Title of Invention	"AN IMPROVED APPARATUS FOR PRODUCING COMPACTED GRAPHITE IRON AT A REDUCED COST AND A PROCESS FOR PRODUCING THE SAME"
Abstract	An improved apparatus comprising plunger rod (5) having counterweight (1) fitted at the top end and plunger head (7) fitted at the bottom end thereof and lock-and-lift clamp (2) fitted at the top outside surface of cover (A) of ladle (6), having a plurality of exhaust pipes (3) on outside surface thereof, characterised in that a predetermined length at the bottom end of plunger rod (5) is coated with a known refractory material, in that the bottom end of plunger head (7) is provided with cover (8), and in that plunger head (7) is made of known refractory or graphite material, and is provided with perforations in the body thereof, if required, and a process comprising taking molten iron in ladle (6), magnesium or magnesium alloy In plunger head (7), placing cover (4) on ladle mouth, lowering plunger rod (5) into molten iron and holding the same in position, and adding ferrosilicon.

Title of Invention

"AN IMPROVED APPARATUS FOR PRODUCING COMPACTED GRAPHITE IRON AT A REDUCED COST AND A PROCESS FOR PRODUCING THE SAME"

Abstract

An improved apparatus comprising plunger rod (5) having counterweight (1) fitted at the top end and plunger head (7) fitted at the bottom end thereof and lock-and-lift clamp (2) fitted at the top outside surface of cover (A) of ladle (6), having a plurality of exhaust pipes (3) on outside surface thereof, characterised in that a predetermined length at the bottom end of plunger rod (5) is coated with a known refractory material, in that the bottom end of plunger head (7) is provided with cover (8), and in that plunger head (7) is made of known refractory or graphite material, and is provided with perforations in the body thereof, if required, and a process comprising taking molten iron in ladle (6), magnesium or magnesium alloy In plunger head (7), placing cover (4) on ladle mouth, lowering plunger rod (5) into molten iron and holding the same in position, and adding ferrosilicon.

Full Text	The present Invention relates to an improved apparatus for producing compacted graphite iron at a reduced cost and a process for producing the same. The invention relates more particularly to an apparatus comprising a plunger rod fitted with a plunger head at the bottom end and a counter weight at the top end thereof, a clamp of lock-and-lift type for holding the plunger rod which is movable in upward and downward direction through an annular hole in the cover of a ladle containing molten iron to be treated with metallic magnesium or magnesium bearing alloy put inside the plunger head. The invention related also to a process for producing compaoted graphite iron by plunging metallic magnesium or magnesium bearing alloy into the molten iron by means of the invented apparatus in a relatively smooth way without causing any violent explosion at a reduced consumption of magnesium in the process. In one of the existing processes for producing compacted graphite iron, magnesium is plunged directly into molten iron. Magnesium, being of lower density than iron, floats on the surface of the molten iron, and being combustible, burns with vapourisation leading to violent explosion and ejection of molten iron from the ladle, thus making the process hazardous. In another existing process magnesium is added to molten iron by means of bell shaped or open ended crucibles. This process is also found to be hazardous. In another existing process, instead of a magnesium bearing alloy, such as Ni-Mg or Fe-Si-Mg., alloy having density higher than that of molten iron is introduced at the bottom of the ladle containing the molten iron,,through various ways such as placing the alloy at the inside bottom surface of the ladle and covering the same with iron or steel turnings/millings/scraps. But the process is expensive because of the high cost of the alloy material used. In another existing process magnesium granules/powder, suspended in nitrogen gas, is injected into the molten iron, or magnesium is introduced into the molten iron by plunging a refractory material impregnated with molten magnesium and by holding the said material in a special chamber made on the inside bottom surface of the ladle. But the process is found to be expensive. In yet another existing process magnesium taken in a container having perforations is attached to the bottom end of a plunger rod which is plunged into the molten iron taken in a ladle to allow the magnesium vapour generated in the said container to react with the molten iron. But the container used in the plunger rod is expensive to fabricate and not suitable for repeated applications, thus making the process expensive. One object of the present invention is to provide an apparatus of plunger rod type for producing compacted graphite iron in a non-hazardous and relatively economic way. We Claim :- 1. An improved apparatus for producing compacted graphite iron at a reduced cost, comprising plunger rod (5) having counter¬ weight (1) fitted at the top end and plunger head (7) fitted at the bottom end thereof and lock-and-lift clamp (2) fitted at the top outside surface of cover (4) of ladle (6), having a plurality of exhaust pipes (3) on outside surface thereof, characterised in that a predetermined length at the bottom end of plunger rod (5) is coated with a known refractory material, in that the bottom end of plunger head (7) is provided with cover (8), and in that plunger head (7) is made of known refractory or graphite material, and is provided with perforations in the body thereof, if required. 2. The process for producing compacted graphite iron using the apparatus as claimed in claim 1, comprising the following steps in sequence :- (i) taking molten iron from a cupola or blast furnace or any other source in ladle (6); (ii) putting the required quantity of metallic magnesium or magnesium bearing alloy into plunger head (7); (iii) placing ladle cover (4) with a plurality of exhaust pipes (3) and the said apparatus fitted thereon on the open mouth at the upper end of the ladle (6); (iv) lowering plunger rod (5) in position by means of a known hoisting equipment till the bottom of plunger head (7) touches the inside bottom surface of the ladle and keeping the same in that position by counter weight (1) placed at the top end of the plunger rod; (v) lifting the plunger rod and locking the same in position by means of the lock-and-lift clamp (2) when the lower end of the plunger head is at a height upto 50mm above the inside bottom surface of the ladle; (vi) adding the required quantity of finely-ground ferro-silicon to molten iron in the ladle; and (vii) casting the molten iron in moulds.

Full Text

The present Invention relates to an improved apparatus for producing compacted graphite iron at a reduced cost and a process for producing the same.
The invention relates more particularly to an apparatus comprising a plunger rod fitted with a plunger head at the bottom end and a counter weight at the top end thereof, a clamp of lock-and-lift type for holding the plunger rod which is movable in upward and downward direction through an annular hole in the cover of a ladle containing molten iron to be treated with metallic magnesium or magnesium bearing alloy put inside the plunger head. The invention related also to a process for producing compaoted graphite iron by plunging metallic magnesium or magnesium bearing alloy into the molten iron by means of the invented apparatus in a relatively smooth way without causing any violent explosion at a reduced consumption of magnesium in the process.
In one of the existing processes for producing compacted graphite iron, magnesium is plunged directly into molten iron. Magnesium, being of lower density than iron, floats on the surface of the molten iron, and being combustible, burns with vapourisation leading to violent explosion and ejection of molten iron from the ladle, thus making the process hazardous.
In another existing process magnesium is added to molten iron by means of bell shaped or open ended crucibles. This process is also found to be hazardous.

In another existing process, instead of a magnesium bearing alloy, such as Ni-Mg or Fe-Si-Mg., alloy having density higher than that of molten iron is introduced at the bottom of the ladle containing the molten iron,,through various ways such as placing the alloy at the inside bottom surface of the ladle and covering the same with iron or steel turnings/millings/scraps. But the process is expensive because of the high cost of the alloy material used.
In another existing process magnesium granules/powder, suspended in nitrogen gas, is injected into the molten iron, or magnesium is introduced into the molten iron by plunging a refractory material impregnated with molten magnesium and by holding the said material in a special chamber made on the inside bottom surface of the ladle. But the process is found to be expensive.
In yet another existing process magnesium taken in a container having perforations is attached to the bottom end of a plunger rod which is plunged into the molten iron taken in a ladle to allow the magnesium vapour generated in the said container to react with the molten iron. But the container used in the plunger rod is expensive to fabricate and not suitable for repeated applications, thus making the process expensive.
One object of the present invention is to provide an apparatus of plunger rod type for producing compacted graphite iron in a non-hazardous and relatively economic way.

We Claim :-
1. An improved apparatus for producing compacted graphite
iron at a reduced cost, comprising plunger rod (5) having counter¬
weight (1) fitted at the top end and plunger head (7) fitted at
the bottom end thereof and lock-and-lift clamp (2) fitted at
the top outside surface of cover (4) of ladle (6), having a plurality of exhaust pipes (3) on outside surface thereof, characterised in that a predetermined length at the bottom end of plunger rod (5) is coated with a known refractory material, in that the bottom end of plunger head (7) is provided with cover (8), and in that plunger head (7) is made of known refractory or graphite material, and is provided with perforations in the body thereof, if required.
2. The process for producing compacted graphite iron
using the apparatus as claimed in claim 1, comprising the
following steps in sequence :-
(i) taking molten iron from a cupola or blast furnace or any other source in ladle (6);
(ii) putting the required quantity of metallic magnesium or magnesium bearing alloy into plunger head (7);
(iii) placing ladle cover (4) with a plurality of exhaust pipes (3) and the said apparatus fitted thereon on the open mouth at the upper end of the ladle (6);
(iv) lowering plunger rod (5) in position by means of a known hoisting equipment till the bottom of plunger head (7) touches the inside bottom surface of the ladle and keeping the same in that position by counter weight (1) placed at the top end of the plunger rod;

(v) lifting the plunger rod and locking the same in position by means of the lock-and-lift clamp (2) when the lower end of the plunger head is at a height upto 50mm above the inside bottom surface of the ladle;
(vi) adding the required quantity of finely-ground ferro-silicon to molten iron in the ladle; and (vii) casting the molten iron in moulds.

Documents:

437-del-1998-abstract.pdf

437-del-1998-claims.pdf

437-del-1998-correspondence-others.pdf

437-del-1998-correspondence-po.pdf

437-DEL-1998-Description (Complete).pdf

437-del-1998-drawings.pdf

437-del-1998-form-1.pdf

437-del-1998-form-19.pdf

437-del-1998-form-2.pdf

437-del-1998-form-4.pdf

437-del-1998-gpa.pdf

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Patent Number

215164

Indian Patent Application Number

437/DEL/1998

PG Journal Number

10/2008

Publication Date

07-Mar-2008

Grant Date

21-Feb-2008

Date of Filing

20-Feb-1998

Name of Patentee

STEEL AUTHORITY OF INDIA LIMITED

Applicant Address

ISPAT BHAWAN, LODHI ROAD, NEW DELHI-110003

Inventors:

#	Inventor's Name	Inventor's Address
1	KEDAR NATH PANDEY	RDCIS/SAIL, DORANDA, RANCHI-834002
2	OM PRAKASH SHARMA	SAIL CORPORATE OFFICE, ISPAT BHAWAN, LODI ROAD, NEW DELHI-110003
3	BHARAT CHANDRA ROY	RDCIS/SAIL, DORANDA, RANCHI-834002
4	SHILOWBHADRA BANERJEE	EX-DIRECTOR OF RDCIS/SAIL, A-19, CHAITRABAN RESIDENCY, 127/2, ITI ROAD, AUNDH, PUNE--411007

PCT International Classification Number

B22D 1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA