JP5889170B2 - PCB contaminated element processing equipment - Google Patents

Description

  The present invention relates to a processing apparatus for PCB contaminated elements.

  Although PCB has been widely used as an insulating oil for transformers, capacitors, and the like, it is necessary to treat PCB due to its strong toxicity. For this reason, various decomposition processing methods for detoxifying PCB have been proposed (see Patent Documents 1 to 5).

Japanese Patent Laid-Open No. 11-253895 Japanese Patent Laid-Open No. 11-253796 JP 2000-126588 A JP 2004-31235 A JP 2005-21830 A

However, conventional insulation paper and wood element detoxification processing contaminated with PCB has the following problems.
1) PCB contaminants are vacuum-heated, slurried after PCB separation, sent to a hydrothermal decomposition apparatus, and after decomposition in this hydrothermal decomposition process, the PCB is treated according to the treatment standard (PCB concentration in wastewater) In the case of a wastewater treatment determination method that satisfies 3 ppb or less), there are some that cannot be crushed and pulverized by a pulverizing mill for slurrying. This is because, in the slurrying pulverization mill processing apparatus, the pulverization inlet condition is 3 mm or less, so that the pulverization inlet condition cannot be shredded, and all processing cannot be performed.

  Therefore, 2) After vacuum heat separation, there is a method in which the vacuum heat-treated product is washed with a solvent washing device, and after this washing, it is judged whether the elution test is below the treatment standard in the elution test judgment. The organic solvent (for example, IPA, isopropyl alcohol, and other hydrocarbon solvents) used for cleaning that interferes with the graduation decision at the factory, and the cellulose-derived wood vinegar component whose elements were decomposed by vacuum heating stored PCB Therefore, there is a problem that graduation determination cannot be performed when the PCB concentration in the eluate is 3 ppb or less because the elution is accompanied during the graduation determination operation. As a result, in the detoxification treatment, the hydrothermal decomposition treatment method must be used, but in the hydrothermal decomposition treatment method, there is a limit to the amount of treatment per day and a residue (sludge) is generated. There is a problem.

  Currently, in the PCB processing business in Japan, a large amount of PCB-containing contaminants are processed, but there is an urgent need for more rapid processing technology.

  In view of the above problems, an object of the present invention is to provide a processing apparatus for PCB contaminated elements that can rapidly process insulating paper, wood, and the like, which are PCB contaminants.

The first invention of the present invention for solving the above-mentioned problems is a vacuum heating drying apparatus for vacuum heating treatment of a PCB-containing element containing PCB, and combustion incineration of a heat-treated product heat-treated by the vacuum heating drying apparatus. A combustion furnace that is provided on the downstream side of the combustion furnace , cools the exhaust gas from the combustion furnace and removes moisture in the exhaust gas as condensed water, and condensate water recovery that recovers the condensed water there are a tank, a dust removing means for removing dust in the exhaust gas dehumidified, the processor of PCB pollution device characterized by comprising a.

The second invention communicates with a vacuum heat drying device for vacuum heat treatment of a PCB-containing element containing PCB, and a discharge port of the vacuum heat drying device, and gradually supplies the heat-treated heat-treated product for combustion incineration. A combustion furnace, a first exhaust gas introduction line for introducing exhaust gas from the vacuum heating and drying apparatus into the combustion furnace, and a downstream side of the combustion furnace to cool the exhaust gas from the combustion furnace and, wherein a cooler, a condensed water recovery tank for collecting the condensed water, a dust removing means for removing dust in the exhaust gas dehumidified, by including the removal of moisture in the exhaust gas as condensed water It is in the processing apparatus of the PCB contaminated element.

  According to a third invention, in the first invention, an exhaust gas return line for returning the exhaust gas of the combustion furnace to the combustion furnace again, an aromatic compound detection means for detecting a residual aromatic compound concentration in the exhaust gas, and the aromatic A control device that performs control to switch the exhaust gas flow path in order to introduce the exhaust gas to the combustion furnace side when the concentration of the aromatic compound in the exhaust gas is equal to or higher than a predetermined value as a result of the measurement of the compound detection means. It is in the processing apparatus of the PCB contamination element characterized.

The fourth invention is the second invention, an exhaust gas return line returning the exhaust gas of the combustion furnace around the vacuum heating drying device, the exhaust gas which has heated the surroundings before Symbol vacuum heat drying apparatus, introduced into the combustion furnace And a second exhaust gas introduction line. The PCB contamination element processing apparatus is provided.

  According to a fifth invention, in any one of the first to fourth inventions, the first PCB detection means for detecting the PCB concentration in the condensed water condensed by the cooler, and the exhaust gas on the downstream side of the dust collector And a second PCB detecting means for detecting the PCB concentration.

  According to a sixth aspect of the invention, there is provided the processing apparatus for a PCB contamination element according to any one of the first to fifth aspects, wherein the combustion furnace is a rotary kiln furnace provided with a rotary kiln and a recombustion chamber.

  According to the present invention, PCB contaminants are processed into low-concentration PCB with a vacuum heating and drying apparatus, and then further completely burned with a combustion furnace, thereby efficiently detoxifying PCB contaminated elements such as paper and wood. Can be implemented well.

FIG. 1 is a schematic diagram of a PCB contaminated element processing apparatus according to a first embodiment. FIG. 2 is a schematic diagram of the PCB contaminated element processing apparatus according to the second embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

FIG. 1 is a schematic diagram of a PCB contaminated element processing apparatus according to a first embodiment.
As shown in FIG. 1, a PCB contaminated element processing apparatus 10A according to the present embodiment is a vacuum heating drying process in which an insulating paper containing PCB and a wooden PCB containing element (hereinafter, “PCB containing element”) 11 are vacuum heat treated. An apparatus 12, a combustion furnace 14 that combusts and incinerates an embrittled element 13 that is a heat-treated product heat-treated by the vacuum heating and drying apparatus 12, and an exhaust gas 15 from the combustion furnace 14 that is provided on the downstream side of the combustion furnace 14. A cooler 17 that removes moisture therein as condensed water 16, and a dust collector 19 that is dust collection means for removing the soot 18 in the dehumidified exhaust gas 15 are provided.
In the present embodiment, a waste heat boiler 20 is interposed between the combustion furnace 14 and the cooler 17 to heat the air 20a, and the heated air 20b is introduced into the combustion furnace 14 (note that The illustration of the introduction of the air 20a is omitted).
Here, in this embodiment, the combustion kiln 14 is a rotary kiln furnace provided with a rotary kiln 14a and a recombustion chamber 14b for supplying heavy oil or the like to reburn.
The element 13 embrittled by the pusher 22 is gradually supplied to the rotary kiln 14a.
In FIG. 1, reference numeral 21 denotes a hopper for supplying elements, 23 denotes a slag conveyor for discharging the slag 24 provided at the lower part of the recombustion chamber 14b, 25 denotes a slag bunker for storing the slag 24, and 26 denotes condensed water 16. A condensed water tank to be stored, 27 is an ash discharge container, and 28 is a chimney for discharging the exhaust gas 15 to the outside.

In this embodiment, an exhaust gas return line L ₂ for returning the exhaust gas 15 from the recombustion chamber 14 b to the rotary kiln 14 a side of the combustion furnace 14 is further branched from the exhaust gas discharge line L ₁ by the flow path switching means 30.

Further, the exhaust gas discharge line L ₁ is provided with an aromatic compound detection means 31 for detecting the residual aromatic compound concentration in the exhaust gas 15 to measure the concentration of the residual aromatic compound in the exhaust gas 15.

  Then, as a result of the measurement by the aromatic compound detection means 31, when the concentration of the aromatic compound in the exhaust gas 15 is equal to or higher than a predetermined value, in order to introduce the exhaust gas 15 to the rotary kiln 14a side of the combustion furnace 14, the flow path switching means 30 is controlled by a control device (not shown).

  Further, in this embodiment, the PCB concentration detecting means in the liquid which is the first PCB detecting means 32 for detecting the PCB concentration in the condensed water 16 condensed by the cooler 17 and the exhaust gas on the downstream side of the dust collector 19. 15, a second PCB detection means 33 for detecting the PCB concentration in the air, and a third PCB detection means 34 for detecting the PCB concentration in the dust 18 collected from the dust collector 19. The PCB concentration detecting means in the solid is provided, and it is confirmed that each is within the discharge standard.

  An example of processing a PCB contaminated element using such a PCB contaminated element processing apparatus 10A will be described.

1) A predetermined amount of the PCB-containing element 11 stored is put into the vacuum heating and drying apparatus 12, and is subjected to vacuum heat treatment at a temperature of 230 ° C. under a vacuum condition (for example, about 230 to 250 ° C., about 6 to 7 Pa) for a predetermined time. The PCB-containing element 12 is embrittled.

2) Next, the embrittled element 13 is put into the hopper 21 and is gradually conveyed by the pusher 22 into the rotary kiln 14a.

3) In the rotary kiln 14a, the embrittled element 13 is burned while being rotated and conveyed. Here, most of the embrittled elements 13 are combusted, and part of them are vaporized and flow to the recombustion chamber 14b which is a secondary combustion furnace. Ashes and slag 24 generated by this combustion fall to the slag conveyor 23 side, and then are collected and carried out to the slag bunker 25.

4) Fuel and air, such as heavy oil, are supplied in the recombustion chamber 14b, secondary combustion is performed, and PCBs and other harmful organic substances remaining in the exhaust gas are completely burned.
Here, the combustion temperature in the rotary kiln 14a and the recombustion chamber 14b is, for example, 850 ° C. or more and 1,100 ° C., which are temperatures that can be made harmless even if dioxins are generated. However, when the element contains a large amount of an inorganic substance, the inorganic substance exhibits a heat insulating action, so that the combustion temperature may be increased to about 1,300 ° C. for processing.

5) In the furnace exit of the re-combustion chamber 14b, the aromatics detecting means 31 interposed in the exhaust gas discharge line L _1, and so as to monitor the unprocessed organic matter in the exhaust gas 15.
As this aromatic compound detection means 31, the aromatic benzene ring double bond is measured, for example, by measurement using a UV absorption method (wavelength 274 nm).
Thereby, it is made to monitor whether there exists any PCB-derived aromatic decomposition product.

6) When the benzene ring substance remaining in the exhaust gas 15 is detected by the measurement of the aromatic compound detection means 31, the flow path switching means 30 is switched by a control device (not shown) and returned to the rotary kiln 14a for recombustion processing. However, the aromatic compound concentration in the exhaust gas is set to a predetermined value or less.

7) The treated exhaust gas 15 is used by the waste heat boiler 20 as a preheating source of combustion air.

8) The exhaust gas 15 is further introduced into the cooler 17, the water contained in the exhaust gas is cooled and condensed as condensed water 16, and collected in the condensed water tank 26.

9) The condensed water 16 in the condensed water tank 26 is confirmed by the first PCB detection means 32 in the liquid to have a PCB concentration in water of 3 ppb or less. In addition, when it fails, it introduces into a hydrothermal decomposition processing apparatus separately, and decomposes.
As the first PCB detection means 32 in the liquid, the PCB in the liquid is subjected to solid phase extraction, and the extract is analyzed by an analyzer such as ECD / GC.

10) The exhaust gas 15 after dehumidification is dust-removed by a dust collector (for example, electric dust collector or bag filter) 19 to remove the dust 18. The exhaust gas after the dust removal is analyzed by the second PCB detection means 33 in the air, and it is discharged after confirming that the air PCB is 0.1 mg / m ³ or less.
The second PCB detection means 33 in the air is measured by the TOFMS method or the official method.

  Moreover, the dust 18 such as ash and solid matter discharged from the dust collector 19 is discharged after confirming the PCB concentration in the solid by the third PCB detecting means 34 and confirming that it is 3 ppb or less in the elution test. To do. In addition, in the case of disqualification, it discharges after judging by a dissolution test after washing with a separate solvent washing device.

  According to this PCB contamination element processing apparatus 10A, the vacuum heating / drying apparatus 12 performs processing to a PCB concentration of about 5,000 ppm or less, and then further completes in a combustion furnace 14 equipped with a rotary kiln 14a and a recombustion chamber 14b. By performing the combustion treatment, it is possible to efficiently carry out the detoxification treatment of the PCB-polluting elements such as paper and wood.

  As a result, the processing temperature of the conventional vacuum heating and drying apparatus is carried out at a high temperature (for example, 500 degrees), so that the heat treatment is not performed for a long time, and the processing can be speeded up.

  Moreover, since it is a trace amount PCB contamination of 5,000 ppm (mg / kg), the processing speed is increased, and a large amount of PCB contamination can be processed in one day.

  Further, by using a rotary kiln furnace provided with a rotary kiln 14a and a recombustion chamber 14b as the combustion furnace 14, and using a two-stage flame as the recombustion chamber 14b, a reliable combustion treatment of PCB contaminants becomes possible. In addition, by measuring the PCBs at various locations, it is possible to carry out a process in which no harmful substances are discharged from the facilities.

  In the present embodiment, the rotary kiln furnace is used as the combustion furnace 14. However, the present invention is not limited to this, and any incinerator may be used as long as it can burn the embrittled element 13. May be.

FIG. 2 is a schematic diagram of the PCB contaminated element processing apparatus according to the second embodiment. In addition, about the same component as the structure of Example 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIG. 2, the PCB contaminated element processing apparatus 10 </ b> B according to the present embodiment includes a vacuum heating / drying apparatus 41 that vacuum heat-treats the PCB-containing element 11 containing PCB, and an outside covering the vacuum heating / drying apparatus 41. A combustion furnace 14 that communicates with the chamber 43 through a communication port 44 and a discharge port of the outer chamber 43 that covers the vacuum heating and drying apparatus 41, gradually supplies the heat-treated embrittled element 13 and burns it; and the vacuum A first exhaust gas introduction line L ₁₁ for introducing the exhaust gas 46 from the inside of the heating and drying apparatus 41 to the combustion furnace 14 side, and an exhaust gas 15 from the combustion furnace 14 provided on the downstream side of the combustion furnace 14. It comprises a cooler 17 that removes moisture in the interior, and a dust collector 19 that removes soot 18 in the dehumidified exhaust gas.

  In the first embodiment, the vacuum heating / drying device 12 provided separately is used, and the embrittled PCB element 13 is gradually introduced through the hopper 21. However, in this embodiment, the vacuum heating / drying device 41 is installed. By using the combustion furnace 14 provided, the embrittled PCB elements 13 are continuously supplied.

  In the present embodiment, the aromatic compound remaining in the gas is measured by the aromatic compound detection means 31 in the exhaust gas, but vacuum heating drying is performed regardless of whether or not the remaining benzene ring substance is detected. It is used as a heat source for the device 41 and complements the heating of the vacuum heating and drying device 41.

The exhaust gas 15 introduced into the outer chamber 43 around the vacuum heating and drying apparatus 41 is introduced into the combustion furnace 14 via the second exhaust gas introduction line L ₁₂ and processed in the rotary kiln 14a.

The exhaust 46 from the vacuum pump 42 of the vacuum heating and drying apparatus 41 contains a small amount of PCB gas, so that it is pushed into the pusher 22 side via the first exhaust gas introduction line L ₁₁ and becomes brittle. Processing is performed in the rotary kiln 14 a while accompanying the element 13.

  Conventionally, it has been troublesome to store and transport the embrittled element 13 by attaching a vacuum heating and drying apparatus, which has been adopted as a high concentration treatment, to communicate with the combustion furnace 14. According to the embodiment, it is possible to save these troubles and the like, and it is possible to perform continuous processing that is almost continuous.

10A, 10B PCB contaminated element processing equipment 11 Insulated paper containing PCB, wood PCB containing element (PCB containing element)
DESCRIPTION OF SYMBOLS 12 Vacuum heating drying apparatus 13 Embrittlement element 14 Combustion furnace 15 Exhaust gas 16 Condensed water 17 Cooler 18 Dust 19 Dust collector 20 Waste heat boiler

Claims (6)

A vacuum heating and drying apparatus for vacuum heating a PCB-containing element containing PCB;
A combustion furnace for burning and incinerating the heat-treated product heat-treated by the vacuum heating and drying apparatus;
A cooler that is provided on the downstream side of the combustion furnace , cools the exhaust gas from the combustion furnace, and removes moisture in the exhaust gas as condensed water ;
A condensed water recovery tank for recovering the condensed water;
Processor of PCB pollution element characterized by comprising a dust removing means for removing dust in the exhaust gas dehumidified, the. A vacuum heating and drying apparatus for vacuum heating a PCB-containing element containing PCB;
A combustion furnace that communicates with the discharge port of the vacuum heating and drying apparatus, gradually supplies the heat-treated heat-treated product, and burns and incinerates;
A first exhaust gas introduction line for introducing exhaust gas from the vacuum heating and drying apparatus into a combustion furnace;
A cooler that is provided on the downstream side of the combustion furnace , cools the exhaust gas from the combustion furnace, and removes moisture in the exhaust gas as condensed water ;
A condensed water recovery tank for recovering the condensed water;
Processor of PCB pollution element characterized by comprising a dust removing means for removing dust in the exhaust gas dehumidified, the. In claim 1,
An exhaust gas return line for returning the exhaust gas of the combustion furnace to the combustion furnace again;
An aromatic compound detection means for detecting the concentration of residual aromatic compound in the exhaust gas;
A control device that performs control to switch the exhaust gas flow path in order to introduce the exhaust gas to the combustion furnace side when the concentration of the aromatic compound in the exhaust gas is equal to or higher than a predetermined value as a result of the measurement by the aromatic compound detection means; A device for treating a PCB contaminated element. In claim 2,
An exhaust gas return line for returning the exhaust gas of the combustion furnace to the periphery of the vacuum heating and drying device ;
Processor of PCB contaminated elements of the exhaust gas which has heated the surroundings, characterized in that it comprises a second exhaust gas introduction line for introducing into the combustion furnace, the pre-Symbol vacuum heat drying apparatus. In any one of Claims 1 thru | or 4,
First PCB detecting means for detecting the PCB concentration in the condensed water condensed by the cooler;
And a second PCB detecting means for detecting the PCB concentration in the exhaust gas on the downstream side of the dust collector. In any one of Claims 1 thru | or 5,
The apparatus for treating a PCB contamination element, wherein the combustion furnace is a rotary kiln furnace having a rotary kiln and a recombustion chamber.

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