cvs presentation

theMill for Minimills

CVS MAKİNAİNŞAAT SAN. ve TİC.LTD.ŞTİ

CVS MAKINA İNŞ. SAN. ve TİC. LTD. ŞTİ.

Dilovası Organize Sanayii Bölgesi 3. Kısım Muallimköy Cad. No:21 Gebze 41400 KOCAELİ / TURKEY

Tel. +90 262 759 15 05 Fax. +90 262 759 18 80 www.cvs.com.tr [email protected]

GOOD COMBINATION OF OPERATIONAL PEOPLE AND DESIGNERS

WE ARE IN THE CORE OF STEEL – CVS MAKINA

D. ERTAS – CVS MAKINA – Project And Contracting Department

Located in the industrial region of Gebze, just east of Istanbul, close to many major ports, CVS

provides plants & equipment for minimills, also in “turn-key” solution. CVS covers the complete

design and manufacturing activities for green-field projects as well as revamping/upgrading of

existing plants and equipment. Additional to technical assistance and consulting service to steel

Production and Rolling, CVS manufactures spare parts & components for steel sector.

Having more than 40,000 sqm of closed area and additional approx. 40,000 sqm open area, CVS

workforce is formed by over than 500 specialized workers and engineers with a modern machinery

park to undertake even the most challenging projects. Over than 200 engineers and administrative

employees are involved in the design and management of the projects.

From Water Cooled Panels to complete Electric Arc Furnaces, from Ladles to complete Ladle

Furnaces, from Tundishes to complete Continuous Casting Machines, from Ducts to complete Fume

Treatment Systems and from Engineering Services to Turn-Key Plants, CVS offers economically viable

solutions at European standards.

CVS general plant design foceses low production costs, higher process flexibility,iIncreasing

productivity while improving energy efficiency, İmproving the quality of the finished product, Meet

environmental requirements at a minimum cost and Better coordination of process/environmental

requirements

EAF

Steelmaking is always a growing sector and steelmakers are always asking for more flexible and more

easy operation for meltshop units. As design, manufacturing and erection of this kind of units, CVS

Machina put his experience for combining more simple design with flexible operation. Additionally,

CVS fulfills any requirement when it comes to the choice of furnace type and melting technology for

cost efficient operation. Options include burners, wall mounted supersonic lances, and bottom






tuyeres for oxygen injection to name a few. The basis of all CVS design is good accessibility, low

maintenance and operational reliability.

The CVS electric steelmaking technology is the solution for strong, simple and reliable design. As the

product of continuous development improvements, our furnaces features maximized power-on-

time, high-speed movements and easy access to all components for maintenance. The furnace is

ideal for ultra-high-power input and overall furnace performance can be additionally enhanced with

the latest oxygen and carbon injection technologies.

150 TON EAF VIEW TYPICAL FURNACE DESIGN

CVS has more than 50 Electric Arc Furnaces supplied worldwide with furnace sizes ranging between

12 to 180 tapped steel.

Electric Arc Furnace (EAF) design condiders always for short tap-to-tap times thanks to several

technologies such as:

- UHP (Ultra High Power) design, with high secondary voltages and longer arc

- High-current-conducting electrode arms in copper-clad box design

- State-of-the-art electrode control system

- Extensive use of alternative energy sources (chemical energy)

- Better energy and thermal balance inside the furnace thanks to the multiunit injection.

- High yield of alloy additives and high ladle refractory life thanks to EBT slag-free tapping.

- More heat input in cold EBT area thanks to special design of EBT-burner system.

- Heavy construction design to sustain hard working conditions, allowing very fast movements

and safe operations.

- High flexibility and high efficiency of furnace operation with closed slag door application.






- Easy maintenance operation for special design like roof lifting system, furnace locking

system.

- Split-shell design

- Copper or combi-panels with high-speed cooling water flow

- Continuous DRI/HBI feeding systems

- Additional chemical energy based on carbon, fuel and oxygen is used as substitute of electric

power.

- SIM-ARC electrode regulation design

- Hot heel practice

- Fast scrap charging

- Scrap yard flexibility.

Electrode movements of EAF are controlled by SIM-ARC electrode regulation system which allows a

constant ratio between electrode voltage and current to be maintained. Together with the hydraulic

system of electrode movement control, system acts on arc voltage to maximise the efficiency of

melting process. Using special algorithm following benefits can be obtained:

- Fast adjustment of arc length,

- Fast response and fast and stable control,

- Minimizing of power consumption,

- Minimizing of flicker effects due to regulation quality,

- Minimizing of electrode and refractory consumption.

