JP3285752B2 - 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. 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, which is fueled by heavy oil or LNG containing almost no chlorine, and has a remarkably low power generation efficiency of about 30 to 40%, which is a plant capable of setting the boiler tube temperature to 500 to 600 ° C. I was

[0004] In view of such technical problems, the present inventors have filed a simultaneous application for an invention relating to the production of superheated steam capable of efficiently obtaining high-temperature, high-pressure superheated steam while preventing high-temperature corrosion of the boiler tube due to chlorine. Patent application (reference number 96
P0191). Such a basic invention is substantially as follows:
Using steam water pressurized so as to have a boiling point at about 00 ° C. to 320 ° C., the heating of the steam water is performed in at least two or more stages, and the heating up to the substantially boiling point temperature is performed using chlorine-containing heat energy. The superheating for obtaining the superheated steam at a predetermined temperature from the substantially boiling point is performed by dechlorination heat energy containing no chlorine.

According to the basic invention, for example, as shown in FIG. 4, waste such as municipal waste is pyrolyzed, for example, even if it is a chlorine-containing pyrolysis gas containing HC1 or the like in the pyrolysis gas. Since the steam water is heated by the thermal energy of the chlorine-containing pyrolysis gas at a substantially boiling point of about 200 ° C. to 320 ° C., even if the chlorine-containing pyrolysis gas acts on the tube of the steam generating boiler. The tube surface temperature can be reduced to about 350 ° C. or less, which does not corrode. In this case, since the boiling point of the steam water is set to about 200 ° C. to 320 ° C. by pressurization, even if the application of heat energy to the steam water of the chlorine-containing pyrolysis gas varies, it is not affected by the steam. The surface temperature of the heat exchange tube of steam water rises above the chlorine corrosion temperature because it is used to absorb the latent heat of water (in other words, it is used only for the phase conversion from water to steam and does not act as a temperature rise) Thus, steam water or steam at a stable heating temperature can be obtained without performing the above.

The undecomposed residue which has not been decomposed by the thermal decomposition at about 350 ° C. to 500 ° C. has already been dechlorinated.
Approximately 200 ° C. using heat energy of about 950 ° C.
Even if superheated steam of 400 to 550 ° C. is obtained by performing secondary to tertiary heating of steam water or steam that has been primarily heated to about 320 ° C., there is no risk of tube corrosion. As a result, even when power is generated by refuse incineration, a power generation efficiency of about 30 to 40% can be obtained as in a plant using fuel oil, LNG, or the like containing almost no chlorine as a fuel.

[0007] An apparatus embodying the present invention is a temperature of 300 ° C or more, preferably a temperature of 350 to 500 ° C.
Supply waste into the space of ℃ to cause thermal decomposition reaction,
For example, a fluidized bed, a rotary kiln, a pyrolysis means using a horizontal screw stirring tank or the like for separating a char mixture and a non-flammable substance comprising a pyrolysis gas generated by the reaction, an undecomposed residue and a fluidized medium, Char combustion means, such as a high-speed fluidized bed, a bubble fluidized bed, or another fluidized bed for burning the undecomposed residue while flowing the char mixture, and utilizing the heat after directly or reburning the pyrolysis gas. And a first steam producing means for producing hot water or steam at a temperature of about 400 ° C. or less, specifically 200 to 320 ° C., and the first steam producing means by the heat of the combustion gas obtained by the char burning means. A superheated steam production apparatus utilizing the heat of incineration of wastes including a second steam production means for converting the produced hot water or steam into superheated steam is used in the basic invention. It is draft.

The present invention is to further develop such a basic technology and to provide an apparatus for producing superheated steam capable of more efficiently reducing chlorine and obtaining superheated steam at a high temperature as compared with the aforementioned basic technology. is there. Another object of the present invention is to
It is an object of the present invention to provide an invention relating to the production of superheated steam which enables stable production of steam over a long period of time in any of the above-mentioned steam production apparatuses. Another object of the present invention is to provide an apparatus for producing superheated steam, which makes more efficient use of the pyrolysis gas. Another object of the present invention is to provide an apparatus for producing superheated steam capable of producing aggregates by melting ash obtained by separating the pyrolysis gas or combustion gas.

