Catalytic patio heater

Abstract

A patio heater is disclosed comprising a cylindrical catalytic heating chamber mounted on a base. The patio heater of the present invention comprises a base to physically support a cylindrical catalytic heater chamber which is mounted inside a fuel vapor cavity. The catalytic heater chamber provides a cylindrical heating zone capable of heating a nearby human form the knee to the face. The fuel vapor chamber surrounds the catalytic heating chamber and acts to accumulate sufficient fuel and air mixture to ignite to provide uniform and sufficient heat to the catalyst surface to attain catalytic ignition on start up. The base offers physical stability for the assembly and storage space for a fuel tank and houses the fuel deliver system and ignitor controls.

1 . A patio heater comprising a cylindrical catalytic heating chamber vertically mounted on a base. 
   
   
       2 . The patio heater according to  claim 1  wherein said cylindrical catalytic heating chamber comprises:
 (a) a low density ceramic pad coated with a highly dispersed oxidation catalyst;   (b) a high density ceramic insulating pad;   (c) said low density ceramic pad and said high density ceramic pad being rolled together to form a cylinder around the outer surface of a perforated metal cylinder to form a fuel chamber with said high density ceramic pad being located between said low density ceramic pad and said perforated metal cylinder.   
   
   
       3 . The patio heater according to  claim 2  further comprising:
 (d) a cylindrical sleeve around said catalytic heating chamber, said sleeve being formed from expanded metal and having openings of from one-quarter square inch to five square inches with a total open area of from 50% to 90%; and   (e) caps covering either end of said catalytic heating chamber and overlapping said sleeve and sealing said fuel chamber.   
   
   
       4 . The patio heater according to  claim 2  wherein said oxidation catalyst is selected from the group consisting of platinum, palladium, rhodium, or cobalt oxide. 
   
   
       5 . The patio heater according to  claim 4  wherein the oxidation catalyst is one to 10 percent platinum based upon the total weight of the low density ceramic pad. 
   
   
       6 . The patio heater according to  claim 5  wherein said low density ceramic pad having a density of from between 1 to 8 pounds per cubic foot and the density of said high density ceramic pad being between 8 and 50 pounds per cubic foot. 
   
   
       7 . The patio heater according to  claim 4  wherein the oxidation catalyst is one to 10 percent palladium based upon the total weight of the low density ceramic pad. 
   
   
       8 . The patio heater according to  claim 7  wherein said low density ceramic pad having a density of from between 1 to 8 pounds per cubic foot and the density of said high density ceramic pad being between 8 and 50 pounds per cubic foot. 
   
   
       9 . The patio heater according to  claim 4  wherein the oxidation catalyst is one to 10 percent rhodium based upon the total weight of the low density ceramic pad. 
   
   
       10 . The patio heater according to  claim 9  wherein said low density ceramic pad having a density of from between 1 to 8 pounds per cubic foot and the density of said high density ceramic pad being between 8 and 50 pounds per cubic foot. 
   
   
       11 . The patio heater according to  claim 4  wherein the oxidation catalyst is one to 20 percent cobalt oxide based upon the total weight of the low density ceramic pad. 
   
   
       12 . The patio heater according to  claim 11  wherein said low density ceramic pad having a density of from between 1 to 8 pounds per cubic foot and the density of said high density ceramic pad being between 8 and 50 pounds per cubic foot. 
   
   
       13 . The patio heater according to  claim 3  further comprising:
 (f) an expanded metal cylinder spaced away from and around said catalytic heating chamber forming a vapor cavity annular to said catalytic heating chamber.   
   
   
       14 . The patio heater according to  claim 13  wherein said vapor cavity is from one-half inch to two inches in diameter outside the catalytic heating chamber. 
   
   
       15 . The patio heater according to  claim 13  wherein said expanded metal cylinder has a porosity between 25 and 70% and a wire diameter of between 0.01 and 0.08 inches. 
   
   
       16 . A patio heater comprising:
 (a) a base comprising a cabinet for containing a fuel tank;   (b) a cylindrical catalytic heating chamber vertically mounted on said base, said catalytic heating chamber comprising:
 (i) a low density ceramic pad coated with a highly dispersed oxidation catalyst; 
 (ii) a high density ceramic insulating pad; 
 (iii) said low density ceramic pad and said high density ceramic pad being rolled together to form a cylinder around the outer surface of a perforated metal cylinder to form a fuel chamber with said high density ceramic pad being located between said low density ceramic pad and said perforated metal cylinder; 
   (c) a cylindrical sleeve around said catalytic heating chamber, said sleeve being formed from expanded metal and having openings of from one-quarter square inch to five square inches with a total open area of from 50% to 90%;   (d) caps covering either end of said catalytic heating chamber and overlapping said sleeve and sealing said fuel chamber to form said catalytic heating chamber; and   (f) an expanded metal cylinder spaced away from and around said catalytic heating chamber forming a vapor cavity annular to said catalytic heating chamber said vapor cavity being from one-half inch to two inches in diameter outside the catalytic heating chamber.   
   
   
       17 . The patio heater according to  claim 16  wherein said oxidation catalyst is one to 10 percent platinum based upon the total weight of the low density ceramic pad of material selected from the group consisting of platinum, palladium, rhodium, or one to 20 percent cobalt oxide based upon the total weight of the low density ceramic pad cobalt oxide.