JPH11287412A - Internal melt furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance melt treatment capacity by a method wherein a molten slug reservoir of an ash melt part bottom is deepened to generate a quantity of molten slug and incinerated ash is completely molten. SOLUTION: In an internal melt furnace to melt by the combustion generation heat of a combustible content in ash serving as a main melt heat source, the internal melt furnace 1 consists of a combustion part 2, an ash melt part 3, and a slug cooling part 8. The combustion part 2 comprises an incinerated ash storage tank 6; and a furnace bed 5 connected to the lower part of the incinerated ash storage tank 6 and provided at a bottom with a combustion air nozzle 4. The ash melt part 3 is formed in a horizontal cylindrical state and the furnace bed 5 of the combustion part 2 is connected in the direction of a tangential line to one end of the bottom of the ash melt part 3 and an assist device 9 is connected in the tangential line direction of the ash melt part 3. A swirl flow of combustion gas 10 is formed in the ash melt part 3 and the molten slug reservoir 3a for molten slug 13 is formed in the bottom of the ash melt part 3. In a so formed internal part melt furnace 1, a horizontal cylindrical assist melt part 14 having a radius smaller than that of the ash melt part 3 and provided at a lower end with a gutter part 15 is interposed between the ash melt part 3 and a slug cooling part 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal melting furnace for melting incinerated ash and the like containing unburned components discharged from municipal waste incinerators and various incinerators.

[0002]

2. Description of the Related Art Waste such as municipal solid waste and sewage sludge has been incinerated in an incineration facility, and the resulting incinerated ash and dust have been conventionally disposed of in landfills. However, due to the problem of depletion of landfill sites and the problem of groundwater pollution due to elution of harmful heavy metals, the necessity of weight reduction, volume reduction and detoxification by melting is increasing.

[0003] From such a background, when incinerating refuse in a refuse incinerator, the refuse is suppressed and burned (gasification and pyrolysis) to leave unburned ash in the incinerated ash, and the incinerated ash containing the unburned ash is contained. Is burned in the ash melting furnace on the downstream side, and an internal melting furnace that reduces the amount of heat supplied from the outside by using the heat generated by the combustion as the main heat source of ash has been proposed. ing.

[0004] In this internal melting furnace, the inside of the furnace is kept at a high temperature by the heat of combustion of the unburned portion contained in the incineration ash and the heat of a combustion assist device such as a kerosene burner, and the radiant heat from the furnace walls and the gas from the furnace gas are used. Melt incineration ash by convective heat transfer. The molten slag is
The slag is continuously discharged, falls into a slag cooling section provided on the downstream side, is rapidly cooled and solidified into water-cooled slag, and is then conveyed to a slag pit by a conveyor. The air that burns the unburned components in the incineration ash is heated by steam or exhaust gas from the internal melting furnace, and then supplied to the combustion air nozzle as high-temperature air. The furnace wall facing the melting portion of the internal melting furnace has a water-cooled wall structure in order to suppress melting damage caused by fly ash and the like.

[0005] However, in the above internal melting furnace, if the amount of ash discharged from the refuse incinerator and the amount of ash to be melted in the melting furnace are not balanced, unmelted slag in the molten slag due to excessive ash on the melting furnace side. Ash may be mixed.

In order to solve these problems, the applicant of the present application melts the ash by means of a water pool even if unmelted ash is mixed due to an excessive amount of ash on the melting furnace side, and generates combustion gas by a swirling flow. Of an internal melting furnace designed to improve the melting processing capacity by increasing the residence time in the furnace and increasing the combustion efficiency in the furnace, and filed a patent application (Japanese Patent Application No. Hei 9 (1998) -108).
-224791 (not disclosed)).

FIGS. 6 and 7 show Japanese Patent Application No. 9-22479.
1 relates to the internal melting furnace, FIG. 6 is a sectional view thereof, and FIG. 7 is a view taken along the line AA of FIG. In the figure, reference numeral 1 denotes an internal melting furnace including a combustion section 2 and an ash melting section 3. The combustion unit 2 includes an incineration ash storage tank 6 and an incineration ash storage tank 6.
And a pusher 7 that pushes out the incineration ash 12 in the incineration ash storage tank 6 to the hearth 5. The ash fusion part 3 has a laterally cylindrical shape, and the hearth 5 of the combustion part 2 is tangentially connected to one end of the bottom of the ash fusion part 3, and the other end of the ash fusion part 3 is connected to the slag cooling part 8. An auxiliary combustion device 9 is connected in a tangential direction of one end of the upper part of the ash fusion part 3 which is connected. A swirling flow 11 of the combustion gas 10 is formed in the ash fusion part 3, and a pool 3 a of the molten slag 13 is formed at the bottom of the ash fusion part 3.

[0008]

However, in the internal melting furnace disclosed in Japanese Patent Application No. Hei 9-224791, the depth of the molten slag is reduced because the pool is formed along the arc surface at the bottom of the molten portion. It is shallow and not always sufficient to melt unmolten ash.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an internal melting device in which a water pool at the bottom of a melting furnace is formed deep and an area of a water cooling wall structure portion is reduced. It is intended to provide a furnace.

[0010]

According to the present invention, in order to achieve the above object, incinerated ash containing unburned components and RDF is melted using the heat generated by combustion of the combustible components in the ash as a main heat source of fusion. An internal melting furnace, which includes a combustion section, an ash melting section, and a slag cooling section, and the combustion section is connected to an incineration ash storage tank and a lower portion of the incineration ash storage tank, and has a combustion air nozzle at a bottom portion. Hearth, and a pusher that pushes out the incineration ash in the incineration ash storage tank to the hearth, the ash melting part has a cylindrical shape in a horizontal direction, and the hearth of the combustion part is at one end of the bottom of the ash melting part. A tangential connection, an auxiliary combustion device is connected tangentially to one end of the ash fusion part, a swirling flow of combustion gas is formed in the ash fusion part, and a molten slag pool is formed at the bottom of the ash fusion part. In the melting furnace, a half of the ash melting part is located between the ash melting part and the slag cooling part. Small, has a trough portion at the lower end, and an internal melting furnace is interposed lateral cylindrical auxiliary melting portion was formed to be flush with the trough bottom face and the ash melting portion bottom is provided. Note that RDF is a solidified fuel.

According to another embodiment of the present invention, there is provided an internal melting furnace for melting incinerated ash containing unburned components and RDF using heat generated by combustion of combustible components in the ash as a main melting heat source. The internal melting furnace is composed of a combustion part, an ash melting part, and a slag cooling part.The combustion part is connected to a lower part of the incineration ash storage tank, a hearth having a combustion air nozzle at a bottom part, and an incineration ash storage tank. A pusher that pushes out the incinerated ash to the hearth, the ash melting part has a laterally cylindrical shape, and the hearth of the combustion part is tangentially connected to one end of the bottom of the ash melting part, The other end of the section is connected to the slag cooling section, and a combustion assist device is connected in a tangential direction of one end of the ash melting section, forming a swirling flow of combustion gas in the ash melting section, and forming a swirl flow of the molten slag at the bottom of the ash melting section. An opening at the lower end in the middle of the ash melting part in an internal melting furnace with a water pool formed Internal melting furnace fitted in the ring is provided.

Next, the operation of the present invention will be described. The incinerated ash containing unburned matter discharged from the refuse incinerator is pushed out of the incinerated ash storage tank by the pusher to the hearth of the combustion section. The extruded incineration ash burns unburned components by the high-temperature air jetted from the combustion air nozzles on the hearth, and is melted by the heat to form molten slag, which flows down from the hearth to the ash melting part on the downstream side. I do. This molten slag contains unmelted ash that is not completely melted, and fly ash is contained in the combustion gas from the combustion part, but the combustion gas from the combustion part is contained in the ash fusion part. A swirling flow is formed by the combustion gas from the combustion assist device and the unmelted ash and fly ash are melted while swirling along the cylindrical inner wall of the ash melting portion by the swirling flow. At this time, even if the unmelted ash is extruded in a solidified state, the flow of the molten slag is limited because the small-diameter auxiliary combustion portion having a shank at the bottom and a ring having an opening at the lower end are internally fitted, and the ash melting portion A large amount of molten slag is stored at the bottom, and the ash comes into contact with the molten slag and melts. Further, since the combustion gas swirls in the cylindrical ash melting portion, the residence time in the furnace is lengthened, the ash can be completely melted, and the melting processing ability is improved. Since molten slag hardly adheres to the furnace wall on the downstream side of the auxiliary combustion section and the ring, there is no need for a water cooling wall, and the heat loss is small. The molten slag falls into the slag cooling section and solidifies rapidly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 to 3
1 shows an embodiment of the present invention, and FIG. 1 is a perspective view of an internal melting furnace according to the present invention. FIG. 2 is a side view of FIG. 1, and FIG. 3 is a view taken in the direction of arrows BB in FIG. Members common to the internal melting furnace described with reference to FIGS. 6 and 7 will be described using the same reference numerals.

In the figure, reference numeral 1 denotes incinerated ash 1 containing unburned components.
2 is an internal melting furnace for melting processing. This internal melting furnace 1
Is composed of a combustion section 2, an ash melting section 3, and a slag cooling section 8.

The combustion section 2 includes an incineration ash storage tank 6, a hearth 5 connected to a lower portion of the incineration ash storage tank 6 and having a combustion air nozzle 4 disposed at the bottom, and an incineration ash 12 in the incineration ash storage tank 6. And a pusher 7 for extruding the floor 5. Further, the combustion air nozzle 4 has a large number of air holes, and a plurality of combustion air nozzles are provided.

The ash fusion part 3 has a cylindrical shape in a horizontal direction, and one end of the bottom of the ash fusion part 3 is connected to the hearth 5. 3a is a molten slag 1 formed at the bottom of the ash fusion portion 3.
It is the third pool. An auxiliary burner 9 such as a heating burner or plasma is connected in a tangential direction at one end of the ash melting portion 3.
10 is a combustion gas, and 11 is a swirling flow of the combustion gas 10. Reference numeral 13 denotes a molten slag, and 13a denotes a cooling slag cooled in the slag cooling unit 8.

Reference numeral 14 denotes one end of the ash melting section 3 and the slag cooling section 8
The auxiliary melting portion interposed between the slag discharging portion 16 and the slag discharging portion 16. The auxiliary melting portion has a smaller radius than the ash melting portion 3 and has a concave shank
have. Further, the auxiliary melting part 14 is
5 and the bottom surface of the ash fusion part 3 are made to be on the same plane.

Reference numeral 17 denotes an exhaust gas discharge pipe provided in the middle of the slag discharge section 16.

Next, the operation of the embodiment of the present invention will be described. The incinerated ash 12 containing unburned components discharged from the refuse incinerator is pushed out from the incinerated ash storage tank 6 to the hearth 5 of the combustion unit 2 by the pusher 7. The extruded incineration ash 12 burns unburned components by the high-temperature air jetted from the combustion air nozzle 4 on the hearth 5 and is melted by the heat to form a molten slag 13, which is downstream from the hearth 5. Down to the ash fusion zone 3 The molten slag 13 contains unmelted ash that is not completely melted, and the combustion gas from the combustion section 2 contains fly ash. 2
The swirling flow 11 is formed by the combustion gas 10 from the combustion gas and the combustion gas from the auxiliary combustion device 9, and the unmelted ash and fly ash are swirled along the cylindrical furnace inner wall of the ash melting part 3 by the swirling flow 11. While melting. At this time, even if the unmelted ash is extruded in a solidified state, the small-diameter auxiliary combustion portion 14 having the shaving portion 15 at the bottom and the ring 18 having the opening at the lower end are formed.
, The flow of the molten slag 13 is restricted, and a large amount of the molten slag 13 is accumulated at the bottom of the ash fusion part 3.
The ash touches the molten slag 13 and melts. Further, since the combustion gas 10 swirls in the cylindrical ash melting portion 3, the residence time in the furnace is lengthened, the ash can be completely melted, and the melting processing ability is improved. Since the molten slag 13 hardly adheres to the furnace wall on the downstream side of the auxiliary combustion section 14 and the ring 18, there is no need for a water cooling wall and the amount of heat loss is small. The molten slag 13 falls into the slag cooling section 8 and solidifies rapidly.

FIGS. 4 and 5 show another embodiment of the present invention. FIG. 4 is a side view of the internal melting furnace.
FIG. 6 is a sectional view taken along line BB of FIG. 4. In the figure, reference numeral 18 denotes a ring which is fitted in the middle of the cylindrical ash fusion part 3 and has an opening 18a at the lower end, and a large amount of molten slag 13 is introduced into the ash fusion part 3 on the upstream side of the ring 18. Let it stay. The other configuration is the same as that of the internal melting furnace shown in FIGS. 1 to 3, and redundant description will be omitted.

The present invention is not limited to the above-described embodiment. In the above-described embodiment, the description has been given of the melting of incinerated ash containing unburned components. Is a solid waste fuel (RDF (Refused Deri)
Of course, various changes can be made without departing from the gist of the present invention, for example, by using ved Full)) as a heat source for melting ash.

[0022]

As described above, according to the present invention, a large amount of molten slag is retained in the sump at the bottom of the ash fusion zone, so that unburned ash can be completely burned. Excellent effects such as the area of the water-cooling wall structure can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an internal melting furnace according to the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 4 is a side view of an internal melting furnace according to another embodiment of the present invention.

FIG. 5 is a view taken in the direction of the arrows CC in FIG. 4;

FIG. 6 is a side sectional view of an internal melting furnace disclosed in Japanese Patent Application No. 9-224791.

FIG. 7 is a view on arrow AA of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal melting furnace 2 Burning part 3 Ash melting part 3a Hot water 4 Burning air nozzle 5 Hearth 6 Incineration ash storage tank 7 Pusher 8 Slag cooling part 9 Burning aid 10 Combustion gas 11 Swirling flow 12 Burning ash 13 Melting slag 14 Auxiliary melting part 15 Sharp part 16 Slag discharge part 17 Exhaust gas discharge pipe 18 Ring 18a Opening

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23G 7/00 103 B09B 3/00 ZAB F23J 1/00 303L

Claims (2)

[Claims] 1. An internal melting furnace for melting incinerated ash containing unburned components and RDF using heat generated by combustion of combustible components in the ash as a main heat source of fusion, wherein the internal melting furnace comprises a combustion part and an ash. Composed of a melting section and a slag cooling section, the combustion section is an incineration ash storage tank, a hearth connected to the bottom of the incineration ash storage tank and having a combustion air nozzle at the bottom, and extruding incineration ash in the incineration ash storage tank to the hearth. The ash melting portion is formed in a laterally cylindrical shape, and the hearth of the combustion portion is tangentially connected to one end of the ash melting portion bottom, and the ash melting portion is tangentially connected to one end of the ash melting portion. Are connected to each other to form a swirling flow of the combustion gas in the ash melting part and form a pool of molten slag at the bottom of the ash melting part. Radius smaller than the fusion zone, with a sharp end at the lower end, and ash fusion with the bottom of the sharp end An internal melting furnace characterized by interposing a horizontal cylindrical auxiliary melting portion having the same bottom surface as the surface. 2. An internal melting furnace for melting incinerated ash containing unburned components and RDF using heat generated by combustion of combustible components in the ash as a main melting heat source. Composed of a melting section and a slag cooling section, the combustion section is an incineration ash storage tank, a hearth connected to the bottom of the incineration ash storage tank and having a combustion air nozzle at the bottom, and extruding incineration ash in the incineration ash storage tank to the hearth. The ash melting part has a cylindrical shape in a horizontal direction, the hearth of the combustion part is tangentially connected to one end of the bottom of the ash melting part, and the other end of the ash melting part is connected to the slag cooling part. In an internal melting furnace in which an auxiliary combustion device is connected in the tangential direction of one end of the ash melting portion and forms a swirling flow of the combustion gas in the ash melting portion, and a molten slag pool is formed at the bottom of the ash melting portion. In the middle of the ash fusion part, a ring with an opening at the lower end is fitted inside Internal melting furnace.