JP2815149B2 - Hot air generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hot air generator, in which a heat source is built in a tubular body, and a cool air flows through a ventilation path in which the heat source is built. By forming the passage coaxially, the temperature rise of the outer wall of the tube is suppressed low, safety is ensured, heat loss is reduced, and efficiency is improved.

<Prior Art> This type of hot air generator is used in combination with a blower for applications such as purging moisture or drying. Third
FIG. 1 schematically shows the configuration of a conventional hot air generator. In the figure, 1 is a tube, 2 is a heat source, and 3 is a blower.

The outer cylindrical body 102 of the tubular body is formed in a cylindrical shape using a material having high heat resistance, for example, a cement tube or the like, and one end in the axial direction is a blower inlet a and the other end is a blower outlet b.

The heat source 2 is generally constituted by an electric resistance heating element such as a nichrome heater. This heat source is disposed inside the inner diameter portion 101 of the tube 1.

The blower 3 is connected to a blower inlet a of the tube 1. The blower 3 is generally configured by a blower that drives a rotating blade by an electric motor.

The air blown from the blower 3 is heated by the heat source 2 when passing through the inside of the tube 1, and is blown as hot air from the blower outlet b.

<Problems to be Solved by the Invention> However, in the above-described conventional hot air generator, since the hot air heated by the heat source 2 directly touches the tube 1, the temperature of the outer surface of the tube 1 is extremely low. Get higher. For example, in the vicinity of the air outlet b where the temperature rise is the largest, the temperature becomes 100 ° C. or more with the air outlet b open. For this reason, when touching the outer surface of the tubular body 1, there is a risk of burns, and there is a problem that the safety is lacking.

In addition, there is also a problem that heat is largely dissipated from the outer surface of the tubular body 1 and thermal efficiency is poor.

In order to alleviate the above problems, the outer cylinder 102 of the tube 1 must be made of a material having poor heat conductivity and heat resistance. Such materials are generally expensive and economically impractical. Further, there is also a problem that the outer cylinder body 102 becomes heavy due to an increase in thickness, becomes difficult to handle, has a large heat storage effect, and continues a dangerous high temperature state for a long time even after the air supply is stopped.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems, to reduce the temperature rise of the outer tube of the tube with a simple structure, to ensure safety, to reduce heat loss, and to improve efficiency. It is an object of the present invention to provide a hot-air generator.

<Means for Solving the Problems> In order to solve the above-described problems, the hot-air generator according to the present invention includes a tube 1 and a heat source 2 as shown in FIG. The tube 1 has a ventilation inlet a at one end and a ventilation outlet b at the other end, and has at least two ventilation passages 4 and 5 between the ventilation inlet a and the ventilation outlet b. Each ventilation path 4, 5 is surrounded by cylindrical bodies 102, 103 arranged coaxially, and
Are separated from each other. The innermost ventilation passage 4 has the heat source 4 therein. The two ventilation paths 4, 5
Communicate with each other on the side of the air inlet a and the side of the air outlet b.

Of the cylindrical bodies 102 and 103, an outermost cylindrical body (hereinafter, referred to as an outer cylindrical body) 102 has an inlet-side protruding portion 104 at an end on the air inlet a side, and an end on the air outlet b side. The portion has an outlet-side protruding portion 105.

The inlet-side protruding portion 104 has an inner diameter that is enlarged in a direction (b) in which air flows, and a maximum inner diameter R1 of the outer cylindrical body 104 increases.
The outer diameter R2 of an adjacent cylindrical body (hereinafter, referred to as an inner cylindrical body) 103 inside 102 is larger than R2.

The outlet-side protruding portion 105 has an inner diameter reduced in the direction of air flow (b), and has a maximum inner diameter R1 and an outer cylindrical body 10.
It is larger than the outer diameter R2 of the inner cylinder 103 adjacent to 2.

<Operation> The tube 1 has a blower inlet a at one end and a blower outlet b at the other end.
And at least two ventilation paths 4 and 5 between the ventilation inlet a and the ventilation outlet b. Each of the ventilation passages 4 and 5 is surrounded by an outer cylinder 102 and an inner cylinder 103 arranged coaxially, and is separated from each other. According to this structure, the air blown by a blower such as a blower as shown by the arrow (a) is divided into the ventilation path 4 and the ventilation path 5 from the ventilation inlet a.

The innermost ventilation path 4 has the heat source 2 built therein. According to this structure, the air that has entered the ventilation path 4 is heated by the heat source 2, becomes hot air, and is blown from the blowing outlet b.

On the other hand, the air diverted into the ventilation path 5 as shown by the arrow (b)
Cold air that is not heated. This cold air flow flows so as to surround the ventilation passage 4 and touches the inner cylindrical body 103 constituting the ventilation passage 4 to take away the heat. For this reason, the temperature rise of the outer cylinder body 102 of the tube body 1 is suppressed to a low level, and the safety is enhanced, the heat loss is reduced, and the efficiency is improved.

The two ventilation paths 4 and 5 communicate with each other on the side of the air inlet a and the side of the air outlet b. According to this structure, the air that has passed through the ventilation path 5 joins the ventilation path 4 on the side of the ventilation outlet b. Therefore, since most of the heat energy given to the air passing through the ventilation passage 5 is recovered at the air outlet b, the heat loss due to the provision of the ventilation passage 5 is small.

Next, in general, the compressed pressure curve when the compressed air is diffused has a fan shape. In the present invention, the inlet side projecting portion
104 has an inner diameter enlarged along the direction of air flow (b). Therefore, according to the general properties of the gas described above, in the present invention, the compressed air blown by the blower such as the blower from the blower inlet as shown by the arrow (a) is:
It is diffused along the inner wall of the entrance-side protruding portion 104 as shown by an arrow (b).

Moreover, the inlet-side protruding portion 104 has a maximum inner diameter R1 larger than the outer diameter R2 of the inner cylindrical body 103. According to this structure, the air diverted as shown by the arrow (b) smoothly flows into the ventilation path 5 without being hindered by the inner cylindrical body 103, so that not only the ventilation path 4 but also the ventilation path 5 A large amount of air is diverted.
For this reason, the temperature rise of the outer cylinder body 102 of the tube body 1 is further suppressed, and the safety is further enhanced, and the heat loss is significantly reduced, and the efficiency is extremely increased.

The outlet-side protruding portion 105 has an inner diameter reduced in the direction of air flow (b), and the maximum inner diameter R1 of the outer cylindrical body 105 is reduced.
It is larger than the outer diameter R2 of the inner cylinder 103 adjacent to 102. According to this structure, the outlet side projecting portion 105 is
It does not hinder the flow of air that has passed through.

In addition, since the inlet-side protruding portion 104 and the outlet-side protruding portion 105 have symmetry, contrary to the embodiment, the inlet-side protruding portion 10
4 can be used as the air outlet b, and the outlet side protruding portion 105 can be used as the air inlet a.

<Example> FIG. 2 is a partial front sectional view showing a specific example of the hot air generator according to the present invention. The tube 1 has an air inlet a at one end in the axial direction and an air outlet b at the other end. An inlet-side protruding portion 104 made of a cylindrical flange is arranged at the air inlet a, and an outlet-side protruding portion 105 made of a cylindrical flange is arranged at the air outlet b. The inlet-side protruding portion 104 and the outlet-side protruding portion 105 are formed of a metal molded product. An outer cylinder 102 and an inner cylinder 103 constituting an outer cylinder of the tube 1 are coaxially interposed at a distance d between the inlet-side protruding portion 104 and the outlet-side protruding portion 105. . The interval d is desirably about 5 to 10 mm.

The outer cylindrical body 102 is formed in a cylindrical shape using a steel plate or the like, and both ends thereof are attached and fixed to the inlet-side protruding portion 104 and the outlet-side protruding portion 105.

The inner cylindrical body 103 is formed in a cylindrical shape using, for example, a stainless steel plate or the like, and both ends in the axial direction are provided on the inner surfaces of the inlet-side protruding portion 104 and the outlet-side protruding portion 105 at intervals so as to be provided with ribs 106, It is attached to 107. Since the heat source 2 is disposed inside the inner cylindrical body 103, both ends of the inner cylindrical body 103 are connected to the inlet-side protruding portion 104 and the outlet-side protruding portion 105 via an electrical insulator.
When supported, the leakage from the heat source 2 can be prevented.

The ventilation passage 4 is constituted by an inner diameter portion of the inner cylinder 103, and the ventilation passage 5 is constituted by an annular space formed at a distance d between the inner cylinder 103 and the outer cylinder 102. The heat source 2 arranged in the ventilation path 4 formed inside the inner cylindrical body 103 is not limited to the electric resistance heat element, but may be another heat element using a steam pipe or the like.

The ventilation path 5 outside the inner cylindrical body 103 is different from the ventilation path 4
The air inlet a and the air outlet b communicate with each other.
Since ribs 106 and 107 are provided at intervals on the inner surfaces of the inlet-side protruding portion 104 and the outlet-side protruding portion 105 at the blower inlet a and the blower outlet b,
The space between 107 and 107 is a communication path. The number of ventilation passages 5 is not limited to one, and a plurality of ventilation passages may be provided. The number of ventilation passages 5 can be easily changed by increasing or decreasing the number of inner cylinders 103. When the number of the ventilation passages 5 is increased, the structure becomes complicated, but the effect of suppressing the temperature rise is further improved.

The air blown by a blower such as a blower as shown by an arrow (a) is divided into a ventilation path 4 and a ventilation path 5 at a ventilation inlet a. The air that has entered the ventilation passage 4 is heated by the heat source 2, becomes hot air, and is blown from the blowing outlet b.

On the other hand, the cold air flow that has flowed through the space between the ribs 106 and 106 into the ventilation path 5 as shown by the arrow (b) comes into contact with the surface of the inner cylindrical body 103 that surrounds the ventilation path 4 and flows while removing heat. Then, at the air outlet b, the air passes through the ribs 107 and 107 and merges into the air passage 4. The rise of the temperature of the outer cylinder 102 of the tube 1 is suppressed to be low by the cool air flow.

In general, compressed air has a fan-shaped isobar when diffused. According to the present invention, the inlet-side protruding portion 104 has an inner diameter that is enlarged along the direction of air flow (b). Therefore, according to the general properties of the gas described above, in the present invention, the compressed air blown by the blower such as the blower from the blower inlet a as shown by the arrow (a) flows along the inner wall of the inlet-side protruding portion 104. Is diffused as shown by the arrow (b).

The inner diameter of the inlet-side protruding portion 104 is increased in the direction of air flow (b).
3, larger than the outer diameter R2. According to this structure, the arrow (b)
The air diverted as described above flows into the ventilation path 5 without being hindered by the inner cylindrical body 103, so that a large amount of air is diverted not only to the ventilation path 4 but also to the ventilation path 5.

The outlet-side protruding portion 105 has an inner diameter reduced in the direction of air flow (b), and the maximum inner diameter R1 of the inner cylindrical body is reduced.
It is larger than 103 outer diameter R2. According to this structure, the outlet-side protruding portion 105 does not hinder the flow of air that has passed through the ventilation path 5. In addition, since the inlet-side protruding portion 104 and the outlet-side protruding portion 105 have symmetry, contrary to the embodiment, the inlet-side protruding portion 104 is used as the air outlet b,
The outlet side protruding portion 105 can be used as the air inlet a.

When specific data is raised, in the present embodiment, in a state where the air outlet b is opened, the point A set on the outlet side protruding portion 105 on the air outlet b side, the outer surface of the outer cylindrical body 102 When the temperatures at the set points B and C were measured, the temperature at the point A was 101 ° C., the temperature at the point B was 32 ° C., and the temperature at the point C was 27 ° C. On the other hand, in the conventional hot air generator in which the outer cylinder 102 of the pipe 1 is formed of a cement pipe, the temperature at the point A is 95%.
° C, the temperature at point B was 102 ° C, and the temperature at point C was 55 ° C.
As is apparent from this data, according to the present invention, the outer surface temperature of the outer cylinder 102 of the tube 1 was increased from the conventional 102 ° C. to 32 ° C.
Can be significantly reduced.

According to calculations, the loss energy dissipated from the outer cylinder 102 is about 20% lower in the hot air generator according to the present invention than in the conventional product, and the thermal efficiency is improved by about 20%. Was.

<Effect of the Invention> As described above, according to the present invention, with a simple structure,
It is possible to provide a hot-air generator that suppresses a rise in the temperature of the outer tube of the tube, secures safety, reduces heat loss, and improves efficiency.

[Brief description of the drawings]

FIG. 1 is a view showing the configuration of a hot air generator according to the present invention, FIG. 2 is a partially cutaway front view showing a specific embodiment of the hot air generator according to the present invention, and FIG. 3 is a conventional hot air generator. FIG. 3 is a diagram showing the configuration of FIG. DESCRIPTION OF SYMBOLS 1 ... Tube, 2 ... Heat source 102 ... Outer cylinder, 103 ... Inner cylinder 104 ... Inlet side protruding part, 105 ... Outlet side protruding part 4, 5 ... Ventilation path

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F24H 3/04 302

Claims (2)

(57) [Claims] 1. A hot air generator comprising a tube and a heat source, wherein the tube has a blower inlet at one end and a blower outlet at the other end, and at least two tubes between the blower inlet and the blower outlet. It has two ventilation paths, each ventilation path is surrounded by a cylindrical body arranged coaxially,
And, it is separated from each other, the innermost ventilation path has the built-in heat source inside, and the two ventilation paths communicate with each other on the ventilation inlet side and the ventilation outlet side, The outermost cylindrical body of the body has an inlet-side protruding portion at an end on the air inlet side, and has an outlet-side protruding portion on an end on the air outlet side, and the inlet-side protruding portion The inner diameter is enlarged in the direction of air flow, the maximum inner diameter is larger than the outer diameter of an adjacent cylindrical body inside the outermost cylindrical body, and the outlet-side protruding portion has an inner diameter of A hot air generator, wherein the hot air generator is reduced in a direction in which air flows, and has a maximum inner diameter larger than an outer diameter of an adjacent cylindrical body inside the outermost cylindrical body. 2. The hot air generator according to claim 1, further comprising a blower connected to the air inlet side.