Apparatus and methods for variably sterilizing aqueous liquids

Abstract

A flow through aqueous liquid sterilization apparatus which employs substantially fixed temperatures and pressures and variable flow rates through the apparatus for controllably processing aqueous liquids to achieve predetermined values of SALs.

1 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value, said apparatus comprising: 
 a source of the liquid at an influent site;    a heating bath comprising a non-linear heat-sink about an elongated closed pathway through which liquid flows from the source and which is heated thereby;    a variable flow controller which is variably set to provide a predetermined unidirectional flow rate which is directly related to achieving a predetermined SAL of said source liquid as it is displaced through said pathway;    a heating source which provides a predetermined substantially constant temperature of said heating bath;    a temperature sensor disposed to measure temperature of liquid in said pathway;    a pressure regulating valve disposed to open at a desired first predetermined pressure and close at a second predetermined pressure which is lower than the first predetermined pressure thereby providing a substantially constant back-pressure in liquid flowing through said pathway;    a second valve controlled to open at a first predetermined desired temperature sensed by the temperature sensor and close at a second predetermined temperature which is lower than the first predetermined desired temperature, said second valve being disposed in series with said pressure regulating valve, thereby making control by the second valve and pressure regulating valve an “AND” combination; and    an effluent port assembly by which liquid sterilized to the desired SAL value is dispensed from the pathway.    
     
     
         2 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value according to  claim 1  wherein said flow controller comprises a pump.  
     
     
         3 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value according to  claim 1  wherein said elongated pathway comprises structure by which liquid raised to a temperature and pressure for sterilization is maintained in a liquid state.  
     
     
         4 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value according to  claim 1  wherein said apparatus comprises a second pressure sensor and an AND gate which has inputs from said second pressure sensor and temperature sensor and an output connected to control operation of said second valve.  
     
     
         5 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value according to  claim 1  wherein said heating bath comprises a second temperature sensor used to control temperature of said heating bath to a desired substantially fixed temperature.  
     
     
         6 . Apparatus for sterilizing aqueous liquid to a predeterminable SAL value according to  claim 1  wherein said apparatus further comprises a container into which effluent is dispensed and from which samples are taken for testing to assure achievement of a desired SAL.  
     
     
         7 . A method by which an aqueous liquid influent contaminated by microbes is sterilized to a predetermined SAL, said method comprising the steps of: 
 establishing a substantially fixed predetermined anti-microbial temperature, establishing a pressure correlated to the fixed temperature in a closed flow-through system which is otherwise free of all other sources of contamination;    displacing, at a preset flow-rate, the microbe-containing influent liquid into the closed flow-through system, said flow rate being correlated to the substantially fixed values of temperature and pressure;    imposing the established temperature, pressure and preset flow rate conditions upon the aqueous liquid as it is displaced through the system without use of radiation causing microbes to be killed thereby producing a predetermined SAL while preventing vaporization of the aqueous liquid;    preventing subsequent introduction of microbes into the aqueous liquid treated to be sterilized to the predetermined SAL; and    discharging the aqueous liquid as a non-radiated effluent from the system.    
     
     
         8 . A method by which an influent aqueous liquid containing microbes is sterilized to a predetermined SAL in a closed system and discharged from the closed system as a so treated effluent comprising the acts of: 
 providing a closed flow-through system free of microwave radiation wherein the only source of contamination is the microbe-containing influent aqueous liquid;    controlling the system to achieve start-up of the system by preventing flow in the system while collectively elevating temperature and pressure conditions within the system to predetermined substantially fixed levels effective for sterilizing the influent aqueous liquid to the predetermined SAL;    after non-flow temperature and pressure levels have been reached within the system, controlling the system to achieve into and through the system a unidirectional flow rate of each unit volume of the aqueous liquid while retaining the substantially fixed temperature and pressure conditions within the system such that each unit volume of aqueous liquid is resident within retained temperature and pressure conditions for a sufficient period to be sterilized to the SAL.