JP2965489B2 - Waste incineration 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 waste incineration method used for incinerating waste such as sewage sludge dewatered cakes and various industrial wastes.

[0002]

2. Description of the Related Art A fluidized-bed furnace has been widely used for incineration of wastes as described above, and recently, a high-speed circulating fluidized-bed furnace in which the combustion speed has been improved by increasing the gas flow rate in the furnace has also been used. Have been. In this high-speed circulation type fluidized-bed furnace, the scattered fluidized medium is recovered by a cyclone or the like, and then returned to the inside of the furnace.

[0003] By the way, incineration of waste in a high-speed circulating fluidized-bed furnace as described above is generally carried out by a method in which waste is put into a fluidized bed from an inlet of a side wall of a furnace body. Since the waste introduced into the furnace is instantaneously dried, crushed, and incinerated by contact with the fluidized medium, if the amount of waste input per hour is not constant, a certain amount of air is supplied. Combustion takes place in the fluidized bed)
There is a problem that harmful gases such as CO are easily generated.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, enables stable combustion even when the amount of waste input fluctuates, and reduces generation of harmful gases such as CO. The purpose of the present invention is to provide a waste incineration method capable of reducing the burden on the exhaust gas treatment equipment at a minimum.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention is directed to sandwiching input waste into a layer by a circulating high-temperature fluid medium in a high-speed circulating fluidized-bed furnace. While being dried and thermally decomposed, it is transported and burned.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In FIG. 1, reference numeral 1 denotes a furnace body of a high-speed circulation type fluidized furnace. The average flow velocity in the furnace of this high-speed circulation type fluidized furnace is 5 to 8
m / sec, and the temperature is about 800-900 ° C. 4
Is a hot cyclone provided near the upper part of the furnace body 1, and is a high-temperature fluid medium 5 scattered from the high-speed circulation type fluidizing section 2.
And the separated exhaust gas is sent to an exhaust gas treatment facility 6.

[0007] A cushion hopper 7 is provided below the hot cyclone 4 to temporarily store the high-temperature fluid medium 5 recovered by the hot cyclone 4, and through a valve 8 to a lower thermal decomposition section. 9 at the top. In this part, the fluid medium 5
It maintains a high temperature of about 800-900 ° C.

A waste inlet 10 is provided in the upper side wall of the thermal decomposition section 9 to receive waste 11 such as sewage sludge dewatered cake and various industrial wastes. By adjusting the timing of charging the waste 11 and the timing of opening and closing the valve 8, the waste 11 can be heated as shown in FIG.
Between the layers. The lower end of the pyrolysis section 9 communicates with the lower portion of the furnace body 1 of the high-speed circulation type flow section 2, and the fluid medium 5 in the pyrolysis section 9 and the waste 11 inserted therein are gradually circulated at high speed. It is transported toward the formula flow section 2. The means for this transfer is not particularly limited, and may be by gravity, mechanical transfer means, or a method utilizing fluid pressure.

The waste material 11 sandwiched between the high-temperature fluid mediums 5 is dried by the heat of the high-temperature fluid medium 5 while gradually moving inside the pyrolysis section 9.
It is decomposed in an oxygen-deficient state and simultaneously generates pyrolysis gas. The pyrolysis gas passes through the gap in the fluid medium 5 and reaches the upper portion of the pyrolysis section 9, is supplied to the high-speed circulation type flow section 2 through the degassing pipe 12, and is burned. Since the pyrolysis gas is completely burned by the free board, there is no possibility of generating harmful gases such as CO. On the other hand, the pyrolysis product of the remaining waste 11 that has released the pyrolysis gas is transferred to the lower part of the furnace body 1 and is flow-combusted in the high-speed circulation type flow section 2.

As described above, according to the waste incineration method of the present invention, the waste 11 is transported to the high-speed circulating flow section 2 and burned while being thermally decomposed by being inserted into the layer with the high-temperature fluid medium 5 and thermally decomposed. As a result, the waste 11 can be efficiently thermally decomposed by the retained heat of the high temperature fluid medium 5, and the pyrolysis gas can be gas-burned. CO for this
There is no risk of generating harmful gases such as Therefore, the exhaust gas can be made clean, and the burden on the exhaust gas treatment equipment can be reduced.

Further, according to the waste incineration method of the present invention, the waste is not directly charged into the furnace as in the prior art, but is burned after passing through the thermal decomposition section 9. For this reason, the waste 11 is sent to the lower part of the furnace 1 of the high-speed circulating flow section 2 in a state where it is sufficiently heated and dried. Fluctuations in the operating conditions of the furnace are reduced, and stable furnace operation is possible.

[0012]

As described above, according to the waste incineration method of the present invention, it is possible to incinerate waste such as sewage sludge dewatered cake and various industrial wastes without generating harmful gases such as CO. Thus, there is an advantage that the burden on the exhaust gas treatment equipment can be reduced, and stable combustion can be performed even when the amount of waste input varies.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention.

[Explanation of symbols]

1 Furnace body, 2 High-speed circulation type fluidizing section, 4 Hot cyclone, 5 Fluid medium, 6 Exhaust gas treatment equipment, 7 Cushion hopper, 8 Valve, 9 Thermal decomposition section, 10 Waste inlet, 11 Waste, 12 Gas vent pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23G 5/30 ZAB F23G 5/50 ZAB

Claims (1)

(57) [Claims] 1. A method of transporting and burning while drying and thermally decomposing a waste that is put in a layered manner by a hot fluid medium circulating in a high-speed circulation type fluidized furnace. Waste incineration method.