JPH0391609A - Treatment of ash by melting and solidification - Google Patents

Abstract

PURPOSE:To make it difficult for a slag discharging section to be clogged by providing between the melting section and slag discharge section of a melting furnace a funnel section which catches molten slag that is flowing down and pours the caught slag downwards. CONSTITUTION:A funnel section 18 which catches molten slag that is flowing down and pours the caught slag downwards is provided between the melting section 6 and slag discharging section 8 of a rotating flow type melting furnace 1. Since this funnel section 18 has the function to catch downwardly flowing slag, the slag discharging section 8 is not required to have a tilting section as in conventional slag discharging devices and it can be constituted of a vertical section (vertical slag discharging section). When ash is treated by melting and solidifying it in such a device, the molten ash flows down along the funnel wall of the rotating flow type melting furnace 1 and the molten slag that passes a throttling section 7 falls down to a funnel section and is caught there. The caught slag is poured into the vertical slag discharge section from the funnel section 18, flows down to a molten slag transportation means from the slag discharging section 8. The slag is cooled and solidified as it is transported, and it is recovered as solid slag. With this arrangement the flowing slag is difficult to develop clogging in the slag discharging section, and there is, therefore, no trouble of clogging in the slag discharging section and the transporting means of the molten slag causes no trouble in the discharge and recovery of the slag and the treatment of ash by melting and solidification can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ash melting and solidifying treatment apparatus, and more particularly, to an ash-containing body produced from treated materials such as sewage sludge, municipal garbage, and waste, that is, An ash-containing mixture produced by heat treatment such as heat drying of the treated material, an ash-containing body such as incineration ash discharged from an incinerator that incinerates the treated material, or a boiler or kiln that uses charcoal as fuel. , relates to an ash melting and solidifying processing apparatus that melts coal ash (hereinafter referred to as ash) discharged from an industrial furnace or the like, converts it into slag, and then cools and solidifies the molten slag while continuously conveying it.

(Prior Art) Conventionally, the above-mentioned ash (that is, ash-containing materials such as the ash-containing mixture and incinerated ash, and coal ash) has been mainly used in ocean landfills for disposal. That is, the ash-containing mixture is landfilled after treatment to remove combustible materials from the mixture, and incineration ash and coal ash are landfilled as they are without such treatment. However, in recent years, it has become difficult to secure landfill sites and stricter disposal standards related to marine pollution prevention have made it difficult to use them for marine landfills.

Therefore, various methods for processing the above-mentioned ash have been studied, and recently a method has been developed in which the ash is melted in a swirling flow melting furnace, turned into slag, and then the molten slag is cooled and solidified.
2-187453). This method aims to reduce the amount of ash to be disposed of and to immobilize harmful substances such as heavy metals.

Such ash melting and solidification processing requires a swirling flow melting furnace having a melting section in the upper part that turns the ash into molten slag while swirling, and a slag part in the lower part for discharging the molten slag, and An apparatus for melting and solidifying ash is used, which is equipped with a conveying means for continuously conveying the molten slag.

FIG. 4 shows a cross-sectional side view of a typical example of the device, and FIG. 5 shows a cross-sectional plan view of its upper part. Based on these figures, the details of the above-mentioned conventional ash melting and solidifying processing apparatus and the method of ash melting and solidifying processing using this apparatus will be described below.

As shown in FIG. 4, the conventional ash melting and solidification processing apparatus has at least a melting section (6) in the upper part that turns the ash into molten slag while swirling it, and a slag section (6) that discharges the molten slag. 8) at the bottom thereof, and a conveying means (a) for continuously conveying the molten slag from the slag discharge section (8).

The melting furnace (1) is provided with a constriction part (7) between the melting part (6) and the slag discharge part (8), and the constriction part (7) and the slag discharge part (
8) is provided with an exhaust gas outflow portion 07). The slag discharge section (8) is composed of an inclined section for receiving the falling molten slag and causing it to flow down, and a vertical section connected to the inclined section. The conveyance means 02) is a chain conveyor 04
, a group of molds placed on the conveyor side, and a heat insulating hood (30) placed above the conveyor 041. The heat insulating hood (30) has an opening directly below the slag outlet (8).

