Filtration Device with Gas Cushion and Piston

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Solution Overview

Problem

Existing liquid sample filtration devices face issues such as contamination of the filtrate due to permanent contact with the filter membrane, high technical complexity, risk of glass breakage, inefficient filtration times with negative pressure, and high operational noise and costs.

Innovation Solution

A filtration device with a tube and piston arrangement that minimizes contact between the liquid sample and the filter surface, using a gas cushion for compression to facilitate filtration without external power sources, and featuring a simple design with few components for easy handling and reduced contamination risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the filtrate remains in the collection volume in permanent contact with the filter membrane, then the filtration device is simple in design, but the filtrate becomes contaminated by substances diffusing from the filter membrane

Engineering Contradiction:
Improvefiltration device designVSAvoidfiltrate contamination
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful contact between filtrate and filter membrane by introducing a gas cushion that separates the two. The filtrate is drawn off through a valve before permanent contact occurs, removing the contamination source while maintaining system simplicity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A gas cushion acts as an intermediary layer between the filtrate and filter membrane. This gas layer prevents direct contact and substance diffusion while allowing the filtration process to continue, solving the contamination issue without adding complex mechanical components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a glass collection vessel inside the flask is used to prevent permanent contact, then filtrate contamination is reduced, but the device complexity increases and glass breakage risk arises

Engineering Contradiction:
Improvefiltrate contaminationVSAvoidfiltration device structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent employs a simple, disposable plastic filter unit with integrated collection volume rather than reusable glass vessels. This eliminates the need for complex assembly and removes breakage risks while maintaining contamination prevention through the gas cushion mechanism

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The collection volume is merged with the filter membrane in a single integrated plastic component rather than using separate glass vessels. This simplifies the device structure, eliminates multiple parts, and removes the breakage risk associated with glass while preventing contamination through design integration

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If negative pressure is used to drive filtration, then the device structure is simplified, but the filtration time increases and technical demands on the vacuum device are high

Engineering Contradiction:
Improvefiltration system structureVSAvoidfiltration speed
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent uses a dynamic piston mechanism that can be manually operated to apply positive pressure for rapid filtration. The system transitions from static negative pressure to dynamic positive pressure application, enabling faster throughput while keeping the overall device structure relatively simple

Inventive Principle:
Principle #15Dynamics

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 solution enables efficient, contamination-free filtration with faster processing times, reduced operational noise, and lower costs, while being safe and reproducible with low demands on material and technical peripherals.

Implementation Method 1

inserting the plunger into the tube causes a gaseous cushion, such as an air cushion, to be trapped. This gas cushion is compressed during the insertion process.

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 2

The liquid sample to be filtered passes through the filter membrane and the filtrate reaches the collection volume above.

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP3074133B1Filtration device for liquid samples
Publication Date: 2018.06.13 SARTORIUS STEDIM BIOTECH GMBH
  • EP3074133B1 patent drawingFigure 1
  • EP3074133B1 patent drawingFigure 2A~2B
  • EP3074133B1 patent drawingFigure 3

AI summary

The present invention relates to a filtration device for liquid samples and to a closing and push-through device for said filtration device (Fig. 1).