Burner

Abstract

An object of the present invention is to provide a burner such as a two-fluid spray burner which can produce a large amount of combustion exhaust gas with a simple structure, does not cause unburned gas and accidental fire, and furthermore can provide shortened flame and a uniform distribution of the flow rate of the combustion exhaust gas. Accordingly, the burner includes: a cylindrical combustion air passage ( 15 ) formed between a two-fluid sprayer ( 12 ) and a burner outer cylinder ( 48 ) surrounding a periphery of the two-fluid sprayer; a plate (shield plate) ( 18 ) separating the combustion air passage and a combustion space portion ( 13 ); and a combustion air passage hole ( 52 ) provided in the outer periphery of the plate. Combustion air ( 50 ) flowing down the combustion air passage is blocked by the plate and introduced to the outer periphery of the plate to be kept away from the two-fluid spray nozzle ( 38 ). The combustion air then flows through the combustion air passage hole into the combustion space portion. Furthermore, a first cylinder ( 16 ) for delaying supply of the combustion air and a second cylinder ( 17 ) for preventing stagnation are provided on the undersurface of the plate. A throttle plate with a passage hole opened in central part is provided in the combustion space portion.

1 . A burner which sprays fuel from a fuel spray nozzle of a fuel spray to a combustion space portion under the fuel spray nozzle for combustion and burns the fuel, the burner characterized by comprising:
 a cylindrical combustion air passage formed between the fuel spray and a burner outer cylinder surrounding a periphery of the fuel spray;   a shield plate separating the combustion air passage and the combustion space portion; and   a combustion air passage hole provided at the outer periphery of the shield plate, characterized in that   the combustion air flowing down the combustion air passage is blocked by the shield plate and introduced to the outer periphery of the shield plate to be kept away from the fuel spray nozzle and then flown through the combustion air passage hole into the combustion space portion.   
   
   
       2 . The burner according to  claim 1 , characterized in that
 a cylinder extending downward from a undersurface of the shield plate for delaying supply of combustion air is provided to form different cylindrical combustion air passage between the extending cylinder and the burner outer cylinder, the different cylindrical combustion air passage leading to the combustion air passage hole, and   the combustion air passing through the combustion air passage hole flows down the different combustion air passage into the combustion space portion from a lower end of the different combustion air passage.   
   
   
       3 . The burner according to  claim 2 , characterized in that
 one or a plurality of cylinders for preventing stagnation extending downward from the undersurface of the shield plate are provided within the cylinder for delaying supply of combustion air.   
   
   
       4 . The burner according to  claim 1 , characterized in that the shield plate includes a plurality of other combustion air passage holes in a position inner to the center than the combustion air passage hole. 
   
   
       5 . The burner according to  claim 1 , characterized in that
 the fuel spray sprays liquid fuel from the fuel spray nozzle,   a cylindrical gas fuel passage is formed between a gas fuel supply tube surrounding a periphery of the fuel spray and the fuel spray, and   gas fuel flows down the gas fuel passage and is sprayed to the combustion space portion from a lower end of the gas fuel passage and is burned.   
   
   
       6 . The burner according to  claim 1 , characterized in that
 a throttle plate with a passage hole opened in a central part is provided for the combustion space portion, and   combustion air flowing down the combustion space portion is introduced by the throttle plate to the central part of the combustion space portion and then passed through the passage hole of the throttle plate.   
   
   
       7 . The burner according to  claim 6 , characterized in that
 swirling blades are provided above the throttle plate, and   the combustion air passing through the passage hole of the throttle plate is formed into a swirling flow by the swirling blades.   
   
   
       8 . The burner according to  claim 6 , characterized in that
 a porous plate with a passage hole in a central part is provided above the throttle plate in the combustion space portion, and   a part of the combustion air flowing down the combustion space portion is introduced by the porous plate to the central part of the combustion space portion to pass through the passage hole of the porous plate.   
   
   
       9 . The burner according to  claim 7 , characterized in that
 a porous plate with a passage hole in a central part is provided above the throttle plate in the combustion space portion, and   a part of the combustion air flowing down the combustion space portion is introduced by the porous plate to the central part of the combustion space portion to pass through the passage hole of the porous plate.