JP3081733B2 - Method for melting inorganic substances in organic sludge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently melting inorganic substances contained in organic sludge such as surplus sludge generated from a biological treatment apparatus for organic wastewater represented by sewage.

[0002]

2. Description of the Related Art Sewage sludge, a typical organic sludge, is:
Approximately 50 million m ³ annually throughout Japan (based on concentrated sludge: water content 9)
8%), which is increasing year by year.
Generally, organic sludge such as sewage sludge contains large amounts of organic substances such as proteins, fats and carbohydrates together with water, so it is easy to rot, and it is necessary to stabilize, detoxify, and reduce its volume from the viewpoint of preventing odors and public health. It has been. In many sewage treatment plants in large cities, sludge is incinerated from the viewpoint of difficulty in securing landfill sites. The incinerated ash obtained by the incineration has been landfilled. The incineration of organic sludge is performed on the cake after dehydration, but the volume of incinerated ash is
Since it is reduced to 1/8 to 1/10, the area of the final disposal site is also drastically reduced. However, in recent years, even for incinerated ash, it has become difficult to secure disposal sites in large urban areas, and soaring disposal costs due to the long distance of disposal sites is becoming a problem. As a method capable of coping with such a problem, a melting system in which incinerated ash or dried sludge is melted by exposing it to a high temperature of 1,200 to 1,500 ° C. and cooled to form slag has been attracting attention. This method has the advantage that the volume of the slag is glass-coated with silica in the sludge, and the elution of heavy metals is greatly suppressed, while achieving further volume reduction. In addition, the slag obtained by this method has an advantage that it has a high compressive strength and can be used as an aggregate.

According to this melting method, the inorganic substances contained in the sludge can be melted. However, in this case, the temperature of the entire melting furnace must be as high as 1200 to 1500 ° C. Includes various issues as shown. (1) Since the melting furnace is exposed to a high temperature of 1,200 to 1,500 ° C., it is necessary to develop equipment (fusing furnace body and heat recovery process) that can withstand high temperatures including refractory materials. (2) Since the temperature of the furnace wall of the melting furnace becomes high, the amount of heat lost from the furnace wall increases, so that the total amount of heat input to the furnace increases. (3) Since the melting furnace waste gas has a very high temperature as described above, a substance which has not been transferred by the conventional incineration method is transferred to a heat recovery process, and becomes a trouble source such as blockage and corrosion. (4) Considering the amount of heat of the organic matter in the sludge, melting dried sludge is superior in energy to melting incinerated ash, but in this case, the drying process becomes very large and a large installation area is required. Need. (5) In the melting of dry sludge, combustion of organic matter and melting of ash are performed in the same furnace, so that a large amount of waste gas can be reduced to 1,20.
The temperature must be as high as 0-1,500C. (6) Depending on the drying method, a crusher is required for finely dividing and pulverizing the dried sludge, and the power cost for the crusher is high.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for efficiently melting inorganic substances in organic sludge such as sewage sludge with energy saving.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in a method for melting inorganic matter in organic sludge , the organic sludge is subjected to a dehydration treatment.
The dewatered sludge is subjected to high-temperature and high-pressure treatment to form a liquefied product. <br/> The organic sludge liquefied product is ejected from a burner together with oxygen-containing gas for combustion and burned, and at least a part of the combustion flame is burned. Is maintained at a temperature equal to or higher than the melting temperature of the inorganic substance contained in the liquefied organic sludge, and the inorganic substance is melted in the flame to provide a method for melting the inorganic substance in the organic sludge.

The organic sludge used as the raw material to be treated in the present invention includes sewage sludge discharged from ordinary sewage treatment plants and excess sludge discharged from various organic wastewater biological treatment apparatuses. In the present invention, the organic sludge is used as a fuel in a liquefied state. The liquefied organic sludge can be obtained by maintaining dehydrated sludge obtained by dehydrating organic sludge at a temperature of 150 ° C. or more and a pressure of a saturated steam pressure or more at that temperature. As the dehydration of the organic sludge, mechanical dehydration (vacuum dehydration, pressure dehydration, belt press dehydration, and centrifugal dehydration) is usually used, but is not particularly limited. However, it is desirable to add a sludge conditioning chemical to the organic sludge before dehydration, and it is particularly advantageous to add a polymer flocculant. Therefore, regarding the dehydration method, belt press dehydration or centrifugal dehydration, which is suitable for adding a polymer flocculant, is desirable. The organic sludge is dehydrated so that the moisture content of the obtained dewatered sludge is in the range of 60 to 90% by weight, preferably 65 to 75% by weight.

In order to convert the dewatered sludge into a liquefied substance, the dewatered sludge is reacted at a temperature of 150 ° C. or higher, preferably 200 to 250 ° C., and a pressure higher than the saturated steam pressure at the reaction temperature, for example, a reaction temperature of 200 ° C. In case of 16kg /
What is necessary is just to hold | maintain under the conditions of reaction pressure more than cm < ² > (absolute pressure). The liquefaction of the dehydrated sludge can be performed, if necessary, in the presence of an alkaline substance as a liquefaction accelerator.
This alkaline substance, with respect to the solid content in the dewatered sludge,
It is advisable to add 0-20% by weight, preferably 0-5% by weight. Examples of the alkaline substance include, for example, alkali metal compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium formate, potassium formate, calcium oxide, calcium hydroxide, and hydroxide. And alkaline earth metal compounds such as magnesium. The time for maintaining the dewatered sludge under the reaction conditions varies depending on the type of the target sludge, but is generally within 120 minutes, usually,
0-60 minutes. The liquefaction device may be any heat exchanger of the indirect heating type, but since it handles sludge presenting a solid state, there are scrape type heat exchangers having a scraper inside and screw type heat exchangers having helical blades. Use is preferred. As the pressure in the liquefaction reaction, a self-generated pressure due to water vapor from sewage sludge can be used, but if necessary, the pressure can be increased using, for example, nitrogen gas, carbon dioxide gas, argon gas, or the like. The sludge liquefied matter thus obtained has a very good fluidity and is sufficiently pumpable.

In the present invention, in order to melt the inorganic substances contained in the organic sludge, the liquefied organic sludge obtained as described above is finely divided together with oxygen-containing gas for combustion from a burner of a combustion furnace. Spray and burn. As the oxygen-containing gas for combustion, air, oxygen-enriched air or oxygen gas is used. The ejected particles of the liquefied sludge ejected from the burner are 300 μm or less, preferably 30 to 1 μm.
50 μm. The type of burner is not particularly limited, but it is preferable to use an external or internal mixing two-fluid spray burner or a low-pressure air spray burner.

FIG. 1 shows a structural example of a burner portion of a combustion furnace used in the present invention. FIG. 2 shows an enlarged view of the tip of the atomizer. 1 and 2, the burner unit includes an atomizer body 1 and an air register 6, and the atomizer body 1
Consists of an inner pipe 2 to which a sludge liquefied substance is supplied and an outer pipe 3 which forms a passage for the spray medium, and is attached to the air register 6. A sludge liquefied material supply line 4 is connected to the inner pipe 2, a spray medium supply line 5 is connected to the outer pipe 3, and a combustion oxygen-containing gas supply line 7 is connected to the air register 6. Reference numeral 8 denotes a burner tile, 9 denotes a flame holding chamber, 10 denotes a combustion furnace, 11 denotes a combustion furnace wall, 1
Reference numeral 2 denotes a combustion chamber. The furnace wall 11 has a temperature of 800.
It is composed of a heat insulating material that can withstand temperatures of up to 1200 ° C. In the combustion furnace 10 of FIG. 1, the sludge liquefied material supplied from the sludge liquefied material supply line 4 is atomized by the spray medium supplied from the spray medium supply line 5 and is ejected from the tip of the atomizer main body 1. . As the spray medium, air, oxygen-enriched air, oxygen gas, or the like is used. On the other hand, a predetermined amount of oxygen-containing gas for combustion is supplied from the periphery of the atomizer body 1 from the oxygen-containing gas supply line 7 for combustion. The atomized sludge liquefied matter spouted from the burner and the oxygen-containing gas for combustion are mixed in the flame holding chamber 9, ignited, and burned in the combustion chamber 12.

In the present invention, at the time of burning the sludge liquefied material, the temperature of at least a part of the combustion flame is maintained at a temperature equal to or higher than the melting temperature of the inorganic substance contained in the sludge. The melting temperature of the inorganic substance in the sludge varies depending on the type of the sludge, but generally, the inorganic substance can be melted by heating to 1200 ° C. or more. Therefore, in order to melt the inorganic substance in a combustion flame, the temperature of at least a part of the flame is set to 12
The temperature may be maintained at 00 ° C. or higher, preferably 1400 to 1500 ° C. When burning sludge liquefied matter, the temperature of the combustion flame can be adjusted by various methods. Generally, the preheating temperature of the oxygen-containing gas for combustion, the oxygen concentration in the oxygen-containing gas for combustion, the sludge It can be adjusted by controlling the calorific value of the liquefied material and the amount of the combustible substance added. Hereinafter, the method of adjusting the flame temperature will be described in detail.

(Method of Controlling Preheating Temperature of Oxygen-containing Gas for Combustion) The combustion flame temperature changes with the preheating temperature of the oxygen-containing gas for combustion, and the flame temperature can be increased by increasing the preheating temperature. For example, when sludge liquefaction having a water content of 70% by weight is air-combusted, when the preheating temperature of the combustion air is 100 ° C, the maximum temperature of the combustion flame is 900 ° C.
To the extent that the preheating temperature is 200 ° C., 400 ° C. and 60 ° C.
When raised to 0 ° C, the maximum combustion flame temperature is
Increase to 1000 ° C, 1100 ° C, 1200 ° C. In the case of burning sludge liquefied matter having a water content of 60% by weight, the preheating temperature of the combustion air is set to 200 ° C, 400 ° C and 6 ° C.
When the temperature is increased to 00 ° C., the maximum combustion flame temperatures become about 1250 ° C., 1350 ° C., and 1450 ° C., respectively.

(Method of Controlling Oxygen Concentration in Oxygen Gas for Combustion) The combustion flame temperature changes depending on the oxygen concentration in the oxygenated gas for combustion, and it is possible to raise the combustion flame temperature by increasing the oxygen concentration. it can. For example, if the water content is 7
When burning 0% by weight sludge liquefied matter, if the oxygen concentration is 21% (air), the maximum temperature of the flame is 900.
℃, but the oxygen concentration is 40%, 60%, 80%,
When the temperature is increased to 100% (oxygen gas), the maximum combustion flame temperature increases to about 1150 ° C, 1300 ° C, 1380 ° C, and 1450 ° C, respectively. In the case of burning a sludge liquid having a water content of 60% by weight, when the oxygen concentration in the oxygen-containing gas for combustion is 21%, 40% and 60%, the maximum combustion flame temperature is 1200 ° C., respectively. ,
It is about 1550 and 1750 ° C. Furthermore, when burning the sludge liquefied matter having a water content of 50% by weight, when the oxygen concentration in the oxygenated gas for combustion is 21% and 40%,
They are about 1300 ° C and 1850 ° C, respectively.

(Method of Controlling Heat Generation of Sludge Liquefied Material) The flame temperature changes depending on the calorific value of sludge liquefied material which is a fuel for combustion, and the combustion flame temperature can be raised by increasing the calorific value. For example, when the sludge liquefied product is burned by air, the lower heating value of the sludge liquefied product is 1
At 260 kcal / kg, 2150 kcal / kg, and 3050 kcal / kg, the maximum temperatures of the combustion flames are 1170 ° C., 1520 ° C., and 17 ° C., respectively.
It will be 40 ° C. The lower heating value of the sludge liquefied product changes depending on the water content of the sludge liquefied product. For example, the sludge liquefied product having a lower heating value of 3970 kcal / kg in an anhydrous state has a water content of 20% by weight. , 40% by weight, 60% by weight and 80% by weight, the lower calorific values are 3050 kcal / kg and 2150 kcal / kg, respectively.
kcal / kg, 1260 kcal / kg and 360k
cal / kg. The lower heating value of the liquefied sludge is represented by the following equation. H (L) = H (U) -600 × W In the above formula, H (L) indicates a lower calorific value (kcal / kg). H (U) indicates a higher calorific value (kcal / kg), which is a calorific value measured by a calorimeter and is a calorific value including latent heat when water vapor condenses. W indicates the amount of water vapor (kg) generated during combustion. When sludge is burned in a combustion furnace, the steam generated during the combustion flows out to the outside together with the combustion gas without being condensed. Therefore, the latent heat of the steam is not used for heating the sludge. Therefore, the lower calorific value is adopted as the calorific value used for studying the combustibility of sludge.

(Method of controlling the amount of combustible substance added) The temperature of the combustion flame can also be adjusted by the amount of combustible substance added to the sludge liquefied matter. Sludge containing a combustible substance has an increased apparent heating value, and the flame temperature increases in accordance with the amount of the combustible substance added. Examples of the combustible substance include hydrocarbon oils such as heavy oil and kerosene, various waste oils, various organic wastes, pulverized coal, and the like.

As is clear from the above examination, the combustion flame temperature at the time of burning the liquefied sludge includes the preheating temperature of the oxygenated gas for combustion, the oxygen concentration in the oxygenated gas for combustion, and the calorific value of the liquefied sludge. And the amount of the flammable substance added. The preferred method of adjusting the combustion flame temperature in the present invention is a method of controlling the water content in the sludge liquefied matter. For this purpose, there are a method of evaporating and removing water contained in the sludge liquefied material, a method of separating the sludge liquefied material into an aqueous phase and a precipitated phase, and removing the aqueous phase. A method of controlling the oxygen concentration in the oxygen-containing gas for combustion and the preheating temperature of the oxygen-containing gas for combustion is also a simple and advantageous method. In the present invention, the liquefied sludge is burned by a burner, and at least a part of the combustion flame is maintained at a temperature equal to or higher than the melting temperature of the inorganic substance contained in the sludge. Therefore, the inorganic substances in the sludge are melted in the flame and become molten slag. The molten slag is very fine, and those having a particle size of 5 μm or less show 50% or more. The molten slag has a spherical shape due to the effect of surface tension when the inorganic substance is melted. This molten slag is
It flows out of the furnace together with the combustion gas, but is separated and recovered from the combustion gas by a filter installed outside the furnace.

In the present invention, the temperature of at least a part of the combustion flame needs to be maintained at a high temperature as described above, but the temperature of the entire furnace does not need to be at such a high temperature.
In the case of the present invention, the temperature of the furnace wall inner surface is 500 to 1000 ° C.
It is not necessary to use a special material as the furnace wall material, and by maintaining the furnace wall inner surface temperature at such a low temperature, heat loss escaping from the inside of the furnace to the outside of the furnace can be obtained. Is also suppressed.

FIG. 3 shows an example of a flow sheet for implementing the present invention. In FIG. 3, reference numeral 101 denotes a dehydrator, 1
02 is a liquefaction device, 103 is a flash tank, 104
Denotes an evaporator, 105 denotes a combustion furnace, 106 denotes a first waste heat boiler, and 107 denotes a second waste heat boiler.

The concentrated organic sludge having a water content of about 98% by weight is introduced into a dehydrator 101 through a line 108. The separated filtrate is returned to the water treatment facility through the line 109, and the dewatered sludge is introduced into the liquefaction apparatus 102 through the line 110. This liquefaction apparatus is a heat exchange type reaction apparatus, in which a heating medium is introduced through a line 118 and heats the organic sludge in the apparatus to a liquefaction temperature. It is desirable that the heat source used here is the amount of heat recovered in the first waste heat boiler 106 in the subsequent stage. The liquefaction conditions at this time are 150 ° C. or higher, preferably 200 to 250 ° C.
And a reaction pressure that is equal to or higher than the saturated steam pressure at the reaction temperature. The reaction time is usually within 60 minutes. The type of the liquefaction apparatus used here is preferably a scraped surface heat exchanger or a screw type heat exchanger, but is not particularly limited. The sludge liquefied material in the high temperature and high pressure state is introduced into the flash tank 103 through the line 111, and the pressure is rapidly reduced to the atmospheric pressure. At this time, the temperature of the liquefied material rapidly drops from the reaction temperature to 100 ° C., and steam corresponding to the sensible heat is generated. This water vapor is introduced into a downstream combustion furnace through a line 112. On the other hand, concentrated sludge liquefied material is supplied from line 113 from the lower part of the flash tank.
Is sent to the evaporator 104 via This evaporator 104
In this case, the vapor evaporated through the line 114 and the liquefied matter that is the evaporation residue from the line 115 flow out, and both the steam and the liquefied matter are introduced into the combustion furnace 105.
The evaporating operation is performed to a moisture content at which the liquefied material can be burned in the combustion furnace 105 by flame. At this time, the water content of the liquefied product is 70% or less, preferably 50 to 60%. The heat source used here is the second waste heat boiler 1
It is desirable to set the recovered heat amount at 07.

