“BY PROVIDING AND INSULATION LINING”
CARRIED OUT BY:
K.S.V.S. APPARAO (08651A0305)
M.SESHAGIRI RAO (08651A0343)
CARRIED OUT AT: NAVA BHARAT VENTURES LIMITED
GUIDED BY: G.ANAND RAO
INTRODUCTION TO LADLE AND ITS DESIGN
FACTORS EFFECTING SKULL
METHOD TO REDUCE SKULL
FORMULATION USED FOR STUDY
MATLAB AND ANSYS RESULTS
In the era of nano and precise accuracies we have great concern of
productivity, finish in all levels of manufacturing which includes casting
A ladle is a component used for carrying the molten metal in the
casting process, this undergoes a considerable heat loss and metal gets
solidified and a skull will be formed. So we surely require to make an
alternative to reduce this skull to reach the required productivity and yield.
The work in the project is focussed to give a theoretical and analytical
information about the heat loss, problem of skull in the ladle, the
mathematical formulation used for solving of the problem is presented.
It also presents the results graphically and comparisons will be laid out
using MAT LAB Software.
In a foundry, a ladle is a vessel used to transport and pour out
molten metals. Ladles range in size from
1. small hand carried vessels that hold 20 kilograms (44 lb)
2. large steel mill ladles that hold up to 300 tones (330 tons).
1. Casting ladle: a ladle used to pour molten metal into moulds to
produce the casting.
2. Transfer ladle: a ladle used to transfer a large amount of molten
metal from one process to another.
3. Treatment ladle: a ladle used for a process to take place
within the ladle to change some aspect of the molten metal.
The ladle under consideration is composed of three layers
1. mild steel (20mm) outer layer
2. Fireclay (80mm) middle layer
3. Graphite (120mm) inner layer
The ladle is used to carry (simn) metal at a temperature of about
The tapping time is 20min
The carrying and pouring time is 20min
The hot metal carried by the ladle is too hot and because of this heat
loss occurs this results in decrease of liquid temperature ,therefore
metal starts solidifying and a layer near the boundaries will be
formed, this it self is the skull.
Liquid alloy Graphite Brick M.S
L alloy skull Graphite Brick M.S
Ferro Alloys are used as inputs in the manufacture of iron and steel
for removal of oxygen and imparting specific properties. These are
alloys of iron and elements like manganese, silicon, chromium, etc.
While manganese and silicon alloys impart strength and hardness
and act as powerful deoxidizing agents, chromium alloys make steel
resistant to corrosion and heat.
Typical examples of end products comprise rail road rails, structural
steel, automobile bodies, etc. for manganese alloys.
The principal mechanisms responsible for heat loss from the molten
1. Conduction into the walls of the ladle
2. Radiation from the top exposed surface
3. Possibly convection happens naturally
Consequently, a boundary separating
two different phases develops and moves in the matter during the
Because of this the volume carried by the ladle reduces
Scrap might increase
Cleanliness of the metal will reduce
Wastage of liquid metal
Chip removal process requires
An expendable lining may be applied over the interior walls of a
metal handling vessel for molten metal, The expendable lining is
usually applied over a relatively permanent, e.g. refractory
brick, lining, Good insulator.
By pre-heating the ladle surface will
considerably reduce the heat loss thus
By providing a cap on the ladle will
reduce heat through radiation.
An insulation will be provided in between the layers of brick and
Liquid alloy skullgraphite insulation Brick M.S
Heat transfer equations were laid out for all the layers and interface
Finite difference formulation is chosen for solving the problem
For solving boundary conditions we have chosen explicit method
For phase change problems we have chosen fixed grid method
One- dimensional transient heat conduction equation
Over all diffusivity equation
Can be approximated with a forward finite difference formulation
Can be approximated with a central difference formulation
Combining both we get general equation to calculate temperature at
required time and distance step (n,i)
X(t) is the position of the solid-liquid interface (moving boundary)
With out insulation after tapping and before pouring respectively
With insulation of 20mm after tapping and before pouring
With insulation of 80mm after tapping and before pouring
Variation of skull with respect to time without insulation and
Excellent insulating properties
Improved molten metal temperature control
Reduced labour cost /Lower energy cost
Safer /cleaner working environment
Improved metallurgical control
Reduced re-oxidation rate
Reduced slag carryover/fewer slag related inclusions
Improved ladle preparation productivity
Improved alloy recovery
Optimal balance between refractory life and clean ladle practice
When the insulation is provided the skull reduced to considerable
Comparison of the skull thickness via graphs
Ladle shell surface temperature with respect to temperatures and
time for system without lining and with lining
Rate of Heat Loss from Different Size Ladle with respect to
temperature and weight for system Brick Lining compared with
Typical cooling profile for ladle with respect to temperature and
weight remaining in the ladle for system Brick Lining compared
with insulation lining