To melt and solidify ash using such a device, first, the inside of the furnace (1) and the furnace wall are heated by the main burner (2) installed at the top of the swirl flow melting furnace (the ash). The temperature is maintained at a temperature higher than the temperature at which the ash can melt and flow down (hereinafter referred to as the ash melt temperature). At this time, in order to burn the fuel F4 ejected from the burner (2), combustion air is passed through the pipe. (9)
As shown in FIG. 5, the combustion air is blown into the combustion air from the tube ODD (Go), which is arranged so that the direction of combustion air blown is tangential to the furnace wall when viewed from above.

Next, the ash in the hopper (3) is transferred to the table feeder (4).
) and pipe (9) through valve (5).
The combustion air is mixed with the combustion air flowing in the pipe (9), and is blown into the furnace (1) together with the air. In this way, the solid-gas two-phase flow consisting of ash and air is heated while swirling on the furnace wall surface in the furnace (1), and the ash is melted and turned into slag. In FIG. 5, (It) indicates the swirling flow of the solid-gas two-phase flow.

The molten slag flows down along the furnace wall and reaches the constriction section (7).
, falls onto the slope of the slag outlet (8), flows down along the slope, passes through the opening on the insulating hood side from the vertical part of the slag (8), and enters the mold G3). The molten slag flows down and is conveyed by the conveyor (+41) together with the mold (+31). During the conveyance, the molten slag is cooled and solidified, and is dropped into the solidified slag container QG and solidified. In Fig. 4, the molten slag is S, solidified slag is indicated by C.

In the ash melting and solidification process, the exhaust gas generated in the melting furnace (1) is discharged from the exhaust gas outlet 0'I).

Since the exhaust gas has a high temperature, the exhaust gas causes the throttle part (
7) and the exhaust gas outlet q″71 are heated to a high temperature,
The slag (8) is hardly heated, and if the temperature of the slag (8) is low, the molten slag becomes semi-molten and adheres to the slag (8), and eventually solidifies and causes blockage. .

Therefore, in order to prevent such blockages from occurring, zero auxiliary burners are provided, and the burners (15) apply force U heat to the vicinity of the slag outlet (8).

(Problem to be Solved by the Invention) However, from the viewpoint of the structure near the slag extraction part (8), the zero auxiliary burners uniformly heat the entire slag extraction part (8) to a temperature higher than the ash melt flow temperature. Since it is difficult to heat the slag to a temperature of It often hardens and causes blockages.

Furthermore, the melting furnace (1) undergoes furnace pressure fluctuations during operation. When furnace pressure fluctuations occur, the slag part (
8) Air enters the melting furnace (1) from the opening at the bottom,
At this time, the temperature of the slag discharge portion (8) decreases. The temperature drop caused by such air intrusion may also cause the molten slag to become semi-molten and adhere to the molten slag, resulting in blockage.

Therefore, the conventional ash melting and solidification processing apparatus has a problem in that the molten slag is semi-molten and adheres to the slag, and is likely to solidify and cause blockage in the slag. The occurrence of such blockage is an extremely serious problem because it makes it impossible to discharge the slag and forces the operation of the ash melting and solidification process to be stopped.

The present invention has been made in view of these circumstances, and its purpose is to solve the above-mentioned problems of the conventional methods, and to reduce the semi-molten slag produced by heating the ash. It is an object of the present invention to provide an ash melting and solidification processing apparatus in which ash formation and adhesion are less likely to occur, and therefore, clogging in the slag extraction section is less likely to occur.

(Means for Solving Problem m1) In order to achieve the above-mentioned problem, the ash melting and solidifying treatment apparatus according to the present invention has the following configuration.

That is, the ash melting and solidification processing apparatus according to claim 1 has a melting section in the upper part that melts and converts coal ash or ash-containing material generated from treated materials such as sewage sludge, municipal garbage, and waste into slag. An ash melting and solidification processing apparatus comprising: a swirling flow melting furnace having a slag discharging section at the bottom thereof for discharging the molten slag; and a conveying means for continuously transporting the molten slag from the slag discharging section. , between the melting part and the slag extraction part of the melting furnace,
This is an ash melting and solidifying processing device characterized by having a funnel portion that collects the flowing molten slag and pours it downward. In other words, this device is the conventional ash melting and solidifying device provided with the funnel portion as described above.

The ash melting and solidification processing apparatus according to claim 2 is characterized in that the conveyance means is a closed conveyance means disposed in a case connected to a lower part of the slag discharge part of the melting furnace and capable of shutting off outside air. This is the ash melting and solidification processing apparatus according to item 1.

(Function) As explained above, the ash melting and solidifying processing apparatus according to the present invention, in contrast to the conventional ash melting and solidifying processing apparatus, has a funnel part that collects the flowing molten slag and pours it downward. It is arranged between the melting section and the slag tapping section of the swirl flow melting furnace.

Since the funnel part has the function of collecting the flowing molten slag, the slag outlet part does not need to have an inclined part as in the case of the typical example of the conventional apparatus, and is composed of only a vertical part ( Hereinafter, it can be referred to as a vertical slag).

When the ash is melted and solidified using such a device, the molten slag flows down along the wall of the swirling flow melting furnace, passes through the constriction part, falls into the funnel part, is collected, and is then released vertically from the funnel part. The molten slag is poured into a slag, flows down from the slag into a molten slag conveying means, is conveyed by the means, is cooled and solidified during the conveyance, and is recovered as solidified slag.

At this time, by adjusting the volume of the funnel, the injection port to the slag, etc., a large amount of molten slag can be poured into the slag while accumulating in the funnel. Since such a large amount of molten slag has a large heat capacity, it is difficult for the temperature to drop.Furthermore, the funnel section is placed between the f9 melting section and the slag section, and the space between the cores is heated to a high temperature by the high-temperature exhaust gas. The temperature of the molten slag in the funnel and the flowing slag between the cores is more difficult to decrease. Therefore, semi-melting and adhesion of the slag do not occur in the funnel portion, and the molten slag maintained at a high temperature can be poured into the slag portion.

By adjusting the position of the inlet of the funnel, the high-temperature molten slag poured into the slag does not come into contact with the wall of the vertical slag, and can flow into the central space of the slag. may be passed through and injected into the molten slag conveyance means. Therefore, it is possible to prevent molten slag from adhering to the slag portion. Furthermore, even if the molten slag is scattered and comes into contact with the wall of the slag outlet, the amount of slag is extremely small and the temperature is high, so it is difficult to adhere, and even if it does adhere, the amount is extremely small. Therefore, blockage at the slag outlet can be prevented. Therefore, the ash can be melted and solidified without causing trouble in discharging and recovering the molten slag to the conveying means.

In the ash melting and solidification processing apparatus according to the present invention, as the conveying means for the molten slag, the conveying means as in the case of the typical example of the conventional apparatus may be used. It is preferable to use a closed conveying means arranged in a connected case that can shut off the outside air. In this way, even if the furnace pressure of the melting furnace decreases, the slag can be transported from the lower part of the outlet into the melting furnace. Since air intrusion becomes less likely to occur,
This is because the temperature inside the furnace is less likely to drop due to the air intrusion, and therefore slag adhesion at the slag portion and funnel portion is less likely to occur. An example of such a closed conveyor means is a closed case conveyor.

(Example) Fig. 1 shows an outline of an ash melting and solidifying apparatus according to Example 1. The device has a slag discharge part (8) consisting of only a vertical part,
The funnel part side is disposed between the slag discharge part (8) and the constricted part (7) at the lower part of the melting part (6), and a closed case conveyor 09) is further provided as a conveying means for the molten slag. 8) It has a feature in that it is connected at the bottom, and except for these points, it is the same as the representative example of the conventional device shown in the fourth rpJ. However, the distance between the throttle part (7) and the slag outlet part (8) is slightly long.

FIG. 2 shows a perspective view of the main parts of the funnel part am. In FIG. 2, (22) is a molten slag collection part, and (23)
indicates the injection port to the slag outlet.

Using this equipment, sewage sludge incineration ash was melted and solidified. First, combustion air was blown into the swirling flow melting furnace (1) from the pipe (9) and the pipe 0 [D], and heavy oil: 501/Hr was burned by the main burner (2), and the inside of the furnace (1) was heated. The temperature is maintained at or above the ash melt temperature (1250"C).

Next, the ash in the hopper (3) is transferred to the table feeder (4).
) and pipe (9) through valve (5).
The mixture was dropped into the furnace (1), mixed with the combustion air flowing through the pipe (9), and blown into the furnace (1) together with the air to form molten slag.

The molten slag S flows down along the furnace wall, passes through the constriction part (7), falls into the collection part (22) of the funnel part 0ω, is collected, and is discharged from the inlet (23) of the funnel part θω. part (8) and flows down into the mold 03) in the outside air-blockable case (to) of the closed case conveyor Ogl, and the mold 0
3) is conveyed by a conveyor (b), and during the conveyance, the molten slag is cooled and solidified. The solidified slag C is removed by opening a shutoff valve (21) with a double damper.
It was dropped into solidified slag container 00 and collected.

At this time, a large amount of molten slag is removed from the funnel section marked a (2
The molten slag can flow down to the slag (8) while accumulating in the slag (2), and the molten slag can flow down to the slag (8) without coming into contact with the wall of the slag (8).
It was possible to inject the slag into the mold a''!J by passing through the central space of the melting furnace (8).Furthermore, even when the furnace pressure of the melting furnace decreased, air did not enter the melting furnace and the slag was poured into the mold a''!J. ) could be maintained at a high temperature.Furthermore, the temperature inside the conveyor 09) did not decrease and could be maintained at a constant temperature, making it possible to precisely adjust the cooling rate of the molten slag.

When the above ash melting and solidification operation was carried out, slag adhered to the funnel part 00 and the slag part (8), and the slag part (8)
8), continuous operation was possible without any blockage occurring.

In addition, since the accuracy of the cooling rate of the slag is good, the properties of the solidified slag can be reliably controlled, and by controlling the cooling rate to 5"C/g+in or less, a slowly cooled slag with advanced crystallization can be obtained.
A glassy quenched slag was obtained by controlling the temperature to be above °C/win.

In addition, instead of the funnel part aω shown in FIG.
As shown in the figure, when a device having V-shaped inclined grooves was used, the same effects as above were obtained.

100East1 90% of the ash fed into the swirling flow melting furnace is melted and flows down, but the remaining 10% is in the form of ash, semi-molten ash, or evaporated slag (hereinafter referred to as waste). Together with the exhaust gas, it passes through the flue from the exhaust gas outlet and is discharged outside the furnace. At this time, the discharged matter adheres to the flue, and this adhesion sometimes causes an increase in furnace pressure and the occurrence of blockage of the flue.

Embodiment 2 is therefore intended to prevent the occurrence of blockage in the slag outlet, and also to prevent the occurrence of adhesion of discharged materials in the flue.

The melting and solidification processing apparatus according to the second embodiment is characterized by an exhaust gas flue section connected to an exhaust gas flow mountain section, and is the same as the apparatus shown in FIG. 1 except for this point. FIG. 6 shows an outline of the exhaust gas flue section of the above device. The exhaust gas flue part is connected to the exhaust gas outflow part G force, and is connected to an upwardly inclined inclined flue part (24) and an upper part of the inclined flue part (24),
A substantially vertical cylindrical mist separation part (27) extending downward, a bottomed cylindrical pot (28) connected to the lower part of the vertical mist separation part (27), and a bottomed cylindrical pot (28) connected to the side wall of the mist separation part (27). and an exhaust gas discharge section (29). A panfur material (25) is provided in the inclined flue portion (24>).

When the above-mentioned apparatus was used to carry out the melting and solidification treatment under the same conditions as in Example 1, the same effects as in Example 1 were naturally obtained, and furthermore, the emission from the flue section was It was possible to prevent the occurrence of matter adhesion. That is, the ash in the discharge, semi-molten ash, collides with the baffle material (25) or contacts the wall of the inclined flue part (24) and adheres lightly, and then melts and flows into the inclined flue. part (24) and was discharged into a mold. The evaporated slag, which is the evaporated substance of the molten slag, is passed through the air inlet (26) in the mist separation section (27).
The ash was cooled to below the softening temperature of the ash by the air introduced from the ash, solidified, fell into the bot (28), and was collected. Note that the exhaust gas is discharged from the exhaust gas discharge section (29).

Therefore, according to the melting and solidifying treatment apparatus as in the case of Embodiment 2, it is possible to prevent the occurrence of blockage in the slag outlet part, and also to prevent the occurrence of discharged substances from adhering to the flue part, and therefore, the molten slag conveying means This makes it possible to melt and solidify ash without causing problems such as discharge and solidification, and problems such as clogging of the flue due to adhesion of the ash. Furthermore, the amount of waste discharged outside the furnace can be extremely reduced.

(Effects of the Invention) According to the ash melting and solidifying treatment apparatus according to the present invention, during the ash melting and solidifying treatment, the molten slag generated by heating the ash becomes semi-molten and hardly adheres, so that blockage is less likely to occur. Therefore, the ash can be melted and solidified without causing troubles in discharging and solidifying the molten slag to the conveying means.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing an overview of the ash melting and solidification processing apparatus according to the first embodiment, Fig. 2 is an external perspective view of the main part of the funnel section according to the first embodiment, and Fig. 3 is a side sectional view showing the outline of the ash melting and solidification processing apparatus according to the first embodiment. FIG. 4 is a cross-sectional side view showing a typical example of a conventional ash melting and solidification processing device, FIG. 5 is a cross-sectional plan view of the upper part of the device, and FIG. 6 is a perspective view of the main part of the funnel. FIG. 7 is a side cross-sectional view showing an outline of the exhaust gas flue section of the melting and solidifying treatment apparatus according to Example 2. (1) - Swirling flow melting furnace (2) - Raw burner (3) - Hopper <4) - O table feeder (5) - Valve (6) - Melting section (7) - Squeezing section (8) - Slag section (
9) OI-pipe (10-swirling flow rm-slag transport means 03)--mold (b)-chain conveyor 051-auxiliary burner 06)-solidified slag container 07)-exhaust gas outlet G8)-funnel part 09= Closed case conveyor 21 - A case (21) that can shut off outside air - A shutoff valve (22) with a double damper - A molten slag collection part (23) - An inlet to the slag part (25) - - Baffle material (27L - Mist separation section (2) - Exhaust gas discharge section S - m - Molten slag (24) - One inclined flue section (26) - One air blower (28) - Bot (30) ~Insulation hood C---Solidified slag

Claims (2)

[Claims] (1) The upper part has a melting part that turns ash-containing bodies or coal ash generated from treated materials such as sewage sludge, municipal garbage, and waste into molten slag, and the lower part has a slag part that discharges the molten slag. An ash melting and solidification processing apparatus comprising: a swirling flow melting furnace having a slag; and a conveying means for continuously transporting molten slag from the slag tapping section; An apparatus for melting and solidifying ash, characterized in that a funnel part is arranged between the parts to collect the flowing molten slag and pour it downward. (2) The ash melting and solidification processing apparatus according to claim 1, wherein the conveying means is a closed type conveying means disposed in a case connected to a lower part of the slag discharge part of the melting furnace and capable of shutting off outside air. .