Salt Reduction Pretreatment, Precision Filtration, Fully Automatic Reverse Osmosis with Water tank

Product description

This system is an integrated water purification equipment with the core goal of “deep desalination”. Through the full process design of “salt reduction pretreatment → precision filtration → reverse osmosis desalination → water storage”, it is designed to treat high salinity water sources (such as groundwater, some industrial wastewater, brackish water) and produce low salt pure water, which is widely used in drinking water purification, industrial process water, agricultural irrigation and other scenarios. The following provides a detailed explanation from three aspects: system composition, working principle, and core advantages:
1、 Core components and functions of the system
1. Salt Reduction Pretreatment Unit
Salt reduction pretreatment does not directly remove salt, but creates “low pollution, easy desalination” inlet conditions for subsequent reverse osmosis systems by improving water quality characteristics, while reducing damage to equipment in high salt environments.
Core components:
Grille filter: made of stainless steel material, with a filter aperture of 1-5mm, it intercepts large volume impurities such as tree branches and plastics in the raw water, protecting the subsequent pump body.
Anti pollution multi-media filter: 304 stainless steel tank body, filled with quartz sand (lower layer) and anthracite (upper layer), some scenes add garnet filter material (to enhance wear resistance), remove suspended solids and colloids (turbidity reduced from 10-30NTU to ≤ 1NTU), and reduce the risk of particulate matter pollution in reverse osmosis membranes.
Salt resistant activated carbon filter: filled with high iodine value coconut shell activated carbon (specially treated to withstand high salt environments), it adsorbs organic matter (such as humic acid, industrial solvents) and residual chlorine in water (removal rate>99%), avoiding irreversible pollution of organic matter on the surface of reverse osmosis membrane and preventing residual chlorine oxide film material.
Scale inhibitor dosing system: salt resistant chemical storage tank (made of PPH material)+corrosion-resistant metering pump. Special anti salt scale inhibitors (such as phosphonates and sulfonic acid copolymers) are added to inhibit the crystallization of calcium carbonate and calcium sulfate in high salt water (calcium and magnesium ions are more likely to precipitate in high salt environments), preventing reverse osmosis membrane scaling.
Core functions:
Reduce influent turbidity, organic matter, and residual chlorine, and control the pollution index (SDI) to ≤ 5;
Inhibit the scaling tendency caused by high salt, provide “friendly” inlet water for the reverse osmosis system, and extend the membrane cleaning cycle.
2. Precision Filtration Unit
As the “last line of defense” of the reverse osmosis system, precision filtration further intercepts fine impurities and absolutely protects the membrane components.
Construction: 304 stainless steel shell, built-in 1-5 μ m PP folding filter element (or polyether sulfone filter element, with stronger chemical resistance), the number of filter elements is configured according to the flow rate (usually 3-5 filter elements per 10m ³/h of water production), equipped with a quick opening top cover (easy to replace).
Function:
Retain fine particles (such as activated carbon powder and colloidal fragments) remaining after pretreatment, ensuring that the particle diameter entering the reverse osmosis membrane is ≤ 1 μ m;
Monitoring pre-treatment effect: When the pressure difference of the filter element is greater than 0.1MPa, it indicates that the pre-treatment unit may fail (such as backwashing for multi-media filters).

3. Fully Automatic Reverse Osmosis System
This is the core desalination unit of the system, which achieves the separation of salt and water molecules through the selective permeability of reverse osmosis membranes.
Core components:
Salt resistant high-pressure pump: made of 316L stainless steel material (impeller and pump casing resistant to salt corrosion), designed as a multi-stage centrifugal pump, providing a pressure of 1.5-2.5MPa according to the inlet salinity (the higher the salinity, the greater the required pressure, such as 1.8-2.0MPa for brackish water), equipped with a variable frequency controller (adjusting the speed according to the water production demand, saving 30% energy).
Reverse osmosis membrane components:
Membrane element: Anti pollution bitter and salty water membrane (such as Dow BW30FR-400, Heideneng LFC3-LD) is selected, with a desalination rate of ≥ 99.5%, and stable retention efficiency for Na ⁺, Cl ⁻, Ca ² ⁺, etc. in high salt water;
Membrane shell: made of fiberglass material (pressure resistance ≥ 3.0MPa), with membrane elements arranged in series (usually 3-6 tubes/shell), and the number of membrane shells designed according to the water production rate.
Fully automatic control valve group: including water production valve, concentrated water valve, flushing valve, etc., controlled by PLC to adjust the concentrated water discharge ratio, ensuring stable system recovery rate (high salt water sources are usually controlled at 50% -60% to avoid scaling caused by high concentrated water salinity).
Online monitoring system: conductivity meter (real-time monitoring of salinity of produced water and concentrated water, automatic discharge of excess produced water), pressure transmitter (monitoring pressure before and after the membrane to determine the degree of membrane fouling), flow meter (recording water production and concentrated water flow).
Function:
Deep desalination: removing over 99% of soluble salts, reducing the TDS (total dissolved solids) of raw water from 1000-5000mg/L (brackish water) to ≤ 50mg/L (TDS of produced water);
Fully automatic operation: automatic low-pressure flushing upon startup (1-2 minutes, washing away residual salt on the membrane surface), automatic start stop based on water tank level, timed chemical cleaning (triggered based on pollution level), automatic alarm shutdown due to faults (such as high pressure overload, high salinity).

