The document summarizes the different zones of a cupola furnace: 1. The crucible zone collects molten metal between taps. 2. The combustion zone reaches temperatures over 1550°C, where fuel is combusted and heat is generated. 3. The reducing zone extends above, where the temperature drops to 1200°C and the atmosphere protects the charge from oxidation.

1. Cupola Furnace

3. Various zones of cupola :
1.Crucible zone
2.Combustion or oxidizing zone
3.Reducing zone
4.Melting zone
5.Pre heating or charging zone
6.Slack zone

4. 1.Crucible zone
This zone is the zone between top of the sand bed
and bottom of the tuyeres. This is also called well of
the cupola, molten metal is accumulated here
between taps.

5. Combustion or oxidizing 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 librated in this zones and is supplied
to other zones.
-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

6. Reducing 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.

7. Melting zone
-Extends from 1st layer of metal charge above the coke bed
upto the height of about 900mm.
-Temp : 1600 C which causes CI in the charge to melt.
- molten IRON + CO  Fe3C and CO2

8. Pre heating or charging 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.

9. Slack zone
-Extends from above the pre-heating zone to top of the
cupola.
-Carries the flue gases and discharges these gases to
atmosphere.