Aerosolizing nozzle and method of operating such aerosolizing nozzle
Inventors
Assignees
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Publication Number
US-9573147-B1
Publication Date
2017-02-21
Expiration Date
Abstract
A nozzle and a method of generating an aerosol from a fluid and a gas by operating the nozzle. The nozzle has an aerosol exit orifice of a larger diameter and a fluid exit orifice of a smaller diameter aligned on a common central axis. A pressurized gas from a pressurized gas exit in close proximity to the fluid exit orifice intersects a fluid jet exiting from the fluid exit orifice at that acute angle and in a distance from the aerosol exit orifice. The method includes aerosolizing a fluid with a viscosity exceeding 4 cSt delivering an inhalable medication at a rate of more than 1 ml/minute, thereby delivering a medication at a mass flow rate of at least 30 mg/minute in form of the fluid particles having a mass median aerodynamic diameter (MMAD) of 6 μm or less.
Core Innovation
The invention relates to a nozzle for generating an aerosol from a fluid and a gas, where the nozzle includes an aerosol exit orifice and a fluid exit orifice aligned on a central axis, and a converging annular pressurized gas channel that extends at an acute gas flow angle with respect to the central axis. The pressurized gas exit is provided in close proximity to the fluid exit orifice so as to intersect with fluid exiting from the fluid exit orifice. An aerosol exit channel extends from an outer nozzle surface toward an aerosolizing space within the nozzle.
The converging annular pressurized gas channel includes a first partial annular channel with inner and outer walls formed by a conical wall and an inner front insert wall along which the pressurized gas flows. The acute gas flow angle is determined by the conical wall angle and the front insert wall angle in an area of the fluid exit orifice, and the first partial annular channel diverges at an acute divergence angle between 1 and 30°.
Hydrophobic, omniphobic or lyophobic surfaces are incorporated for the inner front insert wall and the conical wall. The nozzle geometry establishes a relationship in which the aerosol exit orifice diameter is at least 1.3 times larger than the fluid exit orifice diameter, and the nozzle supports aerosol formation in an aerosolizing space and the generation of fluid particles as an aerosol.
Claims Coverage
The partial content provides two independent claims, a nozzle claim and a method claim, defining multiple inventive features. These features include aligned orifice geometry, converging and diverging annular gas-channel geometry with acute flow-angle constraints, wettability limitations, and aerosolizing performance defined by viscosity, delivery rate, mass flow rate, and MMAD.
Aligned aerosol and fluid exit orifices with relative diameters
An aerosol exit orifice extending to an outer nozzle surface and aligned on a central axis with a fluid exit orifice, where the aerosol exit orifice diameter is at least 1.3 times larger than the fluid exit orifice diameter.
Converging annular pressurized gas channel at an acute flow angle intersecting the fluid jet
A converging annular pressurized gas channel extending at an acute gas flow angle with respect to the central axis, with a pressurized gas exit in close proximity to the fluid exit orifice so as to intersect with fluid exiting from the fluid exit orifice.
Hydrophobic/omniphobic/lyophobic conical and insert walls forming the gas channel
The first partial annular channel includes inner and outer walls formed by a conical wall and an inner front insert wall along which the pressurized gas flows, and the inner front insert wall and the conical wall are hydrophobic, omniphobic or lyophobic.
Acute divergence angle of the first partial annular channel
The first partial annular channel diverges at an acute divergence angle between 1 and 30°, where the acute divergence angle is the difference between the conical wall angle and the front insert wall angle.
Cone-shaped fluid supply nozzle insert forming the conical wall
A fluid supply channel is provided within a cone-shaped fluid supply nozzle insert forming the conical wall that is the inner wall of the first partial annular channel.
Aerosolizing an inhalable medication fluid with MMAD 6 µm or less
Operating the nozzle to aerosolize a fluid with a viscosity exceeding 4 cSt and delivering an inhalable medication at a mass flow rate of at least 30 mg/minute, with fluid particles having a mass median aerodynamic diameter (MMAD) of 6 µm or less.
Across the independent claims, the core inventive structure is the combination of aligned aerosol and fluid exit orifices with the defined relative diameter relationship, together with a converging annular pressurized gas channel intersecting the fluid at an acute flow angle and a first partial annular channel with acute divergence and conical/insert wall geometry. The claims further require hydrophobic, omniphobic or lyophobic wall surfaces for selected conical and insert surfaces, and the method claim adds aerosolizing conditions characterized by viscosity, delivery rate, mass flow rate, and MMAD.
Stated Advantages
Forming aerosol substantially within the nozzle.
Providing a particle-free gas sheath to prevent nozzle wetting and dripping.
Avoiding dead volumes and potential backflow via divergence and surface wettability limitations.
Achieving high efficiency and long run times.
Documented Applications
Delivering an inhalable medication.
Surfactant delivery in ARDS/ALI contexts.
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