JP3037097B2 - Metal discharge method and apparatus for electric ash melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal discharge method for adjusting the amount of base metal in a plasma type or arc type ash melting furnace for heating and melting incinerated ash such as municipal waste and industrial waste. And equipment.

[0002]

2. Description of the Related Art Conventionally, incinerated ash is thrown into an ash melting furnace and heated and melted in order to reduce the volume and detoxification of incinerated ash discharged by incineration of municipal waste and industrial waste in an incinerator. And produces slag. By the way, in a plasma type or arc type ash melting furnace, the molten slag of the injected ash and the molten metal (base metal) are mixed, and the base metal melted in the lower layer on the furnace bottom side due to the difference in specific gravity becomes the upper layer. Contains molten slag. When new incinerated ash is supplied there, unburned ash is burned, and the ash becomes molten slag. Further, metals contained in the ash are dissolved and mixed into the base metal, and the level of the molten metal of the base metal gradually increases. When the base metal reaches the slag outlet, the metal is mixed and discharged into the molten slag, so it is necessary to periodically extract the base metal.

[0003] As means for extracting the base metal, a furnace body is configured to be tiltable, and a metal extraction outlet is formed in a lower side wall portion during tilting.
In some cases, a metal outlet port that can be opened and closed by a gate was formed on the furnace side wall.

[0004]

However, in the case of the furnace tilting type, a large number of mechanical devices are required to tilt the furnace main body, and a large space and a large amount of work are required. A special connection structure was required for the ash supply device and the connection part of the exhaust gas duct, which took time for extraction. Further, at the time of extraction, since the molten slag is discharged to the base metal, there is a problem that all the molten slag that does not need to be extracted is also discharged. When all of the molten slag is discharged, the ash must be melted from the beginning when restarting, and the operation is not stable. Further, in the case of the gate type, since the base metal is blocked by the gate during the discharge, the metal or slag is likely to be fixed to the metal outlet and the gate, and the base metal may leak due to the bite of these. .

The present invention solves the above-mentioned problems, and does not require a large number of mechanical devices, hardly discharges molten slag, and can safely perform tapping work without dangerous work. An object of the present invention is to provide a method and an apparatus for discharging metal from a furnace.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for discharging a metal of an electric ash melting furnace according to the present invention is disclosed. When extracting a predetermined amount of the base metal that increases due to the melting of the metal that has been melted, first, the valve element in the furnace is lowered, and the metal extraction hole formed at the furnace bottom is filled with refractory particles and closed by the valve element outside the furnace. After closing the opening inside the furnace, and then opening the outer valve body to discharge the refractory granules, raise the inner valve body to discharge the base metal from the metal outlet and discharge a predetermined amount of the base metal. After that, the inner valve body is lowered to close the furnace opening of the metal extraction hole, the outer valve opening is closed by the external valve body, and refractory particles are filled in the metal extraction hole, and further, It raises the internal valve body and waits above the molten slag. .

[0007] The metal discharge device of the electric ash melting furnace is
A metal extraction hole is formed at a predetermined position on the bottom wall of the furnace main body, and an internal valve body is openably and closably provided at an opening in the furnace at the metal extraction port. A valve element is provided so as to be openable and closable, and a refractory particle supply means for filling refractory particles is provided in a slag outlet between the inner valve element and the outer valve element.

Further, a part of the bottom wall of the furnace main body in which the metal extraction hole having the above structure is formed is set to the same level as the initial level in which the minimum required amount of the base metal is stored.

Further, the refractory granule supply means having the above-mentioned structure is provided with a refractory granule supply hole which is bored in the inner valve body and opens toward the metal extraction hole. And a refractory granule supply device for sending out the powder.

[0010]

According to the above construction, the inner valve element is temporarily immersed in the molten slag and the base metal, but is always on standby above the molten slag, and the outer valve element is connected to the base metal via the refractory granules. Because of holding, the internal valve body and the external valve body can be prevented from being burned out by high-temperature molten slag or base metal, and the life can be prolonged. In addition, the intermediate metal can be easily and safely extracted in a short time without the need for a large-scale device. Furthermore, since the slag can be extracted first from the base metal, the molten slag can be left in the furnace, and the ash can be stably melted upon restart.

Further, by setting the bottom wall where the metal extraction hole is formed at the same level as the initial level of the base metal, the internal valve can be closed when the molten slag starts to be discharged. The closing time of the body can be easily detected, the remaining amount of the base metal can be kept constant, and the base metal can be reliably prevented from being excessively extracted.

Furthermore, since the refractory material supply hole is formed in the inner valve body, the whole can be made compact.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a metal discharge device for a plasma type ash melting furnace according to the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, a pair of electrodes 2A and 2B penetrating through a ceiling wall 1a are suspended in a furnace main body 1 made of a refractory material. 2
Gas supply holes 2a and 2b for supplying a nitrogen gas for forming an ionized gas are formed in the axial center portions of A and 2B. An ash supply device (not shown) is provided at one end of the furnace main body 1 for supplying ash into the furnace by a predetermined amount using a pusher or the like, and a slag discharge outlet for discharging molten slag Sf to the other end. A slag cooling chamber 4 for cooling the molten slag Sf with water to generate granulated slag Sw is provided below the slag discharge outlet 3. Further, the bottom wall 1b of the furnace main body 1 holding the base metal M and the molten slag Sf has a large depth portion 5A for storing the base metal M, and a bottom surface on one side where the minimum required amount of the base metal M is stored. A small depth portion 5B set identically to the level LML is formed,
A taphole 6 for overhaul is formed in the large depth portion 5A,
The metal discharge device 7 according to the present invention is provided in the small depth portion 5B.

In the metal discharge device 7, a metal extraction hole 11 is formed through the small depth portion 5B of the bottom wall 1b, and the metal extraction device 7 is slidably fitted to the through hole 12 of the top wall 1a above the metal extraction hole 11. The furnace opening 11a of the metal outlet 11
An internal valve rod (an example of an internal valve body) 13 made of a refractory material capable of opening and closing the valve is provided. This internal valve rod 13
It is supported by a valve body lifting / lowering device 14 arranged on the furnace body 1 so as to be able to move up and down. In addition, at the axial center of the internal valve rod 13,
A sand supply hole (refractory particle supply hole) 15 for supplying sand F, which is an example of a refractory particle, into the metal extraction hole 11 is formed and opened on the bottom surface of the valve portion 13a of the internal valve rod 13, and the furnace is opened. Sand supply device (refractory granule supply device) 1 arranged on main body 1
6 is the sand supply hole 1 through the flexible tube 17.
5, the metal extraction hole 11 and the sand supply device 16 constitute refractory granule supply means.

The outside opening 11b of the metal outlet 11
Is provided with an opening / closing gate (an example of an external valve body) 19 capable of opening and closing the outside opening 11b of the furnace via a link and a pin by a gate opening / closing cylinder 18.

The metal discharging method in the above configuration will be described with reference to FIGS. When the tapping timing is detected by a signal indicating level control by a load cell for detecting the amount of base metal from the weight of the furnace body 1 or level control by a timer set based on the amount of ash melting, first, FIG. As shown in (1), the internal valve rod 13 is lowered by the valve body lifting / lowering device 14, and the furnace opening 11a of the metal extraction hole 11 is closed. Next, as shown in FIG.
The opening / closing gate 19 is opened and closed by the gate opening / closing cylinder 18 to open the furnace opening 11b of the metal extraction hole 11, so that the sand F in the metal extraction hole 11 is discharged.
Then, as shown in FIG. 3 (c), the internal valve rod 13 is raised by the valve body lifting / lowering device 14 and the furnace opening 11a is released, so that the base metal M at the bottom of the furnace main body 1 is removed from the metal outlet 11 Is discharged from

As shown in FIG. 4 (a), the excess base metal M is discharged, the molten metal surface becomes the initial level LML of the base metal, the base metal M disappears in the small depth portion 5B, and the molten slag Sf is formed. When discharging starts, the internal valve rod 13 is lowered by the valve body lifting / lowering device 14, the furnace opening 11a is closed, and the discharge of the molten slag Sf is stopped. Then, as shown in FIG.
Compressed air is blown into the metal extraction hole 11 by an air gun 20 which is an example of the first cleaning means, and the attached molten steel and slag are removed. Further, as shown in FIG. 3 (c), the opening / closing gate 19 is closed by the gate opening / closing cylinder 18, the outside opening 11b is closed, and the sand F is supplied from the sand supply device 16 through the sand supply hole 15. It is supplied and filled into the metal extraction hole 11. And the valve body lifting device 1
4 raises the internal valve rod 13 to open the furnace opening 11
a is released.

According to the above configuration, the inner valve rod 13 is temporarily immersed in the molten slag Sf and the base metal M, but is always on standby above the molten slag Sf. Since the base metal M is held through the sand F, the internal valve rod 13 and the opening / closing gate 19 can be prevented from being burned out by the high-temperature molten slag Sf or the base metal M, and the life of each member can be extended. can do.

By the above operation, as compared with the conventional tilting type of the furnace body, a large amount of equipment and a large space are not required, and the middle metal can be easily extracted in a short time. In addition, the metal extraction hole 11 is closed by the opening / closing gate 19 via the sand F, and the metal extraction hole 11 is cleaned every time the metal is extracted to remove the adhering matter and filled with new sand F. Compared with the gate type, there is no danger or blockage of tapping, tapping can be performed reliably, and stable extraction of the base metal M becomes possible.

Since the molten slag Sf can be left in the furnace main body 1 because it can be extracted first from the base metal M, the ash can be stably melted at the time of restart.

The metal extraction hole 11 is formed in the small depth portion 5B whose bottom surface is set to be the same as the initial level LML in which the minimum required amount of the base metal M is stored.
By closing the internal valve rod 13 when f starts to be discharged, an appropriate amount of the base metal M can be left in the large depth portion 5A, and the closing timing of the internal valve rod 13 can be easily detected, Further, the remaining amount of the base metal M can be kept constant, so that excessive removal can be reliably prevented.

Since the sand supply hole 15 is formed in the internal valve rod 13, the whole structure can be made compact.

FIG. 5 shows an embodiment in which the positions where the metal extraction holes are formed are changed. That is, the small depth portion 35 of the furnace body 31
B is formed so as to protrude from one side of the large depth portion 35A.

In the above embodiment, the plasma type ash melting furnace is used, but an arc type ash melting furnace may be used.

[0026]

As described above, according to the present invention, the internal valve element is temporarily immersed in the molten slag and the base metal.
Nevertheless, it is always on standby above the molten slag, and since the external valve body holds the base metal through the refractory granules, it prevents the internal and external valve bodies from burning due to high-temperature molten slag and base metal. Can extend the life. In addition, the intermediate metal can be easily and safely extracted in a short time without the need for a large-scale device. Furthermore, since the slag can be extracted first from the base metal, the molten slag can be left in the furnace, and the ash can be stably melted upon restart.

By setting the bottom wall where the metal extraction hole is formed at the same level as the initial level of the base metal, the internal valve can be closed when the molten slag starts to be discharged. The closing time of the body can be easily detected, the remaining amount of the base metal can be kept constant, and the base metal can be reliably prevented from being excessively extracted.

Further, since the refractory particle supply hole is formed in the internal valve body, the whole can be made compact.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a plasma type ash melting furnace provided with a metal discharge device according to the present invention.

FIG. 2 is a plan sectional view of the plasma type ash melting furnace.

3 (a) to 3 (c) are longitudinal sectional views of metal extraction holes showing operation procedures of the metal discharging device.

4 (a) to 4 (c) are longitudinal sectional views of metal extraction holes showing operation procedures of the metal discharging device.

FIG. 5 is a plan sectional view showing another embodiment of the plasma type ash melting furnace.

[Explanation of symbols]

 M Base metal Sf Molten slag F Sand (refractory granules) 1 Furnace main body 1b Bottom wall 2A, 2B electrode 3 Slag outlet 4 Slag cooling room 5A Large depth section 5B Small depth section 7 Metal discharge device 11 Metal extraction hole 11a Inside Opening 11b External opening 13 Internal valve rod (internal valve element) 13a Valve section 14 Valve element lifting / lowering device 15 Sand supply hole (refractory particle supply hole) 16 Sand supply device (refractory particle supply device) 18 Gate opening / closing cylinder 19 Opening / closing gate (external valve body)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kosaka 5-28-3 Nishikujo, Konohana-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Michio Ishida 5-cho, Nishikujo, Konohana-ku, Osaka-shi, Osaka No. 3-28 Within Hitachi Zosen Corporation (72) Inventor Tsutomu Kuwahara 5-28 Nishikujo, Konohana-ku, Osaka-shi, Osaka Prefecture 3-72 Inside Hitachi Zosen Corporation (72) Inventor Hideo Sato Nishikujo, Konohana-ku, Osaka, Osaka 5-3-28 Hitachi Zosen Corporation (56) References JP-A-64-6611 (JP, A) JP-A-60-122812 (JP, A) JP-A-3-294712 (JP, A) Table Hei 5-505444 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23G 5/00 115 F23J 1/00 ZAB

Claims (4)

(57) [Claims] 1. During the operation of an electric ash melting furnace for heating and melting ash, when extracting a predetermined amount of base metal increased by melting of metal contained in the ash, first, a valve element in the furnace is lowered and the furnace is lowered. After filling the refractory granules formed on the bottom and closing the in-furnace opening of the metal extraction hole closed by the outer valve body, then opening the outer furnace valve body to discharge the refractory particles The internal valve is raised to discharge the base metal from the metal outlet, and after a predetermined amount of base metal has been discharged, the internal valve is lowered to close the furnace opening of the metal outlet and the external valve The metal of the electric ash melting furnace is characterized in that the opening outside the furnace is closed by the body, the refractory particles are filled in the metal extraction hole, and the internal valve body is raised to stand by above the molten slag. Discharge method. 2. A metal extraction hole is formed at a predetermined position on the bottom wall of the furnace main body, and an internal valve body is openably and closably disposed at an opening in the furnace at the metal extraction port. An outer furnace valve body is provided in the opening so as to be openable and closable, and a refractory granule supply means for filling refractory particles is provided in a slag outlet between the inner valve body and the outer valve body. Metal discharge device for electric ash melting furnace. 3. The furnace according to claim 2, wherein a part of the bottom wall of the furnace main body where the metal extraction hole is formed is set at the same level as the initial level in which the minimum required amount of the base metal is stored.
The metal discharge device of the electric ash melting furnace described in the above. 4. A refractory granule supply means, comprising: a refractory granule supply means, wherein the refractory granule supply means is provided in the inner valve body and opened to face a metal extraction hole.
4. A metal discharge device for an electric ash melting furnace according to claim 2, wherein said refractory material supply device feeds refractory particles into said refractory material supply hole.