Methanol distillation tower
Thread Content
Why does an excessive amount of circulating water in the water cooler of the methanol distillation recovery tower cause negative pressure at the tower top, and why does restoring the circulating water flow restore positive pressure?
Because the saturated vapor pressure of methanol is low. With an excessive amount of circulating water in the water cooler, methanol is fully condensed into a liquid state. The temperature of methanol in the return tank is low, and the methanol that enters the distillation tower causes the material at the top of the tower to cool significantly, resulting in a higher proportion of liquid components and thus negative pressure at the top of the tower
The high condensation load causes the methanol in the reflux tank to become supercooled; without hot steam to maintain pressure, the reflux tank will end up under negative pressure.
Too much circulating water is used in the water cooler, causing methanol to be fully condensed into a liquid state; this results in a sudden decrease in volume and the creation of negative pressure
When the cooling water is first turned on, the temperature is low, so more methanol condenses, creating a negative pressure momentarily. As the amount of methanol evaporating increases, the temperature rises gradually, and positive pressure is then generated.
When too much circulating water is used, the methanol vapor condenses too quickly, resulting in negative pressure at the top of the tower
Because of the excellent cooling effect at the top of the tower, the gas there liquefies and its volume decreases sharply, resulting in a negative pressure at the top of the tower; therefore, adjusting the circulating water restores positive pressure.
Negative pressure seems not to be good; inhaling air poses a risk, so a nitrogen breath valve should be installed for protection
All of the above answers are correct; nothing further needs to be added