JPH1114151A - Hot air blower - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a hot air blower capable of completely burning fuel to improve thermal efficiency and not requiring a chimney. SOLUTION: A combustion furnace 8 is disposed in a cylindrical wind tunnel 1 whose both ends are closed, and a nozzle 12a of a burner 12 faces the combustion furnace 8, and the fuel is injected into the combustion furnace 8 from the nozzle 12a. A hot air blower that burns the fuel, introduces air into the wind tunnel 1 by the blowers 6 and 5, warms the air, and then blows hot air from the opening 1a of the wind tunnel 1 to the outside, A refractory ceramic plate 16 as a “shielding plate” made of a material having heat resistance and to which the fuel is apt to adhere is used to receive a fuel injected from the nozzle 12 a in the combustion furnace 8 and generate a flame generated by combustion. It is arranged in the position where it receives.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hot air blower that burns fuel, warms air with the heat, and blows the hot air.

[0002]

2. Description of the Related Art Conventionally, there are hot air heaters for heating vegetables, fruits, horticultural houses and factories. This is done by burning fuel with a burner, using this heat to warm the air, blowing this hot air with a blower, and spreading it through a vinyl duct connected to the hot air into the house, etc. The inside is heated.

[0003]

However, in such a conventional apparatus, it is difficult to completely burn the fuel, the heat efficiency is low, and a chimney is provided to discharge incomplete combustion gas. Because of this, heat escapes from this chimney, and the work of arranging the chimney is troublesome.In addition, the arrangement position of the hot air blower is restricted and it is not possible to move it freely, and it is easy to use. I can't say.

Accordingly, the present invention enables complete combustion of fuel to improve thermal efficiency,
The chimney arrangement is to provide a hot air heater that is free.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a combustion furnace is provided in a cylindrical wind tunnel whose both ends are closed, and the combustion furnace is provided in the combustion furnace. With the nozzle of the burner facing, the fuel injected from the nozzle into the combustion furnace is burned, and air is introduced into the wind tunnel by a blower, and after the air is warmed, warm air is discharged from the opening of the wind tunnel to the outside. And a member made of a material having heat resistance and easily adhering the fuel, the inner wall of the combustion furnace being disposed at a position for receiving the fuel injected from the nozzle. It is characterized by the following.

According to a second aspect of the present invention, a combustion furnace is disposed in a cylindrical wind tunnel whose both ends are closed, a nozzle of a burner faces the combustion furnace, and the combustion furnace is introduced from the nozzle into the combustion furnace. A hot air blower that burns injected fuel, introduces air into the wind tunnel by a blower, warms the air, and then blows warm air from the opening of the wind tunnel to the outside, and has heat resistance. The shield plate made of a material to which the fuel easily adheres is characterized in that it is a hot air blower arranged at a position in the combustion furnace that receives the fuel injected from the nozzle and receives a flame generated by combustion. I do.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the shielding plate is disposed in a high temperature region of the flame.

[0008] The invention according to claim 4 is the invention according to claims 1 to 3.
In addition to the configuration according to any one of the above, the combustion furnace has a tubular shape, and an opening is formed at a tip end opposite to the nozzle arrangement portion, while the blower is the combustion furnace. It is characterized in that it is located on the nozzle disposition portion side from the tip end, and the opening formed in the wind tunnel is located forward of the tip end of the combustion furnace.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, an opening formed at a front end of the combustion furnace is closed by a cover having a plurality of through holes. It is characterized by.

According to a sixth aspect of the present invention, a combustion furnace is provided in a cylindrical wind tunnel whose both ends are closed, and a burner nozzle faces the inside of the combustion furnace. A hot air blower that burns injected fuel, introduces air into the wind tunnel by a blower, warms the air, and then blows warm air to the outside through a hot air port of the wind tunnel, and has heat resistance. A shield plate made of a material to which the fuel easily adheres, receives the fuel injected from the nozzle in the combustion furnace,
And, while being disposed at a position for receiving the flame generated by combustion, a primary air vent for discharging air from the combustion furnace is a hot air blower set at a position protruding outward from a hot air port of the wind tunnel. Features.

[0011] The invention according to claim 7 is the invention according to claims 1 to 6.
In addition to the configuration described in any one of the above, a heat storage unit that stores heat generated by the combustion is provided in the combustion furnace.

