JPH1054520A - Method and device for incinerating sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the environment from being polluted even if sludge is dried before it is incinerated by a method wherein sludge is dried by means of incineration heat before it is incinerated and the moisture is removed or partially removed from the gas produced in the drying of sludge and the residual gas is mixed with a combustion air to incinerate the sludge. SOLUTION: In a drying silo 20, sludge before being incinerated is dried or the moisture of the sludge is reduced, and an exhaust gas pipe 21 is connected to the top of the silo 20 to lead gas produced in the drying of sludge to a succeeding condenser 30. The gas containing methane, acetone, phenol etc., from which moistures are removed at the condenser 30, is drawn into a fan 5 together with air from an air intake pipe 34 and fed into an air chamber 4. The gas containing methane, etc., fed into the chamber 4 fluidizes fluidized bed constituting material M and also is burnt as combustion gas. That is, sludge is heated by the heated material M and solid combustibles also are burnt together with combustible volatile components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge incineration method for incinerating sludge such as sewage sludge, liquid marc, and the like in the food industry or the pharmaceutical industry, and an incineration apparatus used for carrying out this method. .

[0002]

2. Description of the Related Art Sludge such as sewage sludge is partially or biologically or physically treated and used as fertilizers, but most of it is incinerated. The incinerator for incinerating such sludge is well known without mentioning a document name, and a moving bed incinerator, a rotary kiln incinerator, a fluidized bed incinerator and the like are known. Fluid bed incinerators include incinerators,
It comprises an air distribution plate disposed below the incinerator, an air chamber below the air distribution plate, and the like. A refractory powder composed of a fluidized bed constituent material, such as silica sand, is placed on the air dispersion plate. The upper space of the incinerator is a free board. The flue gas is discharged from the upper part of the free board, and heat is recovered. The discharged combustion exhaust gas is discharged to the atmosphere after being cooled and removed by a dust removal device.

[0003] Since the fluidized bed incinerator is configured as described above, when air is blown into the refractory powder from an air chamber through an air dispersion plate by a blower fan, the refractory powder having a fixed layer is formed. Becomes a fluidized bed that moves like a boiling state. Then, when the sludge is supplied, the sludge is heated by the heated refractory powder and the release of volatile components is started. The volatiles are burned immediately above the air distribution plate, and the nitrogen oxide concentration increases with the burning. Solid combustibles are burned in the particulate rich phase. Then, the generated gas reaches the free board section. In this free board portion, secondary combustion of unburned components, concentration control of nitrogen oxides, and the like are performed. In addition, it is incinerated by other moving bed incinerators, rotary kiln incinerators and the like in a known manner.

[0004]

The incinerator can also be incinerated by the above-mentioned conventional moving bed incinerator, rotary kiln incinerator and the like. In particular, according to the fluidized bed incinerator, the fluidized refractory powder stores heat. It has the advantage that it acts as a body and that the refractory powder is in good contact with the sludge, which promotes combustion and efficiently incinerates the sludge. However, the conventional incinerator has a disadvantage that a large amount of auxiliary fuel such as kerosene, heavy fuel oil A, heavy fuel oil C or the like is required. In more detail, sludge is generally dewatered by a press, but contains about 80% of water, so when it is incinerated, it cannot be burnt with sludge alone due to heat of evaporation.
There is a disadvantage that a large amount of auxiliary fuel such as kerosene, fuel oil A and fuel oil C is required. For example, sewage sludge is reduced to 100 ton / day, that is, 4.2 ton / h by a conventional fluidized bed incinerator.
To incinerate at the rate of r 1 requires 320 l / hr of heavy fuel oil C as an auxiliary fuel. In order to reduce auxiliary fuel, it is conceivable to use waste heat generated during incineration of sludge to dry prior to incineration.However, when drying, odors such as methane, acetone, and phenol are generated, polluting the environment. Therefore, in reality, sludge is not dried by exhaust heat. According to the conventional fluidized bed combustion method, the reaction rate, that is, the combustion rate is low,
There is a problem that the combustion maintaining temperature must be maintained at a high temperature of 700 to 900 ° C., the amount of generated nitrogen oxides increases, and it is costly to take countermeasures. Furthermore, according to the conventional fluidized-bed incineration method, a freeboard portion for performing secondary combustion must be secured above the incinerator, and thus there is a disadvantage that the height of the incinerator increases. In addition, since the combustion speed is low, a large amount of air must be supplied, and there is a disadvantage that the blower fan becomes large.

The present invention aims at providing a method and an apparatus for incinerating sludge which have solved the above-mentioned conventional disadvantages. Specifically, the present invention aims to provide a method for incinerating sludge which does not pollute the environment even if dried before incineration. It is intended to provide an incineration method and an incineration apparatus. Another invention provides a sludge incineration method and an incineration apparatus that generate less nitrogen oxides and can further reduce the height of an incinerator, the blowing capacity of a blowing fan, and the like as compared with conventional ones. It is intended to be.

[0006]

The above objects of the present invention can be attained by employing means for utilizing a gas which emits malodor such as methane, acetone and phenol generated when drying sludge as a combustion gas. . Further, another invention is achieved by adopting the above means and applying an oxidation catalyst to the fluidized bed constituent material. Oxidation catalytic combustion burns with a lean fuel below the flame combustion limit due to catalytic oxidation of the catalyst.It is known that the reaction speed is high and the combustion temperature is low. because it is merely a platinum catalyst honeycomb structures are used, but not applied to the fluidized bed combustion method, the present invention is _{BaO6Al 2 O 3, SrO6Al 2 O} 3, C
_{aO6Al 2 O 3, MgAl 2 O} 4+ α, at least one of ZrO ₂₊ alpha is selected as an oxidation catalyst. That is,
In order to achieve the above object, the present invention, when incinerating sludge in an incinerator, dries the sludge by incineration heat prior to incineration, and removes or reduces moisture from the gas generated at this time for combustion. It is configured to incinerate sludge by mixing with air. The invention according to claim 2 is
When incinerating sludge by injecting gas into the fluidized bed constituent material of the fluidized bed incinerator to form a fluidized bed, the sludge is dried by incineration heat prior to incineration, and the remaining gas obtained by removing or reducing moisture from the gas generated at this time. The gas body is configured to be used as a part of air for forming a fluidized bed. Claim 3
The invention described as the fluidized bed constituting material according to claim 2,
Silica sand, lime, BaO.6Al ₂ O ₃ , SrO.6Al
₂ O ₃ , CaO.6Al ₂ O ₃ , MgAl ₂ O ₄₊ α, ZrO ₂₊
At least one is selected from α, K ₂ O · 11Al ₂ O ₃ and La ₂ O ₃ · 11Al ₂ O ₃ . The invention according to claim 4 is generated from a fluidized bed incinerator, a drying device in which sludge is dried or reduced by the combustion heat of the sludge incinerated in the fluidized bed incinerator, and a sludge treated in the drying device. The dehumidifier is configured to guide a gas body, and the treated gas body processed by the dehumidifier is configured to be guided to an air chamber of the fluidized bed incinerator. The invention according to claim 5 is a fluidized bed incinerator, a heat exchanger for recovering the combustion heat of the sludge incinerated in the fluidized bed incinerator, a drying device for drying or reducing the amount of sludge, A dehumidifying device through which gas generated from sludge treated in the device is guided, wherein heat recovered in the heat exchanger is a drying device, and a preheating heat exchanger for combustion air of the fluidized bed incinerator. And the gas body after the treatment performed by the dehumidifier is guided to an air chamber of the fluidized bed incinerator. The invention according to claim 6 is the invention according to claim 7, wherein the dehumidifying device according to claim 4 or 5 is a condenser, and the condensed water condensed in the condenser is used as cooling water. Is a dehumidifier according to claim 4 or 5,
The invention according to claim 8 comprises a cooling cylinder, and the drying apparatus according to any one of claims 4 to 7 is provided with a screw for stirring and transferring.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be applied to various types of incinerators. First and second embodiments applied to a fluidized bed incinerator will be described below. As shown in FIG. 1, a fluidized bed incinerator 1 according to the first embodiment includes an incinerator 2, a drying silo 20, a condenser 30, and other accessory devices.

The incinerator 2 has a cylindrical shape as is well known in the prior art, but the height of the incinerator is lower than that of the conventional incinerator, as will be described later. An air distribution plate 3 is provided below the incinerator 2, and an air chamber 4 is provided below the air distribution plate 3. The incinerator 1 is provided with an oil tank 7 in which auxiliary fuel, for example, fuel oil C is stored. From the oil tank 7, fuel oil C is introduced into the incinerator 2 by a pipe 8 when necessary, such as at the time of ignition. It is being supplied. A discharge pipe 25 for discharging incineration ash is provided on a lower side of the incinerator 2.

A well-known refractory powder such as silica sand or lime can be put on the air dispersion plate 3 as a fluidized bed constituent material, but according to the present embodiment,
Fluidized bed constituent material M _{is, BaO · 6Al 2 O 3,} SrO · 6A
l ₂ O ₃ , CaO.6Al ₂ O ₃ , MgAl ₂ O _{4 +} α, ZrO
_At least one of _{2 +} α, K ₂ O · 11Al ₂ O ₃ and La ₂ O ₃ · 11Al ₂ O ₃ is selected. The composition, sintering temperature, S / S (Al ₂ O ₃ ) (surface ratio between the additive material and alumina alone) of these fluidized bed constituent materials M and the crystal phases are as shown in Table 1 below. Table 1 Composition Firing temperature ° C S / S Crystal phase (BaO) _0.14 (Al ₂ O ₃ ) _0.86 1450 4.3 BaO.6Al ₂ O ₃ (SrO) _0.14 (Al ₂ O ₃ ) _0.86 1450 3.0 SrO. 6Al ₂ O ₃ (CaO) _0.14 (Al ₂ O ₃ ) _0.86 1450 3.6 CaO.6Al ₂ O ₃ (MgO) _0.10 (Al ₂ O ₃ ) _0.90 1450 0.8 MgAl ₂ O ₄₊ α (ZrO) _0.10 (Al ₂ O ₃ ) _0.90 1450 0.7 ZrO ₂₊ α (K ₂ O) _0.08 (Al ₂ O ₃ ) _0.92 1300 5.0 K ₂ O · 11 Al ₂ O ₃ (La ₂ O ₃ ) _0.08 (Al ₂ O ₃ ) O ₃ ) _0.92 1300 3.0 La ₂ O ₃ .11Al ₂ O ₃ (La ₂ O ₃ ) _0.05 (Al ₂ O ₃ ) _0.95 1200 8.0 La ₂ O ₃ .11Al ₂ O ₃ IA shown in Table 1, The oxide of IIA, IIIB or IVB is calcined and supported on aluminum oxide, and platinum and Similarly, it has an oxidation catalytic action. Such an oxidation catalyst,
Since porous alumina of 0.5 to 8 mmφ is used as a carrier and the additive is calcined, it can be obtained at low cost.

As described above, the air supply pipe 6 to which the blower fan 5 is connected is opened in the air chamber 4 of the incinerator 2 in which the fluidized-bed constituent material M is put. A tube 12 is provided. The exhaust pipe 12 is connected to a heat radiating pipe 13 provided in the drying silo 20. The radiator tube 13 is connected to a discharge tube 14 provided with a dust removal device 15 and a chimney 16.

The drying silo 20 is for drying or reducing the amount of sludge before being incinerated, and an exhaust gas pipe 21 for guiding gas generated during drying to the next condenser 30 is connected to a top portion thereof. . Further, a supply pipe 22 is connected to a lower portion via a rotary feeder or the like, so that dried dry sludge is supplied to the incinerator 2 to a predetermined amount. The drying silo 20 is provided with a hopper 23 for storing wet sludge before drying.
The drying silo 20 and the drying silo 20 are connected by a closed conduit 24.
Therefore, when the wet sludge is supplied from the hopper 23 to the drying silo 20, the odor generated by the wet sludge is not bothered.

In the present embodiment, the condenser 30 is of a water-cooled type. That is, a chilled water coil 31 for circulating cooling water is provided inside the condenser 30. A gas vent pipe 33 is connected to the top of the condenser 30, and the gas vent pipe 33 is connected to a suction port of the blower fan 5. Note that an air intake pipe 34 for introducing air for fluidization or combustion is also connected to the gas vent pipe 33. A drain pipe 35 connected to a water treatment tank 36 is connected to a lower part of the condenser 30. In the water treatment tank 36, the condensed water that is dissolved and becomes acidic by dissolving sulfurous acid gas or the like is chemically treated. Then, the water is sent to the water storage tank 40 by the pipe 37.

The water storage tank 40 is provided with a cooling water suction pipe 41. The cooling water suction pipe 41 extends toward the cooling tower 45 and is connected to a heat exchange pipe 44 of the cooling tower 45. The heat exchange pipe 44 and the cold water coil 31 of the condenser 30 are connected by a cooling water supply pipe 47, and the cold water coil 31 and the water storage tank 4 are connected.
0 is connected by a cooling water return pipe 48. Therefore, when the water pump 42 provided in the cooling water suction pipe 41 is started, the cooling water in the water storage tank 40 is cooled by the cooling tower 45 and the condenser 30.
And the water tank 40 is circulated. The cooling tower 45 is provided with a fan 46 for cooling the cooling water with the atmosphere. Further, an overflow pipe 49 is provided in the water storage tank 40, and condensed water surplus as cooling water is appropriately discharged to the sewer.

Next, the operation of the fluidized bed incinerator 1 will be described. The blower fan 5 is activated to blow air from the air chamber 4 through the air dispersion plate 3 into the fluidized bed constituent material M.
Then, the fluidized-bed constituent material M, which has been in the fixed bed, becomes a fluidized bed that moves like a boiling state. Therefore, while dry sludge is supplied from the drying silo 20, fluid fuel such as heavy fuel oil C is supplied from the oil tank 7 as appropriate to ignite. Thereafter, the sludge is heated by the heated fluidized bed constituent material M, and the solid combustibles are burned together with the combustible volatiles.

The high-temperature combustion exhaust gas is supplied to the radiator pipe 13 of the drying silo 20 by the exhaust pipe 12. The wet sludge in the drying silo 20 is dried or reduced in water by the heat radiated from the radiator tube 13. The combustion exhaust gas whose temperature has been lowered due to heat release is removed by the dust removing device 15 and discharged from the chimney 16 into the atmosphere. The dried or reduced-water dry sludge is sent to the incinerator 2 to a predetermined amount by a supply pipe 22. And it is incinerated. Dry silo 20
Inside, the wet sludge generates odorous gases such as methane, acetone, and phenol together with water vapor by a drying action. These mixed gases are sent to the condenser 30 by the exhaust gas pipe 21. Cold water coil 3 being cooled
Due to 1, the water vapor in the mixed gas is condensed to become condensed water. The condensed water is appropriately chemically treated in the water treatment tank 36 and sent to the water storage tank 40.

The gas containing methane, acetone, phenol, etc., from which water has been removed in the condenser 30, is sucked into the blower fan 5 together with the air from the air intake pipe 34 from the gas vent pipe 33, and then is sent from the air supply pipe 6 to the air supply pipe 6. It is supplied to the chamber 4. The gas containing methane, acetone, phenol and the like supplied to the air chamber 4 fluidizes the fluidized-bed constituent material M and is burned as a combustion gas. It burns continuously as described above. The incineration ash generated at this time is
5, and the heat of combustion is recovered by a cooling pipe (not shown). Note that the condensed water, that is, the cooling water is supplied to the cooling tower 45, the condenser 30, and the water storage tank 4 as described above.
Cycles between zero. During this time, the cooling water is air-cooled by the fan 46 of the cooling tower 45.

According to the present embodiment, the fluidized bed constituent material M
Since the oxidation catalyst is selected, the combustion rate is about 1000 times larger than that of the conventional one. Since the combustion speed is high, the combustion maintaining temperature is low. Therefore, a freeboard section is not required unlike the conventional fluidized bed combustion, and the height of the combustion furnace 2 can be reduced. Further, since the combustion maintaining temperature is low, generation of harmful nitrogen oxides is reduced. Furthermore, the amount of supplied air is small, and the size of the blower fan 5 can be reduced.

[0018]

【Example】

Example 1 A combustion test of sewage wet sludge having a water content of 80% and dry sludge treated according to the present embodiment was performed on an actual machine having a treatment capacity of 100 ton / day with wet sludge. Table 2 shows the results. The calorific value of the 80% sewage wet sludge is 4%.
At 0 kcal / kg, the calorific value of dry sludge is 340
It was 0 kcal / Kg. Table 2 Sludge supply amount (Kg / hr) 750 (DRY) 4200 (WET) C heavy oil supply amount (L / hr) 42 320 As is clear from Table 2, large oil is obtained only by drying using waste heat. Can be saved. Incidentally, even when the wet sludge was dried, no odor was perceived.

