JP2008049207A - Heat treatment apparatus of contaminant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus of contaminants which is excellent in a decompositional function of organic chlorine compounds such as dioxin contained in contaminants and which prevents the condensation of moisture, tar and the like contained in circulation gas. <P>SOLUTION: The heat treatment apparatus of contaminants is provided with a double tubular rotor 10 comprised of an inner tube 11 and an outer tube 12, an introduction device 21 of the material to be treated having a primary air introduction part 20 at the front end part of the inner tube 11 and a spiral plate 22 for transferring the material to be treated in the inner wall surface of the inner tube, a material to be treated discharge hood 17 at the front end part of the outer tube 12 and an exhaust gas discharge hood 18 at the rear end part of the outer tube and further provided with a secondary air introduction part 24 and a material to be treated discharge part 25 at the material to be treated discharge hood 17, and an exhaust gas discharge part 26 at the exhaust gas discharge hood. Further, the double tubular rotor 10 is inclined forward so that the front end is lower than the rear end and a heating means 16 is installed at the outside of the double tubular rotor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat treatment apparatus for pollutants that detoxifies pollutants such as soil and sludge (hereinafter referred to as sediment) contaminated with organic chlorine compounds such as dioxins (DXNs) and PCBs.

  Conventionally, as shown in FIG. 4, two heating devices 51 and 52 are installed in two upper and lower stages, and an outlet 53 of the upper heating device 51 and an inlet 54 of the lower heating device 52 are connected by a substantially vertical connecting duct 55. There has been proposed a heat treatment method for pollutants that renders the pollutants m contaminated with organic chlorine compounds such as dioxins (DXNs) and PCBs harmless using the connected heat treatment apparatus 50 (see, for example, Patent Document 1). ).

  In this heat treatment method, the contaminant m heated by the upper heating device 51 is supplied to the lower heating device 52 through the connecting duct 55, but is heated by the upper heating device 51 while passing through the connecting duct 55. It has been found that the pollutant m significantly decreases in temperature (for example, about 150 to 200 ° C.). In order to compensate for this temperature decrease, the length of the lower heating device 52 is increased, or the capacity of an electric heater (not shown) provided in the lower heating device 52 or a kerosene burner (not shown) is increased. However, in this case, there is a problem that the power consumption of the electric heater and the amount of kerosene consumed by the kerosene burner increase while the lower heating device 52 becomes long.

  On the other hand, since the secondary air j supplied to the lower stage heating device 52 flows into the high-temperature separator 56 installed on the upper portion thereof via the connection duct 55, a large amount of dust accompanying the contaminant m falling in the connection duct 55 is produced. Will be blown up. For this reason, there is a possibility that a filter such as a high temperature bag filter or a ceramic filter provided in the high temperature separator 56 may be clogged. The symbol i is primary air supplied to the lower stage heating device 51. Further, as described above, when the two heating devices 51 and 52 are installed in two upper and lower stages, the height of the heat treatment device 50 is inevitably high, and the maintenance of the heat treatment device 50 becomes a work at a high place. There was a problem.

  In order to solve such a problem, a double cylinder-shaped heat treatment apparatus composed of an inner cylinder and an outer cylinder has been devised, but as shown in FIG. It has been found that there is a heavy cylindrical heat treatment apparatus 60 (see, for example, Patent Document 2).

  However, since the conventional heat treatment apparatus 60 transfers the incineration ash n from the inlet 63 through the gap between the inner cylinder 61 and the outer cylinder 62 to the back of the outer cylinder 62, as shown in FIG. Since the screw-like blade 65 is provided on the outer peripheral surface of the portion 64 and the plurality of partition blades 66 and the spiral guide blades 67a and 67b parallel to the axis are provided on the outer peripheral surface of the inner cylinder 61, the structure is improved. It is complicated. In addition, since the independent rotation mechanisms 68 and 69 are provided so that the rotation of the inner cylinder 61 and the outer cylinder 62 is different, there is a problem that the rotation mechanism is complicated. Therefore, construction costs and maintenance costs increase.

  Further, in the conventional heat treatment apparatus 60, a partition wall 70 is provided in the inner cylinder 61 in order to scrape the incinerated ash n in the outer cylinder 62 into the inner cylinder 61 against the gravity on the back side of the outer cylinder 62. In addition, a large number of inclined guide plates 71 and 72 are provided on the side surfaces. Further, since the screw blades 73 for discharging the incineration ash are provided in the small diameter pipe portion 64, the structure is very complicated.

