US Water Systems Aquapurion 200-APRO Series, Руководство пользователя

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Installation Instructions
Residential Reverse Osmosis Drinking Water System
Page 18
Water quality
Water quality from an RO system is normally determined with
a TDS Meter, which measures total dissolved solids in water,
measuring conductivity. The results are normally measured in
parts per million or milligrams per liter. Fewer dissolved solids
results in higher quality water.
RO membranes are rated by the amount of dissolved solids
they reject expressed as “rejection percentage”.
For example:
If feed water contains 100 ppm of dissolved solids and the
product water after the membrane has 10 ppm of dissolved
solids the rejection rate is 90%.
The formula is as follows:
RO membranes should operate between an 80 - 97% rejection
rate. Once the rejection falls below 80%, the membrane must
be replaced.
Water production
PRODUCT WATER RATE
Usable water production from an RO system is designated
product water rate , produced on a daily basis. The rate is
normally described in gallons per day (gpd) or milliliters
per minute (ml/min).
REJECT WATER RATE
The flow of water to drain is designated as reject water
rate , as measured in gallons per day (gpd) or milliliters per
minute (ml/min).
Using a graduated cylinder the formulas are:
REJECT RATIO
The reject ratio is the amount of water produced
compared to the amount of water flowing to drain.
The formula is as follows:
PERCENT RECOVERY
The
percent recovery
is another way to measure the amount
of water produced compared to the amount of water which is
actually used.
The formula to determine percent recovery is as
follows:
NOTE:
Product water rate is the sum of the feed water
flow rate and reject water flow rate.
For example:
Water pressure and temperature
Product water quality and production of RO systems is
dependent on pressure and temperature. Typically, RO
membranes are treated at standard conditions of 77°F (25°C)
and 60 psi (4 bar) discharging to atmosphere. In general, the
higher the pressure differential and temperature, the greater
the quality and quantity of water produced. These factors
should be considered when sizing RO systems for a particular
application.
Milliliters per minute x 0.38
= gallons per day
Ounces per minute x 11.2 = gallons per day
Product water rate =10 gpd
Reject water rate = 40 gpd
Feed water = (10 gpd + 40 gpd) or 50 gpd
Percent Recovery = 20%
Percent Rejection
=
(Feed H
2
O TDS - Product H
2
O TDS) x 100%
Feed H
2
O
Reject Ratio =
Reject Rate
Product Rate
Percent Recovery
=
Product H
2
O Rate x 100%
Feed H
2
O Rate