According to an eighth aspect of the present invention, in addition to the configuration of any one of the first to third and fifth to seventh aspects, the combustion furnace further includes a secondary ventilation for removing air from the combustion furnace. An opening / closing device that forms an opening and closes the secondary ventilation opening when burning and opens when not burning is provided.

[0013]

Embodiments of the present invention will be described below.

[First Embodiment of the Invention] FIGS. 1 to 8 show a first embodiment of the present invention.

First, the structure will be described. In FIG. 1, reference numeral 1 denotes a wind tunnel, which is a front opening of a cylindrical body 2 (FIG. 1).
The middle left side opening) is closed by a lid 3, a heat insulating board 4 is disposed inside the lid 3, and the right end side in FIG. 1 is also closed.

Above the cylindrical body 2, first and second blowers 6 and 5 are provided along the longitudinal direction.
5 is set so that outside air is introduced into the wind tunnel 2.

A combustion furnace 8 is provided in the wind tunnel 1 and supported by a stand 9. This combustion furnace 8
It has a cylindrical combustion furnace main body 10 having one end 10a side closed and an opening 10e formed at the other end side. A mounting hole 10b is formed at the one end 10a.
Is connected to the burner 12. A heat insulating material 10 made of a heat-resistant ceramic, which is a material having heat resistance and to which fuel easily adheres, is provided on the inner wall of the combustion furnace body 10.
c is provided.

Further, inside the combustion furnace main body 10, that is,
In the combustion chamber 14, a refractory ceramic plate 16 as a "shielding plate" is provided, and a heat storage unit 15 is provided on the side of the refractory ceramic plate 16 opposite to the burner 12 side.

More specifically, the heat storage section 15 has a plurality of ceramic heat storage tubes 15a connected to each other as shown in FIG. 7 and the like, and a ceramic heat storage element spirally wound in each of these heat storage tubes 15a. 15b is provided. If the temperature is not so high, stainless steel can be used.

As shown in FIG. 1, an extension 15c extending toward the burner 12 is formed in a central portion of the heat storage cylinders 15a, and a refractory ceramic plate 16 is formed on the extension 15c. Fixed and supported. The refractory ceramic plate 16 has heat resistance and easily adheres to fuel.

The wind tunnel 1 is mounted on a gantry 18. An opening 1a is formed in the lower portion of the wind tunnel 1 so as to penetrate the inside and outside of the wind tunnel 1, and a square cylindrical mounting portion is formed in the opening 1a. 19 are provided. And this mounting part 19
In addition, a connecting body 20 for connecting the vinyl duct 22 and the vinyl duct 22 is attached.

The connecting body 20 has the shape of a square tube with a bottom and an open upper end, and the upper part 20a is mounted on the mounting part 19 with bolts or the like. Hexagonal air outlets 20b are formed on opposing side walls of the connecting body 20, and the end of the vinyl duct 22 fits outside a flange portion 20c formed on a peripheral portion of the air outlet 20b. And attached by a band (not shown). Since the upper end opening of the connecting body 20 has a square shape, the mounting position can be changed by 90 degrees.

The vinyl duct 22 is arranged in various forms depending on the size of the house 110 and the like. FIGS. 5 and 6 show examples.

An air intake duct 25 is connected to the burner 12, and this duct 25 is extended to the outside of the house 110 as shown in FIG.

The burner 12 is provided with a nozzle 12a for injecting fuel, and an electrode rod (not shown) for igniting the fuel injected from the nozzle 12a.

The fuel is injected from the nozzle 12a at a total angle of 120 ° as shown in FIG. 1, and the ignited flame burns as shown in FIG. .

The refractory ceramic plate 16 is set to the position and size for receiving the fuel injected at such an angle and the burning flame. Moreover, the refractory ceramic plate 16 is placed in a high temperature region of the flame.

The blowers 6 and 5 and the opening 1 of the wind tunnel 1
a, the relative positions of the combustion furnace main body opening 10e and the like are such that the blowers 6 and 5 are located closer to the nozzle 12a disposition portion side than the combustion furnace main body opening 10e which is the tip of the combustion furnace 8; The opening 1a of the wind tunnel 1 is positioned halfway forward (left side in FIG. 1) from the tip of the combustion furnace 8.

Next, the operation will be described.

When the power switch is turned on, the indicator lamp of the power turns on and the temperature controller operates. And first, first
When the blower 6 is operated and the second blower 5 is operated thereafter, an air flow is formed from the rear of the wind tunnel 1 to the front, and the air flow from the inside of the wind tunnel 1 to the vinyl duct 22 is smoothly performed. Will be

On the other hand, in the burner 12, when the electrode rod is preheated and heated, fuel is injected from the nozzle 12a, and the fuel is ignited by the electrode rod, so that combustion is performed.

In this case, 120 ° from the nozzle 12a
The unburned fuel injected at an angle of? Is first adsorbed to the heat insulating material 10c on the inner wall of the combustion furnace main body 10. Insulation material 10c
The unburned fuel reflected without being adsorbed and the unburned fuel directly injected are adsorbed on the refractory ceramic plate 16.

The refractory ceramic plate 16 is heated to a high temperature by the flame generated by igniting the fuel and stores heat, and the unburned fuel adsorbed on the refractory ceramic plate 16 is completely burned as described above. You. Therefore, unburned fuel is not blown to the vinyl duct 22 side. In addition, the flame raises the temperature of the refractory ceramic plate 16 and becomes a heating element, so that the fuel is burned when the refractory ceramic plate 16 is hit. In particular, since the refractory ceramic plate 16 is disposed in a high temperature region of the flame, the effect as a heating element is remarkable.

Therefore, the fuel injected from the nozzle 12a is completely burned. This is clear from the test. In the prototype machine embodying Embodiment 1 of the present invention, the maximum temperature of the flame generated from the burner 12 during normal operation was about 800 ° C. It has been confirmed that the central surface temperature was about 1,100 ° C.

A heat storage section 15 is provided on the left side of the refractory ceramic plate 16 in the drawing, so that the heat storage section 1 is provided.
The temperature of the heat storage cylinder 15a and the heat storage body 15b of No. 5 rises, and heat is stored in this portion. As a result, a heat storage effect is exerted on the entire combustion furnace 8, and the thermal efficiency is improved.

Further, in this state, the air in the house 110 is introduced into the wind tunnel 1 outside the hot air blower 100 by the first and second blowers 6 and 5, and the air is converted into heat in the combustion furnace 8. To make it warm air,
The air is blown within 0.

At this time, the arrangement positions of the first and second blowers 6 and 5 are located on the right side in the figure from the tip of the combustion furnace 8 and are located at the connection portion (opening 1a) of the vinyl duct 22. Since about half is located on the left side in the figure from the tip of the combustion furnace 8, the wind from both the blowers 6, 5 does not flow directly into the combustion chamber 14, and the air in the wind tunnel 1 Air is blown from the opening 1a at the position. Therefore, the flow of the wind in the wind tunnel 1 is as shown by the arrow, and a rise in the pressure in the combustion chamber 14 can be suppressed, so that the ignitability and the combustibility can be improved.

When the room temperature in the house 110 reaches the set temperature, the operation of the burner 12 is stopped by the control device, and the combustion in the combustion chamber 14 is stopped. However, if both the blowers 6 and 5 are stopped at the same time as the combustion is stopped, the temperature of the combustion furnace 8 increases due to residual heat.
By operating both the blowers 6 and 5 continuously for a certain period of time after stopping the combustion, the temperature of the combustion furnace 8 is prevented from rising abnormally.

Thereafter, when the room temperature in the house 110 becomes lower than the set temperature, the burner 12 automatically operates again to start combustion, and warm air is blown into the room to increase the room temperature.

By repeating such an operation, the room temperature in the house 110 is controlled to the set temperature.

That is, the graph shown in FIG. 8 shows the relationship between the burning time and the temperature rise. The fuel is lamp fuel, the room volume is 981.12 m ³ , and the room temperature before operation is 8.
This shows the results of experiments conducted under the conditions of 6 ° C., the temperature of the combustion furnace 8 is 9.0 ° C., the set temperature of the indoor thermostat is 18 ° C., and the upper limit of the temperature of the opening 1a is 60 ° C. Referring to this graph, the temperature of the opening 1a continues to rise to about 37 ° C. until about 15 minutes from the start of combustion, while the room temperature continues to rise to about 19 ° C. to about 20 minutes. In this case, since the burner 12 is turned off at the elapsed time of 19 minutes, the temperature of the opening 1a and the room temperature decrease. Then, when the room temperature falls below 18 ° C., the burner 12 is turned on again, and the room temperature rises and this is repeated.