[0009]

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, char combustion means for burning the undecomposed residue while air-flowing a char mixture comprising the undecomposed residue and the fluidized medium taken out by the pyrolysis means, and utilizing the combustion heat energy of the pyrolysis gas A first steam producing means for producing hot water or steam having a temperature of about 400 ° C. or less, and the hot water or steam produced by the first steam producing means is converted into superheated steam by thermal energy obtained by the char combustion means. Second
Between the pyrolysis means and the first steam production means, by the primary combustion heat of the pyrolysis gas, from the respective gases extracted from the char combustion means or the pyrolysis means. provided with an ash melting separation means for performing melt separation of the separated ash, provided secondary combustion means before Symbol ash make a secondary combustion of the separated pyrolysis gas, wherein
The pyrolysis gas obtained by the pyrolysis means is melted and separated by ash.
Along with the stage, a part thereof is branched and supplied to the secondary combustion means.
It is characterized by feeding .

According to this invention, the following effects can be obtained. That is, in the char combustion means, it is inevitable that ash is mixed into the combustion gas due to the thermal contact between the char mixture in the carbonized state and the fluidized sand. The same applies to the pyrolysis gas obtained by the pyrolysis means. Therefore, by providing ash melt separation means for performing ash melt separation after gas separation or while performing gas separation as required, it is possible to produce aggregates and the like using the molten ash.
Further, by performing secondary combustion using the pyrolysis gas and arranging the first steam production means such as a boiler in the secondary combustion means, it is possible to more efficiently perform primary heating of the boiler water. .

The ash contained in the pyrolysis gas and the ash contained in the combustion gas account for about 10% of the waste. Therefore, it is necessary to melt the ash using all the pyrolysis gas supplied. Is not always necessary, but rather tends to be excessive heat energy. Also, the amount of oxygen-enriched air required for burning the pyrolysis gas at a high temperature until the ash can be melted increases. Therefore the invention, together with ash melt separation means pyrolysis gas obtained by the pyrolysis unit, it also has features to supply to the secondary combustion unit branches a part of
You. The invention according to claim 2 is characterized in that the temperature of 300 ° C. or more
The waste is supplied into the space to cause a thermal decomposition reaction,
Pyrolysis gas generated by reaction, undecomposed residue and flow
Separates medium char mixture and incombustibles from each other
Pyrolysis means, and undecomposed taken out by the pyrolysis means
The char mixture consisting of the residue and the flowing medium is
To burn the undecomposed residue while flowing
Utilizing combustion means and combustion heat energy of the pyrolysis gas
To produce hot water or steam below about 400 ° C.
Steam production means and heat obtained by the char combustion means
The temperature produced by the first steam producing means by energy
Including a second steam production means that uses water or steam as superheated steam
Between the pyrolysis means and the first steam producing means.
The primary combustion heat of the pyrolysis gas generates char combustion means.
Or from each gas extracted from the pyrolysis means
Ash melt separation means to perform melt separation of ash
And secondary combustion of the pyrolysis gas from which the ash has been separated
Secondary combustion means for performing
A part of the pyrolysis gas is branched off to the inlet side of the pyrolysis means.
It is characterized by supplying . According to the invention,
Part of the pyrolysis gas obtained by the pyrolysis means is branched
Since it is supplied to the inlet side of the pyrolysis means,
Thermal decomposition of high temperature flammable gas of 350 ℃ ～ 500 ℃
The pyrolysis gas is empty because it can be circulated to the means.
Inert gas such as N ₂ , CO ₂ , H ₂ O etc.
Heat dilution per unit volume by minimizing dilution
Higher temperature makes it easier to maintain the temperature of the ash melting furnace.

