What is the reason why the pressure at the bottom of the lower column is higher than the pressure at the top of the column?
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This post was last edited by huaguiyi on 2010-11-14 at 14:25. Please explain why the pressure at the bottom of the tower is higher than the pressure at the top of the tower?
Is the author referring to a distillation column? The gas phase flows from bottom to top, and flow of the gas phase occurs only when the pressure at the bottom of the column is higher than the pressure at the top.
It can be understood in this way: Starting from the bottom of the tower, heat is applied to it, causing the temperature of the liquid to rise; the liquid then evaporates. The evaporated gas rises upward, and during this ascent it comes into contact with the fluid flowing downward, as well as with the packing or trays. After mass and heat transfer occur, the gas continues to rise. Along the way, it inevitably encounters resistance. By the time the gas reaches the top of the tower, the pressure decreases, which is why the pressure at the bottom of the tower is high.
What was said upstairs is very good. To add something: the closer the material is to the top of the tower, the more cold material there is, which means more steam gets condensed and the pressure drops.
This is quite normal in production
Why is there a pressure drop? Material flow requires power; wherever there is flow, there is energy loss. Therefore, the pressure decreases gradually in the direction of flow, resulting in a pressure difference.