Next, a second embodiment of the present invention will be described with reference to FIG. The same elements as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals to avoid duplication, and similar elements are denoted by the same reference numeral with a dash "'".
A brief description will be given. The first embodiment is described in the first embodiment.
As compared with the embodiment of FIG.
0, a dryer 20 ′, a condenser 30 ′ instead of the condenser 30, and the first and second heat exchangers 50, 5,
4 in that the exhaust gas treatment equipment 60 is further provided.
Of this embodiment.

The dryer 20 'is composed of a horizontally long container, and is provided therein with a screw 22' having a relatively large pitch, which is driven to rotate by a motor 21 '.
Therefore, the sludge is transported forward while being stirred by the rotating screw 22 '. The cooling cylinder 30 ′ is composed of a vertical container, and below the container, an exhaust gas pipe 21, one of which is connected to the dryer 20 ′.
Is connected. A gas vent pipe 33 is connected to the upper part of the container, and a watering nozzle device 32 'for spraying cooling water above the inside of the container has a fin unit 33' below it.
Are provided respectively. A drain pipe 34 'is provided at the bottom of the container. This drainage pipe 34 '
Thereby, water injected from the water spray nozzle device 32 'and water separated from the combustion exhaust gas are discharged in a state containing the water-soluble components in the combustion gas.

The air supply pipe 6 is provided with a blower fan 5 as in the first embodiment, and its suction pipe is connected to a gas vent pipe 33 and an air introduction pipe 34. In this embodiment, a heat exchanger 7 'for preheating the combustion air is interposed in the air introduction pipe 34. Although not shown in the figure, air heated by a first heat exchanger 50 described later is supplied to the heat exchanger 7 ′, and preheated combustion air is supplied to the air chamber 4 of the combustion furnace 2. It is supplied to. A secondary combustion air supply pipe 8 ′ connected to the combustion furnace 2 branches off from the air supply pipe 6, and a start-up used during startup is provided between the air supply pipe 6 and the air chamber 4. A burner 9 'is interposed.

The exhaust pipe 12 of the combustion furnace 2 is connected to the top of the first heat exchanger 50. An outlet pipe 51 for the exhaust gas after the heat exchange is provided on the lower side.
Inside the first heat exchanger 50, there is provided a heat transfer tube 52 through which air to be heat-exchanged flows from below to above, and this heat transfer tube 52 is connected to the heat exchanger 7 for preheating the combustion air. 'And connected. A second heat exchanger 54 is provided in series with the first heat exchanger 50. That is, the outlet pipe 51 of the first heat exchanger 50 is connected to the second heat exchanger 5
An outlet pipe 55 for the flue gas which has been connected to the lower side of the tube 4 and has finished heat exchange is provided above. A cooling air supply pipe 57 provided with a blower fan 58 is connected to a lower inlet end of the heat transfer pipe 56 of the second heat exchanger 54, and an exhaust pipe 12 'is connected to an upper outlet end. Have been. The end of the exhaust pipe 12 'is open near the sludge supply port of the dryer 20'. Therefore, the drying air flows in the dryer 20 ′ in the axial direction from one end to the other end. In addition, below the first and second heat exchangers 50 and 54, a discharge pipe 5 for discharging combustion ash is provided.
3 and 59 are provided respectively.

At the downstream side of the outlet pipe 55 of the second heat exchanger 54, a bag filter 61 and a venturi scrubber 6
Conventionally-known exhaust gas treatment equipment 60, such as an exhaust gas treatment equipment 60, is connected. In addition, a cleaning cylinder 63 to which cleaning water is injected from a water supply pipe 64, an induction fan 65, and the like are provided attached to the exhaust gas treatment equipment 60. Invitation Juan 65 and Chimney 1
6 are connected by a pipe 66, and the exhaust pipe 12 'is connected to the pipe 66.
Is connected to a hot air supply pipe 13 ′ for preventing white smoke. Therefore, as is well known, the combustion exhaust gas treated by the exhaust gas treatment equipment 60 is washed by the washing water injected from the water supply pipe 64 while passing through the washing cylinder 63, and is not trapped by the bag filter 61. Gases and the like are collected, sucked and pumped by the attracting fan 65, and discharged from the chimney 16 in a colorless state.

It is clear that sludge can be burned in the same manner in the second embodiment, and therefore will not be described again. However, in particular, according to the second embodiment, the dryer 20 'is used.
The sludge supplied from one end is transferred to the other end while being stirred by the screw 22 ′,
Hot air for drying also flows from one side to the other, so that moisture is efficiently removed during that time. Further, in the cooling cylinder 30 ', the fin unit 33' below the watering nozzle device 32 'is provided.
And the flue gas rises, so that the flue gas and the water flow in opposite directions and are efficiently contacted and cooled. As a result, the amount of saturated steam is reduced, and water is removed from the flue gas by that amount. The combustion exhaust gas containing methane, acetone, phenol and the like after the removal of the water is supplied to the air chamber 4 of the incinerator 2 together with the air preheated by the heat exchanger 7 '. In addition, since the flue gas and water come into contact efficiently, nitrogen oxides, sulfur oxides, etc. in the flue gas are dissolved in water, recovered as acids such as nitric acid and sulfurous acid, and discharged to the outside through a drain pipe 34 '. Is done. Therefore, corrosion of the incinerator 2, the first and second heat exchangers 50 and 54, etc. due to these oxides is prevented.

According to the second embodiment, the first,
Since the two heat exchangers 50 and 54 are provided, clean hot air heat-exchanged with the combustion exhaust gas can be supplied to the heat exchanger 7 ′ for preheating the combustion air to preheat the combustion air. In addition, clean hot air flows through the heat exchanger 7 ′ and the dryer 2.
Since it is supplied to 0 ', etc., it is possible to keep the pipes such as the exhaust pipe 12' leading to these devices in a clean state and also to use it as hot air for preventing white smoke.

The second embodiment can be variously modified. For example, in the present embodiment, two heat exchangers, a first heat exchanger 50 and a second heat exchanger 54, are provided. In the first heat exchanger 50, heat exchange for preheating combustion air is performed. In the second heat exchanger 54, hot air is supplied to the dryer 20 ′, whereas the first heat exchanger 50 generates hot air to be supplied to the dryer 20 ′. Obviously, it can be implemented to obtain hot air supplied to the dryer 20 '. It is also clear that the hot air obtained by one heat exchanger can be supplied separately to the dryer 20 ′, the heat exchanger 7 ′ for preheating the combustion air, and the white smoke prevention. Further, the present invention can be implemented by combining the elements of the first embodiment and the elements of the second embodiment. For example, the cooling cylinder 3 of the second embodiment
It is clear that the condenser 30 of the first embodiment can be applied instead of 0 ', and a heat exchanger can be provided in the first embodiment. In the first and second embodiments, the incinerator 2 is constituted by a fluidized-bed incinerator. However, the incinerator 2 can be implemented by a conventionally-known incinerator such as a moving-bed incinerator and a rotary kiln incinerator. It is also clear that the effect of the above-described embodiment can be obtained even if the present embodiment is implemented.

[0027]

