JPH08327044A - Cooling construction of tap hole in fusion furnace - Google Patents

Abstract

PURPOSE: To stably and continuously tap a fused substance from a tap hole irrespective of an amount tapped and extend a service life of a refractory at the tap hole. CONSTITUTION: An overflow tap type fusion furnace fuses and treats a substance being fused, such as incineration ash, smoke dust and the like, to make the fused substance 5 overflow from a tap hole 2. Provided in a refractory at the tap hole 2 is a cooling block 7, in which a plurality of cooling passages 7a are formed and compartmented, and a cooling medium is suitably supplied to the respective cooling passages 7a in the cooling block 7 to enable adjusting a cooling capacity of the cooling block 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outlet tap of a melting furnace of an overflow tapping method, which is used for melting objects to be melted, such as incineration ash and soot from a refuse incinerator, or general waste and industrial waste. Regarding cooling structure.

[0002]

2. Description of the Related Art Generally, most of incinerated ash and dust generated in a refuse incinerator are landfilled. But,
Since the incinerated ash and dust contain harmful substances such as heavy metals and dioxins, there is a risk that environmental pollution will occur after landfill treatment, and securing landfill sites is becoming difficult year by year. There are various problems.

By the way, when the incinerated ash and the soot and dust are melted and solidified, not only the volume is greatly reduced, but also the elution of heavy metals and the like is eliminated, and it is possible to effectively use the aggregate and the roadbed material. Therefore, recently, incineration ash and soot dust are being melted. Further, not only incinerated ash and dust, but also waste and sewage sludge are being melted.

Conventionally, an electric melting furnace such as an arc furnace, a plasma furnace, an electric resistance furnace or a combustion type melting furnace using a fuel such as oil or gas is used for melting a material to be melted such as incineration ash or dust. In an incinerator equipped with a power generation facility, an overflow tap type electric melting furnace is often used.

FIG. 5 shows an example of a conventional overflow hot-melting type melting furnace, which melts a material 22 to be melted, such as incinerated ash, charged into a furnace body 21 by arc heat from an electrode 23 or the like. , The melt 22a accumulated in the furnace is sequentially tapped from the tap 24
The hot water is discharged to the outside from the overflow portion 21a. Further, the gas 25 generated by melting the melted material 22 is discharged from the gas discharge port 26 to the outside of the furnace through a bag filter (not shown) and the like. In FIG. 5, reference numeral 27 is a molten material supply device, 28 is a start electrode, and 29 is a furnace bottom electrode.

[0006]

By the way, in the overflow hot-melting type melting furnace, the hot water outlet 24 has a water cooling structure (not shown) in order to suppress the consumption of the furnace material (refractory) of the hot water outlet 24. , Protects the furnace material. However, immediately after the start of the operation of the melting furnace (when the heat storage of the furnace material is insufficient), or when the amount of molten metal 22a discharged (the amount of overflow) is smaller than planned, the molten material in the tap hole 24 The phenomenon that 22a is easily cooled and solidified and does not easily overflow occurs. Therefore, in a conventional melting furnace, a heating device (not shown) such as an auxiliary burner or an auxiliary electrode is provided at the tap hole 24 of the melting furnace, and the molten material 22a in the tap hole 24 is heated by the heating device. The molten material 22a is prevented from solidifying by cooling at the tap hole 24. or,
On the contrary, when the amount of molten metal 22a discharged is larger than planned, the cooling is insufficient and the furnace material near the outlet 24 is exposed to high temperature, and the flow velocity of the melt 22a is high, and the consumption of the furnace material is severe. Become.

As described above, in the conventional overflow hot-melting type melting furnace, the furnace material (refractory) of the tap hole 24 is supercooled, and the melt 22a is heated by a heating device such as an auxiliary burner or an auxiliary electrode. Since it is heated to prevent solidification by cooling, heat loss is large and it is extremely uneconomical.

The present invention was created in order to solve the above problems, and its purpose is to minimize the heat loss in the vicinity of the outlet and to change the temperature of the furnace material at the outlet to change the amount of tapping. Even if the temperature of the molten material does not solidify, the molten material can be stably and continuously discharged, and the rapid exhaustion of the furnace material at the outlet can be suppressed. To provide.

[0009]

In order to achieve the above-mentioned object, the structure for cooling the outlet of the melting furnace of the present invention is provided with a cooling block in which a plurality of cooling passages are formed in the refractory at the outlet. The cooling medium supply mechanism appropriately supplies the cooling medium into the respective cooling passages of the cooling block so that the cooling capacity of the cooling block can be adjusted. Further, the cooling medium supply mechanism is connected to each cooling passage of the cooling block, connected to each of the cooling water supply pipes for supplying cooling water to each cooling passage, and each cooling passage of the cooling block to cool each cooling passage. A cooling air supply pipe that supplies air, and a plurality of cooling water valves that are provided in each cooling water supply pipe to control the flow of cooling water into and out of each cooling passage, and a cooling air supply pipe that is provided in each cooling air supply pipe. There is provided a plurality of cooling air valves for adjusting the flow of cooling air into and out of the cooling passage, and the cooling water valve and the cooling air valve are respectively controlled based on the temperature detection of the refractory near the cooling block, It is preferable that the cooling medium supplied to each cooling passage of the cooling block can be switched and controlled.

[0010]

[Operation] In a melting furnace having an overflow tap, a melted material such as incineration ash or dust supplied to the furnace is the arc heat of the electrode, the plasma heat, or the Joule heat of the melted material itself. Is melted into a fluid melt, overflows from the tap hole, is cooled by water cooling or air cooling, and is then discharged to the outside.

At the tap of the melting furnace, the temperature of the refractory near the cooling block embedded in the refractory at the tap is detected and supplied to each cooling passage of the cooling block based on the detected temperature. The refrigerating material at the tap hole is appropriately cooled and maintained at an appropriate temperature by controlling the cooling medium. As a result, the melt flowing through the tap hole does not solidify even when the tap amount changes, and flows stably and continuously. Further, the refractory in the vicinity of the cooling block will not be abruptly consumed by being kept at the temperature at which the consumption rate is slow, and the life of the refractory will be greatly extended.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a main part of an overflow melting type electric melting furnace according to an embodiment of the present invention, in which 1 is a furnace body and 2 is a furnace body.
Is a hot water outlet, 3 is a hot water outlet, 4 is a gas outlet, 5 is a melt, 6 is an exhaust gas, 7 is a cooling block, and 8 is a cooling medium supply mechanism.

The furnace body 1 is formed in a substantially box shape by a side wall, a ceiling wall and a furnace bottom made of refractory such as castable refractory and refractory brick, and the side wall or ceiling wall is incinerated into the furnace. A melted material supply port (not shown) for introducing a melted material such as ash or soot and a tap hole 2 for discharging the melted material 5 in the furnace are formed on the side wall. In addition, on the downstream side of the tap hole 2, the melt 5 discharged from the tap port 2
A hot water discharge port 3 for guiding the cooling water to a cooling water tank (not shown) and a gas discharge port 4 for discharging the exhaust gas 6 to the outside are formed in communication with each other.

The cooling block 7 is, as shown in FIG.
It is formed in a substantially rectangular parallelepiped shape by a metal material having a high thermal conductivity such as copper, and a plurality of cooling passages 7a are formed inside. In this embodiment, the cooling passages 7a are formed at predetermined intervals in the longitudinal direction of the cooling block 7 and in the width direction and the vertical direction of the cooling block 7. And, this cooling block 7 is, as shown in FIG.
Is buried in the overflow portion 1a of the tap hole 2 so that the refractory can be cooled. The length and width of the cooling block 7 are set to a size capable of cooling the refractory material in substantially the entire area of the overflow portion 1a.

As shown in FIG. 3, the cooling medium supply mechanism 8 has a branched cooling water supply pipe 9 connected to one end of each cooling passage 7a of the cooling block 7, and a branch of the cooling water supply pipe 9. A branched cooling air supply pipe 10 connected to the portions 9a, 9b, 9c, ..., A cooling tower 11 connected to the cooling water supply pipe 9, and a cooling water pump provided in the cooling water supply pipe 9. 12, a compressor 13 connected to the cooling air supply pipe 10, and branch parts 9a, 9b, 9 of the cooling water supply pipe 9.
Cooling water valve 14 (solenoid valve) provided in each of c, ...
And the branched portions 10a, 10b, 1 of the cooling air supply pipe 10.
0c, ..., A cooling air valve 15 (solenoid valve), a cooling medium discharge pipe 16 connecting the other end of each cooling passage 7a of the cooling block 7 and the cooling tower 11, and a cooling medium discharge. A steam separator 17 provided in the pipe 16, a temperature sensor 18 for detecting the temperature of the refractory on the cooling block 7,
A controller 19 for controlling each of the cooling water valve 14 and the cooling air valve 15 based on the temperature detected by the temperature sensor 18, and the like. Based on the temperature detection of the refractory on the cooling block 7, each valve (14 ), (15) are controlled to be opened and closed, and the cooling medium (cooling water W, cooling air A) supplied to each cooling passage 7a of the cooling block 7 can be switched and controlled. That is, the cooling medium supply mechanism is 8
Is configured so that the cooling capacity of the cooling block 7 can be arbitrarily adjusted.

When the cooling capacity of the cooling block 7 is adjusted by the cooling medium supply mechanism 8, only the cooling water W is caused to flow through each cooling passage 7a of the cooling block 7 and each cooling water valve 14 is appropriately opened. The cooling capacity of the cooling block 7 is adjusted by controlling the flow rate of the cooling water W by opening and closing. By opening / closing each cooling water valve 14 and cooling air valve 15, a part of the cooling medium (cooling water W) flowing in each cooling passage 7a of the cooling block 7 is switched from the cooling water W to the cooling air A. The cooling capacity of the cooling block 7 is adjusted by causing the cooling passage 7a through which the cooling air A flows to act as a heat insulating layer. The cooling capacity of the cooling block 7 is adjusted by switching all the cooling medium (cooling water W) flowing in the cooling passages 7a of the cooling block 7 from the cooling water W to the cooling air A for air cooling. The cooling capacity of the cooling block 7 is adjusted by flowing only the cooling air A into each cooling passage 7a of the cooling block 7 and controlling the flow rate of the cooling air A by opening / closing each cooling air valve 15 as appropriate. A part of the cooling medium (cooling air A) flowing in each cooling passage 7a of the cooling block 7 is cooled from the cooling air A to the cooling water W.
The cooling capacity of the cooling block 7 is adjusted by switching to. All of the cooling medium (cooling air A) flowing in each cooling passage 7a of the cooling block 7 is cooled from the cooling air A to the cooling water W.
The cooling capacity of the cooling block 7 is adjusted by switching to and cooling with water. There is a method such as.

In the electric melting furnace configured as described above, the materials to be melted such as incineration ash and soot dust supplied into the furnace are
It is melted by the arc heat of an electrode (not shown) or the Joule heat of the material to be melted to become a fluid melt 5 and the tap hole 2
From the overflow portion 1a to the hot water discharge port 3 side, is cooled in a cooling water tank (not shown), and is then discharged to the outside. Further, the gas 6 generated in the furnace passes through the tap hole 2 and is discharged to the outside from the gas discharge port 4.

At the overflow portion 1a of the tap hole 2, the temperature sensor 18 detects the temperature of the refractory material on the cooling block 7, and the controller 19 is based on this detected temperature.
The respective cooling water valve 14 and cooling air valve 15
Are appropriately opened and closed to operate each cooling passage 7 of the cooling block 7.
The cooling water and cooling air supplied to a are controlled, and the refractory in the overflow section 1a is cooled to an appropriate temperature by the cooling block 7. That is, the cooling capacity of the cooling block 7 is adjusted by the above methods (1) to (3) and the overflow portion 1
The refractory a is kept at an appropriate temperature. The refractory material in the overflow portion 1a does not solidify the melt 5 flowing in the overflow portion 1a even if the amount of tapped water changes, and flows stably and continuously, and the refractory material on the cooling block 7 is rapidly consumed. Is cooled by the cooling block 7 so that the above can be suppressed. As a result, the melt 5 flowing through the tap hole 2 does not solidify even if the amount of tapped water changes, and flows stably and continuously. Further, the refractory material in the vicinity of the cooling block 7 will not be abruptly consumed by being kept at the temperature at which the consumption speed is slow, and the life of the refractory material will be greatly extended.

The cooling medium flowing through the cooling passage 7a of the cooling block 7 is either the cooling water W to the cooling air A or the cooling air A.
When the water is switched from the cooling water W to the cooling water W, the cooling water W and the cooling air A are mixed in the flow path of the cooling medium, but since the steam / water separator 17 is provided in the cooling medium discharge pipe 16, cooling is performed. Air A
Is discharged to the atmosphere side, and the cooling water W is cooled in the cooling tower 11 and then recirculated for use, so that there is no problem.

In the above embodiment, the cooling water W or the cooling air A is used as the cooling medium, and these are flowed to the respective cooling passages 7a of the cooling block 7. However, in other embodiments, the cooling water W or the cooling air A is used. The medium is a mixture of cooling air A and cooling water W,
The cooling capacity of the cooling block 7 may be adjusted by flowing this into each cooling passage 7a. That is, as shown in FIG. 4, the mixer 20 for mixing the cooling air A and the cooling water W is connected to each cooling passage 7 a of the cooling block 7,
Even if the temperature of the upper refractory is detected by the control sensor 18, the cooling water valve 14 is controlled based on the detected temperature, and the amount of cooling water is adjusted so that the refractory is kept at an appropriate temperature. good. This embodiment can also achieve the same effects as those of the above embodiment.

In the above embodiment, the cooling passages 7a are formed in the cooling block 7 in the upper and lower two stages, but in other embodiments, the cooling passages 7a are formed in the upper and lower three stages. You may do it.

In the above embodiment, only one cooling block 7 is buried in the overflow portion 1a of the tap hole 2. In other embodiments, a plurality of cooling blocks 7 are buried in the overflow portion 1a. It may be done.

[0023]

As described above, in the tap hole cooling structure of the present invention, a refrigerating material at the tap hole is provided with a cooling block having a plurality of cooling passages defined therein, and the cooling blocks are introduced into the respective cooling passages of the cooling block. The cooling medium supply mechanism appropriately supplies the cooling medium so that the cooling capacity of the cooling block can be adjusted. That is, since the refractory at the tap hole is provided with a cooling block capable of adjusting the flow rate of the cooling medium, the type of cooling medium, the cooling range, etc. Can be maintained at an appropriate temperature. As a result, it is possible to minimize the heat loss near the outlet,
The temperature of the furnace material at the tap hole can be maintained at a temperature at which the melt does not solidify even if the tap amount changes, and the melt can be stably and continuously tapped. Further, the refractory in the vicinity of the cooling block will not be abruptly consumed by being kept at the temperature at which the consumption rate is slow, and the life of the refractory will be greatly extended.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of an overflow melting type electric melting furnace adopting a discharge hole cooling structure of the present invention.

FIG. 2 is a perspective view of a cooling block.

FIG. 3 is a schematic system diagram showing an example of a cooling medium supply mechanism that supplies a cooling medium to a cooling block.

FIG. 4 is a schematic system diagram showing another example of a cooling medium supply mechanism.

FIG. 5 is a schematic cross-sectional view of a conventional overflow melting type electric melting furnace.

[Explanation of symbols]

2 is a tap hole, 5 is a melt, 7 is a cooling block, 7a is a cooling passage, 8 is a cooling medium supply mechanism, 9 is a cooling water supply pipe, and 1 is a cooling water supply pipe.
Reference numeral 0 is a cooling air supply pipe, 14 is a cooling water valve, 15 is a cooling air valve, W is cooling water, and A is cooling air.

Claims (2)

[Claims] 1. An overflow tap type melting furnace in which a melted material such as incinerated ash or dust is melted and the melt (5) is allowed to overflow from the tap hole (2). A refrigerating material (2) is provided with a cooling block (7) having a plurality of cooling passages (7a) defined therein, and a cooling medium supply mechanism () into each cooling passage (7a) of the cooling block (7). 8) A cooling structure for a tap of a melting furnace, characterized in that the cooling capacity of the cooling block (7) can be adjusted by appropriately supplying a cooling medium respectively. 2. A cooling water supply pipe for connecting a cooling medium supply mechanism (8) to each cooling passage (7a) of the cooling block (7) and supplying cooling water (W) to each cooling passage (7a). (9) and a cooling air supply pipe (10) connected to each cooling passage (7a) of the cooling block (7) and supplying cooling air (A) to each cooling passage (7a), and each cooling water supply A plurality of cooling water valves (1) provided in the pipe (9) for controlling the flow of cooling water (W) into and out of each cooling passage (7a).
4) and a plurality of cooling air valves (15) that are provided in the cooling air supply pipe (10) and that regulate the flow of cooling air (A) into and out of each cooling passage (7a). The cooling water valve (14) and the cooling air valve (15) are respectively controlled based on the temperature detection of the refractory near the block (7) and supplied to each cooling passage (7a) of the cooling block (7). The taphole cooling structure for a melting furnace according to claim 1, wherein the cooling medium is configured to be switched and controlled.