JP3209912B2 - Chimney for refuse incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates incinerator chimney for discharging exhaust gas containing corrosive gas or vapor exhausted from the incinerator.

[0002]

2. Description of the Related Art Conventionally, when waste containing harmful substances such as industrial waste and household waste is burned and incinerated in a waste incinerator,
Exhaust gas containing a large amount of water vapor is generated to inject corrosive gas generated by combustion and cooling water for controlling temperature for the purpose of exhaust gas treatment. It is well known that in a chimney that discharges this into the atmosphere, dew point corrosion occurs due to condensation of water vapor in the low-temperature part, but at this time, dew water and corrosive metals accompany the exhaust gas and are scattered into the atmosphere, It may fall as water mist around the refuse incinerator and cause pollution and corrosion problems.

[0003] In recent years, housing development has progressed to the outback, and many houses have been built around the refuse incinerators that were built in depopulated areas, and because plastics have increased in the garbage, As the combustion temperature rises, the amount of cooling water sprayed into the exhaust gas to control the temperature of the exhaust gas is also increasing, and many small incinerators constructed in rural areas are assumed to operate continuously for 24 hours. Not furnace increases,
The number of furnaces that shut down every weekend and furnaces that shut down every night increased,
Water droplet mist countermeasures have come to be regarded as important due to the increased chance of dew condensation on the exhaust gas duct and the inner surface of the chimney.

[0004]

As a countermeasure against dew condensation, it is conceivable that the burner is heated or electric heat is used to actively maintain the chimney or exhaust gas duct and the heat insulating material is strengthened. There is a problem that even if the heat insulating material is strengthened, the effect is limited if the operation stop time is long. As a countermeasure against dew condensation, there is also an operation of dehumidifying and drying exhaust gas. However, a method of once cooling and dehumidifying a large amount of exhaust gas and then raising the temperature is not worth the treatment cost of a refuse incinerator.

The present invention focuses on the fact that by turning exhaust gas, it is possible to separate a central gas flow containing almost no water droplet mist and an outer peripheral multi-phase flow containing many water droplet mist. In particular, garbage incineration that can effectively prevent the discharge of water droplets that have condensed on the inner surface of the chimney and the exhaust gas duct during startup, and prevent pollution caused by water droplet mist
It is intended to provide a furnace chimney .

[0006]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a fuel injection system having a lower end portion of a chimney body.
It is installed and swirls the exhaust gas and contains almost water droplet mist
The central gas flow and the multi-phase flow containing a large amount of water droplet mist are separated and the liquid film in which the water droplet mist is condensed is separated from the chimney body.
Gas swirling means for rising along an inner surface, and the chimney main body
At the upper part of the stack, an impingement plate protruding from the inner surface of the chimney body separates the outer peripheral multiphase flow from the core gas flow, guides it to the outside of the chimney from the separation port, and water rising along the inner surface of the chimney Membrane
And the outer flow separating means for taking out the chimney outwardly from said separation opening, before
The outer peripheral multiphase flow separated by the serial outer peripheral flow separating means separating plate
Ri and mist separation means for separating the water droplets mist contained in the outer peripheral multiphase flow to bypass downwardly, the upper end of the chimney body, wherein
Restrictor that increases the flow velocity by restricting the central gas flow of the peripheral flow separation means
And the outer peripheral multiphase flow where the water droplet mist is separated.
Peripheral flow merging flow path that merges with
The outlet is connected to the outlet of the outer peripheral junction flow path, and
The outer peripheral multi-phase flow is suctioned using the suction force generated at the throttle
Peripheral flow suction means for merging.

[0007] The invention according to claim 2 provides a mist separating device.
Place a collecting tray to receive the separated water below the step, and collect the water
Drainage means for discharging separated water from the tray is provided.
You.

[0008]

[0009]

According to the first aspect of the present invention, the gas swirl means separates the gas flow into a central gas flow substantially containing no water droplet mist and an outer peripheral multi-phase flow containing a large amount of water droplet mist. The water film to which the mist is attached effectively moves upward. The outer peripheral flow separation means impinges the outer peripheral multiphase flow on the impingement plate, guides the outer peripheral multiphase flow from the separation port to the outside of the chimney, separates the outer peripheral multiphase flow from the central gas flow, changes the flow direction of the outer peripheral multiphase flow, and causes a water droplet mist. And the water film rising on the inner surface of the chimney is taken out of the chimney from the separation port . Further, the separation plate of the mist separating means diverts the outer peripheral multiphase flow downward to further reduce the flow velocity, thereby separating water mist contained in the outer peripheral multiphase flow. Thereby, the water droplet mist can be effectively separated and removed from the exhaust gas discharged from the chimney. Also the center gas generated in the throttle
Due to the venturi effect caused by the flow, the outer peripheral flow from the separation port
Actively sucks the multi-phase flow at the outer periphery of the flow path and merges with the central gas flow
And can be effectively discharged to the sky.

