JP3534552B2 - Waste incineration apparatus and superheated steam production apparatus using incineration heat of the waste - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an invention relating to the production of superheated steam by incinerating municipal waste, industrial waste, etc. and producing steam by the heat of the combustion exhaust gas, for example, using the steam in a power plant or the like. More specifically, it relates to a waste incinerator.

[0002]

2. Description of the Related Art Conventionally, a fluidized bed incinerator is often used as an incinerator for incinerating wastes such as municipal solid waste, and such an apparatus is housed on a dispersion plate (for example, a perforated plate) in a fluidized bed incinerator. By blowing air or incineration exhaust gas into the fluid medium such as sand from below the dispersion plate, the fluidized medium is fluidized and heated, and waste such as municipal solid waste is put into the fluidized bed thus formed. To burn. Combustion gas generated by this combustion reaches a boiler through a combustion gas outlet line, generates steam by thermal contact with hot water in the boiler, and uses the steam as a turbine drive source of a power plant or the like.

A chlorine-containing organic compound such as vinyl chloride plastic is mixed in the waste such as municipal waste, and the combustible content thereof is about 0.2 to 0.5% as C1. And chlorine contained in PVC plastics mixed in waste such as municipal waste becomes HC1 by combustion (normally, HC1 in municipal waste combustion exhaust gas is about 500 to 1).
000ppm), and acts on the tube of the steam generating boiler installed downstream of the incinerator to corrode it. Particularly when the tube surface temperature is about 350 ° C. or higher, high temperature corrosion becomes remarkable as the temperature increases. Therefore, in the past, the tube surface temperature had to be 350 ° C. or lower, and the temperature of the vapor produced was limited to about 300 ° C. As a result, the power generation efficiency of the conventional waste incineration is about 15% or less, and the power generation efficiency of the plant that can make the boiler tube temperature 500 to 600 ° C. is about 30 to 40 with heavy oil or LNG containing almost no chlorine as fuel. It is remarkably low as compared with%, and its improvement has been strongly desired.

In order to solve such a problem, the above-mentioned Japanese Patent Application No. 8
-69067, heating boiler water by at least 2
The combustion heat energy of the pyrolysis gas obtained in the pyrolysis step in which at least one step heating is performed in at least one step heating and the waste is supplied into the space containing the fluidized medium to cause the pyrolysis reaction. Directly or indirectly by utilizing it, while other stage heating is performed by burning the undecomposed residue while flowing a char mixture consisting of the undecomposed residue taken out from the thermal decomposition means and the fluidized medium by air or combustion exhaust gas. It proposes a method for producing superheated steam using the heat energy obtained by the char burning process.

That is, as shown in FIG. 2, for example, the effect of the multi-step heating is that the waste such as municipal waste is thermally decomposed (in the invention of the prior application, the waste is supplied into a space having a temperature of 300 ° C. or higher). And pyrolysis gas generated by the reaction to separate a char mixture composed of an undecomposed residue and a fluid medium and an incombustible substance from each other.) And the pyrolysis. Even if the chlorine-containing pyrolysis gas contains HCl or the like in the gas, heating the boiler water by the thermal energy of the chlorine-containing pyrolysis gas is approximately 200 ° C.
Since the boiling point temperature is around ~ 320 ° C, even if the chlorine-containing pyrolysis gas acts on the tube of the steam generating boiler, the tube surface temperature does not exceed about 350 ° C, so it does not corrode. . In this case, since the boiling point of the boiler water is set to about 200 ° C. to 320 ° C. by pressurization, even if the thermal energy of the chlorine-containing pyrolysis gas is applied to the boiler water inconsistently, the boiler water is not the same. The surface temperature of the boiler water heat exchange tube rises above the chlorine corrosion temperature because it is used to absorb the heat of the water (in other words, it is used only for the phase conversion of water to steam and does not act as a temperature rise). Without doing so, it is possible to obtain boiler water or steam with a stable heating temperature.

Since the undecomposed residue that has not been decomposed by the thermal decomposition at about 300 ° C. to 500 ° C. has already been dechlorinated, it can be obtained by burning it, for example, 500
Heat energy of about 950 ° C. (in the present invention, a char combustion means for combusting the undecomposed residue while flowing a char mixture composed of the undecomposed residue and the fluidized medium taken out from the thermal decomposition means by the char combustion means). ~
The heat energy around 950 ° C is obtained. ) Is mainly used to secondarily to thirdly heat the boiler water or steam that is primarily heated to about 200 ° C. to 320 ° C. to 400 to 50
0 ° C heated steam (boiler tube temperature approx.
Even if a low grade material is obtained, there is no risk of tube corrosion. As a result, even when power is generated by incineration of waste, it is possible to obtain a power generation efficiency of 30 to 40% at a low cost, which is similar to a plant using fuel oil such as heavy oil or LNG containing almost no chlorine.

