DE102009016542A1 - Method for disinfecting inner surfaces of device with ozone-containing gas, involves saturating gas stream with steam of aqueous solution - Google Patents

Abstract

The method involves saturating the gas stream with the steam of an aqueous solution. The gas stream carries aerosol of the solution such that a three-phase contact steam-aqueous solution-material or a water-containing covering layer is formed on the inner surface. The ozone or other active secondary product of the ozone contained in the gas stream are guided for production of cell membrane permeable or damaging or cytotoxic products such as hydroxyl radical, atomic oxygen, hydroperoxyl radical or singlet oxygen. The products are volatile in contact with the inner surface.

Description

The The invention relates to a method for the disinfection of interiors of devices. The interiors become with device use flows through fluid media. The ones in contact with the medium standing inner walls are freed from pathogenic germs. Germs within the meaning of the invention may be bacteria, fungi, spores and be viruses too. The liberation (is in the sense of the definition to understand microbiology and virology as inactivation) of germs (hereinafter referred to as germs) is by disinfection with a gaseous medium which causes germicidal Active ingredients and aqueous aerosols contains. To contains the gas in addition to the normal air constituents ozone and gaseous hydrogen peroxide fractions. The aqueous aerosol phases contain dissolved ozone, secondarily from this formed hydrogen peroxide and others added hydrogen peroxide. It becomes non-volatile on the addition Compounds, such as catalytically active metal compounds, and consistently dispensed with halogen compounds. Disinfection is carried out in a closed circuit, so that none of highly effective disinfecting components escape into the environment can. For the disinfection of medical devices, such as B. ventilators are adapted for this Pre-set process parameters, compliance with these at different sizes measured and deviations made clear by error message.

It is a large number of methods of disinfection of Gases, liquids and material surfaces Application of disinfecting gases, through the coupling of Energy from, for example, UV rays or plasma discharges and Combinations of material and energetic action known. Some of these come in the area without physical stimulation of the substance to be disinfected and use disinfectants, the chemical decomposition of these after application no disturbing Leave residues. Decay products are essentially oxygen and water.

DE 102 01 037 A1 describes a method in which ozone or an ozone-water mixture is used under increased pressure for disinfection, but also for the oxidation of waste water from fish farms. This concentrated solution of ozone is favorable in terms of expected rates of action and the formation of highly effective ozone solution derivatives, which are lower in concentrations of H ₂ O ₂ , the radicals • OOH and in traces • OH. In the presence of organic compounds, the concentration of peroxy radicals and hydroxyl radicals • OH can be effectively higher. Ozonization processes are also established in drinking water disinfection.

The Disinfection with aqueous solutions is for to exclude the intended applications of this application in the rule.

DE 103 16 759 A1 describes for electrochemically generated hydroxyl radicals • OH method and device for the purification and disinfection of gas streams. Hydroxyl radicals are the biologically and chemically most effective reagents but also extremely short-lived (atmospheric about 1 ns). Their use is therefore proposed because processes for the removal of germs from gas streams based on electrochemical ozone generation are unsuitable. In the mentioned method, an aqueous phase acts on the substance to be disinfected, for example the air flow. Conversely, for the intended method of the present invention, the disinfecting gas in conjunction with another phase acts on the surfaces to be disinfected. It is safe to acknowledge that other reagents from the group of reactive oxygen species (ROS) may also be decisive for the disinfection. Thus, in the antimicrobial photodynamic therapy of paradontitis photochemically formed excited oxygen ¹ O ₂ , the so-called singlet oxygen, the bacterial membrane and then the DNA damage (M. VOCK).

In the patent DE 10 2005 004 237 there is presented a "sanitizing system and method for disinfecting parts to be disinfected" in which substantially an ozone generator and a closed circuit moisture generator are connected to a container having the contents to be disinfected via a flow generator. In this method, the simultaneous action of both gases with germicidal components as well as moisture is emphasized. Moisture is necessary to activate fungal spores. Water vapor and condensed water phases allow the formation of more active secondary products.

The object of the invention is to disinfect or possibly sterilize the interiors of equipment, wherein the interiors of the devices are flowed through by fluid media, which are by their synergistic effect in a position to inactivate germs (in the sense of the above definition). The effect is achieved via a gaseous medium containing germicidal agents and aqueous aerosols. For this purpose, the gaseous medium contains, in addition to the normal air constituents, especially ozone and gaseous hydrogen peroxide. The aqueous aerosol phases contain dissolved ozone, secondarily from this formed hydrogen peroxide and further added hydrogen peroxide. It is consistently dispensed with the addition of non-volatile compounds, such as catalytically active metal compounds, and halogen compounds. The disinfection or sterilization is in a closed circuit so that none of the highly effective disinfecting components can escape into the environment. Since the device interior to be disinfected generally have a complicated geometry and z. B. can also run labyrinthine, UV irradiation of the inner walls is excluded. For the disinfection of medical devices, such as respirators, for these adjusted process parameters are preset, the compliance of these measured at different sizes and deviations made clear by error message.

