JPH0979542A - Superheated steam making apparatus utilizing incineration heat of waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high temperature/high pressure superheated steam while preventing high temperature corrosion of a boiler tube as caused by chlorine. SOLUTION: This superheated steam making apparatus has a thermal decomposition means 1 (for thermal decomposition reaction within a space at a temp. of at least 300 deg.C), a char combustion means 10, a first steam making means 24 (for obtaining steam at a temp. of at most 400 deg.C) and a second steam making means 20. On the outlet side 7 of the thermal decomposition means 1, air less in quantity than the air to be supplied to a reheating means 40, specifically, the air less than the theoretical air quantity is introduced into a thermal decomposition gas path on the outlet side of the thermal decomposition means to prevent adhesion of tar and coking in an outlet line. Then, a sufficient air is supplied to the reheating means 40 provided in the outlet line 7 to accomplish complete combustion of a thermal decomposition gas.

Description

Detailed Description of the Invention

[0001] The present invention is an invention relating to the production of superheated steam in which municipal waste, industrial waste, etc. are incinerated, steam is produced by the heat of the combustion exhaust gas, and the steam is used in, for example, a power plant.

[0002]

2. Description of the Related Art Conventionally, fluidized bed incinerators are often used as incinerators for incinerating waste such as municipal solid waste, and such apparatuses are accommodated on a dispersion plate (for example, a perforated plate) in a fluidized bed incinerator. The fluidized medium is fluidized and heated by blowing air or incineration exhaust gas etc. from below the dispersion plate into the fluidized medium such as sand, and waste such as municipal solid waste is thrown into the fluidized bed thus formed. Burn. The combustion gas generated by the combustion reaches a boiler via 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.

[0003]

The waste such as municipal waste contains a chlorine-containing organic compound such as vinyl chloride plastic, and the combustible content is about 0.2 to 0.
Contains 5%. Then, chlorine contained in PVC plastic mixed in the waste such as municipal waste becomes HC1 by combustion (usually, HC in exhaust gas from combustion of municipal waste is
1 is about 500 to 1000 ppm), which acts on the tube of the steam generating boiler installed downstream of the incinerator to corrode it. In particular, when the tube surface temperature is about 350 ° C. or higher, high-temperature corrosion becomes remarkable as the temperature increases. For this reason, conventionally, the tube surface temperature had to be 350 ° C. or less, and the temperature of the produced steam was limited to about 300 ° C. As a result, the power generation efficiency of conventional waste incineration is about 15
% Or less and the fuel efficiency is about 40%, which is significantly lower than the power generation efficiency of a plant that uses a heavy oil containing almost no chlorine, LNG, etc. as a fuel, and the boiler tube temperature can be set to 500 to 600 ° C., and its improvement has been strongly desired. .

In view of such technical problems, the inventors of the present invention have filed in the previous application (application number: Japanese Patent Application No. 6-324843).
No. 7-140484), in a fluidized bed as the incinerator at a temperature of 300 to 700 ° C.,
It has been found that a char mixture consisting of the undecomposed residue from the fluidized bed and the fluid medium gives an undecomposed residue which is substantially free of chlorine. That is, it was found that chlorine contained in the waste is substantially contained in the pyrolysis gas and is discharged to the pyrolysis gas outlet line.

Based on such knowledge, waste is supplied to the incinerator side in a space having a temperature of 300 ° C. or higher to cause a thermal decomposition reaction, and the thermal decomposition gas generated by the reaction and undecomposed residue and With a first fluidized bed (hereinafter referred to as a thermal decomposition means) for separating a char mixture composed of a fluid medium and an incombustible substance from each other, the char mixture is completely blown up by air or combustion exhaust gas while completely burning the undecomposed residue. A second fluidized bed (hereinafter referred to as char combustion means) is provided, while the first and second boilers are connected in series on the boiler side, and the heat of the pyrolysis gas is utilized by the low-stage boiler. About 400 ° C or less, specifically 30
Combustion gas obtained by the char combustion means by producing hot water or steam at around 0 ° C. (hereinafter referred to as first steam producing means), and then introducing the hot water or steam at around 300 ° C. into a second boiler It has been proposed to manufacture superheated steam by manufacturing superheated steam at a temperature of approximately 500 ° C. or higher (hereinafter referred to as a second steam manufacturing means) by the heat of.

The present invention further develops the above-mentioned prior art and provides an invention relating to the production of superheated steam capable of efficiently obtaining high temperature and high pressure superheated steam while preventing high temperature corrosion of a boiler tube due to chlorine. There is something to do. Another object of the present invention is to efficiently perform char combustion in the char combustion means and pyrolysis in the pyrolysis means, and to more efficiently reduce chlorine and obtain high temperature superheated steam as compared with the prior art. Another object of the present invention is to provide an invention relating to the production of superheated steam.

[0007]

According to the first aspect of the present invention,
Waste is supplied into a space having a temperature of 300 ° C. or higher, preferably 300 to 700 ° C. to cause a pyrolysis reaction, and a char mixture composed of a pyrolysis gas generated by the reaction, an undecomposed residue and a fluidized medium and non-combustible. A thermal decomposition means such as a fluidized bed for separating things from each other, and a char combustion means such as a fluidized bed or a thermal decomposition furnace for completely burning the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, A first steam producing means for producing hot water or steam having a temperature of about 400 ° C. or less, specifically about 300 to 350 ° C. or less by utilizing the heat after directly or re-combusting the pyrolysis gas; A second steam producing means for converting the hot water or the steam produced by the first steam producing means into superheated steam by the heat of the combustion gas obtained by the char combustion means. The pyrolysis gas passageway, in which air was introduced, characterized in that to conduct the pre-combustion and / or tar combustion.

According to a second aspect of the present invention, the above-mentioned invention is further embodied, and an amount of air smaller than the theoretical amount of air is introduced into the thermal decomposition gas passage on the outlet side of the thermal decomposition means. For example, a reheating means for reheating the pyrolysis gas is provided between the pyrolysis means and the first steam producing means, and the pyrolysis gas passage between the pyrolysis means and the reheating means is provided. It is characterized in that a smaller amount of air than the air supplied to the reheating means is introduced therein.

According to the above invention, in any of the above claims, the char mixture separated by the thermal decomposition means does not substantially contain chlorine, so that it is used as a superheat source for the second steam producing means. Even if it is configured to obtain superheated steam above ℃, high temperature corrosion of equipment does not occur.

Although a pyrolyzed gas containing chlorine is used as the heat source of the first steam producing means, the heat is used to generate about 40
Since the production of hot water or steam at 0 ° C. or lower, specifically about 300 to 350 ° C. or lower, only the temperature not higher than the high temperature corrosion temperature is heated. Therefore, there is no risk of corrosion of the boiler tube or the like. Absent.

Since the outlet gas from the thermal decomposition means has an outlet temperature of about 350 to 450 ° C., a gas containing a tar component may come out, and the tar component may adhere to the outlet line. There is. Also, the outlet temperature is 3
At 50 to 450 ° C, it is insufficient as a superheat source for producing steam at around 300 ° C.

Therefore, in the first aspect of the invention, air is introduced into the pyrolysis gas passage to perform pre-combustion and / or tar combustion. Furthermore, the present invention separates the reheating and the tar combustion, and introduces an appropriate amount of air, which is smaller than the theoretical air amount, into the pyrolysis gas passage on the outlet side of the pyrolysis means to burn tar or the like. It is intended to prevent tar from adhering to the outlet line and prevent coking, and then, if necessary, supply sufficient air to the outlet line to completely burn the pyrolysis gas. This prevents tar adhesion and coking in the exit line,
Since the temperature of the pyrolysis gas introduced into the first steam producing means can be set high, it is possible to produce a large amount of steam at around 300 ° C. produced by the producing means. In this case, the tar combustion air 21 (air excess ratio B) introduced on the outlet side of the thermal decomposition means is significantly larger than the air 21 (air excess ratio A) on the downstream side thereof for complete combustion of the pyrolysis gas. It is better to set it to a small value, specifically, excess air ratio A: excess air ratio B = (0.6 to 1.05):
(0.05 to 0.3), preferably A: B = 0.9: 0.1. Here, the excess air ratio means (supply air amount / theoretical air amount).

In a third aspect of the invention, the first
Alternatively, the steam heated by the second steam producing means or the hot water or part of the steam introduced into any one of the producing means may be appropriately introduced into the heat exchange means arranged on the high temperature side of the combustion means. It is a feature. That is, in the combustion means, the char mixture is blown upward by air or combustion exhaust gas to decompose the undecomposed residue, so that the combustion gas contains a high-temperature fluid medium.

Therefore, in the present invention, by utilizing the high temperature fluid medium, a heat exchange means is disposed on the high temperature side of the char combustion means and is heated by the first or second steam producing means. By exchanging heat with the steam, or with part of the hot water or steam introduced into any of the above-mentioned manufacturing means, the operation described below can be performed. That is, the first
By introducing the hot water introduced into the steam producing means into the heat exchanging means to raise the temperature to some extent, the heat exchanging means-
It is possible to increase the temperature in three stages substantially in series with the first steam producing means and the second steam producing means, and to obtain a large amount of sufficiently heated superheated steam.

Further, the hot water or steam introduced into the second steam producing means is introduced into the heat exchanging means in parallel with the first steam producing means so that the heating amount of the second steam producing means is increased. Can be increased and a large amount of superheated steam can be obtained.

Further, disposing the heat exchanging means on the high temperature side of the char combustion means is unnecessarily high at around 950 to 1300 ° C., and if it is allowed to flow through the outlet line as it is, the ordinary metal line has no temperature. However, by dropping this to 800 to 950 ° C., it becomes possible to use a normal refractory metal line. Even if the temperature is lowered to 800 to 950 ° C as described above, the steam temperature in the second steam producing means is 500 to 600 ° C.
There is no hindrance in maintaining it.

According to a fourth aspect of the present invention, there is provided a separation means connected to the outlet side of the combustion means for separating the combustion gas and the fluidized medium from the combustion means. A part of the heated steam or hot water or steam introduced into any of the manufacturing means is appropriately introduced into the fluid medium outlet side of the separating means, and heated by thermal contact with the fluid medium. To do.

According to the invention, since the separating means for separating the combustion gas and the fluidized medium is provided on the outlet side of the char combustion means, in other words, the fluidized medium having a high temperature of about 800 to 950 ° C. is heated. By returning to the decomposition means and the char combustion means respectively, formation of a fluidized bed at a target temperature and temperature control become easy. And in the present invention, a heat exchange means is arranged on the fluid medium outlet side of the separating means, and the steam heated by the first or second steam producing means or the hot water introduced into any of the producing means or By appropriately heating a part of the vapor by thermal contact with the fluidized medium, the same effect as that of the invention according to claim 1 can be achieved.

In this case, heat exchange means (hereinafter referred to as first heat exchange means) on the high temperature side of the char combustion means and heat exchange means (hereinafter referred to as second heat exchange means) also on the fluid medium outlet side of the separation means. May be arranged. Further, by arranging the first heat exchanging means, the first steam producing means, the second steam producing means, and the second heat exchanging means, it is possible to substantially raise the temperature in four stages in series. A high, sufficiently heated superheated steam can be obtained. In addition, as shown in the examples described later (the first heat exchange means and the first steam production means are arranged in parallel)-
By arranging the second steam producing means and the second heat exchanging means in series, it is possible to substantially raise the temperature in parallel / series in three stages, and to obtain a large amount of sufficiently heated superheated steam. I can. Further, either the first heat exchanging means or the second heat exchanging means may be selectively used. Further, it is preferable to use a super heater or a boiler as the heat exchange means.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. However, 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 unless otherwise specified, and are merely illustrative examples. It's just FIG.
(A) shows an apparatus for producing superheated steam using the heat of incineration of waste according to an embodiment of the present invention. In the figure, 1 is a pyrolysis furnace comprising a fluidized bed, which is flown on a dispersion plate 3 such as a perforated plate. A fluid medium 2 such as sand is stored, and fluid sand and waste such as municipal solid waste are input from a waste supply line 4 and a sand circulation line 5,
Air or combustion exhaust gas supplied from the air or combustion exhaust gas inlet line 6 generates a fluidized bed space having a temperature of 300 ° C. or higher to cause a thermal decomposition reaction of waste, and the thermal decomposition gas generated by the reaction is a thermal decomposition gas. Separately from the outlet line 7, the char mixture consisting of undecomposed residue and fluidized sand from the char mixture take-out line 9 and the non-combustible substance from the non-combustible substance take-out line 8, respectively. An air inlet line 21 is attached to the starting position of the pyrolysis gas outlet line 7 immediately after the exit of the pyrolysis furnace 1, and the pyrolysis gas taken out from the pyrolysis furnace 1 is supplied to the air inlet line 2
The air is introduced from 1 to partially burn the tar and the like contained in the pyrolysis gas to prevent tar from adhering to the outlet line 7 and prevent coking.