[0007]

According to such prior art, by efficiently combining the pyrolysis furnace, the char combustion furnace, the boiler and the super heater, it is possible to reduce chlorine and obtain superheated steam at high temperature. However, there is a large amount of water in the domestic waste containing the garbage that is put into the pyrolysis furnace, and the pyrolysis gas obtained in the pyrolysis furnace is caused by the evaporated water from the water-containing waste. As a result of dilution, calorie reduction will occur, and in order to raise the temperature of the ash melting furnace to 1300 ° C. or higher, as a pyrolysis gas combustion air source,
The need to use 50% oxygen enriched air results in a significant increase in oxygen enrichment equipment and its operating power costs. The present invention is
It is an object of the present invention to eliminate the drawbacks of the prior application technique.

[0008]

The invention according to claim 1 is
Wherein in the invention relates to apparatus for obtaining thermal energy for the production of superheated steam, dry hand to dry the waste together with the fluidized medium under and <br/> insufficient oxygen at a temperature of 100 to 300 ° C. <br / > With a fluidized medium in a space with a temperature of 300 ° C or more
Pyrolysis means for separating the pyrolysis gas generated by the reaction and the pyrolysis gas generated by the reaction, the char mixture composed of the undecomposed residue and the fluidized medium, and the incombustible material from each other to supply the dried waste to perform the pyrolysis reaction. A char mixture consisting of an undecomposed residue and a fluidized medium introduced by the thermal decomposition means,
When the char combustion means for combusting the undecomposed residue while flowing by air is constituted by independent furnaces,
In addition, the high temperature sand obtained by the char burning means is used as the drying means.
And the thermal decomposition means , the dispersion plate is inclined downward in the one-flow direction from the inlet part to the outlet side, and the fluidized bed region between them is opened at the upper part and the bottom part of the fluidized bed, respectively. Formed with a fluidized bed having a plurality of fluidized areas divided by partition walls , and among the plurality of fluidized areas
The gas superficial velocity in the descending flow region is calculated as the gas superficial velocity in the ascending flow region.
It is characterized in that the waste supplied to the fluidized bed is formed in a fluidized tank which is pyrolyzed while circulating in the fluidized zone by setting it to a degree smaller than the above. According to such an invention, by sequentially circulating the wastes in a plurality of fluidized regions, it is possible to perform sufficient thermal decomposition and continuous charging without the treatment product short-passing to the outlet, and to reduce fluidized gas. It becomes possible to suppress the reduction of calorie of the pyrolysis gas.

In order to achieve the action shown in FIG. 2, the thermal decomposition is carried out so that the thermal calorie ratio of the thermal decomposition gas and the char mixture is "about 7 (pyrolysis gas): about 3 (char mixture)". It is preferable. This is because the boiler water to be heated is pressurized to around 100 Kgf / cm ² and its boiling point is 309
Since the temperature is set to around ℃, in the case of pyrolyzed gas, the boiler water from the room temperature in the water-cooled wall boiler 36 and the first boiler 27 (both are referred to as the first steam manufacturing process (means)) shown in FIG. In other words, the ratio of the calorie that rises to almost vaporize at 309 ° C. and the calorie that rises the vapor from the boiling point of 309 ° C. to 500 ° C. is about 7: 3. by. Therefore, according to the above-mentioned invention, the thermal decomposition can be sufficiently carried out, whereby the thermal energy of the thermal decomposition gas can be sufficiently increased.

As described above, when waste such as municipal waste containing food waste is directly charged into the pyrolysis furnace, the pyrolysis gas is diluted with water, resulting in a reduction in calories. Therefore, claim 2
In the invention described above, the drying means, the dispersion plate is inclined downward in the one-flow direction from the inlet portion toward the outlet side,
The fluidized bed area in between is formed by a fluidized bed having a plurality of fluidized areas divided by partition walls having an opening at the top and the bottom of the fluidized bed, and the fluidized bed is lowered among the plurality of fluidized areas.
The gas superficial velocity in the fluidized region is compared with the gas superficial velocity in the ascending fluidized region.
It is characterized in that the waste fed to the fluidized bed is formed in a fluidized tank which is dried while being circulated in the fluidized zone by setting it to a smaller value .

When the drying temperature of the above-mentioned municipal solid is 300 ° C. or higher, hydrocarbon gas is generated, which is not preferable.
At 0 ° C or lower, sufficient evaporation cannot be achieved. A dry atmosphere is preferable because low temperature combustion does not occur in the absence of oxygen. Therefore, it is preferable that the drying means has the same structure as the thermal decomposition means and that only the temperature is controlled. That is, for example, the drying means may be any one of a fluidized bed, a kiln, and a horizontal stirring tank for drying waste by using high-temperature sand obtained by a char combustion means similar to the pyrolysis means. The effective use of heat energy can be achieved. Then, it is preferable to sufficiently dry the waste to be put into the thermal decomposition step using the high temperature sand obtained in the char combustion step. As a result, in addition to solving the above-mentioned problems, the high temperature sand obtained from the char burning step has a sufficient size both in terms of temperature and heat capacity, so that it can be easily dried. Further, the present invention has the same effect as that of the first aspect of the present invention because the drying means performs the drying while the waste circulates in a plurality of flow zones divided by the partition wall.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be exemplarily described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Only. FIG. 3 shows a thermal decomposition furnace and a drying furnace each comprising a fluidized bed, which are used in the superheated steam manufacturing apparatus using the heat of incineration of waste according to the embodiment of the present invention in FIG. 1, both of which are dispersion plates such as perforated plates. A fluidized medium such as fluidized sand is deposited on 3-1 to form a fluidized bed, and the fluidized bed can be circulated by a descending flow and an ascending flow.
The partition plate 3-3 is opened at the top and bottom of the fluidized bed. Further, the dispersion plate 3-1 is inclined downward toward the incombustibles outlet 9 side, and the combustion exhaust gas supply line 25 / is provided at the bottom of the space below the dispersion plate 3-1 partitioned by the partition plate 3-3. 6-1 / 6-
2 are connected to branch lines 6A / 6B, and the branch lines 6A / 6B are each provided with a flow rate adjusting valve (not shown), and each flow region is divided into two by a partition plate 3-3. , So that the air flow supplied to the can be controlled.

