2nd Qtr. 2013
The 4th IFCE International was organized by Pakistan Foundry Association
with the help of local and international participants. It was suitably arranged
and was attended by participants who were able to review the tectological
developments and scope of work since the 3rd IFCE. PFA was encouraged with
the support extended by international organizations like PUM, CBI, GIZ etc.
One of the major problems faced by the foundry industries of Pakistan is
energy crisis which has affected the production and their supplies resulting in
major financial loss. For the solution of energy problem, PFA with the support of
GIZ (a team of German experts) and SMEDA have introduced Energy
Management System (EnMS) in foundry industries. It is encouraging that GIZ has selected five members of
PFA to be provided EnMS free of cost, while additional members will be required to pay Rs 7 Lakh each.
CBI an Agency of Netherland has selected Pakistan Foundry Association as Business Support
organization (BSO) for a four year Export Coaching Program (ECP). The objective is to guide and
motivate the foundry industry through BSO for export purpose to European countries. CBI will provide the
sustainable strength for competitive capacity of SME exporters and manufacturers by removing
obstacles. PFA members should take a lead in acquiring their guidance for export development of their
products.
The PUM experts are also helping to improve knowledge and skills development in Pakistan foundries.
I welcome the efforts of PFA and PUM in organizing a joint seminar in Faisalabad. The participation of Mr.
Robert Dresen, First Secretarty, Embassy of Netherland is gratefully acknowledged. His offer to support
PFA for export development to European market specially Netherlands will help our industry.
It is my sincere desire that our foundrymen would benefit from the above organizations support and
improve their technology to export products from Pakistan
Sikandar Mustafa Khan
President PFA
Contents
Chief Editor
Mr. Fahad Iqbal
Colour Changing Refractory Coatings As Quality
Control Tool For Various Foundry Sand Systems
& Its Economics
01
Export Coaching Program (ECP) by CBI
11
Energy Efficient Foundries
13
Facility of Energy Management System by
GIZ (Germany) with SMEDA for PFA
23
Instrumentation for Energy Conservation
25
Energy saving and controlling cost of
Ownership to reduce the production cost
FA News
Dephosphorization and Desulfurization of
molten Ductile Iron and its effect on Ductility
28
Joint Secretary - PFA
Editor
Mr. Abdul Waheed
30
31
G.M. Foundry
M/s, Ravi Spherocast
2.5 km, Defense Road of Bhobatain Chowk,
Raiwind Road Lahore. Ph: +92-42-37970474
Mob#: 0321-4989797
Email: abdul.waheed56@hotmail.com
Coordinator
Mr. Abdul Rashid
Secretary - PFA
93-B, Hali Road, Gulberg-II, Lahore Pakistan.
Ph: +92 42 35023525, 35753619
Fax: +92 42 35755743
Cell: +92 322 8487873
Email: info@pfa.org.pk
pakistanfoundryassociation@gmail.com
URL: www.pfa.org.pk
01
Colour Changing Refractory Coatings
As Quality Control Tool For Various Foundry
Sand Systems & Its Economics
Sushil Sharma
B.Tech (Chemical Engg.)
MD, Shamlax Metachem P. Ltd.
Abstract
This paper deals with the latest development in India, to ensure complete dehydration of water based
coatings. The new concept of Colour Changing Refractory Coatings technology acts as a Quality control
tool for the today's modern foundries, which are switching over to the latest resin sand systems. The change
over from traditional solvent based coatings to latest water based coatings in most of the foundries, these
Colour changing coatings not only enables visual confirmation of complete dehydration of coatings, but also
optimize on energy consumption in drying these coatings and increases productivity of the foundry. At the
same time it eliminates all moisture related defects such as metal penetration, scabbing and blow holes. The
present paper explains in detail these Colour changing refractory coatings for various Foundry Sand
systems.
Introduction
It is a well known fact that the Foundry Coatings are
widely used to improve the surface casting finish
and to achieve the best cosmetic look of the
castings. But at the same time we all know that the
best of the Foundry coating can never achieve this
on a bad core or moulds. A conventional foundry
using Sodium silicate – CO2 gassed binder system
uses mostly solvent based refractory coatings. In
view of improving productivity, castings quality, to
reduce rejection %, to have cleaner environment in
the foundry, all modern foundries are shifting to
modern resin systems such as phenolic acid cured,
cold box resins, shell sand (Hot-Box), Furan Resin,
Alpha set etc. Most of these sand resin systems
whether for moulds or cores utilizes water based
coatings to avoid casting defects such as metal
penetration, sand erosion, veining etc.
Two Types of Coatings are used
by Foundry 1. Solvent Based Coatings
2. Water Based Coatings
Now-a-days Modern Foundry is switching over
to New Resin Binder Sand Systems, where water
based coatings are getting more popular due to
following factors -
-
Cost
Environment Friendly
Safety
Storage Regulations
Better Shelf Life
Hassle free Transportation
While using these Water based coatings the
Challenges before a Foundryman are
- Complete de-hydration of coating
- Are Drying Oven parameters working
efficiently ?
Above process of complete dehydration is
critical as wet coatings results into serious casting
defects such as -
Scabbing
Metal penetration
Blow holes
Surface Porosity
Solutions to these Casting Defects are latest
Technological based Colour Changing Refractory
Coatings, which changes Colour on drying or
ignition.
Different types of Colour changing water and
solvent based coatings can be solutions for these
castings defects.
02
For Water Based Coatings the Colour
change of coating can be on drying from Pink to Yellow , or
Purple to Yellow, or
Yellow to Red.
-
To avoid over dilution of coating as Colour
of the coating will fade & the coating will
take more time to change Colour due to
higher moisture content.
-
To make convenient to apply multiple coats
as Pink Colour coating will be applied on
dried yellow coating, as the applicator
knows areas where multiple coats are
applied.
-
To reduces production cycle time.
For Solvent Based Coatings the Colour
change of coating can be on ignition from Yellow to Orange, or
Yellow to Red
The basic fact is that the Foundryman needs
visual confirmation of drying of coating for the
following reasons –
-
To visually confirm Complete drying of
coating
-
To eliminate all moisture related defects.
-
To identify poor sand compaction in a core
or mould.
[as these areas will absorb more moisture from
coating and will take longer time to dry].
-
To optimize on cost of drying and to avoid
over heating by oven / torch.
But we are very well aware of the fact that
normally Foundries use various types of sand
systems such as Three Part Alkyd Resin, Two Part
Alpha set (Alkaline Cure), Shell core (Hot Box) &
(Cold Box), Furan Resin, Phenolic Two Part (Acid
Cured), Cement Molasses, Cement Dextrose, where
water based coatings finds application. Similarly,
for Sodium-Silicate, Alpha Set & Olvine Sand
(Manganese Steel) solvent based coatings are
popular. The need is to have Colour changing
coatings for various Foundry sand systems. Hence,
different water based Refractory coatings (nongraphite) based were developed for various sand
systems and the results obtained are as per Table
No.1 and solvent based Refractory coatings as per
Table no.2.
Table No.1 :
Colour changing Water Based Foundry Coatings developed for various Sand Systems
S.No.
1.
2.
3.
4.
Type of Sand System
Three Part Alkyd Resin
System
Two Part Alp Set
(Alkaline Cure) System
Shell Core
[Hot Box]
Shell Core
[Cold Box]
Colour of Wet
Coating
Colour of Dried
Coating
Air Dried / Oven Dried
Pink
Yellow
Air Dried / Oven Dried
Pink
Yellow
Air Dried / Oven Dried
Pink
Yellow
Air Dried / Oven Dried
Pink/ Purple
Yellow
Air Dried / Oven Dried
5.
Furan Resin
Pink
Yellow
Air Dried / Oven Dried
6.
Two Part [Acid Cure]
System
Yellow
Pink
Air Dried / Oven Dried
7.
Cement Molasses System
Pink
Yellow
Air Dried / Oven Dried
8.
Cement Dextrose
System
Pink
Yellow
Air Dried / Oven Dried
03
Table No.2 :
Colour Changing Solvent Based Foundry Coatings for various Sand Systems
S.No.
Type of Sand System
Colour of Wet
Coating
Colour of Dried
Coating
Air Dried / Oven Dried
1.
Sodium Silicate – CO2
Yellow
Orange
On Ignition
2.
Alpha Set Resin Sand
Yellow
Orange
On Ignition
3.
Olivine Sand System
[Manganese Steel]
Yellow
Red
On Ignition
It was necessary to ascertain whether the
coating has really dried or not on change of Colour.
Hence, the lab trials were conducted for various
sand systems and the experimental results are
tabulated for Two Part Alpha Set sand system as
per (Table. 3) & Three Part Alkyd Sand Cores as
per (Table 4) & Cold Box Sand Cores as per (Table
5). The weight of the naked core was noted as (W)
and the cores were dipped in the coatings suitable
for dipping application and weight of the core was
noted as (W0). The cores were dried at 150 deg.
cent. And the readings were noted at different time
intervals of 3, 6, 9, 12, 15 & 18 minutes. It was
found that the weight of the core decreases due to
moisture evaporation which was indicated by the
change of Colour of the coating. (Fig.1). It was
found that the weight of the core remained constant
as soon as complete dehydration of the coating was
over after 15 mins. and the Colour of the coating
also changed as the case may be for the sand
system, completely from pink to yellow. This visual
confirmation of change of Colour of coating
indicates complete drying and no further drying of
cores is required, was confirmed from the various
reading noted for the weight of the core at
different time intervals.
Calculations :
W
– Weight of naked (uncoated) core
Wc - Constant weight of the core after 100%
drying
Wt - Weight of core at time 't’
W0 – Weight of core at time 'Zero'
% of Moisture at Wt = (Wt-Wc)/(W0-Wc)*100
Laboratory Experimental Results:
Table 3 : Cores were prepared of Two Part Alpha set Core @ 150° C
Time
[Min]
Weight of
Dipped Core
Weight of
Coating
Moisture %
0
227.50 gm
14.00 gm
100.00%
3
225.50 gm
12.00 gm
82.60%
6
223.00 gm
9.50 gm
60.87%
9
220.50 gm
7.00 gm
39.13%
12
218.50 gm
5.00 gm
21.74%
15
216.00 gm
2.50 gm
0.00%
18
216.00 gm
2.50 gm
0.00%
Weight of Dried Core
213.50 gm (W)
04
Table No.4 :
Three Part No Bake Core @ 150° C
Time
[Min]
Weight of
Coating
Weight of
Dipped Core
Weight of Dried Core
Moisture %
100.00 gm
0
109.00 gm
9.00 gm
100.00%
3
108.50 gm
8.50 gm
83.33%
6
108.00 gm
8.00 gm
66.67%
9
107.50 gm
7.50 gm
50.00%
12
107.00 gm
7.00 gm
33.33%
15
106.00 gm
6.00 gm
0.00%
18
106.00 gm
6.00 gm
0.00%
Table No.5 :
Cold Box Core @ 150° C
Time
[Min]
Weight of
Dipped Core
Weight of
Coating
Moisture %
0
246.00 gm
10.00 gm
100.00%
3
244.50 gm
8.50 gm
80.00%
6
243.50 gm
7.50 gm
66.67%
9
241.50 gm
5.00 gm
33.33%
12
240.00 gm
4.00 gm
20.00%
15
238.50 gm
2.50 gm
0.00%
18
238.50 gm
2.50 gm
0.00%
Weight of Dried Core
236.00 gm
Moisture% Variation @150 deg.cent.
120.00
Moisture%
100.00
80.00
Cold Box Cores
60.00
Two Part Phenolic Alpha Set
40.00
Three Part No Bake
20.00
0.00
0
3
6
9
12
15
18
Time (min)
Graph – Moisture % variation @ 150 deg. Cent.
05
Fig. 1
Naked Core
Dipped Core [100% Wet]
Partially dried core
100% Dried Core
Moisture on Core
Re-Dried Core
Shop Floor Experimental Results :
The Colour changing coating was also tested at a renowned Foundry manufacturing Automotive castings, for
hub cores.
The Cold box cores were dipped in the purple Coloured coating and left for air drying. The air-drying
phenomenon was visible as the coating was changing Colour during the drying process. Fig.2
06
Fig. 2
We need to analyze the various advantages of
colour changing refractory coatings in detail.
Advantages of Colour Changing
Refractory Based Coatings 1. To eliminate all moisture related defects –
As it is clear from the data collected for various
types of resin sand systems, the Colour of coating
changes completely as soon as the total moisture is
removed. This ensures that no moisture is present in
the coating.
In conventional WHITE coating there is no visual
confirmation to the applicator whether total
moisture has been removed or not, particularly
from grooves or any area has been left out during
the drying process. This visual confirmation
eliminates all moisture related defects.
2. To identify poor sand compaction in a core or
mould
coatings is Energy Saving.
l
Visual confirmation of drying avoids over
heating by oven / torch.
l
In case of drying ovens it acts as an Energy
saver as cores can be taken out on Colour
change of coating.
l
In case of drying by torch overheating of cores
/ molds is avoided.
l
Saves Time for drying.
l
Cores are ready for assembling.
l
Improves Production cycle.
4. Visual confirmation of Over Dilution
Over dilution of coating can be controlled as
Colour of coating will fade & Coating will take
more time to change Colour due to higher moisture
content
Visual confirmation is more important particularly
in case of Flood & Dip coating applications.
5. Easy to apply multiple coats as Pink Coloured
coating will be applied on dried yellow
coating .
l
Applicator knows areas where multiple coats
are applied.
l
In Conventional White coating few areas can
be left out with single coating.
l
Thickness of coating is visible due to distinct
Colours.
3. To optimize on cost of drying –
l
Most important advantage of Colour change
6 . Reduces production cycle time
l
Visual identification makes operator
During core / mold making process, particularly
in case of hand molding, if sand compaction is not
proper, these areas will absorb more moisture from
coating, resulting in more moisture penetration
inside the sand surface and the coating will take
longer time to dry.
07
understands cores / molds can be sent for final
pouring.
l
In case of air drying, no further waiting is
required as visual confirmation of coating
getting dried is possible.
l
Production cycle time is reduced.
7. Coatings are reversible in nature in few cases
l
Cores / Moulds on storage if absorb moisture,
particularly in monsoon season change Colour
from Yellow to Pink OR Yellow to Purple.
l
Visual confirmation in case of water spillage on
core / moulds due to reversal Colour change is
possible.
l
Operator knows moisture is absorbed and
moisture can be removed before closing the
boxes and pouring.
l
This feature eliminates Moisture related defects
completely.
Un-burnt coating portion is visible due to distinct
l
Colour change.
l
Easy to apply multiple coats.
Colour changing Solvent Based
Coatings :
Colour changing coating acts as a Quality control
tool for almost all the Foundry sand systems. Except
for Graphite based coatings, Colour changing
coating has an edge over conventional white or
Coloured (non-Colour changing) coating. Colour
changing technology not only eliminates moisture
related defects but helps in increasing the
productivity, helps during application of multiple
coats, helps in saving the energy consumed for
drying and in application process. These Colour
changing coatings proved to be a technoeconomical solution over conventional refractory
coatings. It has cost saving on drying operations
and by way of increase in production cycle and
reduction in % rejection.
In case of solvent based coatings the coating
changes its Colour from yellow to orange on
ignition, in case of silicate-CO2 cores and AlphaSet alkaline cure sand systems. In case of
Manganese steel castings, Magnesite coatings
changes Colour from yellow to deep red on ignition.
Orange Colour (On ignition)
Conclusions :
Acknowledgements :
Solvent based Colour changing Coating
[ Yellow Colour before ignition]
The author acknowledges the support fro m the
ACC-Nihon Castings Ltd., Jayaswal's Neco
Industries Limited, Beekay Engineering Corporation
Ltd., L&T Kansbahal for the shop floor trials in
evaluating the performance of the Colour changing
refractory coatings.
Advantages of Colour changing
Solvent based coatings –
l
Wet patches can be identified as these patches
do not change Colour.
08
TCT TESIC
Foundry Marketing & Services
1993 - 2013
20 Jahre / 20th Anniversary
20
Export Coaching Program (ECP) by CBI
By Mr. Abdul Rashid – Secretary PFA
CBI (Centre for the Promotion of Imports from developing countries) is an Agency of the Netherlands Ministry of
Foreign Affairs. It was established in 1971 in order to support producers / exporters to get a foothold in the
Netherlands market, support to Business Support Organizations in improving their capabilities. CBI is supporting 48
developing countries in 27 sectors, providing them sustainable strengthening of the competitive capacity of SME
exporters and producers, focusing primarily on European markets.
CBI's project for Pakistan is one of the four projects of the
program for the Metalworking Sector Asia. On January12,
2013, 1st Coordination Meeting for CBI Pakistan
Engineering Sector Export Development was held at Expo
Centre, Karachi in which all the stakeholders actively
participated and the project plan for Pakistan was disclosed
by CBI. 2nd meeting of CBI stakeholders for Export
Coaching Program (ECP) was held on March 14, 2013 at
DART office Islamabad in which CBI local expert Mr. Imtiaz
Rastgar and Mr. Zaheeruddin Dar once again elaborated
the whole idea and expressed the hope that outcomes of this
program will have far reaching constructive impacts
specially on the SME of Pakistan, participants acknowledged their efforts and responded in a very positive way by
enrolling themselves into the program.
CBI trainer Mr. Wouter Put joined the executive meeting of PFA along CBI local Expert Mr. Zaheeruddin Dar. They
explained the house in detail about the role of CBI and they briefly discussed the four year long Export Coaching
Program (ECP) in which PFA will participate as their Business Support Organization (BSO). The objective of selecting
PFA as BSO is to guide and motivate the foundry industry for export purpose to European countries etc.
In this regard five associations from Pakistan have been selected by CBI as BSO's which are
l
Trade Development Authority of Pakistan (TDAP)
l
Pakistan Foundry Association (PFA)
l
Engineering Development Board (EDB)
l
Small and Medium Enterprises Development Authority (SMEDA)
l
Pakistan Association of Automotive Parts and Accessories Manufacturers (PAAPAM)
In Pakistan, CBI's project duration is 4 years (from Nov. 2012 till the end of 2016). This project aims to achieve
l
Increased export turnover of participant selected 20 companies up to € 10 million through the Export Coaching
Program (ECP), directly supported by CBI
l
Increased export turnover of another 15 companies up to € 7.5 million through parallel ECP, supported by
selected Business Support Organizations (BSO)
This whole Export Coaching Program is divided in 14 activities out of which 1st activity “Workshop on Process
Control for manufacturing companies” has been done
on 25-27 June, 2013 at PAAPAM. Mr. Robert Dresen,
First Secretary Economic Department, Embassy of the
Netherlands inaugurated that workshop in which CBI
consultants Mr. Staf Henderieckx and Mr. Wouter Put
delivered the subject matter in detail with industry visits
of MECAS Engineering, METLINE Industries and
presentations by BSOs.
11
Plot #: CIB-11,12,13, Sector-16,
Korangi Industrial Area. Karachi.74900
Pakistan. Phone: 0092-21-35056849
Fax: 0092-21-35075025, Cell: 0092-3212660867
Email: info@g-group.org, businessdevelopment@g-group.org
ENERGY EFFICIENT FOUNDRIES
Dr. Khalid Mahmood Ghauri
Department of Metallurgical and Materials Engineering,
University of Engineering & Technology, Lahore, Pakistan
Abstract
This article mainly focuses upon energy efficient foundries. We are fully aware of this factthat energy is
the single most important factor in Countries race to economic superpower status. If there is a short fall of
energy in a country then this shortage badly affects the industry, commerce and daily life of people. So the
main theme of the article is to discuss the deficiencies and the improved methodologies of energy saving
especially in a foundry industry. Sincethe foundry industry is energy intensive and has an important role to
play from an environmental point of view while seeking to develop and play an important role in the nation's
continued economic growth and development.The same has been received and shared in the light of
information available in the published literature.
Keywords:Energy efficient foundries, improved methodologies, continued economic growth and development.
1) Introduction:
Energy is the single most important factor in Pakistan's race to economically developed status. Pakistan is
presently facing a serious energy crisis. Despite strong economic growth during the past decade and
consequent rising demand for energy, no worthwhile steps have been taken to install new capacity for
generation of the required energy sources. Now, the demand exceeds supply and hence “load-shedding” is
a common phenomenon through frequent power shutdowns. Pakistan needs about 14000-15000MW
electricity per day, and the demand is likely to rise to approximately 25,000 MW per day by 2015.
Presently, it can produce about 11, 500 MW per day and thus there is a shortfall of about 3500-4000MW
per day. This shortage is badly affecting industry, commerce and daily life of people.
The foundry industry is energy intensive and has an important role to play from an environmental point of
view while seeking to develop and play an important role in the nation's continued economic growth and
development.
There are a number of barriers to energy efficiency:
l
Lack of awareness, education and customized training
l
Economic and market distortions
l
Lack of standardization and labeling on equipment and devices
l
Lack of financing
l
Lack of effective coordination
l
Complacency – a feeling that everything possible has been done
l
A mistaken feeling that energy monitoring and energy reduction equipment is expensive.
13
Energy stats: India vs Pakistan
Coal consumption
Indian Energy statistics
339,000,000
Pakistani Energy statistics
4,600,000
Ranked 3rd. 73 times more than Pakistan
Ranked 28th.
Coal > Production
407,013,000 ton
4,871,000 ton
Ranked 3rd in 2005. 83 times more than Pakistan
Ranked 21st in 2005.
Commercial energy use
494.03
463.14
Ranked 100th. 7% more than Pakistan
Ranked 105th.
Electricity > Production
by source > Fossil fuel
Electricity > Production
by source > Nuclear
81.7%
68.8%
Ranked 105th in 2003. 19% more than Pakistan
Ranked 120th in 2003
3.4%
3%
Ranked 29th in 2003. 13% more than Pakistan
Ranked 30th in 2003.
Gasoline prices
0.98
0.87
Ranked 78th. 13% more than Pakistan
Ranked 89th.
Natural gas reserves
542,400,000,000 cubic feet
695,600,000,000 cubic feet
Ranked 23rd.
Ranked 22nd. 28% more than India
Nuclear Electricity
Generation
Nuclear Energy
Consumption
17.8 terawatt-hours
1.8 terawatt-hours
Ranked 18th. 9 times more than Pakistan
Ranked 29th.
19.4 terawatt-hours
1.7 terawatt-hours
Ranked 18th. 10 times more than Pakistan
Ranked 29th.
Energy Comparison Chart[1]
Pakistan is facing major energy crisis as compared to its neighboring country.
Power distribution in foundries is shown below:
Power Distribution Tree
Transmission
losses 3.47 %
Input Power
100%
Available Power after
loss 96.53 %
Melting
83.25 %
Environmental
control 5.33 %
Furnace
78.76 %
Auxiliary
4.49 %
Melting
69.52 %
Holding
9.24 %
Utilities
2.97 %
Sand plant
1.0 %
Cooling
Pumps 3.86 %
Moulding
2.80 %
Finishing
2.18 %
Mixer
1.80 %
Crane &
Hoist 0.63 %
Power Distribution Chart[2]
“Foundries need to understand not only how they use energy,
but also how energy consumption patterns affect costs.” – L.V.WHITING
14
Basic Energy Saving Measurement:There are many factors affecting energy consumption in industrial production, and many countries take
factors such as tax or special policy to reduce yields, so as to reduce energy consumption would transfer to
developing countries where labor cost is low. The reduced yield, however does not solve the problem of
energy saving globally. In addition to measures above, the proactive approach of energy ef? ciency
improvement can be achieved via improving the energy efficiency of equipment, or deleting directly
thehigh-energy part. It is the direct energy-saving measurements; at the same time, indirect measurements
such as by means of technological advancements which can lead to higher energy ef? ciency.
(1)
Direct Energy-Saving Measurement:-
Melting is a key procedure in casting production, and improving the energy efficiency of melting
equipment is the most direct way to reduce the energy consumption in melting part[3, 4]. Energy consumption
in heat treatment of casting production in China is great, and efficiency of heat treatment equipment is low.
Let us take ductile iron as an example. Traditionally there is a requirement of graphitization annealing or
normalizing where high temperature is needed. If qualified as per specs as cast ductile iron can be
produced. Heat treatment part could be eliminated or just low-temperature stress-relief annealing is
needed. Hence the contribution to energy saving would be considerable [5,6]
(2)
Indirect Energy-Saving Measurement:-
Nowadays, the forming technology of castings is developing in the direction of high-precision, short
process, clean and high quality. Advanced casting technology is not only an important measurement in
improving casting quality, but it can also be used in optimizing the entire process[7-8] so as to improve the
near- net-shape level of casting, which could results in the decrease of rejection rate and increase of process
yield and ? nished rate[9,10] Herein, it leads to the improvement of energy ef? ciency in casting production,
namely, indirect energy-saving measurements.
Chen et al. [11] carried out a case study on the comparison between direct and indirect energy-saving
measurements in an iron casting plant, where the earlier production situation is: large cupola for melting,
general sand casting, graphitization annealing for ductile iron, with reject rate of 10%, process yield of
70% and ? nished rate after machining was 60%. Its average unit ? nished energy consumption was 583
kilogram Coal Equivalent per ton (kgce/t). After modernization, the cupola was replaced by induction
furnace, and the sand casting was replaced by lost-foam casting, it succeeded in producing the cast ductile
iron and therefore eliminated the heat treatment process. The plant utilized computer technology to optimize
products design and simulate the production process also. Thus, its current average unit finished energy
consumption has been dropped to 212 kgce/t already. Chen et al. assessed the contribution of equipment,
forming technology, computer technology and as-cast ductile iron to energy saving. Results indicate that the
production rate of as-cast ductile iron is the largest, 37% of energy consumption was cut due to the
elimination of heat treatment process; equipment contribution is not as large as expected, just 26%; it is
worth mentioning that technology measurements which has no direct effect on energy consumption play an
important role in energy conservation, where the contribution rates of lost-foam casting and computer
technology are 20% and 17%, respectively
2) Energy Saving Opportunities:2.1.Scrap selection and preparation:l
Safety
l
Correct Size
l
Density
15
Cleanliness:
Ø
Sheared versus shredded scrap
Ø
Rusted scrap
Ø
Briquetted scrap.
l
Preheating of scrap
l
Induction melting Limits the range of scrap used
2.2 Charging of scrap:l
Prepare the Charge Sequence
l
Vibrating Systems
l
Continuous Charging During the Melt
l
Pre Heat the Charge in the Furnace
l
Focus on Reducing the Duration of Charging to
Maximize the Melting Process
2.3. Melting:l
Mains versus medium Frequency / cupola
l
Theoretical Power Versus “Best Practice”
l
Benefits of Batch Melting
l
Efficiency (No Holding) 97 Percent
l
Max Power
l
Power Density
l
Melting Rate
l
Furnace Size
l
Production Planning
l
Less Emission
l
Improved Control
Estimated Iron Induction Melting Energy Usage
Per Ton Melt
Tacit
10 Btu Tacit Tacit
h/Ton Kwh
10 Btu 10 Btu
/ Ton / Ton / Ton**
/Ton
Gross
Kwh/
Ton
Melt
Loss
Heel Melting Calculated
800
1.5%
812
2550
2.77
8.71
14.52
Heel Melting and Holding Estimated
954
1.5%
969
3041
3.31
10.39
17.31
Modern Batch Melter Caclulated
500
1.5%
508
1594
1.73
5.44
9.07
Item
1.5% 538% 1690 1.84 5.77
9.62
Batch Melter and Holding Estimated
530
Includes Hold Power for 8 Hours per day and preheat gas at 74 kWh/ton melt for heel melter
Estimated Iron Induction Melting Energy UsageChart [12]
2.4. Alloying/Refining/Treatment/Sampling:-
2.7. Transporting Metal:-
l
Ferro – Alloy Additions
l
Speed and Accuracy of the Operation
l
Sampling – Floor Controls
l
Temperature Control
l
Sampling – Spectrometer Analysis
l
Skimming
l
Slag Removal – Tools, Efficiency
2.8. Pouring:l
High Power Thermal Plasma Heating
Ø
Efficient Heating
Ø
Fast
Ø
Offers Metallurgical Benefits
l
Existing Systems = Ladles & Auto Pouring Units
l
Both have Disadvantages
l
Improved Temperature Control to +- 5 degree
Celius.
l
Energy Efficiency Improvement of 20%
l
Slag Wall, Slag Build – Up – Use of Fluxes
l
Treatment of Metal
2.5. Holding:l
Avoid Holding Metal in Batch Furnaces
l
Melt Cold – Pour Hot
2.6. Tapping / Ladles:l
Refractories
l
Pre Heating Using Oxy–Fuel to Improve
Efficiency
l
Management
“No industrial society has been successful without a vibrant foundry industry base.” – MICHAEL PROMOLI
16
3) Some practical steps for improving energy
efficiency in foundries:Here are some initial questions for consideration
by all foundries:
1. Have we undertaken an assessment of energy
efficiency?
2. Can we benefit from implementing an energy
monitoring program to manage energy use?
3. Can we optimize the efficiency of our metal
melting and holding processes?
4. Can we optimize the efficiency of the ancillary
services in the operation?
5. Can we benefit from investing in energy control
systems to shut down equipment when not in use?
6. Can we develop greater staff awareness of
energy efficiency and run an effective 'switchoff' program?
7. Can we improve the ladles and refractory
materials used in the furnaces?
8. Can we recover energy from any sources for reuse
elsewhere in the foundry?
9. Can we benefit from investing in energy efficient
equipment and up-grading old equipment (e.g.
lighting, ladle preheating, sand reclamation,
furnaces etc)?
The main areas for energy usage are listed
below and then considered in turn.
a) Compressed air usage
b) Operational controls for energy saving and
economy
c) Better recovery in terms of input (reduce waste)
d) Waste heat recovery
e) Energy monitoring and audit
a) Compressed air:Air is free but compressed air is not! Compressed
air can be considered colorless gold in the
industry.
Leakage is a major cause of energy wastage. A
3 mm hole will result in a 26 cfm leak and a
financial loss of Rs1,93,000 (£2,624.56).
Steps recommended to arrest leakage:
l
Listen for leaks during idle periods
l
Conduct leak test at least once a fortnight and
record quantum of leaks area visible.
l
Optimize nozzle size (Where different types of
machines are used requiring nozzles for blowing
l
air, it is prudent to use different nozzle sizes
depending on the machine size and air
required).[13]
b) Operational controls for energy saving and
economy:Keep tapping temperatures as low as possible.
Conduction and radiation losses of a one tonne
high-frequency furnace 500 Hz and 900kW at a
tapping temperature of 1500°C are 50 kW and
35 kW respectively. These losses can be reduced
by approximately 10 kW by having a tapping
temperature of 1400°C. To keep the tapping
temperature lower, optimize inoculation, reduce
ladle travelling distance, preheat the ladle and
cover it during metal transfer. It is good practice
to display the tapping temperature.
Keep the furnace cover closed as far as possible.
Radiation loss from the molten metal surface is
proportional to the fourth power of temperature.
Thus the heat loss at a temperature of around
1500°C comes to 60-70 kW/m2.
Hold the molten metal at as low a temperature as
possible and for the shortest time. Molten metal
should be held, when required, at a low
temperature, or turn off the power supply. The
rated power should be turned on to heat up
again, any chemical analysis of molten metal,
preliminary furnace tests and temperature
measurements should be performed quickly, and
preparatory operations should be performed so
that there are no delays from mis-matching with
mould assembly or waiting for the crane.
Covering the ladle always reduces heat losses.
One small foundry was able to save 3 units per
melt which equated to 60 units/day and 1500
units/month. At Rs5/-unit (£0.07p), the annual
saving was Rs1,25,000 (£1,701.33).[13]
c) Better recovery in terms of input (reduce waste):How many tonnes of metal do we melt for each
tonne of usable castings? In the worst case, for
every tonne of casting produced for sale, up to
two tonnes of metal are melted. Consider the
major areas of loss (e.g. melt losses, spilt metal,
pigged metal, runners and risers, reject castings,
or grinding losses). Can metal losses be reduced
by minimizing metal spills, or reducing over or
under pours through precision pouring
techniques? There are often opportunities to
17
redesign, optimize or change the casting process
used to increase the metal yield and to work with
customers to redesign the casting to reduce its
weight or improve its casting characteristics? Can
the gating system be redesigned - gating
systems (i.e. runners, risers and sprues) are often
larger than necessary and wall thicknesses are
sometimes over-specified to compensate for
porosity and other metal quality problems.
Redesign can reduce machining allowances to
reduce grinding losses or even eliminate some
fettling operations from the foundry?
Excess metal melted means more energy used in
melting and holding the metal, increased capital
costs for unnecessary metal handling capacity,
increased fettling costs, unnecessary metal
collection and sorting time, increased
maintenance of equipment, lost time that could
be used for value adding activities and customer
relations issues. These all affect the bottom line.
Raw material selection and control is also
significant since sand or rust in scrap reacts with
the furnace refractory to form slags. If slags are
formed to about 1% during melting of 3 tonnes
of iron, the power loss at 1500°C is about
10kWh/t. In addition the raw material charged
should be as dense as possible to improve
melting efficiency.[13]
d) Waste heat recovery:This relates to the recovery of the maximum
energy that is otherwise being wasted in thermal
operations. Waste heat recuperators installed to
tap the sensible heat from the flue gas coming out
of the furnaces, evaporating cooling systems in
reheating furnaces and other high temperature
installations of a plant are all examples of the
drive to recover and reuse a part of the energy
that would have gone waste. A hot blast cupola
which uses the sensible heat of the exhaust gases
to heat the incoming air blast is a good example
to cite.[13]
e) Energy monitoring and audit:The following are the recommendations for all
foundries:
l
Installation of proper metering and data
collection of all major power consuming
equipment and operating parameters.
l
Formation of energy conservation committee to
study specific energy consumption and sustain the
same.
l
Energy audit by an independent authority.
l
Facts and figures collected on energy and
production to be displayed to create an
awareness.
l
Learn from others who have implemented energy
saving measures.[13]
Environmental considerations:
Improved energy efficiency reduces greenhouse gas
emissions in two ways:
Ø
Energy efficiency measures for on-site
combustion systems (e.g., furnaces, boilers,
cupolas, heat-treating ovens) reduce emissions in
direct proportion to the amount of fuel not
consumed.
Ø
Reductions in consumption of electricity lead to
reductions in demand for electricity and,
consequently, reductions in emissions from
thermal electric power generating stations.
“Taking care of the environment makes good
business sense.” – JACK WELCH, former CEO, GE
“We want to save energy because we know it
helps achieve a higher order objective – the
environment in which we live. We do it because it is
the right thing to do!” [14]
Auditing energy use in a foundry:
We will focus on the initial energy audit. An
energy audit is a key step that establishes the
baseline from which you will measure future energy
efficiency improvements. (Other energy audits may
be performed later to, for example, verify
achievements or uncover other incremental energysaving opportunities.)
Following is a list of practice-proven steps in
energy auditing.[14]
Energy audit purpose:
Why have an audit? Can't an excellent energy
conservation project yielding good financial return
be undertaken without an audit?
Yes, it can. It is likely, however, that without the
systematic approach of the audit, this ad hoc
application of energy management may cause many
opportunities – some of which could be better than
expected – to be missed; thus the benefits of projects'
synergies would remain hidden.
18
An audit has four main stages:
1. Initiating the audit;
2. Preparing the audit;
3. Auditing; and
4. Reporting the audit results[14]
Auditor's Toolbox:The following sections include details of the
instruments commonly found in the energy auditor's
toolbox: [15]
Ø
Electric power meter
Plan
Do
Ø
Combustion analyser
Ø
Digital thermometer
Ø
Infrared thermometer
Ø
Airflow measurement devices
Ø
Tachometer
Ø
Ultrasonic leak detect
Before arriving at conclusion there has been
shared an energy management plan (fig 1) which
need customization at the user and in order to
maximize profit and growth.
Check
Act
Obtain insight
(energy audit)
Create awareness
Review results
Correct
deficiencies
Get management
commitment
Train key
resources
verify
effectiveness
Review original
energy policy
Nominate energy
champion
implement
projects
Review objectives
and targets
Policy. objectives,
structure
Monitor progress
Examine
opportunities for
continual
improvement
Assign
responsibilities
Lock in the gains Set new targets
Update action
plans
Develop program(s)
Communicate
results
Start the cycle
anew
Set targets and
measures
Celebrate success
Review energy
program
Set priorities
Develop action
plans
© Lorn & associates inc. 2000
19
4) Conclusion:In conclusion many of the methods that have been identified here are indicative and it should be noted
that practices will vary from foundry to foundry depending on the alloy system, the process, the weight of the
castings, volume, application, mechanization, type of equipment's and a most of other factors.
However, it should be noted that all foundries can identify areas where energy efficiencies can be achieved
and these will help from an environmental point of view which is of course of significant importance.
Acknowledgements:In the name of “Allah”, the most beneficent and merciful who gave us strength and knowledge to
complete this Case study report “Energy Efficient Foundries”. This report has been made under the
supervision of Prof. Dr. Khalid Mahmood Ghauri by Mubbusher Zia khan & Zeeshan Khalid.
References:[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
http://www.nationmaster.com/compare/India/Pakistan/Energy
Latest trends in Energy Efficiency-Foundry Industry By Brakes India Limited Foundry Division.
Prosanto P, Girish S, Abhishek N and Sanjeev S W. Towards cleaner technologies in small and micro
enterprises: a process- based case study of foundry industry in India. Journal of Cleaner Production,
2008, (16): 1264-1274.
Wijayatunga P D C, Siriwardena K, Fernando W J L S, Shreshtha R M and Attalage R A. Strategies to
overcome barriers for cleaner generation technologies in small developing power systems: Sri Lanka
case study. Energy Conversion and Management, 2006, 47: 1179-1191
Xue H Q, Bayraktar E and Bathias C. Damage mechanism of a nodular cast iron under the very high
cycle fatigue regime. Journal of Materials Processing Technology, 2008, 202(20): 216-223.
Gonzaga R A and Carrasquilla J F. In? uence of an appropriate balance of the alloying elements on
microstructure and on mechanical properties of nodular cast iron. Journal of Materials Processing
Technology, 2005, 162-163: 293-297.
Shehata F and Abd-Elhamid M. Computer aided foundry die- design. Materials & Design, 2003,
24(8): 577-583. [31] Liu B C. Modeling and simulation's role in equipment manufacturing and
prospects. Aeronautical Manufacturing
Shehata F A. Computer-aided foundry cupola and mold analysis. Journal of Materials Processing
Technology, 1997, 63(1-3): 655-660
Askeland D R. Lost Foam Casting (Disposable Mold). Encyclopedia of Materials: Science and
Technology, 2008: 4641-4644.
Ye Shengping and Sun Zhicheng. Application of aluminum lost foam castings in America and
suggestions for promoting LFC of aluminum alloys in China. Foundry, 2008, 57(3): 203-207. (in Chinese
Chen Weiping, Huang Dan, Jiang Fan, Luo Hongfeng. Strategy analysis on energy conservation and
emission reduction in foundry industry. In: 2008 Guangdong Foundry Conference, Guangdong, China,
2008: 65-75
Practical Application of Improving Energy Efficiency in Foundry By: John T Davis CEO-South Africa
Institute of Foundry Men.
foundrygate.com/en/noticias/ver/556/india-energy-efficiency , Source: Foundry Trade Journal
Guide to Energy Efficiency Opportunities in Canadian Foundries In Partnership with the Canadian
Foundry Association.
Energy SavingS Toolbox – an Energy audit Manual and Tool((CIPEC)
Guide to Energy Efficiency Opportunities in Canadian Foundries In Partnership with the Canadian
Foundry Association (Canadian Industry Program for Energy Conservation)
20
Facility of Energy Management System
by GIZ (Germany) with SMEDA for PFA
By Mr. Abdul Rashid – Secretary PFA
Pakistan Foundry Association is always engaged for the development of its
member foundries. One of the major problems faced by the foundry industries
of Pakistan is energy crisis which has affected the production and their supplies
to the OEM resulting in financial crisis. For the solution of energy problem,
Pakistan Foundry Association with the support of SMEDA and GIZ (a team of
German experts) has planned to bring out its member foundries from the crisis
of energy. In this regard GIZ team has conducted several meetings with PFA
team and updated about the salient features of their program.
Energy Management System (EnMS) is the sole interest of SMEDA and GIZ. After proving EnMS cost benefits in
25 textile industries, GIZ/SMEDA aimed to introduce this system in foundry industry of Pakistan. In this regard a
meeting was held on April 25, 2013 at Foundry Service Center (FSC), UET Lahore between the team (Germany
trained) of SMEDA and PFA members. A thorough presentation was given by Mr. Azeem-Project Manager and
highlighted the salient features of this project.
After several meetings PFA informed its members about the
possible potential benefits of EnMS and provided them
registration and declaration forms to apply for EnMS registration.
PFA team also advised GIZ and SMEDA to organize a seminar for
the PFA member foundries to update them about EnMS by your
experts. Finally a dissemination seminar was conducted on June 7,
2013 at hotel Avari for the introduction of Energy Management
System for our members. Mr. Bernhard Meyhoefer, a
representative of GIZ informed the house about the potential
benefits of EnMS for foundry industry which was followed by
question answer session. Mr. Bernhard Meyhoefer also added that for the proper implementation of EnMS, a foundry
must fulfill the basic criteria as per described in registration and declaration forms and this offer is only for the
members of Pakistan Foundry Association. Mr. Azeem-Project Manager introduced the guide lines to fill the
registration and declaration form and submit to GIZ/SMEDA team.