In this way, since the fuel is completely burned, the thermal efficiency is improved, so that the fuel consumption can be reduced and a chimney for discharging incomplete combustion gas is not required. Therefore, no chimney equipment is required, and as a result, there is no restriction on the installation position of the chimney, so that the degree of freedom of the installation position of the hot air blower 100 is improved.

Such a hot air blower is provided with various safety devices. When the temperature of the combustion furnace 8 rises abnormally or when the burner 12 becomes abnormal, an alarm is issued or operation is started. Or to stop.

On the other hand, the hot air blower 100 is
When the vinyl duct 22 is extended in a direction (vertical direction in the figure) orthogonal to the longitudinal direction (horizontal direction in the figure) of the hot air blower 100 as shown in FIG. When cultivating the upper and lower ranges H1 of the hot air blower 100 with a tractor or the like, the hot air blower 100 is in the way and many parts cannot be cultivated.

Then, the connecting body 20 is removed from the state shown in FIG. 1 and the like and rotated by 90 ° so that the pair of air outlets 20b face the longitudinal direction of the warm air blower 100 (vertical direction in the figure). If the vinyl duct 22 is connected to the air outlet 20b, the hot air blower 100 can be arranged along the side surface of the house 110 as shown in FIG. 6, and the dead space of the hot air blower 100 is in a range indicated by H2. Becomes
The range of the dead space can be narrower than in the case of H1.

Since the direction of the air outlet 20 b can be changed by changing the mounting position of the connecting body 20 in this manner, the direction in which the vinyl duct 22 is disposed with respect to the hot air blower 100 is It can be changed appropriately according to the position. In this embodiment, a pair of air outlets 20 b
Are formed, and a pair of air outlets 20 are formed on adjacent side walls.
b can also be formed.

As shown by a two-dot chain line in FIG. 1, a cover 29 made of a ceramic plate having a large number of through holes 29a may be attached to the tip of the heat storage cylinder 15a. By doing so, the intrusion of wind into the combustion chamber 14 can be further reduced, and a rise in pressure can be prevented, so that ignitability and combustibility can be further improved.

[Second Embodiment of the Invention] FIGS. 9 to 11 show a second embodiment of the present invention.

The second embodiment differs from the first embodiment in the configuration of the combustion furnace 8 and the like.

That is, the combustion furnace body 10 of the combustion furnace 8
In the upper part of the second fan, a secondary ventilation port 10 d is formed below the second blower 5, and the ventilation port 10 d is opened and closed by the opening and closing device 11. In the opening / closing device 11, the secondary ventilation port 10d is opened and closed by a shutter 11a, and the shutter 11a is rotated upward by a weight 11b, whereby the secondary ventilation port 11d is opened.
Of course, the position of the opening / closing device 11 may be provided only below the first blower 6 or may be provided below both the blowers 6 and 5.

During the operation (combustion) of the second blower 5, the shutter 11 a
Is rotated counterclockwise against the weight of the weight 11b, the secondary ventilation port 10d is closed, and when the second blower 5 is stopped (during non-combustion), the weight of the weight 11b The shutter 11a is rotated clockwise to open the secondary ventilation port 10d.

A heat storage plate 15d as shown in FIG. 10 is provided at the left end of the heat storage section 15 of the combustion chamber 14 in the drawing. The heat storage plate 15d is made of stainless steel, has a disk shape, is formed in a mesh shape, and is easily heated and cooled.

Further, in the lower part of the wind tunnel 1, a warm air conditioning room 1 is provided.
b is extended downward, and FIG.
A hot air port 1c is formed at each of the four ends of the center 1 and a flange 1d is formed around the hot air port 1c so as to protrude.

Further, an upper end portion 13a of an extension pipe 13 is connected to a lower portion of a left end portion of the combustion furnace main body 10 in the drawing,
On the lower side, a branching portion 13 branched in four directions as shown in FIG.
b are formed, and primary ventilation holes 13c formed at the distal ends of these branch portions 13b project outward from the warm air ports 1c, respectively, and are set at the same positions as the distal ends of the flange portions 1d.

As described above, any one of the four hot vents 1c and the primary vent 13c can be used, but in this embodiment, the flange 1d at the left and right hot vents 1c and the primary vent 13c is shown in FIG. The vinyl duct 22 is connected as shown by the two-dot chain line, and the left and right vinyl ducts are used, and the front and rear ones are closed by blind covers 30 as shown in FIG.

