EP0412977A1

EP0412977A1 - Process and device for disinfecting objects

Info

Publication number: EP0412977A1
Application number: EP19890904792
Authority: EP
Inventors: Dieter Kleinschmidt
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-04-23
Filing date: 1989-04-20
Publication date: 1991-02-20
Also published as: DE8813423U1; EP0493372A2; EP0493372A3; AU3430789A; WO1989010145A1

Abstract

Un procédé permet de désinfecter des objets dans une chambre hermétiquement fermable ou la chambre elle-même au moyen d'au moins un émetteur de rayonnements UV (62) et d'un catalyseur connectable et déconnectable (60, 74, 76) qui sert à décomposer l'ozone généré par l'émetteur de rayonnements UV (62, 64). Afin d'améliorer l'effet de stérilisation, on fait descendre puis monter une ou plusieurs fois la pression dans la chambre pendant le traitement des objets ou de la chambre avec de l'ozone. On accélère et intensifie ainsi l'échange de gaz dans les pores et dans les cavités internes des objets à désinfecter. On peut utiliser pour générer les rayonnements UV et l'ozone une unité mobile qui comprend deux montants (64) entre lesquels s'étendent plusieurs tubes de rayonnements UV (62), un agencement catalyseur tubulaire (60, 74, 76) et des barres de protection (66, 84). Le ventilateur (60) de l'agencement catalyseur est de préférence agencé dans le tuyau (74).A method makes it possible to disinfect objects in a hermetically closable chamber or the chamber itself by means of at least one UV radiation emitter (62) and a connectable and disconnectable catalyst (60, 74, 76) which serves to decompose the ozone generated by the UV radiation emitter (62, 64). In order to improve the sterilization effect, the pressure is lowered and then raised one or more times in the chamber during the treatment of the objects or of the chamber with ozone. This accelerates and intensifies the exchange of gases in the pores and in the internal cavities of the objects to be disinfected. A mobile unit can be used to generate UV radiation and ozone which comprises two uprights (64) between which several UV radiation tubes (62) extend, a tubular catalyst arrangement (60, 74, 76) and bars protection (66, 84). The fan (60) of the catalyst arrangement is preferably arranged in the pipe (74).

Description

Method and device for disinfecting objects

The invention relates to a method and a device for disinfecting objects in a tightly closable room or the tightly closable room itself with at least one UV lamp and a catalyst device which can be switched on and off for the reduction of ozone formed by the UV lamp.

Such methods and devices can also be used to disinfect objects of complex shape, in particular with cavities, into which germs can penetrate from the outside, but which are inaccessible to external rays, without the use of heat and without harmful effects on health. The device is simple and very effective at the same time because, with a single device, namely the ozone-forming UV emitter, it optimally exploits two different bactericidal effects, namely that of UV radiation and that of ozone, since the treatment is tight in one lockable room from which the ozone cannot escape. It concentrates during the treatment and also penetrates into corners, angles and cavities where bacteria, fungi or other germs would be unreachable for the UV radiation. At the same time, a more effective germ reduction is achieved on the outer, irradiated surfaces than with UV radiation alone, because the bactericidal action of ozone is added. This also acts in the sealed space for a long time after the UV lamp has been switched off, so that the device can be operated economically. Finally, the catalytic device removes the harmful ozone quickly and completely in a very simple manner, before the tightly closed room is opened again, so that the ozone does not appear outside the treatment room at all. Experience with the device mentioned in practice has meanwhile shown that even further; Improvements of the process sequence and the mechanical construction are possible, and the object of the invention directed thereon is solved procedurally in that during disinfection of the objects or the room with ozone the pressure in the room is lowered one or more times and raised again becomes.

The proposal according to the invention achieves an improvement in the disinfection effect, particularly in the case of porous, cracked, and generally substances or objects with cavities. Very good results have been obtained e.g. B. achieved in the disinfection of feed for laboratory animals.

The positive effect of the above proposal is based on the fact that the alternating compression and dilution of the sterilizing gas creates a pumping effect which enables the penetration of the ozone into the smallest gaps, pores and capillaries. The penetration depth and thus the sterilizing effect of the ozone depends on the pressure difference and the number of cycles. At Versucr.εr. was good experience with about four to ten cycles. ge made. The pressure difference should be about 500 mbar.

The device according to the invention for carrying out the new method is characterized in that a suction channel with a vacuum pump and a catalyst for the depletion of ozone is present between the tightly closable space and the outside atmosphere.

In addition, the impingement surfaces can unregelmäßiqer Ober¬ with ozone in addition by at least one geo _^ äse for circulating the ozone without the intervention of the catalyst is promoted. A movable catalyst device in the form of a tube with catalyst and blower can be used for the method according to the invention, in which the tube is essentially as long as one or more UV radiation tubes and together with these between two stands with inlet and outlet Outlet openings for gas pumped through the pipe by means of the blower is attached. In a preferred embodiment of the invention, the fan is arranged in the tube in this case. This has the advantage of a shorter overall length. The mobile unit fits into smaller incubators and offers better illumination with UV radiation, since the stands can be very narrow on both sides.

Finally, a further improvement provides that protective rods are attached to the stands in addition to the UV lamp tubes. This results in a stable construction, even if the stands are made of plastic.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. Show it:

Fig. 1 shows a longitudinal section through a mobile

Disinfectant device for insertion in a tightly lockable. Cabinet is intended;

FIG. 2 shows a cross section through the device according to FIG. 1;

3 shows a longitudinal section through a material lock with a permanently installed device for disinfecting; FIG. 4 shows a simplified cross section through the material lock according to FIG. 3;

5 shows a front view of the material lock according to FIGS. 3 and 4;

Fig. 6 u. 7 views corresponding to Figures 1 and 2 of a modified embodiment.

8 shows a recording of pressure fluctuations over time to illustrate the process sequence during sterilization with UV rays and ozone by means of a device according to FIGS. 1 to 7.

The mobile device for disinfection shown in FIGS. 1 and 2 consists in the example of a left cuboid stand 10 and a right, also cuboid stand 12. With the stands 10, 12 aligned in parallel, three tubular ones extend between them ÜV-Strannlerrohrπ 14. A pipe 16 screwed to the IG ur.ά 12 stands via end flanges ensures, on the one hand, a firm mechanical connection of the parts mentioned and, on the other hand, forms a flow channel which closes from the air inlet openings (not shown) in the stand 12 also not shown air outlet openings in the stand 10 leads. If a blower 18 mounted in the stator 10 and driven by an electric motor is switched on, it sucks air from the surrounding space through the air inlet opening in the stator 12 attracts them through the pipe 16 over a catalyst 20 present there, for example in the form of granules, and ejects them back into the surrounding space through the air outlet openings in the stand 10. Ozone contained in the air is converted into atmospheric oxygen 0 ₂ by the catalyst 20.

The timing of the UV lamps 14, the blower 18, any desired indicator and warning lights and locking devices on cabinet doors is carried out by a sequence control indicated at 22, which allows the parameters of the disinfectant treatment to be preset.

The mobile device according to Figures 1 and 2 can temporarily e.g. in a CO 2 incubator, a lockable la inflow bank or another tightly lockable cabinet in which objects and / or the inner walls are to be disinfected. After the treatment, the device according to FIGS. 1 and 2 can be removed from the cabinet and inserted in another cabinet.

3 to 5, on the other hand, show a cupboard - in this case, a material lock - with a permanently installed device for disinfecting. The material lock is installed, for example, in the wall between two building rooms and is accessible from both building rooms through two opposite doors 24 and 26. As can be seen from FIGS. 3 and 4, UV lamp tubes 14 are attached to the doors as well as to the side walls, the floor and the ceiling. The interior designated 28 is lined on all sides with reflective metal sheet in order to reflect as high a portion of the UV radiation as possible onto the objects to be disinfected. These rest during the treatment, for example, on wire mesh floors (not shown), which are, for example, on strips on the side walls of the interior 28, can be easily removed and can be used again at another level. In this case, the catalyst device according to FIG. 4 is located next to the interior 28. It consists of a flow channel 30 which is connected to the top of the interior 28 via air inlet openings in a side wall of the interior 28 and opens into it again at the bottom through air outlet openings. A motor-blower unit is shown at 32 which, when switched on, circulates the gas volume in the interior 28 through the flow channel 30. Of course, the direction of flow can also be reversed. It is only essential that after a certain circulation time the entire gas volume of the interior 28 is circulated through the flow channel 30 one or more times and thereby came into contact with a catalyst indicated at 34, through which ozone in atmospheric oxygen 0 _? is converted.

In order to ensure pressure equalization between the interior 28 and the outside atmosphere, a line 36 leading to the outside is provided, in which a catalytic converter 38 and also an activated carbon filter 40 and a sterile filter 42 are also arranged.

5, on one front side there is a main switch 44 with indicator light and also an operating hours counter 46. Safety switches 48 and an electrical door lock 50 are located on both door sides. Finally, there are a start button 52 and numerous Control and indicator lights 54 are present, which indicate whether the UV lamps 14 or the catalyst device 32, 34 are working.

The above-mentioned UV lamps 14 are preferably low-pressure mercury vapor discharge lamps which, in terms of size and power, correspond to the hot cathode lamps available under the Sterisol brand, but are not produced with the special glass used in them, which the Ozone formation prevented. On the contrary, the UV lamps 14 of the device according to the invention, regardless of their design in detail, are to be designed specifically so that ozone is formed outside the lamps.

The catalysts 20 and 34 described above can contain any material by which ozone is effectively converted to oxygen 0 ₂ . In a practical embodiment, the catalyst on an aluminum support contains approximately 0.1% palladium and 0.2% platinum.

To the effectiveness of the new device for disinfecting. To investigate, the treatment of a microbial suspension shown schematically below and a blind sample were carried out in parallel.

5 ml of sterile saline

St. aureus, P is. aeruginosa Cand. al bi cans. E-col i

2 ml germ suspension 2 ml germ suspension

cabinet 50 ° C

with 1 NaCl

suspension on r r - agar

24 hours

The evaluation showed that after the treatment with UV rays and ozone no colony-forming units (no growth) were found at all, while after the blind test the result was growth positive (plate tight).

6 and 7 show a mobile device for disinfection similar to FIGS. 1 and 2, which is even easier to manufacture. Another advantage is that a blower 60 is arranged between UV lamp tubes 62. The length of the device can thus be reduced substantially to the length of the UV radiation tubes 62, which are now the only dimension-determining elements. This is particularly advantageous if, for. B. the incubators are relatively small and should be illuminated over a large area.

The device according to FIGS. 6 and 7 consists of left and right stands 64 which are held together by spacer bars 66. On the left side, the stand 64 is shown in section. It consists of only three molded plastic parts, namely a housing

65, a lid 70 and three corners 72. The spacing

66, six in the example, are firmly screwed to the housing 68. The tube 74 with the enclosed catalyst 76 is guided and held in an annular slot 78 of the housing 68. Furthermore, sockets 80 are fastened to openings 82 on the housing 68. They hold the UV lamp tubes 62 in position. Thus, the housing 68 with the spacer bars 66 assumes a carrier function for the entire device. The cover 70 and the corners 72 only take on covering functions, the right and left covers 70 being connected to three bars 84 and being screwed by means of screws 86. As a result, the corners 72 are held at the same time. To replace defective UV lamps, all that is required is to loosen the screws 86. This allows the covers 70 and corners 72 to be removed and enables easy access to the holder 80.

The rods 66 and 84 are not only intended as fastening rods, but at the same time have a protective function due to the star-like arrangement around the UV lamps.

When the fan 60 is switched on, it sucks air from the surrounding space through air inlet openings 88 and then presses it through slots 90, the pipe 74 and via the catalytic converter 76. This air exits into the surrounding space on the other side . The air inlet openings 88 arranged on the side and on the front side make it possible for the device to be independent of the position and thus also to be placed on edge. Another advantage is that the plastic parts 68, 70, 72 forming the uprights 64 are independent of the emitters 62 used in each case, because with other lengths of the UV emitters 62 only a tube 74 and rods 66, 84 needed.