As described above, according to the present invention, when sludge is incinerated by an incinerator, the sludge is dried by incineration heat prior to incineration, and the remaining gas obtained by removing or reducing moisture from the gas generated at this time. Since the sludge is incinerated by mixing the body with the combustion air, even if the sludge is dried, an effect peculiar to the present invention is obtained that the environment is not polluted by a bad smell. Also, because the sludge is dried and then incinerated,
This also has the effect of greatly reducing auxiliary fuel for incineration. According to the invention of claim 2, when gas is blown into the fluidized bed constituent material of the fluidized bed incinerator to form a fluidized bed and incinerate the sludge, the sludge is dried by incineration heat prior to incineration, and the gas generated at this time Since the remaining gaseous matter from which water is removed or reduced is used as a part of air for forming a fluidized bed, the same effect as the above invention can be obtained, and since it is incinerated in a fluidized bed incinerator, the fluidized bed configuration Due to the heat storage effect of the material, it is incinerated more efficiently. According to the invention of claim 3, BaO.6Al ₂ O is used as the fluidized bed constituent material.
_{3, SrO · 6Al 2 O 3} , CaO · 6Al 2 O 3, MgAl 2
O ₄₊ α, ZrO ₂₊ α, K ₂ O · 11Al ₂ O ₃ , La ₂ O ₃ ·
Since at least one kind is selected from 11Al ₂ O ₃ , oxidation catalyst combustion by a fluidized bed is possible and incineration can be performed at a relatively low temperature. Therefore, generation of harmful gases such as nitrogen oxides can be suppressed. The effect of being able to do so is added. Further, since the combustion rate is high and the combustion maintaining temperature is low, a freeboard section is not required unlike a conventional fluidized bed incinerator. Therefore, the height of the fluidized bed incinerator used for carrying out the present invention can be reduced. In addition, since the amount of supplied air can be reduced, the effect of reducing the size of the blowing fan required for the fluidized bed incinerator can be obtained. According to the fifth aspect of the present invention, the heat recovered by the heat exchanger is guided to the preheat heat exchanger for the combustion air in the fluidized bed incinerator, so that the combustion air is preheated and the sludge is efficiently incinerated. . According to the invention of claim 6, since the condensed water condensed in the condenser is supplied to the condenser as cooling water, the effect of saving the cooling water can be obtained. According to the seventh aspect of the present invention, since the dehumidifying device is constituted by the cooling cylinder, water is removed or reduced from the flue gas, and at the same time, water solubility such as nitrogen oxides and sulfur oxides in the flue gas is reduced. The effect is obtained that the components are dissolved and recovered in water. According to the eighth aspect of the present invention, since the drying device has the screw for stirring and transferring, the sludge is transferred while being stirred by the screw. Therefore, the sludge has an effect of drying or reducing the amount of water without unevenness.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 2 Fluidized bed combustion furnace 7 'Heat exchanger for preheating combustion air 15 Fluidized bed 20 Dry silo 20' Dryer 30 Condenser 30 'Cooling cylinder 50, 54 First and second heat exchanger M Fluid bed constituent material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display F23G 5/30 ZAB F23G 5/30 ZABR 5/46 ZAB 5/46 ZABA (72) Inventor Yoshihisa Ishibashi 1-1 Nikkocho, Fuchu-shi, Tokyo Inside Japan Steel Works, Ltd.

Claims (8)

[Claims] When incinerating sludge by an incinerator (2), the sludge is dried by incineration heat prior to incineration, and the remaining gas obtained by removing or reducing moisture from the gas generated at this time is mixed with combustion air. A method for incinerating sludge, comprising incinerating sludge. 2. When sludge is incinerated by blowing a gas into a fluidized bed constituent material (M) of a fluidized bed incinerator (2) to form a fluidized bed (15), the sludge is dried by incineration heat prior to incineration, A method for incinerating sludge, characterized by utilizing the remaining gas obtained by removing or reducing moisture from the gas generated at this time as a part of air for forming a fluidized bed (15). 3. The fluidized bed constituent material (M) according to claim 2, wherein the material is silica sand, lime, BaO.6Al ₂ O ₃ , SrO.6A.
l ₂ O ₃ , CaO.6Al ₂ O ₃ , MgAl ₂ O _{4 +} α, ZrO
_A method for incinerating sludge, wherein at least one of _{2 +} α, K ₂ O · 11Al ₂ O ₃ and La ₂ O ₃ · 11Al ₂ O ₃ is selected. 4. A fluidized bed incinerator (2), and a drying device (20, 20 ′) for drying or reducing the amount of sludge by the heat of combustion of the sludge incinerated in the fluidized bed incinerator (2).
And a dehumidifier (30, 30 ') through which gas generated from sludge treated by the drying device (20, 20') is guided. After the treatment performed by the dehumidifier (30, 30 ') The sludge incinerator according to claim 1, characterized in that the gaseous substance is introduced into the air chamber (4) of the fluidized bed incinerator (2). 5. A fluidized bed incinerator (2), a heat exchanger for recovering the heat of combustion of the sludge incinerated in the fluidized bed incinerator (2), and a drying device for drying or reducing water the sludge. 20, 20 ') and a dehumidifying device (30, 30') into which gas generated from sludge treated in the drying device (20, 20 ') is led, and heat recovered by the heat exchanger. Is the drying device (20,
20 ′) and a treated gas body guided to the heat exchanger (7 ′) for preheating combustion air of the fluidized bed incinerator (2) and treated by the dehumidifier (30, 30 ′). Is configured to be guided to an air chamber (4) of the fluidized bed incinerator (2). 6. The sludge incinerator according to claim 4, wherein the dehumidifying device is a condenser (30), and condensed water condensed in the condenser (30) is used as cooling water. 7. A sludge incineration device according to claim 4, wherein the dehumidification device is a cooling cylinder (30 ′). 8. The screw (2) for agitating and transferring the drying device (20 ') according to any one of claims 4 to 7.
2 '), a sludge incinerator.