Spiral Wound Permeate Flow Controller for Flux Balance
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Solution Overview
Problem
Spiral wound filtration assemblies experience permeate flux imbalances due to increasing feed pressure and permeate back pressure, leading to premature membrane fouling and reduced water production, which existing techniques have not adequately addressed.
Innovation Solution
A spiral wound assembly with serially connected modules and a variable area orifice flow controller within the permeate pathway that increases resistance as permeate flow increases, maintaining consistent flow across the modules and reducing flux imbalances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple spiral wound modules are serially arranged in a pressure vessel, then the volume of water production increases, but permeate flux imbalances occur leading to premature membrane fouling
Solution Approach 1:
The patent applies local quality by implementing a flow controller at specific locations within the permeate collection system. The flow controller creates localized resistance adjustments in downstream modules to balance permeate flux across all modules. This targeted intervention at specific points (downstream modules) rather than uniform treatment throughout the system resolves the flux imbalance problem while maintaining overall system productivity.
2Productivity
If feed pressure increases to maintain flow rate, then productivity increases, but permeate back pressure increases causing flux imbalances
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the flow resistance parameter within the permeate collection system. The flow controller modifies local flow parameters (resistance) to compensate for changes in feed pressure and permeate back pressure. This allows the system to maintain balanced permeate flux across modules even when operating pressure conditions change, enabling sustained productivity without excessive back pressure buildup.
3Stress or pressure
If conventional flow restriction techniques are used, then permeate back pressure is reduced, but device complexity increases
Solution Approach 1:
The patent applies self-service by designing a flow controller that automatically balances permeate flux without requiring external control systems or complex mechanisms. The flow controller utilizes the inherent pressure differential and flow characteristics of the system to self-regulate and distribute permeate flow evenly across modules. This self-regulating mechanism reduces permeate back pressure while avoiding the need for complex external control systems, actuators, or multiple moving parts.
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 solution effectively reduces permeate flux imbalances and minimizes premature membrane fouling, ensuring consistent water production and extending the operational lifespan of the filtration assembly.
Implementation Method 1
a flow controller within the permeate pathway between the first and last elements that comprises a variable area orifice that decreases as permeate flow increases
Implementation Method 2
During operation pressurized feed fluid is introduced into the vessel, successively passes through the individual modules and exits the vessel in at least two streams: concentrate and permeate
Data Source
Figure 1
Figure 2
AI summary
A spiral wound assembly including: i) a pressure vessel including a feed inlet, concentrate outlet and permeate outlet, and ii) a plurality of spiral wound modules, each including at least one membrane envelop wound around a permeate tube, and wherein the spiral wound modules are serially arranged within the pressure vessel with a first element of the series positioned adjacent to a first end of the pressure vessel and a last element of the series positioned adjacent to an opposing second end of the pressure vessel, and wherein the permeate tubes of the spiral wound elements are serially connected to form a permeate pathway which is connected to the permeate outlet. The assembly is characterized by including a flow controller within the permeate pathway that provides a resistance that varies as a function of permeate flow.