JP3831789B2 - Liquid fuel combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid fuel combustion apparatus, and more particularly, a liquid fuel capable of preventing condensation of a heat exchanger through a cooling air box disposed above a burner and preventing overheating of the cooling air box. The present invention relates to a combustion apparatus.
[0002]
[Prior art]
Conventionally, as a liquid fuel combustion apparatus used for a hot water heater or the like, a combustion disc that forms a combustion chamber in which fuel such as kerosene burns, a vaporization cylinder provided in a substantially center in the combustion disc, and this A scattering ring that is provided at a lower portion of the vaporization cylinder and scatters liquid fuel into the combustion chamber, a blower that is disposed below the vaporization cylinder and supplies air into the vaporization cylinder, and above the combustion disk and the combustion disk And a cooling air box arranged between the arranged heat exchangers.
[0003]
In the liquid fuel combustion apparatus, the liquid fuel is scattered into the combustion chamber from the gap between the vaporization cylinder and the scattering ring by the rotation of the vaporization cylinder, and spray combustion is performed by igniting the liquid fuel. The liquid fuel in the vaporization cylinder is vaporized by heating the vaporization cylinder with combustion heat, and the vaporized fuel is mixed with the air supplied into the vaporization cylinder from the blower to form the air-fuel mixture in the combustion disk. Vaporization combustion is performed by ejecting the gas from the flame hole into the combustion disk. In addition, the cooling air box is configured to eject cooling air from an air supply hole formed on an upper surface portion of the cooling air box, and to prevent condensation on the wall surface of the heat exchange element.
[0004]
[Problems to be solved by the invention]
However, since the liquid fuel combustion apparatus has a configuration in which the upper surface portion of the cooling air box is simply provided with air supply holes, the inner peripheral surface side of the cooling air box generates the combustion heat in the combustion chamber. There is an inconvenience that it may be directly overheated.
[0005]
OBJECT OF THE INVENTION
The present invention has been devised by paying attention to such inconveniences. The object of the present invention is to prevent condensation on the wall surface of the heat exchanger through the cooling air box. An object of the present invention is to provide a liquid fuel combustion apparatus capable of preventing overheating at the same time.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a liquid fuel combustion apparatus disposed at a lower part of a heat exchanger, wherein a liquid is provided at a lower part of a combustion disc forming an upper combustion chamber and a vaporization cylinder disposed in the combustion chamber. The vaporizing cylinder includes: a scattering ring that scatters fuel into the combustion chamber; a blower passage that supplies air to a lower surface side of the scattering ring; and a blower that supplies air to an air chamber provided in a lower portion of the combustion disc. Liquid fuel supplied into the vaporization cylinder by igniting the liquid fuel scattered in the combustion chamber from the gap between the gas and the scattering ring and performing spray combustion, and heating the vaporization cylinder with the combustion heat of this spray combustion In a liquid fuel combustion apparatus that performs vaporization combustion by ejecting the vaporized fuel from a flame hole formed in a side wall of the combustion disc,
A cooling air box having a closed loop shape in plan view to which cooling air is supplied is provided between the combustion plate and the heat exchanger, and air is provided on the upper surface of the cooling air box along the wall surface of the heat exchanger. while the first supply hole for jetting are provided, said the lower inner peripheral surface of the cooling air box, the second air supply hole is provided for ejecting air to avoid overheating of the inner peripheral surface Rutotomoni, the On the inner peripheral surface side of the cooling air box, there is provided a guide member having a plurality of guide surface portions for causing the air ejected from the second air supply hole to follow the inner peripheral surface of the cooling air box, guiding surface section Ru provided a discontinuity, take the configuration that, thereby, while preventing condensation in the walls of the heat exchanger in the air jetted from the first supply hole, the air jetted from the second air supply hole Thus, it is possible to prevent overheating of the inner peripheral surface side of the cooling air box. In addition, the cooling air ejected from the second air supply hole becomes a flow that surely follows the inner peripheral surface, and the inner peripheral surface can be efficiently cooled to prevent overheating of the cooling air box.
[0008]
Furthermore, a leading end of a communication pipe for introducing air from the blower is connected to an outer peripheral portion of the cooling air box, and a cooling air rectifying guide is disposed inside the cooling air box corresponding to the leading end. It is good to adopt the configuration of. With such a configuration, it is possible to prevent a relatively large amount of cooling air from flowing into the air supply hole near the tip of the communication pipe, and to flow the cooling air over the entire circumference of the cooling air box having a closed loop shape. Can span.
[0009]
In the present specification, “spray combustion” means combustion performed by igniting liquid fuel, and “vaporization combustion” refers to an air-fuel mixture obtained by mixing vaporized liquid combustion with air. It means the combustion performed by igniting.
[0010]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0011]
FIG. 1 shows a schematic plan view of a burner as a liquid fuel combustion apparatus according to the present embodiment, and FIG. 2 shows a schematic plan view of the burner with parts partially removed from FIG. Has been. Moreover, FIG. 3 shows a schematic end view taken along line AA in FIG. In these drawings, the burner 10 has a top structure 12 including a combustion chamber 11 that is substantially square in a plan view, and a case having a bottomed container shape that supports the top structure 12 from below and has an open top. 13 (see FIG. 3) and a blower 14 for supplying air to the air chamber 13A in the case 13.
[0012]
As shown in FIG. 3, the upper structural body 12 includes a combustion chamber outer cylinder 15 having a bottomed substantially rectangular tube shape located outside, and an inner side of the combustion chamber outer cylinder 15, and on the bottom side of the case 13. Combustion plate 16 having a bottomed substantially rectangular tube shape forming air chamber 13A, and an air-fuel mixture that is located in the approximate center inside combustion plate 16 and vaporizes liquid fuel such as kerosene to form an air-fuel mixture. The forming unit 18 is provided on the lower side of the air-fuel mixture forming unit 18 and includes an air introduction unit 19 that introduces air from the air chamber 13 </ b> A into the combustion chamber 11. In this embodiment, the space formed between the upper part of the combustion disk 16, that is, the air-fuel mixture forming means 18 is the combustion chamber 11, and the heat exchanger 20 (see FIG. 3) is provided on the upper part. Is placed.
[0013]
The combustion chamber outer cylinder 15 includes a bottom wall 15A having a substantially square outer shape in plan view, and four side walls 15B rising upward from the outer periphery of the bottom wall 15A. In the bottom wall 15A, the first central through hole 21 is formed in a substantially central region, and at a plurality of locations along the circumferential direction of the first central through hole 21, in this embodiment, the peripheral wall except for the blower 14 side. First outer through-holes 22 having a smaller diameter than the first central through-hole 21 are formed at three locations spaced approximately 90 degrees in the direction.
[0014]
The combustion disc 16 is disposed inside the combustion chamber outer cylinder 15 with a gap therebetween, and a gas chamber 24 through which the air-fuel mixture formed by the air-fuel mixture forming means 18 passes is formed by the gap. Moreover, the combustion disc 16 includes a bottom wall 16A having a substantially square outer shape in plan view, and four side walls 16B that rise upward from the outer periphery of the bottom wall 16A. A second central through hole 26 and a second outer through hole 27 are formed in the center of the bottom wall 16A above the first central through hole 21 and the first outer through hole 22, respectively. In addition, a large number of flame holes 29 are formed in the side wall 16B so that the air-fuel mixture from the gas chamber 24 can be ejected into the combustion chamber 11, and the upper side of the side wall 16B, that is, the upper side of the combustion plate 16 is cooled. Air box 30 is provided [0015]
The cooling air box 30 has an inner / outer double wall structure having an inner peripheral surface 30 </ b> A and an outer peripheral surface 30 </ b> B made of a material having good drawability, such as SUS430LX, and the air chamber 31 is formed therebetween. As shown in FIG. 3, the outer peripheral surface 30 </ b> B communicates with a tip (upper end) of a communication pipe 32 that bypasses a part of the air from the blower 14 as tertiary air. In addition, a plurality of first air supply holes 33 are formed in the upper surface portion of the cooling air box 30, that is, the upper inclined surface 30 </ b> C along the circumferential direction, and the cooling air ejected from these first air supply holes 33. Is configured to flow along the inside of the wall surface of the heat exchanger 20. A plurality of second air supply holes 34 are formed along the circumferential direction at the lower part of the inner peripheral surface 30A, and are used for cooling that are jetted from the second air supply holes 34 into the space above the combustion chamber 11. The air flows upward along the inner peripheral surface of the cooling air box 30 via a guide member 35 supported between the upper end portion of the combustion plate 16 and the cooling air box 30. The guide member 35 is made of an inexpensive material such as SUH409L, and the guide member 35 follows a substantially square trajectory in plan view as shown in FIGS. The support surface portion 35A has four sides, and a guide surface portion 35B that extends inward and obliquely upward and continues to each inner edge of the support surface portion 35A. Four guide surface 35B in this embodiment is that provided discontinuously. Also, the cooling air box 30 inside, i.e., in the air chamber 31, at a position corresponding to the tip of the communicating pipe 32 is rectified guide 38 is provided in the cooling air. The rectifying guide 38 is configured by partially pushing the outer peripheral surface 30 </ b> B of the cooling air box 30 inwardly. By providing the rectifying guide 38, the first rectifying guide 38 corresponds to the first opening position of the communication pipe 32. Further, it is possible to prevent a relatively large amount of air from being ejected from the second air supply holes 33 and 34 so that the cooling air reaches the inside of the cooling air box 30 having a closed loop shape along the surface of the rectifying guide 38. It has become.
[0016]
As shown in FIG. 3, the air-fuel mixture forming means 18 has a fine gap S1 between a bell-shaped vaporizing cylinder 39 whose lower part opens to the air chamber 13A side and the lower end of the vaporizing cylinder 39. While being supported by the formation ring region of the scattering ring 40 and the first central through hole 21 arranged, the upper end side opens to the vaporization cylinder 39 side, while the lower end side opens to the air chamber 13A side and from the air chamber 13A. A substantially cylindrical blow cylinder 41 that introduces the air into the vaporization cylinder 39 as primary air for combustion, a fuel diffuser 42 positioned above the blow cylinder 41, and liquid fuel is supplied to the combustion diffuser 42 And a fuel supply pipe 44.
[0017]
The fuel diffuser 42 is connected to the substantially cylindrical side portion 42A that is open at both the upper and lower sides, the outward flange portion 42B that is continuous with the upper end of the side portion 42A, the lower end side of the side portion 42A, and the reverse hook shape. A receiving portion 42C that can receive liquid fuel from the fuel supply pipe 44 and a top portion 42D that is fixed to the upper surface side of the flange portion 42B with a minute gap S2 therebetween. The vaporizing cylinder 39 and the fuel diffuser 42 are supported by a common rotating shaft 46 located at the center thereof, and are provided so as to be integrally rotatable by driving a motor M1 having the rotating shaft 46 as an output shaft. At this time, the liquid fuel supplied to the receiving portion 42 </ b> C of the fuel diffuser 42 is jetted from the gap S <b> 2 toward the upper portion of the inner wall 39 </ b> B of the vaporizing cylinder 39 by the centrifugal force accompanying the rotation.
[0018]
An air introduction portion 19 for sending air into the combustion chamber 11 includes a cylindrical air supply pipe 49 serving as an air supply passage connecting the first and second outer through holes 22 and 27, and the air supply pipe 49. The air supply guide ring 50 is provided between the upper end open side and the scattering ring 40 and is capable of forming an air supply gap P between the scattering ring 40 and the air supply guide ring 50. The air introduction unit 19 can supply air that has passed through the air chamber 13 </ b> A as secondary air into the combustion chamber 11 from the air supply gap P through the air supply pipe 49.
[0019]
The air supply guide ring 50 is provided on the bottom wall 16A of the combustion plate 16 with a screw 51 (see FIG. 2) or the like, and is provided on the upper end side of the base member 52. It comprises an upright member 53 having a substantially L-shaped cross section for forming an air supply gap P between it and the scattering ring 40.
[0020]
The fan 14 can supply air to the air chamber 13A as the fan F is rotated by driving the motor M2. As shown in FIG. 4, the blower 14 includes a hollow rectangular block portion 60 that is continuous with the air chamber 13 </ b> A of the case 13. Partition walls 61 and 62 are formed inside the block portion 60, and the partition walls 61 and 62 form a primary air passage 63 in the center, and secondary walls on both sides sandwiching the primary air passage 63. An air passage 64 and a tertiary air passage 65 are formed. Here, in the air chamber 13A in the case 13, as shown by a dotted line in FIG. 2, the lower region of the vaporizing cylinder 39 and the blower 14 side region, the lower region of the three air supply pipes 49, and the outside of the air chamber 13A. A partition wall 68 for partitioning the region into two regions is formed. The partition wall 68 is provided at a height that reaches the bottom surface of the bottom wall 15 </ b> A of the combustion chamber outer cylinder 15, and the partition wall 68 communicates the primary air chamber 70 that connects the blower cylinder 41 and the primary air path 63, and the vaporization cylinder 39. A secondary air chamber 71 that allows the surrounding air supply pipe 49 and the secondary air passage 64 to communicate with each other is formed.
