SECTION 6-2
APPENDIX
FLOWMAX RO MANUAL REV: B 05/1999
USFilter
United States Filter Corporation
Calculated Values:
1:
RO FILTER PRESSURE DROP
is equal to filter inlet pressure MINUS filter outlet pressure.
2:
RO FEED FLOW
rate is equal to RO product flow PLUS the RO reject flow.
3:
RO PRODUCT RECOVERY
is equal to the RO product flow rate DIVIDED by the RO feed
flow rate, MULTIPLIED by 100.
EXAMPLE: Product flow = 30 GPM
Feed flow
= 40 GPM
(30
÷
40) x 100 = 75% recovery
4:
RO PERCENT REJECTION*
is equal to the RO feed conductivity MINUS the RO product
conductivity, DIVIDED by the feed conductivity, TIMES 100.
EXAMPLE: Feed conductivity
= 380 micromoh
Product conductivity = 5 micromoh
{(380-5)
÷
380} x 100 = 98.6% rejection
* the RO Quality monitor is set up at the factory to display this value.
5:
NORMALIZED PRODUCTIVITY
is a true indication of membrane performance. It is
calculated as follows:
NPF = MPF X TCF X (225
÷
MFP)
Where:
NPF = NORMALIZED PRODUCTIVITY FLOW
MPF = MEASURED PRODUCT FLOW
TCF = TEMPERATURE CORRECTION FACTOR (See table next page)
MFP = MEASURED FEED PRESSURE
EXAMPLE: MPF = 35 GPM
FEED WATER TEMP = 60
o
F, THEN TCF = 1.44
MFP = 285 PSIG
NPF = 35 x 1.44 x (225
÷
285)
NPF = 35 x 1.44 x .789
NPF = 39.8