JP4928876B2 - Heat purification equipment for contaminated soil - Google Patents

Description

  The present invention relates to an apparatus for heating and purifying contaminated soil containing pollutants such as dioxin and PCB in addition to light oil, heavy oil and VOC (volatile organic compound).

In recent years, it has been suggested that the soil in each business site and its surrounding areas has been contaminated with waste liquids of pollutants such as oil and contaminated groundwater flowing under the soil due to industrial activities. Is a problem. As a method for purifying the soil contaminated in this way, a purification treatment is performed by volatilizing and decomposing volatile organic compounds that have been soaked in the soil using a rotary kiln for heating. And in addition to kerosene and light oil, in the contaminated soil purification treatment apparatus described in Patent Document 1, slaked lime is added to neutralize sulfur oxides and hydrogen chloride, which are harmful substances generated when the contaminated soil is heated. In this way, heavy oil, machine oil, VOC, etc. can be processed.
JP 2005-169327 A

  However, the above apparatus can purify contaminated soil containing kerosene, light oil, heavy oil, machine oil, and VOC, but is not suitable for purifying dioxin, PCB, and the like.

  This invention makes it a subject to provide the heating purification apparatus of the contaminated soil which can heat-purify the contaminated soil containing dioxin etc. suitably in view of said point.

In order to solve the above-mentioned problem, in the heat purification apparatus for contaminated soil according to claim 1 of the present invention, a heat treatment kiln configured to withstand a high temperature atmosphere by constructing a refractory material on the inner peripheral wall , and oxidative decomposition furnace for thermally decomposing the contaminants gasify the waste gas of the heat treatment kiln to dwell predetermined time, a cooling tower to lower the exhaust gas temperature downstream of the oxidation-decomposition furnace, is dust collector downstream of the cooling tower Combustion amount for controlling the burner combustion amount of the heat treatment kiln so that the exhaust gas temperature at the outlet of the oxidative decomposition furnace and the bag filter is sequentially taken in and the exhaust gas temperature at the outlet of the oxidative decomposition furnace is maintained at a preset exhaust gas temperature. Rotational speed control that controls the rotational speed of the heat treatment kiln so that the discharged soil temperature is maintained at a preset soil temperature by successively taking in the temperature measured values of the discharged soil of the adjuster and the heat treatment kiln The exhaust gas set temperature at the outlet of the oxidative decomposition furnace and the discharged soil set temperature of the heat treatment kiln are set to a predetermined temperature that enables the thermal decomposition of the pollutants contained in the contaminated soil to be purified. The burner combustion amount and rotation speed of the treatment kiln are controlled, the contaminated soil is heated in the heat treatment kiln to volatilize or thermally decompose the pollutants in the soil, and the exhaust gas is retained in the oxidation decomposition furnace for a predetermined time for gasification The pollutant is thermally decomposed, and water is sprayed onto the high-temperature exhaust gas in the cooling tower to cool it to a temperature at which dioxin does not reprecipitate or to a temperature that can be processed by the bag filter. It is characterized in the thing.

Moreover, in the heat purification apparatus for contaminated soil according to claim 2, a stock bin for temporarily storing the heated soil is disposed at the lower side of the discharge side of the heat treatment kiln so as to directly receive the heated soil discharged from the kiln. In addition, an oxidative decomposition furnace is installed above the stock bin, and the inside of the stock bin is exposed to a high temperature atmosphere by the high-temperature exhaust gas introduced into the oxidative decomposition furnace to thermally decompose or volatilize trace contaminants in the heated soil. It is easy to use.

  The contaminated soil heating and purifying device according to claim 3 is characterized by comprising a slaked lime supply device for blowing slaked lime mixed with activated carbon on the inlet side of the bag filter.

