# 2001 NCEES #139



## dpolet (Jun 16, 2013)

Air flowing at a rate of 3600cfm, and initially at 80F db/67 wb, is passing through a spray of water solution, which has stabilized at 100F. assume a 0.05 bypass factor for spray chamber.

What is the flow of dry air at initial conditions (lb/hr)?

I am a little confused. How to solve this problem? Which part in MERM will be used?

Thanks.


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## SNAPE/SMOTT PE (Oct 8, 2013)

Bump, I'd like to know too.


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## CRNewsom (Oct 11, 2013)

I meant to answer this one before but I got distracted:

Using Appendix 38A in the MERM (12th Edition) which is the psychrometric chart:

Rho-air=13.9 ft^3/lb

(3600 ft^3/min) / (13.9 ft^3/lb) = 259 lb/min = 15539 lb/hr of dry air


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## SNAPE/SMOTT PE (Oct 11, 2013)

Thanks!


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## uzairsyedahmed (Oct 13, 2013)

CRNewsom. is that the answer in the NCEES? I would have dismissed that as a distractor since it seems quite simple! I guess the other information given is redundant as they are asking for initial "dry " air.


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## CRNewsom (Oct 14, 2013)

uzairsyedahmed said:


> CRNewsom. is that the answer in the NCEES? I would have dismissed that as a distractor since it seems quite simple! I guess the other information given is redundant as they are asking for initial "dry " air.




I no longer have the practice exam materials, so I do not know what answer they provide.


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