Apparatus and method for controlled delivery of a gas

Abstract

Disclosed are apparatus for delivery of a gas, e.g., carbon dioxide and/or chlorine dioxide, and methods of its use and manufacture. The apparatus includes an envelope, and a sachet within the envelope that contains reactant, which generates a gas in the presence of an initiating agent, e.g., water. The envelope allows release of the gas from the envelope. In another embodiment, the apparatus includes an envelope and a partition that separates two reactants within the envelope. The envelope allows an initiating agent into the envelope and release of the gas generated by the reactants in the presence of the initiating agent.

What is claimed is:  
     
         1 . An apparatus for delivery of a gas comprising: 
 an envelope;    a sachet disposed within the envelope; and    a reactant disposed within the sachet that generates a gas in the presence of an initiating agent,    wherein the envelope allows release of the gas from the envelope.    
     
     
         2 . The apparatus of  claim 1  wherein the sachet comprises a material having a pore size between about 0.01 μm and about 50 μm.  
     
     
         3 . The apparatus of  claim 1  wherein the sachet comprises a hydrophobic material.  
     
     
         4 . The apparatus of  claim 1  wherein the sachet comprises a hydrophilic material.  
     
     
         5 . The apparatus of  claim 1  wherein the sachet comprises a material having one or more hydrophilic zones and one or more hydrophobic zones.  
     
     
         6 . The apparatus of  claim 5  wherein the one or more hydrophilic zones are created by printing an acid onto a surface of the sachet that is hydrophobic.  
     
     
         7 . The apparatus of  claim 1  wherein the sachet comprises a material having a first surface that is hydrophilic and a second surface that is hydrophobic.  
     
     
         8 . The apparatus of  claim 1  wherein sachet comprises a material having a bubble point between about 3 psi and about 100 psi.  
     
     
         9 . The apparatus of  claim 3  wherein the sachet has a flow time between about 10 sec/500 ml and about 3,500 sec/500 ml for 100% IPA at 14.2 psi.  
     
     
         10 . The apparatus of  claim 4  wherein the sachet has a flow time between about 5 Lmh/kPa and about 500 Lmh/kPa for 100% water at 14.2 psi.  
     
     
         11 . The apparatus of  claim 1  wherein the envelope comprises a material having a water vapor transmission rate between about 50 g/m 2 /24 hrs and about 1,000 g/m 2 /24 hrs.  
     
     
         12 . The apparatus of  claim 1  wherein the envelope comprises a material having a selective gas transmission rate of between about 500 cc/m 2 /24 hrs and about 30,000 cc/m 2 /24 hrs for CO 2 .  
     
     
         13 . The apparatus of  claim 1  wherein the envelope comprises a material having a selective gas transmission rate of between about 1,000 cc/m 2 /24 hrs and about 10,000 cc/m 2 /24 hrs for O 2 .  
     
     
         14 . The apparatus of  claim 1  wherein the reactant comprises an aqueous soluble acid and an aqueous soluble chlorite and the gas is chlorine dioxide.  
     
     
         15 . The apparatus of  claim 14  wherein the aqueous soluble acid is selected from the group consisting of phosphoric acid, fumaric acid, glycolic acid, acetic acid, ascorbic acid, oxalic acid, maleic acid, lactic acid, tartaric acid, citric acid and mixtures thereof.  
     
     
         16 . The apparatus of  claim 14  wherein the aqueous soluble chlorite is selected from a group consisting of sodium chlorite and potassium chlorite and mixtures thereof.  
     
     
         17 . The apparatus of  claim 14  wherein the weight ratio of the aqueous soluble chlorite to the aqueous soluble acid is between about 1:2 to about 1:6.  
     
     
         18 . The apparatus of  claim 1  further comprising a second sachet disposed within the envelope.  
     
     
         19 . The apparatus of  claim 18  further comprising a third sachet disposed about the first sachet and the second sachet, the third sachet being disposed within the envelope.  
     
     
         20 . An apparatus for delivery of a gas comprising: 
 a first reactant disposed within a first sachet;    a second reactant disposed within a second sachet;    a third sachet disposed about the first sachet and the second sachet;    an envelope disposed about the third sachet;    a frangible pouch disposed within the envelope adjacent to the third sachet; and    an initiating agent disposed within the frangible pouch,    wherein the first reactant and the second reactant generate a gas in the presence of the initiating agent, and the envelope allows release of the gas from the apparatus.    
     
     
         21 . An apparatus for delivery of a gas comprising: 
 an envelope;    a partition disposed within the envelope defining a first volume and a second volume;    a first reactant disposed in the first volume; and    a second reactant disposed within the second volume,    wherein the first reactant and the second reactant generate a gas in the presence of an initiating agent, and the envelope allows entry of the initiating agent into the apparatus.    
     
     
         22 . An apparatus for delivery of a gas comprising: 
 a sachet; and    a reactant disposed within the sachet that generates a gas in the presence of an initiating agent,    wherein the sachet allows contact of the initiating agent with the reactant and release of the gas from the apparatus.    
     
     
         23 . The apparatus of  claim 22  wherein the sachet comprises a hydrophobic material having a pore size between about 0.01 μm and about 50 μm.  
     
     
         24 . A method of forming an apparatus for delivery of a gas comprising: 
 (a) providing a multi-layer structure comprising a reactant layer centrally disposed between two sachet layers, and two envelope layers disposed adjacent to the two sachet layers such that the two sachet layers are centrally disposed between the two envelope layers; and    (b) stamping the multi-layer structure such that the two envelope layers form an envelope defined about its perimeter by the stamp, and the two sachet layers form a sachet defined about its perimeter by the stamp.    
     
     
         25 . The method of  claim 24  further comprising the steps: 
 (c) providing a second two envelope layers and an initiating agent in a frangible pouch; and  
 (d) stamping the second two envelope layers to form a second envelope defined about its perimeter by the stamp, such that the frangible pouch and the envelope formed in step (b) are disposed within the second envelope.  
 
     
     
         26 . A method of delivering gas: 
 (a) providing an apparatus for delivery of a gas comprising: 
 an envelope,  
 a sachet disposed within the envelope, and  
 a reactant disposed within the sachet that generates a gas in the presence of an initiating agent,  
 wherein the envelope allows release of the gas from the envelope; and  
   (b) disposing the apparatus in an environment that comprises an initiating agent.    
     
     
         27 . The method of  claim 26  wherein the environment is liquid and the initiating agent is water.  
     
     
         28 . The method of  claim 26  wherein the environment is gaseous and the initiating agent is water vapor.