JPS6033419A - Disposal device for incineration slag - Google Patents

Abstract

PURPOSE:To prevent a melt slag from adhering to and solidifying on a grate, and thereby allowing for a continuous operation, while at the same time substantially reducing a fuel cost remarkably by burning and melting from inside a slag layer with the temperature retained by the slag layer. CONSTITUTION:An incineration slag N containing unburned carbons is stacked on a grate 20 and falls towards the inclining direction as a moving layer 11 over the grate. On the other hand, a burning air with an elevated temperature is supplied to an air box 27 via a burning air supply tube 30, and wherefrom to a moving layer through a burning air spousing port 31 defined in the overlapped portion of grate 20, and thereby burning unburned carbons and the accompnaying heat is utilized to melt an incineration ash. An air is thus supplied in a parallel fashion from the lower portion of slag to the moving layer directly. The slag thus can be burnt from its internal portion, radiating less amount of heat. Therefore, a burning heat may be retained in the moving layer so that it may be effectively utilized form melting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an incineration residue processing device for melting incineration residue discharged from an incinerator, and in particular aims to accelerate the combustion of unburned carbon in the incineration residue, and to melt molten slag. The present invention relates to an incineration residue processing device that can prevent incineration residue from adhering to furnace walls and solidifying.

Generally, municipal garbage and industrial waste are incinerated, but the incineration residue that is discharged is usually disposed of in a landfill.

Incidentally, this landfill disposal poses larger social problems than issues such as securing a landfill site and measures for inundation activation.

Therefore, recently, a method for melting and solidifying incineration residue has been developed which solves these problems all at once and makes it non-polluting.

This treatment method will be explained based on Fig. 1. 1 is an incinerator such as a stoker type furnace or a rotary kiln type furnace, in which waste M such as municipal garbage is incinerated by combustion air 2 introduced. It is processed.

The discharged incineration residue N is transferred to the melting furnace 4 of the incineration residue processing equipment 3.
The unburned carbon introduced into the melting furnace and remaining therein is combusted by the combustion air 5 supplied at the inlet of the melting furnace, and the ash is heated and melted by this combustion heat. The molten slag 6 flows obliquely downward through the hearth 7 and sequentially falls into a predetermined shaped lump from the discharge end 8 into the slag cold section water tank 9 located below.
A cooling process produces a bowl-shaped solid.

By the way, in this type of conventional example, since the combustion air 5 is supplied at the inlet of the melting furnace to combust the unburned carbon, the molten slag 6 flowing through the hearth 7 does not contain enough heat products. There was a problem in that the slag was not supplied, and this slag adhered to the hearth 7 and solidified, clogging the inside of the C furnace.

Moreover, this phenomenon occurs not only on the hearth 7 but also on the furnace walls, and not only does the operation have to be interrupted to remove the adhered and solidified slag, but it also takes a lot of time to remove it because it is firmly adhered. , had to require effort.

For this reason, oxygen has been supplied instead of air in order to increase the combustion thirst La and prevent the solidification of molten slag, but in this case, the power consumption of the oxygen generator is large;
Moreover, this handling was also not easy.

On the other hand, in addition to the above-mentioned conventional methods, the surface of the incineration residue may be directly irradiated with a flame from an oil burner to melt it, or an electrode may be inserted into the incineration residue or molten slag to melt it using Joule heat. However, the method using a bleed burner is not recommended because the surface area, which is the high temperature melting area, is exposed.
Heat loss due to heat is large, and furthermore, the thermal conductivity of molten slag is poor, which inevitably increases oil consumption and increases running costs. In addition, the method using Joule heat cannot use the unburned carbon in the residue as fuel, resulting in increased power consumption and is not suitable for practical use.

The present invention has focused on the above-mentioned problems and has been devised to effectively solve the problems.

The object of the present invention is to provide a combustion air supply means for supplying combustion air into a moving bed of incineration residue transferred into a melting furnace, and a heating means for heating the moving bed or molten slag. By providing heat retention through the residual layer, combustion and melting takes place from within the layer, thereby significantly reducing fuel costs, as well as preventing molten slag from adhering to the hearth, etc. and assimilating it, allowing for continuous operation. To provide a residue processing device.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 2 is a longitudinal sectional view showing a first embodiment of the processing arrangement according to the present invention.

As shown in the figure, the incineration residue treatment device includes a melting furnace 10 that burns and melts unburned carbon in the incineration residue N discharged from the incinerator, and a movement of the incineration residue N transferred into the melting furnace 10. It is mainly composed of a combustion air supply means 12 that supplies combustion air into the layer 11, and a heating means 13 that heats the moving layer 11.

The melting furnace 10 is formed as a substantially cylindrical casing 14 whose outer shell is made of refractory bricks, etc., and one end of the earth part is expanded upward to be connected to the residue discharge port of the incinerator 1. hopper or incineration residue inlet 15
is formed (see Figure 1). This melting furnace 10 is
The moving layer 1 is tilted downward at a predetermined angle mark along the direction of transfer of the incineration residue or molten slag transferred therein.
1 can flow down under its own weight.

A molten slag discharge oil 1M16 is connected to the other end of the lower part of the casing 140 and extends vertically to discharge the generated molten slag. A slag cooling water tank 9 is provided for cooling and solidifying the falling molten slag (see FIG. 1).

In the middle of the exhaust passage 16, a flue 17 is provided which is branched from this and inclined slightly upward, and the combustion exhaust gas is sucked by a gas cooler 19 and cooled by a gas cooler 19. It is designed to be released into the atmosphere.

As shown in the enlarged view of FIG. 3, a large number of grate plates 2o are provided at the bottom of the melting furnace 1o constructed in this way along the inclination direction or the direction of transport of the residue. This grate plate 20 is made of fire-resistant ceramics molded into a rectangular shape, and the ends of the grate-like pieces that are adjacent to each other in the inclination direction are overlapped vertically with a predetermined gap between them to form the entire grate plate 2o.
are installed, forming a hearth 21 as a whole.

A support member 22 is provided on the lower surface of the lower end of this grate plate 20 for abutting against the upper surface of the upper end portion of the grate plate 20 adjacent in the inclination direction to maintain the above-mentioned gap.

-6= Both ends of these grate plates 20 are supported by the side walls of the furnace so that the angle of inclination thereof can be varied, so that the speed of movement of the incineration residue in eight layers can be adjusted.

In addition, heating means 13, which is a feature of the present invention, is provided at the bottom of these floorboards 20 along the longitudinal direction thereof. This heating means is composed of a heating element 23 and a heating element protection case 24 that covers the heating element 23. The heating element 23 is
In order to prevent the solidification of molten slag, a high humidity chamber is required, so it is made of, for example, silicon carbide molded into a rod shape, and by passing an electric current through it, it can be heated to a high temperature that cannot be obtained with a metal heating element (such as a chrome wire). The moving layer 11 and the molten slag transferred onto the grate plate 20 can be heated to prevent them from solidifying. The heating element 20 is not limited to the above-mentioned silicon carbide as long as it can generate a high temperature higher than the melting point of the molten slag. Of course, it is made of ceramics, etc.).

Each heating element 23 is covered by the heating element protection case 24 having a semicircular cross section at a predetermined interval, and the stiffness protection case 24 has its upper end connected to the grate plate 2.
It is attached to the lower surface of 0 and fixed integrally thereto. In order to prevent the heating element 23 from deteriorating, it is preferable that the inside of the heating element protection case 24 be made into a closed space structure and filled with an inert gas such as nitrogen.

A plurality of partition walls 26 are provided on the upper side surface 25a of the furnace bottom plate 25, and extend obliquely upward toward the respective protective cases 24, and whose upper ends slide into contact with the outer surfaces of the protective cases 24. The air box 27 is constructed by dividing the lower space of the grate board 20 into a large number of sections in the longitudinal direction.

A combustion air supply pipe 30 with an on-off valve 28 and an orifice 29 interposed therebetween is inserted into each of these wind boxes 27 through the furnace bottom plate 25, and this air supply pipe 30 and the wind box 2
7 constitutes a combustion air supply means 12. That is, the heated combustion air introduced into the wind box 27 is supplied into the I11 layer from the gap formed in the overlapped portion of the grate plate 20, that is, the amount of combustion air @ Ll 31.

In the above embodiment, since the angle of inclination of the grate plate 20 is variable, the protective case 24 is placed at one angle against the partition wall 26. '! In order to make this possible for the first time, a structure was adopted in which this outer surface and the upper end of the partition wall 2G were in sliding contact.
If the structure has a fixed inclination angle of 0, the partition wall 26 and the protective case 24 may be connected and fixed to increase this strong electric current.

The operation of the present invention configured as above will be described.

First, as shown in Figs. 1 and 2, industrial waste such as municipal waste M[:1 input 1] is supplied into the incinerator 1, and after normal combustion is performed therein, the generated incineration waste is The J1 residue is transferred to the incineration residue inlet 1 of the melting furnace 4 connected to the end of the incinerator 1.
5. During combustion, the combustion in the furnace is controlled so that unburned carbon remains in the range of 7 to 25%, preferably 10 to 20%, during the residual soaking. Specifically, the amount of garbage input,
Combustion is controlled by adjusting the amount of combustion air, the feed rate of the stoker in the stoker type, and the rotation speed in the 9-rotation kiln type.

As shown in FIGS. 2 and 3, the incineration residue N containing unburned carbon is stacked on the bottom plate 20 in the melting furnace 10, and this -F becomes a moving layer 11 and flows down in an inclined direction.

On the other hand, the high-temperature combustion air supplied into the wind box 27 via the combustion air supply pipe 30 is supplied into the moving bed from the combustion air injection port 31 formed in the overlapping part of the grate plate 20. This causes the unburned carbon to burn, and the heat generated at this time melts the incineration ash. In this way, since air is supplied from the bottom of the residue in parallel and directly into the moving bed, combustion can occur from inside the residue, and there is also little heat radiation, and combustion heat is retained within the bed to facilitate melting. It is possible to make an effective contribution. This molten slag flows under its own weight over the grate plate 20 which is heated to a high temperature by the heating element 23, that is, above the melting point of the molten slag, and becomes molten slag of a predetermined size from the lower discharge end, and is turned into molten slag in the molten slag discharge passage 16. The slag cools and solidifies in the cooling water tank 9. The combustion exhaust gas is sucked in by the blower 18 in the same direction as the molten slag flows out, and the flue gas is sucked into the flue 17 while preventing the exhaust end of the grate plate from being cooled.
Garlic is discharged. In this way, even after the unburnt carbon has burned out, the molten slag is maintained in a molten state by constantly receiving heat from the grate plate 20 heated above its melting point. 11 does not solidify on the furnace wall, and stable operation can be performed.

In addition, since the incineration residue can be heated with heat other than combustion heat, this combustion is promoted and it can be used even during low-load operation or when there is little unburned carbon in the residue. can.

Furthermore, since the combustion of unburned carbon takes place in a direct portion of the grate plate 20, the grate plate 20 is heated even better, the molten slag flows better, and the separation of the unmelted ash and molten slag is improved. This promotes good contact between unburned carbon and combustion air.

Further, in order to change the flow velocity boundary of the incineration residue or molten slag, this is done by increasing or decreasing the inclination angle of each grate board 20.

In the above embodiment, heating is performed from the lower part of the fire bed with the heating element 23, but the invention is not limited to this. For example, heating with the heating element may be performed through the side or upper furnace wall. Alternatively, the heating elements may be arranged in the furnace alone or inserted into a protective case.

In addition, when supplying combustion air, a method of blowing it out from the combustion air injection port 31 formed on the grate board 32 was adopted, but the method is not limited to this, and for example, a method of blowing it from the side of the furnace with a nozzle (side nozzle method ), or this side nozzle method and the method according to this embodiment may be used in combination, and the combination is made in consideration of thermal efficiency and combustion efficiency.

Next, a second embodiment will be described based on FIG.

In this second embodiment, combustion air is supplied only to the high-temperature part where unburned carbon in the incineration residue burns, and the high-temperature part of the moon is kept warm with an ash layer or a residue layer to reduce τ heat loss. This is the purpose.

The same parts as in the first embodiment are given the same reference numerals and the explanation thereof will be omitted. .

In this embodiment, in order to simplify the structure, the ceramic grate plate 32 is formed continuously and integrally without being divided, and is provided with a slope in the flow direction of the incineration residue N. This constitutes a hearth 33.

A heating means 34 is continuously formed on the lower surface of this hearth 313 along its longitudinal direction. This heating means 34 is made of silicon carbide (two heating elements 23 and a heating element protection case 24 formed to cover them), as in the first embodiment.
It is composed of.

The combustion section (upper part of the furnace) that mainly burns unburned carbon
A plurality of injection nozzles 36 are attached to the furnace side wall that partitions the incineration residue N along the flow direction of the incineration residue N, and each injection nozzle 36 has an on-off valve 28 and an A-refrigerator 29 interposed in the middle for combustion. An air supply pipe 30 is connected to constitute a combustion air supply means 37 as a whole. Therefore, high-temperature combustion air is directly supplied from the injection nozzle 36 into the moving bed of incineration residue.

The operation of this embodiment is almost the same as that of the first embodiment, but especially in the high temperature section 35, the injection nozzle 36 provided on the side wall of the furnace
Since high-temperature combustion air is supplied horizontally directly into the moving bed 11, it is possible to form molten slag by burning from inside the bed while keeping it warm in the ash layer.

Therefore, since radiant heat is reduced, heat loss can be reduced and thermal efficiency can be significantly improved.

Further, as in the first embodiment, since the molten slag flowing on the grate plate 32 is heated by the heating element 23 of the heating means 34, it can flow down smoothly without adhering to the furnace wall or the like and solidifying.

Although it is thermally desirable that the present incineration residue processing device be installed in series with the incinerator, it may be installed independently.

In summary, the present invention exhibits the following excellent effects.

(1) Molten slag adheres to the hearth and furnace walls and solidifies 1
Since 4- can be prevented and 11- can be prevented, blockage failures can be eliminated and stable operation can be achieved.

(2) Even if molten slag adheres and solidifies, will the hearth and furnace walls be high? Since it is in a crystalline state, the viscosity of the attached part is low.
ll il can lea.

(3) Since combustion and melting are performed inside the ash layer while keeping the heat in the ash layer, there is no heat radiation or heat loss to the outside, and the thermal combustion efficiency can be improved as much as possible.

(4) Therefore, the amount of auxiliary fuel used can be reduced, and air can be used as the combustion gas instead of oxygen.

(5) In addition, since there is no need to use oxygen, the electricity cost for oxygen generation is eliminated, and the IJ required for this is eliminated.
All devices of type F3 can be eliminated.

[Brief explanation of the drawing]

Figure 1 [, 1 firing No. 11] Furnace 1. "A conventional incineration residue processing device installed offshore" is a vertical sectional view, FIG. 2 is a sectional view of group J showing the first embodiment of the present invention, and FIG. 3 is an enlarged perspective view of the main parts of the present invention. , FIG. 4 is a longitudinal sectional view showing a second embodiment of the present invention. In the figure, 1 is an incinerator, 10 is a melting furnace, 11 is a moving bed,
12.37 is a combustion air supply means, 13.34 is a heating means, and N is an incineration residue. Patent applicant: Patent attorney representing Ishikawajima-Harima Heavy Industries Co., Ltd.
Nobuo Kinuya

Claims (1)

[Claims] An incineration residue processing device that burns unburned carbon contained in incineration residue discharged from an incinerator to obtain molten slag, a melting furnace for transferring the discharged incineration residue for melting treatment; Combustion air supply means for supplying combustion air into a moving bed of incineration residue transferred into the melting furnace to burn unburned carbon; and heating means for heating the moving bed in the furnace. An incineration residue processing device characterized by comprising: