JP3272582B2 - Superheated steam production equipment using waste incineration heat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of superheated steam by incinerating municipal refuse or industrial waste, producing steam by the heat of the combustion exhaust gas, and using the steam in a power plant or the like. .

[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 solid waste contains a chlorine-containing organic compound such as PVC plastic, and the flammable component has a C1 content of about 0.2 to 0.1%.
Contains 5%. Chlorine contained in PVC plastic and the like mixed into waste such as municipal waste becomes HC1 by combustion (usually, HC1 contained in flue gas from municipal waste combustion).
(1 is about 500 to 1000 ppm), which acts on the tube of the steam generation 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.

Therefore, conventionally, the tube surface temperature is 35
The temperature of the steam to be produced was limited to about 300 ° C. As a result, the power generation efficiency of the conventional refuse incineration is about 15% or less, and the power generation efficiency of a plant that can use boiler tube temperature of 500 to 600 ° C. using heavy oil or LNG containing almost no chlorine as fuel is used.
%, Which is significantly lower than the above, and its improvement has been strongly desired.

[0005] In view of such technical problems, the present inventors have filed an earlier application (application number: Japanese Patent Application No. 6-324843).
, 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 uncracked residue from the fluidized bed and the fluidized medium results in a substantially chlorine-free uncracked residue. That is, it was found that substantially all chlorine contained in the waste was contained in the pyrolysis gas and was discharged to the pyrolysis gas outlet line.

[0006] Based on such knowledge, the incinerator side supplies waste to a space having a temperature of 300 ° C or higher to cause a pyrolysis reaction, and generates a pyrolysis gas generated by the reaction, undecomposed residues and A first fluidized bed (hereinafter referred to as a pyrolysis means) for separating a char mixture composed of a fluidized medium and an incombustible substance from each other, and a method for completely burning the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas. 2 fluidized beds (hereinafter referred to as char combustion means), while the first and second boilers are connected in series on the boiler side, and the heat of the pyrolysis gas is utilized in the lower stage boiler. About 400 ° C or less, specifically 30
Hot water or steam at about 0 ° C. is produced (hereinafter referred to as first steam producing means), and then the hot water or steam at about 300 ° C. is introduced into a second boiler to obtain combustion gas obtained from the char burning means. Has been proposed to produce superheated steam of about 500 ° C. or higher by the heat of the superheated steam (hereinafter referred to as second steam production means).

The present invention further develops such prior art and relates to the production of superheated steam capable of efficiently (in large quantities) producing high-temperature, high-pressure superheated steam while preventing high-temperature corrosion of the boiler tube due to chlorine. It is to provide an invention. Another object of the present invention is to provide an invention relating to the production of superheated steam capable of reducing chlorine more efficiently and obtaining 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 which can stably produce steam over a long period of time without any incorporation of ash or the like in any of the above steam production apparatuses. .

[0008]

According to the first aspect of the present invention,
Pyrolysis that supplies waste to a space having a temperature of 300 ° C. or higher to cause a pyrolysis reaction, and separates a pyrolysis gas generated by the reaction, a non-decomposed residue, a char mixture composed of a fluidized medium, and a non-combustible material from each other. Means, a combustion means for completely burning the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, and directly or reburning the pyrolyzed gas, and then using the heat to about 400 ° C. A first steam producing means for producing the following hot water or steam, and a second steam producing superheated steam using the hot water or steam produced by the first steam producing means by heat of the combustion gas obtained by the burning means. wherein steam production means, between said combustion means and the second steam producing means, as well as distribution of the high temperature filter unit, the first steam production and the pyrolysis means
Between the means and the primary combustion heat of the pyrolysis gas,
Melt separation of the ash separated by the high temperature filter means
Ash melt separation means to be performed, and pyrolysis in which the ash is separated
A secondary combustion means for performing secondary combustion of gas is provided .

Further , the invention according to claim 2 has a temperature of 300.
Supplying waste into a space above ℃ to perform thermal decomposition reaction
Pyrolysis gas and undecomposed residue
The char mixture and the incombustibles
By means of pyrolysis means to separate and air or flue gas
The above undecomposed while blowing the char mixture upward
Combustion means for completely burning the residue and the pyrolysis gas directly
After contacting or reburning, use the heat to
First steam production means for producing hot water or steam at a temperature of not more than ℃
If, on the heat of the combustion gas obtained by the combustion means
The hot water or steam produced by the first steam production means
A second steam producing means to heat steam out of the combustion means
A combustion gas and the fluid medium from the combustion means connected to the mouth side;
Means for separating the fluid and a fluid medium outlet of the separating means
Ash separation means for separating ash from the fluid medium
Between the combustion means and the second steam producing means.
Filter means, and the thermal decomposition means and the first steam
Between the primary combustion heat of the pyrolysis gas and the gas production means.
Ash melting and separating means for separating and melting the ash,
Pyrolysis gas combustion for secondary combustion of separated pyrolysis gas
Means, the ash separated by the ash separation means
It is characterized in that it is introduced into the ash melt separation means .

According to a fifth aspect of the present invention, the high-temperature fill
Heat exchange means at the inlet side of the
Steam heated by the second steam producing means or
With some of the hot water or steam introduced into any of these manufacturing means
Combustion introduced into the high temperature filter means by thermal contact of
It is characterized by pre-cooling the gas temperature. In addition, billing
Item 6. The invention according to Item 6, wherein the high-temperature filter means
Ash separation and unburned organic in the combustion gas
It is characterized by performing compound combustion.

According to this invention, since the char mixture separated by the pyrolysis means does not substantially contain chlorine in any of the above-mentioned claims, it is used as a superheat source of the second steam production means. Even if it is configured to obtain superheated steam of not less than ° C, high-temperature corrosion of equipment does not occur.

In addition, a pyrolysis gas containing chlorine is used as a heating source of the first steam producing means.
Since it is intended to manufacture hot water or steam at a temperature of 0 ° C. or less, specifically, about 300 to 350 ° C. or less, only a temperature lower than a high temperature corrosion temperature is heated. Absent.

Further, according to the first and second aspects of the present invention,
A high-temperature filter is disposed between the combustion means and the second steam producing means. In order to separate the ash in the combustion gas by the filter means, the high-temperature filter means is provided in the combustion gas introduced into the second steam producing means. Steam can be stably produced over a long period of time without contamination of ash and the like, and the combustion of unburned chlorine compounds in the combustion gas is reliably performed on the filter surface, so that harmful substances such as dioxins are generated. The substance can be completely burned and made harmless.

A heat exchanging means (hereinafter referred to as a third heat exchanging means) is provided on the inlet side of the high-temperature filter means, and the steam heated by the first or second steam producing means or any of the above-mentioned ones is provided. By pre-cooling the combustion gas introduced into the high temperature filter means by thermal contact with a part of the hot water or steam introduced into the production means, the load applied to the high temperature filter can be reduced.

Further, the third heat exchange means exchanges heat with steam heated by the first or second steam production means or a part of hot water or steam introduced into any one of the production means. The following functions can be performed.
That is, the hot water introduced into the first steam producing means is introduced into the third heat exchanging means to raise the temperature to a certain extent, whereby the third heat exchanging means-the first steam producing means-the 2
The temperature can be raised in three stages substantially in series with the steam production means of the above, and a large amount of sufficiently heated superheated steam can be obtained.

Further, by introducing hot water or steam introduced into the second steam producing means together with the first steam producing means into the third heat exchange means in parallel, the second steam producing means is provided. Can be increased, and a large amount of superheated steam can be obtained. Further, by introducing the superheated steam heated by the second steam production means to the third heat exchange means, a further heated superheated steam can be obtained, and a sufficiently heated superheated steam can be obtained. .

Further, between the pyrolysis means and the first steam producing means, the ash fraction which is melted and separated from the ash separated from the high temperature filter means by primary (or secondary) combustion heat of the pyrolysis gas. By providing the melt separation means, it is possible to produce aggregates and the like using the molten ash. Further, since the ash is at a high temperature, it is possible to reheat the separated pyrolysis gas using the heat.

According to the first aspect of the present invention, a separating means for separating the combustion gas and the fluid medium is provided on the outlet side of the char burning means, in other words, 800 to 950.
By returning the high-temperature fluid medium of about ° C. to each of the pyrolysis means and the char combustion means, formation of a fluidized bed at a desired temperature and temperature control become easy. Further, according to the invention described in claim 2,
According to the present invention, since the ash separating means for separating ash from the fluid medium is provided on the fluid medium outlet side of the separating means, ash and the like are mixed into the fluid medium returning to the pyrolysis means and the char combustion means. Without this, stable pyrolysis and char combustion can be achieved over a long period of time. On the other hand, the ash is introduced into the ash melting / separating means described above, thereby making it possible to produce an aggregate or the like using the molten ash, and the ash is separated using the heat because of its high temperature. It is also possible to reheat the pyrolysis gas that has been generated.

[0019] The inventions of claim 5, wherein a portion of the hot water or steam is introduced into the first or second steam or any one of the manufacturing means heating with steam production means, said combustion means It is characterized in that it is appropriately introduced into heat exchange means (hereinafter referred to as first heat exchange means) arranged on the high temperature region side. That is, since the combustion means decomposes the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, the combustion gas contains a high-temperature fluid medium.

Therefore, in the present invention, the third heat exchanging means is disposed on the high temperature side of the char combustion means by utilizing the high temperature fluid medium, and the first or second steam producing means is provided. By performing heat exchange with the steam heated by the means or with a part of the hot water or steam introduced into any of the above-mentioned production means, it is possible to perform the operation described later in combination with the third heat exchange means. That is, the hot water introduced into the first steam producing means is introduced into the first heat exchanging means to raise the temperature to a certain extent, whereby the first heat exchanging means-the first steam producing means-the first The temperature can be raised in four stages substantially in series with the second steam production means and the third heat exchange means, and a large amount of sufficiently heated superheated steam can be obtained.

Further, by introducing the hot water or steam introduced into the second steam production means together with the first steam production means into the first heat exchange means in parallel, the second steam production means is provided. Can be increased, and a large amount of superheated steam can be obtained. Further, since the high-temperature side of the char combustion means is heated to about 950 to 1300 ° C., the superheated steam heated by the second steam production means is introduced into the first heat exchange means, thereby further increasing the temperature. For example, heated superheated steam of 500 to 600 ° C. can be obtained, and sufficiently heated superheated steam can be obtained.

The provision of the heat exchange means on the high temperature side of the char combustion means is unnecessarily high at about 950 to 1300 ° C., and if it is passed through the outlet line as it is, the ordinary metal line has no temperature. However, by dropping the temperature to 800 to 950 ° C., a normal heat-resistant metal line can be used. Further, even if the temperature is lowered to 800 to 950 ° C. as described above, the steam temperature in the second steam producing means is set to 500 to 600 ° C.
There is no hindrance in maintaining it.

According to a fourth aspect of the present invention, there is provided a separator connected to an outlet side of the combustion means for separating the combustion gas and the fluid medium from the combustion means. The heated steam or a part of the hot water or steam introduced into any one of the production means is appropriately introduced to the fluid medium outlet side of the separation means, and heated by thermal contact with the fluid medium. Is what you do.

According to this invention, since the separation means for separating the combustion gas and the fluid medium is provided at the outlet side of the char combustion means, in other words, the high temperature fluid medium of about 800 to 950 ° C. is heated. By returning to the decomposition means and the char combustion means, it becomes easy to form a fluidized bed at a desired temperature and to control the temperature.

In the present invention, a heat exchange means is arranged on the fluid medium outlet side of the separation means, and is introduced into the steam heated by the first or second steam production means or any one of the production means. By heating a portion of the hot water or steam by appropriate thermal contact with the fluid medium, the same operation as the invention described in claim 4 can be performed.

In this case, a first heat exchanging means may be arranged on the high temperature region side of the char combustion means and a heat exchanging means (hereinafter referred to as a second heat exchanging means) also on the fluid medium outlet side of the separating means. . Also, first heat exchange means-first steam production means-
Second steam production means-second heat exchange means-(or in parallel)
By arranging the third heat exchange means, the temperature can be raised substantially in series in 4 to 5 steps, and an extremely high sufficiently heated superheated steam can be obtained.

Further, as shown in the embodiment described later, (first heat exchange means and first steam production means are arranged in parallel) -second steam production means-second heat exchange means- (or in parallel) By arranging the three heat exchange means in series, it is possible to substantially increase the temperature in three stages in parallel / serial, and to obtain a large amount of sufficiently heated superheated steam. Either the first heat exchange means or the second heat exchange means may be selectively used. It is preferable to use a superheater or a boiler as the heat exchange means.

[0028]

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.
1 shows a superheated steam production apparatus utilizing the heat of incineration of waste according to an embodiment of the present invention. Fluid medium and waste such as municipal solid waste are supplied from a waste supply line 4 and a sand circulation line 5, and the temperature is controlled by air or flue gas supplied from air or flue gas inlet line 6. A fluidized bed space of 300 ° C. or higher is generated to cause a pyrolysis reaction of the waste, and the pyrolysis gas generated by the reaction is supplied to a pyrolysis gas outlet line 7. From the char mixture take-out line 9, incombustibles are separately taken out from the incombustibles take-out line 8. The air or the combustion exhaust gas supplied to the pyrolysis furnace 1 from the air or the combustion exhaust gas inlet line 6 contains a small amount of oxygen (3 to 5) in order to efficiently perform the thermal decomposition in the range of 300 to 700 ° C.
%) And the flue gas whose temperature is maintained at 100 to 300 ° C., specifically, the flue gas extracted from the outlet line 25 of the first boiler 24 is preferably used.

The pyrolysis gas extracted from the pyrolysis gas outlet line 7 is supplied to the ash melting furnace 31 and the pyrolysis gas combustion furnace 34.
And is introduced into the first boiler 24. That is, the ash melting furnace 31 introduces air or oxygen-enriched air together with the pyrolysis gas into the melting furnace 31 from the line 30 while swirling and separating the sand mixed pyrolysis gas ash by the swirling flow. A high temperature of 1300 ° C. or more is formed by the heat of combustion of the pyrolysis gas, the ash is melted by the heat, and the melted ash is dropped into the water storage portion 32A through the molten ash outlet line 32, and is cooled by about several mm of water. A slug is generated and the slug is used as building aggregate.

In the ash melting furnace 31, ash separated from a high-temperature filter 40 provided in a gas outlet line 17 to be described later is provided with an ash separator 41 (screen) provided in a dust line 29 and a sand outlet line 18 of the cyclone 16. And the ash is removed from the dust lines 29a and 29-1
And these are also melted and separated. Then, the pyrolysis gas from which the ash has been removed is introduced into a pyrolysis gas combustion furnace through an outlet line 33, and is reheated and completely burned by air supplied from an air supply line. To the first boiler 24.

Then, the pyrolysis gas from which the ash has been removed is introduced into a pyrolysis gas combustion furnace 34 through an outlet line 33, and is completely burned by the air supplied from the air supply line 21. The outlet line 35/23 Through the first boiler 2
Introduce to 4.

Reference numeral 10 denotes a char combustion furnace composed of a tower type fluidized bed furnace. The char mixture supplied from the char mixture take-out line 9 onto the dispersion plate 11 disposed at the bottom and the fluidized sand circulated from the sand circulation line 19 Is stored. Further, air is further supplied from the air supply line 12 below the dispersion plate 11 from the air supply line 13 in the middle region of the char combustion furnace 10 to burn undecomposed residues, thereby generating a combustion gas at about 1500 ° C. A water-cooled wall boiler 36 or a superheat for introducing boiler water from a branch line 26 'is disposed in an upper region of the char combustion furnace 10, and 950-1
Unnecessarily high combustion gas at around 300 ° C
While the temperature is lowered to 50 ° C., a part of the boiler water supplied to the first boiler 24 is heated. The heating temperature of the boiler water is 300
℃. As described above, the combustion gas temperature is set to 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.

Small incombustibles that are not burned in the combustion furnace in the combustion furnace are taken out of the incombustibles take-out line 14. The combustion gas of the sand mixture heated as described above is introduced into a gas / solid separation device, for example, a cyclone 16 from a fluidized sand / combustion gas outlet line 15, where the fluidized sand and the combustion gas are separated, and the combustion gas is separated. 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 separated into ash by an ash separator 41 (screen), and then separated into a combustion furnace 10 through a sand circulation line 19 and a pyrolysis furnace 1 through a sand circulation line 5. Supplied. Ash separator 41
The ash separated in the (screen) is transferred to the dust line 29
a / 29 is introduced into the ash melting furnace 31.

