JPH09236221A - Manufacture of superheated steam utilizing incinerated heat of waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce chlorine and to obtain the superheated steam of high temperature by dissolving to separate the ash content separated from the gas removed by char combustion or thermally decomposing means by primary combustion heat of the pyrolysis gas between the decomposing means and steam manufacturing means, and conducting secondary combustion. SOLUTION: Fluid sand and waste such as municipal refuse are introduced from a line 5, fluidized bed space of 300 deg.C or higher is generated by combustion exhaust gas, and pyrolysis reaction is conducted. The pyrolysis gas from a pyrolysis gas outlet line 7 is introduced into an ash melting furnace 31, the air is introduced together with the pyrolysis gas from a line 30 into the furnace 31 while turning and separating the sand mixed pyrolysis gas ash, the ash content is melted by pyrolysis gas combustion heat (primary), and dropped via a melted ash outlet line 32. A pyrolysis gas burning furnace 34 formed of a combustion duct is disposed at the downstream end of an outlet line 33, sufficient air is supplied from a line 21A to the combustion of the pyrolysis gas to conduct the complete combustion (secondary) of the pyrolysis gas.

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 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 30 to 40%, which is significantly lower than the plant power generation efficiency of about 30 to 40%, in which the boiler tube temperature can be set to 500 to 600 ° C. by using heavy oil or LNG, which contains almost no chlorine, as fuel. Was there.

In view of the above technical problems, the present inventors simultaneously applied for 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. Patent application (reference number 96
P0191). The basic invention is approximately 2
Steam water pressurized to have a boiling point of around 00 ° C. to 320 ° C. is used, the heating of the steam water is performed in a plurality of stages of at least two stages, and heating up to the above-mentioned boiling point temperature is performed with chlorine-containing heat energy. The heating is performed by dechlorination heat energy containing no chlorine to obtain superheated steam at a predetermined temperature from the substantially boiling point.

According to such a basic invention, for example, as shown in FIG. 4, even if chlorine-containing pyrolysis gas in which HC1 or the like is contained in the pyrolysis gas by thermally decomposing waste such as municipal waste Since the steam water is heated by the thermal energy of the chlorine-containing pyrolysis gas to a boiling point of about 200 ° C. to 320 ° C., the chlorine-containing pyrolysis gas may act on the tube of the steam generating boiler. The tube surface temperature can be kept below about 350 ° C, and it will 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 heat energy of the chlorine-containing pyrolysis gas is varied in application of heat energy to the steam water, The surface temperature of the heat exchange tube of steam water rises above the chlorine corrosion temperature because it is used to absorb the heat of water (in other words, it is used only for the phase conversion of water to steam and does not act as a temperature rise). Without doing so, it is possible to obtain steam water or steam with a stable heating temperature.

Since the undecomposed residue that has not been decomposed by the thermal decomposition at about 350 ° C. to 500 ° C. has already been dechlorinated, it can be obtained by burning it, for example, 500
Approximately 200 ° C. using heat energy of about 950 ° C.
Even if steam water or steam that is primarily heated to around 320 ° C is secondarily to thirdly heated to obtain superheated steam at 400 to 550 ° C, tube corrosion does not occur. As a result, even when power is generated by incineration of waste, it is possible to obtain a power generation efficiency of about 30 to 40%, which is similar to that of a plant using heavy oil containing little chlorine, LNG, or the like as a fuel.

A device for embodying the invention is a temperature of 300 ° C. or higher, preferably a temperature of 350 to 500.
The waste is supplied into the space of ℃ to carry out the thermal decomposition reaction,
Pyrolysis gas generated by the reaction, a char mixture composed of undecomposed residue and fluid medium and incombustibles are separated from each other, for example, a fluidized bed, a rotary kiln, a thermal decomposition means using a horizontal screw stirring tank, and the like by air. A char combustion means for combusting the undecomposed residue while fluidizing the char mixture, such as a high-speed fluidized bed, a bubbling fluidized bed or other fluidized bed, and directly or re-combusting the pyrolysis gas, and then using the heat At about 400 ° C. or less, specifically 200 to 320 ° C., by the first steam producing means and the heat of the combustion gas obtained by the char combustion means. In the above basic invention, there is provided a superheated steam manufacturing apparatus using the incineration heat of waste, which includes a second steam manufacturing means for converting the manufactured hot water or steam into superheated steam. It is draft.

The present invention further develops such basic technology, and provides a superheated steam production apparatus capable of more efficiently reducing chlorine and obtaining superheated steam at high temperature as compared with the above-mentioned 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 for a long period of time in any of the above steam production apparatuses. Another object of the present invention is to provide an apparatus for producing superheated steam in which the pyrolysis gas is used more efficiently. Another object of the present invention is to provide a superheated steam production apparatus capable of producing aggregate or the like by melting ash obtained by separating the pyrolysis gas or combustion gas.

[0009]

According to the first aspect of the present invention,
Pyrolysis in which waste 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 undecomposed residue and a fluid medium, and an incombustible substance are separated from each other. Means, a char combustion means for combusting the undecomposed residue while flowing a char mixture composed of the undecomposed residue and the fluidized medium taken out from the thermal decomposition means by air, and utilizing combustion energy of the thermally decomposed gas First steam producing means for producing hot water or steam having a temperature of 200 to 320 ° C., and the hot water or steam produced by the first steam producing means by the thermal energy obtained by the char combustion means as superheated steam. A second steam producing means is included, which is similar to the basic technique described above, but the pyrolysis gas is provided between the pyrolysis means and the first steam producing means. The first feature is that an ash melting and separating means for melting and separating the ash separated from each gas taken out from the char combustion means or the thermal decomposition means by the primary combustion heat is provided, and preferably the ash content is A second feature is that a secondary combustion means for performing secondary combustion of the pyrolysis gas separated from is separated.

According to this invention, the following effects can be obtained. That is, in the char combustion means, it is inevitable that ash is mixed in the combustion gas due to 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, after the gas is separated as necessary, or by providing an ash melting / separating means for melting and separating the ash while the gas is being separated, it is possible to manufacture an aggregate or the like using the molten ash.
Further, the secondary combustion is performed by utilizing the pyrolysis gas, and the first steam producing means such as the boiler is provided in the secondary combustion means, whereby the primary heating of the boiler water can be further efficiently performed. .

The ash contained in the pyrolysis gas and the ash contained in the combustion gas account for about 10% of the waste. Therefore, the ash contained in the pyrolysis gas should be melted using all the pyrolysis gas supplied. Is not always necessary, but rather tends to become excess heat energy. Also, the oxygen-enriched air required to burn the pyrolysis gas at a high temperature until ash can be melted increases. Therefore, the invention according to claim 2 is characterized in that the pyrolysis gas obtained by the pyrolysis means is supplied to the secondary combustion means together with the ash melting separation means and a part of the gas is branched.

According to a third aspect of the present invention, waste is supplied into an oxygen-deficient space having a temperature of 300 ° C. or higher to cause a pyrolysis reaction, and the pyrolysis gas generated by the reaction is subjected to secondary combustion means or heat exchange. A throttle portion is provided in the pyrolysis gas outlet path supplied to the means, and air inlet means for appropriately flowing a small amount of air is provided at the pressure outlets provided on the inlet side and the outlet side of the throttle portion, respectively. To do.

Now, in order to measure and control the flow rate of the pyrolysis gas required for melting the ash, a differential pressure gauge such as an orifice is arranged in the path of the pyrolysis gas to measure the flow rate (flow velocity). There is. Therefore, it is necessary to arrange a differential pressure gauge (throttle) such as an orifice in the outlet path from the thermal decomposition means to measure the flow rate. The outlet gas from the thermal decomposition means has an outlet temperature of 350 to 500 ° C. The gas containing the tar component may come out due to the front and rear, and the tar component adheres to the throttle portion and the pressure tap (the pressure outlet of the pore shape), which makes it difficult to measure the flow rate smoothly. Therefore, in the present invention, an air inflow means for appropriately flowing a small amount of air (the word "air" is used to mean a gas containing a combustion-supporting gas) to the pressure outlets provided on the inlet side and the outlet side of the throttle portion. By providing the above, the tar content can be burned to prevent adhesion and the pressure can be stably measured.

The invention according to claim 4 is characterized in that a part of the pyrolysis gas obtained by the pyrolysis means is branched and supplied to the inlet side of the pyrolysis means. According to this invention, a part of the pyrolysis gas obtained by the pyrolysis means is branched and supplied to the inlet side of the pyrolysis means. In other words, at a high temperature of 350 ° C. to 500 ° C. Since the combustible gas can be circulated and supplied to the thermal decomposition means, the thermal decomposition gas can be diluted with the inert gas such as N ₂ , CO ₂ , H ₂ O in the air or the combustion exhaust gas to a minimum. Further, the calorific value per unit volume is increased, and the temperature of the ash melting furnace 31 can be easily maintained.

[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 a superheated steam production apparatus using the heat of incineration of waste according to an embodiment of the present invention. In the figure, 1 is a pyrolysis furnace composed of a fluidized bed, and a dispersion plate 3 such as a perforated plate is used to disperse fluidized sand or the like. Fluid medium 2-
1 is stored, and the wastes such as fluidized sand and municipal waste are input from the waste supply line 4 and the sand circulation (return) line 5, and the combustion exhaust gas supplied from the combustion exhaust gas inlet line 6 (this thermal decomposition Since the furnace is basically not a combustion but a thermal decomposition, most of the gas supplied is the combustion exhaust gas that consumed oxygen, but a small amount of air is added to control the temperature.) A fluidized bed space of 300 ° C. or higher is generated to cause a thermal decomposition reaction of waste, and the thermal decomposition gas generated by the reaction is discharged from the thermal decomposition gas outlet line 7
The char mixture consisting of undecomposed residue and fluidized sand is separated from the char mixture take-out line 9 and the incombustible is taken out from the non-combustible take-out line 8, respectively.

At this time, it is preferable to perform the thermal decomposition so that the thermal calorie ratio of the thermal decomposition gas and the char mixture is "about 7 (pyrolysis gas): about 3 (char mixture)". This is because the boiler water to be heated is pressurized to around 100 Kgf / cm ² and its boiling point is set to around 309 ° C.
For the pyrolysis gas, the water-cooled wall boiler 36 and the first boiler 24
Then, the ratio of the calorie that rises boiler water from room temperature to "boiling point 309 ° C + latent heat of vaporization" in other words at 309 ° C until it almost vaporizes, and the calorie that raises the raised steam from boiling point 309 ° C to 500 ° C are It is about 7: 3. Further, the differential pressure measuring means 100 shown in FIG. 3 may be formed in the thermal decomposition gas outlet line 7 on the outlet side of the thermal decomposition furnace 1. In particular, as shown in FIG. 7-1
When branching as, it is necessary to measure the branch flow rate by the differential pressure measuring means 100. This differential pressure measuring means 100 is
Flow rate (flow velocity) of the pyrolysis gas extracted from the pyrolysis furnace 1
Is measured, and a small amount of air is appropriately made to flow through the pressure outlets 109, 109 provided on the inlet side and the outlet side of the throttle portion 110 forming the differential pressure measuring means 100, respectively, so as to be contained in the pyrolysis gas. By burning tar or the like, it is possible to prevent tar from adhering to the throttle portion 110 and the pressure outlet 109 and prevent coking.

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

The pyrolysis gas from the pyrolysis gas outlet line 7 or the pyrolysis gas that has been branched as shown in FIG. 2 and passed through the differential pressure measuring means 100 is introduced into the ash melting furnace 31. The ash melting furnace 31 swirls and separates the sand-mixed pyrolysis gas ash by, for example, a swirl flow, and air or oxygen-enriched air is introduced into the ash melting furnace 31 together with the pyrolysis gas in a line 3
0, and the ash content is melted at 1300 ° C. or higher by the heat of combustion of the pyrolysis gas, and the melted ash content is dropped through the molten ash outlet line 32 into the water storage section 32A, and is heated for several mm.
It is configured to generate a degree of water-cooled slug and utilize the slug as a building aggregate. Further, the ash melting furnace 31 has a cyclone 16 outlet line 18 / dust line 29.
The ash is introduced via the ash, and the incombustibles in the line 14 and / or the ash collected by the bubb filter or the electrostatic precipitator are also separated by melting.

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 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, by introducing the ash separated by the cyclone 16 and / or the incombustibles in the line 14 into the ash melting furnace 31, it is possible to use the molten ash to manufacture an aggregate or the like. Become. Further, ash etc. are not mixed in the pyrolysis gas introduced into the pyrolysis gas combustion furnace 34 and the first boiler 24, which enables stable steam production over a long period of time, and also the pyrolysis gas. Since the temperature of the pyrolysis gas introduced into the combustion furnace 34 and the first boiler 24 can be set as high as approximately 800 to 900 ° C. (around 950 ° C. at the maximum), a larger amount of boiler water / steam produced by the boiler or the like can be produced. Can be manufactured.

Numeral 10 is a char combustion furnace consisting of a bubbling fluidized bed furnace, and a char mixture supplied from a char mixture take-out line 9 on a dispersion plate 11 arranged at the bottom and a sand circulation line 19-2 / 19-1. The fluidized sand circulated between the auxiliary char combustion furnace 10B and the auxiliary char combustion furnace 10B is stored. Then, air is supplied from an air supply line 12 below the dispersion plate 11 and heated to 700 to 800 ° C. in the fluidized bed 2-3 to burn undecomposed residue, and further air supply to the middle region of the char combustion furnace 10. About 800 ~
A combustion gas of around 1300 ° C. is generated, and a second superheater 29-1 or / and a boiler is arranged in the upper region of the char combustion furnace 10, and a line is provided from a second steam producing means (first superheater 20). Along with the superheat of the superheated steam introduced through 28-1, the combustion gas which has risen unnecessarily high at around 950 to 1300 ° C is dropped to 800 to 950 ° C. Incidentally, instead of the second superheater 29-1, a water-cooled wall boiler may be heated.

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. Then, the small incombustibles that are not burned in the char combustion furnace 10 are taken out from the incombustibles taking-out line 14.

On the other hand, the char combustion furnace 10 is additionally 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 fluidized medium path 19-1 / for returning the fluidized medium heated by the char combustion furnace 10 to the pyrolysis furnace 1
It is preferable to interpose the auxiliary char combustion furnace 10B provided with the third super heater 29-2 in the No. 5 chamber.

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

Reference numeral 20 is a first superheater and 24 is a first boiler. In the first boiler 24, the pyrolysis gas taken out from the pyrolysis gas outlet line 7 is 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 together with the combustion exhaust gas that has been burned inside and discharged from the boiler gas outlet 22 of the first superheater 20 and taken in through the boiler water inlet 26 is heated to around 300 ° C. From the boiler exit line 27 to the first super heater 2
Supply steam or heated water to 0. 25 is an exhaust gas discharge line.

The boiler water is also introduced into the water-cooled wall boiler 36 in the combustion gas combustion furnace 34 via the branch line 26 'and supplies steam or heated water to the first super heater 20 via the 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 temperatures of the water-cooled wall boiler 36 and the first boiler 24 can be maintained at around 309 ° C. following the heated water, and chlorine or HCl can be added to the heat-decomposed pyrolysis gas. Corrosion does not occur even if it is included.

In the first superheater 20, steam / heated water taken out from the outlet lines 27, 27 'of the first boiler 24 and the water-cooled wall boiler 36 and heated by the water-cooled wall boiler 36 are taken out via the branch steam line 27'. Introduced steam / heated water is heated by the combustion gas supplied through the combustion gas line 17 to produce superheated steam of about 400 to 550 ° C., and the second from the steam outlet line 28-1. Introduced in series to the superheater 29-1, and further to the third superheater 29-2 from the line 28-2, respectively.
The superheated steam superheated to ˜550 ° C. is taken out and sent to the generator.

Although the operation of the above-described embodiment has already been described along with its structure, a brief repetitive explanation will be made. In the waste such as municipal solid waste supplied to the pyrolysis furnace 1, chlorine-containing organic compounds such as vinyl chloride plastic are mixed. The content of C1 in the combustible content is 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 a slight temperature adjustment is made to the combustion exhaust gas from the lower air or the combustion exhaust gas inlet line 6. By treating at a temperature of 300 to 500 ° C. in a fluidized bed in which the working air is supplied to fluidize the fluidized sand 2, an undecomposed residue containing substantially no chlorine is obtained from the char mixture withdrawing line 9. That is, the chlorine contained in the waste is substantially 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.

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

The pyrolysis gas taken out from the pyrolysis outlet line 7 of the pyrolysis furnace 1 is taken out from the pressure taps 109 on the inlet side and the outlet side of the differential pressure measuring means 100 by passing through the throttle portion 110. The pressure difference is detected by the differential pressure gauge 104, the gas flow rate (flow velocity) is measured, and the necessary thermal decomposition gas is supplied to the ash melting furnace. And the differential pressure measuring means 10
In the case of 0, the tar content in the pyrolysis gas is the pressure tap 109.
Adheres to the entrance portion and the narrowed portion 110. Therefore, in this embodiment, the air amount adjusting valve 111 and the air introducing pipes 105 to 10
A small amount of air controlled by the flow meter 112 is constantly supplied via 8 to burn the adhered tar by the air to prevent the tar from adhering to the throttle portion 110 and the outlet line 7 and preventing coking.

In the ash melting furnace 31, the outlet line 1 of the cyclone 16 together with the pyrolysis gas as described above.
8 / The ash of the combustion gas is introduced through the dust line 29, the air or the oxygen-enriched air introduced through the line 30 is burned together with the pyrolysis gas to melt the ash, and the molten ash is stored in the water storage section. It is dropped to 32 A to generate a water-cooled slug of about several mm, and the slug is used as a building aggregate. Further, a pyrolysis gas combustion furnace 34 composed of a combustion duct is disposed at the downstream end of the outlet line 33 of the ash melting furnace 31, and air is supplied to the pyrolysis gas from a sufficient line 21A to perform the pyrolysis. Complete gas combustion. 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 up to a boiling point of near 200 to 309 ° C. can be produced. .

In the pyrolysis combustion furnace 34, a water-cooled wall boiler 36 is also provided.
The pyrolysis gas that has exchanged heat with is supplied from the first boiler gas inlet 23 to the first boiler 24 together with the combustion exhaust gas from the first super heater boiler gas outlet line 22. Since the gas introduced into the pyrolysis combustion furnace 34 and the first boiler 24 contains HC1 in an amount of about 500 to 1000 ppm, the flow rate of boiler water is adjusted to adjust the water-cooled wall boiler 36 and the first boiler 24. The tube surface temperature is about 350, which is the same as the conventional one
C. or lower to suppress high-temperature corrosion. Therefore, high-temperature superheated steam cannot be obtained in the water-cooled wall boiler 36 and the first boiler 24, but since it can be heated up to about 200 to 320 ° C., it can be further heated to the super heaters 29-1 and 29- after the first super heater 20. If heated at 2, 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 undecomposed residue, and a char mixture containing substantially no chlorine is obtained.
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 flowing the fluidized sand. Air supply line 1 for complete combustion
3 or / and further air may be supplied from the line 19-3. The temperature of the combustion furnace 10 rises due to the combustion exothermic reaction. This temperature value is the char mixture take-out line 9
Calorific value of undecomposed residue and air supply line 1
Depending on the amount and temperature of the air of 2 and 13 and the fluidized sand in the sand circulation line 19, the temperature may become as high as around 1000 to 1200 ° C.

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

Since the fluidized medium of the char combustion furnace 10 circulates between the fluidized medium of the pyrolysis furnace 1, the temperature of the fluidized medium of the char combustion furnace 10 is about 600 to 850 ° C., while the fluidized medium of the pyrolysis furnace 1 is Has a large heat drop between the two, and therefore, when the fluidized medium of the char combustion furnace 10 is directly introduced into the pyrolysis furnace 1 side, the heat drop causes the thermal decomposition in the pyrolysis furnace 1 to occur. There is a risk that the temperature will rise and heat fluctuations will occur, and thus the adjustment of the amount of the fluid medium to be returned will be complicated.

Therefore, the fluidized medium path 19 for returning the fluidized medium heated from the char combustion furnace 10 to the pyrolysis furnace 1
By interposing the auxiliary char combustion furnace 10B provided with the third super heater 29-2 in -1/5, the fluidized medium heated to 700 to 800 ° C in the first char combustion furnace 10 is supplied through the line 12 '. The third super heater 29-2 is introduced in the auxiliary char combustion furnace 10B while introducing and flowing air.
The temperature is reduced to 500 to 700 ° C by heat removal by
Since the fluidized medium dropped to ˜700 ° C. can be returned to the thermal decomposition furnace 1, a gentle thermal gradient can be achieved. As a result, the thermal decomposition temperature in the thermal decomposition furnace 1 can be changed from 350 ° C. to 50 ° C.
Stable control is possible around 0 ° C.

On the other hand, 800 to 9 produced in the char combustion furnace 10.
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 super heater 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 if the surface temperature of the boiler tube is 350 ° C or higher, high temperature corrosion is significantly reduced. Therefore, the temperature of the fluid in the tube can be set to about 400 to 550 ° C., and 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 oxygen amount of the flowing gas supplied from the combustion exhaust 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 24, and a part of the fluidized sand at a high temperature of about 500 to 700 ° C. from the auxiliary char combustion means 10B is partially fed to the sand circulation line 5
It is supplied from and used as a heat source.

In addition, 11, 3-1, 3-2 are dispersion plates, 2-
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 explained in the explanation of the above-mentioned embodiment. To explain the difference from the example, a part of the pyrolysis gas obtained by the pyrolysis furnace 1 is supplied upstream of the ash melting furnace 31 to the pyrolysis gas combustion furnace 34 via a branch line 7 ′. It is configured to do. That is, the ash contained in the pyrolysis gas or combustion gas is about 10% of the waste, and therefore it is not always necessary to use all of the pyrolysis gas supplied to melt the ash. To prevent it from becoming heat energy. Therefore, it is necessary to arrange the differential pressure measuring means 100 shown in FIG. 3 on the upstream side of the ash melting furnace 31 where the pyrolysis gas outlet line 7 is branched or on the branch line 7 ′ to adjust the flow rate thereof.

[0043]

As described above, according to the present invention, when the waste is burned to obtain the superheated steam without using the expensive high-grade material, the high temperature and high pressure of the boiler tube are prevented while preventing the high temperature corrosion of the boiler tube due to chlorine. 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 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 a superheated steam manufacturing apparatus using heat of incineration of waste according to a second embodiment of the present invention.

FIG. 3 is a differential pressure measuring means arranged in a pyrolysis gas outlet line, (A) is a differential pressure measuring means formed by using an orifice, and (B) is a differential pressure measuring means formed by using a trumpet-shaped diaphragm. 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 incineration heat of waste according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Pyrolysis Furnace (Pyrolysis Means) 10 Combustion Furnace (Char Combustion Means) 11 Dispersion Plate 20 First Superheater (Second Steam Manufacturing Means) 29-1 Second Superheater (Second Steam Manufacturing Means) 20-2 3 Super Heater (Second Steam Production Means) 24 First Boiler (First Steam Production Means) 31 Ash Melting Furnace 34 Pyrolysis Gas Combustion Furnace 36 Water Cooled Wall Boiler (First Steam Production Means)

Front page continuation (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F23G 5/48 ZAB F23G 5/48 ZAB F23J 1/00 F23J 1/00 B

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. Thermal decomposition means for separating from each other, char combustion means for combusting the undecomposed residue while flowing a char mixture consisting of the undecomposed residue and the fluidized medium taken out by the thermal decomposition means with air, and the thermally decomposed gas About 400 using the combustion heat energy of
A first steam producing means for producing hot water or steam having a temperature of not higher than 0 ° C .; and a second steam producing means for superheating the hot water or steam produced by the first steam producing means by the heat energy obtained by the char combustion means. Including steam producing means, and separating the respective gases taken out from the char combustion means or the pyrolytic means by the primary combustion heat of the pyrolytic gas between the pyrolytic means and the first vapor producing means. An ash-melting / separating means for melting and separating the separated ash is provided, and preferably 2 ash of the pyrolysis gas from which the ash is separated is provided.
A superheated steam manufacturing apparatus utilizing the heat of incineration of waste, which is provided with a secondary combustion means for performing a secondary combustion. 2. The waste according to claim 1, wherein the pyrolysis gas obtained by the pyrolysis means is supplied to the secondary combustion means together with the ash melting and separating means and a part of the gas is branched. Superheated steam production equipment that uses the heat of incineration. 3. Heat is supplied to a secondary combustion means or a heat exchange means by supplying waste to an under-oxygenated space having a temperature of 300 ° C. or higher to cause a thermal decomposition reaction, and thermally decomposing gas generated by the reaction. A throttling part is provided in the decomposition gas outlet path,
An air inflow means for appropriately flowing a small amount of air (gas containing a combustion-supporting gas) is provided at the pressure outlets provided on the inlet side and the outlet side of the throttle portion to measure the differential pressure to measure the flow rate of the pyrolysis gas. A superheated steam manufacturing device that uses the heat of incineration of waste, which is characterized by measuring. 4. The heat of incineration of waste according to claim 1, wherein a part of the pyrolysis gas obtained by the pyrolysis means is branched and supplied to the inlet side of the pyrolysis means. Superheated steam production equipment.