Chemical apparatus and process disinfecting – deodorizing – preser – Process disinfecting – preserving – deodorizing – or sterilizing – Using direct contact steam to disinfect or sterilize
Reexamination Certificate
1998-12-15
2001-10-09
Warden, Sr., Robert J. (Department: 1744)
Chemical apparatus and process disinfecting, deodorizing, preser
Process disinfecting, preserving, deodorizing, or sterilizing
Using direct contact steam to disinfect or sterilize
C422S021000, C422S026000, C422S298000, C422S299000, C422S300000, C422S307000
Reexamination Certificate
active
06299837
ABSTRACT:
This application claims priority under 35 U.S.C. §119 to German patent application number 197 55 688.4, filed Dec. 16, 1997, which for purposes of disclosure is incorporated herein by specific reference.
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates to apparatus and procedures for producing a disinfecting hot atmosphere within the inside space of a gassing incubator. More specifically, the present invention relates to supplying a quantity of water within the inside space of a gassing incubator and heating the atmosphere and the surfaces of the inside space in a heat-up phase (I) after the inside space is sealed to the surrounding atmosphere.
2. Present State of the Art
German Patent No. 44 06 632 C1 (“the '632 patent”) discloses a solids bioreactor for culturing microorganisms on solid, particulate substrates. The '632 patent discloses regulating the temperature between −27 and+100° C., and the relative humidity from 40-99% using cold water vapor produced by ultrasound. The invention produces a directional forced flow of the gas atmosphere whose composition can be metered (the oxygen content is adjustable from 0 to 100% in the mixture with nitrogen, carbon dioxide, and possibly other gases) and whose volume flow can be adjusted. The '632 patent also discloses devices for superheated steam sterilization of the bioreactor and devices to carry off and sterilize the condensate and exhaust air.
One of the problems with the invention disclosed in the '632 patent is that proper superheated steam sterilization requires an additional unpressurized superheated steam supply or an additional connection to such a supply.
German Patent No. 29 24 446 C2 (“the '446 patent”) also discloses a procedure for cultivating cells and tissues of humans and animals or microorganisms by means of containers which are put in an incubator. The incubator is gassed in a controlled manner with carbon dioxide, air, or oxygen or nitrogen, and the atmosphere thereof is humidified and kept at a specified temperature. In this process, the gases are fed, individually or together, through a sterilization filter within the line in the incubator's double-walled jacket to a by-pass canal. The gasses are then mixed with water vapor from the line. The water vapor is sterilized by superheating in the evaporator outside the useful space and then cooled. A controller for the relative humidity keeps the humidity in the range from about 60 to 95 percent. This means that the relative humidity can be adjusted not only close to the saturation limit, but can also be adjusted in the broad range from 60 to 95 percent. The useful space and/or by-pass, including the probe, can be sterilized by baking up to 180° C. with a heater associated with the useful space.
One of the problems with the invention of the '466 patent is the relatively high disinfection temperature. Specifically, the high disinfection temperature can detrimentally affect temperature-sensitive components, such as, for example, sensors, seals, or recirculation devices.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
One of the objects of the present invention is to specify a procedure and/or a device for effective sterilization, especially in the empty inside space of a gassing incubator, which avoids the high temperatures commonly used in high-humidity disinfection.
To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a process is provided which includes feeding water to form water vapor within a chamber such as in a gassing incubator. Once the atmosphere of water vapor reaches a temperature of 90° C. and a relative humidity of more than 80%, the atmosphere of water vapor is maintained for a disinfection phase (II) of at least 9 hours. The high-humidity atmosphere according to the present invention produces greater heat sensitization of the unwanted cells within the chamber than that produced by a dry atmosphere. The present invention thus has the advantage that practically all of the cells can be thermally killed in the nine-hour disinfection phase.
In a one embodiment of the present invention, a quantity of at least 300 ml of water is put into an inside space of a chamber having a volume ranging from about 15 liters to about 400 liters, with about 150 liters being more preferred. Next, heat is fed through substantially all the surfaces bounding the inside space so as to reach a desired disinfection temperature.
It is advantageous for the disinfection process to take place automatically, achieving a decontamination which includes all fixtures and sensors within the inside space. It is also advantageous that the disinfection procedure be performed in an atmosphere whose pressure differs only negligibly from the surrounding atmosphere.
In one embodiment, the above objectives and process steps are achieved by a gassing incubator with a heatable inside space. The inside space is in part bounded by a floor area configured for holding fluid. At least one temperature stabilization element is disposed at the floor area and in at least one of the side walls and/or ceiling area bounding the inside space. The temperature stabilization elements in the floor area are separately controlled from the other stabilization elements.
One of the advantageous of the present invention is that relatively low temperatures are used which produce a substantially lower material load on the inside space than known procedures. Another advantage of the present invention is that the pressure within the inside space does not have to be substantially higher than that of the surrounding atmosphere. As a result, the possible sealing problems resulting from different inside and outside pressures is substantially eliminated.
In one embodiment, the temperature stabilization elements associated with the floor area consist of heating and/or cooling elements. The present invention thus provides the advantage that both a rapid heating phase and a relatively short condensation phase can be achieved.
In another embodiment of the present invention, the inside space has a front-side opening which can be sealed gas-tight by an inside door. The temperature of the inside door can be stabilized to prevent condensation thereon. The inside door can also be made to be at least partially transparent.
It is an advantage of the present invention that possible condensation on the inside door and on the walls of the inside space is prevented, to as great an extent possible, from reaching dry surfaces of the walls, ceiling, and inside door. That is, it is another objective of the present invention to provide a dry surface on some or all of the side walls, back wall, ceiling area, and inside door bounding the inside space after sterilization in order to prevent accidental contact and contamination by an operator of a wet surface of the inside space. This is accomplished by heating the various surfaces, except the floor, bounding the inside space after sterilization.
The inside space includes a useful space which is the actual space available for holding the material to be processed. The inside space also includes its periphery as well as, e.g., a fan and the area covered by water on the floor.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
REFERENCES:
patent: 4039775 (1977-08-01), Amdra
patent: 4336329 (1982-06-01), Hesse et al.
patent: 4447399 (1984-05-01), Runnells et al.
patent: 4685507 (1987-08-01), Schafer
patent: 4716676 (1988-01-01), Imagawa
patent: 5019344 (1991-05-01), Kutner et al.
patent: 5309981 (1994-05-01), Binder
patent: 44 06 632 C1 (1994-01-01), None
Heeg Hubert
Paul Elke
Pieczarek Waldemar
Kendro Laboratory Products GmbH
Soubra Imad
Warden, Sr. Robert J.
Workman & Nydegger & Seeley
LandOfFree
Procedure to produce a disinfecting hot atmosphere and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Procedure to produce a disinfecting hot atmosphere and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Procedure to produce a disinfecting hot atmosphere and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2598491