JPH0346723B2 - - Google Patents

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, the present invention relates to an incineration residue processing device that melts incineration residue discharged from an incinerator, and particularly includes forming a preheating section, a combustion section, and a melting section for incineration residue in the melting furnace. The present invention relates to an incineration residue processing device that enables fine combustion and melting control, significantly reduces running costs by reducing fuel consumption, and prevents molten slag from adhering and solidifying to ensure stable operation.

Generally, municipal waste, industrial waste, etc. 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 of melting and solidifying incineration residue has been developed which solves these problems all at once and makes it non-polluting.

This processing method will be explained based on Fig. 1.
Reference numeral 1 denotes an incinerator such as a stoker type furnace or a rotary kiln type furnace, in which waste M such as municipal garbage is incinerated with combustion air 2.

The discharged incineration residue N is introduced into the melting furnace 4 of the incineration residue treatment device 3, and the unburned carbon remaining therein is combusted by the combustion air 5 supplied at the inlet of the melting furnace, and the combustion heat is used to burn it. Heat and melt the combustion ash.
This molten slag 6 flows diagonally downward through the hearth 7 and forms a predetermined shaped lump from the discharge end 8 and falls one after another into the slag cooling water tank 9 located below, where it is cooled and solidified into lumps. will be generated.

By the way, in this type of conventional example, since the combustion air 5 is supplied at the inlet of the melting furnace to burn unburned carbon, a sufficient amount of heat is not supplied to the molten slag 6 flowing through the hearth 7. There was a problem that this slag adhered to the hearth 7 and the furnace wall and solidified, clogging the inside of the furnace. For this reason, operations had to be interrupted in order to remove the adhered and solidified slag, and this removal work also required a great deal of time and effort.

For this reason, attempts have been made to increase the combustion temperature and prevent the solidification of molten slag by supplying oxygen instead of air, but in this case, the power consumption of the oxygen generator is large, and the handling It wasn't easy either.

On the other hand, in addition to the above-mentioned conventional examples, the surface of the incineration residue is directly irradiated with flame from an oil burner to melt it.
Another method is to insert an electrode into the incineration residue or molten slag and melt it using Joule heat, but the method using an oil burner exposes the surface area, which is a high-temperature molten part, and therefore cannot be heated by radiant heat. In addition to the large loss, the molten slag has poor thermal conductivity, which inevitably increases oil consumption and increases running costs. In addition, the method using Joule heat cannot use 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 them.

The object of the present invention is to provide a preheating section forming means for preheating a moving layer of incineration residue flowing down in the melting furnace, and a combustion section forming means for forming a combustion section for burning the preheated residue. and a melting zone forming means for forming a melting zone for melting the generated combustion ash, respectively, are sequentially formed along the flow direction of the moving bed to perform fine combustion and melting control. It is an object of the present invention to provide an incineration residue processing device that can be operated continuously by preventing the adhesion and solidification of slag, and can improve combustion efficiency and significantly reduce running costs.

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 processing apparatus according to the present invention.

As shown in the figure, the incineration residue processing device is designed to melt and process incineration residue discharged from an incinerator.
It has a melting furnace 11 for forming a moving layer 10. The melting furnace 11 is formed as a substantially cylindrical casing 12 whose outer shell is made of refractory bricks, etc., and one end of the upper part of the casing 12 is expanded upward to be connected to the residue outlet of the incinerator 1. A hopper or incineration residue inlet 13 is formed (see FIG. 1).

This melting furnace 11 is tilted downward at a predetermined angle along the direction of transport of incineration residue or molten slag to be transferred therein, so that the moving bed 10 therein can flow down under its own weight. . At the bottom of the melting furnace 11, a grate plate 15 is attached, which is positioned above the furnace bottom plate 14 by a predetermined distance and extends along the inclination direction of the furnace, and constitutes a hearth 16.

This grate plate 15 is made of heat-resistant ceramics or the like and is formed into a flat plate shape to improve the flow of molten slag. A pusher 17 connected to a cylinder mechanism or the like is provided on one side wall of the melting furnace 11 in the upper direction in the inclination direction so as to be movable back and forth along the longitudinal direction of the grate plate 15 to control the moving speed of the moving layer 11. It is configured so that it can be done.

