How do Adsorption Type Hydrogen Dryers Work?

At lower temperatures, various compounds called "molecular sieves" have an affinity for H₂O, CO₂, and other dipoles. The attachment of dipole to sieve is "adsorption." When the molecular sieve becomes saturated, it can be reactivated by heating it and thus driving off the adsorbed molecules. This adsorb-reactivate cycle is then repeated.

The molecular sieve can become contaminated with stray or trace chemicals, which may have happened in your case.

You may like to look into the possibility of water leakage from the hydrogen cooler. In such a case, there would be a continuous water entering the generator casing. Even small leakage would be sufficient to keep the moisture level high. Is the hydrogen pressure in side the casing higher than that of water outlet pressure? In that case, water would be entering the casing only when leakage is so big so as to cause water to fall due to gravity.

Dear sir,

In the generator system there are liquid level indicator(for detect leakage inside generator) installed that indicator having local guage and alarm switchies but that level indicator showing 0 level and switch also not acting.

Thanks

Check the following (sorry if repeats from others):

As you regenerate the alumina, can you trend the water being driven off the alumina (via downstream separator on the regen stream)? Is the level "planing off", meaning that the regenerating gas is getting dryer and dryer, indicating you are completely regenerating the alumina?

Check your regeneration pressures and temperatures. Both of these can affect the ability of the alumina to regenerate.

Check your system's transition from online to regeneration; usually this involves the depressurization of the bed (and repress on the way back up). If this is happening too quickly, it can literally crush the alumina or lift it which is obviously bad.

Check your inlet fluid conditions, I'm assuming that the H2 coming in is saturated and coming out of the top of a separator. Check the temperature and pressure of this stream and check for any low spots in piping heading to the dryer.

Also, is the time it takes to complete the regeneration (outlet temperature should be close to inlet temperature) staying the same length, getting shorter, etc.?

yes actually in the bottom of tower there is one water trap and that trap drain having continiously water droping.

Dear gopal gadhavi, Have you checked any of the points I had suggested at #2. You have to do some thing to to find solution.

I agree that this poster's comments should be addressed as well, particularly #1 since you mention liquid water in the feed pipe.

I would suggest then that you are carrying some liquid water into the dryer. This will damage the adsorbent.

Is the inlet piping insulated?

You have two towers, right! One in line for drying hydrogen & other in regeneration. Which tower trap drain having continuously water dropping? These towers may be operating at different pressures when in service and when in regeneration. If your change over valves at inlet or balancing is passing, then also you may not get trouble.

Gopal, it appears you are not presenting your case properly. Try to utilise the vast potential of CR4 by giving the information asked by experts so that you can get better advise from them.

GA. It's a good point "change over valves at inlet or balancing is passing". Also the following:

"Try to utilise the vast potential of CR4 by giving the information asked by experts so that you can get better advise from them."

It is worth emulating for all OP's like gopal gadhavi.

yes, sir that dryer having two towers and One in line for drying hydrogen & other in regeneration mode at the regeneration mode operating pressure is same but temperature is different during heating cycle adsorbing tower set point is 204 c and it is going around 142 maximum in the 4 hour heating cycle at that time drop by drop water is coming from water trap (liquid trap).

Now with this information, I can guess two more issues which may be responsible for your problem.

1) Heating (or overall heat addition in 4 hour cycle) in regeneration gas is less. Try for more temp.

2) As the gas coming out from the bottle under regeneration contain lot of free moisture, there must be a separater before it mixes again with the gas entering to the bottle in line. Check the condition of separator and its functioning. Improper separation will lead to avoidable increase in drier load.