[0021]
As shown in FIG. 4, in the primary air passage 63 and the tertiary air passage 65, opening and closing plates 73 and 74 having a substantially square planar shape are arranged, respectively. The opening and closing plates 73 and 74 are supported by a single rotating shaft 75 that penetrates the plate surface and forms a common axis. The rotary shaft 75 extends in a direction crossing the primary or tertiary air passages 63 to 65, and one end side thereof is connected to a motor M <b> 3 provided outside the block portion 60 and is rotatable. The opening / closing plates 73 and 74 are provided smaller than the opening areas of the corresponding primary air passage 63 and the tertiary air passage 65, respectively, and even when the plate surface is in a substantially vertical posture, the primary air passage 63 and the tertiary air passage are provided. A constant gap is formed between the air passage 65 and the inner peripheral surface of the air passage 65 so that a minimum air flow is achieved. Further, although not particularly limited, in this embodiment, when the open / close plate 73 in the primary air passage 63 is in a substantially vertical posture, the open / close plate 74 in the tertiary air passage 65 is substantially horizontal. Is set to
[0022]
Next, the combustion operation of the burner 10 will be described.
[0023]
First, when a switch (not shown) is turned on, the blower 14 and the motor M1 operate simultaneously. When the blower 14 is operated, air is supplied from the blower 14 to the primary air chamber 70 and the secondary air chamber 71 through the primary air path 63 and the secondary air path 64, and the tertiary air path 65 and the communication pipe 32 are supplied. Then, air is supplied into the air chamber 31 of the cooling air box 30. The air sent to the primary air chamber 70 is supplied into the vaporization cylinder 39 through the blower cylinder 41 and consumed as combustion air, while the air sent to the secondary air chamber 71 passes through the air supply pipe 49 to the combustion chamber. 11 and is used as cooling air for the vaporizing cylinder 39 while being partially consumed as combustion air. In addition, the air supplied into the cooling air box 30 is ejected upward from the first air supply hole 33 and flows along the inside of the wall surface of the heat exchange element 20 arranged at the upper part. At the same time, the cooling air ejected from the second air supply hole 34 to the upper inside of the combustion chamber 11 is guided by the upward flow by the inclination direction of the guide surface portion 35B of the guide member 35, and this air is cooled by the cooling air box. By flowing along the inner peripheral surface of 30, overheating of the cooling air box 30 is prevented. At this time, the air supplied into the cooling air box 30 from the communication pipe 32 is likely to flow along the circumferential direction of the cooling air box 30 by a kind of baffle action by the rectifying guide 38, and the communication pipe 32. No large amount of cooling air locally flows through the air supply holes 33 and 34 in the vicinity of the tip. In addition, the amount of the air which flows through each air path 63-65 will be adjusted relatively by adjusting the opening degree of the opening-and-closing plates 73 and 74 which comprise a damper by the drive of the motor M3.
[0024]
The vaporizing cylinder 39 rotates together with the fuel diffuser 42 when the motor M1 is operated, and liquid fuel such as kerosene is supplied from the fuel supply pipe 44 to the receiving portion 42C of the fuel diffuser 42. This liquid fuel is ejected from the minute gap S2 formed in the fuel diffuser 42 by the rotation of the fuel diffuser 42 toward the inner wall 39B of the vaporizing cylinder 39, and between the vaporizing cylinder 39 and the scattering ring 40. It is scattered into the combustion chamber 11 from the formed gap S1. The scattered liquid fuel is ignited by a spark of an ignition device (not shown) such as an igniter extending into the combustion chamber 11, and spray combustion starts.
[0025]
When the spray combustion is started, the vaporizing cylinder 39 is heated by the combustion heat, and the liquid fuel ejected to the inner wall 39B of the vaporizing cylinder 39 is vaporized. The vaporized fuel is mixed with the primary air supplied to the inside of the vaporizing cylinder 39 to become an air-fuel mixture, and the air-fuel mixture passes through the gas chamber 24 from each flame hole 29 of the combustion disc 16 and enters the combustion chamber 11. And is vaporized and combusted.
[0026]
Therefore, according to such an embodiment, the cooling air box 30 is provided between the combustion plate 16 and the heat exchanger 20, and the first and second air supply holes 33 and 34 are provided in the cooling air box 30. Since it provided, the effect that the dew condensation in the wall surface of the heat exchanger 20 and the overheating of the cooling air box 30 can be prevented simultaneously is acquired.
[0027]
The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this.
That is, the present invention has been illustrated and described primarily with respect to particular embodiments, but without departing from the scope of the technical idea and purpose of the present invention, Various modifications can be made by those skilled in the art in shape, material, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.
[0028]
For example, in the above embodiment, the rectifying guide 38 is provided at a position corresponding to the tip of the communication pipe 32. However, the opening diameters of the first and second air supply holes 33 and 34 at the position corresponding to the tip and in the vicinity thereof are set. If the diameter is relatively small, the straightening guide 38 is not necessarily provided.
[0029]
Moreover, in the said Example, although the burner 10 provided with the combustion chamber 11 which makes a substantially square shape by planar view was demonstrated, this invention is not limited to this, The combustion chamber of other polygonal shape, cylindrical shape, or elliptical shape is used. It can also be applied to the burner provided.
[0030]
【The invention's effect】
As described above, according to the present invention, it is possible to flow cooling air to the inner peripheral surface side of the cooling air box that prevents dew condensation on the wall surface of the heat exchange element disposed at the upper part of the combustion disk. Thus, it is possible to provide a liquid fuel combustion apparatus that has an unprecedented excellent effect of preventing overheating of the cooling air box.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a burner according to an embodiment.
FIG. 2 is a schematic plan view of the burner in a state where a vaporizing cylinder and a scattering ring are removed from FIG.
FIG. 3 is a schematic end view taken along the line AA in FIG. 1;
FIG. 4 is a schematic perspective view showing a lower shape of the blower.
FIG. 5 is a schematic perspective view of a guide member.
FIG. 6 is a plan view of a guide member.
7 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Burner (liquid fuel combustion apparatus), 11 ... Combustion chamber, 16 ... Combustion board, 20 ... Heat exchanger, 29 ... Flame hole, 30 ... Cooling air box, 30A ... Inner peripheral surface, 30B ... Outer peripheral surface, 31 DESCRIPTION OF SYMBOLS ... Air chamber, 32 ... Communication pipe, 33 ... 1st air supply hole, 34 ... 2nd air supply hole, 35 ... Guide member, 38 ... Rectification guide, 39 ... Vaporization cylinder, 40 ... Scattering ring, 49 ... Air supply pipe ( Air supply passage)

Claims (2)

A liquid fuel combustion apparatus disposed at a lower part of a heat exchanger, wherein the liquid fuel is scattered in a combustion chamber provided at a lower part of a combustion disc forming a combustion chamber in an upper part and a vaporization cylinder disposed in the combustion chamber. A scattering ring, an air supply passage for supplying air to the lower surface side of the scattering ring, and a blower for supplying air to an air chamber provided at a lower portion of the combustion disc, and between the vaporizing cylinder and the scattering ring The liquid fuel scattered in the combustion chamber is ignited and spray combustion is performed, and the vaporization cylinder is heated by the combustion heat of the spray combustion to vaporize the liquid fuel supplied into the vaporization cylinder, and the vaporization In a liquid fuel combustion apparatus that performs vaporization combustion by ejecting the fuel that has been discharged from a flame hole formed in the side wall of the combustion disc,
A cooling air box having a closed loop shape in plan view to which cooling air is supplied is provided between the combustion plate and the heat exchanger, and air is provided on the upper surface of the cooling air box along the wall surface of the heat exchanger. while the first supply hole for jetting are provided, said the lower inner peripheral surface of the cooling air box, the second air supply hole is provided for ejecting air to avoid overheating of the inner peripheral surface Rutotomoni, the On the inner peripheral surface side of the cooling air box, there is provided a guide member having a plurality of guide surface portions for causing the air ejected from the second air supply hole to follow the inner peripheral surface of the cooling air box, The liquid fuel combustion apparatus is characterized in that the guide surface portions are provided discontinuously . A front end of a communication pipe for introducing air from the blower is connected to an outer peripheral portion of the cooling air box, and a cooling air rectifying guide is disposed inside the cooling air box corresponding to the front end. The liquid fuel combustion apparatus according to claim 1.

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