JP3526012B2 - Toxic substance separation and removal equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an apparatus for separating and removing various harmful substances such as oil and organic chlorine compounds contained in contaminated soil, industrial waste, sludge and the like from the contaminated soil and the like.

[0002]

2. Description of the Related Art Fuel oil and machine oil are sometimes mixed with excavated soil and carried out when foundation work is performed on a site of a factory.
If such oil-contaminated soil is left as it is, the oil content mixed in the soil volatilizes and diffuses to the surroundings, hindering the lives of neighboring residents, and when it is released from soil particles by rainwater, groundwater, etc. It can also cause contamination of water quality. Therefore, for such oil-contaminated soil, it is necessary to remove the oil content by incineration, for example, to prevent its diffusion into the environment.

Further, the soil at the site of the factory may be contaminated with organic chlorine compounds such as trichlorethylene and tetrachloroethylene, and sufficient measures must be taken to prevent the diffusion of such pollutants.

[0004]

However, it goes without saying that when incinerating contaminated soil, sludge, industrial waste, etc., considerable energy is required during incineration and soil characteristics change. However, there has been a problem that harmful by-products such as dioxins may be generated depending on contaminants or incineration temperature.

On the other hand, there is also a method in which quick lime is added to contaminated soil or the like to react with the contained water, and the pollutants are volatilized by the heat generated at that time, but in addition to the problem that the soil characteristics change, heat generation It is difficult to efficiently remove toxic substances by volatilization, and the entire working space is made an airtight space so that the vaporized toxic substances do not diffuse into the atmosphere. There was a problem that all the air in the room had to be purified.

There is also a method of washing the excavated contaminated soil with water or the like. However, such a method requires not only circulation equipment for cleaning water and purification equipment, but also treated soil in the form of slurry. Therefore, there has been a problem that the labor for dehydration treatment is increased.

The present invention has been made in consideration of the above-mentioned circumstances, and efficiently separates and removes various harmful substances from contaminated soil etc. without generating harmful by-products and troublesome post-treatment. It is an object of the present invention to provide a separation / removal device for harmful substances that can be used.

[0008]

In order to achieve the above object, the device for separating and removing harmful substances according to the present invention has an airtightness in which an object containing a harmful substance is accommodated as described in claim 1. A container, an exhaust pipe communicated with an airtight space in the container, and a gas in the container is drawn out through the exhaust pipe to reduce the atmospheric pressure to volatilize the harmful substance from the inside of the object. A vacuum pump for discharging the volatilized harmful substance to the outside of the container, a collection device connected to the upstream side or the downstream side of the vacuum pump for collecting the harmful substance discharged from the container, and the inside of the container A heating means for heating the container, the container is configured to be rotatable about a horizontal axis, and a stirring blade is projectingly provided on an inner surface of the container, and an object inlet is provided on a peripheral surface of the container. Is provided.

Further, as described in claim 2, the apparatus for separating and removing harmful substances according to the present invention comprises an airtight container for accommodating an object containing a harmful substance and an airtight space inside the container. An exhaust pipe communicated with the container, and the gas inside the container is drawn out through the exhaust pipe to reduce the atmospheric pressure so that the harmful substance is volatilized from the inside of the object and the harmful substance volatilized to the outside of the container. The housing includes a vacuum pump for discharging, a collecting device connected to an upstream side or a downstream side of the vacuum pump for collecting harmful substances discharged from the container, and a heating unit for heating the inside of the container. A body is configured to be rotatable about a horizontal axis, a stirring blade is projectingly provided on an inner surface of the housing, and the heating means is provided on the stirring blade.

[0010]

In the device for separating and removing harmful substances according to the present invention, first, an object containing a harmful substance is put into an airtight container and sealed. Next, the air in the housing is reduced by a vacuum pump through the exhaust pipe communicating with the airtight space in the airtight housing to reduce the air pressure.

In this way, the boiling point of the harmful substance is lowered in the container due to the decrease in the air pressure, and the harmful substance in the object is volatilized. Therefore, the harmful substance is discharged to the outside of the container and further collected by the collecting device. to recover.

