Membrane Distillation Module with Multi-Effect Heat Recovery
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Solution Overview
Problem
Current membrane distillation technologies are not energy efficient and require significant investment and large footprints, necessitating a more efficient and cost-effective membrane distillation module that can easily fabricate and generate distilled water effectively.
Innovation Solution
A membrane distillation module with a porous membrane and non-porous conduits, where the hot feed is outside the membrane and the cold feed is inside the conduits, allowing water vapor to pass through the membrane and condense on the conduits, generating distilled water, and a multi-effect process where the hot feed is used as a coolant for condensation in subsequent modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional membrane distillation configurations (DCMD, AGMD, VMD, SGMD) are used, then salt rejection is achieved, but energy efficiency is poor and investment cost is high
Solution Approach 1:
The module divides the distillation process into multiple stages with sequential heat transfer. Each stage processes feed at different temperatures, segmenting the thermal energy utilization to maximize efficiency while maintaining salt rejection through staged membrane contactors
Solution Approach 2:
The system changes temperature parameters across multiple stages, using progressive heating of feed streams. The first stage operates at lower temperature while subsequent stages operate at progressively higher temperatures, optimizing energy utilization at each stage while maintaining effective salt rejection
2Ease of manufacture
If conventional membrane distillation configurations are used, then separation is achieved, but device complexity and footprint are large
Solution Approach 1:
The invention merges the heating and distillation functions into a single integrated module. The feed stream serves dual purposes as both the process feed and the heating medium for subsequent stages, eliminating the need for separate heating systems and reducing overall device complexity
Solution Approach 2:
The feed stream performs multiple functions: it is processed for distillation, serves as heating medium for the next stage, and provides thermal energy for vapor generation. This multi-functionality reduces the number of dedicated components needed, simplifying manufacturing and reducing footprint
3Use of energy by moving object
If hot feed is used as coolant in subsequent modules, then energy consumption is reduced, but process complexity increases
Solution Approach 1:
The system maintains continuous useful action by immediately routing the hot feed from one stage to the next stage without interruption or cooling in between. The thermal energy is continuously transferred from higher temperature stages to lower temperature stages, maximizing energy utilization while maintaining a straightforward process flow
Solution Approach 2:
The hot feed from each stage automatically serves the next stage as heating medium without requiring external intervention. The system uses its own output (hot feed) to drive the next processing stage, creating a self-sustaining thermal cascade that reduces external energy input requirements
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 configuration enhances water evaporation efficiency and generates distilled water more effectively, reducing energy consumption and operational costs while maintaining high salt rejection rates.
Implementation Method 1
MD utilizes a hydrophobic, micro-porous membrane as a contactor to achieve separation by liquid-vapor equilibrium
Implementation Method 2
This vapor is driven across the membrane by the difference in the partial vapor pressure maintained at the two sides of the membrane created by the difference of temperatures
Implementation Method 3
water vapor to pass through the membrane and condense on the conduits, generating distilled water
Implementation Method 4
The evaporator 117 also includes an evaporation surface 121 on the exterior of the evaporator
Implementation Method 5
A pre-heated feed solution is brought into contact with the membrane, which allows only the water vapor to go through the membrane pores
Data Source
AI summary
A membrane distillation module includes a housing having a hot inlet for receiving a hot feed and a hot outlet for expelling the hot feed; a porous membrane located inside the housing and having an outside surface that defines an enclosure, the outside surface being configured to contact the hot feed, wherein the porous membrane is configured to prevent the hot feed from passing from outside the porous membrane to an inside of the enclosure; and a non-porous conduit located inside the enclosure, the non-porous conduit having an inlet for receiving a cold feed and an outlet for expelling the cold feed.