JPH06174209A - Vaporizing type burner - Google Patents

Abstract

PURPOSE:To improve the combustion efficiency on a simple structure, make the combustion chamber shorter in length to achieve structural compactness, and prevent emission of white smoke at the time of ignition. CONSTITUTION:Inside a body 28 closed at one end by a wall plate 18 a supporting body 32 holding a fuel-absorbent material 36 in a closed state is housed. A mixing tube 54, which produces fuel-air mixture by mixing gasified fuel from a circulation chamber 42 with air for fuel from an air chamber 14, is projected into the combustion chamber 52. A multiplicity of ejection holes 60 are formed in the mixing tube 54 so that the fuel-air mixture is ejected into the combustion chamber 52 through the ejection holes 60. A stay 70 in which a hole 64 is formed partitions the inside of the mixing tube 54 at an intermediate point; the stay 70 is fitted with a cylindrical metal net 72 in such a manner as to have the inside of the cylindrical metal net 72 and the hole 64 in connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporative burner used for a heating device such as a heater for a vehicle, a heater for ships, a general-purpose portable heater and the like, and more particularly to an evaporative burner for preventing generation of white smoke.

[0002]

2. Description of the Related Art Generally, for example, Japanese Unexamined Patent Application Publication No. Sho 5-
Evaporative burners for heating vehicles and ships, such as that shown in No. 9-60109, are provided. In this evaporative burner, a combustion chamber is formed inside a tubular body, and a fuel absorber is arranged directly in the combustion chamber, or a fuel absorber is provided facing the combustion chamber, and the heat inside the combustion chamber is reduced. To vaporize the fuel from the fuel absorber to produce fuel vapor. On the other hand, an inflow hole for combustion air is formed on the wall surface of the body, the combustion air from the inflow hole and the fuel vapor generated from the fuel absorber are mixed in the fuel chamber, and the fuel vapor and the combustion air are mixed. Ignite the mixture with a spark plug.

[0003]

In the conventional evaporative burner, the fuel vapor and the combustion air flow into the combustion chamber from different positions. For this reason, it is difficult to completely mix the fuel vapor and the combustion air, and it is also difficult to set the inflow hole for the combustion air, so that there is a problem that good combustion cannot be obtained. Further, since the fuel absorber is arranged in the combustion chamber, over time, products of combustion are deposited on the fuel absorber, evaporation from the fuel absorber is impaired, and combustion failure occurs. It was easy to occur.
In addition, the product is similarly deposited on the coil-wound spark plug that is arranged so as to project in the combustion chamber, which causes disconnection and burning of the coil, and the heater cannot be used easily. Further, when heavy oil is used as a fuel, there is a problem that white smoke is likely to be generated in the combustion chamber due to poor ignitability.

The present invention has been made in view of the above circumstances, and prevents the accumulation of products on the fuel absorber and the heater to prolong the life of the fuel absorber and to move the air-fuel mixture in which air and fuel vapor are mixed. An object of the present invention is to provide an evaporative burner capable of improving the combustion efficiency by increasing the distance and mixing well and preventing the generation of white smoke in the combustion chamber.

[0005]

In order to achieve the above object, the present invention vaporizes a fuel contained in a fuel absorber, mixes the vaporized vaporized fuel with combustion air to form a mixture, and In an evaporative burner that ignites an air-fuel mixture with a spark plug in a combustion chamber provided inside a tubular body,
A support that accommodates the fuel absorber therein without directly exposing it to the combustion chamber, an air chamber into which the combustion air is introduced, air from the air chamber, and vaporized fuel vaporized from the fuel absorber. And a mixing pipe that forms a mixing passage into which is introduced and that projects into the combustion chamber, and a mixing pipe that projects into the combustion chamber to connect the mixing passage and the combustion chamber. A large number of injection holes formed on the outer circumference, a stay that is provided in the mixing pipe and defines a mixing passage therein, and a mixing passage that is formed in the stay and before and after the stay are connected. And a cylindrical metal net that connects the internal space with the hole, and the ignition plug is arranged in the vicinity of the combustion air introduction side of the mixing pipe partitioned by the stay, and the fuel absorption Burned vapor from the body And combustion air from the air chamber are mixed in the mixing passage to form an air-fuel mixture, and when the flow velocity of the combustion air is low, most of the air-fuel mixture is burned from the injection holes provided in the mixing pipe before the stay position. When the air is injected into the room and the flow velocity of the combustion air becomes faster, a large amount of air-fuel mixture passes through the stay holes, and the air-fuel mixture is almost evenly supplied from the injection holes provided in the mixing pipes before and after the stay position. It is designed to be injected into the combustion chamber.

[0006]

The fuel absorber is housed in the support so as not to directly face the combustion chamber. This prevents the combustion residue generated by the combustion of the fuel from accumulating on the fuel absorber. Since the air-fuel mixture is preformed in the mixing tube and the air-fuel mixture is jetted into the combustion chamber, the combustion efficiency is improved. The air-fuel mixture is radially injected into the combustion chamber from a large number of injection holes provided on the outer circumference of the mixing pipe. In other words, the flame becomes a radial flame in the body, so the burner length can be made to match the length of the combustion chamber and heat exchanger, and the axial length of the body can be shortened to reduce the burner size. Can be converted. The inside of the mixing tube is divided into stays having holes, and the front and rear of the stays are connected via the holes and the tubular metal net. As a result, at the time of ignition when the flow velocity of the air-fuel mixture is slow, most of the air-fuel mixture does not pass through the stay hole, and the air-fuel mixture is injected from the injection hole near the ignition plug of the mixing pipe, and the ignition plug The mixture is immediately ignited by. Therefore, even with heavy oil, it is possible to prevent the generation of white smoke at the time of ignition. In steady operation, the velocity of the air-fuel mixture increases and the air-fuel mixture passes through the holes in the stay. As a result, the carburetor can be injected almost uniformly from all the injection holes of the mixing tube.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1 is a sectional view showing an embodiment of an evaporative burner according to the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. In the evaporative burner, by the casing 10 and the cover 12,
An air chamber 14 is formed inside the casing 10, and an air introduction port 16 for introducing air into the air chamber 14 is also formed. The wall plate 18 that constitutes the casing 10 includes a plurality of spiral guide plates 2 on the air chamber 14 side.
0 is provided, and the plurality of spiral guide plates 20 are provided.
2, the air introduced into the air chamber 14 is swirled and directed toward the center of the air chamber 14, as shown in FIG. At the center of the wall plate 18, a tubular portion 22 projecting to the opposite side of the guide plate 20 is integrally formed.
The air passage 24, which is the inner space of the second passage, communicates with the air chamber 14, and the combustion air introduced into the air passage 24 from the air chamber 14 is ejected in a swirled state from the ejection port 26 of the air passage 24. .

On a surface of the wall plate 18 of the casing 10 opposite to the guide plate 20, a cylindrical body 2 having both ends open.
8 is attached via the sealing material 30. Casing 1
The zero wall plate 18 serves as one closed end surface of the tubular body 28. Inside the body 28, a tubular support 32 is provided with a slight gap from the wall plate 18. An annular fuel absorber 34 made of porous ceramic, metal or the like is housed inside the support 32 in a sealed state. A fuel supply pipe 36 for supplying fuel to the fuel absorber 34 is provided so as to penetrate the cover 12 and the casing 10. The support 32 accommodating the fuel absorber 34 is fixed to the wall plate 18 with bolts 40 with a spacer 38 interposed between the support 32 and the wall plate 18. The spacer 38 forms a circulation chamber 42 formed of a space between the support 32 and the wall plate 18. This support 32
A pressure equalizing chamber 44, which communicates with a space for accommodating the fuel absorber 34, is provided inside the chamber on the side close to the circulation chamber 42.
The fuel vaporized from the fuel absorber 34 is introduced into the pressure equalizing chamber 44 through the vaporization port 46. The vaporized fuel is made to have a uniform concentration in the pressure equalizing chamber 44, and the vaporized fuel made uniform is ejected from the communication hole 48 into the circulation chamber 42.

The tubular axis of the support 32 and the tubular axis of the body 28 are arranged to be the same, and the tubular outer wall of the support 32 and the tubular inner wall of the body 28 are arranged. A gap is formed between the two, and the annular space formed by this gap serves as a communication passage 50 connected to the circulation chamber 42. That is, the internal space of the body 28, which is closed at one end by the wall plate 18, is the main space located on the opposite side of the wall plate 18 from the position of the support 32, and the combustion chamber 52. The communication passage 50 communicating with the chamber 52, and the communication passage 50
And the circulation chamber 42 communicating with the above. That is, the circulation chamber 42
Are set to communicate with the combustion chamber 52 via the communication passage 50.

A tubular mixing tube 54 is attached to the support 32 by penetrating through the center of the tubular support 32 and the annular fuel absorber 34. The tip of the mixing tube 54 extending into the combustion chamber 52 is closed by a detachable lid 56. In this mixing tube 54, an opening is formed on the side opposite to the side where the lid 56 is attached, and the opening is the wall plate 1 described above.
8 is facing. The central axis of the mixing tube 54 is set to coincide with the central axis of the tubular portion 22 formed on the wall plate 18, and the inner diameter of the mixing tube 54 is set to be larger than the outer diameter of the tubular portion 22. As shown in FIG. 1, it is desirable that the tip end opening portion of the tubular portion 22 does not enter the opening portion of the mixing tube 54. The mixing passage 58, which is an internal space of the mixing pipe 54, communicates with the circulation chamber 42 through a gap between the opening of the mixing pipe 54 and the tip of the tubular portion 22. In addition,
The tip end opening portion of the ejection port 26 of the cylindrical portion 22 may enter into the opening portion of the mixing tube 54. The mixing pipe 54
Is sufficiently projected into the combustion chamber 52 from the position of the support 32, and a large number of injection holes 60 serving as flame ports are provided on the cylindrical outer periphery of the mixing pipe 54 protruding into the combustion chamber 52. .

An ignition plug 62 is provided in parallel with the mixing pipe 54 and in a state of penetrating the support 32. The tip of the spark plug 62 extends to an appropriate position in the combustion chamber 52. The spark plug 62 is preferably a glow plug generally made of a ceramic such as silicon nitride and a tungsten wire embedded in the ceramic. The structure of the glow plug is not limited to this.

A hole 64 is formed in the center of the mixing tube 54.
Around the hole 66 and the disk portion 66 forming the
A stay 70 integrally formed with a tubular portion 68 having a right angle to is attached (FIGS. 1 and 3). Disk part 6 of stay 70
The outer diameter of 6 is set so as to fit exactly on the inner wall of the mixing tube 54. Further, the inner diameter of the hole 64 and the outer diameter of the tubular portion 68 are the same, and the diameter thereof is not fixed, but the disc portion 6
About half the outer diameter of 6 is desirable. The stay 70 can be attached to any position of the mixing pipe 54. Preferably, the disk of the stay 70 is installed at the support 32.
Let L be the in-tube length of the mixing pipe 54 from the tip end position from the side of the most combustion chamber 52 to the position of the lid 56, and let the length from the lid 56 to the position of the disc portion 66 be M, M ≧ 1 / 2L is desirable. As shown in FIG. 1, a stay 70 is attached to the mixing pipe 54 so that the tubular portion 68 is located on the side opposite to the lid 56, and a tubular wire net 72 is provided outside the tubular portion 68.
Install. That is, the internal space of the tubular wire net 72 and the hole 64 of the stay 70 are communicated with each other. This wire net 7
2 is selected to have a mesh so that the air-fuel mixture can pass from the inside to the outside. The spark plug 62 is an existing one and has a limited length, and the position of the stay 70 is mixed from the free end position of the spark plug 62 attached to the base side (the side opposite to the lid 56) of the mixing pipe 54. It is set so as to be located on the distal end side of the tube 54.

Next, the function of the evaporative burner will be described. The air that has entered the air chamber 14 through the air inlet 16 is swirled by the guide plate 20 while being swung by the guide plate 20.
Are collected in the center of the inside, and then the air passage 2 in the tube portion 22
4 into the spiral shape, and is jetted from the jet outlet 26 of the air passage 24 toward the mixing passage 58 in the mixing pipe 54 while maintaining the spiral shape. On the other hand, fuel is supplied from a fuel supply pipe 36 to the fuel absorber 34 provided in the support 32. The fuel absorber 34 is heated by the spark plug 62, and the fuel contained in the fuel absorber 34 is vaporized and becomes vaporized fuel. The vaporized fuel vaporized from the fuel absorber 34 enters the pressure equalizing chamber 44 located next to the fuel absorber 34,
Then, the gas is ejected into the circulation chamber 42. The vaporized fuel ejected into the circulation chamber 42 is introduced into the mixing passage 58 together with the combustion air by the suction action of the combustion air ejected in a spiral shape from the ejection port 26 into the mixing passage 58. The vaporized fuel and the combustion air are uniformly mixed in the mixing passage 58. At this time, since the combustion air is introduced into the mixing passage 58 in a swirling state, the combustion air and the vaporized fuel are mixed well. The air-fuel mixture that has been sufficiently mixed in the mixing pipe 54 has the injection holes 6 formed in the mixing pipe 54.
It is injected radially into the combustion chamber 52 from 0. In the conventional one in which the combustion air and the fuel are separately introduced into the combustion chamber, a flame is generated from a position where the combustion air and the vaporized fuel are mixed, but in the present invention, the combustion air and the vaporized fuel are used. Are mixed in advance to form a mixture, and the mixture is supplied from a large number of injection holes 60 formed on the outer surface of the cylinder of the mixing pipe 54 to the combustion chamber 5.
Since the gas is radially ejected into the combustion chamber 2, a radial flame train can be formed in the combustion chamber 52. As a result, the combustion chamber 52
Can be shorter than the conventional one.

A stay 70 in the mixing tube 54 as in the present invention.
If not equipped, the mixing tube 54 and the combustion chamber 5 at the time of ignition.
Since 2 is not warmed, when heavy oil is used as fuel, the air-fuel mixture in the combustion chamber 52 which immediately blows out near the base of the mixing pipe 54 where the ignition plug 62 is located. Although it is ignited, it takes a long time to transfer the air-fuel mixture injected into the combustion chamber 52 located away from the spark plug 62, and white smoke is liable to be generated. On the other hand, in the present invention, the hole 64 is provided in the middle of the length in the mixing pipe 54.
The stay 70 is formed, and a cylindrical wire net 72 having a space communicating with the hole 64 is attached to the stay 70. With this configuration, since the velocity of the air-fuel mixture ejected into the mixing passage 58 in the straight-ahead direction is small at the time of ignition, most of the air-fuel mixture is blocked by the disc portion 66 of the stay 70 and passes through the hole 64. Therefore, the amount of air-fuel mixture reaching the tip side of the mixing pipe 54 is small. As a result, of the air-fuel mixture injected into the mixing passage 58, most of the air-fuel mixture is injected into the combustion chamber 52 from the injection hole 60 on the base side of the installation position of the stay 70. Since the spark plug 62 is located on the base side of the mixing pipe 54, most of the air-fuel mixture injected into the combustion chamber 52 is immediately ignited by the spark plug 62.
The flame transfer time to the air-fuel mixture injected into the combustion chamber 52 can be shortened, and the generation of white smoke can be prevented.

After ignition, steady combustion rises and the velocity of the air-fuel mixture introduced in the mixing passage 58 in the straight direction increases, so that the air-fuel mixture passes through the inside of the cylinder of the wire net 72 and the hole 64 of the stay 70. It can reach the tip side of the mixing tube 54.
Further, when passing through the inside of the wire net 72, the air-fuel mixture is
2 leaks from the inside to the outside. In this way, the tubular wire mesh 7
The straightness of the air-fuel mixture is secured by 2 and the hole 6 of the stay 70 is
After passing through 4, the air-fuel mixture is evenly distributed from the installation position of the stay 70 to the tip side of the stay 70. Further, since the air-fuel mixture is passed from the inside of the wire net 72 to the outside on the root side of the installation position of the stay 70, the air-fuel mixture can be evenly distributed to the mixing passage 58 on the root side of the installation position of the stay 70. it can. Therefore, during steady combustion, the air-fuel mixture stays at 70
Is almost evenly sent before and after the installation position, and the air-fuel mixture is injected from the injection holes 60 of the mixing pipe 54 into the combustion chamber 52 almost evenly to make the flame length in the combustion chamber 46 substantially uniform. be able to.

After the air-fuel mixture is ignited, the support 3 is heated by the combustion gas generated by the combustion of the air-fuel mixture in the combustion chamber 52.
2 is heated and the fuel absorber 34 is heated by the conduction heat from the support 32. Further, a part of the high temperature combustion gas generated in the combustion chamber 52 is discharged from the communication passage 50 into the circulation chamber 4
Since it circulates around the support 32 to reach 2, the fuel absorber 34 held in the support 32 is further heated. Further, a part of the combustion gas generated in the combustion chamber 52 is
From the communication passage 50 through the circulation chamber 42, the air passage 24
Since it is introduced into the mixing passage 58 together with the combustion air from the jet outlet 26, the combustion air entering the mixing passage 58 has a high temperature, and the air-fuel mixture formed in the mixing passage 58 also has a high temperature, so that the combustion chamber Ignition of the air-fuel mixture ejected into 52 can be promoted.

[0017]

As described above, according to the evaporative burner according to the present invention, the air-fuel mixture is ejected radially into the combustion chamber from the injection holes provided on the outer periphery of the mixing tube, and the air-fuel mixture ejected is ejected. It is designed to ignite immediately. That is, the cylindrical burner is provided with a large number of burner holes for ejecting holes on the outer periphery thereof, and flames are generated in the radial direction of the combustion chamber. Therefore, the burner length can be adjusted to match the length of the combustion chamber or heat exchanger, and the overall length of the evaporative burner is longer than that of the conventional one that ejects the air-fuel mixture in the axial direction of the cylinder. The length can be shortened. Further, since a stay having a hole in the middle of the mixing tube is provided and a cylindrical wire mesh is provided on the air introduction side of the hole position, most of the air-fuel mixture from the stay position to the tip side of the mixing tube reaches at the time of ignition. Since most of the air-fuel mixture is ejected from the injection hole near the spark plug, the air-fuel mixture injected into the combustion chamber is immediately ignited. Therefore, even when the heavy oil is used as the fuel, the air-fuel mixture is immediately ignited and the generation of white smoke can be prevented. Further, since the flame of the combustion chamber does not directly reach the fuel absorber, combustion products do not deposit on the fuel absorber, and the life of the evaporative burner can be extended. In addition, the fuel absorber is heated by the conduction heat from the support, the heat generated by a part of the combustion gas circulating around the support and the heat generated by the ignition plug. The fuel residue is less likely to be deposited, and the life of the evaporative burner can be extended. Further, since the combustion air in the swirling state and the vaporized fuel are mixed in the mixing passage, the mixing can be performed well. Moreover, since the air-fuel mixture in the swirling state passes through the inside of the wire net, the air-fuel mixture passes from the inside of the wire net to the outside when passing through the inside of the wire net, and the air-fuel mixture is dispersed almost evenly in the mixing passage. Can be made.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an evaporative burner according to the present invention.

2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a stay.

[Explanation of symbols]

 14 Air Chamber 20 Guide Plate 28 Body 32 Support 34 Fuel Absorber 42 Circulation Chamber 52 Combustion Chamber 54 Mixing Tube 58 Mixing Passage 60 Injection Hole 62 Spark Plug 64 Hole 70 Stay 72 Wire Mesh

Claims (4)

[Claims] 1. The fuel contained in the fuel absorber is vaporized,
In the evaporative burner in which combustion air is mixed with the vaporized vaporized fuel to form an air-fuel mixture, and the air-fuel mixture is ignited by a spark plug in a combustion chamber provided inside a tubular body, the fuel absorber is A support that is housed inside without being directly exposed to the combustion chamber, an air chamber into which the combustion air is introduced, a mixture of air from the air chamber and vaporized fuel vaporized from the fuel absorber. A mixing pipe for forming a passage therein and projecting into the combustion chamber, and a large number of mixing pipes formed on the outer periphery of the mixing pipe at a portion projecting into the combustion chamber for connecting the mixing passage and the combustion chamber. An injection hole, a stay that is provided in the mixing pipe and defines a mixing passage therein, a hole that is formed in the stay and that connects the mixing passage before and after the stay, and the inside thereof A mixing chamber having a tubular metal net that connects the space and the hole, a spark plug is disposed in close proximity to the combustion air introduction side of the mixing pipe partitioned by the stay, and fuel vaporized from the fuel absorber is provided. Combustion air from the air chamber is mixed in the mixing passage to form an air-fuel mixture, and when the flow velocity of the combustion air is low, most of the air-fuel mixture is discharged from the injection holes provided in the mixing pipe before the stay position. When the flow velocity of the combustion air increases, a large amount of air-fuel mixture passes through the stay holes, and the air-fuel mixture is burned almost evenly from the injection holes in the mixing pipes in front of the stay position and at the back of the stay position. An evaporative burner characterized by being injected indoors. 2. The evaporative burner according to claim 1, wherein the spark plug has a rod-shaped heat generating portion, and the heat generating portion is arranged in parallel with the mixing tube. 3. A circulation chamber is provided, one of which communicates with the combustion chamber and the other of which communicates with an inlet side of the mixing tube for introducing combustion air, and a part of the combustion gas burned in the combustion chamber is provided in the circulation chamber. 2. The evaporative burner according to claim 1, wherein a part of the combustion gas introduced into the circulation chamber in the absence thereof is introduced into the mixing passage together with combustion air. 4. An air swirling guide plate is provided in the air chamber so that the combustion air introduced from the air chamber to the mixing passage swirls toward the mixing passage. Evaporative burner described.