Here, when the air is extracted by the vacuum pump, at the same time as or before the air is extracted, the inside of the container is heated by the heating means and the container is rotated around the horizontal axis.

In this way, the vapor pressure of the harmful substance increases due to the temperature rise in the container, and it becomes possible to volatilize and recover the harmful substance without raising the vacuum degree too much. Further, by rotating the container, the object inside the container is agitated by the stirring blades, which promotes the above-mentioned volatilization action and evenly volatilizes the harmful substances mixed in the object. It is also possible to do. Here, how to configure the heating means is arbitrary, for example, irradiating with electromagnetic waves to heat, surplus heat of a dust incinerator or the like is sent into the airtight space in the form of warm air, heat generation of electric heating means, etc. It is possible to install the body in the container or pass warm water through the container.

Even after the air is removed, the gas in the airtight space, that is, the volatilized harmful substance is removed to maintain the reduced pressure state, so that the harmful substance in the object is continuously volatilized.

As the object containing the harmful substance,
Although it is mainly contaminated soil, it also includes slag, incineration ash, sludge, concrete waste, plastic waste, waste wood, etc.

As harmful substances, oils, trichloroethane, trichloroethylene, tetrachloroethylene, P
Includes organochlorine compounds such as CB, and aromatic hydrocarbons such as benzene, toluene, naphthalene, and phenol, as well as all substances that have a boiling point below room temperature under reduced pressure, especially at a vacuum of several mmHg or less. To be done. Therefore, heavy metals such as mercury are also included in the harmful substances in the present invention.

The air pressure in the airtight space is preferably set to be equal to or lower than the vapor pressure of harmful substances at the temperature in the space. If the atmospheric pressure is lowered to this extent, the harmful substances contained in the target object will immediately volatilize. The vapor pressure of the harmful substance does not necessarily have to be lower than the vapor pressure, and although the efficiency is slightly lowered, a considerable volatilization action can be expected if the pressure is close to the vapor pressure.

Here, the object insertion port for accommodating the object in the container may have any structure, but the object insertion port is provided on the peripheral surface of the container. Then, by rotating the container about the horizontal axis so that the object input port faces downward, the object input port can also be used as the object discharge port.

Although the heating means may be arbitrarily configured and arranged, if the heating means is provided on the stirring blade, a sufficient area for contacting the object can be secured and the object can be efficiently heated. It becomes possible to do.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a device for separating and removing harmful substances according to the present invention will be described below with reference to the accompanying drawings. It should be noted that parts and the like which are substantially the same as those of the conventional technique are designated by the same reference numerals and the description thereof is omitted.

FIG. 1 is an overall view showing a device for separating and removing harmful substances according to this embodiment, and FIG. 2 is an overall perspective view of the same. As can be seen from these figures, the hazardous substance separation / removal device 1 according to the present embodiment is an object containing hazardous substances such as heavy oil, light oil, kerosene, oil components such as gasoline, and organic chlorine compounds such as trichlorethylene and tetrachloroethylene. The airtight container 3 in which the polluted soil 2 is contained, the exhaust pipe 4 communicating with the airtight space in the container, and the vacuum pump 6 connected to the exhaust pipe via the gas-liquid separation tank 5.
And a collecting device 7 connected to the downstream side of the vacuum pump.

The vacuum pump 6 draws out the gas in the container 3 through the exhaust pipe 4 and lowers the atmospheric pressure in the container 3, so that the boiling point of the harmful substance is lowered as the atmospheric pressure in the container 3 decreases. The harmful substances in the polluted soil 2 are volatilized, and the volatilized harmful substances are discharged to the outside of the container 3.

A barometer 10 is attached to the gas-liquid separation tank 5 so that the atmospheric pressure in the communicating container 3 can be measured, and a drain valve 12 is provided near the bottom surface of the tank. By opening the drain valve, it is possible to remove harmful substances accumulated in the gas-liquid separation tank 5 and water evaporated from the contaminated soil 2.