According to the heating purifier of contaminated soil according to claim 1, wherein according to the present invention, a heat treatment kiln was set to withstand high temperature atmosphere by applying a refractory material to the inner wall, the heat treated flue gas for a predetermined time in the kiln An oxidative decomposition furnace for thermally decomposing the polluted gasified, a cooling tower for lowering the exhaust gas temperature downstream of the oxidative decomposition furnace , a bag filter as a dust collector downstream of the cooling tower, and the oxidative decomposition furnace Combustion amount regulator for controlling the burner combustion amount of the heat treatment kiln so that the exhaust gas temperature at the outlet is sequentially taken in and the exhaust gas temperature at the oxidation decomposition furnace outlet is maintained at the preset exhaust gas temperature, and the discharge of the heat treatment kiln A rotational speed controller for controlling the rotational speed of the heat treatment kiln so that the soil temperature measurement value is sequentially taken in and the discharged soil temperature is maintained at a preset soil temperature, and the oxidative decomposition furnace The exhaust gas set temperature at the outlet and the discharge soil set temperature of the heat treatment kiln are set to a predetermined temperature at which the pollutants contained in the contaminated soil to be purified can be thermally decomposed, and the burner combustion amount and rotation speed of the heat treatment kiln Control, heat the contaminated soil in a heat treatment kiln to volatilize or decompose the pollutants in the soil, and heat and decompose the gasified pollutants in an oxidative decomposition furnace for a predetermined time to cool and cool The tower is cooled to a temperature at which dioxin does not reprecipitate or the bag filter can be processed by spraying water on the hot exhaust gas, and the bag filter removes fines in the exhaust gas, so the pyrolysis temperature is high. In the case of contaminated soil containing dioxins, set the discharge soil set temperature of the heat treatment kiln to about 600 ° C, and set the exhaust gas set temperature at the outlet of the oxidative decomposition furnace to about 800 ° C. By controlling over Na combustion amount and the rotation speed of the heat treatment kiln (residence time), the heat treatment kiln was constructed of refractory material can be heated to contaminated soil containing dioxin at a predetermined elevated temperature, volatilization dioxin in the soil, are thermally decomposed together can be purified by gasification, it can thermally decomposed by exposing a predetermined time in a high temperature exhaust gas atmosphere at a predetermined temperature dioxin obtained by gasification in oxidative decomposition furnace, also cooled passed through the oxidative decomposition furnace exhaust gas and quenched by the tower Ki de be pressed to re-precipitation of dioxin, contaminated soil containing the dioxin can be processed Kiyoshi reduction.

For heavy oil or VOC, etc., which has a lower thermal decomposition temperature than dioxin, the exhaust gas set temperature at the outlet of the oxidative decomposition furnace is about 800 ° C., and the discharge soil set temperature of the heat treatment kiln is the thermal decomposition temperature according to the pollutant For example, if the burner combustion amount and the rotation speed (residence time) of the heat treatment kiln are set to about 400 ° C., heavy oil, VOC, etc. in the soil can be suitably purified, and the thermal decomposition temperature is low. Contaminated soil containing kerosene, light oil, heavy oil, machine oil, VOC, dioxin or PCB having a high thermal decomposition temperature can be suitably purified.

According to the heating and purifying apparatus for contaminated soil according to claim 2 of the present invention, the stock bin for temporarily storing the heated soil is arranged in the lower side of the discharge side of the heat treatment kiln and directly receives the heated soil discharged from the kiln. In addition, an oxidative decomposition furnace is installed above the stock bin, and the inside of the stock bin is exposed to a high-temperature atmosphere by high-temperature exhaust gas introduced into the oxidative decomposition furnace to thermally decompose or volatilize trace contaminants in the heated soil. Having easier, with gasified contaminants may also thermal decomposition process is guided as it is to the oxidative decomposition furnace rises in the stock bottle, preferably made compact by stacking a device stereoscopically.

  According to the heating and purifying apparatus for contaminated soil according to claim 3 of the present invention, the apparatus includes the slaked lime supply device for blowing slaked lime mixed with activated carbon on the inlet side of the bag filter. The cloth surface can be coated and dioxins in the exhaust gas can be adsorbed and removed with activated carbon, the acid gases (Sox, HCL) in the exhaust gas can be neutralized, and the contaminated soil containing dioxins and the like can also be suitably purified.

  According to the heating and purifying apparatus for contaminated soil according to claim 1 of the present invention, a refractory material is applied to the inner peripheral wall so that dioxin contained in the contaminated soil can be effectively purified, for example, about 1800 ° C. A heat treatment kiln that can withstand high temperatures is provided. In addition, a stock bin for temporarily storing heated soil is disposed on the discharge side of the heat treatment kiln, exhaust gas derived from the heat treatment kiln is retained for about 2 seconds, for example, and the exhaust gas temperature is about 800 ° C. An oxidative decomposition furnace that heats and decomposes pollutants gasified with the exhaust gas is provided by maintaining them. A cooling tower for rapidly cooling the exhaust gas temperature at a high temperature to about 180 ° C., for example, is disposed downstream of the oxidative decomposition furnace, and a bag filter as a dust collector is disposed downstream of the cooling tower.

A temperature measuring device for measuring the exhaust gas temperature is installed at the outlet of the oxidative decomposition furnace. Then, the outlet temperature of the oxidative decomposition furnace is measured by the temperature measuring instrument and taken into the combustion amount regulator, and the gasified pollutant is compared with a preset exhaust gas temperature capable of being thermally decomposed, and based on the amount of the difference value. The burner combustion amount of the heat treatment kiln is controlled. If the exhaust gas set temperature is about 800 ° C. and the inside of the oxidative decomposition furnace is maintained at a high temperature atmosphere of about 800 ° C. and the exhaust gas is retained for about 2 seconds, dioxin, heavy oil, VOC in the exhaust gas The gasified contaminants such as can be reliably decomposed by heating.

Moreover, the temperature measuring device which measures the temperature of discharge | emission soil is installed in the discharge side of the said heat processing kiln. Then, the temperature of the discharged soil is sequentially measured by the temperature measuring device, the measured value is taken into a rotation speed adjuster, compared with a preset discharged soil temperature, and the rotation speed of the heat treatment kiln is based on the difference value amount. To control. At this time, if the rotation speed of the heat treatment kiln is increased, the residence time of the soil in the kiln is shortened and the temperature of the discharged soil is lowered. Conversely, if the rotation speed is decreased, the residence time of the soil in the kiln is decreased. It becomes longer and the temperature of the discharged soil rises. The discharge soil set temperature is about 600 ° C in the case of contaminated soil containing dioxins with a high pyrolysis temperature, and in the case of heavy oil or VOC with a pyrolysis temperature lower than that of dioxins, the pyrolysis according to the pollutant Setting the temperature, for example, about 400 ° C., is suitable for heating and purifying contaminants.

  Then, when the contaminated soil containing dioxin is put into the kiln while burning the burner of the heat treatment kiln, the contaminated soil is exposed to a high temperature atmosphere of about 1800 ° C. while rolling down the kiln, and the soil temperature is about When the temperature reaches about 300 to 400 ° C., dioxins in the soil volatilize and thermally decompose to gasify. The soil is heated as it is to raise the temperature to about 600 ° C. and then put into a stock bottle for storage. By storing the heated soil at about 600 ° C. in the stock bottle for a while, for example, for about 1 hour and performing aeration, a trace amount of dioxin remaining in the soil is also gasified.

Exhaust gas derived from the heat treatment kiln and dioxin gasified in a stock bottle are led to an oxidative decomposition furnace, and are exposed to an exhaust gas at about 800 ° C. for about 2 seconds in the oxidative decomposition furnace. to heat decompose dioxin gasified. Subsequently, the exhaust gas that has passed through the oxidative decomposition furnace is guided to a cooling tower, rapidly cooled to about 180 ° C. to suppress reprecipitation of dioxins, and then fines in the exhaust gas are removed with a bag filter.

Thus, heat treatment kiln was constructed with refractory material on the inner peripheral wall, oxidative decomposition furnace for thermally decomposing contaminants gasified at exhaust of pressurized heat treatment kiln, cooling tower, the purification device provided with a bag filter, the oxidation The burner combustion amount and the heat treatment kiln are set to a predetermined temperature that enables the thermal decomposition of the pollutants contained in the contaminated soil to purify the exhaust gas set temperature at the outlet of the cracking furnace and the discharge soil set temperature of the heat treatment kiln. Contaminated soil containing kerosene, light oil, heavy oil, machine oil, VOC with high thermal decomposition temperature, dioxin or PCB with high thermal decomposition temperature is also suitable if the contaminated soil is purified while controlling the rotation speed Can be purified.

  Moreover, according to the heat purification apparatus for contaminated soil according to claim 2 of the present invention, a stock bin is disposed in the lower discharge side of the heat treatment kiln so as to directly receive the heated soil discharged from the kiln. The oxidative decomposition furnace is installed at the top of the stock bin. As a result, the pollutant gasified in the stock bottle rises and is directly introduced into the oxidative decomposition furnace to be thermally decomposed, and the apparatus can be made compact.

Moreover, according to the heat purification apparatus for contaminated soil according to claim 3 of the present invention, slaked lime storage bottles for storing slaked lime mixed with activated carbon, screw feeders for cutting out a predetermined amount of slaked lime, and slaked lime on the inlet side of the bag filter A slaked lime supply device composed of a blower or the like to be blown is provided. Then, the coated filter cloth by blowing slaked lime mixed with activated carbon on the inlet side of the bag filter over. As a result, dioxins in the exhaust gas can be adsorbed and removed by activated carbon, and acid gases (Sox, HCL) in the exhaust gas can be neutralized, and contaminated soil containing dioxin, heavy oil, VOC, etc. is also suitable. Can be purified.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 in FIG. 1 is a heat treatment kiln that heats and purifies contaminated soil. For example, a drum 2 with a refractory material applied to the inner peripheral wall so as to withstand a high temperature atmosphere of about 1800 ° C. is placed on the machine base 3. It is tilted and supported so as to be freely rotatable, and is rotated at a predetermined speed by a variable speed freely driving motor 4. And while forming a flame in the drum 2 from the burner 6 arrange | positioned at the injection | throwing-in hopper 5 side of the one end part of the drum 2 and sending a hot air, the contaminated soil discharged | paid out from the contaminated soil storage hopper 7 is conveyed via the conveyors 8 and 9. In the drum 2, the contaminated soil is exposed to a high-temperature atmosphere, and the contaminants in the contaminated soil are purified by volatilization or thermal decomposition.

  On the soil discharge side of the heat treatment kiln 1, a temperature measuring device 10 for measuring the discharged soil temperature is provided, and a measured value measured by the temperature measuring device 10 is taken into the rotation speed adjuster 11 and discharged in advance. Compared with the soil temperature, the rotational speed of the drive motor 4 of the kiln 1 is controlled based on the amount of the difference value so that the discharged soil temperature maintains the set temperature. Increasing the rotation speed of the kiln 1 shortens the residence time of the soil in the kiln and lowers the temperature of the discharged soil, and decreasing the rotation speed increases the residence time of the soil in the kiln and The temperature rises.

  In addition, a stock bin 12 that can temporarily store heated soil is disposed below the discharge side of the heat treatment kiln 1, and aeration is performed by temporarily storing the heated soil in the stock bin 12. In this way, trace amounts of pollutants remaining in the soil are gasified and removed. The purified soil is supplied to the soil cooling means described later by the transport means 13.

  The exhaust gas from the heat treatment kiln 1 is introduced into the upper part of the stock bin 12 and is retained for a predetermined time, for example, about 2 seconds, and the pollutants in the exhaust gas are exposed to an exhaust gas atmosphere at a high temperature, for example, about 800 ° C. for thermal decomposition. An oxidative decomposition furnace 14 is mounted. The exhaust flue 15 at the outlet of the oxidative decomposition furnace 14 is provided with a temperature measuring device 16 for measuring the exhaust gas temperature, and the measured value measured by the temperature measuring device 16 is taken into the combustion amount adjuster 17 and set in advance. Compared with the set temperature, the combustion amount of the burner 6 is controlled based on the difference value amount so that the exhaust gas temperature at the outlet of the oxidative decomposition furnace 14 is kept constant.

  A water-cooled cooling tower 18 for cooling high-temperature exhaust gas is disposed downstream of the oxidative decomposition furnace 14, and water is sprayed on the exhaust gas so that the gas temperature is rapidly cooled to about 180 ° C. Thus, reprecipitation of dioxin can be suppressed.

  A bag filter 19 as a dust collector is disposed downstream of the cooling tower 18, while neutralizing sulfur oxides and hydrogen chloride, which are harmful substances generated in the heating and purification process of heavy oil and VOC. A slaked lime storage bottle 20 for storing slaked lime is provided, and includes a screw feeder 21 that cuts out a predetermined amount of slaked lime, a blower (not shown) that blows slaked lime into the exhaust flue 15, and the like. An appropriate amount of slaked lime is blown into the exhaust flue 15 on the inlet side of the bag filter 19 by the apparatus so that sulfur oxides and hydrogen chloride are neutralized in the bag filter 19. In addition, when activated carbon is mixed into slaked lime and blown into the bag filter 19 to cover the filter cloth, dioxins in the exhaust gas can be adsorbed on the activated carbon and removed.

  Downstream of the bag filter 19, an exhaust fan 22 that sucks and exhausts exhaust gas is disposed, and in order to suck the combustion gas supplied from the burner 6 into the heat treatment kiln 1 without excess or shortage, a corner portion of the charging hopper 5 is provided. The amount of suction is adjusted by controlling the opening degree of the air volume adjusting damper (not shown) in the exhaust flue 15 or the rotational speed of the exhaust fan so that the static pressure detected at 1 becomes approximately atmospheric pressure. And the exhaust gas which passed the exhaust fan 22 is discharge | released in the air | atmosphere from the chimney 23. FIG.

  The chimney 23 is provided with a concentration measuring device (not shown) for measuring the concentration of sulfur oxide and / or hydrogen chloride so that the measured value by the concentration measuring device becomes a predetermined value or less. The rotational speed of the drive motor of the screw feeder 21 of the slaked lime supply device may be controlled, and a necessary amount of slaked lime may be blown into the exhaust flue 15 to neutralize sulfur oxides and hydrogen chloride in the exhaust gas.

  The soil stored in the stock bin 12 is hot, and a soil cooling device 24 is provided to cool the soil and make it easy to handle. As the soil cooling device 24, for example, a rotary kiln type is adopted, and a cylindrical drum 25 having a scraping blade disposed therein is rotatably supported on a machine base 26, and a driving device (not shown). To rotate at a predetermined speed.

  A charging hopper 27 is disposed at one end of the drum 25, and a discharging hopper 28 is disposed at the other end. Heated soil is charged from the charging hopper 27 side and moved to the discharging hopper 28 side while being scraped up by a lifting blade. In the meantime, the heated soil is cooled by water sprayed from a water spray nozzle 29 disposed on the input side, and the moisture content is increased to such an extent that dust is not easily produced, thereby making it easy to handle.

  Further, dust and water vapor generated in the soil cooling device 24 are sucked and exhausted by the exhaust fan 31 disposed at the end of the exhaust duct 30 and from the chimney 23 via the bag filter 32 for capturing the scattered dust. It is released into the atmosphere.

  Next, the case where the contaminated soil containing dioxin is purified by the heating and purification apparatus will be described. In the case of the purification treatment, first, the burner 6 of the heat treatment kiln 1 is combusted while being sucked and exhausted by the exhaust fan 22, and, for example, a combustion gas of about 1800 ° C. is supplied into the kiln 1. The contaminated soil in 7 is supplied into the kiln 1 by the conveyors 8 and 9 and heated.

  At this time, the temperature of the outlet gas of the oxidative decomposition furnace 14 is sequentially measured by the temperature sensor 16, and the burner 6 is combusted so as to reach a temperature at which dioxins set by the combustion amount regulator 17 can be thermally decomposed, for example, about 800 ° C. Control the amount. Moreover, water is injected in the cooling tower 18 to control the exhaust gas temperature so that the exhaust gas temperature is rapidly cooled to about 180 ° C. at which dioxins do not reprecipitate. In addition, the soil discharged from the kiln 1 measures the temperature of the discharged soil by the temperature sensor 10 and controls the rotational speed of the drive motor 4 via the rotational speed adjuster 11 so as to be about 600 ° C., for example. To control the rotational speed of kiln 1.

  When the contaminated soil supplied into the heat treatment kiln 1 is heated to about 300 to 400 ° C., dioxins in the soil volatilize and thermally decompose to gasify. The soil is heated as it is, heated up to about 600 ° C., and then put into the stock bin 12 at the kiln 1 outlet for storage. In the stock bottle 12, the heated soil at about 600 ° C. is stored for a while, for example, for about 1 hour, and aerated, whereby a trace amount of dioxin remaining in the soil is gasified and separated.

  The dioxins gasified in the heat treatment kiln 1 and in the stock bottle 12 are led to the oxidative decomposition furnace 14 along with the exhaust gas, and are exposed to the exhaust gas at about 800 ° C. for about 2 seconds in the oxidative decomposition furnace 14. The gasified dioxin is decomposed by heating. Subsequently, the exhaust gas led out from the oxidative decomposition furnace 14 is led to the cooling tower 18, rapidly cooled to about 180 ° C. to suppress the reprecipitation of dioxin, and then led to the bag filter 19.

  In front of the bag filter 19, slaked lime mixed with activated carbon is blown by a slaked lime supply device to cover the filter cloth surface of the bag filter 19, and dioxins in the exhaust gas are adsorbed by the activated carbon. In addition, if heavy oil is contained in the soil, sulfur oxides are produced by sulfur components during the heating process, and if VOC is contained, phosgene is produced in the process of oxidative decomposition and thermal decomposition, and water vapor is added to this. When added, hydrogen chloride is generated by hydrolysis, so acid gases (Sox, HCL, etc.) in these exhaust gases are neutralized with slaked lime. The slaked lime, activated carbon, and dust fine particles are removed by the bag filter 19, and the purified gas is discharged from the chimney 23 to the atmosphere. In addition, the slaked lime etc. which are captured and collected by the bag filter 19 are disposed as special industrial waste.

  In the above, slaked lime stored in the slaked lime storage bottle 20 is cut out and supplied in a predetermined amount by the screw feeder 21, but the concentration of sulfur oxide and / or hydrogen chloride is measured by the chimney 23. The number of rotations of the drive motor of the screw feeder 21 may be controlled so that the measured density is not more than a predetermined value.

  In addition, the heated soil stored in the stock bin 12 is supplied to the soil cooling device 24 in order to cool the heated soil to a temperature that is easy to handle because of the high temperature. The soil supplied to the soil cooling device 24 is cooled by being sprayed with water from the water spray nozzle 29 while rolling down in the drum 25, becomes easy to handle, and is discharged from the discharge hopper 28. After being transported to a suitable place and piled up, it is processed. When the amount of water sprayed from the water spray nozzle 29 is determined and sprayed in consideration of the amount of soil to be supplied and the temperature, etc., it is possible to prevent adhesion and clogging due to excessive humidification, and due to insufficient humidification. Dust generation can be minimized. Also, dust and water vapor generated in the drum 25 are sucked and exhausted by the exhaust fan 31 and guided to the downstream bag filter 32, where the dust is captured and exhausted from the chimney 23.

Thus, the heat processing kiln 1 which constructed the refractory material on the inner peripheral wall, the stock bin 12 for temporarily storing the heated soil, the oxidative decomposition furnace 14 for burning and decomposing dioxin gasified by the exhaust gas of the heat processing kiln 1, the cooling tower 18, a bag filter 19, and a slaked lime supply device that blows in slaked lime mixed with activated carbon, and is contained in contaminated soil that purifies the exhaust gas temperature at the outlet of the oxidative decomposition furnace 14 and the discharged soil temperature of the heat treatment kiln 1. so as to maintain a predetermined temperature to contaminants heating degradable by Rukoto controls burner combustion amount and heat treatment rpm kiln 1 (retention time), it is possible to purify treating contaminated soil containing dioxin, light Contaminated soil containing oil, heavy oil, VOC (volatile organic compound), PCB and the like can be purified by this purification device.

  In the above embodiment, the stock bin 12 is arranged at the lower side of the discharge side of the heat treatment kiln 1 so that the heated soil discharged from the kiln 1 is directly received, and the oxidative decomposition furnace is provided above the stock bin 12. However, the present invention is not limited to this structure. The heated soil discharged from the kiln 1 may be transported by the vertical transport device by leaving the stock bin apart. Appropriate design changes are possible.

In addition, the temperature at which the contaminated soil is heated by the heat treatment kiln 1 is preferably about 600 ° C. if dioxin is included, but it is contained in soil such as light oil, heavy oil, VOC (volatile organic compound), PCB, etc. It is preferable to appropriately set a preferable temperature for heating and purifying according to the pollutant. Further, if the contaminated soil does not contain dioxin but contains heavy oil and VOC, it is preferable to blow only the slaked lime not mixed with activated carbon into the bag filter 19. As described above, in the present heat purification apparatus, not only dioxins but also contaminated soil containing pollutants such as light oil, heavy oil, VOC (volatile organic compound), and PCB can be suitably heat-purified.

It is a schematic explanatory drawing which shows one Example of the heat purification apparatus of the contaminated soil which concerns on this invention.

DESCRIPTION OF SYMBOLS 1 ... Heat processing kiln 6 ... Burner 7 ... Contaminated soil storage hopper 10 ... Temperature sensor 11 ... Rotational speed regulator 12 ... Stock bottle 14 ... Oxidation cracking furnace 16 ... Temperature sensor 17 ... Combustion amount regulator 18 ... Cooling tower 19 ... Bug Filter 20 ... Slaked lime storage bottle 21 ... Screw feeder (slaked lime supply device)
24 ... Soil cooling device

Claims (3)

A heat treatment kiln was set to withstand high temperature atmosphere by applying a refractory material to the inner wall, and oxidative decomposition furnace for thermally decomposing the contaminants gasify the waste gas of the heat treatment kiln to dwell predetermined time, the oxidation A cooling tower that lowers the exhaust gas temperature downstream of the cracking furnace, a bag filter that is a dust collector downstream of the cooling tower, and a measured value of the exhaust gas temperature at the outlet of the oxidation cracking furnace are sequentially taken in, and the exhaust gas temperature at the oxidation cracking furnace outlet is The combustion volume regulator that controls the burner combustion amount of the heat treatment kiln so as to maintain the set exhaust gas temperature, and the temperature measurement value of the discharged soil of the heat treatment kiln are sequentially taken in, and the discharged soil temperature becomes the preset soil temperature. A rotation speed controller for controlling the rotation speed of the heat treatment kiln so as to be maintained, an exhaust gas set temperature at the outlet of the oxidation cracking furnace, and a discharge soil set temperature of the heat treatment kiln Set the temperature at which the pollutants contained in the contaminated soil to purify the heat can be decomposed by heating, control the burner combustion amount and the rotation speed of the heat treated kiln, and heat the contaminated soil with the heat treated kiln. The pollutants inside are volatilized or thermally decomposed, and the exhaust gas stays in the oxidation decomposition furnace for a predetermined time to heat and decompose the gasified pollutants, and the cooling tower sprays water on the hot exhaust gas to reprecipitate the dioxins. Heating and purifying apparatus for contaminated soil, characterized in that it is cooled to a temperature at which it cannot be processed or to a bag filter processable temperature, and fine contents in the exhaust gas are removed by the bag filter . A stock bin for temporarily storing heated soil is arranged at the lower side of the discharge side of the heat treatment kiln so that the heated soil discharged from the kiln is directly received, and an oxidative decomposition furnace is mounted above the stock bin , 2. The heat purification of contaminated soil according to claim 1, wherein the inside of the stock bottle is exposed to a high temperature atmosphere by a high temperature exhaust gas introduced into the cracking furnace to facilitate thermal decomposition or volatilization of trace amounts of pollutants in the heated soil. apparatus.   The apparatus for heating and purifying contaminated soil according to claim 1 or 2, further comprising a slaked lime supply device for blowing slaked lime mixed with activated carbon into an inlet side of the bag filter.

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