[0012] Still preferably, in the invention, as the invention described in claim 3, by supplying the waste to a temperature 300 ° C. or more oxygen under-space to perform the thermal decomposition reaction, pyrolysis generated by the reaction A throttle is provided in the pyrolysis gas outlet path to supply gas to the secondary combustion means or the heat exchange means, and a small amount of air (combustion-resistant) is provided at pressure outlets provided at the inlet and outlet sides of the throttle, respectively . (A gas containing gas) is provided, and an air inflow means is provided to flow the pyrolysis gas by measuring the differential pressure.
The flow rate of the gas should be measured.

Now, it is necessary to arrange a differential pressure gauge such as an orifice in the path of the pyrolysis gas to measure and control the flow rate of the pyrolysis gas required for melting the ash, and to measure the flow rate (flow rate). There is. For this reason, it is necessary to arrange a differential pressure gauge (throttle) such as an orifice in the outlet path from the thermal decomposition means and measure the flow rate. The outlet gas from the thermal decomposition means has an outlet temperature of 350 to 500 ° C. Because of before and after, a gas containing a tar component may come out, and the tar component adheres to the throttle portion and the pressure tap (pore-shaped pressure outlet), making it difficult to measure the flow rate smoothly. Accordingly, the present invention provides an air inflow means for appropriately flowing a small amount of air (the term air is used to mean a gas containing a supporting gas) into pressure outlets provided on the inlet side and the outlet side of the throttle unit, respectively. By providing the above, the tar component is burned to prevent adhesion and the like, and the pressure can be measured stably.

[0014]

[0015]

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 an apparatus for producing superheated steam using the heat of incineration of wastes according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a pyrolysis furnace comprising a fluidized bed, wherein fluidized sand or the like is dispersed on a dispersion plate 3 such as a perforated plate. Fluid medium 2-
1 is stored therein, and waste such as fluidized sand and municipal solid waste is supplied from a waste supply line 4 and a sand circulation (return) line 5, and the combustion exhaust gas and the like supplied from a combustion exhaust gas inlet line 6 (this thermal decomposition The furnace is basically not for combustion but for thermal decomposition, so the supplied gas is mostly flue gas that consumes oxygen, but air is slightly added as needed for temperature control.) A fluidized bed space of 300 ° C. or higher is generated to cause a pyrolysis reaction of waste, and a pyrolysis gas generated by the reaction is supplied from a pyrolysis gas outlet line 7.
The char mixture composed of the undecomposed residue and the fluidized sand is taken out of the char mixture take-out line 9 and the incombustibles are taken out of the incombustibles take-out line 8 separately from each other.

At this time, it is preferable to carry out the thermal decomposition so that the thermal calorie ratio of the pyrolysis gas and the char mixture becomes "about 7 (pyrolysis gas): about 3 (char mixture)". This is because the boiler water to be heated is pressurized to about 100 kgf / cm ² and its boiling point is set at about 309 ° C.
In the case of the pyrolysis gas, the water-cooled wall boiler 36 and the first boiler 24
Then, the ratio of the calorie that starts boiler water from room temperature to “boiling point 309 ° C. + latent heat of vaporization” until it is almost vaporized at 309 ° C. and the calorie that raises the started steam from the boiling point 309 ° C. to 500 ° C. is: It is about 7: 3. The pyrolysis gas outlet line 7 on the outlet side of the pyrolysis furnace 1 may be formed with a differential pressure measuring means 100 shown in FIG. 3, and in particular, as shown in FIG. 7-1
In the case of branching, it is necessary to measure the branch flow rate by the differential pressure measuring means 100. This differential pressure measuring means 100
Flow rate (flow rate) of pyrolysis gas taken out of pyrolysis furnace 1
Is measured, and a small amount of air is appropriately flowed through the pressure outlets 109, 109 provided on the inlet side and the outlet side of the throttle unit 110 forming the differential pressure measuring means 100, respectively. The tar and the like are burned to prevent tar adhesion and caulking in the narrowed portion 110 and the pressure outlet 109.

