Title of Invention	"AN IMPROVED COOLING GRATE USEFUL IN OIL/GAS BASED MELTING FURNACES"
Abstract	1. An improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8), the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes.

Title of Invention

"AN IMPROVED COOLING GRATE USEFUL IN OIL/GAS BASED MELTING FURNACES"

Abstract

1. An improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8), the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes.

Full Text	This invention relates to an improved cooling grate useful in oil/gas melting furnaces. Cooling grates are generally used in oil / gas based melting furnaces The basic purpose ot the cooling grate is to hold the charge above the grate. The grates provide dual role - one to provide support to the charge above it and the other to make a support for permeable balls & charge to prevent extinction of oil or gas burner. The use of the grates also facilitates to use suitable size oi the refractory balls imparting sufficient permeability to the shaft for the easy escape of the products of combustion through it. Hither-to known grates which are mentioned in the literature for use in Cokeless Cupola, consist of a cast steel hollow pipe for holding water if desired to keep it cool. The above indicated design of the hitherto known cooling grates provide for unidirectional tlow of water. Further the single wall tubular cast steel grates provided in the furnace have to bear the full impact of the charge material being thrown from the inlet nozzle of the furnace which is at a height of 6 to 8 times the diameter of the Cupola from the level where the grate is fixed. Thus the water flowing through the inner space of the grates may lead to hazarduous explosions in case the grate gives way &- when the water leaks. rhe industrialisation of a country while benefitting the country economically, also results in creating atmospheric pollution Ihis pollution not only adversely alTects the natural phenomenon such as ram, heat etc but also affects the health of human beings and animals. Such atmospheric pollution also damages hisloricai monuments Ihe world has realised the importance of keeping the environment free from pollution. The Governments of various countries inciuding Irxiia are framing stringent rules for avoiding generation of polluting materials and releasing them to the atmosphere and also to control the pollution within permissible limits. In this context Supreme Court of India has passed orders to close down all the foundries in and around Atira which are running furnaces employing coke thereby producing dust particles and oxides of sulphur and nitrogen which pollutes the atmosphere These orders are directed to prevent damages to historical monuments located in that area due to the pollutants. Such an action has placed the industries m great difficulties, i here is. therefore, an urgent need to provide alternate lurnaces which do not use coke thereby preventing pollution to the environment. Research and development efforts are being directed towards the development of such furnaces without the use of coke Efforts are being made to employ refractory materials preferably in the form of balls which can replace coke turnaces which are burnt by oil/gas. The main object of the present invention is therefore to provide an improved cooling grate for using in oil/gas melting furnaces which avoids breaking away from the location where it is fixed in a furnace thereby prevent explosions. The improved cooling grate of the present invention use seamless pipes of suitable sizes (depending on the diameter of the shaft of the furnace). In the cooling grate of the present invention, one seamless pipe ol a smaller diametre goes into the another similer pipe of bigger diameter. Water is introduced from one end of the bigger diameter pipe and gets out of through the smaller diameter pipe. A high refractory meterial may be coated on the outer surface of the outer tube. The material used may preferably have a composition consisting of alumina 90% with Graphite & calcium-silicate. The coating ma\ be of a thickness in the range of of 20-25mm on the outer pipe to safeguard the tube from the hot metal. Refractory material may be reinforced with suitable meteriais welded to the body of the pipe the nc function oi tne reiraciory material is to protect the pipes from heat and also from mechanical shock of tl>e falling mass to be melted. In bigger furnaces another cooimg grate is provided at nghi angles to the previous grates with suitable configuration which almost touches the first grate. An embodiment of the improved cooling grate of the present invention is shown in figure 1 of the drawings accompanying this specification. Figure 1 depicts ihe sectional View of a cooling tube of the present invention. Figure 2 depicts the sectional view of a furnace incorporating the cooling grate consisting of plurality of the cooling tubes of the present invention. Accordingly, the present invention provides an improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8) , the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes. According to a feature of the invention plurality of the tubes defined above forming a set of cooling pipes, designated as cooling grate, may be provided in larger furnaces for example of the capacity of more than 7 Ton/hr., to ensure enhanced cooling and safety. This embodiment of the present invention is depicted in Figure 2. According to another feature of the invention the refractory used for the outer tube may be preferably high alumina castable refractory having more than 90% alumina with graphite 0-2% & calcium-silicate cement 8-10%. The seamless pipes used for the construction of the grates may be of mild steel or any other steel composition. The diameters of bigger tube may range from 1/6 to Vi in relation to the inner diamtiter of the furnace and smaller may be 30-50 mm shorter in diameter - compared to the bigger one. By the use of improved cooling tubes Cooling grates of the present invention in the melting furnaces enhanced and effective cooling is effected. Further since the possibility of the grates giving way is reduced to the minimum consequently there is no chance of the water getting mixed with the molten metal thereby preventing explosions. The main advantages of the present invention are : 1. Improved safety from thermal & mechanical shock 2 The cooling pipes of the improved grate of the present mvention are easily removable & replaceable which makes the maintenance of the pipes easy and checks for safety are possible without problom. 3. Easy in cheking the safty of the pipes being worn out and replacement thereby avoiding the chance of explosion We Claim: 1. An improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8), the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes. 2. An improved cooling tube as claimed in claim 1 wherein the refractory coating (8) is selected from high alumina castable refractory (having 90-92% alumina), graphite 0-2% & calcium silica cement 8-10%. 3. An improved cooling grate as claimed in claims 1&2 wherein the diameter of the outer tube is in the range of 1/6 to V4 in relation to the inner diameter of the furnace. 4. An improved cooling grate useful in oil/gas based melting furnaces substantially as herein described with reference to Figure 1 & 2 of the drawings accompanying this specification.

