IJIRST –International Journal for Innovative Research in Science & Technology| Volume 4 | Issue 10 | March 2018
ISSN (online): 2349-6010
Design of Gating System of Windmill Hub
Isha Sanitha
Assistant Professor
Department of Mechanical Engineering
I E S college of Engineering, Thrissur, India
Joshy James
Student
Department of Mechanical Engineering
I E S college of Engineering, Thrissur, India
Mohamed Mubassir
Student
Department of Mechanical Engineering
I E S college of Engineering, Thrissur, India
Ajmal Muhamed
Student
Department of Mechanical Engineering
I E S college of Engineering, Thrissur, India
Fayis K T
Student
Department of Mechanical Engineering
I E S college of Engineering, Thrissur, India
Abstract
The purpose of the study is to identify improved gating system of windmill hub. The windmill hub is a portion of windmill which
houses the bearing and contains blades. Here we made some modifications in gating system and find a suitable design by various
factors. The study is done in on the basis of manufacturing of windmill hub at Autokast Ltd Cherthala. Here the windmill hub has
a pouring weight of 2250kg. The calculations are modified on the basis of this weight.
Keywords: windmill hub; gating system
_______________________________________________________________________________________________________
I.
INTRODUCTION
The aim of the study is to determine a suitable gating system for windmill hub and also study various methods in casting. The
gating system is the passage through which the molten metal enters to the mould cavity. In this study various gating system are
analyzed using ANSYS software on the basis of the factors like pressure and velocity. The material used for the manufacturing of
windmill hub is spheroidal graphite (SG) iron instead of cast iron. SG iron is a bridge between grey iron and steel casting with
combined properties of grey iron and steel. This iron is also known as Nodular iron and ductile iron.
Casting is a manufacturing process in which complex part and components are produced. Molten liquid is poured into molten
cavity of desired shape.
Autokast Ltd is the company which manufactures all type of ferrous casting. They produce castings from 25 to 8000 kg single
piece weighing.
II. LITRATURE REVIEW
Quality Casting of Motor Body Using Design of Experiment and Casting Simulation:
By Shailee G. Acharya; Jeetendra A. Vadher; Manojkumar V. Sheladiya; Mahesh Madhnani By using casting simulation software
and good feeding system casting defects can be reduced. The effect of turbulence and flowability are controlled by gating system.
In this research, by using design of experiment and casting simulation solidification framework the gating system are remodeled
Optimization of Ingot Casting Wheel Design using SPH Simulation:
Mahesh Prakash, Paul W. Cleary, John Grandfield, Patrick Rohan, Vu Nguyen
In this paper it explains improvement of performance for an aluminium ingot casting from a combination of smoothened particles
hydrodynamics (SPH) and pilot scale testing.
Optimization of Green Sand Casting Process Parameters for Enhancing Quality of Mild Steel Casting:
Sanjiv Kumar Tiwari, Ritesh Kumar Singh, Sharad Chandra Srivastava
In this paper it explain about obtaining optimal parameter of green sand casting process for enhancing the quality of casting of
mild steel by reducing casting defects.
Characteristics of Friction Behaviour of Flake, Spheroidal and Compact Vermicular Graphite Cast Iron:
Kyungmok Kim, Myung-Jin Yoon
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In this paper the characteristics of friction behavior of flake, spheroidal and compact vermicular graphite cast iron are explained.
Corrosion in View Point of Metal Microstructure of Grey Cast Iron and Ductie Cast Iron in Hcl Soluttion and Presence of
Thiourea:
Sayed S. Abd El Rehim, Sayed H. El-Nekhaly, Ahmed El Essawy Abdou
In this work two type of materials are used for studying first type is grey cast iron and second one is ductile cast iron. Two
specimens from each type is selected. One specimen of each type is kept without heat treatment and other one is heat treated.
Potentiodynamic technique are used to collect corrosion data in HCL solution in the presence and absence of thiourea.
III. AUTOKAST LTD
Autokast limited is an ISO 9001-2008 certified ferrous casting manufacturing company under the government of Kerala. It was
established in the year 1984, situated at Cherthala. It has an annual production capacity of 6000 metric tons. Autokast production
produces and markets different grades of Grey iron and SG iron casting for the domestic and international markets. It produces
quality sand castings in all grades of Grey iron and SG iron. An expansion proposal to include steel castings is on the anvil. It
provides parts to manufacturers like Asian wind turbines, KAMCO, kakathiakarshak Industries, Fouress Engineering, L&T.
The plant has the following sections –
1) Melting shop
2) Pattern shop
3) Moulding and Core shop
4) Shot blasting and fettling shop
5) Quality control shop
Melting Shop:
The raw materials are melt to produce different grades of cast iron in the medium frequency coreless induction furnace. The
chemical composition is kept before pouring into the mould Pouring temperature and pouring speed of individual items are
monitored to ensure consequently high quality of casting. The facility has two main induction furnace of six metric tonne capacity
and additional induction furnace of 5 metric tonne and 3 metric tonne each.
Pattern Shop:
All patterns and core boxes are inspected and corrected in the pattern shop, before being released for production of moulds and
cores. New patterns and core boxes are checked for dimensions. This facilities for inspection, repair and mounting of patterns on
match plates.
Moulding & Core Shop:
Moulding sand is prepared for moulding sieving, drying and finally mixing it with additives.Moulding sand composition is 85%
Silica sand, 2.5% Bentonite(Clay), 4.5% is Silicate, 5% is moisture.Autokast has two moulding line: Conventional Prouction Line
and Non-Conventional Production Line.
Shot Blasting:
The casting produced are cleaned of sand sticking.The running and risering system are removed from the castings. They are then
ground, finished, painted, packed and made ready for shipping shot blasting machine.
Quality Control Shop:
Quality checks are conducted at every stage. Quality control department has quality control facilities like Gamma Ray, Ultrasonics
for non-destructive testing. Physical testing laboratory with 60 Ton Universal Testing Machine, Brinnel and Rockwell Hardness
Testers.
IV. PROBLEM DESCRIPTION
This study is inorder to find improved gating system for windmill hub. The parameters like velocity and pressure are used in the
simulation of gating system. The simulation is done using software named ANSYS. The gating system with different ingates such
as circular, rectangular, trapezoidal, rectangular with curved, trapezoid with curved edge are simulated and best one among them
is selected. The gating system is important factor in manufacturing of a product by casting. For a good casting the mould cavity
should be filled fastly. The gating system helps in controlling turbulence and the rate of molten metal to be poured. A good gating
system will helps in directional solidification in casting. The velocity and temperature determine the solidification of molten metal
in casting. So the study helps to create an optimum design of gating system for a windmill hub.
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V. METHODOLGY
The figure below shows the 3-D view of windmill hub with gating system. It consists of sprue, runner bar, ingates and riser.
Analysis of INGATES:
Velocity Analysis of Circular INGATE:
Here the maximum velocity is 2.522 m/s. The maximum velocity obtained in ingates.
Velocity Analysis of Rectangular INGATES:
The maximum velocity obtained in rectangular ingate is 2.179m/s.
Velocity Analysis of Trapezoidal INGATE:
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The maximum velocity obtained in trapezoidal ingate is 2.526m/s.
Velocity Analysis of Trapezoidal INGATE with Curved EDGE:
The maximum velocity obtained by using trapezoidal ingate with curved edge is 4.284m/s.
Velocity Analysis of Rectangular INGATE with Curved EDGE:
The maximum velocity for rectangular ingate with curved edge is 5.105m/s.
Comparison Chart:
From the above chart the rectangular ingate with curved edge is having large velocity comparing other ingates.
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Pressure Analysis of INGATES:
Circular INGATE:
The maximum pressure obtained while using circular ingate is 9.50E+05 Pa.
Rectangular INGATES:
The maximum pressure in rectangular ingate is 9.52E+05Pa.
Trapezoidal INGATE:
The maximum pressure in trapezoidal ingate is 9.55E+05 Pa.
Trapezoidal INGATE with Curved EDGE:
The maximum pressure obtained by using trapezoidal ingate with curved edge is 9.55E+05 Pa.
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Design of Gating System of Windmill Hub
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Rectangular INGATE with Curved EDGE:
The maximum pressure obtained while using rectangular ingate with curved edge is 9.88E+05 Pa.
Comparison Chart:
The maximum pressure obtained is while using trapezoidal ingate.
VI. CONTENT MANUFACTURING OF WINDMILL HUB
The first step in manufacturing is based on the requirement demanded by the customer in the form of a machine drawing. With the
help of a machine drawing casting drawing is prepared considering the machine allowances. Casting drawing is followed by process
drawing which involves section of the parting line, the core details, tapering, print and pattern draft. The pattern layout is drawn in
1:1 scale adding the contraction and other allowances to the process drawing dimensions which are derived out of original
component drawing. It is used for direct reading of measurement for the use of pattern making and also for the inspection of the
pattern.
From the layout, the pattern maker manufactures the master pattern in soft wood. The soft wood is used since it is a single use
pattern. Then an aluminium pattern casting is made. The aluminium casting s machined to produce required dimension and surface
finish.
VII. PROPERTIES OF SG IRON
SG iron stands for spheroidal graphite iron also known as nodular or ductile iron. Graphite is present in spheroidal form instead of
flakes. It has higher mechanical strength, ductility and increased shock resistance compared to grey cast iron.
In SG iron the graphite is in the form of spheroids or nodules, thus inhibiting the creation of cracks and providing the enhanced
ductility. The formation of nodule is achieved by addition of nodulizing element, most commonly magnesium, ceramic and
tellurium.
Table – 1
Chemical Composition of SG Iron
Elements
% composition
C
3.6-4.2
C-combined
0.0-0.2
Si
1.25-2.0
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Design of Gating System of Windmill Hub
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Mn
P
Ni
Mg
.35
.08
0.0-1.0
0.05-0.08
VIII. DESIGN OF THE GATING SYSTEM
Casting weight for the weight for the windmill hub is 1580kg. On the basis of this theoretical calculations are done.
Steps in Design:
Pouring weight of the liquid metal
=Casting weight/0.7
=1580/0.7
=2250kg
Pouring time in second (T)
T=0.97*sqrt(pouring weight)
=0.97*sqrt(2250)
=46.011 seconds=46 seconds.
Total choke area in sq.cm
=pouring weight/(1.1*pouring time)
=2250/(1.1*46)
=44.47sq.cm
Since there are 6 ingates, the choke area of each gate
=Total choke area /number of ingates
=44.47/6
=7.41sq.cm
Diameter of ingate =sqrt{(choke area of each gate *6)/pi}
=3.76cm
We are analysing different ingates with constant area inorder to identify the gate with redud pressure drop and velocity drop.
Various type of ingates are
Circular ingates.
Trapezoidal ingate
Rectangular ingate
Trapezoidal with curved edge
Rectangular with curved edge
Gating System:
The gating system serves many purposes. The most important being conveying the liquid material to the mould, It also controls
shrinkage, the speed of liquid metal, turbulence and trapping dross The gates are usually attached to thickest part of casting. In
large castings multiple runners are required to fill mould cavity. The speed of material is important because if material travels too
slowly may cause solidification before filling. There are three types of gates
Top gate
Bottom gate
Parting line gate
Sl no
1.
2.
3.
4.
5.
Table – 2
Comparison Table
INGATE TYPE
VELOCITY(m/s)
Circular
2.522
Rectangular
2.179
Trapezoidal
2.526
Trapezoidal with curved edge
4.284
Rectangular with curved edge
5.105
PRESSURE(Pa)
9.50E+05
9.52E+05
9.95E+05
9.55E+05
9.88E+05
IX. CONCLUSION
In this paper we made a study for improving gating system for windmill hub. We made this study by practical way of casting.
Some attempts are made to modify the ingates for getting an improved gating system design. Every designes are simulated by
using ANSYS software.
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REFERENCE
[1]
[2]
[3]
[4]
[5]
QUALITY CASTING OF MOTOR BODY USING DESIGN OF EXPERIMENT AND CASTING SIMULATION. by Shailee G. Acharya; Jeetendra A.
Vadher; Manojkumar V. Sheladiya; Mahesh Madhnani
OPTIMISATION OF INGOT CASTING WHEEL DESIGN USING SPH SIMULATION. Mahesh Prakash, Paul W. Cleary, John Grandfield, Patrick
Rohan, Vu Nguyen
OPTIMISATION OF GREEN SAND CASTING PROCESS PARAMETERS FOR ENHANCING QUALITY OF MILD STEEL CASTING Sanjiv Kumar
Tiwari, Ritesh Kumar Singh, Sharad Chandra Srivastava
CHARACTERISTICS OF FRICTION BEHAVIOUR OF FLAKE,SPHEROIDAL AND COMPACT VERMICULAR GRAPHITE CAST IRON Kyungmok
Kim, Myung-Jin Yoon
CORROSION IN VIEW POINT OF METAL MICROSTRUCTURE OF GREY CAST IRON AND DUCTIE CAST IRON IN HCL SOLUTTION AND
PRESENCE OF THIOUREA Sayed S. Abd El Rehim, Sayed H. El-Nekhaly, Ahmed El Essawy Abdou
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