Hydraulic Mould Oscillation - Recent Installations in India - Presentation

5th International Iron & Steelmaking Conf, Vizag 6-7 Aug10 2010

Corus Process Engineering

Hydraulic Mould Oscillation – Recent Installations in India


• Overview of mould oscillation• Comparison of Electro-mechanical and Hydraulic oscillation systems• Considerations before upgrading an existing caster• Recent hydraulic oscillation installations in India

Presentation Outline


Slab

Billet


Mould Operations


• Within the mould a solid shell is formed• Mould Oscillation is essential

• Delivering lubricant between shell and mould walls• Minimising mould friction• Obtaining good surface quality• Promoting uniform shell thickness• Controlling lubricant consumption

Overview of mould Oscillation


• Typical electro-mechanical oscillation system

• Electric motor• Gearbox• Eccentric• Overload spring box

Comparison of Electro-mechanical and Hydraulicoscillation systems


Mould hydraulic oscillation cylinder


• Typical hydraulic oscillation system

• Hydraulic cylinder• Control valve• Accumulators

Comparison of Electro-mechanical and Hydraulicoscillation systems


• Pros• Simple• Easily maintained• Low electrical power consumption• Basic Control

• Cons• Waveform fixed (Sinusoidal)• Compromise between steel grades and section sizes• Stroke cannot be changed whilst casting

Pros & Cons of Electro-mechanical Systems


• Pros• Each steel grade & section size can be optimised• Not restricted to sinusoidal waveforms• During development, practices can be easily altered• Mould powder consumption optimised

• Cons• Requires hydraulic power pack and clean fluid• Electrical power consumption high• If using mineral oil – fire hazard• Relatively complex control equipment• Hydraulic equipment maintained by specialists

Pros & Cons of Hydraulic Oscillation Systems


• Market Considerations• What does the market want ?• What current product is being produced ?• How will the future change ?

• Existing Practices• How good are the current practices

• Consistency• Mould level control• Mould powder practices

• Have current oscillation practices been optimised

Considerations before upgrading an existing caster


• Engineering Considerations• What is the condition of the mould table ?• Can a hydraulic cylinder be installed safely ?• Is there space & protection for a power pack ?

• People Considerations• Do the existing people have the experience to operate and maintain a hydraulic oscillation system ?

Considerations before upgrading an existing caster


• Casting Machine A• 3 strand Billet / Bloom machine• Section sizes 130 x 130 – 280 x 340

• Casting Machine B• Single strand Bloom machine• 300 x 300 – 350 x 350

• Steel grades of both machines• LC, MC, HC, LAS, SS & BG

Recent hydraulic oscillation installations in India


• Operational• Stroke +/- 25mm @ cylinder (+/- 12mm @ mould)• Waveform sinusoidal or +/- asymmetric• Frequency range 5 – 250 c.p.m.• Can alter stroke, frequency and waveform during casting

• Control System• Allan Bradley PLC control• Oscillation parameters automatically downloaded from main PLC• Control via SCADA or local HMI• Can operate individual strands

Description of hydraulic mould oscillation system


Hydraulic cylinders being tested prior to despatch


Control PLCCabinet andLocal HMI Panel


Operator’s SCADA Screen


• Hydraulic & Mechanical• Hydraulic fluid - Mineral oil • Single servo-cylinder per strand• Automatic burst hose protection system• Hydraulic accumulators on cylinder and in main pressure line• Typical power pack 2 x 90kW motors powering 2 x 220l/min hydraulic pumps

Description of hydraulic mould oscillation system


Hydraulic power pack


Main line accumulators


Mould hydraulic oscillation cylinder


Individual strand burst hose protection device


• Ability to optimise oscillation practices for each steel grade and section size• Much smoother start and finish to casting• Better surface quality on cast product

Benefits Achieved


Corus Process Engineering

Hydraulic Mould Oscillation – Recent Installations in India

Hydraulic Mould Oscillation - Recent Installations in India - Presentation

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