Two-fluid spray burner

Abstract

An object of the present invention is to provide a two-fluid spray burner in which liquid fuel can be stably supplied without causing large fluctuation in flow rate of supplied liquid fuel even when the flow rate of supplied liquid fuel is low. In a two-fluid spray burner ( 11 ) which atomizes liquid fuel ( 24 ) with atomizing air and burns the same, the burner includes: a liquid fuel tank ( 19 ) including a cylindrical side portion ( 20 ) and a bottom portion ( 21 ) provided at a lower end of the side portion ( 20 ), the liquid fuel tank ( 19 ) storing liquid fuel ( 24 ) supplied from a liquid fuel supply tube ( 25 ) and discharging the stored liquid fuel ( 24 ) from a liquid fuel discharge hole ( 22 ) opened in the bottom portion ( 21 ) below a liquid level ( 23 ) of the stored liquid fuel ( 24 ). The liquid fuel ( 24 ) discharged from the liquid fuel discharge hole ( 22 ) of the liquid fuel tank ( 19 ) is atomized with atomizing gas ( 46 ) and is burned.

1 . A two-fluid spray burner which atomizes liquid fuel with atomizing gas and burns the atomized liquid fuel, the burner comprising:
 a liquid fuel tank including: a cylindrical side portion and a bottom portion provided at a lower end of the side portion, the liquid fuel tank storing liquid fuel supplied from a liquid fuel supply tube and discharging the stored liquid fuel from one or a plurality of liquid fuel discharge holes opened in the side or bottom portion at a position below a liquid level of the stored liquid fuel, the burner characterized in that   the liquid fuel discharged from the liquid fuel discharge hole of the liquid fuel tank is atomized with the atomizing gas and burned.   
   
   
       2 . The two-fluid spray burner according to  claim 1 , characterized in that the liquid fuel discharge holes are opened in the bottom portion of the liquid fuel tank,
 the burner further comprising:   a cylindrical atomizing gas passage formed between the side portion of the liquid fuel tank and an outer cylinder surrounding a periphery of the side portion; and   a two-fluid spray nozzle provided at a lower end portion of the outer cylinder and including a lower nozzle main body and an upper atomizing gas introduction portion, the two-fluid spray nozzle having:
 a two-fluid converging space portion formed under the liquid fuel discharge holes, in central part of the nozzle main body and the atomizing gas introduction portion; 
 one or a plurality of spray holes formed in the nozzle main body and leading to the two-fluid converging space portion; and 
 one or a plurality of grooves formed in the atomizing gas introduction portion and allowing the two-fluid converging space portion and the atomizing gas passage to communicate with each other, 
   the burner characterized in that   the liquid fuel tank is installed on the atomizing gas introduction portion, and   the liquid fuel which is discharged from the liquid fuel discharge holes to flow into the two-fluid converging space portion converges at the two-fluid converging space portion with the atomizing gas which flows down the atomizing gas passage and flows through the grooves at the atomizing gas introduction portion to be introduced to the two-fluid converging space portion, and the liquid fuel is then sprayed together with the atomizing gas from the spray holes.   
   
   
       3 . The two-fluid spray burner according to  claim 2 , further comprising
 an undersurface of the bottom portion of the liquid fuel tank formed as a tapered surface portion which is tapered,   a top surface of the atomizing gas introduction portion also formed as a tapered surface portion which is tapered, and   the liquid fuel tank installed on the atomizing gas introduction portion with the tapered surface portion of the liquid fuel tank abutted and fitted to the tapered surface portion of the atomizing gas introduction portion.   
   
   
       4 . The two-fluid spray burner according to  claim 1 , characterized in that the liquid fuel discharge holes are opened in the bottom portion of the liquid fuel tank, the burner further comprising:
 a cylindrical atomizing gas passage formed between the side portion of the liquid fuel tank and an outer cylinder surrounding a periphery of the side portion; and   a two-fluid spray nozzle provided at a lower end portion of the outer cylinder, the two-fluid spray nozzle having:
 a two-fluid converging space portion formed in central part under the liquid fuel discharge holes, and 
 one or a plurality of spray holes formed, leading to the two-fluid converging space portion, 
   the burner characterized in that   the undersurface of the bottom portion of the liquid fuel tank is formed as a tapered surface portion which is tapered,   the top surface of the two-fluid spray nozzle is also formed as a tapered surface portion which is tapered,   the liquid fuel tank is installed on the two-fluid spray nozzle with the tapered surface portion of the liquid fuel tank abutted and fitted to the tapered surface portion of the two-fluid spray nozzle,   one or a plurality of grooves are formed at the bottom portion of the liquid fuel tank, the grooves allowing the atomizing gas passage and the two-fluid converging space portion to communicate with each other, and   the liquid fuel discharged from the liquid fuel discharge holes to flow into the two-fluid converging space portion converges at the two-fluid converging space portion with the atomizing gas which flows down the atomizing gas passage and then flows through the grooves at the bottom portion of the liquid fuel tank to be introduced to the two-fluid converging space portion, and the liquid fuel is then sprayed together with the atomizing gas from the spray holes.   
   
   
       5 . The two-fluid spray burner according to  claim 2 , wherein
 the two-fluid converging space portion has a circular shape in a top view, and   the grooves of the atomizing gas introduction portion or the grooves of the bottom portion of the liquid fuel tank are formed along tangent directions of a circumference of the two-fluid converging space portion in the top view.   
   
   
       6 . The two-fluid spray burner according to  claim 2 , wherein the two-fluid converging space portion has a circular shape in a top view, and
 the grooves of the atomizing gas introduction portion or the grooves of the bottom portion of the liquid fuel tank are formed along radial directions of the two-fluid converging space portion in the top view.   
   
   
       7 . The two-fluid spray burner according to  claim 5 , wherein the plurality of grooves of the atomizing gas introduction portion or the plurality of grooves of the bottom portion of the liquid fuel tank are formed at positions rotationally symmetric around a central axis of the two-fluid converging space portion. 
   
   
       8 . The two-fluid spray burner according to  claim 2 , further comprising:
 a press member pressing the liquid fuel tank downward, characterized in that   the bottom portion of the liquid fuel tank is pressed against the atomizing air introduction portion of the two-fluid spray nozzle to be brought into firm contact or   the bottom portion of the liquid fuel tank is pressed against the two-fluid spray nozzle to be brought into firm contact.   
   
   
       9 . The two-fluid spray burner according to  claim 1 , wherein
 the liquid fuel discharge holes are opened in the bottom portion of the liquid fuel tank,   the burner characterized by further comprising:   a cylindrical first atomizing gas passage formed between the side portion of the liquid fuel tank and an outer cylinder surrounding a periphery of the side portion; and   a two-fluid spray nozzle provided at a lower end portion of the outer cylinder, the two-fluid spray nozzle having:
 a two-fluid converging space portion formed in center part under the liquid fuel discharge holes and 
 one or a plurality of spray holes formed, leading to the two-fluid converging space portion, 
   the burner characterized in that   the top surface of the two-fluid spray nozzle is formed as a tapered surface portion which is tapered,   the undersurface of the bottom portion of the liquid fuel tank is formed as a tapered surface portion which is tapered,   a plurality of supporting portions protrude on the side portion of the liquid fuel tank, and each undersurface of the supporting portions is formed as a tapered surface portion,   the liquid fuel tank is installed on the two-fluid spray nozzle with the tapered surface portions of the supporting portions being abutted and fitted to the tapered surface portion of the two-fluid spray nozzle,   gap formed by the supporting portions between the tapered surface portion of the liquid fuel tank and the tapered surface portion of the two-fluid spray nozzle is a second atomizing gas passage, and   the liquid fuel discharged from the liquid fuel discharge holes to flow into the two-fluid converging space portion converges at the two-fluid converging space with the atomizing gas which flows down the first atomizing gas passage, passes through atomizing gas passage portions between the supporting portions, and flows through the second atomizing gas passage to be introduced to the two-fluid converging space portion and is then sprayed together with the atomizing gas from the spray holes.   
   