That is, by making the air flow rate of the branch line 6A smaller than that of the branch line 6B, the left flow region can be a downward flow region and the right flow region can be an upward flow region. Specifically, the gas superficial velocity in the descending flow region is 0.0 to 0.3 m / sec, preferably 0.0 to 0.2 m / sec, and the gas superficial velocity in the ascending flow region is 0.3. ~ 1.0 m / sec, preferably 0.
It is preferable to set it to 4 to 0.6 m / sec. Dispersion plate 3
The inclination angle of -1 is 5 to 45 °, preferably about 10 to 45 °. Related gas superficial velocity and dispersion plate 3-
The structure such as the inclination angle of 1 is the same in the pyrolysis furnace of FIG.

In the fluidizing tank on the drying furnace 1B side, the waste feed line 4 is provided on the upper part of the fluidized bed on the lower fluidizing zone side.
A waste line, such as municipal waste, is connected to the line 4 and the outlet end of a branch line 52 through which the fluidized sand of the char combustion furnace 10 flows back through the cyclone 18 is connected to the line 52. It is configured such that high temperature fluidized sand of about 650 ° C. can be charged from the outlet end of each.

On the upper surface of the fluidized bed on the side of the ascending fluidized area, dry waste can be charged by gravity into the fluidized bed on the side of the descending fluidized area of the thermal decomposition furnace 1A, and downward toward the side of the thermal decomposition furnace 1A. An inclined exit line 9-2 is provided. At this time, the outlet end of the inclined outlet line 9-2 on the pyrolysis furnace 1A side is preferably provided with an outlet opening 9-2a in the fluidized bed in order to prevent backflow and serve as a gas seal. Most of the fluidized medium is also introduced into the pyrolysis furnace 1A through the inclined outlet line 9, but in order to transfer incombustibles such as metal in the fluidized medium, the fluidized bed bottom surface on the rising fluidized zone side is transferred. It is preferable to provide a transfer line 9-1 on the dispersion plate 3-1 via a pusher or a screw conveyor 9-3.

According to the drying furnace 1B, the combustion exhaust gas and the like supplied from the combustion exhaust gas inlet line 6-2 through the branch lines 6A / 6B, respectively (this drying furnace is basically used for drying under lack of oxygen). , Most of the supplied gas is combustion exhaust gas that has consumed oxygen.) Wastes such as municipal waste from line 4 and high temperature fluidized sand at around 650 ° C from line 52 are in the fluidized bed. The temperature is 100-300 while repeating the circulation flow by the descending flow area and the ascending flow area.
A circulating fluidized bed space of ℃, preferably 100 ~ 250 ℃ is generated to dry the waste, and the moisture gas generated by the evaporation is discharged from the outlet line 72 via the flow rate adjusting valve 57 as shown in FIG. The boiler 36 is introduced into the pyrolysis gas combustion furnace 30B in which it is housed, while the dried waste is introduced into the pyrolysis furnace 1A by gravity from the inclined outlet line 9-2 inclined downward together with the fluidized sand. In addition, a part of the fluidized medium is obtained by removing large incombustibles from the incombustibles discharge line 8 with a filter 80, and then the remaining fluidized medium is passed through a return line 5 composed of a bucket conveyor or the like to the drying furnace 1B or the char combustion furnace 10. Is controlled to control the circulation of the fluidized medium.

On the other hand, in the pyrolysis furnace 1A into which the dry waste and the fluidized sand are introduced, as in the case of the drying furnace 1B, the sand of the char combustion furnace 10 is inserted into the fluidized bed on the side of the descending fluidized area via the cyclone 18. The return branch line 51 is opened so that high-temperature fluidized sand at about 650 ° C. can be introduced from the line 51. On the upper surface of the fluidized bed on the side of the ascending fluidized area, an inclined outlet line 9 is provided which is inclined downward toward the char combustion furnace 10 side so that the char mixture can be injected into the fluidized bed of the char combustion furnace 10 by gravity.

At this time, the incombustibles accumulated on the dispersion plate 3-1 of the pyrolysis furnace 1A are provided with an incombustibles discharge line 8 on the dispersion plate 3-1 at the bottom of the fluidized bed on the side of the ascending fluidized region. 8
After the large incombustibles are removed by the filter 80 arranged in the middle of the path, the remaining char mixture is returned to the drying furnace 1B or the char combustion furnace 10 through the return line 5 including a bucket conveyor. Since the char mixture after removing the large incombustibles has already been cooled to 150 ° C. or less by thermal contact with the filter 80 or the like, it does not necessarily have to be constituted by the air flow conveying means described later and may be a normal bucket conveyor.

FIG. 4 shows the structure of a four-chamber pyrolysis furnace (the drying furnace has the same structure, so the description of the structure on the drying furnace side will be omitted). partition,
Four fluid zone spaces are formed in the shape of "rice field", and the high temperature fluidized sand of the waste supply line 4 and the char combustion furnace 10 is returned to the inlet side wall of the descending fluidized zone of the leftmost pyrolysis furnace 1A. The outlet end of the branch line 52 is connected to the outlet wall of the ascending flow region at the right end, and the inclined outlet line 9 is inclined downward toward the char combustion furnace 10 side, and the dispersion plate 3-1 at the bottom of the ascending fluidized bed. Incombustible discharge line 8 (8A,
8B) are provided respectively. The dispersion plate 3-1 includes the first dispersion plate 3-1A downward from the flow region side where the lines 8 and 9 are provided, and the flow region side from the flow region side. The second dispersion plate 3 downwards toward
The heights of the partition plates 3-3A and 3-3B are set such that 1B is respectively arranged, and overflow can be made to the flow area side from the further flow area side and to the flow area side from the other flow area side.

Further, as described above, the branch line 6 of
By setting the air flow rate of A to be smaller than that of the branch line 6B of and, the flow region portions of and can be set as the descending flow region, and the flow regions of and can be set as the ascending flow region. In addition, the first and second dispersion plates 3-1A and 3-1B are at the downward end positions of and the dispersion plate 3 on the upward flow region side of and.
The incombustibles discharge lines 8B and 8A are provided on the side walls above -1. In the case of a drying furnace, the incombustible discharge lines 8B and 8A
Instead of pusher or screw conveyor 9-3
A transfer line 9-1 is provided. On the upper surface of the fluidized bed on the side of the ascending fluidized area, an inclined outlet line 9 is provided which is inclined downward toward the char combustion furnace 10 side so that the char mixture can be injected into the fluidized bed of the char combustion furnace 10 by gravity.

According to such a pyrolysis furnace 1A, due to the combustion exhaust gas or the like supplied through the branch lines 6A / 6B, the fluid regions of and become the descending fluid regions, and the fluid regions of the and become the ascending fluid regions, In the descending flow region of No. 3, when the char mixture is introduced from the line 9 and the high-temperature fluidized sand of 650 ° C. is introduced from the line 51 in which the sand of the char combustion furnace 10 is circulated back and forth, 350 → 5 in the order of → → → →
A fluid zone space is formed in which a downward flow and an upward stream of 00 ° C. are repeatedly circulated, and a thermal decomposition reaction of the dry waste is carried out in the fluid zone space, and the thermal decomposition gas generated by the reaction is a thermal decomposition gas outlet line. 71 to the ash melting furnace 31, the char mixture composed of undecomposed residue and fluidized sand to the char combustion furnace 10 from the char mixture take-out line 9, and the incombustibles to take out from the incombustible take-out line 8 separately from each other. Can be done.

FIG. 5 is a modification example in which the thermal decomposition furnace and the drying furnace shown in FIG. 3 are integrated with each other. The downward flow area, the upward flow area, and the thermal decomposition furnace of the drying furnace are sequentially arranged from the left side to the right side in the figure. The descending flow area of the drying furnace is disposed, and the waste supply line 4 and the char combustion furnace 1 are provided on the inlet side wall of the descending flow area of the drying furnace at the left end.
The outlet end of the branch line 52 through which the high temperature fluidized sand of 0 is returned is connected, and the right end of the ascending flow region of the pyrolysis furnace, the outlet wall is an inclined outlet line 9 inclined downward toward the char combustion furnace 10 side. In addition, the incombustible discharge line 8 is provided on the dispersion plate 3-1 on the bottom of the rising fluidized bed. The dispersion plate 3-1 is arranged in the pyrolysis furnace 1 from the rising flow zone side of the drying furnace 1B.
The partition plate 33 is arranged in a series inclining downward toward the descending flow region of A and further between the ascending flow region of the drying furnace 1B and the descending flow region of the thermal decomposition furnace 1A. The opening 33a is formed above the plate 3-1 and the partition plate 33 is formed.
The upper end should be opened toward the downward flow zone of the pyrolysis furnace 1A, a rectangular (reverse L-shaped) outlet line 92 should be provided at the opening 33a, and the bottom should be opened into the downward flow zone of the thermal decomposition furnace 1A. Thus, the dried waste is put into the descending fluidized region of the thermal decomposition furnace 1A by gravity from the outlet line 92 together with the fluidized sand. Since the temperature of the fluidized sand has already dropped from the outlet line 92 due to heat exchange in the drying furnace 1B, the branch line 51 for returning sand of the char combustion furnace 10 is opened above the descending fluidized zone of the pyrolysis furnace 1A. It is preferable that high temperature fluidized sand of about 650 ° C. can be introduced from the line 51.

FIGS. 1 and 6 and 7 show an apparatus for producing superheated steam utilizing the heat of incineration of waste according to an embodiment of the present invention, FIG. 1 is an overall view thereof, and FIGS. 6 and 7 are a drying furnace and thermal decomposition. FIG. 3 is a front view and a plan view showing the main configuration of a furnace and a char combustion furnace. Since the drying furnace and the thermal decomposition furnace in this figure are the same as those in FIG. 3, their explanations are omitted. Char combustion furnace 1 consisting of fluidized bed furnace
As shown in FIGS. 6 and 7, 0 is a char mixture introduction line 9 and a fluid medium take-out line 160 in the fluidized bed on the top side of the dispersion plate 11, which is arranged at the bottom with a downward inclination toward the outlet side of the incombustibles. Connect to each of them and introduce the above-mentioned introduction line 9
A sub-fluidized bed 10B is formed on the inclined lower side of the dispersion plate 11 of the main fluidized bed 10A made of the introduced char mixture through the partition wall 10C. The main fluidized bed 10A and the sub-fluidized bed 10B are supplied from the air supply line 12 below the dispersion plate 11.
First, air is supplied to the main fluidized bed 10A.
The undecomposed residue is burned by heating to 0 to 750 ° C., and the undecomposed residue is circulated and the fluidized sand is circulated between the main fluidized bed 10A and the sub-fluidized bed 10B adjacent to each other via the partition wall 10C. And the third super heater 29-2 is disposed in the fluidized medium of the sub fluidized bed (sub char combustion part) 10B, and the second super heater 29 is disposed in the upper region of the char combustion furnace 10. -1 and the line 40 are connected. The main fluidized bed 10A may also be configured to circulate in the descending fluidizing region and the ascending fluidizing region, as in FIG.

The second super heater 29-1 arranged above the char combustion furnace 10 is heated to about 950 to 1300 ° C. together with the superheat of the superheated steam introduced from the first super heater 28 through the line 28-1. Char combustion furnace 10 has the function of dropping unnecessarily high combustion gas to about 850 ° C.
A boiler 36-2 is arranged in the upper duct area and serves to drop the combustion gas that has become unnecessarily high. Even if the combustion gas temperature is lowered to about 850 ° C as described above, there is no problem in maintaining the steam temperature in the first superheater 28 at 400 to 520 ° C.

Small incombustibles that are not burned in the char combustion furnace 10 are taken out from the incombustibles taking-out line 14, and a second filter 140 having a mesh of about 2 mm is inserted in the incombustibles taking-out line 14. Small incombustibles and fluidized sand / ash are separated from the discharged matter discharged from the line 14, and the fluidized sand is dried from the line 5 / 5-5-1 / 5-2 such as the bucket conveyor in the fluidized bed descending fluidized area of the drying furnace 1B. Alternatively, it is configured to be fed to the char combustion furnace 10. Now, the fluidized medium in the char combustion furnace 10 is guided from the outlet passage to the air flow transfer mechanism 16, and the transfer mechanism 16
After being imparted with a conveying force by an air flow at, it is introduced into a gas / solid separation device such as a cyclone 18 through a line 17,
Here, it is separated into a fluid medium and a high temperature air flow, the high temperature air flow is returned to the ash melting furnace 31, and the high temperature fluid medium is returned to the drying furnace 1B and the pyrolysis furnace 1A via the branch valve 50 and the branch lines 51 and 52, respectively. It

An air flow transfer mechanism provided on the side of the fluidized medium outlet line 160 in the char combustion furnace 10, and a horizontal passage connected to the end of the outlet line 160 on the bottom side wall of the vertical passage portion 161 leading to the cyclone 18. A part 162 is provided,
A normal pressure air flow of about 20 to 200 ° C. continuously from the bottom surface of the vertical passage portion 161 and 2 from the end of the horizontal passage portion 162 side.
A compressed air flow of 3 to 6 Kgf / cm ^{2 at} around 0 to 200 ° C. is intermittently supplied. Then, by setting the solid-gas weight ratio of the fluid medium and the air flow to (sand / air): 1/1 to 5/1, it is possible to obtain an air flow transport force capable of smoothly transporting the fluid medium to the cyclone. .

In the ash melting furnace 31, high temperature air from the char combustion furnace is introduced into the ash melting furnace 31 via the cyclone 18, and pyrolysis gas from the pyrolysis furnace is introduced via a line, and further dust-removing bag. Dust 2 taken out from the filter 37
9 and / or char combustion furnace 10 incombustibles in line 3
From above 0 through an air stream, for example, while swirling and separating ash by swirling flow, the heat of combustion of the high temperature air and pyrolysis gas is set to 1300 ° C. or higher to melt the dust 29 and incombustibles, and the melting The ash thus formed is dropped through a molten ash outlet line into a water reservoir (not shown) to generate a water-cooled slug of about several mm or air-cooled to remove the slag, and the slag is used as an aggregate for construction. To do. Further, a pyrolysis gas combustion furnace 30B is arranged in the upper region of the ash melting furnace 31, and the water-cooled wall boiler 36 arranged in the pyrolysis gas combustion furnace 30B is heated to a boiling point close to 200 to 309 ° C. Produces start-up steam / boiler water.

