Claims:We Claim:

1. A guiding system for pouring molten aluminiumfrom a ladle into a mould, said system to be adapted over the mould carrying system and comprising:
a guide plate for receiving hot liquid metal from the ladle;
a pouring tray coupled to the guide plate, said pouring tray having a hole to reduce area of flow of hot molten aluminium and deliver the hot molten aluminiumsubstantially ator near the centre of mould;
a support framefor supporting the guide plate and the pouring tray over the mould, said support frame having a raising means to lower the guide plate and pouring traydown below opening of the mould at the time of pouring the hot molten aluminium to reduce the pouring height between the pouring tray and bottom of the mould and to raise the guide plate and pouring tray above the opening of the mould while movement of the mould over the mould carrying system.

2. The guiding system as claimed in claim 1 further comprises a sensor for controlling pouring of the hot metal liquid.

3. The guiding system as claimed in claim 1, wherein the support frame comprises at least one sensor to sense the movement of the moulds for raising and lowering the guide plate and pouring tray.

4. The guiding system as claimed in one of the preceding claims 1-3, wherein the guiding plate and the pouring tray are at separate level forming a step for the flowing molten aluminium.

5. The guidingsystem as claimed in one of the preceding claims 1-4, wherein the hole is at the center of the poring tray.

6. The guiding system as claimed in one of the preceding claims 1-5, wherein the support frame includes a splash guard.

7. The guiding system as claimed in one of the preceding claims 1-6,wherein the guide plate and pouring tray are made of stainless steel.

8. A method for guiding a molten aluminium for pouring from ladle into mould, said method comprising steps of:
dividing a pouring height between the ladle and molten aluminium into at least two flowing steps; and
guiding flow of the molten aluminium at or near center of the mould with a reduced flow area of the molten aluminium.

9. The method as claimed in claim 8, wherein the pouring height is preferably divided into three flowing steps.
10. The method as claimed in claim 8, wherein the flow area is substantially reduced to at least half of an area of the flow from the ladle.

Dated this 22nd day of February, 2017

FOR Hindalco Industries Limited
By their Agent

(GIRISH VIJAYANAND SHETH) (IN/PA 1022)
KRISHNA & SAURASTRI ASSOCIATES LLP
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

A GUIDING SYSTEM FOR POURING MOLTEN ALUMINIUM AND A METHOD THEREOF;

HINDALCO INDUSTRIES LIMITED, A COMPANY ORGANIZED UNDER THE LAWS OF INDIA, HAVING ITS PLACE OF BUSINESS AT 7TH FLOOR, BIRLA CENTURION, PANDURANG BUDHKAR MARG, WORLI, MUMBAI-400 030, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of the invention
The present invention mainly relates to the production of aluminium sow ingots and more particularly to a guiding system and method for pouring molten aluminiumin the production of aluminiumsow ingots.
Background of the invention
Usually, in metal industries including aluminium industries, a sow ingot, is a form of a relatively pure material cast into a shape suitable for downstream industries for further processingincluding re-melting of the sow ingot, cold/hot working, cutting, or milling for making final products.
Generally, there are two major types of sow ingots sold in the aluminium industry today. The first type is the "traditional" sow ingot and the second type is the "low profile" sow which is gaining wide acceptance within the aluminium industry as it is suitable to charge in smaller size of furnaces.Usually, sow casting machineproduces aluminium sow ingots in a range of sizes and it can be operated on a continuous or semi-continuous basis.The sow casting machine is designed for automatic operation with minimal operator input required and having a production capacity of 15MT/hr. of sow ingot with weight of 450±50kg each. Referring Figure 1 shows a presently used a pouring system (110) comprising aplurality of moulds (140) in line adapted on mould carrying system (150) and a ladle (120) being placed directly on the ladle tilter (not shown) to execute pouring operation in to the moulds (140) one after another. Generally, from one ladle around 23-24 (twenty-three) sows of weight 450±50kgcan be produced. Just after the pouring, there is a provision of skimming by a robotic skimmer (160) to remove excess dross from the top surface of sows. Dross is a mass of solid impurities floating on a molten aluminium and forms on the surface by oxidation of metal. Then,the sows are cooled by forced air cooling method. Once sows get solidified in the moulds,they are demoulded from the moulds by pneumatic demoulding arrangement (not shown). For better traceability, each sow is being engraved with cast identification and sow number. However, inventor(s) of the present invention observed that the sows were having dross on the side surfaces. The dross on the side surfaces of finished sows could not get removed even after doing robotic skimming or increasing number or time of the skimming. The presence of dross on the side surface of sows deterioratesthe overall quality of sows with even higher purity grades like P1020, P0610, and P0406 etc. Referring Figure 2 shows four sows (180) stacked one over another, each having dross (D) as indicated by the oval lines on the side surfaces. Moreover, the surface obtained is also rough.
Further, it is found that all the machines with similar technology are having same issues of dross formation over the side surfaces of sow ingots.After thorough investigation, the inventor(s) of the present applications concluded that the excess dross formation over sow ingots during sow production is due to the high instability of metal during pouring from ladle to sow mould.Various known attempts have been made by the inventors such as increasing number of robotic skimming, intensive robotic skimming, cleaning mould time to time which constantly failed to provide a dross-free ingot.
Therefore, there is a need of means to solve the above-mentioned problem.

