JP2001269538A - Device and method for treating waste gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste gas treating device and a method therefor which treat harmful materials such as dioxins, or the like, in a waste gas with high efficiency and which are not affected by corrosion due to SOx. SOLUTION: A gas cooling device 102 for cooling the waste gas 11 discharged from various incinerators 101, a front stage side dust collecting device 201 for removing soot and dust in the waste gas and for removing a chlorine-based gas and for desulfurization by introducing a neutralizing agent 13, a rear stage side catalytic dust collecting device 202 for removing the remaining soot and dust in the waste gas which has been treated for removing dust and an acidic gas in the waste gas, and a stack 106 for discharging the cleaned waste gas outside through an induction fan 105. The temperature (T1) of the inlet gas of the front stage side dust collecting device 201 is <=250 deg.C, and the temperature (T2) of the inlet gas of the rear stage side dust collecting device 202 is >150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various incinerators such as municipal waste incinerators, industrial waste incinerators, sludge incinerators, etc.
It relates to technology for purifying exhaust gas discharged from pyrolysis furnaces, melting furnaces, etc., especially for halogenated aromatic compounds such as nitrogen oxides and dioxins, highly condensed aromatic hydrocarbons and environmental hormones contained in the exhaust gas. The present invention relates to an exhaust gas treatment device and a treatment method for detoxification.

[0002]

BACKGROUND ART Exhaust gas discharged from various incinerators such as municipal garbage incinerators, industrial waste incinerators, and sludge incinerators includes, for example, hydrogen chloride (HCl), sulfur oxides (SOx), and nitrogen oxides (SOx). NOx), as well as harmful halogenated aromatic compounds represented by dioxins and PCBs, highly condensed aromatic hydrocarbons, and harmful substances such as environmental hormones,
It is a serious social problem as it causes damage to the human body, animals and plants, and destroys the natural environment.

FIG. 5 shows an example of a conventional exhaust gas treatment in a municipal solid waste incineration plant. As shown in FIG. 5, the conventional exhaust gas treatment system includes an object to be treated (for example, municipal waste) 10.
Municipal garbage incinerator 101 for incineration of the incinerator 1 and the incinerator 1
A gas cooling device 102 for cooling the high-temperature (750 to 950 ° C.) exhaust gas 11 discharged from the exhaust gas 11 to about 200 ° C. by heat recovery equipment or water spraying, and hydrogen chloride (HCl), sulfur oxide ( A reaction tower 103 for desulfurizing and desalinating harmful substances such as SOx), a bag filter 104 for filtering dust in the exhaust gas 11 with a filter cloth, and discharging the purified exhaust gas to the outside via an induction blower 105. And a chimney 106. According to this exhaust gas purification system, after neutralization in the reaction tower 103, dust in the exhaust gas can be removed by the bag filter 103, and harmful substances in the exhaust gas 11 can be collected and removed on the filter cloth surface. By collecting harmful substances in the exhaust gas at the same time, dust and harmful substances are removed.

In the reaction tower 103, a considerable amount of slaked lime (Ca (OH) ₂ ) powder is sprayed as a neutralizing agent, and hydrogen chloride ((HCl)), sulfur oxide (S
After neutralizing Ox), dust and neutralized reaction products (CaCl ₂ , CaSO ₄ ) are collected by a filter cloth provided in the bag filter 104. Further, unreacted acidic components and unreacted slaked lime which have not reacted in the reaction tower 103, or dioxins and heavy metals are also removed in the bag filter 104.

However, the bag filter 104 has a problem in that harmful substances in exhaust gas are completely removed only by the bag filter 104. Further, on the downstream side of the bag filter, a large amount of SOx contained in the exhaust gas causes SOx, which could not be removed by the bag filter, to cause corrosion in the piping, thereby further improving the SOx removal efficiency. The emergence of an exhaust gas treatment device for achieving this is desired.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an exhaust gas treatment apparatus and a treatment method which can treat harmful substances such as dioxins in exhaust gas with high efficiency and are free from the influence of SOx corrosion. I do.

[0007]

Means for Solving the Problems The invention of claim 1 of the present invention for solving the above problems is an exhaust gas treatment for removing harmful substances in exhaust gas discharged from incinerators, pyrolysis furnaces, melting furnaces and the like. An apparatus, comprising: a pre-stage dust remover that collects dust in exhaust gas and performs desalination and desulfurization processing; and a post-stage dust remover provided on the downstream side of the pre-stage dust remover. The exhaust gas temperature (T ₁ ) at the inlet of the pre-stage dust remover is T ₁ ≦
The temperature is set to 250 ° C., and the exhaust gas temperature (T ₂ ) at the inlet of the latter-stage dust remover is set to 150 ° C. <T ₂ .

According to a second aspect of the present invention, in the first aspect, the exhaust gas temperature (T ₂ ) at the inlet of the latter-stage dust removing device is 1
It is characterized in that 60 ° C. <T ₂ <200 ° C.

The invention of claim 3 is characterized in that, in claim 1 or 2, the front-stage dust collector and the rear-stage dust collector are bag filters.

[0010] The invention of claim 4 is characterized in that, in claim 3, the front-stage dust collector is a bag filter carrying a catalyst.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the front-stage dust collector and the rear-stage dust collector are integrally formed.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the neutralizing agent introduced into the front-stage dust removing device is an alkali compound. The alkali compound is preferably calcium hydroxide, magnesium hydroxide, or the like.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, an adsorbent spraying means for spraying the adsorbent on the upstream side of the downstream-side dust remover is provided. .

The invention according to claim 8 is an exhaust gas treatment method for adsorbing and removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace, or the like. A harmful substance contained in exhaust gas is decomposed and removed by the exhaust gas treatment device according to one of the above aspects.

According to a ninth aspect of the present invention, in the eighth aspect, the harmful substance in the exhaust gas is selected from dioxins, polyhalogenated biphenyls, halogenated benzenes, halogenated phenols, and halogenated toluenes. It is characterized in that it is at least one halogenated aromatic compound, a highly condensed aromatic hydrocarbon, and an environmental hormone.

The invention of claim 10 is the invention according to claim 9, wherein the dioxins are polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polybrominated dibenzo-p-dioxins. (PBDDs), polybrominated dibenzofurans (PB
DFs), polyfluorinated dibenzo-p-dioxins (P
FDDs), polyfluorinated dibenzofurans (PFDF)
s), polyiodinated dibenzo-p-dioxins (PI
DDs), polyiodinated dibenzofurans (PIDFs)
It is characterized by being.

An eleventh aspect of the present invention is an exhaust gas treatment system for removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace, etc., wherein a cooling means for cooling the exhaust gas, An exhaust gas treatment apparatus according to any one of claims 1 to 7, which removes soot and dust contained in the exhaust gas.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

[First Embodiment] FIG. 1 is a schematic diagram of an exhaust gas treatment system according to a first embodiment. First, as shown in FIG.
A gas cooling device (cooling means such as a boiler or water spray) 102 for cooling exhaust gas 11 discharged from various incinerators 101 such as an incinerator for municipal waste, an industrial waste incinerator, and a sludge incinerator;
A front-stage dust remover 201 that removes dust in the exhaust gas 11 and performs desalination and desulfurization by introducing a neutralizing agent 13.
And a subsequent-stage catalyst dust remover 202 that removes dust in the exhaust gas and the remaining dust in the exhaust gas that has been treated with the acid gas,
A chimney 106 that discharges the purified exhaust gas to the outside via an induction blower 105. The exhaust gas temperature (T ₁ ) at the inlet of the front-stage dust remover 201 is set to T ₁ ≦ 250 ° C., and the rear-stage dust remover is set. The temperature of the exhaust gas at the inlet of the device 202 (T ₂ ) is set to 150 ° C. <T ₂ .

That is, in the present exhaust gas purification system, the exhaust gas temperature (T ₁ ) at the inlet of the exhaust gas is controlled to T ₁ ≦ 250 ° C. while the neutralizing agent 13 is charged in the pre-stage dust remover 201, and In order to remove dust and neutralizers and reaction products, and to further purify the exhaust gas purified by the first-stage dust remover 201, the second-stage dust remover 20 is used.
In step 2, the inlet exhaust gas temperature (T ₂ ) is controlled to 150 ° C. <T ₂ to remove harmful substances such as low-boiling metals and dioxins.

The pre-stage dust removing device 201 and the post-stage dust removing device 202 according to the present embodiment are not particularly limited as long as they are known dust removing devices for removing dust in exhaust gas. Examples include a dust collector (EP), a bag filter (BF), and a multicyclone (MC), and a bag filter is particularly preferable.

Here, the material of the filter cloth of the bag filter may be a known one such as a woven cloth such as polyester, polyamide and polypropylene, or a non-woven cloth such as felt. Other materials include glass fiber, heat-resistant nylon (trade name), and Teflon (trade name). In addition, as a method of removing the attached dust, a vibration type,
Known means such as a reverse cleaning type and a pulse jet type may be applied.

Further, the front-stage dust remover 201 may be a bag filter, and the bag filter may carry a catalyst. When a bag filter carrying a catalyst is used, the temperature of the exhaust gas at the inlet (T ₁ ) is set to 250 ° C. or lower in order to improve the catalytic activity. Inlet exhaust gas temperature (T ₁ ) can be 200 ° C. or less.

The dioxin-decomposing catalyst carried on the bag filter body of the above-mentioned bag filter 201 and having the denitration and dioxin-decomposing effects is not particularly limited. For example, titanium (Ti), silicon (S)
i), aluminum (Al), Zr (zirconium),
For example, vanadium (V), tungsten (W), molybdenum (Mo) is applied to a carrier made of at least one selected from P (phosphorus) and B (boron) or a carrier made of a composite oxide containing two or more of these elements. A catalyst such as one carrying an active component composed of at least one oxide of oxides of niobium, niobium (Nb) and tantalum (Ta), and a known dioxin decomposition catalyst can be used. Not something.

In the above system, the dust in the exhaust gas is removed with high efficiency by the pre-stage dust remover 201. Further, acid gas such as HCl and SOx in the exhaust gas reacts with a neutralizer of an alkali compound such as Ca (OH) ₂ to react with CaCl ₂ or CaS _2.
Although it is removed as a solid such as O ₃ and CaSO ₄ , a very small amount of unreacted SOx or the like is carried into the subsequent-stage dust removing device 202.

The low-boiling-point vapors become liquid and are removed together with the dust below the boiling point due to their physical properties. is there. Further, gaseous organic halogen compounds such as dioxins are brought into the latter-stage dust remover 202 due to their vapor pressure and the like. Therefore, in the present invention, in order to efficiently adsorb and remove these gaseous substances, solid-gas contact is achieved by supplying and adding an adsorbent 203 such as activated carbon on the upstream side of the latter-stage dust remover 202. Efficient removal can be efficiently performed by the succeeding-stage dust removing device 202.

Further, in the present invention, the front-stage dust remover 20
1, the exhaust gas temperature (T ₁ ) is set to T ₁ ≦ 250 ° C., and the exhaust gas temperature (T ₂ ) at the inlet of the downstream-side dust remover 202 is set.
Is set to 150 ° C. <T ₂ , so even if there is SOx or the like leaked from the pre-stage dust remover 201, it is sent to the post-stage as it is in a gaseous state because the temperature is higher than the acid dew point temperature. This prevents internal corrosion in the rear-side dust removing device 202 from occurring.

Here, the reason why the temperature of the exhaust gas at the inlet (T ₂ ) of the latter-stage dust removing apparatus 202 is set to a temperature exceeding 150 ° C. in the present invention is “the dew point temperature of the sulfuric acid mist” shown in FIG.
As shown in the figure below, at 150 ° C or lower, the dew point rises due to the effect of moisture in the exhaust gas (the average moisture content in the exhaust gas is about 30 to 40%), forming a mist and coagulating to form a dust removal device or the like. This is because they adhere to the inside of the casing, and as a result, internal corrosion occurs.

Further, as the inlet temperature (T ₂ ) of the exhaust gas of the latter-stage dust remover 202, it is particularly preferable that the inlet gas temperature (T ₂ ) be 160 ° C. or more and the outlet gas temperature (T ₃ ) of the latter-stage dust remover 202. Preferably, the temperature is higher than 150 ° C. This prevents agglomeration inside the apparatus and prevents the occurrence of corrosion.

According to this exhaust gas purification system, most of the dust is removed by removing dust in the exhaust gas and removing hydrochloric acid and sulfur oxides (SOx) in the exhaust gas 11 by the pre-stage dust remover 201. Therefore, a large amount of dust component does not adhere to the rear-stage bag filter 202, which facilitates washing and regeneration of the bag filter body.

Here, examples of the activated carbon as an example of the adsorbent 203 include coal coal, coconut charcoal, resin charcoal, wood charcoal, and peat charcoal, but the present invention is not limited thereto. Not something.

The adsorbent 203 other than the activated carbon is a porous adsorbent for adsorbing dioxins.
For example, volcanic ash, silica-based substances such as silica gel, shirasu, and chromosolve, clay minerals such as zeolite and mordenite, apatite, bone charcoal, phosphate compounds such as ammonium magnesium phosphate granules, carbonate compounds such as coral fossils, calcium carbonate, Alumina, crystalline silicate, silica-alumina and the like are used, and it is particularly preferable to use silica gel, crystalline silicate, granulated ammonium magnesium phosphate, coral fossil, zeolite and volcanic ash.

FIG. 3 shows the relationship between the inlet temperature of the rear bag filter and the dioxin removal rate (%). Activated carbon 20
When the amount of No. 3 was changed to 0%, 5% and 10%, if the inlet temperature was 160 ° C. or higher, dioxins were almost 10%.
It was found to be 0% degraded. Therefore, it was found that a decomposition rate of 95% could be obtained if the inlet temperature (T ₂ ) was about 200 ° C. even when there was no activated carbon (0%).

Here, the sulfur oxide treated in the present invention,
The harmful substances in the exhaust gas other than hydrogen chloride are harmful substances such as harmful halogenated aromatic compounds represented by dioxins and PXB (X represents halogen), and highly condensed aromatic hydrocarbons. However, the present invention is not limited to these as long as they are harmful substances (or environmental hormones) in the exhaust gas treated according to the present invention.

The aromatic halogen compound to be treated in the present invention is not limited to harmful substances (for example, environmental hormones) represented by dioxins and PCBs. Here, the dioxins are:
Polyhalogenated dibenzo-p-dioxins (PXD
Ds) and polyhalogenated dibenzofurans (PXDF)
s) (X represents halogen), and is said to be generated in a small amount when a halogen compound and a certain organic halogen compound are burned. Depending on the number of halogens, there are monohalides to octahalides, of which dibenzo-p-dioxin tetrachloride (T ₄ CDD) is known to have the highest toxicity. The harmful halogenated aromatic compounds include, in addition to dioxins, various organic halogen compounds which are precursors thereof (for example, aromatic compounds such as phenol and benzene (for example, halogenated benzenes, halogenated phenols and halogenated phenols). Toluene) and alkyl halide compounds) and need to be removed. That is, dioxins represent not only chlorinated dioxins but also halogenated dioxins such as brominated dioxins.
PXBs (polyhalogenated biphenyls) are a general term for compounds in which several halogen atoms are added to biphenyl, and there are isomers depending on the number and position of substitution of halogen, but in the case of PCB (polychlorinated biphenyl), , 2,6
-Dichlorobiphenyl, 2,2'-dichlorobiphenyl,
2,3,5-Trichlorobiphenyl and the like are typical, are highly toxic, and are known to cause the generation of dioxins when incinerated, and need to be removed. In addition, PXBs are naturally coplanar PX.
It goes without saying that B is also included.

[0036] Highly condensed aromatic hydrocarbons are a general term for polynuclear aromatic compounds, which may contain one or more OH groups, are recognized as carcinogenic substances, and need to be removed from exhaust gas. .

In many production processes, exhaust gas containing, for example, gaseous organic compounds such as formaldehyde, benzene or phenol in addition to dust may be generated. These organic compounds are also environmental pollutants and significantly impair human health and need to be removed from the exhaust gas.

The nitrogen oxide to be treated in the present invention usually means NO and NO ₂ , and a mixture thereof.
It is also called NOx. However, the NOx often contains various oxidation numbers and unstable nitrogen oxides in addition to the above. Accordingly, x is not particularly limited, but is usually a value of 1 to 2. It becomes nitric acid, nitrous acid, etc. in rainwater or NO, or NO is said to be one of the main causes of photochemical smog, and is a harmful compound to the human body.

In the present invention, the dioxin-decomposing catalyst carried on the bag filter body of the bag filter 201 in the former stage and having the denitration and dioxin-decomposing effects is not particularly limited. Ti), silicon (Si), aluminum (A
l), a carrier composed of at least one selected from Zr (zirconium), P (phosphorus) and B (boron) or a carrier composed of a composite oxide containing two or more of these elements,
For example, catalysts such as those carrying an active component comprising at least one oxide of oxides of vanadium (V), tungsten (W), molybdenum (Mo), niobium (Nb) or tantalum (Ta); A known dioxin decomposition catalyst can be used, and is not particularly limited.

By the catalytic action of the dioxin decomposition catalyst, halogenated aromatic compounds, precursors of halogenated aromatic compounds, halogenated aromatic compounds such as PXB in the exhaust gas of the harmful substances, aromatic compounds having a high degree of condensation, Decomposes hydrocarbons and environmental hormones.

[Second Embodiment] FIG. 2 shows a schematic diagram of an exhaust gas treatment apparatus according to a second embodiment. The processing apparatus of the present embodiment is one in which the front-stage dust collector and the rear-stage catalyst bag filter are integrated. As shown in FIG. 2, the exhaust gas treatment apparatus according to the present embodiment includes a front-stage bag filter 301 that collects dust in the exhaust gas 11 and performs desalination and desulfurization processing. The rear-stage bag filter 302 provided is integrally formed, the inlet exhaust gas temperature (T ₁ ) of the front-stage bag filter 301 is set to T ₁ ≦ 250 ° C., and the inlet exhaust gas temperature of the rear-stage bag filter 302 ( T ₂ ) at 150 ° C. <T
_It is made to be ₂ .

The front-stage bag filter 301 and the rear-stage bag filter 302 both include an inlet duct 21 for introducing the exhaust gas 11 and a plurality of bag filter bodies communicating with the inlet duct 21 for removing dust. Chamber (in this embodiment, four chambers) 22 and an outlet duct 24 for discharging exhaust gas after the dust treatment,
The outlet duct 24 of No. 01 and the inlet duct 21 of the latter-stage bag filter 302 are connected by a communication pipe 303.
Further, the neutralizing agent 13 is supplied to the inlet duct 21 of the front-stage bag filter 301 by supply means (not shown).
Activated carbon 14 is supplied to the inlet duct of the latter-stage bag filter 302 by supply means (not shown).

As a result, dust is removed from the front bag filter 301, desalting and desulfurization by the neutralizing agent 13 are performed, and dioxins and the like are adsorbed by the activated carbon 14 in the rear bag filter 302, and the exhaust gas is discharged. The processing unit can be made more compact,
Even if there is SOx or the like leaked from the pre-stage dust remover, since the exhaust gas temperature at the inlet of the post-stage dust remover is higher than the acid dew point temperature, the gas is sent to the post-stage as it is in a gaseous state. Can prevent the occurrence of internal corrosion.

[0044]

As described above, according to the invention of claim 1 of the present invention, an exhaust gas treatment apparatus for removing harmful substances from exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace or the like. And a front-stage dust remover that collects dust in exhaust gas and performs desalination, desulfurization, and denitration processing, and a rear-stage dust remover that is provided downstream of the front-stage dust remover. , The inlet exhaust gas temperature (T ₁ ) of the pre-stage dust removing apparatus is set to T ₁ ≦
Since the temperature is set to 250 ° C. and the exhaust gas temperature (T ₂ ) at the inlet of the downstream side dust remover is set to 150 ° C. <T ₂ , even if there is SOx or the like leaked from the upstream side dust remover, the inlet exhaust gas of the downstream side dust remover Since the temperature is set to be equal to or higher than the acid dew point temperature, the gas is sent to the subsequent stage in a gaseous state, thereby preventing the occurrence of internal corrosion in the latter-stage dust remover.

According to the second aspect of the present invention, the exhaust gas temperature (T ₂ ) at the inlet of the latter-stage dust remover is 160 ° C. <T ₂ <
Since the temperature is set to 200 ° C., the gas outlet temperature of the latter-stage dust remover can be maintained at the acid dew point temperature or higher, and the internal corrosion can be further prevented.

According to the third aspect of the present invention, since the front-stage dust collector and the rear-stage dust collector are bag filters, the ability to remove dust from exhaust gas is improved.

According to the fourth aspect of the present invention, since the front-stage dust collector is a bag filter carrying a catalyst, it is possible to decompose and remove harmful substances together with dust.

According to the fifth aspect of the present invention, the front-stage dust collector and the rear-stage dust collector are integrally formed.
The device can be made compact.

According to the invention of claim 6, since the neutralizing agent introduced into the pre-stage dust removing device is an alkaline compound such as calcium hydroxide, removal by the neutralization reaction can be performed efficiently.

According to the seventh aspect of the present invention, the adsorbent spraying means for spraying the adsorbent such as activated carbon on the upstream side of the downstream-side dust remover is provided, so that gaseous harmful substances can be efficiently removed. Done.

According to the invention of claim 8, there is provided an exhaust gas treatment method for adsorbing and removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace or the like.
A system that can efficiently remove harmful substances in exhaust gas and efficiently protect the inside of the dust removal equipment from corrosive environments because the harmful substances in exhaust gas are decomposed and removed by the exhaust gas treatment device of any one of Can be provided.

According to the invention of claim 09, at least one selected from dioxins, polyhalogenated biphenyls, halogenated benzenes, halogenated phenols and halogenated toluenes, which are harmful substances in the exhaust gas. Halogenated aromatic compounds, highly condensed aromatic hydrocarbons and environmental hormones can be removed.

According to the tenth aspect of the present invention, the 0th aspect
9, the dioxins polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polybrominated dibenzo-p-
Dioxins (PBDDs), polybrominated dibenzofurans (PBDFs), polyfluorinated dibenzo-p-dioxins (PFDDs), polyfluorinated dibenzofurans (P
FDFs), polyiodinated dibenzo-p-dioxins (PIDDs), polyiodinated dibenzofurans (PID)
Fs).

According to the invention of claim 11, the incinerator,
An exhaust gas treatment system for removing harmful substances in exhaust gas discharged from a pyrolysis furnace, a melting furnace, or the like, comprising a cooling means for cooling the exhaust gas, and removing dust in the cooled exhaust gas. The exhaust gas treatment apparatus according to any one of the above aspects enables efficient exhaust gas treatment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of an exhaust gas treatment system according to a first embodiment.

FIG. 2 is a dew point temperature diagram of a sulfuric acid mist.

FIG. 3 is a diagram showing a relationship between a dioxin removal rate and a filter inlet temperature.

FIG. 4 is a schematic diagram of an exhaust gas treatment apparatus according to a second embodiment.

FIG. 5 is a schematic diagram showing an example of an exhaust gas treatment system according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Exhaust gas 13 Neutralizer 14 Activated carbon 21 Inlet duct 22 Dust removal room 24 Outlet duct 100 Processing object (garbage) 101 Incinerator 102 Gas cooling device 103 Reaction tower 104 Bag filter 105 Induced blower 106 Chimney 201 Front stage dust remover 202 Rear stage Dust removal device 203 Adsorbent 301 Front-stage bag filter 302 Rear-stage bag filter 303 Communication pipe

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01D 53/86 ZAB B01D 53/36 ZABG 53/94 101A F23G 5/44 ZAB F23J 15/00 B F23J 15 / 00 H (72) Inventor Kenichi Sato 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. F-term (reference) 3K065 AA24 AB01 AB02 AB03 AC01 AC02 BA05 BA08 BA10 HA02 HA03 3K070 DA02 DA03 DA05 DA07 DA09 DA16 DA22 DA23 DA26 DA29 DA30 DA33 DA37 DA48 DA58 4D002 AA02 AA12 AA21 AA32 AA33 BA03 BA13 DA14 DA06 DA06 DA07 DA47 DA70 EA02 EA05 EA13 GA01 GA03 GB03 HA01 4D048 AA02 AA11 AB03 BA03Y BA04Y BA06Y BA07Y BA08Y BA23Y BA24Y BA26Y BA27Y BA44Y BB08 CA03 CA07 CC33 CC38 CD05 DA01 DA02 DA06 EA07 4D058 JA04 KB12 MA01 MA12 MA15 MA25 SA20 TA06

Claims (11)

[Claims] An exhaust gas treatment device for removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace, etc., which collects dust in the exhaust gas and performs desalination and desulfurization. A front-stage dust remover, and a rear-stage dust remover provided downstream of the front-stage dust remover, wherein the inlet exhaust gas temperature (T ₁ ) of the front-stage dust remover is T ₁ ≦ 25.
An exhaust gas treatment apparatus characterized in that the temperature is set to 0 ° C. and the exhaust gas temperature (T ₂ ) at the inlet of the downstream side dust removing apparatus is set to 150 ° C. <T ₂ . 2. The exhaust gas temperature (T ₂ ) at the inlet of the downstream-side dust removing device according to claim 1,
An exhaust gas treatment apparatus characterized by satisfying the condition of <° C. <T ₂ <200 ° C. 3. The exhaust gas treatment device according to claim 1, wherein the front-stage dust collector and the rear-stage dust collector are bag filters. 4. The exhaust gas treatment device according to claim 3, wherein the front-stage dust collector is a bag filter carrying a catalyst. 5. The exhaust gas treatment apparatus according to claim 1, wherein the front-stage dust collector and the rear-stage dust collector are integrally formed. 6. The exhaust gas treatment apparatus according to claim 1, wherein the neutralizing agent introduced into the pre-stage dust remover is an alkali compound. 7. An exhaust gas treatment apparatus according to claim 1, further comprising adsorbent spraying means for spraying the adsorbent on the upstream side of the downstream side dust removing apparatus. 8. An exhaust gas treatment method for adsorbing and removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace, or the like, wherein the exhaust gas treatment apparatus according to any one of claims 1 to 7. An exhaust gas treatment method comprising decomposing and removing harmful substances in exhaust gas. 9. The method according to claim 8, wherein the harmful substance in the exhaust gas is at least one halogenated aromatic selected from dioxins, polyhalogenated biphenyls, halogenated benzenes, halogenated phenols and halogenated toluenes. An exhaust gas treatment method comprising a compound, a highly condensed aromatic hydrocarbon and an environmental hormone. 10. The method of claim 9, wherein the dioxins are polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polybrominated dibenzo-p-dioxins (PBDDs), polyodors. Dibenzofurans (PBD
Fs), polyfluorinated dibenzo-p-dioxins (PF
DDs), polyfluorinated dibenzofurans (PFDFs),
Polyiodinated dibenzo-p-dioxins (PIDD
s), an exhaust gas treatment method characterized by being polyiodinated dibenzofurans (PIDFs). 11. An exhaust gas treatment system for removing harmful substances in exhaust gas discharged from an incinerator, a pyrolysis furnace, a melting furnace, or the like, comprising: a cooling means for cooling the exhaust gas; An exhaust gas treatment system comprising the exhaust gas treatment device according to any one of claims 1 to 7 for removing dust.