Returning to FIG. 1, 20 is a first super heater 28.
And a heat exchange tower provided with a boiler 27,
The combustion gas from the ash melting furnace 31 and the combustion gas from the char combustion furnace 10 are respectively introduced to the 0 top through the second super heater 29-1, and the gas temperature is first dropped by heating with the first super heater 28, The first boiler 27 is heated. As a result, the boiler water taken in from the boiler water inlet 26 is heated to around 300 ° C. in the first boiler 27, and steam or heated water is supplied to the first super heater 28 from the first boiler outlet line 25. Boiler water is branched line 26 ', 2
6 '' through the boiler 36-2 of the char combustion furnace 10 and the boiler 36 of the ash melting furnace 31 to branch line 2
Steam or heated water is supplied to the first super heater 28 via 5 ′ and 25 ″.

The boiler water whose pressure is set to around 100 Kgf / cm ² and whose boiling point is set to around 309 ° C. is introduced into the boilers 27, 36 and 36-2 to perform the first stage heating. However, the water flow rate is controlled so that the heating temperature is around 309 ° C., which is close to the boiling point.
As a result, the tube surface wall temperature of each of the boilers 36, 36-2, and 27 can be maintained at around 309 ° C. following the heated water, and the heat exchanged pyrolysis gas contains chlorine or HCl. Also, low grade materials do not cause corrosion.

In the first super heater 28, each of the boilers 3 is
6, 36-2, 27 exit lines 25, 25 ', 2
Introduce the steam / heated water taken out from 5 ",
Superheated steam is produced by the combustion gas at around 50 ° C., and then the second super heater 29-1 from the steam outlet line 28-1.
And from the line 28-2 to the third super heater 29-2
Are introduced in series or in parallel, respectively, and the superheated steam superheated to 400 to 550 ° C. is taken out and fed to the generator.

To briefly explain the operation of the above embodiment, the drying furnace 1B is provided with the char combustion furnace 10 through the outlet line 160, the air flow transfer mechanism 16, the line 17, the cyclone 18, and the branch line 51/52. Circulating fluidized sand at 600 to 700 ° C., specifically 650 ° C. is supplied by air flow, while water-containing waste such as municipal waste is supplied from the waste supply line 4, and further air or combustion exhaust gas inlet line 6 at the lower part. -2 from the combustion exhaust gas by supplying a slight temperature control air to the fluidized bed in which the fluidized sand is made to flow, and is circulated by a descending flow and an ascending flow while maintaining the temperature in the drying furnace 1B at 100 to 300 ° C. Then, the dried waste mixture consisting of the dried waste and the fluidized sand is introduced into the pyrolysis furnace 1A through a line 9-2. Moisture gas generated by drying in the drying furnace 1B is introduced from the outlet line 72 into the pyrolysis gas combustion furnace 30B above the ash melting furnace 31 in which the boiler 36 is housed, and the pyrolysis gas combustion furnace 3
The combustion gas temperature in 0B is controlled to around 850 ° C.

A chlorine-containing organic compound such as vinyl chloride plastic is mixed in the waste such as the municipal waste mentioned above, and the combustible content contains about 0.2 to 0.5% of C1.
Then, the dry waste mixture is supplied from the line 9-2 and the circulating fluidized sand of 600 to 700 ° C. is supplied from the branch line 51 to the pyrolysis furnace 1A, respectively, and a slight amount of combustion exhaust gas is supplied from the lower air or the combustion exhaust gas inlet line 6-2. A temperature of 350 to 500 ° C. while circulating and flowing by a downward flow and an upward flow in a fluidized bed in which fluidized sand is fluidized by supplying various temperature adjusting air.
By treatment with 1, the undecomposed residue containing substantially no chlorine is obtained from the char mixture withdrawing line 9 inclined downward.

That is, substantially all the chlorine contained in the waste is contained in the pyrolysis gas and discharged to the pyrolysis gas outlet line 71. The large incombustibles separated by the thermal decomposition reaction in the thermal decomposition furnace 1A are discharged from the incombustibles extraction line 8 to the outside of the apparatus through the filter 80. The pyrolysis gas obtained by the pyrolysis furnace 1A is supplied to the ash melting furnace 31 via a line 71.

As a result, the pyrolysis gas in the line 71 becomes high calorie gas because it is not diluted with the moisture gas, and in the ash melting furnace 31, high temperature air of 500 to 600 ° C. separated from the fluidized sand of the char combustion furnace through the cyclone 18 is used. The temperature of the ash melting furnace 31 is easily burned to 1300 to 1500
Can be ℃.

On the other hand, the char mixture consisting of the fluidized sand and undecomposed residue taken out from the char mixture taking-out line 9 in the pyrolysis furnace 1A and containing substantially no chlorine is supplied to the lower part of the combustion furnace 10 and the air supply line. 600 to 75 by burning with the air supplied from 12 through the branch lines 12-1 and 12-2 and the dispersion plate 11.
The undecomposed residue is burned while the fluidized sand is fluidized by raising the temperature to 0 ° C., and the air supply line 63 for complete combustion.
By further supplying air from the above, the temperature of the combustion furnace 10 rises due to the combustion exothermic reaction. This temperature value depends on the calorific value of the undecomposed residue supplied from the char mixture take-out line 9 and the amount and temperature of air in the air supply lines 12 and 63 and the fluidized sand in the sand circulation line 19, but 100
The temperature may be as high as 0 to 1300 ° C. Therefore, the char combustion furnace 10 is provided with a boiler 362, and after being controlled to about 850 ° C. by heat exchange with the boiler 36-2,
After exchanging heat between the combustion gas containing substantially no chlorine and the second super heater 29-1 through the line 40, the line 1
It is introduced into the heat exchange column 20 via 5.

On the other hand, in this embodiment, as shown in FIGS. 1 and 6, the char combustion furnace 10 is provided with a sub-char combustion section 10B provided with a third super heater 29-2. The fluidized medium is cooled to 600 to 750 ° C. by heat removal by the third super heater 29-2,
The fluidized medium dropped to 50 ° C. can be returned to the thermal decomposition furnace 1A and the drying furnace 1B with the fluidized sand at 500 to 650 ° C. through the line 160, the air flow transfer mechanism 16, the cyclone 18, and the branch line 51/52. As a result, the pyrolysis furnace 1A
It is possible to stably control the thermal decomposition temperature in the inside to 350 ° C. to 500 ° C., and the temperature in the drying furnace 1B at around 100 to 250 ° C. A third super heater 29-2 is installed in the auxiliary char combustion unit 10B, which helps stabilize the char combustion temperature.

In the ash melting furnace 31, as described above, the ash separated from the dust filter, etc. is introduced together with the pyrolysis gas / high temperature air, and the ash is melted by the combustion energy of the pyrolysis gas. The molten ash is dropped into a water reservoir (not shown) to generate a water-cooled slug of about several mm or air-cooled, and the slag is used as a building aggregate. Further, a pyrolysis gas combustion furnace 30B is disposed above the ash melting furnace 31, and a sufficient amount of air is supplied to the unburned pyrolysis gas from a line 62 to supply the pyrolysis gas and the moisture from the drying furnace 1B. Perform further complete combustion of the gas. As a result, since the temperature in the pyrolysis gas combustion furnace 30B can be maintained at around 850 ° C., the steam temperature of the boiler water introduced into the boiler 36 is raised to near the boiling point of 200 to 309 ° C.
A large amount of boiler water can be produced.

On the other hand, 850 taken out from the ash melting furnace 31
The high temperature exhaust gas at around ℃ is diluted with the combustion gas from the char combustion furnace 10 that does not substantially contain chlorine, and the diluted combustion gas is introduced into the heat exchange tower 20, and the first boiler 27 and the water cooling wall 200-32 manufactured in the boiler 36
It is used to heat the steam / boiler water around 0 ° C. by the first super heater 28 into superheated steam. Ash melting furnace 31
Since the exhaust gas that has passed through is diluted by combustion and by mixing with the combustion gas from the char combustion furnace 10, even if the boiler tube surface temperature of the first superheater 28 is 350 ° C. or higher, high temperature corrosion is reduced, It is preferable that the load on the first super heater be as small as possible.

Next, in the heat exchange tower 20, each boiler 3
The steam / boiler water whose boiling point is increased to near 200 to 309 ° C. by 6, 36-2 and 27 is the first super heater 2
85 introduced into the top of the heat exchange tower 20 while being introduced into
The combustion gas around 0 ° C. heats the first super heater 28,
Superheated steam can be obtained. The gas introduced into the pyrolysis gas combustion furnace 30B contains HC1 of about 500 to 1
Since it contains 000 ppm, the tube surface temperature of the boiler 36 is about 350 which is the same as the conventional one by adjusting the flow rate of boiler water.
High temperature corrosion is suppressed by keeping the temperature below ℃. Therefore, boiler 3
No high-temperature superheated steam can be obtained in No. 6, but about 200-32
Since it can be heated up to 0 ° C., if it is further heated by the super heaters 29-1 and 29-2 after the first super heater 28, high temperature superheated steam of about 400 to 550 ° C. can be obtained.

The flue gas after passing through the heat exchange tower 20 is dust-removed by the dust filter 37 and desalinated by the dechlorination bag filter 38. The line 25 is supplied to the drying furnace 1B and the thermal decomposition furnace 1A. Further, the dust removed by the bag filter 37 for dust removal is supplied to the ash melting furnace. Incidentally, the line 2
The exhaust gas flowing through 5 contains 3 to 4% oxygen and its temperature is 150.
It is around ℃.

[0041]

As described above, according to the first aspect of the present invention, the waste material is circulated in a plurality of flow zones in sequence, whereby sufficient thermal decomposition and continuous charging can be performed.

According to the second aspect of the present invention, since the waste put into the thermal decomposition means is sufficiently dried by the drying means, the calorie of the thermal decomposition gas does not fluctuate and high calorie is obtained. A stable and stable pyrolysis gas is obtained. or
According to the present invention, since the drying is performed while the waste circulates in the plurality of flow zones divided by the partition wall, the effect of the invention according to claim 2 can be further promoted.

[Brief description of drawings]

FIG. 1 is a system diagram showing an overheated steam production apparatus using heat from incineration of waste according to an embodiment of the present invention.

FIG. 2 is a graph showing a procedure for producing superheated steam using heat of incineration of waste according to the basic configuration of the present invention.

3A and 3B show the drying furnace and the thermal decomposition furnace of FIG. 1, where FIG. 3A is a plan view and FIG. 3B is a front view.

FIG. 4 shows a pyrolysis furnace in which the fluidized area is divided into four in the shape of “T”, (A) is a plan view, (B) is an AA line and BB, respectively.
It is a line and CC sectional view taken on the line.

5 shows a drying furnace and a pyrolysis furnace showing a modification of FIG. 3 in which the drying furnace and the pyrolysis furnace are integrated, (A) is a plan view, and (B) is a plan view.
Is a front view.

FIG. 6 is a front view showing a main configuration of a drying furnace, a pyrolysis furnace, and a char combustion furnace shown in FIG.

FIG. 7 is a plan view showing the main configuration of the drying furnace, the pyrolysis furnace, and the char combustion furnace shown in FIG.

[Explanation of symbols]

1A Pyrolysis furnace 1B Drying furnace 10 Char combustion furnace 10A Main char combustion section 10B Sub char combustion section 16 Air flow transfer mechanism 18 Cyclone 20 Heat exchange tower 27, 36, 36-2 Boiler (first steam producing means) 28, 29 -1,29-2 Super Heater (Second Steam Manufacturing Means) 31 Ash Melting Furnace 37, 38 Bag Filter

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshihito Shimizu, 1-8, Sachiura, Kanazawa-ku, Yokohama-shi 1 Mitsubishi Heavy Industries, Ltd. Yokohama Research Laboratory (72) Shizuo Hota, 12 Nishikicho, Naka-ku, Yokohama Mitsubishi Heavy Industries, Ltd. Yokohama Works (72) Inventor Yoshimasa Kawami 12 Nishiki-cho, Naka-ku, Yokohama City Yokohama Works, Ltd. (56) References JP 50-43766 (JP, A) JP 56-30523 (JP) , A) JP 52-46683 (JP, A) JP 6-74433 (JP, A) JP 7-174301 (JP, A) JP 8-121735 (JP, A) JP 7-332614 (JP, A) JP-A-53-30480 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 5/027 F23G 5/02

Claims (4)

(57) [Claims] 1. A a drying means for drying the waste together with the fluidized medium under oxygen-deficient and at a temperature of 100 to 300 ° C., a temperature 300 ° C. or higher in space, wherein with the fluidized medium drying
Pyrolysis gas for supplying pyrolysis reaction by supplying dried waste, pyrolysis gas generated by the reaction, char mixture consisting of undecomposed residue and fluid medium, and pyrolysis means for separating incombustibles from each other, the guided undegraded residue and consisting of the fluidized medium char mixture from the pyrolysis unit, and a char combustion means for combusting the undecomposed residue while fluidized by air respectively Germany
It consists of an upright furnace and is obtained by char combustion means.
The hot sand that has been circulated is circulated through the drying means and the thermal decomposition means, and the thermal decomposition means is inclined downward in the one-flow direction from the inlet part toward the outlet side, and the fluidized bed region between them is in the upper part of the fluidized bed. With a fluidized bed having a plurality of fluidized areas divided by a partition wall whose bottom is opened, respectively, and the superficial velocity of the gas in the descending fluidized area of the plurality of fluidized areas,
It is characterized in that the waste supplied to the fluidized bed is formed in a fluidized tank that is pyrolyzed while circulating in the fluidized zone by setting the gas superficial velocity in the ascending fluidized zone to be lower than the gas superficial velocity. Waste incinerator. 2. The drying means, wherein the dispersion plate is tilted downward from the inlet to the outlet in the one-flow direction, and the fluidized bed region between them is divided by a partition wall having an open top and a bottom of the fluidized bed. It is formed by a fluidized bed having a plurality of fluidized areas that are
Set the gas superficial velocity to be smaller than the gas superficial velocity in the rising flow region.
Incinerator of claim 1 waste according to waste fed to the fluidized bed is characterized by being formed in a fluidized tank performing drying while circulating the flow field by a constant. 3. The waste according to claim 1 , wherein an outlet line connected to the thermal decomposition means provided on the outlet side of the dispersion plate of the drying means is formed by a transfer line via a pusher or a screw conveyor. Incinerator. 4. A fluidized bed on the rising fluidized zone side of the drying means.
On the surface of the pyrolysis furnace descending fluidized bed
Can be input by force, tilts downward toward the pyrolysis furnace
Claims, characterized in that a has been tilted outlet line
Incinerator for waste according to 1 .