Further, a slag discharge port 18 formed at the lower end of the melting furnace 11 in the inclined direction is connected to a molten slag discharge passage 19 extending vertically to discharge the generated molten slag. A slag cooling water tank 9 is provided at the lower end for cooling and solidifying the molten slag 20 that falls in the form of lumps (see FIG. 1). In addition, the discharge passage 19
A flue 21 is provided in the middle of the flue 21, which is branched from this and inclined slightly upward, and the combustion exhaust gas is sucked in by a blower 22, cooled by an exhaust gas cooler 23, and then released into the atmosphere. ing.

In the melting furnace 11 configured as described above, a preheating section forming means 24, a combustion section forming means 25, and a melting section forming means 26, which are features of the present invention, are sequentially arranged along the flow direction of the moving bed 10. It is provided.

Specifically, each of these means is constituted by a combination of a large number of heating elements 27 arranged in the lower part of the grate plate 15 along its longitudinal direction, and a combustion air supply means 28. 3 is an enlarged perspective view showing section A in FIG. 2. FIG.

As shown in the figure, the heating element 27 is made of, for example, silicon carbide molded into a rod shape because it requires a high temperature. A moving layer 10 on the grate plate can be obtained.
will be heated. The heating elements 27 are arranged in four groups of a predetermined number (four in the illustrated example) along the movement direction of the residue from the upper part in the inclined direction of the hearth, and the preheating parts 27 are arranged from the upper part to the lower part in the inclined direction. They are configured as a heating element group 29, a combustion part heating element group 30, a melting part heating element group 31, and a sprue heating element group 32. The wiring 33 of each heating element is connected to a heating element controller 34, so that the temperature can be adjusted for each group.

Each heating element 27 is covered and protected by a heating element case 35 having a semicircular cross section at a predetermined distance from the heating element 27, and this protective case 3
5 has its upper end attached to the lower surface of the fire bed plate 15 and is integrally fixed thereto. In order to prevent the heating element inside the case from deteriorating, it is preferable that the inside of the case be a closed space structure and filled with an inert gas such as nitrogen.

Further, the combustion air supply means 28 includes combustion air blowing ports 36 that are formed oppositely to each other in the furnace side wall at predetermined intervals along the inclination direction thereof;
It consists of an on-off valve 37 interposed in the middle and a combustion air supply pipe 38 connected to each of these inlets, so that air is blown from the side of the moving bed across the hearth 16. It's getting old. Each combustion air blowing port 36 and each combustion air supply pipe 38 connected thereto are arranged in a predetermined number (four in the illustrated example) along the direction of movement of the residue in order to correspond to the heating element group. ), and are configured from the top to the bottom in the inclination direction as a preheating section combustion air supply group 39, a combustion section combustion air supply group 40, and a melting section combustion air supply group 41. Note that it is not provided in a portion corresponding to the sprue heating element group 32.

The air supply pipes 38 are grouped into groups and connected to a blower 42, so that a combustion air controller 43 can control the air supply amount for each group. In addition, instead of grouping the supply pipes into groups as in the illustrated example, all of these pipes are combined into one main supply pipe, and the opening degree of the on-off valve 37 interposed in the middle is changed for each group to control the amount of air supplied. Control may be performed for each group.

The preheating section combustion air supply group 39 and the preheating section heating element group 29 constitute the preheating section forming means 24, thereby forming the preheating section 44 for preheating the moving bed. Further, the combustion section combustion air supply group 40 and the combustion section heating element group 30 constitute the combustion section forming means 25, thereby forming the combustion section 45 for burning unburned carbon in the residue. . Further, the above-mentioned melting section combustion air supply group 41 and melting section heating element group 32 constitute the above-mentioned melting section forming means 26, thereby forming a melting section 46 for melting the residue.

Therefore, the preheating section 44, the combustion section 45, and the melting section 4 are formed from above in the downward direction of the inclination of the hearth 16.
6 will be sequentially divided, and the amount of heating of the moving layer will be controlled by appropriately increasing or decreasing the calorific value of the heating element group provided corresponding to each position and the air supply amount of the air supply group. Become.

