(I) Product Overview
The ultrafiltration+two-stage RO complete system is a dual stage membrane deep purification combined water treatment equipment. It uses tap water, groundwater, production cleaning wastewater, reclaimed water, etc. as the inlet water, and first completes the front-end precision filtration through ultrafiltration (UF) to remove colloids, suspended solids, bacteria, and large molecular organic matter. The SDI of the inlet water is stably controlled within 3, protecting the back-end reverse osmosis membrane; After undergoing two-stage reverse osmosis desalination, trace ions such as calcium and magnesium hardness, heavy metals, soluble silicon, inorganic salts, and CO ₂ are significantly removed from the water. The comprehensive desalination rate of the entire system is ≥ 99%, and the conductivity of the secondary produced water can be stably controlled within 5 μ S/cm. The water quality is much better than that of single-stage RO produced water. It is often used as a pre standard process for EDI ultrapure water equipment and is widely used in high-end pure water preparation scenarios such as lithium batteries, photovoltaics, semiconductors, laboratories, pharmaceuticals, cosmetics, etc. It can also be used for high standard water reuse and centralized direct drinking water central water production systems.
(I) Core features of the equipment
1. Pre protection of ultrafiltration greatly extends the service life of RO membrane. Ultrafiltration intercepts colloids, flocs, and microorganisms, avoiding colloid pollution and biofouling blockage of secondary RO membrane, reducing the frequency of membrane chemical cleaning, and lowering the cost of consumables in the later stage.
2. Two stage reverse osmosis deep desalination ensures stable and excellent effluent quality. The first stage RO removes most of the salt, while the second stage RO deeply removes residual ions, silicate ions, and carbon dioxide. The fluctuation of raw water quality has minimal impact on the final water production, making it suitable for high hardness, high silicon, and high salt raw water.
3. Fully automatic air-water washing+membrane automatic flushing, simple operation and maintenance, ultrafiltration configuration, timed air-water combined scrubbing; The secondary RO has automatic start stop flushing and timed flushing programs, with fully automated operation and 24-hour unmanned operation.
4. Multi stage recovery of concentrated water, high water resource utilization rate. Ultrafiltration concentrated water, first stage RO concentrated water, and second stage RO concentrated water can all be recycled back to the front-end water tank for treatment. The comprehensive water recovery rate of the system can reach 70%~85%, saving water and reducing emissions.
5. Modular integrated design, flexible expansion of ultrafiltration membrane components, standardized modularization of primary/secondary RO membrane racks, and direct increase in membrane components for later production capacity without the need to replace the entire host.
6. Multiple online monitoring of water quality, graded control of water quality, monitoring the conductivity/turbidity of ultrafiltration produced water, primary produced water, and secondary produced water separately, segmented judgment of filtration effect, automatic reflux for reprocessing if water quality exceeds the standard.
7. The entire process is made of anti-corrosion and clean materials, with no secondary pollution. The water related components are made of PVDF ultrafiltration membrane, 304 stainless steel membrane shell, and UPVC pipeline, which can be matched with alkali adding devices to reduce the conductivity of secondary water production. It is suitable for electronic and pharmaceutical clean water.
8. Improve chain protection, ensure safe and stable operation, low pressure shutdown due to water shortage, high pressure overload protection, high and low liquid level linkage, membrane flow protection, fault sound and light alarm, and avoid pump and membrane component dry burning and high pressure damage.
(III) Complete system composition
The entire system is divided into five main units: raw water pretreatment unit, ultrafiltration UF pretreatment unit, primary RO desalination unit, secondary deep RO unit, and automatic monitoring and auxiliary supporting unit
1. Raw water pretreatment unit
Raw water tank, raw water lifting pump;
Multi media filter, activated carbon filter (for removing sediment and residual chlorine);
Softener/scale inhibitor dosing device (optional for high hardness water source);
5 μ m pre security filter to protect the ultrafiltration membrane fibers from scratches.
2. Ultrafiltration UF core pre filtration unit
PVDF hollow fiber ultrafiltration membrane module and membrane frame;
Ultrafiltration circulation pump, aeration fan (dedicated for air washing);
Backwash pipeline, water/concentrate reflux pipeline;
Chemical cleaning kit (sodium hypochlorite, acid-base cleaning solution);
Ultrafiltration production water tank, cache ultrafiltration clean water supply to primary RO.
3. First stage reverse osmosis (RO) unit
Primary high-voltage variable frequency booster pump;
RO membrane shell and reverse osmosis membrane element;
Primary concentrated water reflux pipeline, returning to the original water tank for recycling;
The first stage water production buffer tank serves as the inlet for the second stage RO.
4. Secondary reverse osmosis (RO) deep purification unit
Secondary booster pump;
Secondary RO membrane module;
PH alkali addition device (optional, removes CO ₂ from water, reduces water conductivity);
The secondary concentrated water flows back to the primary production water tank for recycling;
Secondary water production pipeline, transported to EDI or pure water tank.
5. Self control monitoring and auxiliary supporting units
Online turbidity meter (ultrafiltration water production), multi-channel conductivity meter (primary/secondary water production);
Pressure, flow, and liquid level sensors;
PLC touch screen control cabinet, unified control of ultrafiltration flushing, RO automatic flushing, and regeneration dosing;
Electric switching valve, reflux valve;
Pure water tank, delivery pump, UV sterilizer (optional at the back end).
(IV) Core functions of the system
1. Ultrafiltration precision pretreatment stabilizes the inflow SDI, protects the two-stage RO membrane by screening and intercepting colloids, suspended solids, bacteria, and large organic molecules through 0.01~0.1 μ m, eliminates impurities that can cause irreversible fouling of the RO membrane, and reduces membrane loss from the source.
2. Two stage stepped deep desalination produces low conductivity pure water, and the first stage RO removes over 97% of inorganic salts; The secondary RO further removes residual silicon, heavy metals, carbonates, and carbon dioxide, with a comprehensive desalination rate of over 99%, meeting the EDI inlet water quality standards.
3. Ultrafiltration air-water combined cleaning, automatic timed air scrubbing+positive and negative water washing to prevent membrane fiber blockage, peeling off membrane surface and intercepting pollutants, long-term stable ultrafiltration water production flux, reducing offline chemical cleaning cycles.
4. RO membrane automatic flushing protection, delaying membrane fouling pollution equipment startup, shutdown, and timed automatic flushing of two-stage reverse osmosis membranes, flushing out salt impurities intercepted on the membrane surface, and slowing down the accumulation of inorganic and organic scale.
5. Online monitoring of graded water quality, automatic reflux of unqualified water, segmented monitoring of ultrafiltration, first and second level water quality, automatic reflux of any section with substandard water quality, and re filtration of the front-end to prevent unqualified water from flowing into the back-end equipment.
6. Multi stage concentrated water recycling, efficient water-saving ultrafiltration, first and second stage RO concentrated water staged reflux front-end water tank for repeated treatment, reducing wastewater discharge and lowering the cost of tap water intake.
7. PH adjustment to reduce conductivity (optional), improve the purity of pure water. Add a small amount of alkaline solution to the secondary influent to convert free carbon dioxide in the water into removable carbonates, greatly reducing the conductivity of the secondary produced water and meeting the pre production requirements of high-purity ultrapure water.
8. Fully automated linkage operation throughout the entire process, unmanned production water tank high and low liquid level linkage pump group start and stop, ultrafiltration flushing, RO flushing, and dosing program fully automated execution, with fault alarm and parameter recording, suitable for 24-hour continuous water production in factories.
