JP2000034112A - Activated carbon for dioxin adsorption, its production, apparatus and dioxin adsorption treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an activated carbon suitable for dioxin adsorption. SOLUTION: This method comprises repeating a series of processes of mixing a large amount of dried sludge circulating through an air flow dryer 36 and a dried sludge hopper 34 with a dehydrated cake of sludge, grinding the dried sludge by a grinder 38, drying the ground dried sludge, further drying the powder dry sludge by an air flow drying pipe 46 and recycling the sludge to the dry sludge hopper 34 to give a dried raw material sludge, introducing the sludge to a carbonizing furnace 40 of indirect heating type in which hot air for heating and the material to be treated flow in a countercurrent, water in the dried sludge is evaporated in the previous portion of carbonizing treatment (drying zone 78), then the dried sludge is thermally decomposed and carbonized. The carbonized sludge is activated (activated carbon treatment) by steam generated by the previous portion of the carbonizing treatment and steam produced during the thermal decomposition (carbonizing/activating zone 80) to produce a carbonized sludge (activated carbon of sludge) having pores having a large diameter suitable for dioxin adsorption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an activated carbon suitable for adsorbing dioxins (hereinafter simply referred to as "dioxin") produced from sewage sludge, and a method for producing activated carbon for dioxin adsorption from sewage sludge. And a method for adsorbing dioxin in gas or liquid using the activated carbon for adsorbing dioxin. In addition, the present invention is not limited to sewage sludge,
It can also be applied to night soil sludge, livestock waste, waste from various industrial wastewaters, and the like.

[0002]

2. Description of the Related Art Conventionally, carbonized sludge has been produced by carbonizing and activating sewage sludge and the like, and this carbonized sludge is used as an adsorbent. Is a dewatered cake or a block of dry sludge, and it is difficult to uniformly heat the raw material supplied to the carbonization device. Further, a conventional carbonizing device is, for example, as shown in FIG.
As shown in FIG. 1, a rotatable cylindrical pipe 14 is disposed inside a carbonization furnace 12 surrounded by a heat retaining wall 10, and a sewage sludge (a dewatered cake or a dried cake) is supplied from a sludge inlet 16 at one end of the cylindrical pipe 14. ) Is supplied, and the sludge is transferred to the other end by the rotation and inclination of the cylindrical tube 14 and is stirred and heated (externally heated rotary kiln). Cylindrical tube 1
A combustion burner 18 is provided outside the cylinder 4 so that the pyrolysis gas of the sludge ejected from the gas outlet pipe 20 provided on the peripheral wall of the portion near the sludge inlet 16 of the cylindrical tube 14 ignites and burns. Has become. Reference numeral 22 denotes a carbide outlet, 24 denotes a secondary combustion burner, and 26 denotes a smoke outlet. In such a conventional carbonization device, the evaporated water generated from the sludge in a portion near the inlet does not come into contact with the carbonized sludge on the outlet side,
The gas was discharged from the gas outlet pipe near the inlet to the outside of the system, and the steam activation of the carbonized sludge could not be performed sufficiently. Therefore, sufficient dioxin adsorption performance was not exhibited.

[0003] In the conventional sludge carbonization treatment,
Dewatered sludge (dewatered cake) obtained with water treatment as described in JP-A-7-242408
There is known a method of subjecting it to carbonization treatment as it is or after drying it, followed by molding or granulation. Utilization of the carbonized sludge obtained by the above method as an adsorbent was an alternative to granular activated carbon in a packed tower type activated carbon adsorption and deodorization apparatus.

[0004]

As described above, a carbonization apparatus for directly charging sludge dewatered cake has been developed from the viewpoint of omitting an independent drying step and simplifying equipment and work. However, the drying efficiency could not be sufficiently increased, resulting in an increase in the size of the apparatus and an increase in the amount of fuel used, which was not practical. Furthermore, since the drying and carbonization proceed simultaneously, the degree of carbonization and activation becomes uneven,
There is a problem that the dioxin adsorption effect of the obtained carbonized sludge is not stable. In addition, carbonization equipment that uses bulk dry sludge as a raw material has been developed for use in packed tower type adsorption equipment. However, since heat is slowly transmitted to the interior of the mass, the residence time is not long. , Resulting in an increase in the size of the device. In addition, the generated carbide also had a difference in the degree of carbonization between the inside and the surface of the lump. Therefore, sufficient dioxin adsorption performance was not exhibited.

[0005] Due to an inappropriate drying step in combination with the above-described carbonization, the carbonization speed of sludge is low, the degree of carbonization of the generated carbide is also non-uniform, and the dioxin adsorption performance of the generated carbide is poor. There was a problem of uniformity. In addition, there is a problem that the device becomes large. Further, in the conventional carbonizing apparatus, there is a problem that the evaporated water due to the drying of the sludge is discharged out of the system, and the steam activation of the carbonized sludge cannot be sufficiently performed. In addition, when the packed column method is used as the adsorption device, granular carbide is required.However, the degree of carbonization of the granular material is likely to be non-uniform. Had become.

[0006] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a raw material dry sludge suitable for carbonization in the production of activated carbon by carbonization and activation treatment using sewage sludge or the like as a raw material. By combining the drying process, to produce activated carbon suitable for dioxin adsorption,
An object of the present invention is to provide activated carbon excellent in dioxin adsorption performance, a method and an apparatus for producing the same, in order to reduce the volume of sludge waste and to effectively use the waste. Further, an object of the present invention is to activate carbonized sludge by water vapor generated by evaporating water in dry sludge in a carbonization apparatus in the production of activated carbon by carbonization and activation treatment using sewage sludge or the like as a raw material (active carbonization). And a method and apparatus for producing activated carbon suitable for dioxin adsorption.
Another object of the present invention is to provide a method for performing a high-efficiency adsorption treatment of dioxin in gas or liquid using the activated carbon for adsorbing dioxin.

[0007]

In order to achieve the above object, the activated carbon for dioxin adsorption of the present invention is obtained by repeating a process of forming a sludge dewatered cake thin film on the surface of dried sludge particles and drying. It is configured to form pores with a large diameter suitable for dioxin adsorption on the surface layer of carbide by carbonizing and activating dry sludge having a uniform water content distribution in the radial direction of the particles (see FIGS. 3 to 5). ).

In the method for producing activated carbon for dioxin adsorption according to the present invention, a sludge dewatered cake is mixed with a large amount of circulating dried sludge, a thin film of the sludge dewatered cake is formed on the surface of the dried sludge particles, and the dried sludge is dried. A series of steps of further circulating and mixing the sludge dewatering cake with the dried sludge are repeated to obtain a raw dry sludge having a uniform water content distribution in the diameter direction of the particles, and the raw dry sludge is carbonized and activated. It is characterized by producing carbonized sludge (sludge activated carbon) having large pores suitable for dioxin adsorption on the surface layer of carbide (see FIGS. 1, 2, 6 to 8, and 14). .

The method for producing activated carbon of the present invention comprises mixing a sludge dewatered cake with a large amount of circulating dried sludge.
The dried sludge obtained by mechanically pulverizing, drying the layer of the sludge dewatered cake thinly formed on the surface of the dried sludge particles and having an enlarged exposed surface, and uniformly drying the inside is used as a raw material,
This raw material dried sludge is carbonized and activated to produce carbonized sludge (sludge activated carbon) in which pores having a large diameter suitable for dioxin adsorption are formed on the surface layer of carbide (FIGS. 1 and 2). , FIGS. 6 to 8 and FIG. 14).

