JP2001033027A - Method and apparatus for preventing adherence of dust of waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adherence of a dust in a gas due to a temperature drop of generated gas to an accessory equipment by blowing a cooling water atomized by a vapor or the like from an exhaust gas duct of a waste melting furnace. SOLUTION: A cooling water suction port 13 for blowing a cooling water atomized by a vapor or inert gas into generated gas is provided in an exhaust gas duct immediately after a waste melting furnace. Temperature detecting means 14, 15 are respectively provided at upstream and downstream of the port 13. A scattered water amount of the water is regulated by scattered water amount blown from the port 13 and a result obtained by the means 14 of the downstream side of the port 13, and a generated gas temperature is lowered to an optimum temperature. Thus, the temperature of the generated gas blown directly into the generated gas atomized by the vapor or the inert gas to the water is controlled, and hence a stable operation can be performed for a long period without adhering the dust in the generated gas to the exhaust gas duct.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the prevention of dust adhesion in a waste melting furnace for preventing the dust generated from a waste melting furnace for thermally decomposing and melting waste such as general waste and industrial waste. A method and an apparatus therefor.

[0002]

2. Description of the Related Art General wastes, industrial wastes, and intermediate treatments obtained by drying, incineration, crushing, and the like thereof (incineration ash and landfill waste containing sediment that has been once excavated and then excavated again. As a method for disposing of waste such as sludge, there is known a method for disposing and melting waste in a melting furnace by drying, preheating, pyrolyzing, burning, melting, and extracting it as slag or metal.

FIG. 2 is an overall view of a conventional waste melting and embedding facility, in which waste is transferred from a waste pit 1 to a waste crane 2.
Is charged from the upper part of the shaft furnace type pyrolysis melting furnace,
Limestone or coke is charged from the auxiliary raw material storage tank 3 as an auxiliary raw material. Oxygen-containing gas or oxygen-enriched gas is blown from the tuyere 4 at the furnace bottom, or air is blown from the tuyere 5 above the gas. The carbonaceous matter generated by coke and pyrolysis is burned at a high temperature in a high-temperature hearth, and sequentially passed through a drying zone, a pyrolysis zone and a combustion melting zone in the furnace to form molten slag. The fuel is burned in the secondary combustion chamber 6, heat is recovered in the waste heat recovery wheel 7, cooled in the gas cooling tower 8, neutralized with a neutralizing agent such as slaked lime, and separated into solid and gas in the dust collector 9. The air is discharged from the chimney 11 by the induced draft fan 10.

[0004]

The gas generated from a shaft furnace type pyrolysis melting furnace or pyrolysis furnace contains a large amount of dust. However, these gases contain a large amount of salts such as chlorides and sulfides. Dust in gas is high temperature (600-800
(° C), it becomes a molten or semi-molten state, adheres to the duct and its accessories, and grows. Therefore, there is a problem that stable operation cannot be performed for a long period of time due to the shutdown of the equipment due to the adhesion and the maintenance and inspection of the duct and its attached devices.

[0005] Therefore, the present invention is to reduce the temperature of the gas generated in the waste melting furnace, so that the dust contained in the gas becomes molten or semi-molten and adheres to the exhaust gas duct and its attached equipment. The present invention provides a method and apparatus for preventing dust from adhering to a waste melting furnace.

[0006]

According to the present invention, there is provided a method for preventing dust deposition in a waste melting furnace, wherein cooling water atomized by steam or an inert gas is blown into generated gas from an exhaust gas duct immediately after the waste melting furnace. Thereby, the temperature of the generated gas is reduced.

Further, according to the present invention, there is provided a dust melting prevention apparatus for a waste melting furnace, wherein a cooling water blown into a generated gas by spraying cooling water atomized by steam or an inert gas into an exhaust gas duct immediately after the waste melting furnace. And a temperature detecting means provided upstream and downstream of the cooling water blowing port.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention makes it possible to prevent dust contained in a generated gas from adhering to and growing on a duct of the generated gas and its attached equipment by lowering the temperature of the generated gas. . Further, by lowering the temperature of the generated gas by the latent heat of vaporization, the gas volume is reduced, the collision force of dust at a bent portion or the like is reduced, and dust adhesion is prevented. Therefore, by blowing the cooling water atomized by steam or an inert gas directly into the generated gas, the temperature of the generated gas is reduced by using the heat of evaporation to 400 to 400 ° C, which is lower than the temperature at which the dust becomes a semi-molten state. By lowering the temperature to 500 ° C. or less, stable operation without blockage of the exhaust gas duct becomes possible. The spray direction is desirably the same as the generated gas flow.

By arranging the temperature detecting means at or before and after the furnace outlet, the temperature of the generated gas is detected at an early stage, and the cooling water atomized by steam or an inert gas is directly blown into the generated gas. Start. The degree of control is adjusted based on the amount of water sprayed from the cooling water inlet and the result obtained by the temperature detector for measuring the wake of the cooling water inlet to control the generated gas temperature to an optimum temperature.

FIG. 1 is an explanatory view of an apparatus for preventing dust adhesion in a waste melting furnace according to the present invention. In the waste melting furnace, the same components as those described in FIG. I do.

In the exhaust gas duct 12 immediately after the waste melting furnace,
A cooling water inlet 13 is provided in the exhaust gas duct for blowing cooling water atomized by steam or an inert gas into the generated gas. Temperature detecting means 14 and 15 are provided upstream and downstream of the cooling water inlet 13. Based on the amount of water sprayed from the cooling water inlet and the result obtained by the temperature detecting means 14 measured downstream of the cooling water inlet, the amount of water sprayed on the cooling water is adjusted to lower the generated gas temperature to an optimum temperature. .

Table 1 shows the exhaust gas amount and the exhaust gas temperature depending on whether or not water is sprayed.

[0013]

[Table 1] From Table 1, water spray reduces the temperature of the exhaust gas to a temperature of 400 ° C. lower than the temperature at which the dust is in a semi-molten state,
It can be seen that the gas volume has decreased.

[0014]

According to the present invention, the dust in the generated gas is discharged to the exhaust gas duct by controlling the temperature of the generated gas by directly blowing the cooling water atomized by steam or an inert gas into the generated gas. There is no sticking, and stable operation can be performed for a long time.

Further, by controlling the temperature of the generated gas, the flow rate of the generated gas can be optimized, so that the diameter of the exhaust gas duct can be set to a minimum, and the layout and maintenance become easy.

Furthermore, since the temperature of the generated gas is not controlled by controlling the process in the furnace but directly applied to the generated gas, the temperature can be controlled without a time difference. In addition, by optimizing the position of the temperature control mechanism and temperature detection means,
The operation of the generated gas temperature control device can be easily automated, and the spray amount control method can be used for both ON / OFF operation and flow rate control operation.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a dust adhesion preventing device of a waste melting furnace of the present invention.

FIG. 2 is a schematic view of a conventional waste melting treatment facility.

[Explanation of symbols]

 1: Waste pit 2: Waste crane 3: Secondary material storage tank 4: Furnace low tuyere 5: Tuyere 6: Combustion chamber 7: Boiler 8: Gas cooling tower 9: Dust collector 10: Induction ventilator 11: Chimney 12 : Exhaust gas duct 13: Cooling water inlet 14, 15: Temperature detecting means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsumasa Todaka 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu Nippon Steel Plant Design Co., Ltd. F-term (reference) DB22 EA06

Claims (2)

[Claims] 1. A waste melting method characterized by lowering the temperature of a generated gas by blowing cooling water atomized by steam or an inert gas into the generated gas from an exhaust gas duct immediately after a waste melting furnace. A method for preventing dust from adhering to the furnace. 2. A cooling water injection port for blowing cooling water atomized by steam or an inert gas into a generated gas is provided in an exhaust gas duct immediately after a waste melting furnace, and a temperature upstream and downstream of the cooling water injection port is provided. An apparatus for preventing dust from adhering to a waste melting furnace, comprising a detection means.