   
       10 . The two-fluid spray burner according to  claim 2 , wherein the two-fluid converging space portion is a reverse conical shape, and the spray holes are formed at a vertex position of the reverse conical space. 
   
   
       11 . The two-fluid spray burner according to  claim 2 , further comprising a cylindrical gas fuel passage formed between the outer cylinder and a gas fuel supply tube surrounding a periphery of the outer cylinder,
 the burner characterized in that gas fuel flows down the gas fuel passage and is sprayed from a lower end of the gas fuel passage to be burned.   
   
   
       12 . The two-fluid spray burner according to  claim 1 , wherein an end of the liquid fuel supply tube is in contact with an inner peripheral surface of the side portion of the liquid fuel tank. 
   
   
       13 . The two-fluid spray burner according to  claim 4 , wherein
 the two-fluid converging space portion has a circular shape in a top view, and   the grooves of the atomizing gas introduction portion or the grooves of the bottom portion of the liquid fuel tank are formed along tangent directions of a circumference of the two-fluid converging space portion in the top view.   
   
   
       14 . The two-fluid spray burner according to  claim 4 , wherein the two-fluid converging space portion has a circular shape in a top view, and
 the grooves of the atomizing gas introduction portion or the grooves of the bottom portion of the liquid fuel tank are formed along radial directions of the two-fluid converging space portion in the top view.   
   
   
       15 . The two-fluid spray burner according to  claim 13 , wherein the plurality of grooves of the atomizing gas introduction portion or the plurality of grooves of the bottom portion of the liquid fuel tank are formed at positions rotationally symmetric around a central axis of the two-fluid converging space portion. 
   
   
       16 . The two-fluid spray burner according to  claim 6 , wherein the plurality of grooves of the atomizing gas introduction portion or the plurality of grooves of the bottom portion of the liquid fuel tank are formed at positions rotationally symmetric around a central axis of the two-fluid converging space portion. 
   
   
       17 . The two-fluid spray burner according to  claim 13 , wherein the plurality of grooves of the atomizing gas introduction portion or the plurality of grooves of the bottom portion of the liquid fuel tank are formed at positions rotationally symmetric around a central axis of the two-fluid converging space portion. 
   
   
       18 . The two-fluid spray burner according to  claim 4 , further comprising:
 a press member pressing the liquid fuel tank downward, characterized in that   the bottom portion of the liquid fuel tank is pressed against the atomizing air introduction portion of the two-fluid spray nozzle to be brought into firm contact or   the bottom portion of the liquid fuel tank is pressed against the two-fluid spray nozzle to be brought into firm contact.   
   
   
       19 . The two-fluid spray burner according to  claim 4 , wherein the two-fluid converging space portion is a reverse conical shape, and the spray holes are formed at a vertex position of the reverse conical space. 
   
   
       20 . The two-fluid spray burner according to  claim 9 , wherein the two-fluid converging space portion is a reverse conical shape, and the spray holes are formed at a vertex position of the reverse conical space. 
   
   
       21 . The two-fluid spray burner according to  claim 4 , further comprising a cylindrical gas fuel passage formed between the outer cylinder and a gas fuel supply tube surrounding a periphery of the outer cylinder,
 the burner characterized in that gas fuel flows down the gas fuel passage and is sprayed from a lower end of the gas fuel passage to be burned.   
   
   
       22 . The two-fluid spray burner according to  claim 9 , further comprising a cylindrical gas fuel passage formed between the outer cylinder and a gas fuel supply tube surrounding a periphery of the outer cylinder,
 the burner characterized in that gas fuel flows down the gas fuel passage and is sprayed from a lower end of the gas fuel passage to be burned.