In the combustion gas line 17 between the combustion furnace 10 and the second boiler 20, a heat exchanger 37 composed of a super heater and a high temperature filter 40 are arranged in series.
The combustion gas heated to about 00 ° C. is heat-exchanged with the superheated steam after heating in the second boiler introduced from the line 28 in the heat exchanger 37, and the heating temperature is dropped to about 600 ° C. and introduced into the high temperature filter 40. You. After the ash in the combustion gas is separated by the high temperature filter 40, the ash is introduced into the second boiler through the line 141. And the high temperature filter 40
The ash separated in the above is introduced into the ash melting furnace 31 through the dust line 29.

Reference numeral 20 denotes a second boiler and reference numeral 24 denotes a first boiler. In the first boiler 24, the pyrolysis gas taken out from the pyrolysis gas outlet line 7 is reburned by the air taken in from the air inlet line 21. The boiler water introduced into the first boiler 24 and taken in from the boiler water inlet 26 together with the combustion exhaust gas discharged from the second boiler gas outlet 22
The mixture is heated to about 0 ° C., and steam is supplied from the first boiler steam outlet 27 to the second boiler 20. In the second boiler 20, the steam taken out from the first boiler steam outlet line 27 of the first boiler 24 and the steam heated by the water-cooled wall boiler 36 and taken out through the branch steam line 27 'are introduced.
It is heated by the combustion gas supplied through the combustion gas outlet line 17 to produce superheated steam at about 500 to 600 ° C., and is taken out from the second boiler steam outlet 28.

Next, the operation of the above embodiment will be described in detail.
Chlorine-containing organic compounds such as PVC plastics are mixed in the waste such as municipal waste supplied to the pyrolysis furnace 1, and the combustibles contain about 0.2 to 0.5% as C1. . Then, municipal solid waste from the waste supply line 4 and high-temperature circulating sand from the sand circulation line 5 are supplied 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 to flow. By treating at a temperature of 300 to 700 ° C. in the fluidized bed in which the sand 2 is fluidized, an undecomposed residue substantially free of chlorine is obtained from the char mixture removal line 9. That is, substantially all of the chlorine contained in the waste is contained in the pyrolysis gas and discharged to the pyrolysis gas outlet line 7. The large-sized incombustibles separated by the thermal decomposition reaction in the thermal decomposition furnace 1 are taken out of the furnace through an incombustibles take-out line 8.

The pyrolysis gas extracted from the pyrolysis outlet line 7 of the pyrolysis furnace 1 by the pyrolysis furnace 1 contains low calorie gas, oil, tar and HC1, which are converted into an ash melting furnace. After being completely burned in the combustion furnace 31 and the pyrolysis combustion furnace 34, the fuel 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. Therefore, the steam can be stably produced for a long period of time without mixing ash or the like into the combustion gas of the pyrolysis gas introduced into the first boiler 24, and
The temperature of the pyrolysis gas introduced into the boiler 24 is approximately 850 to 9
Since the temperature can be set as high as about 00 ° C. (about 950 ° C. at the maximum), a large amount of steam at about 300 ° C. produced by the boiler 24 can be produced.

The gas at the first boiler gas inlet 23 is HC1
Is contained at about 500 to 1000 ppm, so that the flow rate of the boiler water is adjusted to keep the tube surface temperature of the first boiler 24 at about 350 ° C. or less, which is the same as the conventional one, thereby suppressing high-temperature corrosion. For this reason, high-temperature superheated steam cannot be obtained in the first boiler 24, but can be heated up to about 300 ° C., and if this is further heated in the second boiler 20, about 500 to 600 ° C.
High temperature superheated steam can be obtained.

In the pyrolysis furnace 1, the char mixture consisting of the char mixture sand extracted from the char mixture extraction line 9 and the undecomposed residue and containing substantially no chlorine is dispersed in the combustion furnace 10 from the air supply line 12 through a dispersion plate. Combustion by air supplied via 11. In this case, the amount of air supplied from the air supply line 12 is adjusted, and the non-decomposed 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 a combustion exothermic reaction. This temperature value is determined by the calorific value of the undecomposed residue supplied from the char mixture take-out line 9, the amount of air in the air supply lines 12, 13 and the amount of fluidized sand in the sand circulation line 19 and the temperature. May become hot. Therefore, it is easy to make the mixed sand combustion gas 800 to 950 ° C. by exchanging heat with the boiler water introduced from the branch pipe 26 by the water-cooled wall boiler 36. Miniaturized incombustibles such as glass and cans are extracted from the incombustibles take-out line 14.

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

Therefore, according to the present embodiment, the cyclone 1
6. Since the ash separator 41 for separating the ash from the fluidized sand is provided on the side of the sand outlet line 18 of 6, the ash and the like are mixed in the fluid medium returning to the pyrolysis furnace 1 and the char combustion furnace 10, respectively. And stable pyrolysis and char combustion can be achieved over a long period of time. On the other hand, the ash is introduced into the ash melting furnace 31 described above, thereby making it possible to produce aggregates and the like using the molten ash, and the ash is separated using the heat because of its high temperature. It is also possible to reheat the pyrolysis gas that has been generated.

On the other hand, the 800-950 ° C. high-temperature combustion gas taken out from the gas outlet line 17 of the cyclone 16 is pre-cooled in the heat exchanger 37 by heat exchange with superheated steam introduced through the line 28, Since the ash is introduced into the high temperature filter 40 through the line 39 and the ash in the combustion gas is separated by the filter 40, the ash and the like are not mixed into the combustion gas introduced into the second boiler 20. In addition to the stable production of steam over a long period of time, and the burning of unburned chlorine compounds in the combustion gas, the so-called dioxin can be reliably rendered harmless.

Then, a heat exchanger 37 is arranged on the inlet side of the high-temperature filter 40, and the superheated steam heated from the second boiler 20 is introduced into the heat exchanger 37, and
By pre-cooling the combustion gas introduced to zero, the load applied to the high-temperature filter 40 can be reduced. Also heat exchanger 37
The superheated steam superheated in is sent to a generator (not shown) via a line 38.

The superheated steam heated by the second boiler 20 is introduced into the heat exchanger 37, so that the superheated steam further heated can be obtained. In some cases, the superheat capacity becomes insufficient due to the introduction of the steam from the water-cooled wall boiler 36. In this embodiment, however, the heat capacity becomes insufficient to introduce the superheated steam heated by the second boiler 20 into the heat exchanger 37. And a sufficiently heated superheated steam can be obtained. Further, the ash separated by the high-temperature filter 40 and the ash separator 41 is separated by the ash melting and separating furnace 3.
By introducing the molten ash, aggregates and the like can be manufactured using the molten ash. Since the ash content is high in temperature, it is possible to reheat the separated pyrolysis gas by using the heat.

The second boiler 20 is used to further heat the steam produced in the first boiler 24 to be superheated steam. Since the exhaust gas passing through the gas outlet line 17 does not substantially contain chlorine, even if the surface temperature of the boiler tube of the second boiler 20 is set to 350 ° C. or higher, high-temperature corrosion is greatly reduced. Therefore, the steam temperature in the tube can be set to about 500 to 600 ° C. and 100 kgf / cm ^2, and a 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 amount of oxygen in the air or the flowing gas supplied from the flue gas inlet line 6 is adjusted, in other words, It is preferable to adjust the flow rate of exhaust gas from one boiler 24 or to supply a part of the fluidized sand having a high temperature of about 800 to 950 ° C. taken out from the sand outlet line 18 from the cyclone 16 from the sand circulation line 5 as a heat source. .

To do so, in the combustion furnace 10, the gas emptying speed (gas flow rate in the furnace / cross-sectional area of the furnace) is set to 3 to 6 m / s, and the fluid sand supplied from the char mixture take-out line 9 is blown off. A high-speed circulating fluidized bed that burns undecomposed residues and separates fluidized sand from combustion gas in a cyclone 16 and circulates it to the pyrolysis furnace 1 and the combustion furnace 10 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 is made 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. As a result, the power generation efficiency can be increased to 30% or more. Therefore, in this embodiment, chlorine in the garbage is substantially separated and removed, and the char recovery rate is 50%.
As a condition that can be achieved as described above, the temperature of the pyrolysis furnace 1 is set to 300 to
700 ° C., preferably 350 to 450 ° C.

Now, the sand exit line 1 from the cyclone 16
Since the fluidized sand taken out of 8 has a high temperature of about 800 to 950 ° C., if it is supplied to the pyrolysis furnace 1 from the sand circulation line 5 as it is, the temperature of the pyrolysis furnace 1 becomes 350 to
It may be difficult to maintain the temperature at 450 ° C. In such a case, as shown in FIG. 2, a superheater 129 and other heat exchange means are arranged on the sand outlet line 18 side of the cyclone 16 so that the superheated steam heated by the second boiler 20 is transferred to a steam line 28a. The liquid is introduced into the super heater 129 through a heat exchanger and exchanges heat with the fluidized sand to lower the temperature of the fluidized sand to about 500 to 800 ° C.
The shortage of the heating amount of 0 can be compensated. In particular, the second boiler 20 is apt to suffer from heat shortage due to the introduction of the steam from the water-cooled wall boiler 36 together with the first boiler 24, but this embodiment can smoothly eliminate this.

FIG. 3 shows another embodiment of the present invention, in which a part of the pyrolysis gas obtained by the pyrolysis furnace is partially converted into an ash melting furnace 31.
In other words, the high-temperature combustible gas of 350 ° C. to 400 ° C. is supplied to the pyrolysis furnace 1 on the upstream side of the pyrolysis furnace through the branch line 7a to the inlet side below the dispersion plate 3 of the pyrolysis furnace.
The amount of heat generated per unit volume can be minimized by minimizing dilution of the pyrolysis gas with air or inert gas such as N ₂ , CO ₂ , H ₂ O, etc. in the combustion exhaust gas. And the combustion temperature required for melting the ash can be easily increased to 1300 ° C., and the temperature fluctuation can be suppressed to achieve stable thermal decomposition.

[0051]

As described above, according to the present invention, it is possible to prevent high temperature corrosion of a boiler tube by chlorine while preventing high temperature corrosion.
High-pressure superheated steam can be obtained efficiently. Further, according to the present invention, heat distribution and heat absorption can be performed more efficiently than in the prior application, and moreover, pyrolysis and char combustion can be performed more efficiently, and high-temperature superheated steam can be obtained. Further, according to the present invention, in any of the above steam producing apparatuses (boilers), ash or the like is not mixed, and the steam can be produced stably for a long period of time. In addition, the present invention melts the separated ash and makes it possible to produce aggregates and the like by using the molten ash.Thus, it is possible to significantly reduce landfill waste and effectively use slugs such as building materials. Become. And so on.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a superheated steam production apparatus using waste incineration heat according to an embodiment corresponding to the first to third, fifth, and sixth aspects of the present invention.

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

FIG. 3 is a system diagram showing a superheated steam production apparatus using incineration heat of waste according to a modification of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pyrolysis furnace (pyrolysis means) 2 Fluid medium, such as sand 7a Branch line 10 Combustion furnace (char combustion means) 11 Dispersion plate 16 Cyclone (separation means) 20 2nd boiler (2nd steam production means) 24 1st Boiler (first steam production means) 31 Ash melting furnace 34 Pyrolysis gas combustion furnace 36 Water-cooled wall boiler (Heat exchange means arranged on high temperature side of char combustion means) 37 Heat exchanger 40 High temperature filter 129 Super heater (the above Heat exchange means on the fluid medium outlet side of the separation means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI F23C 10/20 F23G 5/00 ZAB F23G 5/00 115 5/16 ZABE ZAB 5/30 ZABK 5/16 ZAB ZABM 5/30 ZAB 5/32 ZAB 5/46 ZABA 5/32 ZAB ZABB 5/46 ZAB 7/00 103A ZAB 7/00 103 F23J 1/00 ZABB ZAB F23C 11/02 ZAB F23J 1/00 ZAB 312 (72) Hirotoshi 1-8-1 Koura, Kanazawa-ku, Yokohama-shi, Mitsubishi Heavy Industries, Ltd. Yokohama Research Laboratory (72) Inventor Katsuhiko Kobayashi 1-8-1, Koura, Kanazawa-ku, Yokohama-shi Yokohama Heavy Industries, Ltd. 5-346204 (JP, A) JP-A-58-95104 (JP, A) JP-A-4-174206 (JP, A) JP-A-346222 (JP, A) JP-A-7-198124 (JP, A) JP-A-7-119951 (JP, A) JP-A-1-252806 (JP, A) JP-A-7-35322 (JP, A) JP-A-5-141636 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 5/027 F22B 1/18 F22G 1/16 F23C 10/00 F23C 10/20 F23G 5 / 00 F23G 5/16 F23G 5/30 F23G 5/32 F23G 5/46 F23G 7/00 F23J 1/00