The collecting device 7 is composed of an activated carbon adsorption tower, adsorbs volatile components, which are harmful substances, from the gas discharged from the vacuum pump 6, and exhausts the air from which the volatile components have been removed. It is designed to release from 15. As the adsorbent to be filled in the collection device 7, other than activated carbon,
It may be appropriately selected from silica / alumina-based adsorbents, synthetic adsorbents such as molecular sieving carbon, zeolite, and acid clay also called activated clay, depending on the adsorption property of harmful substances.

On the other hand, the airtight container 3 has a substantially cylindrical shape, and is disposed laterally above the inside of the gantry 21 assembled from a steel frame or the like.

Here, as shown in FIG.
The guide groove 22 is provided so that the container 3 can be rotated around the horizontal axis as shown by the arrow in FIG. 1 by fitting the roller 24 of the load receiver 23 attached to the pedestal 21 into the guide groove. And a rotary shaft 27 of a drive motor 26 attached to the frame 21 while being rotatably supported by the housing 25 and provided at one end (right end in FIG. 1) of the housing 3.
The housing 28 can be rotated about the horizontal axis by hanging the belt 28 between the housing 3 and the belt 28. The exhaust pipe 4 described above is attached so as to penetrate near the center of the pulley 25 attached to the container 3,
The container 3 is communicated with the internal space of the container so that the airtight state of the container 3 is maintained.

The load receivers 23 are appropriately installed so that the containing body 3 can be stably supported so as to be rotatable about a horizontal axis, and in this embodiment, as an example thereof, three places are installed at 120 ° intervals. There is.

On the peripheral surface of the container 3, a earth and sand inlet 29 is provided as an object inlet, through which the contaminated soil 2 can be injected into the hollow space inside. When the container 3 is turned upside down, the treated soil can be discharged from the earth and sand inlet and dropped into the treated soil receiving tank 30 arranged below the container 3 so as to be freely drawn out. There is. That is, the earth and sand inlet 29 also functions as an earth and sand outlet that is an object outlet.

The container 3 is formed of a steel container having an appropriate thickness so that the container 3 will not be damaged even if the inside pressure is reduced to a vacuum or a state close thereto, and the container 3 is smoothly rotated about the horizontal axis. As described above, it is preferable to attach a balancer 31 as shown in FIG. 1 as needed to prevent the weight from being biased.

As can be seen clearly in FIG. 3 (b), a stirring blade 32 is provided on the inner surface of the container 3, and the stirring blade 32 is rotated by the rotation of the container 3 so that the container 3 is accommodated. The polluted soil 2 can be stirred. Further, in the cross section of the stirring blade 32, the electric heater 3 as a heating means is provided.
3 is embedded and connected to a power source (not shown), and a temperature sensor 3 for measuring the temperature inside the container 3.
5 is attached to the inner surface of the container.

On the other hand, a control board 34 for controlling the power source connected to the drive motor 26 and the electric heater 33 is attached to the pedestal 21, and the control board 34, as shown in the block diagram of FIG. While monitoring the rotation state of the drive motor by the encoder 37 built in the drive motor, the drive motor 26 is driven and controlled so that the container 3 rotates in a desired rotation mode or rotation speed, and the temperature inside the container 3 is controlled by the temperature. The power source 36 can be controlled to adjust the energization state and the energization amount to the electrothermal heater 33 so that the temperature inside the container can be maintained at a desired temperature while being monitored by the sensor 35. As the rotation mode of the container 3, for example, continuous or intermittent rotation in only one direction, switching rotation in both forward and reverse directions, swinging rotation within a desired angle range, and the like can be considered.

In order to separate and remove harmful substances from the contaminated soil 2 using the separation / removal device 1, first, as shown in FIG. 6 (a), the contaminated soil 2 is charged from the earth / sand input port 29 of the container 3. Then, the vacuum pump 6 is actuated to draw out the air in the container 3 to reduce the air pressure in the container.

As for the degree of lowering the air pressure, it is desirable to operate the vacuum pump 6 so that the air pressure in the container 3 becomes equal to or lower than the vapor pressure of harmful substances at the temperature in the container. Specifically, when the harmful substance is kerosene, its vapor pressure curve becomes as shown in FIG. 5, and therefore, if the temperature is about 25 ° C., it may be lowered to about 60 mmHg or less. For reference, the vapor pressure curves of water and ethyl alcohol are also drawn in the figure, and it can be seen from the figure that the volatile oil content can be recovered prior to the steam.

When the air pressure in the container 3 is reduced in this way, the boiling point of the harmful substance is lowered in the container due to the decrease in the air pressure, and the harmful substance in the polluted soil 2 is immediately volatilized. At 6, suction is performed from the container 3. Then, the sucked volatile matter is collected in the gas-liquid separation tank 5 in the form of liquid or contained in the liquid, and the remaining volatile matter is adsorbed and collected by the collecting device 7, and the purified air is discharged through the exhaust port 15
Discharge from. On the other hand, the solution containing the harmful substance accumulated in the gas-liquid separation tank 5 is sent to a waste water purification facility or a waste treatment facility for appropriate treatment.

Here, when air is extracted by the vacuum pump 6, the inside of the container 3 is heated by the electric heater 33 at the same time as or before the air is extracted, and
As shown in FIG. 6 (b), the drive motor 26 rotates the container 3 about the horizontal axis.

In this way, the vapor pressure of the harmful substance increases due to the temperature rise in the container 3, and it is possible to volatilize and recover the harmful substance without raising the vacuum degree too much. Further, since the contaminated soil 2 contained in the container 3 is stirred by the stirring blade 32 as the container 3 is rotated, the above-mentioned volatilization action is promoted and the contaminated soil 2 is mixed into the contaminated soil 2. It is also possible to volatilize existing harmful substances uniformly.

Even after the air is evacuated, the volatile matter in the container 3 is evacuated by the vacuum pump 6 to maintain the reduced pressure state, so that the harmful substances in the contaminated soil 2 are continuously volatilized.

The time for operating the vacuum pump 6 is appropriately adjusted depending on how much harmful substance is desired to be removed. Further, after the pressure is once lowered to a predetermined atmospheric pressure, it is sufficient to intermittently operate the vacuum pump 6 or operate with the output weakened so that the pressure is reduced by an amount corresponding to the pressure increase due to the harmful substances volatilized in the container 3. .

When the harmful substances in the contaminated soil 2 are separated and removed to a desired degree, the vacuum pump 6 is stopped and the earth and sand inlet 29 is housed so as to face downward as shown in FIG. 6 (c). The body 3 is rotated about the horizontal axis, and then the treated soil is dropped into the treated soil receiving tank 30 through the earth and sand inlet 29. The treated soil may be used as an embankment material, for example.

By installing a detection sensor in the vicinity of the exhaust port 15 of the collection device 7, the content of volatile components from the exhaust port 15 is monitored, and when the measured value exceeds a certain value, the collection device 7 is collected. It is preferable to determine that the adsorption capacity of the activated carbon in 7 has decreased and recover the adsorption ability by heating the activated carbon in the collection device 7 or the like.

As described above, according to the hazardous substance separating / removing apparatus of this embodiment, the harmful substance contained in the polluted soil 2 is immediately volatilized due to the drop in the boiling point of the hazardous substance due to the decrease in atmospheric pressure. 3 can be discharged to the outside.

Therefore, a large amount of incineration energy is not consumed, harmful by-products such as dioxins are not generated during incineration, and there is no concern that vaporized harmful substances diffuse to the outside. It is possible to separate and remove harmful substances from the polluted soil 2 in a time. Moreover, since the treated soil has not been treated with quick lime or incinerated, the soil characteristics have not changed, and since it has not been treated with water, there is no need for dehydration. Therefore, the treated soil can be diverted to the embankment material as it is.

Further, since the harmful substance can be recovered in the gas state, there is an effect that the post-treatment becomes easier as compared with the case of recovering in the liquid state.

Further, according to the device 1 for separating and removing harmful substances according to the present embodiment, the stirring blade 32 is provided so as to project from the inner surface of the container 3, and the stirring blade 32 contaminates as the container 3 rotates. Sat 2
Since the stirring is performed, the volatilization action of the harmful substance due to the boiling point drop is promoted, and the harmful substance mixed in the contaminated soil 2 can be evenly volatilized.

