JP4675804B2 - Polychlorinated biphenyl contaminant treatment facility - Google Patents

Description

The present invention relates to a polychlorinated biphenyl contaminant treatment facility for detoxifying a contaminant containing heavy metal contaminated with polychlorinated biphenyl.

PCB contaminants such as sludge containing polychlorinated biphenyl (hereinafter also simply referred to as PCB), waste with PCB attached, industrial products containing PCB such as fluorescent ballasts or pressure-sensitive copying paper have various properties and PCB content Is not constant. For this reason, a demonstration test of a system in which PCB contaminants are sealed in a sealed container such as a drum can and put into a plasma decomposition apparatus (plasma melting furnace) as it is and detoxified (thermal decomposition) is performed (for example, Patent Documents 1 and 2).
Here, when the PCB is detoxified by the plasma decomposition apparatus, hydrogen chloride is generated from the chloride in the PCB contaminated material, and a part of the heavy metal (for example, lead and cadmium) is volatilized to generate dust (flying). Ashes are mixed into the exhaust gas and discharged from the plasma decomposition apparatus. Furthermore, hydrogen chloride generated by the decomposition of PCBs, PCB decomposition products, dioxins generated by thermal polymerization from PCB decomposition products, and harmful organic substances including one or more of undecomposed PCBs are also mixed in the exhaust. It is discharged from the plasma decomposition apparatus. For this reason, when exhaust gas discharged from the plasma decomposition apparatus is drawn into the dust removal apparatus and dust is removed, an alkaline agent such as slaked lime and activated carbon are blown into the dust removal apparatus, for example, slaked lime and heavy metals and hydrogen chloride in the exhaust gas. Are reacted to collect heavy metals and hydrogen chloride as heavy metal hydroxides and calcium chloride, and adsorb the harmful organic substances on the activated carbon to remove the harmful organic substances.

Japanese Patent Laid-Open No. 11-190798 JP 2000-2411 A

However, since the dust collected by the dust removal device contains heavy metals and hydrogen chloride that have reacted with alkaline chemicals and activated carbon that has adsorbed harmful organic substances, the collected dust can be used, for example, for landfill disposal. Is necessary to treat heavy metals with chemicals so that the elution amount satisfies the landfill standard value, and activated carbon must be treated to detoxify harmful organic substances. There is a problem that costs increase. On the other hand, in order to prevent the melting temperature of the slag bath existing in the plasma decomposition apparatus from rising and the fluidity of the slag from decreasing, basicity adjusting agents (for example, alkali metals such as sodium carbonate and slaked lime, alkaline earths) Since a substance containing metal) is put into the plasma decomposition apparatus, there is a problem that the running cost of the plasma decomposition apparatus also increases.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a treatment facility for polychlorinated biphenyl contaminants containing heavy metals contaminated with polychlorinated biphenyl, whose running cost and final disposal cost are both low. .

The polychlorinated biphenyl contaminant treatment facility according to the present invention, which meets the above-mentioned object, treats contaminant contaminated with polychlorinated biphenyl containing heavy metal at a high temperature to volatilize the heavy metal and decomposes the polychlorinated biphenyl with plasma. A polychlorinated biphenyl contaminant treatment facility equipped with a plasma decomposing apparatus and a dust removing apparatus for removing dust contained in exhaust gas discharged from the plasma decomposing apparatus,
The dust removing device draws in the exhaust gas, passes through a filter cloth on which an alkaline agent adsorption layer is formed in advance, and collects the dust and contains the alkaline agent in the alkaline agent adsorption layer and the exhaust gas. A first bag filter that reacts and removes hydrogen chloride and the volatilized heavy metal, respectively, and discharges the primary treatment exhaust;
The primary treatment exhaust is drawn in, and passes through a filter cloth in which an adsorption layer of an alkaline agent and activated carbon is formed in advance, and remains in the primary treatment exhaust while collecting dust remaining in the primary treatment exhaust. Hydrogen chloride and volatilized heavy metal react with the alkaline agent in the adsorption layer to form a reaction product, and a decomposition product of the polychlorinated biphenyl present in the primary treatment exhaust gas, a part of the decomposition product A harmful organic substance containing any one or more of dioxins synthesized from the above and undecomposed polychlorinated biphenyl is adsorbed on activated carbon in the adsorption layer and removed from the primary treatment exhaust gas to obtain a secondary It has a second bag filter for discharging process exhaust,
In addition, the dust taken out from the second bag filter, and the adsorption layer containing the reactant, the activated carbon that adsorbs the harmful organic substance, and the unreacted alkaline agent are supplied into the plasma decomposition apparatus. A recycling channel is provided .

