JP4540445B2 - Soil purification equipment - Google Patents

Description

  The present invention relates to a soil purification apparatus that removes contaminants from contaminated soil contaminated with contaminants composed of oil, organic solvents, and other organic compounds to purify the contaminated soil.

  For example, factory sites, gas station sites, etc. are often contaminated with various pollutants such as oil and organic solvents. Land owners are being forced to remove contaminants from their social or legal responsibilities as they may harm the health of the community.

Contaminants can be removed from soil contaminated with pollutants by separating and removing soil contaminants by washing the soil with water flow and mixed jet water. There are known a method of adsorbing and removing substances with an adsorbent, a method of incinerating soil with a rotary kiln to burn and remove pollutants, a method of decomposing and removing pollutants in soil with microorganisms (bioremediation), and the like.
JP 2003-94038 A

  However, the method of separating and removing contaminants in the soil by washing the contaminated soil with a water stream and mixed-air jet water cannot remove organic compounds adhering to the soil with a small particle size. There is a problem that small sediment must be collected, incinerated and solidified, disposed of in a managed landfill, and drained from the water used to clean the contaminated soil.

  Also, in the method of adsorbing and removing pollutants in the soil with the adsorbent, the adsorbent that has adsorbed the pollutant must be incinerated or disposed of in the final disposal site, and also due to residual adsorbent etc. There is a problem that there is a risk of secondary contamination.

  In addition, the method of incinerating soil containing pollutants with a rotary kiln to remove the pollutants by burning may cause harmful substances such as dioxins, and a large amount of heat energy is required for incineration. There is also a problem that a large-scale facility called a rotary kiln is required.

  In addition, the method of decomposing and removing contaminants in the soil with microorganisms requires a method of injecting microorganisms into the soil and an activation method, and it takes time to decompose the contaminants, and also to a high concentration of contamination. There is a problem that can not cope.

  This invention solves such a problem, and it aims at providing the soil purification apparatus which can clean the soil of the land contaminated with the harmful substance efficiently and reliably in the present position. To do.

  A soil purification apparatus according to the present invention includes a soil supply device that supplies contaminated soil containing a pollutant, a superheated steam generation and supply device that generates and supplies superheated steam, and the contaminated soil that is supplied from the soil supply device. A soil purification furnace that exposes the superheated steam supplied from the superheated steam generation and supply device to move pollutants contained in the contaminated soil into the superheated steam, and cools the superheated steam discharged from the soil purification furnace. And a contaminant separator for separating contaminants from the superheated steam.

  Here, the soil purification furnace includes a sealed vertical furnace, a superheated steam discharge tube provided substantially vertically through the vertical furnace, and the superheated steam discharge tube in the vertical furnace. A fluidized hearth provided in a spiral around the ground, a soil supply device for supplying the contaminated soil on the fluidized hearth, superheated steam spraying means for spraying superheated steam on the contaminated soil on the fluidized hearth, You may comprise with the vibration apparatus which gives a vibration to the said fluid hearth.

  In this case, the superheated steam discharge cylinder is provided with a plurality of through holes to communicate the superheated steam discharge cylinder with the vertical furnace, and the soil charging device is provided at the top of the vertical furnace. The water vapor discharge cylinder is connected to the pollutant separation device, and the superheated steam spraying means is connected to the superheated steam supply device.

  The vertical furnace is composed of an upper preheating part and a main blowing part connected to the lower part of the preheating part via a connecting part, and a crushing device for crushing contaminated soil is connected to the connecting part. You may make it provide.

  Further, the fluidized hearth is partitioned into an outer region and an inner region by a substantially ring-shaped partition wall, and a bucket that connects an outer region of the lowermost fluid hearth and an inner region of the uppermost fluidized hearth. A conveyor may be provided.

  In addition, the superheated steam supply device may be constituted by a steam generating device that generates steam and a steam superheating device that generates superheated steam by heating the steam generated by the steam generating device. In addition, the soil purification apparatus may be provided with a water vapor return mechanism that guides the water vapor from which the pollutants have been separated and removed in the pollutant separation apparatus to the water vapor superheater.

  The soil purification apparatus may be provided with a drilling device for excavating the contaminated soil, or the soil purification apparatus is provided on a moving means such as a trailer so that the entire apparatus can be freely moved to an arbitrary place. You may be able to do it.

  Further, the pollutant separation device may be a mechanism for cooling the superheated steam stepwise to separate the pollutants from the superheated steam by component, and the residual heat recovered by the pollutant separation device may be You may provide the residual heat utilization mechanism utilized for the heat insulation of the apparatus or piping which connects this apparatus.

  Since the present invention can make the soil purification device large enough to be carried and installed at the contaminated site, the contaminated soil at the contaminated site without incurring the extra cost of transporting the contaminated soil to the treatment plant. Therefore, there is an effect that the contaminated soil can be purified at a low cost.

  In addition, the present invention purifies the contaminated soil at the contaminated site and returns the purified soil to the contaminated site, so that it is not necessary to incur an extra cost incurred when bringing another soil to the contaminated site. There is an effect that the contaminated site can be repaired at low cost.

  Further, according to the present invention, when the superheated steam is cooled, it becomes water, and the contaminants (oil and organic solvent) in the superheated steam have no affinity for water and are easily separated from the water. The substance can be easily separated and collected in a concentrated state, and therefore, there is an effect that the subsequent treatment and utilization of the pollutant becomes easy.

  In addition, the present invention has an effect of separating and recovering pollutants for each component and further facilitating the subsequent processing and utilization if the temperature of the superheated steam extracted from the processing apparatus is lowered and cooled in stages. There is.

  In addition, in the present invention, if superheated steam is brought into contact with contaminated soil in a non-oxidizing atmosphere or a low-oxygen atmosphere, there is no ignition, little oxidation reaction occurs, and generation of harmful substances such as dioxin is suppressed. Thus, it is possible to separate and remove pollutants from the contaminated soil.

  In addition, since the present invention uses superheated steam having a large amount of heat, the contaminated soil can be efficiently purified, and therefore the contaminated soil can be purified in a short time with a compact facility. There is an effect that can be done.

  In addition, since the present invention does not use a special chemical agent or microorganism, there is no risk of secondary contamination of the soil, and the safety is high. Therefore, there is an effect that the contaminated soil can be purified without anxiety.

  Moreover, since this invention does not discharge | emit drainage like the case where contaminated soil is washed with water, there is no need for wastewater treatment, and therefore there is an effect that the equipment for purifying the soil can be made compact.

  In addition, the present invention has the effect that it is not necessary to incinerate the adsorbent adsorbing harmful components or dispose of it at the final disposal site, and there is no need to worry about residual adsorbent (secondary contamination).

  Moreover, since this invention does not generate | occur | produce harmful substances, such as dioxin, in air | atmosphere at the time of purification processing of contaminated soil, it can safely process contaminated soil, without giving danger to the surrounding with contaminated soil. effective.

  In addition, since the present invention reuses the water vapor used to purify the soil, there is an effect that it is not necessary to take time and effort like water treatment, and the amount of water vapor produced by the boiler can be reduced.

  FIG. 1 is a conceptual diagram of a soil purification apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram and a diagram of a soil purification furnace (at the time of internal storage of the purified soil) of the soil purification apparatus according to an embodiment of the present invention. 3 is an enlarged view of part A of FIG. 2, FIG. 4 is an explanatory view of a soil purification furnace (at the time of external discharge of the purified soil) of the soil purification apparatus according to one embodiment of the present invention, and FIG. 5 is another embodiment of the present invention. FIG. 6 is an explanatory view showing a planar arrangement of the actual soil purification apparatus, and FIG. 7 is an explanatory view showing a side arrangement of the actual soil purification apparatus.

  In these drawings, reference numeral 10 denotes a vertical soil purification furnace. The soil purification furnace 10 connects and communicates an upper preheating section 12, a lower main blowing section 14, a preheating section 12 and a main blowing section 14. Connecting portion 16.

  In the internal space of the preheating part 12 and the main blowing part 14, a fluidized hearth 18 made of, for example, a wire mesh of about 0.2 mm mesh is provided in a spiral shape, and the upper surface of the fluidized hearth 18 is inclined. A steam discharge pipe 20 is disposed on the fluidized hearth 18 so that superheated steam is discharged downward. The fluidized hearth 18 is vibrated slightly by a vibration device (not shown).

  In the center of the fluidized hearth 18, a superheated steam discharge cylinder 22 is erected so as to penetrate and connect the preheating part 12 and the main blowing part 14. The internal space of the preheating unit 12 and the internal space of the main blowing unit 14 communicate with the internal space of the superheated steam discharge cylinder 22. The lower end portion of the superheated steam discharge tube 22 is closed, and the superheated steam discharge tube 24 is provided with the upper end portion of the superheated steam discharge tube 22.

  A soil hopper 26, which is a soil supply device, is provided above the preheating unit 12, and a continuous supply device 30 is provided between the soil hopper 26 and the preheating unit 12, and the contaminated soil 28 placed in the soil hopper 26 is preheated. The inside of the section 12 is continuously supplied onto the fluidized hearth 18.

  A crushing device 32 for crushing contaminated soil is provided inside the connecting portion 16. The contaminated soil 28 purified by the preheating unit 12 is crushed by the crushing device 32, and the crushed contaminated soil 28 is supplied to the inside of the main blowing unit 14 and onto the fluidized hearth 18.

  A storage tank 34 for storing soil purified by superheated steam is provided at the bottom of the main blowing unit 14, and an open / close lid 36 is provided between the main blowing unit 14 and the storage tank 34 so as to be openable and closable. The bottom of the storage tank 34 is a purified soil discharge port 35, and a discharge lid 38 is provided at the purified soil discharge port 35 so as to be openable and closable.

  The steam discharge pipe 20 provided on the fluidized hearth 18 is connected to a superheater 40 which is a steam heating device via a superheated steam supply pipe 42. Further, the upper portion of the superheated steam discharge cylinder 22 is connected to a pollutant separation device 48 via a superheated steam discharge pipe 24 and a steam recovery pipe 44 which are steam return mechanisms.

  The superheater 40 is connected to a boiler 46 so that steam is supplied from the boiler 46 to the superheater 40. A water tank 50 is connected to the boiler 46, and water is supplied from the water tank 50 to the boiler 46.

  The pollutant separation device 48 is configured to lower the temperature of the superheated steam to separate the steam at 100 ° C. and the pollutant, and the steam from which the pollutant has been removed is returned to the superheater 40. The separated contaminants are stored in an oil storage tank 52 provided adjacent thereto.

  The pollutant separation device 48 is provided with a residual heat recovery device 54. The residual heat recovery device 54 recovers the residual heat emitted from the pollutant separation device 48 and uses it to keep the devices or pipes connecting the devices together. It is configured.

  Each of these devices and pipes is installed on a trailer 56, and moves or travels by itself to a place where contaminated soil is present, and the contaminated soil can be purified at that place.

  Next, the operation of the soil purification apparatus according to the present invention will be described.

  First, the soil purification apparatus according to the present invention is transported by a trailer 56 to a place contaminated with a pollutant or, if equipped with a self-propelled apparatus, is self-propelled and stopped at an appropriate position in a place contaminated with a pollutant. Install and fix in that position.

  Next, the operation of the boiler 46 and the superheater 40 is started. The water supplied from the water tank 50 is heated by the boiler 46 to become 100 ° C. steam, and further heated by the superheater 40 to become 500 ° C. superheated steam. The superheated steam is supplied to the soil purification furnace 10 through the superheated steam supply pipe 42 and is continuously discharged from the steam discharge pipe 20 toward the fluidized hearth 18.

  Next, the soil containing the pollutant is excavated by a drilling device (not shown), and the excavated contaminated soil 28 is sequentially put into the soil hopper 26. The contaminated soil 28 introduced into the soil hopper 26 is supplied onto the fluidized hearth 18 of the preheating unit 12 by the continuous supply device 30.

  Since the fluidized hearth 18 is inclined and vibrated by a vibration device (not shown), the contaminated soil 28 on the fluidized hearth 18 moves down in the preheating portion 12 while moving.

  The superheated steam is discharged from the steam discharge pipe 20 to the fluidized hearth 18, and the superheated steam is sprayed onto the contaminated soil 28 that is gradually lowered while moving on the fluidized hearth 18. The surface of the contaminated soil 28 becomes hot due to the heat of the superheated steam, and the contaminant adhering to the surface of the contaminated soil 28 is vaporized and mixed in the superheated steam, and the superheated steam mixed with the contaminant is preheated. The superheated steam discharge cylinder 22 is entered from the section 12.

  The contaminated soil 28 that has finished moving through the fluidized hearth 18 inside the preheating section 12 enters the connecting section 16 from the bottom of the preheating section 12 and is crushed by the crushing device 32 to become fine, and the inside is exposed, and the main blow It is supplied on a fluidized hearth 18 inside the section 14.

  The fluidized hearth 18 in the main blowing unit 14 is also vibrated by a vibration device (not shown), and the contaminated soil 28 sequentially moves down the main blowing unit 14 while moving on the fluidized hearth 18. The contaminated soil 28 is further heated by the superheated steam on the fluidized hearth 18, the pollutant adhering to the exposed interior is vaporized and mixed into the superheated steam, and the superheated steam mixed with the pollutant is The superheated steam discharge cylinder 22 is entered from the main blowing section 14.

  The contaminated soil that has finished moving through the fluidized hearth 18 in the main blowing section 14 is accumulated at the bottom of the main blowing section 14. When an appropriate amount of purified soil is collected, the purified soil enters the storage tank 34 when the opening / closing lid 36 is opened.

  When the discharge lid 38 is opened at an appropriate time and place, the purified soil in the storage tank 34 is discharged, the purified soil is backfilled in the original place where the contaminated soil was dug, and the contaminated soil purification process is completed. . Instead of the opening / closing lid 36, a continuous discharge device may be used.

  The superheated steam that has entered the superheated steam discharge cylinder 22 enters the pollutant separation device 48 through the steam recovery pipe 44, is cooled to 100 ° C. by the pollutant separation device 48, and precipitates oil or the like that is a pollutant. The steam is sent to the superheater 40. The recovered oil or the like is appropriately sent to the oil storage tank 52 for storage.

  In addition, although the soil purification furnace 10 of the soil purification apparatus which concerns on embodiment of this invention is as above-mentioned, the soil purification furnace 10 is not restricted to the thing of the above-mentioned structure, Another structure as shown in FIG. A thing may be adopted.

  That is, the soil purification furnace 10 having another structure is basically the same as the soil purification furnace 10 described above, but the furnace is configured in one stage, and a bucket conveyor 58 is provided outside the soil purification furnace 10. The flow hearth 18 is different in that it is divided into an outer region 62 and an inner region 64 by a ring-shaped partition wall 60.

  The movement of the contaminated soil 28 in the soil purification furnace 10 is slightly different from the movement of the contaminated soil 28 in the soil purification furnace 10 described above, as will be described later.

  That is, the contaminated soil 28 introduced into the soil hopper 26 is supplied to the uppermost stage of the fluidized hearth 18 by the continuous supply device 30 and gradually moves to the region 62 outside the fluidized hearth 18 while being purified by superheated steam. Go.

  The contaminated soil 28 that has moved to the region 62 outside the fluidized hearth 18 flows through the region 62 outside the fluidized hearth 18 and descends while being purified by superheated steam. The contaminated soil 28 that has reached the lowest level of the fluidized hearth 18 is scraped up to the upper level of the fluidized hearth 18 by the bucket conveyor 58 and supplied to the region 64 inside the fluidized hearth 18.

  The contaminated soil 28 supplied to the region 64 inside the fluidized hearth 18 flows and descends in the region 64 inside the fluidized hearth 18 while being further purified by superheated steam. Contaminated soil 28 reaching the bottom of the soil purification furnace 10 is stored in a storage tank 34.

  First, prepare dry soil that is not contaminated with oil, etc. and waste lubricating oil with a known component composition, mix 2 parts by weight of waste lubricating oil with 100 parts by weight of soil, and mix thoroughly to contaminate Soil was made artificially.

  Next, this contaminated soil was put into a purification device, sprayed with 500 ° C. atmospheric superheated steam for 5 minutes, taken out of this contaminated soil and ground, returned to the purification device, and again sprayed with 500 ° C. superheated steam for 10 minutes.

  The soil subjected to the above purification treatment was analyzed and examined for the presence of waste lubricant. As a result, no waste lubricant was detected.

  Further, when the liquid obtained by cooling the superheated steam used in the above purification treatment was allowed to stand, the upper layer became oil and the lower layer became water. And when the component of the oil of the upper layer was analyzed, it was a component substantially the same as a waste lubricating oil. Moreover, dioxin was not contained in oil and water.

  In addition, when an experiment similar to the above was performed using trichlorethylene instead of the waste lubricant, a result almost the same as that of the waste lubricant was obtained.

  The present invention can be applied to the purification of terrestrial oil-contaminated soil, marine oil-contaminated soil and bottom mud, oil-contaminated bottom mud in closed waters, and general soil contaminated with organic compounds other than oil.

It is a conceptual diagram of the soil purification apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the soil purification furnace (at the time of internal storage of purification soil) of the soil purification apparatus which concerns on one embodiment of this invention. It is the A section enlarged view of FIG. It is explanatory drawing of the soil purification furnace (at the time of external discharge | emission of purification soil) of the soil purification apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the soil purification furnace of the soil purification apparatus which concerns on other embodiment of this invention. It is explanatory drawing which shows the planar arrangement | positioning of the actual soil purification apparatus. It is explanatory drawing which shows the side surface arrangement | positioning of the actual soil purification apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Soil purification furnace 12 Preheating part 14 Main blowing part 16 Connection part 18 Fluidized hearth 20 Steam discharge pipe 22 Superheated steam discharge pipe 24 Superheated steam discharge pipe 26 Soil hopper 28 Contaminated soil 30 Continuous supply apparatus 32 Crushing apparatus 34 Storage tank 36 Opening and closing Lid 38 Discharge lid 40 Superheater 42 Superheated steam supply pipe 44 Steam recovery pipe 46 Boiler 48 Contaminant separation device 50 Water tank 52 Oil storage tank 54 Residual heat recovery device 56 Trailer 58 Bucket conveyor 60 Partition wall 62 Area 64 Area

Claims (9)

A soil supply device that supplies soil containing pollutants (hereinafter referred to as “contaminated soil”), a superheated steam generation and supply device that generates and supplies superheated steam, and the contaminated soil that is supplied from the soil supply device A soil purification furnace that exposes the superheated steam supplied from the superheated steam generation and supply device to move pollutants contained in the contaminated soil into the superheated steam, and superheated steam discharged from the soil purification furnace. A pollutant separation device that cools and separates the pollutants from the superheated steam , and the soil purification furnace is provided substantially vertically through the sealed vertical furnace and the vertical furnace A superheated steam discharge tube, a fluidized hearth provided in a spiral around the superheated steam discharge tube in the vertical furnace, a soil supply device for supplying the contaminated soil on the fluidized hearth, and the flow To the contaminated soil on the hearth Superheated steam spraying means for spraying hot steam and a vibration device for vibrating the fluidized hearth, the superheated steam discharge cylinder is provided with a plurality of through holes, the superheated steam discharge cylinder and the vertical furnace are The soil charging device is provided in the upper part of the vertical furnace, the superheated steam discharge tube is connected to the pollutant separation device, and the superheated steam spraying means is connected to the superheated steam generation and supply device . A soil purification apparatus characterized by that.   The vertical furnace comprises an upper preheating part and a main blowing part connected to the lower part of the preheating part via a connecting part, and the connecting part is provided with a crushing device for crushing the contaminated soil. The soil purification apparatus of Claim 1 characterized by the above-mentioned.   The fluidized hearth is partitioned into an outer region and an inner region by a substantially ring-shaped partition wall, and a bucket conveyor that connects the outer region of the lowermost fluid hearth and the inner region of the uppermost fluidized hearth. The soil purification apparatus according to claim 1, wherein the soil purification apparatus is provided.   The said superheated steam supply apparatus consists of a steam generator which produces | generates water vapor | steam, and a steam heater which produces | generates superheated steam by heating the water vapor | steam produced | generated by this steam generator. The soil purification apparatus as described in.   5. The soil purification apparatus according to claim 3, further comprising a water vapor return mechanism that guides the water vapor from which contaminants have been separated and removed in the pollutant separation apparatus to the water vapor heating apparatus.   The soil purification apparatus according to any one of claims 1 to 5, further comprising a drilling device that drills the contaminated soil.   The soil purification apparatus according to any one of claims 1 to 6, further comprising a moving means.   8. The pollutant separation device includes a pollutant separation device that cools the superheated steam stepwise and separates the pollutant from the superheated steam according to components. The soil purification apparatus as described.   9. A residual heat recovery and utilization mechanism that uses the residual heat recovered by the pollutant separation device to keep the temperature of each of the devices or a pipe connecting the devices is provided. Soil purification device.

Images