Regardless of whether a mobile, UV radiation and at the same time ozone generating unit according to FIGS. 1 and 2 or FIGS. 6 and 7 in a tightly closable room or a room according to FIGS. 3 to 5 with a permanently installed flow channel and built-in According to the invention, a single or multiple pressure change is provided in the treatment room, as is shown schematically in FIG. 8. The procedure is preferably such that the pressure in the treatment room 28 is reduced by approximately 500 mbar even when the UV lamps are switched on. As a result, air is sucked out of the pores and inner cavities of the objects to be disinfected. If a pressure equalization then takes place, that is to say the pressure in space 28 again by approximately 500 mbar increases, ozone is pressed into the pores and internal cavities of the objects to be disinfected. According to FIG. 8, the process described can be repeated one or more times during the time t1 while the UV lamp is switched on, a fan 91 arranged in a suitable place in the space 28 preferably causing the ozone to circulate , and in the exemplary embodiment several pressure changes of the order mentioned take place even after the UV emitters have been switched off. These pressure changes can be carried out both before and during the time t2 after switching on the fan 18 or 32 or 60, which causes the catalytic decomposition of the ozone.

To generate the pressure changes according to FIG. 8, it is sufficient, analogous to the illustration in FIG. 4, in the housing of the tightly closable space 28, on the one hand, between this and the outside atmosphere, a suction duct corresponding to the flow duct 30, but with an outlet 92, one Vacuum pump instead of the blower 32 and a catalyst corresponding to the catalyst 34 to remove ozone, on the other hand a ventilation duct according to the line 36 for pressure equalization with the outside atmosphere, in the latter also a sterile filter 42 and preferably, for. B. at 40, a controllable valve and at the same time shut-off valve should be present in order to control the pressure increase. This valve and a shut-off valve 94 at the outlet 92 of the suction channel can be opened or closed alternately or both can also be kept closed for a certain period of time if the pressure in the space 28 is at a certain level during this period should be kept. It is understood that the pressure changes according to FIG. 8 can be generated by manual actuation of the valves mentioned or by means of an automatic control and that the suction channel and the ventilation channel not only on a cabinet in which an ozone generator according to FIG. 1 or 6 is used, but also in a cabinet according to FIGS. 3 to 5 can be present, either in addition to the flow channel 30 and Line 36 or in combination of the suction channel with the flow channel 30 and the ventilation channel with the line 36.

Claims

O89 / 10145 claims PCT / EP89 / 00427

1. A method for disinfecting objects in a sealable room or the sealable room itself, with at least one UV lamp and a catalyst device that can be switched on and off for the degradation of ozone formed by the UV lamp, characterized in that during the Disinfect the objects or the room with which ozone the pressure in the room is lowered one or more times and raised again.

2. The method of claim 1, d a d u r c h g e ¬ k e n n z e i c h n e t that the pressure difference is about 500 mbar.

3. The method according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that the ozone is circulated in the room during disinfection without switching on the catalyst.

4. Device for carrying out the method for disinfecting objects in a tightly closable room or the tightly closable room itself with at least one UV lamp and a catalytic device which can be switched on and off for the degradation of those formed by the UV lamp Ozone according to one of claims 1 to 3, characterized in that between the space (28) and the outside atmosphere there is a suction channel 92 with a vacuum pump and a catalyst for the depletion of ozone.

5. The device according to claim 4, gekennzeich¬ net by at least one installed in the room blower 91 for circulating the ozone without switching on the catalyst (20, 34, 76).

6. Device for disinfecting objects in a tightly closable room or in the tightly closable room itself, with at least one UV lamp and a catalyst device that can be switched on and off for the reduction of ozone formed by the UV lamp in the form of a tube with catalyst and blower, the tube being essentially as long as one or more UV lamp tubes and, together with these, fastened between two stands with inlet and outlet openings for gas pumped through the tube by means of the blower, characterized in that the Fan (60) is arranged in the tube (74).

7. The device according to claim 6, d a d u r c h g e k e n n z e i c h n e t that protection rods (66, 84) are attached to the stands (64) in addition to the UV lamp tubes (62).