Dometic SPOTZERO SZIII 2000, User Manual & Installation Manual

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Rejection, Recovery, and Flow Rates
The Spot Zero SZIII system is designed to produce product water at the capacities indicated by
the model number. For example, the SZIII-2000 produces 2000 gallons per day (1.39 gallons per minute)
of permeate water at the listed operating test conditions. Meanwhile the SZIII-3000 produces 3000
gallons per day (2.08 gallons per minute) at the same test condition.
The amount of total dissolved solids (TDS) rejected by the membrane is expressed as a
percentage. Spot Zero SZIII is designed to reject up to 99% of Total Dissolved Solids, meaning at best only
approximately 1% of dissolved solids do not pass through the membrane. To calculate the % rejection,
use the following formula.
% Rejection = [(Feed TDS Product TDS) / Feed TDS] x 100
Example:
95% = [(300-15)/300] x 100
The amount of product water recovered for use is expressed as a percentage. To calculate the %
recovery use the following formulas.
% Recovery = (Product Water Flow Rate/ Feed Water Flow Rate) x 100
Example:
36% = [(1.52)/4.22] x 100
NOTE
All TDS figures must be expressed in the same units, typically parts per million (PPM) or
milligrams per liter (mg/L). All flow rates must also be expressed in the same units, typically
gallons per minute or liters per minute.
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