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packie81
12-12-2007, 03:58 AM
How do I calculate the mass flow of vapor being produced by flashing NH3 from a HPR to a Flash Tank?

I know I need 1482 lbs/hr of 25°F liquid to send to the LPR so I need 1482 lbs/hr of 90°F liquid + flash gas to send to the Economizer from the HPR. The economizer suction will see 767 lbs/hr from the low temp. evaps + this flash gas. I'd like to be able to calculate it by hand.

Not worried about defrosting at this point.

Steve

mag1969
20-12-2007, 02:31 AM
By my calculations... 228.4 lbs/hr.

Always ask yourself, how much energy does it take to cool 1482 lbs/hr of liquid ammonia from 90 to 25?

Now that you know the ammount of energy you need. Then ask yourself, how much mass of ammonia would i need that would absorb this ammount of energy from a phase change from 90 degrees F liquid to 25 degrees F vapor.

Simple problem if you break it down.