JPH05280726A - Slag discharging device - Google Patents

Abstract

PURPOSE:To release solidified slag easily from a mold and contrive the stabilized operation of a slag discharging device by pouring molten slag, which flows down from a slag discharging port, surely to eliminate the bad affection with respect to a chain conveyer. CONSTITUTION:This device is constituted so that water-cooled slag guide plates 7, 7, cooled by cooling water, are supported by supporting pillars 7a established on the rails 4f below a slag discharging port 3 in the chevron from to guide molten slag, which flows down along the inner walls of the slag discharging port 3 while being deviated from the center of the slag discharging port 3 into a reverse truncated shape of mold 4d along the slanted surfaces of the slag guide plates 7, 7. According to this method, the adhesion of the molten slag S to chassis 4c, guide rollers 4e or rails 4f can be prevented and high- temperature exhaust gas, blown out of the slag discharging port 3, can be shielded whereby the generation of elongation of the chains 4c or the faulty operation of the chain conveyer can be reduced while solidified slag can be released easily from the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag discharge device,
More specifically, sewage sludge, municipal waste, industrial waste and their incinerated ash discharged from the slag outlet at the bottom of the melting furnace, or coal ash discharged from boilers, kilns, industrial furnaces that use coal as fuel ( Hereinafter, the present invention relates to a slag discharge device for cooling and solidifying a molten slag (hereinafter referred to as ash) while being continuously conveyed and discharging the solidified solidified slag from a discharge port.

[0002]

2. Description of the Related Art In recent years, when treating ash as described above, for example, as disclosed in JP-A-62-187453, after ash is melted in a swirling flow melting furnace to form slag. An apparatus for melting and solidifying ash for cooling and solidifying the molten slag has been developed.

This ash melting and solidifying apparatus is intended to reduce the volume of ash to be disposed and to fix harmful substances such as heavy metals, which is shown in a side sectional view of FIG. As described above, a melting furnace 20 having a melting part 26 for melting and converting the ash into molten slag while rotating the ash, and a slag part 28 for discharging the molten slag S at the bottom, and the slag part 28.
And a slag discharge device 1 for discharging the solidified slag C solidified by cooling, while cooling the molten slag S discharged from the slag part 28 while continuously conveying the slag.

The melting furnace 20 includes a melting section 26 and a slag section 2.
8, a throttle 27 is provided, and an exhaust gas outflow portion 29 is provided between the throttle 27 and the slag 28. The slag portion 28 is composed of an inclined portion for receiving the molten slag S falling from the throttle portion 27 and causing the molten slag S to flow down, and a vertical portion continuous with the inclined portion.

Further, the slag discharging device 1 includes a chain conveyor 4 and a chain 4c of the chain conveyor 4.
The mold 4d has an inverted truncated cone shape and is circulated at a predetermined interval by means of, and is arranged so as to cover the upper side of the chain conveyor 4, and has an opening portion directly below the slag portion 28. It is composed of a heat insulating hood 2.

Therefore, the molten slag S flowing down from the vertical portion of the slag portion 28 passes through the opening 3 and is received by the mold 4d, and the molten slag S thus received by the mold 4d is transferred to the chain conveyor 4. During transportation by circulation, it is cooled and solidifies and solidifies. Then, the solidified slag C is released by reversing the mold 4d on the destination side, and is discharged into the solidified slag container 5 arranged below.

The main burner 22 is provided on the top of the melting section 26, and a table feeder 24 and a valve 25 are connected to a fuel air supply pipe 21 communicating with the main burner 22 for supplying air and fuel. Reference numeral 23 communicating via
Is a hopper for supplying the ash to be molten slag into the melting portion 26, and the reference numeral 30 communicating with the melting portion 26 near the upper portion of the melting portion 26 is for burning the fuel ejected from the main burner 22. An air supply pipe for blowing combustion air.

However, since it is difficult to uniformly bring the entire slag portion 28 to the ash melt temperature by the auxiliary burner,
A portion below the melt flow temperature is likely to exist in the slag portion 28, so that the molten slag S is semi-molten and adheres to the wall surface of the slag portion 28, and in some cases, the slag portion 28 is clogged. There was something.

