Flachstahl GmbH has awarded Tenova Metals Germany GmbH the contract for
delivery of a new secondary metallurgical unit at their Salzgitter,
Germany plant location. A new Duplex RH plant, used for the vacuum
treatment of liquid steel with a nominal heat size of 220 tons, will be
designed and supplied.
The LD steelmaking shop of Salzgitter
Flachstahl GmbH produces about 4.7 million tons of slabs per year. With
the installation of the new duplex RH plant, Salzgitter Flachstahl GmbH
increases its production volume of vacuum treated steel by another 2
million tons per year. The main purpose for the installation of the new
facilities is the production of automotive steel grades (Ultra Low
Carbon IF Steel) as well as heavy plate grades.
For the execution of
this project Tenova undertakes the complete engineering, supply of the
entire mechanical and electrical equipment, hardware, software,
installation and commissioning of the plant equipment. The start of
production of the new plant is scheduled for spring 2017.
Plant concept and Project Details
production is carried out in three LD converters, supplying liquid
steel to the secondary metallurgical facilities. Therefore five lines
(VPL1-5) with two twin ladle furnaces and one additional single ladle
furnace completes the secondary metallurgical facilities as they are
today. In three lines (VPL 1-3) VD (Vacuum Degassing) Plants are
operated. Subsequently, the refined liquid steel will be casted by 4
slab casting machines.
The Duplex RH plant consists of two
independent treatment stations, operated with a Hybrid Steam Jet Pump
System. Ladle lifting is conducted by a winch system for each station.
Each treatment station is also equipped with 2 ladle cars. After
receiving the liquid steel in the converter bay the ladle will be
transported to the RH treatment station by ladle car “north”.
treatment, the ladle will be received by ladle car “south” and
transported to the caster bay. Depending on the metallurgical
requirements post vacuum treatment will be carried out in the ladle
treatment station supplying metallurgical wires as well as insulation
Snorkle and vessel maintenance
maintenance is performed by three service cars operated in rectangular
direction to the RH ladle car tracks. Two of these cars are equipped
with snorkel deskulling devices, the third car is designed for making
use of an automatic FF-snorkel gunning machine.
Exchange of the
different RH vessel parts the ladle winch lifting system will be used as
well. The respective vessel part of the split-type vessel is lowered to
the ladle car “north” and transported by overhead crane to the taking
over position of the maintenance area, where break out, relining and
preheating takes place.
TOP Lance Systems
The RH treatment
stations are equipped with a combined TECHNOMETAL? TOP lance. The TOP
lance systems have metallurgical functions of oxygen blowing for
decarburization and chemical heating as well as the burner function for
keeping the refractory lining hot during the non-operating time of the
RH Plants. The lance systems are equipped with the patented external
TECHNOMETAL? ignition devices, which ensure reliable operation of the
Alloys and dedusting
Both treatment stations
will be connected to the alloy system of the existing ladle furnace.
Furthermore, a new bunker group will be installed with an additional 18
weighing hoppers. The Vacuum Alloying Systems are designed with 2 vacuum
locks as well as 2 direct feeding systems for the quick supply of
aluminum and scrap. In order to collect the resulting dust loaded
process gases resulting from the alloy system and ladle treatment
stations a new dust filter system with a capacity of 90.000 m3/h will be
provided. The new dust filter system ensures that emissions will not
exceed 10 mg/m3.
Vacuum System and Water Treatment Plant
of the RH treatment station will be executed with a moveable elbow
device that can connect to either of the stations. The 4-stage Hybrid -
Steam Jet Vacuum Pump System is equipped with liquid ring pumps as
atmospheric stage. For the main working range of the vacuum system 3
parallel ejectors are installed in order to constantly maintain
appropriate vacuum pressures for the required process steps, such as
decarburization, oxygen blowing or degassing.
The condenser cooling
water system of the vacuum pump has been designed for an economic
operation mode: After having passed the first condensation stage the
water is conveyed to the second condensation stage for reuse. By that
operation the cooling water circulation compared to a conventional
system can be reduced by about 30%.
After final condensation, the
cooling water is conveyed to the new water treatment plant for filtering
and sludge treatment. After cleaning, the cooling water will be pumped
to the cooling towers and subsequently back to the vacuum pump system.
Additionally, the existing machine cooling system will be extended in
order to serve the new cooling equipment to be installed.
Source: Tenova Press Releases