2001 NCEES #139

[dpolet]

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.

 

[SNAPE/SMOTT PE]

Bump, I'd like to know too.

 

[CRNewsom]

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

 

[SNAPE/SMOTT PE]

Thanks!

 

[uzairsyedahmed]

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.

 

[CRNewsom]

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.