WO2001027533A1 - Refuse exhaust gas treating system and treating method - Google Patents

Refuse exhaust gas treating system and treating method Download PDF

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Publication number
WO2001027533A1
WO2001027533A1 PCT/JP1999/005638 JP9905638W WO0127533A1 WO 2001027533 A1 WO2001027533 A1 WO 2001027533A1 JP 9905638 W JP9905638 W JP 9905638W WO 0127533 A1 WO0127533 A1 WO 0127533A1
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WO
WIPO (PCT)
Prior art keywords
gas
combustor
exhaust gas
heat exchanger
incineration
Prior art date
Application number
PCT/JP1999/005638
Other languages
French (fr)
Japanese (ja)
Inventor
Tsutomu Okusawa
Satoru Nomoto
Terufumi Kawasaki
Masanori Takahashi
Osamu Yokomizo
Hitoshi Ishimaru
Kazuhito Koyama
Susumu Yamashita
Kazumi Iwai
Original Assignee
Hitachi, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi, Ltd. filed Critical Hitachi, Ltd.
Priority to AU61219/99A priority Critical patent/AU6121999A/en
Priority to PCT/JP1999/005638 priority patent/WO2001027533A1/en
Publication of WO2001027533A1 publication Critical patent/WO2001027533A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/006—Layout of treatment plant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
    • F23G7/061—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating
    • F23G7/065—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel
    • F23G7/066—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel preheating the waste gas by the heat of the combustion, e.g. recuperation type incinerator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/06—Arrangements of devices for treating smoke or fumes of coolers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2900/00—Special arrangements for conducting or purifying combustion fumes; Treatment of fumes or ashes
    • F23J2900/15081—Reheating of flue gases
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/30—Technologies for a more efficient combustion or heat usage

Definitions

  • the present invention relates to a waste gas treatment system and a treatment method for treating waste gas generated by incinerating waste or waste.
  • the exhaust gas is cooled by using a quenching device that publishes the exhaust gas in a cooling water tank in which the cooling water is stored, thereby suppressing dioxin regeneration.
  • a quenching device that publishes the exhaust gas in a cooling water tank in which the cooling water is stored, thereby suppressing dioxin regeneration.
  • the temperature of the exhaust gas to be cooled is in a high temperature state of 700 ° C or higher, and in order to rapidly cool this exhaust gas to a low temperature state of 300 ° C or lower, this device is applied particularly to large-scale incineration equipment. This requires a large amount of cooling water, and a separate wastewater treatment device must be installed to purify the cooling water discharged from the quenching device.
  • the present invention has been made in view of the above points, and has as its object to provide a waste gas treatment system and a treatment method capable of reducing dioxin in exhaust gas without using a wastewater treatment device. And there. Disclosure of the invention
  • the present invention provides the following waste gas treatment system.
  • the refuse exhaust gas treatment system of the present invention comprises a combustor for burning incineration gas obtained by incinerating refuse, and indirectly exchanging heat between the combustion gas burned in the combustor and the incineration gas. And a cooler for further cooling the combustion gas from the heat exchanger.
  • the present invention provides the following waste gas treatment method.
  • the exhaust gas treatment system of the present invention is characterized in that incineration gas obtained by incinerating refuse is burned in a combustor to decompose dioxin contained in the incineration gas, and the combustion gas discharged from the combustor is led to a heat exchanger.
  • the combustion gas is cooled by indirectly exchanging heat with the incineration gas supplied to the combustor, and the combustion gas cooled by the heat exchanger is indirectly heat-exchanged by a cooler to remove the exhaust gas. Further cooling.
  • FIG. 1 shows a waste gas treatment system according to one embodiment of the present invention.
  • FIG. 2 c 3 illustrates a waste gas treatment system according to another embodiment of the present invention
  • ⁇ 4 shows a waste gas treatment system according to another embodiment of the present invention
  • t 5 shows a waste gas treatment system which is another embodiment
  • t 6 illustrates a waste gas treatment system according to another embodiment of the present invention
  • FIG. 7 is a graph showing the relationship between the dust concentration and the dioxin concentration.
  • Fig. 8 shows the emission control values of dioxin in waste incinerators.
  • Figure 9 shows the average values of the exhaust gas flow rate and dioxin concentration in a typical waste incineration plant.
  • FIG. 10 is a diagram showing rated performance values of the dust collector.
  • FIG. 11 is a diagram showing the relationship between exhaust gas combustion temperature and residence time.
  • FIG. 1 shows a system diagram of a waste gas treatment system according to one embodiment of the present invention.
  • the scale of the waste gas treatment system in this example is an incinerator with a waste treatment amount of 4 tZh or more.
  • the waste gas amount is 7800 kgZh
  • the waste incineration scale is 100%.
  • t Z h dioxin emission concentration 15 ng—This is assumed to be an incinerator with a scale of TE QZm 3 N.
  • used as the unit of dioxin emission concentration described above - ng of [ng TEQ / m 3 N] is, 1 0- 9 g
  • TEQ is, Toxicity
  • Dioxins are generated by incineration of refuse or waste, especially by incomplete combustion of organic substances (plastics) containing chlorine.
  • the aggregation of multiple unburned hydrocarbons (soot, pure carbon, and part of the benzene ring) generated by incomplete combustion forms polycyclic hydrocarbons, which are aggregates of benzene rings. You. This is reacted with hydrochloric acid by the catalytic action of dust to form a dioxin precursor, which is said to combine with each other to produce dioxin.
  • the dust concentration refers to the concentration measured by the method specified by JIS
  • the dioxin concentration refers to the concentration measured by the method specified in the country.
  • the residence time (for combustion pyrolysis and cooling of the heat exchanger) was calculated from the gas volume flow rate, the cross-sectional area of the flow path, and the gas temperature under the standard conditions, and the time was calculated using the following flow rate. ing.
  • Flow rate Flow rate (m 3 NZ h) Flow area (m 2 ) 2 7 3 .15 x (Temperature + 27 3 .15)
  • the waste gas treatment system shown in Fig. 1 consists of an incinerator 1 that burns waste, and a dust collector cooler 13 3 that exchanges heat with flue gas 2 generated by burning waste to reduce the temperature of flue gas 2.
  • a dust collector 3 that collects dust in the cooled exhaust gas 2, and a mixer 5 that mixes air 7 with the exhaust gas 30 from which dust is collected by the dust collector 3 to form an aerated exhaust gas 28.
  • the waste gas treatment system according to the present embodiment includes a combustor 9 that burns fuel 8 using the aerated exhaust gas 25 and the combustion air 20 as an oxidant, and an exhaust gas 26 that is combusted by the combustor 9.
  • a heat exchanger 10 for exchanging heat with the aerated exhaust gas 28 and an evaporator 14 for cooling the exhaust gas 27 cooled by the heat exchanger 10 are provided. I have.
  • the blower 4 is provided to supply the exhaust gas 30 collected by the dust collector 3 to the mixer 5.
  • the blower 6 supplies the air 7 mixed with the exhaust gas 30 to the mixer 5 and at the same time supplies the air 7 to the combustor 9 as combustion air 20.
  • water 105 is supplied to the evaporator 14 as an indirect cooling medium by a pump 101.
  • Fig. 8 shows the emission control values of dioxin in waste incinerators that came into effect in February 1997.
  • dioxin emission control conditions differ depending on the incinerator scale and whether the incinerator is an existing furnace or a new one. For existing furnaces, it is obliged to achieve the above regulation values within five years from the enforcement date (February 1, 1997).
  • Fig. 9 shows the average of the exhaust gas flow rate and dioxin concentration in typical waste incineration facilities, and shows them by incinerator incineration scale in comparison with the national regulation values.
  • the rated performance of the dust collector 3 for removing dust in the combustion exhaust gas 2 is as shown in FIG. 10 respectively.
  • the performance of the dust collector 3 to be actually used may be a device capable of collecting dust having a particle size of 10 ⁇ or more, but preferably a device capable of completely collecting dust having a particle size of 1 ⁇ or more. What is collected is desirable.
  • waste is incinerated in the incinerator 1 to generate high-temperature combustion exhaust gas 2 of about 850 ° C or more, which is incineration gas containing dioxin. Is done.
  • the flue gas 2 is led to a desuperheater 13 via a pipe 2a, where it is cooled to a temperature of about 150 to 230 ° C or near.
  • a pipe 2a As means for cooling the flue gas 2, it is also possible to cool it by spraying water upstream of the dust collector 3 or in the incinerator 1.
  • Figure 7 shows the results of a verification test using the exhaust gas from the facility. The vertical axis shows the dioxin concentration at the outlet when a cooler is used to cool the reburn exhaust gas, and the horizontal axis shows the dust concentration.
  • the concentration of dioxin is about 100 times higher than that before the cooler.
  • the reason why the concentration of dioxin is plateau when the concentration of dust is 0.1 gZm 3 N or more is that the surface area of dust that mediates the dioxin regeneration reaction is more than necessary for the reaction and saturates.
  • dioxin can be reduced to 0.25 ng-TEQ / m 3 N or less only when the dust concentration is 0.1 g / m 3 N or less.
  • This value given the 2 0 0 percent measurement accuracy 5 0 die Okishin at very low concentrations, 0. 1 ng - since it is the upper limit to be considered a TEQ / m 3, the subject of the I Li present invention thereto
  • the dust concentration of the exhaust gas was set to 0.1 g Zm 3 N or less.
  • the temperature of the exhaust gas at the inlet of the dust collector 3 is reduced to about 150 to 230 ° C. by the desuperheater 13 so that the dust can be efficiently collected by the electric dust collector. I'm doing it. Since the purpose here is solely for dust collection, suppression of dioxin regeneration is performed in a separate step described later. In this way, the combustion exhaust gas 2 cooled to a temperature of about 150 to 230 ° C. is supplied to the dust collector 3 through the pipe 2 b, where the fly ash of the combustion exhaust gas 2 is ashed. (dust) concentration 0. 1 g Z m 3 N following conditions, dust is collected in earthenware pots by comprising, for example, 0. 0 0 1 ⁇ 0.
  • the exhaust gas 30 that has passed through the dust collector 3 is guided to the blower 4 via the pipe 3a, and further supplied to the mixer 5 via the pipe 30a.
  • the temperature of the exhaust gas 30 supplied to the mixer 5 by the blower 4 is about 200 ° C. or lower.
  • the dioxin concentration in the exhaust gas 30 passing through the dust collector 3 is 15 ng—TEQ / m 3 N. The lower the dust concentration here, the more room is allowed in the cooling process in which later dioxin regeneration occurs, and the longer the cooling time can be.
  • the exhaust gas 30 is supplied to the mixer 5 by the blower 4 via the pipe 30a.
  • a part of the air 7 supplied from the pipe 7 a is supplied to the mixer 5 by the blower 6 via the pipe 5 a.
  • the supplied exhaust gas 30 and the air 7 are mixed to form an aerated exhaust gas 28.
  • the exhaust gas 30 and a part of the air 7 are mixed, and the exhaust gas 30 is diluted with air to adjust the oxygen concentration or the dust concentration (fly ash concentration).
  • the concentration of dioxin in the aerated exhaust gas 28 mixed with air 7 remains at 15 ng-TEQ / m 3 N.
  • the aerated exhaust gas 28 coming out of the mixer 5 is supplied to the heat exchanger 10 via a pipe 28a.
  • heat exchanger 10 heat exchange is performed with a high-temperature exhaust gas 26 guided from a combustor 9 described later, and the temperature of the aerated exhaust gas 28 is raised to a temperature of about 600 ° C. Exhaust gas 26 from vessel 9 is being cooled.
  • the aerated exhaust gas 25 heated in the heat exchanger 10 is supplied to the combustor 9 via the pipe 25.
  • the combustor 9 is supplied with the aerated exhaust gas 25 heated by the heat exchanger 10.
  • fuel 8 city gas, kerosene, heavy oil, etc.
  • air 7 is used as combustion air for the fuel 8.
  • a part of the combustion air 20 is supplied via a pipe 20a. Further, in the combustor 9, a part of the steam 102 generated in the evaporator 14, which will be described later, is passed through the pipe 102 a via the pipe 104 a, and the NO. Supplied as steam 104 for x reduction. In the combustor 9, the fuel 8 and the combustion air 20 supplied to the combustor 9 are burned while injecting steam 104, and the dioxin is decomposed into the aerated exhaust gas 25 at about 600 ° C. The heating is performed to a temperature of about 750 ° C or more, preferably about 850 ° C or more.
  • the rest of the steam 102 guided from the evaporator 14 is supplied to other steam utilization equipment via the pipe 103a.
  • the exhaust gas 26 heated to a high temperature in the combustor 9 is guided to the heat exchanger 10 via a pipe 26 a provided downstream of the combustor 9.
  • the exhaust gas 26 heated in the combustor 9 is maintained at a high temperature while the exhaust gas 26 is separated from the exhaust gas 26.
  • the dioxin in the exhaust gas 26 is thermally decomposed by exposing the exhaust gas 26 to the high-temperature region for about 1 second or more, desirably about 1.6 seconds or more.
  • the time for exposing the exhaust gas 26 to a high temperature region of about 75 ° C. or more, preferably about 850 ° C. or more, is about 1 second or more, and preferably about 1.6 seconds or more. This is based on the results of the verification experiment shown in Fig. 11.
  • the decomposition temperature and residence time of dioxin are determined by Enviro miien ta l in the United States.
  • the longer the residence time of the exhaust gas 26 in the high-temperature region the more the decomposition of dioxin progresses to the limit. Therefore, the longer the residence time, the more advantageous in terms of dioxin thermal decomposition.
  • the inner wall of the piping arranged downstream of the combustor 9, including the high-temperature region including the combustor 9 and the piping 26a is made of a material that does not contribute to the regeneration of dioxin, such as stainless steel or S
  • a high decomposition rate can be secured.
  • a baffle plate in the high temperature region for example, a weir inside the pipe 26a, the time during which the exhaust gas 26 stays in the high temperature region can be extended.
  • exhaust gas 26 can be homogenized at a high temperature to improve the dioxin decomposition rate.
  • the flue gas 2 generated in the incinerator 1 is dedusted in the dust collector 3, mixed with air in the mixer 5, and heated to a high temperature in the combustor 9.
  • the dioxin concentration at this time is reduced to 0.0 lng—TEQZ m 3 N level or less.
  • the concentration of dust in the exhaust gas 30 the lower the concentration of redoxin can be reduced.However, since the exhaust gas 26 in which dioxin has been decomposed to a low concentration is in a high temperature state, It cannot be released from the chimney without cooling.
  • the exhaust gas cooling equipment first, the exhaust gas 26 after being heated to a high temperature in the combustor 9 to decompose dioxin is supplied to the heat exchanger 10 via the flue 26a.
  • the high-temperature exhaust gas 26 guided to the heat exchanger 10 undergoes heat exchange with the low-temperature aerated exhaust gas 28 that is the first cooling medium supplied from the mixer 5 and is regenerated. Is cooled to around 400 ° C, where almost no occurrence occurs.
  • almost no regeneration occurs in the heat exchanger 10, and therefore, the heat exchanger 10 is not restricted by the residence time of the exhaust gas 26. Therefore, the latest heat exchange technology can be applied to the heat exchanger 10. Wear.
  • the exhaust gas 27 cooled to about 400 ° C. in the heat exchanger 10 is supplied to the evaporator 14 via a pipe 27 a provided downstream of the heat exchanger 10.
  • Water 105 supplied from a separately installed system is supplied by pump 101. Then, the pressure of the water is increased and the water 15 passed through the pump 101 is supplied to the evaporator 14 via the pipe 15a.
  • the exhaust gas 27 guided from the heat exchanger 10 undergoes heat exchange with water 15 as the second cooling medium, and the temperature of the exhaust gas 27 is maintained in the dioxin regeneration temperature region. It has been cooled to a certain temperature of 200 ° C or less.
  • the evaporator 14 cools the exhaust gas 27 guided from the heat exchanger 10 from 400 ° C to 200 ° C or less within about 5 seconds, and discharges it from the evaporator 14 outlet.
  • the dioxin concentration in the exhaust gas is reduced to less than 0.1 ng—TEQZ m 3 N level.
  • the cooling time of the exhaust gas 27 is desirably within about 3.5 seconds, and more desirably, from 38 ° C to 33 ° C within 1 second. Dioxin regeneration can be further suppressed.
