JP2006185757A - Heat treatment device using microwave - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment device using microwaves and capable of easily preventing the intrusion of the microwaves into an original radiation opening or an adjacent radiation opening by properly dispersing the radiated microwaves. <P>SOLUTION: This heat treatment device is composed by installing a plurality of microwave oscillators 2 in a casing 3 to radiate the microwaves from the respective microwave oscillators 2. Conical reflecting plates 1 each having an apex directed to the radiation opening 21 are mounted in front of radiation openings 21 of the microwave oscillators 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat treatment apparatus using microwaves, and in particular, easily disperses irradiated microwaves to easily prevent microwaves from entering the original irradiation port or adjacent irradiation ports. The present invention relates to a heat treatment apparatus that uses microwaves.

For example, as one of devices using a microwave oscillator, there is a heat treatment device that processes fly ash containing harmful substances such as dioxins.
As shown in FIGS. 3 to 4, the heat treatment apparatus includes a casing 3 including a microwave oscillator 2 and a screw conveyor 4 disposed at an inner lower portion of the casing 3. While stirring the fly ash, the microwave is irradiated and sent to the discharge port 8.
Although the microwave oscillator 2 is provided according to the amount of fly ash to be processed and the processing time, a large microwave oscillator is expensive, and thus a large number of small microwave oscillators 2 are installed in the housing 3.

By the way, in such a heat treatment apparatus using a microwave oscillator, when the microwave oscillated from the microwave oscillator is reflected by the wall surface of the casing and enters the irradiation port, the inside of the microwave oscillator is damaged. There is.
In contrast, conventionally, a fan-like blade is rotated in front of the irradiation port, and the microwave applied to the blade is diffused in a random direction to enter the original irradiation port or an adjacent irradiation port. It is hard to do.

  However, when a large number of microwave oscillators are installed in accordance with fly ash, as in the case of the heat treatment apparatus, a very difficult technique is required for setting the blade mounting pitch and angle. There is a problem that the setting conditions of the blades must be determined by repeating the above.

  In view of the problems of the above-described conventional heat treatment apparatus using microwaves, the present invention accurately disperses the irradiated microwaves, so that the microwaves enter the original irradiation port and the adjacent irradiation ports. It is an object of the present invention to provide a heat treatment apparatus using a microwave that can easily prevent the above.

  In order to achieve the above object, a heat treatment apparatus using microwaves according to the present invention is a heat treatment apparatus using microwaves that radiates microwaves from a plurality of microwave oscillators installed in a casing. A conical reflector having a vertex facing the irradiation port is provided in front of the irradiation port of the microwave oscillator.

  According to the heat treatment apparatus using microwaves of the present invention, in the heat treatment apparatus using microwaves that irradiates microwaves from a plurality of microwave oscillators installed in the housing, irradiation of each microwave oscillator Since a conical reflector is provided in front of the mouth with the apex facing the irradiation port, the angle and height of the reflection plate are set according to the pitch of the irradiation port, etc. It is accurately dispersed, and microwaves can be easily prevented from entering the original irradiation port and adjacent irradiation ports.

  Embodiments of a heat treatment apparatus using microwaves according to the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of a heat treatment apparatus using a microwave according to the present invention.
In this heat treatment apparatus using microwaves, a plurality of microwave oscillators 2 are installed in a casing 3 so that microwaves are emitted from each microwave oscillator 2. In front of 21, conical reflectors 1 each having an apex directed toward the irradiation port 21 are provided.

As shown in FIGS. 2 to 4, the casing 3 is provided with the plurality of microwave oscillators 2 on the ceiling surface, and a screw conveyor 4 is provided in the lower part on the inside thereof, and is supplied by the screw conveyor 4. The fly ash is sent to the discharge port 8 while stirring.
A storage tank 5 for storing fly ash discharged from a large dust collector at a garbage incineration site is disposed upstream of the screw conveyor 4. The storage tank 5 is opened and closed by opening and closing a rotary valve 6 disposed therein. Fly ash is supplied evenly onto the screw conveyor 4.
In addition, a dust collector 7 is provided in the housing 3, and a suction port 7 a made of a punching metal is provided for dust contained in smoke generated when the fly ash charged in the housing 3 is heated by microwaves. Then, the air is sucked in by a suction fan (not shown), and only the purified air is discharged to the outside by a filter 7b disposed in the dust collector 7.