FIG. 3A shows a differential pressure measuring means formed by using an orifice, 101 and 101 'are pipes forming an outlet line 7, 102 is a flange, 103 is an orifice plate, 104 is a differential pressure gauge, 105 106, 107, 1
08 is an air introduction pipe, 109 is a pressure tap as a pressure outlet, 110 is a throttle, 111 is an air amount adjustment valve, 1
Reference numeral 12 denotes a flow meter and other flow meters. The pressure tap 109 is 90 ° in the circumferential direction as shown in the sectional view along the line AA.
Four are provided at the positions where the angles are changed. FIG. 3B shows a differential pressure measuring unit 10 formed by using a trumpet-shaped throttle unit 110.
0, the configuration is the same as that of FIG.

The pyrolysis gas from the pyrolysis gas outlet line 7 and the pyrolysis gas branched as shown in FIG. 2 and having passed through the differential pressure measuring means 100 are introduced into an ash melting furnace 31. The ash melting furnace 31, for example, swirls and separates the sand-mixed pyrolysis gas ash by a swirling flow, and feeds air or oxygen-enriched air into the ash melting furnace 31 together with the pyrolysis gas into a line 3.
0, the ash is melted at 1300 ° C. or more by the heat of combustion of the pyrolysis gas, and the melted ash is dropped into the water reservoir 32A through the molten ash outlet line 32, and a few mm
A degree of water-cooled slag is generated, and the slag is configured to be used as building aggregate. The ash melting furnace 31 has an outlet line 18 of the cyclone 16 and a dust line 29.
The ash is introduced via the ash, and also the incombustibles in the line 14 and / or the ash collected by the bub filter or the electric precipitator are also melted and separated.

At the downstream end of the outlet line 33 of the ash melting furnace 31, a pyrolysis gas combustion furnace 34 comprising a combustion duct is provided.
Is provided, and sufficient air is supplied to the pyrolysis gas through a line 21.
A to complete combustion of the pyrolysis gas. Therefore, according to the present embodiment, the ash separated in the cyclone 16 and / or the incombustibles in the line 14 are introduced into the ash melting furnace 31 described above, so that aggregates can be manufactured using the molten ash. Become. Further, it is possible to stably produce steam over a long period of time without mixing ash or the like in the pyrolysis gas introduced into the pyrolysis gas combustion furnace 34 and the first boiler 24. Since the temperature of the pyrolysis gas introduced into the combustion furnace 34 and the first boiler 24 can be set as high as about 800 to 900 ° C. (up to about 950 ° C.), a larger amount of boiler water / steam is produced by the boiler or the like. Can be manufactured.

Reference numeral 10 denotes a char combustion furnace consisting of a bubble fluidized bed furnace, which is supplied on a dispersion plate 11 disposed at the bottom through a char mixture take-out line 9 and a sand circulation line 19-2 / 19-1. The fluidized sand circulated between the auxiliary char combustion furnace 10B is stored. Then, air is supplied from an air supply line 12 below the dispersion plate 11 and is heated to 700 to 800 ° C. in the fluidized bed 2-3 to burn undecomposed residues. Air is introduced from line 13 and further heated to about 800-
A combustion gas of about 1300 ° C. is generated, and a second superheater 29-1 and / or a boiler is disposed in an upper region of the char combustion furnace 10, and a line is provided from a second steam production means (the first superheater 20). Along with the superheating of the superheated steam introduced via 28-1, the combustion gas that has become unnecessarily high, around 950 to 1300 ° C, is dropped to 800 to 950 ° C. The second super heater 29-1 may be used for heating a water-cooled wall boiler.

As described above, the combustion gas temperature is set to 800-9.
Even if the temperature is lowered to 50 ° C., there is no problem in maintaining the steam temperature in the first superheater 20 at 400 to 520 ° C. Small incombustibles that are not burned in the char combustion furnace 10 are taken out from an incombustibles take-out line 14.

On the other hand, the char combustion furnace 10 is provided with a sub-char combustion furnace 10B as a sub-fluidized bed, and the sub-char combustion furnace 10B is provided via a sand circulation line 19-2 / 19-1.
And the third superheater 2 in the flowing medium of the auxiliary char combustion furnace 10B.
9-2, and is connected to the outlet side of the second superheater 29-1 via the line 28-2.

