Apparatus for controlling the concentration of a sterilant chemical in a fluid
View Patent ↗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;
a controller including a data storage device for storing a plurality of data values indicative of an electrical property of a first sensor when exposed to a plurality of known concentrations of the sterilant chemical, wherein said controller is programmed to:
control said first and second regulating means to produce a blended liquid sterilant comprised of the first and second liquid sterilant;
determine the concentration of the sterilant chemical in the blended liquid sterilant by use of:
(a) a signal generated by the first sensor when exposed to the blended liquid sterilant, and
(b) the plurality of data values stored in the data storage device; and
control the first and second regulating means to produce a blended liquid sterilant having the sterilant chemical at a desired concentration;
a vaporizer for vaporizing said blended liquid sterilant having the sterilant chemical at the desired concentration to produce a vaporized sterilant; and
a chamber for receiving said vaporized sterilant.
2. A system according to claim 1 , 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.
3. 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.
4. A system according to claim 3 , wherein said controller is further programmed to control said first and second regulating means in accordance with the concentration of said sterilant chemical in the vaporized sterilant, as sensed by said second sensor.
5. A system according to claim 3 , 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.
6. A system according to claim 1 , wherein said first concentration is greater than the second concentration.
7. A system according to claim 1 , wherein said sterilant chemical is hydrogen peroxide.
8. A system according to claim 1 , wherein said second liquid sterilant is comprised of 90% to 100% water, by weight.
9. 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.
10. 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.
11. A system according to claim 1 , wherein said controller is further programmed to determine the concentration of the sterilant chemical in the blended liquid sterilant by searching the plurality of data values stored in the data storage device according to the signal generated by the first sensor when exposed to the blended liquid sterilant.