Bubble generating arrangement, system & method

Abstract

An arrangement to generate foam, the arrangement comprising: a porous material; a plenum having an aperture disposed to supply gas to the porous material; and a tub containing a foamable liquid, disposed to at least partially submerge the porous material in the foamable liquid; foam being generated as the gas is injected via the porous material into the foamable liquid.

1 . An arrangement to generate foam, the arrangement comprising: 
 a porous material;    a plenum having an aperture disposed to supply gas to the porous material; and    a tub containing a foamable liquid, disposed to at least partially submerge the porous material in the foamable liquid;    foam being generated as the gas is injected via the porous material into the foamable liquid.    
   
   
       2 . The foam-generating arrangement of  claim 1 , wherein: 
 the porous material is one of a sponge, an aerogel and a porous resin.    
   
   
       3 . The foam-generating arrangement of  claim 1 , wherein: 
 the porous material includes at least one of macropores, mesopores and macropores.    
   
   
       4 . The foam-generating arrangement of  claim 1 , wherein the pressure of the foamable liquid is about atmospheric pressure.  
   
   
       5 . The foam-generating arrangement of  claim 1 , wherein at least a portion of the porous material is fitted as a plug into the aperture.  
   
   
       6 . The foam-generating arrangement of  claim 1 , wherein the gas is air.  
   
   
       7 . The foam-generating arrangement of  claim 1 , wherein a maximum speed V max  at which the gas is injected into the foamable liquid is  
         V   max ≦(≈1.5 V   b ),  
     where V b  is the minimum speed at which injection of the gas into the foamable liquid can achieve bubble formation.  
   
   
       8 . The foam-generating arrangement of  claim 7 , wherein V max ≈1.2V b .  
   
   
       9 . A system to suppress fire within a substantially enclosed volume, the system comprising: 
 a first plurality of foam generators, each foam generator including 
 stream-forming means for forming a second plurality of low-speed streams of gas and for introducing the same into a foamable liquid, the foamable liquid being at about atmospheric pressure.  
   
   
   
       10 . The system of  claim 9 , wherein each stream-forming means includes a porous material via which the gas is introduced into the foamable liquid.  
   
   
       11 . The system of  claim 10 , wherein the porous material is at least partially submerged in the foamable liquid.  
   
   
       12 . The system of  claim 9 , wherein the second plurality of low-speed streams is a multitude.  
   
   
       13 . The system of  claim 9 , further comprising: 
 a source of gas;    a plurality of plenums arranged to conduct gas to the plurality of stream-forming means, respectively.    
   
   
       14 . The system of  claim 9 , wherein the first plurality of foam generators are dispersed within the substantially enclosed volume.  
   
   
       15 . The system of  claim 9 , wherein at least a majority of the first plurality of foam generators are dispersed proximate to a ceiling region of the enclosed volume.  
   
   
       16 . The system of  claim 9 , wherein the low-speed of the streams of gas has a maximum V max ,  
         V   max ≦(≈1.5 V   b ),  
     where V b  is the minimum speed at which introduction of the gas into the foamable liquid can achieve bubble formation.  
   
   
       17 . The system of  claim 16 , wherein V max ≈1.2V b .  
   
   
       18 . A method of generating foam comprising: 
 providing a porous material;    at least partially submerging the porous material in a foamable liquid;    forcing a gas into the foamable liquid via the porous material.    
   
   
       19 . The method of  claim 18 , further comprising: 
 using the foamable liquid at about atmospheric pressure.    
   
   
       20 . The method of  claim 18 , further comprising: 
 using air as the gas.    
   
   
       21 . The method of  claim 18 , wherein a maximum speed V max  at which the gas is forced into the foamable liquid is  
         V   max ≦(≈1.5 V   b ),  
     where V b  is the minimum speed at which the gas can be forced into the foamable liquid and still can achieve bubble formation.  
   
   
       22 . The method of  claim 21 , wherein V max ≈1.2V b .  
   
   
       23 . An arrangement to generate foam, the arrangement comprising: 
 a tub containing a foamable liquid;    stream-forming means for forming a plurality of low-speed streams of gas and for introducing the same into the foamable liquid.    
   
   
       24 . The foam-generating arrangement of  claim 23 , wherein the plurality of low-speed streams is a multitude.  
   
   
       25 . The foam-generating arrangement of  claim 23 , wherein the low-speed of the streams of gas has a maximum V max ,  
         V   max ≦(≈1.5 V   b ),  
     where V b  is the minimum speed at which introduction of the gas into the foamable liquid can achieve bubble formation.  
   
   
       26 . The foam-generating arrangement of  claim 25 , wherein V max ≈1.2V b .