Gas sintered block and method

Abstract

The present invention relates to an effective and rapid method and apparatus for sintering filter blocks having a polymeric binder. The method employs direct contact heat transfer by gas molecule to powder particle, as opposed to conduction heat transfer from an external heating source, using commercially available sintered porous metal sheets and cylinders to form the mold and confine the powder, while allowing heated gas to pass uniformly through the mixture.

1 . A method for producing a sintered block by direct heat transfer, the method comprising: 
 a) selecting a mixture comprising least one polymer and at least one adsorbent;    b) providing a mold defined by interior and exterior walls, wherein at least one interior wall and at least one exterior wall is permeable to a heated gas;    c) introducing said mixture into said mold between said interior and exterior walls;    d) providing a gas;    e) heating said gas to an elevated temperature, said temperature being determined by the composition of the polymer and adsorbent mixture whereby the polymer softens without melting;    f) introducing said heated gas into the mold;    g) passing said heated gas through said mixture between said interior and exterior walls; and    h) heating said mixture by direct heat transfer at said temperature for a predetermined time period sufficient to allow said mixture to sinter,    whereby a sintered carbon block is formed.    
   
   
       2 . The method of  claim 1  wherein the gas is heated to a temperature from approximately 100° F. to approximately 275° F.  
   
   
       3 . The method of  claim 1 , wherein the gas is selected from the group comprising carbon dioxide (CO 2 ), nitrogen (N 2 ), helium, steam or air.  
   
   
       4 . The method of  claim 1 , wherein the heated gas passes through at least one permeable surface of said mold selected from the group comprising an interior wall, upper surface or lower surface of said mold, though said mixture, and out through at least one permeable exterior wall.  
   
   
       5 . The method of  claim 1 , further comprising the step of cooling said sintered carbon block, wherein a gas is cooled, introduced into the mold by way of at least one at least one permeable surface of said mold selected from the group comprising an interior wall, upper surface or lower surface of said mold, passes through said sintered carbon block and is exhausted by way of at least one permeable exterior wall.  
   
   
       6 . The method of  claim 1  wherein said adsorbent material is selected from the group comprising a zeolite, silica gel, sepiolite, activated alumina, activated clay, and thermoplastic resin particles, selected from the subgroup comprising polyethylene, ultra high molecular weight polyethylene, polycarbonate, polyamide acrylonitrile-butadiene-styrene resins, polyimide, polyvinyl chloride, cellulose, acetate, polysulfone, polystyrene phthalate and polypropylene.  
   
   
       7 . The method of  claim 1  wherein said mixture of step a) further includes a component providing green strength reinforcement capability.  
   
   
       8 . The method of  claim 7  wherein the green strength reinforcing component is selected from the group consisting of latexes, resins, styrenebutadiene, methyl-cellulose, polyolefin fibers, polyester fibers, nylon fibers, rayon fibers, cellulose fiber, hemp fibers, wool fibers, graphite fibers and glass fibers.  
   
   
       9 . A method for producing a sintered block by direct heat transfer, the method comprising: 
 a) selecting a mixture comprising least one polymer, at least one adsorbent and at least one active material;    b) providing a mold defined by interior and exterior walls, wherein at least one interior wall and at least one exterior wall is permeable to a heated gas;    c) introducing said mixture into said mold between said interior and exterior walls;    d) providing a gas;    e) heating said gas to an elevated temperature, said temperature being determined by the composition of the polymer and adsorbent mixture whereby the polymer softens without melting;    f) introducing said heated gas into the mold;    g) passing said heated gas through said mixture between said interior and exterior walls; and    h) heating said mixture by direct heat transfer at said temperature for a predetermined time period sufficient to allow said mixture to sinter,    whereby a sintered carbon block is formed.    
   
   
       10 . The method of  claim 9  wherein the active material is metal and/or metal oxide particles selected from the group comprising silver oxide, zinc oxide, copper oxide, manganese oxide, iron oxide, titanium oxide, platinum oxide, manganese, silver, copper, zinc, iron, vanadium, nickel, titanium, palladium, platinum, ion exchange resins.  
   
   
       11 . The method of  claim 9  wherein the active material is a fiber coated with a metal and/or metal oxide.  
   
   
       12 . The method of  claim 9  wherein the mold is shaped as a cylinder, disk, cone or rectangle.  
   
   
       13 . The method of  claim 9  wherein the active material is a zeolite.  
   
   
       14 . The method of  claim 9  wherein said adsorbent material is selected from the group comprising a zeolite, silica gel, sepiolite, activated alumina, activated clay, and thermoplastic resin particles, selected from the subgroup comprising polyethylene, ultra high molecular weight polyethylene, polycarbonate, polyamide acrylonitrile-butadiene-styrene resins, polyimide, polyvinyl chloride, cellulose, acetate, polysulfone, polystyrene phthalate and polypropylene.  
   
   
       15 . The method of  claim 9  wherein the gas is heated to a temperature from approximately 100° F. to approximately 400° F.  
   
   
       16 . A method for producing a sintered block by direct heat transfer, the method comprising: 
 a) selecting a mixture comprising least one polymer and at least one active material;    b) providing a mold defined by interior and exterior walls, wherein at least one interior wall and at least one exterior wall is permeable to a heated gas;    c) introducing said mixture into said mold between said interior and exterior walls;    b) providing a gas;    c) heating said gas to an elevated temperature, said temperature being determined by the composition of the polymer and adsorbent mixture whereby the polymer softens without melting;    d) introducing said heated gas into the mold;    e) passing said heated gas through said mixture between said interior and exterior walls; and    d) heating said mixture by direct heat transfer at said temperature for a predetermined time period sufficient to allow said mixture to sinter,    whereby a sintered carbon block is formed.    
   
   
       17 . The method of  claim 16  wherein the active material is metal and/or metal oxide particles selected from the group comprising silver oxide, zinc oxide, copper oxide, manganese oxide, iron oxide, titanium oxide, platinum oxide, manganese, silver, copper, zinc, iron, vanadium, nickel, titanium, palladium, platinum, ion exchange resins.  
   
   
       18 . The method of  claim 16  wherein the gas is heated to a temperature from approximately 100° F. to approximately 400° F.