The major industry representatives in this seminar were from Millat Tractors
Ltd, Millat Equipment Ltd, Ravi Autos Pvt. Ltd unit 1 & 2, Qadri Group of
Engineering Pvt. Ltd, KSB Pumps Company Ltd, Paras Engineering Works,
Chenab Engineering Works and Foundries Pvt. Ltd, Golden Pumps Pvt. Ltd, Excel
Engineering Pvt. Ltd etc.
It was interesting that participants showed their great interest in the
submission of registration forms. These forms have been analyzed by GIZ team
and as a pilot project 5 foundries will be picked up on merit basis to get the
services of EnMS free of cost. I would like to add EnMS implication in a foundry
will cost Rs. 700,000. In case of PFA members 5 foundries will be selected in pilot project, will not pay any expenses
incurred during this process.
PFA members have shown keen interest in EnMS and their filled registration and declaration forms have been
submitted to GIZ/SMEDA by PFA. After analyzing the forms and short listing foundries, GIZ/SMEDA has selected 11
foundries in which their team is going for initial survey begining from July 11, 2013.
23
Instrumentation for Energy Conservation
Vishwas Kale
Managing Director, Vijayesh Instruments Pvt Ltd,
E mail vijayesh@vsnl.net / vishwask@vsnl.com
Instrumentation and process control play a vital role in all processes. For energy conservation, resourceful
use of instrumentation is possible. Resource means source or possibility of help. Resources are means of
raising money, or means of support. Instrumentation is a big resource. It has possibility of help: to measure,
control and log data. It is also a means of raising money/support: make better product with lowest possible
rejections and with ease of production. Saving energy is important for environment as well as for cost control.
To manage saving of energy, we should have answers for this.
What is to be measured, controlled and recorded / logged ?
And why for every item.
Let us measure correctly. Accuracy is comparison between a reading and the truth. Precision is
comparison of different readings of the same thing. So let us be precise and accurate. If not at least measure
repeatedly with limited accuracy but with reliability. Why ?
Temperature
It is possible to take temperature of molten metal at lesser number of times if taken correctly. This will
reduce cost of temperature measurements, furnace operations etc. and in effect energy will be saved.
Any measurement done correctly and quickly in the first instance saves shutdown or ON/OFF time of
furnace or any device, which has to be put OFF electrically or otherwise for measurement. First correct
measurement avoids second measurement for verification. In the case of melting of metals, correct tapping
temperature is a good clue for the next temperatures in ladle, and while pouring into moulds. In continuous
casting machines, a good tapping temperature and only one temperature measurement in ladle is enough to
control entire process of casting.
To achieve this reliability of temperature measurements, follow the technique correctly.
Ladle Preheating
Ladle Preheating is to be controlled to get the least temperature drop when hot liquid metal is poured
into it. During preheating by burners, a suitable simple thermocouple is inserted and the temperature is
checked. This will avoid under heating and unnecessary cooling of hot molten metal when poured into the
ladle. Pouring molten metal at right temperature in ladle and avoiding the unnecessary temperature drop
means saving in energy.
Furnaces-Heat Treatment, Forging etc
Does the furnace consume lowest possible energy?
Do we actually know job temperature?
Do we get uniformity of temperature?
Is the furnace fully loaded to use full heat capacity of job?
Are the best possible temperature and atmosphere controls achieved?
Are we prepared to show customer the true data of heat cycle?
Does the furnace consume lowest possible energy?
So, can we use better furnace controls? Perhaps yes. Burners could be of self-proportioning type and
maintain air to fuel ratio to save fuel. It is also possible to control by motorized valves to again save fuel In
case of electric heaters control by thyristor – pulses may be done To achieve uniformity of temperature, try
using a circulating fan or a blower.
25
Do mapping of furnace to understand the temperature profile.
Replace aged thermocouples from time to time.
Use PID controlled action of temperature controllers for tight tolerance of temperature set points.
Make sure that the oil is preheated to correct temperature as specified.
All this will save energy.
Temperature Mapping Of Furnace
The thermocouples, datalogger/scanner has valid calibration certificate with NABL accreditation. The
data is compared with the actual reading obtained from the thermocouples and instruments used with the
furnace for measurement of temperatures. The furnace mapping, apart from satisfying the customer, helps
the user to understand the behaviour of furnace and helps to use it better by saving energy.
Procedure 1
For furnace temperature mapping, flexible thermocouples are inserted into the furnace and their sensing
tips are located at the points or at the jobs where temperature is to be measured. The number of
thermocouples is depending on the points to be checked. They are connected to a datalogger/scanner. At
predetermined temperatures the readings are recorded at regular short intervals. API has specified a
standard for this.
Procedure 2
These days more stringent tests are performed- SYSTEM ACCURACY TEST (SAT) and TEMPERATURE
UNIFORMITY SURVEY REPORT ( TUS ) ref CQI 9 and AMS 2750 D. The procedure is based on the furnace
dimensions, working temperature, application of furnace, furnace class, instrumentation class, number of
sensors to be used etc.
For any procedure the following information is necessary:
Furnace identification:
Temperature range :
Working temperature: ( at which to be checked ?)
Temperature tolerance:
Work zone dimensions:
Heating method : electric / fuel
Process : annealing/tempering/hardening/quenching
Belt/conveyor speed: min and max
Furnace atmosphere:
Controlling instruments: Temperature Controller type On/OFF/ type PID ? Temperature Datalogger ?
Recording instruments: Chart Recorder? Datalogger?
Instruments and thermocouples: Do you have valid calibration certificates? check ?
Thermal Analysis
For thermal analysis with no rejection of samples, requirements are:
1. Sample should solidify white
2. Pouring of metal must be at a high enough temperature to obtain liquidus arrest point.
3. Iron must not be heavily nucleated by inoculation or by melting technique
4. Metal must not be treated with Magnesium or Cerium
5. Metal should not be heavily alloyed. This may affect the eutectic arrest points.
6. Verify the calibration of instruments regularly
26
7. Connect holder and cable correctly
8. Check chemical analysis against this method periodically to ensure that the results are not affected by
any changes in alloying elements
9. Carbon readings by thermal analysis should generally lie within +/- 0.05 percent of results
obtained by analytical method and Silicon readings should generally lie within +/- 0.15 percent
10. The cups must be free from moisture (if hot, then warm them before use by keeping near the furnace).
They should be always kept upside down so that foundry dust does not fall in it to give rejected readings.
Correct analysis of metal means less operations of furnace or delay in melting and saves energy.
Spectrometers
Typical difficulties in getting correct analysis from spectrometer analysis are traced to some causes. The
ambient temperature, relative humidity around the spectrometer is important to be as specified. The vacuum
pump and the O-rings need periodic maintenance and replacement of vacuum pump oil and rings as
needed. The optics or lenses have to be cleaned.
The sample is taken from an immersion sampler in case of molten metals to avoid contamination. The
sample preparation needs polishing by flat cloth and any lines engraving on the sample surface have to be
avoided. A straight paper machine is preferred.
The sample is burnt into an inert atmosphere of Argon and the gas plays big role. The gas has to be of
high purity or needs purification by an argon gas purifier. An Argon gas cylinder is never made empty fully
and if any cylinder is found to be containing impurities as shown by the bad burn of sample, it should not be
used again, even if refilled. The cylinder may retain the impurities. For burning of sample, the electrodetungsten or silver need correct conical shape of 60 degrees or as recommended. The software with the
spectrometer shows all possible causes of incorrect analysis. A good sample saves spectrometer usage,
furnace hold up for want of analysis and saves energy.
Calibrations
Most industries use the calibration services of their in-house facilities or of an external agency.
All those who are involved in the process maintain the quality. Everyone contributes some view how best
to achieve it. But it must be remembered that such points are not necessarily the requirement. For example,
the shop floor engineer demands a tolerance of + / - 5 degrees centigrade temperature while tapping the
furnace, and the R & D engineer may demand a temperature within lesser tolerance. Someone has to decide
the actual need, which is going to affect the process. If a consensus is not reached then, many a times
unnecessarily expensive equipment and methods are used. It is worth to note that the user decides the
process, tolerances etc. and this has nothing to do, in some cases, with the internationally accepted norms.
Whatever affects the process must be standardized and checked, even a clock for that matter.
Some points to ponder could be: measurement parameters, accuracy required, possible utility, special
features or requirements, storage conditions, expertise available in the organization. It is better to buy from
a reputed source at a higher price with a contract for at least two-three year service. Consider MTBF [mean
time between failures or simply how many times failure is possible] as well as MTBR [mean time between
repairs or how much time is required for repairs], this will make the equipment useless for use. What is the
ease of operations and controls? Is it user friendly? If it is giving quick results? Is it necessary to have them if
they cannot be used for any rational use? In some, the range could be large but the span could be made
smaller for very accurate and best performance. All these considerations would be useful even for general
procurements.
A good calibration will give most accurate possible results and in effect saves energy.
27
PRESS RELEASE
ENERGY SAVING AND CONTROLLING COST OF
OWNERSHIP TO REDUCE THE PRODUCTION COST
BY Mr. Imtiaz A. Rastgar
”To compete in international export market Pakistani
manufacturers should consider for latest and more
efficient technology that helps in lowering the production
cost. CompAir air compressors are one of the best
compressors in energy consumption and efficient in air
production”, as stated by Mr. Aslam Riaz, Chairman
S.I.T.E. Superhighway Association of Industry, while
addressing a large gathering of industrialist and
KARACHI, 18 June, 2013: In current scenario of energy crises and
businessmen on “Energy saving and Controlling Cost of price hiking of raw material and increase in GST, it is necessary to
focus on air efficiency to reduce production cost
Ownership” seminar organized by Rastgar & Co. in
collaboration with CompAir and S.I.T.E. Superhighway Association of Industry.
Speaking on the occasion, Mr. Chris Goldsworthy, CompAir air compressor expert, stressed on the selection
and use of air compressors and detailed the factors which control life time ownership costs of air compressor
installations. Chris shed light upon the selection criteria for air compressors, service and spares considerations,
efficient piping systems, pressure, filtration and humidity requirements peculiar to each installation. New, energy
efficient technologies, like variable speed compressors, oil free water lubricated compressors and Quantima Oil
Free Turbo compressors from CompAir were introduced to the audience, who took keen interest in the
presentation.
Chris said that it is possible to achieve up to a 30% reduction in compressed air energy costs by judicious
selection of compressed air equipment like air compressors, dryers, filters, piping layout and piping materials. He
further elaborated that it is important to monitor the compressed system on a regular basis, so as to identify and
control those areas of the installation where air losses occur. He highlighted that running the compressors at higher
than needed pressures will increase energy consumption un-necessarily. When machines which run on air, like airjet weaving and air motors, start leaking air, their efficiency goes down.
Chris Goldsworthy appreciated Rastgar & Co's AirAudit initiative in identifying inefficiencies in compressed
air system and assistance with entire system performance optimization, leak reduction and practical air
management processes, as it helps industries in reducing power consumption and reduction in compressed air
system load and wear and tear. This prolongs life of entire compressed air system.
The Seminar was organized by Rastgar & Co., Pakistan's leading air compressor distributor and the Best
Distributor of the Year 2012, recognized by Gardner Denver. Rastgar & Co. has been distributing CompAir,
Quantima, Hydrovane and Reavell compressors in Pakistan for the last 32 years. Speaking on the occasion, CEO
Rastgar & Co., Maqsood Zulfqar gave an outline of the training facilities provided for customers' engineers and
technical staff in Pakistan and abroad. He also informed the audience about the sales, spares and air audit
services provided by Rastgar & Co. Mr. Maqsood Zulfqar CEO of Rastgar & Co. introduced new product “Parker
specializes in Low pressure and High pressure piping and fitting”.
Mr. Aslam Riaz, Chairman S.I.T.E. Superhighway Association of Industry, appreciated the organizer's efforts
for the excellent presentation for bringing in the sharp focus of important aspect of cost control and said he
looked forward to more specialized training of technical staff of industrial units in BQA on topics pertaining to
compressed air.
28
PFA News
PUM and PFA Seminar in Faisalabad
Pakistan Foundry Association and Foundry - Engineering Owners
Association Faisalabad organized a seminar on 30thMay, 2013 at
Chamber of Commerce and Industries Faisalabad for the introduction
of PUM activities. Mr. Robert Dresen, First Secretary at Embassy of
Netherlands, and Mr. Omer Ali, Economic Affairs specially traveled to
Faisalabad to introduce the house about various economic activities
and development programs offered by Netherland's Government. He
told the participants our government is interested to promote export
of various products from Pakistan to their homeland to boost economy.
PUM therefore promotes entrepreneurship, self-sufficiency and the sustainable development of small and
medium-sized enterprise locally.PUM deploys experienced
Dutch senior managers and experts to provide assistance to
entrepreneurs in developing countries and emerging markets
in a highly effective & efficient manner.
Mr. Asim Qadri (PUM Coordinator) Introduced PUM
program and briefly discussed PUM success stories in
Pakistan. To get the facilities of PUM experts Mr. Abdul
Rashid-Secretary PFA introduced the application procedure
and offered assistance in filing.
At the close of seminar Mr. Muneer Ahmad-Foundry consultant replied many questions from participants about
their problems facing in castings and foundry products.
Pakistan Foundry Association is highly obliged and grateful to the cabinet Chamber of Commerce and Industries
Faisalabad for their hospitality, reception and high tea served to our guests.
Iftar cum Dinner by Mr. Sikandar Mustafa Khan President PFA
Mr. Sikandar Mustafa Khan President Pakistan Foundry Association
continued its traditions and hosted a sumptuous Iftar cum Dinner in the
honor of Pakistan Foundry Association members at Pearl Continental
Hotel Lahore on Wednesday July 24, 2013. He provided an opportunity
to all participants to develop business relations and understanding with
each other. There were 32 guests who spared their time and participated
in this dinner. Those present were Mr. Laeeq Uddin Ansari, Mr. Asim
Qadri, Mr Irfan Ahmad, Mr. Adil J Mansoor, Mr. Umer Farooq, Dr. Faiz Ul
Hassan ex-vice chansllor, Dr. Iqbal Qurashi ex Pro-rector, Mr. M.Alamgir
Chaoudhry, GM outreach SMEDA and many worthy members.
30
DEPHOSPHORIZATION AND
DESULFURIZATION OF MOLTEN DUCTILE IRON
AND ITS EFFECT ON DUCTILITY Rub Nawaz Ansari
(Deputy Manager, Bolan Castings Ltd. Pakistan)
PROBLEM:
The importance of phosphorus in the chemistry of the Ductile is vital. It is kept at a level of 0.045 %
maximum. The only way to keep it at this level is to use the raw material which should be low in the
phosphorus.
The consistency in the raw material of the foundry is not much appreciable in Pakistan. The chemistry
fluctuates from supplier to supplier and source to source. Therefore it becomes sometimes very hard to keep
the phosphorus below the desired level. The surprises result in sub standard production of the ductile iron
which has not the up to the mark mechanical properties and premature failure is observed at the end.
If there is some fluctuation in sulfur level that has been treated with the soda ash. The sulfur issue is
obvious as higher values of sulfur in the melt simply do effect the Mg treatment and consequently nodules are
not produced. In other words if the sulfur level is high it do not let the ductile iron to be produced and the
problem is highlighted at the earlier stages and addressed accordingly. But it is not in the case of
phosphorus. Phosphorus let the ductile iron to be produced but with some low ductility. After mechanical
testing or even in service of the part foundry man comes to know that the mechanical properties were not up
to the mark.
Ductile Iron foundries do not have any method to reduce the phosphorus level in the melt if is introduced
through the raw material.
In this research it is tried to keep the phosphorus level at minimum level through dephosphorization of the
liquid metal. The principles used in dephosphorization in Pig Iron and steel with additives that promote P2O5
in the slag. The most suitable way found is ladle treatment as we could not take risk to add additives in the
furnace which may harm its lining.
Previous Workings:
We found from the literature that oxygen lancing with basic slag forming additives has very good results
for the removal of the phosphorus from the steel.
We also learned from the literature that Na2CO3 has been used as desulfurizing and dephosphorizing
agent for the liquid pig iron.
According to Takaharu Mori Ya and Masanobu Fujii, “It has been known for some time that
dephosphorization, simultaneously with desulfurization, can be attained by oxidation refining using a
Na2C03 or Na20 system slag, but it can hardly be said that the basic investigations are satisfactory.”
(“Dephosphorization and Desulfurization Pig Iron by Na2CO3” by Takaharu Mori Ya and Masanobu
Fujii) Na2CO3 has also been used in the ductile iron desulfurization. But the practice tells it does not have any
considerable impact on the dephosphorization in the case of ductile iron.
According to Hitoshi Ono, Tamenori Mas Ui and Hisashi Mori, “The slagging rate of CaO has a great
effect on the slag-metal reaction in the steel making process. For this reason, many fundamental and
practical studies have so far been made on the mechanism of CaO dissolution into slag and the dissolution
rate. In hot metal dephosphorization by lime injection, however, it is not always clear how the injected lime
forms slag in hot metal and reacts with phosphorus. It might be thought that the lime injected with oxygen into
hot metal forms slag rapidly and participate in the dephosphorization reaction.”
(“ Dephosphorization Kinetics and Reaction Region in during Lime Injection with Oxygen” By Hitoshi Ono,
Tamenori Mas Ui and Hisashi Mori)
31
Experiments Basis:
It is not advisable to lance oxygen for this
purpose as it will oxidize the necessary elements
like C and Si as well and the cost of re-addition of
these will be in creased.
The author tried to combine the additives of
pig iron and steel together for the simultaneous
desulfurization and dephosphorization of the
ductile iron without any oxygen lancing which was
successful to certain limit.
Objectives
The project focused on:
i. The study of process for reduction of
phosphorus percentage.
ii. The investigation of the elongation and
strength of ductile iron.
iii. Fused Lime with Soda Ash ware used as
dephosphorising agent.
iv. Standard UTS wedge was cast to study the
mechanical properties.
Materials:
The compositions of the
available pig iron in the market are as below:
CHEMICAL COMPOSITION OF PIG IRON
C
Si
Mn
S
P
0.015
0.015
0.011
0.043
Imported 1
4.30
0.77
0.035
Imported 2
4.12
0.31
0.015
SCOPES
i. The Ladle treatment was used to remove
phosphorus from the melt.
ii. The process was designed for simultaneous
removal of sulfur and phosphorus.
Imported 3
4.15
0.45
0.046
0.018
0.046
4.17
0.53
0.049
0.016
0.05
Table 1: Chemical composition of available pig iron
Typical Compositions of the Ductile Iron GGG450 Produced without Dephosphorization
The following composition is taken for a ferritic S.G. Iron. The cast part is supposed to bear shock loads as
well as the nominal stress.
Carbon
Silicon
Mn
S
P
UTS Kg/mm2
Elongation %
3.79
2.52
0.17
0.02
0.044
460
13
3.81
2.44
0.17
0.019
0.043
450
14
3.8
2.59
0.19
0.023
0.045
455
12.3
3.78
2.63
0.15
0.021
0.043
440
13
3.81
2.47
0.15
0.02
0.044
452
11.5
3.79
2.42
0.12
0.019
0.041
460
12
3.8
2.63
0.17
0.019
0.043
470
11
3.81
2.55
0.14
0.021
0.044
445
13
3.78
2.39
0.16
0.02
0.042
457
12
Table 2: Current compositions of ductile iron without dephosphorization
32
Methodology:
Additives:
The additives chosen for this purpose were:
1. Soda Ash (Na2CO3) 2. Fused Lime Powder. (CaO)
Both of the additives were sourced from the local sources in powder form.
Furnace: Induction coreless medium frequency furnace was used to melt.
Treatment Ladle: Simple open mouth ladle with one ton capacity was
used as treatment ladle.
Size of the batch: 500 kg liquid metal
Temperature:
1430 °C
Stirring Time:
10 min
Nodule Micrograph 100 X
Experimental Work:
In a series of experiments the concentration of the additives and the method of addition were altered one by
one. We started from using lime powder 1% of the liquid bath size and end up to 3%. However the Soda Ash was
kept 2% of the bath size in all the experiments. The best results we obtained when Soda Ash (10kg i.e., 2% of the
bath size) and Lime Powder (5 kg i.e., 1% of the bath size) were premixed in the mixer to make a homogeneous
mixture before putting them into the ladle bottom. The hot metal was tapped over it. Rest of 5 kg (i.e., 1% of the
bath size) of the pure lime was added with the stream of the tapped liquid metal.
Results: The results of the experiments were as follows:
We do not see any significant effect on C, Si and Mn by the treatment. We also observe no significant change
in nodule size and count of the ductile iron. However the amount of S and P has been decreased as shown the
following table.
Experiment No Carbon Silicon
Mn
S
P
UTS Kg/mm2
Elongation %
1
3.8
2.5
0.18
0.02
0.041
460
12.5
2
3.81
2.52
0.16
0.015
0.034
456
13.3
3
3.78
2.5
0.18
0.014
0.028
450
13.6
4
3.81
2.55
0.19
0.013
0.025
453
14
5
3.79
2.52
0.19
0.013
0.022
452
14.6
6
3.8
2.53
0.18
0.013
0.023
446
14.5
Table 3: Ductile Iron compositions after dephosphorization
Discussion: The phosphorus is reduced from 0.043% to 0.022% with this process that means 48.86%
reduction in Phosphorus level is observed with this process as shown in the table below.
Experiment
No.
Lime
addition
%age
Initial Average
Phosphorus
%age
Final
P level (%)
Reduction
in P
Phosphorus
Reduction
%ge
1
2
3
4
5
6
1
1
2
2
2
3
0.043
0.043
0.043
0.043
0.043
0.043
0.041
0.034
0.028
0.025
0.022
0.023
0.002
0.009
0.015
0.018
0.021
0.02
4.65%
20.93%
34.88%
41.86%
48.84%
46.51%
Table 4: Phosphorus reduction values
33
Process Efficiency
0.045
0.04
0.035
0.03
Ph
os
ph
or
us
%
0.025
Final P level
0.02
0.015
0.01
0.005
0
1
2
3
4
5
6
Experiment No.
Similarly we see the increase in elongation with reduced phosphorus level. We observe a maximum of 34%
increase in the elongation as shown in the table.
Experiment
No.
Lime
addition
%age
1
1
12.4
12.5
0.1
0.81%
2
1
12.4
13.3
0.9
7.26%
3
2
12.4
13.6
1.2
9.68%
4
2
12.4
14
1.6
12.90%
5
2
12.4
14.6
2.2
17.74%
6
3
12.4
14.5
2.1
16.94%
Previous Ave
Current
Increase in
Elongation
Elongation
%
Elongation
%
%
Increase
%age
Elongation
Table 7.3: Elongation values
If we compare the data of phosphorus level
and elongation, we find that there is increase in
elongation with decrease in phosphorus level
keeping all other factors effecting elongation
constant as shown in the table.
After treatment
Experiment
Final
P
level
Elongation %
No.
1
2
3
4
5
6
0.041
0.034
0.028
0.025
0.022
0.023
12.5
13.3
13.6
14
14.6
14.5
Table 7.4: Phosphorus contents and Elongation values
34
After treatment Elongation %
15
14.5
14
Ph
os
ph
or
us
%
13.5
After Treatment
Elongation %
13
12.5
12
11.5
11
0.041
0.034
0.028
0.025
0.022
0.023
Conclusions
We concluded from the results of the experiments as following:
1. The results of the experiments that the process is efficient up to a certain limit.
2. The phosphorus and sulfur can be eliminated simultaneously from the ductile iron melt by use of this process.
3. By keeping all other factors affecting constant the ductility of the ductile iron increases with the reduction of
the phosphorus level.
4. The fluidity of the metal did not create any problem so we did not need to increase the carbon equivalent
value through carbon or silicon increase.
5. The process has a low cost as both additives are readily available in the local market at lower prices.
Based upon the data regarding the ductility and quality assurance together with its relatively low cost, the
potential use of low phosphorus s-g iron castings would be expected for diverse machine parts with high quality
and reliability.
REFERENCES:
1. {Takaharu Mori Ya and Masanobu Fujii} “Dephosphorization and Desulfurization Pig Iron by Na2CO3”
http://student.sut.ac.th/sakhob/DeP/Dephosphorization%20and%20Desulfurization%20of%20Molten%
20Pig%20Iron%20by%20Na2CO3.pdf (SUT student web portal, Thailand)
2. {Hitoshi Ono, Tamenori Mas Ui and Hisashi Mori} “ Dephosphorization Kinetics and Reaction Region in
during Lime Injection with Oxygen”
https://www.jstage.jst.go.jp/article/isijinternational1966/25/2/25_2_133/_pdf (J-STAGE , Japan
Sceince and Technology Information Aggregator, Electronic,)
3. {Haruyoshi Tanabe and Masayuki Nakada} “Steelmaking Technologies Contributing to Steel Industries”,
http://www.jfe-steel.co.jp/archives/en/nkk_giho/88/pdf/88_04.pdf, (JFE Steel Corporation)
35
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