According to the invention the problem is solved by the features of the main claim. Embodiments of the invention are in the subclaims shown.

The advantage of the invention is that by the synergistic effect of the inactivation of germs by the combination of disinfecting / sterilizing components in the fluid medium a decisive improvement in the effect can be achieved. Using the im DE 10 2005 004 237 In order to demonstrate the method effectiveness of the invention described here, hydrogen peroxide solution was added to the moisturizer in defined form. It has been shown that the number of germs is significantly more than after the process DE 10 2005 004 237 could be inactivated.

The invention will be explained in more detail with reference to an embodiment. To carry out the method is used in 1 illustrated disinfection system. This contains a disinfection device 1 , an ozone generator assembly 2 with an ozone generator 3 , a moisturizer 4 with a water level sensor 5 , a direct or indirect heat generator, a measuring chamber 6 with sensors for recording the process parameters such as ozone content, humidity and flow and a control unit 7 with memories for adjustable reference values for the process parameters such as ozone content, moisture content and time. In this case, the ozone generator 3 at the same time be the heat generator. Is the ozone generator 3 As in the exemplary embodiment, an amalgam-doped low-pressure mercury vapor radiator is a conventional electronic ballast for operating it 8th arranged. Is the moisturizer 4 As in the exemplary embodiment, a piezoelectrically operating moisture generator, it requires an AC transformer for functionality 9 , The disinfection system also includes a flow generator 10 and a container 11 with content to be disinfected. The flow generator 10 , the measuring chamber 6 , the moisturizer 4 , the ozone generator assembly 2 and the container 11 are each sealed gas-tight and contain input and output connections for incorporation into the closed circuit of the disinfection system. To connect the system components is also a gas-tight tube system, consisting of a first gas-tight tube 12 , a second gastight tube 13 , a third gas-tight tube 14 , a fourth gastight tube 15 and a fifth gas tight tube 16 , intended. The flow generator 10 For example, a pump or a fan, promotes the air through the first tube 12 through the measuring chamber 6 , over the second hose 13 through the moisturizer 4 and over the third hose 14 into the ozone generator assembly 2 where it is enriched with ozone. This ozone-air mixture is via the fourth hose 15 through the container 11 transported and then passes through the fifth hose 16 back in the flow generator 10 , The system thus represents a closed circuit. The container 11 may contain parts to be disinfected, but it may itself be a device to be disinfected. Contains the container 11 a flow generator or is the container 11 for example, an intact active ventilator, the ozone-air mixture from this immediately via a sixth gastight tube 17 the measuring chamber 6 fed so that on the external flow generator 10 can be waived. The external flow generator 10 but is needed, for example, a defective ventilator to be disinfected. The in the measuring chamber 6 values measured by ozone sensor, humidity sensor and flow sensor are in the control unit 7 compared with set default values, and only when the process parameters ozone, humidity and flow are reached, the system releases the disinfection and it begins the predetermined disinfection time for the container 11 , For the safety of the disinfection system 1 is an external ozone sensor 18 with mini fan 19 provided to check the outside air for any ozone present. If the MAK value in the ambient air is exceeded, which can only occur in the event of a fault, an alarm signal is emitted. A standard switching power supply 20 generates all necessary voltages for the disinfection device 1 , Usually, the disinfection device 1 an on / off switch 21 and a display 22 with a display board 23 arranged on which all readings, reference values and error messages appearing in the control unit 7 both stored and / or generated as well as logged. In order to be able to further process and / or print these values or protocols, the control unit instructs 7 an interface 24 for a PC 25 on.

It is crucial for the invention that in the moisture generator 4 a depot of hydrogen peroxide solution is present and from there the effective for the disinfection aerosols in the circulation into the container 11 can be brought there to be effective for the inactivation of the germs can. In different applications, the design and arrangement of the moisture generator 4 be made in a more useful way the application. Application-specific optimizations are to be determined via the design of the process parameters which are most useful for the respective application, and finally, as above, as reference values in the control unit 7 to deposit.

As shown in the embodiment, the interiors of the container 11 which z. B. may be a respirator, device usage of the disinfection system 1 be traversed by fluid media. The interior walls of the container in contact with the medium 11 become now according to the invention more effective than in the process DE 10 2005 004 237 inactivated by germs. The aqueous aerosol phases of the medium produced in this arrangement contain dissolved ozone, secondarily hydrogen peroxide formed therefrom, ROS and further added hydrogen peroxide and form three-phase contacts steam-aqueous solution-material and water-containing cover layers in the interior spaces. It is consistently dispensed with the addition of non-volatile compounds, such as catalytically active metal compounds, and halogen compounds. Apart from the hydrogen peroxide H ₂ O ₂ , all other ROS are more reactive than ozone. This is sufficient reason to trace the fundamental improvement of the ozone-based process. On the one hand, H ₂ O _{2 should} easily penetrate cell membranes and have cytotoxic effects, while other assumptions (S. SCHULTE) suggest the lack of disinfecting action against bacterial films. Because of the latter connection, combinations with synergistic substances, such as peracetic acid or metal catalysts (eg. DE 19736336 A1 ) and widely used. Hydrogen peroxide must also be considered to react with hydroperoxyl radicals, especially after the HABER-WEISS process, and after the FENTON process, heavy metal ions such as Fe ²⁺ can be activated to form hydroxyl radicals • OH , Among the more effective ROS are the hydroxyl radicals • OH, two forms of atomic oxygen, • O •, hydroperoxyl radicals, • OOH (or their anions, the superoxide radical ions • OO ^- ), and two forms of singlet oxygen, ¹ O ₂ . The half-lives are about in order by many orders of magnitude lower than for ozone (• OH about 1 ns). Some peroxyl radicals reach half-lives of a few seconds. Thus, the likelihood of such molecules being present at the site of disinfection is also higher. It was attempted, the relatively inert hydrogen peroxide H ₂ O ₂ , therefore activated by other inventors by the Sterrad process in H ₂ O ₂ gas plasma, to use in the proposed method only as a synergistic substance. Thus, by reacting ozone with the anions of the hydrogen peroxide present under conditions which are not too acidic in solution, the activity is increased by the formation of two radicals (hydroperoxyl radicals, superoxide radical ions). After O ₃ + HO ₂ ^- (anion of H ₂ O ₂ , hardly effective in acidic) → OH • + • OO ^- + O ₂ , the activity should be increased by the formation of two radicals. On the other hand it speaks that already by the interaction of ozone with water such products develop. Without the use of hydrogen peroxide, when there are no organic contaminants, three OH molecules produce two OH radicals during ozonation. The concentrations of the OH radicals, including radicals, such as the cited superoxide radical ions, are said to be significantly increased overall by synergistic substances. Their concentration should be significantly increased. Equally negative could be that H ₂ O _{2 is} at the beginning of a deactivating chain reaction in which first the hydroxyl radical is converted to the chemically less active hydroperoxyl radical. In addition to the already known favorable features of the simultaneous action of both ozone-containing moist gases as well as moisture, in particular as a film on the surface contaminated with germs, the synergistic effect for the formation of more active molecules and ions there is effective. It can form a series of ROS in the liquid film. These must first penetrate or at least damage the cell membrane in order subsequently to act cytotoxic in the cell interior. Thus formed OH • causes lipid peroxidation in the membranes, depolymerizes membrane molecules, deactivates enzymes and damages the DNA. Certainly other species have participated. If one excludes the volatile atomic oxygen, it is the hydroperoxyl radicals • OOH (not their anions, the superoxide radical ions • OO ^- because of the lack of membrane permeability as ions). Because of the ambivalent effect of the hydrogen peroxide, its concentration in the gas stream and in the liquid film should be limited. In fact, it was found in the process development that low concentrations in the atomizer or shorter exposure phases of the aerosols are detected on the ozone-containing gas stream. It could be demonstrated in the experiment that hydrogen peroxide is still detectable even after exposure. The hydrophobic singlet oxygen molecules should also show a good membrane permeability, also attack the membrane (lipid peroxides) and are cytotoxic.

1

disinfector

2

Ozone generator assembly

3

ozone generator

4

moisture generator

5

Water level sensor

6

measuring chamber

7

control unit

8th

electronic ballast

9

AC transformer

10

external Flow generator

11

container

12

first tube

13

second tube

14

third tube

15

fourth tube

16

fifth tube

17

sixth tube

18

external ozone sensor

19

Mini fan

20

Switching Power Supply

21

On / off switch

22

display

23

display board

24

interface

25

PC

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10201037 A [0003]
• DE 10316759 A1 [0005]
• - DE 102005004237 [0006, 0009, 0009, 0012]
• DE 19736336 A1 [0012]

Claims (4)

Method for disinfecting inner surfaces with ozone - containing gas, characterized in that the gas stream is saturated with the vapor of an aqueous solution and at least as much aerosol carries this solution, that at the germinated inner surfaces a three - phase contact steam - aqueous solution - material and / or form a hydrous overcoat that carries ozone and other ozone active secondary products in the gas stream to produce cell membrane permeable and / or damaging as well as cytotoxic products such as hydroxyl radicals, atomic oxygen, hydroperoxyl radicals and / or singlet oxygen, and that all compounds are in contact with the inner surface are fleeting. Method according to claim 1, characterized in that a solution component is hydrogen peroxide. Method according to claims 1 to 2, characterized that process parameters are optimized application-specific as reference parameters stored in the system exist and available promptly stand. Method according to Claims 1 to 3, characterized that an assembly as a reservoir with the required components, which are used to form the disinfectant effective components in the system optional can be arranged and thus optimal application-specific Effect can be achieved.