Support system for smelting-furnace exhaust-gas stack

Abstract

A furnace has a top from which very hot gases are exhausted. An exhaust system has a vent stack connected to the top of the furnace. The stack is cooled with a heat-transfer medium to a predetermined temperature. A plurality of support elements hold the stack off a floor, and the support elements are heated with a heat-transfer medium generally to the predetermined temperature.

1 . In combination with a furnace having a top from which very hot gases are exhausted,. a system comprising: 
 an exhaust stack connected to the top of the furnace;    means for cooling the stack with a heat-transfer medium to a predetermined temperature;    a plurality of support elements holding the stack off a floor; and    means for heating the support elements with a heat-transfer medium generally to the predetermined temperature.    
   
   
       2 . The exhaust-gas vent system defined in  claim 1  wherein the support elements have lower ends all at generally the same level.  
   
   
       3 . The exhaust-gas vent system defined in  claim 1  wherein the predetermined temperature is at least 150° C.  
   
   
       4 . The exhaust-gas vent system defined in  claim 3  wherein both of the cooling mediums are boiling water.  
   
   
       5 . The exhaust-gas vent system defined in  claim 1  wherein the supports are tubular and the respective cooling medium is a fluid circulated through the supports.  
   
   
       6 . The exhaust-gas vent system defined in  claim 1  wherein the supports have upper ends pivoted on the stack and lower ends pivoted on the floor.  
   
   
       7 . The exhaust-gas vent system defined in  claim 6  wherein each lower end is provided with a spring supporting it resiliently on the floor.  
   
   
       8 . The exhaust-gas vent system defined in  claim 1  wherein the supports have lower ends all supported above the floor at the same level, a height between the level and the floor being determined by the temperature differential between the stack and the furnace.  
   
   
       9 . The exhaust-gas vent system defined in  claim 1  wherein the stack has vertical and horizontal sections.  
   
   
       10 . The exhaust-gas vent system defined in  claim 9  wherein the stack is downwardly U-shaped, has two horizontally spaced vertical sections, and is provided with a brace extending horizontally from one of the vertical sections and bearing horizontally on the other of the vertical sections.