Exhaust Purge Regenerative Air Dryer

[Divya11]

I am buying an exhaust purge type regenerative air dryer, installed in the downstream of integrally geared 3 stage centrifugal air compressor. The dryer package consists of pre-filters (dual with isolation valves)and after filters (dual with isolation valve) in the upstream and downstream of dryer vessels respectively. Dryer vendor has not provided any differential pressure transmitters across either of these filters. I do not foresee any upset conditions where these filters are likely to get choked suddenly. If these filters are maintained regularly, do we need differential pressure transmitters across these filters to assess their choking? The air compressor in the upstream of the dryer has a 2 stage inlet filter with differential pressure transmitter. Please share your experiences.
Also if someone can let me know the expected desiccant carry over rate to the after filter. Desiccant used is activated alumina.

 

[chicopee]

Since the vendor is of no help, I would call the manufacturer's engineering division, after all you would be dealing with the designer and not sales people.

 

[Compositepro]

A filter of any type should have some sort of indicator to tell when it needs to be changed. Often gauges somewhere upstream and downstream are sufficient, and these are already present for other reasons. Otherwise you have to change filters on a schedule.

Desiccant does breakdown over time, which creates dust that can plug filters. This rate increases with age of the desicant.