SnowPure Electropure EXL Series, Руководство по проектированию OEM

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SNOWPURE, LLC, 2005-2018 VERSION 3.5 (XL+EXL)
–FEBRUARY 2018
PAGE 33
The system design is the responsibility of the OEM.
Our goal in this section is to lay out how one can put together a system with the proper
features and components. If the OEM chooses not to include equipment or controls in
order to drop the cost, then it is at its own risk. Important factors include:

EDI pretreatment (feed water quality control)

system protection and controls

system design for easy operation

minimum required system components

optional system components (and the benefits)

design for safety
The optimum system depends on the customers’ need. Some systems will be optimized
to provide 10 MΩ.cm water at the lowest capital cost, and some systems will be
optimized to provide the highest resistivity and the lowest silica.
Electropure EDI Pretreatment Philosophy
Pretreatment of the EDI feedwater is extremely important
Module lifetime, module performance, module maintenance frequency, and the cost of
power all depend on the impurities in the feedwater. Pretreatment is as important for the
success of the EDI as it is for the success of the RO. See the EDI feedwater
specifications.
Module cleaning frequency is minimized by providing better pretreatment for the EDI.
This includes minimizing fouling organics (TOC), scaling hardness (Ca
+2
), and fine
particulates. The decisions on pretreatment level will be a capital-operating cost
decision between the OEM system designer and their customer.
Electropure EDI Simple System Philosophy
Electropure EDI believes that a simple EDI system serves the customer best.
A simple RO-EDI system (with no EDI concentrate recirculation) avoids excess costs
and makes the EDI more robust and more reliable.
Electropure EDI modules are designed such that all streams may be fed directly from the
RO, assuming it produces 1-20
μS/cm. Because of this, a very simple EDI system can
be designed and built.
The more complicated systems with concentrate recirculation require control of
conductivity, circulating flow, and the balancing of pressure. These require a pump,
valves, conductivity- and flow-meters, and possibly a softener. A brine injection system
may seem advantageous, but requires the maintenance of a chemical source, and
lessens the “no-chemical-addition” benefit of EDI.
Chapter 6: System Design Schematics and Safeguards