JP2946076B2 - Hot air circulation furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of circulating hot air in a tunnel-type furnace to wash and dry a washed product, bake and dry a coated product, cure an adhesive product with an adhesive, and cure a rubber vulcanized product. The present invention relates to a hot-air circulating furnace for performing various drying or heating treatments.

[0002]

2. Description of the Related Art Conventionally, as a baking furnace for baking and drying a coated product, a degassing chamber 72 inclined downward is provided at one end of a high-floor tunnel type furnace body 71 as shown in FIG. The trolley conveyor 74 is opened from the opening 73 of the deaeration chamber.
The conveyed product is conveyed into the furnace by the conveyor, carried out of the furnace through the same opening 73, and bake-drying of the coating film is performed by hot air circulating in the furnace. I have. As the hot air circulation device, an air heating device 75 having a heater such as a gas burner is used.
And hot air from a hot air generator 77 composed of a fan 76.
Hot air is supplied to the lower duct 79 provided on the hearth through an external duct 78 to supply hot air into the furnace from a discharge port (not shown) of the lower duct. A type in which hot air sucked from an air inlet (not shown) is returned to a hot air generator 77 through an external duct 81 is widely used. The degassing chamber 72 is provided with the furnace 7
It is provided to prevent a large amount of the heated air in 1 from being diffused outside the furnace.

[0003]

However, in the above baking furnace 70, long external ducts 78 and 81 are provided outside the furnace.
Therefore, the pressure loss of the hot air circulation system is large, the equipment cost is increased, and in addition to having the deaeration chamber 72, the total length, overall width and overall height of the furnace are increased, and a large installation space is required. There was a problem that.
In addition, the trolley conveyor 7 is moved along the inclined deaeration chamber 72.
When transporting at 4, the conveyor is likely to knock.
As a result, there is also a problem that dusts fall from the conveyor chain and the guide rails and stain the painted product.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and has a small pressure loss, a small furnace, a small installation space, and no need to drive up and down along a slope of a trolley conveyor. It is intended to provide a hot air circulation furnace.

[0005]

According to a first aspect of the present invention, there is provided a hot air circulating furnace in which a treated product is provided from an inlet provided at one end wall of a tunnel type furnace body to an outlet provided at the other end wall. In a hot air circulating furnace equipped with a trolley conveyor for conveying the inside of the furnace, an intake port extending in the furnace width direction extends above the other end wall beside the outlet, and extends in a furnace width direction below the end wall. An air inlet is provided, a base end of a duct extending in the furnace length direction provided on the hearth and having outlets on the upper surface and both side surfaces is connected to the air inlet, and the air inlet and the air inlet are connected to the air inlet. Between,
A heating chamber formed along the outer surface of the other end wall and having air heating means, and an elongated impeller having a central axis extending in the furnace width direction are rotatably supported in a casing, and are formed from the intake port. A multi-blade fan that blows air in the furnace to the air supply port through the heating chamber is connected, and the furnace inside the one end wall near the furnace center side edge of the inlet, in the furnace length direction. An extended partition wall is attached, and a windbreak plate is provided at a side outlet of the duct closest to the inlet toward a furnace side wall that partitions between the outlet and the inlet, and near a furnace center side edge of the outlet. A partition wall extending in the furnace length direction is attached to the inside of the furnace at the other end wall, and hot air flowing toward a furnace side wall that guides hot air from the air outlet is provided at a side outlet of the duct closest to the outlet. A drift plate is provided.

A hot air circulating furnace according to a second invention of the present application is a trolley for conveying a processed product in a furnace from an inlet provided on one end wall of a tunnel type furnace body to an outlet provided on the other end wall. -In a hot-air circulating furnace equipped with a conveyor, an inlet extending in the furnace width direction above the one end wall beside the inlet,
An air supply port extending in the furnace width direction is provided at a lower portion of the end wall, and a base end portion of a duct extending in a furnace length direction provided on the hearth and having air outlets on the upper surface and both side surfaces is provided as the air supply port. A heating chamber formed along the outer surface of the one end wall and having an air heating means between the intake port and the air supply port, and an elongated impeller having a central axis extending in the furnace width direction. A multi-blade fan that is rotatably supported in the shing and blows the furnace air from the intake port to the air supply port through the heating chamber and near the furnace center side edge of the outlet; A partition wall extending in the furnace length direction is attached to the inside of the furnace at the other end wall of the above, and at a side outlet of the duct closest to the outlet,
A windbreak plate is provided toward a furnace side wall that partitions between the outlet and the inlet, and a partition wall extending in a furnace length direction is attached to the inside of the one end wall near the furnace center side edge portion of the inlet on the inside of the furnace, A hot air deflector plate is provided at a side outlet of the duct closest to the inlet to guide a hot air from the outlet toward a furnace side wall.

[0007] A hot air circulating furnace according to a third invention of the present application is a trolley for transporting a processed product in the furnace from an inlet provided at one end wall of a tunnel-shaped furnace body to an outlet provided at the end wall. In a hot-air circulating furnace equipped with a conveyor, an intake port extending in the furnace width direction is provided above the other end wall of the furnace body, and an air supply port extending in the furnace width direction is provided below the end wall. The base end of a duct extending in the furnace length direction and having outlets on the upper surface and both side surfaces provided at the upper end and connected to the air inlet, between the air inlet and the air inlet, the other end wall of the A heating chamber formed along the outer surface and provided with air heating means, and an elongated impeller whose center axis extends in the furnace width direction are rotatably supported in a casing, and the furnace air from the suction port is supplied to the heating chamber. A multi-blade fan that blows air to the air inlet through a heating chamber is connected, and a furnace at the inlet is connected. A partition wall extending in the furnace length direction is attached to the inside of the furnace near the one end wall near the side edge, and a side outlet of the duct closest to the inlet is provided between the outlet and the inlet. A windbreak plate facing the furnace side wall to be partitioned, a partition wall extending in a furnace length direction attached to the inside of the one end wall near the furnace center side edge of the outlet, and a side wall of the duct closest to the outlet. The air outlet is provided with a windbreak plate directed to a furnace side wall that partitions between the air outlet and the outlet.

A hot air circulating furnace according to a fourth aspect of the present invention is a trolley for transporting processed products in a furnace from an inlet provided at one end wall of a tunnel-shaped furnace body to an outlet provided at the end wall. In a hot air circulating furnace equipped with a conveyor, an intake port extending in the furnace width direction above the one end wall between the inlet and the outlet, an air supply port extending in the furnace width direction below the end wall, Each provided, a base end of a duct extending in the furnace length direction provided with an outlet on the upper surface and both side surfaces provided on the hearth is connected to the air supply port, between the air intake and the air supply port, A heating chamber formed along the outer surface of one end wall and provided with air heating means, and an elongated impeller whose center axis extends in the furnace width direction are rotatably supported in the casing, and are formed from the inlet port. Connect a multi-blade fan that blows air in the furnace to the air supply port through the heating chamber. , The furnace inner side of the inlet of the furnace center side edge said one end wall in the vicinity of attaching a partition wall extending into the furnace length direction, to the side outlet portion closest the duct inlet,
A hot air drift plate is provided toward the furnace side wall that guides the hot air from the outlet, and a partition wall extending in the furnace length direction is attached to the inside of the one end wall near the furnace center side edge of the outlet, and A hot-air drift plate is provided at a side outlet of the duct closest to the outlet to a furnace side wall for guiding hot air from the outlet.

[0009]

In the hot air circulating furnace according to the present invention, the hot air heated by the heating means as it passes through the heating chamber is sent into the duct from the air supply port, and blows into the furnace through the outlets of various parts of the furnace to process the product. Is heated, flows through the furnace body toward the air inlet at the end wall of the furnace body, and is circulated and sent again to the duct via the heating chamber.

[0010] The heating chamber and the multi-blade fan can be arranged along the outer surface of the end wall of the furnace body, and a long space is provided between the heating chamber and the multi-blade fan, and between them and the intake port and the air supply port. Since no external duct for connection of the furnace is required and no intake duct for the ceiling of the furnace is required, the pressure loss due to the circulation of hot air can be reduced.

[0011] Further, on the side provided with the intake port and the air supply port, that is, at the furnace end on the base end side of the duct, a partition wall provided at an inlet or an outlet provided at an end wall is provided with a cool air outside the furnace. Prevents suction from the inlet or outlet directly into the inlet. In addition, a part of the hot air that is pressure-fed in the duct flows as a rising flow while flowing toward the furnace side wall while being guided by the hot-air drift plate when being blown out from the side outlet closest to the inlet or the outlet. It acts as an air curtain that prevents cold air from entering through the inlet or outlet.

On the other hand, on the side where the air inlet and the air inlet are not provided, that is, at the furnace end on the tip end side of the duct, a partition wall provided at an inlet or an outlet provided at an end wall generates hot air in the furnace. The windbreak plate provided at the side outlet closest to the inlet or outlet prevents the hot air blown out from the inlet or outlet from flowing out of the furnace directly from the inlet or outlet. To prevent The partition walls and the windbreak plate prevent a large amount of heated air in the furnace body from being diffused outside the furnace even without the conventional gas-blowing chamber of the chevron furnace.

Further, since the furnace body has a flat furnace structure without an air cut chamber, it is not necessary to drive the trolley conveyor up and down along the inclined path of the conventional trolley conveyor in the air cut chamber, and a smooth trolley conveyor without knocking is required. Driving can be performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the first invention will be described below with reference to FIGS. In the figure, reference numeral 1 denotes a tunnel-shaped furnace, which is a flat furnace having no conventional degassing chamber 72 (see FIG. 9) and arranged close to the floor. One end wall 2 of the furnace body 1
A from the three inlets provided at A to the outlet 4 provided at the other end wall 2B
And a trolley conveyor 6 for transporting the processed product 5 as a coated product in the furnace.
Are arranged so as to circulate between the coating bush on the side of the furnace (not shown) and the inside of the furnace body 1, and the chain is driven by a driving mechanism (not shown).
7 (see FIG. 3). In FIG. 3, reference numeral 8 denotes a guide rail for guiding the chain 7;
Is a hanger suspended from the chain 7, and the processed product 5 is detached from the hanger 9.

An inlet 11 extending in the furnace width direction is formed in an upper portion of the end wall 2B of the furnace body 1 on the side of the outlet 4, and an air supply port 12 extending in the furnace width direction is formed in the lower portion. And
A base 14 a of a duct 14 provided on the hearth 13 and extending in the furnace length direction is connected to the air supply port 12. The duct 14 has a number of upper outlets 15 and side outlets 1 on the upper surface and both side surfaces.
6 are arranged side by side, 17a and 17b are slide plates for adjusting the opening of these outlets, and 18a and 18b are guides for slidably guiding both edges of the slide plates.

An air heating device 2 comprising a heating chamber 22 surrounded by an outer shell 21 and a multi-blade fan 24 is provided on the outer surface of the end wall 2B.
0 is provided. The upper portion of the heating chamber 22 communicates with the intake port 11, and has a gas burner 23 as a heating means at an intermediate portion. The multi-blade fan 24 is constituted by rotatably supporting a slender impeller 26 having a central axis 25 extending in the furnace width direction on a casing 27, and an outlet 28 of the casing 27 is connected to the air supply port 12. , The suction port 29 is the outlet 22a of the heating chamber 22
Connected to the unit.

In the impeller 26, a number of elongated blades 31 having a section curved in a concave shape with respect to the rotation direction are arranged side by side on the circumference, and both ends thereof are fixed to a disk 32. A support shaft 33 protrudes from the motor 32 and is driven by a motor 34 with a belt. The casing 27 is provided with the rectangular suction port 29 extending upward in the furnace width direction and opening upward.
It has a curved flow path 35 leading to a rectangular discharge port 28 that opens in a plane orthogonal to this, and the impeller 26 is housed in this flow path 35.

As shown in FIG. 1 and FIG. 2, the furnace center side edge of the inlet 3 of the inner wall surface of the end wall 2A (furnace center line 40).
A partition wall 41 extending in the furnace length direction is attached to a position near the edge 3a), and the duct 14 closest to the inlet 3 is attached.
At the side of the duct at the side of the end of the duct, specifically at the side of the side of the duct at the end of the furnace,
5 is provided with a windbreak plate 42 protruding therefrom.

A partition wall 43 extending in the furnace length direction is provided at a position near the furnace center side edge 4a of the outlet 4 on the inner wall surface of the end wall 2B.
And the side outlet 1 of the duct 14 closest to the outlet 4
A hot-air drift plate 44 is attached to six parts, specifically, to the duct tip 14b side of the outlet, toward a furnace side wall 45 for guiding hot air from the outlet. This hot air drift plate 4
4 is preferable to insert a part of the hot air into the duct 14 as shown in the figure, since a desired amount of hot air can be reliably discharged to the side of the duct and the air curtain function described later can be performed. .

The partition walls 41 and 43 are provided in the vertical direction from the furnace ceiling 46 to the hearth 13 (in this embodiment, the lower part interferes with the duct 14 and a part thereof extends to the upper surface of the duct 14). Is determined by a test run or the like of an actual furnace.
It may be about 5 m. The partition walls 41 and 43 are
The furnace centerline 4 shown in FIG.
The arrangement may be slightly inclined with respect to zero.

In the baking furnace 51 having the above-described structure, when the fuel gas is burned by the gas burner 23 in the air heating device 20 and the multi-blade fan 24 is operated to blow air, hot air flows from the air blow port 12. Since it is pressure-fed into the duct 14 and blows out into the furnace body 1 from the upper outlet 15 and the side outlet 16, the processed product 5, which is a painted part, is conveyed in the furnace by the trolley conveyor 6 and the coating film is baked. Drying can be performed. The hot air after the heating of the processed product flows in the furnace body 1 toward the end wall 2B side, is sucked into the heating chamber 22 from the suction port 11, is heated again, and is circulated and supplied to the duct 14.

At this time, in the end wall 2B, the partition wall 4
3 prevents a large amount of cold air outside the furnace from being sucked into the inlet 11 from the outlet 4, and a portion of the hot air flowing through the duct 14 blows out from the side outlet 16 closest to the outlet 4. To
The hot air flows as an ascending flow (because of high temperature) while being guided in the direction toward the furnace side wall 45 by the hot air deflector 44, and this hot air flow acts as an air curtain and, together with the partition wall 43, flows out of the cool air outlet 4. Suppress intrusion.

In the end wall 2A of the furnace body on the tip end 14b side of the duct 14, a partition wall 41 prevents the hot air in the furnace from flowing out of the furnace from the inlet 3 and the most in the inlet 3. Since the windbreak plate 42 at the near side outlet 16 prevents the hot air blown out from the side outlet from flowing out of the furnace from the inlet 3, the hot air is blown out without using a conventional deaeration chamber. The amount of outflow can be suppressed to a small amount. When a burner is used as the air heating means as in this embodiment, the combustion gas of the burner is constantly supplied into the furnace, so that the furnace gas corresponding to the supply amount is supplied from the inlet 3 or the outlet 4. The air flows out, and the partition wall 41 and the windbreak plate 42 do not prevent the outflow of the air in the furnace.

As described above, the heating chamber 22 and the multi-blade fan 24
Can be arranged and connected along the outer surface of the end wall 2B without passing through a long outer furnace duct, and in combination with not providing the furnace side duct on the intake side, the pressure loss accompanying the hot air circulation is small. The total height, width and length of the furnace were shortened, and the installation space was reduced.
Can be small. Further, since the furnace body 1 has a flat furnace shape, the conventional inclined air-discharging chamber is not required, so that the knocking accompanying the trolley-conveyor inclining in the air-discharging chamber part is also eliminated, and the transfer of the processing product 5 is performed on a large inclined path. Trolley without
The operation can be smoothly performed by the conveyor 6.

In the above embodiment, since the heating chamber 22 is arranged on the upper side (upstream side) and the multi-blade fan 24 is arranged on the lower side (downstream side) in the air heating device 20, the gas bar is provided.
The heating gas from the nozzle 23 is supplied to the duct 14 in a state where the temperature of each portion of the hot air flow is small due to the pressurizing and stirring action of the multi-blade fan 24, and the temperature of the hot air blown out from each outlet is also small. However, as shown in FIG. 5, the multi-blade fan 24 can be arranged on the upper side, and the heating chamber 22 can be arranged on the lower side. In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals.

FIG. 6 shows an embodiment of the second invention.
The entrance 3 and the exit 4, that is, the traveling directions of the trolley-conveyor 6 are the same as those of the first embodiment of the present invention, except that the traveling directions of the trolley-conveyor 6 are reversed. Therefore, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. (The same applies to other embodiments below.)

Also in the baking furnace 52 of this embodiment, the partition wall 43 and the hot-air drift plate 44 at the one end wall 2A on the base end portion 14a side of the duct 14, and the distal end portion 14b of the duct 14
Partition wall 41 and windbreak plate 42 at the other end wall 2B side
Thus, the same effect of preventing cold air intrusion and hot air blowing as in the first embodiment can be obtained.

FIG. 7 shows an embodiment of the third invention.
An inlet 3 and an outlet 4 are provided on one end wall 2A with respect to the embodiment of the first invention, and the other end wall 2 without an entrance is provided.
B in that an air heating device 20 is provided.
Is provided on the end wall 2B having no entrance, so that the first
In the embodiment of the present invention, the hot air drift plate 44 is not provided, and the wind outlets 42, 42 are provided at the side air outlets 16, 16 near the distal end portion 14b of the duct 14 closest to the inlet 3 and the outlet 4, and the end plates are provided. Partition walls 41, 41 are provided at positions close to the furnace center side edge 3a of the inlet 3 and the furnace center side edge 4a of the outlet 4 of the inner wall surface of the wall 2A, respectively. This is the same as the embodiment.

In the baking furnace 53 of this embodiment, the partition walls 41, 41 and the windproof plates 42, 42 at the one end wall 2A on the tip end 14b side of the duct 14 are the same as those of the first embodiment of the invention. A hot air blowing prevention effect can be obtained.

FIG. 8 shows an embodiment of the fourth invention. In the embodiment of the first invention, an inlet 3 and an outlet 4 are provided at one end wall 2A, and furthermore, at the same end wall 2A. The difference is that an air heating device 20 is provided between the inlet 3 and the outlet 4.
Is located near the base end 14a of the duct 14 near the base end 14a of the duct 14 which is closest to the inlet 3 and the outlet 4 without the windbreak plate 42 in the embodiment of the first invention. Hot air drift plates 4
4 and 44, and a furnace center side edge 3a of the inlet 3 and a furnace center side edge 4a of the outlet 4 on the inner wall surface of the end wall 2A.
Partition walls 43, 43 are provided at positions close to each other, and the other configuration is the same as that of the embodiment of the first invention.

In the baking furnace 54 of this embodiment as well, the partition walls 43, 43 and the hot-air drift plates 44, 44 on the base end 14a side of the duct 14 prevent cold air from entering as in the first embodiment of the present invention. Is obtained.

The present invention is not limited to the above embodiments. For example, an air heater other than a gas burner such as an electric heater may be used. The present invention is also applicable to a hot-air circulation furnace other than a baking furnace for painted products.

[0033]

As described above, according to the present invention,
The heating chamber for air heating and the multi-blade fan can be arranged along the outer surface of the end wall of the furnace body, eliminating the need for a long outside furnace duct and the intake side duct inside the furnace. The loss is small, and the installation of the partition wall and the windbreak plate eliminates the necessity of an aeration chamber, so that the furnace is downsized and the installation space is small. In addition, the furnace body has a flat furnace shape,
It is not necessary to drive the trolley conveyor up and down along the inclined path of the conventional trolley conveyor in the aeration chamber, and the trolley conveyor can be smoothly operated without knocking.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view of a baking furnace according to an embodiment of the first invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 omitting an intermediate portion.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a sectional view taken along line CC in FIG. 1;

FIG. 5 is a diagram corresponding to FIG. 4, showing another embodiment of the first invention.

FIG. 6 is a view corresponding to FIG. 1 showing an embodiment of the second invention.

FIG. 7 is a diagram corresponding to FIG. 1 showing an embodiment of the third invention.

FIG. 8 is a diagram corresponding to FIG. 1 showing an embodiment of the fourth invention.

FIG. 9 is a perspective view showing an example of a conventional baking furnace.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Furnace body, 2A ... End wall, 2B ... End wall, 3 ... Entrance, 3a ...
Furnace center side edge, 4 ... Exit, 4a ... Furnace center side edge, 5 ... Processed product, 6 ... Trolley conveyor, 11 ... Inlet, 12 ... Inlet, 13 ... Hearth, 14 ... Duct, 14a … Proximal end, 1
5: upper outlet, 16: side outlet, 22: heating chamber, 2
3 gas burner (heating means), 24 multi-blade fan, 25
... Center axis, 26 ... Wing wheel, 27 ... Cassing, 40 ... Furnace center line, 41 ... Partition wall, 42 ... Winding plate, 43 ... Partition wall, 4
4: hot air drift plate, 45: furnace side wall, 51: baking furnace, 52:
Baking furnace, 53: baking furnace, 54: baking furnace.

Claims (4)

(57) [Claims] 1. A hot-air circulating furnace having a trolley conveyor for transporting processed products in a furnace from an inlet provided on one end wall of a tunnel-shaped furnace body to an outlet provided on the other end wall of the furnace. An inlet port extending in the furnace width direction is provided above the other end wall on the side of the outlet, and an air inlet port extending in the furnace width direction is provided below the end wall. Connect the base end of a duct extending in the furnace length direction having an outlet to the air supply port, between the air intake and the air supply port,
A heating chamber formed along the outer surface of the other end wall and having air heating means, and an elongated impeller having a central axis extending in the furnace width direction are rotatably supported in a casing, and are formed from the intake port. A multi-blade fan that blows air in the furnace to the air supply port through the heating chamber is connected, and the furnace inside the one end wall near the furnace center side edge of the inlet, in the furnace length direction. An extended partition wall is attached, and a windbreak plate is provided at a side outlet of the duct closest to the inlet toward a furnace side wall that partitions between the outlet and the inlet, and near a furnace center side edge of the outlet. A partition wall extending in the furnace length direction is attached to the inside of the furnace at the other end wall, and hot air flowing toward a furnace side wall that guides hot air from the air outlet is provided at a side outlet of the duct closest to the outlet. A hot-air circulating furnace provided with a drift plate. 2. A hot-air circulating furnace having a trolley conveyor for transporting processed products in a furnace from an inlet provided on one end wall of a tunnel-shaped furnace body to an outlet provided on the other end wall of the furnace. An intake port extending in the furnace width direction is provided above the one end wall on the side of the inlet, and an air supply port extending in the furnace width direction is provided below the end wall. Connect the base end of a duct extending in the furnace length direction having an outlet to the air supply port, between the air intake and the air supply port,
A heating chamber formed along the outer surface of the one end wall and having an air heating means, and an elongated impeller whose center axis extends in the furnace width direction are rotatably supported in a casing, and are formed from the intake port. A multi-blade fan that blows the furnace air through the heating chamber to the air supply port is connected to the furnace, and the other end wall near the furnace center side edge of the outlet is inside the furnace, in the furnace length direction. An extended partition wall is attached, and a windbreak plate is provided at a side outlet of the duct closest to the outlet toward a furnace side wall for partitioning between the outlet and the inlet. A partition wall extending in the furnace length direction is attached to the inside of the furnace at the one end wall, and hot air flowing toward a furnace side wall that guides hot air from the air outlet is provided at a side air outlet of the duct closest to the inlet. A hot-air circulating furnace provided with a drift plate. 3. A hot air circulating furnace provided with a trolley conveyor for transporting treated products in a furnace from an inlet provided on one end wall of a tunnel-shaped furnace body to an outlet provided on the end wall. An intake port extending in the furnace width direction is provided above the other end wall of the body, an air supply port extending in the furnace width direction is provided below the end wall, and air outlets are provided on the furnace floor and on the upper surface and both side surfaces. A base end of the provided duct extending in the furnace length direction is connected to the air supply port, and an air heating means is formed between the intake port and the air supply port along an outer surface of the other end wall. A heating chamber and an elongated impeller whose center axis extends in the furnace width direction are rotatably supported in a casing, and the furnace air from the suction port is blown to the air supply port through the heating chamber. A multi-blade fan is connected to the inside of the one end wall near the furnace center side edge of the inlet. A partition wall extending in the furnace length direction is attached to the side outlet of the duct closest to the inlet.
A windbreak plate is provided toward a furnace side wall that partitions between the outlet and the inlet, and a partition wall extending in a furnace length direction is attached to the inside of the one end wall near the furnace center side edge of the outlet, inside the furnace, A hot-air circulating furnace, wherein a windbreak plate is provided at a side outlet of the duct closest to the outlet to a furnace side wall separating the outlet and the outlet. 4. A hot-air circulating furnace provided with a trolley conveyor for transporting processed products in a furnace from an inlet provided at one end wall of a tunnel-type furnace body to an outlet provided at the end wall. And an inlet extending in the furnace width direction at an upper portion of the one end wall between the outlet and the outlet, and an air inlet opening extending in the furnace width direction at a lower portion of the end wall. A base end of a duct extending in a furnace length direction having an outlet on a surface is connected to the air supply port, and is formed along the outer surface of the one end wall between the air intake and the air supply port. A heating chamber having air heating means and an elongated impeller whose center axis extends in the furnace width direction are rotatably supported in a casing, and the furnace air from the suction port is sent to the heating chamber through the heating chamber. While connecting a multi-blade fan that blows air into the vent, the vicinity of the furnace center side edge of the inlet A partition wall extending in the furnace length direction is attached to the inside of the furnace at one end wall, and a hot air drift plate directed to a furnace side wall that guides hot air from the outlet at a side outlet of the duct closest to the inlet. A partition wall extending in the furnace length direction is attached to the inside of the one end wall near the furnace center side edge of the outlet, and a side wall outlet portion of the duct closest to the outlet is provided with the blower. A hot-air circulation furnace comprising a hot-air drift plate directed toward a furnace side wall for guiding hot air from an outlet.