Melting equipment and operation method for melting equipment

Patent metadata

Field	Value
Publication number	US-2024377136-A1
Application number	US-202418643250-A
Country	US
Kind code	A1
Filing date	Apr 23, 2024
Priority date	May 10, 2023
Publication date	Nov 14, 2024
Grant date	—

Abstract

The present invention relates to a melting equipment including: two direct-current arc furnaces each including two or more graphite electrodes; a power supply unit including four or more power supply devices; a connection switching unit configured to selectively connect each of the power supply devices to each of the direct-current arc furnaces; and a power supply control unit configured to control power supply from each of the power supply devices to each of the direct-current arc furnaces, in which power supply to only any one of the two direct-current arc furnaces and simultaneous power supply to both direct-current arc furnaces are selectable, and during the simultaneous power supply, power is supplied exceeding 50% of capacities of all the power supply devices to any one of the direct-current arc furnaces.

First claim

What is claimed is:

1 . A melting equipment comprising:
two direct-current arc furnaces each including two or more graphite electrodes; a power supply unit including four or more power supply devices; a connection switching unit configured to selectively connect each of the power supply devices to each of the direct-current arc furnaces; and a power supply control unit configured to control power supply from each of the power supply devices to each of the direct-current arc furnaces, wherein power supply to only any one of the two direct-current arc furnaces and simultaneous power supply to both direct-current arc furnaces are selectable, and during the simultaneous power supply, power is supplied exceeding 50% of capacities of all the power supply devices to any one of the direct-current arc furnaces.

2 . The melting equipment according to claim 1 , wherein
the number of the power supply devices provided in the power supply unit is larger than a total number of the graphite electrodes provided in the two direct-current arc furnaces.

3 . The melting equipment according to claim 2 , wherein
each of the two direct-current arc furnaces includes the two graphite electrodes, and the power supply unit includes the six or more power supply devices.

4 . The melting equipment according to claim 1 , further comprising a backup power supply device in addition to the power supply device essential for supplying maximum input power per direct-current arc furnace, wherein
the backup power supply device is connected to the direct-current arc furnace in a power-suppliable manner.

5 . The melting equipment according to claim 4 , wherein
during power supply, power is supplied to the direct-current arc furnace also from the backup power supply device in addition to the essential power supply device.

6 . The melting equipment according to claim 1 , wherein
the plurality of power supply devices are installed separately in two or more machine chambers.

7 . An operation method of the melting equipment as described in claim 1 to melt steel in the two direct-current arc furnaces, the method comprising:
dividing a furnace period of the direct-current arc furnace into a melting period including a maximum power period in which maximum input power is supplied, a refining period in which power smaller than the maximum input power is supplied, a slag discharging period, a tapping period of tapping molten metal, and a charging period of charging a metal raw material;
when the maximum input power per furnace in the melting period is denoted as Sd, and a total capacity value of the power supply devices is denoted as Seqip, setting the maximum input power such that Seqip≥Sd is satisfied; and
supplying power to each of the direct-current arc furnaces so that the maximum power period of one direct-current arc furnace overlaps at least one of the slag discharging period, the tapping period, and the charging period of the other direct-current arc furnace, and that the melting period excluding the maximum power period and the refining period of the one direct-current arc furnace overlaps the melting period excluding the maximum power period and the refining period of the other direct-current arc furnace.

Assignees

• Daido Steel Co Ltd

Inventors

• Hori Satoshi
• Yamauchi Takashi
• Shiratori Masayuki
• Kitabayashi Shoji
• Mizutani Kota
• Kato Masashi

Classifications

• F27B14/20

  Arrangement of controlling, monitoring, alarm or like devices · CPC title

• F27B14/14

  Arrangements of heating devices · CPC title

• F27B14/08

  Details specially adapted for crucible or pot furnaces · CPC title

• F27B14/06 Primary

  heated electrically, e.g. induction crucible furnaces with or without any other source of heat (F27B14/04 takes precedence) · CPC title

• Y02P10/20

  Recycling · CPC title