Filter Element With Alternating Pleat Heights

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Solution Overview

Problem

Conventional filter elements with uniform fold heights face issues with reduced filter surface area due to fold contact and instability, leading to decreased filtration performance over time, especially in systems with limited space and fluctuating fluid flows.

Innovation Solution

The filter element features filter folds of different heights, where shorter folds support taller ones, maintaining a larger surface area and preventing fold contact, with an alternating arrangement that stabilizes the fold geometry and maximizes exposure to fluid flow, supported by a circular cylinder and M-fold structure for optimized filtration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform fold heights are used in filter elements, then manufacturing is simplified, but fold contact occurs reducing effective filter surface area

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoideffective filter surface area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The filter element divides the filter medium into multiple layers with different fold heights. The first layer has folds of first height while the second layer has folds of second height (different from first height). This segmentation prevents adjacent folds from contacting each other, maintaining larger effective filter surface area while remaining manufacturable through standard pleating processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the filter element have different fold heights to optimize local performance. The first layer provides maximum filtration surface area while the second layer with different fold heights provides structural support and prevents fold contact. This local differentiation resolves the contradiction between manufacturing simplicity and effective surface area maintenance.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If uniform fold heights are used, then structural consistency is maintained, but fold stability decreases leading to performance degradation

Engineering Contradiction:
Improvestructural consistencyVSAvoidfold stability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The filter medium is segmented into multiple layers with different fold heights. The first layer with folds of first height provides structural consistency, while the second layer with folds of second height provides enhanced stability. This segmentation allows both structural consistency and fold stability to be maintained simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter element uses a composite structure with multiple layers of filter medium having different fold heights. This composite approach combines the benefits of structural consistency from uniform folding with the stability benefits of varied fold heights, preventing performance degradation over time.

Inventive Principle:
Principle #40Composite materials

3Area of stationary object

If larger filter surface area is provided, then filtration performance improves, but device space requirements increase

Engineering Contradiction:
Improvefilter surface areaVSAvoiddevice space
Core Design Contradiction:
Area of stationary objectVSVolume of moving object

Solution Approach 1:

The invention utilizes the radial dimension by creating folds of different heights in the pleated filter medium. This allows the filter element to pack more filter surface area into a compact cylindrical volume. The varied fold heights enable greater surface area within the same device space by optimizing the three-dimensional arrangement of filter material.

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

Solution Approach 2:

The multi-layered structure with different fold heights creates a nested arrangement where folds are positioned at different radial distances from the center. This nesting maximizes the use of available space, allowing larger filter surface area to be contained within compact device dimensions suitable for hydraulic systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4094819A1Filter element
Publication Date: 2022.11.30 HYDAC FILTERTECHNIK GMBH
  • EP4094819A1 patent drawingFigure 1
  • EP4094819A1 patent drawingFigure 2~3
  • EP4094819A1 patent drawing

AI summary

2. A filter element (1) with a preferably multi-layered structure of a filter medium (3) which has pleated filter folds (5, 7) with different fold heights (h1, h2), with filter folds (7) with a first fold height (h1) and with filter folds (5) with a correspondingly lower second fold height (h2), wherein the filter element has a flow direction for the fluid to be cleaned from a dirty side to a clean side (R), is characterized in that the transitions of all filter folds (5, 7) arranged adjacent to the clean side (R) or to the dirty side (S) terminate along an imaginary circular cylinder (9) which extends coaxially through the filter medium (3) to its longitudinal axis (LA).