SAFETY CONSIDERATIONS

FOR OPERATING

CORELESS INDUCTION

MELTING FURNACES

BY

JACK MCMILLIN

AJAX TOCCO MAGNETHERMIC

SAFELY MELTING WITH

CORELESS INDUCTION

FURNACES BEGINS WITH

OPERATOR TRAINING

The following program

outlines considerations for

that training..

THE FOUNDRY

ENVIRONMENT

The foundry

can look

ominous,

but it need

not be

intimidating.

THE FOUNDRY

ENVIRONMENT

With proper

training and

understanding

the foundry

can be a safe

workplace.

Safety Through Operator Training

1- Employer Responsibility

Understanding that the reason for a foundry to be in business is to make a profit and grow.

Safety Through Operator Training

1- Employer Responsibility

Part of good

business is to put

programs in place

to minimize

accidents, injuries,

and lost time

incidents that are

harmful and

costly.

Safety Through Operator Training

1- Employer Responsibility

1.0 Employer responsibility --- Provide a safe working environment with the training and

tools to perform the required tasks in a safe manner.

1.1 The 29 CFR Section 1910.132 (Code of Federal Regulation) requires the

employer to do hazard assessment and to thereafter provide and require

conformity to that assessment by having employees wear proper PPE

(Personal Protective Equipment)

1.2 Provide safe furnace equipment with proper grounding and emphasize the

importance for operating safely.

1.3 Maintain the equipment and ensure it operates as intended.

1.4 Develop and maintain reporting systems to ensure consistent operational

efficiencies and safety.

Safety Through Operator Training

1- Employer Responsibility

Define primary

protective clothing

standards.

Safety Through Operator Training

1- Employer Responsibility

Define and or

provide secondary

protective clothing

standards.

Safety Through Operator Training

2 - Define Work Space

2.0 Define operator work space and equipment to be used and maintained. Define

procedures. Be certain they know the equipment.

2.1 Define the proper PPE (Personal Protective Equipment) and instruct it's

proper use.

2.2 Define melt deck area and operator's responsibility

2.3 Define melt deck organization and why to locate items in their best desired

position

2.4 Define use of run out pits and the importance of keeping them dry

2.5 Discuss and understand scrap drying, pre-heating or batch melting versus

tap and charge melting.

2.6 Understand fume collector operations for various furnace stages, melt,

holding, sintering, and charging

2.7 Protect against mechanical equipment hazards, pinch points, open pits, moving

equipment.

Safety Through Operator Training

2 - Define Work Procedures

2.8 Electrical equipment hazards.

2.9 Bridging and Run outs.

2.10 What to do when you get a ground trip.

2.11 Handling power supply shut-downs vs. furnace melt conditions and the

impact on refractory.

2.12 Maintain heat log sheets for proper recommended documentation

keeping/future referral.

2.13 Ground test to ensure proper grounding for operator/equipment safety.

2.14 Use of furnace energy monitors computerized with load cells on furnace.

2.15 Use of furnace energy monitors, such as kWh counters.

Safety Through Operator Training

2 - Define Emergency Procedures

Bridging occurs when a “cap” forms over the top of the furnace, allowing a buildup of superheated gases in the void below.

The void separating molten metal from the bridge of solid charge material acts as an insulator.

The molten metal will superheat and the temperature will rise rapidly.

Safety Through Operator Training

2 - Define Work Procedures

2.16 Furnace grounding and importance for operating safety.

2.17 Furnace energy melt calculations for efficient melting.

2.18 Calculating a super heat time on various melt system combinations.

2.19 Use of slag coagulants for optimum slag removal.

2.20

Safety Through Operator Training

3 – Furnace Charging Procedures

We do not want to leave anything to chance.

Know what is being charged into the furnace.

Safety Through Operator Training

3 – Charging Furnace

Safety and security are

of primary importance.

Personnel safety

depends on knowing

what goes into the

furnace.

Quality production

depends on consistency

in operations.

Safety Through Operator Training

3 – Charging Furnace

Safety Through Operator Training

3 – Charging Furnace

Safety Through Operator Training

3 – Charging Furnace

Pouring or

inoculating can

be just as

dangerous and

should be

performed with

proper caution.

Safety Through Operator Training

3 – Charging Furnace

3.0 Charge make up, charging safety, charge procedures, charge sequence.

3.1 Scrap storage.

3.2 Charging a furnace, material sequence.

3.3 Charge material make-up and type.

3.4 Charge material and the effects on operation, refractory, energy and safety:

chips, oily scrap, effects of none metallic's, charging large pieces, etc.

3.5 Safety precautions to follow when charging a furnace, charge sequence,

weighed charges.

3.6 Proper time to add alloy and the effects on refractory lining and chemistry

Safety Through Operator Training

4 – Furnace Relining

4.0 Relining- monitoring the furnace lining, determining when to reline, tearing out a

spent lining.

4.1 Lining measurement sheet for proper lining dimensional installation as well

as lining monitoring when it wears

4.2 Available lining penetration sensing, such as “Safeway”, etc.

4.3 Electronic systems covering lining wear charting/indication

4.4 Refractory materials and the desired operating temperatures

4.5 Patching refractory - "Do not patch over the ground probes"

Safety Through Operator Training

4 – Furnace Relining

4.6 Lining removal procedure and the importance of restoring the furnace for

the next reline, grout repair, use of slip plane materials.

4.7 Coil coat material selection, installation, patching and drying

4.8 Furnace refractory selection for the alloys being melted

4.9 Lining installation systems, such as Gradmatic

Safety Through Operator Training

5 – Sintering the Furnace Lining

5.0 Refractory lining sintering practices and procedures.

5.1 Sintering refractory linings

5.2 Proper sinter charge material, stacking, starter blocks, and following the

recommended temperature ramp-ups: keeping records.

5.3 Sintering and proper monitoring with thermocouple installation.

5.4

5.5

Proper sinter power level for given furnace size.

Consistency is important.

Safety Through Operator Training

5 – Sintering the Furnace Lining

The success

or failure of a

lining

campaign

starts with the

sintering.

Safety Through Operator Training

6 – Furnace Shut Down and

Cold Starting

6.0 Proper furnace shut down and cold start procedures.

6.1 Cold start ups and cool downs

6.2 Fan cooling

6.3 Torch preheat procedures.

6.4 Power preheat procedures

6.5 Overnight holding.

6.6 Auto restart.

Safety Through Operator Training

7 – Furnace Maintenance

7.0 Furnace Maintenance Procedures and Considerations

7.1 Safety precautions for Maintenance personnel

7.2 Electrical equipment hazards

7.3 Mechanical equipment hazards

7.4 Looking after maintenance people, as they may be less familiar with furnace

and power supply than you as the operator

Safety Through Operator Training

7 – Furnace Maintenance

7.5 Heat log sheets for proper recommended documentation keeping/referral

7.6 GLD ground leak detector operation

7.7 Furnace grounding and importance for operating safety

7.8 Water flows and temperatures

7.9 Power lead polarization for maximum efficiency/minimum loss and proximity

heating

Safety Through Operator Training

8 – Other considerations for specific

installations or processes.

This is a work in

progress.

Questions ?

Comments ?

Opinions ?

Suggestions ?

Assistance ?

Input ?