Watts PWR4021 - Manual (Page 2)

2
I. Introduction
The separation of dissolved solids and water using RO membranes
is a pressure driven temperature dependent process. The membrane
material is designed to be as permeable to water as possible while
maintaining the ability to reject dissolved solids.
The main system design parameters require the following:
• Internal flows across the membrane surface must be high enough
to prevent settling of fine suspended solids on the membrane
surface.
• The concentration of each dissolved ionic species must not exceed
the limits of solubility anywhere in the system.
• Pre-treatment must be sufficient to eliminate chemicals that would
attack the membrane materials.
A. Specifications
RO Membrane
Feed Water Product Water
Reject Water
B. RO Overview
Reverse osmosis systems utilize semipermeable membrane ele-
ments to separate the feed water into two streams. The pressurized
feed water is separated into purified (product) water and concentrate
(reject) water. The impurities contained in the feed water are carried
to drain by the reject water. It is critical to maintain adequate reject
flow in order to prevent membrane scaling and/or fouling.
PWR40213023 PWR40213033 PWR40213043 PWR40213053 PWR40213063
Productivity (gallons per day / gallons per minute) Maximum production based on standard
membranes and feed water of 25°C, SDI < 3, 1000 ppm TDS, and pH 8. Individual membrane
productivity may vary (± 15%).
3600 / 2.5 5400 / 3.75 7200 / 5.0 9000 / 6.25 10800 / 7.5
Quality (typical membrane percent rejection) Based on membrane manufactures
specifications, overall system percent rejection may be less.
98 % 98 % 98 % 98 % 98 %
Recovery without reject recycle 29 % 39 % 50 % 57 % 62 %
Recovery with reject recycle (adjustable) 50 % 50 % 75 % 75 % 75 %
Membrane Size 4 x 40 4 x 40 4 x 40 4 x 40 4 x 40
Number Of Membranes Per Vessel 1 1 1 1 1
Pressure Vessel Array 1:1 1:1:1 1:1:1:1 1:1:1:1:1 1:1:1:1:1:1
Number Of Membranes 2 3 4 5 6
Prefilter (system ships with one 5 micron cartridge) 20" BB 20" BB 20" BB 20" BB 20" BB
Feed Water Connection 1" NPT 1" NPT 1" NPT 1" NPT 1" NPT
Product Water Connection 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT
Reject Water Connection 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT 3 ⁄
4
" NPT
Feed Water Required (feed water required will be less if reject recycle is used) 9 gpm 10 gpm 10 gpm 12 gpm 13 gpm
Feed Water Pressure (minimum) 20psi 20psi 20psi 20psi 20psi
Drain Required 9 gpm 10 gpm 10 gpm 12 gpm 12 gpm
Electrical Requirement 230 VAC, 3-ph, 60 Hz (other voltages available) 15 amps 15 amps 15 amps 15 amps 15 amps
TEFC Motor (horse power) 5 5 5 5 5
Dimensions L x W x H (inches) 60 x 18 x 56 60 x 18 x 56 60 x 18 x 56 60 x 18 x 56 60 x 18 x 56
Shipping Weight (estimated pounds) 400 500 600 700 800