Description:A MELTING AND SAND CASTING FURNACE SYSTEM AND PROCESS THEREOF
FIELD OF THE INVENTION
The present invention relates to a sand casting and melting furnace system for the production of molten metal and casting them at a low pressure. In particular, the present invention also relates to the process for production of molten metals using the same system.
BACKGROUND OF THE INVENTION
CA2640751A1, Disclosed are a method and a casting/rolling plant for producing hot-rolled metallic, particularly steel, strips (7) having great surface quality from slabs or flat thin bars (2, 2a) that are cast in a continuous casting process, descaling being performed based on a rotary descaling process. In order to take into account parameters which are not considered in prior art in addition to rotary descaling, the hydraulically oscillated permanent mold (9) travels along several different oscillation curves (16, 17, 18) while the oscillation marks are deep-cleaned by adjusting the oscillation pattern that is determined to be optimal for each casting material.
CA2351322A1 discloses a system for producing cast components from molten metal. One form of the present system includes a system for the precision pouring of molten metal (108) within a casting mold (80). The precision pouring system is driven by a pressure differential between the molten metal delivery system (106) and the mold (80).
ES2143341A1 discloses a Casting furnace for improved automatic melting, of the types which comprise, at least, a discharge aperture-nozzle for loading metal in the pre-inoculation state, a pressurising gas in the body and, at least, a melting metal casting and filling nozzle, above the level of the metal in the body there being a thermal plasma torch providing hold-up energy and a furnace preheating oxy-combustion thermal lance. Of application in the field of metallurgical melting.
US10464123B2 discloses a production method for producing cast parts from metal using a sand casting mold (1). The sand casting mold (1) is produced in this case in a molding box (2) by means of a negative-pressure molding method. According to the invention, the sand casting mold (1), which is under negative pressure, in the molding box (2) is first of all filled with molten metal (5). The molding box (2) with the sand casting mold (1), which is under negative pressure therein, is then completely or partially impinged upon by a cooling fluid (4) and after, at the same time as, or before the cooling fluid impingement is opened at places with cooling fluid impingement. As a result of this, cooling fluid (4) is sucked into the sand casting mold (1) which is under negative pressure, as a result of which the solidifying cast part (3) is quenched more quickly.
Therefore there is a need in the art to provide a sand casting and melting system, which provide maximum of production quantity as close to the capacity of the furnace, moreover the furnace can be made empty and restart at any point of time instead waiting for weekends or special monitoring at weekends. The present invention furnace is a use of Conventional Induction Furnace with detachable Dome. And the present invention furnace can operate 2 furnaces at a time or transfer metal in between for a non-stop production.
OBJECTIVES OF THE INVENTION
The principal objective of the present invention is to provide a sand casting and molding furnace system having one or more furnaces, moulds, allowing low pressure casting with low-turbulence and a turbulence free mold filling.
Another objective of the present invention is to provide a sand casting and molding furnace system in which the casting furnace works at a low pressure.
Yet another objective of the present invention is to provide a sand casting and molding furnace system in which the furnace comprises of a casting furnace, snout pre-heating furnace and a melting furnace.
Still another objective of the present invention is to provide a sand casting system in which casting of stainless steel , steel alloys, Aluminium alloys, Vacuum DeGas and heat resistant alloys is done,
Yet another objective of the present invention is to provide a process for sand casting and melting the metals using the sand casting and melting system.
SUMMARY OF THE INVENTION
Accordingly the present invention provides a sand casting and melting system for producing molten metal and preparing it for casting having one or more furnaces, one or more moulds, a crucible lid with riser, one or more heating devices, and one or more charging units. In the system there are 3 types of furnaces that is casting furnace, snout pre-heating furnace and melting furnace.
Furthermore, the present invention also discloses the process for production of molten metal and casting them using the system comprises the steps as
(i) melting the metals at a temperature of 1540◦- 1570◦ C by using the melting furnace to get the molten metal ;
(ii) transferring the molten metal as obtained in step (i) to casting furnace of the system for casting followed by preheating the furnace lid with a snout (7) in the pre-heating furnace (102) for a minimum time of 6-7 hours for initial start or in a continuous mode at a temperature 1200-1300°C;
(iii) Pouring the melt furnaces as obtained in step (ii) in to the casting furnace whereas the pouring temperature of up to 1600°C and it depends upon the metal being melted and settling pressure is Less than 1.5 bar;
(iv) Cooling the casting as obtained in step (iii) for 30 minutes using the mould conveyor that make the cast free from hot tear and forms the cracks;
(v) Knocking out the metal cast as obtained in step (iv) followed by cutting and fettling the metals.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure. The present invention will be described in more detail herein after with the aid of the description which relates to preferred embodiments of the invention explained with reference to the accompany schematic drawings, in which
Figure 1 is a representation of low pressure sand casting furnace schematic layout.
Figure 2 is a representation of the Snout Pre-heating Furnace.
Figure 3 represents the old front view - changes related to modified plan and side view.
Figure 4 represents the modified plan and side view of the casting and melting furnace.
Figure 4 (A) represents the Dome assembly cross section, and 4(B) represents the details of furnace clamping and mould placing.
Figure 5 represents the mould pattern, 5(a) is the Cope pattern, and 5(b) is the Drag Pattern.
Figure 6 illustrates the process flow diagram.

DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by “a melting and sand casting furnace system and process thereof”, succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/modification(s) applied to the structural alternative(s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the spirit or essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.

In an embodiment of the present invention is disclosed a casting and melting furnace system, comprising: one or more furnaces.
Based on the number of furnaces, the casting and melting furnace system is either a single furnace system or a double furnace system. In single furnace system both the casting and melting happen in a single furnace with the melting unit in direct communication with the upper external surface of the dome of the furnace and the molten metal via the snout or riser is configured to enter the mould directly and into the mould assay.
In double furnace system the casting furnace and the melting furnace are physically apart. They are independent in functioning. Although, the dome with the riser can be interchangeably used for both the casting and the melting furnace. The process according to the invention is implemented with two furnaces, wherein one is operated in melting mode and one in casting mode alternately. If two furnaces are used, a single dome with a riser tube can be used, which is arranged alternately on one crucible furnace and the other crucible furnace and is provided with in between positioning in the snout preheat furnace (102) to the riser to the operating temperature of the casting furnace or the melting furnace. The melting furnace is configured to receive the metal parts and
In another embodiment the present system operates on a single furnace coupled to the mould carrier on the top of the dome. In another embodiment, the furnace system may comprise one or more furnaces. One furnace for the casting and another furnace for melting.
In a first embodiment of the present invention discloses a single furnace casting and melting system, and depicted by Figure 1, comprising: a melting furnace (101) with a melting unit (30) and a casting unit (40). The melting unit (30) is the furnace where the metals are charged for melting. The furnace comprises a furnace body with a melting chamber (11), this melting chamber houses the molten metal (11a) at high temperature. The metal is molten by the induction heating, for exemplary embodiment the induction heating is provided by the heat coil (09) and the graphite susceptor (08) with high heat conductivity and resistance. The body of the melting furnace comprises : a cylindrical container with the dome (04) integrated to the snout (07) configured for vacuum sealing at the top, one or more gas inlets (13) and outlet (03), from the interior of the melt chamber is the lining or susceptor (8) in contact with the molten metal in the chamber (11), water cooling line (10) in contact with susceptor (08), a heating element, preferably a heat coil (09) surrounding the furnace for melting the charge or metal. The metal to be casted is melted in the melting furnace with a riser pipe or fill pipe (07) configured to be pre-heated in the pre-heating furnace (102), the system induces gas in the vertically downward direction on the surface of the charge to induce pressure causing the molten metal to travel in upward direction (as depicted in the Figure 1) through the filltube or the snout, and communicated to the mould in the mould assembly on the outer side of the dome. The gas flow from the pressure line as depicted in Figure 1, in the vertically downward direction causes the movement of the molten metal through the riser pipe, at low pressure and reduced turbulence which is an advantage of the present system.
