Smoking Substitute Air Seal With Gurney Flap for Aerosol Size Control

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Solution Overview

Problem

Existing smoking substitute systems inefficiently deliver nicotine to the lungs due to inappropriate aerosol droplet sizes, with large particles depositing in the mouth and upper respiratory tract, and small particles being exhaled without delivering nicotine.

Innovation Solution

A smoking substitute apparatus with an air seal featuring a Gurney flap and specific airflow configurations to control aerosol particle size, ensuring efficient delivery of nicotine to the lungs by adjusting airflow velocity, turbulence, and cooling rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If aerosol droplets are made small (sub-micron) for lung inhalation, then aerosol can be inhaled into the lungs, but the particles are exhaled without delivering nicotine to the lungs

Engineering Contradiction:
Improveaerosol droplet sizeVSAvoidnicotine delivery efficiency
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The invention optimizes aerosol droplet size parameters to fall within the 1-10 µm range, specifically targeting a median diameter (Dv50) of 2-5 µm. This parameter optimization ensures particles are large enough to deposit in the lungs via impaction and sedimentation, yet small enough to be inhaled deep into the respiratory tract, resolving the contradiction between inhalability and deposition efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control through sensors that monitor aerosol generation in real-time and adjust heating power and airflow rate accordingly. This closed-loop control maintains aerosol droplet sizes within the optimal 1-10 µm range, ensuring reliable nicotine delivery while adapting to varying user inhalation patterns and environmental conditions

Inventive Principle:
Principle #23Feedback

2Reliability

If aerosol droplets are made large for lung delivery, then particles can be deposited in the lungs, but the particles are deposited in the mouth and upper respiratory tract instead

Engineering Contradiction:
Improvenicotine delivery efficiencyVSAvoidaerosol droplet size
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The invention precisely controls aerosol droplet size parameters to fall within the 1-10 µm range, with a median diameter (Dv50) of 2-5 µm. This optimized parameter range prevents premature deposition in the oral cavity by ensuring particles are sufficiently small to remain suspended during oral passage, while still large enough to deposit efficiently in the lungs through impaction and sedimentation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts aerosol generation parameters including heating power, airflow rate, and liquid delivery rate in real-time. This dynamic control adapts aerosol droplet size and velocity to ensure optimal deposition location, preventing large particles from depositing in the mouth while maintaining sufficient size for lung delivery efficiency

Inventive Principle:
Principle #15Dynamics

3Quantity of substance

If heating power is increased to produce more aerosol, then nicotine concentration in aerosol increases, but aerosol particle size becomes too large and deposits in upper respiratory tract

Engineering Contradiction:
Improvenicotine concentration in aerosolVSAvoidaerosol droplet size
Core Design Contradiction:
Quantity of substanceVSLength of moving object

Solution Approach 1:

The system dynamically balances heating power and airflow rate to maintain optimal aerosol characteristics. When heating power is increased to raise nicotine concentration, the airflow rate is simultaneously increased to prevent excessive droplet coalescence and size growth. This dynamic parameter coordination ensures high nicotine concentration is achieved without producing oversized particles that would deposit in the upper respiratory tract

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention optimizes multiple parameters simultaneously including heating power, airflow rate, liquid delivery rate, and chamber pressure. By coordinating changes in these parameters, the system achieves high nicotine concentration in the aerosol while maintaining droplet sizes within the 1-10 µm range, preventing premature deposition in the oral cavity and upper respiratory tract

Inventive Principle:
Principle #35Parameter changes

4Speed

If airflow velocity is increased to deliver aerosol faster to lungs, then nicotine delivery speed increases, but aerosol particles are exhaled before deposition

Engineering Contradiction:
Improveaerosol delivery speedVSAvoidnicotine absorption efficiency
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The invention optimizes airflow velocity parameters to fall within a specific range that balances delivery speed and deposition efficiency. The airflow rate is controlled to provide sufficient velocity to transport aerosol particles deep into the lungs quickly, while not exceeding the threshold that would cause particles to be exhaled before deposition. This optimal velocity range ensures rapid nicotine delivery while maintaining reliable absorption efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses sensors to monitor aerosol generation and airflow characteristics in real-time, providing feedback control that adjusts heating power and airflow rate to maintain optimal delivery conditions. This feedback mechanism ensures that airflow velocity remains within the range that maximizes lung deposition while minimizing exhalation of undelivered particles, adapting to varying user inhalation patterns

Inventive Principle:
Principle #23Feedback

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 achieves controlled aerosol particle sizes between 1 µm and 10 µm, improving nicotine absorption in the lungs and user satisfaction by enhancing aerosol interaction with the respiratory system.

Implementation Method 1

adjusting airflow velocity, turbulence, and cooling rate

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

achieves controlled aerosol particle sizes

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a vaporisation chamber with inlet and outlet configured to receive an air flow and configured to vaporise an aerosol precursor

Methodology Applied
Scientific EffectVaporisation: Evaporation

Data Source

PatentEP4447729B1Smoking substitute apparatus
Publication Date: 2026.03.11 IMPERIAL TOBACCO LTD
  • EP4447729B1 patent drawingFigure 1~2
  • EP4447729B1 patent drawingFigure 3
  • EP4447729B1 patent drawingFigure 4

AI summary

Provided is a smoking substitute apparatus with an air seal positioned between a holder which retains a heatable wick and an aerosol delivery conduit for guiding aerosol from the holder region to the user's mouth. The air seal has, at the end farthest from the wick, an inwardly projecting Gurney flap.