On the other hand, six microwave oscillators 2 are installed on the ceiling surface of the housing 3 in accordance with the amount of fly ash to be processed and the processing time. The fly ash that moves while being stirred by the conveyor 4 is heated to detoxify harmful substances such as dioxins.
In front of the irradiation port 21 of each microwave oscillator 2, as shown in FIGS. 1 to 2, a conical reflection with the apex directed to the irradiation port 21 in a state where the central axes 1 a and 21 a are aligned. Each plate 1 is provided.
The reflecting plate 1 is made of a conical metal plate having a skirt portion having a larger diameter than the irradiation port 21, and is fixed to the housing 3 by an arm 11 extending from the periphery of the irradiation port 21.

  By the way, the setting conditions such as the angle and height of the reflecting plate 1 in such a heat treatment apparatus can be obtained as follows, for example.

As shown in FIG. 2, the angle θ ₁ formed with the horizontal plane of the reflecting plate 1 is not particularly limited, but is set to 50 ° in the present embodiment. I decided to. Incidentally, in order not to return the reflected wave K of the microwave to above the horizontal plane, θ ₁ > 45 ° needs to be set, so that the angle θ ₁ formed with the horizontal plane of the reflecting plate ₁ is larger than 45 °. Try to set.
here,
θ ₁ = 50 °
Then, the angles θ ₂ , θ ₃ , θ ₄ and θ ₅ shown in FIG. 2 are as follows.
θ ₂ = 90 ° −θ ₁ = 40 °
θ ₃ = 180 ° -2 · θ ₂ = 100 °
θ ₄ = θ ₃ −90 ° = 10 ° (the reflected wave K is downward from the horizontal plane)
θ ₅ = θ ₃ −90 ° + θ ₁ = 60 °

[Case 1]
Then, the condition that the reflected wave K of the microwave reflected by the reflecting plate 1 does not hit the reflecting plate 1 adjacent to the reflecting plate 1 is as follows.
(P−D / 2) · tan θ ₄ > h
Here, P: pitch of the irradiation port 21
D: Diameter of the reflector 1 (here, 0.20 m)
h: Height of the reflector 1
from now on,
h = D / 2 · tan θ ₁ = 0.12 m
P> h + D / 2 · tan θ ₄ = 0.14 m
It becomes.
Thus, by setting the pitch P of the irradiation port 21 and the like, the reflected wave K of the microwave reflected by the reflection plate 1 is irradiated so as not to hit the reflection plate 1 adjacent to the reflection plate 1. The microwave can be accurately dispersed and irradiated downward.

[Case 2]
Further, as shown in FIG. 2, when the reflected wave K of the microwave reflected by the reflecting plate 1 hits the reflecting plate 1 adjacent to the reflecting plate 1, the following two formulas are established.
ha · tan θ ₂ = hb
(P−hb) · tan θ ₄ = hb
Here, ha: the distance in the height direction of the position where the reflected wave K of the microwave reflected by the reflecting plate 1 hits the reflecting plate 1 adjacent to the reflecting plate 1 (the distance in the height direction from the apex of the reflecting plate 1) )
hb: horizontal distance at which the reflected wave K of the microwave reflected by the reflecting plate 1 hits the reflecting plate 1 adjacent to the reflecting plate 1 (the horizontal distance from the apex of the reflecting plate 1)
P: Pitch of irradiation port 21 (here, 0.30 m)
It is.
from now on,
hb = P · tan θ ₄ / (1 + tan θ ₄ ) = 0.04 m
ha = hb / tan θ ₂ = 0.05 m
It becomes.

The condition that the reflected wave K of the microwave reflected by hitting the reflecting plate 1 twice does not return to the irradiation port 21 above the reflecting plate 1 is as follows.
R> W / 2-hb
Here, R: the distance in the horizontal direction between the position where the reflected wave K of the microwave hitting the reflecting plate 1 hits the casing 3 and the position hitting the reflecting plate 1
W: Diameter of the irradiation port 21 (here, 0.11 m)
It is.
from now on,
R> W / 2−hb = 0.015 m
It becomes.
Further, the following formula is established.
R = (ha + h0) · tan (90 ° − (180 ° −2 · θ ₅ + θ ₄ ))
= (Ha + h0) · tan (2 · θ ₅ −θ ₄ −90 °)
= (Ha + h0) .tan20 °
Here, h0: distance from the lower surface of the housing 3 to the top of the reflector 1 (here, 0.05 m)
It is.
from now on,
R = 0.04m
Thus, the condition of R> W / 2−hb is satisfied.
Further, the following formula is established.
R ′ = (h0 + h) · tan (90 ° − (180 ° −2 · θ ₅ + θ ₄ ))
= (H0 + h) · tan (2 · θ ₅ −θ ₄ −90 °)
= (H0 + h) · tan20 °
Here, R ′: the horizontal distance between the position where the reflected wave K of the microwave reflected by the reflecting plate 1 hits the housing 3 and the position passing through the height position corresponding to the lower edge of the adjacent reflecting plate 1 It is.
from now on,
R '= 0.06m
It becomes.

The condition that the reflected wave K of the microwave reflected by the casing 3 does not hit the adjacent reflector 1 is as follows.
hb + R + R ′ <P−D / 2
here,
hb + R + R ′ = 0.04 + 0.04 + 0.06 = 0.16 m
PD / 2 = 0.30-0.20 / 2 = 0.20m
Thus, the above condition of hb + R + R ′ <P−D / 2 is satisfied.
In this way, by setting the pitch P of the irradiation port 21 or the like, the reflected microwave K reflected by the reflecting plate 1 is sequentially reflected on the adjacent reflecting plate 1 and the casing 3 and irradiated. Can be accurately dispersed and irradiated downward.

  Thus, according to the heat treatment apparatus using microwaves of the present embodiment, in each of the heat treatment apparatuses using microwaves irradiated with microwaves from the plurality of microwave oscillators 2 installed in the housing 3, Since the conical reflector 1 with the apex directed to the irradiation port 21 is provided in front of the irradiation port 21 of the microwave oscillator 2, the angle of the reflection plate 1 is irradiated as in the case 1 or the case 2. By setting according to the distance between the mouths 21 and the like, it is possible to accurately disperse the irradiated microwaves and easily prevent the microwaves from entering the original irradiation port and the adjacent irradiation ports.

  As mentioned above, although the heat processing apparatus using the microwave of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure described in the Example is demonstrated. The configuration can be changed as appropriate within a range that does not depart from the spirit of the invention, for example, as appropriate.

  The heat treatment apparatus using the microwave of the present invention can accurately disperse the irradiated microwave by simply setting the angle and height of the reflector according to the pitch of the irradiation port, and the like. Since it has the characteristic of easily preventing the microwave from entering the adjacent irradiation port, for example, it can be used in a heat treatment apparatus using microwaves for detoxifying fly ash dioxins. In addition, it can be suitably used for other heat treatment apparatuses including a plurality of microwave oscillators.

It is a principal part enlarged view which shows the reflecting plate of the heat processing apparatus using the microwave of this invention. It is explanatory drawing of the setting conditions of the reflecting plate. It is a side view which shows the heat processing apparatus using the microwave of the Example. The same heat processing apparatus is shown, (a) is the top view, (b) is the sectional view on the AA line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reflector 1a Central axis 11 Arm 2 Microwave oscillator 21 Irradiation port 21a Central axis 3 Case 4 Screw conveyor 5 Storage tank 6 Rotary valve 7 Dust collector 8 Discharge port

Claims (1)

  In a heat treatment apparatus using microwaves that radiates microwaves from a plurality of microwave oscillators installed in a housing, a conical shape with the apex directed to the irradiation opening is located in front of the irradiation opening of each microwave oscillator. A heat treatment apparatus using microwaves, each having a reflector.

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