Pleated Sorption Filter for Low-Pressure CO2 and Moisture Removal

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Solution Overview

Problem

In electrically powered vehicles, recirculating air for air conditioning can lead to water and carbon dioxide accumulation in the passenger compartment, causing fogging and health issues, which need to be addressed for safety and comfort.

Innovation Solution

A sorption filter with a pleated structure and sorbent granulate layer for adsorbing and absorbing gases like CO2, water, and VOCs, sandwiched between pleated material layers to increase contact surface area and reduce pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a conventional flat filter structure is used, then the device complexity is low, but the contact surface area is small leading to high pressure loss

Engineering Contradiction:
Improvecontact surface areaVSAvoidfilter structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The filter medium is transformed from a flat two-dimensional structure to a pleated three-dimensional structure. This dimensional change increases the contact surface area between the filter medium and the air flow, allowing for greater adsorption capacity while maintaining a compact form factor suitable for vehicle installation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The filter medium is divided into multiple pleated sections or layers, each contributing to the overall contact surface area. This segmentation allows the filter to achieve a large effective filtering area without increasing the external dimensions of the filter housing, thus reducing pressure loss while maintaining manageable device complexity.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If the contact surface area is increased to reduce pressure loss, then energy efficiency improves, but the device complexity increases

Engineering Contradiction:
Improvepressure energy lossVSAvoidfilter structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

By pleating the filter medium, the surface area is expanded in the third dimension without proportionally increasing the volume or external footprint of the filter. This reduces the pressure energy loss across the filter while keeping the overall device complexity within acceptable limits for automotive applications.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The pleated structure introduces curvature and wave-like patterns to the filter medium, maximizing the surface area within a constrained space. This curved geometry allows air to flow through multiple pathways, reducing pressure drop while maintaining structural integrity and manageable complexity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Use of energy by moving object

If recirculation mode is used to save energy, then energy consumption decreases, but water and CO2 accumulation occurs leading to fogging and health issues

Engineering Contradiction:
Improveair conditioning energy consumptionVSAvoidwater and CO2 accumulation
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The filter incorporates sorbent granulate with porous structure that can absorb and adsorb water vapor and carbon dioxide from the recirculated air. This allows the vehicle to maintain energy-efficient recirculation mode while actively removing harmful substances that would otherwise accumulate and cause fogging or health issues.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The filter combines different materials with complementary functions: a pleated filter medium for particulate filtration and sorbent granulate for gas and vapor absorption. This composite structure enables simultaneous removal of particles, water, and CO2, making recirculation mode safe and effective without compromising energy efficiency.

Inventive Principle:
Principle #40Composite materials

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 sorption filter enhances energy efficiency by reducing pressure loss and effectively adsorbs and absorbs harmful substances, preventing fogging and health risks in the vehicle compartment.

Implementation Method 1

a sorbent granulate layer (41) configured to adsorb and/or absorb gases, in particular CO2, water and/or VOCs

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

a sorbent granulate layer (41) configured to adsorb and/or absorb gases, in particular CO2, water and/or VOCs

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP4599919A1Sorption filter, sorption filter cartridge and method for producing sorption filter
Publication Date: 2025.08.13 MANN HUMMEL GMBH
  • EP4599919A1 patent drawingFigure 1
  • EP4599919A1 patent drawingFigure 2
  • EP4599919A1 patent drawingFigure 3

AI summary

A sorption filter (9) includes a sorbent granulate layer (41) configured to adsorb and/or absorb gases, in particular CO2, water and/or VOCs, a first material layer (42) having a pleated shape, and a second material layer (43) having the pleated shape, the first material layer (42) and the second material layer (43) sandwiching the sorbent granulate layer (41) so that the sorbent granulate layer (41) has the pleated shape.