According to the second aspect of the present invention, the water collecting
From the water droplets due to the water film raised by the ray and the peripheral multiphase flow
The collected water droplets can be collected and drained by drainage means.
Thus, the separated water can be reliably drained.

[0012]

[0013]

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Here, the smoke for a refuse incinerator of the present invention is described.
An embodiment of the protrusion will be described with reference to FIGS. FIG.
, 1 is a cylindrical chimney body for discharging exhaust gas G discharged from a refuse incinerator, and at the lower end of the chimney body 1 ,
Gas swirling means 2 is provided for swirling the exhaust gas G in the chimney main body 1 and separating it into a central flow Gi and an outer peripheral multi-phase flow Go.
A mist separation unit 3 for separating o and separating and discharging a water droplet mist from the outer peripheral multi-phase flow Go is provided. A separated water discharge unit 4 is provided below the mist separation unit 2.

The gas swirling means 2 may be one in which swirling vanes are provided inside the chimney main body 1, but preferably have as little fluid resistance as possible. In this case, as shown in FIG. The exhaust gas G is blown in the tangential direction of the chimney main body 1 by being connected to a position eccentric to the base end of the stack 1 to form a swirling flow Gm. In this way, the exhaust gas G is swirled in the chimney main body 1, and thereby the exhaust gas G
Is urged to the outer peripheral side by centrifugal force to be separated into a central gas flow Gi containing almost no water droplet mist and an outer gas flow Go containing a large amount of water droplet mist.
Further, in the outer peripheral multi-phase flow Go, the water droplet mist is pressed against the inner surface of the chimney main body 1, solidifies to form a water film, is accompanied by the outer peripheral multi-phase flow Go, and is transferred obliquely upward.

As shown in FIG. 2, the mist separating portion 3 projects from the inner surface of the chimney main body 1 to the center over the entire circumference, and is a curved collision plate 6 for separating the outer peripheral multiphase flow Go from the central gas flow Gi. An outer peripheral flow separation means including a separation port 7 for guiding the outer peripheral multiphase flow Go colliding with the collision plate 6 to the outside of the chimney main body 1 is provided. In addition, the separated outer peripheral multiphase flow Go is guided downward outside the chimney main body 1 and then detoured further upward, so that the separation plate 8 serving as mist separating means for separating the water droplet mist contained in the outer peripheral multiphase flow Go collides. A cylindrical cover body 9 that is provided continuously to the plate 6 and guides the outer peripheral multiphase flow Go bypassed around the outer peripheral portion of the separation plate 8 upward.
Are arranged, and a peripheral flow bypass 10 is formed in the lower part of the separation plate 8 and in the cover body 9.

Below the separating plate 8, an outer peripheral portion is covered by a cover 9.
Is provided, and the lower end of the separation plate 8 in which a plurality of communication ports 8 a are formed is connected to the bottom plate of the water collection tray 11. One or more drainage pipes 12 as drainage means are connected to the water collecting tray 11, and the drainage pipes 12 have a semi-cylindrical or cylindrical shape and have a chimney main body 1.
Mounted downward along the outer surface of the

At the upper end of the chimney main body 1, there is provided an outer peripheral flow suction means 13 for joining the outer peripheral multiphase flow Go from which the water droplet mist is separated to the central gas flow Gi. This peripheral flow suction means 13 is a narrowing portion 1 which is reduced in diameter toward the upper end at the upper end of the chimney main body 1 to increase the flow velocity of the central gas flow Gi and generate a suction force.
3a, and a tapered cylinder 13b which is reduced in diameter toward the upper end at the upper part of the cover body 9 and connects the outlet of the peripheral flow detour 10 to the outlet of the throttle portion 13a.

The separated water discharge part 4 has a ring-shaped water collecting basin 1.
4 is attached to the outer periphery of the chimney main body 1 and the outlet of the drainage pipe 12 is open. Further, a drain hose 15 is connected to the water collecting box 14, so that the separated water can be collected and drained.