[0010] In addition, the method for producing activated carbon of the present invention comprises mixing a sludge dewatered cake with a large amount of circulating dried sludge.
Mechanically pulverized until the drying exhaust gas temperature reaches 60
To 200 ° C, desirably 80 to 120 ° C, and the dry matter temperature is 40 to 100 ° C, desirably,
It is dried in a low-temperature constant-rate dryer at a temperature in the range of 40 to 60 ° C., and the obtained raw material dried sludge is carbonized and activated to form large pores suitable for dioxin adsorption on the surface layer of the carbide. It is characterized by producing carbonized sludge (sludge activated carbon) (see FIGS. 1, 2, 6 to 8, and 14). As described above, from the viewpoint of preventing odor generation from sludge and drying sludge without thermal decomposition, the temperature of the dry exhaust gas is 200 ° C or lower, preferably 120 ° C or lower, and the material temperature is 100 ° C or lower, preferably 60 ° C or lower. The temperature should be below ℃. In consideration of drying efficiency, the drying exhaust gas temperature is set to 60 ° C. or higher, preferably 80 ° C. or higher, and the material temperature is set to 40 ° C. or higher.

Further, in the method for producing activated carbon of the present invention, a sludge dewatering cake is mixed with a large amount of dry sludge circulating in a flash dryer and a dry sludge hopper to form a thin film of the sludge dewatering cake on the surface of the dried sludge particles. Then, the dried sludge is pulverized (crushed) with a crusher of a flash drying device and dried with hot air, and the powdery dried sludge is further dried with hot air in a flash drying tube of the flash drying device and circulated to a drying sludge hopper. The process is repeated, and the obtained raw material dried sludge is carbonized and activated to produce carbonized sludge (sludge activated carbon) having large pores suitable for dioxin adsorption on the surface layer of carbide. (See FIGS. 1, 2, 6 to 8, and 14).

In the method for producing activated carbon of the present invention, the raw dry sludge is introduced into a carbonization apparatus in which the hot air for heating for carbonization and the flow of the object to be treated are countercurrent and the indirect heating system is used. The moisture contained therein is evaporated at a stage prior to the carbonization treatment, and then the dried sludge is thermally decomposed and carbonized, and the carbonized sludge is activated by steam generated at the stage prior to the carbonization process and steam generated at the time of thermal decomposition ( (Activated carbonization) to produce carbonized sludge (sludge activated carbon) having large pores suitable for dioxin adsorption on the surface layer of carbide (see FIGS. 1, 2, and 6 to 8). .

[0013] The apparatus for producing activated carbon for dioxin adsorption of the present invention comprises: a dry sludge hopper in which circulating dry sludge is stored;
The sludge dewatering cake supply means for supplying and mixing the sludge dewatering cake to the dried sludge extracted from the drying sludge hopper, and the hot air heated by the combustion heat of the pyrolysis gas of the sludge generated in the carbonization device is used as a heat source for drying. A crusher that is supplied with a mixture of dried sludge and sludge dewatered cake for crushing (crushing) the object to be processed and drying with hot air;
A flash drying tube for air-flowing the powdery dry sludge from the crusher and further drying with hot air, and a powdery dry sludge conveyed with the hot air from the flash-drying tube for gas-solid separation to dry sludge. A dust collector for circulation to the hopper,
The raw dry sludge supplied from the dry sludge hopper is indirectly heated while moving in countercurrent to the hot air for heating, and the upstream side in the moving direction of the dry sludge has a low temperature for evaporating moisture in the dry sludge. In the drying zone, the dry sludge is thermally decomposed and carbonized as it proceeds in the moving direction of the dried sludge, and the sludge carbonized by the steam generated in the drying zone and the steam generated during the pyrolysis is activated (activated carbonization). It is a high-temperature carbonization / activation zone.To use the heat of combustion of the pyrolysis gas of the sludge generated in the carbonization / activation zone as the drying heat source to heat the hot air introduced into the crusher, the exhaust gas is discharged. And a carbonization device having a secondary combustion zone near the outlet (FIG. 1).
reference).

Further, the activated carbon manufacturing apparatus of the present invention supplies a dried sludge hopper for storing circulating dried sludge and a sludge dewatered cake to the dried sludge extracted from the dried sludge hopper.
Sludge dewatering cake supply means for mixing, and exhaust gas from a gas turbine or a diesel engine are introduced as a heat source for drying, and dry sludge and sludge dewatering cake for crushing (disintegrating) the object to be processed and drying with hot air are provided. The powdered sludge conveyed together with the hot air from the crusher to which the mixture is supplied, the powdery dry sludge from the crusher, and the flash drying tube for hot air drying, and the hot air drying. A dust collector for gas-solid separation and circulation of the dry sludge to the dry sludge hopper, and the raw dry sludge introduced from the dry sludge hopper are heated indirectly while moving in countercurrent to the hot air for heating. The upstream side in the moving direction of the dried sludge is a low-temperature drying zone for evaporating water in the dried sludge, and pyrolyzes and carbonizes the dried sludge as it proceeds in the moving direction of the dried sludge. Both are characterized by including a carbonization device serving as a high-temperature carbonization / activation zone for activating (activated carbonization) sludge carbonized by steam generated in the drying zone and steam generated during thermal decomposition ( See FIG. 14). In the apparatus of the present invention, the entire drying equipment can be combined with a stationary carbonization apparatus as a compact on-board equipment.

In the production of activated carbon by carbonization and activation treatment using sewage sludge or the like as a raw material of the present invention, drying to a water content of about 20% is performed in a dryer separate from a carbonization apparatus (carbonization furnace).
It is characterized by the combination of a dryer that can obtain the raw material dry sludge most suitable for carbonization. In other words, carbonization mainly involves the process of heating the raw material by blocking it from the air, raising the temperature of the raw material by heat conduction, gasifying the organic matter in the raw material, and fixing the carbon. A flash dryer capable of producing advantageous powdery dry sludge is suitable for combination with a carbonizer. In addition, as moisture for utilizing steam to be carried out together with carbonization in the carbonization apparatus (carbonization furnace), moisture (about 20% content) in dry sludge supplied from the flash drying apparatus to the carbonization apparatus is used. Specifically, since there is no steam outlet in the drying zone where the moisture in the dried sludge evaporates in the carbonization device, the steam is introduced into the carbonization / activation zone together with the dried sludge, and the dried sludge is carbonized by pyrolysis. In contact with water vapor in the state
Activation (activated carbonization) is performed. Activation (activated carbonization) is also performed by steam generated from inside the dried sludge in the process of thermal decomposition. By the above operation, uniform carbonization
Activation is performed to produce activated carbon (sludge activated carbon) having large pores suitable for dioxin adsorption.

The dioxin adsorption treatment method of the present invention comprises:
A filter cloth support (for example, a bag filter) is provided in the line of the gas to be treated, and the activated carbon for dioxin adsorption produced by the method of the present invention is mixed with the gas to be treated on the upstream side of the filter cloth support. Thus, a coating layer of activated carbon is formed on the filter cloth support to adsorb dioxin in the gas to be treated (see FIGS. 9 and 10). Further, in the adsorption treatment method of the present invention, a filtration device (for example, a sand filtration device) is provided in the line of the liquid to be treated, and the activated carbon for dioxin adsorption produced by the above-described method of the present invention is supplied upstream of the filtration device. By mixing with the liquid to be treated, a coating layer of activated carbon is formed on the filtration support of the filtration device to adsorb dioxin in the liquid to be treated (see FIG. 13).

In these adsorption treatment methods of the present invention,
The resulting activated carbon for dioxin adsorption is introduced into a classifier, for example, activated carbon having a large particle diameter of 100 μm or more,
For example, it is classified into activated carbon having a small particle diameter of less than 100 μm and activated carbon having a large particle diameter is upstream of a filtration device (eg, a sand filtration device) provided as a dioxin adsorbent for a liquid in a line of a liquid to be treated. The activated carbon having a small particle size is preferably introduced as a dioxin adsorbent for gas upstream of a filter cloth support (for example, a bag filter) provided in a line of a gas to be treated (FIG. 1). , FIGS. 2, 7,
See FIG. 8). Thus, the activated carbon has a diameter of 1 to 10
It is obtained in the form of a powder of about 00 μm.
By classifying at the boundary of 00 μm, large-diameter particles are formed on the surface layer such as a sand filtration layer to be used as an aqueous dioxin adsorbent such as leachate, and small-particle diameter particles are used as bag filter filters. By coating, it can be used as a gas-based dioxin adsorbent that is easily exchanged.

Further, in the adsorption treatment method of the present invention, the activated carbon for adsorbing dioxin produced by the above-mentioned method of the present invention is formed into granules or tablets (pellets), and the formed activated carbon is filled into a packed tower for filling. A layer is formed, and a gas to be treated is passed through the packed layer to adsorb dioxin in the gas to be treated (see FIGS. 6 and 11).
For example, it is possible to adopt a configuration in which granular activated carbon is filled in a packed tower to form a moving bed, and the exhaust gas passes through the moving bed in a cross flow direction. It is of course possible to adopt a configuration in which a fixed layer is formed. Further, in the adsorption treatment method of the present invention, a wet cleaning device (for example, a scrubber) is provided in a line of a gas to be treated, and the activated carbon for dioxin adsorption produced by the above-described method of the present invention is provided upstream of the wet cleaning device. The method is characterized in that activated carbon is mixed with a gas to be treated and the activated carbon is made into a slurry in a wet cleaning device to adsorb dioxin in the gas to be treated (see FIG. 12).

[0019]

1 and 2 show an apparatus for manufacturing activated carbon for dioxin adsorption according to a first embodiment of the present invention. FIG. 2 shows a main part of the configuration shown in FIG. In the present embodiment, as an example, a dewatered cake of sewage sludge is mixed with a large amount of powdered dry sludge, powdery dry sludge is obtained by a flash drying apparatus, and the raw dry sludge is mixed with hot air for heating and raw material. It is introduced into a carbonization furnace (carbonization apparatus) where the flow is countercurrent, and carbonized and activated in the carbonization furnace to produce activated carbonized powdery carbonized sludge. In addition to the sewage sludge, it is also possible to use human waste sludge, livestock waste, waste from various industrial wastewaters, and the like.

As shown in FIG. 1, the sewage sludge dewatered cake supplied to the dewatered cake hopper 30 from the dewatered cake transport conveyor 28 is extracted by the dewatered cake feeder 32 and the powder extracted from the dried sludge hopper 34 Mix with dry sludge. Here, the mixing ratio of the powdery dried sludge to the sludge dewatered cake is 10 to 500 times, preferably 50 to 200 times in terms of dry weight ratio. A thin layer of sludge dewatering cake is formed on the surface of the dried sludge, and the sludge is introduced into a crusher 38 of a flash drying device 36. Hot air obtained by exchanging heat of the combustion exhaust gas discharged from a secondary combustion zone 42 of a carbonization furnace 40 described later with an air heater 44 into the crusher 38 is introduced as a heat source for drying. The powder dried sludge finely crushed by the crusher 38 and dried by hot air is
The air is conveyed through the flash drying tube 46 of the flash drying device 36 and further dried with hot air.

The powder dried sludge from the flash drying tube 46 is separated into gas and solid by a dust collector 48 (for example, cyclone), and the dried sludge on the solid side is stored in the dried sludge hopper 34, and most of the dried sludge is dewatered sewage sludge cake. Mixing and flash drying device 36
It is circulated and used for grinding and drying. On the other hand, the dried exhaust gas on the gas side is at a temperature of 80 to 120 ° C. and contains a large amount of evaporated water in the sludge dewatered cake.
Is sent to the dehumidification tower 52 and cooled to condense and separate water vapor. For example, it is cooled by sludge supplied from the sludge concentration tank 54 to the digestion tank 56, and is used for heating the sludge. The exhaust gas cooled by sludge is further cooled by treated water. The sludge from the sludge concentration tank 54 is heated by circulating through the dehumidification tower 52 by the sludge transfer pump 58 and the dehumidification tower circulation pump 60. Most of the exhaust gas discharged from the dehumidifying tower 52 is introduced into the air heater 44 by the exhaust gas circulation fan 62 together with the exhaust air from the dewatering cake hopper 30, heated, and again heated by the flash drying device 3.
6 is introduced into the crusher 38.

The amount of the dried sludge in the dried sludge hopper 34 is increased by an amount corresponding to the sludge dewatering cake input, and the increased amount is supplied to the carbonization furnace 40 by a cut-out feeder (dry powder supply device) 64 of the dried sludge hopper 34. The dried sludge was extracted from the cut-out feeder 64 and formed by the forming machine 66.
In some cases, it is used for fertilizer or fuel. The powder dry sludge (water content: about 20%) charged into the casing (cylindrical pipe) 68 of the carbonization furnace 40 is surrounded by the outer surface of the casing 68 and the heat retaining wall 72 by the screw feeder 70 provided in the casing 68. It moves in countercurrent to the hot air from the burner 74 that is jetted into the space, and is indirectly heated by heat conduction through the casing 68. The structure of the carbonization furnace 40 is the casing 6
In the vicinity of the dry sludge inlet 76 of FIG. 8, a relatively low temperature (for example, 60 to 120 ° C.) drying zone 78 in which water in the dry sludge evaporates is formed. At high temperature (for example, 500 to 800 ° C.) where carbonization and activation are performed
It becomes 0. The black arrows indicate the flow of the dried sludge, and the white arrows indicate the flows of the hot air and the exhaust gas.

The organic matter thermally decomposed in the carbonization / activation zone 80 is gasified, and the gas exhaust pipe 8 provided in the casing 68 is provided.
2, and in a secondary combustion zone 42 near the gas outlet of the carbonization furnace 40, a part of the exhaust gas from the exhaust gas circulation fan 62 of the dehumidifying tower 52 is completely burned as combustion air and deodorized. Is introduced into the air heater 44 and is used for heating the hot air for drying supplied to the crusher 38 of the flash drying device 36 described above. When SO ₂ is contained in the flue gas from the secondary combustion zone 42, the flue gas heat-exchanged by the air heater 44 further includes
From the heat exchanger 84 for preventing white smoke, the gas is introduced into the desulfurization tower 88 via the exhaust gas fan 86, and the desulfurization tower 88 is supplied from an alkali agent, for example, a NaOH tank 90 by a NaOH supply pump 92.
Chimney 94 desulfurized by the NaOH aqueous solution supplied to the
Is discharged from Reference numeral 96 denotes an air fan for preventing white smoke, and 98 denotes a washing water circulation pump. When it is not necessary to desulfurize the flue gas, the flue gas is converted into a white smoke preventing heat exchanger 8.
4 to the chimney 94.

In the drying zone 78 of the carbonization furnace 40, since the casing 68 for transferring the dried sludge has no exhaust port, the evaporated steam is transferred to the inside of the casing 68 in the sludge moving direction without being discharged out of the system. The water reaches the activation zone 80, and the water vapor contacts the sludge in a carbonized state to perform activation (activated carbonization). Activation (activated carbonization) is also performed by steam generated from inside the dried sludge in the process of thermal decomposition. The sludge that has been carbonized and activated is activated carbonized, and this powdered carbonized sludge (sludge activated carbon) is discharged from the carbide discharge port 100 of the carbonization furnace 40.

The discharged carbonized sludge is classified into a classifier 102
(Eg, vibrating sieve), for example, with a diameter of 10
Those having a small particle size of less than 0 μm (below the sieve) are used, for example, as a dioxin adsorbent in a gas by being injected into the upstream side of the bag filter 104 together with the gas to be processed to form a coating layer on the filter cloth surface. You. For example,
Those having a large particle diameter (on a sieve) having a diameter of 100 μm or more are used, for example, as a dioxin adsorbent in a liquid by forming a coating layer on a sand layer by being introduced into an upstream of a water-based sand filter 106. You. Details of the dioxin adsorption treatment will be described later.

Next, the process of carbonizing and activating powder dry sludge (water content: about 20%) charged into the carbonizing furnace will be described with reference to FIGS. As shown in FIG. 3, the surface of the dried sludge particles is heated to, for example, 100 ° C. or higher, and the evaporation of water from the surface proceeds, and the surface of the sludge particles 108 is dried as shown in FIG. In addition, a highly dry region 110 having a moisture content close to 0 is formed near the surface, and a moisture content of about 20
% Of the low dry area 112 is formed. Then, the sludge particles 108 that have moved inside the casing of the carbonization furnace are carbonized from the surface to form a carbonized region 114, as shown in FIG. Further, the steam generated in the drying process of FIG. 3 moves inside the casing of the carbonization furnace together with the sludge particles 108, and this steam contacts the surface of the carbonization region 114 as shown by the arrow in FIG. Activation is performed. Further, the inside of the sludge particles 108 is on the way from the low drying region 112 to the high drying region 110, and the water vapor generated from the low drying region 112 near the center causes the sludge particles 1
08 is also activated from the inside. As shown in FIG. 5, the sludge particles 108 which have been carbonized to the inside and the steam activation has been completed have pores 11 which become larger toward the surface as shown in FIG.
6 is formed and activated carbonized.
Pores 116 having a large diameter of 50 ° or more in the surface layer 14
Are formed, and large molecules of dioxins (elongated shape with an average of about 150 °) are easily adsorbed on the surface.

FIG. 6 shows a main part of an apparatus for producing activated carbon for dioxin adsorption according to a second embodiment of the present invention. In the present embodiment, a powdered carbonized sludge (sludge activated carbon) produced in the same manner as in the first embodiment is formed by a molding machine 11.
The pellets are formed into granules or tablets (pellets) at 8 and used as an adsorbent to be packed in the packed tower 120.
As an example, a configuration in which granular activated carbon is packed in a packed tower to form a moving bed, and exhaust gas is passed through the moving bed in a cross-flow direction to adsorb dioxin in the exhaust gas.
Further, a configuration in which a fixed layer is formed is also possible. Details of the dioxin adsorption treatment using the moving bed will be described later. Other configurations and operations are the same as those of the first embodiment.

FIG. 7 shows a main part of an apparatus for manufacturing activated carbon for dioxin adsorption according to a third embodiment of the present invention. In the present embodiment, powdery dry sludge obtained in the same manner as in the first embodiment is fed into a crusher 122 by a cut-out feeder 64 of a dry sludge hopper 34 and finely crushed. Is passed through a classifier 124 (for example, a vibrating sieve) to introduce those having a small particle size suitable for carbonization and activation into a carbonization furnace 40, and those having a large particle size to return to a dry sludge hopper 34. In the present embodiment, since a large amount of carbonized sludge having a small particle size is obtained, a large amount of activated carbon that can be used for the bag filter 104 can be manufactured. Other configurations and operations are the same as those of the first embodiment.

FIG. 8 shows a main part of an apparatus for producing activated carbon for dioxin adsorption according to a fourth embodiment of the present invention. In the present embodiment, a powdery carbonized sludge (sludge activated carbon) produced in the same manner as in the first embodiment is classified into a classifier 1
02, and at least a part of the carbonized sludge having a large particle diameter is charged into a crusher 126 to be finely crushed to have a small particle diameter suitable for carbonization and activation, and then introduced into the carbonization furnace 40 again. It is something to do. In the present embodiment, a large amount of carbonized sludge with a small particle diameter uniformly carbonized and activated inside is obtained. Other configurations and operations are the same as those of the first embodiment.

Next, the first, third and fourth embodiments of the present invention will be described.
A specific example of the treatment of adsorbing dioxin in exhaust gas by the bag filter described in the embodiment will be described in detail. As shown in FIG. 9, the exhaust gas discharged from a furnace 128 such as a waste incinerator is sent to a bag filter 134 via a boiler 130 and a gas cooler 132. Powdery carbonized sludge (sludge activated carbon) is continuously blown into the upstream side of the bag filter 134, and dioxin in the exhaust gas is adsorbed together with the dust.
Removed. Carbonized sludge (spent coal) after the adsorption treatment contains a large amount of fly ash with a high dioxin content.
It is processed by another system without returning to 28. It should be noted that powdered carbonized sludge (sludge activated carbon) is mixed with the exhaust gas on the upstream side of the bag filter 134 to form a pre-coating layer of activated carbon on the filter, thereby adsorbing and removing dioxin in the exhaust gas. You can also.

As shown in FIG. 10, exhaust gas discharged from a furnace 128 such as a waste incinerator is supplied to a boiler 130,
The gas is sent to the primary bag filter 136 via the gas cooler 132. Powdery carbonized sludge (sludge activated carbon) is continuously blown into the upstream side of the primary bag filter 136, and a part of dioxin in exhaust gas is adsorbed and removed together with dust. The carbonized sludge (old coal) after the adsorption treatment contains a large amount of fly ash with a high dioxin content, and is treated in another system without returning to the furnace 128. Primary bag filter 1
The exhaust gas that has passed through is mixed with powdered carbonized sludge (sludge activated carbon) upstream of the secondary bag filter 138,
Next, a coating layer or a pre-coating layer of activated carbon is formed on the filter of the bag filter 138 to further adsorb and remove dioxin in the exhaust gas. The carbonized sludge (recycled coal) after the adsorption treatment is returned to the furnace 128, and the dioxin in the carbonized sludge is thermally decomposed in the furnace 128.

Next, a specific example of the process of adsorbing dioxin in exhaust gas by the packed tower described in the second embodiment of the present invention will be described in detail. As shown in FIG. 11, exhaust gas discharged from a furnace 128 such as a waste incinerator is
After passing through the gas cooler 132, it is sent to the moving bed type adsorption tower 140. In this case, the exhaust gas guided to the moving bed type adsorption tower 140 passes in a cross flow direction in a moving bed filled with carbonized sludge (sludge activated carbon) formed into granules or tablets (pellets). The formed carbonized sludge is continuously or intermittently supplied into the moving bed type adsorption tower 140 and moves down in the moving bed, and the carbonized sludge (recycled coal) after the dust removal and dioxin adsorption treatment is discharged out of the system. Separately processed. Reference numeral 142 denotes a permeable support made of a louver, a wire mesh, a punched metal or the like.

Next, a specific example of the process of adsorbing dioxin in exhaust gas, except when using only the bag filters described in the first, third, and fourth embodiments of the present invention, will be described in detail. As shown in FIG. 12, a furnace 12 such as a waste incinerator
The exhaust gas discharged from 8 is sent to a primary bag filter 136 via a boiler 130 and a gas cooler 132. 1
The powdered carbonized sludge (sludge activated carbon) is continuously blown into the upstream side of the next bag filter 136, and a part of dioxin in the exhaust gas is adsorbed and removed together with the dust. The carbonized sludge (old coal) after the adsorption treatment contains a large amount of fly ash with a high dioxin content, and is treated in another system without returning to the furnace 128. The primary bag filter 13
Powdered carbonized sludge (sludge activated carbon) in the exhaust gas upstream of 6
To form a pre-coating layer of activated carbon on the filter to adsorb and remove dioxin in exhaust gas. The exhaust gas that has passed through the primary bag filter 136 is mixed with powdered carbonized sludge (sludge activated carbon) on the upstream side of the scrubber 144,
In 44, dioxin in the exhaust gas is further adsorbed and removed by the slurry-like carbonized sludge. The carbonized sludge slurry after the adsorption treatment is dehydrated by the dehydrator 146, and the waste coal (dehydrated cake) is returned to the furnace 128, and the dioxin in the carbonized sludge is thermally decomposed in the furnace 128. 148 is a circulation pump.

Next, the first, third and fourth embodiments of the present invention will be described.
A specific example of the treatment of adsorbing dioxin in wastewater by the sand filtration device described in the embodiment will be described in detail. As shown in FIG. 13, when dioxin is adsorbed and removed from wastewater such as leachate from soil, powdery carbonized sludge (sludge activated carbon) is charged into the upstream side of the sand filtration device 150 to form a sand filtration layer. A layer of activated carbon is formed on the surface layer of Thereby, the dioxin in the wastewater is adsorbed and removed together with other solids. This intermediate treated water may be further treated if necessary.

FIG. 14 shows an apparatus for producing activated carbon for dioxin adsorption according to a fifth embodiment of the present invention. In the present embodiment, the entire drying equipment is configured as an on-vehicle type apparatus, the exhaust gas of a gas turbine is introduced as a drying heat source of a flash drying apparatus, and combined with a stationary carbonization furnace, the powder obtained by the on-vehicle equipment is used. Dry sludge is carbonized and activated. As shown in FIG. 14, the dehydrated cake hopper 3
The sewage sludge dewatered cake in 0 is extracted by the dewatered cake feeder 32 and mixed with the powdery dried sludge extracted from the dried sludge hopper 34. Here, the mixing ratio of the powder dried sludge to the sludge dewatered cake is 10 to 5 in terms of dry weight ratio.
00 times, desirably 50 to 200 times. A thin layer of sludge dewatering cake is formed on the surface of the dried sludge, and the sludge is introduced into a crusher 38 of a flash drying device 36. A part of the combustion exhaust gas from the gas turbine 152 is introduced into the crusher 38, and is used as hot air for drying. The generator 154 connected to the gas turbine 152 has a control panel 156.
The amount of power generation is controlled by means of, and although not shown, the obtained power is supplied to components of the on-vehicle equipment (for example, a crusher, a molding machine, etc.). Fifteen
8 is a fuel injection device. Note that a configuration using a diesel engine instead of the gas turbine is also possible.

The powder-dried sludge finely pulverized by the crusher 38 and dried by hot air is transported in a stream by way of a stream drying pipe 46 of a stream dryer 36 and further dried by hot air. The powder dried sludge from the flash drying pipe 46 is collected by a dust collector 48.
The dried sludge on the solid side is stored in a dried sludge hopper 34, and most of the dried sludge is circulated and used for mixing with the sewage sludge dewatered cake and pulverizing and drying in the flash drying device 36. . On the other hand, the drying exhaust gas on the gas side is supplied to the air flow control valve 16 by a signal from the temperature indicating controller 160.
2. When the opening degree is adjusted and the exhaust gas temperature is high (for example, 8
(0 to 120 ° C.), the opening of the air volume control valve 162 becomes smaller, and the air volume circulating in the upstream line of the crusher 38 increases, so that the amount of exhaust gas taken in by the gas turbine 152 decreases. In addition, a signal from a flow indicator (ammeter) 168 connected to the exhaust gas fan 166 receives
Is controlled so that the air volume passing through the crusher 38 is always kept constant. When the flow rate of the air flowing through the scrubber 164 is reduced by the flow rate control valve 162, the opening of the flow rate control valve 170 increases, and a part of the exhaust gas is circulated upstream of the crusher 38. 172 is a circulation pump.

The amount of the dried sludge in the dried sludge hopper 34 is increased by an amount corresponding to the sludge dewatering cake input, and the increased amount is supplied to a forming machine 66 by a cut-out feeder (dry powder supply device) 64 of the dried sludge hopper 34. The steps performed so far in the on-vehicle equipment (portion surrounded by a broken line) are described below.
The dried sludge formed in 6 is stored in the dried sludge receiving bag 174. The dried sludge is put into a stationary carbonization furnace 40 where it is carbonized and activated to produce powdered activated carbon (carbonized sludge). The configuration and operation of the carbonization furnace 40 are the same as those of the carbonization furnace described in the first embodiment. The powdered activated carbon in the carbonized sludge receiving bag 176 is, for example, as shown in FIGS.
Is used for the dioxin adsorption treatment.
The waste heat of the carbonization furnace 40 is used for utilities of other stationary equipment. In the present embodiment, by adopting a compact on-board drying equipment, it becomes possible to treat sewage sludge and the like individually by circulating through small and medium-sized sewage treatment plants and the like, and carbonize the obtained raw material dried sludge. It is possible to efficiently produce carbonized sludge (sludge activated carbon) by consolidating the facilities. Other configurations and operations are the same as those of the first embodiment. It should be noted that the present embodiment includes the second embodiment and the third embodiment.
It is also possible to adopt a configuration combining the modes or the fourth mode.