The auxiliary char combustion furnace 10B may be provided independently, but a fluid medium path 19-1 / for returning the fluid medium heated from the char combustion furnace 10 to the pyrolysis furnace 1.
5, it is preferable to interpose a sub-char combustion furnace 10 </ b> B provided with a third superheater 29-2.

The combustion gas heat-exchanged by the second superheater 29-1 is introduced from a sand / combustion gas outlet line 15 into a gas / solid separation device, for example, a cyclone 16 as necessary, where it is combusted with dust and ash. The gas is separated from the gas, and the combustion gas is introduced into the first superheater 20 through the gas outlet line 17.

Reference numeral 20 denotes a first superheater and reference numeral 24 denotes a first boiler. In the first boiler 24, the pyrolysis gas extracted from the pyrolysis gas outlet line 7 is supplied to a combustion gas combustion furnace 34 in which a water-cooled wall boiler 36 is installed. 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 boiler gas outlet 22 of the first superheater 20 through the boiler gas outlet 22 is heated to about 300 ° C. 1st superheater 2 from boiler outlet line 27
Supply steam or heated water to zero. 25 is an exhaust gas discharge line.

The boiler water is also introduced into a water wall boiler 36 in a combustion gas combustion furnace 34 via a branch line 26 'and supplies steam or heated water to the first superheater 20 via a branch line 27'. The boiler water, which is pressurized to about 100 kgf / cm ² and its boiling point is set at about 309 ° C., is introduced into the water-cooled wall boiler 36 and the first boiler 24 to perform the first-stage heating. However, the flow rate of water is controlled so that the heating temperature is about 309 ° C., which is near the boiling point.

As a result, the tube surface wall temperature of the water-cooled wall boiler 36 and the first boiler 24 can be maintained at about 309 ° C. following the heated water, for example, chlorine or HCl is added to the heat-exchanged pyrolysis gas. Even if included, corrosion does not occur.

In the first superheater 20, steam / heated water taken out from the outlet lines 27 and 27 'of the first boiler 24 and the water-cooled wall boiler 36 and heated by the water-cooled wall boiler 36 and taken out through a branch steam line 27'. The heated steam / heated water is introduced and heated with the combustion gas supplied through the combustion gas line 17 to produce superheated steam at about 400 to 550 ° C. The super heater 29-1 and the third super heater 29-2 are introduced in series from the line 28-2 to the third super heater 29-2, respectively.
Take out the superheated steam heated to 過 550 ° C. and feed it to the generator.

Although the operation of the above embodiment has been described together with the structure, the repetition will be briefly described. The chlorine-containing organic compound such as PVC plastic is mixed in the waste such as municipal waste supplied to the pyrolysis furnace 1. And about 0.2 to 0.5% as C1 in combustibles. Then, municipal solid waste from the waste supply line 4 and high-temperature circulating fluidized sand from the fluidized sand circulation line 5 are supplied to the pyrolysis furnace 1, respectively, and the temperature is slightly adjusted to the combustion air from the lower air or the combustion exhaust gas inlet line 6. By processing at a temperature of 300 to 500 ° C. in a fluidized bed in which the fluidized sand 2 is fluidized by supplying air for use, 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.

Now, as shown in FIG. 5, a part of the pyrolysis gas obtained by the pyrolysis furnace is distributed upstream of the ash melting furnace 31 through the branch line 7-2 to the dispersion plate 3 of the pyrolysis furnace. You may comprise so that it may supply to the lower entrance side. As a result, the pyrolysis gas in the line 7-1 is converted into a fluidizing gas (N ₂ , CO ₂ ,
Since not diluted with H ₂ O the main component of the inert gas) becomes high calorie, easily 1300 to the temperature of the ash melting furnace 31
It can be 1500 ° C.

