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View Full Version : Derating factor for ice maker using salty water



Gonzalo Arias
17-05-2007, 07:31 PM
Dear friends:
I have a MORRIS nugget ice maker RA NIM 80. This equipment was originally purchased for fresh water, but is installed taken water from a river that is influenced by the sea tide, and for the rains, so during the year and even during the day the salinity contents varies from 2 to 25 ppt (sea water salinity is about 35 ppt). The evaporator pressure that the system can reach with a VILTER 901 (200 hp) single screw compressor is 18#(saturate temp.=3F), that is far above the typical saturate temperature of -30F used for by example a HOWE sea water ice maker.
The capacity of this equipment is about 1/3 of the fresh water rating, which looks to me so low. I will like to know the derating factor for the salty water from 2 to 25 ppt, to see if the equipment is only influenced by the salt contents or if the system components are not working fine.

Best regards

Peter_1
18-05-2007, 03:57 PM
I should say that the evaporating temperature should decrease (just the opposite as you told) due to the salt.
You have to go lower to pass the latent phase of the water if you can pass it.
Wow, a 200 HP ice machine. Never seen that before.

Is SH within specs with this machine?
Flooded ice generator or DX?
Is the screw fully loaded?