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These stringent pollution specifications, as laid down by CPCB,
India, have been a threat to most of the 6000 foundries operating as
clusters at Agra, Batala, Ahmedabad, Rajkot, Coimbatore, Howrah, etc. Public
awareness and the pressure from the environmental activities have also
forced foundry owners to look into the pollution aspects and to take
corrective measures for its mitigation to the lowest permissible limits. The
directives of the Honorable Supreme Court of India further strengthened the
development of eco-friendly coke-less cupola in the year 1995. It prohibits
the use of coke in all the foundries particularly in the Taj trapezium and
in all the Indian foundries at large. The National Metallurgical Laboratory,
Jamshedpur responded to this National need and submitted a project proposal
to the Technology Information Forecasting and Assessment Council (TIFAC),
Department of Science of Technology (DST). Govt. of India for the
development of the environment friendly coke-less cupola and initiated the
technology development work in May 1996. The use of low sulphur gaseous
/liquid fuel promises extremely low level of SPM and SOx.
The studies were initiated by converting a small existing
conventional coke-fired cupola of 500 mm ID of NML Pilot plant to suit
initially for oil (LDO) and then for gas firing during 1996-97.The rated
capacity of converted cupola is 1t/h. During the developmental stage many
problems such as location, selection and their angle of orientation of
appropriate burners, design of grates and selection of suitable permeable
medium were encountered and sorted out. The number of trials (30 numbers on
oil, 25 numbers on LPG) producing to the total of 2t to 3t was carried out.
Some of these trials were also witnessed by TIFAC monitoring committee,
foundry associations of Agra, Ahmedabad and M/s Tata Korf.
Based on above-mentioned success by the end of 1997, M/s. Tata
Korf and NML reached a Memorandum of Understanding (MOU) to commercialise
the NML process and to provide technology for Pollution-free Coke less
Cupolas. Subsequently, M/s. Tata Korf and the Agra Iron Founders Association
(AIFA) entered into an agreement in early 1998 for the transfer of the NML's
developed technology involving installation, commissioning and demonstration
of natural gas based cokeless cupola of 2T/hr capacity. The first cupola of
2 t/h capacity based on NML Technology was installed in the premises of Agra
Loh Udyog, Agra. The natural gas was made available to the cupola site
through the pipeline of Gas Authority of India Limited (GAIL).
After erection and commissioning of the said cupola at Agra
Loh Udyog, Agra, the first melt was taken on 14th May'98. In the subsequent
10 trials, some of the teething problems with respect to the metal
temperature and metal and slag composition and flow ability of the slag and
the like were circumvented. Incorporating these modifications in the above
units and conducting repeated trials (from 10th to 14th), all the problems
were scientifically and systematically addressed and various operational
parameters were critically examined, determined and optimised. Accordingly,
after several successful demonstration trails (from 15th to 20th) resulting
in the production of a total 16t to 20t of hot metal during June-August' 99,
the melting unit was finally handed over to AIFA.
A gas based cupola of 3t/hr is then engineered and installed
in the premises of M/s Goel Engineering Works, Agra in 2001 by M/s Tata Korf
Engineering based on NML's know how and technology.
The process parameters for 2t/h cokeless cupola were again
examined, analysed and optimized in the scaled up cokeless cupola of 3t/h
operation . These trials of 10t to 15t, having each conducted in two phases,
have now been successfully accomplished. · 1st phase from 18th to 26th May
_ 2003 · 2nd phase from 22nd June to 30th June (23-6, 26th, 29th) ·
Temperature with out oxygen obtained from 13800C to 14200C · Good flow able
of slag/metal obtained · Thin casting (pipe & pipefitting) and thick
casting (drain cover etc.) ---About 95% acceptable obtained · Temperature
was controllable depending on requirement. · De slogging was smooth. ·
System pressure was controllable. · The present system indicated that the
Cupola can be operated on Alternate days. · The furnace achieved a melting
@ 3.8T/hr which is 25 % more than its rated capacity @ 3t/h
NML's
KNOW HOW ON ECO FRIENDLY COKELESS CUPOLA BASED ON USING NATURAL GAS IS NOW
READY TO TAKE OFF IN INDIAN FOUNDRIES & ELSEWHERE
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