Switchgear Cabinet Filter With Absorber Mat for Liquid Ingress

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Solution Overview

Problem

Existing air inlet or air outlet filters for control cabinet housings have high permeability for liquids, which weakens the IP protection class of the control cabinet.

Innovation Solution

The use of a non-woven fabric with absorbing properties, potentially coated with a superabsorber, integrated into the wrinkle filter or as a separate absorber mat, to minimize liquid permeability. The superabsorber increases in volume when loaded with liquid, reducing the filter's permeability and potentially blocking the air passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional air filter with pleated filter substrate is used, then air filtration is achieved, but liquid permeability remains high compromising IP protection class

Engineering Contradiction:
ImproveIP protection classVSAvoidliquid permeability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The filter substrate is formed as a composite structure combining a pleated filter component with a nonwoven fabric component. The pleated filter provides air filtration while the nonwoven fabric component absorbs liquids, creating a multi-functional composite material that simultaneously achieves both air filtration and liquid protection to maintain IP protection class.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The nonwoven fabric component is specifically positioned within the filter substrate to provide localized liquid absorption functionality. This component has different properties from the pleated filter portion, with the nonwoven fabric specifically designed to absorb liquids while the pleated filter focuses on air particle filtration, allowing each region to perform its specialized function.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the filter substrate is completely covered by nonwoven fabric with superabsorbent, then liquid permeability is reduced, but air passage may be blocked

Engineering Contradiction:
Improveliquid permeabilityVSAvoidair flow
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The superabsorbent material is applied locally rather than uniformly across the entire filter substrate. By concentrating the superabsorbent in specific areas where liquid exposure is most likely, the design achieves effective liquid protection while leaving other areas open for air passage, thus maintaining productivity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The nonwoven fabric component has specific parameters optimized for liquid absorption (such as basis weight less than 250 g/m²) that allow it to absorb liquids effectively while maintaining sufficient porosity for air flow. The parameters of the nonwoven fabric are carefully selected to balance liquid absorption capacity with air permeability.

Inventive Principle:
Principle #35Parameter changes

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 significantly reduces the permeability of the air filter for liquids, enhancing the IP protection class of the control cabinet by preventing liquid ingress, even under conditions of high fluid volume flow.

Implementation Method 1

a superabsorbent (5), wherein the superabsorbent (5) has the property of (significantly) increasing its volume when exposed to liquid

Methodology Applied
Scientific EffectSuperabsorbency: Hydrogel

Implementation Method 2

the nonwoven fabric may inherently have absorbent properties with respect to liquid, preferably water

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

water can run off the nonwoven fabric vertically and be absorbed into the liquid-absorbing material strip

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP4395911B1Air-inlet or air-outlet filter for a switchgear cabinet housing, and corresponding switchgear cabinet assembly
Publication Date: 2025.04.23 RITTALWERK RUDOLF LOH GMBH & CO KG
  • EP4395911B1 patent drawingFigure 1
  • EP4395911B1 patent drawingFigure 2
  • EP4395911B1 patent drawingFigure 3~4

AI summary

The invention relates to an air-inlet or air-outlet filter (1.1, 1.2) for a switchgear cabinet housing (100), comprising a filter housing (2), in which a filter substrate (3) having a folded filter (4) is disposed, the filter substrate completely covering an air passage cross-section (d) of the filter housing (2), characterized in that the filter substrate (3) comprises a liquid-absorbing absorber mat made of non-woven fabric (6). The invention also relates to a corresponding switchgear cabinet assembly.