Summary of the Invention
Accordingly, the inventor of the present invention in one aspect invented a guidingsystem for pouring molten aluminiumfrom a ladle into a mould in the production of sow ingots. Said system is to be adapted between a ladle and moulds over a mould carrying system, comprising: a guide plate for receiving hot liquid metal from the ladle, a pouring tray coupled to the guide plate and a support frame for supporting the guide plate and the pouring tray over the mould. The pouring tray has a hole to reduce area of flowof hot molten aluminium and deliver the hot molten aluminium substantially at or near the centre of mould. The support frame comprises a raising means to lower the guide plate and pouring tray down at the time of pouring the hot molten aluminium below opening of the mould to reduce the pouring height between the pouring tray and bottom of the mould and to raise the guide plate and pouring tray above the opening of the mould while movement of the mould over the mould carrying system.
According to an embodiment of the present invention, the guiding system may comprise a sensor for controlling pouring of the hot metal liquid.
According to one another embodiment of the present invention, the support frame may comprise at least one sensor to sense the movement of the moulds for raising and lowering the guide plate and the pouring tray. Alternatively, the raising and lowering of the guide plate and pouring tray may be done manually.
According to one another embodiment of the present invention, the guiding plate and the pouring tray are coupled at separate level forming a step for the flowing molten aluminium.
In another aspect, the present invention provides a method for guiding a molten aluminium for pouring from ladle into mould, comprising steps of dividing a pouring height between the ladle and molten aluminium into at least two flowing steps and guiding flow of the molten aluminium at or near center of the mould with a reduced flow area of the molten aluminium.
According to an embodiment, the pouring height is preferably divided into three flowing steps.
According to a further embodiment of the invention, the flow area is substantially reduced to at least half of an area of the flow from the ladle.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

Brief description of the drawings
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
Figure 1 shows a present pouring system used for hot liquid metal including aluminium in moulds;
Figure 2 shows stacked aluminium sows obtained from the pouring system shown in Figure 1;
Figure 3 shows a system for pouring molten aluminium in a sow of the present invention along with a mould carrying system;
Figure 4 shows a system for pouring molten aluminium in a sow of the present invention along with ladle and moulds;
Figure 5 shows a system for pouring molten aluminium in a sow of the present invention with the ladle in poring position;
Figure 6A shows a liquid metal flowing on the guide plate and pouring tray according to the invention
Figure 6B shows liquid flow directions of the prior art and the present invention; and
Figure 7 shows a sow obtained from the trial taken using the guiding system for pouring molten aluminium in a sow of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