In order to improve such a problem, the applicant of the present invention discloses in Japanese Patent Application No. 1-222870, a funnel portion directly below a narrowed portion 27 of the fusion zone 26, as shown in FIG. A melt-solidification treatment apparatus is provided in which 31 is provided, and the molten slag S is made to flow down through the central portion of the molten slag S so that the molten slag S does not touch the inner wall of the slag portion 28 and is injected into the inverted frustoconical mold 4d. ..

[0010]

As described above, according to the melting and solidifying apparatus of the present applicant, most of the molten slag flows down through the central portion of the slag and is poured into the mold. However, a part of it is removed from the central part of the slag part or flows down the inner wall of the slag part so that it is not injected into the mold and the chain of the chain conveyor that circulates the mold, the chain guide roller and the guide roller. Will fall and stick to rolling rails, etc., or will fall further downward and accumulate.

As described above, when the high temperature molten slag falls on the chain, the guide rollers, the rails, etc., the heat, the chain, the guide rollers, the rails, etc. are damaged, and the chain is not only extended but also dropped. The molten slag sticks to the mold, which hinders the transport of the mold, and the vicinity of the slag outlet is exposed to the high-temperature radiant heat of the molten slag and the high-temperature exhaust gas blown from the slag outlet, which causes damage to the guide rollers due to chain extension. There is a problem to be solved in transportation related to. That is, it is difficult to continue stable operation of the slag discharge device, which hinders improvement of ash processing efficiency and reduction of maintenance cost of the melt solidification processing device.

Further, as shown in FIG. 6, the mold has a shape of an inverted truncated cone made of steel. Therefore, when the mold is filled with molten slag and solidified and solidified, the coefficient of thermal expansion and the coefficient of thermal contraction of the mold and the slag are increased. Therefore, even if a force is applied to the slag from the mold from the surroundings, the mold sandwiches the solidified slag.In this condition, even if a slight mechanical impact is applied to the mold, the solidified slag is released from the mold. Becomes difficult. For this reason, there is a problem that the solidified slag is not released from the mold due to the reversal of the mold on the destination side.

In order to prevent this, the inventors tried to apply a release agent such as zirconium to the inner wall of the mold, but the satisfactory result was not obtained. Moreover, the detachability of the solidified slag from the mold was investigated by changing the side wall inclination angle θ of the mold in the range of 55 ° to 73 °, but the effect by changing the side wall inclination angle θ was not obtained. After all, it was found that in order to release the solidified slag from the mold, it was necessary to heat the mold to about 500 ° C. to thermally expand the mold and form a gap with the solidified slag. This requires a separate heating device and fuel.

Therefore, the object of the present invention is to solve the above-mentioned problems of the conventional one, to stably convey the mold, and to easily detach the solidified slag from the mold. To provide a slag discharge device.

[0015]

In order to achieve the above object, the feature of the means adopted by the slag discharge device according to the present invention is that it receives molten slag and solidifies the received molten slag in the circulation. Along with, in a slag discharge device provided with a plurality of molds for discharging the solidified slag solidified by inversion from the discharge port, in the space between the slag port and the moving region of the mold on the molten slag receiving side, cooling water inside There is a slag guide having a slope for guiding the molten slag to the mold that has been circulated to the position below the outlet port.

Further, in a slag discharge device provided with a plurality of molds for receiving the molten slag, solidifying the received molten slag in the circulation, and discharging the solidified slag solidified by inversion from the discharge port, the mold shape is an inverted pyramid. The above-mentioned slag discharge device has a trapezoidal shape, and the mold having the shape of an inverted truncated pyramid has a sidewall inclination angle of 50 ° or more and 70 ° or less.

[0017]

According to the slag discharge device of the present invention, the molten slag is guided to the mold circulated below the slag port into the space between the slag port and the moving region of the mold on the molten slag receiving side. Since the slag guide is provided, the molten slag that comes off the central part of the slag part and flows down the inner wall of the slag part is guided into the mold by the slope of the slag guide, and high temperature radiant heat and The high temperature exhaust gas blown from the slag is blocked by the slag guide. Further, since the slag guide is cooled by the cooling water flowing inside, the molten slag is unlikely to adhere to the slag guide, and the progress of wear due to high temperature is suppressed.

By changing the shape of the mold to the shape of an inverted truncated pyramid, unlike the shape of an inverted truncated cone, the directions of the force for sandwiching the solidified slag are not uniform, and the solidified slag can be easily detached from the mold. Further, the solidified slag is cracked with time, and the solidified slag is more easily detached from the mold.

As for the side wall inclination angle, the side wall inclination angle 70
At 30 °, the mold reversal angle (the angle of inclination of the mold with respect to the horizontal) for releasing the solidified slag from the mold is 30 minutes after the mold is filled with molten slag.
This is 5 °, and this reversal angle means that the mold is almost upside down. Therefore, the upper limit of the sidewall inclination angle is considered to be 70 °, and if the sidewall inclination angle becomes larger than this, the solidified slag may not be detached from the mold.

On the other hand, when the side wall inclination angle becomes smaller, the complete crystallization rate of the solidified slag decreases. The reason for this is considered that as the side wall inclination angle becomes smaller, the surface area becomes larger than the inner volume of the mold, and the molten slag is easily cooled. Therefore, in order to obtain the target perfect crystallization rate, the lower limit of the sidewall inclination angle is 50 °.

The properties of the solidified slag in the mold are as follows.
As shown in FIG. 7, in order from the inner wall surface of the mold 4d, a thin layer of glassy material G, a transition layer CG in which some glassy material is mixed in crystalline material, and a crystalline material CR are formed. Also, by changing the side wall inclination angle with the adjacent side wall, the anisotropy of the force for sandwiching the solidified slag becomes stronger, the solidified slag can be easily detached from the mold, and the internal volume of the mold can be increased relative to the surface area. Since it can be relatively large, the complete crystallization rate is also high. The slag of the transition layer has substantially the same physical properties as the crystalline slag and has sufficient strength.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a slag discharge device according to the present invention will be described below with reference to FIG. 1 which is a side sectional view thereof and FIG.
2a of FIG. 2a and FIG. 2b of the arrow B of FIG. 2a, the same parts and those having the same function as those of the related art will be described with the same reference numerals. Reference numeral 1 shown in FIG. The slag discharge device 1 is a slag discharge device, and the slag discharge device 1 has a structure which will be described later.
The casing 2 in which the
A slag spout 3 for connecting the molten slag S down to the casing 2 is connected to the casing 2.

The chain conveyor 4 has a casing 2
A pair of driven sprockets 4a provided at predetermined intervals in the vicinity of the end in the longitudinal direction, and a drive sprocket 4b driven by a motor M provided on the casing 2, and each pair of sprockets 4a, Four
The endless chains 4c, 4c are hung so as to circulate across b.

Further, inside the chains 4c and 4c, a plurality of molds 4d having an inverted truncated pyramid shape are arranged at predetermined intervals, and on the opposite sides of the chains 4c and 4c are horizontally arranged at predetermined intervals. A guide roller 4e that rolls around the axis is attached, and the guide roller 4e
Are configured to roll on rails 4f, as shown in FIG. 2a. That is, the mold 4d is configured to be transported to the destination side in the right direction in FIG. 1 by the circulation drive of the chains 4c and 4c.

On the other hand, a discharge port 2a having a double slide gate 2b is provided on the lower side of the carrying side of the casing 2, and the double slide gate 2b is opened to invert the inverted pyramid-shaped mold 4d. Thus, the solidified slag C released from the mold is dropped into the solidified slag container 5 disposed immediately below the discharge port 2a.

The port 2c provided at the upper center of the casing 2 in the longitudinal direction introduces the high temperature exhaust gas in the melting furnace into the casing 2 by the suction action of the ejector 6, and the inside of the casing 2 is heated to a predetermined temperature. It has a function of maintaining the. As well understood from the above description, the structure of the slag discharge device is the same as the structure of the slag discharge device of the melting and solidification processing device proposed by the applicant of the present application in Japanese Patent Application No. 1-228870.

In the slag discharge device according to the present invention, a flat water-cooled slag guide plate 7 having a water channel in which the cooling water meanders and flows therein is provided as a slag guide in the slag discharge device having the above-described structure. It is arranged directly below the slag mouth 3.

More specifically, as shown in FIGS. 2a and 2b, a support 7a is erected on the rail 4f so that the rail 4f is axisymmetric with respect to a vertical line passing through the center of the rail 4f in the width direction. The opening width of is wider than the opening size of the outlet port 3,
In addition, the lower opening width is supported so as to be narrower than the opening width of the mold 4d, and each opening width is supported so as to be wider on the transfer destination side than on the transfer source side of the mold 4d. That is,
As shown in FIG. 2b, the molten slag S, which is supported in the shape of “inverted C” and flows down to the opposite slopes of the water-cooled slag guide plates 7, 7, is smoothly guided into the mold 4d. In consideration. By the way, as a material of the water-cooled slag guide plate 7, for example, a stainless plate, a carbon steel plate, a copper plate or the like is suitable.

The water-cooled slag guide plate 7 has a flat box structure, and three partition plates are installed in parallel inside the water-cooled slag guide plate 7, and as shown in FIG. 7i
The cooling water supplied from the above meanders in a zigzag manner from left to right, left to right, and flows out from the cooling water outlet 7o provided on the upper right side.

The mode of operation of the slag discharge device having the above-mentioned structure will be described below. The molten slag S melted in a melting furnace (not shown) is removed from the center of the outlet 3 as shown in FIG. 2b. Even if the water-cooled slag guide plates 7 and 7 flow down along the slope of one of the water-cooled slag guide plates 7, even if they flow down along the inner wall of the slag port 3, they are conveyed directly below the slag port 3. It is guided into the mold 4d having the inverted truncated pyramid shape.

Incidentally, in this embodiment, 500 kg / h
Although the molten slag S of No. 1 was slagged from the slag port 3, the molten slag S did not leak onto the chains 4c, 4c, the guide rollers 4e or the rails 4f as in the conventional case, and almost all of the molten slag S was It could be injected into the inverted truncated pyramid shaped mold 4d.

By the way, although 3 m ³ / h of cooling water was passed through each of the water-cooled slag guide plates 7, 7, the water-cooled slag guide plates 7, 7 are cooled by the cooling water. Therefore, the adhesion of the molten slag S deteriorates, the molten slag S easily slides down the slopes of the water-cooled slag guide plates 7, 7, and the adhesion of the molten slag S to the water-cooled slag guide plates 7, 7 was not recognized. .. Further, even with the water-cooled slag guide plates 7 and 7 made of copper plates, almost no damage or thinning was observed, and the operation of the slag discharge device could be continued in a stable state for a long period of time.

Of course, it is possible to make the slag guide not to pass cooling water, but in that case, it is necessary to stretch the heat resistant member on the surface of the slag guide, and in addition, it is necessary to stretch it. Since molten slag is also attached to the surface of the heat-resistant member, it is not always preferable from the economical point of view and the continuous operation of the slag discharge device 1.

On the other hand, the temperature between the water-cooled slag guide plates 7, 7 was about 670 ° C., but the radiant heat of the molten slag S and the high-temperature exhaust gas blown out from the outlet 3 were the water-cooled slag guide plate 7,
Rails 4f, chains 4c, 4 because they are blocked by 7
The temperature in the vicinity of c and the guide roller 4e was lowered to 200 ° C. (about 600 ° C. in the past).

In this way, the rail 4f, the chains 4c and 4c and the guide rollers are guided by the guiding action of the molten slag S of the water-cooled slag guide plates 7 and 7 and the shielding action of the radiant heat and the high temperature exhaust gas blown out from the slag outlet 3. As the molten slag S that falls to 4e disappears, the ambient temperature of them decreases. As a result, as in the conventional case, solidification of the molten slag S that has fallen off causes the sticking to the rails 4f, the chains 4c and 4c, and the guide rollers 4e, and the chains 4c and 4c due to high temperature.
The solidified slag C can be continuously discharged for a long period of time in an extremely stable state without damaging the guide roller 4e or the like, and is greatly effective in improving the processing efficiency of the slag and reducing the maintenance cost of the melt solidification processing device. there were.

In addition, the casing 2 usually has a screw feeder (not shown) for moving the solidified slag that has fallen to the lower floor and solidified through the discharge port 2a so as to move it toward the discharge port 2a. Although it is installed along the floor, since there is almost no molten slag S that falls onto the lower floor of the casing 2 as described above, the effect that a screw feeder with a small capacity is sufficient has been brought about.

In the above description, the slag discharging device 1 having the conveying means for conveying the inverted truncated pyramid shaped mold 4d by the chain conveyor 4 has been described as an example, but the present invention is not particularly limited to such a constitution and other conveying means. Even if the water-cooled slag guide plates 7, 7 having the above-described configuration are arranged in the slag discharge device having the above-mentioned structure, it is possible to achieve the same effect as the above.

There are three types of molds used in the above embodiments, and the plan view and front view of each are shown in FIG. The inner volume of the mold is 30 liters, and the side surface inclination angle θ is 70 ° on all sides in the figure, 50 ° on all sides in the Y type, and 70 ° and 50 ° on opposite sides in the Z type. These molds were filled with molten slag, and after 20 hours, the mold was inverted to release the solidified and solidified slag from the mold, and the inversion angle and complete crystallization rate at that time were investigated. For X type, 30
The reversal angle after minutes was also investigated. The results are shown in Table 1.

[0039]

[Table 1]

As shown in Table 1, the solidified slag could be desorbed from the mold without reheating the mold in all three types of X type, Y type and Z type. Further, by changing the side wall inclination angle like the Z type, the anisotropy of the force for sandwiching the solidified slag becomes strong, and the solidified slag can be easily detached from the mold with a small reversal angle.

X-type (61.8%) in ascending order of complete crystallization rate
, Z type (60.6%), and Y type (49.0%) in that order, and the smaller the side wall inclination angle, the lower the complete crystallization rate. Table 2 shows the physical properties of the completely crystallized slag. Table 2
As shown in, the slag satisfies the characteristic values specified in JIS A500, has very high strength, and can be sufficiently used as a building material or a roadbed material.

[0042]

[Table 2]

[0043]

As described above in detail, according to the slag discharge device of the present invention, the guide function of the molten slag of the slag guide, the shielding effect of the radiant heat and the high temperature exhaust gas ejected from the outlet, and the mold Due to the detaching action of the solidified slag, the molten slag that falls on the rails, chains, and guide rollers disappears, and the ambient temperature of these drops. The damage to the rollers etc. is eliminated, the solidified slag can be easily removed from the mold, and the solidified slag can be continuously discharged for a long period of time in an extremely stable state. It has an extremely great effect on the reduction of maintenance cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of a slag discharge device according to an embodiment of the present invention.

FIG. 2a is an enlarged view of part A of FIG. 1, and FIG.
[Fig. 2] is a view on arrow B of Fig. 2a.

FIG. 3 is a diagram of three types of mold shapes used in the embodiment of the present invention, in which a, c and e are plan views, b, d and f, respectively.
Is a front view of each.

FIG. 4 is a side sectional view of a melting and solidifying apparatus according to a first conventional example.

FIG. 5 is a side sectional view of a melting and solidifying apparatus according to a second conventional example.

6A and 6B are views showing a mold according to a conventional example, in which a is a plan view and b is a sectional view.

FIG. 7 is a diagram showing properties of solidified slag in a mold.

[Explanation of symbols]

1 ... slag discharge device, 2 ... casing, 2a ... discharge port,
2b ... double slide gate, 2c ... port, 3 ... debris outlet, 4 ... chain conveyor, 4a ... driven sprocket,
4b ... Drive sprocket, 4c ... Chain, 4d ... Mold, 4e ... Guide roller, 4f ... Rail, 5 ... Solidified slag container, 6 ... Ejector, 7 ... Water-cooled slag guide plate, 7a ... Strut, 7i ... Cooling water inlet, 7o … Cooling water outlet, C… solidified slag, M… motor, S… molten slag, θ
... sidewall inclination angle, CR ... crystalline, CG ... transition layer, G ... vitreous.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshio Kasai 1-3-18 Wakihama-cho, Chuo-ku, Kobe-shi, Hyogo Kobe Steel Works, Kobe Head Office (72) Masao Matsuda Wakihama, Chuo-ku, Kobe-shi, Hyogo 1-318, Machi Kobe Steel Works, Ltd. Kobe Head Office

Claims (2)

[Claims] 1. A slag discharge device provided with a plurality of molds for receiving molten slag, solidifying the received molten slag in circulation, and discharging solidified slag solidified by inversion from an outlet, In the space between the molten slag receiving side and the moving area of the mold, cooling water was passed inside, and a slag guide having a sloped surface for guiding the molten slag to the circulating mold was provided below the outlet. A slag discharge device characterized in that 2. A slag discharge device provided with a plurality of molds for receiving molten slag, solidifying the received molten slag in circulation, and discharging solidified slag solidified by inversion from a discharge port, wherein the mold shape is an inverted pyramid. The trapezoidal shape and the side wall inclination angle of this inverted truncated pyramid shaped mold are 50
The slag discharge device according to claim 1, further comprising a mold having an angle of not less than 70 ° and not more than 70 °.