CVS has special oxy-burner system for higher productivity. The injection system consists of a set of jet

burners installed on the EAF shell. The jet burners are supersonic oxygen injectors combined with a

hydrocarbon burner, all in the same housing. Installed in the upper shell’s side wall, The jet burners

have functions of decarburization of the steel bath, thermal energy input, formation of foaming slag,

reduced need of charge carbon with the scrap, the thermal energy is efficiently transferred to the

bath with less fuel, lower offgas temperature and much better control of CO emissions. The location

and the direction of the burners are determined to reduce the cold spots effect generated by the

three-phase arc of the furnace, thus obtaining an even and faster melting.






The evolution in electric arc furnace technology has progresively led to the utilisation of alternative

energy contributing to the heat balance, optimising the consumption of electrical energy and

increasing productivity. A further effect of the correct adoption of this practice is the formation of a

high level of foaming slag, with all the benefits arising from the resulting arc coverage. To obtain

better slag foaming, additional slag door manipulator with two oxygen and one carbon lance is

installed which yields faster operation.

Burners are distributed for the aim to cancel cold spot areas and also to obtain good foamy slag. In

other words, the configuration was selected in order to have an as homogenous as possible supply of

chemical energy to the bath. The module philosophy follows the target of efficient management of

electrical and chemical energy, combining efficient dynamic control of the electric arc with a

balanced injection of oxygen and carbon in order to increase EAF productivity.

BURNER DISTRIBUTION INSIDE THE FURNACE SUPERSONIC FLAME SHAPE

In addition to oxy-fuel burners, the lance manipulator for the Electric Arc Furnace is primarily

designed for safe oxygen injection. As well, solid materials like Carbon can be given from burner

case. The Carbon injection in the bath have demonstrated of outmost importance to work with

proper foaming of the slag and to obtain recarburisation of liquid steel bath if required to control

bath composition.

The carbon injectors provide the possibility to control the bath conditions by regulating the flowrate

and promoting slag foaming. This slag condition has many advantages in terms of furnace wall

protection, more efficient power utilisation and reduced maintenance.






Foaming slag is used to increase the thermal efficiency of the furnace during the refining period,

when the side walls are fully exposed to the arc radiation. A foaming slag will rise and cover the

electric arcs, thus permitting the use of a high tap setting without increasing the thermal load on the

furnace walls. In addition, an electrical arc covered by a foaming slag will have a higher efficiency in

transferring the energy into the steel phase. Slag foaming is obtained by injecting oxygen into the

liquid steel, where mainly iron is oxidized according to the reaction:

O2 + 2 Fe = 2 (FeO)

Carbon powder is then injected simultaneously into the slag

phase where iron oxide is reduced.

(FeO) + C = Fe + CO (g)

The resulting CO gas is a critical component in order to

obtain a foaming slag.

LADLE FURNACE

The final quality of the steel is obtained by means of a powerful ladle furnace capable of operating in

accordance with the required short tap-to-tap times. The furnace is conceived for reheating the steel

in the ladle placed on a ladle car and is designed and built according to the most modern techniques

in the field and is in particular provided with:

- Water cooled ladle roof equipped with indirect fume collecting hood to reduce steel

oxidation.

- Roof lifting mechanism, with hydraulic cylinder.

- Electrode arms with reduced electrode pitch diameter.

- Water cooled secondary circuit and water cooled flexible cables.

- Electro-hydraulic electrode regulation.

The advantages of a ladle furnace are saving of ferroalloy,

saving of energy, increasing productivity, decreasing

refining time of EAF, decreasing tapping temperature at

EAF, precise temperature control, improved of inclusions,

cleanliness of the steel, possibilities of wrong analysis

limited.






VD / VOD Plant

The purpose of secondary metallurgical steel

treatment under vacuum conditions is to

produce high-purity steel with low content of

harmful elements such as sulphur, phosphorus,

trace elements and/or carbon, lowering of

oxygen, nitrogen and hydrogen gases dissolved

in the steel, as well as major improvements of

steel purity, including shape control of non-

metallic inclusions.

CVS Vacuum Technology in Secondary Metallurgy includes Dry Pump technology for Vacuum System,

Integrated solution for Process and Plant Automation (level 1 + 2 Automation), Innovative Process

Control: AI@SOLIS and AI@GAS, Advanced Process Simulation and Optimization, Substantial Energy

Saving Solution, Environmental Safe Solution

CVS expertise extends to all types of Secondary Metallurgy Vacuum Processes: VD, VOD, VT, RH, VIM.

The sizes of the installations delivered to industry by CVS ranges from 6t up to 230t. Standard Design

for 12 t; 50t, 80t, 100t.

DRY MECHANICAL PUMPS TYPICAL VD DESIGN






CVS has developed an efficient Filter System which brings operational benefits in regards with other

suppliers. The filter technology allow an almost perfect dust separation with a very small pressure

drop, withstand the harsh conditions of the process without being damaged by temperature and

ignition of the dust, Automatic System for Integrity Filter Monitoring as the filter damage may

result in pumps destruction. The Filter System developed by CVS has efficiency of 99% gas load is less

than 5 mg/m3, Pressure drop of 0.1-0.2 mbar and operational temperature range between 20 -

1000° C

CONTINUOUS CASTIN MACHINES

CCM can be designed for the production of structural, low-carbon low alloy steels, high alloy steels,

Si-killed and Al-killed steels including free cutting stells. Billets up to 220 mm square and rounds up to

400 mm can be cast from the machine. The CCM can be designed with 2 to 8 strands and 5 to 9

meter radius and cartridge type multi-tapered moulds with the length ranging between 750 mm to

1.000 mm according to Production requirements.

CVS CCM design gives flexibility with two casting modes; open stream casting and closed casting for

special steel grades and Al-killed steels. In open stream casting, the fast nozzle changing device is

normally used for long casting sequences in order to reach very good productivity and reliability

levels.

T-shaped tundish design with high nominal capacity promotes inclusion removal, assuring a stable

steel flow, increasing steel residence time and homogenization for temperature patterns between

strands. The use of pool type impact pad also helps in creating a good steel flow pattern and an even






temperature through the tundish. The temperature difference between hot nad cold spots is

designed to be less than 10°C.

The flow between ladle and tundish is with an automatically controlled slide gate system. Weight

cells on cantilever type tundish car measure the weight of liquid steel in the tundish and

automatically open or close the ladle slide gate to maintain the depth of steel required. For inclusion

control, ladle shroud can be applied. Additionally, tundish automatic weight control can be

implemented by small additions to slide-gate hydraulic unit and automation system.

Mould technology with long copper mould and tapered design yields for high casting speed by

increasing heat transfer equally all around the mould. Thanks to the multi-tapered design, the air gap

that is formed inside the mould is reducing. Air gap is normally formed because of in the lower part

of the mould by billet shrinkage and in the upper part by the difference in heat Exchange between

the faces and corners.

Quick and safe mould changing can be achieved by cartridge type mould yielding pre-assembled and

self-centering design, together with self-sealing connections for cooling water supply. Foot Roll

design underneath the mould helps to overcome bulging of semi-product.

Mould External/Internal Electromagnetic Stirrers (M-EMS) and/or final EMS (F-EMS) can be

implemented to help improve the internal structure of the billet. This is an important tool when

casting high quality steels to help in the formation of the cast structure (equaxial zone), and to avoid

deposits of non-metallic or gaseous inclusions in the sub-surface area of the solidified shell. These

inclusions may lead to serious defects during the successive processes downstream of the caster.






Magnetic or Co60 Radioactive source is used for Automatic Mould Level Control System. It controls

the liquid steel level in the by adjusting the speed of withdrawal and straightening unit variably for

open casting. Control system is not effected by the vibrations created by steel stream impact into the

tundish and by the vibration of the casting platform. It allows flying tundish change, fly nozzle change

without casting stop. Thanks to the system having high accuracy with quick response features, for

precise control of meniscus level in the mould, surface quality problems arising especially from

oscillation marks are cancelled .

The oscillating table with electro-mechanical or hydraulically driven designs is of heavy-duty design

and is sized to support the mould housings. The real oscillating curve overlaps the ideal one with

strict tolerances and is stable during machine life in order to insure quality of the billet and a longer

mould life by reducing friction between steel and copper tube. The mould oscillation system is

designed to maintain surface quality, limiting oscillation marks depth and cracks generation, to allow

an adequate lubrication of the solidifying shell, to obtain good heat transfer in mould, to get shallow

oscillation mark by short stroke and high frequency values. Automatic Break-out prediction system

and mould oscillation monitoring systems are the equipments used for better contol of operation.

The secondary cooling design is generally devided into four zones, each having its own regulation

loops. The cooling for all zones is with water by correctly balanced flowrates and pressures. Sprayer

designs of this multi zone secondary cooling system is arranged to reach the goal to avoid reheating

of strand surface and to promote the continuation of shell growth, which has very ig influence on the

internal quality of end product. Additionally, to decrease the risk of break-out and avoiding internal

crack, secondary cooling system automatically controlled in accordance with section size and casting

speed.

The withdrawal and straightening module is to carry out dummy-bar insertion and withdrawal of the

billet. A hydraulic cylinder lifts and lowers the top roll and applies the required pressure on the

dummy bar or the billet. The pressure of the rolls on the billet is adjusted highly enough to avoid

skidding on the billet surface.






The billets are cut-to-length automatically by a mechanical shear or by a single torch oxycutting car

according to length measurement from encoder installed on withdrawal motor. As the billet reaches

the length required, shear or the oxycutting car automatically start to cut. For oxycutting torch,

Clamping action enables the car to travel forward with the same speed of the strand. After cutting

operation is finalised, clamps are opened and car returns back to park position.

After cutting, billet is transported along the run-out roller table up to billet transfer zone and lifted by

hydraulic cylinder. After completion of one billet lifted for each strand, transfer car moves them

sideways to the walking beam cooling bed. Along this unit, billet is transported by 90° rotation for

even cooling. At the end of the bed, billets are off-loaded by magnet crane and stockpiled.

SCRAP PREHEATING SYSTEM

Heat energy contained in a gas evacuated from an EAF accounts for 15 to 20 % of the total energy

used in EAF steel making process and that is 100 – 150 kwh/ton. CVS scrap pre-heater is a system

which utilizes this heat energy to heat scrap in a bucket before charged into an EAF and thus

contributes towards energy saving. Gas evacuated from the EAF is led to a combustion chamber

through a suction duct together with air induced through gap between EAF elbow and sliding sleeve

duct to burn CO contained in the gas, a part of this burned gas is introduced in to the bucket placed

at the scrap to heat scrap. After passing the bucket, the gas is returned to the combustion chamber

by a preheating fan. This is called Recycle Flow in the system.

When scrap does not contain oil and other combustibles, the gas after preheating my be sent to the

duct collector. This is called Direct Flow in the system.






For Recycle flow, combustibles contained in the gas after preheating is burned by mixing with the gas

from the EAF. This enables to eliminate an air pollution after dust collector.

It is important to minimize gas leakage in a preheating line. For this purpose, special sealing devices

are provided between hood pipe and inlet duct, hood and scrap bucket top edge, bucket cylinder and

clamp shells.

By use of the adequate sealing devices, air introduced into the scrap pre-heater is very small. By

provision of preheating fan, existing fume treatment plant can employ the scrap preheater without

modification. As the system is fully automatically operated, this system does not require additional

worker. EAF operation will not be interrupted even if the preheating system run into a trouble.

Recycling method of preheating system can be controlled separately from dust collector system.

Proper adjustment of the preheating temperature prevents the scrap bucket from being deformed.

Condition of temperature on the preheating system:

- Inlet temperature of preheater: approx. 800°C – 200°C

- Outlet tempearture of preheater: approx. 250°C – 50°C

- Temperature of preheated scrap: approx. 400°C – 100°C

- Temperature at combustion chamber inlet widely varies between 1200°C to 300°C according to the

time and conditions of the steelmaking stages.

Outlet temperatures of the preheating system stays at low temperatures which indicates that heat

absorption by scrap is fully accomplished. Temperature of scrap indicates the difference between

upper and lower parts of the charging bucket.

Main Profit of the system is preheated scrap with average temperature is between 150°C - 200°C,

resulting energy saving is 20 – 30 kwh/ton in practice.

Carbon Handling System

Main design advantages for carbon handling system are low dust, fast pay-back, minimum

Investment, maintenance friendly design, low operation cost, higher productivity, safe and fully-

automated operation.






Up to 5.000 ton/month 0-8 mm carbon with less than 1 % humudity can be produced from starting

Carbon of 0-100 mm and Humidity of Up to %25. Production yields less than 6 % dust emission, less

than 8 kWh/ton-C energy consumption and 30 Nm3/ton-C Natural gas consumption.

Depending on unit price of consumable items 30 USD/ton Carbon Handling Cost and 70 USD/ton

saving from operation can be achieved which yields investment pay-back of around only 10-months.

FTP DESIGN

From EAF Roof Elbow to Stack, CVS provides

complete Fume Treatment Plants with

engineering, design, manufacturing and

installation. Design considers also LF, MHS,

canoppy and other dust emitting points by the

goal of ZERO DUST EMITION to environment.

CVS offers economically viable solutions at

European standards.

CVS designs FTP to collect, suck and treat the primary and secondary emissions generated by the

EAF, the primary emission generated by the LF and the emission emitted by the Material Handling

System.

The dedusting system consists of a set of fume collection points and a set of ducting lines (water-

cooled or radiant type), which convey the various emissions to the bag fitler already under

implementation.

CVS designs FTP with the following aim: reliability, minimum operation and maintenance costs, low

residual dust content at stack, low noise emission, optimal utilization of spaces inside/ outside the

meltshop, automatic operation, “hands-off” type, and twenty-four hours operation.

Material Handling System






Material Handling System is considered to reduce manual work and to avoid losing time-demanding

material handling and automatic operation. The main operations are the storage into bins,

extraction, weighing, transport and charging of ferroalloy, additives and fluxes into scrap bucket, into

the ladle in tapping position and to the ladle refining station. All plant functions, specifically from

storage bins up to loading to the final users, are controlled automatically. The dosage is carried out

with high accuracy to obtain maximum technical results and, at the same time, to use additives and

fluxes in the best possible way to minimize expenses. Suitable interlocks are to guarantee the right

positioning of the devices.

AUTOMATION

All meltshop is normally equipped with sophisticated automation system based on Local Area

Network supporting the PLC Unit, operator workstations. Each phase of the process can be

automatically controlled and constantly monitored to help making the various phases of the process

repeatable to guarantee the overall production cycle.






Through the MMIs, the operator has an immediate overview of the process. They incorporate easy-

to-read graphics and user-friendly systems for rapid access and control of all phases. Alarms and

diagnostics are displayed on the screen to enable quick corrections to be carried out when necessary.

Thanks to open architecture of SQL database, parameters can be accessed not only by the operator

but also a higher level computer system which is called level 2. It is able to built a level 2 hardware &

software on level 1,5 substructure. The user access to level 1,5 can also be classified into several

authorization levels, such as operator access level, meltshop chief access level, etc.

Main aim in designing user interfaces is to create a virtual bridge between user and machine. User

interface pages on HMI screens are designed by using Siemens WinCC HMI software which offers

screens with rich graphical objects displaying process variables, such as temperature, pressure, flow,

animated graphics and status of machine. User screens can also be used to monitor machine

conditions for maintenance purposes, for instance, monitoring the total working hours of motors,

temperature variation graphics versus time, etc.

CVS ROLLING MILL

From Bar mill to Section Mill, From Chimney to complete Reheating Furnaces, from Roll Stands and

water quenching system to complete Rolling Mill Train, from Cooling Bed Area to Handling Area,

from Flying Shears to Cold Shears, Full Automation System and from Engineering Services to Turn-Key

Plants, CVS offers economically viable solutions at European standards.

All mechanical equipment incorporates the latest known and proven technology.






- All mill stands are housingless series, which are known worldwide for their rigidity and ease

of maintenance.

- The stands can be used for producing all grades of steel up to and including stainless high

speed and high alloy steel.

- Special "robots" are used for quick roll changing thus reducing the requirement for costly

spares and stand by equipment.

- All the rolling mill stands are individually driven by motors

- Inter-stands tension of the bar can be controlled to acceptable limit.

- Improved quality of the finished product

- Reduced risk of scrap or cobbled bar.

- Flying shear is provided to remove the oversize head of the bar as it progresses down the

rolling line.

- Maintenance friendly design

Training and Technology Transfer

Whenever CVS recieves an order for steelmaking equipment, engineering services and know-how

transfer are mutually agreed upon between both parties. Thanks to our experience, there is no

question that we know that this is fundamental basis for succesful production equipment.

The second step of know-how transfer is an off-site training of customer’s engineers, technicians and

skilled workers.

The main target of training on the customer’s site is to familiarise their personel with hands-on

operation ofthe supplied machines and equipment. The operators and maintenance personel are

trained step by step to prepare them for successful operation of the equipment.