must be a place that allows thorough contact between gas and liquid, enabling interphase heat and mass transfer, namely the tray (or packing). 2) On each tray, both phases – the gas with an unbalanced composition (rising oil and gas) and the liquid (descending reflux) – must be present simultaneously. To ensure that there is rising vapor and oil on each tray in the distillation column, a heat source is required ； To achieve descending reflux on the trays, external reflux must be introduced below the top of the tower and at each full extraction hopper, so as to create internal reflux on the other trays. 3) To achieve distillation, not only are trays necessary, but a certain number of trays is also required ； Not only must there be a return flow, but also an appropriate amount of it.
Rising vapor and falling liquid are two essential conditions in the distillation process
The necessary conditions for a distillation process are: (1) the relative volatility of the substances to be separated must be greater than 1; this is the primary requirement for distillation. (2) Sufficient reflux of both the vapor and liquid phases must be provided, with these phases coming into contact in counterflow. (3) The two phases in contact must have imbalances, that is, differences in temperature and concentration.
1 There must be a location that allows for thorough contact between gas and liquid, enabling heat and mass transfer between the phases, namely the tray (or packing). 2 On each tray, both phases – the gas with an unbalanced composition (rising oil and gas) and the liquid (descending reflux) – must be present simultaneously. To ensure that there is rising vapor and oil on each tray in the distillation column, a heat source is required ； To achieve descending reflux on the trays, external reflux must be introduced below the top of the tower and at each full extraction hopper, so as to create internal reflux on the other trays. 3 To achieve distillation, not only are trays necessary, but a certain number of trays is also required ； Not only must there be a return flow, but also an appropriate amount of it. 4 The volatilities of the separated components should differ
Feed, discharge, and reflux liquid. . . . . . .