JP3054797B2 - Liquid organic sludge treatment method - 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 treating 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. Many sewage treatment plants in large cities burn sludge from the viewpoint of difficulty in securing landfills. JP-A-5-337497 proposes a method in which organic sludge is subjected to high-temperature and high-pressure treatment in advance to form a liquefied material, and then the liquefied material is burned. According to this method, since the organic sludge is supplied to the combustion furnace as a liquefied material having good fluidity,
At the time of the combustion treatment, a spray combustion method having good combustion efficiency can be adopted, and there is an advantage that the combustion furnace can be downsized and the operation can be easily determined.

[0003] However, when the water content of the liquid organic sludge is high, the lower heating value based on the water content is low, and the fire temperature at the time of combustion becomes low. There is a problem that the melting of the inorganic substances contained in the steel does not occur or is insufficient. When the inorganic substances contained in the organic sludge are not sufficiently melted, the resulting ash becomes bulky and the heavy metals contained therein are easily eluted, and the ash is landfilled. During the treatment, the heavy metal component is eluted, which may cause environmental pollution.

[0004] The inventors of the present invention first maintain at least a part of the combustion flame of the liquid organic sludge at a temperature higher than the melting temperature of the inorganic substance contained in the sludge when the liquid organic sludge is burned. A method for melting an inorganic substance was proposed (Japanese Patent Application No. 5-22089). In this method,
In order to increase the flame temperature, a method has been included in which the liquid organic sludge is concentrated and the concentrate is burned. When the liquid organic sludge is concentrated and the concentrated liquid is subjected to combustion treatment, the water content and the viscosity of the concentrated liquid may fluctuate due to, for example, a change in the composition of the liquid organic sludge. In such a case, when the concentrated liquid is burned, the spray state deteriorates, a stable flame is not formed, or the lower heating value based on water content decreases, so that the temperature of the flame does not become sufficiently high. As a result, problems such as melting of the inorganic substance in the sludge did not occur.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for concentrating a liquid organic sludge and subjecting the concentrated liquid to a combustion treatment, wherein the concentrated liquid is stably burned, and the combustion flame temperature of the sludge is reduced. It is an object of the present invention to provide a method for maintaining the temperature at or above the melting temperature.

[0006]

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, from a liquid organic sludge, a concentrated liquid having a high solid content and a concentration step of obtaining a dilute liquid having a low solid content or substantially no solid content, A step of burning the concentrated solution obtained in a combustion furnace, measuring the water content and / or viscosity of the concentrated solution, and adjusting the concentration rate of the liquid organic sludge in the concentration step based on the measured value. In addition, there is provided a method for burning liquid organic sludge, wherein a combustion flame having a temperature equal to or higher than a melting temperature of an inorganic substance contained in liquid organic sludge is formed in the burning step.

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. As the liquid organic sludge in the present invention, organic sludge having a relatively high water content before dehydration is also an object of treatment, but dewatered sludge obtained by once dehydrating the organic sludge having a high water content At 150 ° C
The liquid organic sludge obtained by maintaining the above-mentioned temperature and the conditions of the pressure higher than the saturated steam pressure at that temperature is a preferable object. As the dehydration of the organic sludge described above, 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 dewatering of the organic sludge is carried out when the water content of the obtained dewatered sludge is 60 to 9
It is good to carry out so as to be 0% by weight, preferably in the range of 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 more, 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.

The present invention includes a step of concentrating the liquid organic sludge obtained as described above, and blowing the concentrated liquid together with oxygen-containing gas for combustion from a burner of a combustion furnace in the form of fine particles for combustion. . As the oxygen-containing gas for combustion, air, oxygen-enriched air or oxygen gas is used. The ejected particles of the concentrated liquid ejected from the burner are 300 μm or less, preferably 30 to 150 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
Is composed of an inner pipe 2 to which a concentrated liquid of liquid organic sludge (hereinafter, also simply referred to as a concentrated liquid) is supplied, and an outer pipe 3 which forms a passage of a spray medium, and is attached to the air register 6. The inner pipe 2 is connected to a concentrate supply line 4, the outer pipe 3 is connected to a spray medium supply line 5, and the air register 6 is connected to a combustion oxygen-containing gas supply line 7. 8 is a burner tile, 9 is a flame holding room, 1
0 indicates a combustion furnace, 11 indicates a combustion furnace wall, and 12 indicates a combustion chamber. The furnace wall 11 is made of a heat insulating material that can withstand a temperature of 800 to 1200 ° C. In the combustion furnace 10 of FIG. 1, the concentrated liquid supplied from the concentrated liquid 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 concentrate and the oxygen-containing gas for combustion ejected from the burner section are mixed and ignited in the flame holding chamber 9, and burn in the combustion chamber 12.

In the present invention, when the concentrated liquid is burned, the water content and / or viscosity of the concentrated liquid is measured, and based on the measured value, the concentration of the liquid organic sludge is adjusted to generate heat of the concentrated liquid. The amounts and viscosities are kept in predetermined ranges.

FIG. 3 shows an example of a flow sheet of the method of the present invention including a step of adjusting the concentration rate of liquid organic sludge.
In FIG. 3, 101 is a liquid organic sludge storage tank, 1
02 is a liquid organic sludge supply pump, 103 is a concentrator,
104 is a diluent tank, 105 is a concentrate tank, 106
Is a diluted liquid supply pump, 107 is a concentrated liquid supply pump, 11
Reference numeral 3 denotes a combustion burner, 114 denotes a combustion furnace, 115 denotes a combustion flame, and 116 denotes a dilute liquid spraying device. Also, 202
Denotes a device for measuring the water content and / or viscosity of the concentrated liquid, and 204 denotes a control device. In order to carry out the present invention in accordance with the flow sheet shown in FIG. 3, the liquid organic sludge is supplied from its storage tank 101 through a liquid organic sludge supply pump 102 to a concentrating device 103, where the concentrated liquid and the dilute solution are diluted. Separated into liquid. The concentrated liquid is collected in the tank 105, and the dilute liquid is collected in the tank 104. As the concentration device 103,
Various conventionally known apparatuses such as a separation apparatus utilizing specific gravity difference separation such as stationary separation and centrifugal separation, and an evaporator can be used. The solid content concentration in the concentrate is 10 to 50% by weight, particularly 30 to 50% by weight. On the other hand, the solid content concentration in the dilute solution is less than 10% by weight, particularly 0 to 5% by weight. The concentrate recovered in the concentrate tank 105 is supplied to the concentrate supply pump 107, the valve 108, the line 1
09 to the burner 113. Further, oxygen or an oxygen-containing gas as a combustion supporting gas is introduced into the burner 113 through a line 120. The concentrate and oxygen or oxygen-containing gas introduced into the burner 113 are sprayed and burned into the combustion furnace 114 from the burner tip, and a combustion flame 115 is formed in the furnace.

On the other hand, the diluted liquid collected in the diluted liquid tank 104 is introduced into the spraying device 116 through the diluted liquid supply pump 106, the line 111, and the valve 112, and is sprayed into the furnace from there. The diluted liquid sprayed into the furnace is instantaneously heated to the furnace temperature, and the organic matter contained in the diluted liquid is decomposed. The number of the spray devices 116 is not limited to one, but may be plural. Further, the diluted liquid can be sprayed toward a central portion in the combustion furnace by a spraying device, but preferably can be sprayed toward a furnace wall surface. When spraying toward the furnace wall, the temperature of the furnace wall can be lowered and the durability of the furnace wall can be improved. The combustion gas generated by the combustion of the concentrated liquid in the furnace and the decomposition gas generated by the oxidative decomposition of the organic matter in the dilute liquid are discharged out of the furnace through the line 117. The high-temperature exhaust gas discharged outside the furnace is subjected to heat recovery from the exhaust gas through a heat exchanger, and then sent to a downstream exhaust gas treatment facility, where harmful gases contained in the exhaust gas are removed, and then discharged to the atmosphere. Released.

