JP2003171667A - Method for carbonization treatment of sludge or the like - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating a sludge or the like which can continuously carry out the carbonization treatment of an object like a sewage sludge having a high water content, being an indefinite shape, and having a high viscosity and, simultaneously, has remarkably suppressed fuel consumption. <P>SOLUTION: The method for treating a sludge comprises (1) kneading an ore powder with a water-containing indefinite-shaped sludge to reduce the water content, passing the kneaded mixture in this state through a molding machine to render the cross-sectional shape a definite form, making each shaped sludge in the surface state of non- adhering or non-bonding to one another, then continuously supplying the shaped sludge to the upstream portion of a cylindrical rotary kiln 1 having a spiral conveying wall 2 at the inner peripheral surface and an agitation wall 3 crossing the conveying wall 2 formed at a part of the conveying wall 2 while rotating the rotary kiln 1; (2) flaming the inside of the above rotary kiln 1 from its downstream portion and stopping flaming when the above sludge ignites; (3) sucking gas in the inside of the above rotary kiln 1 from its upstream portion, carrying out the treatment for rendering the gas harmless, and then exhausting the harmless gas; and (4) discharging a carbonized product of the above sludge from the lower portion of the rotary kiln 1 by carrying out the above operations (1) to (3). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously carbonizing sludge waste such as sewage sludge by utilizing rotary giraffe.

[0002]

2. Description of the Related Art In general, a rotary kiln blows a flame into the inside of a cylindrical body from its lower side when the cylindrical body whose inner surface is fire-resistant is tilted slightly from the horizontal and rotated at a slow speed. It is known as a material for feeding a raw material such as cement raw material from the upper side and firing the raw material.

Recently, there has been proposed a method of treating combustible wastes using the above-mentioned rotary giraffe, but the proposed method has a high water content such as sewage sludge and is amorphous and viscous. It is almost impossible to efficiently carbonize a high object to be treated. In addition, not only in the case of irregularly shaped products such as sewage sludge, but also in the treatment of regular waste materials,
The flame blown from the lower side of the rotary kiln into the inside of the rotary kiln is continuously blown during the treatment, so that the fuel cost thereof is significantly increased.

[0004]

Therefore, in the present invention, not only can an object such as sewage sludge having a high water content, an indefinite shape and a high viscosity be continuously carbonized, but the fuel consumption in the treatment can be significantly suppressed. It is an object of the present invention to provide a method for treating sludge and the like.

[0005]

Means for Solving the Problems The constitution of the method of the present invention aimed at solving the above-mentioned problems is (a) reducing the water content by kneading ore powder with an amorphous sludge containing water. In this state, pass through a molding machine to standardize the cross-sectional shape,
After making each of the standardized sludge a surface state in which they do not adhere or stick to each other, the standardized sludge is provided with a spiral transport wall on the inner peripheral surface and the transport wall on a part of the transport wall. Above the cylindrical rotary kiln having a transverse stirring wall, the rotary kiln is continuously supplied in a predetermined unit amount while rotating the rotary kiln. (B) The rotary kiln in the state of (a) above. A flame is blown into the rotary kiln from below, and when the sludge is ignited in the rotary kiln, the blow of the flame is stopped. (C) The rotary kiln in the above (a) and (b) states Suction the gas inside the rotary kiln from above, detoxify and exhaust it, (d) discharge the carbide of the sludge from the lower part of the rotary giraffe by performing the operations (a) to (c). It is characterized by.

[0006] In the present invention, in order to form a surface state in which the standardized sludges do not adhere or stick to each other, appropriate heating means or air blowing means or heating air blowing means is used, for example, the surface is made almost dry. You can also do it.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the method of the present invention will be described with reference to the drawings. FIG. 1 is a side view with a partial cross section schematically showing a carbonization treatment apparatus for carrying out the method of the present invention, and FIG. 2 shows a transfer wall of the carbonization treatment apparatus shown in FIG. Is a partially enlarged perspective view of a transfer wall provided with different stirring walls, and FIG. 3 is a cylindrical body 1 showing a state in which the transfer wall shown in FIG. 2 is used and carbonization is performed by the apparatus shown in FIG.
4 is a cross-sectional view of the tubular body 1 showing a state in which the tubular body 1 is rotated from the state shown in FIG.

In the figure, 1 is a length of about 10 m and an inner diameter of 40
A tubular body made of a steel pipe having a length of about 50 cm, in which a plurality of required unit length tubular bodies are connected to each other through joints in the form of outer flanges to form a single tubular body 1.

Reference numeral 2 denotes a conveying wall provided on the inner surface of the cylindrical body 1 so as to form a spiral over the entire length of the cylindrical body 1, and at a front side (left side in the figure) of the entire length of the cylindrical body 1. Is provided with a stirring wall 3 in a direction traversing the conveying path formed by the spiral conveying wall 2.

Reference numeral 4 denotes a heat insulating layer provided on the outer surface of the entire length of the tubular body 1, and the rotary kiln body Kb is formed by the above-described configurations of the tubular body 1 to the heat insulating layer 4.

The rotary kiln body Kb is provided at three positions in its length direction, specifically, at the front and rear end portions and the central portion.
When the belt-like rings 5 are attached, and the lower portions of the rings 5 are supported by rotatable support rollers 6, 7, and 8, and at least one of the rollers is driven by a motor or the like, the rotary kiln body Kb Rotate in place on the rollers 6-8. In addition, 6a, 7a and 8a are roller mounts, and BF is a base frame on which the roller mounts 6a to 8a are fixed. In the illustrated example, the rotary kiln body Kb
Is provided in a substantially horizontal posture, but it may be arranged with a downward slope (the right side in the drawing is downward).

Reference numeral 9 denotes a gas burner for flames arranged on the lower side (right side in the figure) of the rotary kiln body Kb, and the flame injection port 9a of the burner 9 is provided toward the inside of the body Kb. In front of the gas burner 9, a pit P is formed in which a container 20 for containing a carbonized product is arranged.

Numeral 10 is a means to be treated which is disposed on the upper side of the rotary kiln body Kb, and is specifically formed by a conveyor, a hopper with a shutter or the like, and is disposed inside the rotary kiln body Kb to be treated. It is formed so that waste such as sludge can be continuously supplied at a unit amount / hour.

Reference numeral 11 is a pretreatment section arranged on the front side of the charging means 10. The pretreatment section 11 is composed of a molding section 11a and a surface drying section 11b. In the forming unit 11a, when the treatment target is sewage sludge, although not shown, it has a mixer for kneading ore powder in the sludge, and a function of continuously discharging the mixture kneaded by the mixer from the discharge nozzle. , For example, by a pellet molding machine. Also,
The pretreatment unit 11 is selectively or in parallel arranged above the rotary kiln body Kb. In the surface drying section 11b of the pretreatment section 11, the sludge shaped and shaped by the shaping section 11a is received, and the surface of the sludge is dried by the heating means or the air blowing means or the heating air blowing means.
As such a means, for example, a drum type dryer is used, but if it has a similar function, other heating,
Blowers can also be used. This surface drying section 11b
The sludge, the surface of which has been dried, is conveyed to the charging means 10 by a belt conveyor. The surfaces of the sludges thus formed are dried so that the sludges adhere to each other or stick to each other when the sludge is thrown into the throwing means 10 or conveyed inside the rotary kiln body Kb. In order to prevent the sludge from coming off, if there is a method in which each sludge does not adhere or stick to each other in addition to drying the surface, that method can be naturally used.

Reference numeral 12 denotes an exhaust treatment means for detoxifying the gas present inside the kiln during the treatment process at the upper open end of the rotary kiln body Kb, which is schematically shown as a block. ing. Of these, 12a is a combustion block by an afterburner and a combustion chamber for burning and processing black smoke, an offensive odor, and a bad odor that may be generated depending on the processing target, 12b is a cooling block for cooling the exhaust gas emitted from this combustion block 12a, and 12c is , A neutralization block filled with slaked lime to neutralize the Cl components in the cooled exhaust and activated carbon to increase the dust collection efficiency of the filter cloth in the next filter block.This activated carbon is a rotary kiln. It is possible to use crushed carbonized sludge. 12d
Is a filter suction block including a filter block for filtering ash and dust in the exhaust gas and a suction block such as a cyclone as cooling means.

As described above, since an example of the carbonization apparatus utilizing the rotary kiln for carrying out the method of the present invention is constructed,
Next, carbonization treatment of sludge using this device will be described.

First, in the pretreatment section 11, ore powder is mixed with dehydrated sewage sludge to be treated at a ratio of about 3 to 8% by volume, and the whole is kneaded to reduce the water content of the sludge into a kneaded form. Similarly to the above, it is supplied to the charging means 10 by being extruded from the molding machine.

On the other hand, for the rotary kiln body Kb,
By rotating the driving rollers among the rollers 6, 7, and 8 prior to loading by the loading means 10 for processing,
The inside of the kiln body Kb is preheated by blowing flame from the burner 9 while being rotated in the feeding direction by the conveying wall 2. This preheating is performed for about 20 minutes, and the processing target (sludge) is treated with the charging means while the flame is being blown.
Continuously feed from above the rotary kiln body Kb from 10.

The sludge to be charged is the rotary kiln body Kb.
Due to the rotation of the inside of the kiln main body Kb, it is sequentially fed by the action of the conveying wall 2 inside. In this feeding, in the portion where the agitation wall 3 is provided, the action of the wall 3 causes sludge to be repeatedly lifted up to the ceiling side of the kiln body Kb and dropped, thereby promoting drying. In addition, since the flame is blown into the kiln body Kb from the burner 9 at the time of feeding, the water content in the sludge will be evaporated and the water content of the sludge itself will decrease as it goes to the downstream side of the rotary kiln body Kb. It almost disappears. Further, the exhaust processing means 12 is already driven at this stage, and sucks the inside of the rotary kiln body Kb.

As a result, the dry sludge introduced into the rotary kiln main body Kb, conveyed to the lower side by the rotation of the main body Kb, and reaching the lower end of the rotary kiln main body Kb has a combustible gas component released from the inside thereof, and the burnable gas component is Ignite with a flame of 9. In the present invention, when the sludge thus ignites its gas component, the blowing of the flame from the burner 9 is stopped.
Even if the blowing of flame is stopped, the combustion state of the gas component does not change, but the ignited portion gradually goes up inside the rotary kiln body Kb to the upper side (the input side of the processed material), for example, the upper end. It is localized (combustion position F) at a position about 2 to 3 m from the section, and the combustion of the combustible gas component released from the sludge continues there. At this time, the internal temperature of the rotary kiln body Kb is about 800 ° C to 830 ° C.

As described above, the combustible gas component released from the inside of the sludge is combusted inside the rotary kiln body Kb, and the carbonization mechanism of the sludge due to this combustion will be described. At the fixed position F inside the rotary kiln body Kb, it seems that the processed material M (sludge) is burning because of the combustion of the combustible gas released from the inside of the processed material M. This combustion is maintained at the fixed position F because inside the rotary kiln body Kb, the sludge, which is the processed product, which is sequentially sent from above to the fixed position F by the rotation of the rotary kiln body Kb, is just This is because the combustion conditions of the combustible gas released from the inside of the sludge are adjusted at the position F. That is, the oxygen necessary for the combustion of the combustible gas is constantly supplied from below (downstream) the rotary kiln body Kb (suction action of the exhaust treatment means 12), but the oxygen supplied is almost at the fixed position F. Burned in, consumed
This is because oxygen for burning the sludge itself is deficient in the rotary giraffe body Kb.

As a result, the combustible gas continues to burn at the fixed position F inside the rotary kiln body Kb, and the inside of the kiln body Kb receives the suction action of the exhaust treatment means 12, The upstream side of the combustion position F is almost anoxic or oxygen-deficient, and the oxygen sucked in the downstream side is consumed for combustion at the fixed position F, and becomes oxygen-deficient or its approximate state. On the other hand,
With the combustion continued at the fixed position F as a heat source, the inside of the rotary kiln body Kb is maintained at about 800 ° C. to 830 ° C. except for the lower end portion (outside air inflow end). The treated material M (sludge) transported inside the rotary kiln body Kb in such oxygen environment and temperature environment is thermally decomposed without being burned, and its carbonization proceeds. From the lower end of the rotating rotary kiln body Kb, carbonized sludge drops into the container 20 in the pit P, and the carbide is recovered there.

