Sea Recovery Aqua Whisper DX 1400-2 Owner'S Manual Download

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Aqua Whisper DX Modular 450-1800

Page 1-2

Introduction

SPIRAL-WOUND MEMBRANE

The spiral-wound membrane consists of multiple
membrane envelopes each formed by enclosing a
channelized product water carrying material between two
large flat membrane sheets. The membrane envelope
is sealed on three edges with a special adhesive and
attached with the adhesive to a small diameter pipe.
A polypropylene screen is used to form the feed water
channel between the membrane envelopes. A wrap
is applied to the membrane element to maintain the
cylindrical configuration. The center tube is also the
permeate (product water) collecting channel. Several
elements may be connected in series within a single or
multiple pressure vessels).

WATER TEMPERATURE EFFECT

The product water flow through the membrane is
significantly affected by the water temperature. At any
given pressure this flow increases with increasing water
temperature and is reduced at lower temperatures.
The System over comes this factor by self adjusting
the operating pressure to maintain a precise amount of
Product Water Flow.

In addition to inferior product water quality, low brine
flows can increase the precipitation of sparingly soluble
salts which will foul the R.O. membrane element surface
(concentration polarization). If this occurs, the product
water flux (production) will decline.
The Feed Pump integrated design provide a relatively
smooth and continual flow of Feed Water across and
through the R.O. membrane element.

COMPACTION

Some densification of the membrane structure may
take place while operating at elevated pressures, above
1000 PSI. The change is known as compaction and is
accompanied by a reduction in the water permeation rate.
When the R.O. membrane element is subjected to
elevated pressures beyond 1000 PSI the Product Water
Channel becomes squeezed which results in restriction
and in turn product water recovery reduction.

OSMOTIC PRESSURE

The transfer of the water from one side of the membrane
to the other will continue until the head (pressure) is
great enough to prevent any net transfer of the solvent
(water) to the more concentrated (feed water) solution.
At equilibrium, the quantity of water passing in either
direction is equal, and the head pressure is then defined
as the ”Osmotic Pressure” of the solution having that
particular concentration of dissolved solids.

PRESSURE

The operating pressure has a direct affect on product
water quality and quantity. Both factors will increase
as the system pressure increases (higher quantity and
higher quality within design limits).
The system must be operated at the lowest pressure
required to achieve the designed product water flow
rate. This parameter also minimizes compaction, which
proceeds at a faster rate at higher pressures as well as
at higher temperatures.
The System self adjusts its operating pressure to maintain
a precise amount of Product Water Flow. However in
so doing, at low temperatures and or high salinity feed
water conditions the system will operate at higher than
normal pressure in maintaining the specified amount of
product water flow. This is normal, to be expected, and is
due to the design characteristics of the system.