The present invention relates to a gas supplied atomiser for atomising a liquid. In particular, the present invention relates to an atomiser having a flow of gas which is introduced into the atomised liquid.

A gas supplied device for atomising liquids is disclosed in

WO201 1/082838, the contents of which is incorporated herein by reference in its entirety. The device of WO201 1/082838 comprises a nozzle through which a gas flows. The nozzle is in fluidic communication with a reservoir of the liquid to be atomised. As the gas flows through the nozzle the liquid is drawn into the gas flow by the Venturi effect. The liquid becomes entrained in the gas flow as small droplets. To reduce the size of the larger liquid droplets produced by this process, the flow of gas and liquid droplets is impacted against a die surface in close proximity to the outlet of the nozzle. The entrained droplets impact the die surface and break up into yet smaller droplets. The smallest droplets flow out of the device with the flow of gas while the largest droplets return to the liquid reservoir, under the action of gravity, to be re-atomised.

The device of WO201 1/082838 uses an air compressor or gas bottle to provide the required flow of gas through the nozzle.

Another device for atomising liquids into nano or micro sized droplets is know from EP 2 229 204, the contents of which is incorporated herein by reference in its entirety. In this device, a liquid to be atomised is forced through a small opening under pressure causing the liquid to be dispensed from the device as an atomised mist. The pressure is applied to the liquid by a piston which may be directly mechanically driven, or which may be hydraulically or pneumatically driven. Atomised liquids produced by devices such as those described above can be used for many purposes. One such use is for therapy, for example, by application to the skin or by inhalation. One example is the atomisation of sodium chloride solution for inhalation to assist with the removal of mucus and debris from the lungs. Another example is the atomisation of hyaluronic acid for skin beauty purposes.

The present invention provides an atomiser for atomising a liquid, the atomiser comprising an atomising chamber for holding a liquid to be atomised and a gas supply outlet, wherein the atomising chamber comprises an upstream orifice for dispensing atomised liquid, and wherein the gas supply outlet is located downstream of the orifice so that a gas may be introduced into the atomised liquid in use. In one example, the atomising chamber is a cartridge containing the liquid to be atomised. The cartridge may either be disposable or refillable.

The gas supply outlet can be arranged to be supplied by a gas having a greater oxygen content in comparison to atmospheric air. In one example, the gas supply outlet is supplied by substantially pure oxygen or any other suitable gas or gas mix such as HELIOX (RTM) or ENTONOX (RTM).

In one embodiment, the gas supply outlet is supplied by a gas cylinder. In another embodiment, the gas supply outlet is supplied by a gas

compressor. The gas supply outlet may also be supplied by an oxygen concentrator.

The atomising chamber may comprise an orifice through which the liquid is forced in use to form atomised liquid particles. Such a chamber may be mechanically, pneumatically or hydraulically driven. In an alternative, the atomising chamber may be of the sort having a Venturi nozzle and a die against which atomised particles impact in use.

In a particular example, the atomiser is arranged so that the gas supplied to the gas supply outlet in use is provided from the same supply as the gas supply used to drive the atomising chamber in use.

In another aspect, the invention provides a method of enriching an atomised liquid comprising adding a flow of gas to a flow of atomised liquid particles using any of the atomisers described above.

In one example, the flow of liquid particles emerge from an orifice in an atomising chamber and the flow of gas is added to the flow of liquid particles upstream of the orifice.

The flow of gas may comprise a greater amount of oxygen than atmospheric air.

In one particular embodiment, the gas added to the flow of liquid particles is also used to drive the atomising chamber producing the liquid particles.

The properties and/or usefulness of a flow of atomised liquid particles may be improved by the addition of a gas. For example, the gas may be a breathing gas with certain medical benefits such as increased oxygen transport to the lungs. This is desirable in combination with a breathable medically efficacious liquid mist. To reduce package size and weight, it may be desirable to use the same gas to power the atomiser and enrich the liquid particle mist.

Examples of the present invention will now be described with reference to the following figures in which: Figure 1 shows a schematic view of an atomisation device according to the present invention; and

Figure 2 shows a schematic view of an alternative atomisation device according to the present invention.

Referring to Figure 1 , an atomisation device 22 comprises a disposable cartridge 70 which contains a liquid 78 to be atomised. The cartridge 70 comprises an outer shell 71 and a piston 72. An orifice 73 is provided at the downstream end 74 of the cartridge 70. The orifice 73 is closed by a seal 75 which is arranged to be broken when a certain pressure is reached in the liquid 78 within the cartridge. Alternatively, the seal 75 may be a pierceable or removable plug or similar.

The piston 72 comprises an engagement feature (not shown) on its upstream surface for engagement with the end of a piston rod 81 of a gas pressure actuator 80. The gas pressure actuator 80 comprises an outer housing 82 and a gas piston 83.

The downstream end 74 of the cartridge 70 is arranged to dispense the atomised liquid particles 204 into an outlet chamber 205. The outlet chamber 205 is provided with a gas outlet opening 206 which is connected by additive gas tube 203 to driving gas feed tube 201 at branch 202.

