JPH10197162A - Spray-cooled furnace lid - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure that a proper amount of cooling water is always sprayed in each area of a spray-cooled furnace lid, thereby saving cooling water and increasing cooling capacity. A spray pipe for spraying cooling water.
a to 8d are provided inside the furnace lid 2 so that the spray amount can be adjusted for each of the plurality of sections 6a to 6d, and the temperature at which the temperature of the waste water discharged from the furnace lid 2 can be measured for each section. A measuring means was provided, and the spray amount was automatically controlled for each zone according to the measured temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray-cooled furnace cover for covering a furnace body such as an arc furnace or a ladle used for melting metal or waste.

[0002]

2. Description of the Related Art An electric furnace such as an arc furnace used for melting and refining metals or melting waste such as refuse incineration ash is conventionally provided with a spray-cooled furnace lid at the upper end opening of the furnace body. I'm wearing The spray-cooled furnace lid is, for example, as disclosed in Japanese Patent Publication No. 3-22559, formed of a steel plate in a hollow shape, and sprays a water supply pipe which is disposed in a branched or branched shape in its internal space. By providing a pipe and spraying a cooling medium such as cooling water from the nozzle holes, the furnace lid is cooled and the furnace lid is protected from high heat in the furnace. The spray-cooled furnace lid disclosed in Japanese Patent Application Laid-Open No. 7-260367 has a series of annular drainage gutters (drainage boxes) formed on the lower surface of the outer periphery of the furnace lid, and the cooling water sprayed into the internal space is supplied to the furnace. It is made to flow down to a drain gutter, and the drainage is naturally discharged by its own weight without using a vacuum pump.

[0003]

However, in the conventional arrangement of the spray pipe as described above, since the spray amount of the cooling water can only be increased or decreased as a whole, for example, the deviation of the heat load of the furnace lid due to the change of the operation state. There was a drawback that appropriate measures could not be taken according to the situation. That is, for example, if the spray amount of the cooling water is increased in accordance with the portion having a high heat load, the spray amount of the cooling water in the portion having a low heat load is similarly increased. It was efficient. The present invention is to solve the technical problem in such a spray-cooled furnace lid.

[0004]

For this purpose, a spray-cooled furnace lid according to the present invention is provided with a spray pipe for spraying cooling water inside the furnace lid so that the spray amount can be adjusted in each of a plurality of sections. Temperature measuring means for measuring the temperature of the waste water discharged from the furnace lid in each of the sections, and the spray amount is automatically controlled in each section according to the measured temperature. is there. As a result, the cooling water can be sprayed to each area of the furnace lid at all times, so that the cooling capacity can be increased and the waste of the cooling water can be eliminated.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to a longitudinal sectional view of a spray-cooled furnace lid shown in FIG. 1, and a sectional view taken along line AA of FIG. I do. This embodiment shows a spray-cooled furnace lid covering an upper end opening of a three-phase AC arc furnace, 1 is the furnace body, and 2 is a 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 is disposed in the inner space 5. The water supply header 6 is divided into four sections 6a to 6d at intervals of 90 degrees as shown in FIG.
Cooling water supply pipes 7a to 7d are provided in the respective sections. Numerals 8a to 8d are spray pipes provided in the respective sections 6a to 6d. Reference numerals 9a, 9b, and 9c denote electrode insertion openings formed in the central portion 10 of the furnace lid 2. The heat-resistant steel plate 3 and the steel plate 4 are arranged in an inclined manner so that the central portion 10 is higher than the peripheral portion 11.

An annular drain gutter 12 is formed in a series on the lower surface of the outer periphery of the furnace lid 2, and four drain suction pipes 13a to 13d are formed.
13d are provided at intervals of 90 degrees corresponding to the respective sections 6a to 6d. As shown in FIG. 2, the drainage suction pipes 13a to 13d are connected to the flow control valves 14a to 14d, respectively.
4d and thermocouples 15a to 15d so that the temperature of the waste water in each of the drain suction pipes 13a to 13d can be measured.
, And the tip thereof is focused on one drain collecting pipe 17 via a drain header 16, and the drain collecting pipe 17 is connected to an ejector pump 18. The ejector pump 18 is provided with a nozzle 20 at the base of a venturi tube 19, and generates a negative pressure in the venturi tube 19 by ejecting water pressurized by a hydraulic pump 21 at a high speed from the nozzle 20. The drainage in the drainage collecting pipe 17 can be suctioned by vacuum.

Also, 22a to 22d are the water supply pipes 7a to 7d.
7d, the water supply pipes 7a to 7d
The cooling water is pressure-fed from the water supply source via the water supply header 23. The controller 24 controls the flow rate of the cooling water in the water supply pipes 7a to 7d by issuing opening degree command signals to the corresponding flow rate control valves 22a to 22d in accordance with the temperature measurement signals of the waste water obtained from the thermocouples 15a to 15d. Can be done.

For this reason, the spray pipes 8a to 8d are supplied from the respective sections 6a to 6d of the water supply header 6 through the water supply pipes 7a to 7d.
d, cooling water is sprayed from the nozzle holes of the spray pipes onto the inner surface of the internal space 5 to cool the furnace cover 2, and the water is drained by the slope of the heat-resistant steel plate 3 to drainage gutters on the outer periphery. The drainage pipe 17 is evacuated by operating the ejector pump 18, and the drainage in the drainage gutter 12 can be sucked and discharged from the lower end openings of the drainage suction pipes 13a to 13d.

At that time, the drainage suction pipes 13a to 13a
d is measured by the thermocouples 15a to 15d and analyzed by the controller 24, and by adjusting the flow control valves 22a to 22d according to the level of the measured temperature, the spray amount for each of the sections 6a to 6d can be reduced. Automatically controlled. For this reason, it is necessary to spray more cooling water to the area with high drainage temperature and reduce the spray amount to the area with low drainage temperature, so that appropriate cooling according to each area is not too much or not enough. This is done to prevent overheating due to insufficient cooling and at the same time to save cooling water.

[0010]

As described above, according to the present invention, a proper amount of cooling water is always sprayed in each area of the spray-cooled furnace lid, so that the cooling water can be saved and the cooling capacity can be reduced. There are beneficial effects such as being able to increase.

[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 of FIG. 1 and a water supply / drainage system diagram thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace body 2 Furnace lid 5 Internal space 6 Water supply header 6a-6d Area 7a-7d Water supply pipe 8a-8d Spray pipe 12 Drain gutter 13a-13d Drain suction pipe 15a-15d Thermocouple 22a-22d Flow control valve 24 Controller

Claims (1)

[Claims] 1. A spray pipe for spraying cooling water is provided inside a furnace lid so that a spray amount can be adjusted in each of a plurality of sections, and a temperature of waste water discharged from the furnace lid is set in each of the sections. Providing a temperature measuring means capable of measuring,
A spray-cooled furnace lid, wherein the spray amount is automatically controlled for each zone according to the measured temperature.