In the above configuration, the exhaust gas G discharged from the exhaust gas pipe 5 is supplied to the gas swirling means 2 at the lower end of the chimney body 1.
And a centrifugal force separates the swirling flow Gm into a central gas flow Gi containing almost no water droplet mist and a peripheral multiphase flow Go containing a large amount of water droplet mist.
Is raised along. Further, the water droplet mist is condensed and formed into a liquid film on the inner surface of the chimney main body 1 with which the outer peripheral multi-phase flow Go comes into contact with the outer peripheral multi-phase flow Go, which is pushed by the outer peripheral multi-phase flow Go and rises along the inner surface.

When reaching the mist separation section 3, the outer peripheral multiphase flow G
o collides with the collision plate 6 and flows from the separation port 7 to the peripheral flow detour 10
And the water film is discharged from the separation port 7. At this time, the outer peripheral multi-phase flow Go collides with the collision plate 6 and changes its direction, whereby water mist is separated.
The flow velocity is reduced by being guided downward along the, and the water droplet mist is condensed and dropped. These separated waters are dropped on the water collecting tray 11 as droplets, sent from the drainage pipe 12 to the water collecting section 14 and discharged from the drainage hose 15.

On the other hand, the flow rate of the central gas flow Gi is increased by the flow path being narrowed by the narrowing portion 13a, and the outer circumferential flow detour 1
The outer peripheral multiphase flow Go of 0 is sucked and merged with the central gas flow Gi, and is discharged to the outside.

Here, an experimental example which has reached the above embodiment will be described with reference to FIGS. Experimental Example 1 As shown in FIG.
A fan 22 and a spray nozzle 23 are arranged below a transparent acrylic pipe 21 having a length of 1000 mm, and guide fins 24 for forming a swirling flow at a lower end entrance of the pipe 21.
Was provided. Then, air was blown at about 10 m / sec by the fan 22, and water was sprayed from the spray nozzle 23 at the same time.

As a result, a central air flow Ai containing almost no water droplet mist was found at the center of the pipe 21, and a multiphase air flow Ao containing many water droplet mistakes was found at the outer periphery. In this multi-phase air flow Ao, the pipe 21
A water film is formed on the inner surface of the pipe 21 and is pushed upward by the swirling multi-phase airflow Ao, and is blown upward from the upper end of the pipe 21,
Falling to the surroundings was observed. The moving direction of the water film was obliquely upward along the swirling flow and pressed against the inner surface of the pipe 21 to be transferred. Next, when the same experiment was performed with the guide fins 24 removed, it was found that the water film rising on the inner surface of the pipe 21 was disturbed in some places, and that the water droplet mist also rose at the center of the pipe.

Therefore, it has been found that the centrifugal force (cyclone effect) of the swirling flow can be used to separate a central air flow Ai containing almost no water droplet mist and a multiphase air flow Ao containing a large amount of water droplet mist. Also pipe 2
It was presumed that the water film rising along the inner surface of No. 1 was also satisfactorily raised along with the gas flow in the swirling flow, and drainage could be performed effectively.

Experimental Example 2 As shown in FIG. 5, a predetermined gap 32 (5 mm) was provided at the upper end of the pipe 21 of the experimental apparatus of FIG.
A ring-shaped flange plate (collision plate) 31 having an outer shape of 130 mm and protruding 5 mm in the pipe 21 was arranged. Then, air was blown at about 10 m / sec by the fan 22 and water was sprayed from the spray nozzle 23 at the same time, and a swirling flow was formed in the pipe 21 by the guide fins 24.

As a result, it was observed that the rising water film formed on the inner surface of the pipe 21 collides with the flange plate 31 and is blown outward in a substantially horizontal direction from the gap together with the mixed phase air amount Ao. Therefore, it was found that the water film rising along the inner surface of the pipe 21 can be prevented from scattering to the surroundings by being guided to the outside of the pipe 21 using the flange plate 31 and the gap 32. It has also been found that the peripheral multi-phase flow collides with the flange plate 31 to suddenly change the flow and decelerate the flow, thereby exerting a water droplet mist separation effect.

In practical use, the shape of the flange plate 31 is such that the collision surface is formed as a curved surface as shown in FIG. 2 so that the gas flow can be minimized without difficulty in consideration of the aerodynamic characteristics. desirable.

Experimental Example 3 As shown in FIG. 6, an inner diameter of 140 mm and a length of 10 mm were formed at a predetermined interval on the outer peripheral portion of the flange plate 31 of the experimental apparatus of FIG.
0 mm transparent acrylic pipe 41 (corresponding to the cover body 9.
Hereinafter, it is referred to as an outer pipe 41. ) Are arranged coaxially.
Then, the air is blown at about 10 m / sec by the fan 22 and water is sprayed from the spray nozzle 23 at the same time.
4 formed a swirling flow in the pipe 21.

As a result, the multi-phase airflow Ao spouted outward in the substantially horizontal direction by the flange plate 31 is further transmitted to the outer pipe 4.
As a result, most of the water was separated and captured, and the water flowed downward. Further, the mixed-phase air flow Ao after the collision was separated into an upward flow and a downward flow, and almost no water droplet mist was observed in the upward flow. This is because the flow velocity decreases as the air flow spreads outward, and when the air flow collides with the inner surface of the outer pipe 41, the flow velocity decreases to a flow velocity at which the water droplet mist can be separated, and energy that can accompany the water droplet mist is lost. It is presumed.

In practical use, the overhang in the horizontal direction at the top of the chimney is not preferable in terms of strength and aesthetics, and in order to reduce the pressure loss of the gas flow, as shown in FIG.
It is better to reduce the flow velocity by extending the outer peripheral side of 1 and curving it downward, and to use both cyclone separation of water droplet mist by gravity and gravity separation.

Experimental Example 4 As shown in FIG. 7, a restrictor tube 51 (top inner diameter 60 mm, length 100 mm) was placed at the upper end of the pipe 21 of the experimental apparatus shown in FIG.
And a tapered cylinder 52 (top inner diameter 70 mm, length 100 mm) was also attached to the upper end of the outer pipe 41. Then, air was blown at about 10 m / sec by the fan 22 and water was sprayed from the spray nozzle 23 at the same time, and a swirling flow was formed in the pipe 21 by the guide fins 24.

As a result, the flow velocity of the central air flow from the pipe 21 increases and is discharged upward, and at that time, the outer pipe 41
It was found that the air flow Ao 'in the inside was strongly sucked. The airflow that is ejected in this manner contains almost no water droplet mist.

In practical use, the exhaust gas discharged to the outside after demisting in Experimental Examples 2 and 3 cannot be retained around the chimney, and thus needs to be suction-treated. By improving the structure of the top of the current chimney, the central gas flow is sucked using the Venturi effect, and the outer peripheral multiphase flow after water droplet mist separation is accompanied by the central gas flow and discharged.
It can spread over the sky.

According to the above embodiment, the gas swirling means 2
As a result, the exhaust gas G rising in the chimney main body 1 can be separated into a central gas flow Gi containing almost no water droplet mist and an outer peripheral multi-phase flow Go containing a large amount of water droplet mist. The water film formed by the adhesion can be effectively moved upward. The collision plate 6
The peripheral multi-phase flow Go from the center gas flow Gi is separated by collision with the peripheral flow separating means Go composed of the central gas flow Gi and is guided to the outside of the chimney main body 1 and the flow direction is changed, thereby separating the water droplet mist. At the same time, the water film rising on the inner surface of the chimney main body 1 can be taken out of the chimney main body 1 from the separation port 7. Further, the separation plate 8 as the mist separating means guides the flow of the outer peripheral multi-phase flow Go downward and circumvents the flow, thereby lowering the flow velocity, whereby the water droplet mist contained in the outer peripheral multi-phase flow Go can be separated. Therefore, the water droplet mist can be effectively separated and removed from the exhaust gas G discharged from the chimney main body 1.

Further, the outer peripheral mixed phase flow Go after the water droplet mist separation is guided by the outer peripheral flow joining flow path 10 formed by the cover body 9 to merge with the central gas flow Gi, and further generated in the throttle portion 13a by the central gas flow Gi. By virtue of the venturi effect, the outer peripheral multiphase flow Go of the outer peripheral merging flow path 10 can be positively sucked and merged with the central gas flow Gi, and the exhaust gas can be effectively discharged to the sky without staying around the chimney. Can be.

Further, since the water collecting tray 11 collects water droplets taken out of the water film rising along the inner surface of the chimney main body 1 and water droplets separated from the outer peripheral multi-phase flow Go, the water can be drained from the drainage pipe 12. The water separated and recovered at the upper end of the chimney main body 1 can be reliably recovered and treated without being scattered.

[0038]

As described above, according to the first aspect of the present invention, the gas swirling means converts the gas flow into a central gas flow containing almost no water droplet mist and an outer peripheral multiphase flow containing many water droplet mist. While separating, the water film with the water droplet mist attached to the chimney inner surface is effectively moved upward. The outer peripheral flow separation means impinges the outer peripheral multiphase flow on the impingement plate, guides the outer peripheral multiphase flow from the separation port to the outside of the chimney, separates the outer peripheral multiphase flow from the central gas flow, changes the flow direction of the outer peripheral multiphase flow, and causes a water droplet mist. And a water film that rises inside the chimney
Take out of the chimney from the separation port . Furthermore, mist separation means
The separator circumvents the outer peripheral multiphase flow downward to further reduce the flow velocity, thereby separating water mist contained in the outer peripheral multiphase flow. Thereby, the water droplet mist can be effectively separated and removed from the exhaust gas discharged from the chimney. Also aperture
Venturi effect due to the center gas flow generated in the part
And positively sucks the outer mixed phase flow of the outer mixed flow path from the separation port.
To merge with the central gas stream and discharge it effectively to the sky
be able to.

According to the second aspect of the present invention, the water collecting
The water droplets collected from the water film by the ray and the peripheral multiphase flow are separated.
Since the separated water drops can be collected and drained by drainage means,
The separated water can be reliably collected and processed.

[0040]

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a chimney according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the chimney.

FIG. 3 is a cross-sectional plan view showing the outer turning means of the chimney.

FIG. 4 is a perspective view showing a test apparatus of Experimental Example 1.

FIG. 5 is a partial cross-sectional view showing a test apparatus of Experimental Example 2.

FIG. 6 is a partial cross-sectional view illustrating a test apparatus of Experimental Example 3.

FIG. 7 is a partial cross-sectional view illustrating a test apparatus of Experimental Example 4.

[Explanation of symbols]

 G Exhaust gas Gm Swirling flow Gi Central gas flow Go Outer multi-phase flow 1 Chimney body 2 Gas swirling means 3 Mist separation unit 4 Separated water discharge unit 5 Exhaust gas pipe 6 Collision plate 7 Separation port 8 Separation plate 9 Cover body 10 Outer flow detour 11 Water collecting tray 12 Drainage cylinder 13 Peripheral flow suction means 13a Narrowing section 13b Tapered cylinder

──────────────────────────────────────────────────の Continuing on the front page (72) Keizo Nomachi Inventor Hitachi Zosen Co., Ltd. 5-28 Nishikujo, Konohana-ku, Osaka-shi, Osaka (72) Inventor Tsuneo Komi Nishikujo, Konohana-ku, Osaka-shi, Osaka 5-3-28 Inside Hitachi Zosen Corporation (56) References JP-A-50-44532 (JP, A) JP-A-56-44520 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ F23J 15/00 F23L 17/14

Claims (2)

(57) [Claims] 1. A center gas flow provided at a lower end portion of a chimney main body and swirling exhaust gas to substantially contain no water droplet mist ;
Separates into an outer multiphase flow containing a large amount of droplet mist,
Raises the condensed liquid film along the inner surface of the chimney body.
A gas swirl means that, at the top of the chimney body, collision projecting from the inner surface of the chimney body
Separating port by separating outer peripheral multiphase flow from center gas flow by veneer plate
From well as induction chimney outside, and the outer flow separating means for taking out the chimney outside the water film increases along the chimney inner surface from said separation opening, the outer periphery multiphase flow separated by the outer circumferential flow separation means separating plate
A mist separation means for separating the water droplets mist contained more outer peripheral multiphase flow to bypass downwardly, the upper end of the chimney body, core gas flow in the peripheral flow separating means
The squeeze section and the water mist are separated to increase the flow velocity
Outer peripheral flow merging of the mixed outer peripheral multiphase flow with the central gas flow
Path, and the outlet of the outer peripheral merging flow path to the outlet of the throttle section.
Connection to reduce the suction force generated in the throttle by the central gas flow.
A peripheral flow suction means for suctioning and merging the peripheral multiphase flow using
A chimney for a refuse incinerator , comprising: 2. A collector for receiving separated water below the mist separating means.
The chimney for a refuse incinerator according to claim 1, further comprising a water tray, and a drainage means for discharging the separated water from the water collecting tray .