The melting furnace in an embodiment of the present invention is provided with a chute (06) for exiting the molten metal. In case of a double furnace system wherein the casting occurs in a second casting furnace, the charging units are containers with the metal scrap which are conveyed to the melting furnace for melting by the heat generated using the heating coils.

The casting furnace comprises mould clamp (1) to clamp the mould to the lid or the dome (04). Pouring carrier (02), Gas inlet (13),Gas exhaust (3), Dome (4), a cooling unit (5), Chute (6), Snout (7), Graphite Suscepter (8), Coil (9), Lining (10),Chamber for keeping molten metal (11), Hydraulic cylinder (12), the metal to be casted is melted in the melting furnace and conveyed to the casting furnace for casting, the furnace lid with a snout (7) is configured to be pre-heated in the pre-heating furnace and alternately close the melting and the casting furnace, the melt in the melt furnace is introduced in the casting furnace at low pressure. The mould comprises a pouring carrier (2) which has a cope and a drag.
In an embodiment of the present invention the dome (4) comprises of carrier with mould assay (14) holds the mould which receives the melt from the riser tube for casting, safety relief valve (15), Smith clamp (16), Metallic pad for ceramic blanket mounting (17), Furnace lining (18), Carrier locator (19), pipe line for gas two in number (20) one for inlet and the other for outlet, Lifting eye bolt – Four in number (21), Ceramic blanket (22), Silicone gasket (23).
In another embodiment of the present invention, in the casting and melting furnace system, the gas is selected from noble gases selected from Inert gas or Air. The sand casting and melting furnace system ,wherein the silicone gasket (23) of the dome (4) is of 25mm in width and 6mm thick. The space between the molten metal (11a) in the melting chamber (11) of the crucible furnace is filled with inert gas. The pouring of the molten metal through the riser tube from below into the mould by pressurising the melt in the crucible furnace occurs by means of inert gas. Preferably, helium or argon can be used as the inert gas.
In another embodiment of the present invention, the sand casting and melting furnace system, the snout pre-heating furnace is equipped to be in between the casting and melting furnaces in a double furnace system. In a single furnace system there is a single melting and casting furnace, and a snout pre-heat furnace. Both the cases the snout pre-heating furnace as depicted in figure 2 comprises of an outer blanket (22), a heating element (27), a ceramic module (28), alumina refractories (25) and an insulation layer (26) in the base. The riser pipe is fixed to the manual door (29) of the furnace.
In another embodiment of the present invention, in the sand casting and melting furnace system, wherein the snout (7) is made of ceramic material that is attached with the dome (4) of the casting furnace.
In another embodiment of the present invention, in the sand casting and melting furnace system, wherein the system is provided with a moveable charging system (24) for charging materials for producing the molten metal.
In another embodiment of the present invention, in the sand casting and melting furnace system, wherein the system is used for casting of stainless steel, steel alloys, Aluminium alloys, Vacuum DeGas and heat resistant alloys.
In another embodiment of the present invention, in the sand casting and melting furnace system, wherein the system has a suction system for removing the flue gases produced during melting above the crucible furnace through the gas exhaust (3).
In another embodiment of the present invention, in the sand casting and melting furnace system, wherein the system comprises a double furnace unit with one furnace in the melting mode and the other furnace is in casting mode. The process according to the invention can also be implemented with two furnaces, wherein one is operated in melting mode and one in casting mode alternately. If two furnaces are used, a single lid with a riser tube can be used, which is arranged alternately on one furnace and the other crucible furnace and is provided in between in a waiting position in which the heating of the riser tube takes place. If the lid with the riser tube is on one furnace which is the melting furnace and the other furnace is a casting furnace. In the melting furnace the metal parts are conveyed by the charging units and melted. In the casting furnace melt is brought and the casting process is complete, the lid with the riser tube is removed from the furnace and guided back to the waiting position for heating or placed directly on the other furnace if the riser tube still has a sufficiently high temperature.
In one embodiment of the present invention, the process for sand casting and melting the metals using the double furnace system, comprises the steps of,
(vi) melting (201) the metals at a temperature of 1540◦- 1570◦ C by using the melting furnace to get the molten metal;
(vii) transferring (202) the molten metal as obtained in step (i) to casting furnace of the system for casting followed by preheating the furnace lid with a snout (7) in the pre-heating furnace for a minimum time 6-7 hours for initial start and not required in a continuous mode at a temperature in the range of 1200-1300°C;
(viii) Pouring (203) the melt furnace as obtained in step (ii) in to the casting furnace whereas the pouring temperature upto 1600°C depending on melt and settling pressure of less than 1.5 bar ;
(ix) Cooling (204) the casting as obtained in step (iii) for 30 minutes using the mold conveyor that make the cast free from hot tear and forms the cracks;
(x) Knocking out (205) the metal cast as obtained in step (iv) followed by cutting and fettling the metals.
In an embodiment of the present invention, the process for sand casting and melting the metal, wherein the flue gases produced during the production of melt is removed off above through the gas exhaust (3) of the furnace.
In a second embodiment of the present invention, the process for sand casting and melting the metals using the single furnace system, comprises the steps of,
(i) preheating (301) of the snout or riser with the lid in the pre-heat furnace to the required temperature (1200◦- 1300◦ C)
(ii) melting (302) the metals at a temperature of 1540◦- 1570◦ C by using the melting furnace to get the molten metal in the melting chamber (11) by the heat generated by the heating coil (09);
(iii) impinging (303) of the gas from the gas inlet (13) as illustrated in the figure 1, vertically downwards to create low pressure on the surface of the melt, and pushing of the melt through the riser tube (07) into the dome ;
(iv) transferring (304) the molten metal as obtained in step (i) to the mould assay (14) of the melting unit (30) of the single furnace system for casting, pouring the melt furnace as obtained in step (iii) in to the at pouring temperature upto 1600°C depending on melt and settling pressure of less than 1.5 bar ;
(v) cooling (305) the casting as obtained in step (iv) for 30 minutes using the mold conveyor that make the cast free from hot tear and forms the cracks;
(vi) knocking out (306) the metal cast as obtained in step (v) followed by cutting and fettling the metals.

ADVANTAGES OF THE PRESENT INVENTION
1. The present invention system provides a higher yield by avoiding full gating system.
2. The present invention system provides gas defect reduction by avoiding turbulence in metal filling.
3. The present invention system provide a counter gravity metal feeding.
4. The present invention system provides metal melting and pouring in the same station.
, Claims:WE CLAIM:
1. A melting and casting furnace system (100), comprising:
one or more furnaces;
one or more moulds;
a crucible lid or dome (04) integrated with riser or fill pipe (07) or snout;
one or more heating coils (09);
one or more charging units to charge the metal, a chute (06) for exiting the molten metal (11a);
wherein the furnace comprises a casting melting furnace (101), snout pre-heating furnace (102), the casting and melting furnace (101) comprising a gas inlet (13) and outlet (03), chamber for keeping molten metal (11), hydraulic cylinder (14), the body of the furnace is a cylindrical container with the dome (04) integrated to the snout (07) configured for vaccum sealing at the top, one or more gas inlets (13) and outlets (03), lining or susceptor (08) in contact with the molten metal (11a) in the chamber (11), water cooling line (10) in contact with susceptor (08), a coil (09) as the heating element surrounding the furnace for melting the charge or metal, and
wherein the metal to be casted is melted in the melting furnace in a chamber (11) with a snout (07) configured to be pre-heated in the pre-heating furnace (102), gas flow through inlet (13) impinges in vertically downward direction on the surface of the charge induces pressure causing the molten metal (11a) to travel in upward direction through the filltube or the snout (07), and communicated to the mould in the mould assembly on the outer side of the dome, at low pressure and reduced turbulence and the furnace is either a single casting and melting crucible furnace or a double furnace with the casting and melting furnace separately placed.

