WO2020073075A1

WO2020073075A1 - Sterilisation device

Info

Publication number: WO2020073075A1
Application number: PCT/AU2019/050989
Authority: WO
Inventors: Brian Sydney Hutchings
Original assignee: Wellkleen Pty Ltd
Priority date: 2018-10-10
Filing date: 2019-09-13
Publication date: 2020-04-16

Abstract

A device adapted for sterilising fluid, the device comprising a reservoir adapted to store a fluid, wherein the reservoir is mounted to the device. An elongate static mixer adapted for mixing ozone and fluid, the elongate static mixer connected to the reservoir, wherein a first end of the elongate static mixer is positioned inside the reservoir, and wherein a second end of the elongate static mixer is positioned outside the reservoir. A pump positioned between the reservoir and the second end, wherein the pump is adapted to pump the fluid from the reservoir to the second end. An ozone injection valve positioned between an ozone generator and the second end, wherein the ozone injection valve is adapted to inject generated ozone to the second end, and wherein a predetermined concentration of ozone in fluid is reached in the reservoir.

Description

STERILISATION DEVICE

TECHNICAL FIELD

[0001] The present invention relates to sterilisation methods and a device for sterilisation of articles. More particularly, the present invention may relate to a sterilisation device for sterilising environments and objects more effectively.

BACKGROUND

[0002] Sterilisation devices can be used to clean articles, surfaces, and environments.

The sterilisation devices are generally used to eradicate microscopic bacteria pests and other organisms.

[0003] Sterilisation is desirable for destruction of virus, bacteria, fungus or other microorganism, whether in a vegetative or in a dormant spore state. Conventional sterile processing procedures for medical in truments involve high temperature (such as steam and dry heat units) or chemicals (such as ethylene oxide gas, hydrogen peroxide, or ozone).

[0004] Sterilisation methods and apparatus using gaseous sterilants are well known. Sterilisers using hydrogen peroxide as the sterilant are widely used. The hydrogen peroxide is generally supplied as an aqueous solution and evaporated prior to injection into a sterilisation chamber of the steriliser, by heating of the solution, or by applying a vacuum to the sterilisation chamber, or both. After evaporation of the solution, the sterilisation atmosphere in the sterilisation chamber includes water vapor and hydrogen peroxide gas. It is a disadvantage of this process that the water vapor tends to condensate on articles in the chamber as the sterilisation proceeds. The resulting layer of water condensate on the articles to be sterilised interferes with the sterilizing action of the hydrogen peroxide. Numerous apparatus and process modifications have been developed to address this problem, all of which are aimed at limiting the relative humidity in the sterilisation atmosphere during the sterilisation process. However, these modifications invariably increase operating cost and/or sterilisation cycle times. [0005] Sterilisers using ozone containing gas as the sterilant are also known. The ozone gas is generally produced externally to the sterilisation chamber and supplied into the chamber under vacuum to increase penetration of the sterilant gas into restricted spaces on the articles to be sterilised. In order to improve the sterilisation effect of ozone gas, the sterilisation atmosphere is generally humidified with water prior to the injection of ozone gas into the sterilisation chamber. However, the amount of ozone gas needed is relatively high (85 mg/1) and the sterilisation cycle times are relatively long, making ozone based sterilisation processes comparatively expensive. Furthermore, many articles to be sterilised are damaged by the high levels of ozone required to achieve complete sterilisation and can therefore not be sterilised in an ozone sterilisation process.

[0006] Sterilisation processes using both hydrogen peroxide gas and ozone gas have been used, but with unsatisfactory results especially with respect to the sterilisation of articles with long internal lumens, and with respect to sterilisation costs. Although ozone based processes are satisfactory with respect to sterilisation of articles with long lumens, material compatibility represents a problem. Hydrogen peroxide based processes are generally unsatisfactory regarding the sterilisation of long lumens.

[0007] A known sterilisation device is disclosed in US 20110076192 Al. This document discloses a method of sterilizing an article by sequentially exposing the article to hydrogen peroxide and ozone. Hydrogen peroxide can be a relatively volatile compound and exposure can cause irritation of the eyes, throat, respiratory airway, and skin. As such, it is desirable to avoid contact with this compound. In addition, the hydrogen peroxide is the main sterilant used by the device of this disclosure.

[0008] Another apparatus for sterilisation by hydrogen peroxide and ozone is disclosed in EP 2471560 Al. Again, while this device uses ozone, the device supplements the sterilisation process with hydrogen peroxide to achieve the desired sterilisation over several sterilisation cycles.

[0009] It is advantageous to provide for a device which can readily sterilise an article without the requirement of irritant chemicals. Further, it may be advantageous to provide for a device which can sterilise more effectively, and more efficiently. Further, it may be advantageous to provide for a device which can more efficiently produce a gas, such as ozone.

[0010] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

SUMMARY

[0011] PROBLEMS TO BE SOLVED

[0012] It may be advantageous to provide for a device for sterilisation.

[0013] It may be advantageous to provide for a device improved sterilisation.

[0014] It may be advantageous to provide for a device generating ozone in a desired volume and/or concentration and/or quantity.

[0015] It may be advantageous to provide for a device sterilising a room or chamber.

[0016] It may be advantageous to provide for a device extraction of ozone.

[0017] It may be advantageous to provide for a device efficient method for ozone sterilisation.

[0018] It may be advantageous to provide for a device which uses ozone as the only sterilant.

[0019] It may be advantageous to rapidly generate a sterile gas for sterilisation.

[0020] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0021] MEANS FOR SOLVING THE PROBLEM

[0022] In a first aspect of the present disclosure, there may be provided a device for sterilisation. The device comprising a compressor for providing a gas to an ozone generator. The ozone generator converting at least a portion of the gas to ozone gas at a first rate. The ozone gas being injected into a chamber for a predetermined holding time; and wherein the system comprises a multi-stage filter system to remove ozone from the chamber at a second rate which is higher than the first rate than the system can produce ozone.

[0023] Preferably, the multi-stage filter system may be an activated carbon catalyst filter system. Preferably, the multi-stage filter is a three-stage filter. Preferably, the injection of ozone gas is delivered by a delivery device. Preferably, the delivery device may comprise a conduit and a probe. Preferably, the probe may further comprise a plurality of apertures to deliver the ozone gas. Preferably, the ozone generator is at least one corona cell. Preferably, the device may further comprise a vacuum apparatus for removing sterilant gases from said chamber. Preferably, a control panel may be provided for activating said ozone generator. Preferably, the device can be remotely activated and deactivated. Preferably, the device sterilisation chamber may comprise a plurality of channels for distributing ozone gas.

[0024] In another aspect of the present disclosure, there may be provided a method of sterilisation comprising the following steps; providing an article to a sterilisation chamber; sealing the sterilisation chamber with said article; sterilising the article by injecting ozone gas to the sterilisation chamber, and retaining the ozone in said chamber for a desired residence period; substantially removing the ozone gases from the sterilisation chamber via a vacuum apparatus; and providing sterilant gases through a multi-stage catalyst filter for decomposition of said sterilant gases.

[0025] Preferably, the method sterilises the article by injecting ozone at least once further. Preferably, atmosphere in the sterilisation chamber is at least partially removed before injecting ozone into said chamber. Preferably, sterilisation may be carried out under the condition where the pressure inside the sterilisation chamber is higher than atmospheric pressure, and the ozone provided produced by converting an oxygen- containing substance outside the sterilisation chamber. Preferably, sterilisation may be carried out under the condition where the pressure inside the sterilisation chamber is atmospheric pressure, and the ozone provided is produced by converting oxygen from a predetermined oxygen source. Preferably, a sterilisation device, the sterilisation device having an ozone generator, a vacuum apparatus, a delivery device for delivering ozone to a target location, and an ozone decomposer for converting ozone into a breathable gas. Preferably, sterilisation device further comprises a pressure restorer which restores the pressure inside the sterilisation chamber to atmospheric pressure after a sterilisation process is completed. Preferably, said ozone generator may convert an oxygen- containing substance outside the sterilisation chamber into ozone, and provides the converted ozone into the sterilisation chamber so that the pressure inside the sterilisation chamber maintains a pressure higher than atmospheric pressure when the article is sterilised.

[0026] In another aspect of the present disclosure, there may be provided a device adapted for sterilising fluid. The device may comprise a reservoir adapted to store a fluid, wherein the reservoir may be mounted to the device. An elongate static mixer may be adapted for mixing ozone and fluid. The elongate static mixer may be connected to the reservoir, wherein a first end of the elongate static mixer may be positioned inside the reservoir, and wherein a second end of the elongate static mixer may be positioned outside the reservoir. A pump may be positioned between the reservoir and the second end, wherein the pump is adapted to pump the fluid from the reservoir to the second end. An ozone injection valve may be positioned between an ozone generator and the second end, wherein the ozone injection valve may be adapted to inject generated ozone to the second end, and wherein a predetermined concentration of ozone in fluid may be reached in the reservoir.

[0027] Preferably, the device may comprise a control panel with a plurality of buttons, each button may operate at least one of selected from the group of: the pump, the ozone generator, the ozone injection valve. Preferably, the elongate static mixer may have a labyrinth for dividing the flow and for increasing the surface area of which the fluid contacts with ozone. Preferably, the reservoir may comprise a pressure sensor such that ozone injection stops when the pressure of the reservoir reaches a predetermined threshold pressure.

[0028] In the context of the present invention, the words“comprise”,“comprising” and the like are to be construed in their inclusive, as opposed to their exclusive, sense, that is in the sense of“including, but not limited to”.

[0029] The invention is to be interpreted with reference to the at least one of the technical problems described or affiliated with the background art. The present aims to solve or ameliorate at least one of the technical problems and this may result in one or more advantageous effects as defined by this specification and described in detail with reference to the preferred embodiments of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

[0030] Figure 1 illustrates a perspective view of an embodiment of a device for delivery of a sterilant;

[0031] Figure 2 illustrates a front view of an embodiment of a device for delivering a sterilant;

[0032] Figure 3 illustrates a top view of yet a further embodiment of a device for dispersing of a sterilant;

[0033] Figure 4 illustrates a rear view of another embodiment of a device with an sterilant delivery means;

[0034] Figure 5 illustrates a side view of a further embodiment of a device with an ozone generator removed; and [0035] Figure 6 illustrates a top view of an embodiment of an ozone generator dismounted and a filter removed from the catalyst converter;

[0036] Figure 7 illustrates a flow chart of an embodiment of a method of sterilisation using an embodiment of the device; and

[0037] Figure 8 illustrates an embodiment of a flexible sterilisation chamber which may be used for sterilisation of articles.

[0038] Figure 9 illustrates another embodiment of a device for delivery of a sterilant. [0039] Figure 10 illustrates a schematic drawing of a process of ozonising water.

[0040] Figure 11 illustrates a device for sterilising fluid.

[0041] Figure 12 illustrates an apparatus for use for mixing fluid for a device for delivery of a sterilant.

DESCRIPTION OF THE INVENTION

[0042] Preferred embodiments of the invention will now be described with reference to the accompanying drawings and non-limiting examples.

[0043] An embodiment of a sterilant device 10 is illustrated in Figures 1 to 6. The device 10 is preferably used for injecting ozone into a room, chamber or controlled environment. The device 10 may be used to fill a desired room with ozone over a predetermined period of time. Ozone may pumped into an environment or sterilisation chamber by the device 10 from the ozone generator. The ozone generator converts an oxygen-containing substance outside the sterilisation chamber into ozone and provides it into the sterilisation chamber.

[0044] The preferred sterilisation apparatus 10 in accordance with the invention as illustrated schematically in Figure 1 includes a housing 102 and a control panel 110. A delivery device 300 (seen in Figures 4 and 5) can be connected to the device 10 for delivering a sterilant to a desired location. The control panel is shown with a plurality of buttons 114, which may allow for desired functions of the device 10 to be activated. The buttons 114 may effect sterilant generation, vacuuming, conversion of a sterilant, or any other desired function. The controller 112 on the control panel 110 may allow for activating pre-set modes or functions (algorithms) which may relate to the desired use of the machine. For example, if the machine is to be used for general sterilisation, only a single cycle may be needed and a longer residence period may be used. Alternatively, if the device is to be used for sterilisation for pests, a plurality of pre-set cycles and residence times may be activated corresponding to the types of pests likely to be present. The controller 112 may have a processor, storage means, a wireless communication module, and a battery.

[0045] Preferably, there are two independent buttons for activation of sterilant generators 200. In at least one embodiment, the sterilant generators are ozone generators 200. The ozone generators 200 may be used to convert oxygen into ozone for use in sterilisation of an article or environment.

[0046] To assist with moving the device, a pair of wheels 108 and a handle 150 are provided. The wheels 108 may be temporarily locked in place when the device 10 is at a desired location. A wheel guard may also be provided on the housing as shown in Figure 1.

[0047] The ozone generator 200 preferably has access to an external gas supply and/or oxygen supply. A flow rate controller may be disposed between the corona cell and the gas supply, which is used to restrict or limit the flow of a gas from the gas supply to the corona cell. A valve can turn on and off the flow of gas from the gas supply to the corona cell and a flow meter can detect and measure the flow of gas from the gas supply to the corona cell (ozone generator). A transformer is connected to the corona cell to provide voltage to said corona cell to convert oxygen to ozone. Excess ozone generated can be stored in excess ozone traps or can be cycled through to a catalyst for conversion into a breathable gas and/or carbon dioxide. A valve may be disposed between the corona cell and the ozone traps and/or the catalyst.

[0048] In one embodiment, the corona cell includes a high tension electrode, a dielectric and a low tension electrode such that electricity leaps a discharge gap from the high tension electrode to the low tension electrode causing ionisation of the gas therebetween forming ozone. It will be appreciated that the gas supply will generally have compressed oxygen therein or a gas with a relatively high amount of oxygen (i.e. greater than 20% oxygen). Optionally, at least a portion of the gases which are not ozone may be filtered out by the system such that they are not introduced into the sterilisation chamber.

[0049] The delivery device 300 is connected to an outlet for the ozone generator such that the ozone can be directly provided to the delivery device 300. The delivery device 300 comprises a conduit 310 extending from the ozone generator. As shown in Figures 4 and 5, a pair of conduits are shown which may be connected to independent ozone generators, or two independent cells of the ozone generator. Each conduit 310 is shown with a probe 320 at a distal end which can be inserted into a sterilisation chamber 400. Each probe is connected to the conduit 310 and a collar may be used to crimp the probe to the conduit 310. A probe 310 has at least one aperture adapted to disperse a sterilant, from the sterilant generator. If there is a plurality of apertures, the apertures are preferably arranged in an ordered array to more evenly disperse a sterilant. It is preferred that the distal end of the probe may be tapered into a point or spike which can assist a user to insert the probe into a desired location. A desired location may be into a sterilisation chamber 400 or into an article, for example, into a bed. Apertures may also preferably be disposed at the distal end of the probe, or may extend substantially the length of the probe 320. Near to the collar of the probe, a locking means may be provided which can mate with a corresponding locking means of a sterilant chamber.

[0050] The locking means may also be fitted with a pressure switch or other mechanism to prevent release of a sterilant if the locking means is not engaged with said

corresponding locking means 412. In this way sterilants which may be potentially harmful are not released before a suitable seal is formed. The external portion of the probes or the conduits may also have a sensor (s) 330 mounted thereon such that leaks of sterilant can be detected. If a leak is detected, the device 10 may be adapted to issue a warning to a user of the device and/or may begin to remove ozone from the chamber to be decomposed to return the chamber 400 to a safe state for humans to be in contact with or be near.

[0051] Alternatively, the delivery device 300 may be in communication with vents 106 on the exterior of the housing to deliver sterilants to an environment. A valve may be used to switch between which delivery device 300 is to be used.

[0052] Sterilisation chamber 400 can be sealed to contain a vacuum. An example of a flexible sterilisation chamber 400 with a chamber port 410. The chamber port 410 allows for probes 320 to be inserted into the chamber 400. A corresponding locking port 412 is also mounted on the port 410 to engage with a locking means of the delivery device 300. A bag can be used to enclose, encapsulate, or otherwise partly cover an article to be sterilised. The bag may be flexible and provide a barrier between an environment and the interior of the bag. Preferably, sterilants are not permeable to the sterialnt. Throughout the specification, a“bag” may be referred to as a“sterilisation chamber”. Once a bag has been deployed, the interior of the bag containing the article can be filled with a sterilant gas for a desired residence period. The bag may have at least one port, which may be selected from the following group; a connection location, membrane seal, a self-healing seal, a fluid tight port and/or a male/female port, or any other desired aperture, orifice or connection means to allow for insertion of a probe or connection of a delivery conduit.

[0053] Channels 420 may be formed in the bag to allow for more effective distribution of sterilants into the sterilisation chamber 400. The channels 400 may be used to force movement of sterilant into predetermined locations within the sterilisation chamber to allow for improved sterilisation of articles therein. A channel may extend from a port to allow for delivery of sterilants from the device through the channel into the bag. The channel may have a plurality of disbursement apertures at predetermined intervals to allow for irrigation of sterilants into the bag and to the article. [0054] The channel 400 may be formed with a primary channel 422, and at least one secondary channel 424 extending from the primary channel. In at least one embodiment, the primary channel 422 may be formed without irrigation apertures, and the secondary 424 channel(s) are formed with irrigation apertures. Secondary apertures may extend from the primary channel(s) at generally perpendicular angles or any other predetermined angles to effectively distribute sterilants. The edges of the flexible sterilisation chamber 400 may be reinforced 440 to assist with retaining sterilant gases.

[0055] The chamber 400 is shown as being open with the upper end allowing for receipt of an article. In addition, while the ports are shown as being mounted on the body of the chamber, the ports may alternatively be mounted at the opening such that when the device is sealed, sensors are closer to the opening to more effectively detect potential leaks.

[0056] In one embodiment, ambient air can be sucked into the ozone generator and a high voltage corona cell converts the oxygen (0₂) into ozone (0₃). The ozone can then be pumped via a hose to a desired location. Alternatively, the device can be used to disperse ozone into an environment via vents. Vents 106 on the device can be directed towards surfaces to be sterilised, such as towards the ground or walls of an environment.

[0057] The ozone generator of the present invention can output between lOOmg/hr and 4000 mg/hr of ozone and have the capacity to clean between O.lm³ and 300m³ of an environment.

[0058] The ozone generator of this embodiment comprises an ozone generator, air supply pump 232 and a filter 233. The air supply pump 232 sucks in air outside the sterilisation chamber through a filter 233, and the ozone generator converts oxygen contained in the air to ozone and provides it into the sterilisation chamber.

[0059] The system may include at least one of the following components 2x corona cells 240V, Pumps, LEDs, Fans, transformers, water tank, water pressure pump, blower powder gun, spikes, fragrant blower, ozone detector, air and vacuum attachment, ATP meter, vacuum head with motor, mist spray, mist tip cleaner, mattress plastic bag, vacuum conduit, monitor, controller, activated carbon, vacuum tank, HEPA filter.

[0060] The device may be used for sterilising a room or large area as the production of ozone form the device can be in the range of lm³ to 100m³ within 2 minutes to 5 minutes, depending on the desired output and/or desired parts per million.

[0061] As the ozone can be toxic in an enclosed space or in high volumes, the ozone generator must be used to remove the ozone effectively without the ozone being released into the atmosphere. As such, the ozone generator may be adapted to rapidly convert ozone into oxygen in large volumes. For example, the device 10 may be adapted to generate ozone at a rate of 4m³ to 5m³ at lOppm to 40ppm in around 6 to 10 minutes. More preferably, the device may generate 4m³ of ozone at approximately 15ppm to 25ppm, in around 8 minutes. Even more preferably, the device may generate 4m³ of ozone at approximately 20ppm, in around 8 minutes. Ozone at this level is generally unsafe for human consumption, and therefore the chamber will be required to contain all of the ozone, or substantially all of the ozone before being removed and filtered through the catalyst 230. Further, generation of ozone in the range of 15 to 25ppm, or 20ppm, is far higher than prior art devices due to the unsafe nature of ozone, and the use of hydrogen peroxide prior to injecting ozone gases (sterilant gases).

[0062] In yet another embodiment, the ozone decomposing material catalyst 230 may convert ozone into a breathable gas within around half the time it takes to generate said ozone. For example, if it were to take around 8 minutes to generate 4m³ of ozone at approximately 20ppm, the catalyst may convert the ozone into breathable gas in around 4 minutes.

[0063] In addition, UV light can be used to supplement the ozone or create the ozone.

UV generators or vacuum-ultraviolet (VUV) ozone generators can be used by the system for generation of ozone if environments do not allow for the use of plasma converters. [0064] Any filtration system may be used with the device 10. A three-stage activated carbon filtration system can be used to ensure maximum conversion of ozone. A one tier or two tier filtration system may be used to remove ozone from the atmosphere. In other embodiments, the filtration system may have any number of filtration tiers for

redundancy. For example, in a preferred embodiment, the device comprises a four tier filtration system.

[0065] In addition, a high-efficiency particulate air (HEP A) filter can be used to remove ozone from the chamber or environment. The HEPA filter may be part of a three-stage filter and is a mechanical filter which can interact gases produced by the device causing the ozone to decompose into a breathable gas, such that ozone cannot escape into breathable atmosphere. As ozone does not get released into atmosphere the device 10 may provide for a safer device for injection of ozone into a controlled environment.

[0066] In another embodiment, the device 10 provides a vacuum mount 270 at the upper end of the device 10 which is shown in Figures 5 and 6. The mount is formed with a hollow body with a top end including a port 104 for connection of a vacuum hose or the like, a side wall and bottom are used to retain the vacuum apparatus 250 therein. A pair of clamps 120, or connecting arrangement 120, are provided on the exterior of the housing which are adapted to engage with the vacuum apparatus 250 with the device housing 102. The vacuum is preferably retained in an upright position by the connecting arrangement. The arrangement may include an external recess in the side wall of the vacuum apparatus and the housing having an elongate member with a radially inwardly extending tab for engagement with the recess to provide a snap fit connection of the vacuum apparatus 250 to the housing 102. The recess is preferably a groove and the housing preferably includes at least two tabs for engagement of the groove. The locking arrangement may be such that it allows only a single orientation of the vacuum apparatus 250 to avoid misalignment. Around the recess, a strip of LEDs may be disposed, which may indicate the status of the device 10. The device status may include generating ozone, standby, active, degeneration or any other status. [0067] In another embodiment, the invention provides an ozone metering unit for an ozone steriliser, comprising body defining a metering passage having a fixed volume and upstream and downstream ends. There may be provided an upstream valve for selectively closing the upstream end and a downstream valve for selectively closing the downstream end, and a controller for operating the valves in a non-overlapping and opposite manner for selectively preventing opening of both valves at the same time.

[0068] The controller 112 preferably sequentially operates the valves for sequential connection of the metering passage to the ozone generator. Preferably, the volume of the passage is known, the evaporator is under vacuum and the controller 112 tracks the number of valve operating cycles for determination of an injected volume of ozone and the number of cycles and the volume of the metering passage.

[0069] A steriliser in accordance with the invention as illustrated schematically in Figure 1 operates generally in the following manner. An article to be sterilised (not shown) is placed into a sterilisation chamber 10 and the chamber is sealed. A vacuum is applied to the chamber 10. Medical quality oxygen is subjected in an ozone generator 22 to an electrical field, which converts the oxygen into ozone containing gas. The ozone containing gas is then fed into the chamber 10. The ozone containing gas sterilises the article. Remaining sterilant gases are subsequently decomposed into water and oxygen using a catalyst 52. The only residues left at the end of the sterilisation cycle are oxygen.

[0070] The ozone sterilisation method of the invention is preferably carried out at room temperature and, thus, requires substantially no aeration or cooling down of sterilised articles so that they can be used immediately following the sterilisation cycle. Moreover, the gases used diffuse more quickly into long lumens to be sterilised, reducing the cycle times required for sterilisation. This allows hospitals to reduce the cost of maintaining expensive medical device inventories. The sterilisation method of the invention offers several further advantages. It produces no toxic waste, does not require the handling of dangerous gas cylinders, and poses no threat to the environment or the user's health. Stainless-steel instruments and heat-sensitive instruments can be treated simultaneously, which for some users will obviate the need for two separate sterilisers. [0071] The apparatus 10 further includes an ozone generator 200 for supplying ozone- containing gas to the sterilisation chamber, sterilisation, and a vacuum pump. The vacuum apparatus 250 is used for the application of a sufficient vacuum to the sterilisation chamber 400 to increase the penetration of the sterilising gas into an article. The vacuum apparatus 250 may be used to provide a sufficient vacuum in the sterilisation chamber. Ozone produced in the ozone generator 200 is degraded using an ozone catalyst 230 to which ozone-containing gas is fed either after passage through the sterilisation chamber 10 or directly from the ozone generator 200 through by-pass valve. The ozone catalyst 230 is connected in series after the vacuum apparatus 250 to prevent ozone gas escaping to ambient. Preferably, the gas is passed through the catalyst more than once. The ozone decomposing material catalyst 230 is preferably carulite® and/or activated carbon. The catalyst may have a further filter or mesh to prevent larger particles being passed through the catalyst as seen in Figure 6. It will be appreciated that other catalysts may be used for decomposition of ozone. For economic and practical reasons, it is preferred to use a catalyst 230 for decomposition of the ozone in the sterilisation gas exhausted from the sterilisation chamber 400. The catalyst 230 destroys ozone on contact and retransforms it into oxygen and carbon dioxide with heat being produced as a by-product. Furthermore, other means for breaking down ozone sterilisation will be readily apparent to a person skilled in the art.

[0072] The ozone generator may be a corona discharge type and which can be cooled to decrease the ozone decomposition rate. As generation of ozone is generally high energy, there are a number of issues with respect to heat being generated, which can subsequently cause decomposition of ozone at an accelerated rate relative to cooler temperatures. As such, the device may be adapted to cool the ozone and/or ozone generator to reduce the potential for ozone deterioration. The ozone generator in the apparatus may be cooled to around 1 °C to 10°C, and more preferably in the range of 3°C to 6°C by a cooling system (not shown). The cooling system may be an indirect cooling system with cooling water recirculation, or a direct cooling system with an air cooling unit or a refrigeration unit for cooling (not shown). [0073] In an embodiment, the cooling system is kept at 4°C so that the ozone-containing gas generated by generator is at the ambient temperature of around 20 to 35°C. Thus, the ozone-containing gas entering into the sterilisation chamber for humidification and sterilisation is kept at ambient temperatures of between 15 to 35°C. This means that ozone decomposition is minimized and the sterilisation process is most efficient. The ozone-generator is preferably supplied with medical grade oxygen. Oxygen may also be supplied directly to the sterilisation chamber through oxygen supply valve. The apparatus can be connected to a wall oxygen outlet common in hospitals or to an oxygen cylinder or to any other source capable of supplying the required quality and flow. The supply of oxygen to the generator takes place across a filter, a pressure regulator, a flow meter and an oxygen shut off valve. The generator is protected against oxygen over pressure by a safety pressure switch. The ozone-oxygen mixture generated by the generator is directed to the sterilisation chamber through a flow regulator orifice and a ixture supply solenoid valve.

[0074] In another embodiment, the mixture can also be directly supplied to the ozone catalyst by way of a bypass solenoid valve. In a preferred embodiment in which a sterilisation chamber of five (5) litres volume is used, the pressure regulator and the regulator valve preferably control the oxygen input at a pressure between approximately 10 to 16 kPa and a flow rate of about 1.5 litres per minute. If there are multiple tanks, the supply rate of the oxygen can be increased to therefore increase the rate in which the ozone can be generated for the sterilisation chamber. It is preferred that the supply of ozone to the chamber can be achieved in a desired volume within 1 to 5 minutes, but more preferably in around 3 minutes.

[0075] The valves used with the device are preferably solenoid fluid valves. For example, a Teflon® solenoid valve may be used with the device, a direct acting valve, a pilot operated valve, a two-way valve, a three-way valve, and/or a four way valve. The selection of the solenoid valve may depend on whether additional sterilants are to be used with for sterilisation or whether additional gases or fluids are to be mixed in with the ozone or oxygen to be converted into the ozone. [0076] Articles to be sterilised, such as medical instruments, can be placed directly into the sterilisation chamber, but are preferably sealed in sterile packaging containers, sterile wraps or pouches such as those generally used in the hospital environments and then placed into the sterilisation chamber.

[0077] After insertion of the article to be sterilised has been placed into the sterilisation chamber, the sterilisation chamber is sealed and a vacuum is applied to the sterilisation chamber until a first desired pressure is reached in the chamber 400. An ozone containing gas, preferably in the form of a mixture of dry ozone and oxygen is then supplied to the chamber 400 via the conduits and/or probes of the device and the chamber maintained sealed for a preselected second exposure period. Before the application of the vacuum, second exposure gases are provided to the chamber such that there is no removal of any sterilisation atmosphere components so that none of the components of the atmosphere are removed before the end of the second exposure period. The steps of vacuum application, ozone gas injection with a first exposure period, are preferably repeated at least once (depending on whether pests are being destroyed), the number of repetitions of sterilants being injected may be related to the article being treated, and/or the reason the article is being treated. To remove all remaining sterilants from the sterilisation chamber after the sterilisation cycle(s) is completed a ventilation phase is commenced, which preferably includes multiple cycles of evacuation of the chamber in which the sterilants are passed through a filter or catalyst to break down, remove or contain sterilants. After the ventilation phase, the sterilisation chamber can be opened and the article removed from the sterilisation chamber 400. The internal temperature of the sterilisation chamber 400 may be controlled throughout the sterilisation process to more reliably control the sterilants within the sterilisation chamber.

[0078] The method of sterilisation can include encapsulating an article in a bag and subsequently sealing said bag. Atmosphere can be removed from the bag via a vacuum apparatus, or by a one way valve which can allow for ejection or removal of fluids within the bag. Ozone can be injected into the bag after atmosphere removal from inside the bag. Ozone can be maintained within the bag for a predetermined period of time. Optional additional cycle (s) of ozone may be provided to the interior of the bag. Ozone may then be extracted after all cycles of ozone have been completed and the ozone decomposed into a breathable gas. The bag can be opened and the articles can be removed.

[0079] Other methods for using the device are described below in further detail.

[0080] Referring to Figure 7, there is illustrated a method 500 for sterilisation of an article. The article is placed in a chamber 505 and sealed. An inert gas deployment means (such as delivery device 300) is connected to said chamber 510. Optionally, a vacuum apparatus 250 is used to withdraw atmosphere in the chamber 515. A sterilant gas may then be generated 520 and injected into the chamber 525. The sterilant gas is retained in the chamber for a predetermined time 530. Optionally, further gases may be added to the chamber which may be sterilant or other desired reactive or inert gases. The natural atmosphere is returned to the chamber 545, and the article is removed from the chamber, or the chamber is removed from around the article 550.

[0081] In one embodiment, there may be provided a method for sterilizing an article in a sealable sterilisation chamber, comprising the steps of a) placing the article into the sterilisation chamber, b) sealing the chamber, c) applying to the chamber a vacuum of a first pressure, d) injecting into the sealed chamber a gaseous conditioning agent for forming free radicals, e) maintaining the chamber sealed for a first exposure period, f) injecting, after the first exposure period, a sterilant gas for creating or regenerating the free radicals into the sealed chamber, g) maintaining the chamber sealed for a second exposure period, h) removing residual sterilant from the chamber at the end of the second exposure period, and i) removing the sterilised article from the chamber.

[0082] The sterilant gas is preferably ozone. Optionally, a supplementary gas may be injected such as nitrogen oxide (NOx) or chlorine dioxide (C10₂). Supplementary gases may also be removed by the filtration system of the device 10.

[0083] Optionally, a force sensor can be fitted to allow the release of ozone or limit the pressure within a chamber or a sterilisation bag. In another embodiment, the bag can have a safety interlock arrangement such that only when the spike is engaged with the safety interlock arrangement can the ozone be generated and/or deployed. The safety interlock.

[0084] In yet another embodiment, an article to be sterilised is placed in a sterilisation chamber 400, such as a flexible sterilisation bag 400 as seen in Figure 8. The article is then sealed within said chamber and the device for delivery of a sterilant is then connected to the sterilisation chamber 400. A probe or conduit of the device 10 is connected with the sterilant chamber in a fluid tight manner such that sterilants are prevented, or substantially prevented, from escaping the chamber. The first sterilisation step is begun after an article is held in a sterilisation chamber 400 and the sterilisation chamber 400 is sealed off. In a first sterilisation step, an ozone generator 200 converts oxygen included in the air inside the sterilisation chamber 400 to ozone and provides it again into the sterilisation chamber 400. At this time, the pressure inside the sterilisation chamber 400 is maintained substantially the same as atmospheric pressure, but it may decrease below atmospheric pressure when the first sterilisation step is continued for a long time.

[0085] In general, a sterilisation apparatus requires at least 2 to 5 minutes of sterilisation time as the half-life of sterilants may be relatively short (in the order of minutes).

Optionally, the device may be used to provide a sterilant to multiple sterilisation chambers simultaneously. When a plurality of sterilisation chambers are used, sterilisation time can be reduced as compared when only one sterilisation chamber is used. For instance, even when a sterilisation process is being carried out in one sterilisation chamber, another sterilisation process may be started in another sterilisation chamber. Therefore, the sterilisation of other medical instruments can be started without having to wait until the operation of the sterilisation chamber is finished. Further, although a plurality of sterilisation chambers are used, the components connected to the sterilisation chambers, i.e., vacuumisation accelerator, sterilant supplier, sterilant decomposer, pressure restorer, etc., can be used commonly, manufacturing cost of the sterilisation apparatus can be reduced while significantly reducing sterilisation time.

[0086] A sterilisation apparatus 10 is shown in Figure 1, which uses ozone a sterilant according to an embodiment of the present invention. The mixed sterilisation apparatus 1 comprises: an ozone generator 200 which provides ozone into the sterilisation chamber 400; a vacuum apparatus for removing fluids present inside the sterilisation chamber 400; and optionally a pressure restorer 290 which restores the pressure inside the sterilisation chamber 400 to atmospheric pressure after a sterilisation process is completed.

[0087] The article requiring sterilisation, such as a medical instrument or other article, is held inside the sterilisation chamber 400 through a chamber opening. After the chamber is closed and sealed, the sterilisation chamber 400 is sealed from outside such that gas may not enter.

[0088] The ozone generator 200 is connected at one side of the sterilisation chamber 400. The ozone generator 200 converts oxygen supplied from outside of the sterilisation chamber 400 into ozone and provides it into the sterilisation chamber 400. The oxygen supplied from outside of sterilisation chamber 400 may be supplied using a common oxygen-containing substance. In this embodiment, air outside the sterilisation chamber 400 is used as oxygen-containing substance.

[0089] The ozone generator 200 of this embodiment comprises an ozone generator 200, air supply pump 232 and a filter 234. The air supply pump 232 can be used to take in air outside the sterilisation chamber through an air filter, and the ozone generator 200 converts oxygen contained in the air to ozone and provides it into the sterilisation chamber 400. For example, the ozone generator 200 may be a plasma device, which may use super-heated air from high voltage to convert oxygen to ozone.

[0090] The sterilisation chamber 400 is also connected to a vacuum apparatus. The vacuum apparatus extracts gases inside the sterilisation chamber 400 before ozone is provided into the sterilisation chamber during the sterilisation process, and discharges it out of the sterilisation chamber 400. It will be appreciated that the vacuum apparatus may only be used for removal of ozone from the chamber after the sterilisation process, or between cycles of sterilisation. The creation of vacuum inside the sterilisation chamber by discharging the gas in the chamber may assist to maximize sterilisation of the ozone to be provided. Vacuuming the chamber may be effective if the article is in a bag type chamber. However, when the device 10 is being used for an environment, such as for sterilising a room, atmosphere may not be vacuumed before sterilants are provided to the atmosphere to sterilise the room.

[0091] The vacuum apparatus may be equipped with a vacuum valve and a vacuum pump. An ozone decomposer may be provided between the vacuum valve and the vacuum pump of the vacuum apparatus. The ozone decomposer decomposes ozone into a breathable gas after the sterilisation process, or if there is a puncture or significant leak in the chamber. Leaks may be detected by an ozone detector on the exterior of the device or in another predetermined location such as on the conduits or probes. In addition ozone may be monitored by said ozone detector when being used to sterilise an environment or room. Ozone may be decomposed using a heater, catalyst device (not illustrated in the figure), or the like. In a preferred embodiment, ozone is passed through an activated carbon filter. Decomposition of ozone may be achieved by the activated carbon filter system more rapidly than conventional filtration systems. In addition, the device 10 preferably uses a multi-stage activated carbon filter with at least one cycle of the gases provided thereto to ensure that the levels of ozone being ejected or released from the device are within safe breathable tolerances.

[0092] In addition, the sterilisation chamber may be equipped with a pressure restorer 290 which restores the pressure inside the sterilisation chamber to atmospheric pressure. The sterilisation chamber seal may be separated to open the sterilisation chamber after the sterilisation process is completed. Preferably, the ozone has been withdrawn from the sterilisation chamber before the seal of the sterilisation chamber has been broken/opened. The pressure restorer 290 comprises a pressure restoration valve (not shown) and a filter (not shown), and is in communication with the chamber.

[0093] In another example, an article to be sterilised (such as a medical instrument) is placed inside the sterilisation chamber 400 through a chamber opening. The chamber opening is then sealed to ensure that the gases delivered into the chamber are retained therein. Subsequently, the ozone generator 200 is operated to provide ozone into the sterilisation chamber 400. Then, a first sterilisation step begins by the ozone provided into the sterilisation chamber 400.

[0094] As described earlier, the ozone generator 200 converts oxygen contained in an oxygen-containing substance outside the sterilisation chamber 400 to ozone and provides it into the sterilisation chamber 400. In this embodiment, oxygen included in air outside the sterilisation chamber 2 is converted to ozone and is provided it into the sterilisation chamber 400. Because the ozone converted from the oxygen-containing substance is provided into the sterilisation chamber 400 after the sterilisation chamber 400 is sealed off, the pressure inside the sterilisation chamber 400 in the first sterilisation step is higher than atmospheric pressure. In the first sterilisation step of this embodiment, ozone is provided such that the pressure inside the sterilisation chamber 400 is about twice atmospheric pressure (latm). By providing the sterilant ozone gas such that the pressure inside the sterilisation chamber 400 is above atmospheric pressure, sterilisation efficiency of the article can be increased as desired.

[0095] After carrying out the first sterilisation step for a predetermined period of time, the ozone provided in first sterilisation step is discharged out of the sterilisation chamber 400, or more preferably is extracted from the chamber. Prior to the discharge of ozone, the ozone discharged from the sterilisation chamber 400 into the atmosphere passes through an ozone decomposer 260 in order to convert the ozone to unharmful substance (first decomposition step). The unharmful gas decomposed by the ozone decomposer 260 is completely discharged out of the sterilisation chamber 400 by the operation of the vacuum apparatus, and the pressure inside the sterilisation chamber 400 is decreased to a substantial vacuum or a reduced atmosphere. The step during which the ozone inside the sterilisation chamber 400 is decomposed and the pressure inside the sterilisation chamber 400 is decreased is represented as“ozone decomposition” step. The discharge of the gas remaining inside the sterilisation chamber 400 and the lowering of the pressure inside the sterilisation chamber 400 may assist with improving the sterilisation efficiency of the sterilant to be provided subsequently.

[0096] The ozone generator 200 can be operated to provide ozone into the sterilisation chamber 200. The component for providing ozone and operation thereof are the same as those of the first sterilisation step. Also, as in the first sterilisation step, the third sterilisation step is accomplished under the condition where the pressure inside the sterilisation chamber is optionally around twice atmospheric pressure. Accordingly, sterilisation efficiency of the article can be maximised as compared to the conventional sterilisation by which sterilisation is carried out under the condition where the pressure inside the chamber is below atmospheric pressure.

[0097] In order to ensure sufficient sterilisation of the article held in the sterilisation chamber 400, the aforesaid second sterilisation step and the ozone decomposition step may be repeated as desired. The second sterilisation step, (and any potential further sterilisation step) and the ozone decomposition step may be repeated at least two times.

If necessary, including the first sterilisation step and the ozone decomposition step, the process from the first sterilisation step through the ozone decomposition step may be repeated.

[0098] Following the ozone decomposition step after sterilisation is completed as desired, a pressure restoration step is carried out in order to restore the pressure inside the sterilisation chamber 400 to atmospheric pressure, so that the article can be taken out easily from the sterilisation chamber 400 by opening the chamber at a sealing location of the sterilisation chamber 400. As described earlier, the pressure restoration step is accomplished by operating the pressure restorer 290.

[0099] The ozone generator 200 does not generate ozone to be provided into the sterilisation chamber 400 by converting an oxygen-containing substance outside the chamber 400, but converts oxygen included in the air existing inside the sterilisation chamber 400 to ozone and provides it again into the sterilisation chamber 400.

Accordingly, the ozone generator 200 does not require the air supply pump 232 or the air filter, which are used to suck in oxygen from the outside oxygen-containing substance. It is simply constructed by connecting the inlet and outlet of the ozone compressor 200 to the sterilisation chamber 400.

[00100] In at least one embodiment, each sterilisation step can be carried out at atmospheric pressure or at a pressure substantially the same as atmospheric pressure.

[00101] A first sterilisation step is begun after an article is held in a sterilisation chamber 400 and the sterilisation chamber 400 is sealed off. In a first sterilisation step, an ozone generator 200 converts oxygen included in the air inside the sterilisation chamber 400 to ozone and provides it again into the sterilisation chamber 400. At this time, the pressure inside the sterilisation chamber 400 is maintained substantially the same as atmospheric pressure, but it may decrease below atmospheric pressure when the first sterilisation step is continued for a long time.

[00102] After the first sterilisation step is completed, an ozone decomposition step, a second sterilisation step, a third sterilisation step, and an ozone decomposition step are carried out. However, as described above, in the third sterilisation step, the pressure inside the sterilisation chamber 400 is substantially the same as atmospheric pressure.

[00103] Also, more than two sterilisation chambers 400 may be used. An ozone generator 200, a vacuum apparatus, an ozone decomposer 260 and a pressure restorer 290 are shared by the two sterilisation chambers 400. In another embodiment, some of the aforesaid components may be provided with the same number as the sterilisation chamber 400, so that they can be used separately by each of the sterilisation chambers 400.

[00104] In general, a sterilisation apparatus requires around 1 to 3 minutes of sterilisation time for a sealed apparatus, and for environments may require 5 minutes to 300 minutes of sterilisation time, depending on the size of an environment. When sterilising a room residence times may be higher and the rate of conversion of ozone may be variable such that ozone can be provided to a significant portion of the environment.

[00105] When a plurality of sterilisation chambers are used, sterilisation time can be reduced as compared when only one sterilisation chamber is used. For instance, even when a sterilisation process is being carried out in one sterilisation chamber, another sterilisation process may be started in another sterilisation chamber. Therefore, the sterilisation of other medical instruments can be started without having to wait until the operation of the sterilisation chamber is finished. Further, although a plurality of sterilisation chambers are used, the components connected to the sterilisation chambers may be standardised to be connected to any one of the; vacuum apparatus, sterilant supplier, sterilant decomposer, pressure restorer, etc., can be used commonly,

manufacturing cost of the sterilisation apparatus can be reduced while significantly reducing sterilisation time.

[00106] A corona cell converts air or pure oxygen gas at least in part by a corona discharge. The corona discharge is used to split a diatomic oxygen molecule into valant oxygen atoms. These oxygen atoms have a negative charge and will bond quickly with another oxygen molecule to produce ozone. For each split oxygen molecule 2 ozone molecules are produced. [00107] A power supply is used to produce an electrical discharge across a dielectric, and an air gap. The dielectric is used to diffuse the discharge across a large area as opposed to single point like a normal spark. The oxygen molecules passing through the air gap are exposed to the electrical discharge and are split into ozone (at least that is the hope). A great deal of heat is generated from this process and is removed from the electrodes as shown.

[00108] Ozone generation corona cell, the dielectric is a tube allowing the air gap to flow around the outside of the dielectric, with the electrode around the outside. This allows heat to be dissipated to the outside of the electrode efficiently.

[00109] The device 10 may use commercial ozone generation techniques, and hardware. Preferably, the device comprises a pair of corona cells which can be used to generate ozone in a desired volume or concentration at a relatively more rapid rate. A corona discharge (electrical discharge field) can be generated from the corona, high voltage sparks at medium to high frequencies can be generated which generates ozone at medium to high concentrations (up to between 20 to 25% conversion rate).

[00110] Corona cells generally have low operation costs, and improved reliability this will be the main method of ozone generation for many years to come.

[00111] A compressor may extract air from an environment and provide the air to a corona cell. The corona cell can split 0₂ to generate 0₃.

[00112] The compressor motor may be activated when the device 10 is turned on. The compressor motor may be used to siphon air from outside the machine and then provide the air to the corona cell or ozone generator.

[00113] Using ozone alone as a sterilant has the following advantages; reduced or no chemical residue, powerful anti-microbial intervention, no chemicals to purchase, less harsh on metal and wood, reduces chemical handling and storage, sanitized water drainage systems, and reduces risk of resistant microorganisms. These are of particular advantage for reuse of articles or rooms quickly after sterilisation. Further, no wipe- downs or additional cleaning is required after the initial sterilisation for the article or room to be used safely by persons, which is of particular advantage to daycares, schools and hospitals.

[00114] The system may use a compressor to an oxygen concentrator and then pass the oxygen to an ozone generator. The ozone may then be provided to a desired target site to sterilise said target site or article therein.

[00115] Instead of using external air for the generation of ozone, the device may use oxygen from a predetermined source. For example, liquid oxygen or compressed oxygen (such as compressed oxygen cylinders) may be used to provide a pure stream of oxygen to an ozone generator or corona cell. Other oxygen rich sources may also be used, such as water, hydrogen peroxide, or any other desired oxygen source.

[00116] Another method is to use an oxygen concentrator, preferably one that uses the PSA or Pressure Swing Adsorption method. Pressure swing adsorption is a process whereby a special molecular sieve is used under pressure to selectively remove nitrogen, carbon dioxide, water vapour, and hydrocarbons from air, producing an oxygen rich (70% to 95% 0₂) feed gas. This method is similar in the quality of oxygen that would come from an oxygen cylinder. The two are not similar in the pressure that they can deliver. Compressed cylinders have a much higher pressure (PSI).

[00117] It will be appreciated that the volume and/or concentration of the ozone being generated may make the device a steriliser, rather than just an antimicrobial device.

[00118] Commonly, the use of such high volumes and/or concentrations of ozone are prohibited or avoided due to the potential health impacts due to exposure. In view of the high volumes and/or concentrations of ozone produced by the device, the device may also have the capacity to rapidly remove ozone from the sterilisation chamber/ozone exposed environment to be converted into a breathable gas, such as oxygen 0₂. [00119] Throughout this specification, a breathable gas may refer to a gas which is safe or generally unharmful for a person to breathe.

[00120] In yet another embodiment, the device can be used to supply a sterilant to the interior of a bed. For this process, at least one aperture can be made in a side of a mattress, preferably near to the end of the bed. Probes can be inserted into the mattress via the apertures to deliver ozone to the interior of the mattress. Optionally, but preferably, the mattress can be sealed or encapsulated within a bag or other sterilisation chamber to keep the ozone within a controlled environment. Ozone may be injected into the sterilisation chamber for a desired residence time. In addition, ozone may be cycled to and from the sterilisation chamber to ensure that a constant level of ozone can be maintained for a desired period of time, and may also assist with eradicating or removing pests, microbes or the like. If cycling is employed, the cycle times may be dependent on the types of pests which are expected to be present. Each cycle time may also have a variable concentration of ozone, and/or residence time of said ozone.

[00121] In one example, a first residence time may be in the range of 1 minute to 5 minutes, and a second residence time may be in the range of 30 seconds to 10 minutes. Between residence times a further gas which is a non-sterilant gas may be injected into the chamber. Alternatively, ozone may be allowed to break down into dioxide which may be a breathable gas. Upon a breathable gas returning to the chamber, pests within may wake from a dormant stage upon which a further cycle of ozone can be injected into the chamber. Most pests cannot withstand further cycles or repeated cycles of a sterilant gas, even if they have natural mechanisms to fall into a dormant state during an initial exposure. As such, the sterilant gas being cycled for predetermined residence times and with predetermined concentrations with respect to known pests can assist with improving the removal rate of pests.

[00122] The device 10 may have pre-set functions in relation to pest types such that the device 10 may be adapted to automatically cycle sterilant gases to correspond to predetermined residence periods and number of cycles. Pre-set functions may be stored in a storage medium which can be accessed by the controller. The controller may be used at a distance from the device such that the device can be deployed and a safe working distance may be used to activate the device 10. Sensors 330 may be disposed in or on the probes 320 to detect ozone or sterilant gas concentrations or levels within a sterilant chamber to ensure that a desired concentration of sterilant gas is achieved. As ozone has a relatively short half-life, the device 10 may also periodically generate further ozone or sterilant gases to be delivered via the delivery device 300 into the sterilisation chamber to maintain a desired concentration of sterilant gas over the residence time. In addition, as ozone degrades (or decays) the device may extract a volume of gas and replace it with further ozone or sterilant gas to maintain a desired internal pressure for the sterilisation chamber.

[00123] Additional sensors may be disposed on the housing 102 of the device to detect leaks or detect gas concentrations within the atmosphere or environment in which a sterilant gas is to be deployed.

[00124] In another embodiment, the device 10 may be preferably used for injecting ozone into a room, chamber or controlled environment. The device 10 may be used to fill a desired room with ozone over a predetermined period of time. Ozone may be pumped into an environment or sterilisation chamber by the device 10 from the ozone generator. The ozone generator may convert an oxygen-containing substance outside the

sterilisation chamber into ozone and provides it into the sterilisation chamber.

[00125] The preferred sterilisation apparatus 10 in accordance with the invention as illustrated schematically in Figure 9 may include a housing 102 and a control panel 110. An ozonated water module 501 as illustrated in Figures 9 and 10 may be connected to the device 10 for delivering a sterilant to a desired location. The control panel may be shown with a plurality of buttons 114, which may allow for desired functions of the device 10 to be activated. The buttons 114 may effect sterilant generation, vacuuming, conversion of a sterilant, or any other desired function. The controller 112 on the control panel 110 may allow for activating pre-set modes or functions (algorithms) which may relate to the desired use of the machine. For example, if the machine may be used for general sterilisation, only a single cycle may be needed and a longer residence period may be used. Alternatively, if the device may be used for sterilisation for pests, a plurality of pre-set cycles and residence times may be activated corresponding to the types of pests likely to be present. The controller 112 may have a processor, storage means, a wireless communication module, and a battery.

[00126] Preferably, there may be independent buttons for activation of sterilant generators 300. In at least one embodiment, the sterilant generators are ozone generators 300. The ozone generators 300 may be used to convert oxygen into ozone for use in sterilisation of an article or environment.

[00127] To assist with moving the device 10, a pair of wheels and a handle are provided. The wheels may be temporarily locked in place when the device 10 is at a desired location. A wheel guard may also be provided on the housing as shown in Figure

9.

[00128] As shown in Figure 10, the ozonated water module 501 may have a reservoir 502 for containing a fluid 503. The reservoir 502 may be mounted to the device

10. The fluid 503 may be water when the reservoir 502 is first filled. An elongate static mixer 511 may be adapted for mixing ozone and fluid 503. The elongate static mixer may be connected to the reservoir 502, wherein a first end of the elongate static mixer 701 may be positioned inside the reservoir 502, and wherein a second end of the elongate static mixer 703 may be positioned outside the reservoir 502. The fluid 503 may be ozonated when ozone gas or 0₃ is bubbled in the fluid 503 for a predetermined time. Depending on the pressure and temperature, ozone decomposes over a short variable period of time. It may be appreciated that the ozone be generated and newly generated ozone be used or circulated in the ozonated water module 501 to maximise the time of the fluid 503 is mixing with the ozone. The generated ozone from the ozone generator 300 may be directed to a manifold 510, which may be a junction between the ozone and the fluid 502 are directed to the mixer 511, which mixes the ozone and fluid together through the mixer 511 into the reservoir 502. The reservoir pump 505 may in operation such that the fluid 503 is pumped from the reservoir to the manifold 510 via fluid conduits or a pipes 504, 506, 507, such that the fluid 503 comes in contact and mixes with ozone to generate ozonated water. The cycle may continue until the ozonated fluid 503 reaches a safe predetermined concentration in water. The safe predetermined ozone concentration in water may be 3 to 8 ppm in water.

[00129] Once the safe predetermined concentration of ozone in water is achieved, the injection of ozone into the reservoir may stop. There may be provided, a solenoid switch 507 which may be positioned between the pump 505 and the manifold 510. There may be provided a pipe 506 in fluid communication between the pump 505 and the solenoid switch 507, and there may be provided a pipe 509 in fluid communication between the solenoid switch 507 and the manifold 510. The solenoid switch 507 may direct the ozonated water out of the ozonated water module 501 through the nozzle or ozonated water outlet 508 for use in applications. There may also be an ozone solenoid switch 512 which may direct newly generated ozone from the ozone generator 300 through the ozone gas nozzle 513 for direct ozone usage in other applications.

[00130] As illustrated in Figure 12, the mixer 511 may be a static mixer. The static mixer may be elongated. The static mixer 511 may have a manifold connection portion 703 which may connect to the manifold 510 of the ozonated water module 501 as shown in Figure 10. The static mixer 51 1 may have a mixer region 702 between the manifold connection 703 and the mixer outlet 701. The mixer region 702 may be a labyrinth for dividing the flowpath of the fluid and ozone such that the surface area of the fluid in contact with the ozone is increased for efficiently obtaining the desired predetermined concentration of ozone in fluid in the reservoir. The mixer outlet 701 may be adapted to be connected to the fluid filled reservoir 502 such that the mixer outlet 701 may be in contact with the fluid 503. The mixer region 702 may comprise of a series of baffles 704, which may be composed of a material which may be inert to the gases and/or fluids that the static mixer 511 is suitably used for mixing. The material may be made of metal or alloy or plastic. Preferably, the construction materials for static mixer components may include one of a group selected from: stainless steel, polypropylene, Teflon™, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), and polyoxymethylene. Similarly, the housing of the static mixer 511 may also be made of the same material as the series of baffles 704. The series of baffles 704 in this configuration as shown in the two-dimensional profile of the static mixer 511 may allow for the efficient and/or optimal mixing of both ozone and water to produce ozonated water in short predetermined of time. The series of baffles 704 may allow for the flow division of the two fluids and may allow for increasing the surface area of which water can contact the ozone. In another embodiment, as shown in Figure 11, there may be an ozone misting device 603 which may include a fogger device 604 in fluid connection to a storage reservoir 605 via a conduit or a pipe. The storage reservoir 605 may contain the ozonated water or fluid 503 from the ozonated water module 501, which can be directed to the fogger device 604 for misting ozonated water. Misting ozonated water may be useful for fumigation and pest control applications.

[00131] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms, in keeping with the broad principles and the spirit of the invention described herein.

[00132] The present invention and the described preferred embodiments specifically include at least one feature that is industrial applicable.

Claims

1. A device for sterilisation, the device comprising;

a compressor for providing a gas to an ozone generator;

the ozone generator converting at least a portion of the gas to ozone gas at a first rate;

the ozone gas being injected into a chamber for a predetermined holding time; and wherein the system comprises a multi-stage filter system to remove ozone from the chamber at a second rate which is higher than the first rate than the system can produce ozone.

2. The device of claim 1, wherein the multi-stage filter system is an activated carbon catalyst filter system.

3. The device of claim 1 or claim 2, wherein the multi-stage filter is a three-stage filter.

4. The device of any one of the previous claims, wherein the injection of ozone gas is delivered by a delivery device.

5. The device of claim 4, wherein the delivery device comprise a conduit and a probe.

6. The device of claim 5, wherein the probe further comprises a plurality of apertures to deliver the ozone gas.

7. The device of any one of the previous claims, wherein the ozone generator is at least one corona cell.

8. The device of any one of the previous claims, further comprising a vacuum apparatus for removing sterilant gases from said chamber.

9. The device of any one of the previous claims, wherein a control panel is provided for activating said ozone generator.

10. The device of any one of the previous claims, wherein the device can be remotely activated and deactivated.

11. The device of any one of the previous claims, wherein the device sterilisation chamber comprises a plurality of channels for distributing ozone gas.

12. A method of sterilisation, the method comprising;

providing an article to a sterilisation chamber;

sealing the sterilisation chamber with said article;

sterilising the article by injecting ozone gas to the sterilisation chamber, and retaining the ozone in said chamber for a desired residence period; substantially removing the ozone gases from the sterilisation chamber via a vacuum apparatus; and

providing sterilant gases through a multi-stage catalyst filter for decomposition of said sterilant gases.

13. The method for sterilisation as claimed in claim 12, wherein sterilising the article by injecting ozone is repeated at least once.

14. The method for sterilisation as claimed in claim 12 or claim 13, wherein atmosphere in the sterilisation chamber is at least partially removed before injecting ozone into said chamber.

15. The method for sterilisation as claimed in any one of claims 12 to 14, wherein the sterilisation is carried out under the condition where the pressure inside the sterilisation chamber is higher than atmospheric pressure, and the ozone provided produced by converting an oxygen-containing substance outside the sterilisation chamber.

16. The method for sterilisation as claimed in any one of claims 12 to 15, wherein the sterilisation is carried out under the condition where the pressure inside the sterilisation chamber is atmospheric pressure, and the ozone provided is produced by converting oxygen from a predetermined oxygen source.

17. The method for sterilisation as claimed in any one of claims 12 to 16, wherein a sterilisation device, the sterilisation device having an ozone generator, a vacuum apparatus, a delivery device for delivering ozone to a target location, and an ozone decomposer for converting ozone into a breathable gas.

18. The method for sterilisation as claimed in claim 17, wherein said sterilisation device further comprises a pressure restorer which restores the pressure inside the sterilisation chamber to atmospheric pressure after a sterilisation process is completed.

19. The method for sterilisation as claimed in claim 17, wherein said ozone generator converts an oxygen-containing substance outside the sterilisation chamber into ozone, and provides the converted ozone into the sterilisation chamber so that the pressure inside the sterilisation chamber maintains a pressure higher than atmospheric pressure when the article is sterilised.

20. A device adapted for sterilising fluid, the device comprising:

a reservoir adapted to store a fluid, wherein the reservoir is mounted to the device;

an elongate static mixer adapted for mixing ozone and fluid, the elongate static mixer connected to the reservoir, wherein a first end of the elongate static mixer is positioned inside the reservoir, and wherein a second end of the elongate static mixer is positioned outside the reservoir;

a pump positioned between the reservoir and the second end, wherein the pump is adapted to pump the fluid from the reservoir to the second end; an ozone injection valve positioned between an ozone generator and the second end, wherein the ozone injection valve is adapted to inject generated ozone to the second end, and wherein a predetermined concentration of ozone in fluid is reached in the reservoir.