Metal Melting Furnaces

Sub :- Manufacturing process – 2

Bhavik Nakrani_140990119027_MP2_2141908

Ankit Panchal_140990119028_MP2_2141908

Raj Parekh_140990119029_MP2_2141908

Dwij Patel_140990119032_MP2_2141908

Metal Melting Furnaces THE FURNACES USED IN METAL CASTING ARE AS FOLLOWING:.

Cupola Furnace Electric Arc Furnace Induction Furnace Metal pot Furnace

Cupola Furnace

Cupola furnaces are tall, cylindrical furnaces used to melt iron and ferrous alloys in foundry operations. Alternating layers of metal and ferrous alloys, coke, and limestone are fed into the furnace from the top.

Preparation of cupola. Firing the cupola. Soaking of iron. Opening of air blast. Pouring the molten metal. Closing the cupola.

Operation of Cupola

This zone is the zone between top of the

sand bed and bottom of the tuyers.

This is also called well of the cupola,

molten metal is accumulated here

between taps.

Zones

Crucible Zone

- situated 150 to 300 mm above the top

of the tuyers.

-The actual combustion of fuel occurs in

This zone using oxygen in the air blast.

-A lot of heat Is liberated in this zones

and is supplied to other zones.

Zones Combustion Zone

- Some heat is also evolved in this zone due to oxidation

Of silicon & manganese. The temp of this zone is of 1550

to 1850 C.

- Because of this temperature molten drops of CI pour

into the heart.

- Product : co2 , SiO2 and MnO2

Reaction in this zone

C + O2 ————> CO2 + Heat

Combustion Zone

- Extends from the combustion zone to top of the coke bed.

- CO2 produced in previous zone reduces to CO and temp drops to 1200 C.

- Because of reducing Atmosphere in this zone the charge is protected from oxidation.

Reaction in this zone

CO2 + C ————> 2CO - Heat

Zones Reducing Zone

- Extends from 1st layer of metal charge above the coke bed upto the height of about 900 mm.

- Temp : 1600 C which causes CI in the charge to melt.

Reaction in this zone 3Fe + 2CO ————> Fe3C

+ CO2

Zones Melting Zone

- Starts from above the melting zone and up to bottom of the Charging door.

- Alternate layers of coke, flux and metal charge are preheated in this zone to temp of about 1100 C before entering melting zone.

Zones Pre-heating Zone

Reaction in this zone FeS + CaO + C ————>

Fe + CaS + CO

- Extends from above the pre-heating zone to top of the cupola.

- Carries the flue gases and discharges these gases to atmosphere.

Zones Slack Zone

ELECTRIC ARC FURNACE

The Electric Arc Furnace (EAF) uses three vertical carbon rods as electrodes for producing arcs, striking on to the charge and heating it to the required temperature.

Charge is melted by heat generated from an electric arc High power consumption, but electric arc furnaces can ‑

be designed for high melting capacity Used primarily for melting steel

Induction Furnaces

Uses alternating current passing through a coil to develop magnetic field in metal

Induced current causes rapid heating and melting

Electromagnetic force field also causes mixing action in liquid metal

Since metal does not contact heating elements, the environment can be closely controlled, which results in molten metals of high quality and purity

Melting steel, cast iron, and aluminum alloys are common applications in foundry work

Metal Pot Furnace

Relatively low melting point alloys like alloys of aluminium,magnesium,zinc,lead or tin can be melted in a metal pot usually made of cast iron or steel.

The metal pot is supported by its lid in a stationary fired by gas, or oil.

The products of combustion are discharged through a flue and do not come into contact with the molten metal.

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