In the polychlorinated biphenyl contaminant treatment facility according to the present invention, it is preferable that a cooler for rapidly cooling the exhaust discharged from the plasma decomposition apparatus is provided on the downstream side of the plasma decomposition apparatus.

In the treatment facility for polychlorinated biphenyl contaminants according to claim 1, since the activated carbon is not contained in the dust and alkaline chemical adsorption layer taken out from the first bag filter, the treatment of organic matter caused by the activated carbon, Because there is no need to dispose of harmful substances adsorbed on activated carbon, it can be easily disposed of as landfill by treating heavy metal hydroxides and chlorides contained in the dust and alkaline chemical adsorption layers. Become. Further, in the second bag filter, the decomposition product of polychlorinated biphenyl contained in the primary treatment exhaust gas can be sufficiently collected by adjusting the content of the activated carbon, so the secondary treatment exhaust gas is cleaned. At the same time, synthesis of dioxins can be prevented in the secondary treatment exhaust.

In particular, in this polychlorinated biphenyl contaminant treatment facility, the activated carbon portion in the adsorption layer serves as a heat source for the plasma decomposition device, and the alkali metal or alkaline earth metal component derived from the alkaline chemical in the adsorption layer serves as the plasma decomposition device. Each of them can be recycled as a basicity adjusting agent of the slag bath, and it is possible to reduce the running cost of the plasma decomposing apparatus and to make the activated carbon adsorbing harmful organic substances harmless at low cost.

Furthermore, if a cooler for rapidly cooling the exhaust discharged from the plasma decomposition apparatus is provided, it is possible to prevent dioxins from being synthesized from the decomposition product of polychlorinated biphenyl contained in the exhaust. Further, the exhaust temperature is lowered, so that the filter cloths of the first and second bag filters can be prevented from being damaged, and the dust removing apparatus can be stably operated over a long period of time.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a block diagram of a polychlorinated biphenyl contaminant treatment facility according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a plasma decomposition apparatus of the polychlorinated biphenyl contaminant treatment facility.

As shown in FIG. 1, the polychlorinated biphenyl contaminant treatment facility 10 according to one embodiment of the present invention uses, for example, heavy metal (eg, cadmium, lead) enclosed in a metal container such as a pail can or a drum can. A plasma decomposition apparatus 12 that treats a contaminant 11 contaminated with PCB (hereinafter referred to as PCB contamination 11) at a high temperature and decomposes the PCB with plasma, and a plasma decomposition apparatus 12 provided downstream of the plasma decomposition apparatus 12 The dust contained in the exhaust gas is collected while passing through the cooler 13 that rapidly cools the exhaust gas containing the dust discharged from the air and the filter cloth 14 in which the exhaust gas is drawn and formed with the slaked lime layer as an example of the adsorption layer of the alkaline agent The first bag filter 15 that discharges the primary treatment exhaust and the primary treatment exhaust are drawn in to form an adsorption layer of slaked lime and activated carbon, which is an example of an alkaline chemical. A dust removing device 18 having a second bag filter 17 that collects dust remaining in the primary treatment exhaust gas while passing through the filter cloth 16 and discharges the secondary treatment exhaust gas; A recycle channel 19 is provided for supplying the extracted discharge into the plasma decomposition apparatus 12. Hereinafter, these will be described in detail.

As shown in FIG. 2, the plasma decomposition apparatus 12 contains a PCB contaminant 11 and, for example, a plasma decomposition furnace 20 that melts and thermally decomposes the PCB contaminant 11 with plasma at a furnace temperature of 1400 ° C. to 1600 ° C. The plasma decomposition furnace 20 is provided with a contaminant input chamber 21 for introducing the PCB contaminant 11. Here, the pollutant input chamber 21 is connected to the inside of the plasma decomposition furnace 20 on the downstream side, and a cylindrical transfer unit 22 held in a horizontal state and a first openable / closable provided at an intermediate part of the transfer unit 22. Door 23, a second door 25 that is provided on the downstream side so as to be openable and closable, has a water cooling function, an inlet (not shown) that is provided on the upstream side of the transport unit 22 and into which the PCB contaminants 11 are loaded, And a pusher 26 which is provided at the upstream end of the section 22 and pushes the PCB contaminant 11 inserted from the inlet into the downstream side.

With such a configuration, the PCB contaminant 11 sealed in the metal container can be charged from the loading port to the upstream side of the contaminant charging chamber 21 in a sealed state. Then, by opening the first door 23 and the second door 25 and pushing out the PCB contaminant 11 to the downstream side by the pusher 26, the transport unit 22 can be rolled and put into the plasma decomposition furnace 20.
Here, by providing the second door 25 having a water cooling function, the airtightness in the plasma decomposition furnace 20 is maintained when the PCB contaminant 11 is charged from the inlet to the upstream side of the contaminant input chamber 21. In addition, it is possible to prevent the PCB contaminant 11 and the pusher 26 charged on the upstream side of the contaminant input chamber 21 from being exposed to high heat in the plasma decomposition furnace 20. This prevents the gas in the plasma decomposition furnace 20 from passing through the transport unit 22 and being discharged from the loading port when the PCB contaminant 11 is charged into the contaminant input chamber 21. It is possible to prevent the enclosed metal container from being damaged in the contaminant input chamber 21 and contaminating the contaminant input chamber 21 with the PCB contaminant 11 or damaging the pusher 26.

The plasma decomposition furnace 20 is a furnace that generates a plasma arc. For example, two plasma torches 27 and 28 are mounted. Here, as the plasma torches 27 and 28, non-migration type plasma torches having an anode and a cathode are used. As a result, even if the PCB contaminant 11 contains an electrically insulating material such as concrete waste, a plasma arc can be generated efficiently. Further, the plasma torches 27 and 28 are provided with a gas injection port (not shown), and a gas (for example, air) can be continuously sent between the anode and the cathode, and the temperature of the gas between the anode and the cathode can be controlled. Can be hot. Further, the plasma torches 27 and 28 are provided with a movable device (not shown) that freely moves the plasma torches 27 and 28 in three dimensions (vertical, horizontal, and height three directions). Thereby, the plasma torches 27 and 28 can be moved according to the processing state of the PCB contaminant 11 in the plasma decomposition furnace 20, and the PCB contaminant 11 can be selectively irradiated with plasma.

In addition, the plasma decomposition furnace 20 is provided with a tilt mechanism (not shown), and by tilting the plasma decomposition furnace 20, the molten slag 31 can be taken out from the slag discharge port 30 formed in the lower part of the plasma decomposition furnace 20. ing. The extracted slag 31 is sequentially injected into the slag recovery container 32 arranged below the plasma decomposition furnace 20, and the slag recovery container 32 into which the slag 31 has been injected is sequentially discharged outward. It has become.
Further, dust generated in the plasma decomposition furnace 20, volatilized heavy metal, hydrogen chloride and PCB decomposition products generated by thermal decomposition of the PCB contaminant 11, and exhaust gas containing undecomposed PCB are placed in the upper part of the plasma decomposition furnace 20. The gas is discharged from the formed gas discharge port 33 to the outside. The slag 31 is produced by melting one or more incombustible materials of the earth, sand, metal, and concrete in the PCB pollutant 11 in the plasma decomposition furnace 20. It is a mixture containing any two or more of alumina and calcium oxide.

The cooler 13 has a plurality of water spray nozzles that spray water on the exhaust gas taken out from the gas discharge port 33 of the plasma decomposition furnace 20, and a plurality of air spray nozzles that spray air. For example, the temperature of the exhaust gas that has flowed into 13 can be rapidly cooled to 200 ° C. or lower and discharged. By rapidly cooling the exhaust gas temperature to 200 ° C. or lower, it is possible to suppress the formation of dioxins from the PCB decomposition product in the exhaust gas. The moisture content in the exhaust gas discharged from the cooler 13 is adjusted so that the first and second bag filters 15, 17 installed at the subsequent stage of the cooler 13 can be operated satisfactorily.

The first bag filter 15 includes an exhaust storage container 34 that receives the exhaust discharged from the cooler 13, and dust contained in the exhaust while being provided in the exhaust storage container 34 while passing the exhaust from the outside to the inside. And filter cloth 14 to be collected. The first bag filter 15 includes slaked lime spraying means (not shown) for blowing slaked lime stored in the slaked lime tank 35 into the exhaust storage container 34. By operating the dust collecting function provided in the first bag filter 15 while blowing slaked lime into the exhaust container 34 by the slaked lime spraying means, the blown slaked lime can be adhered to the outer surface of the filter cloth 14. A slaked lime layer can be formed on the outer surface of the cloth 14.
Thus, when exhaust gas is introduced into the first bag filter 15 having the filter cloth 14 in which the slaked lime layer is formed in advance on the outer surface, the exhaust gas flows from the outer surface to the inner surface of the filter cloth 14 on which the slaked lime layer is formed. At that time, a part of hydrogen chloride reacts with slaked lime to change to calcium chloride, a part of heavy metal reacts with slaked lime to change to a heavy metal hydroxide, and is removed from the exhaust gas. A part of can be captured by the slaked lime layer on the surface of the filter cloth 14. The first bag filter 15 passes through the primary processing exhaust gas containing the remainder of dust, the remainder of hydrogen chloride, the remainder of heavy metal, PCB decomposition products, dioxins, and undecomposed PCB. Introduced into the filter 17.

The second bag filter 17 includes an exhaust storage container 36 that receives the primary processing exhaust gas introduced from the first bag filter 15, and the primary processing exhaust gas that is provided in the exhaust storage container 36 from the outside to the inside. And a filter cloth 16 that collects the remainder of the dust contained in the primary treatment exhaust gas. Further, the second bag filter 17 includes a mixture injection means (not shown) for blowing the slaked lime stored in the slaked lime tank 35 and the activated carbon stored in the activated carbon tank 37 into the exhaust storage container 36 in a mixed state. By operating the dust collecting function provided in the second bag filter 17 while blowing the mixture of slaked lime and activated carbon into the exhaust container 36 by the mixture injection means, the blown slaked lime and activated carbon adhere to the outer surface of the filter cloth 16. The adsorption layer can be formed on the outer surface of the filter cloth 16.
As a result, when the primary treatment exhaust gas is introduced into the second bag filter 17 having the filter cloth 16 in which the adsorption layer is formed in advance on the outer surface, the primary treatment exhaust gas is passed through the filter cloth 16 on which the adsorption layer is formed. Flowing from the outer surface to the inner surface, the remaining hydrogen chloride reacts with slaked lime to react with calcium chloride (reactant) and the remaining heavy metal with slaked lime to react with the heavy metal hydroxide (reactant) The PCB decomposition product, dioxins, and undecomposed PCB are adsorbed by activated carbon and removed from the primary treatment exhaust gas, and the remainder of the dust is filtered by the filter cloth 16. Can be captured. Then, the purified secondary processing exhaust can be discharged from the second bag filter 17.

On the other hand, the discharged matter taken out from the first bag filter 15 contains dust, calcium chloride, heavy metal hydroxide, and unreacted slaked lime, and is any one of PCB decomposition products, dioxins, and undecomposed PCB. Or the harmful organic substance containing 2 or more is hardly contained. For this reason, the discharge | emission taken out from the 1st bag filter 15 can be carried out out of the system from the processing equipment 10 of polychlorinated biphenyl contaminants by processes, such as an insolubilization process of a heavy metal. Further, since the activated carbon adsorbing the harmful organic substance is contained in the discharged matter taken out from the second bag filter 17, the discharged substance (that is, activated carbon adsorbing the dust, the reactant, and the harmful organic substance, And an adsorption layer containing unreacted slaked lime) are supplied into the plasma decomposition furnace 20 through the recycling flow path 19 and are treated together with the PCB contaminant 11.

Next, a method for treating the PCB contaminant 11 using the polychlorinated biphenyl contaminant treatment facility 10 according to an embodiment of the present invention will be described.
As shown in FIG. 2, first, a PCB contaminant 11 containing heavy metal contaminated with PCB enclosed in a pail can is charged into the inlet of the contaminant input chamber 21 of the plasma decomposition apparatus 12. The loaded PCB contaminant 11 opens the first door 23 and the second door 25 and pushes it out downstream by the pusher 26. The PCB contaminant 11 pushed out to the downstream side is thrown into the plasma decomposition furnace 20 while rolling on the transport unit 22. When the PCB contaminant 11 is put into the plasma decomposition furnace 20, the pusher 26 is immediately returned to the original position, and then the doors 25 and 23 are closed in the order of the second door 25 and the first door 23.

The PCB contaminant 11 put into the plasma decomposition furnace 20 is heated by the plasma arc generated from the plasma torches 27 and 28 attached to the plasma decomposition furnace 20, and the earth, sand, metal, concrete scraps, etc. in the PCB contaminant 11. The incombustible material melts to become slag 31. For this reason, the slag bath by the molten slag 31 is formed in the bottom part in the plasma decomposition furnace 20. Therefore, in a state where the PCB contaminant 11 is continuously charged and a slag bath is formed at the bottom of the plasma decomposition furnace 20, the PCB contaminant 11 charged into the plasma decomposition furnace 20 is turned into a slag bath. Since a part is immersed, the part immersed in the slag bath is melted by heat transfer from the slag bath, and the part not immersed in the slag bath is heated and melted by the high-temperature gas generated by the plasma arc. PCB melts are efficiently melted and decomposed.

When the amount of slag 31 forming the slag bath increases, the plasma decomposition furnace 20 is tilted and the slag 31 is discharged from the slag discharge port 30 into the slag collection container 32. The slag collection container 32 into which the slag 31 has been injected is gradually sent out from the position below the slag discharge port 30 to the outside each time the slag 31 is injected into the slag collection container 32. For this reason, when the slag collection container 32 is taken out, the slag 31 is solidified in the slag collection container 32.

On the other hand, when the PCB contaminant 11 is heated, a part of the non-combustible material in the PCB contaminant 11 evaporates to form dust, and a part of the heavy metal in the PCB contaminant 11 also volatilizes, resulting in plasma. It mixes in the gas in the cracking furnace 20. Further, hydrogen chloride and PCB decomposition products generated by the thermal decomposition of PCB and undecomposed PCB are also mixed in the gas in the plasma decomposition furnace 20. The gas in the plasma decomposition furnace 20 mixed with dust, heavy metal, hydrogen chloride, PCB decomposition products, and undecomposed PCB is discharged as exhaust from the gas discharge port 33 and supplied to the cooler 13.

The exhaust gas supplied to the cooler 13 is quenched with water and air, for example, at 200 ° C. or lower. Here, since water is sprayed in the form of a mist, the water becomes steam while rapidly cooling the exhaust, and is mixed into the exhaust. Furthermore, air is blown in, and the temperature of the exhaust gas is further lowered, and the moisture content in the exhaust gas is adjusted to be, for example, 40% by volume or less. The rapidly cooled exhaust gas is discharged from the cooler 13 and supplied to the first bag filter 15 of the dust removing device 18. In addition, since the temperature of the exhaust gas discharged from the plasma decomposition furnace 20 is rapidly cooled to 200 ° C. or less, synthesis of dioxins from a PCB decomposition product contained in the exhaust gas can be suppressed.

The exhaust gas supplied to the first bag filter 15 flows from the outer surface to the inner surface of the filter cloth 14 on which the slaked lime layer is formed. At that time, dust in the exhaust gas is captured by the filter cloth 14, and a part of hydrogen chloride contained in the exhaust gas reacts with slaked lime to change into calcium chloride and is fixed in the slaked lime layer. In addition, part of the heavy metal in the exhaust gas reacts with slaked lime to change to a heavy metal hydroxide and is fixed in the slaked lime layer. For this reason, the first bag filter 15 discharges the primary processing exhaust gas including the dust residue, the hydrogen chloride residue, the heavy metal residue, the PCB decomposition product, and the undecomposed PCB. In addition, when a trace amount dioxins are synthesize | combined from PCB decomposition product, the synthesize | combined dioxins are also discharged | emitted in the state contained in the primary treatment exhaust gas. The primary processing exhaust gas is supplied to the second bag filter 17.

Here, when the differential pressure between the pressure on the inlet side and the pressure on the outlet side of the first bag filter 15 at a predetermined flow rate is measured, and the value of the differential pressure exceeds a preset value, the filter cloth 14 Inside, for example, high-pressure (for example, 0.2 to 0.7 MPa) air is blown, and dust trapped in the filter cloth 14 is lifted from the outer surface of the filter cloth 14 together with the slaked lime layer and discharged into the exhaust storage container 34. Drop. Then, slaked lime stored in the slaked lime tank 35 is blown into the exhaust container 34 to newly form a slaked lime layer on the outer surface of the filter cloth 14. In addition, since the moisture content in the exhaust gas supplied to the first bag filter 15 is set to a dew point or higher by keeping the outer surface warm, the dust and slaked lime layer that have fallen into the exhaust storage container 34 are exhausted. By giving vibration to the bottom of the container 34, it can be easily discharged to the outside. Here, the slaked lime layer is relatively small as the amount of PCB, and the others include only slaked lime, calcium chloride, and heavy metal hydroxide. The dust and slaked lime layer can be finally disposed of, for example, for landfill.

The primary treatment exhaust gas supplied to the second bag filter 17 flows from the outer surface to the inner surface of the filter cloth 16 on which the adsorption layer of slaked lime and activated carbon is formed. At that time, dust in the primary treatment exhaust is captured by the filter cloth 16, and hydrogen chloride contained in the primary treatment exhaust is reacted with slaked lime to be converted into calcium chloride and fixed in the adsorption layer. In addition, heavy metal in the primary treatment exhaust gas reacts with slaked lime to change to a heavy metal hydroxide and is fixed in the adsorption layer. Further, PCB decomposition products, dioxins (when synthesized from PCB decomposition products), and undecomposed PCB in the primary treatment exhaust are adsorbed by activated carbon and fixed in the adsorption layer. For this reason, the secondary processing exhaust discharged from the second bag filter 17 contains almost no PCB decomposition products, dioxins (when synthesized from PCB decomposition products), and undecomposed PCBs. So it can be diffused into the atmosphere as it is.

Here, when the differential pressure between the pressure on the inlet side and the pressure on the outlet side of the second bag filter 17 is measured at a predetermined flow rate, and the value of the differential pressure exceeds a preset value, the filter cloth 16 Inside, for example, high-pressure air is blown, and the dust trapped on the filter cloth 16 is lifted from the outer surface of the filter cloth 16 together with the adsorption layer, and is blown off into the exhaust container 36. Then, the slaked lime stored in the slaked lime tank 35 and the activated carbon stored in the activated carbon tank 37 are blown into the exhaust container 36 to newly form an adsorption layer on the outer surface of the filter cloth 16. Since the moisture content in the primary treatment exhaust gas supplied to the second bag filter 17 also keeps the outer surface to be above the dew point, the dust and adsorbed layers that have fallen into the exhaust storage container 36 are removed. The vibration can be easily discharged to the outside by applying vibration to the bottom of the exhaust container 36.

Then, the dust and adsorbed layer discharged to the outside are put into the plasma decomposition furnace 20 through the recycle channel 19. Here, the calcium content (unreacted slaked lime and calcium chloride) in the adsorption layer charged into the plasma decomposition furnace 20 acts as a basic regulator, and is a slag bath formed at the bottom of the plasma decomposition furnace 20. The fluidity of the slag 31 is increased. For this reason, the decomposition reaction is promoted by the slag bath, and the operation of inclining the plasma decomposition furnace 20 and injecting the slag 31 from the slag discharge port 30 into the slag collection container 32 is facilitated. On the other hand, the activated carbon in the adsorption layer introduced into the plasma decomposition furnace 20 acts as a heat source and is used to keep the temperature in the plasma decomposition furnace 20 at a high temperature. Furthermore, when activated carbon burns, PCB decomposition products, dioxins (when synthesized from PCB decomposition products) adsorbed on the activated carbon, and undecomposed PCBs can be treated at low cost and rendered harmless. .

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. The case where the treatment facility for polychlorinated biphenyl contaminants of the present invention is configured by combining some or all of the forms and modifications is also included in the scope of the present invention.
For example, you may install the camera which can observe the condition in a furnace in a plasma decomposition furnace. Thereby, the plasma torch can be moved to efficiently irradiate the PCB contaminants with the plasma. Moreover, although the case where the PCB contaminant in the state enclosed with the pail can was processed was demonstrated, even when using a container larger than a pail can, it is applicable. Further, the plasma decomposing apparatus is constituted by a plasma decomposing furnace equipped with a plasma torch, but any apparatus having a function of decomposing PCB by generating plasma while volatilizing heavy metals contained in PCB contaminants can be used. Can be used as
The adsorption layer formed on the second bag filter was formed by adhering a mixture of slaked lime and activated carbon to the filter cloth. The adsorption layer was composed of each layer of slaked lime and activated carbon by alternately attaching slaked lime and activated carbon to the filter cloth. It is also possible to have a multilayer structure. Moreover, although slaked lime was used as an alkaline chemical | medical agent, quick lime and sodium carbonate can also be used instead of slaked lime.

It is a block diagram of the processing equipment of the polychlorinated biphenyl contaminant which concerns on one embodiment of this invention. It is sectional drawing of the plasma decomposition apparatus of the processing equipment of the same polychlorinated biphenyl contaminant.

Explanation of symbols

10: treatment equipment for polychlorinated biphenyl contaminants, 11: PCB contaminants, 12: plasma decomposition device, 13: cooler, 14: filter cloth, 15: first bag filter, 16: filter cloth, 17: second Bag filter, 18: dust removing device, 19: recycling flow path, 20: plasma decomposition furnace, 21: contaminant input chamber, 22: transfer section, 23: first door, 25: second door, 26: Pusher, 27, 28: Plasma torch, 30: Slag outlet, 31: Slag, 32: Slag collection container, 33: Gas outlet, 34: Exhaust container, 35: Slaked lime tank, 36: Exhaust container, 37: Activated carbon tank

Claims (1)

Contained in the exhaust gas discharged from the plasma decomposing apparatus, and a plasma decomposing apparatus that decomposes the polychlorinated biphenyl with plasma by treating the pollutant contaminated with polychlorinated biphenyl containing heavy metal at a high temperature to volatilize the heavy metal In a polychlorinated biphenyl contaminant treatment facility equipped with a dust removal device that removes dust
The dust removing device draws in the exhaust gas, passes through a filter cloth on which an alkaline agent adsorption layer is formed in advance, and collects the dust and contains the alkaline agent in the alkaline agent adsorption layer and the exhaust gas. A first bag filter that reacts and removes hydrogen chloride and the volatilized heavy metal, respectively, and discharges the primary treatment exhaust;
The primary treatment exhaust is drawn in, and passes through a filter cloth in which an adsorption layer of an alkaline agent and activated carbon is formed in advance, and remains in the primary treatment exhaust while collecting dust remaining in the primary treatment exhaust. Hydrogen chloride and volatilized heavy metal react with the alkaline agent in the adsorption layer to form a reaction product, and a decomposition product of the polychlorinated biphenyl present in the primary treatment exhaust gas, a part of the decomposition product A harmful organic substance containing any one or more of dioxins synthesized from the above and undecomposed polychlorinated biphenyl is adsorbed on activated carbon in the adsorption layer and removed from the primary treatment exhaust gas to obtain a secondary It has a second bag filter for discharging process exhaust,
In addition, the dust taken out from the second bag filter, and the adsorption layer containing the reactant, the activated carbon that adsorbs the harmful organic substance, and the unreacted alkaline agent are supplied into the plasma decomposition apparatus. A polychlorinated biphenyl contaminant treatment facility characterized by a recycling channel .

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