In the case of sewage sludge, since the water content varies by about 10% depending on the season, even if the sludge that is standardized in the pretreatment section 11 and the surface is dried, the water content inside them is increased. Rates vary according to the season. However, since the conditions are such that they do not adhere or stick to each other, even if the water content changes, the above rotary kiln body Kb
In the same manner, carbonization treatment is carried out. That is, when the water content is low, the fixed position F where the combustion conditions are set in the rotary kiln body Kb moves to the upstream side (the flame moves to the upstream side),
If the water content is large, it takes a long time to dry, so the fixed position F where the combustion conditions are adjusted moves to the downstream side (the flame moves to the downstream side). This means that the position where the sludge is dried and the flammable gas component released from the inside is automatically moved to the upstream side or the downstream side in the rotary kiln body Kb due to the water content.

The exhaust gas of the gas inside the main body Kb caused by the gas combustion inside the rotary kiln main body Kb and the carbonization phenomenon is sucked into the exhaust processing means 12, and the black smoke and the odor are removed from the combustion block. After being treated by 12a, Cl components and the like pass through the cooling block 12b, are purified by the next neutralization block 12c, and are then discharged from the filtration suction block 12d to the outside of the system.

Next, a stirring wall 31 as shown in FIG. 2 having a shape different from that of the above example is provided on the conveying wall 2 in the cylindrical body 1 of the rotary kiln body Kb of the carbonization apparatus shown in FIG. Another example will be described. This stirring wall 31 is the transfer wall 2
The semicircular arc-shaped cross section is formed to bulge inward from the outer peripheral edge of the conveying wall 2. The stirring wall 31 prevents the processed material M from entering the inner peripheral edge of the conveying wall 2, , 2
During this period, the front and back of the treated product M are inverted and agitated so as to roll, so that the treated product M is preferably carbonized without burning. That is, the heated hot air passes through the inner side of the inner peripheral edge of the transfer wall 2 in the cylindrical body 1. However, when the processed material M enters inside the inner peripheral edge, the flame directly hits the processed material M in advance. If they are not mixed, they will burn and a considerable amount will be incinerated. Therefore, as described above, if the processed material M is located between the front and rear transfer walls 2 and 2 and is agitated so as not to enter the inner peripheral edge of the transfer wall 2 (see FIGS. 3 and 4),
Since it does not burn, and the oxygen between the front and rear transfer walls 2 and 2 is consumed for the combustion of the combustible gas discharged from the processed material M, the oxygen between the transfer walls 2 and 2 is extremely low. In this state, when heated to a high temperature by the heated hot air that passes inside the inner peripheral edge of the transport wall 2, a flammable gas is further generated from the processed material M, and a so-called steamed state is produced, which promotes carbonization. To be done. Therefore, when this stirring wall 31 is used, it is not necessary to mix the ore with the processed material M in advance, and thus a carbide having high purity can be obtained. The shape of the stirring wall 31 is substantially semicircular in cross section, but in addition to this, if the processed material M can be stirred in the same manner as described above, it may be substantially triangular in cross section, substantially trapezoidal in cross section, or substantially mountain-shaped in cross section. Alternatively, the outer surfaces of these stirring walls, including the stirring wall having a substantially semicircular arc shape in cross section, may be formed into a corrugated surface. It should be noted that the carbonization apparatus of this example is of course shown in FIG.
Also in the carbonization treatment apparatus shown in (1), in order to obtain uniform charcoal, the shape of the treated matter M such as sludge needs to be adjusted.

