On the liquid-to-gas ratio in packed towers
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Hello everyone, I would like to humbly ask for your advice here, as a way to discuss an issue. During the operation of a packed tower, if the gas load remains significantly below the design value for an extended period of time – that is, if the designed gas-liquid ratio is much higher than the actual gas-liquid ratio – then from the perspective of gas purification, will the performance of the tower deteriorate if I refuse to reduce the amount of liquid sprayed? Because packed towers usually focus on flooding, that is, situations where the gas velocity is too high, but when the gas velocity is too low, does the resistance to gas upward movement decrease or increase? Personally, I believe that when the flow rate of the liquid remains constant, resistance and gas velocity are positively correlated. Similarly, according to my logic, when the amount of liquid sprayed remains unchanged and the gas flow operates at a low level for an extended period, apart from the waste purification liquid, it should not have a significant negative impact on the performance of the tower. What are your thoughts? Thank you all for sharing your opinions.
Original poster, if the liquid phase load does not exceed the design load, then this mode of operation is beneficial for gas purification; however, it results in increased energy consumption, making it uneconomical to use.
Thank you. What this means is that if both the liquid-phase load and the gas-phase load are at their design values initially, and then the gas-phase load is reduced to a very low level while the liquid-phase load remains unchanged, it won’t cause abnormal operation of the absorption tower; instead, the purification effect will be better?
The main concern is that as the gas load decreases, whether the gas-phase flow channels will all be occupied by the liquid phase, thereby increasing the resistance to the upward gas flow
Using this post as an opportunity to ask further: In a gas absorption packed tower, the liquid-phase spray load has already reached its critical value (the flooding threshold). If the gas load is then increased by about 50%, the gas velocity in the empty tower remains low, at around 1.1. Under these conditions, if the liquid phase remains unchanged, will flooding occur? !