Soda lime half life indicator
First Claim
1. In an apparatus for removing CO2 from a gas stream, said apparatus comprising a container having a gas inlet and a gas outlet and a CO2 absorbent selected from the group consisting of soda lime and other suitable non-toxic alkali and alkaline earth metal hydroxides disposed in said container which produces an exothermic reaction when said gas stream is passed therethrough, the improvement comprising:
- an indicator for monitoring the capacity of the absorbent to absorb CO2, said indicator comprising,temperature sensing means immersed in said absorbent for sensing the temperature of the temperature cycle of the heat generated by the chemical reaction of the hydroxide and CO2, said temperature cycle including a rise, a levelling off and fall in temperature;
temperature to voltage converter means for converting said sensed temperature to an electrical voltage signal;
temperature trend processing means for processing said electrical voltage signal into a selected electrical output signal characteristic of said rising, levelling off and falling temperature trend and indicative of the present effectiveness of the CO2 absorbent; and
display means for converting said selected electrical output signal to a predetermined visual display indicative a first indication of said rising, a second indication of said levellng off and a third indication of said falling temperature and wherein each said first, second and third indications being visually unique and materially different from one another and thereby indicating the capacity of the CO2 absorbent to absorb CO2.
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Accused Products
Abstract
The invention disclosed is an indicator for monitoring the capacity of a CO2 absorbent to absorb CO2. The indicator is typically used in association with a closed circuit breathing apparatus, including a container for a CO2 absorbent. The indicator comprises temperature sensing means immersed in the absorbent, a temperature to voltage converter for converting a sensed temperature reading to an electrical voltage signal, temperature trend processing means for processing said electrical voltage signal into a selected electrical output signal characteristic of a temperature trend; and display means for converting said selected electrical output signal to a predetermined visual display indicative of the capacity of the CO2 absorbent to absorb CO2.
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Citations
15 Claims
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1. In an apparatus for removing CO2 from a gas stream, said apparatus comprising a container having a gas inlet and a gas outlet and a CO2 absorbent selected from the group consisting of soda lime and other suitable non-toxic alkali and alkaline earth metal hydroxides disposed in said container which produces an exothermic reaction when said gas stream is passed therethrough, the improvement comprising:
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an indicator for monitoring the capacity of the absorbent to absorb CO2, said indicator comprising, temperature sensing means immersed in said absorbent for sensing the temperature of the temperature cycle of the heat generated by the chemical reaction of the hydroxide and CO2, said temperature cycle including a rise, a levelling off and fall in temperature; temperature to voltage converter means for converting said sensed temperature to an electrical voltage signal; temperature trend processing means for processing said electrical voltage signal into a selected electrical output signal characteristic of said rising, levelling off and falling temperature trend and indicative of the present effectiveness of the CO2 absorbent; and display means for converting said selected electrical output signal to a predetermined visual display indicative a first indication of said rising, a second indication of said levellng off and a third indication of said falling temperature and wherein each said first, second and third indications being visually unique and materially different from one another and thereby indicating the capacity of the CO2 absorbent to absorb CO2. - View Dependent Claims (2, 3, 4, 5, 6, 15)
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7. In a closed circuit underwater breathing apparatus, comprising
a breathing tube through which a diver may inhale and exhale breathing gas; -
a re-breathing bag; a canister containing a CO2 absorbent selected from the group consisting of soda lime and other suitable non-toxic alkali and alkaline earth metal hydroxides, disposed between said breathing tube and said re-breathing bag, such that fluid communication from said re-breathing bag to said breathing tube is achieved through said cannister wherein an exothermic reaction occurs when exhaled gas is passed therethrough; inlet means in said re-breathing bag; a breathing gas reservoir; gas conduit means for fluid communication between said inlet means and said breathing gas reservoir; one-way valve means in said gas conduit means to permit breathing as flow from said breathing gas reservoir to said re-breathing bag; blow-off valve means connected with said re-breathing bag to permit pressure equalization, the inprovement comprising providing an indicator comprising; temperature sensing means immersed in said absorbent for sensing the temperature of the temperature cycle of the heat generated by the chemical reaction of the hydroxide and CO2, said temperature cycle including a rise, a levelling off and a fall in temperature; temperature to voltage converter means for converting said sensed temperature to an electrical voltage signal; temperature trend processing means for processing said electrical voltage signal into a selected electrical output signal characteristic of said rising, levelling off and falling temperature trend and indicative of the present effectiveness of the CO2 absorbent; and display means for converting said selected electrical output signal to a predetermined visual display indicative of a first indication of said rising, a second indication of said levelling off and a third indication of said falling temperature and wherein each said first, second and third indications being visually unique and materially different from one another and thereby indicating the capacity of the CO2 absorbent to absorb CO2. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification