Cylindrical Filter Screen Tensioning Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Cylindrical filter screens face integrity issues due to thermal expansion and contraction of support frames made from materials with different thermal expansion coefficients, leading to cracking or crazing of the filter screen.

Innovation Solution

A filter assembly with a dynamic tensioning mechanism that allows the filter screen ends to move bi-directionally, incorporating a low friction coating and a support frame made from a different material, which mitigates thermal expansion effects by enabling the screen to expand and contract concentrically with the frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the support frame is made from a material with different thermal expansion coefficient than the filter screen, then cost and weight are reduced, but thermal expansion and contraction cause cracking or crazing of the filter screen

Engineering Contradiction:

ImprovecostVSAvoidintegrity of filter screen

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies the dynamics principle by transitioning from a rigid, fixed connection between the filter screen and support frame to a dynamic, flexible connection. The filter screen is formed from a flexible band material that can dynamically adjust its circumference through elastic deformation. This allows the screen to expand and contract in response to thermal changes in the support frame without developing damaging stresses, thereby maintaining integrity while using cost-effective dissimilar materials.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies parameter changes by utilizing the elastic properties of the flexible band material. The band can elastically stretch and compress to accommodate thermal expansion and contraction of the support frame. This elastic parameter change allows the system to absorb thermal stress without permanent deformation or cracking, resolving the contradiction between using dissimilar materials and maintaining screen integrity.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If the filter screen is permanently secured to the support frame, then structural stability is improved, but thermal expansion differences cause cracking or crazing

Engineering Contradiction:

Improvestructural stabilityVSAvoidintegrity of filter screen

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent replaces the static, permanent securing method with a dynamic system. The flexible band maintains continuous contact with the support frame through elastic tension, providing stable attachment that can dynamically adapt to thermal changes. This dynamic stability allows the screen to remain securely attached while accommodating dimensional changes in the support frame.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The elastic properties of the flexible band enable parameter changes in the connection system. The band's elastic tension adjusts automatically as the support frame expands or contracts thermally, maintaining stable attachment without transmitting damaging stresses to the screen. This elastic parameter adjustment resolves the contradiction between permanent securing and preventing thermal damage.

Inventive Principle:

Principle #35Parameter changes

3Strength

If the filter screen is made from rigid material, then filtration strength is improved, but it cannot accommodate thermal expansion of the support frame

Engineering Contradiction:

Improvefiltration strengthVSAvoidthermal adaptability

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material principles by combining the flexible band (which provides thermal adaptability) with the rigid support frame (which provides structural strength). The flexible band acts as a composite element that bridges the thermal expansion mismatch between dissimilar materials, allowing the rigid screen to maintain strength while the system as a whole gains thermal adaptability.

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 dynamic tensioning mechanism maintains the filter screen's cylindrical configuration and integrity by allowing it to expand and contract with the support frame, reducing the risk of cracking or crazing and ensuring consistent filtration performance.

Implementation Method 1

at least one of the inner surface (39) or outer surface (39') includes a low friction coating or covering having a coefficient of friction less than 0.3

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

the support frame undergoes significant thermal expansion and contraction during operation

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3233236B1Cylindrical filter screen with tensioning mechanism

Publication Date: 2019.10.16 DOW GLOBAL TECHNOLOGIES LLC

Figure 1A~1B
Figure 2
Figure 3A

AI summary

A filter assembly including a filter screen (27) comprising a band (27') of porous material extending between two axially aligned opposing ends (38, 38') and defining a cylindrical periphery (29), wherein the ends (38, 38') are each secured to a dynamic tensioning mechanism (46) that permits the ends (38, 38') to move bi-directionally relative to one another about the periphery (29) of the filter screen (27).