Ceramic article, ceramic extrudate and related articles

Abstract

A ceramic article is provided. The ceramic article includes a ceramic tube comprising a sintered helical tape. The sintered helical tape has adjacent windings, which are joined together. Another aspect provides an article comprising a ceramic extrudate having an outer surface and a pattern of surface features along the outer surface.

1 . An article comprising: 
 a ceramic tube comprising sintered helical tape, the tape having adjacent windings that are joined together.    
   
   
       2 . The article of  claim 1 , wherein the sintered helical tape comprises an extrudate.  
   
   
       3 . The article of  claim 1 , wherein the ceramic tube is comprised of a single layer of joined adjacent windings.  
   
   
       4 . The article of  claim 1 , wherein the ceramic tube is cylindrical or tapered.  
   
   
       5 . The article of  claim 4 , wherein the ceramic tube is cylindrical.  
   
   
       6 . (canceled)  
   
   
       7 . The article of  claim 1 , wherein the ceramic tube is comprised mainly of ceramic.  
   
   
       8 . (canceled)  
   
   
       9 . (canceled)  
   
   
       10 . The article of  claim 7 , wherein the ceramic is an oxide.  
   
   
       11 . The article of  claim 10 , wherein the ceramic tube is comprised of at least one oxide material selected from the group consisting of SiO 2 , Al 2 O 3 , CaO, Na 2 O, MgO, Fe 2 O 3 , TiO 2 , K 2 O, MnO, P 2 O 5 , Cr 2 O 3 , and ZrO 2  and combinations thereof.  
   
   
       12 . (canceled)  
   
   
       13 . (canceled)  
   
   
       14 . The article of  claim 1 , wherein the ceramic tube is a burner sheath.  
   
   
       15 . (canceled)  
   
   
       16 . The article of  claim 1 , the ceramic tube having of a pattern of surface features.  
   
   
       17 . The article of  claim 16 , wherein the pattern of surface features is a pattern of perforations extending through the thickness of the tube.  
   
   
       18 . (canceled)  
   
   
       19 . The article of  claim 17 , further comprising a transport tube for delivering combustible gas to the burner sheath, the transport tube being positioned inside the burner sheath.  
   
   
       20 . The article of  claim 19 , wherein the transport tube has an open first end and a closed second end, the transport tube having a plurality of holes along its length through which the combustible gas flows, to the burner sheath.  
   
   
       21 . (canceled)  
   
   
       22 . The article of  claim 17 , wherein the pattern of perforations defines an open surface area not greater than about 50%.  
   
   
       23 . The article of  claim 22 , wherein the open surface area is not less than about 20%.  
   
   
       24 . The article of clam  18 , wherein the pattern of perforations is comprised of perforations, each perforation having a diameter not less than about 0.025 centimeters and not greater than 0.25 centimeters.  
   
   
       25 . An article comprising: 
 a ceramic extrudate having an outer surface and a pattern of surface features along the outer surface, the surface features of the pattern of surface features being spread apart from each other along circumferential and longitudinal directions.    
   
   
       26 . The article of  claim 25 , wherein the ceramic extrudate comprises a sintered ceramic extrudate.  
   
   
       27 . The article of  claim 25 , wherein the ceramic extrudate is hollow.  
   
   
       28 . The article of  claim 27 , wherein the ceramic extrudate comprises a helical tape having adjacent windings, the windings being joined to form a tube.  
   
   
       29 . (canceled)  
   
   
       30 . The article of  claim 28 , wherein the tube has a tube wall and the pattern of surface features comprises an array of perforations extending through the tube wall.  
   
   
       31 . (canceled)  
   
   
       32 . (canceled)  
   
   
       33 . The article of  claim 28 , wherein the ceramic extrudate is a burner component, wherein the tube forms a sheath.  
   
   
       34 . The article of  claim 33 , further comprising a transport tube for delivering combustible gas to the sheath, the transport tube being positioned inside the sheath.  
   
   
       35 . he article of  claim 25 , wherein the pattern of surface features is a pattern of perforations.  
   
   
       36 . (canceled)  
   
   
       37 . The article of  claim 25 , wherein the ceramic extrudate is comprised mainly of ceramic.  
   
   
       38 . (canceled)