Apparatus and method for humidifying a sterilization chamber
AssigneeTso3 Inc.
InventorRéal Champagne
Life of this patent
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Abstract
A method for increasing a relative humidity in an enclosed space (10) comprising a plurality of graduated steps. The relative humidity is increased from a first relative humidity to a target relative humidity. The method is issued to humidify a chamber (10) wherein a sterilization process using a humidified ozone takes place. The method is carried out by an apparatus for effecting the humidified ozone sterilization comprising a processor programmed to effect humidification in a plurality of gradual steps.
Claims17
A process for humidifying an atmosphere in a sterilization chamber to a target relative humidity, the process comprising the steps of
- a) providing an amount of water in a water reservoir at a reservoir temperature Ts at or above a temperature of the chamber atmosphere Tc;
- b) reducing a pressure in the chamber to a value below the boiling point of water at the reservoir temperature Ts,
- c) bringing the reservoir into fluid communication with the chamber via a conduit for exposing the water in the reservoir at the temperature Ts to the reduced pressure in the chamber for a preselected exposure time so that water in the reservoir is boiled and to allow resulting water vapour to enter the chamber and disconnecting said fluid communication after said preselected exposure time;
- and repeating at least steps b) and c) a plurality of times, wherein at least one of the amount, of water and the exposure time are controlled such that the relative humidity in the chamber progressively increases with each repetition until the target humidity is reached and wherein after each step c) the conduit is closed for a time sufficient to heat the water in the reservoir and to adjust the reservoir temperature Ts so that the reservoir temperature Ts is equal to or above the temperature Tc of the chamber atmosphere, and a temperature differential ΔT during each step c) is controlled to maintain the temperature Tc of the chamber atmosphere substantially constant, wherein ΔT is defined by the formula ΔT =Ts−Tc.
A method of humidifying an enclosed space to a target relative humidity, the method comprising a plurality of humidification stages Sx . . . Sn, wherein x is an integer from 1 to n and each x represents an individual stage, each said stage having a corresponding water vapour pressure hx, . . . hn, and hn representing the water vapour pressure corresponding to the target relative humidity, each said stage Sx including the steps of:
- a) supplying water vapour from a water vapour source to the enclosed space to increase the water vapour pressure in the enclosed space to at least the value hx corresponding to said stage Sx;
- b) disconnecting the source from the enclosed space for a preselected equilisation period;
- and
- c) repeating steps a) and b) until said water vapour pressure hn is reached in the space, wherein the water vapour source is a water reservoir, the temperature of the water vapour source is Ts, the temperature of the enclosed space is Tc, which is represented by the equation Ts−Tc=ΔT wherein Ts is the same as, or higher than, Tc so that ΔTx≦0, and step b) comprises disconnecting the source from the enclosed space for a time sufficient to adjust Ts or Tc to achieve the value for ΔTx and controlling the temperature differential ΔT to maintain Tc substantially constant.
An apparatus for sterilization with humidified ozone, the apparatus comprising
- a sterilization chamber,
- a reservoir to hold water while in operation, to provide a source of water vapour to humidify the ozone,
- a conduit in fluid communication between the reservoir and the sterilization chamber,
- a valve in the conduit to open and close the conduit,
- a first heating means to control the temperature of the chamber,
- a second heating means to control the temperature of the reservoir,
- a first temperature sensing means to monitor the temperature of the sterilization chamber,
- a second temperature sensing means to monitor the temperature of the reservoir,
- a pressure sensing means to monitor the pressure in the chamber,
- vacuum means to reduce the pressure in the chamber,
- a processor to control the first and second heating means in response to information from the first and second temperature sensing means and the pressure sensing means,
- wherein the processor is programmed to effect a humidification of the sterilization chamber in a plurality of stages and to control a temperature difference between the first and second heating means to maintain the temperature of the chamber substantially constant.
Dependencies are inferred from the claim text.