JPH07324717A - Method and apparatus for igniting ignitable material - Google Patents

Abstract

PURPOSE:To enable a more complete combustion of ignitable material to be attained by a method wherein flowing medium is inserted into a side wall of a secondary combustion chamber and a group of particles of high concentration of ignitable material is contacted with the flowing medium. CONSTITUTION:Thermal decomposition of ignitable material is carried out within a primary combustion chamber 1, generated ignitable gas passes through a narrowed passage 18, is guided to a secondary combustion chamber 12 and its combustion is performed. Then, a part of the flowing medium taken out of a flowing medium outlet 7 at a lower part of the primary combustion chamber 1 is fed from a flowing medium inlet 18 through a flowing medium circulation passage 29 to a side wall of the secondary combustion chamber 12. Then, a part of the flowing medium drops at a hopper part 14 at.;the lower part of the secondary combustion chamber 12, thereafter the medium is returned back from the flowing medium outlet 7 to the primary combustion chamber 1 and subsequently a circulation flow of the flowing medium is formed between the primary combustion chamber 1 and the secondary combustion chamber 12. Ignitable gas sucked into the secondary combustion chamber 12 is centrifugally separated into fine particle not-yet ignited substances and rough particle not-yet ignited substances and an inner circulation flow of the fine particle not-yet ignited substances is formed within the secondary combustion chamber 12. With such an arrangement as above, a staying time of the fine particle not-yet ignited substances within the furnace is extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator burning method and apparatus.

[0002]

2. Description of the Related Art Generally, an incinerator combustor, such as a waste incinerator, is designed to put incinerators such as municipal waste and other wastes into a combustion chamber and burn them. The incinerated material is burned through two stages of thermal decomposition of the incinerated material and combustion of combustible gas generated by the thermal decomposition.

However, in the conventional incinerator combustor, the thermal decomposition of the incineration and the combustion of the combustible gas are performed in the same combustion chamber, so that both the thermal decomposition of the incineration and the combustion of the combustible gas are sufficient. Not performed, for example, combustible gas, because the residence time in the combustion chamber is not sufficient, mixing with air is insufficient, causing incomplete combustion, harmful substances may be generated and discharged as it is. there were.

Therefore, in recent years, there has been proposed an incinerator combustion apparatus in which the thermal decomposition of the incinerator and the combustion of the combustible gas are performed in independent combustion chambers.

FIGS. 5 and 6 show an incinerator combustion apparatus having an independent combustion chamber which is currently proposed.

In the figure, 1 is a primary combustion chamber in which an incineration material supply port 2 is formed in the upper portion and a hopper portion 3 is formed in the lower portion, 4 is an air diffusing pipe provided in the primary combustion chamber 1, and 5 is an air diffusing pipe 4. A fluidized bed formed of a fluidized medium such as fluidized sand, 6 is a primary combustion chamber 1
A burner attached to the fluidized bed 5 in the middle portion of the fluidized bed, 7 a fluidized medium outlet provided at the lower end of the hopper portion 3, 8 a fluidized medium inlet formed in the middle portion of the primary combustion chamber 1, and 9 a fluidized medium. A fluid medium circulation passage such as a bucket conveyor connecting the outlet 7 and the fluid medium inlet 8 is a fluid medium circulation passage 9
The fluidized medium conveyor 11 is provided in the middle of the above, and 11 is a sieve device provided on the fluidized medium conveyor 10 exit side of the fluidized medium circulation path 9.

Reference numeral 12 denotes a secondary combustion chamber which is disposed above the primary combustion chamber 1 and has a combustion gas discharge port 13 at its upper end and a hopper portion 14 at its lower end, and 17 denotes a hopper portion. 14 is an ash outlet formed at the lower end.

18 is a flow passage for sending the combustible gas 15 from the primary combustion chamber 1 to the secondary combustion chamber 12, and 19 is a tangential line connected to the side wall of the secondary combustion chamber 12 in a tangential direction. It is a direction connection part.

Reference numeral 20 is an air supply passage connected to an external fan 21, 22 is a primary air supply passage branched from the air supply passage 20 to supply air to the diffuser pipe 4, and 23 and 24 are from the air supply passage 20. Secondary air supply passages 25, 2 which are branched to supply air to several positions of the squeezing passage 18.
Reference numerals 6 and 27 are valves provided in the middle of the primary air supply passage 22 and the secondary air supply passages 23 and 24, respectively.

Then, the air blower 21 is operated to supply air to the diffuser pipe 4 of the primary combustion chamber 1 through the air supply passage 20 and the primary air supply passage 22, thereby causing the fluidized bed 5 to flow and The fluidized bed 5 in the primary combustion chamber 1 is preheated by the burner 6, and in this state, the incinerated matter is introduced into the primary combustion chamber 1 through the incinerator supply port 2.

Then, the incinerated matter thrown into the primary combustion chamber 1 is pyrolyzed in the preheated fluidized bed 5 to generate the combustible gas 1
Solid unburned components such as 5 and char (charcoal) are generated.

Then, the solid unburned matter such as char is burned by the air supplied from the air diffuser 4 to the primary combustion chamber 1, and the thermal decomposition promotes the thermal decomposition of the incineration product.

The combustible gas 15 generated by the thermal decomposition of the incineration material is escaped to the secondary combustion chamber 12 through the squeezing passage 18 and the tangential connection portion 19, so that the combustion of the combustible gas 15 in the primary combustion chamber 1 is completed. The incineration will be pyrolyzed at a constant rate without being affected.

On the other hand, the squeezing passage 18 and the tangential connecting portion 1
The combustible gas 15 sent to the secondary combustion chamber 12 through 9
A part of the solid unburned component is supplied with air from the secondary air supply passages 23 and 24 in the squeezing passage 18 on the way, and after being mixed to some extent, introduced into the secondary combustion chamber 12 from the tangential direction. It

Then, in the secondary combustion chamber 12, a swirl flow is formed by the combustible gas 15 mixed with air, the swirl flow further promotes the mixing of the combustible gas 15 and air, and the swirl causes Since the retention of the combustible gas 15 inside the next combustion chamber 12 is sufficiently ensured, the combustible gas 15 is completely combusted, and generation of harmful substances due to incomplete combustion is prevented.

The combustion gas generated by the combustion is discharged from the combustion gas discharge port 13 at the upper end of the secondary combustion chamber 12.

Separately from the above, in the primary combustion chamber 1, a part of the fluidized medium constituting the fluidized bed 5 is passed from the fluidized medium outlet 7 at the lower end of the hopper 3 to the sieve device 11 via the fluidized medium conveyor 10. After the incombustibles are removed by the sieving device 11, the fluid is circulated from the fluidized medium inlet 8 to the primary combustion chamber 1 via the fluidized medium circulation passage 9.

Further, the ash that has been entrained in the combustible gas 15 and has risen in the squeezing passage 18 is centrifugally separated by a swirling flow in the secondary combustion chamber 12, and from the ash outlet 17 at the lower end of the hopper portion 14 of the secondary combustion chamber 12. Is discharged.

[0019]

However, the incinerator burning device has the following problems.

That is, when the thermal decomposition of the incineration product and the combustion of the combustible gas are performed in independent combustion chambers, it is possible to burn the incineration product such as waste in a state of almost complete combustion. However, the combustion gas discharged from the combustion gas discharge port 13 at the upper end of the secondary combustion chamber 12 still contains about several ppm (9 ppm) of carbon monoxide, and there is room for further improvement of the combustion state.

In view of the above situation, it is an object of the present invention to provide an incinerator burning method and apparatus capable of burning the incinerator more completely.

[0022]

According to the present invention, the combustible gas generated in the primary combustion chamber is guided tangentially to the side wall of the secondary combustion chamber to form a swirling flow of the combustible gas inside the secondary combustion chamber. At the same time, the swirling flow separates the combustible gas and the unburned gas contained in the combustible gas to form a high-concentration particle group of unburned gas along the side wall of the secondary combustion chamber. Incineration characterized in that by inserting it into the side wall of the combustion chamber, the fluid medium is brought into contact with the high-concentration particles of the unburned component formed along the side wall of the secondary combustion chamber to completely burn the unburned component. It relates to the method of burning things.

Further, according to the present invention, a fluidized bed type primary combustion chamber and a secondary combustion chamber are separately provided, and a combustible gas generated in the primary combustion chamber is guided tangentially to a side wall of the secondary combustion chamber. A connecting part is provided to connect a fluidized medium circulation path between the fluidized medium outlet in the lower part of the primary combustion chamber and the side wall of the secondary combustion chamber, and the fluidized medium outlet formed in the hopper part in the lower part of the secondary combustion chamber is connected to the primary side. The present invention relates to an incinerator combustor characterized by being connected to a combustion chamber.

In this case, the connection position of the fluidized medium circulation path to the side wall of the secondary combustion chamber is located downstream of the connection position of the tangential connection portion to the side wall of the secondary combustion chamber in the flow direction of the combustible gas. You may do it.

Further, the secondary combustion chamber may be arranged above the primary combustion chamber.

Alternatively, the secondary combustion chamber may be arranged on the side of the primary combustion chamber.

[0027]

The operation of the present invention is as follows.

In the fluidized bed type primary combustion chamber, the incineration material introduced from the incinerator supply port is thermally decomposed, and the combustible gas generated by the thermal decomposition of the incineration material passes through the squeezing passage together with the ash content. The combustible gas is guided to the secondary combustion chamber, a swirling flow of the combustible gas is generated in the secondary combustion chamber, and the combustible gas is combusted during the swirling.

Then, in the primary combustion chamber, a part of the fluidized medium constituting the fluidized bed taken out from the fluidized fluid outlet at the bottom is
It is sent from the fluidized medium inlet via the fluidized medium circulation path to a side wall of the secondary combustion chamber, in particular, to a position above the tangential connection.

Then, first, a part of the fluidized medium sent to the inside of the secondary combustion chamber drops in the hopper portion below the secondary combustion chamber to clean the hopper portion, and then from the fluidized medium outlet to the primary combustion chamber. After that, a circulating flow of the fluidized medium is formed between the primary combustion chamber and the secondary combustion chamber.

The combustible gas blown into the secondary combustion chamber contains fine-grain unburned components and coarse-grain unburned components, which are blown into the secondary combustion chamber through the tangential connection. Due to the swirling flow of the combustible gas, the unburned fine particles and the unburned coarse particles are centrifugally separated.

Then, the fine-grained unburned component separated in the secondary combustion chamber rises together with a part of the fluidized medium in association with the swirling flow of the combustible gas generated in the secondary combustion chamber, and the flow velocity of the swirling flow. Circulates in such a manner that it is entrained in the swirl flow whose flow velocity has increased again, and an internal circulation flow of unburned fine particles is formed in the secondary combustion chamber.

As a result, the residence time of the unburned fine particles in the furnace becomes longer, so that the combustion state of the unburned fine particles is improved.

Moreover, due to the centrifugal force of the swirling flow, the surface is destroyed by the fluid medium in the high-concentration particle group of fine unburned particles formed along the wall of the combustion chamber, and a new surface always appears. Therefore, the combustion of the fine grain unburned matter is promoted.

On the other hand, the unburned coarse particles separated in the secondary combustion chamber fall in the hopper section at the lower part of the secondary combustion chamber, are returned to the primary combustion chamber and are burned in the fluidized bed. Thus, an external circulation flow of coarse-grained unburned components and ash is formed between the primary combustion chamber and the secondary combustion chamber.

As a result, the residence time of the unburned coarse particles in the furnace becomes longer, so that the combustion state of the unburned coarse particles is improved.

From the above, even if the unburned component is flame-retardant,
A more complete combustion state is achieved.

[0038]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention.

Further, in the figures, as in FIGS. 5 and 6, 1 is a primary combustion chamber, 2 is an incinerator supply port formed in the upper part of the primary combustion chamber 1, and 3 is formed in the lower part of the primary combustion chamber 1. Hopper part, 4
Is an air diffuser provided in the primary combustion chamber 1, 5 is a fluidized bed formed on the air diffuser 4, 6 is a burner disposed toward the fluidized bed 5 in the primary combustion chamber 1, and 7 is the lower end of the hopper section 3. The fluidized medium outlet formed at 10, the fluidized medium conveyor 10 provided in the middle of the fluidized medium circulation path 9, and the sieve device 11 provided at the exit side of the fluidized medium conveyor 10.

Further, 12 is a secondary combustion chamber having a cylindrical side wall independently provided above the primary combustion chamber 1, 13 is a combustion gas discharge port formed at the upper end of the secondary combustion chamber 12, 14
Is a hopper portion formed in the lower part of the secondary combustion chamber 12, 18 is a squeezing passage for sending the combustible gas 15 rising from the upper part of the primary combustion chamber 1 to the secondary combustion chamber 12, and 19 is a squeezing passage. 1
8 is a tangential direction connecting portion formed on the upper end of the secondary combustion chamber 12 and connected to the side wall of the secondary combustion chamber 12 in the tangential direction.

Reference numeral 20 is an air supply passage for supplying air from an external fan 21, 22 is a primary air supply passage for supplying air from the air supply passage 20 to the air diffusing pipe 4 of the primary combustion chamber 1, 23 , 24 are secondary air supply paths for supplying the air from the air supply path 20 to the squeezing path 18, 25, 26,
27 is the primary air supply path 22 and the secondary air supply paths 23, 2
It is a valve provided in the middle of 4.

Further, in the present invention, the fluidized medium outlet 7 in the lower part of the primary combustion chamber 1 and the side wall of the secondary combustion chamber 12, in particular, the position above the connection position a of the tangential connection portion 19 (downstream position). ), A fluid medium circulation path 29 such as a bucket conveyor is connected between the fluid medium inlet 28 and the fluid medium inlet 28.

Further, the fluidized medium outlet 30 formed in the lower portion of the secondary combustion chamber 12 is connected to the fluidized medium inlet 32 of the primary combustion chamber 1 via an L-shaped valve 31.

In the figure, 33 is a sealing air supply path connecting the air supply path 20 and the L-shaped valve 31, and 34 is a valve provided in the middle of the sealing air supply path 33.

Further, 35 is a fine grain unburned component, and 36 is a coarse grain unburned component.

Next, the operation will be described.

The process of thermally decomposing the incineration product in the primary combustion chamber 1 and the combustion of the combustible gas 15 generated by the thermal decomposition of the incineration product in the secondary combustion chamber 12 is the same as in FIGS. Omit it.

In the present invention, in the primary combustion chamber 1, the hopper portion 3
A part of the fluidized medium constituting the fluidized bed 5 taken out from the fluidized medium outlet 7 at the lower end is sent to the sieving apparatus 11 via the fluidized medium conveyor 10, and after the incombustibles are removed by the sieving apparatus 11, Through the fluidized medium circulation passage 29, the fluidized medium inlet 28
To the side wall of the secondary combustion chamber 12, in particular the tangential connection 19
Is sent to a position above the connection position a.

Then, first, a part of the fluidized medium sent to the side wall of the secondary combustion chamber 12 is partially hopper 14 of the secondary combustion chamber 12.
To clean the hopper portion 14.

The fluidized medium which has cleaned the hopper portion 14 of the secondary combustion chamber 12 is sent from the air supply passage 20 to the L-shaped valve 31 through the sealing air supply passage 33 to supply and discharge the seal air through the valve 34. By adjusting by using it, it is dropped into the primary combustion chamber 1 intermittently, and thereafter, a circulating flow of the fluidized medium is formed between the primary combustion chamber 1 and the secondary combustion chamber 12.

Further, the combustible gas blown into the secondary combustion chamber 12 contains a fine grain unburned component 35 and a coarse grain unburned component 36, but the fluidized medium is used as a side wall of the secondary combustion chamber 12. , In particular, a position above the connection position a of the tangential direction connection portion 19 (downstream side)
Since the combustible gas 15 is swirled, the fine-grain unburned component 35 and the coarse-grain unburned component 36 are centrifugally separated.

Then, the fine-grained unburned component 35 separated in the secondary combustion chamber 12 rises together with a part of the fluidized medium together with the swirling flow of the combustible gas 15 generated in the secondary combustion chamber 12. When the flow velocity of the swirling flow decreases, the flow velocity of the swirling flow decreases, and then the flow velocity of the swirl flow increases again while being accompanied by the swirling flow having a high flow velocity on the upstream side. An internal circulation flow of the unburned grains 35 is formed.

Due to this internal circulation flow, the fine-grained unburned matter 35
Since the residence time in the furnace is sufficiently long,
The combustion state of is improved.

Moreover, due to the centrifugal force of the swirling flow, as shown in FIG. 2, the fine grain unburned components 35 gather along the combustion chamber wall of the secondary combustion chamber 12 and the fine grain unburned components 35 thus formed. In the high-concentration particle group (1), the fluidized medium destroys the surface of the fine particle unburned component 35 so that a new surface always appears, so that the combustion of the fine particle unburned component 35 is promoted.

Furthermore, the fine-grain unburned component 35 and the fine-grain unburned component 35
Since the fluidized medium entrained in the combustible gas 15 flows along the combustion chamber wall of the secondary combustion chamber 12 together with these,
The inside of the secondary combustion chamber 12 is cleaned.

On the other hand, the coarse-grained unburned component 36 separated in the secondary combustion chamber 12 falls in the hopper portion 14 below the secondary combustion chamber 12 and is returned to the primary combustion chamber 1, where it is burned in the fluidized bed 5. To be done. In this way, an external circulation flow of the coarse-grained unburned material 36 is formed between the primary combustion chamber 1 and the secondary combustion chamber 12.

By this external circulation flow, the coarse-grained unburned matter 36
Since the residence time in the furnace is sufficiently long, the combustion state of the coarse-grained unburned material 36 is improved.

As described above, even if the unburned components of the fine grain unburned component 35 and the coarse grain unburned component 36 are flame-retardant, a more complete (higher by one digit or more) combustion state is achieved. In the conventional case,
The combustion gas discharged from the combustion gas discharge port 13 at the upper end of the secondary combustion chamber 12 still contains carbon monoxide of about several ppm (9 ppm) as shown by the line a in FIG. In the case of the invention, as shown by the line B, it is possible to reduce carbon monoxide in the combustion gas to 0 ppm.

FIG. 4 shows a second embodiment of the present invention, which has substantially the same structure as the above embodiment except that the secondary combustion chamber 12 is arranged in parallel to the side portion of the primary combustion chamber 1. Therefore, the same action and effect can be obtained.

Further, in the figure, reference numeral 38 is an ash discharge passage such as a bucket elevator connected between the hopper portion 14 below the secondary combustion chamber 12 and the primary combustion chamber 1.

The present invention is not limited to the above-mentioned embodiment, and instead of using the fluid medium of the primary combustion chamber as the fluid medium, a fluid medium dedicated to the secondary combustion chamber is separately used. Needless to say, various modifications can be made without departing from the scope of the present invention.

[0063]

As described above, according to the present invention,
The excellent effect that the incinerated material can be burned more completely can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the radial position of the secondary combustion chamber and the concentration of unburned fine particles.

FIG. 3 is a graph showing the relationship between time and the concentration of carbon monoxide contained in the combustion gas discharged from the secondary combustion chamber.

FIG. 4 is a schematic side sectional view of a second embodiment of the present invention.

FIG. 5 is a schematic side sectional view of a conventional example.

6 is a VI-VI arrow view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary combustion chamber 7 Fluid medium outlet 12 Secondary combustion chamber 14 Hopper part 15 Combustible gas 18 Squeezing passageway 19 Tangential direction connection part 28 Fluid medium inlet 29 Fluid medium circulation path a Connection position of tangential direction connection part 19

Front page continuation (72) Inventor Hiroshi Aramaki 1-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Ltd. Tokyo 1st factory (72) Inventor Masanobu Naito 1-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Ltd. Tokyo No. 1 Factory

Claims (5)

[Claims] 1. A combustible gas generated in the primary combustion chamber is guided tangentially to a side wall of the secondary combustion chamber to form a swirl flow of the combustible gas inside the secondary combustion chamber, and the swirl flow causes the combustible gas to flow. And the unburned component contained in the combustible gas are separated to form a high concentration particle group of unburned component along the side wall of the secondary combustion chamber, and further, the fluidized medium is inserted into the side wall of the secondary combustion chamber. According to the method, the incinerator burning method is characterized in that the fluidized medium is brought into contact with the high-concentration particles of the unburned matter formed along the side wall of the secondary combustion chamber to completely burn the unburned matter. 2. A fluidized bed type primary combustion chamber and a secondary combustion chamber are provided separately, and a tangential direction connecting portion for guiding combustible gas generated in the primary combustion chamber tangentially to a side wall of the secondary combustion chamber is provided. ,
A fluidized medium circulation path was connected between the fluidized medium outlet in the lower part of the primary combustion chamber and the side wall of the secondary combustion chamber, and the fluidized medium outlet formed in the hopper section in the lower part of the secondary combustion chamber was connected to the primary combustion chamber. An incinerator combustion device characterized in that 3. The connection position of the fluidized medium circulation path to the side wall of the secondary combustion chamber is formed downstream of the connection position of the tangential connection part to the side wall of the secondary combustion chamber in the flow direction of the combustible gas. The incinerator combustion device according to claim 2. 4. The incinerator combustion apparatus according to claim 2, wherein the secondary combustion chamber is arranged above the primary combustion chamber. 5. The incinerator combustor according to claim 2, wherein a secondary combustion chamber is arranged laterally of the primary combustion chamber.