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DESIGN AND MODELLING OF CUPOLA

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DONE BY
CEASE JUNIOR
FIJO GEORGE
FOUZIYA C M
HAREESH MOHANAN
JESBIN JOSE
JIBIN JOSEPH

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CONTENTS
OBJECTIVE OF PROJECT
INTRODUCTION
CONSTRUCTION
CUPOLA OPERATIONS
ADVANTAGES AND LIMITATIONS
DESIGN CONSIDERATIONS
DESIGN
FABRICATION DETAILS
BIBLIOGRAPHY

OBJECTIVE OF PROJECT
TO DESIGN AND FABRICATE A MODEL OF SIZE 2 CUPOLA IN THE RATIO 1:2
FURNACES
FURNACES ARE OF TWO TYPES
1. BLAST FURNACES
2. FOUNDRY FURNACES
Blast furnaces performs basic melting operations i.e. melting of metal ores.
Foundry furnaces are used to casting purposes.
Heat in a remelting furnace is created by
1. Combustion of fuel
2. Electric arc
3. Electric resistance
HISTORY OF CUPOLA
DEVELOPMENT OF BLAST FURNACE FOR THE REDUCTION OF IRON ORE GAVE BIRTH TO IRON FOUNDING
AS TIME WENT ON REMELTING OF PIG IRON FOR MAKING GRAY IRON CASTINGS - WHICH LEAD TO THE EVOLUTION OF CUPOLA
CUPOLA PLAYED A MAJOR ROLE IN THE INDUSTRIAL REVOLUTION
FIG SHOWS STATITICS OF FURNACES IN THE PERIOD 1962-63 IN U.S AND CANADA
CONSTRUCTIONAL FEATURES
CUPOLA OPERATIONS
PREPARATION OF CUPOLA
LIGHTING THE FIRE IN THE COKE BED
CHARGING OF CUPOLA
MELTING
SLAGGING AND METAL TAPPING
DROPPING DOWN THE BOTTOM
PREPARATION OF CUPOLA
The bottom door is dropped down and cleaned
Damaged firebricks are replaced
Repairing and patching of refractory lining
Ramming of sand bed
Drop door is closed ,when the furnace is reconditioned

LIGHTING THE FIRE IN THE COKE BED
Cupola is started 3hr before the molten metal is to be poured
Soft and dry pieces of wood is placed over the sand bed
Coke is placed over the wooden pieces
Air enters through the tuyeres
Electric spark igniters and gas torches are also used for ignition

CHARGING OF CUPOLA
Charged from the charge door
Alternate layers of Limestone (flux), Iorn, Coke (fuel) up to charge door
Sodium carbonate ,calcium carbide etc also used as flux
A metal charge would have pig iron, scrap iron, returns etc

MELTING
Soaking period of 30-60 minutes to preheat
Blast is turned on
Molten metal accumulated at bottom

SLAGGING AND METAL TAPPING
Slag hole is opened, slag spouted is collected in a container
As air blast continues, melting progresses and the molten iron is tapped for pouring into the molds


DROPPING DOWN THE BOTTOM
All the contents are allowed to melt till one or two charges are left above the coke bed
Blast is shut off, the drop door is opened
and remains in the cupola is removed

ZONES
WELL
COMBUSTION ZONE
REDUCING ZONE
MELTING ZONE
PREHEATING ZONE
STACK ZONE
COMBUSTION ZONE
15-30 cm above the tuyeres
1550-1850 0c
C+O2CO2+heat
2Mn+o2Mno2+heat
Si+O2SiO2+heat
REDUCTION ZONE
Top of combustion zone to the top of the coke bed
CO2+C2CO-Heat
MELTING ZONE
It starts from first layer of metal charge to a
ht of 90 cm
3Fe+2COFe3C+CO2
1600c

PREHEATING ZONE
From Melting zone to the bottom of charging of the charge door
1100c
Stack zone
From preheating zone to the cupola shell ends.
Hot gases passes escape through the stack

ADVANTAGES
SIMPLE DESIGN AND EASIER CONSTUCTION
LOW COST OF MELTING
SIMPLE TO OPERATE AND MAINTAIN IN GOOD CONDITION
ECONOMY IN OPERATION AND MAINTANENCE
LESS FLOOR REQUIREMENTS
COULD BE CONTINOIUSLY MELTED
ADEQUATE TEMPERTURE CONTROL
CHEMICAL COMPOSITION CONTROL
EFFICIENCY OF CUPOLA VARIES FROM 30 TO 50%.
LIMITATIONS
SINCE MOLTEN IRON AND COKE ARE IN CONTACT WITH EACH OTHER, CERTAIN ELEMENTS LIKE Si, Mn ARE LOST AND OTHERS LIKE SULPHUR ARE PICKED UP. THIS CHANGES THE FINAL ANALYSIS OF MOLTEN METAL.
CLOSE TEMPERATURE CONTROL IS DIFFICULT TO MAINTAIN
DESIGN CONSIDERATIONS
COST EFFECTIVE
PORTABILITY
EASY TO HANDLE
ABLE TO EXPLAIN THE WORKING CONDITIONS
DESIGN
USING THE DESIGN CONSIDERATIONS WE ARE AIMING TO DESIGN AND FABRICATE THE CUPOLA OF SIZE 2 IN THE RATIO 1:2.


FABRICATION DETAILS
MATERIALS REQUIRED
QTY OF GI SHEET 5 sq.metres
QTY OF 8mm dia iron rod 21 metres
OTY of ¾ hollow pipe 6.5 metres
QTY of 25*25*6 angle iron 1 metre
QTY of 6*3 ms flat 10 metres
QTY of 50*8 ms rectangular pipe 4 metres
MODELLING DETAILS
First of all, we have constructed the structure or the base to be which the sheets have to be rolled and the legs.


After the construction of the base we have gas welded the sheets, tuyeres, wind box, spark arrester



Then we coated primer to it. And the charging platform is done with the ladder.



Then we fabricated the inside surface of the cupola and the painting is done.

BIBLIOGRAPHY
PHILIP C ROSENTHAL. RICHARD W HEINE, CARL R LOPER, PRINCIPLES OF METAL CASTING, TATA McGraw “ HILL EDITION
Dr. O P KHANNA, FOUNDRY TECHNOLOGY, DHANPAT RAI PUBLICATIONS.