Reverse Osmosis Membrane Flow Switching for Continuous Scale Washing
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Solution Overview
Problem
Existing RO membrane systems face scaling issues due to dissolved salts precipitating on the membrane surface, which current methods like chemical injection and backwashing require stopping operations and discharging permeated water, leading to reduced efficiency and recovery rates.
Innovation Solution
A water treatment system with multiple RO membrane devices and switchable flow lines allows for in-situ washing of RO membranes without stopping operations, using permeated and concentrated water from one device to wash another, and controlled chemical addition based on measured parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If backwashing is performed by causing permeated water to flow from the permeated water side of an RO membrane, then silica scale can be suppressed, but normal operation of the RO membrane device must be stopped
Solution Approach 1:
The system divides the RO membrane treatment into multiple independent devices (first RO membrane device, second RO membrane device, third RO membrane device). While one device undergoes washing treatment, others continue normal operation. This segmentation allows washing operations to be performed without stopping the entire water treatment process, resolving the contradiction between scale suppression and operational continuity.
2Ease of manufacture
If permeated water is used for washing the RO membrane, then washing can be performed, but the permeated water is discharged out of the system
Solution Approach 1:
Instead of discharging the permeated water used for washing into the environment, the system recovers it by returning the washed water to the raw water tank. This recovered water can be重新 utilized in the treatment process, thereby reducing water loss while maintaining effective washing capability.
3Reliability
If chemical agents are added to suppress scaling, then scale generation can be reduced, but defective injection or water property fluctuations can still cause scaling
Solution Approach 1:
The system employs self-service washing where permeated water automatically flows through the RO membrane in reverse direction to wash and remove scales. This eliminates the need for complex chemical injection systems and external washing equipment, as the system uses its own produced permeated water for maintenance purposes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively removes scale from RO membranes without interrupting treatment processes, maintaining efficiency and recovery rates by alternating flow paths and using treated water for washing.
Implementation Method 1
reverse osmosis membrane device A for treating a water to be treated; reverse osmosis membrane device E for treating permeated water from the reverse osmosis membrane device A
Implementation Method 2
a first connection line passing water to the concentrated water flow line AB and the concentrated water flow line EC and a second connection line passing water to the concentrated water flow line AC and the concentrated water flow line EB are switchable to each other
Data Source
AI summary
A water treatment system including: a reverse osmosis membrane device A for treating a water to be treated; a reverse osmosis membrane device E for treating permeated water from device A; a reverse osmosis membrane device B for treating concentrated water from device A or E; a reverse osmosis membrane device C for treating concentrated water from device E or A; and each of water flow lines through which the concentrated water and permeated water from devices A to E respectively flow downstream, wherein the connections of each of the water flow lines are switchable so that while the concentrated water from device E flows to device B to wash device B, the concentrated water from device A is treatable by device C, and while the concentrated water from device E flows to device C to wash device C, the concentrated water from device A is treatable by device B.