Gas Detection Inlet Nozzle Assembly for Field Filter Replacement

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Solution Overview

Problem

Conventional gas detection instruments require disassembly to replace the hydrophobic filter, making field servicing impractical and costly, as it is typically located internally downstream of the inlet assembly.

Innovation Solution

A gas inlet nozzle assembly design where both the hydrophobic and particulate filters are removably mounted through the inlet end of the inlet tube, allowing for field replacement without disassembling the instrument, using a retainer with locking means and sealants for secure and fluid-tight mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the hydrophobic filter is placed internally downstream of the inlet assembly, then the instrument provides effective filtration protection, but the filter cannot be easily removed and replaced in the field

Engineering Contradiction:
Improvefiltration protectionVSAvoidfilter replacement
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The inlet assembly is segmented into modular components: the inlet tube, retainer, and filter assembly can be separated and removed as a unit. This allows the filter to be accessed and replaced without disassembling the entire instrument, resolving the contradiction between maintaining reliable internal filtration and enabling easy field replacement.

Inventive Principle:
Principle #1Segmentation

2Ease of repair

If the hydrophobic filter is integrated into the inlet assembly, then both filters can be removed together, but the inlet tube must be disassembled from the instrument

Engineering Contradiction:
Improvefilter replacementVSAvoidinlet tube disassembly
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The filter assembly (including both filters and retainer) is extracted as a complete removable unit from the inlet tube. The inlet tube itself remains integrated with the instrument, requiring no disassembly. This extraction approach allows filter replacement without increasing device complexity or requiring instrument disassembly.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of repair

If the inlet assembly is disassembled to replace the hydrophobic filter, then the filter can be replaced, but the instrument requires return to manufacturer or service centre

Engineering Contradiction:
Improvefilter replacementVSAvoidinstrument downtime
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The inlet assembly is designed to enable user self-service replacement of both filters in the field. The removable retainer and filter assembly can be easily detached and reattached by the user without requiring manufacturer intervention, eliminating instrument downtime and service center returns.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If conventional design is used, then the particulate filter is easily replaceable, but the hydrophobic filter requires instrument disassembly

Engineering Contradiction:
Improveparticulate filter replacementVSAvoidhydrophobic filter replacement
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

Both the particulate filter and hydrophobic filter are merged into a single removable filter assembly held by the retainer. This combined assembly maintains the ease of operation for replacement (like the particulate filter in conventional designs) while simultaneously improving the ease of repair for the hydrophobic filter, as both filters are now replaced together without instrument disassembly.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables user-friendly and cost-effective field replacement of both filters, eliminating the need for instrument disassembly and reducing downtime, as both filters can be serviced externally.

Implementation Method 1

The retainer furthermore preferably includes seal means such as an O ring which engages with the inlet tube for effecting a fluid tight seal between the retainer and the inlet tube

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a hydrophobic filter which is sealingly connected to the inlet tube such that fluid passing through the inlet tube is constrained to pass through the hydrophobic filter

Methodology Applied
Scientific EffectHydrophobe: Hydrophobe

Data Source

PatentEP3344985B1Gas detection instrument inlet nozzle assembly
Publication Date: 2020.01.01 GAS MEASUREMENT INSTR
  • EP3344985B1 patent drawingFigure 1~3b

AI summary

A gas inlet nozzle assembly comprises an inlet tube (10) having an inlet end (10a) and an outlet end (10b). A hydrophobic filter (15) is removably engageable in the inlet tube (10) through the inlet end (10a), and a particulate filter (12) is removably engageable in the inlet tube (10) through the inlet end (10a). A retainer (13) is lockingly engageable in the inlet end (10a) of the inlet tube (10) so as to retain the hydrophobic filter (15) and the particulate filter (12) in the inlet tube (10).