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Keywords

Y3

equipment or facility

Z3Electric power

DConstruction industry
NIPPON STEEL CORPORATION

NS-Tundish Plasma HeaterFeatures
The NS Tundish Plasma Heater is a device used in continuous casting machines (equipment for coolingand solidifying molten steel) at steel plants. The device provides the function of generating a plasma arc
between the plasma torch and the molten steel, to maintain a constant temperature of the molten steel inthe continuous casting machine.
The device has the following features(1) Lower energy consumption of steelmaking plant⇒Reduce production cost and CO2 emission(2) Stabilization of casting quality(3) Higher productivity(4) Less casting stop by nozzle clogging
Basic Concept or Summary
The NS Tundish Plasma Heater heats molten steel by generating a plasma arc between a plasma torch
inserted from above the tundish and the molten steel inside the tundish.
Additionally, the NS Tundish Plasma Heater can be added to an existing continuous casting machine thatis already in operation.

Effects or Remarks
S Energy saving effects• Specific implementation effects are described below:(1) CO2 emission reduction: 4,800 tons CO2/year at 500,000 tons steel/year* 9.6 kg CO2/ton steel (at 0.434 tons CO2/MWh)(2) Electric power consumption reduction: 11,000 MWh/year at 500,000 tons steel/year** 22 kWh/tons steel• Energy saving effects are described below:
The device provides the function of sustaining, at a constant temperature, the temperature of molten
steel in the continuous casting machine, by generating a plasma arc between the plasma torch and themolten steel. This makes it possible to reduce the temperature drop in the continuous casting machineand reduce the tapping temperature from the converter furnace (converter), electric furnace (electricarc furnace) and secondary refining equipment (ladle smelting furnace), which is in the previous
processes of the continuous casting machine. This reduces the power consumption of the EAF and LF
and reduces CO2 emissions.
Simply lowering the tapping temperature in the previous process would ordinarily result in thetemperature of the molten steel dropping below the liquidus temperature (solidification startingtemperature) during the final stage of casting, in the continuous casting machine (location E in thegraph), which renders production impossible. Production can continue even when the tapping
temperature in the previous process is lowered, however, by compensating for the temperature dropin the continuous casting machine with the NS Tundish Plasma Heater.
Furthermore, the NS Tundish Plasma Heater heats about the last half of the molten steel in a production unit. This makes it possible to save energy compared to heating in a converter, electric furnace orLF, which requires heating all the molten steel in a production unit.

Installation in Practice or Schedule
Domestic
Overseas

Contact:

Domestic: 19 units (as of March 2023)
Nippon Steel Corporation and others
Overseas: 3 units (as of March 2023)
People's Republic of China/Tianjin Rockcheck Union Steel Group Co., Ltd./No. 3CC
People's Republic of China/Tianjin Rockcheck Union Steel Group Co., Ltd./No. 5CC
People's Republic of China/Qingdao Special Iron and Steel Co., Ltd./No. 3CC
NIPPON STEEL CORPORATION
Plant/Machinery Engineering & Construction Management Center
6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 100-8071, Japan
Tel: +81-3-6867-6058
URL: https://www.nipponsteel.com/en/

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