Since the dried sludge in the dried sludge receiving bag 174 can be used as a product as a fertilizer, fuel or the like, the sewage sludge or the like in a small- or medium-sized sewage treatment plant is individually processed by an on-vehicle facility. Also, it is possible to produce fertilizers, fuels, and the like from sludge even in small and medium-sized treatment plants that do not have a drying facility. As a result, it is possible to meet the needs of each treatment plant for reducing the volume and effective use of sludge waste.

[0039]

As described above, the present invention has the following effects. (1) In the production of activated carbon by carbonization and activation treatment using sewage sludge as a raw material, a drying means (flash drying device) most suitable for carbonization is combined, so that the carbonization speed is high and the equipment is enlarged. Activated carbon having excellent dioxin adsorption performance can be produced without causing the above. (2) Since a carbonization device that can perform carbonization and steam activation most effectively is used, it is possible to produce carbonized sludge (sludge activated carbon) having large pores suitable for dioxin adsorption on the surface layer of carbide. it can. (3) Volume reduction of sludge waste and effective use of waste can be achieved. (4) Since powdered carbonized sludge (sludge activated carbon) is obtained, a coating layer is formed on a filter cloth support such as a bag filter to adsorb and remove dioxin in the gas, and filtration by a sand filtration device or the like. Dioxin in the liquid can be adsorbed and removed by forming a layer on the support. (5) In the case of classifying the obtained activated carbon, those having a small particle size are formed on a filter cloth support such as a bag filter by forming a coating layer and used for adsorption and removal of dioxin in a gas.
A layer having a large particle diameter can be formed on a filtration support such as a sand filtration device and used for adsorption and removal of dioxin in a liquid. (6) The obtained activated carbon can be molded and used as a dioxin adsorbent of a packed tower system. (7) The obtained activated carbon can be used as a dioxin adsorbent for a wet cleaning device such as a scrubber. (8) In the case where the entire drying equipment is a compact on-board type, it is possible to separately treat sewage sludge by circulating through small- and medium-sized sewage treatment plants and placing the obtained raw material dried sludge in place. It is possible to efficiently manufacture carbonized sludge (sludge activated carbon) by consolidating the carbonized sludge into a carbonization device of the type.

[Brief description of the drawings]

FIG. 1 is a systematic schematic configuration diagram showing an apparatus for producing activated carbon for dioxin adsorption according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a main part of the configuration shown in FIG.

FIG. 3 is a cross-sectional view schematically showing a state of sludge particles near an inlet of a carbonization furnace.

FIG. 4 is a cross-sectional view schematically showing a state in which sludge particles are carbonized and activated in a carbonization furnace.

FIG. 5 is a cross-sectional view schematically showing a state of sludge particles after completion of carbonization and activation.

FIG. 6 is a schematic configuration diagram illustrating a main part of an apparatus for producing activated carbon for dioxin adsorption according to a second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing a main part of an apparatus for producing activated carbon for dioxin adsorption according to a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a main part of an apparatus for producing activated carbon for dioxin adsorption according to a fourth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing an example of a process for adsorbing dioxin in exhaust gas.

FIG. 10 is a schematic configuration diagram showing another example of a process for adsorbing dioxin in exhaust gas.

FIG. 11 is a schematic configuration diagram showing another example of a process for adsorbing dioxin in exhaust gas.

FIG. 12 is a schematic configuration diagram showing still another example of a process for adsorbing dioxin in exhaust gas.

FIG. 13 is a schematic diagram showing an example of a process for adsorbing dioxin in wastewater.

FIG. 14 is a schematic system configuration diagram showing an apparatus for producing activated carbon for dioxin adsorption according to a fifth embodiment of the present invention.

FIG. 15 is a schematic configuration diagram showing an example of a conventional carbonizing device.

[Explanation of symbols]

 10, 72 Insulation wall 12, 40 Carbonization furnace 14 Cylindrical tube 16 Sludge inlet 18 Burning burner 20 Gas outlet tube 22, 100 Carbide outlet 24 Secondary combustion burner 26 Smoke outlet 28 Dewatering cake conveyor 30 Dewatering cake hopper 32 Dewatering Cake feeder 34 Dry sludge hopper 36 Air flow drying device 38 Crusher 42 Secondary combustion zone 44 Air heater 46 Air flow drying tube 48 Dust collector 50, 62 Exhaust gas circulation fan 52 Dehumidification tower 54 Sludge concentration tank 56 Digestion tank 58 Sludge transfer Pump 60 Dehumidification tower circulation pump 64 Cut-out feeder (dry powder supply device) 66, 118 Molding machine 68 Casing (cylindrical tube) 70 Screw feeder 74 Burner 76 Dry sludge inlet 78 Drying zone 80 Carbonization / activation zone 82 Gas exhaust pipe 84 White smoke Prevention heat exchanger 86, 166 88 Gas desulfurization tower 90 NaOH tank 92 NaOH supply pump 94 Chimney 96 White smoke prevention air fan 98 Washing water circulation pump 102, 124 Classifier 104, 134 Bag filter 106, 150 Sand filter 108 Sludge particles 110 High drying area 112 Low drying Region 114 Carbonized region 116 Pores 120 Packing tower 122, 126 Crusher 128 Furnace 130 Boiler 132 Gas cooler 136 Primary bag filter 138 Secondary bag filter 140 Moving bed type adsorption tower 142 Gas permeable support 144, 164 Scrubber 146 Dehydration 148, 172 Circulation pump 152 Gas turbine 154 Generator 156 Control panel 158 Fuel injection device 160 Temperature indicator controller 162, 170 Air volume control valve 168 Flow indicator (Ammeter) 174 Dry sludge receiving bag 176 Coal Sludge received bag

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 18, 1999 (1999.6.1
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In order to achieve the above object, the activated carbon for dioxin adsorption of the present invention is obtained by repeating a process of forming a sludge dewatered cake thin film on the surface of dried sludge particles and drying. Carbonization and activation of dry sludge having a uniform water content distribution in the radial direction of the particles enables uniform charcoal
It is configured to be activated and activated to form pores having a large diameter suitable for the adsorption of dioxin, which is a large molecule, on the surface layer of the carbide (see FIGS. 3 to 5).

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

The method for producing activated carbon for adsorbing dioxin according to the present invention is characterized in that the mixing ratio of powdered dry sludge to sludge dewatered cake
Is 10 to 500 times by dry weight ratio, preferably 50 to 20 times.
The sludge dewatered cake is mixed with a large amount of circulating dried sludge so as to be 0 times, a thin film of the sludge dewatered cake is formed on the surface of the dried sludge particles, and the dried sludge is dried and further circulated. A series of steps of mixing the sludge dewatering cake into the raw material is repeated to obtain a raw material dry sludge having a uniform water content distribution in the diameter direction of the particles, and the raw material dry sludge is uniformly carbonized and dried.
It is characterized by producing an activated carbonized sludge (sludge activated carbon) having a large diameter pore suitable for adsorbing dioxin, which is a large molecule, on the surface layer of carbide by an activation treatment (FIG. 1, 2, 6 to 8, and 14).