In the present invention, a part of the concentrate in the concentrate tank 105 is sent to a moisture content and / or viscosity measuring device 202 through a line 201, where the moisture content of the concentrate is measured. And / or the viscosity is measured. And
This measurement is sent to the controller 204 via line 203 as moisture content information and / or viscosity information of the concentrate,
Here, the liquid organic sludge is converted into concentration rate control information and sent to the concentration device 103 through the line 205.

As the apparatus for measuring the water content and / or viscosity of the concentrated liquid, various conventionally known apparatuses can be used. As the moisture content measuring device, for example, a transmission light type or an ultrasonic type can be used, and as the viscosity measuring device, for example, a rotating double cylindrical type can be used. In the present invention, the water content and the viscosity of the concentrated liquid can be measured separately and the measured values can be sent to the control device 204.However, since the water content and the viscosity have a correlation,
One of the moisture content and the viscosity may be measured, and the measured value may be sent to the control device 204.

The information of the measured values obtained in the water content and / or viscosity measuring device 202 can be sent to the control device 204 continuously or intermittently. The information on the measured value is sent to the control device 204 as an electric signal.

The control device 204 has a function of converting the measured value information into an operation signal of the concentrating device 103, and is usually constituted by a computer. This control device 2
04 stores the relationship between the operating conditions of the concentration device and the concentration ratio, and the relationship between the concentration ratio and the water content and / or viscosity of the concentrated liquid. When input to this control device, the control device determines whether or not the measured value information of the water content and / or viscosity is a value within a preset range of the water content and / or viscosity, and When the value deviates from the value in the set range, the concentration rate required to change the water content and / or the viscosity to a value in the predetermined range is calculated, and the electric power according to the calculated concentration rate is calculated. A signal is sent to the concentrator and the concentrator is operated based on the signal. As an operation factor of the concentrator, for example, when using a centrifugal concentrator,
Examples include the number of rotations of the ball and the depth of the impeller.

As described above, the concentrating device 103 is operated so as to always provide a concentrated liquid having a predetermined range of water content and viscosity, and the burner 113 always supplies a concentrated liquid having a predetermined range of water content and viscosity. The liquid is supplied and the concentrate is burner 1
From 13, a flame 115 having a predetermined temperature is formed while being smoothly sprayed into the combustion furnace.

The water content of the concentrate is related to the calorific value of the concentrate, and also to the flame temperature when the concentrate is sprayed and burned. By lowering the water content of the concentrate, the calorific value of the concentrate increases and the flame temperature also increases. For example, when the concentrate is burned by air, the lower heating value of the concentrate is 1260 k
cal / kg, 2150 kcal / kg, and 3050
At kcal / kg, the maximum temperatures of the combustion flames are 1170 ° C., 1520 ° C. and 1740 ° C., respectively.
Becomes The lower heating value of the concentrated solution changes depending on the water content of the concentrated solution. For example, a concentrated solution having a lower heating value of 3970 kcal / kg in an anhydrous state has a water content of 20% by weight and 40% by weight. % And 60% by weight, the lower heating value is 3050 kcal /
kg, 2150 kcal / kg and 1260 kcal / kg
kg. The lower calorific value of the concentrated liquid 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 the concentrated liquid is burned in the combustion furnace, the steam generated during the combustion flows out together with the combustion gas without being condensed, so that the latent heat of the steam is not used for heating the solid content (sludge) in the concentrated liquid. Therefore, as the calorific value used to study the flammability of the concentrate,
The lower heating value is adopted.

In the present invention, as described above, the water content of the concentrated solution is controlled by adjusting the concentration ratio of the organic sludge in the concentration step, that is, by adjusting the operating conditions of the concentration device 103. However, in this case, the water content of the concentrated solution is usually controlled to 90% by weight or less, preferably 70% by weight or less. On the other hand, the concentrated liquid has a higher viscosity as its water content decreases. If the viscosity is too high, the concentrated liquid cannot be sprayed smoothly from the burner. Therefore, from this viewpoint, the viscosity of the concentrated liquid is 20 ° C.
The apparent viscosity at a shear rate of 10 s ^-1 measured in
It is good to control to 000 cp or less, preferably 50 cp or less.

