Refractory application process and method

Abstract

A refractory insulation on boiler tubes using studs circular in cross-section and having shoulders intermediate their ends with washers frictionally engaged on the studs sandwiching a mesh therebetween. The shoulder restrains movement of the first washer and mesh toward the substrate and the second washer retains the mesh from movement away from the substrate. A first insulation is applied to the substrate through the mesh and a second insulation layer is applied over the mesh to a predetermined thickness determined by the height of the studs above the shoulders. Pins can be welded to the tops of the studs and used to impale fibrous insulation.

What is claimed is:  
     
         1 . A stud for applying refractory to a substrate comprising a leg having a first free end adapted to be stud welded to said substrate, a shoulder attached to a second end of said leg, and an arm having a free first end and a second end attached to said shoulder and aligned with said leg.  
     
     
         2 . The stud of  claim 1  wherein the arm and leg are circular in cross-section.  
     
     
         3 . The stud of  claim 1  wherein the shoulder is rounded on the top.  
     
     
         4 . The stud of  claim 3  wherein the shoulder has a spherical outer surface.  
     
     
         5 . The stud of  claim 1  wherein the free end is chamfered or rounded.  
     
     
         6 . The stud of  claim 1  wherein the leg and shoulder have a predetermined length equal to the desired thickness of a first layer of refractory adapted to be gunned or trowled onto the substrate plus the amount of stud consumed by the weld, and the stud arm has a predetermined length equal to the thickness of a top layer of refractory adapted to be trowled onto the substrate.  
     
     
         7 . A refractory installation comprising: 
 a substrate,    a plurality of studs welded to said substrate, said studs having a shoulder intermediate their ends,    first washers frictionally positioned on the studs and restrained from movement toward the substrate by the shoulders,    a mesh positioned on the studs and restrained from movement toward the substrate by the first washers,    second washers frictionally positioned on the studs and restraining the mesh from movement away from the substrate, and    refractory positioned between the mesh and the substrate.    
     
     
         8 . The installation of  claim 7  including a second layer of refractory positioned over the mesh and having a thickness substantially the distance between the shoulders and the free ends of the studs.  
     
     
         9 . The installation of  claim 8  including pins positioned on the free ends of the studs and insulation impaled on the pins and retained thereon.  
     
     
         10 . The installation of  claim 9  including a protective cover over the impaled insulation and fastened to the pins.  
     
     
         11 . The installation of  claim 8  wherein the studs are circular in cross-section.  
     
     
         12 . The installation of  claim 8  wherein the stud shoulders are rounded on the top.  
     
     
         13 . The installation of  claim 12  wherein the first washers have concave under surfaces which mate with the stud shoulder rounds.  
     
     
         14 . The installation of  claim 11  wherein the free ends of the studs are chamfered or rounded to facilitate passage of the washers.  
     
     
         15 . The installation of  claim 8  wherein the stud leg and shoulder have a predertermined length equal to the desired thickness of the first layer of refractory on the substrate plus the amount of stud consumed by the weld, and the stud arms have predetermined lengths equal to the thickness of the top layer of refractory.  
     
     
         16 . The installation of  claim 8  wherein the substrate is boiler tubes.  
     
     
         17 . A method of applying insulation to a substrate including the steps of welding the studs of  claim 1  to the substrate, 
 frictionally engaging first washers onto the studs against the shoulders,  
 positioning mesh onto the studs whereby the first washers restrain the mesh from movement toward the substrate,  
 frictionally engaging second washers onto the studs over the mesh to restrain the mesh from movement away from the substrate,  
 applying a first layers of insulting material to the substrate to a thickness of the mesh, and  
 applying a second insulating layer to the first insulating layer to a thickness defined by the free ends of the studs.  
 
     
     
         18 . The method of  claim 17  including the steps of positioning pins on the free ends of the studs, impaling fibrous installation onto the pins and restraining the fibrous insulation on the pins.  
     
     
         19 . The method of  claim 17  wherein the substrate is boiler tubes.