Fume Hood Ionization Electrode for Weighing Precision

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Solution Overview

Problem

Weighing processes involving pharmaceutically active or toxic substances in fume hoods face challenges due to electrostatic adhesion of powdery substances on non-conductive surfaces, leading to precision issues and contamination risks, especially with particles in the micro- or nanometer range.

Innovation Solution

A laboratory fume hood design featuring a movably mounted front window, an armrest with integrated ionization electrode, and a flow-optimized air supply system to minimize particle adhesion and enhance safety and accuracy during weighing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional non-conductive surfaces are used in the fume hood workspace, then the structural integrity and ease of cleaning are maintained, but electrostatic adhesion of powdery particles occurs on these surfaces

Engineering Contradiction:
Improveease of cleaningVSAvoidparticle adhesion
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the electrical parameter of the armrest surface from non-conductive to conductive by applying a conductive coating or using conductive material. This parameter change eliminates electrostatic charge accumulation, preventing particle adhesion while maintaining the smooth, easy-to-clean surface characteristic of conventional designs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful electrostatic effect into a beneficial one by making the armrest conductive. The same electrical properties that previously caused particle attraction now allow for controlled charge dissipation, preventing adhesion and potentially creating a slight repulsive effect that further reduces particle accumulation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Measurement precision

If high-resolution scales are used for weighing substances, then measurement precision is improved, but particle adhesion to the scale and surrounding surfaces impairs weighing accuracy

Engineering Contradiction:
Improveweighing precisionVSAvoidweighing accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The conductive armrest acts as an intermediary between the laboratory personnel and the weighing equipment. By providing a conductive surface that prevents particle adhesion, it creates a clean zone that protects the high-resolution scale from particle contamination, thereby maintaining both measurement precision and weighing accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the armrest is positioned close to the work opening for easy access, then ease of operation is improved, but particle contamination risk to the laboratory worker increases

Engineering Contradiction:
ImproveaccessibilityVSAvoidcontamination risk
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the armrest from a potential contamination source to a protective element by making it conductive. The conductive surface prevents particle accumulation and may actively dissipate charged particles away from the worker's forearms, transforming the previously harmful proximity into a beneficial protective barrier.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Device complexity

If conventional fume hood designs are used, then device complexity is kept simple, but safety of laboratory personnel is compromised due to particle adhesion and contamination risks

Engineering Contradiction:
Improvestructural simplicityVSAvoidsafety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a single parameter change - making the armrest conductive - which fundamentally alters the safety characteristics of the fume hood. This minimal modification eliminates electrostatic particle adhesion and contamination risks while preserving the overall structural simplicity and ease of maintenance of conventional designs.

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

The design reduces particle adhesion, improves weighing precision, and enhances safety by neutralizing airborne particles and reducing contamination risks, while allowing for easy cleaning and maintenance.

Implementation Method 1

an ionization electrode that is arranged in an inflow profile arranged on the front edge of the worktop

Methodology Applied
Scientific EffectIonization: Ionisation

Data Source

PatentEP3768443B1Fume hood
Publication Date: 2024.02.14 WALDNER LABOREINRICHTUNGEN GMBH & CO KG
  • EP3768443B1 patent drawingFigure 1
  • EP3768443B1 patent drawingFigure 2
  • EP3768443B1 patent drawingFigure 3

AI summary

The present invention relates to a fume hood (1), comprising: a housing (10) which defines a working space (19), the housing (10) having a movably mounted front pane (14) on its front side; a work surface (20) which delimits the working space (19) on the bottom side; and an ionisation electrode (100) which is located in an inflow profile (102) located on the front edge of the work surface (20). The fume hood according to the invention also comprises an arm support (40) which is located in the region of the working opening (11) and at a distance from the inflow profile (102), wherein the arm support (40) extends along its longitudinal direction substantially over the entire width of the weighing fume hood (1) and has end faces, and wherein a side wall (15), which laterally defines the working space (19), a face of the armrest (40), and the inflow profile (102) are connected to a one-piece corner profile (50), wherein the side wall (15), a face of the armrest (40), and the inflow profile (102) are inserted into said corner profile (50).