Since the water content and the viscosity of the concentrated liquid have a correlation, both the calorific value and the viscosity of the concentrated liquid can be controlled by adjusting the water content of the concentrated liquid. From this viewpoint, the water content of the concentrated liquid is set to 50 to
By controlling the content to 90% by weight, preferably 50 to 70% by weight, the spray from the burner can be performed smoothly, and moreover, the amount required for melting the inorganic substances in the sludge is 1%.
A flame of 200 ° C. or higher can be formed. Also,
Conversely, by controlling the viscosity of the concentrate to a range of 10 to 2000 cp, preferably 10 to 500 cp, the spray of the concentrate from the burner can be performed smoothly, and moreover, it is necessary to melt the inorganic substances in the sludge. A flame of 1200 ° C. or higher can be formed.

In the present invention, the concentrate is burned by a burner, and at least a part of the combustion flame is maintained at a temperature 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 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.

In the case of the present invention, at least a part of the flame 115 is kept at a temperature higher than the melting temperature of the inorganic substance contained in the sludge, and the inorganic substance is melted when the concentrated liquid is burned. Since the inorganic substance usually melts at a temperature of about 1200 ° C., a flame having a temperature of 1200 ° C. or more may be formed. In such combustion of the concentrated liquid, the temperature of the entire furnace is in the range of 700 to 800 ° C.

[0025]

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

Example 1 Sewage sludge was selected as the organic sludge, and a dewatered cake of mixed raw sludge discharged from a treatment plant using the 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
It has a water content of 79% by weight, an organic matter ratio of 78% by weight, and a lower calorific value of 3940 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 about 265 ° 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
It was performed for about 10 hours, and about 400 kg (two drums) of a steady sample was used as sludge liquefied material for melting experiments. Next, 100 parts by weight of the sludge liquefied product having a water content of 79% by weight (solid content concentration: 21% by weight) obtained as described above is treated by a centrifugal separator to obtain a concentrated liquid 48 having a solid content concentration of 35% by weight. In this way, 52 parts by weight of a dilute solution which produces a bad odor having a solid content of 7.5% by weight was obtained. In this case, the concentration of the sludge liquefaction was 52%. The enrichment ratio is calculated by the following equation. Concentration ratio = (BA) / B × 100 (%) A: Weight of concentrated solution B: Weight of sludge liquefied material before concentration treatment

The thus obtained concentrated liquid was sent to an external mixing type high-pressure two-fluid spray burner at a flow rate of 150 kg / h 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. Next, when the combustion was stabilized, the diluted liquid obtained above was sprayed into the combustion furnace at a flow rate of 150 kg / h to decompose organic substances in the diluted liquid. In addition, a sampling probe was inserted into the outlet of the exhaust gas duct and connected to a bag filter to collect molten slag. 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.

[0029]

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

[0030]

[Table 2]

Next, an experiment was conducted in the same manner as in the above experiment except that the concentration ratio was variously changed. Table 3 shows the sprayability of the concentrate and the theoretical temperature of the flame formed by spray combustion of the concentrate in relation to the water content and viscosity of the concentrate.

[0032]

[Table 3]

As can be seen from the results shown in Table 3, when the concentration ratio is increased, the water content of the concentrated solution is decreased, and the viscosity of the concentrated solution is increased. The concentrated liquid having a water content of 45% has too high a viscosity to measure the viscosity (1000 cp or more),
It was difficult to spray the concentrate. Further, when the water content of the concentrated liquid is 75% or more, the theoretical flame temperature becomes 1050.
° C or less, and flame combustion was impossible. From these facts, it turns out that the flame temperature and the sprayability of the concentrated liquid can be controlled by the concentration rate of the liquid organic sludge, and by controlling the concentration rate to correspond to a predetermined moisture content, The concentrated liquid can be sprayed smoothly from the burner, and a high-temperature stable flame required for melting the inorganic substance in the sludge can be formed.

