Pressure-Stabilising Valve for Reverse Osmosis Concentrate Flow
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Solution Overview
Problem
Existing reverse osmosis filtration plants face fluctuations in concentrate flow rate due to varying osmotic membrane efficiency, leading to unstable pressure conditions that affect permeate purity and plant performance, with existing solutions being complex, prone to malfunction, or energy wasteful.
Innovation Solution
A pressure stabilising valve with a shutter element and spring mechanism that automatically adjusts to maintain consistent pressure by varying the passage port based on flow rate, without manual intervention or complex controls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a flow restrictor with fixed geometry is used to create pressure delta, then the pressure difference between chambers is maintained, but the pressure becomes unstable when concentrate flow rate varies
Solution Approach 1:
The valve replaces the fixed geometry flow restrictor with a dynamic adjustment mechanism. The shutter element can move axially to change the passage port geometry, allowing the valve to adapt the flow resistance dynamically in response to varying concentrate flow rates, thereby maintaining stable pressure differential across the membrane.
Solution Approach 2:
The valve incorporates a feedback mechanism where the varying concentrate flow rate automatically adjusts the shutter position. When flow rate decreases, the reduced force on the shutter allows the spring to close the passage port, increasing resistance to maintain pressure. This self-regulating feedback loop stabilizes pressure despite flow variations.
2Productivity
If manual adjustment of flow restrictor geometry is performed, then optimal concentrate flow can be achieved, but the system requires operator skill and frequent intervention
Solution Approach 1:
The valve is designed to automatically self-regulate the concentrate flow without manual intervention. The interplay between the spring force and the concentrate flow creates a self-balancing system that automatically adjusts the passage port to maintain optimal flow conditions, eliminating the need for operator skill and frequent adjustments.
3Stability of the object's composition
If recirculating pressure regulators are used to overcome pressure surges, then pressure stability is improved, but energy is wasted and membranes may be damaged
Solution Approach 1:
The valve extracts and addresses the root cause of pressure instability at its source - the concentrate outlet - rather than using recirculating regulators that treat the symptom downstream. By directly modulating the concentrate flow through the adjustable passage port, the valve stabilizes pressure without the energy waste and membrane damage risks associated with recirculation systems.
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 valve maintains optimal pressure and flow rates, preventing stagnation and precipitation of salts, reducing the risk of clogging, and ensuring consistent operation across varying conditions.
Implementation Method 1
a spring adapted to push the shutter element towards a first end-of-stroke position
Implementation Method 2
which is adapted to transform the pressure prevailing in the inlet chamber into a force that pushes the shutter element in contrast with the action of the spring towards a second end-of-stroke position
Implementation Method 3
the difference in osmotic pressure produces a migration of the solvent (such as water) from the solution with the lower concentration to the solution with the higher concentration
Implementation Method 4
two solutions with a different concentration of dissolved substances (e.g. salts) have a different molarity and consequently a different osmotic pressure value
Implementation Method 5
the concentrate outlet duct is generally intercepted by a flow restrictor that increases the pressure in the first and third chambers of the vessel to such an extent that the pressure difference between these chambers and the second chamber is greater than the osmotic pressure difference
Data Source
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AI summary
A pressure stabilising valve (100) is described, comprising: an inlet chamber (120), an outlet chamber (125), a cylindrical hole (130) adapted to make the inlet chamber (120) communicate with the outlet chamber (125), a shutter element (135) provided with a stem (140) coaxially fitted into the cylindrical hole (130), a spring (210) adapted to push the shutter element (135) towards a first end-of-stroke position, wherein the stem (140) defines with the cylindrical hole (130) a passage port which leaves open the communication between the inlet chamber (120) and the outlet chamber (125), and a pushing surface (185) radially protruding with respect to the stem (140) and adapted to at least partially delimit the inlet chamber (120), which is adapted to transform the pressure prevailing in the inlet chamber (120) into a force that pushes the shutter element (135) in contrast with the action of the spring (210) towards a second end-of-stroke position, progressively increasing the passage port between the stem (140) and the cylindrical hole (130).