RO Storage Tank Segmentation for Backpressure Relief
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Solution Overview
Problem
Reverse osmosis (RO) water filtering systems face inefficiencies due to increased backpressure in storage tanks as they fill, reducing the production rate of purified water and causing pressure fluctuations at the faucet, leading to decreased membrane effectiveness.
Innovation Solution
The system uses a storage tank arrangement where concentrate water pressurizes the permeate, and a synchronized flow of concentrate into the tank when the faucet is open to relieve backpressure, utilizing off-the-shelf components for cost-effective manufacturing and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a pre-charged storage tank with a gas-filled bladder is used to store permeate under pressure, then permeate can be stored and delivered at pressure to the faucet, but backpressure increases as the tank fills, reducing the production rate of the RO system
Solution Approach 1:
The storage tank is divided into two separate chambers: a first chamber for storing permeate and a second chamber for receiving concentrate liquid. This segmentation allows the concentrate chamber to serve as a pressure relief mechanism without compromising the permeate storage function, thereby maintaining production rate while enabling pressure delivery.
Solution Approach 2:
Concentrate liquid serves as an intermediary substance that performs dual functions: it is discharged to the drain to relieve backpressure on the RO membrane, and it pressurizes the permeate in the first chamber to enable pressure delivery to the faucet. This intermediary use of concentrate resolves the contradiction between maintaining pressure and preserving production rate.
2Reliability
If concentrate water is discharged to the drain through a flow restrictor, then an air gap is provided to prevent siphoning, but this creates additional backpressure and reduces system efficiency
Solution Approach 1:
The concentrate discharge path is segmented into two routes: a primary path through the flow restrictor to the drain for anti-siphon protection, and a secondary path to the second chamber of the storage tank for pressure relief. This segmentation allows the system to maintain reliability while reducing backpressure impact on productivity.
Solution Approach 2:
The operable connection between the second chamber and drain acts as a controlled porous pathway that allows concentrate to pass through with minimal resistance when needed for pressure relief, reducing backpressure while maintaining anti-siphon protection through the primary restricted path.
3Quantity of substance
If the storage tank capacity is increased to provide larger quantities of permeate, then more permeate can be stored for dispensing, but the time and concentrate water consumed to fill the tank increase significantly
Solution Approach 1:
The system uses itself to fill the storage tank by utilizing the concentrate liquid generated during normal RO operation to pressurize and facilitate permeate flow into the first chamber. This self-service mechanism eliminates the need for additional time-consuming filling operations while maintaining large storage capacity.
Solution Approach 2:
The concentrate discharge to the second chamber operates continuously during permeate dispensing, maintaining pressure in the first chamber and enabling continuous refilling of storage capacity without interruption or time loss. This continuous action ensures that storage capacity is maintained without additional time consumption.
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
This arrangement reduces backpressure within the system, maintains steadier pressure at the faucet, and enhances the efficiency of the RO membrane by minimizing resistance and ensuring consistent permeate delivery.
Implementation Method 1
a reverse osmosis (RO) water filtering process uses a semi-permeable membrane that has the ability to remove and reject a wide spectrum of impurities and contaminants from water using only water pressure
Implementation Method 2
a tank having a first chamber for storing the permeate and a second chamber for receiving the concentrate liquid, the first and second chambers being operatively connected so that the concentrate liquid in the second chamber pressurizes the permeate in the first chamber
Implementation Method 3
Concentrate water is routed from the concentrate outlet port through a flow restrictor for disposal down a drain
Data Source
AI summary
A valve assembly having a first valve defining an inlet connected to the inlet supply and an outlet connected to the concentrate chamber, a second valve defining an inlet connected to the permeate chamber and an outlet connected to the faucet, and a third valve defining an outlet connected to drain, a port connected to the concentrate chamber, and an inlet connected to the inlet supply. The port is selectively in fluid communication with the third valve outlet and inlet. When the faucet opens, the first valve opens, the second valve has permeate flowing, and the third valve opens a flowpath between the third valve port and the inlet due to pressure dropping in the second valve. When the faucet closes, the first valve closes and the third valve opens another flowpath between the third valve port and outlet due to pressure created in the second valve.