Cross-Pleated Membrane Cartridge Structure for Leak-Resistant ERV Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat and water vapor exchanger designs, such as planar plate-type and pleated membrane cartridges, face challenges with labor-intensive and expensive manufacturing, limited durability, and leakage due to delamination and cross-contamination issues.
Innovation Solution
A cross-pleated membrane cartridge is developed using a method where two membrane strips are folded at 45° angles to form diagonal seams, creating a stack of layered passageways with alternating fluid flow configurations, reducing the number of edges that need to be sealed and enhancing sealing characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If planar plate-type heat and water vapor exchangers use discrete membrane pieces stacked and sealed, then heat and water vapor transfer is achieved, but manufacturing becomes labor intensive and expensive with limited durability
Solution Approach 1:
The membrane is divided into multiple pleated layers that are stacked together, with each layer containing discrete membrane pieces arranged in alternating flow patterns. This segmentation allows for modular assembly while maintaining durability through reduced seal requirements.
Solution Approach 2:
Multiple membrane layers are combined into a single cartridge structure where alternating layers handle different fluid streams. The pleated configuration merges heat transfer and moisture transfer functions within the same structural framework, improving durability while simplifying manufacturing.
2Reliability
If planar plate-type exchangers use multiple sealed joints and edges, then fluid stream separation is achieved, but leakage and cross-contamination occur due to delamination and seal failure
Solution Approach 1:
The cartridge is segmented into alternating layers where each layer is sealed independently at its edges. This segmentation reduces the total number of seals required compared to a fully sealed multi-plate structure, while maintaining effective fluid stream separation and reducing leakage points.
Solution Approach 2:
Instead of sealing all edges of all membrane pieces, the invention inverts the approach by leaving alternate edges of alternate layers unsealed, allowing fluid communication while maintaining separation where needed. This reduces the number of seals and associated leakage risks.
3Ease of manufacture
If concertina-style pleated membrane cartridges are used, then the number of edges to be bonded is reduced, but flow configuration options are limited and pressure drop increases
Solution Approach 1:
The pleated membrane is segmented into multiple discrete layers that can be independently configured. Each layer can be folded or pleated to create different flow patterns, allowing for greater flow configuration versatility while maintaining the manufacturing advantage of reduced bonding requirements.
Solution Approach 2:
The invention transitions from a single-dimensional concertina fold to a multi-dimensional layered structure where alternating layers are oriented differently. This dimensional change enables cross-flow, counter-flow, and co-flow configurations while preserving the reduced bonding advantage.
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 cross-pleated design reduces leakage and cross-contamination, improves durability, and allows for efficient heat and water vapor transfer while being scalable and cost-effective, with superior performance in pressurized applications compared to conventional designs.
Implementation Method 1
a water-permeable membrane via which water vapor and, provided there is a temperature differential across the membrane, heat is transferred between fluid streams flowing on opposite sides of the membrane
Implementation Method 2
provided there is a temperature differential across the membrane, heat is transferred between fluid streams flowing on opposite sides of the membrane
Data Source
AI summary
A membrane cartridge is manufactured by repeatedly folding and joining two strips of membrane to form a cross-pleated cartridge with a stack of openings or fluid passageways configured in an alternating cross-flow arrangement. The cartridge can be modified for other flow configurations including co-flow and counter-flow arrangements. Methods for manufacturing such cross-pleated membrane cartridges, as well as apparatus used in the manufacturing process are described. Cross-pleated membrane cartridges comprising water-permeable membranes can be used in a variety of applications, including in heat and water vapor exchangers. In particular they can be incorporated into energy recovery ventilators (ERVs) for exchanging heat and water vapor between air streams being directed into and out of buildings.