JPH07145920A - Low-concentration oily waste water incinerating method - Google Patents

Abstract

PURPOSE:To incinerate waste water containing oil at a low concentration at high efficiency with a little stabilizing fuel in a rotary kiln-type incinerator. CONSTITUTION:When waste water containing oil of a low concentration of 1 to 10% is incinerated by a rotary kiln-type incinerator, the oily waste water is sprayed in the form of coarse particles having a diameter of 0.2 to 2.0mm, and flames of a stabilizing burner for the oily waste water are brought into contact with the kiln inner wall, and the waste water is incinerated by being dropped on the wall surface locally kept at high temperatures. Thereby, decrease of stabilizing fuel is made possible by keeping only the limited narrow range at high temperatures by the wall surface combustion, moreover the miniaturization of the facility is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for incinerating low-concentration oil-containing waste water such as cold-rolled coolant waste water in a waste oil incinerator.

[0002]

2. Description of the Related Art FIG. 1 shows a rotary kiln type incinerator which is often used for incineration of oil-containing wastewater. Reference numeral 1 is a spray combustion burner for oil-containing waste water, and the oil-containing waste water is stored in a tank 11 and pumped to the burner by a pump 13.
In the burner, compressed air from the compressor 12 is sprayed into the kiln 3. In order to evaporate the water content of the sprayed oil-containing wastewater and incinerate the oil content, it is necessary to keep the inside of the kiln at a high temperature by the auxiliary combustion burner 2, and the wastewater with less oil content requires more fuel.

In general, finer water droplets (generally 0.1 mm or less) are better for improving combustion efficiency, but if the oil content is 5% or less, the water content is completely evaporated and combustion of the oil content is completed. Since it takes about 3 seconds, the kiln length must be lengthened. 9 is a blower for fuel air of auxiliary fuel, 10
Is a fuel supply pipe. In order to completely burn the incinerator exhaust gas that has left the kiln, after removing the dust in the exhaust gas with the dust collector 6 through the secondary incinerator 4 and exhaust gas cooling 5 etc.
It is discharged from the chimney 8 by the exhaust fan 7.

As an existing method suitable for this, for example, as shown in Japanese Patent Application Laid-Open No. 4-52413, at the same time as the treatment water, a heating medium such as a small ball made of ceramics is simultaneously sprayed so that the treatment water in the liquid state and the heat treatment are heated. For example, a method of mixing the media, bringing the treated water into contact with a heat medium heated to a high temperature, and rapidly completely burning the water is observed.

[0005]

In the conventional method for incinerating oil-containing wastewater, it takes a long time for the water content to completely evaporate and the oil content to complete the combustion, thus requiring a large amount of auxiliary fuel for combustion and the kiln. It has the drawback of having to lengthen the furnace,
Further, if the method of Japanese Patent Laid-Open No. 4-52413 is applied to the kiln system, it is necessary to add equipment for collection, spraying, sorting, etc., which is not preferable. Therefore, the present invention intends to efficiently incinerate low-concentration oil-containing wastewater of 10% or less, which required a large amount of auxiliary fuel and a long kiln furnace in the conventional incineration method.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to incinerate low-concentration oil-containing wastewater of 1-10% in a rotary kiln type incinerator at a low concentration of 0.2-2.0 mm.
The method for incinerating low-concentration oil-containing wastewater is characterized in that the low-concentration oil-containing wastewater is sprayed in an incinerator with a coarse particle size of No. 1, and the atomized low-concentration oil-containing wastewater is dropped into contact with a high-temperature wall surface for incineration. That is, according to the present invention, the inner wall surface of the kiln is heated to a high temperature, and the low-concentration waste oil is 0.2 to 2.0 m.
By spraying and dropping to a coarse particle size of m, a large amount of waste oil can be treated in a small combustion chamber.