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009] In addition, the manufacturing method of the activated carbon of the present invention, the sludge
Mixing ratio of powdered dry sludge to dewatered cake is dry weight ratio
10 to 500 times, preferably 50 to 200 times
As described above, the sludge dewatered cake is mixed with a large amount of circulating dried sludge, and then mechanically pulverized to dry the layer of sludge dewatered cake formed thinly on the surface of the dried sludge particles and having an enlarged exposed surface, and evenly into the interior. Sludge obtained by drying the dried sludge as a raw material, uniformly carbonizing and activating the raw dry sludge to form pores having a large diameter suitable for adsorbing dioxin, which is a large molecule, on the surface layer of the carbide. (Sludge activated carbon) (see FIGS. 1, 2, 6 to 8, and 14).

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] In addition, the manufacturing method of the activated carbon of the present invention, the sludge
Mixing ratio of powdered dry sludge to dewatered cake is dry weight ratio
10 to 500 times, preferably 50 to 200 times
Thus, the sludge dewatered cake is mixed with a large amount of circulating dried sludge, and then mechanically pulverized, and the drying exhaust gas temperature is in the range of 60 to 200 ° C. until the drying is completed, preferably 80 to 1
Range of 20 ° C., dry matter range of temperature is 40 to 100 ° C., desirably dried at a low temperature constant drying machine such as a range of 40 to 60 ° C., uniformly obtained material dried sludge carbonization and
It is characterized by producing an activated carbonized sludge (sludge activated carbon) having a large diameter pore suitable for adsorbing dioxin, which is a large molecule, on the surface layer of carbide by an activation treatment (FIG. 1, 2, 6 to 8, and 14). As described above, from the viewpoint of preventing the generation of odor from the sludge and drying the sludge without thermally decomposing, the temperature of the drying exhaust gas is set at 20.
0 ° C. or lower, preferably 120 ° C. or lower, and the material temperature is 10 ° C.
The temperature is set to 0 ° C. or lower, preferably 60 ° C. or lower. In consideration of drying efficiency, the drying exhaust gas temperature is set to 60 ° C. or higher, preferably 80 ° C. or higher, and the material temperature is set to 40 ° C. or higher.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011] In addition, the manufacturing method of the activated carbon of the present invention, the sludge
Mixing ratio of powdered dry sludge to dewatered cake is dry weight ratio
10 to 500 times, preferably 50 to 200 times
Thus , a sludge dewatering cake is mixed with a large amount of dry sludge circulating through a flash drying device and a dry sludge hopper to form a thin film of the sludge dewatering cake on the surface of the dried sludge particles. A series of steps of pulverizing (crushing) and drying with hot air, further drying the powdery dried sludge with a flash drying tube of a flash drying device and circulating the dried sludge through a hopper for drying sludge are repeated, and the obtained raw material dried sludge is homogenized. carbonization and to
It is characterized by producing an activated carbonized sludge (sludge activated carbon) having a large diameter pore suitable for adsorbing dioxin, which is a large molecule, on the surface layer of carbide by an activation treatment (FIG. 1, 2, 6 to 8, and 14).

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

In the method for producing activated carbon of the present invention, the raw dry sludge is separated from the hot sludge for heating by carbonizing and the flow of dry sludge in the indirect heating system in which the flow of the material to be treated is countercurrent.
Is introduced into a carbonization device that does not have a water vapor outlet at the stage prior to evaporating the water, the moisture in the dried sludge is evaporated at the stage prior to the carbonization treatment, and then the dried sludge is thermally decomposed and carbonized to obtain carbonized sludge. Generated in the previous stage of carbonization and
The steam <br/> generated from the drying sludge inside the time migrated steam and pyrolysis later with activation treatment (activated carbon of), uniform
It is preferable to produce carbonized sludge (sludge activated carbon) in which large pores suitable for the adsorption of dioxin, which is a large molecule, are formed on the surface layer of the carbide by being carbonized and activated (FIGS. 1 and 1). 2, see FIGS. 6 to 8).

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013] The apparatus for producing activated carbon for dioxin adsorption of the present invention comprises: a dry sludge hopper in which circulating dry sludge is stored;
The sludge dewatering cake supply means for supplying and mixing the sludge dewatering cake to the dried sludge extracted from the drying sludge hopper, and the hot air heated by the combustion heat of the pyrolysis gas of the sludge generated in the carbonization device is used as a heat source for drying. A crusher that is supplied with a mixture of dried sludge and sludge dewatered cake for crushing (crushing) the object to be processed and drying with hot air;
A flash drying tube for air-flowing the powdery dry sludge from the crusher and further drying with hot air, and a powdery dry sludge conveyed with the hot air from the flash-drying tube for gas-solid separation to dry sludge. A dust collector for circulation to the hopper,
The raw dry sludge input from the dry sludge hopper is heated indirectly while moving in countercurrent to the hot air for heating, and the upstream side in the moving direction of the dry sludge is water vapor for evaporating moisture in the dry sludge. in low-temperature drying zone without the outlet of the drying sludge as one proceeds in the direction of movement of the drying sludge occurs in a drying zone with carbonized by thermal decomposition sludge
Steam moving in the moving direction and inside the dried sludge during pyrolysis
A high-temperature carbonization / activation zone for activating (activated carbonization) the sludge carbonized by the steam generated from the steam. The combustion heat of the pyrolysis gas of the sludge generated in the carbonization / activation zone is used as a heat source for drying. In order to utilize the hot air introduced into the crusher, it is characterized by including a carbonization device having a secondary combustion zone near the outlet of the pyrolysis gas (see FIG. 1).

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Further, the activated carbon manufacturing apparatus of the present invention supplies a dried sludge hopper for storing circulating dried sludge and a sludge dewatered cake to the dried sludge extracted from the dried sludge hopper.
Sludge dewatering cake supply means for mixing, and exhaust gas from a gas turbine or a diesel engine are introduced as a heat source for drying, and dry sludge and sludge dewatering cake for crushing (disintegrating) the object to be processed and drying with hot air are provided. The powdered sludge conveyed together with the hot air from the crusher to which the mixture is supplied, the powdery dry sludge from the crusher, and the flash drying tube for hot air drying, and the hot air drying. A dust collector for gas-solid separation and circulation of the dry sludge to the dry sludge hopper, and the raw dry sludge introduced from the dry sludge hopper are heated indirectly while moving in countercurrent to the hot air for heating. The upstream side of the moving direction of the dried sludge is a water vapor outlet for evaporating water in the dried sludge.
In a low-temperature drying zone where no drying is provided , the dried sludge is pyrolyzed and carbonized as it proceeds in the moving direction of the dried sludge, and is generated in the drying zone and transferred to the sludge moving direction and generated from inside the dried sludge during the pyrolysis. It is characterized by including a carbonization device serving as a high-temperature carbonization / activation zone for activating (activated carbonization) the sludge carbonized by steam (see FIG. 14). In the apparatus of the present invention, the entire drying equipment can be combined with a stationary carbonization apparatus as a compact on-board equipment.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4D012 BA03 4D059 AA01 AA02 AA03 AA08 BB03 BD01 BD40 CA01 CC03 CC10 EB06 EB07 EB10 4G046 HA09 HB00 HB02 HC01 HC09 HC14 HC26 4G066 AA05B AA14D AC39A BA03 FA05 FA09 FA10 FA33 FA34 FA40

Claims (13)