In use, pressurised gas is supplied from a gas supply 200 to the upstream side 84 of the gas piston 83 via driving gas feed tube 201 and gas inlet 85. The pressure within the gas pressure actuator 80 causes the gas piston 83 to be driven in a downstream direction towards the cartridge 70, thus causing the piston 72 to move towards the downstream end 74 of the cartridge 70 and expel the liquid 78 from the inside of the cartridge 70 via the orifice 73 as atomised particles 204. The droplet size may be varied by varying the size of the orifice 73 and/or the driving gas pressure. Simultaneously, gas from the gas supply 200 is supplied to gas outlet opening 206 via additive gas tube 203 so that some of the gas driving the gas piston 83 is diverted to the gas outlet opening 206 and introduced into the atomised liquid particles 204 downstream of the orifice 73.

It may be the case that the pressure of the gas required to drive the piston 83 is greater than that desirable at the gas outlet opening 206. Valves and/or regulators 207, 208 can be fitted to the gas supply tubes 201 , 203 to control the flow and pressure of gas to the gas inlet 85 and gas outlet opening 206 respectively.

With reference now to Figure 2, another example of a gas operated atomiser 21 is shown. The atomiser 21 comprises a disposable cartridge 50 having an outer shell 51 which surrounds an internal chamber 52. Within the chamber 52 there is provided a nozzle 53 and a die 54 having a die surface 55. A capillary channel 56 connects an opening 57 at the top of the nozzle 53 to a reservoir of liquid 58 located at the base of the nozzle 53.

The cartridge 50 has a gas inlet opening 60 at its lower end 59. The upper end 61 of the cartridge is closed by a pierceable or removable foil seal 62. The gas inlet opening 60 is connected to a gas supply 100 by a driving gas feed tube 101 .

The upper end 61 of the cartridge 50 is arranged to feed the atomised liquid particles into an outlet chamber 105. The outlet chamber 105 is provided with a gas outlet opening 106 which is connected by additive gas tube 103 to the driving gas feed tube 101 at branch 102.

In use, gas flows from the gas supply 100 to the cartridge 50 via the gas inlet 60 and flows through the nozzle 53. Liquid 58 is drawn up the capillary tube 56 to the nozzle tip by suction caused by the Venturi effect as the gas flows through the nozzle 53. The liquid 58 becomes entrained in the gas flow as small droplets.

To reduce the size of any relatively large droplets in the fluid stream exiting the nozzle 53, the fluid flow, comprising gas and entrained liquid drops, strikes the die surface 55 of the die 54. The largest of the droplets fall back into the liquid reservoir 58 under the influence of gravity, while the smallest of the droplets are carried by the gas flow out of the cartridge 50 via the openings in the exit seal 62.

Simultaneously, gas from the gas supply 100 is supplied to gas outlet opening 106 so that some of the gas driving the atomisation cartridge 50 is diverted to the gas outlet opening 106 and introduced into the atomised liquid particles downstream of the outlet from the atomisation cartridge 50.

It may be the case that the pressure of the gas required by the cartridge 50 is greater than that desirable at the gas outlet opening 106.

Valves and/or regulators 107, 108 can be fitted to the gas supply tubes 101 , 103 to control the flow and pressure of gas to the gas inlet 60 and gas outlet opening 106 respectively.

It is not necessary that the atomiser be provided as a disposable cartridge. If desired, the atomisers 22 and 21 described above may be designed to be re-usable and re-fillable. Alternatively, the atomisers 22, 21 may have a chamber for receiving a disposable cartridge 70, 50, the remainder of the atomisers 22, 21 being suitable for multiple uses.

The gas source 200, 100 may be any suitable gas source such as a pressurised gas cylinder, or a compressor. The gas ideally comprises 23% by volume oxygen. Such a gas may be provided from a cylinder or from an oxygen concentrator. If the gas is provided from a gas cylinder, it may be necessary to reduce the working pressure of the gas from cylinder pressure, which may be as much as 300 bar, to a lesser working pressure. This can be achieved by a gas regulator located upstream of the branch 202,102. The gas may them be further controlled/regulated by valves/regulators 207, 208. 107, 108.

It may be that it is not desirable to drive the atomiser 70 using the same gas as that introduced into the atomised liquid. High quality additive gases may be expensive and/or unsuitable for driving the piston 83. For example, high purity oxygen is highly explosive and should not be used for driving the piston 83. If desired, a separate gas supply can be provided to feed the driving gas supply tube 201 , and another gas provided to supply additive gas feed tube 203. Alternatively, the piston 83 may be mechanically or hydraulically driven. In both examples discussed above with reference to Figures 1 and 2, an outlet chamber 205, 105 having a gas outlet opening 206, 106 is provided. If desired, this arrangement may be altered so that the outlet of the additive gas supply tube 203, 103 is held in a suitable location downstream of the atomiser outlet so that the additive gas may be added to the flow of atomised liquid particles. For example, the additive gas supply tube 203, 103 may be held by a plastic support or any other suitable support structure. In this case, the outlet chamber 205, 105 may be dispensed with if desired.

The liquid to be atomised my be any suitable liquid such as a sodium chloride solution, hyaluronic acid, essential oils, traditional Chinese medicines (or extracts thereof).