Detail description of the Invention
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
Figures, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that would limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged communications system. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions, in no way limit the scope of the invention. Terms first, second, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. A set is defined as a non-empty set including at least one element.
In general, the present invention provides a guiding system and method for pouring hot molten aluminium from a ladle into a mould at a minimum heightwith a minimum pouring area by dividing the pouring height between the ladle and the mould into two or more steps and guiding the hot molten aluminium and delivering at or substantially near the centre of the mould. The pouring height of the pouring tray depends upon the height of the sow which may vary based on the weight of the sows.
Referring Figures3-5 shows a guiding system (200) for pouring molten aluminium from a ladle (120) into a mould in the production of aluminium sow ingots. The guiding system (200)is adapted between the ladle (120) and mould over the mould carrying system (150).
The guiding system (200) for pouring molten aluminium comprises a pouring tray (230) coupled to a guide plate (210). The guide plate (210) and the poring tray (230) may be coupled with a flow step for reducing a flowing angle of the hot metal liquid step by step. The guide plate and pouring tray can beaunitary structure or made of two separate pieces fixed together permanently or removably with one or more steps. Moreover, the coupling of the guide plate and pouring tray may be hinged together.
The pouring tray (230) has a hole (235) to deliver the hot metal liquid (125). Advantageously, the hole is provided in such away that the hot molten aluminium (125) will be delivered/guided at or the centre of the mould (140) The hole (235) is preferably provided at the centre of the pouring tray (230).
The guide plate (210) and the pouring tray (230) are fixed over an upper frame (220A)of a support frame (220). The support frame (220) is adapted over the mould carrying system (150) and includes the upper frame (220) adapted overa raising means (224) and a splash guard (230) adapted over the upper frame (220A) around the guide plate (210) and the pouring tray (230). The raising means (224) moves the upper frame of the support frame up and down. As shown in the Figures 3-5, the raising means (224)comprises four pneumatically or hydraulically operated cylinders or any other known means that can be used to move the upper frame of the support frame up and down.
Referring Figure 4-6A shows themethod of pouring with the operation of the guiding system (200) of the present invention in step by step.
In Figure 4, the ladle (125) containing hot metal liquid (125) is in vertical position and the guiding system for pouring metal is in raised position means the upper frame of the support frame along with the guide plate and pouring plate are above the opening edges of the moulds for easy movement of the moulds (140) on the mould carrying system (150) below the support frame (220). As shown in Figure 4 the rods (224A) of the hydraulic/pneumatic cylinders (224B)are at raised position keeping the pouring tray and the guide plate mounted on the upper frame (220A) of the support frame (220) above the mould.
Referring Figure 5 shows the ladle (120) in the tilted position for pouring the hot metal liquid (125) in the mould (140) below the pouring tray (230). As shown in Figure 5 and 6A, the pouring tray (230) is lowered below the opening edgesof the mould (140) by the raising means (220). As shown in Figure 6A,the guide plate (210)guides flow (Fi) of the hot molten aluminium into the pouring tray (230) which guides and delivers the molten aluminiumat the centre or near the centre of the mould.In an another embodiment, the raising means may maintain a minimum constant distance by raising the pouring tray and guide plate continuously with the filling of the molten aluminium in the mould.
The pouring system (200) of the present invention comprises one or more sensors (240) to control pouring of the molten aluminium in the mould including titling of the ladle (120), raising or lowering the upper frame of the support frame, movement of the moulds over the mould carrying system, molten aluminium height in the mould.
Figure 6B compares the flow (Fi) of hot molten aluminium using the pouring system of the present invention with the flow (Fp) of the current method of pouring.As shown in Figure 6A and 6B, the height of the flow is divided in to three steps namely, ladle to guide plate, guide plate to pouring tray and pouring tray to the mould and moreover guide plate and pouring tray has slopes that reduces or eliminates the turbulence in the flow of molten aluminium.Alternatively, the present invention delivers the hot molten aluminium into the mould at or near the centre a reduced height by dividing the current height at least two steps namely, ladle to guide plate and pouring tray to mould. Accordingly, the present invention delivers the hot molten aluminium at a minimum height ascompared to the height distance between the ladle and mould and the present invention allows the pouring tray to lower below the opening edges of the mould and reduced flow area. Further as the present invention delivers the molten aluminium near the centre of the mould without turbulence. Hence, dross formed during the pouring operation remains at the centre of the mould which can be easily removed by the robotic skimmer (160) which is followed by cooling of the sows takes places by forced air cooling method. Once sows get solidified in the moulds it is demoulded from moulds by pneumatic demoulding arrangement Therefore, the guiding system for pouring molten aluminium in a mould of the present inventionprovides excellent side surface quality in the sow ingots.
Figure 7 shows the aluminum sows (280) obtained by using the pouring system of the present invention during the test conducted as an experiment. As there are no dross on the side surface as well as the dross formed during the pouring process is substantially removed by the robotic skimmer, it has been observed that the present invention provides excellent quality sows and has no impact on the rate of production of the machine. This will stop rejecting or reducing the cost of sows and increased economic cost of the sows.
Those skilled in this technology can make various alterations and modifications without departing from the scope and spirit of the invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.
Figures are merely representational and are not drawn to scale. Certain portions thereof may be exaggerated, while others may be minimized. Figures illustrate various embodiments of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
In the foregoing detailed description of embodiments of the invention, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description of embodiments of the invention, with each claim standing on its own as a separate embodiment.
It is understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively.