Technical Field

The present technical solution relates to equipment for disinfection, decontamination and sterilization of materials and surrounding spaces using gaseous agents.

Background Art

Ozone generators are one of the available options for sterilization of materials. Ozone generators are intended for being placed in a particular space (namely closed spaces, such as rooms or car interiors) where they generate ozone for a certain amount of time, the ozone reliably destroying viruses and bacteria. At higher concentrations, ozone is harmful to human health, and therefore no persons are allowed in the closed space while the ozone generator is running.

Devices are known which comprise a closable chamber in which an ozone generator is installed. Articles are placed into the closable chamber and sterilized by the ozone. Since this process takes place in a closed space, the environment around the device is safe for humans. There is a disadvantage in that a complex device must be manufactured: in addition to the ozone generator, there must be the casing of the device, which houses all the components, a fan, an electric power source (high-voltage transformer) and control elements.

The purpose of the present technical solution is to provide an engineering design of an ozone sterilizer which protects the persons in the vicinity from ozone and is easy and affordable to manufacture.

Disclosure of Invention

This technical solution involves a design of an ozone sterilizer with a closable chamber for sterilizing articles and, if needed, the space around the sterilizer. The sterilizer comprises a casing which contains a first chamber for sterilizing articles. The first chamber is provided with a closable door. After the door is closed, the chamber becomes a closed space. In the first chamber, an ozone generator with at least one fan is placed. Typically, the ozone generator relies on high-voltage discharge. After inserting the articles to be sterilized and closing the door, ozone is generated by starting the ozone generator in the first chamber. At least one fan of the ozone generator causes ozone to circulate throughout the entire first chamber. In this fashion, ozone reaches all locations on the articles being sterilized and effectively acts against harmful viruses and bacteria. Preferably, the ozone generator is placed in a recess in the top wall (ceiling) of the first chamber and covered with a lid which leaves a slit between the lid edge and the perimeter of the recess to enable ozone to flow through freely. Holes in the lid may be considered as well. As a result, the ozone generator does not take up space inside the first chamber and is protected from accidental damage.

The casing comprises control elements for operating the sterilizer. The casing further comprises a second chamber in which there is at least one fan for primary air. The primary air fan outlet discharges into the first chamber. In the second chamber, an electric power source is placed which is a high-voltage transformer connected to the ozone generator.

The second chamber may be a closed space as well. In such case, the primary air fan may be arranged on the inner side of the perforated outer wall of the casing (typically the rear wall). The primary air fan draws air through the perforated outer wall of the casing and discharges into the closed second chamber. The outlet of the primary air fan from the second chamber discharging into the first chamber may be in the form of a perforated partition between the first and second chambers. Preferably, the primary air fan inlet is provided with a filter which prevents contaminants from entering the interior of the casing. The main object of the primary air fan is to force air into the first chamber during and/or after the sterilization process. As a result, ozone in the first chamber can be diluted to a harmless concentration or blown out purposefully outside the sterilizer in order to sterilize the outside space, as described below. Further, the primary air fan can be used advantageously for cooling the sterilizer components which are placed in the second chamber (namely the electric power source in the form of a high-voltage transformer).

Further, the first chamber is provided with an outlet for exhausting the first chamber. The outlet may be fitted with a closable flap to prevent ozone from leaking prematurely from the first chamber. Preferably, the flap may be controlled by means of a servomotor. After sterilization is completed, it is desirable to exhaust ozone from the first chamber before any person opens its door. This protects the person from undesirable exposure to ozone. The casing with the first chamber and the second chamber has at least two shells. It comprises at least an inner shell and an outer shell and an intermediate space between the inner shell and the outer shell. The outer shell provides protection of the inner shell from damage. The intermediate space between the inner and outer shells also protects the safety of persons around the ozone sterilizer. It captures ozone which may have leaked from the first chamber. The ozone may be pumped out from the intermediate space in a controlled fashion or may be diluted with air to achieve harmless concentration. Preferably, the double shell casing is a casing from a microwave oven. A microwave oven casing typically includes a recess in the top wall (ceiling) of the first chamber, into which the ozone generator can be placed.

The outlet from the first chamber in the inner shell may discharge into the intermediate space between the inner and outer shells. At the same time, the outer shell may be provided with at least one outlet between the intermediate space and the outer environment of the casing.

At least one outlet from the outer shell may be provided with an extension with an open end placed outside the reach of persons or configured for connecting an external exhaust device. In that case, other outlets, if any, in the outer shell are closed. Consequently, any ozone exhausted is concentrated in a single outlet from which it can be effectively removed away from persons. Where an extension is fitted to the outlet, the extension may include an exhaust fan. The exhaust fan on the outlet helps exhaust ozone from the interior of the first chamber.

The first chamber may comprise a driven rotating plate. Rotation of the article being sterilized improves the access of ozone to all locations on the article. Along with or instead of the rotating plate, there may be at least one shelf. The shelf may be placed on the rotating plate and rotate together with the plate. The shelf should be permeable to air (e.g. made from a wire mesh) as much as possible to ensure that its construction does not obstruct ozone flow.

Preferably, the volume of the first chamber is at least 10 litres. This (and larger) volume provides an advantageous ratio between the volume (and therefore the quantity of the articles being sterilized) and the energy expended on ozone generation. Furthermore, this volume roughly matches the inner volume of the first chamber in a microwave oven casing.

If the casing with the first chamber and the second chamber is a casing of a microwave oven, it is preferable that the primary air fan is the existing primary air fan of a microwave oven. Furthermore, it is preferable that the electric power source in the form of a high-voltage transformer is the existing power source in the form of a high-voltage transformer of a microwave oven. The driven rotating plate may also be the existing driven rotating plate of the microwave oven. The microwave oven casing has an adequate construction and positions of the chambers. Namely, it contains a first chamber which can be closed with a door and an adjacent closed second chamber. In the second chamber of the microwave oven casing, there is a primary air fan discharging into the first chamber, an electric power source in the form of a high-voltage transformer and control elements. The microwave oven (a new or discarded one) may be preferably used for an easy conversion into an ozone sterilizer.

In the course of a conversion of a microwave oven to an ozone sterilizer, the magnetron for generating microwaves must be removed (or at least disconnected - deactivated) from the second chamber. The magnetron, as a part of the microwave oven, has no use in an ozone sterilizer. Furthermore, depending on the configuration, the microwave oven voltage multiplier which is used by the magnetron may be disconnected or retained. If the voltage multiplier is retained, it can be used for generating negative ions which have a favourable effect on human mental condition. Furthermore, a voltage multiplier may perform the function of a voltage divider used for indicating correct operation of the sterilizer, e.g. via a LED lamp. This prevents a scenario where a blown fuse of the electric power source in the form of a high voltage transformer leads to ozone generation and sterilization failure despite the device being active (activated fan of the ozone generator).

Furthermore, depending on the configuration, the rotating plate and its drive may be removed from or retained in the first chamber of the microwave oven. In the first chamber, an ozone generator with at least one fan is placed. Preferably, the ozone generator is electrically connected to the existing electric power source in the form a high voltage transformer and, if relevant, to the control elements of the microwave oven in the second chamber. The ozone generator fan is also electrically connected to the control elements, preferably via different conductors than the ozone generator. Hence, the fan operating time may be controlled independently of the ozone generator. Typically, the control elements of the microwave oven enable the operating time and the power of the microwave oven to be set. Preferably, they can be used for setting the operating time and power of the ozone sterilizer. An ozone sterilizer may be provided with a control system with an algorithm for controlling separate ozone sterilizer processes.

Preferably, the first chamber may be provided with a UV radiation source or a UV-C radiation source. The UV or UV-C radiation source is preferably located in the recess in the top wall (ceiling) of the first chamber together with the ozone generator and covered with a lid. This shields the UV or UV-C radiation which could otherwise damage the articles being sterilized. At the same time, the UV or UV-C source is placed in the location of the strongest flow of ozone at the time of its destruction while the ozone generator fan is running. The UV or UV-C radiation reacts with ozone and reduces its concentration by converting it back to two-atom molecular oxygen. The source of UV or UV-C radiation can thus be used for reducing the ozone concentration to a safe level after sterilization. In such a case, the sterilizer components are connected in such manner that in the first step, the ozone generator is activated together with at least one fan. This produces ozone which is distributed throughout the first chamber. Then, once sufficient ozone concentration is achieved in the first chamber, the ozone generator is deactivated and ozone circulates in the interior of the first chamber by means of at least one ozone generator fan. After the sterilization period ends, the UV or UV-C radiation source is activated while at least one ozone generator fan continues to run. The source reduces the ozone concentration while at least one ozone generator fan ensures that the entire volume of gas (air) in the first chamber comes into contact with UV or UV-C radiation. This reduces the ozone concentration in the interior of the first chamber to a safe level and makes it possible to open the sterilizer door. As a result, this sterilizer configuration provides faster reduction in ozone concentration in the first chamber than the mere use of the outlets, exhaustion etc.

Together with the UV or UV-C source or as its replacement, an air pump may be employed. The air pump is a device which is configured to transport gas (air) from one location to another. In such case, the first chamber is provided with a suction inlet of the air pump. Depending on the location of the air pump, this may be an actual inlet of the air pump or a hose which is connected to the air pump inlet. The discharge opening of the air pump is configured for being placed in a vessel with water. Typically, it is a hose which may be inserted into or removed from the vessel with water repeatedly. The vessel may be part of the sterilizer, either inside or outside. Alternatively, it may be a separate vessel, such as a glass. The end opening of the hose must discharge under water. The air pump draws ozone-containing air from the first chamber and blows it into water. Here, a chemical reaction between water and ozone produces a powerful disinfectant. It can be preferably used for further processing (disinfecting articles and surfaces) or destroyed as a waste product of sterilization. However, it is important that by drawing ozone from the first chamber, the ozone concentration in the interior of the first chamber is reduced to a safe level, making it possible to open the sterilizer door. The location of the actual pump is not important, as it may be placed within the first or second chambers or outside the casing. Hence, the air pump may be placed directly in the first closed chamber and may communicate with the external vessel via a hose passing through an opening in the casing. Naturally, the casing of a microwave oven need not be used. However, it is the most economical option which is fully sufficient for medium-scale sterilization. Large-scale (volume) sterilization may be considered in an alternative configuration with a special casing, in which the volume of the first chamber is considerably larger than the above-mentioned 10 litres. Essentially (regardless of the interior volume of the first chamber), two different configurations of ozone sterilizer are preferred - for domestic use and for industrial use, namely in laboratories, hospitals etc., as described below. When the ozone generator and primary air fan are activated simultaneously, the device may also be used for sterilizing the environment around the sterilizer (e.g. an interior of a building or a transport vehicle, in personal or mass transportation). For sterilizing the environment around the sterilizer, the ozone from the first chamber must be blown outside the sterilizer. This can be achieved particularly with outlet openings. An alternative sterilizer configuration may be considered which enables the ozone generator to be activated even when the door is open. The ozone thus enters the open space around the sterilizer where it sterilizes all surfaces and the air. However, exposure of persons to ozone must be prevented. In particular, persons should wait before they approach the sterilizer after it was turned off, in order for the ozone around the device to decompose sufficiently.

Brief Description of Drawings

An example embodiment of the invention is described with reference to drawings where Fig. 1 - a front view of the ozone sterilizer which comprises a microwave oven casing and an extension with an exhaust fan;

Fig. 2 - a front view of the ozone sterilizer from Fig. 1, where the door of the first chamber and the face panel of the second chamber were removed for clarity and in order to show their interiors;

Fig. 3 - a vertical section through an empty casing of the ozone sterilizer from Fig. 1 with an extension with an exhaust fan aligned with outlet openings, with the outlet openings displayed (the outlet opening in the bottom of the casing is closed) and the flow of air from the primary air fan through the second chamber, first chamber and the intermediate space into the extension; Fig. 4 - a front view of the ozone sterilizer in a configuration with no extension and exhaust fan, where the door of the first chamber and the face panel of the second chamber were removed for clarity and to show their interiors; Fig. 5 - a vertical section through an empty casing of the ozone sterilizer from Fig. 4 aligned with outlet openings, with the outlet openings displayed (the outlet opening in the bottom of the casing is open) and the flow of air from the primary air fan through the second chamber, first chamber and the intermediate space into both outlet openings in the outer shell;

Fig. 6 - a vertical section through a casing of the ozone sterilizer (an alternative to the configuration from Fig. 4 and Fig. 5) aligned with outlet openings, with the outlet openings displayed (the outlet opening in the bottom of the casing is open) and the flow of air from the primary air fan through the second chamber, first chamber and the intermediate space into both outlet openings in the outer shell, with a recess in the ceiling of the first chamber, in which there is the ozone generator and a UV or UV-C radiation source above the lid.

Best Mode for Carrying Out the Invention

Example 1

An ozone sterilizer with a closable chamber for sterilizing articles includes a casing. The casing comprises the first chamber 1 for sterilizing articles with closable door 4. In the first chamber 1, there is the ozone generator 5 with fans and the rotating plate 14 with a drive. The casing also comprises a closed second chamber 2. In the second chamber 2, there is the primary air fan

7 whose outlet discharges into the first chamber 1 via a perforated partition between the first chamber 1 and the second chamber 2. In the second chamber 2, there is the electric power source

8 in the form of a high-voltage transformer connected to the ozone generator 5. In the wall of the second chamber 2, there are control elements 3 for operating the sterilizer. The control elements 3 include an element for setting the duration of the operation of the ozone sterilizer and an element for setting the power of the ozone sterilizer. They are modified control elements 3 which are not from a microwave oven. They include timers and algorithms for individual tasks.

The casing with the first chamber 1 and the second chamber 2 is a casing of a microwave oven. The casing consists of two shells and contains the inner shell 9, outer shell 10 and an intermediate space 11 between the inner shell 9 and the outer shell 10. The outlet opening 12 of the first chamber 1 in the inner shell 9 discharges into the intermediate space 11. The outer shell 10 is provided with two outlet openings 12 between the intermediate space 11 and the exterior of the casing. The first outlet opening 12 is in the outer shell 10 in the bottom of the casing below the first chamber 1 and is closed. Said second outlet opening 12 is in the top wall of the outer shell 10 above the first chamber 1. This second outlet opening 12 in the outer shell 10 is provided with an extension 13 in the form of a chimney stack. The extension 13 is provided with an exhaust fan 6.

The primary air fan 7 in the second chamber 2 is a primary air fan of a microwave oven and the electric power source 8 in the form of a high-voltage transformer in the second chamber 2 is an electric power source in the form of a high-voltage transformer of a microwave oven.

This was a discarded microwave oven. In the first chamber 1, an ozone generator 5 with fans was installed and electrically connected to the electric power source 8 in the form of a transformer from a microwave oven. From the second chamber 2 of the microwave oven, the magnetron for generating microwaves was disconnected and removed. The voltage multiplier of the microwave oven was retained. Its purpose is to generate negative ions which have a favourable impact on human mental condition. Furthermore, a voltage multiplier may perform the function of a voltage divider which is used for indicating correct operation of the sterilizer via a blue LED lamp.

Thanks to the configuration of the outlet opening 12 with an extension 13 and exhaust fan 6, the entire sterilization process may be faster. The ozone generator 5 with its fans and the drive of the rotating plate 14 are activated at the same time for approximately 2 minutes. To generate a sufficient amount of ozone in the first chamber 1, the ozone generator 5 is deactivated and only its fans remain in operation, as they cause ozone in the first chamber 1 to circulate. After another approximately 30 seconds which are necessary for sterilization, the primary air fan 7 is activated along with the exhaust fan 6 in the extension 13 for exhausting the first chamber 1 into an external exhaust line (e.g. fume hood, chimney stack etc.). Hence, the ozone concentration in the first chamber 1 is reduced within several dozen seconds to under 5 ppm, which is safe for human health and the door 4 of the first chamber 1 can be opened.

Since the extension 13 must be connected to external exhaust piping, the above-described ozone sterilizer is more suitable for industrial purposes, namely in laboratories, hospitals etc.

The example embodiment is shown in Figs. 1 through 3. Example 2

Essentially, an ozone sterilizer according to this example has the same design and configuration as in example 1. The only difference is in that the original control elements 3 were retained from a microwave oven. The control elements 3 include an element for setting the duration of the operation of the ozone sterilizer and an element for setting the power of the ozone sterilizer. The connection of the control element for setting the duration of operation with the primary air fan 7 was disconnected in the course of conversion of the microwave oven. Instead of the primary air fan 7, the ozone generator 5 fans are connected to the control element for setting the duration of operation. Therefore, the primary air fan 7 is not (need not be) active after the sterilizer has been turned on, which prevents undesired blowing of the generated ozone from the first chamber 1 to the outside. By contrast, fans of the ozone generator 5 are active for the entire operation of the ozone sterilizer thanks to the connection to the control element for setting the duration of operation.

Another difference from the configuration in example 1 is in that the first outlet opening 12 in the outer shell 10 in the bottom of the casing below the first chamber 1 is open. The second outlet opening 12 is in the top wall of the outer shell 10 above the first chamber 1. The outlet openings 12 on the outer shell of the casing are not provided with an extension 13 or an exhaust fan 6.

Owing to the absence of technical means for rapid removal of ozone from the entire equipment to a place away from persons, the sterilization process is slower. After ozone generation and activation of ozone generator 5 fans for approximately 2 minutes, a waiting time of approximately 10 minutes is necessary before opening the door 4, to ensure that the ozone has decomposed. The primary air fan 7 can gradually dilute ozone in the first chamber 1, while the overpressure from the first chamber 1 is spontaneously relieved by blowing from outlet openings 12. In order to maintain safe ozone concentration around the sterilizer, this process is slower than in the configuration according to example 1. For this reason, the configuration according to example 2 is better suited for domestic use because there is no need for dealing with connections of exhaust piping. The lower efficiency of the sterilizer resulting from the longer process does not pose a limitation: it is sufficient for domestic (non-industrial) use.

The example configuration can be seen in Figs. 4 and 5. List of reference symbols

1 - first chamber

2 - second chamber

3 - control elements

4 - door

5 - ozone generator

6 - exhaust fan

7 - primary air fan

8 - electric power source

9 - inner shell

10 - outer shell

11 - intermediate space between the inner shell and outer shell

12 - outlet opening

13 - extension

14 - rotating plate

15 - source of UV or UV-C radiation