Offset Heating Element Assembly for Consistent Smoke Generation

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Solution Overview

Problem

Existing smoke generation methods for testing smoke detectors are inconsistent due to direct contact between rising smoke and particulate with radiant heat sources, leading to heat intensity variations and potential fires, and previous configurations like square-shaped radiant heat sources provide non-uniform heating and are difficult to adjust.

Innovation Solution

A heat-generating apparatus with an adjustable heating support assembly that positions heating elements offset from the target material, allowing for precise control of heat intensity and direction to prevent contact and ensure consistent smoke generation, featuring a frame assembly with adjustable heating elements that can be moved horizontally and vertically to maintain a clear path for smoke and particulate to rise unobstructed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If radiant heat sources are positioned directly over the target material, then heat intensity is improved, but smoke and particulate contact the heat sources causing inconsistency and potential fires

Engineering Contradiction:
Improveheat intensityVSAvoidconsistency of smoke generation
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The heating elements are arranged in a planar configuration (e.g., triangular, square, or rectangular pattern) rather than being positioned directly above the target material. This spatial reconfiguration in two dimensions allows the heat sources to be offset from the vertical smoke path while still providing effective heating to the target material, preventing contact between smoke/particulate and heat sources.

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

Solution Approach 2:

The heating elements are positioned asymmetrically relative to the target material, with each element located at a specific offset distance and angle. This asymmetric arrangement ensures that the smoke plume rising vertically from the target material does not contact the heating elements, while still receiving sufficient radiant heat for consistent smoldering.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If radiant heat sources are positioned remote from the target material to prevent contact, then reliability is improved, but heating uniformity deteriorates

Engineering Contradiction:
Improveconsistency of smoke generationVSAvoiduniformity of heating
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The heating system is divided into multiple discrete heating elements (typically three or more) arranged in a specific geometric pattern around the target material. Each element contributes to the overall heating, and their distributed arrangement ensures uniform heat distribution across the target material surface while maintaining safe distances to prevent smoke contact.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple heating elements are combined in a coordinated arrangement where their individual radiant heat contributions merge to create a uniform overall heating field. The geometric configuration (triangular, square, or rectangular patterns) ensures that the combined effect provides consistent heating across the entire target material surface.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If fixed square-shaped radiant heat sources are used, then device complexity is reduced, but adaptability deteriorates

Engineering Contradiction:
Improvesimplicity of structureVSAvoidadjustability of heat intensity
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The heating support assembly incorporates adjustable mechanisms that allow the heating elements to be repositioned relative to the target material. This dynamic capability enables users to adjust the distance and orientation of heating elements to optimize heat intensity for different test conditions, target materials, or smoke detector configurations, while maintaining the relatively simple overall structure.

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 apparatus enables consistent and repeatable smoke and particulate generation without damaging the heating elements, allowing for precise control of heat flux to achieve desired smoldering without combustion, thereby improving the reliability of smoke detector testing.

Implementation Method 1

radiant heat sources were employed to initiate smoldering in target materials

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP2779131B1Heat-generating apparatus and method of generating smoke
Publication Date: 2021.04.28 UL LLC
  • EP2779131B1 patent drawingFigure 1
  • EP2779131B1 patent drawingFigure 2
  • EP2779131B1 patent drawingFigure 3

AI summary

A heat-generating apparatus includes a frame assembly and a securement assembly carried by the frame assembly. The securement assembly includes a panel member arranged in a first vertical plane for supporting a target material parallel to the first vertical plane. The heat-generating apparatus also includes a heating support assembly adjustably supported by the frame and including at least one heating element arranged in a second vertical plane that is parallel to and offset from the first vertical plane. The heating support assembly is adjustable along a horizontal first adjustment axis that is perpendicular to each of the first and second vertical planes and along a second adjustment axis that is disposed in or adjacent to the second vertical plane.