[0007]

The operation of the present invention will be described with reference to FIGS. Figure 2
Is a conventional method, 2 is an auxiliary burner, and 1 is an oil-containing wastewater spray burner. For the spray particles 15 of the waste water, a method of incinerating the inside of the kiln just by using it is used. FIG. 3 shows the method of the present invention in which the spray particles 15 of waste water are 0.2 to 2.0 mm.
It is made into coarse particles and dropped onto the inner wall of the kiln. The flame of the auxiliary burner 2 is arranged so as to come into contact with the inner wall of the kiln so as to locally keep the temperature high.

That is, by making the spray particles of the wastewater into a specific coarse particle, the spray particles are lowered to the inner wall of the kiln, and the inner wall of the kiln on which the spray particles are dropped is heated to a high temperature by the flame of the auxiliary combustion burner, and a local wall surface is formed. By burning, the oil-containing wastewater is efficiently burned. The reason why the spray particle size of 0.2 to 2.0 mm is suitable is 0.2 mm.
If it is less than, there is a risk that it will not fall to the inner wall near the auxiliary combustion burner and will be discharged from the kiln along with the exhaust gas flow.
On the other hand, if it is larger than 2.0 mm, it takes time for the water to evaporate when it falls on the inner wall, so that the temperature of the inner wall is lowered and the oil is not promptly incinerated. As shown in FIG. 4, it is practical to newly add an auxiliary burner 14 for heating the inner wall. If there is a relatively high oil content wastewater containing 15% or more of oil content, it is also effective to use this as the fuel for the auxiliary burner 14.

Next, the means for adjusting the coarse particle size of the oil-containing wastewater in the present invention will be described. Atomized air pressure is 0.1 to 3.0 kg /
A particle size of 0.2 to 2.0 mm can be obtained by adjusting the spraying to cm ² . That is, the present inventors photographed the atomized particle size ejected at an atomizing air pressure of 0.1 to 0.3 kg / cm ² with a video camera, and analyzed the imaged content to find that the atomized particle size was 0. It was confirmed to be within the range of 0.2 to 2.0 mm. In the present invention, the low-concentration oil-containing wastewater is intended for those having an oil content of 1 to 10%, and the oil-containing wastewater having an oil content of more than 10% is 0.2 to 2.0.
Combustion is sufficiently possible without using a coarse particle size of mm. Therefore, the present invention is intended for waste water containing 1 to 10% oil.

[0010]

【Example】

[0011]

[Table 1]

[0012] In the incinerator shown in Table 1, the rolling coolant wastewater was subjected to spray combustion according to the present invention. As shown in Table 2, the auxiliary fuel for complete incineration could be greatly reduced by the method of the present invention. Conversely, with the same fuel, 2.
Incineration capacity has been improved by a factor of zero.

[0013]

[Table 2]

[0014]

【The invention's effect】

(1) Compared with the conventional method, since the combustion is performed on the wall surface, it is only necessary to keep the temperature at a high temperature in a limited narrow area of the kiln, so that the fuel for supporting combustion can be reduced. (2) Since the length of the kiln is short, the equipment can be downsized.

[Brief description of drawings]

[Figure 1] Illustration of a rotary kiln type incinerator

FIG. 2 is an explanatory view showing a method for incinerating contained wastewater by a conventional method.

FIG. 3 is an explanatory view of an embodiment showing an incineration method of low-concentration oil-containing wastewater according to the present invention.

FIG. 4 is an explanatory diagram of another embodiment showing the method for incinerating low-concentration oil-containing wastewater according to the present invention.

[Explanation of symbols] 1 spray combustion burner 2 auxiliary combustion burner 3 kiln 4 secondary incinerator 5 exhaust gas cooling 6 dust collector 7 exhaust fan 8 chimney 9 blower 10 fuel supply pipe 11 tank 12 compressor 13 pump 14 auxiliary burner 15 spray particles

Claims (1)

[Claims] 1. A rotary kiln incinerator for 1 to 10
% Of low-concentration oil-containing wastewater is incinerated, the low-concentration oil-containing wastewater is made into a coarse particle size of 0.2 to 2.0 mm and sprayed into an incinerator, and the atomized low-concentration oil-containing wastewater is dropped onto a high temperature wall surface. A method for incinerating low-concentration oil-containing wastewater, which comprises incinerating it.