The pyrolysis gas taken out of the pyrolysis outlet line 7 of the pyrolysis furnace 1 is taken out from the pressure tap 109 on the inlet side and the outlet side by passing through the throttle 110 of the differential pressure measuring means 100. The detected pressure is detected by the differential pressure gauge 104, the gas flow rate (flow rate) is measured, and the necessary pyrolysis gas is supplied to the ash melting furnace. And such a differential pressure measuring means 10
In the case of 0, the tar content in the pyrolysis gas is
Adheres to the entrance portion and the squeezing portion 110. Therefore, in this embodiment, the air amount adjustment valve 111 and the air introduction pipes 105 to 10
A small amount of air, always controlled by the flow meter 112, is supplied via the air 8, and the adhered tar is burned by the air to prevent tar adhesion and caulking in the throttle unit 110 and the outlet line 7.

In the ash melting furnace 31, together with the pyrolysis gas, as described above, the outlet line 1 of the cyclone 16 is used.
8 / Ash of the combustion gas is introduced through the dust line 29, and the air or oxygen-enriched air introduced from the line 30 is burned together with the pyrolysis gas to melt the ash, and the melted ash is stored in the water storage section. It is dropped to 32A to generate a water-cooled slag of about several mm, and the slag is used as building aggregate. At the downstream end of the outlet line 33 of the ash melting furnace 31, a pyrolysis gas combustion furnace 34 composed of a combustion duct is disposed, and sufficient air is supplied to the pyrolysis gas from a line 21A to perform the pyrolysis. Complete combustion of gas. As a result, since the temperature of the pyrolysis gas in the pyrolysis combustion furnace 34 can be set high, a large amount of steam / boiler water that is introduced into the water-cooled wall boiler 36 and the first boiler 24 and rises to a boiling point of about 200 to 309 ° C. can be produced. .

The water-cooled wall boiler 36 in the pyrolysis combustion furnace 34
The pyrolysis gas exchanged with the heat is supplied to the first boiler 24 from the first boiler gas inlet 23 together with the combustion exhaust gas from the first superheater boiler gas outlet line 22. Since the gas introduced into the pyrolysis combustion furnace 34 and the first boiler 24 contains about 500 to 1000 ppm of HC1, the flow rate of the boiler water is adjusted to adjust the flow rate of the water-cooled wall boiler 36 and the first boiler 24. Tube surface temperature is about 350
C. or lower to suppress high-temperature corrosion. For this reason, high-temperature superheated steam cannot be obtained in the water-cooled wall boiler 36 and the first boiler 24, but can be heated up to about 200 to 320 ° C., which is further reduced by the superheaters 29-1 and 29- after the first superheater 20. If heated in 2, it will be about 400-550
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 uncracked residue, and is substantially free of chlorine.
In the combustion furnace 10, the air is supplied to a lower part of the combustion furnace 10 and is burned by air supplied from an air supply line 12 through a dispersion plate 11. In this case, the amount of air supplied from the air supply line 12 is adjusted, and the undecomposed residue is burned while flowing the fluidized sand. Air supply line 1 for complete combustion
3 and / or additional air may be supplied from line 19-3. The temperature of the combustion furnace 10 rises due to a combustion exothermic reaction. This temperature value is determined by the char mixture removal line 9
Calorific value of undecomposed residue and air supply line 1
It depends on the amount of air and the temperature of the flowing sand in the sand circulation line 19, and the temperature in the sand circulation line 19 may be as high as 1000 to 1200C.

Then, the second superheater 29-1 exchanges heat with the superheated steam from the first superheater 20 through the line 28-1 to thereby reduce the combustion gas to 800 to 950.
It is easy to reach ° C. The incombustibles reduced in size by melting glass, cans, and the like are extracted from the incombustibles take-out line 14.

The fluid medium of the char combustion furnace 10 circulates between the pyrolysis furnace 1 and the temperature of the fluid medium of the char combustion furnace 10 is approximately 600 to 850 ° C. Is 350-500 ° C., and the heat drop between the two is large. Therefore, when the fluid medium of the char combustion furnace 10 is directly introduced into the pyrolysis furnace 1 side, the pyrolysis in the pyrolysis furnace 1 is caused by the heat drop. There is a risk that the temperature will rise or heat fluctuations will occur, thus complicating the adjustment of the amount of the fluid medium to be returned.

Therefore, the fluidized medium path 19 for returning the fluidized medium heated from the char combustion furnace 10 to the pyrolysis furnace 1
During 媒体, the fluid medium heated to 700 to 800 ° C. in the first char combustion furnace 10 is supplied by the line 12 ′ by interposing the sub-char combustion furnace 10 B provided with the third superheater 29-2. The third superheater 29-2 is introduced in the sub-char combustion furnace 10B while introducing and flowing air.
To 500-700 ° C.
Since the fluidized medium dropped to ~ 700 ° C can be returned to the pyrolysis furnace 1, a gentle thermal gradient is possible. As a result, the pyrolysis temperature in the pyrolysis furnace 1 is increased from 350 ° C to 50 ° C.
Control is stable around 0 ° C.

On the other hand, 800 to 9
A combustion gas having a high temperature of 50 ° C. and substantially containing no chlorine is introduced into a cyclone 16 through a combustion gas outlet line 15, dust and ash are separated and taken out from an outlet line 18, and exhaust gas is taken out from a gas outlet line 17. It is.
The high-temperature ash taken out of the outlet line 18 is sent to the ash melting furnace 31 described above.

On the other hand, the high temperature exhaust gas of 800 to 950 ° C. taken out from the gas outlet line 17 of the cyclone 16 is introduced into the first superheater 20 and the first boiler 24.
And it is used for heating steam / boiler water at about 200 to 320 ° C. produced by the water-cooled wall boiler 36 to produce superheated steam. Since the exhaust gas passing through the gas outlet line 17 does not substantially contain chlorine, the first superheater 20
Even when the surface temperature of the boiler tube is set to 350 ° C. or higher, high-temperature corrosion is greatly reduced. Therefore, the temperature of the fluid in the tube can be set to about 400 to 550 ° C., and a high-temperature superheated steam can be stably obtained from the first superheater 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 flowing gas supplied from the flue gas inlet line 6 is adjusted, in other words, the first boiler A small amount of air is supplied together with the combustion exhaust gas from the combustion chamber 24, and a part of the fluidized sand at a high temperature of about 500 to 700 ° C.
And heat source.

Reference numerals 11, 3-1 and 3-2 denote dispersion plates,
1, 2-2 and 2-3 are fluidized beds.

FIG. 2 shows an apparatus for producing superheated steam using the heat of incineration of waste according to another embodiment of the present invention, which has already been described in the above embodiment. To explain the difference from the example, a part of the pyrolysis gas obtained by the pyrolysis furnace 1 is supplied to the pyrolysis gas combustion furnace 34 via the branch line 7 'on the upstream side of the ash melting furnace 31. It is configured to be. That is, the ash contained in the pyrolysis gas or the combustion gas is about 10% of the waste, so it is not always necessary to use the entire pyrolysis gas supplied to melt it. To prevent heat energy from being generated. For this reason, it is necessary to arrange the differential pressure measuring means 100 shown in FIG. 3 on the upstream side or the branch line 7 'of the ash melting furnace 31 where the pyrolysis gas outlet line 7 is branched, and to adjust the flow rate thereof.

[0043]

As described above, according to the present invention, when waste is burned to obtain superheated steam without using expensive high-grade materials, it is possible to prevent high-temperature corrosion of the boiler tube by chlorine while preventing high-temperature and high-pressure corrosion. Superheated steam can be obtained efficiently. Further, according to the present invention, any of the above-mentioned steam production apparatuses enables stable production of steam over a long period of time. Further, according to the present invention, it is possible to melt the ash obtained by separating the pyrolysis gas or the combustion gas to produce an aggregate or the like. And so on.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an apparatus for producing superheated steam using heat of waste incineration according to a first embodiment of the present invention.