  • the exhaust gas cooled to 200 ° C. or less in the evaporator 14 is discharged from a chimney (not shown).
  • the water 15 supplied by the pump 101 is heat-exchanged with the exhaust gas 27 to generate steam 102.
  • the steam 102 generated in the evaporator i 4 is supplied to the combustor 9 or another steam utilization device via the pipe 102 a.
  • the exhaust gas heated to a high temperature in the combustor 9 is first cooled by the heat exchanger 10, which is the first cooling means, to a temperature equal to or higher than the dioxin regeneration temperature range.
  • the heat exchanger 10 which is the first cooling means
  • FIG. 6 shows the experimental results of the amount of dioxin regeneration according to this example.
  • the experimental results shown in this figure are based on general waste incineration exhaust gas components, and the waste incineration exhaust gas is once added to 850 ° C (750 ° C or more). Heating and holding for 1 second or more, and then, when cooling from 850 ° C (750 ° C or more) to 200 ° C with a heat exchanger, including the temperature range for promoting dioxin regeneration It shows the relationship between the residence time in the temperature range of 400 ° C to 200 ° C estimated from the above and the dioxin concentration.
  • the points (1) and (2) shown in the figure are the results of a test performed under conditions where ash was not deposited inside the heat exchanger, and only the flow velocity was different.
  • ⁇ the retention time and dioxin are linearly related, as can be seen from the results of the basic experiment conducted in the three cases where ash was not deposited in the interior. This indicates that to achieve 0.1 (ng—TEQ / m 3 N) or less, it is necessary to set the time to 5.5 seconds or less. Is expected to exceed - (TEQ / m 3 N ng ) 5. When staying more than 5 seconds in this temperature range regeneration amount increases 0.1.
  • Ginseng is the result of simulating the situation where ash was deposited and attached to the cooling pipe due to aging, and was obtained by a demonstration facility. From this result, considering that the heat exchanger has changed over time, it is necessary to set the heat exchanger to 3.5 seconds or less to achieve 0.1 l (ng—TE QZm 3 N) or less. In addition, a basic experiment at the test tube level revealed that the temperature range for promoting dioxin regeneration could be narrowed to 380 to 330 ° C. residence time 3.5 seconds, the 3 8 0-3 3 becomes 0 ° ⁇ in 1 second £ Incidentally, the experimental results shown in FIG.
  • the temperature is increased to more than 75
  • Exhaust gas 26 is first cooled by heat exchanger 10.
  • an aerated exhaust gas 28 in which air 5 is mixed into the exhaust gas 30 from the incinerator 1 that collects fly ash is used as a heat exchange medium for the exhaust gas 26, as a heat exchange medium for the exhaust gas 26, an aerated exhaust gas 28 in which air 5 is mixed into the exhaust gas 30 from the incinerator 1 that collects fly ash is used. Therefore, by heat exchange with the high-temperature exhaust gas 26 from the combustor 9, the aerated exhaust gas 28 can be supplied to the combustor 9 after being heated to a higher temperature. In a temperature range from 75 ° C or higher to 400 ° C, where dioxin regeneration is only slight, the exhaust gas 26 from the combustor is cooled by the heat exchanger 10 and the exhaust heat of the exhaust gas 26. We are collecting.
  • the amount of fuel 8 supplied to the combustor 9 can be reduced, and the economic efficiency can be improved.
  • an evaporator 14 having a higher cooling rate than the heat exchanger to the dioxin regeneration temperature range of 400 to 200 ° C, it is possible to suppress the regeneration of dioxin. it can.
  • the exhaust gas is cooled using a quenching device that publishes the exhaust gas in a cooling water tank in which the cooling water is stored.
  • the exhaust gas of 700 ° ⁇ or more was cooled by a single quenching device to 300 ° C, so when applying it to a large-scale incinerator, a large amount of cooling water was required.
  • a purification device for purifying the cooling water separately from the quenching device might be required.
  • the water for cooling the exhaust gas performs indirect heat exchange, so that a purification device is not required. Further, in this embodiment, heat exchange with exhaust gas is performed.
  • the steam generated by the exchange is supplied to the combustor, and can be used for NOx reduction in the combustor.
  • dioxin contained in exhaust gas can be reduced, and regeneration of dioxin can be suppressed, so that an inexpensive waste gas treatment system can be provided.
  • the high-temperature exhaust gas 26 from the combustor 9 is cooled by only one heat exchanger 10.
  • This heat exchanger 10 is provided with two heat exchange sections, and the exhaust gas 26 is firstly separated from the aerated exhaust gas 28 supplied from the mixer 5 by the first heat exchange section 10a.
  • the heat is indirectly exchanged, and the exhaust gas heated to a high temperature of more than 750 ° C in the combustor 9 is cooled to a temperature of about 400 ° C.
  • the exhaust gas cooled in the first heat exchange unit 10a is led to the second heat exchange unit 1Ob installed in the same flow path as the first heat exchange unit 10a,
  • the heat exchange is performed indirectly with the water 105 supplied to the heat exchange unit 1 Ob of No. 2, and the exhaust gas is further cooled to a temperature of 200 ° C. or lower.
  • the exhaust gas 26 heated to a high temperature in the combustor 9 is firstly separated by the first heat exchange unit 10a into a temperature range of dioxin decomposition (about 600 ° C. or more).
  • the dioxin is cooled to a temperature within a temperature range (about 400 ° C. to 600 ° C.) in which the dioxin regeneration and decomposition are equilibrated, and the dioxin is further reduced by the second heat exchange unit 1 Ob.
  • the system reduces the exhaust gas temperature to a temperature even lower than the regeneration temperature range (400 to 200 ° C).
  • the temperature of the exhaust gas from the combustor 9 is reduced in the first heat exchange section 10a.
  • a time limit for cooling to about 400 ° C.
  • the dioxin concentration in the exhaust gas can be reduced to O.lng—TE QZm 3 N level or less.
  • steam 105 is generated by heat exchange of water 15 supplied by the pump 101 with exhaust gas 26.
  • the steam 102 generated in the second heat exchange section 1 Ob is supplied to the combustor 9 via the pipe 102 a and the pipe 104 a to reduce NOx in the combustor 9. It is supplied as steam 104 or as steam 103 to other steam utilization equipment via piping 103a.
  • dioxin contained in exhaust gas can be reduced, and regeneration of dioxin can be suppressed, so that an inexpensive waste gas treatment system can be provided.
  • the exhaust gas is cooled by one heat exchanger 10, so that the entire apparatus can be made more compact than that shown in FIG. Space can be increased.
  • an air preheater 11 for preheating the combustion air 20 is added downstream of the combustor 9.
  • a combustion air pipe is provided between the blower 6 and the air preheater 11.
  • 105 a was also provided.
  • The-part of the air leaving the blower 6 enters the air preheater 11 via the pipe 105a and rises to around 300 ° C. It is heated and supplied to the combustor 9 as combustion air 20 via a pipe 20a.
  • the air preheater 11 and the heat exchanger 10 cover the temperature range of about 850 to 400 ° C., which is a temperature range where dioxin regeneration is only slight, and the dioxin regeneration temperature range Approximately 400 to 200 ° C. is applied to the evaporator 14.
  • the air preheater 11 can absorb the temperature fluctuation of the combustor as the temperature of the combustion air 20, so that the time fluctuation can be made uniform.
  • the dioxin in the exhaust gas can be decomposed to a low concentration, and the heat exchanger of the prior art can be decomposed. It can be used to recover waste heat and reduce fuel by applying from 850 ° C to 400 ° C in the temperature range where dioxin regeneration is very small, and the evaporator of the prior art (cooling speed is faster than heat exchanger) ) Is applied to the dioxin regeneration temperature range of 400 ° C to 200 ° C, and the regeneration can be suppressed, and the temperature fluctuation of the combustor 9 can be made uniform, so that the dioxin reduction performance is high and the price is low. There is an effect that a suitable dioxin purification device can be provided.
  • This embodiment has a configuration in which a superheater 17 is installed downstream of the combustor 9 and upstream of the evaporator 14 in addition to the one shown in FIG.
  • the water 105 is supplied to the evaporator 14 by the pump 101, where it becomes steam 102 at around 300 ° C, and to the superheater 17 via the pipe 102 a.
  • Part of superheated steam 106 passes through piping 106a as superheated steam 106 or more at 400 ° C or more, and is supplied to pipeline 104 as a countermeasure against NOx, and the remaining steam 1 0 3 goes through piping 103 a to the steam utilization equipment or is discarded.
  • the The super-heater 17, air pre-heater 11 and heat exchanger 10 cover the temperature range of about 850 to 400 ° C, where there is little syn regeneration, and it is the dioxin regeneration temperature range Approximately 400 to 200 ° C. is covered with an evaporator 14.
  • the exhaust gas temperature at the evaporator 14 inlet can be adjusted, so that dioxin regeneration can be performed in response to fluctuations in combustion temperature. Deterrence can be prevented.
  • the dioxin in the exhaust gas can be decomposed to a low concentration, and the dioxin is regenerated by the heat exchanger.
  • the temperature range where there is only a slight temperature is about 850 to 400 ° C, waste heat can be recovered and fuel can be reduced, and the evaporator with a higher cooling rate than the heat exchanger is used as a dioxin regeneration temperature range. Is about 400
  • FIG. 5 shows a waste gas treatment system according to another embodiment of the present invention.
  • the same configuration and operation as those described above will not be described.
  • power is generated by using steam 103 as surplus steam from the heater 17 and steam 53 generated in the incinerator 1. Therefore, in this embodiment, the steam turbine 24 driven by the generated steam and the generator
  • the incinerator 1 is provided with an economizer 21, an evaporator 22 and superheaters 23 a and 23 b, and steam is generated by utilizing the heat of the incinerator 1.
  • the hot water 51 generated in the economizer 21 is supplied to the evaporator 22 via the pipe 51a, becomes steam, and becomes a superheater.
  • the steam is supplied to the steam turbine 24 through the pipe 5 2 a.
  • the steam that has completed its work in the steam turbine 24 is returned to water in the condenser 35.
  • the condensed water is supplied to the economizer 21 and the evaporator 14 by the feedwater pump 38 via the pipes 21a and 15a, respectively.
  • the water 15 supplied to the evaporator 14 is turned into steam in the evaporator 14, then superheated in the superheater 17 to become superheated steam 106, and a part of the combustor passes through the steam pipe 106 a.
  • the remaining part is supplied to the pipe 52a via the pipe 103a.
  • the water sent to the combustor 9 is lost from the system, so a pump 46 that supplies water is provided in the condensate line.
  • the dioxin reduction performance is the same as that of the system shown in Fig. 4 and will not be described here.
  • the dioxin in the exhaust gas can be decomposed to a low concentration, and the conventional method can be used. It can be used to recover waste heat and reduce fuel by applying dioxin regeneration from 850 ° C to 400 ° C in a temperature range where there is little dioxin regeneration in the heat exchanger of the technology, and the cooling rate is higher than that of the heat exchanger. Applying a fast evaporator to the dioxin regeneration temperature range from 400 ° C to 200 ° C to suppress regeneration and to cope with fluctuations, high dioxin reduction performance and inexpensive dioxin purification There is an effect that the device can be provided.
  • Industrial applicability INDUSTRIAL APPLICABILITY The waste gas treatment system and treatment method of the present invention are used in the field of reducing dioxin in exhaust gas generated by burning waste or waste in an incinerator.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Chimneys And Flues (AREA)
  • Incineration Of Waste (AREA)

Abstract

A refuse exhaust gas treating system and treating method that are capable of reducing the amount of dioxin in exhaust gas without having to use drain water treating equipment. The refuse exhaust gas treating system is characterized by comprising a combustor for burning the incineration gas from incineration of refuse, a heat exchanger disposed downstream of the combustor to effect indirect heat exchange between the incineration gas and combustion gas flowing down from the combustor so as to cool the combustion gas, and a cooler disposed downstream of the heat exchanger to further cool the combustion gas that has passed through the heat exchanger.

Description

明 細 書  Specification
ごみ排ガス処理システム及び処理方法 技術分野  Waste gas treatment system and treatment method
本発明は、 ごみ或いは廃棄物を焼却 して発生する排ガスを処理するご み排ガス処理システム及び処理方法に闋する。 背景技術  The present invention relates to a waste gas treatment system and a treatment method for treating waste gas generated by incinerating waste or waste. Background art
ごみ焼却炉から排出される焼却排ガス中に含有されるダイォキシン類 を分解するものと して、 これまで種々の装置が提案されている。 例えば. 従来装置と しては特開平 10— 2633 1 号公報に記載の技術があ り 、 この公 報では、 焼却炉の排ガスの一部をバーナーで加熱し高温熱源 （ 1 0 0 0 °C以上） と して熱交換器に送り 、 集塵器を経た排ガスを加熱してダイォ キシンを分解し、 分解後の排ガスを冷却装置で急冷する燃焼装置につい て開示されている。  Various devices have been proposed to decompose dioxins contained in incineration exhaust gas discharged from waste incinerators. For example, as a conventional apparatus, there is a technique described in Japanese Patent Application Laid-Open No. 10-26331. In this publication, a part of the exhaust gas of an incinerator is heated with a burner and a high-temperature heat source (100 ° C As described above, a combustion device is disclosed in which a waste gas sent to a heat exchanger and heated through a dust collector is heated to decompose dioxin, and the decomposed waste gas is rapidly cooled by a cooling device.
前述した特開平 10— 2633 1 号公報の記載の装置では、 冷却水が貯溜さ れた冷却水槽内で排ガスをパブリ ングさせる急冷装置を用いて排ガスを 冷却し、 ダイォキシン再生成の抑制を行っている。 しかし、 冷却する排 ガス温度は 7 0 0 °C以上の高温状態であ り 、 この排ガスを 3 0 0 °C以下 の低温状態まで急冷するには、 特に大規模な焼却設備にこの装置を適用 する際には大量の冷却水が必要となり 、 ま た、 急冷装置から排出する冷 却水を浄化させる排水処理装置を別に設置しなければならなかった。 本発明は、 上記した点について鑑みなされたものであって、 その目的 とすると ころは、 排水処理装置を伴う ことな く 排ガス中のダイォキシン を低減できる ごみ排ガス処理システムおよび及び処理方法を提供する こ とにある。 発明の開示 In the device described in JP-A-10-26331, the exhaust gas is cooled by using a quenching device that publishes the exhaust gas in a cooling water tank in which the cooling water is stored, thereby suppressing dioxin regeneration. I have. However, the temperature of the exhaust gas to be cooled is in a high temperature state of 700 ° C or higher, and in order to rapidly cool this exhaust gas to a low temperature state of 300 ° C or lower, this device is applied particularly to large-scale incineration equipment. This requires a large amount of cooling water, and a separate wastewater treatment device must be installed to purify the cooling water discharged from the quenching device. The present invention has been made in view of the above points, and has as its object to provide a waste gas treatment system and a treatment method capable of reducing dioxin in exhaust gas without using a wastewater treatment device. And there. Disclosure of the invention
上記目的を達成するために、 本発明は以下のごみ排ガス処理システム を提供する。  In order to achieve the above object, the present invention provides the following waste gas treatment system.
すなわち、 本発明のごみ排ガス処理システムは、 ごみを焼却した焼却 ガスを燃焼させる燃焼器と、 前記燃焼器で燃焼された燃焼ガスと前記焼 却ガスと を間接的に熱交換させて該燃焼ガスを冷却する熱交換器と、 前 記熱交換器からの燃焼ガスをさ らに冷却させる冷却器とを備えたもので ある。  That is, the refuse exhaust gas treatment system of the present invention comprises a combustor for burning incineration gas obtained by incinerating refuse, and indirectly exchanging heat between the combustion gas burned in the combustor and the incineration gas. And a cooler for further cooling the combustion gas from the heat exchanger.
ま た、 上記目的を達成するために、 本発明は以下のごみ排ガス処理方 法を提供する。  In order to achieve the above object, the present invention provides the following waste gas treatment method.
本発明の排ガス処理システムは、 ごみを焼却した焼却ガスを燃焼器で 燃焼させて焼却ガス中に含まれるダイォキシンを分解し、 前記燃焼器か ら排出される燃焼ガスを熱交換器に導き、 前記燃焼器に供給される焼却 ガスと間接的に熱交換を行い前記燃焼ガスを冷却 し、 前記熱交換器で冷 却された燃焼ガスを冷却器にて間接熱交換を行って、 前記排ガスをさ ら に冷却するものである。  The exhaust gas treatment system of the present invention is characterized in that incineration gas obtained by incinerating refuse is burned in a combustor to decompose dioxin contained in the incineration gas, and the combustion gas discharged from the combustor is led to a heat exchanger. The combustion gas is cooled by indirectly exchanging heat with the incineration gas supplied to the combustor, and the combustion gas cooled by the heat exchanger is indirectly heat-exchanged by a cooler to remove the exhaust gas. Further cooling.
以上のよう に本発明によれば、 ごみ焼却ガス中に含まれるダイォキシ ンを分解すると共に、 ダイォキシンの再生成を抑制する ことが可能とな る。 ま た、 燃焼器で燃焼して発生する燃焼ガスは、 間接的な熱交換によ つて冷却されるので、 排水処理装置を伴う ことなく ダイォキシンの低減 を図る ことができる。 図面の簡単な説明 第 1 図は、 本発明の一実施例である ごみ排ガス処理システムを示す。 第 2図は、 本発明の他の実施例である ごみ排ガス処理システムを示す c 第 3図は、 本発明の他の実施例である ごみ排ガス処理システムを示す < 第 4図は、 本発明の他の実施例である ごみ排ガス処理システムを示す t 第 5図は、 本発明の他の実施例である ごみ排ガス処理システムを示す t 第 6図は、 本実施例によるダイォキシン再生成量の実験結果を示す。 第 7図は、 煤塵濃度とダイォキシン濃度の関係図である。 As described above, according to the present invention, it is possible to decompose dioxin contained in refuse incineration gas and to suppress regeneration of dioxin. In addition, since the combustion gas generated by combustion in the combustor is cooled by indirect heat exchange, dioxin can be reduced without a wastewater treatment device. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a waste gas treatment system according to one embodiment of the present invention. FIG. 2, c 3 illustrates a waste gas treatment system according to another embodiment of the present invention, <4 shows a waste gas treatment system according to another embodiment of the present invention, the present invention t 5 shows a waste gas treatment system which is another embodiment, t 6 illustrates a waste gas treatment system according to another embodiment of the present invention, experimental results of dioxin regeneration amount according to this embodiment Is shown. FIG. 7 is a graph showing the relationship between the dust concentration and the dioxin concentration.
第 8図は、 ごみ焼却炉におけるダイォキシンの排出規制値。  Fig. 8 shows the emission control values of dioxin in waste incinerators.
第 9図は、 代表的なごみ焼却施設における排ガス流量およびダイォキ シン濃度の平均値を示した図である。  Figure 9 shows the average values of the exhaust gas flow rate and dioxin concentration in a typical waste incineration plant.
第 1 0図は、 集塵機の定格性能値を示した図である。  FIG. 10 is a diagram showing rated performance values of the dust collector.
第 1 1 図は、 排ガス燃焼温度と滞留時間の関係図である。 発明を実施するための最良の形態  FIG. 11 is a diagram showing the relationship between exhaust gas combustion temperature and residence time. BEST MODE FOR CARRYING OUT THE INVENTION
以下、 本発明の実施例について図面を用いて説明する。 第 1 図は、 本 発明の一実施例である ごみ排ガス処理システムの系統図を示す。 なお、 本実施例におけるごみ排ガス処理システムの規模と しては、 ごみ処理量 4 t Z h以上の焼却炉、 例と して、 排ガス量 7 8 0 0 0 kgZ h， ごみ焼 却規模 1 0 t Z h， ダイォキシン排出濃度 1 5 n g— T E QZm3 N の 規模の焼却炉を想定したものである。 ちなみに、 焼却規模 4 t / h以上 の炉におけるダイォキシンの排出規制値は、 既設炉においては 1 n g— T E Q/m3 N、 新設炉では O. l n g— T E QZm3 N と定められてい る。 なお、 前述したダイォキシン排出濃度の単位と して用いている 〔ng - T E Q / m3 N 〕 の n gは、 1 0—9 g、 T E Qは、 Toxicity Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a system diagram of a waste gas treatment system according to one embodiment of the present invention. The scale of the waste gas treatment system in this example is an incinerator with a waste treatment amount of 4 tZh or more. For example, the waste gas amount is 7800 kgZh, and the waste incineration scale is 100%. t Z h, dioxin emission concentration 15 ng—This is assumed to be an incinerator with a scale of TE QZm 3 N. Incidentally, the discharge limits for dioxins in incineration scale 4 t / h or more furnace, in existing furnace 1 ng- TEQ / m 3 N, in the new furnace that has been defined as O. lng- TE QZm 3 N. Note that used as the unit of dioxin emission concentration described above - ng of [ng TEQ / m 3 N] is, 1 0- 9 g, TEQ is, Toxicity
Equivalency Quantity (毒性等価量） の略で、 ダイォキシン類中最毒の 2， 3， 7 , 8テ トラク ロ 口ディべンゾディ ォキシンに毒性換算したと きの量の意味で、 m 3 N は標準状態における排ガス体積を表す。 Abbreviation for Equivalency Quantity, the most toxic of dioxins 2,3,7,8 Tetraclonal dibenzodioxin means the amount when converted to toxicity, and m 3 N indicates the exhaust gas volume under standard conditions.
ダイォキシンは、 ごみ或いは廃棄物の焼却によって、 特に塩素分を含 む有機物 （プラスチック類） の不完全燃焼によ り発生する。 不完全燃焼 によ り生じた未燃炭化水素 （すす、 純粋な炭素は少なく ベンゼン環が一 部存在する） が複数集合する ことで、 ベンゼン環の集合体である多環炭 化水素が形成される。 これが煤塵の触媒作用によ リ塩酸と反応してダイ ォキシン前駆体ができ、 この前駆体同士が結びついてダイォキシンが生 成するといわれる。  Dioxins are generated by incineration of refuse or waste, especially by incomplete combustion of organic substances (plastics) containing chlorine. The aggregation of multiple unburned hydrocarbons (soot, pure carbon, and part of the benzene ring) generated by incomplete combustion forms polycyclic hydrocarbons, which are aggregates of benzene rings. You. This is reacted with hydrochloric acid by the catalytic action of dust to form a dioxin precursor, which is said to combine with each other to produce dioxin.
なお、 本特許中の煤塵濃度は、 J I Sで定められた方法によ り測定し た濃度、 及びダイォキシン濃度は、 国で定めた方法によ り測定した濃度 を指す。 なお、 滞留時間 （燃焼熱分解及び熱交換器冷却での） は、 標準 状態でのガス体積流量， 流路の断面積とガス温度から求めた、 次式の流 速で時間を算出して求めている。  In this patent, the dust concentration refers to the concentration measured by the method specified by JIS, and the dioxin concentration refers to the concentration measured by the method specified in the country. The residence time (for combustion pyrolysis and cooling of the heat exchanger) was calculated from the gas volume flow rate, the cross-sectional area of the flow path, and the gas temperature under the standard conditions, and the time was calculated using the following flow rate. ing.
流速 =流量（m 3 N Z h )ノ流路断面積（m 2 ) 2 7 3 . 1 5 x (温度 + 2 7 3 . 1 5 ) Flow rate = Flow rate (m 3 NZ h) Flow area (m 2 ) 2 7 3 .15 x (Temperature + 27 3 .15)
第 1 図に示すごみ排ガス処理システムは、 ごみを燃焼処理する焼却炉 1 と、 ごみの燃焼によ り発生する燃焼排ガス 2 と熱交換を行い排ガス 2 を減温する集塵機用冷却器 1 3 と、 減温された排ガス 2 中の煤塵を捕集 する集塵機 3 と、 集塵機 3 で煤塵が捕集された排ガス 3 0 に空気 7 を混 合させて空気混入排ガス 2 8 を形成する混合器 5 と を備えている。 ま た 本実施例のごみ排ガス処理システムは、 空気混入排ガス 2 5 と燃焼用空 気 2 0 を酸化剤と して燃料 8 を燃焼させる燃焼器 9 と、 燃焼器 9で燃焼 された排ガス 2 6 と空気混入排ガス 2 8 とを熱交換させる熱交換器 1 0 と、 熱交換器 1 0 で冷却された排ガス 2 7 を冷却する蒸発器 1 4 とを備 えている。 The waste gas treatment system shown in Fig. 1 consists of an incinerator 1 that burns waste, and a dust collector cooler 13 3 that exchanges heat with flue gas 2 generated by burning waste to reduce the temperature of flue gas 2. A dust collector 3 that collects dust in the cooled exhaust gas 2, and a mixer 5 that mixes air 7 with the exhaust gas 30 from which dust is collected by the dust collector 3 to form an aerated exhaust gas 28. It has. The waste gas treatment system according to the present embodiment includes a combustor 9 that burns fuel 8 using the aerated exhaust gas 25 and the combustion air 20 as an oxidant, and an exhaust gas 26 that is combusted by the combustor 9. A heat exchanger 10 for exchanging heat with the aerated exhaust gas 28 and an evaporator 14 for cooling the exhaust gas 27 cooled by the heat exchanger 10 are provided. I have.
なお、 送風機 4は集塵機 3 で集塵された排ガス 3 0 を混合器 5へ供給 するために設置している。 ま た、 送風機 6 は排ガス 3 0 と混合する空気 7 を混合器 5 に供給するのと同時に、 燃焼器 9 に燃焼用空気 2 0 と して 夫々供給している。 また、 蒸発器 1 4 には間接冷却媒体と して水 1 0 5 がポンプ 1 0 1 によって供給される。  The blower 4 is provided to supply the exhaust gas 30 collected by the dust collector 3 to the mixer 5. The blower 6 supplies the air 7 mixed with the exhaust gas 30 to the mixer 5 and at the same time supplies the air 7 to the combustor 9 as combustion air 20. Further, water 105 is supplied to the evaporator 14 as an indirect cooling medium by a pump 101.
第 8 図は、 平成 9年 1 2月から施行されたごみ焼却炉におけるダイォ キシンの排出規制値を示したものである。 第 8 図に示す通り 、 焼却炉の 焼却規模及び、 その焼却炉が既設炉或いは新設炉かによつてダイォキシ ン排出規制の条件が異なっている。 また既設炉においては、 施行日 （平 成 9年 1 2 月 1 日） から 5年以内に上記規制値を達成する ことが義務付 けられている。 なお、 第 9 図は代表的なごみ焼却施設における排ガス流 量およびダイォキシン濃度を平均化し、 国の規制値に対比させて焼却炉 の焼却規模別に表したものである。  Fig. 8 shows the emission control values of dioxin in waste incinerators that came into effect in February 1997. As shown in Fig. 8, dioxin emission control conditions differ depending on the incinerator scale and whether the incinerator is an existing furnace or a new one. For existing furnaces, it is obliged to achieve the above regulation values within five years from the enforcement date (February 1, 1997). Fig. 9 shows the average of the exhaust gas flow rate and dioxin concentration in typical waste incineration facilities, and shows them by incinerator incineration scale in comparison with the national regulation values.
また、 燃焼排ガス 2 中の煤塵を除去する集塵機 3 の定格性能と しては それぞれ第 1 0 図に示す通り である。 実際に使用する集塵機 3 の性能と しては、 通常 1 0 μ ιη以上の粒径の煤塵を捕集できるものでよいが、 好 ま し く は 1 μ πχ以上の粒径の煤塵を完全に捕集するものが望ま しい。 以上のよう に構成されたごみ排ガス処理システムは、 まず焼却炉 1 内 でごみが焼却される ことで、 ダイォキシンを含む焼却ガスである、 約 8 5 0 °C以上の高温の燃焼排ガス 2 が生成される。 燃焼排ガス 2 は配管 2 a を介して減温器 1 3 に導かれ、 こ こで約 1 5 0 ~ 2 3 0 °C、 あるい はその近傍の温度に冷却される。 なお、 燃焼排ガス 2 を冷却する手段と しては、 集塵機 3 の上流側、 或いは焼却炉 1 内で水噴霧を行う ことによ つて冷却する ことも可能である。 第 7図は、 実施設備からの排出ガスを用いた実証試験結果を示したも のである。 縦軸が再燃焼排ガスの冷却に減温器を用いた場合の出口ダイ ォキシン濃度、 横軸が煤塵濃度を示す。 Also, the rated performance of the dust collector 3 for removing dust in the combustion exhaust gas 2 is as shown in FIG. 10 respectively. The performance of the dust collector 3 to be actually used may be a device capable of collecting dust having a particle size of 10 μιη or more, but preferably a device capable of completely collecting dust having a particle size of 1 μππ or more. What is collected is desirable. In the waste gas treatment system configured as described above, first, waste is incinerated in the incinerator 1 to generate high-temperature combustion exhaust gas 2 of about 850 ° C or more, which is incineration gas containing dioxin. Is done. The flue gas 2 is led to a desuperheater 13 via a pipe 2a, where it is cooled to a temperature of about 150 to 230 ° C or near. As means for cooling the flue gas 2, it is also possible to cool it by spraying water upstream of the dust collector 3 or in the incinerator 1. Figure 7 shows the results of a verification test using the exhaust gas from the facility. The vertical axis shows the dioxin concentration at the outlet when a cooler is used to cool the reburn exhaust gas, and the horizontal axis shows the dust concentration.
減温器前のダイォキシン濃度に比べ、 約 1 0 0倍増加している。 この 中で、 煤塵濃度が 0. 1 gZm3 N以上でダイォキシン濃度が高原状にな つている原因は、 ダイォキシン再生反応を媒介する煤塵表面積が反応に 対し必要以上に存在し飽和するためである。 このため、 煤塵濃度 0. 1 g / m3 N 以下とすることによ り始めて、 ダイォキシンを 0. 2 5 n g - T E Q /m3 N 以下に低減可能となる。 この値は、 極低濃度でのダイ ォキシンの測定精度 5 0から 2 0 0 %を考えると、 0. 1 n g - T E Q /m3 と見なされる上限であるため、 これによ リ本発明の対象の排ガ スの煤塵濃度を 0. 1 g Zm3 N 以下と した。 The concentration of dioxin is about 100 times higher than that before the cooler. Among these, the reason why the concentration of dioxin is plateau when the concentration of dust is 0.1 gZm 3 N or more is that the surface area of dust that mediates the dioxin regeneration reaction is more than necessary for the reaction and saturates. For this reason, dioxin can be reduced to 0.25 ng-TEQ / m 3 N or less only when the dust concentration is 0.1 g / m 3 N or less. This value, given the 2 0 0 percent measurement accuracy 5 0 die Okishin at very low concentrations, 0. 1 ng - since it is the upper limit to be considered a TEQ / m 3, the subject of the I Li present invention thereto The dust concentration of the exhaust gas was set to 0.1 g Zm 3 N or less.
なお、 現状の既設の廃棄物焼却施設に多く用いられている電気集塵機 の場合、 排ガス温度が高ければ高いほど煤塵の電気抵抗が下がる ことが わかっている。 このため、 ほぼ同じ集塵性能でコ ロナ電流とコ ロナ電圧 の積である電力を低下させるために、 高温化によるガス体積膨張のデメ リ ッ トのない約 3 0 0 °C以下で使用する ことが望ま しい。 ま た、 減温器 1 3 にて集塵機 3の入口における排ガス温度を約 1 5 0 ~ 2 3 0 °C付近 まで冷却すると しているのは、 この温度以下であれば完全にダイォキシ ンの再生成温度域を外れているため、 ダイォキシンの再生成を抑制でき るためである。 そこで本実施例では、 電気集塵機にて効率良く 集塵が行 えるよ う に、 減温器 1 3 にて集塵機 3の入口における排ガス温度を約 1 5 0 ~ 2 3 0 °C付近となるよ う に している。 こ こでの目的はあ く まで も集塵にあるため、 ダイォキシン再生成の抑制は後述する別の工程で行 Ό 。 このよ う に して、 約 1 5 0 - 2 3 0 °C付近の温度まで冷却された燃焼 排ガス 2は、 配管 2 b を介して集塵機 3 に供給され、 こ こで燃焼排ガス 2の飛灰（煤塵） 濃度が 0. 1 g Z m 3 N以下の状態、 例えば 0. 0 0 1 ~ 0. 1 gZm3 Nになるよ う に煤塵が捕集される。 集塵機 3 を通過した排 ガス 3 0は、 配管 3 aを介して送風機 4に導かれ、 さ らに配管 3 0 aを 経由 して混合器 5に供給される。 こ こで、 送風機 4によって混合器 5に 供給される排ガス 3 0の温度は約 2 0 0 °C程度、 若し く はそれ以下の温 度となっている。 また、 集塵機 3 を通過した排ガス 3 0中のダイォキシ ン濃度は 1 5 n g— T E Q/m3N となる。 こ こでの煤塵濃度が低けれ ば低いほど、 後のダイォキシン再生成が発生する冷却過程での余裕がで き、 冷却時間を大き く 取る ことができる。 In the case of an electric dust collector, which is widely used in existing waste incineration facilities, it is known that the higher the exhaust gas temperature, the lower the electrical resistance of the dust. For this reason, in order to reduce the electric power, which is the product of the corona current and the corona voltage, with almost the same dust collection performance, use it at about 300 ° C or less, where there is no disadvantage of gas volume expansion due to high temperature It is desirable. The reason that the exhaust gas temperature at the inlet of the dust collector 3 is cooled to about 150 to 230 ° C by the desuperheater 13 is that if the temperature is lower than this temperature, dioxin is completely regenerated. The reason for this is that the regeneration of dioxin can be suppressed because the temperature is outside the growth temperature range. Therefore, in this embodiment, the temperature of the exhaust gas at the inlet of the dust collector 3 is reduced to about 150 to 230 ° C. by the desuperheater 13 so that the dust can be efficiently collected by the electric dust collector. I'm doing it. Since the purpose here is solely for dust collection, suppression of dioxin regeneration is performed in a separate step described later. In this way, the combustion exhaust gas 2 cooled to a temperature of about 150 to 230 ° C. is supplied to the dust collector 3 through the pipe 2 b, where the fly ash of the combustion exhaust gas 2 is ashed. (dust) concentration 0. 1 g Z m 3 N following conditions, dust is collected in earthenware pots by comprising, for example, 0. 0 0 1 ~ 0. 1 gZm 3 N. The exhaust gas 30 that has passed through the dust collector 3 is guided to the blower 4 via the pipe 3a, and further supplied to the mixer 5 via the pipe 30a. Here, the temperature of the exhaust gas 30 supplied to the mixer 5 by the blower 4 is about 200 ° C. or lower. The dioxin concentration in the exhaust gas 30 passing through the dust collector 3 is 15 ng—TEQ / m 3 N. The lower the dust concentration here, the more room is allowed in the cooling process in which later dioxin regeneration occurs, and the longer the cooling time can be.
混合器 5には、 送風機 4によつて配管 3 0 aを経由 して排ガス 3 0が 供給される。 一方で、 配管 7 aから供給される空気 7の一部は、 送風機 6によつて配管 5 aを介して混合器 5 に供給される。 混合器 5では、 供 給された排ガス 3 0と空気 7 を混合させて、 空気混入排ガス 2 8が形成 される。 なお、 混合器 5では排ガス 3 0と空気 7の一部を混合させて、 排ガス 3 0を空気で希釈する ことによって酸素濃度或いは煤塵濃度 （飛 灰濃度） を調整している。 なお、 空気 7 と混合された空気混入排ガス 2 8中のダイォキシン濃度は 1 5 n g— T E Q/m3 N のま まである。 混合器 5 を出た空気混入排ガス 2 8は、 配管 2 8 aを経由 して熱交換 器 1 0へ供給される。 熱交換器 1 0では、 後述する燃焼器 9から導かれ る高温の排ガス 2 6と熱交換が行われ、 空気混入排ガス 2 8 を約 6 0 0 °C程度の温度に昇温させると共に、 燃焼器 9からの排ガス 2 6 を減温し ている。 熱交換器 1 0で加熱された空気混入排ガス 2 5は、 配管 2 5を 介して燃焼器 9へ供給される。 燃焼器 9 には、 熱交換器 1 0で加熱された空気混入排ガス 2 5が供給 される。 ま た一方で、 燃焼器 9 には燃料 8 (都市ガス， 灯油， 重油等） ま たは改質化燃料が配管 8 a によ り 、 また燃料 8 の燃焼用空気と して、 空気 7 の一部である燃焼用空気 2 0が配管 2 0 a を経由 して供給される。 さ らに、 燃焼器 9 には、 後述する蒸発器 1 4で発生する蒸気 1 0 2 の一 部が、 配管 1 0 2 a を経由 して配管 1 0 4 a によって、 燃焼器 9での N O x低減用に蒸気 1 0 4 と して供給される。 燃焼器 9 では、 燃焼器 9 に供給される燃料 8及び燃焼用空気 2 0 を、 蒸気 1 0 4 を注入しながら 燃焼させ、 約 6 0 0 °C前後の空気混入排ガス 2 5 をダイォキシンが分解 する温度である約 7 5 0 °C以上、 望ま し く は約 8 5 0 °C以上の温度まで 加熱している。 こ こで、 燃焼用空気 2 0及び空気混入排ガス 2 5 は燃焼 器 9 に入る温度が高いほど投入する燃料 8が節約できるので、 これらは 高温である ことが望ま しい。 なお、 蒸発器 1 4から導かれる蒸気 1 0 2 の残り は配管 1 0 3 a を経由 して、 他の蒸気利用機器へ供給される。 燃焼器 9 で高温に加熱された排ガス 2 6 は、 燃焼器 9下流に設置され た配管 2 6 a を介して熱交換器 1 0 に導かれる。 こ こで、 燃焼器 9及び 燃焼器 9 の下流側に設けられた配管 2 6 a を含む領域では、 燃焼器 9 で 加熱された排ガス 2 6 を高温状態に維持しながら、 排ガス 2 6 をこの高 温領域に約 1 秒以上、 望ま し く は約 1 . 6 秒以上滞留させ、 高温状態に 曝すよ う に している。 このよ う に、 排ガス 2 6 を高温領域に約 1 秒以上、 望ま し く は約 1 . 6 秒以上曝すことで、 排ガス 2 6 中のダイォキシンは 熱分解される。 こ こで、 排ガス 2 6 を約 7 5 0 °C以上、 望ま し く は約 8 5 0 °C 以上の高温領域に曝す時間を約 1 秒以上、 望ま し く は約 1 . 6 秒以上と しているのは， 第 1 1 図に示した実証実験結果からである。 The exhaust gas 30 is supplied to the mixer 5 by the blower 4 via the pipe 30a. On the other hand, a part of the air 7 supplied from the pipe 7 a is supplied to the mixer 5 by the blower 6 via the pipe 5 a. In the mixer 5, the supplied exhaust gas 30 and the air 7 are mixed to form an aerated exhaust gas 28. In the mixer 5, the exhaust gas 30 and a part of the air 7 are mixed, and the exhaust gas 30 is diluted with air to adjust the oxygen concentration or the dust concentration (fly ash concentration). The concentration of dioxin in the aerated exhaust gas 28 mixed with air 7 remains at 15 ng-TEQ / m 3 N. The aerated exhaust gas 28 coming out of the mixer 5 is supplied to the heat exchanger 10 via a pipe 28a. In the heat exchanger 10, heat exchange is performed with a high-temperature exhaust gas 26 guided from a combustor 9 described later, and the temperature of the aerated exhaust gas 28 is raised to a temperature of about 600 ° C. Exhaust gas 26 from vessel 9 is being cooled. The aerated exhaust gas 25 heated in the heat exchanger 10 is supplied to the combustor 9 via the pipe 25. The combustor 9 is supplied with the aerated exhaust gas 25 heated by the heat exchanger 10. On the other hand, fuel 8 (city gas, kerosene, heavy oil, etc.) or reformed fuel is supplied to the combustor 9 through the pipe 8a, and air 7 is used as combustion air for the fuel 8. A part of the combustion air 20 is supplied via a pipe 20a. Further, in the combustor 9, a part of the steam 102 generated in the evaporator 14, which will be described later, is passed through the pipe 102 a via the pipe 104 a, and the NO. Supplied as steam 104 for x reduction. In the combustor 9, the fuel 8 and the combustion air 20 supplied to the combustor 9 are burned while injecting steam 104, and the dioxin is decomposed into the aerated exhaust gas 25 at about 600 ° C. The heating is performed to a temperature of about 750 ° C or more, preferably about 850 ° C or more. Here, the higher the temperature of the combustion air 20 and the air-mixed exhaust gas 25 entering the combustor 9, the more the fuel 8 to be charged can be saved, and therefore it is desirable that these are high in temperature. The rest of the steam 102 guided from the evaporator 14 is supplied to other steam utilization equipment via the pipe 103a. The exhaust gas 26 heated to a high temperature in the combustor 9 is guided to the heat exchanger 10 via a pipe 26 a provided downstream of the combustor 9. Here, in the region including the combustor 9 and the pipe 26 a provided downstream of the combustor 9, the exhaust gas 26 heated in the combustor 9 is maintained at a high temperature while the exhaust gas 26 is separated from the exhaust gas 26. It stays in the high temperature area for about 1 second or more, preferably about 1.6 seconds or more, so that it is exposed to high temperature. As described above, the dioxin in the exhaust gas 26 is thermally decomposed by exposing the exhaust gas 26 to the high-temperature region for about 1 second or more, desirably about 1.6 seconds or more. Here, the time for exposing the exhaust gas 26 to a high temperature region of about 75 ° C. or more, preferably about 850 ° C. or more, is about 1 second or more, and preferably about 1.6 seconds or more. This is based on the results of the verification experiment shown in Fig. 11.
ま た、 ダイォキシンの分解温度と滞留時間は、 米国の Env i ro miien ta l Protection Agency が発行した技術文献であるダイォキシンの熱分解特 '|¾ ίこつレヽての文献、 D. S. Duval and W. A. Rubey著、 Laboratory The decomposition temperature and residence time of dioxin are determined by Enviro miien ta l in the United States. The technical literature published by the Protection Agency, which is the pyrolysis of dioxin. '| 文献 ί Ru 文献, DS Duval and WA Rubey, Laboratory
Evaluation of Hi gh— Tem erature Destruction of Pol ychl or inate Biphenyls and Related Compounds (多塩ィ匕ビフ ェニーノレおよびその関連 化合物の高温分解の実験室評価） ， E P A— 6 0 0 Z 2— 7 7 — 2 8 8 , page 1 8 - 1 ( 1 9 7 7 ) に記載された内容に基づいて分かり 易く 表 示すると、 ダイォキシン濃度が 0. 1 ( 11 ー丁 £ (3 1^3 1 ) 以下の状 態まで低減させるのに必要な分解温度と滞留時間は、 次に示す第 1 1 図 のよう に纏め られる。 同時に発明者等が行った実証試験結果も第 1 1図 の右欄に併記する。 これが、 ダイォキシン分解に関する条件の根拠であ る。 Evaluation of High—Tem erature Destruction of Polichl or inate Biphenyls and Related Compounds (Laboratory evaluation of high-temperature decomposition of polychlorinated biphenylenole and its related compounds), EPA—600Z2—77—28 8, page 1 8-1 (1 9 7 7) When displayed in an easy-to-understand manner based on the contents described in (1), the dioxin concentration is reduced to 0.1 (11-£ £ (3 1 ^ 3 1) or less. The decomposition temperature and residence time required to reduce the temperature are summarized as shown in Fig. 11. At the same time, the results of the verification tests conducted by the inventors are also shown in the right column of Fig. 11. This is the basis for the conditions for dioxin degradation.
こ こで、 高温領域に排ガス 2 6 を滞留させる時間は長ければ長いほど ダイォキシンの分解は極限まで進むので、 滞留させる時間はよ リ長い方 がダイォキシン熱分解の面からは有利である。  Here, the longer the residence time of the exhaust gas 26 in the high-temperature region, the more the decomposition of dioxin progresses to the limit. Therefore, the longer the residence time, the more advantageous in terms of dioxin thermal decomposition.
この際、 燃焼器 9及び配管 2 6 aを含む高温領域部を含め、 燃焼器 9 の下流側に配置された配管の内壁には、 ダイォキシンの再生成に寄与し ない材質、 例えばステンレス鋼や S i Cセラ ミ ックスを使用することで 高い分解率を確保する ことができる。 さ らに、 高温領域部に邪魔板、 例 えば配管 2 6 a内部に堰を設ける ことで、 排ガス 2 6が高温領域部に滞 留する時間を延長させる ことができる。 ま た、 配管 2 6 aの表面或いは 内部に乱流促進部、 例えば配管 2 6 aの表面に凹凸部を設け、 さ らに配 管 2 6 aを曲管や拡大縮小管にする ことで排ガス 2 6 を高温状態に均一 化させて、 ダイォキシン分解率の向上を図る ことができる。  At this time, the inner wall of the piping arranged downstream of the combustor 9, including the high-temperature region including the combustor 9 and the piping 26a, is made of a material that does not contribute to the regeneration of dioxin, such as stainless steel or S By using i C ceramics, a high decomposition rate can be secured. Further, by providing a baffle plate in the high temperature region, for example, a weir inside the pipe 26a, the time during which the exhaust gas 26 stays in the high temperature region can be extended. Also, by providing a turbulence promoting part on the surface or inside of the pipe 26a, for example, an uneven part on the surface of the pipe 26a, and by making the pipe 26a a curved pipe or a scaled pipe, exhaust gas 26 can be homogenized at a high temperature to improve the dioxin decomposition rate.
以上述べたよ う に、 焼却炉 1 で発生した燃焼排ガス 2 を集塵機 3で脱 塵し、 混合器 5で空気と混合させ、 燃焼器 9で加熱して高温状態にする ことで、 排ガス 2 6 中のダイォキシンを 9 9 . 9 %以上分解する ことが 可能となる。 ま た、 このときのダイォキシン濃度は 0 . 0 l n g— T E Q Z m 3 N レベル以下に低減される。 勿論、 排ガス 3 0中の煤塵濃度は低 ければ低いほど、 よ リ ダィォキシン濃度を低減させることが可能となる , しかしながら、 低濃度にダイ ォキシンが分解された排ガス 2 6 は高温 状態であるため、 冷却せずに煙突から放出する ことはできない。 これは. 集塵機 3 で集塵された後の排ガス 3 0 には低濃度ではあるが煤塵（飛灰） は残っており 、 これが排ガス 2 6 を冷却する際にダイォキシン再生成触 媒の働きをするからである。 ダイォキシン再生成に関しては、 約 2 0 0 ~ 4 0 0 °Cの温度範囲がその再生成領域であ り 、 特に約 3 3 0〜 3 8 0 °Cの温度範囲がさ らに顕著な再生成頜域となっている。 また、 ダイォキ シン再生成については、 主と して排ガス中の煤塵濃度及び、 排ガスの冷 却速度によ リ規定される。 As described above, the flue gas 2 generated in the incinerator 1 is dedusted in the dust collector 3, mixed with air in the mixer 5, and heated to a high temperature in the combustor 9. This makes it possible to decompose dioxin in the exhaust gas 26 by 99.9% or more. In addition, the dioxin concentration at this time is reduced to 0.0 lng—TEQZ m 3 N level or less. Of course, the lower the concentration of dust in the exhaust gas 30, the lower the concentration of redoxin can be reduced.However, since the exhaust gas 26 in which dioxin has been decomposed to a low concentration is in a high temperature state, It cannot be released from the chimney without cooling. This is because dust (fly ash) remains in the exhaust gas 30 after being collected by the dust collector 3 although it has a low concentration, and this acts as a dioxin regeneration catalyst when cooling the exhaust gas 26. Because. Regarding the regeneration of dioxin, the temperature range of about 200 to 400 ° C is the regeneration range, and especially the temperature range of about 330 to 380 ° C is more remarkable.頜 area. Regeneration of dioxin is mainly defined by the concentration of dust in the exhaust gas and the cooling rate of the exhaust gas.
以下、 排ガスの冷却設備について説明する。 本実施例では、 まず燃焼 器 9 で高温に加熱されダイォキシンが分解された後の排ガス 2 6 を、 煙 道 2 6 aを介して熱交換器 1 0 に供給している。 熱交換器 1 0 に導かれ た高温状態の排ガス 2 6 は、 こ こで混合器 5 から供給される第 1 の冷却 媒体である低温の空気混入排ガス 2 8 と熱交換が行われ、 再生成がほと んど起きない 4 0 0 °C付近まで冷却される。 このよ う に熱交換器 1 0 内 では再生成がほとんど発生せず、 従って排ガス 2 6 の滞留時間に拘束さ れないため、 この熱交換器 1 0 については、 最新の熱交換技術が適用で きる。  Hereinafter, the exhaust gas cooling equipment will be described. In this embodiment, first, the exhaust gas 26 after being heated to a high temperature in the combustor 9 to decompose dioxin is supplied to the heat exchanger 10 via the flue 26a. The high-temperature exhaust gas 26 guided to the heat exchanger 10 undergoes heat exchange with the low-temperature aerated exhaust gas 28 that is the first cooling medium supplied from the mixer 5 and is regenerated. Is cooled to around 400 ° C, where almost no occurrence occurs. As described above, almost no regeneration occurs in the heat exchanger 10, and therefore, the heat exchanger 10 is not restricted by the residence time of the exhaust gas 26. Therefore, the latest heat exchange technology can be applied to the heat exchanger 10. Wear.
熱交換器 1 0で 4 0 0 °C程度まで冷却された排ガス 2 7 は、 熱交換器 1 0の下流に設置された配管 2 7 a を介して蒸発器 1 4 に供給される。 ま た、 別に設置された系統から供給される水 1 0 5 はポンプ 1 0 1 によ つて昇圧され、 ポンプ 1 0 1 を経た水 1 5 は配管 1 5 a を介して蒸発器 1 4 に供給される。 蒸発器 1 4では、 熱交換器 1 0から導かれた排ガス 2 7 は、 第 2 の冷却媒体である水 1 5 と熱交換が行われ、 排ガス 2 7 の 温度をダイォキシンの再生成温度領域である 2 0 0 °C以下まで冷却して いる。 The exhaust gas 27 cooled to about 400 ° C. in the heat exchanger 10 is supplied to the evaporator 14 via a pipe 27 a provided downstream of the heat exchanger 10. Water 105 supplied from a separately installed system is supplied by pump 101. Then, the pressure of the water is increased and the water 15 passed through the pump 101 is supplied to the evaporator 14 via the pipe 15a. In the evaporator 14, the exhaust gas 27 guided from the heat exchanger 10 undergoes heat exchange with water 15 as the second cooling medium, and the temperature of the exhaust gas 27 is maintained in the dioxin regeneration temperature region. It has been cooled to a certain temperature of 200 ° C or less.
こ こで、 蒸発器 1 4では熱交換器 1 0から導かれる排ガス 2 7 を 400 °Cから 2 0 0 °C以下まで約 5秒以内で冷却する ことで、 蒸発器 1 4出口 部から排出される排ガス中のダイォキシン濃度を 0 . 1 n g — T E Q Z m 3 N レペル以下まで低減している。 なお、 排ガス 2 7 の冷却時間は、 望ま し く は約 3 . 5秒以内で、 さ らに望ま し く は 3 8 0 °Cから 3 3 0 °C まで 1 秒以内で冷却する ことで、 ダイォキシンの再生成をよ リ抑制する ことができる。 蒸発器 1 4で 2 0 0 °C以下まで冷却された排ガスは、 図 示しない煙突から放出される。 Here, the evaporator 14 cools the exhaust gas 27 guided from the heat exchanger 10 from 400 ° C to 200 ° C or less within about 5 seconds, and discharges it from the evaporator 14 outlet. The dioxin concentration in the exhaust gas is reduced to less than 0.1 ng—TEQZ m 3 N level. The cooling time of the exhaust gas 27 is desirably within about 3.5 seconds, and more desirably, from 38 ° C to 33 ° C within 1 second. Dioxin regeneration can be further suppressed. The exhaust gas cooled to 200 ° C. or less in the evaporator 14 is discharged from a chimney (not shown).
なお、 蒸発器 1 4では、 ポンプ 1 0 1 によって供給される水 1 5 が排 ガス 2 7 と熱交換される ことによって蒸気 1 0 2 が発生する。 蒸発器 i 4で発生した蒸気 1 0 2 は、 配管 1 0 2 a を介して燃焼器 9 、 あるい は他の蒸気利用機器に供給される。  In the evaporator 14, the water 15 supplied by the pump 101 is heat-exchanged with the exhaust gas 27 to generate steam 102. The steam 102 generated in the evaporator i 4 is supplied to the combustor 9 or another steam utilization device via the pipe 102 a.
このよう に、 第 1 図に示す本実施例においては、 燃焼器 9 で高温に加 熱した排ガスを、 まず第 1 の冷却手段である熱交換器 1 0 でダイォキシ ンの再生成温度領域以上の温度まで冷却し、 その後、 第 2 の冷却手段で ある蒸発器 1 4で再生成温度領域を短時間で通過するよう に急冷する こ とで、 ダイォキシンの再生成量をよ り抑制させている。  As described above, in the present embodiment shown in FIG. 1, the exhaust gas heated to a high temperature in the combustor 9 is first cooled by the heat exchanger 10, which is the first cooling means, to a temperature equal to or higher than the dioxin regeneration temperature range. By cooling to a temperature and then rapidly cooling the evaporator 14 as the second cooling means so as to pass through the regeneration temperature range in a short time, the amount of dioxin regeneration is further suppressed.
第 6 図は、 本実施例によるダイォキシン再生成量の実験結果を示した ものである。 本図に示す実験結果は、 一般的なごみ焼却排ガス成分を用 いたものであ り 、 ごみ焼却排ガスを一度 8 5 0 °C ( 7 5 0 °C以上） に加 熱して 1秒以上滞留させ、 その後、 熱交換器で 8 5 0 °C (7 5 0 °C以上） から 2 0 0 °Cまで冷却する際に、 ダイォキシン再生成促進温度域を含む と基礎実験から推定された 4 0 0 °Cから 2 0 0 °Cの温度域に滞留する時 間とダイォキシン濃度との関係を示している。 FIG. 6 shows the experimental results of the amount of dioxin regeneration according to this example. The experimental results shown in this figure are based on general waste incineration exhaust gas components, and the waste incineration exhaust gas is once added to 850 ° C (750 ° C or more). Heating and holding for 1 second or more, and then, when cooling from 850 ° C (750 ° C or more) to 200 ° C with a heat exchanger, including the temperature range for promoting dioxin regeneration It shows the relationship between the residence time in the temperature range of 400 ° C to 200 ° C estimated from the above and the dioxin concentration.
図中に示す〇， 口は、 灰を熱交換器内部に堆積させない条件で行った 試験結果で流速のみ異なる。 ま た、 ◊は基礎実験で行った実験結果で同 じ く 内部に灰を堆積させていないケース 3者を見ると分かるよう に、 滞 留時間とダイォキシンが直線関係にある。 これよ り 、 0. 1 ( n g— T E Q /m3 N ) 以下を達成するには 5. 5秒以下にする必要のある こ とが分かる。 5. 5秒以上この温度域に滞留すると再生成量が増え 0. 1 ( n g - T E Q/m3N ) を越える ことが予想される。 The points (1) and (2) shown in the figure are the results of a test performed under conditions where ash was not deposited inside the heat exchanger, and only the flow velocity was different. As for ◊, the retention time and dioxin are linearly related, as can be seen from the results of the basic experiment conducted in the three cases where ash was not deposited in the interior. This indicates that to achieve 0.1 (ng—TEQ / m 3 N) or less, it is necessary to set the time to 5.5 seconds or less. Is expected to exceed - (TEQ / m 3 N ng ) 5. When staying more than 5 seconds in this temperature range regeneration amount increases 0.1.
また、 参は、 経年変化で冷却管に灰が堆積付着した状況を模擬して実 証設備で得た結果であり 、 〇に灰堆積を加えたものである。 この結果か ら同じ く経年変化した熱交換器を考えると、 0. l (ng— T E QZm3 N ) 以下を達成するには 3. 5 秒以下にする必要がある ことが分かる。 ま た、 試験管レベルの基礎実験によ り 、 ダイォキシン再生成促進温度域が 380 〜 3 3 0 °Cに絞れることが分かっ たので、 これを踏まえると、 4 0 0か ら 2 0 0 °Cでの滞留時間 3. 5 秒は、 3 8 0〜 3 3 0 °〇では 1秒となる £ なお、 第 6図に示した実験結果は、 排ガス温度を 4 0 0 °Cから 2 0 0 °Cまで冷却する手段と して熱交換器を使用 した実験結果を示しているが、 第 1 図に示したよ う な蒸発器 1 4を使用する ことで、 さ らに排ガスの冷 却時間を短縮させる ことができる。 したがって、 ダイォキシンの再生成 量をさ らに低減させる ことが可能となり 、 ダイォキシン濃度を国の規制 値以下に低減することができる。 Ginseng is the result of simulating the situation where ash was deposited and attached to the cooling pipe due to aging, and was obtained by a demonstration facility. From this result, considering that the heat exchanger has changed over time, it is necessary to set the heat exchanger to 3.5 seconds or less to achieve 0.1 l (ng—TE QZm 3 N) or less. In addition, a basic experiment at the test tube level revealed that the temperature range for promoting dioxin regeneration could be narrowed to 380 to 330 ° C. residence time 3.5 seconds, the 3 8 0-3 3 becomes 0 ° 〇 in 1 second £ Incidentally, the experimental results shown in FIG. 6 is, 2 0 0 ° the exhaust gas temperature from 4 0 0 ° C Experimental results using a heat exchanger as a means of cooling to C are shown, but the use of an evaporator 14 as shown in Fig. 1 further reduces the time required to cool the exhaust gas. It can be done. Therefore, the amount of regenerated dioxin can be further reduced, and the dioxin concentration can be reduced below the national regulation value.
以上述べたよ う に、 本実施例では、 燃焼器 9で 7 5 0 °C以上に加熱し た排ガス 2 6 を、 まず熱交換器 1 0 によって冷却している。 このと き、 排ガス 2 6 の熱交換媒体と して、 飛灰を集塵した焼却炉 1 からの排ガス 3 0 に空気 5 を混入した空気混入排ガス 2 8 を用いている。 従って、 燃 焼器 9 からの高温の排ガス 2 6 との熱交換によって、 空気混入排ガス 2 8 をよ り高温に した上で燃焼器 9 に供給する ことができる。 すなわち . ダイォキシン再生成が僅かしかない 7 5 0 °C以上から 4 0 0 までの温 度域を熱交換器 1 0 で燃焼器からの排ガス 2 6 の冷却を行う とともに、 排ガス 2 6 の排熱回収を行っている。 よって、 燃焼器 9 に供給する燃料 8 を低減する ことが可能とな り 、 経済性を向上させることができる。 ま た、 ダイォキシン再生成温度領域である 4 0 0 〜 2 0 0 °Cに、 熱交換器 よ り も冷却速度が速い蒸発器 1 4 を適用することで、 ダイォキシンの再 生成を抑制する ことができる。 As described above, in the present embodiment, the temperature is increased to more than 75 Exhaust gas 26 is first cooled by heat exchanger 10. At this time, as a heat exchange medium for the exhaust gas 26, an aerated exhaust gas 28 in which air 5 is mixed into the exhaust gas 30 from the incinerator 1 that collects fly ash is used. Therefore, by heat exchange with the high-temperature exhaust gas 26 from the combustor 9, the aerated exhaust gas 28 can be supplied to the combustor 9 after being heated to a higher temperature. In a temperature range from 75 ° C or higher to 400 ° C, where dioxin regeneration is only slight, the exhaust gas 26 from the combustor is cooled by the heat exchanger 10 and the exhaust heat of the exhaust gas 26. We are collecting. Therefore, the amount of fuel 8 supplied to the combustor 9 can be reduced, and the economic efficiency can be improved. In addition, by applying an evaporator 14 having a higher cooling rate than the heat exchanger to the dioxin regeneration temperature range of 400 to 200 ° C, it is possible to suppress the regeneration of dioxin. it can.
なお、 燃焼器 9 からの排ガス温度を約 4 0 0 °Cまで冷却するのには時 間的な制限はない。 この理由は、 約 6 0 0 °C以上は、 ダイォキシンの熱 分解領域であ り 、 また、 4 0 0 °C〜 6 0 0 °Cの温度領域は再生成と分解 の平衡領域のため、 滞留時間の長さ による再生成への影響がほとんどな いからである。  There is no time limit for cooling the exhaust gas temperature from the combustor 9 to about 400 ° C. The reason for this is that the temperature of about 600 ° C or more is the thermal decomposition area of dioxin, and the temperature area of 400 ° C to 600 ° C stays because of the equilibrium area of regeneration and decomposition. This is because the length of time has little effect on regeneration.
こ こで、 特開平 10— 2633 1 号公報に記載の装置では、 冷却水が貯溜さ れた冷却水槽内で排ガスをパブリ ングさせる急冷装置を用いて排ガスを 冷却させていた。 この従来の装置では、 7 0 0 °〇以上の排ガスを 3 0 0 でまで一つの急冷装置にて冷却 していたので、 大規模な焼却設備に適用 する際には大量の冷却水が必要となる虞があ り 、 ま た、 急冷装置とは別 に冷却水を浄化させる浄化装置等が必要となる可能性があった。  Here, in the device described in Japanese Patent Application Laid-Open No. 10-26331, the exhaust gas is cooled using a quenching device that publishes the exhaust gas in a cooling water tank in which the cooling water is stored. In this conventional device, the exhaust gas of 700 ° 〇 or more was cooled by a single quenching device to 300 ° C, so when applying it to a large-scale incinerator, a large amount of cooling water was required. There was a possibility that a purification device for purifying the cooling water separately from the quenching device might be required.
これに対して、 本実施例では排ガスを冷却する水は間接熱交換を行つ ているため浄化装置は必要と しない。 ま た、 本実施例では排ガスと熱交 換され発生した蒸気を燃焼器に供給してお り 、 燃焼器での N O x低減に 利用する ことができる。 On the other hand, in the present embodiment, the water for cooling the exhaust gas performs indirect heat exchange, so that a purification device is not required. Further, in this embodiment, heat exchange with exhaust gas is performed. The steam generated by the exchange is supplied to the combustor, and can be used for NOx reduction in the combustor.
このよ う に、 本実施例によれば、 排ガス中に含まれるダイォキシンを 低減すると共に、 ダイォキシンの再生成を抑制する ことができ、 安価な ごみ排ガス処理システムを提供できるという効果を奏する。  As described above, according to the present embodiment, dioxin contained in exhaust gas can be reduced, and regeneration of dioxin can be suppressed, so that an inexpensive waste gas treatment system can be provided.
第 2図は、 本発明の他の実施例である ごみ排ガス処理システムを示す t なお、 以下の説明において第 1 図と同一の構成及び作用については説明 を省略する。 Figure 2 is not described here further embodiment t Note showing a waste gas treatment system which is the same configuration and operation as the first drawing in the following description of the present invention.
第 2 図に示す本実施例では、 一つの熱交換器 1 0 のみで燃焼器 9 から の高温の排ガス 2 6 の冷却を行う ものである。 この熱交換器 1 0 は、 二 つの熱交換部を備えたものであ り 、 排ガス 2 6 はまず第 1 の熱交換部 1 0 aによって、 混合器 5から供給される空気混入排ガス 2 8 と間接的 に熱交換が行われ、 燃焼器 9 で 7 5 0 °C以上の高温に加熱された排ガス を 4 0 0 °C程度の温度まで冷却を行う 。 第 1 の熱交換部 1 0 aで冷却さ れた排ガスは、 第 1 の熱交換部 1 0 a と同一流路内に設置された第 2 の 熱交換部 1 O b に導かれ、 この第 2 の熱交換部 1 O b に供給される水 1 0 5 と間接的に熱交換を行われ、 こ こで 2 0 0 °C以下の温度までさ ら に排ガスの冷却を行う 。  In this embodiment shown in FIG. 2, the high-temperature exhaust gas 26 from the combustor 9 is cooled by only one heat exchanger 10. This heat exchanger 10 is provided with two heat exchange sections, and the exhaust gas 26 is firstly separated from the aerated exhaust gas 28 supplied from the mixer 5 by the first heat exchange section 10a. The heat is indirectly exchanged, and the exhaust gas heated to a high temperature of more than 750 ° C in the combustor 9 is cooled to a temperature of about 400 ° C. The exhaust gas cooled in the first heat exchange unit 10a is led to the second heat exchange unit 1Ob installed in the same flow path as the first heat exchange unit 10a, The heat exchange is performed indirectly with the water 105 supplied to the heat exchange unit 1 Ob of No. 2, and the exhaust gas is further cooled to a temperature of 200 ° C. or lower.
すなわち、 本実施例では燃焼器 9 で高温に加熱された排ガス 2 6 を、 まず第 1 の熱交換部 1 0 a によって、 ダイォキシン分解の温度領域 （約 6 0 0 °C以上） の範囲内、 或いはダイォキシン再生成と分解とが平衡す る温度領域（約 4 0 0 °C〜 6 0 0 °C )の範囲内に冷却し、 さ らに第 2 の熱 交換部 1 O b によって、 ダイ ォキシンの再生温度領域 （ 4 0 0 〜 2 0 0 °C ) よ リ低い温度まで排ガス温度を低下させるシステムとなっている。  That is, in this embodiment, the exhaust gas 26 heated to a high temperature in the combustor 9 is firstly separated by the first heat exchange unit 10a into a temperature range of dioxin decomposition (about 600 ° C. or more). Alternatively, the dioxin is cooled to a temperature within a temperature range (about 400 ° C. to 600 ° C.) in which the dioxin regeneration and decomposition are equilibrated, and the dioxin is further reduced by the second heat exchange unit 1 Ob. The system reduces the exhaust gas temperature to a temperature even lower than the regeneration temperature range (400 to 200 ° C).
このとき、 第 1 の熱交換部 1 0 aでは、 燃焼器 9からの排ガス温度を 約 4 0 0 °Cまで冷却するのには時間的な制限を設ける必要は特にないが、 第 2の熱交換部 1 0 bでは、 第 1 図に示す蒸発器 1 4と同様に、 排ガス 2 7 を 4 0 0 °Cから 2 0 0 °C以下まで約 5秒以内、 望ま し く は約 3. 5 秒以内で、 さ らに望ま し く は 3 8 0 °Cから 3 3 0 °Cまで 1秒以内で冷却 する ことで排ガス中のダイォキシン濃度を O . l n g— T E QZm3 Nレ ベル以下まで低減する ことが可能となる。 At this time, the temperature of the exhaust gas from the combustor 9 is reduced in the first heat exchange section 10a. Although there is no particular need to set a time limit for cooling to about 400 ° C., in the second heat exchange section 10b, as in the evaporator 14 shown in FIG. 7 from 400 ° C to below 200 ° C within about 5 seconds, preferably within about 3.5 seconds, and more preferably from 38 ° C to 330 ° C By cooling to within 1 second, the dioxin concentration in the exhaust gas can be reduced to O.lng—TE QZm 3 N level or less.
なお、 第 2の熱交換部 1 O bでは、 ポンプ 1 0 1 によって供給される 水 1 5が排ガス 2 6 と熱交換される ことによって蒸気 1 0 2が発生する。 第 2の熱交換部 1 O bで発生した蒸気 1 0 2は、 配管 1 0 2 aおよび配 管 1 0 4 aを介して燃焼器 9 に供給して、 燃焼器 9での N O x低減用の 蒸気 1 0 4と して、 あるいは配管 1 0 3 aを介して他の蒸気利用機器に 蒸気 1 0 3と して供給される。  In the second heat exchange section 1 Ob, steam 105 is generated by heat exchange of water 15 supplied by the pump 101 with exhaust gas 26. The steam 102 generated in the second heat exchange section 1 Ob is supplied to the combustor 9 via the pipe 102 a and the pipe 104 a to reduce NOx in the combustor 9. It is supplied as steam 104 or as steam 103 to other steam utilization equipment via piping 103a.
以上述べたよう に本実施例によれば、 排ガス中に含まれるダイォキシ ンを低減すると共に、 ダイォキシンの再生成を抑制する ことができ、 安 価なごみ排ガス処理システムを提供できるという効果を奏する。 さ らに 本実施例では、 一つの熱交換器 1 0によって排ガスの冷却を行っている ので、 第 1 図に示すものと比べて装置全体をよ り コ ンパク トにする こと ができ、 従って省スペース化を図る ことが可能となる。  As described above, according to the present embodiment, dioxin contained in exhaust gas can be reduced, and regeneration of dioxin can be suppressed, so that an inexpensive waste gas treatment system can be provided. Further, in this embodiment, the exhaust gas is cooled by one heat exchanger 10, so that the entire apparatus can be made more compact than that shown in FIG. Space can be increased.
第 3図は、 本発明の他の実施例である ごみ排ガス処理システムを示す c なお、 以下の説明において第 1 図と同一の構成及び作用については説明 を省略する。 Figure 3 will be omitted for another embodiment c Note showing a waste gas treatment system which is the same configuration and operation as the first drawing in the following description of the present invention.
本実施例では、 燃焼器 9下流に燃焼用空気 2 0 を予熱する空気予熱器 1 1 を追加したもので、 この追加に伴い、 送風機 6 と空気予熱器 1 1 と の間に燃焼用空気配管 1 0 5 aも設けられた。 送風機 6から出た空気の —部は、 配管 1 0 5 aを介して空気予熱器 1 1 に入り 3 0 0 °C前後に昇 温され燃焼用空気 2 0 と して、 配管 2 0 a を介し燃焼器 9 に供給される。 なお、 本実施例では、 ダイォキシン再生成が僅かしかない温度域である 約 8 5 0 〜 4 0 0 °Cまでを空気予熱器 1 1 と熱交換器 1 0でカバーし、 ダイォキシン再生成温度域である約 4 0 0 〜 2 0 0 °Cを蒸発器 1 4で力 バーする。 ま た、 空気予熱器 1 1 によ り燃焼器の温度変動に対して燃焼 空気 2 0の温度と して吸収できるので時間変動の一様化を図る ことがで きる。 In the present embodiment, an air preheater 11 for preheating the combustion air 20 is added downstream of the combustor 9. With this addition, a combustion air pipe is provided between the blower 6 and the air preheater 11. 105 a was also provided. The-part of the air leaving the blower 6 enters the air preheater 11 via the pipe 105a and rises to around 300 ° C. It is heated and supplied to the combustor 9 as combustion air 20 via a pipe 20a. In this example, the air preheater 11 and the heat exchanger 10 cover the temperature range of about 850 to 400 ° C., which is a temperature range where dioxin regeneration is only slight, and the dioxin regeneration temperature range Approximately 400 to 200 ° C. is applied to the evaporator 14. In addition, the air preheater 11 can absorb the temperature fluctuation of the combustor as the temperature of the combustion air 20, so that the time fluctuation can be made uniform.
以上のよ う に本実施例によれば、 第 1 図の実施例よ り も燃料低減を図 れるばかり でな く 、 排ガス中のダイォキシンを低濃度に分解でき、 かつ、 従来技術の熱交換器でダイォキシン再生成が僅かしかない温度域の 850 °Cから 4 0 0 °Cまで適用 して廃熱回収し燃料低減でき、 かつ、 従来技術 の蒸発器 （熱交換器よ り も冷却速度が速い） をダイォキシン再生成温度 域の 4 0 0 °Cから 2 0 0 °Cに適用し再生成を抑制できるとともに、 燃焼 器 9 の温度変動も一様化できるので、 ダイォキシン低減性能が高く 、 安 価なダイォキシン浄化装置を提供できるという効果がある。  As described above, according to the present embodiment, not only can the fuel consumption be reduced than in the embodiment of FIG. 1, the dioxin in the exhaust gas can be decomposed to a low concentration, and the heat exchanger of the prior art can be decomposed. It can be used to recover waste heat and reduce fuel by applying from 850 ° C to 400 ° C in the temperature range where dioxin regeneration is very small, and the evaporator of the prior art (cooling speed is faster than heat exchanger) ) Is applied to the dioxin regeneration temperature range of 400 ° C to 200 ° C, and the regeneration can be suppressed, and the temperature fluctuation of the combustor 9 can be made uniform, so that the dioxin reduction performance is high and the price is low. There is an effect that a suitable dioxin purification device can be provided.
第 4図は、 本発明の他の実施例である ごみ排ガス処理システムを示す c なお、 以下の説明において前述したものと同一の構成及び作用について は説明を省略する。 Figure 4 will be omitted for another embodiment c Note showing a waste gas treatment system is an example, the same structures and operations as those described above in the following description of the present invention.
本実施例は、 第 3 図に示すものに加えて、 燃焼器 9 の下流で蒸発器 1 4の上流に過熱器 1 7 を設置した構成と している。 水 1 0 5 は、 ボン プ 1 0 1 によ り蒸発器 1 4 に供給され、 こ こで 3 0 0 °C前後の蒸気 102 とな り配管 1 0 2 a を介して過熱器 1 7 に 4 0 0 °C以上の過熱蒸気 106 とな り配管 1 0 6 a を通り過熱蒸気 1 0 6 の一部が N O x対策と して配 管 1 0 4 a ょ リ供給され、 残り の蒸気 1 0 3 は配管 1 0 3 a を通り蒸気 利用機器へ向かう かま たは廃棄される。 なお、 本実施例では、 ダイォキ シン再生成が僅かしかない温度域である約 8 5 0 ~ 4 0 0 °Cまでを過熱 器 1 7 と空気予熱器 1 1 と熱交換器 1 0 でカバーし、 ダイォキシン再生 成温度域である約 4 0 0〜 2 0 0 °Cを蒸発器 1 4でカバーする。 これに よ り 、 この過熱器 1 7 と空気予熱器 1 1 の設定温度を変える ことによ り 蒸発器 1 4入口での排ガス温度の調整ができるので、 燃焼温度の変動に 対応してダイォキシン再生成抑止を防止できる。 This embodiment has a configuration in which a superheater 17 is installed downstream of the combustor 9 and upstream of the evaporator 14 in addition to the one shown in FIG. The water 105 is supplied to the evaporator 14 by the pump 101, where it becomes steam 102 at around 300 ° C, and to the superheater 17 via the pipe 102 a. Part of superheated steam 106 passes through piping 106a as superheated steam 106 or more at 400 ° C or more, and is supplied to pipeline 104 as a countermeasure against NOx, and the remaining steam 1 0 3 goes through piping 103 a to the steam utilization equipment or is discarded. In the present embodiment, the The super-heater 17, air pre-heater 11 and heat exchanger 10 cover the temperature range of about 850 to 400 ° C, where there is little syn regeneration, and it is the dioxin regeneration temperature range Approximately 400 to 200 ° C. is covered with an evaporator 14. By changing the set temperature of the superheater 17 and the air preheater 11, the exhaust gas temperature at the evaporator 14 inlet can be adjusted, so that dioxin regeneration can be performed in response to fluctuations in combustion temperature. Deterrence can be prevented.
以上のよ う に本実施例によれば、 第 3 図の実施例よ リ も燃料低減を図 れるばかりでなく 、 排ガス中のダイォキシンを低濃度に分解でき、 かつ 熱交換器でダイォキシ ン再生成が僅かしかない温度域である約 8 5 0 ~ 4 0 0 °Cまで適用して廃熱回収し燃料低減でき、 かつ、 熱交換器よ り も 冷却速度が速い蒸発器をダイォキシン再生成温度域である約 4 0 0〜 As described above, according to the present embodiment, not only can the fuel be reduced than in the embodiment of FIG. 3, the dioxin in the exhaust gas can be decomposed to a low concentration, and the dioxin is regenerated by the heat exchanger. The temperature range where there is only a slight temperature is about 850 to 400 ° C, waste heat can be recovered and fuel can be reduced, and the evaporator with a higher cooling rate than the heat exchanger is used as a dioxin regeneration temperature range. Is about 400
2 0 0 °Cに適用し再生成を抑制できるとともに、 変動に対する対応もで きるので、 ダイォキシン低減性能が高く 、 安価なダイォキシン浄化装置 を提供できるという効果がある。 Since it can be applied to a temperature of 200 ° C. and can suppress regeneration, and can cope with fluctuations, there is an effect that a dioxin purifying apparatus with high dioxin reduction performance can be provided at a low cost.
第 5 図は、 本発明の他の実施例である ごみ排ガス処理システムを示す なお、 以下の説明では、 前述したものと同一の構成及び作用については 説明を省略する。  FIG. 5 shows a waste gas treatment system according to another embodiment of the present invention. In the following description, the same configuration and operation as those described above will not be described.
本実施例は、 加熱器 1 7 からの余剰蒸気である蒸気 1 0 3 と、 焼却炉 1 で発生した蒸気 5 3 を利用 して発電を行う ものである。 このため、 本 実施例では発生された蒸気で駆動される蒸気タービン 2 4及び発電機 In the present embodiment, power is generated by using steam 103 as surplus steam from the heater 17 and steam 53 generated in the incinerator 1. Therefore, in this embodiment, the steam turbine 24 driven by the generated steam and the generator
3 4 , 仕事を終えた蒸気を復水する復水器 3 5 ， 凝縮した復水を送水す る復水ポンプ 3 8 を備えている。 ま た、 焼却炉 1 にはェコ ノマイザ一 2 1 , 蒸発器 2 2及び過熱器 2 3 a， 2 3 b を設けており 、 焼却炉 1 の 熱を利用 して水蒸気が発生される。 ェコ ノマイザ一 2 1 で発生した熱水 5 1 は配管 5 1 a を経由 して蒸発器 2 2 に供給され、 蒸気となり過熱器 2 3 a , 2 3 b を通過して過熱され、 過熱蒸気 5 3 となり配管 5 3 a通 リ 、 配管 1 0 3 a を通り送られてきた過熱蒸気 1 0 6 の一部と合流し過 熱蒸気 5 2 とな り配管 5 2 a を通り蒸気タービン 2 4 に供給され発電機3 4, A condenser 35 for condensing the steam after work, and a condensate pump 38 for sending condensed condensate. Further, the incinerator 1 is provided with an economizer 21, an evaporator 22 and superheaters 23 a and 23 b, and steam is generated by utilizing the heat of the incinerator 1. The hot water 51 generated in the economizer 21 is supplied to the evaporator 22 via the pipe 51a, becomes steam, and becomes a superheater. Superheated after passing through 23a and 23b, it becomes superheated steam 53 and merges with a part of superheated steam 106 sent through piping 53a and piping 103a to overheat. The steam is supplied to the steam turbine 24 through the pipe 5 2 a.
3 4 を駆動し発電する。 蒸気タービン 2 4で仕事を終えた蒸気は復水器 3 5 にて水に復水される。 復水された水は、 給水ポンプ 3 8 によってェ コ ノマイザ一 2 1 及び蒸発器 1 4にそれぞれ配管 2 1 a , 1 5 aを介し て供給される。 蒸発器 1 4 に供給された水 1 5 は、 蒸発器 1 4で蒸気と なったのち過熱器 1 7 で過熱され過熱蒸気 1 0 6 と して、 蒸気配管 106a を経由 し一部は燃焼器 9 へ残り の一部は配管 1 0 3 a を介して配管 52 a へ供給される。 なお、 燃焼器 9 に送る分の水は、 システムから失われる ため水を補給するポンプ 4 6 が復水ライ ンに設けてある。 Drive 3 4 to generate electricity. The steam that has completed its work in the steam turbine 24 is returned to water in the condenser 35. The condensed water is supplied to the economizer 21 and the evaporator 14 by the feedwater pump 38 via the pipes 21a and 15a, respectively. The water 15 supplied to the evaporator 14 is turned into steam in the evaporator 14, then superheated in the superheater 17 to become superheated steam 106, and a part of the combustor passes through the steam pipe 106 a. The remaining part is supplied to the pipe 52a via the pipe 103a. The water sent to the combustor 9 is lost from the system, so a pump 46 that supplies water is provided in the condensate line.
発電する ことによ り所内電力が賄えた リ売電によって利益が出るため , ダイォキシン処理にかかる費用を軽減する ことができる。 なお、 ダイォ キシン低減性能は、 第 4図のシステムと同一であるのでここでは言及を 省略する。  Since the power generation generates profits from the resale of electricity that the in-house power can cover, the cost of dioxin treatment can be reduced. The dioxin reduction performance is the same as that of the system shown in Fig. 4 and will not be described here.
以上のよ う に本実施例によれば、 前述した実施例よ リ も燃料低減を図 れるばかり でなく 発電による経費の低減が図れ、 排ガス中のダイォキシ ンを低濃度に分解でき、 かつ、 従来技術の熱交換器でダイォキシン再生 成が僅かしかない温度域の 8 5 0 °Cから 4 0 0 °Cまで適用して廃熱回収 し燃料低減でき、 かつ、 熱交換器よ り も冷却速度が速い蒸発器をダイォ キシン再生成温度の域 4 0 0 °Cから 2 0 0 °Cに適用し再生成を抑制でき るとともに、 変動に対する対応もできるので、 ダイォキシン低減性能が 高く 、 安価なダイォキシン浄化装置を提供できるという効果がある。 産業上の利用可能性 本発明のごみ排ガス処理システムおよび処理方法は、 焼却炉でごみ或 いは廃棄物を焼却して発生する排ガス中のダイォキシンを低減する分野 に使用する。 As described above, according to this embodiment, not only the fuel consumption can be reduced, but also the cost due to power generation can be reduced, the dioxin in the exhaust gas can be decomposed to a low concentration, and the conventional method can be used. It can be used to recover waste heat and reduce fuel by applying dioxin regeneration from 850 ° C to 400 ° C in a temperature range where there is little dioxin regeneration in the heat exchanger of the technology, and the cooling rate is higher than that of the heat exchanger. Applying a fast evaporator to the dioxin regeneration temperature range from 400 ° C to 200 ° C to suppress regeneration and to cope with fluctuations, high dioxin reduction performance and inexpensive dioxin purification There is an effect that the device can be provided. Industrial applicability INDUSTRIAL APPLICABILITY The waste gas treatment system and treatment method of the present invention are used in the field of reducing dioxin in exhaust gas generated by burning waste or waste in an incinerator.

Claims

請 求 の 範 囲 The scope of the claims
1 . ごみ或いは廃棄物を焼却した焼却ガスを燃焼させる燃焼器と、 前記燃焼器の下流側に設置され、 前記焼却ガスと燃焼器から流下する 燃焼排ガスとを間接的に熱交換させて該燃焼排ガスを冷却する熱交換器 と、 1. A combustor that burns incineration gas that has been incinerated from refuse or waste, and the combustion that is installed downstream of the combustor and indirectly exchanges heat between the incineration gas and flue gas flowing down from the combustor. A heat exchanger for cooling the exhaust gas,
前記熱交換器の下流側に設置され、 前記熱交換器を経た燃焼排ガスを さ らに冷却させる冷却器とを備えたことを特徴とする ごみ排ガス処理シ ステム。  A waste gas treatment system, comprising: a cooler installed downstream of the heat exchanger for further cooling the combustion exhaust gas passing through the heat exchanger.
2 . 飛灰濃度 0 . 1 〜 0 . 0 0 1 g Z In 3 N のごみ焼却ガスを燃焼させる 燃焼器と、 2. Fly ash concentration 0.1 to 0.001 g Combustor for burning Z In 3 N waste incineration gas
前記燃焼器で燃焼された燃焼排ガスと前記焼却ガスとを間接的に熱交 換させて該燃焼排ガスを冷却する熱交換器と、  A heat exchanger that indirectly exchanges heat between the flue gas burned in the combustor and the incinerated gas to cool the flue gas;
前記熱交換器からの燃焼排ガスをさ らに冷却させる冷却器と を備えた ことを特徴とする ごみ排ガス処理システム。  And a cooler for further cooling the combustion exhaust gas from the heat exchanger.
3 . ごみを焼却して発生する焼却ガスに空気を供給する空気供給手段と 前記空気が供給された焼却ガスを燃焼させる燃焼器と、  3. Air supply means for supplying air to the incineration gas generated by incinerating the refuse, and a combustor for burning the incineration gas supplied with the air;
前記燃焼器の下流側に設置され、 前記焼却ガスと燃焼器から流下する 燃焼排ガスと を間接的に熱交換させて該燃焼排ガスを予め定めた温度ま で冷却し、 前記熱交換されて冷却した燃焼排ガスをさ らに前記予め定め た温度よ り も低い所望の温度まで低下させる熱交換器とを備えたことを 特徴とする ごみ排ガス処理システム。  It is installed downstream of the combustor and indirectly exchanges heat between the incineration gas and the flue gas flowing down from the combustor, thereby cooling the flue gas to a predetermined temperature, and performing the heat exchange and cooling. A waste gas treatment system, further comprising: a heat exchanger for lowering the combustion exhaust gas to a desired temperature lower than the predetermined temperature.
4 . ごみ或いは廃棄物を焼却した焼却ガスを燃焼させる燃焼器と、 前記燃焼器の下流側に設置され、 前記焼却ガスと燃焼器から流下する 燃焼排ガスと を間接的に熱交換させて、 該燃焼排ガスをダイォキシン分 解の温度領域の範囲内、 或いはダイォキシン再生成と分解とが平衡する 温度領域の範囲内に冷却し、 前記熱交換されて冷却した燃焼排ガスを、 ダイォキシンの再生温度領域以下まで間接的熱交換によってさ らに冷却 させる熱交換器とを備えたこ とを特徴とする ごみ排ガス処理システム。 4. A combustor that burns incineration gas that has incinerated refuse or waste, and a heat exchanger that is installed downstream of the combustor and indirectly exchanges heat with the incineration gas and flue gas flowing down from the combustor, Exhaust gas within the temperature range of dioxin decomposition or equilibrium between dioxin regeneration and decomposition A refuse provided with a heat exchanger that cools the combustion exhaust gas cooled by heat exchange within the temperature range and further cools the exhaust gas cooled by the indirect heat exchange below the dioxin regeneration temperature range. Exhaust gas treatment system.
5 . ごみを焼却した焼却ガスを燃焼させる燃焼器と、 5. A combustor for burning the incineration gas from the incineration of the refuse,
該燃焼器の下流側に設置され、 前記燃焼器に供給される空気と、 燃焼 器から流下する燃焼排ガスとを間接的に熱交換させて該燃焼排ガスを冷 却する空気予熱器と、  An air preheater installed downstream of the combustor and indirectly exchanging heat between air supplied to the combustor and flue gas flowing down from the combustor to cool the flue gas;
該空気予熱器の下流側に設置され、 前記空気予熱器から流下する燃焼 排ガスと、 前記焼却ガスとを熱交換させて該燃焼排ガスを冷却する熱交 換器と、  A heat exchanger disposed downstream of the air preheater, for exchanging heat with the combustion exhaust gas flowing down from the air preheater, and cooling the combustion exhaust gas by exchanging heat with the incineration gas;
該熱交換器の下流側に設置され、 該空気予熱器を経た燃焼排ガスをさ らに冷却させる冷却器と を備えたことを特徴とする ごみ排ガス処理シス テム。  A waste gas treatment system, further comprising: a cooler installed downstream of the heat exchanger for further cooling the combustion exhaust gas passing through the air preheater.
6 . 塩素分を含む有機物を焼却した焼却ガスを燃焼させる燃焼器と、 前記燃焼器の下流側に設置され、 前記焼却排ガスと燃焼器から流下す る燃焼排ガスとを間接的に熱交換させて該燃焼排ガスを冷却する第 1 の 熱交換器と、  6. A combustor that burns incineration gas obtained by incinerating organic matter containing chlorine, and indirectly exchanges heat between the incineration exhaust gas and the combustion exhaust gas flowing down from the combustor, which is installed downstream of the combustor. A first heat exchanger for cooling the flue gas;
前記第 1 の熱交換器の下流側に設置され、 該第 1 の熱交換器を経た燃 焼排ガスをさ らに冷却させる第 2 の熱交換器とを備えたことを特徴とす る排ガス処理システム。  An exhaust gas treatment comprising: a second heat exchanger installed downstream of the first heat exchanger for further cooling the combustion exhaust gas that has passed through the first heat exchanger. system.
7 . 塩素分を含む有機物を焼却した焼却ガスを燃焼させる燃焼器と、 前記燃焼器の下流側において、 第 1 の冷却媒体との間接的熱交換によ つて前記燃焼排ガスを冷却する第 1 の熱交換器と、  7. A combustor for burning incineration gas obtained by incinerating organic matter containing chlorine, and a first cooling means for cooling the combustion exhaust gas downstream of the combustor by indirect heat exchange with a first cooling medium. Heat exchanger,
前記第 1 の熱交換器の下流側にあって、 第 2 の冷却媒体と間接的な熱 交換を行い、 前記第 1 の熱交換器を経た燃焼排ガスをさ らに冷却させる 第 2 の熱交換器と を備えたこと を特徴とする排ガス処理システム。On the downstream side of the first heat exchanger, indirect heat exchange with the second cooling medium is performed, and the flue gas that has passed through the first heat exchanger is further cooled. An exhaust gas treatment system comprising: a second heat exchanger.
8 . ごみを焼却 した焼却ガスを燃焼させる燃焼器と、 8. A combustor that burns the incineration gas from the incineration of the refuse,
前記燃焼器からの燃焼排ガスを、 ダイォキシン分解の温度領域の範囲 内、 或いはダイォキシン再生成と分解とが平衡する温度領域の範囲内に 冷却する第 1 の熱交換器と、  A first heat exchanger for cooling the flue gas from the combustor within a temperature range of dioxin decomposition or within a temperature range in which dioxin regeneration and decomposition are balanced;
前記第 1 の熱交換器からの燃焼排ガスを、 ダイォキシンの再生温度領 域以下までさ らに冷却させる第 2 の熱交換器と を備えたこ と を特徴とす る ごみ排ガス処理システム。  A waste heat treatment system, comprising: a second heat exchanger for further cooling the combustion exhaust gas from the first heat exchanger to a dioxin regeneration temperature range or lower.
9 . 前記ごみ排ガス処理システムは、 前記燃焼器から熱交換器に流下す る燃焼排ガスを 7 5 0 °C以上の温度で 1 秒以上保持する保持手段を備え たことを特徴とする請求項 1 から 4のいずれかに記載のごみ排ガス処理 システム。  9. The waste gas treatment system according to claim 1, further comprising holding means for holding the combustion exhaust gas flowing down from the combustor to the heat exchanger at a temperature of not less than 750 ° C for not less than 1 second. A waste gas treatment system according to any of claims 1 to 4.
1 0 . 前記保持手段は、 望ま し く は燃焼排ガスを 8 5 0 °C以上の温度で 1 . 6 秒以上保持するものである こと を特徴とする請求項 9 に記載のご み排ガス処理システム。  10. The waste gas treatment system according to claim 9, wherein the holding means desirably holds the combustion exhaust gas at a temperature of 850 ° C or more for 1.6 seconds or more. .
1 1 . ごみを焼却する焼却炉と、 該焼却炉から排出される排ガス中の煤 塵を捕集する集塵機と、 煤塵が捕集された排ガスに空気を供給する空気 供給手段と、 前記空気が供給された排ガスを燃焼させる燃焼器と、 該燃 焼器の下流に設置され、 燃焼器からの燃焼排ガスと空気が供給された排 ガスと を熱交換して前記燃焼排ガスを冷却する第 1 の熱交換器と、 該第 1 の熱交換器の下流に設置され、 前記第 1 の熱交換器から流下する燃焼 排ガスを間接的な熱交換によってさ らに冷却する第 2 の熱交換器と を備 えたことを特徴とする ごみ排ガス処理システム。  1 1. An incinerator for incinerating refuse, a dust collector for collecting dust in exhaust gas discharged from the incinerator, an air supply means for supplying air to the exhaust gas in which the dust is collected, and A combustor that burns the supplied exhaust gas, and a first device that is provided downstream of the combustor and that exchanges heat between the combustion exhaust gas from the combustor and the exhaust gas supplied with air to cool the combustion exhaust gas. A heat exchanger, and a second heat exchanger installed downstream of the first heat exchanger and further cooling the combustion exhaust gas flowing down from the first heat exchanger by indirect heat exchange. A waste gas treatment system characterized by the following features:
1 2 . 前記ごみ排ガス処理システムは、 前記燃焼器が前記焼却ガスの温 度を 7 5 0 °C以上に燃焼するものであって、 前記燃焼器に導かれる焼却ガスと前記燃焼器から流下する燃焼排ガス と を熱交換させ、 該燃焼排ガスを 4 0 0 °Cの温度まで冷却する熱交換器 と、 12. The refuse exhaust gas treatment system, wherein the combustor combusts the temperature of the incinerated gas to 75 ° C. or more, A heat exchanger for exchanging heat between incineration gas led to the combustor and flue gas flowing down from the combustor, and cooling the flue gas to a temperature of 400 ° C;
該熱交換器を通過した前記燃焼排ガスを、 2 0 0 °Cの温度まで 5秒以 内の時間で冷却する冷却器を備えたこと を特徴とする請求項 1 ま たは 2 に記載のごみ排ガス処理システム。  The refuse according to claim 1, further comprising a cooler that cools the flue gas that has passed through the heat exchanger to a temperature of 200 ° C. within a time period of 5 seconds or less. 4. Exhaust gas treatment system.
1 3. 前記冷却器は、 望ま し く は熱交換器を通過した前記燃焼排ガスを、 2 0 0 °Cの温度まで 3 . 5秒以内で冷却するものである ことを特徴とす る請求項 1 2 に記載のごみ排ガス処理システム。  13. The cooler preferably cools the flue gas that has passed through the heat exchanger to a temperature of 200 ° C. within 3.5 seconds. A waste gas treatment system according to item 12.
1 4. 前記冷却器は、 さ らに望ま し く は熱交換器を通過した前記燃焼排 ガスを、 3 8 0 °Cから 3 3 0 °Cの温度まで 1秒以内で冷却するものであ ること を特徴とする請求項 1 2 に記載のごみ排ガス処理システム。  1 4. The cooler further desirably cools the combustion exhaust gas that has passed through the heat exchanger from a temperature of 380 ° C to 330 ° C within 1 second. 13. The refuse exhaust gas treatment system according to claim 12, wherein
1 5. 前記ごみ排ガス処理システムは、 前記熱交換器から冷却器に導か れた燃焼排ガスを 5 0 °CZ s以上の冷却速度で冷却する冷却器を備えた こと を特徴とする請求項 1 ま たは 2 に記載のごみ排ガス処理システム。 15. The waste gas treatment system further includes a cooler that cools the combustion exhaust gas guided from the heat exchanger to the cooler at a cooling rate of 50 ° CZs or more. Or a waste gas treatment system according to item 2.
1 6 . 前記冷却器は、 望ま し く は熱交換器から導かれた燃焼排ガスを 5 7 °C/ s以上の冷却速度で冷却するものである こと を特徴とする請求 項 1 5 に記載のごみ排ガス処理システム。 16. The cooler according to claim 15, wherein the cooler desirably cools the flue gas introduced from the heat exchanger at a cooling rate of 57 ° C / s or more. Waste gas treatment system.
1 7 . 前記ごみ排ガス処理システムは、 前記冷却器が熱交換器を経た燃 焼排ガスと水とを間接的に熱交換して蒸気を発生させるものであって、 前記冷却器で発生した蒸気を前記燃焼器に供給する蒸気供給手段を備え たこと を特徴とする請求項 1 ま たは 2に記載のごみ排ガス処理システム。 17. The waste gas treatment system, wherein the cooler indirectly exchanges heat with the combustion exhaust gas passing through a heat exchanger and water to generate steam, and the steam generated by the cooler is 3. The refuse exhaust gas treatment system according to claim 1, further comprising a steam supply unit that supplies the waste gas to the combustor.
1 8. ごみ或いは廃棄物を焼却した焼却ガスを燃焼器で燃焼させて焼却 ガス中に含まれるダイォキシンを分解し、 前記燃焼器から排出される燃 焼排ガスを熱交換器に導き、 前記燃焼器に供給される焼却ガスと間接的 に熱交換を行い前記燃焼排ガスを冷却 し、 前記熱交換器で冷却された燃 焼排ガスを冷却器にて間接熱交換を行って、 前記燃焼排ガスをさ らに冷 却することを特徴とする ごみ排ガス処理方法。 1 8. Combustion of the incineration gas from the incineration of refuse or waste in a combustor to decompose dioxin contained in the incineration gas and guide the combustion exhaust gas discharged from the combustor to a heat exchanger, Incineration gas supplied to the Heat exchange to cool the combustion exhaust gas, and indirect heat exchange to the combustion exhaust gas cooled by the heat exchanger in a cooler to further cool the combustion exhaust gas. Waste gas treatment method.
1 9 . 飛灰濃度を 0 . 1 〜 0 . 0 0 1 g Z πl 3 N に した焼却ガスを燃焼器 で燃焼させて焼却ガス中に含まれるダイォキシンを分解し、 前記燃焼器 で燃焼して排出される燃焼排ガスを熱交換器に導き、 前記燃焼器に供給 される焼却ガスと間接的に熱交換させて前記燃焼排ガスを冷却し、 冷却 された前記燃焼排ガスを冷却器にて間接熱交換を行ってさ らに冷却する ことを特徴とする ごみ排ガス処理方法。 1 9. The incineration gas with the fly ash concentration of 0.1 to 0.01 g Z πl 3 N is burned in a combustor to decompose dioxin contained in the incineration gas and burned in the combustor. The discharged flue gas is guided to a heat exchanger, and indirectly exchanges heat with the incineration gas supplied to the combustor to cool the flue gas. The cooled flue gas is indirectly heat-exchanged by a cooler. Waste gas treatment method characterized by further cooling the waste gas.
2 0 . ごみを焼却して発生した焼却ガスに空気を供給し、 空気が供給さ れた前記焼却ガスを燃焼器で燃焼させて焼却ガス中に含まれるダイォキ シンを分解し、 前記燃焼器から排出される燃焼排ガスを熱交換器に導き . 空気が供給され前記燃焼器に導かれる焼却ガスと間接的に熱交換を行い 前記燃焼排ガスを予め定めた温度まで冷却 し、 前記熱交換されて冷却し た燃焼排ガスをさ らに前記予め定めた温度よ リ も低い所望の温度まで低 下させる こと を特徴とするごみ排ガス処理方法。  20. Air is supplied to the incineration gas generated by incineration of refuse, and the incineration gas supplied with air is burned in a combustor to decompose dioxin contained in the incineration gas. The discharged flue gas is led to a heat exchanger. Air is supplied and indirectly exchanges heat with the incineration gas led to the combustor. The flue gas is cooled to a predetermined temperature, and cooled by the heat exchange. A waste gas treatment method characterized by lowering the combustion exhaust gas to a desired temperature lower than the predetermined temperature.
2 1 . ごみを焼却 して発生した焼却ガスを燃焼器で燃焼させて焼却ガス 中に含まれるダイォキシンを分解し、 前記燃焼器から排出される燃焼排 ガスを熱交換器に導き、 空気が供給され前記燃焼器に導かれる焼却ガス と間接的に熱交換を行い前記燃焼排ガスを予め定めた温度まで冷却し、 前記熱交換されて冷却した燃焼排ガスをさ らに前記予め定めた温度よ リ も低い所望の温度まで低下させる こと を特徴とする ごみ排ガス処理方法 2 2 . ごみ或いは廃棄物を焼却した焼却ガスを燃焼器で燃焼させて焼却 ガス中に含まれるダイォキシンを分解し、 前記燃焼器から排出される燃 焼排ガスを熱交換器に導き、 前記燃焼器に供給される焼却ガスと間接的 に熱交換を行い、 該燃焼排ガスをダイ ォキシ ン分解の温度領域の範囲内、 或いはダイォキシ ン再生成と分解とが平衡する温度領域の範囲内に冷却 し、 前記熱交換されて冷却 した燃焼排ガスを、 ダイ ォキシンの再生温度 領域以下まで間接的熱交換によってさ らに冷却させる ことを特徴とする ごみ排ガス処理方法。 2 1. The incineration gas generated from the incineration of garbage is burned in a combustor to decompose dioxin contained in the incineration gas, and the combustion exhaust gas discharged from the combustor is led to a heat exchanger to supply air. Then, heat exchange is indirectly performed with the incineration gas led to the combustor to cool the combustion exhaust gas to a predetermined temperature, and the heat exchanged and cooled combustion exhaust gas is further heated to a temperature lower than the predetermined temperature. Waste gas treatment method characterized by lowering the temperature to a low desired temperature 22. Burning incineration gas obtained by incinerating waste or waste in a combustor to decompose dioxin contained in the incineration gas, and from the combustor The discharged combustion exhaust gas is led to a heat exchanger and indirectly interacts with the incineration gas supplied to the combustor. The flue gas is cooled to a temperature within a temperature range of dioxin decomposition or within a temperature range in which dioxin regeneration and decomposition are balanced. Wastewater exhaust gas treatment method, wherein the wastewater is further cooled to below the dioxin regeneration temperature range by indirect heat exchange.
2 3 . ごみを焼却した焼却ガスを燃焼器で燃焼させて、 前記燃焼器から 流下する燃焼排ガスを第 1 の熱交換器に導き、 前記燃焼器に供給される 焼却ガスと間接的に熱交換を行って前記燃焼排ガスを冷却 し、 前記第 1 の熱交換器で冷却された燃焼排ガスを第 2 の熱交換器に導いて、 間接熱 交換によってさ らに前記燃焼排ガスを冷却することを特徴とする ごみ排 ガス処理方法。  23. The incineration gas from the incineration of the refuse is burned in the combustor, and the flue gas flowing down from the combustor is led to the first heat exchanger, where heat is indirectly exchanged with the incineration gas supplied to the combustor. To cool the combustion exhaust gas, conduct the combustion exhaust gas cooled by the first heat exchanger to a second heat exchanger, and further cool the combustion exhaust gas by indirect heat exchange. The waste gas treatment method.
2 4 . ごみを焼却した焼却ガスを燃焼器で燃焼させて、 前記燃焼器から 流下する燃焼排ガスを第 1 の熱交換器に導き、 第 1 の冷却媒体と間接的 に熱交換を行って前記燃焼排ガスを冷却し、 前記第 1 の熱交換器で冷却 された燃焼排ガスを第 2 の熱交換器に導いて、 第 2 の冷却媒体と間接熱 交換を行ってさ らに前記燃焼排ガスを冷却する こ とを特徴とするごみ排 ガス処理方法。  24. The incineration gas from the incineration of the refuse is burned in a combustor, and the flue gas flowing down from the combustor is led to a first heat exchanger, where heat is indirectly exchanged with the first cooling medium to perform the heat exchange. The flue gas is cooled, the flue gas cooled in the first heat exchanger is guided to a second heat exchanger, and indirect heat exchange is performed with a second cooling medium to further cool the flue gas. A waste gas treatment method characterized by the following:
2 5 . ごみを焼却 した焼却ガスを燃焼器で燃焼させて、 前記燃焼器から 流下する燃焼排ガスを第 1 の熱交換器に導き、 前記燃焼排ガスをダイォ キシン分解の温度領域の範囲内、 或いはダイォキシ ン再生成と分解とが 平衡する温度領域の範囲内で冷却 し、 前記第 1 の熱交換器で冷却された 燃焼排ガスを第 2 の熱交換器に導いて、 ダイォキシ ンの再生温度領域以 下までさ らに冷却すること を特徴とする ごみ排ガス処理方法。  25. The incineration gas from the incineration of the refuse is burned in a combustor, and the flue gas flowing down from the combustor is led to a first heat exchanger, and the flue gas is within the temperature range of dioxin decomposition, or Cooling is performed within a temperature range where dioxin regeneration and decomposition are in equilibrium, and the flue gas cooled by the first heat exchanger is led to a second heat exchanger. A waste gas treatment method characterized by further cooling to the bottom.
2 6 . 焼却炉でごみを焼却 して発生する焼却ガスを集塵機に導き、 前記 集塵機にて焼却ガス中の煤塵を捕集して、 煤塵が捕集された前記焼却ガ スに空気を供給して前記焼却ガス中の煤塵濃度を所望の濃度以下に低減 し、 煤塵濃度が低減された前記焼却ガスを燃焼用燃料が供給される燃焼 器で燃焼させて焼却ガス中に含まれるダイォキシンを分解し、 前記燃焼 器で燃焼して排出される燃焼排ガスを熱交換器に導き、 空気が供給され 前記燃焼器に導かれる焼却ガスと間接的に熱交換を行い前記燃焼排ガス を冷却し、 前記熱交換器で冷却された燃焼排ガスを冷却器にて間接熱交 換を行って、 前記燃焼排ガスをさ らに冷却すること を特徴とする ごみ排 ガス処理方法。 26. The incineration gas generated by incineration of refuse in the incinerator is led to a dust collector, and the dust in the incineration gas is collected by the dust collector. Air is supplied to the incinerator to reduce the concentration of dust in the incineration gas to a desired concentration or less. The dioxin contained therein is decomposed, and the flue gas discharged by burning in the combustor is led to a heat exchanger, and heat is indirectly exchanged with the incineration gas supplied with air and led to the combustor, and the flue gas is discharged. A method for treating refuse exhaust gas, comprising cooling and further indirectly exchanging heat of the flue gas cooled by the heat exchanger with a cooler to cool the flue gas.
2 7 . 前記ごみ排ガス処理方法は、 前記燃焼器から熱交換器に流下する 燃焼排ガスを 7 5 0 °C以上の温度で 1 秒以上保持する ことを特徴とする 請求項 1 8 から 2 5 のいずれかに記載のごみ排ガス処理方法。  27. The waste gas treatment method according to claim 18, wherein the combustion exhaust gas flowing down from the combustor to the heat exchanger is maintained at a temperature of 75 ° C. or more for 1 second or more. A waste gas treatment method according to any of the above.
2 8 . 望ま し く は、 前記燃焼排ガスを 8 5 0 °C以上の温度で 1 . 6 秒以 上保持する ことを特徴とする請求項 2 7 に記載のごみ排ガス処理方法。 2 9 . 前記ごみ排ガス処理方法は、 前記燃焼器が前記焼却ガスの温度を 7 5 0 °C以上の温度に燃焼するものであって、 前記熱交換器では燃焼排 ガスの温度を 4 0 O 'Cまで冷却を行い、 前記冷却器では燃焼排ガスを28. The method according to claim 27, wherein the combustion exhaust gas is desirably held at a temperature of 850 ° C or more for 1.6 seconds or more. 29. The waste gas treatment method, wherein the combustor burns the temperature of the incinerated gas to a temperature of 75 ° C. or higher, and the heat exchanger reduces the temperature of the combustion exhaust gas to 40 ° C. Cooling down to 'C
2 0 0 °Cの温度まで 5秒以内の時間で冷却する ことを特徴とする請求項 1 8から 2 5 のいずれかに記載のごみ排ガス処理方法。 26. The refuse exhaust gas treatment method according to claim 18, wherein the refuse exhaust gas is cooled to a temperature of 200 ° C. within 5 seconds.
3 0 . 望ま し く は、 前記冷却器では燃焼排ガスの温度を 2 0 0 °Cまで 3 . 5 秒以内で冷却する こと を特徴とする請求項 2 9 に記載のごみ排ガ ス処理方法。  30. The method according to claim 29, wherein the cooler cools the temperature of the flue gas to 200 ° C within 3.5 seconds.
3 1 . さ らに望ま し く は、 前記冷却器では燃焼排ガスの温度を 3 8 0 °C から 3 3 0 °Cまで 1 秒以内で冷却する こと を特徴とする請求項 2 9 に記 載のごみ排ガス処理方法。  31. More preferably, the cooler cools the temperature of the flue gas from 38 ° C. to 33 ° C. within 1 second in the cooler. Waste gas treatment method.
3 2 . 前記ごみ排ガス処理方法は、 望ま し く は前記冷却器に導かれた燃 焼排ガスを 5 0 °C Z s 以上の冷却速度で冷却する ことを特徴とする請求 ¾ 1 8 から 2 5 のいずれかに記載のごみ排ガス処理方法。 32. The method for treating waste gas preferably comprises the step of controlling the amount of fuel introduced into the cooler. The waste gas treatment method according to any one of claims 18 to 25, wherein the combustion exhaust gas is cooled at a cooling rate of 50 ° CZs or more.
3 3 . さ らに望ま し く は、 前記冷却器に導かれた燃焼排ガスを 5 7 °C Z s 以上の冷却速度で冷却することを特徴とする請求項 3 1 に記載のごみ 排ガス処理方法。 33. The method according to claim 31, wherein the combustion exhaust gas guided to the cooler is cooled at a cooling rate of 57 ° C Zs or more.
3 4 . 前記ごみ排ガス処理システムは、 前記冷却器では熱交換器を経た 燃焼排ガスと水とを間接的に熱交換して蒸気を発生させ、 前記発生蒸気 を前記燃焼器に供給する こと を特徴とする請求項 1 8から 2 5のいずれ かに記載のごみ排ガス処理方法。  34. The refuse exhaust gas treatment system is characterized in that the cooler indirectly exchanges heat with combustion exhaust gas passing through a heat exchanger and water to generate steam, and supplies the generated steam to the combustor. The waste gas treatment method according to any one of claims 18 to 25.
3 5 . ごみを焼却する焼却炉と、 該焼却炉から排出される焼却ガス中の 煤塵を捕集する集塵機と、 該集塵機から導かれた焼却ガスを燃焼させる 燃焼器と、 前記燃焼器の下流側に設置され、 前記焼却ガスと燃焼器から 流下する燃焼排ガスとを間接的に熱交換させて該燃焼排ガスを冷却する 熱交換器と、 前記熱交換器の下流側に設置され、 該熱交換器を経た燃焼 排ガスをさ らに冷却させる冷却器と、 前記焼却炉の内部に設置され、 焼 却炉でごみを燃焼して発生した焼却ガスと熱交換を行い蒸気を発生させ る蒸気発生器と、 前記発生蒸気によって駆動される蒸気タービンと、 該 蒸気タービンと連結された発電機と を有する こと を特徴とするごみ発電 システム。  35. An incinerator for incinerating refuse, a dust collector for collecting dust in incineration gas discharged from the incinerator, a combustor for burning incineration gas guided from the dust collector, and a downstream of the combustor A heat exchanger for cooling the combustion exhaust gas by indirectly exchanging heat between the incineration gas and the combustion exhaust gas flowing down from the combustor; and a heat exchanger installed downstream of the heat exchanger for heat exchange. A cooler that further cools the combustion exhaust gas that has passed through the incinerator, and a steam generator that is installed inside the incinerator and that generates heat by exchanging heat with the incineration gas generated by burning refuse in the incinerator And a steam turbine driven by the generated steam; and a generator connected to the steam turbine.
3 6 . ごみを燃焼して発生した焼却ガスを燃焼器で燃焼させて焼却ガス 中に含まれるダイォキシンを分解し、 前記燃焼器で燃焼して発生する燃 焼排ガスを熱交換器に導き、 前記燃焼器に供給される焼却ガスと間接的 に熱交換させて焼却ガスを冷却し、 前記熱交換器で冷却された燃焼排ガ スを冷却器で間接熱交換を行い、 前記燃焼排ガスをさ らに冷却すると共 に、 ごみを焼却して発生した焼却ガスを蒸気発生器で熱交換して蒸気を 発生させ、 前記発生蒸気を蒸気タービンに導いて該タービンを駆動し、 前記タービンと連結された発電機を駆動して発電を行う こ と を特徴とす る ごみ発電方法。 36. The incineration gas generated by burning the refuse is burned in a combustor to decompose dioxin contained in the incineration gas, and the combustion exhaust gas generated by burning in the combustor is led to a heat exchanger. The incineration gas is cooled by indirectly exchanging heat with the incineration gas supplied to the combustor, the combustion exhaust gas cooled by the heat exchanger is subjected to indirect heat exchange by a cooler, and the combustion exhaust gas is further reduced. In addition to the cooling, the incinerated gas generated by incinerating the refuse is heat-exchanged with a steam generator to produce steam. Generating the generated steam, guiding the generated steam to a steam turbine to drive the turbine, and driving a generator connected to the turbine to generate power.
PCT/JP1999/005638 1999-10-13 1999-10-13 Refuse exhaust gas treating system and treating method WO2001027533A1 (en)

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CN109764345A (en) * 2019-03-01 2019-05-17 焦作市科元化工设备有限公司 A kind of scrap rubber regenerative response kettle treater for waste gas
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