[Claims] 1. A process of forming and drying a sludge dewatered cake thin film on the surface of a dried sludge particle and drying the dried sludge having a uniform water content distribution in the radial direction of the particle. Activated carbon for adsorbing dioxin, characterized in that pores having a large diameter suitable for adsorbing dioxin are formed on a surface layer. 2. The sludge dewatered cake is mixed with a large amount of circulating dried sludge to form a thin film of the sludge dewatered cake on the surface of the dried sludge particles, and the dried sludge is dried and further circulated. A series of steps of mixing the dewatered cake is repeated to obtain a raw material dry sludge having a uniform water content distribution in the radial direction of the particles, and the raw material dry sludge is subjected to carbonization and activation treatment to be suitable for dioxin adsorption on the surface layer of the carbide. A method for producing activated carbon for adsorbing dioxin, comprising producing carbonized sludge having fine pores formed therein. 3. Mixing the sludge dewatered cake with a large amount of circulating dried sludge, and then mechanically pulverizing to dry a layer of the sludge dewatered cake formed thinly on the surface of the dried sludge particles and having an enlarged exposed surface; Dry sludge obtained by uniformly drying the inside is used as a raw material, and the raw dry sludge is carbonized and activated to produce carbonized sludge having large diameter pores suitable for dioxin adsorption on the surface layer of carbide. A method for producing activated carbon for dioxin adsorption, characterized in that: 4. The sludge dewatered cake is mixed with a large amount of circulating dried sludge, then mechanically pulverized, and the drying exhaust gas temperature is in the range of 60 to 200 ° C. and the dried material temperature is 4 until the drying is completed.
It is dried with a low-temperature constant-rate dryer in a temperature range of 0 to 100 ° C., and the obtained raw material dried sludge is carbonized and activated to form large pores suitable for dioxin adsorption on the surface layer of the carbide. A method for producing activated carbon for adsorbing dioxin, characterized by producing carbonized sludge. 5. A sludge dewatering cake is mixed with a large amount of dried sludge circulating in a flash drying device and a dry sludge hopper to form a thin film of the sludge dewatered cake on the surface of the dried sludge particles. A series of steps of pulverizing with a crusher and drying with hot air, further drying the powdery dried sludge with a flash drying pipe of a flash drying device and circulating the dried sludge into a drying sludge hopper are repeated, and the obtained raw material dried sludge is carbonized and dried. A method for producing activated carbon for adsorbing dioxin, comprising producing activated carbonized sludge having an activation treatment to form pores having a large diameter suitable for adsorbing dioxin on the surface layer of carbide. 6. The raw material dry sludge is introduced into a carbonization device of an indirect heating system in which the flow of hot air for heating for carbonization and the flow of an object to be treated are countercurrent, and the water in the dry sludge is removed before the carbonization treatment. Then, the dried sludge is thermally decomposed and carbonized, and the carbonized sludge is activated with steam generated in the previous stage of the carbonization process and water vapor generated during the pyrolysis to adsorb dioxin on the surface layer of the carbide. The method for producing activated carbon for dioxin adsorption according to any one of claims 2 to 5, which produces carbonized sludge having pores having a large diameter suitable for water. 7. A dry sludge hopper in which circulating dry sludge is stored, sludge dewatering cake supply means for supplying and mixing sludge dewatering cake to dry sludge extracted from the dry sludge hopper, and a carbonization device. A hot air heated by the combustion heat of the pyrolysis gas of the sludge is introduced as a heat source for drying, and a crusher is supplied with a mixture of the dried sludge and the sludge dewatering cake for crushing the object to be processed and drying with hot air. A flash drying tube for air-flowing and drying the powdery dry sludge from the crusher, and further drying the dried sludge by gas-solid separation of the powdery dry sludge conveyed with the hot air from the flash drying tube. The dust collector for circulation to the sludge hopper and the raw dry sludge supplied from the dry sludge hopper are heated indirectly while moving in countercurrent to the hot air for heating, and the movement of the dry sludge The upstream side is a low-temperature drying zone for evaporating the moisture in the dried sludge, and pyrolyzes and carbonizes the dried sludge as it moves in the moving direction of the dried sludge, and generates water vapor generated in the drying zone and during pyrolysis. It is a high-temperature carbonization / activation zone for activating sludge carbonized by water vapor, and heats hot air that is introduced into the crusher as the heat source for drying using the combustion heat of the pyrolysis gas generated from the sludge generated in the carbonization / activation zone. A carbonization device having a secondary combustion zone near the discharge port of the pyrolysis gas for use in the activated carbon for dioxin adsorption. 8. A dry sludge hopper storing circulating dry sludge, sludge dewatering cake supply means for supplying and mixing sludge dewatering cake to dry sludge extracted from the dry sludge hopper, and a gas turbine or a diesel engine. Waste gas is introduced as a heat source for drying, and a crusher is supplied with a mixture of dried sludge and sludge dewatered cake for crushing the object to be treated and drying with hot air. A flash drying tube for conveying and further drying with hot air; and a dust collector for separating the powdery dry sludge conveyed together with hot air from the flash drying tube into gas and solid and circulating the dry sludge to the dry sludge hopper. The raw dry sludge supplied from the dry sludge hopper is heated indirectly while moving in countercurrent to the hot air for heating, and the upstream side in the moving direction of the dry sludge is dried. In a low-temperature drying zone for evaporating the water in the sludge, the dry sludge is pyrolyzed and carbonized as it moves in the moving direction of the dried sludge, and is carbonized by the steam generated in the drying zone and the steam generated during the pyrolysis. A carbonization device serving as a high-temperature carbonization / activation zone for activating sludge. 9. A filter cloth support is provided in a line of a gas to be treated, and the activated carbon for dioxin adsorption produced by the method according to claim 2 is treated on the upstream side of the filter cloth support. A method for adsorbing dioxin, comprising forming a coating layer of activated carbon on a filter cloth support by mixing with a gas to adsorb dioxin in the gas to be treated. 10. A filtration device is provided in a line for a liquid to be treated, and the activated carbon for dioxin adsorption produced by the method according to claim 2 is mixed with the liquid to be treated on the upstream side of the filtration device. A method of adsorbing dioxin, comprising forming a coating layer of activated carbon on a filtration support of a filtration device to adsorb dioxin in a liquid to be treated. 11. The activated carbon for adsorbing dioxin produced by the method according to any one of claims 2 to 6 is introduced into a classification device, and classified into activated carbon having a large particle size and activated carbon having a small particle size. Activated carbon of a diameter is introduced as a dioxin adsorbent for liquid into the upstream side of a filtration device provided in a line of a liquid to be treated, and activated carbon of a small particle diameter is introduced into a line of a gas to be treated as a dioxin adsorbent for gas. The dioxin adsorption treatment method according to claim 9 or 10, wherein the dioxin is introduced into an upstream side of the provided filter cloth support. 12. The activated carbon for dioxin adsorption produced by the method according to any one of claims 2 to 6 is formed into a granular form or a tablet form, and the molded activated carbon is filled in a packed tower to form a packed bed. A process for passing a gas to be treated through the packed bed to adsorb dioxin in the gas to be treated. 13. A wet cleaning device is provided in a line for a gas to be treated, and the activated carbon for dioxin adsorption produced by the method according to claim 2 is converted into a gas to be treated on the upstream side of the wet cleaning device. A method for adsorbing dioxin, comprising mixing active carbon into a slurry in a wet cleaning apparatus to adsorb dioxin in the gas to be treated.