In addition, since the heat treatment apparatus 60 has a structure in which the circulation gas p is discharged from the front end portion of the outer cylinder 62 having a low ash temperature, soil, sediment, etc. that contain more moisture and combustible components than ash. In the case where the pollutant is heat-treated, the circulation gas contains a large amount of moisture evaporated by the heat treatment and combustion of combustible matter, and the hopper 74 is condensed by condensation of moisture and tar content contained in the circulation gas p. There is a possibility that the pipe 75 communicating with the outer cylinder 62 may be blocked or the filter 76 may be clogged. Further, since the heat treatment apparatus 60 has one inlet for the circulating gas p, the amount of oxygen used for decomposing organic chlorine compounds such as dioxins and PCBs is insufficient, and has a function of decomposing harmful organic chlorine compounds. It's not always enough.
JP 2005-152882 A JP 2003-126802 A

  The present invention has been made in order to improve the above-mentioned problems, and a first object is to provide an excellent decomposition function of organic chlorine compounds such as dioxins and PCBs contained in pollutants, and a circulating gas. It is an object of the present invention to provide a heat treatment apparatus for pollutants that can prevent condensation of moisture and tar contained therein. Furthermore, the second object is to provide a contaminant heat treatment apparatus with a simple workpiece feed means, a rotation mechanism, and the like, as compared with a conventional double cylinder heat treatment apparatus.

  In order to achieve such an object, the heat treatment apparatus for pollutants according to the invention described in claim 1 is a pollutant that renders pollutants such as soil and sediment contaminated with organic chlorine compounds such as dioxin and PCB harmless. In this heat treatment apparatus, a double cylinder-shaped rotating body is formed by an inner cylinder and an outer cylinder, a workpiece introduction apparatus having a primary air introduction portion is provided at the front end of the inner cylinder, and an inner portion of the inner cylinder is provided. A spiral plate for transferring an object to be processed is provided on the wall surface, an object discharge hood is provided at the front end of the outer cylinder, and an exhaust gas discharge hood is provided at the rear end of the outer cylinder. A secondary air introduction part and an object discharge part are provided in the waste discharge hood, a waste gas discharge part is provided in the exhaust gas discharge hood, and the front end of the double cylindrical rotating body is lower than the rear end. In addition to tilting forward, the double cylinder Characterized in that a heating means on the outside of the body.

  According to a second aspect of the present invention, in the contaminant heat treatment apparatus according to the first aspect, a connection rib is provided in a gap between the inner cylinder and the outer cylinder to integrate the inner cylinder and the outer cylinder. It is characterized by that.

  As described above, according to the first aspect of the present invention, in the heat treatment apparatus for pollutants, the processed material introducing device having the primary air introducing portion is provided at the front end portion of the inner cylinder, and the processed material discharge hood has 2 A secondary air introduction part is provided, the moisture contained in the pollutant is evaporated by the fresh primary air introduced from the primary air introduction part, the combustible component is burned, and then introduced from the secondary air introduction part By using abundant oxygen contained in fresh secondary air, harmful organic chlorine compounds such as dioxin and PCB contained in contaminated soil can be reliably decomposed.

  In addition, the present invention has a structure in which exhaust gas can be discharged from the part of the exhaust gas exhaust hood where the exhaust gas temperature is high, that is, in the middle of the heat treatment process of the pollutant that is the object to be treated. The resulting blockage of the piping can be prevented. Moreover, by adopting a high-temperature dust collector, it has become possible to carry out slow dusting without causing clogging of the filter.

  In addition, since the inner cylinder and the outer cylinder are connected and the inner cylinder and the outer cylinder rotate together, the structure and the rotation mechanism are simplified and the structure is simplified as compared with the conventional double cylinder-shaped heat treatment apparatus. Became extremely simple. Further, the partition plate, the guide blades, and the like are also a spiral plate having a radial height of about 20 to 30% provided on the inner wall surface of the inner cylinder, or a radial height of about 20 to 30% provided on the inner wall surface of the outer cylinder. Only a spiral plate and stirring means are required, and the structure is simplified.

  For this reason, construction costs can be kept low. In addition, since it is expected that problems will not occur, maintenance costs can be reduced. In addition, this invention has a simpler structure than a conventional double cylinder-shaped heat treatment apparatus because contaminants as an object to be processed naturally fall from the inner cylinder to the outer cylinder by gravity.

  In the invention according to claim 2, since the inner cylinder and the outer cylinder are integrated by providing a connection rib in the gap between the inner cylinder and the outer cylinder, the conventional double cylinder-shaped heat treatment is performed. Compared to the device, both the structure and the rotation mechanism can be simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a contaminated soil treatment facility including a heat treatment apparatus for pollutants according to the present invention, and soil and sludge (hereinafter referred to as sediment) contaminated with organic chlorine compounds such as dioxins (DXNs) and PCBs. It is designed to detoxify pollutants. In this embodiment, sediment is taken as an example of the contaminant.

  For example, the bottom sediment a contaminated with dioxin is temporarily stored in the hopper 2 below after being dried by the drying means 1. The dried sediment b stored in the hopper 2 is subjected to heat treatment by a heat treatment device 3 described later. The bottom sediment c purified or detoxified by the heat treatment apparatus 3 is rapidly cooled by the cooler 4 installed therebelow (for example, about 450 to 470 ° C. → 80 to 100 ° C.).

  On the other hand, the exhaust gas d discharged from the heat treatment apparatus 3 is introduced into the high temperature dust collector 5 and filtered by a filter 6 such as a high temperature bag filter or a ceramic filter in the high temperature dust collector 5. The dust e removed by the filter 6 is returned to the hopper 2. The exhaust gas d that has passed through the filter 6 is heated by the exhaust gas heat treatment device 7, and CO (carbon monoxide), tar content, and dioxins (DXNs) are thermally decomposed. The exhaust gas heat treatment device 7 is supplied with fuel f and combustion air g. The exhaust gas d processed by the exhaust gas heat treatment device 7 is further post-treated by a post-treatment device 8 to which an exhaust gas treatment activated carbon adsorption method, a wet smoke cleaning method, or the like is applied, and then released into the atmosphere.

  As shown in FIG. 2, the heat treatment apparatus 3 includes a double cylindrical rotating body 10 including an inner cylinder 11 and an outer cylinder 12. In the double cylindrical rotating body 10, a plurality of support bodies 13 are provided radially between the inner cylinder 11 and the outer cylinder 12 at two front and rear portions to integrate the two. In addition, the double cylindrical rotating body 10 is inclined forward so that the front end is slightly lower than the rear end. In addition, annular tires 14 are provided at two positions before and after the outer cylinder 12, and these tires 14 are supported by a driving roller 15 so that the double cylindrical rotating body 10 has a predetermined speed (for example, about 1 to 10 rpm). Rotate with. An electric heater 16 is provided outside the outer cylinder 12. The heating temperature of the electric heater 16 is set to 500 to 550 ° C. In addition, the temperature of the electric heater 16 can be adjusted by 10 ° C. within a range of 500 to 550 ° C.

  Further, a workpiece discharge hood 17 is provided at the front end of the outer cylinder 12, and an exhaust gas discharge hood 18 is provided at the rear end of the outer cylinder 12. Further, a workpiece introduction device 21 having a primary air introduction section 20 is provided at the front end of the inner cylinder 11, and a spiral plate 22 for transferring the workpiece is provided on the inner wall surface of the inner cylinder 11. Examples of the workpiece introduction device 21 include a screw feeder, a chute, and a pusher. Further, the height of the spiral plate 22 is preferably about 20 to 30% of the radius of the inner cylinder 11. If it is less than 20%, the transfer of the workpiece is insufficient. If desired, the outer cylinder 12 may be provided with a spiral plate (not shown) on the inner wall portion removed from the heater 16, and the heater portion may be provided with a lifter.

  Further, a secondary air introduction unit 24 is provided at the upper portion of the workpiece discharge hood 17, and a workpiece discharge portion 25 is provided at the lower portion of the workpiece discharge hood 17. Further, an exhaust gas discharge part 26 is provided on the upper part of the exhaust gas discharge hood 18. Further, if desired, the inner wall surface of the outer cylinder 12 may be used as a stirring means. Further, a hammering device for preventing adhesion may be provided outside the outer cylinder 12.

  Next, the effect | action of the said heat processing apparatus is demonstrated.

  The bottom sediment b dried by the dryer 1 is supplied into the inner cylinder 11 of the double cylindrical rotator 10 by the workpiece introduction apparatus 21 as shown in FIG. The bottom material b supplied to the inner cylinder 11 of the double cylindrical rotator 10 is generated by the spiral plate 22 provided on the inner wall surface of the inner cylinder 11 as the double cylindrical rotator 10 rotates. Continuously transferred in the direction. The bottom sediment b moving in the inner cylinder 11 is heated by an electric heater 16 provided outside the outer cylinder 12. At that time, fresh primary air i is supplied into the inner cylinder 11 from the primary air introduction section 20 provided in the casing 23 of the workpiece introduction apparatus 21, so that moisture contained in the bottom material b is present. Evaporates and combustibles burn. Meanwhile, the primary air h flows in parallel with the sediment b. The exhaust gas d generated in the inner cylinder 11 is supplied to the high-temperature dust collector 5 through the exhaust gas discharge part 26 provided in the upper part of the exhaust gas exhaust hood 18.

  The bottom sediment b that has reached the outlet of the inner cylinder 11 naturally falls from the inner cylinder 11 into the outer cylinder 12. The outlet temperature of the inner cylinder 11 is about 300 to 400 ° C. The bottom sediment b that has fallen into the outer cylinder 12 is moved in the direction from the exhaust gas exhaust hood 18 side to the workpiece exhaust hood 17 side by the forward inclined posture of the double cylindrical rotor 10 and the rotation of the double cylindrical rotor 10. It is transferred to. At that time, by providing a lifter (not shown) in the outer cylinder 12, stirring of the bottom material b can be promoted. Meanwhile, the sediment b in the outer cylinder 12 is heated to a predetermined temperature (for example, about 450 to 470 ° C.) by the electric heater 16. At that time, since fresh secondary air j is supplied from the secondary air introduction part 24 provided in the workpiece discharge hood 17, organochlorine compounds such as dioxins (DXNs) and PCB contained in the bottom sediment b Is oxidatively decomposed by oxygen in the secondary air j and becomes harmless bottom sediment c. At this time, since the secondary air j flows in the direction from the workpiece discharge hood 17 to the exhaust gas discharge hood 18, the secondary air j and the bottom material b or c are in a counterflow. The secondary air j is supplied to the high-temperature dust collector 5 from the exhaust gas discharge part 26 of the exhaust gas exhaust hood 18. On the other hand, the detoxified bottom sediment c is supplied to the cooler 4 from the processed product discharge section 26.

  3 is different from the contaminant heat treatment apparatus of FIG. 2 only in that the exhaust gas exhaust hood 18 is changed to a duct type, the same reference numerals are given to the same parts. Detailed description is omitted. In addition to the electric heater, a kerosene burner or the like can be applied as the heating means.

It is a whole block diagram of the heat processing equipment containing the heat processing apparatus of the contaminant which concerns on this invention. It is sectional drawing of the heat processing apparatus of the contaminant which concerns on this invention. It is sectional drawing which shows the other embodiment of the heat processing apparatus of the contaminant which concerns on this invention. It is a schematic block diagram of the conventional upper and lower two-stage type heat treatment apparatus. It is a schematic block diagram of the conventional double tube | pipe type heat processing apparatus. It is principal part sectional drawing of the conventional double pipe | tube type heat processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Double cylinder-shaped rotary body 11 Inner cylinder 12 Outer cylinder 16 Heating means 17 To-be-processed object discharge | emission hood 18 Exhaust gas discharge | emission hood 20 Primary air introduction part 21 To-be-processed object introduction apparatus 22 Spiral plate 24 Secondary air introduction part 25 To-be-processed Waste discharge part 26 Exhaust gas discharge part

Claims (2)

In a pollutant heat treatment device that detoxifies pollutants such as soil and sediment contaminated with organic chlorine compounds such as dioxin and PCB, a double cylinder rotating body is formed by an inner cylinder and an outer cylinder, A processing object introduction device having a primary air introduction unit is provided at the front end of the cylinder, a spiral plate for transferring a processing object is provided on the inner wall surface of the inner cylinder, and further, a processing object is provided at the front end of the outer cylinder. In addition to providing an exhaust hood, an exhaust gas hood is provided at the rear end of the outer cylinder, and further, a secondary air introduction part and an object discharge part are provided in the object exhaust hood, and the exhaust gas exhaust hood Provided with an exhaust gas discharge part, and the double cylindrical rotator is tilted forward so that the front end is lower than the rear end, and a heating means is provided outside the double cylindrical rotator. Contaminant heat treatment device characterized by. The contaminant heat treatment apparatus according to claim 1, wherein a connecting rib is provided in a gap between the inner cylinder and the outer cylinder to integrate the inner cylinder and the outer cylinder.

Images