2. The casting and melting furnace system as claimed in claim 1, wherein the dome is in communication with the melting unit comprising carrier (14) with mould assay to receive the molten metal (11a) from the bottom through the snout (07) or the filltube, and is sealed by a mould clamp (01) operated by a hydraulic cylinder (12).
3. The casting and melting furnace system as claimed in claim 1, wherein the molten metal chamber (11) is maintained with Inert gas in between the surface of the melt and the dome.
4. The casting and melting furnace system as claimed in claim 1, wherein the dome (4) comprises of carrier (14) with mould assay, safety relief valve (15), Smith clamp (16), Metallic pad for ceramic blanket mounting (17), Furnace lining (18), Carrier locator (19), pipe line for gas two in number (20), Lifting eye bolt – Four in number (21), Ceramic blanket (22), Silicone gasket (23).
5. The casting and melting furnace system as claimed in claim 1, wherein the gas is selected from noble gases or air.
6. The sand casting and melting furnace system as claimed in claim 1, wherein the snout pre-heating furnace (102) comprises of an outer blanket (22), a heating element (27), a ceramic module (28), alumina refractories (25) and an insulation layer (26) in the base.
7. The sand casting and melting furnace system as claimed in claim 1, wherein the snout (7) is made of ceramic material that is attached with the dome (4) of the casting furnace.
8. The sand casting and melting furnace system as claimed in claim 1, wherein the system is provided with a moveable charging system (24) for charging materials for producing the molten metal (11a).
9. The sand casting and melting furnace system as claimed in claim 1, wherein the system is for casting of stainless steel, steel alloys, Aluminium alloys, Vacuum De Gas and heat resistant alloys.
10. The sand casting and melting furnace system as claimed in claim 1, wherein the system has a suction system for removing the flue gases produced during melting above the crucible furnace through the gas exhaust (3).
11. The sand casting and melting furnace system as claimed in claim 1, wherein the double furnace system comprises a one crucible furnace in the melting mode and the other crucible furnace is in casting mode.
12. The casting and melting furnace system as claimed in claim 1, wherein the furnace is a standard air melt induction furnace.
13. The process the process for sand casting and melting the metals using the single furnace system (100), comprises the steps of,
(vii) preheating (301) of the snout or riser with the lid in the pre-heat furnace to the required temperature (1200◦- 1300◦ C)
(viii) melting (302) the metals at a temperature of 1540◦- 1570◦ C by using the melting furnace to get the molten metal in the melting chamber (11) by the heat generated by the heating coil (09);
(ix) impinging (303) of the gas from the gas inlet (13) as illustrated in the figure 1, vertically downwards to create low pressure on the surface of the melt, and pushing of the melt through the riser tube (07) into the dome ;
(x) transferring (304) the molten metal as obtained in step (i) to the mould assay of the melting unit (30) of the single furnace system for casting, pouring the melt furnace as obtained in step (iii) in to the at pouring temperature upto 1600°C depending on melt and settling pressure of less than 1.5 bar ;
(xi) Cooling (305) the casting as obtained in step (iv) for 30 minutes using the mold conveyor that make the cast free from hot tear and forms the cracks;
(xii) Knocking out (306) the metal cast as obtained in step (v) followed by cutting and fettling the metals.

14. The process for sand casting and melting as claimed in claim 12, wherein the flue gases produced during the production of melt is removed off above through the gas exhaust (3) of the furnace.

Dated this 16th day of August, 2022 Kalyan Jhabakh (IN/PA-830)
(Agent for Applicant