JP3645978B2 - Spray-cooled furnace lid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spray-cooled furnace lid that covers a furnace body such as an arc furnace or a ladle used to melt metal or waste.
[0002]
[Prior art]
In an electric furnace such as an arc furnace used for melting and refining metals or melting waste such as garbage incineration ash, a spray-cooled furnace lid is conventionally attached to the upper end opening of the furnace body. The spray-cooled furnace lid is formed in a hollow shape by a steel plate, for example, as disclosed in Japanese Examined Patent Publication No. 3-22559, and a spray pipe is provided in the inner space to spray a cooling medium such as cooling water. By doing so, the furnace cover is cooled, and the furnace cover is protected from high heat in the furnace. Further, the spray-cooled furnace lid disclosed in Japanese Patent Application Laid-Open No. 7-260367 forms a series of annular drainage boxes on the outer peripheral lower surface of the furnace lid, and the cooling water sprayed in the internal space flows down to the drainage box. The drainage is naturally discharged by its own weight without using a vacuum pump.
[0003]
However, simply draining the wastewater by its own weight may cause the drainage rate to be slow, so that the wastewater accumulates in the lower part of the furnace lid and may not be able to maintain sufficient cooling capacity. For this reason, a means is also provided in which a drainage suction pipe is suspended from above at the bottom of the furnace lid, and the drainage is sucked and forcibly discharged by a vacuum pump.
[0004]
[Problems to be solved by the invention]
However, in the case where the drainage suction pipe is suspended from above to the drainage basin at the bottom of the furnace lid as described above, the drainage collected in the drainage basin at the bottom of the furnace lid is sucked and forcibly discharged. Since the drainage suction pipe narrows the width of the drainage that can flow inside the drainage, the drainage is difficult to flow between the drainage suction pipe and the steel plate inside the drainage drainage or between the drainage suction pipe and the steel plate outside the drainage drainage. Thus, the water level is low in the furnace lid radial direction of the drainage suction pipe, and the water level is high in the circumferential direction of the furnace lid of the drainage suction pipe. For this reason, there exists a problem of sucking air | atmosphere from the furnace cover radial direction of a waste_water | drain suction pipe, and reducing the suction capability of waste_water | drain.
[0005]
[Means for Solving the Problems]
The present invention is intended to solve the above-mentioned problem, and a furnace lid covering the upper end opening of the furnace body holding the melt is formed in a hollow shape, and a spray pipe for spraying cooling water is disposed in the internal space thereof, and the furnace In the spray-cooled furnace lid in which an annular drainage basin is formed in the lower part of the lid and the drainage suction pipe is suspended in the drainage basin, the inner width of the part where the drainage suction pipe of the drainage hangs down is widened and the widened portion The drainage suction pipe is suspended from the center of the water.
In addition, the present invention provides a furnace lid that covers the upper end opening of the furnace body that holds the melt and is formed in a hollow shape, and a spray pipe that sprays cooling water is disposed in the inner space of the furnace lid, and an annular drainage is provided at the lower portion of the furnace lid. In a spray-cooled furnace lid in which a drainage suction pipe is suspended in the drainage basin, the inner width of the portion of the drainage basin where the drainage suction pipe hangs is more than twice the outer diameter of the drainage suction pipe The drainage suction pipe is drooped at the center of the widened portion.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to a vertical cross-sectional view of the spray-cooled furnace lid shown in FIG. 1 and a cross-sectional view taken along line AA and a drainage system diagram shown in FIG. This embodiment shows a spray-cooled furnace lid that covers the upper end opening of a three-phase AC arc furnace, where 1 is the furnace body and 2 is the furnace lid. The furnace lid 2 has an inner space 5 formed by an inner heat-resistant steel plate 3 and an outer steel plate 4, and an annular water supply header 6 and a plurality of spray pipes extending radially from the outer periphery of the water supply header 6. 7 is disposed. 8 is a water supply pipe for supplying cooling water to the water supply header 6, and 9 a, 9 b, and 9 c are electrode insertion openings established in the central portion 10 of the furnace lid 2. The heat-resistant steel plate 3 and the steel plate 4 are disposed in an inclined manner so that the central portion 10 is higher than the peripheral portion 11. An annular drainage basin 12 is formed in series at the bottom of the furnace lid 2.
[0007]
13a to 13d are drainage suction pipes whose lower ends are suspended in the drainage basin 12, and these four drainage suction pipes 13a to 13d are provided in the drainage basin 12 with a 90-degree interval. Then, the portions where the drainage suction pipes 13a to 13d hang are widened in an arc shape on the outside of the drainage basin, so that the inner width W1 of the drainage basin 12 is set to the outside of the drainage suction pipe as shown in FIG. The drainage suction pipes are suspended in the center of the widened portion 20 by widening the diameter W2 more than twice.
[0008]
The drainage suction pipes 13 a to 13 d are converged on a single drainage collecting pipe 15 via a drainage header 14, and the drainage collecting pipe 15 is connected to an ejector pump 16. The ejector pump 16 is provided with a nozzle 18 at the base of the venturi tube 17, and causes the water pressurized by the water pressure pump 19 to be ejected at a higher speed than the nozzle 18 to generate a negative pressure in the venturi tube 17. The drainage in the drainage collecting pipe 15 can be sucked by vacuum, and since it has a simple structure, it is commercially available at a relatively low price and is easily available.
[0009]
For this reason, cooling water is supplied to each spray pipe 7 from the water supply pipe 8 through the water supply header 6, and the cooling water is sprayed on the inner surface of the internal space 5 from the nozzle hole of each spray pipe 7. And the water is caused to flow down to the outer drainage basin 12 by the inclination of the heat-resistant steel plate 3, and the drainage collecting pipe 15 is vacuumed by the operation of the ejector pump 16, and the drainage suction pipes 13a to 13d are opened from the lower end openings. By sucking up the drainage in the drainage basin 12, the drainage in the drainage basin 12 can be forcibly discharged.
[0010]
The drainage suction pipes 13a to 13d are suspended by the widened portion 20 of the drainage basin 12 and have sufficient water passage intervals on both sides thereof, so that the drainage in the drainage basin 12 is routed to the drainage suction pipes 13a to 13d. It is sucked and discharged smoothly.
[0011]
【The invention's effect】
As described above, the spray-cooled furnace lid of the present invention has widened the inner width of the drainage basin of the drainage suction pipe so that the drainage in the drainage can always flow smoothly into the drainage suction pipe and be sucked up. Therefore, even if a large amount of cooling water is sprayed, there is an effect that the required cooling capacity can be maintained without drainage collecting in the drainage basin.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a spray-cooled furnace lid showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and a system diagram of the drainage device.
FIG. 3 is an enlarged view of a main part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Furnace 2 Furnace lid 5 Inner space 7 Spray pipe 12 Drainage tank 13a-13d Drain suction pipe 14 Drain header 15 Drain collecting pipe 16 Ejector pump 20 Widening part

Claims (2)

The furnace lid covering the upper end opening of the furnace body holding the melt is formed in a hollow shape, and a spray pipe for spraying cooling water is disposed in the inner space, and an annular drainage basin is formed at the lower part of the furnace lid. In the spray-cooled furnace lid in which the drainage suction pipe is suspended in the drainage basin, the inner width of the portion of the drainage basin where the drainage suction pipe hangs is widened, and the drainage suction pipe is suspended in the center of the widening portion. A spray-cooled furnace lid. The furnace lid covering the upper end opening of the furnace body holding the melt is formed in a hollow shape, and a spray pipe for spraying cooling water is disposed in the inner space, and an annular drainage basin is formed at the lower part of the furnace lid. In a spray-cooled furnace lid in which a drainage suction pipe is suspended in a drainage basin, the inner width of the portion of the drainage basin where the drainage suction pipe hangs is widened to more than twice the outer diameter of the drainage suction pipe. A spray-cooled furnace lid, characterized in that the drainage suction pipe is suspended in the center.

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