At the downstream end of the outlet line 7, there is provided a reheating means 40A consisting of a premixer 47 and a combustion duct 40, and a sufficient amount of air 21 'is supplied to the pyrolysis gas to effect the pyrolysis. Complete gas combustion. That is, as shown in FIG. 1B, in the premixer 47, a diffuser pipe 47a for radially diffusing air is inserted into a pipe line 47b forming a part of the pyrolysis gas outlet line 7, and the diffuser 47a After the air and the pyrolysis gas are sufficiently mixed by the trachea 47a, the heat of the high-temperature exhaust gas supplied from the second boiler gas outlet line 22 is used to be completely combusted in the combustion duct 40 and introduced into the first boiler 24. It

In this case, the tar combustion air (air excess ratio B) introduced from the air inlet line 21 becomes the air (air excess ratio A) introduced from the air diffuser 47a of the premixer 47 on the downstream side. It is better to set it to a significantly smaller value in comparison, specifically, excess air ratio A: excess air ratio B = (0.6 to 1.05):
(0.05-0.3), preferably A: B = 0.9:
It is better to set it to around 0.1.

Numeral 10 is a char combustion furnace comprising a tower type fluidized bed furnace. The char mixture is supplied from a char mixture take-out line 9 on a dispersion plate 11 arranged at the bottom and the fluidized sand circulated from a sand circulation line 19. Is stored. Then, air is supplied from the air supply line 12 below the dispersion plate 11 and further from the air supply line 13 in the middle region of the char combustion furnace 10 to burn the undecomposed residue, and about 800 to 1300
A water-cooled wall boiler or superheat for introducing boiler water from a branch line 26 'is disposed in the upper region of the char combustion furnace 10 while generating combustion gas of around ℃, 950
Combustion gas that has risen unnecessarily high at around 1300 ° C is 800
The temperature is lowered to ˜950 ° C. and part of the boiler water supplied to the first boiler is heated. The heating temperature of the boiler water is 300
℃. As described above, the combustion gas temperature is 800 to
Even if the temperature is lowered to 950 ° C, there is no problem in maintaining the steam temperature in the second boiler 20 at 500 to 600 ° C.
Then, small incombustibles that are not burned in the combustion furnace are taken out from the incombustibles taking line 14.

The combustion gas of the sand mixture, which has been heated to a high temperature as described above, is introduced from the sand / combustion gas outlet line 15 into a gas / solid separation device such as a cyclone 16, where the fluidized sand and the combustion gas are separated, The combustion gas is introduced into the second boiler 20 through the gas outlet line 17. The fluidized sand is taken out from the sand outlet line 18, and is sent from the sand circulation line 19 to the combustion furnace 10
Then, they are supplied to the pyrolysis furnace 1 from the sand circulation line 5, respectively.

Reference numeral 20 is a second boiler and 24 is a first boiler. In the first boiler 24, the pyrolysis gas taken out from the pyrolysis gas outlet line 7 is supplied to the air inlet lines 21 and 21 '.
The first boiler 24 together with the combustion exhaust gas re-combusted by the air taken in from the second boiler gas outlet
The boiler water introduced into the boiler water inlet 26 is heated to around 300 ° C., and steam is supplied from the first boiler steam outlet 27 to the second boiler 20.

In the second boiler 20, the steam extracted from the first boiler steam outlet line 27 of the first boiler 24 and the water-cooled wall boiler 36 are heated to form a branched steam line 27 '.
500 is introduced through the combustion gas line 17 and heated by the combustion gas supplied through the combustion gas line 17.
Superheated steam of about 600 ° C. is produced and taken out from the second boiler steam outlet 28.

Next, the operation of the above embodiment will be described in detail.
Wastes such as municipal waste supplied to the pyrolysis furnace 1 contain chlorine-containing organic compounds such as vinyl chloride plastics and are contained in the combustible content as C1 in an amount of about 0.2 to 0.5%. . Then, municipal waste is supplied from the waste supply line 4 and high-temperature circulating fluidized sand is supplied from the fluidized sand circulation line 5 to the pyrolysis furnace 1, respectively, and air or combustion exhaust gas is supplied from the lower air or combustion exhaust gas inlet line 6. By treating at a temperature of 300 to 700 ° C. in a fluidized bed in which the fluidized sand 2 is fluidized, an undecomposed residue containing substantially no chlorine is obtained from the char mixture withdrawing line 9. That is,
Substantially all of the chlorine contained in the waste is contained in the pyrolysis gas and is discharged to the pyrolysis gas outlet line 7. The large incombustibles separated by the thermal decomposition reaction in the thermal decomposition furnace 1 are taken out of the furnace through the incombustibles extraction line 8.

The pyrolysis gas taken out from the pyrolysis exit line 7 of the pyrolysis furnace 1 contains low-calorie gas, oil,
Although it contains tar and HC1, the air supplied from the air inlet line 21 of these pyrolysis furnaces 1 is pre-combusted to burn or evaporate the tar portion, thereby preventing tar adhesion and coking in the outlet line 7. At the same time, a large amount of air 21 ′ is introduced from the air diffuser 47a to introduce a pyrolysis gas mixed with air, and the heat of the high-temperature exhaust gas supplied from the second boiler gas outlet line 22 is used in the combustion duct 40. Completely burn with. As a result, since the temperature of the pyrolysis gas introduced into the first boiler can be set high, a large amount of steam at around 300 ° C. produced by the production means can be produced.

The flue gas from the second boiler gas outlet line 22 is supplied to the first boiler 24 from the first boiler gas inlet 23. The gas at the first boiler gas inlet 23 is H
Since C1 is contained in an amount of about 500 to 1000 ppm, the high temperature corrosion is suppressed by adjusting the flow rate of the boiler water to keep the tube surface temperature of the first boiler 24 at about 350 ° C. or lower, which is the same level as the conventional one. Therefore, although high-temperature superheated steam cannot be obtained in the first boiler 24, it can be heated up to about 300 ° C., so if it is further heated by the second boiler 20, it will be about 500-600.
It is possible to obtain superheated steam at a high temperature of ° C.

The char mixture taken out from the char mixture take-out line 9 in the pyrolysis furnace 1 is composed of fluidized sand and undecomposed residue, and a char mixture containing substantially no chlorine is
In the combustion furnace 10, the air is supplied to the lower part of the combustion furnace 10 and burned by the air supplied from the air supply line 12 through the dispersion plate 11. In this case, the amount of air supplied from the air supply line 12 is adjusted so that the undecomposed residue is burned while blowing the fluidized sand upward. Further air may be supplied from the air supply line 13 for complete combustion. The temperature of the combustion furnace 10 rises due to the combustion exothermic reaction. This temperature value is determined by the calorific value of the undecomposed residue supplied from the char mixture extraction line 9 and the amount and temperature of the air in the air supply lines 12 and 13 and the fluidized sand in the sand circulation line 19; May be.

Then, the branch pipe 26 is provided by the water-cooled wall boiler 36.
It is easy to bring the sand-mixed combustion gas to 800 to 950 ° C. by exchanging heat with the boiler water introduced further. The incombustibles reduced in size by melting glass, cans, and the like are extracted from the incombustibles take-out line 14.

The exhaust gas generated in the combustion furnace 10 at a high temperature of 800 to 950 ° C. and containing substantially no chlorine is introduced into the cyclone 16 through the sand / combustion gas outlet line 15 together with the fluidized sand in the third step, Fluid sand is sand exit line 18
Therefore, the exhaust gas is separated and taken out from the gas outlet line 17. Then, a part of the high temperature fluidized sand of 800 to 950 ° C. taken out from the sand outlet line 18 is returned to the pyrolysis furnace 1 through the sand circulation line 5 to keep the temperature inside the pyrolysis furnace 1 at a predetermined temperature. Used for. The rest is returned to the combustion furnace 10 via the sand circulation line 19.

On the other hand, the high temperature exhaust gas at 800 to 950 ° C. taken out from the gas outlet line 17 of the cyclone 16 is introduced into the second boiler 20 by the second boiler 20, and
It is used to further heat the steam produced in the boiler 24 into superheated steam. Since the exhaust gas that has passed through the gas outlet line 17 does not substantially contain chlorine, even if the boiler tube surface temperature of the second boiler 20 is 350 ° C. or higher, high temperature corrosion is greatly reduced. Therefore, the temperature of the fluid in the tube can be set to about 500 to 600 ° C., and high-temperature superheated steam can be stably obtained from the second boiler steam outlet 28.

In order to maintain the temperature of the pyrolysis furnace 1 at a predetermined temperature of 300 ° C. or higher in the pyrolysis furnace 1, the oxygen amount of the fluid gas supplied from the air or the combustion exhaust gas inlet line 6 is adjusted, in other words, While supplying a large amount of exhaust gas from the 1 boiler 24, the sand outlet line 18 from the cyclone 16
It is preferable to supply a part of the fluidized sand having a high temperature of about 800 to 950 ° C. taken out from the sand circulation line 5 as a heat source. For that purpose, in the combustion furnace 10, the empty loading speed of gas (gas flow rate in the furnace / cross-sectional area of the furnace) is set to 3 to 6 m / s,
The undecomposed residue is burned while blowing the fluidized sand supplied from the char mixture take-out line 9, and the fluidized sand is separated from the combustion gas by the cyclone 16 to separate the pyrolysis furnace 1 and the combustion furnace 10.
A high-speed circulation type fluidized bed, which circulates and supplies to, is suitable. In order to carry out the present invention more efficiently, the amount of the substantially chlorine-free char mixture taken out from the char mixture take-out line 9 should be as large as possible, preferably 40% or more of the combustible material in the raw material, and the combustion furnace 10. It is desirable to increase the amount of heat generated in the second boiler 20 and increase the amount of heat recovered in the second boiler 20. Therefore, in the present embodiment, the temperature of the pyrolysis furnace 1 is set to 300 to 700 under the condition that the chlorine in the waste can be substantially separated and removed and the char recovery rate can be 40% or more.
It is desirable to set the temperature to 350C, preferably 350 to 450C.

FIG. 2 shows an apparatus for producing superheated steam using the heat of incineration of waste according to another embodiment of the present invention. The difference from the above embodiment will be mainly described. After the partial combustion of tar is performed by the air introduced from the air inlet line 21, it is introduced into the ash melting furnace 31 before being introduced into the premixer 47. The ash melting furnace 31 swirls and separates the sand-mixed pyrolysis gas ash by swirling flow,
Air or oxygen-enriched air is introduced into the ash melting furnace 31 together with the pyrolysis gas through the line 30 to melt the ash at 1300 ° C. or higher by the heat of combustion of the pyrolysis gas to melt the molten ash. It is configured to be dropped into the water reservoir 32A through the outlet line 32 to generate a water-cooled slug of about several mm and to use the slug as a building aggregate.

Further, in the ash melting furnace 31, the ash separated from the high temperature filter 40 provided in the gas outlet line 17, which will be described later, contains the dust line 29 and the cyclone sand outlet line 1.
The ash separated from the ash separator 41 (screen) provided in 8 is introduced via the dust line 29a, respectively, and these are also melt-separated. The pyrolysis gas from which the ash has been removed is supplied to the line 33, the pyrolysis gas combustion furnace 34, and the line 35.
And then introduced into the first boiler 24.

Then, the combustion gas of the sand mixture whose temperature is raised in the combustion furnace 15 is introduced from the fluidized sand / combustion gas outlet line 15 into a gas / solid separation device such as a cyclone 16, where the fluidized sand and the combustion gas are separated. Then, the combustion gas is introduced into the second boiler 20 through the gas outlet line 17. The fluidized sand taken out from the sand outlet line 18 is supplied to the combustion furnace 10 through the sand circulation line 19 and the pyrolysis furnace 1 through the sand circulation line 5 after separating the ash by the ash separator 41 (screen). .

The ash separated by the ash separator 41 (screen) is introduced into the ash melting furnace 31 through the dust line 29a / 29. Further, the combustion furnace 10 and the second boiler 2
In the combustion gas line 17 between 0, a high temperature filter 40 is provided via a heat exchanger 37 composed of a super heater and a line 39.
Are arranged in series, for example, the combustion gas heated to around 900 ° C. is heat-exchanged with the superheated steam after heating in the second boiler introduced through the line 28 in the heat exchanger 37, and the heating temperature is 600 ° C. It is dropped back and forth and introduced into a high temperature filter 40 through a line 39.

Then, after the ash content in the combustion gas is separated by the high temperature filter 40, it is introduced into the second boiler 20 through the line 141. Further, the superheated steam is sent to a generator (not shown) via the line 38. On the other hand, the high temperature filter 40
The ash separated in (1) is introduced into the ash melting furnace 31 via the dust line 29.

Next, the operation of the above embodiment will be described in detail.
The pyrolysis gas extracted from the pyrolysis exit line 7 of the pyrolysis furnace 1 in the pyrolysis furnace 1 is the pyrolysis gas exit line 7
After the tar is partially burned by the air introduced from the air inlet line 21 of the above while preventing tar adhesion and coking, it is introduced into the ash melting furnace 31 before being introduced into the premixer 41, and ash melting is performed. , Then pyrolysis gas combustion furnace 3
After complete combustion in No. 4, it is supplied from the first boiler gas inlet 23 to the first boiler 24 together with the combustion exhaust gas from the second boiler gas outlet line 22 via the line 35. Therefore, ash etc. are not mixed in the pyrolysis gas introduced into the first boiler 24, and stable steam production is possible over a long period of time, and the pyrolysis gas introduced into the first boiler 24 is also possible. Since the gas temperature can be set as high as about 850 to 900 ° C. (around 950 ° C. at the maximum), a large amount of steam around 300 ° C. produced by the boiler can be produced.

The combustion gas generated in the combustion furnace 10 at a high temperature of 800 to 950 ° C. and containing substantially no chlorine is introduced into the cyclone 16 through the sand / combustion gas outlet line 15 together with the fluid sand, and the fluid sand is sand. The exhaust gas is separated and taken out from the gas outlet line 17 from the outlet line 18. And 800 taken out from the sand outlet line 18
After the ash is separated by the ash separator 41, a part of the high temperature fluidized sand at a temperature of up to 950 ° C. is separated by the ash separator 41 and then returned to the thermal decomposition furnace 1 through the sand circulation line 5 to bring the temperature inside the thermal decomposition furnace 1 to a predetermined temperature. Used to hold. The rest is sand circulation line 19
And is returned to the combustion furnace 10.

Therefore, according to this embodiment, the cyclone 1
Since the ash separator 41 for separating the fluidized sand and the ash is provided on the side of the sand outlet line 18 of 6, the ash and the like are mixed in the fluidizing medium returning to the pyrolysis furnace 1 and the char combustion furnace 10, respectively. In addition, stable pyrolysis and char combustion can be achieved over a long period of time. On the other hand, by introducing the ash into the ash melting furnace 31 described above, it becomes possible to manufacture aggregate or the like by using the molten ash, and the ash is separated by utilizing its heat because of its high temperature. It is also possible to reheat the pyrolysis gas.

On the other hand, the high temperature combustion gas of 800 to 950 ° C. taken out from the gas outlet line 17 of the cyclone 16 is pre-cooled in the heat exchanger 37 by heat exchange with the superheated steam introduced from the line 28, and then, Since the ash content in the combustion gas is separated by being introduced into the high temperature filter 40 through the line 39, the ash content and the like are not mixed in the combustion gas introduced into the second boiler 20. It is possible to stably produce steam over a long period of time, and to carry out combustion of the unburned chlorine compound in the combustion gas, so that so-called dioxin can be surely performed.

A heat exchanger 37 is arranged on the inlet side of the high temperature filter 40, and the superheated steam heated by the second boiler 20 is introduced into the heat exchanger 37 to introduce the high temperature filter 4 into the heat exchanger 37.
By pre-cooling the combustion gas introduced to 0, the load applied to the high temperature filter 40 can be significantly reduced. Further, by introducing the superheated steam that has been heated in the second boiler 20 into the heat exchanger 37, it is possible to obtain further heated superheated steam. Particularly, in the second boiler 20, the first boiler 24 and the water-cooled wall boiler are used. Although there is a case where the superheat capacity is insufficient due to the introduction of steam of No. 36, in the present embodiment, since the superheated steam after being heated by the second boiler 20 is introduced into the heat exchanger 37, the lack of heat capacity is eliminated. It is possible to obtain sufficiently heated superheated steam.

Further, by introducing the ash separated by the high temperature filter 40 and the ash separator 41 into the ash melting / separating furnace means, it becomes possible to manufacture the aggregate or the like by using the molten ash. Further, since the ash content is high in temperature, it is possible to reheat the separated pyrolysis gas by utilizing the heat.

[0046]

As described above, according to the present invention, the amount of air smaller than the theoretical amount of air is introduced into the pyrolysis gas passage on the outlet side of the pyrolysis means to prevent tar adhesion and coking trouble. For long-term stable and high temperature
High-pressure superheated steam can be obtained efficiently. In addition, according to the present invention, heat distribution and heat absorption can be performed more efficiently than in the above-mentioned prior art, and more efficient thermal decomposition and char combustion can be performed, and superheated steam at a high temperature can be obtained. And so on.

[Brief description of drawings]

FIG. 1 (A) is a system diagram showing an overheated steam production apparatus using heat of incineration of waste according to a first embodiment of the present invention, (B).
FIG. 4 is an enlarged view of a reheating means 40A including a premixer and a combustion duct.

FIG. 2 is a system diagram showing an apparatus for producing superheated steam using incineration heat of waste according to a second embodiment of the present invention.

[Explanation of symbols]

1 Pyrolysis Furnace (Pyrolysis Means) 2 Fluid Medium such as Sand 10 Combustion Furnace (Char Combustion Means) 11 Dispersion Plate 16 Cyclone (Separation Means) 20 Second Boiler (Second Steam Production Means) 24 First Boiler (No. 1 steam production means) 36 water-cooled wall boiler (heat exchange means arranged on the high temperature side of the char combustion means) 40 combustion duct 40A recombustion means 47 premixer 41a diffuser

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F23G 5/00 ZAB F23G 5/00 ZAB 115 115Z 5/16 ZAB 5/16 ZABE 5/30 ZAB 5 / 30 ZABK ZABM ZABE 5/32 ZAB 5/32 ZAB 5/46 ZAB 5/46 ZABA ZABB 7/00 ZAB 7/00 ZAB 103 103A F23J 1/00 ZAB F23J 1/00 ZABB 12 Nishiki-cho, Naka-ku, Yokohama City Yokohama Works, Mitsubishi Heavy Industries Ltd. (72) Inventor Shuta Ogawa 12 Nishiki-cho, Naka-ku Yokohama City, Yokohama Works, Mitsubishi Heavy Industries Ltd.

Claims (4)

[Claims] 1. A waste material is supplied into a space having a temperature of 300 ° C. or higher to cause a pyrolysis reaction, and a pyrolysis gas generated by the reaction, a char mixture composed of an undecomposed residue and a fluid medium and an incombustible material are separated. Pyrolysis means for separating from each other, char combustion means for completely combusting the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, and directly or after recombusting the pyrolysis gas A first steam producing means for producing hot water or steam having a temperature of about 400 ° C. or lower, and the hot water or steam produced by the first steam producing means by the heat of the combustion gas obtained by the char combustion means. A second steam producing means for producing superheated steam, wherein air is introduced into the pyrolysis gas passage for pre-combustion or /
And an overheated steam manufacturing apparatus utilizing the heat of incineration of waste, which is characterized by performing tar combustion. 2. A waste material is supplied into a space having a temperature of 300 ° C. or higher to cause a pyrolysis reaction, and a pyrolysis gas generated by the reaction, a char mixture composed of an undecomposed residue and a fluid medium and an incombustible material are separated. Pyrolysis means for separating from each other, char combustion means for completely combusting the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, and directly or after recombusting the pyrolysis gas A first steam producing means for producing hot water or steam having a temperature of about 400 ° C. or lower, and the hot water or steam produced by the first steam producing means by the heat of the combustion gas obtained by the char combustion means. A second steam producing means for producing superheated steam, and introducing a smaller amount of air than the theoretical air amount into the pyrolysis gas passage on the outlet side of the pyrolysis means. That claim 1 superheated steam producing device using the incineration heat of waste according. 3. The steam heated by the first or second steam producing means, or hot water or a part of the steam introduced into any one of the producing means is arranged on the high temperature side of the char combustion means. The superheated steam manufacturing apparatus utilizing the heat of incineration of waste according to claim 1, 2 or 3, which is appropriately introduced into a heat exchange means. 4. Steam which is connected to the outlet side of said char combustion means and which separates combustion gas and said fluidized medium from said char combustion means, and which is heated by said first or second steam producing means. Alternatively, a part of the hot water or steam introduced into any one of the manufacturing means is appropriately introduced into the fluid medium outlet side of the separating means and heated by thermal contact with the fluid medium. An overheated steam manufacturing apparatus utilizing the incineration heat of the waste according to any one of 4 to 4.