In the hot air blower 100, the secondary vent 10d is closed by the shutter 11a while both the blowers 6 and 5 are operating, and the temperature in the wind tunnel 1 is increased by the rise in the temperature of the combustion furnace 8. The air is heated, and the air is blown into the vinyl duct 22 from the hot air outlet 1c via the hot air adjusting chamber 1b. In this case, the primary ventilation port 13c is
When the warm air is blown from the warm air adjusting chamber 1b to the vinyl duct 22 side via the warm air port 1c, the primary vent 13c side has a negative pressure, so that the primary vent is formed. The air in the combustion chamber 14 is sucked out to the vinyl duct 22 side through 13c. Therefore, since the pressure in the combustion chamber 14 does not increase,
The ignitability and flammability can be improved.

When the temperature inside the house 110 rises to the set temperature, or when the power supply of the hot air blower 100 is stopped, and the operation of the second blower 5 is stopped, the shutter 11a is rotated by the weight of the weight 11b. It is pivoted around to open the secondary ventilation port 10d. Thereby, the high-temperature air in the combustion chamber 14 escapes to the outside through the secondary ventilation port 10, so that the temperature in the combustion chamber 14 can be reduced.

Other structures and operations are the same as those of the first embodiment.

The present invention is not limited to the above embodiments. For example, the heat storage unit 15 may be a heat storage unit 27 as shown in FIG. That is,
The heat storage unit 27 has a disk shape, and a heat storage unit main body 27a is formed from a ceramic plate. A large number of slits 27b are formed concentrically on the heat storage unit main body 27a.
A plurality of ring-shaped grooves 27c are formed concentrically on the heat storage section main body 27a, and the nichrome wires 27 are formed in the grooves 27c.
d is provided.

Even in this case, the heat generated by the combustion of the fuel causes the temperatures of the nichrome wire 27d and the heat storage section main body 27a to rise, thereby exhibiting a heat storage effect.

Although the combustion furnace 8 is preferably cylindrical, the wind tunnel 1
Is not limited to the cylindrical shape shown in the embodiment,
It may be a square cylindrical body. In the case of the present invention,
Since there is no need to install a heat exchange member at the tip of a combustion furnace as in a conventional hot air heater, the size of the wind tunnel can be reduced.

Further, the hot air blower of the present invention can be installed not only in a house, but also in any place where heating is required, such as a factory, and can be used as a hot air supply source such as a dryer.

[0063]

As described above, according to the first aspect of the present invention, a member made of a material having heat resistance and to which fuel easily adheres can be provided on the inner wall of the combustion furnace by the fuel injected from the nozzle. By arranging the stack at the position where the fuel is received, the fuel can be completely burned, the thermal efficiency can be improved, and the arrangement of the chimney is unnecessary, so that the degree of freedom of the installation position can be improved.

According to the second aspect of the present invention, a shield plate made of a material having heat resistance and to which fuel easily adheres is generated in a combustion furnace by receiving fuel injected from a nozzle and burning. By disposing the fuel at a position where the flame is received, the fuel can be completely burned, the thermal efficiency can be improved, and the arrangement of the chimney is unnecessary and the degree of freedom of the installation position can be improved.

According to the third aspect of the present invention, in addition to the above-described effects, by disposing a shielding plate in a high-temperature region of the flame, the temperature of the shielding plate is raised to exhibit the function as a heating element. be able to.

According to the fourth aspect of the present invention, in addition to the above effects, the position of the blower and the position of the opening are set in a predetermined positional relationship with respect to the opening of the combustion furnace, so that the inside of the combustion furnace is An increase in pressure can be suppressed, and ignitability and combustibility can be improved.

According to the fifth aspect of the present invention, in addition to the above effects, the opening formed at the front end of the combustion furnace is closed by a cover having a plurality of through holes, so that the inside of the combustion furnace can be improved. Can be further suppressed, and ignitability and combustibility can be improved.

According to the sixth aspect of the present invention, in addition to the above-described effects, the primary ventilation port is projected from the warm ventilation port to the outside, so that the flow of the warm air blown from the warm ventilation port to the outside allows the primary ventilation port to flow. The pressure on the side becomes a negative pressure, and the air in the combustion furnace is sucked out, so that the pressure increase in the combustion furnace can be further suppressed, and the ignitability and the combustibility can be improved.

According to the seventh aspect of the present invention, in addition to the above effect, by providing a heat storage section for storing heat generated by combustion in the combustion furnace, on the side opposite to the nozzle side of the shield plate, Thermal efficiency can be improved.

According to the eighth aspect of the invention, in addition to the above effects, the combustion furnace is provided with a secondary ventilation port for bleeding air from the combustion furnace, and the secondary ventilation port is closed during combustion.
By providing an opening / closing device that opens during non-combustion, it is possible to suppress a rise in temperature in the combustion furnace.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a warm air blower according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of the warm air blower according to Embodiment 1.

FIG. 3 is a right side view of FIG. 2 according to the first embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 1 according to the first embodiment.

FIG. 5 is an explanatory diagram showing an installation state of the warm air blower according to Embodiment 1.

FIG. 6 is an explanatory diagram showing another installation state of the warm air blower according to Embodiment 1.

FIG. 7 is a perspective view showing a heat storage cylinder and the like according to the first embodiment.

FIG. 8 is a graph showing a relationship between a combustion time and a temperature rise when the hot air blower according to Embodiment 1 is operated.

FIG. 9 is a cross-sectional view of a hot air blower corresponding to FIG. 1 according to Embodiment 2 of the present invention.

FIG. 10 is a front view showing a heat storage plate according to the second embodiment.

FIG. 11 is a front view showing the heat storage plate of FIG. 9 according to the second embodiment.

FIG. 12 is a front view showing another example of the heat storage unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wind tunnel 1a Opening 1c Hot vent 5 Second blower 6 First blower 8 Combustion furnace 10 Combustion furnace main body 10b Opening 10d Secondary ventilation opening 11 Opening and closing device 12 Burner 13c Primary ventilation opening 14 Combustion chamber 15,27 Heat storage section 16 Refractory ceramic Plate (shielding plate) 20 Connected body 20b Blow outlet 22 Vinyl duct 100 Hot air blower 110 House

Claims (8)

[Claims] 1. A combustion furnace is provided in a cylindrical wind tunnel whose both ends are closed, and a burner nozzle faces the combustion furnace, and fuel injected from the nozzle into the combustion furnace is burned. A hot air blower that introduces air into the wind tunnel by a blower, warms the air, and then blows hot air from the opening of the wind tunnel to the outside, and has a heat resistance and a material to which the fuel easily adheres. Wherein the member is disposed on the inner wall of the combustion furnace at a position for receiving the fuel injected from the nozzle. 2. A combustion furnace is provided in a cylindrical wind tunnel whose both ends are closed, and a nozzle of a burner faces the combustion furnace, and fuel injected from the nozzle into the combustion furnace is burned. A hot air blower that introduces air into the wind tunnel by a blower, warms the air, and then blows hot air from the opening of the wind tunnel to the outside, and has a heat resistance and a material to which the fuel easily adheres. Wherein the shield plate is disposed in the combustion furnace at a position for receiving the fuel injected from the nozzle and receiving the flame generated by the combustion. 3. The hot air blower according to claim 2, wherein the shielding plate is disposed in a high temperature region of the flame. 4. The combustion furnace has a tubular shape, and an opening is formed at a tip end opposite to the nozzle placement portion, while the blower is provided with the nozzle from a tip end of the combustion furnace. The hot air blower according to any one of claims 1 to 3, wherein an opening formed in the wind tunnel is located forward of a front end of the combustion furnace. . 5. The hot air blower according to claim 4, wherein an opening formed at a tip portion of the combustion furnace is closed by a cover having a plurality of through holes. 6. A combustion furnace is provided in a cylindrical wind tunnel whose both ends are closed, and a burner nozzle faces the combustion furnace, and fuel injected from the nozzle into the combustion furnace is burned. A hot air blower that introduces air into the wind tunnel by a blower, warms the air, and then blows hot air to the outside from a hot air port of the wind tunnel, and has heat resistance and the fuel easily adheres thereto. A shielding plate made of a material is disposed in the combustion furnace at a position for receiving the fuel injected from the nozzle and receiving a flame generated by combustion, while providing a primary ventilation port for discharging air from the combustion furnace. A hot air blower set at a position protruding outward from a hot air port of the wind tunnel. 7. The hot air blower according to claim 1, wherein a heat storage unit for storing heat generated by the combustion is provided in the combustion furnace. 8. The combustion furnace is provided with a secondary ventilation port for bleeding air from the combustion furnace, and an opening / closing device for closing the secondary ventilation port when burning and opening it when not burning. The hot air blower according to any one of claims 1 to 3, 5 to 7, wherein