4. Water Tank
Used for storing reverse osmosis water to ensure continuous water supply.
Construction: Made of 304 stainless steel material (mirror polished inner wall, Ra ≤ 0.8 μ m), with a capacity of 2-4 hours of water production for the system, equipped with:
Liquid level sensor (linked reverse osmosis system start stop: low liquid level start, high liquid level stop);
Respiratory filter (0.22 μ m sterilization grade, preventing dust and microorganisms from entering the air);
Blender (optional, to prevent trace salt precipitation caused by long-term standing of the produced water).
Function: Stable storage of low salt water, avoiding frequent start stop of reverse osmosis system, and preventing secondary pollution through sanitary design.
2、 System working principle
Salt reduction pretreatment stage: The high salt raw water is first filtered through a grid to remove large impurities, and then the turbidity is reduced by a multi-media filter. The activated carbon filter adsorbs organic matter and residual chlorine; The scale inhibitor dosing system inhibits the crystallization of calcium and magnesium ions, ensuring that the influent meets the requirements of reverse osmosis (SDI ≤ 5, residual chlorine ≤ 0.05mg/L).
Precision filtration stage: The pre treated water passes through a 1-5 μ m precision filter element, intercepting fine particles and providing “non-destructive” inlet water for the reverse osmosis membrane.
Reverse osmosis desalination stage: The high-pressure pump pressurizes the water to 1.5-2.5 MPa and sends it into the reverse osmosis membrane module. Water molecules pass through the membrane to form low salt water (produced water), and salt and impurities are discharged with concentrated water; The system monitors water quality in real-time through sensors and automatically adjusts the operating status.
Water storage and supply stage: The reverse osmosis produced water enters the stainless steel water tank for storage, and is controlled by liquid level linkage to operate the equipment. Finally, it is transported to the water consumption point through the water supply pump (optional).
3、 Core advantages and applicable scenarios
Core advantages
Efficient desalination: For high salt water sources, the TDS of the produced water can be stably controlled below 50mg/L, meeting the needs of multiple scenarios such as drinking and industry;
Anti pollution design: From pre-treatment to membrane components, salt resistant and anti pollution materials are used to adapt to the corrosiveness and scaling tendency of high salt environments;
Fully automatic operation: No manual intervention is required, the system autonomously completes flushing, start stop, and alarm, reducing the difficulty of operation and maintenance;
Stable water production: Through multi-stage filtration and precise control, the fluctuation of water quality is small (conductivity deviation ≤ ± 5 μ S/cm).
Applicable scenarios
Drinking water purification: Treatment of drinking water for residents in brackish water areas (such as northwest and coastal areas) to remove excess salt (such as Na ⁺, Cl ⁻) and improve taste;
Industrial process water: low salt water demand in the electronics and electroplating industries (to avoid product defects caused by salt), boiler feedwater (to prevent salt deposition and scaling);
Agricultural irrigation: Treatment of irrigation water in high salt soil areas to reduce the risk of soil salinization;
Wastewater reuse: Industrial high salt wastewater (such as chemical and printing and dyeing wastewater) is treated and reused to save fresh water.
summarize
This system solves the purification problem of high salt water sources through a combination process of “salt reduction pretreatment to reduce membrane fouling → precision filtration to protect membrane elements → reverse osmosis deep desalination → sterile water storage”. Its core value lies in efficient desalination, stable operation, and adaptability to complex water quality. It is an ideal equipment for obtaining low salt water in high salt areas or industrial scenarios.