Claims (6)

(57) [Claims] 1. A waste material is supplied into a space having a temperature of 300 ° C. or more 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 each other, combustion means for completely burning the undecomposed residue while blowing the char mixture upward by air or combustion exhaust gas, and utilizing the heat after directly or reburning the pyrolysis gas First steam producing means for producing hot water or steam having a temperature of about 400 ° C. or less, and heating the hot water or steam produced by the first steam producing means with superheated steam by the heat of the combustion gas obtained by the combustion means. comprises a second steam producing means and, between the combustion means and the second steam producing means, as well as distribution of the high temperature filter means, said pyrolysis means and first made steam
Between the primary combustion heat of the pyrolysis gas and
The ash separated from the high-temperature filter means.
Ash melting / separating means for separating the ash,
An apparatus for producing superheated steam using incineration heat of waste, comprising a secondary combustion means for performing secondary combustion of cracked gas . (2)Provide waste in a space with a temperature of 300 ° C or higher.
To cause the thermal decomposition reaction, which is generated by the reaction
Char consisting of pyrolysis gas, uncracked residue and flowing medium
Pyrolysis means for separating the mixture and incombustibles from each other, Up the char mixture by air or flue gas
That completely burns the undecomposed residue while blowing
Baking means, After directly or after reburning the pyrolysis gas,
To produce hot water or steam at about 400 ° C or less
First steam producing means; The heat of the combustion gas obtained by the combustion means causes the heat
Superheated steam or hot water produced by the steam production means 1
Second steam producing means to be anxious; The combustion means is connected to an outlet side of the combustion means, and
Separating means for separating the fluid and the fluid medium;
Ash that separates fluid medium and ash at the fluid medium outlet side of the stage
And separating means, A high temperature filter between the combustion means and the second steam producing means;
Means for dissolving the thermal decomposition means and the first steam.
Primary combustion heat of the pyrolysis gas By ash
Means for separating and melting the ash, and the ash is separated
Pyrolysis gas combustion means for performing secondary combustion of selected pyrolysis gas
Is established, The ash separated by the ash separation means is subjected to the ash melt separation.
Letting the means introduce Use the heat of incineration of the characteristic waste
Superheated steam production equipment used. 3. The method according to claim 1, wherein the first or second steam producing means is used.
Introduced into heated steam or any of the above manufacturing means
A portion of the hot water or steam that is
Of the heat exchange means located on the high temperature side of
3. Abolition according to claim 1 or 2, characterized in that
Superheated steam production equipment using waste heat of incineration. (4)The combustion means is connected to the outlet side of the combustion means.
Means for separating the combustion gas from the fluid medium by the means
Including Steam heated by the first or second steam producing means
Or hot water introduced into any of the above-mentioned production means
Or a portion of the steam, as appropriate, on the fluid medium outlet side of the separation means.
And heating by thermal contact with the fluid medium.
4. Incineration of waste according to claim 1, 2 or 3
Superheated steam production equipment using heat. 5. A heat exchanger at the inlet side of said high temperature filter means.
Means, and the first or second steam producing means
Heated steam or introduced into any of the aforementioned means of manufacture
High temperature due to thermal contact with part of hot water or steam
Pre-cool the temperature of the combustion gas introduced into the filter means
3. Incineration of waste according to claim 1 or 2,
Superheated steam production equipment using heat. 6. The ash contained in the combustion gas by said high temperature filter means.
And the unburned organic compounds in the combustion gas.
3. The method according to claim 1, wherein the object is burned.
Superheated steam production equipment using the incineration heat of the wastes listed above .