How to reduce the pressure drop of molecular sieve adsorption columns
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The current problem is that the pressure drop of the gas as it passes through the molecular sieve is quite high, at over 50 KPA, with a height-to-diameter ratio of 2.5. What considerations should be taken into account when designing the adsorption system? Experts, please stop by! My system uses 95% v/v alcohol vapor for dehydration
The molecular screening is inappropriate, the gas velocity in the empty tower is too high; it seems there are also issues with the design. I’ve never seen such a high pressure drop before
Is there a theoretical formula for the pressure drop as air flows through a molecular sieve or alumina adsorbent layer?
Please, experts on 2L, could it be an issue with molecular screening? We use 3A grade products. How can we adjust the gas velocity in the empty tower if it’s too high? Is it the structure of the distributor that matters? Thank you
The factor that determines which molecular sieve to use is not the level of resistance, but rather the properties of the medium to be adsorbed. A high pressure drop is likely due to an excessive flow rate, which is not beneficial for the adsorption process; this issue can be resolved by increasing the diameter of the cylinder.
1. There should be a relationship between pressure drop and feed pressure, right? If the steam inlet pressure is reduced from 2 kg/cm2 to 50 KPa, the flow rate decreases, but the adsorption efficiency gets worse. I’m not sure how to address this issue 2. Reducing the height-to-diameter ratio from 2.5 to 1.2 might help to decrease the pressure drop. I think neither of these two factors is likely to be the key factor; what’s important is the structural design of the distributor. Is that a reasonable way of thinking?
The feed pressure is not determined by you; it is determined by the process flow. Furthermore, as the flow rate decreases, the adsorption effect only improves.
Molecular sieves can also affect the pressure drop. Generally, the pressure drop of strip molecular sieves is slightly lower than that of spherical molecular sieves. Molecular sieves with larger particle sizes have a lower pressure drop than those with smaller particle sizes. Of course, all the methods mentioned above—reducing the flow rate and improving the distributor to lower the pressure drop—are correct.
LS’s friend proposed the factors affecting pressure drop from the perspective of molecular sieve structure； But that is basically not something that can be influenced by manufacturing processes; I hope experts in equipment design, namely those who specialize in molecular sieve adsorbers, can answer this! Thank you so much!
Molecular sieves with larger particle sizes have a lower pressure drop, but a lower packing ratio. Bar-shaped ones have a lower pressure drop, yet lower strength and are prone to crumbling. Last edited by bbslu on 2009-3-25 09:34.]
A further adsorber can be added; by diverting a portion of the flow, the space velocity can be reduced. How about that? It’s the simplest solution
The problem is that the client refuses to add another set of adsorbers; therefore, the focus has shifted to the structural design of the existing adsorbers, with a production capacity of 1000 tons per day
How can it be seen that strip-shaped molecular sieves have low strength? I recently prepared a batch of 3A strip-shaped molecular sieves, with a strength of over 100 Newtons.