Sterilisation apparatus for generating hydroxyl radicals

Patent metadata

Field	Value
Publication number	US-2023398247-A1
Application number	US-202118033945-A
Country	US
Kind code	A1
Filing date	Oct 19, 2021
Priority date	Nov 23, 2020
Publication date	Dec 14, 2023
Grant date	—

Abstract

Sterilisation apparatus suitable for generating hydroxyl radicals for sterilising an enclosed space, in which energy and water mist feeds are combined in a manner that permit the apparatus to be readily scaled to the size of enclosure. In particular, the sterilisation apparatus provides a manifold for providing a plasma generating region to form a plasma arc through which a flow of water mist is directed to form the hydroxyl radicals. A power distribution device transmits microwave energy generated by a microwave source to the manifold and distributes the received microwave energy to a plurality of output ports connected to the manifold.

First claim

1 . A sterilisation apparatus comprising:
a microwave source arranged to generate microwave energy; a mist generator arranged to generate a flow of water mist; a manifold connected to receive the flow of water mist from the mist generator and configured to direct the flow of water mist through an internal volume thereof towards a manifold outlet; and a power distribution device having an input port coupled to the microwave source and a plurality of output ports coupled to the internal volume of the manifold, wherein the power distribution device is configured as a power splitter that operates to distribute microwave energy received at the input port between the plurality of output ports to generate a plasma in a plasma generating region of the internal volume.

2 . The sterilisation apparatus of claim 1 , wherein the power distribution device comprises an assembly of interconnected waveguides.

3 . The sterilisation apparatus of claim 2 , wherein each waveguide comprises a hole in a block made from a conductive material.

4 . The sterilisation apparatus of claim 2 , wherein each waveguide includes a waveguide body made from a plastic material, wherein the waveguide body has a passageway formed therein, an inner surface of which is covered by a conductive layer.

5 . The sterilisation apparatus of claim 1 , wherein the power distribution device comprises a ring coupler, wherein the plurality of output ports extend radially inwards from the ring coupler.

6 . The sterilisation apparatus of claim 5 , wherein a distance between adjacent output ports around the ring coupler is nλ/2, wherein n is an integer and λ is the wavelength of the microwave energy.

7 . The sterilisation apparatus of claim 5 , wherein the input port is disposed on the ring coupler at a location that is equidistant between a pair of output ports.

8 . The sterilisation apparatus of claim 2 , wherein the assembly of interconnected waveguides comprises a plurality of interconnected straight waveguides that provide a plurality of paths from the input port to the outlet ports, where each path comprises a plurality of orthogonally disposed waveguide sections that interconnect junctions between the waveguides.

9 . The sterilisation apparatus of claim 1 , wherein the power distribution device comprises a Wilkinson power divider.

10 . The sterilisation apparatus of claim 1 further comprises a plurality of plasma applicators, which each plasma applicator is connected to a respective output port.

11 . The sterilisation apparatus of claim 10 , further comprising an adapter for connecting the output port to the plasma applicator.

12 . The sterilisation apparatus of claim 1 , wherein the plurality of output ports is disposed around the plasma generating region.

13 . The sterilisation apparatus of claim 1 , wherein the plasma generating region has a torus shape.

14 . The sterilisation apparatus of claim 1 , wherein the manifold comprises a first portion defining a first plasma generating region and a second portion defining a second plasma generating region, wherein preferably the power distribution device is arranged between the first portion and the second portion.

15 . The sterilisation apparatus of claim 1 , comprising a gas supply which is connected to deliver a gas flow to the mist generator, wherein preferably the gas flow entrains water mist formed by the mist generator to create the flow of water mist.

16 . The sterilisation apparatus of claim 10 , wherein each plasma applicator comprises:
a conductive tube; and an elongate conductive member extending along a longitudinal axis of the conductive tube, wherein the conductive tube and elongate conductive member provide a first coaxial transmission line at a proximal end of the plasma applicator, and a second coaxial transmission line at a distal end of the plasma applicator, and wherein the first coaxial transmission line is configured as a quarter wavelength impedance transformer.

17 . The sterilisation apparatus of claim 16 , wherein the second coaxial transmission line is configured with a higher impedance than the first coaxial transmission line.

18 . The sterilisation apparatus of claim 16 , wherein the flow of gas received by each plasma applicator passes between the conductive tube and elongate conductive member.

19 . The sterilisation apparatus of claim 16 , wherein each plasma applicator comprises a gas inlet tube configured to deliver the flow of gas to a space between the conductive tube and the elongate conductive member, wherein the gas inlet tube extends transversely to the longitudinal axis of the conductive tube.

20 . The sterilisation apparatus of claim 1 , wherein the microwave source comprises a magnetron.

21 . The sterilisation apparatus of claim 1 , wherein a manifold outlet of the manifold is couplable to an enclosure that defines a space to be sterilised.

Assignees

• Creo Medical Ltd

Inventors

• Hancock Christopher Paul
• White Malcolm

Classifications

• A61L2103/75

  Room floors or walls · CPC title

• A61L2/14 Primary

  Plasma, i.e. ionised gases · CPC title

• A61L2202/11

  Apparatus for generating biocidal substances, e.g. vaporisers, UV lamps · CPC title

• A61L2202/15

  Biocide distribution means, e.g. nozzles, pumps, manifolds, fans, baffles, sprayers · CPC title

• A61L2202/25

  Human Necessities · mapped topic