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

FIGS. 3A and 3B show differential pressure measuring means provided in a pyrolysis gas outlet line, wherein FIG. 3A shows a differential pressure measuring means formed using an orifice, and FIG. 3B shows a differential pressure formed using a trumpet-shaped throttle. It is a pressure measuring means.

FIG. 4 is a graph showing a procedure for producing superheated steam using waste heat of incineration according to the basic configuration of the present invention.

FIG. 5 is a system diagram showing an apparatus for producing superheated steam using waste incineration heat according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pyrolysis furnace (pyrolysis means) 10 Combustion furnace (char combustion means) 11 Dispersion plate 20 1st superheater (2nd steam production means) 29-1 2nd superheater (2nd steam production means) 20-2 3 Superheater (second steam producing means) 24 First boiler (first steam producing means) 31 Ash melting furnace 34 Pyrolysis gas combustion furnace 36 Water-cooled wall boiler (first steam producing means)

Continuation of the front page (51) Int.Cl. ⁷ identification code FI F23G 5/48 ZAB F23G 5/48 ZAB F23J 1/00 F23J 1/00 B (58) Field surveyed (Int.Cl. ⁷ , DB name) F23G 5/027 F22B 1/18 F23G 5/16 F23G 5/30 F23G 5/48 F23J 1/00

Claims (3)

(57) [Claims] (1) providing waste in a space having a temperature of 300 ° C. or more;
To cause the thermal decomposition reaction, which is generated by the reaction
Char consisting of pyrolysis gas, uncracked residue and flowing medium
A pyrolyzing means for separating the mixture and the incombustible material from each other;
Do not allow the char mixture consisting of the medium to flow with air.
Char combustion means for burning the undecomposed residue; and about 400 using the heat energy of combustion of the pyrolysis gas.
First steam production means for producing hot water or steam at a temperature of not more than ℃
And the thermal energy obtained by the char combustion means.
The hot water or steam produced by the first steam production means
A second steam producing means for producing hot steam, wherein the heat is provided between the thermal decomposition means and the first steam producing means.
Due to the primary combustion heat of the cracked gas, the char combustion means
Is separated from each gas extracted from the pyrolysis means
Ash melt separation means to perform melt separation of waste ash
To,PreviousSecondary combustion of pyrolysis gas from which ash was separated
U secondary combustion meansProvided, The pyrolysis gas obtained by the pyrolysis means is converted to an ash
The secondary combustion means is partially branched together with the separation means.
To supply Utilizes waste incineration heat
Superheated steam production equipment. (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, Undecomposed residue and fluid removed from the pyrolysis means
Do not allow the char mixture consisting of the medium to flow with air.
Char burning means for burning the undecomposed residue, Approximately 400 using the combustion heat energy of the pyrolysis gas
First steam production means for producing hot water or steam at a temperature of not more than ℃
When, The heat energy obtained by the char combustion means causes
The hot water or steam produced by the first steam production means
A second steam producing means for producing hot steam, Between the thermal decomposition means and the first steam producing means,
Primary combustion of cracked gas By heat, char combustion means
Is separated from each gas extracted from the pyrolysis means
Ash melt separation means to perform melt separation of waste ash
In addition, secondary combustion of the pyrolysis gas from which the ash has been separated is performed.
The secondary combustion means is provided and obtained by the thermal decomposition means.
Part of the pyrolysis gas is branched and supplied to the inlet of the pyrolysis means
Superheated steam using the heat of incineration of waste
Qi production equipment. 3. A method in which waste is supplied to an under-oxygen space having a temperature of 300 ° C. or more to cause a pyrolysis reaction, and a pyrolysis gas generated by the reaction is supplied to a secondary combustion means or a heat exchange means. A throttle section is provided in the cracked gas outlet path,
An air inflow means for appropriately flowing a small amount of air (a gas containing a supporting gas) is provided at a pressure outlet provided at each of the inlet side and the outlet side of the throttle section, and the differential pressure is measured to determine the flow rate of the pyrolysis gas. The superheated steam production apparatus using the heat of waste incineration according to claim 1 or 2, wherein the measurement is performed.