The type of the evaporator employed here is preferably a scraped surface heat exchanger or a screw type heat exchanger as in the case of the liquefaction device, but is not particularly limited. Line 11
The liquefied material sent from 5 to the combustion furnace 105 is ejected from the tip of the atomizer body 1 into the furnace together with the oxygen-containing gas for combustion and burns. In the combustion flame, first, the moisture contained in the liquefied material evaporates, and thereafter, the combustion of the organic matter in the liquefied material and the melting of the remaining inorganic matter occur sequentially. At this time, oxygen-containing gas for combustion is fed from the line 116, and in order to raise the combustion flame temperature, oxygen or oxygen-enriched air is used as needed as oxygen-containing gas for combustion. Preheating of the oxygen-containing gas for combustion for the same purpose is also performed as necessary. On the other hand, steam is supplied into the furnace so as to flow on the inner wall surface of the furnace through the lines 112 and 114, and the steam is heated to about 700 to 800 ° C. by flame combustion heat, and The contained malodorous substances are decomposed. As described above, a melting temperature of 1200 ° C. or more is formed in the combustion flame, but 700 to 8
The temperature range is 00 ° C. High-temperature exhaust gas is extracted from the combustion furnace 105 through a line 117 and the first waste heat boiler 10
6 and is led to the second waste heat boiler 107 through the line 119. In the boilers 106 and 107, the heat quantity of the waste gas is exchanged with the heating medium in the liquefier 102 and the evaporator 104, respectively, and finally sent to the subsequent exhaust gas treatment equipment (not shown) through the line 121. Can be In the above method, the evaporation operation is described as a method for reducing the water content of the liquefied material, but it is also possible to employ a specific gravity difference separation such as a stationary separation or a centrifugal separation.

[0020]

As described above, according to the present invention,
This is a method in which an organic sludge liquefied substance is atomized in a burner section and directly burned, and inorganic substances contained in the sludge are melted in the combustion flame. At this time, the furnace wall temperature is 7
The temperature is about 00 to 800 ° C., which can solve various problems in the conventional high-temperature melting method at once. In addition, the present invention can also solve the problems of the drying step, which are one of the problems in the conventional melting method, in terms of the complexity of the drying step and the required installation area, because drying, burning, and melting are simultaneously realized in the combustion flame. . Therefore, it can be said that the method for melting inorganic matter in organic sludge of the present invention is a very technically and economically advantageous method.

[0021]

Next, the present invention will be described in more detail with reference to examples.

Example 1 Sewage sludge was selected as an organic sludge, and a dewatered cake of mixed raw sludge discharged from a treatment plant using a standard activated sludge method was used for the test. This sludge is obtained by adding a polymer flocculant and then dewatering it by a belt press. Its typical properties are
The water content is 80% by weight, the organic matter ratio is 83% by weight, and the lower heating value is 3970 kcal / kg.

The dewatered sludge was liquefied using a continuous sludge liquefaction apparatus (processing capacity: 200 kg / hr). This equipment consists of a press-in pump (snake pump), a reactor (scratch-surface heat exchanger), a cooler (thin-film falling heat exchanger), a pressure reducing valve, and a heat medium boiler. Was supplied by a heating medium boiler. The dehydrated sludge was introduced into the reactor with a press-in pump, and heated to 240 to 270 ° C while performing scraping to prevent clogging and promote heat transfer.
The residence time at the reaction temperature was about 60 minutes. Since the dewatered sludge was sufficiently liquid at the outlet of the reactor, the sludge was allowed to flow down while forming a thin film on the inner tube of the double tube, and was cooled to 100 ° C. or lower with cooling water supplied to the outer tube. Thereafter, the pressure was reduced to atmospheric pressure by a pressure reducing valve and stored in a drum. Liquefaction operation is performed for about 10 hours, and about 400 k
g (two drums) was used as a sludge liquefied material for melting experiments. Further, the sludge liquefied material obtained by the above operation was reheated to 100 ° C. using an electric injection heater, so that the water content was reduced to about 55% by weight. The evaporation residue with a low water content obtained at this time still had sufficient liquid fluidity.

