THERMOCHROMIC INDICATOR FOR REAGENT GAS VESSEL
A dispensing and storage vessel for use in housing a gas such as toxic and hazardous gas in combination with a temperature sensitive label is described. Example dispensing and storage vessels include an adsorbent and a reagent gas within an internal volume of the vessel. A thermochromic label is adhered to the vessel and communicates temperature-sensitive information in a visual fashion to a user.
1 . A storage and dispensing vessel for storing and dispensing reagent gas, the vessel comprising:
an interior volume,
adsorbent within the interior volume,
reagent gas within the interior volume, the reagent gas comprising a portion that is adsorbed on the adsorbent as adsorbed reagent gas, and a portion that is present as gaseous reagent gas in equilibrium with the adsorbed reagent gas,
an exterior surface, and
a reversible thermochromic indicator in thermal contact with the exterior surface, the thermochromic indicator reversibly indicating whether an interior pressure of the vessel is above a desired maximum pressure that is associated with a transition temperature.
2 . A vessel of claim 1 wherein the indicator has an appearance at one or more temperatures below the transition temperature, and the indicator has a different appearance at temperatures above the transition temperature.
3 . A vessel of claim 2 wherein the transition temperature corresponds to a vessel pressure of one atmosphere.
4 . A vessel of any of claim 1 wherein the indicator includes a temperature-indicative material that has a first appearance below an activation temperature and a second appearance above the activation temperature, and the activation temperature is the transition temperature or a temperature slightly below the activation temperature.
5 . A vessel of claim 1 wherein the internal pressure of the vessel is in a range from 0.5 to 1.5 atmospheres.
6 . A vessel of any of claim 1 wherein the transition temperature is a temperature in a range from about 20 to 29 degrees Celsius.
7 . A vessel of any of claim 1 wherein the adsorbent is selected from a material comprising carbon, activated carbon, zeolite, and a metal-organic framework.
8 . A vessel of any of claim 1 wherein the indicator comprises a multi-layer adhesive-coated label adhesively bonded to the exterior surface.
9 . A vessel of any of claim 1 wherein the indicator comprises temperature-indicative material selected from a leuco dye and a liquid crystal thermochromic material.
12 . A method of handling a vessel of any of claim 1 , the method comprising:
observing the indicator to determine if the indicator indicates an internal pressure that is greater than the transition temperature, and if so, reducing the temperature of the vessel.
13 . A method of any of claim 12 comprising maintaining the temperature of the vessel at a temperature below the transition temperature.
14 . A method of claim 12 wherein the reagent gas is present within the interior volume at an internal pressure below about 3 atmospheres (absolute).