123 patents in this list

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Reverse osmosis membranes operating at pressures of 55-80 bar accumulate mineral scaling, biological fouling, and organic deposits that can reduce permeability by up to 30% within operational cycles. During cleaning interventions, these same membranes become vulnerable to chemical degradation and mechanical stress that can compromise their selective barrier properties.

The fundamental challenge lies in removing accumulated foulants while preserving the delicate polymer chemistry and structural integrity of the membrane surface.

This page brings together solutions from recent research—including temperature-adaptive cleaning protocols, two-phase mechanical oscillation systems, and permeate-based flushing techniques. These and other approaches focus on maintaining membrane performance while minimizing cleaning-induced damage across industrial water treatment applications.

1. Reverse Osmosis System with Intermittent Flush Mechanism and Divided Purification Chamber

GUANGZHOU YANQI ENVIRONMENTAL PROTECTION TECH CO LTD, GUANGZHOU YANQI ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD, 2024

Intermittent flush reverse osmosis water purification system to clean the membranes without replacing them, extending membrane life and reducing system maintenance. The system has a purification chamber with a membrane, divided into first and second chambers. A valve isolates the chambers. A flushing device can inject water to clean the membrane. A controller opens the isolation valve and flushing device periodically to flush the membrane, then closes the valve and isolates the membrane for normal filtration. This removes contaminants from the membrane without replacement.

2. Reverse Osmosis Membrane Cleaning Device with Integrated Diagnostic and Automated Dosing Units

GUONENG LANGXINMING NANJING ENVIRONMENTAL PROTECTION TECH CO LTD, GUONENG LANGXINMING NANJING ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD, 2024

Reverse osmosis membrane cleaning device and method for online cleaning of RO membranes to improve performance and prolong membrane life. The device has a cleaning unit, production unit, dosing unit, bypass monitoring unit, and control unit. The method involves diagnosing membrane fouling based on factors like water quality changes, then triggering cleaning modes tailored to the fouling type. Cleaning mode 1 is for inorganic fouling with calcium, magnesium, carbonate, and chloride. Cleaning mode 2 is for fouling with sulfate, fluoride, and organic compounds. The cleaning solutions contain acids, alkali, salts, and biocides. The device automatically dispenses the optimized cleaning solutions based on the diagnosis.

3. Sequential Cleaning Method for Reverse Osmosis Membranes with Contamination-Specific Alkaline and Acid Treatments

HUNAN ZHEXIANG NEW MATERIAL TECH CO LTD, HUNAN ZHEXIANG NEW MATERIAL TECHNOLOGY CO LTD, 2024

Cleaning method for desalinated reverse osmosis membranes in water treatment systems to maintain membrane performance and prevent fouling. The cleaning involves specific steps based on the type of contamination. For organic fouling, alkaline cleaning is followed by acid cleaning. For inorganic scale fouling, acid cleaning is followed by alkaline cleaning. The cleaning steps include soaking the membranes in cleaning solutions, rinsing with water, and using high quality water without residual chlorine.

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4. Multi-Stage Reverse Osmosis System with Front Filtration Stage for Fouling Management

GREENTECH ENV CO LTD, GREENTECH ENVIRONMENTAL CO LTD, 2024

A highly efficient anti-pollution reverse osmosis membrane filtration system that extends the life of membranes in multi-stage RO systems by adding a front filtration stage. The system has pretreatment, front filtration, first-stage RO, second-stage RO, and cleaning. Raw water is pretreated, then filtered in front, then passes through the RO stages. This separates membrane fouling to the front stage, reducing fouling in downstream RO stages. If front stage fouling is bad, cleaning just there instead of all RO stages.

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5. Whole-House Water Filtration System with Dual-Series Membrane Modules and Alternating Backwash Mechanism

TAIZHOU LIOU ENVIRONMENTAL PROT NEW MATERIAL CO LTD, TAIZHOU LIOU ENVIRONMENTAL PROTECTION NEW MATERIAL CO LTD, ZHEJIANG LEO WATER TECH CO LTD, 2023

A whole-house water filtration system with backwashing capability that allows cleaning of the membranes to improve water purification efficiency and membrane lifespan. The system has two membrane modules connected in series, a pump, and separate pipelines for water production and backwashing. By switching valves, the system can backwash one membrane module while the other continues producing filtered water, then reverse the backwash to clean the second module. This removes impurities attached to the membranes.

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6. Sequential Membrane Cleaning Method with Stage Isolation and Multi-Phase Agent Application

CHUXIONG DIANZHONG NONFERROUS METAL CO LTD, 2023

A method for cleaning reverse osmosis membranes in water treatment systems to improve cleaning efficiency and prevent dirt transfer between stages. The method involves sequentially flushing and soaking each membrane section with acidic, neutral, and alkaline cleaning agents. The membranes are separated during cleaning to prevent dirt from front stages washing into later stages. This prevents excessive sediment buildup and maintains membrane performance.

7. Segmented Flushing Device with Stage-Specific Valves for Multi-Core Reverse Osmosis Membranes

CHENGDU SHUOTE TECH CO LTD, CHENGDU SHUOTE TECHNOLOGY CO LTD, 2023

A segmented flushing device for reverse osmosis membrane systems that improves cleaning of multi-stage, multi-core membranes to prevent concentration polarization and scaling. The device has separate flushing sections for each stage. After the primary stage, a backwash valve allows reverse flow to clean the primary stage membrane. Then a secondary positive wash valve flushes the secondary stage membrane with clean water from the tank. This sequential segmented flushing prevents incomplete flushing and concentration issues at the end of stages.

8. Bidirectional Forward Osmosis Cleaning System for Nanofiltration Membranes with Temperature Control

Shandong Jianzhu University, 2023

Online cleaning system for micro-polluted nanofiltration membranes using forward osmosis. The system allows in-situ cleaning of nanofiltration membranes to remove fouling without shutting down the system. It uses a forward osmosis (FO) process where concentrated saline water is pumped into the FO feed solution tank. The FO system draws clean water from the feed and concentrates it into the draw solution tank. This allows bidirectional cleaning by reversing the feed and draw water flow through the membrane. The system also has temperature control to maintain optimal cleaning conditions.

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9. Reverse Osmosis System with Segmented Membrane Shells and Multi-Inlet Configuration

NANJING SHUNSHUIDA ENVIRONMENTAL PROTECTION TECH CO LTD, NANJING SHUNSHUIDA ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD, 2023

A new type of reverse osmosis water treatment system that improves efficiency by reducing scaling and cleaning frequency. The system uses a unique water inlet configuration with high-pressure pumps, filters, and multiple inlet pipes connected to segmented membrane shells. This allows higher recovery rates and lower drainage volumes compared to traditional systems. The increased water production reduces scaling compared to diluting feed water, while the segmented membrane shells prevent full-system scaling. The system also has a dedicated cleaning section to remove fouling.

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10. Integrated Reverse Osmosis Membrane Cleaning System with Adjustable Flow, pH Control, and Heating

HUANENG QUFU THERMOELECTRICITY CO LTD, HUANENG SHANDONG POWER GENERATION CO LTD, 2023

A system for cleaning reverse osmosis membranes online without removing them from the device. The system has a bottom plate with connections for water inlet, clean water, concentrated water, transmission, waste, and chemicals. It allows flushing the membranes with valves and pumps, and also has a separate deep cleaning device for severely fouled membranes. The flushing has features like adjustable flow, pH control, and heating to improve cleaning.

11. Two-Step Cleaning Method for Hollow Fiber Membrane Modules with Initial Water Removal and Air-Induced Membrane Agitation

ASAHI KASEI KABUSHIKI KAISHA, 2023

Cleaning method for hollow fiber membrane modules used in filtering raw water that reduces fouling and maintains filtration performance over time. The cleaning involves two steps: a first cleaning step to remove most of the water and suspended components from the module, followed by a second step to shake the membranes with air to remove the remaining fouling. This two-step process removes 50% or more of the module's original water volume in the first step, then shakes the membranes in the second step to dislodge any remaining fouling. This provides effective cleaning to prevent fouling buildup and deterioration of filtration performance in long-term use of the membrane modules.

12. Reverse Osmosis Membrane Cleaning Method with Reverse Flow Circulation

BAOTOU IRON & STEEL CO LTD, BAOTOU IRON & STEEL GROUP CO LTD, 2023

An improved method for chemically cleaning reverse osmosis membranes to prevent fouling buildup that can clog the membranes and reduce performance. The method involves circulating the cleaning solution from the back of the membrane array towards the front during chemical cleaning, instead of feeding from the front as in traditional cleaning. This prevents front-end fouling from blocking the back-end grid channels during cleaning. The cleaning solution is circulated using the membrane element's former pump to reverse the flow direction.

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13. Reverse Osmosis Membrane Cleaning System with Ultrasonic-Induced Cavitation and Sequential Air-Water Injection

BUCKF CHEMICAL GMBH, 2023

Online cleaning method for reverse osmosis membranes to improve cleaning efficiency. The method involves using an ultrasonic generator, air and water injection ports, and drain pipes between membrane groups. The ultrasonic generator is placed below the membranes and connected to each group. Air and water ports are provided on the cleaning injection mechanism. During cleaning, air is injected first through the air ports, followed by water through the water ports. This creates a cavitation effect using the ultrasonic vibrations to dislodge impurities from the membrane surface. The drain pipes between groups allow the cleaning solution to flow through and flush the membranes.

14. Two-Stage Reverse Osmosis System with Dedicated Flushing and Chemical Cleaning Units

HUIXINYING ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD, HUIXINYING JIAXING ENVIRONMENTAL PROTECTION TECH CO LTD, 2023

High-efficiency two-stage RO water treatment system that improves efficiency, reduces energy consumption, and extends membrane life compared to conventional two-stage RO systems. The system has a pre-treatment unit, a secondary RO unit, a post-treatment unit, and separate flushing and cleaning units. The pre-treatment unit sterilizes and scales the feed water before sending it to the secondary RO unit. The secondary RO unit has dedicated flushing water to prevent membrane fouling. The cleaning unit provides chemical cleaning water to periodically clean the secondary RO membranes. This prevents fouling, maintains efficiency, reduces operating pressure, and extends membrane life compared to shared flushing in conventional two-stage RO systems.

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15. Reverse Osmosis System with Automated Fouling Detection and Cleaning Cycle

HUNAN BG WELL POINT ENVIRONMENTAL SCIENCE & TECH CO LTD, HUNAN BG WELL-POINT ENVIRONMENTAL SCIENCE & TECHNOLOGY CO LTD, 2023

Reverse osmosis water treatment system with automated cleaning to prevent fouling and extend membrane life. The system has an automatic cleaning function that intelligently determines when cleaning is needed based on real-time data analysis. When fouling is detected, the system initiates an automated cleaning cycle using stored chemicals instead of manual intervention. This prevents manual errors and irreversible damage to membrane components. The system monitors parameters like flux, pressure, and water quality to optimize cleaning frequency and timing.

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16. Direct Drinking Water Cleaning Device with Integrated Physical Flushing and Backwashing Mechanisms

CHENGDU CHUANLI SMART FLUID EQUIPMENT CO LTD, 2023

Smart direct drinking water cleaning device and method to prevent clogging and fouling of water treatment systems. The cleaning system is connected to the treatment system and has steps for physical and backwashing. Physical flushing involves filling the circulation tank with water, opening the concentrated water valve, producing water, and adjusting the pump pressure to a low flow rate. Backwashing involves increasing the horizontal shear force by low pressure and high flow rate to flush pollutants out of the membrane elements. This periodic cleaning prevents buildup that can decrease flow rates and cause failures.

17. Reverse Osmosis System with Simultaneous Multi-Stage Operation and Cleaning Mechanism

SHANGHAI BAOHUI ENVIRONMENT TECH CO LTD, SHANGHAI BAOHUI ENVIRONMENT TECHNOLOGY CO LTD, 2023

A reverse osmosis system that enables simultaneous operation and cleaning of multiple stages to maintain continuous production during membrane fouling. The system has multiple stages with separate cleaning lines that can be activated simultaneously. When a stage needs cleaning, the other stages continue operating to increase recovery rate. This allows the system to clean stages without shutting down production.

18. Segmented Cleaning Disc Reverse Osmosis Device with Isolated Membrane Module Circulation System

JIARONG TECH BEIJING CO LTD, JIARONG TECHNOLOGY CO LTD, 2022

Segmented cleaning disc type reverse osmosis device with improved membrane fouling prevention during cleaning. The device has a segmented cleaning main pipe with multiple reverse osmosis membrane modules located between a cleaning pump and a pressure regulating valve. This allows circulating cleaning solution through each membrane module separately instead of recirculating through all modules. It also has a water tank with a filter connected to the cleaning pipe. Cleaning water is drawn from the tank instead of the feed source. This prevents contaminants from the feed source being recirculated during cleaning. The tank can be filled with clean water for mixing with the cleaning solution before entering the membranes.

19. Reverse Osmosis Filtration System with Pre-Filtration and Sequential Membrane Stages

GREENTECH ENV CO LTD, GREENTECH ENVIRONMENTAL CO LTD, 2022

An anti-pollution reverse osmosis filtration system that extends membrane life in water treatment applications. The system has pre-filtration and first-stage RO before the main RO stages. This allows pre-filtering to capture pollutants that could foul the downstream RO membranes. The pre-filter membrane elements are replaced more frequently but the main RO elements last longer due to reduced fouling.

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20. Method for Temperature-Adapted Incremental Chemical Cleaning of Filtration Membranes Based on Performance Triggers

KUBOTA CORPORATION, 2022

Method for cleaning membranes in filtration devices that adapt the cleaning process based on liquid temperature to optimize cleaning effectiveness and minimize costs. The cleaning involves periodic steps using increasing strength chemicals and longer times. The cleaning intervals are triggered when a performance metric (transmembrane pressure difference or permeability) exceeds a threshold. For each trigger, the cleaning strength is increased. The cleaning strength is adjusted based on the liquid temperature to optimize cleaning for that temperature. This prevents overcleaning at high temperatures and insufficient cleaning at low temperatures.

21. Semi-Permeable Membrane Cleaning via Pulsed Water-Induced Oscillation

22. Parallel Membrane Cleaning System with Recoil Valve for In-Situ Reverse Osmosis Maintenance

23. Parallel Membrane Filtration System with Integrated Reverse Flow Cleaning Mechanism

24. Segmented Reverse Osmosis Membrane Cleaning System with Isolated Reflux Branches

25. Sequential In-Situ Chemical Cleaning Process for Reverse Osmosis Membranes with Integrated Sterilization, Pickling, Descaling, and Alkaline Washing

Cleaning membranes without damaging them requires certain safeguarding practices; otherwise, the reverse osmosis system may not run as intended. That is why reverse osmosis preserve membranes during cleaning for efficient operation and purification of water.

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