Method and apparatus for controlling the concentration of a sterilant chemical in a fluid

Abstract

A sterilization system that includes a sensor for determining the concentration of a liquid sterilant in a sterilant fluid. The sterilant fluid is comprised of a blend of sterilant fluids from a plurality of sterilant supplies. The concentration of the liquid sterilant differs in each of the sterilant supplies. The sensor allows a controllable concentration of liquid sterilant to be supplied to a vaporizer.

1 . A decontamination system comprising: 
 a first source of a first liquid sterilant including a sterilant chemical at a first concentration;    a second source of a second liquid sterilant including said sterilant chemical at a second concentration;    first regulating means for regulating a flow rate of the first liquid sterilant;    second regulating means for regulating a flow rate of the second liquid sterilant;    control means for controlling said first and second regulating means to produce a blended liquid sterilant comprised of the first and second liquid sterilant;    a vaporizer receiving said blended liquid sterilant to produce a vaporized sterilant; and    a chamber receiving said vaporized sterilant.    
     
     
         2 . A system according to  claim 1 , wherein said system includes a first sensor for sensing concentration of said sterilant chemical in the blended liquid sterilant.  
     
     
         3 . A system according to  claim 2 , wherein said control means controls said first and second regulating means in accordance with the concentration of said sterilant chemical in the blended liquid sterilant, sensed by said first sensor.  
     
     
         4 . A system according to  claim 2 , wherein said first sensor is a capacitive sensor, wherein an electrical property of a capacitor is indicative of the concentration of said sterilant chemical in the blended liquid sterilant.  
     
     
         5 . A system according to  claim 1 , wherein said system further comprises a second sensor for sensing concentration of the said sterilant chemical in the vaporized sterilant.  
     
     
         6 . A system according to  claim 5 , wherein said control means controls said first and second regulating means in accordance with the concentration of said sterilant chemical in the vaporized sterilant, sensed by said second sensor.  
     
     
         7 . A system according to  claim 5 , wherein said second sensor includes an element having a layer of a material that is reactive with said sterilant chemical in the vaporized sterilant, such that mechanical movement of the element is converted into an electrical signal indicative of the concentration of said sterilant chemical in the vaporized sterilant.  
     
     
         8 . A system according to  claim 1 , wherein said first concentration is greater than the second concentration;  
     
     
         9 . A system according to  claim 1 , wherein said sterilant chemical is hydrogen peroxide.  
     
     
         10 . A system according to  claim 1 , wherein said second liquid sterilant is comprised of 90% to 100% water, by weight.  
     
     
         11 . A system according to  claim 1 , wherein the concentration of said sterilant chemical in said blended liquid sterilant is in a range defined by said first concentration and said second concentration.  
     
     
         12 . A system according to  claim 1 , wherein said first concentration of said sterilant chemical is in a range of 25% to 75% by weight of said first liquid sterilant.  
     
     
         13 . A method for controlling a decontamination system having (a) a first source of a first liquid sterilant including a sterilant chemical at a first concentration, and (b) a second source of a second liquid sterilant including said sterilant chemical at a second concentration, the method comprising: 
 regulating a flow rate of the first liquid sterilant and of the second liquid to produce a blended liquid sterilant comprised of the first and second liquid sterilant;    vaporizing the blended liquid sterilant to produce a vaporized sterilant; and    introducing the vaporized sterilant into a treatment chamber.    
     
     
         14 . A method according to  claim 13 , wherein said method further comprises the step of: 
 sensing concentration of said sterilant chemical in the blended liquid sterilant.    
     
     
         15 . A method according to  claim 14 , wherein the flow rate of the first and second liquid sterilant is regulated in accordance with the sensed concentration of said sterilant chemical in the blended liquid sterilant.  
     
     
         16 . A method according to  claim 13 , wherein said an electrical property of a capacitor is indicative of the concentration of said sterilant chemical in the blended liquid sterilant.  
     
     
         17 . A method according to  claim 13 , wherein said method further comprises the step of: 
 sensing concentration of the said sterilant chemical in the vaporized sterilant.    
     
     
         18 . A method according to  claim 17 , wherein the flow rate of the first and second liquid sterilant is regulated in accordance with the concentration of said sterilant chemical in the vaporized sterilant.  
     
     
         19 . A method according to  claim 13 , wherein mechanical movement of an element is converted into an electrical signal indicative of the concentration of said sterilant chemical in the vaporized sterilant, said element having a layer of material that is reactive with said sterilant chemical in the vaporized sterilant.  
     
     
         20 . A method according to  claim 13 , wherein said first concentration is greater than the second concentration;  
     
     
         21 . A method according to  claim 13 , wherein said sterilant chemical is hydrogen peroxide.  
     
     
         22 . A method according to  claim 13 , wherein the concentration of said sterilant chemical in said blended liquid sterilant is in a range defined by said first concentration and said second concentration.  
     
     
         23 . A method according to  claim 13 , wherein said first concentration of said sterilant chemical is in a range of 25% to 75% by weight of said first liquid sterilant.  
     
     
         24 . A method according to  claim 13 , wherein said second liquid sterilant is comprised of 90% to 100% water, by weight.