In the reverse osmosis with electrodeionization systems, a Double Pass Reverse Osmosis (DPRO) System is when
the permeate water going into a second RO unit to produce more pure water accordingly. Hence, a two or double
stage RO is when the concentrate or reject stream is going into a second RO system to recover water, respectively.
So, reverse osmosis system is briefly to purify water by rejecting around 99% of total dissolved solids from the feed water.
Meanwhile, Single Pass RO Systems produce product water (permeate) and reject water (concentrate) at the same time. Therefore,
most of reverse osmosis + EDI systems have double pass ro unit.

How does double pass ro system work? Working principle of double pass RO:

Double Pass Reverse Osmosis Systems are including of two RO systems (1^st Pass and 2^nd Pass) wherein the 1^st  pass has a bigger volumetric flow rate capacity than the 2^nd pass accordingly. In between them, there can be a break tank. Where either permeate or the concentrate water of the 1^st pass RO is stored and fed into the 2^nd pass RO. Further filtration or directly from 1^st ro permeate output connects to 2^nd ro inlet accordingly.

In the reverse osmosis with electrodeionization edi system, pre-treatment can be neccessary firstly. To provide for both the 1st pass and the 2nd pass RO systems if the application will be water recovery. As the quality of the concentrate water on the 1^st pass should be bordering on the saturation point. On the other hand, an application might only require a 1^st pass pre-treatment. If it starts using as permeate to feed the 2^nd pass.

Why a reverse osmosis with EDI module?

As regards to our experience, if inlet water to edi module is less than 20ppm. So, electrodeionization module efficiency and lifespan is much more better. For double pass reverse osmosis with electrodeionization EDI module, we prefer like some other well-known water treatment companies, Dow filmtec membranes, IonPure or GE EDI modules consequently.

TL-EDI-3000L/H Machine Description	Quantity	Remarks
Raw water tank	1 Set
Raw water pump	1 Set	CM10-3,SS304
Sand filter	1 Set	φ900×1850MM
Carbon filter	1 Set	φ900×1850MM
Cartridge filter	1 Set	5μm
1 stage High pressure pump	1 Set	CR10-12
A. Membrane housing  8040-7core     SS304	1PC
B. Membrane element BW30-400	4pcs
PH adjustment dosing system	1Set
2 stage High pressure pump	1 Set	CR15-18
2 stage Reverse osmosis water production:4m3/h, desalination rate:97～99%	1 Set
2 stage RO water tank	1 Set
EDI Water supply pump	1Set	CM3-7
Cartridge filter	1 Set	0.22μm
EDI deionization device Water production: 3.0m3/h	1 Set	water quality: 10-15 megohms
Pure water storage tank	1Set
Pure Water supply pump	1Set	CHL4-40
Cartridge filter	1 Set	0.22μm
RO cleaning system
Connecting pipe fittings (from the raw water tank outlet to the cartridge filter outlet,food grade UPVC pipe valve parts are used, and the high pressure part of the equipment is made of 304 stainless steel polished pipe valve parts.)	1 Set
Electronic control system	1 Set
Pressure gauges	1 Set
Flowmeter Panel type		0-30GPM