Membrane Distillation Circulating Line for Permeate Flux
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Solution Overview
Problem
Current membrane distillation modules, particularly Water-Gap Membrane Distillation (WGMD) systems, face limitations in maximizing permeate flux and energy efficiency due to stagnant distilled water in the gap, which hampers heat and mass transfer processes.
Innovation Solution
Incorporating a circulating line that circulates a portion of distilled water within the module, allowing it to interact with the coolant stream and enhance heat transfer, thereby increasing permeate flux through the hydrophobic membrane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If distilled water is kept stagnant in the gap of WGMD module, then the structure is simple, but the permeate flux is limited due to insufficient heat and mass transfer
Solution Approach 1:
The patent introduces a circulating line that enables the distilled water in the gap to flow dynamically rather than remain stagnant. This dynamic circulation enhances heat and mass transfer between the feed water and permeate water, directly increasing the permeate flux while maintaining relatively simple system architecture
Solution Approach 2:
The patent employs hydraulic circulation through the distillate zone using a pump to move distilled water through the gap. This hydraulic system creates continuous flow that improves thermal contact and mass transfer efficiency, thereby enhancing permeate flux without requiring complex mechanical structures
2Productivity
If a circulating line is added to circulate distilled water, then the permeate flux increases by up to 50%, but the device complexity increases
Solution Approach 1:
The circulating line serves multiple functions simultaneously: it enhances heat transfer, improves mass transfer, and enables continuous circulation of distillate. By making the circulation system multi-functional, the patent achieves significant permeate flux enhancement while minimizing the need for additional separate components
Solution Approach 2:
The circulating line uses the temperature difference between feed water and permeate water to drive natural convection and circulation, reducing or eliminating the need for external pumping power. This self-service mechanism enhances permeate flux without adding complex controlled systems
3Use of energy by moving object
If distilled water circulates in the gap, then heat transfer efficiency improves, but energy consumption increases due to pumping requirements
Solution Approach 1:
The patent implements periodic or pulsed circulation of distilled water through the gap, rather than continuous high-speed flow. This periodic action maintains effective heat and mass transfer while significantly reducing the energy required for pumping, thereby improving heat transfer efficiency without proportionally increasing energy consumption
Solution Approach 2:
The system dynamically adjusts the circulation rate based on operating conditions to optimize the balance between heat transfer efficiency and energy consumption. By adapting the flow rate to actual process needs, the patent avoids excessive energy use while maintaining effective thermal contact
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 circulating line design enhances permeate flux by up to 50% and reduces specific energy consumption, improving the overall efficiency of the membrane distillation process by promoting turbulent flow and efficient heat and mass transfer.
Implementation Method 1
The temperature difference across the membrane causes a vapor pressure difference, which leads to a flow of water vapor from the feed side of the membrane to the permeate side through the membrane pores
Implementation Method 2
Membrane distillation (MD) is a thermally-driven membrane separation technology for separating water vapor from feed water
Implementation Method 3
The permeated vapor further condenses either on the cold side of the membrane, or on a cooling surface arranged therein
Implementation Method 4
a circulating line for circulating a portion of distilled water inside the gap... The circulating line design enhances permeate flux by up to 50% and reduces specific energy consumption, improving the overall efficiency of the membrane distillation process by promoting turbulent flow and efficient heat and mass transfer
Data Source
AI summary
A membrane distillation module with a circulating line to circulate a portion of distilled water, which is formed and accumulated in a distillate zone, to enhance a permeate flux of water vapor through a hydrophobic membrane of the membrane distillation module. Various combinations of embodiments of the membrane distillation module are provided.