[0026]

EFFECTS OF THE INVENTION The present invention is as described above, and wastes which have not been considered such as carbonization treatment in the past, such as sludge, which has a high water content and which is amorphous and has high viscosity, are added to the ore. In order to reduce the water content by kneading the powder, the cross-sectional shape was standardized through a molding machine, and a cylindrical transfer wall and a stirring wall that crossed the transfer wall were formed in part on the inner peripheral surface. When the rotary kiln is continuously supplied in a predetermined unit amount above the rotary kiln while rotating, the flame is blown into the rotary kiln from below the rotary kiln, and the sludge is ignited in the rotary kiln. Then, while stopping the blowing of the flame, the gas inside the rotary kiln is sucked from above the rotary kiln to detoxify it and exhaust it. Since to be taken out, waste such as pretty energy saving manner sludge is the efficiency can be continuously carbonized. Therefore, the present invention is extremely useful as a method for treating sewage sludge, which is especially poor in final treatment.

Further, according to the carbonization method of the present invention, compared with the conventional method in which sludge is made into a dehydrated cake having a water content of about 70 to 80% and incinerated in an incinerator, the amount of oxygen consumed is self-combustion. Therefore, it is possible to reduce the emission of CO _{2 into} the atmosphere by as much as 35%.
This means that the amount of air used for combustion can be reduced. Therefore, the combustion block for combustion can be downsized, and the cooling block, neutralization block, and filtration / suction block must also be downsized. The effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a side view with a partial cross section schematically showing a carbonization apparatus for carrying out the method of the present invention.

FIG. 2 shows a transfer wall in the carbonization apparatus shown in FIG.
The partially expanded perspective view of the conveyance wall which provided the stirring wall different from the thing of FIG.

FIG. 3 is a cross-sectional view of the tubular body 1 showing a state where carbonization is performed by the apparatus shown in FIG. 1 using the transfer wall shown in FIG.

4 is a cross-sectional view of the tubular body 1 showing a state in which the tubular body 1 is rotated from the state shown in FIG.

[Explanation of symbols]

1 cylinder 2 Transport wall 3 stirring wall 4 heat insulation layer 5 strip ring 6,7,8 Support roller 9 gas burner 9a Flame injection port 10 Input means 11 Pretreatment section 11a Molding part 11b Surface drying section 12 Exhaust treatment means 12a combustion block 12b cooling block 12c Neutralization block 12d filtration suction block Kb rotary kiln body M carbonized products

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/20 F23G 5/20 A 7/00 104 7/00 104A F term (reference) 3K061 AA07 AB02 AC02 BA05 CA01 DA03 DA17 DB14 GA05 KA02 KA16 3K065 AA07 AB02 AC02 BA05 CA03 CA04 4D059 AA03 BB05 BB14 BD01 BD11 BD22 BJ02 BK09 BK10 CB04 CC03 DA51 4H012 HA06

Claims (3)

[Claims] (A) (1) Kneading ore powder to an amorphous sludge containing water to reduce the water content, and in this state, a cross-sectional shape is shaped through a molding machine, and each shaped sludge is A cylinder in which the shaped sludge is formed on its inner peripheral surface with a spiral conveying wall and a stirring wall that crosses the conveying wall at a part of the conveying wall after the surfaces are made to not adhere or stick to each other. Above the rotary kiln, the rotary kiln is continuously supplied in a predetermined unit amount while rotating, (b) From below the rotary kiln in the state of (a), the inside of this rotary kiln Blow a flame into the rotary kiln, and stop blowing the flame when the sludge ignites in the rotary kiln, (c) from above the rotary kiln in the conditions (a) and (b) above the inside of the rotary kiln. Inhale gas, detoxify and exhaust (D) A method for carbonizing sludge, which comprises discharging the carbide of the sludge from the lower part of the rotary giraffe by performing the operations of (a) to (c). 2. The method for carbonizing sludge according to claim 1, wherein the sludge that has been standardized is brought into a surface state in which the sludges are not adhered or adhered to each other by using a heating unit, a blowing unit, or a heating blowing unit. 3. The stirring wall has a substantially semi-circular cross section and is formed so as to bulge inward from the outer peripheral edge of the conveying wall.
Of sludge carbonization.