JPH01200105A - Far infrared ray radiation device - Google Patents

Abstract

PURPOSE:To provide a small and high-efficiency far infrared ray radiation device, by a method wherein an internal pipe the size of which is gradually increased from the upper stream side toward the downstream side is disposed in a far infrared ray radiation pipe. CONSTITUTION:The outer surface of a far infrared ray radiation pipe 1 is coated with far infrared ray radiation paint 4. An internal pipe 5 the size of which is gradually increased from the upper stream side toward the downstream side is disposed in the radiation pipe 1 in a state to be supported by a fin-shaped support member 6. As a result, the wave length and radiation energy of far infrared rays per a unit length from the pipe 1 are uniformized throughout an overall length, and a small and high-efficient far infrared ray radiation device can be provided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention allows high-temperature combustion gas to flow through a far-infrared radiation pipe whose outer surface is coated with far-infrared radiation paint, and emits far-infrared rays from this pipe. This invention relates to a far-infrared radiation device that utilizes the sensible heat of combustion gas as far-infrared rays.

[Conventional technology]

In the above-mentioned far-infrared radiation device, since the combustion gas flows through a far-infrared radiation pipe of a predetermined length, a temperature difference occurs between the upstream side and the downstream side, and the temperature of the outer surface of the upstream side is high, while the temperature of the downstream side is high. The temperature on the side is lower.

[Problem to be solved by the invention]

In the above-mentioned conventional far-infrared radiation device, there is a difference in the amount of radiation energy between the upstream side and the downstream side, and the radiated wavelength is shorter from the upstream side.
The wavelength emitted from the downstream side becomes longer, making it impossible to obtain far-infrared rays of a constant wavelength from the entire far-infrared ray radiating device.

This means that if the predetermined wavelength, for example, the dominant wavelength is 3.8 μm,
In the case of snow melting, where far infrared rays are most effective, and in the case of heating and drying, which require far infrared rays with a certain long wavelength, the energy of far infrared rays with the above wavelengths cannot be effectively emitted, resulting in poor efficiency. A problem arises.

On the other hand, if we try to make the emitted wavelength the same on the upstream and downstream sides, the diameter of the far-infrared radiation pipe must be made larger on the upstream side and smaller on the downstream side. The radiation area of infrared rays is large on the upstream side and small on the downstream side, and therefore the radiant energy of far infrared rays is also large on the upstream side and small on the downstream side because the outer surface temperature of each is the same, so that the same radiant energy is obtained over the entire length. There is a problem that it cannot be done.

The present invention has been developed in consideration of the above-mentioned problems, and it is possible to make the diameter of the far-infrared radiation pipe the same over its entire length, to make the radiation area the same on both the upstream and downstream sides, and to maintain the outer surface temperature over the entire length. As a result, the wavelength and radiation energy of far infrared rays per unit length from the far infrared radiation pipe can be made uniform over the entire length of the pipe, making it possible to create a small and efficient far infrared radiation device. The purpose is to provide

[Means to solve the problem]

In order to achieve the above object, the far-infrared radiation device according to the present invention flows hot combustion gas through a far-infrared radiation pipe whose outer surface is coated with far-infrared radiation paint, and emits far-infrared rays from the far-infrared radiation pipe. In a far infrared radiation device,
It has a configuration in which an internal pipe whose diameter gradually increases from the upstream side to the downstream side is disposed inside the far-infrared radiation pipe.

A far-infrared emitting paint may also be applied to the outer surface of the internal pipe.

Further, the far-infrared emitting paint may be applied to both the inner surface of the emitting pipe and the outer surface of the inner pipe.

Furthermore, a catalytic combustor is connected to the upstream side of the far-infrared radiation pipe, and this combination is made into multiple stages.

Further, a configuration may be adopted in which a combustor and a fuel mixer are installed inside far-infrared radiation pipes that are connected in multiple stages.

[For production]

As the combustion gas flowing in the far-infrared radiation pipe flows from the upstream side to the downstream side, the flow speed increases, and therefore the film heat transfer coefficient in the flow path becomes thicker on the downstream side, and this film heat transfer coefficient increases. This compensates for the temperature drop in the combustion gas,
From the outer surface of the far-infrared radiation pipe, far-infrared rays of the same amount of heat and, therefore, of the same wavelength are emitted from the outer area per unit length over its entire length.

By applying far-infrared radiation paint to the inner and outer surfaces of the far-infrared radiation pipe and the outside surface of the inner pipe,
The amount of heat received by the inner surface of the far-infrared radiation pipe increases,
The flow velocity of the combustion gas can be reduced accordingly.

Combustion gas directly flows into the far-infrared radiation pipe from the catalytic combustor, and the combustion gas heat-exchanged in the far-infrared radiation pipe is supplied to the next-stage catalytic combustor.

Furthermore, when a combustor and a fuel mixer are installed inside a far-infrared radiation pipe, combustion takes place within this pipe.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

Fig. 5 schematically shows a far-infrared radiation device to which the present invention is applied. ), and each radiation pipe 1, 1 .・
A catalytic combustor 3 containing a combustion catalyst 2 inside is connected to the upstream side of . It is. The preheated air supply 3a of the most upstream catalytic combustor is connected to a preheated air generation source (not shown), and the radiation pipe at the final stage is connected to a heat exchanger 3b. The outer surface of the radiation pipe 1 is coated with far-infrared radiation paint, and the combustion gas flowing from the catalytic combustor 3 is applied to the radiation pipe 1.
When the material is heated to a predetermined temperature, far infrared rays are emitted from its outer surface.

Although not shown, each catalytic combustor 3 is connected to a fuel supply pipe.

Each of the above radiation pipes 1, 1. . . . are as shown in FIGS. 1 to 4.

That is, the outer surface of the radiation pipe 1 is coated with far-infrared radiation paint 4.
is applied. Inside the radiation pipe 1, an internal pipe 5 whose diameter gradually increases from the upstream side to the downstream side is installed and supported by a fin-shaped support member 6. Both ends of this internal pipe 5 are closed and are formed into an arrowhead shape to reduce fluid resistance.

The example shown in FIGS. 1 and 2 shows an example in which far-infrared radiation paint 4 is applied only to the outer surface of the radiation pipe 1, but FIG.
As shown in FIG. 4, in addition to the outer surface of the radiation pipe 1,
The paint 4 may also be applied to the inner surface of the radiation pipe 1 and the outer surface of the internal pipe 5.

With the above configuration, the fluid flow path within the radiation pipe 1 becomes annular, and its inner diameter gradually increases and its cross-sectional area gradually decreases.

Therefore, the flow velocity of the combustion gas flowing into the radiation pipe 1 from the catalytic combustor 3 gradually increases as it flows from the upstream side to the downstream side, and as a result, the internal and external surfaces of the radiation pipe 1 and the internal pipe 5 are The film heat transfer coefficient gradually increases as the flow velocity increases.

Thermal energy QT received by the inner surface per unit length of the radiation pipe 1 is the amount of heat QT received by the radiation pipe 1 directly from the combustion gas.
1 and the heat m Q 2 received from the outer surface of the internal pipe 5 heated by the combustion gas.

Also, the amount of heat Q1 directly received from the combustion gas is Q-ΔTX
hXA.

However, ΔT: temperature difference between the combustion gas and the inner surface of the radiant pipe h: film heat transfer coefficient A,: area per unit length of the inner surface of the radiant pipe, and the amount of heat Q2 received from the outer surface of the internal pipe 5 is, however, ε1: Emissivity of the inner surface of the radiant pipe ε2: Emissivity of the outer surface of the inner pipe A1: Area per unit length of the inner surface of the radiant pipe A2: Area per unit length of the outer surface of the inner pipe T1: Temperature of the inner surface of the radiant pipe X T2: The temperature of the outer surface of the internal pipe becomes Thermal energy received by the inner surface per unit length of the radiation pipe 1, that is, thermal energy corresponding to QT-Q1+Q2 is radiated from the outer surface of the radiation pipe 1.

While the combustion gas flowing into the radiation pipe 1 flows from the upstream side to the downstream side, it sequentially releases thermal energy as far infrared rays from the outer surface of the radiation pipe 1, so its temperature gradually decreases to △T. becomes gradually smaller. On the other hand, since the film heat transfer coefficient of the inner surface of the radiation pipe 1 gradually increases from the upstream side to the downstream side, the amount of heat received on the inner surface of the radiation pipe 1 per unit length is Q
T is approximately constant, and the radiant energy from the outer surface per unit length of the radiation pipe 1 is approximately constant. Therefore, the radiation temperature and wavelength are constant over the entire length.

At this time, the outer area of the internal pipe 5 also gradually increases from the upstream side to the downstream side, and the heat m Q 2 received by the external surface of the internal pipe 5 gradually increases, so that
The amount of increase in the film heat transfer coefficient on the downstream side does not need to be simply increased by the amount of decrease in the temperature difference ΔT between the combustion gas and the inner surface of the radiation pipe 1.

Furthermore, as shown in FIGS. 3 and 4, in the embodiment in which the far-infrared emitting paint 4 is applied to the outer surface of the internal pipe 5, in the case of stainless steel, the emissivity of this part is 0846 to 0846 when the above-mentioned paint is not applied. 0.50 can be increased to about 0.9 to 0.92, and by applying the paint 4 to the inner surface of the radiation pipe 1, the heat received from the outer surface of the inner pipe 5 can be reduced. becomes larger.

Therefore, the flow velocity of the combustion gas in the radiation pipe 1 can be made smaller than when the far-infrared radiation paint 4 is not applied to the inner surface of the radiation pipe 1 and the outer surface of the inner pipe 5, and therefore, air is blown to create combustion gas. The pressure of the air can be reduced, the sensible heat of the combustion gas can be utilized to a large extent, and the amount of combustion gas can be reduced.

At the most downstream part of the radiation pipe 1, it bends according to the curvature of the pipe in this part and is supplied to the next catalytic combustor.
At this most downstream part, the internal pipe 5 is eliminated and the cross-sectional area rapidly increases, so that the flow velocity rapidly decreases, so that the flow velocity resistance at this bent part becomes low.

In each of the above embodiments, the inner pipe 5 has a so-called tapered shape in which the outer diameter gradually increases, but
It may also have a shape in which parallel pipes with different diameters are connected in sequence, that is, a stepped shape.

Furthermore, in the first and second embodiments described above, an example was shown in which a plurality of radiation pipes 1 were arranged in parallel to form a multi-stage shape.
As a third embodiment, the radiation pipes may be connected in a straight line to form multiple stages in the longitudinal direction.

6 to 8 show this third embodiment. In the figures, 10 is a radiation pipe of unit construction, and flanges 11° 11 are provided at both ends of this radiation pipe 10. 11.11, each radiation pipe 10 is connected in a straight line. The upstream end of the radiation pipe 10 on the most upstream side is connected to a preheated air source and a fuel mixer, and the downstream end on the most downstream side is connected to a heat exchanger.

The outer surface of the radiation pipe 10 is coated with far-infrared radiation paint 4, and the inside thereof has an internal pipe 1 whose diameter gradually increases from the upstream side to the downstream side.
2 is coated with far-infrared radiation paint 4 on its outer surface.

Further, a combustion catalyst 13 is supported by a support member 14 and installed inside the upstream end of the radiation pipe 10. Further, a fuel temperature mixer 15 is provided at the downstream end. This fuel mixer 15 consists of a fuel permeable member 17 in which a plurality of porous pipes 16 are arranged in parallel, and a support plate 18 that arranges this on the downstream side of the downstream end of the internal pipe 12. A fuel feed pipe 19 is connected to 17.

The support plate 18 has a disk shape and its outer periphery is fixed to the inner surface of the radiation pipe 10, and an expansion portion 18a is provided in the radial middle of the support plate 18 to absorb the difference in thermal expansion between the inner and outer portions. It is arranged in a ring shape.

In this configuration, the mixed fuel that has flowed in from the upstream end of the radiation pipe 10 together with the preheated air is combusted by the combustion catalyst, and this combustion gas flows downstream, during which time the same action as in the first embodiment takes place. Far infrared rays are emitted from the radiation pipe 10.

On the downstream side of the radiant pipe 10, it passes through a fuel mixer 15, during which new fuel is mixed and supplied to the upstream side of the radiant pipe of the next stage.

The far-infrared radiation device according to this embodiment is used to heat a large room, such as a gymnasium or a hall. In this case, the far-infrared radiation device is arranged in a straight line, and a reflecting plate is installed on the back side of the device to be heated, thereby increasing the heating efficiency.

〔Effect of the invention〕

According to the invention, the far infrared radiation pipe 1. By making the diameter of the IO the same over the entire length, the radiation area can be made the same on both the upstream and downstream sides, and the outer surface temperature can be made uniform over the entire length.

Therefore, the wavelength and radiation energy of the far infrared rays per unit length from the far infrared radiation pipes 1 and 10 can be made uniform over the entire length, and a compact and efficient far infrared radiation device can be obtained.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a cross-sectional view of the first embodiment, FIG. 2 is an enlarged cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a schematic overall explanatory diagram of the far-infrared radiation device, and FIGS. 6 to 8 are cross-sectional views of the embodiment. This shows a third embodiment of the present invention, and FIG. 6 is a sectional view;
FIG. 7 is an enlarged cross-sectional view of the main part, and FIG. 8 is a cross-sectional view taken along the line ■-■ in FIG. 7. 1.10 is a far-infrared radiation pipe, 3 is a catalytic combustor, 4 is far-infrared radiation paint, and 5 and 12 are internal pipes. Applicant Nippon Chemical Plant Consultant Co., Ltd. Representative Patent Attorney Masaaki Yonehara

Claims (5)

[Claims] (1) In a far-infrared radiation device that emits far-infrared rays by flowing high-temperature combustion gas through the far-infrared radiation pipes 1 and 10 whose outer surfaces are coated with far-infrared radiation paint 4, far-infrared radiation A far-infrared radiation device characterized in that internal pipes 5 and 12 whose diameters gradually increase from the upstream side to the downstream side of the radiation pipe 1 are disposed within the radiation pipe 1. (2) The far-infrared radiation device according to claim 1, characterized in that the outer surfaces of the internal pipes 5 and 12 are coated with far-infrared radiation paint. (3) The far-infrared radiation device according to claim 1, characterized in that both the inner surfaces of the far-infrared radiation pipes 1 and 10 and the outer surfaces of the internal pipes 5 and 12 are coated with far-infrared radiation paint. (4) The far-infrared radiation device according to claim 1, characterized in that a catalytic combustor (3) is connected to the upstream side of the far-infrared radiation pipe (1). (5) Claim 1 characterized in that a combustor and a fuel mixer are installed inside each far-infrared radiation pipe 10 connected in multiple stages.
The far infrared radiation device described.