Dual-Chamber Filter Bag With Density-Gradient Dust Filtration

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Solution Overview

Problem

Existing filter bags for vacuum cleaners experience a significant decrease in air volume flow as they become filled with dust, leading to clogging of fine filter areas and reduced filtering performance.

Innovation Solution

A filter bag design with a divided interior, featuring a density gradient dividing wall that separates the air flow into pre-filtering and post-filtering chambers, utilizing multi-layer materials like spunbond and meltblow, and allowing air permeability between chambers to extend filter performance and prevent clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single-chamber filter bag is used, then the structure is simple and manufacturing is easy, but the filter performance decreases significantly with increasing filling due to clogging

Engineering Contradiction:
Improvestructure simplicityVSAvoidfilter performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The filter bag interior is divided into at least two chambers (first chamber for pre-filtering, second chamber for fine-filtering) using a dividing wall. This segmentation allows different filtering stages to occur in separate zones, preventing the fine filter area from clogging quickly while maintaining manufacturing feasibility through modular construction

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If a uniform density filter material is used throughout, then manufacturing is simple, but coarse dust clogs the fine filter pores reducing air volume flow

Engineering Contradiction:
Improvematerial uniformityVSAvoidair volume flow
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The dividing wall is designed with a density gradient, being more open (higher porosity) on the inflow side and denser (lower porosity) on the outflow side. This local variation in material properties allows coarse dust to be trapped in the open section while finer filtration occurs in the denser section, maintaining high air volume flow throughout the filter bag's service life

Inventive Principle:
Principle #3Local quality

3Reliability

If the dividing wall is hermetically sealed, then the chambers are completely separated, but air flow between chambers is restricted reducing filtering efficiency

Engineering Contradiction:
Improvechamber separationVSAvoidair flow exchange
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The dividing wall acts as an intermediary structure that provides controlled air flow exchange between chambers through its permeable sections. Rather than complete hermetic sealing, the dividing wall allows sufficient air passage to maintain filtering efficiency while still providing functional separation between pre-filtering and fine-filtering zones

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design maintains high filter performance even with increasing filling by pre-filtering coarser dust and reducing the load on the fine filter material, ensuring consistent air flow and extended usage without premature clogging.

Implementation Method 1

a bag (1) with an interior, wherein the interior is divided into at least two chambers (9, 10), in particular into a first chamber (9) and a second chamber (10)

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

coarser and finer dust can be held back and stored on the dividing wall

Methodology Applied
Scientific EffectParticle deposition: Deposition (physical)

Implementation Method 3

a bag made of air-permeable filter material

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 4

an interior space to absorb dust

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2215951B1Filter bag
Publication Date: 2012.01.18 WOLF PVG GMBH & CO KG
  • EP2215951B1 patent drawingFigure 1~2C
  • EP2215951B1 patent drawingFigure 3A~4

AI summary

The filter bag (1) has a sac formed from an air permeable filter material (2, 3), and an inlet opening (6) formed at the sac for air to be filtered. An inner cavity of the sac is divided into two chambers (9, 10), where the chamber (9) is used for coarse filtering of the air and the chamber (10) is used for fine filtering of the air that is released from the former chamber. A partition wall exhibits a density gradient, and is elastically formed.