[0034]

According to the present invention, the liquid organic sludge is once concentrated and spray-combusted in the form of a concentrated liquid. In addition to the small size, there is an advantage that the combustion can be stably performed and the flame temperature is increased. Therefore, in the case of the present invention, the liquid organic sludge can be efficiently and economically burned, and the inorganic substances contained in the sludge can be efficiently converted into molten slag. In addition, the dilute liquid containing malodorous organic substances by-produced during the concentration of the liquid organic sludge is sprayed into a combustion furnace, and the organic substances contained in the dilute liquid are decomposed, thereby eliminating the drainage problem caused by the dilute liquid. . ADVANTAGE OF THE INVENTION According to this invention, by adjusting the concentration rate of an organic sludge according to the water content and / or viscosity of a concentrate, a smooth spray from a burner of a concentrate can be performed, and the inorganic substance in sludge A stable flame of a high temperature required for melting of the steel can always be formed.

[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 of the method of the present invention including a step of adjusting the concentration rate of the liquefied organic sludge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Atomizer main body 2 Inner pipe 3 Outer pipe 4 Concentrated liquid 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 Liquid organic Sludge storage tank 102 Liquid organic sludge supply pump 103 Concentrator 104 Dilute liquid tank 105 Concentrate liquid tank 106 Dilute liquid supply pump 107, Concentrate liquid supply pump 108, 112 Valve 113 Burner 114 Combustion furnace 115 Combustion flame 116 Spray device 202 Water containing Rate and / or viscosity measuring device 204 Control device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F23G 5/50 ZAB F23G 5/50 ZABQ (72) Inventor Koji Ogata 2-8-1, Nishishinjuku, Shinjuku-ku, Tokyo Within the Bureau (72) Inventor Akira Suzuki 1-4-9, Kawagishi, Toda City, Saitama Prefecture Inside Organo Research Institute (72) Inventor Shinji Ito 5-5-116 Hongo, Bunkyo-ku, Tokyo Organo Corporation ( 72) Inventor Nobuyuki Kojima 5-5-1, Hongo, Bunkyo-ku, Tokyo Organo Co., Ltd. (72) Inventor Shinji Asada 2-4-2, Kyomachibori, Nishi-ku, Osaka-shi, Osaka Inside Chugai Furnace Industry Co., Ltd. 72) Inventor Makoto Inoue 2-4-7 Kyomachibori, Nishi-ku, Osaka-shi, Osaka Inside Chugai Furnace Industry Co., Ltd. (72) Inventor Masao Nonohiro 2-chome, Kyomachibori, Nishi-ku, Osaka-shi, Osaka No.4-7 Inside Chugai Furnace Industry Co., Ltd. (56) References JP-A-61-46812 (JP, A) JP-A-50-31676 (JP, A) JP-A-52-152650 (JP, A) JP-A-52-68767 (JP, A) JP-A-60-28898 (JP, A) JP-A-3-241085 (JP, A) JP-B-38-16392 (JP, B1) JP-B-49-4073 ( JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 7/00 104 F23G 7/00 ZAB C02F 11/06 ZAB F23G 5/02 ZAB F23G 5/50 ZAB

Claims (2)

(57) [Claims] 1. A concentration step for obtaining, from a liquid organic sludge, a concentrated liquid having a high solid content, a dilute liquid having a low solid content or substantially no solid content, and a concentration step obtained in the concentration step. A step of burning the liquid in a combustion furnace, measuring the water content and / or viscosity of the concentrated liquid, adjusting the concentration of the liquid organic sludge in the concentrated step based on the measured values, A method for burning liquid organic sludge, comprising forming a combustion flame having a temperature equal to or higher than the melting temperature of inorganic substances contained in liquid organic sludge in the step. 2. The method according to claim 1, wherein the liquid organic sludge is obtained by dehydrating an organic sludge and subjecting the dehydrated sludge to a high-temperature and high-pressure treatment.