In addition, according to the harmful substance separation / removal apparatus 1 of the present embodiment, since the contaminated soil 2 is heated by the electric heater 33, the vapor pressure of the harmful substance increases due to the temperature rise in the container 3. It becomes large, and it becomes possible to volatilize and recover harmful substances without increasing the degree of vacuum. A synergistic effect that the inside of the container 3 can be heated uniformly by the stirring action of the stirring blade 32 described above can be expected.

Further, according to the harmful substance separating / removing apparatus of the present embodiment, since the earth and sand inlet 29, which is an object inlet, is provided on the peripheral surface of the container 3, the earth and sand inlet 2
By rotating the container 3 around the horizontal axis so that 9 faces downward, the earth and sand inlet 29 can be used also as an earth and sand outlet that is an object outlet, and the treated soil can be smoothed. It can also be discharged.

Further, in the device for separating and removing harmful substances according to the present embodiment, since the electric heater 33 as a heating means is provided on the stirring blade 32, a sufficient area for contacting the contaminated soil 2 is secured. Therefore, it becomes possible to efficiently heat the contaminated soil.

In the present embodiment, the polluted soil 2 is used as the object for separating and removing harmful substances, but the object of the present invention is not limited to the polluted soil 2, and instead of this, slag or incineration is used. The object may be ash, sludge, concrete waste material, plastic waste material, waste wood, or the like.

Further, in the present embodiment, the volatile matter, which is a harmful substance, is collected by adsorption of activated carbon, but instead of this, for example, the volatile matter may be collected in the form of being dissolved in a solvent. .

Further, in this embodiment, the gas-liquid separation tank 5 is installed between the container 3 and the vacuum pump 6 to perform the liquefaction recovery, but this is omitted and only the collecting device 7 is used. Harmful substances may be collected.

Further, in the present embodiment, the gas-liquid separation tank 5, the vacuum pump 6, and the collection device 7 are connected to the container 3 in this order. First, in the gas-liquid separation tank 5, the vacuum pump 6 is a so-called dry type. If it is of a type, this may be omitted, or the order of the vacuum pump 6 and the collection device 7 may be exchanged.

Further, in the present embodiment, the electric heater 33, which is a heating means, is embedded in the stirring blade 32. However, in addition to this arrangement, the inner surface of the container 3 embedded in the main body of the container 3 is not provided. Various forms are conceivable such as sticking or arranging near the rotation center of the container 3.

Although not particularly mentioned in the present embodiment, a pressure sensor is installed in the container 3, a peep window for checking the agitation status, etc. is provided, and harmful substances It is conceivable to provide a gas extraction port to check the volatilization status.

Although not particularly mentioned in this embodiment, in some cases, a liquefying device is provided on the upstream side of the gas-liquid separation tank 5 to quickly liquefy the volatile components in the exhaust pipe 4,
The recovery efficiency in the gas-liquid separation tank 5 may be increased.

Although not particularly mentioned in the present embodiment, when the contaminated soil 2 containing a harmful substance is sealed in the container 3, a predetermined vaporization accelerator may be added to the contaminated soil. Good.

In this way, the harmful substance is likely to volatilize in the container 3 due to the action of the vaporization accelerator, so that even if the harmful substance is not vaporized even when the depressurizing operation is performed, it is promptly removed. It becomes possible to volatilize and separate and remove from the contaminated soil 2. Incidentally, such a vaporization accelerator,
After the contaminated soil 2 is charged, it may be added to the contaminated soil through an inlet (not shown) connected to the inside of the container 3 so as to communicate therewith.

Specific examples of the vaporization accelerator include cyanide which is volatilized as a hydrocyanic acid gas by adding an acidic solution, and arsenic which is volatilized as an arsine gas by adding an acidic solution and an oxidizing agent to increase the redox potential. It contains mercury, etc., which is very easily vaporized by adding hydrochloric acid.In the case of cyan, the acidic solution serves as a vaporization accelerator, in the case of arsenic, the acidic solution and the oxidizing agent serve as a vaporization accelerator, and in the case of mercury, hydrochloric acid It becomes a vaporization accelerator.
In addition, if it is a harmful substance such as oil targeted in the present embodiment, it can be smoothly vaporized only by depressurizing operation without adding the vaporization accelerator, but in addition to the depressurizing operation, the vaporization accelerator is added. Needless to say, if this is done, the efficiency of removing harmful substances can be significantly increased.

[0059]

As described above, according to the apparatus for separating and removing harmful substances according to the present invention, the boiling point of the harmful substance is lowered by vacuum suction, so that the harmful substance contained in the object is immediately volatilized, and Can be discharged to the outside. Therefore, it becomes possible to separate and remove the harmful substances from the target in a short time without spending a large amount of incineration energy and without generating harmful by-products such as dioxins during the incineration. Moreover, since the treated soil has not been treated with quick lime or incinerated, the soil characteristics have not changed, and since it has not been treated with water, there is no need for dehydration. Therefore, the treated soil can be diverted to the embankment material as it is.

Further, the agitating blades provided on the inner surface of the housing promote the volatilization by vacuum suction, and
It is possible to evenly volatilize harmful substances mixed in the object, and by heating the inside of the container with heating means, the vapor pressure of the harmful substances increases due to the temperature rise inside the container, and the degree of vacuum is increased. It is also possible to volatilize and recover harmful substances without raising the temperature too much.

Further, according to the hazardous substance separating / removing apparatus of the first aspect, the object input port is rotated by rotating the container about the horizontal axis so that the object input port faces downward. There is also an effect that it can also be used as a discharge port.

Further, according to the apparatus for separating and removing harmful substances according to the second aspect, the area in contact with the object can be sufficiently secured, and the object can be efficiently heated. Play.

[0063]

[Brief description of drawings]

FIG. 1 is an overall view of a device for separating and removing harmful substances according to the present embodiment.

FIG. 2 is an overall perspective view of a harmful substance separation / removal device according to the present embodiment.

FIG. 3 is a diagram of a device for separating and removing harmful substances according to the present embodiment, in which (a) is a side view as seen from the direction of the line AA in FIG. 1, (b).
2 is a sectional view taken along the line BB of FIG.

FIG. 4 is a block diagram showing an electrical connection relationship between a control panel 34 and its peripheral devices.

FIG. 5 is a graph showing the operation of the harmful substance separation / removal device according to the present embodiment.

FIG. 6 is a perspective view showing the operation of the harmful substance separation / removal device according to the embodiment.

[Explanation of symbols]

1 Separation and removal device 2 Contaminated soil (target) 3 housing 4 exhaust pipe 5 Gas-liquid separation tank 6 vacuum pump 7 Collection equipment 29 Object input port 32 stirring blades 33 Electric heater (heating means)

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) B09C 1/00-1/10 B09B 3/00-5/00

Claims (2)

(57) [Claims] 1. An airtight container for accommodating an object containing a harmful substance, an exhaust pipe communicating with an airtight space inside the container, and a gas in the container extracted through the exhaust pipe. A vacuum pump that volatilizes the harmful substance from the inside of the object by lowering the atmospheric pressure and discharges the volatilized harmful substance to the outside of the container, and the vacuum pump connected to the upstream side or the downstream side of the vacuum pump. It comprises a collecting device for collecting harmful substances discharged from the body, and a heating means for heating the inside of the container, and the container is configured to be rotatable about a horizontal axis and agitated on the inner surface of the container. A device for separating and removing harmful substances, characterized in that the blade is provided in a protruding manner, and an object inlet is provided on the peripheral surface of the container. 2. An airtight container for accommodating an object containing a harmful substance, an exhaust pipe communicating with an airtight space inside the container, and a gas in the container extracted through the exhaust pipe. A vacuum pump that volatilizes the harmful substance from the inside of the object by lowering the atmospheric pressure and discharges the volatilized harmful substance to the outside of the container, and the vacuum pump connected to the upstream side or the downstream side of the vacuum pump. It comprises a collecting device for collecting harmful substances discharged from the body, and a heating means for heating the inside of the container, and the container is configured to be rotatable about a horizontal axis and agitated on the inner surface of the container. An apparatus for separating and removing harmful substances, characterized in that the blade is provided in a protruding manner, and the heating means is provided on the stirring blade.