In the above embodiment, both the air supply means and the heating element are provided for each part, but in parts that do not require much heat, such as the preheating part, only one of the air supply means and the heating element is provided. may be provided.

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

First, as shown in Figures 1 and 2, industrial waste M such as municipal waste is fed into the combustion furnace 1 from the input port, and after normal combustion is carried out therein, the generated incineration residue is transferred to the combustion furnace. Melting furnace 11 connected to the end of 1
is supplied into the incineration residue inlet 13 of the incineration residue. During combustion in an incinerator, 7 to 25% of unburned carbon remains in the residue.
Preferably, combustion is controlled so that it remains in the range of 10 to 20%.

Specifically, combustion control is performed by adjusting the input amount of waste, the amount of combustion air, the stoker feed speed in the case of a stoker type, and the rotation speed in the case of a rotary kiln type.

As shown in FIGS. 2 and 3, the incineration residue N containing unburned carbon is layered on the grate plate 15 in the melting furnace 11, and becomes a moving layer 10 while being pushed by the pusher 17 or by its own weight. and flows down in the direction of the slope.

On the other hand, in the furnace, preheating section forming means 24,
A preheating section 44, a combustion section 45, and a melting section 46 are defined by the combustion section forming means 25 and the melting section forming means 26 along the flow direction of the moving bed. Specifically, the preheating section heating element group 29 and the combustion section are provided so that the temperature of the preheating section is 700 to 1100°C, the temperature of the combustion section is 900 to 1300°C, and the temperature of the melting section is 1100 to 1600°C. The heating element group 30 and the melting part heating element group 31 are heated. These heating controls are performed by changing the amount of current for each heating element group by the heating element controller 34.

At the same time, combustion air is supplied from the preheating section combustion air supply group 39, the combustion section combustion air supply group 40, and the melting section combustion air supply group 41 at the following rates.

Preheating section: 10 to 30%, combustion section: 20 to 40%, melting section: 40 to 80%. These air supply amounts are controlled by controlling the supply pressure of the blower 42 for each group by the combustion air controller 43. It is done differently. In addition, when the combustion air supply pipe 38 is shared, the opening degree of the interposed on-off valve 37 may be adjusted for each group to control the air flow rate.

The moving bed 10 flowing down in the furnace first passes through the preheating section 44.
The unburned carbon in the residue is combusted by a large amount of combustion air that is preheated to a predetermined temperature in the combustor 45 and blown into the moving bed from the combustion air inlet 36 in the combustion section 45, and is moved while being combusted. The combustion ash in the layer 10 flows down to the melting section 46 and is melted by the generated combustion heat. The molten slag further flows down and passes through the tapping port 47, and then falls into the molten slag discharge passage 19 from the slag discharge port 18 as a molten slag of a predetermined size, and then flows into the slag cooling water tank 9. It is cooled and solidified. Incidentally, the sprue heating element group 32 provided at the tap outlet 47 is maintained at a higher temperature than the melting part heating element group 31.

Then, the combustion exhaust gas is sucked in the same direction by the blower 22 as the molten slag flows out, and is sucked into the outlet 47.
is discharged from the flue 21 while preventing cooling of the gas.

In this way, since combustion air is supplied directly into the moving bed in parallel from the combustion air inlet 36 provided along the furnace side wall, combustion can be performed from inside the residue bed, and there is also little heat radiation. Combustion heat can be retained within the layer and effectively contribute to melting.

Further, by appropriately changing the amount of air blown from each combustion air supply group 39, 40, 41, the amount of air commensurate with the flow rate of the residue can be controlled and supplied for each group, thereby improving combustion efficiency. Similarly, by changing the heating temperature of each heating element group 29, 30, 31 as appropriate, the amount of heating commensurate with the flow rate of the residue can be controlled and supplied to each group, so proper heating can be performed and heating power is not wasted. There's nothing to do.

Therefore, by controlling the combination of combustion air supply amount and heating amount for each group, combustion of incineration residue,
It becomes easier to control the amount of melting, and fine control commensurate with the load becomes possible.

In addition, the calorific value of the melting section heating element group 31 and sprue heating element group 32 is increased in particular, and the temperature of the hearth and furnace wall in these parts is maintained above the slag melting point, so that the molten state of the slag is maintained stably. This does not adhere to the hearth or walls and allows stable operation.

Incidentally, in the above embodiment, the hearth (fire bed plate) was constructed from a single piece of integrally molded ceramic, but the present invention is not limited to this and may be constructed as shown in FIG. 4.

That is, a large number of ceramic grate plates 48 formed into strips are installed along the inclination direction, and the ends of the grate plates adjacent to each other in the downward direction of the incline are overlapped vertically with a predetermined gap between them. , so as to form a hearth 49 as a whole.

Then, a heating element 27 and a heating element protection case 35 similar to those in the above embodiment are attached to the lower part of each grate plate 48, and a partition wall 50 is provided at the lower part of each grate plate 48 to partition the lower space of the hearth 49. It is divided to form a large number of wind boxes 51. The combustion air supply pipe 38 is inserted into the wind box 51 to constitute the combustion air supply means 28. In other words, this wind box 5
The combustion air supplied into the chamber 1 is passed through a gap (combustion air inlet) formed at the overlapping part of the end of the grate plate.
52 as shown by the arrow, and is supplied into the moving bed from the bottom.

The combustion air supply means 28 and the heating element 27 are also grouped into groups corresponding to the preheating section, the combustion section, and the melting section, as in the embodiment described above, so that detailed combustion and melting control can be performed respectively.

In the embodiments described above, the moving layer is heated from the lower part of the grate plate, but the heating with the heating element is not limited to this, and the heating with the heating element may be through the furnace wall such as the side or upper part, or it may be It may be inserted into a case and provided in the furnace.

Further, the method of supplying combustion air may be a combination of a method of supplying from the gap (slit) of the grate plate and a method of supplying from the furnace side wall.

Although it is thermally desirable that the present melting furnace be connected to the incinerator, it may be installed independently.

In summary, according to the present invention, the following excellent effects can be achieved.

(1) Since it is possible to prevent molten slag from adhering and solidifying to the hearth and furnace walls, clogging problems can be eliminated and stable operation can be achieved.

(2) Since the temperature inside the furnace is divided and controlled into the preheating section, combustion section, and melting section, fine control of the amount of combustion and melting can be achieved.

(3) Since combustion and melting are carried out inside the ash layer while keeping the temperature in the ash layer, there is no heat radiation or heat loss to the outside, which, together with the reasons in item 2 above, makes it possible to improve combustion efficiency as much as possible. can.

(4) Therefore, the amount of auxiliary fuel used can be reduced, and oxygen is not used as a combustion gas,
Air can be used, significantly reducing running costs.

(5) Also, since there is no need to use oxygen,
Electricity costs for oxygen generation can be eliminated, and all equipment required for this can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional incineration residue processing device connected to an incinerator, FIG. 2 is a vertical cross-sectional view showing a preferred embodiment of the present invention, and FIG. 3 is a section A in FIG. FIG. 4 is an enlarged perspective view of main parts showing another embodiment of the present invention. In the figure, 1 is an incinerator, 10 is a moving bed, 11 is a melting furnace, 20 is a molten slag, 24 is a preheating part forming means, 25 is a combustion part forming means, 26 is a melting part forming means, and 44 is a preheating part , 45 is a combustion section, 46 is a melting section, and N is an incineration residue.

Claims (1)

[Claims] 1. In an incineration residue treatment device that burns the unburned carbon contained in incineration residue discharged from an incinerator and obtains it as molten slag, a moving layer of incineration residue is formed in order to melt and process the above-mentioned incineration residue discharged. a melting furnace, a preheating section forming means for forming a preheating section for preheating a moving layer of incineration residue transferred into the melting furnace to a predetermined temperature, and a moving layer preheated by the preheating section forming means A combustion section forming means for forming a combustion section for burning unburned carbon contained in the incineration residue, and a melting section for melting combustion ash generated by the combustion section forming means to obtain molten slag. 1. An incineration residue processing device comprising: a fusion zone forming means.