HNB Filter Element With Outer Flow Channels

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Solution Overview

Problem

There is a need for an improved design of Heat-Not-Burn (HNB) consumables to enhance user experience and improve the function of HNB smoking substitute systems, as the aerosol produced may not be in a desirable state for inhalation.

Innovation Solution

The design includes an aerosol-forming article with a filter element having unimpeded flow paths along its outer surface, which maintains a desirable level of visible vapour and total particulate matter, and can feature longitudinally-extending channels, flavourants, and a combination of materials like cellulose acetate, polypropylene tow, and activated charcoal, along with a heating element and device for heating the aerosol-forming substrate to release volatile compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the aerosol-forming substrate is heated to release vapour, then volatile compounds like nicotine are released providing recreational effect, but harmful compounds may also be generated and the aerosol state may not be desirable for inhalation

Engineering Contradiction:
Improveharmful compoundsVSAvoidaerosol state quality
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The filter element is divided into multiple functional zones: a first filter material section for initial filtration, a second filter material section with different properties for secondary filtration, and an intermediate section with transition features. This segmentation allows different portions of the filter to address different aspects of aerosol quality and harmful compound removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different filter materials are used in different sections of the filter element, with each material having specific properties optimized for its location. The first filter material section uses one type of filtration material while the second section uses a different material, creating local quality variations that improve overall aerosol quality and reduce harmful compounds at specific stages of the filtration process.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If a conventional filter design is used, then manufacturing is simplified, but the aerosol flow may be impeded and the visible vapour level may not be maintained at a desirable state

Engineering Contradiction:
Improveaerosol flowVSAvoidvisible vapour
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The filter element incorporates longitudinal channels that extend along the length of the filter, creating additional flow pathways in the longitudinal dimension. This dimensional addition allows aerosol to flow through multiple parallel paths, reducing resistance and maintaining desirable vapour levels without compromising filtration effectiveness.

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

Solution Approach 2:

The longitudinal channels act as intermediary flow paths that facilitate smooth transition of aerosol through the filter element. These channels mediate between the inlet and outlet, providing controlled flow paths that maintain aerosol integrity and visible vapour levels while still allowing effective filtration to occur.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If heating temperature is increased to improve vapour release, then more volatile compounds are released, but harmful byproducts from combustion may be generated

Engineering Contradiction:
Improvevapour release efficiencyVSAvoidcombustion byproducts
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system carefully controls and optimizes the heating temperature parameter to remain below the combustion point of tobacco material. By maintaining the heating temperature within a specific range, sufficient vapour release efficiency is achieved while preventing the thermal conditions necessary for combustion and harmful byproduct formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The heating process is designed to induce phase transitions (from solid/liquid to vapour phase) of volatile compounds without reaching combustion temperatures. The filter element works in conjunction with controlled heating to facilitate this phase transition, allowing vapour release through controlled evaporation rather than combustion, thereby improving productivity while avoiding harmful byproducts.

Inventive Principle:
Principle #36Phase transitions

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

This design enhances the user experience by maintaining a desirable aerosol state for inhalation, reducing harmful compounds, and providing a recreational and/or medicinal effect through the release of volatile compounds like nicotine, while resembling a conventional cigarette.

Implementation Method 1

heat may be imparted to the tobacco material by a heating element of the device, wherein airflow through the tobacco material causes moisture in the tobacco material to be released as vapour

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

The filter element may comprise a first filter material section, a second filter material section and an intermediate section

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 3

As the vapour passes through the consumable (entrained in the airflow) from an inlet to a mouthpiece (outlet), the vapour cools and condenses to form an aerosol for inhalation by the user

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

a combination of materials like cellulose acetate, polypropylene tow, and activated charcoal

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3873266B1Smoking substitute consumable
Publication Date: 2024.04.24 IMPERIAL TOBACCO LTD
  • EP3873266B1 patent drawingFigure 1
  • EP3873266B1 patent drawingFigure 2
  • EP3873266B1 patent drawingFigure 3

AI summary

The present disclosure relates to an aerosol-forming article (1) comprising an aerosol-forming substrate (2) and at least one filter element (5) downstream of the substrate. The at least one filter element is a hollow bore filter element and the article has at least one unimpeded flow path (10) along the outer surface of the filter element. The present disclosure also relates to a heat-not-burn (HNB) consumable comprising an aerosol-forming substrate and at least one filter element downstream of the substrate. The consumable has at least one unimpeded flow path along the outer surface of the filter element.