The liquefied product thus obtained was sent to an externally mixed high-pressure two-fluid spray burner using a snake pump, sprayed into a combustion furnace, and burned. At this time, oxygen-enriched air containing 55 vol% of oxygen was used as the oxygen-containing gas for combustion. Under these conditions, the liquefied material formed a flame and burned, and the burning continued. The flame combustion was continued for 1 hour or more, and the combustion flame temperature at this time was 1,200 ° C or more. When the combustion was stabilized, a sampling probe was inserted into the exhaust gas duct outlet, connected to a bag filter, and the molten slag was collected. Examination of the molten slag with a microscope revealed that it had a very small sphere. This means that the inorganic component melted in the combustion flame and became spherical due to surface tension. Next, the analysis results of the component composition of the molten slag are shown in Table 1.

[0025]

[Table 1] Table 2 shows the measurement results of the particle size distribution of the molten slag.

[0026]

[Table 2]

Example 2 The same operation as in Example 1 was carried out except that the sludge liquefied matter used had a water content of about 70% by weight and the oxygen-containing gas for combustion used was oxygen-enriched air having an oxygen concentration of 60 vol%. Experiments. Also in this case, the maximum flame temperature was 1200 ° C. or higher, and the obtained molten slag showed a spherical shape.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view showing the vicinity of a burner of a combustion furnace.

FIG. 2 shows an enlarged view of an atomizer tip.

FIG. 3 shows an example of a flow sheet for implementing the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Atomizer main body 2 Inner pipe 3 Outer pipe 4 Sludge liquefied matter supply line 5 Spray medium supply line 6 Air register 7 Oxygen-containing gas supply line for combustion 8 Burner tile 9 Flame holding chamber 10 Combustion furnace 11 Combustion furnace wall 12 Combustion chamber 101 Dehydration Apparatus 102 Liquefaction apparatus 103 Flash tank 104 Evaporator 105 Combustion furnace 106 First waste heat boiler 107 Second waste heat boiler

Continuing on the front page (72) Koji Ogata, 2-8-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside the Tokyo Sewerage Bureau (72) Inventor Takeshi Yamaura 1-2-28, Konan, Minato-ku, Tokyo Inside Tokyo Sewerage Bureau ( 72) Inventor Akira Suzuki 1-4-9 Kawagishi, Toda City, Saitama Prefecture, within Organo Research Institute (72) Inventor Shinji Ito 1-4-9, Kawagishi, Toda City, Saitama Prefecture, Organo Research Institute ( 72) Inventor Nobuyuki Kojima 5-16, Hongo, Bunkyo-ku, Tokyo Organo Co., Ltd. (72) Inventor Shiro Takahashi 2-4-7, Kyomachibori, Nishi-ku, Osaka-shi, Osaka 72) Inventor Shinji Asada 2-4-7 Kyomachibori, Nishi-ku, Osaka City, Osaka Prefecture Inside Chugai Furnace Industry Co., Ltd. (72) Inventor Makoto Inoue 2-4-7, Kyomachibori, Nishi-ku Osaka City, Osaka Chugai Furnace Industry Co., Ltd. (72) Inventor Masao Nonohiro 2-4-7 Kyomachibori, Nishi-ku, Osaka-shi, Osaka Chugai Furnace (56) References JP-A-60-14008 (JP, A) JP-A-60-126512 (JP, A) JP-A-61-46812 (JP, A) JP-A-54-24457 (JP, A) A) JP-A-5-337497 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 5/00 115 F23G 7/00 104 C02F 11/00

Claims (1)

(57) [Claims] 1. A method for melting inorganic matter in organic sludge, wherein the organic sludge is subjected to a dehydration treatment, and the dehydrated sludge is heated to a high temperature.
A high-pressure treatment is performed to form a liquefied product, and the organic sludge liquefied product is ejected from a burner together with an oxygen-containing gas for combustion to be burned, and at least a part of the combustion flame is contained in the organic sludge liquefied material. Melting the inorganic substance in the flame while maintaining the temperature at or above the melting temperature of organic sludge.