Impaction Nozzle for Metered Dose Inhalers
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Solution Overview
Problem
Propellant-driven inhalers produce aerosols that travel at high speeds, resulting in a significant portion being suspended in the oro-pharyngeal cavity rather than reaching the lungs due to adiabatic expansion and high vapor pressure.
Innovation Solution
A valve system in propellant-driven inhalers is designed to produce at least two aerosol jets that intersect at an angle of greater than 0° and less than 180°, allowing the aerosol particles to impact and lose kinetic energy, with nozzle openings arranged such that the linear extensions of the nozzle channels are bent relative to the main longitudinal axis, typically at angles between 0° and 45°.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single nozzle opening is used in propellant-driven inhalers, then the device structure is simple, but the aerosol travels at high speed and is suspended in the oro-pharyngeal cavity rather than reaching the lungs
Solution Approach 1:
The single nozzle opening is divided into multiple nozzle openings (at least two). Each nozzle opening produces a separate aerosol jet that travels in a different direction. The aerosol jets intersect and impinge on each other, causing the aerosol particles to lose kinetic energy through collision, thereby reducing their speed and improving lung delivery.
2Speed
If the nozzle channels are bent at an angle to reduce aerosol speed, then the aerosol delivery to lungs is improved, but the manufacturing precision requirements increase
Solution Approach 1:
Instead of bending a single nozzle channel at a precise angle, the invention uses multiple straight nozzle channels arranged at specific angles to each other. The channels can be oriented in different spatial dimensions, allowing the aerosol jets to intersect and impinge without requiring complex bent channel geometries, thereby reducing manufacturing precision requirements while achieving the desired speed reduction.
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 intersecting aerosol jets effectively decelerate primary aerosol particles, leading to further comminution and the formation of secondary aerosol particles, improving the delivery of aerosols to the lungs by reducing the high kinetic energy and enhancing the fine particle fraction.
Implementation Method 1
at least two clouds of aerosol, or at least two spray jets, are produced that travel towards one another at an angle of greater than 0° and equal to or less than 180°, so that the individual aerosol particles at least partially impact with one another and thereby lose kinetic energy
Implementation Method 2
When an aerosol formulation is nebulized into an aerosol by means of a propellant driven inhaler known from the prior art by using the adiabatic expansion of the propellant, the aerosol produced travels at high speed
Data Source
AI summary
Propellant gas inhaler fitted with a valve or valve system through which at least two clouds of aerosols or at least two jet streams are produced that travel towards one another at an angle from 0° to 180°, so that the individual aerosol particles at least partially impact with one another and lose kinetic energy thereby.