Full Text

This invention relates to an improved cooling grate useful in oil/gas melting furnaces.
Cooling grates are generally used in oil / gas based melting furnaces The basic purpose ot the cooling grate is to hold the charge above the grate. The grates provide dual role - one to provide support to the charge above it and the other to make a support for permeable balls & charge to prevent extinction of oil or gas burner. The use of the grates also facilitates to use suitable size oi the refractory balls imparting sufficient permeability to the shaft for the easy escape of the products of combustion through it.
Hither-to known grates which are mentioned in the literature for use in Cokeless Cupola, consist of a cast steel hollow pipe for holding water if desired to keep it cool.
The above indicated design of the hitherto known cooling grates provide for unidirectional tlow of water. Further the single wall tubular cast steel grates provided in the furnace have to bear the full impact of the charge material being thrown from the inlet nozzle of the furnace which is at a height of 6 to 8 times the diameter of the Cupola from the level where the grate is fixed. Thus the water flowing through the inner space of the grates may lead to hazarduous explosions in case the grate gives way &- when the water leaks.
rhe industrialisation of a country while benefitting the country economically, also results in creating atmospheric pollution Ihis pollution not only adversely alTects the natural phenomenon such as ram, heat etc but also affects the health of human beings and animals. Such atmospheric pollution also damages hisloricai monuments
Ihe world has realised the importance of keeping the environment free from pollution. The Governments of various countries inciuding Irxiia are framing stringent rules for avoiding generation of polluting materials and releasing them to the atmosphere and also to control the pollution within permissible limits. In this context Supreme Court of India has passed orders to close down all the foundries in and around Atira which are
running furnaces employing coke thereby producing dust particles and oxides of sulphur and nitrogen which pollutes the atmosphere These orders are directed to prevent damages to historical monuments located in that area due to the pollutants. Such an action has placed the industries m great difficulties, i here is. therefore, an urgent need to provide alternate lurnaces which do not use coke thereby preventing pollution to the environment. Research and development efforts are being directed towards the development of such furnaces without the use of coke
Efforts are being made to employ refractory materials preferably in
the form of balls which can replace coke turnaces which are burnt by oil/gas.
The main object of the present invention is therefore to provide an improved cooling grate for using in oil/gas melting furnaces which avoids breaking away from the location where it is fixed in a furnace thereby prevent explosions.
The improved cooling grate of the present invention use seamless pipes of suitable sizes (depending on the diameter of the shaft of the furnace). In the cooling grate of the present invention, one seamless pipe ol a smaller diametre goes into the another similer pipe of bigger diameter. Water is introduced from one end of the bigger diameter pipe and gets out of through the smaller diameter pipe. A high refractory meterial may be coated on the outer surface of the outer tube. The material used may preferably have a composition consisting of alumina 90% with Graphite & calcium-silicate. The coating ma\ be of a thickness in the range of of 20-25mm on the outer pipe to safeguard the tube from the hot metal. Refractory material may be reinforced with suitable meteriais welded to the body of the pipe the nc function oi tne reiraciory material is to protect the pipes from heat and also from mechanical shock of tl>e falling mass to be melted. In bigger furnaces another cooimg grate is provided at nghi angles to the previous grates with suitable configuration which almost touches the first grate.
An embodiment of the improved cooling grate of the present invention is shown in figure 1 of the drawings accompanying this specification. Figure 1 depicts ihe sectional
View of a cooling tube of the present invention. Figure 2 depicts the sectional view of a furnace incorporating the cooling grate consisting of plurality of the cooling tubes of the present invention.
Accordingly, the present invention provides an improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8) , the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes.
According to a feature of the invention plurality of the tubes defined above forming a set of cooling pipes, designated as cooling grate, may be provided in larger furnaces for example of the capacity of more than 7 Ton/hr., to ensure enhanced cooling and safety. This embodiment of the present invention is depicted in Figure 2.
According to another feature of the invention the refractory used for the outer tube may be preferably high alumina castable refractory having more than 90% alumina with graphite 0-2% & calcium-silicate cement 8-10%. The seamless pipes used for the construction of the grates may be of mild steel or any other steel composition. The diameters of bigger tube may range from 1/6 to Vi in relation to the inner diamtiter of the furnace and smaller may be 30-50 mm shorter in diameter - compared to the bigger one.
By the use of improved cooling tubes Cooling grates of the present invention in the melting furnaces enhanced and effective cooling is effected. Further since the possibility of the grates giving way is reduced to the minimum consequently there is no chance of the water getting mixed with the molten metal thereby preventing explosions.

The main advantages of the present invention are :
1. Improved safety from thermal & mechanical shock
2 The cooling pipes of the improved grate of the present mvention are easily removable & replaceable which makes the maintenance of the pipes easy and checks for safety are possible without problom.
3. Easy in cheking the safty of the pipes being worn out and replacement thereby avoiding the chance of explosion

We Claim:
1. An improved cooling grate useful in oil / gas based melting furnaces which comprises: a plurality of cooling tubes (10) each tube consisting of a pair of tubes (1 & 2) one placed inside the other leaving an annular gap between them, characterised in that the outer surface of the said outer tube (1) being provided with a refractory coating (8), the said outer tube (1) having an inlet (3) provided proximity to the end (7) which is open and with a plug (5) at the other end which is closed, the grate being provided with means (plate) (9) at the upper and lower portions for joining plurality of tubes.
2. An improved cooling tube as claimed in claim 1 wherein the refractory coating (8) is selected from high alumina castable refractory (having 90-92% alumina), graphite 0-2% & calcium silica cement 8-10%.
3. An improved cooling grate as claimed in claims 1&2 wherein the diameter of the outer tube is in the range of 1/6 to V4 in relation to the inner diameter of the furnace.
4. An improved cooling grate useful in oil/gas based melting furnaces substantially as herein described with reference to Figure 1 & 2 of the drawings accompanying this specification.

Documents:

1653-del-1997-abstract.pdf

1653-del-1997-claims.pdf

1653-del-1997-complete specification (granted).pdf

1653-del-1997-correspondence-others.pdf

1653-del-1997-correspondence-po.pdf

1653-del-1997-description (complete).pdf

1653-del-1997-drawings.pdf

1653-del-1997-form-1.pdf

1653-del-1997-form-19.pdf

1653-del-1997-form-2.pdf

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Patent Number

199584

Indian Patent Application Number

1653/DEL/1997

PG Journal Number

N/A

Publication Date

17-Nov-2006

Grant Date

06-Oct-2006

Date of Filing

20-Jun-1997

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110 001, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	KAILASH KUMAR MISHRA	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR, JHARKHAND, INDIA
2	SHIWA DHAR SINGH	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR, JHARKHAND, INDIA
3	PATCHA RAMACHANDRA RAO	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR, JHARKHAND, INDIA
4	DILIP KUMAR BISWAS	NATIONAL METALLURGICAL LABORATORY, JAMSHEDPUR, JHARKHAND, INDIA

PCT International Classification Number

F23H 17/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA