MXPA99004208A - Molten metal pump and method of using - Google Patents

Abstract

An inert gas bubble-actuated molten metal pump (PU) is located between one section of a metal-melting furnace (10) and a second section to pump molten metal from the one section, wherein the molten metal is at a higher temperature, into the second section, wherein the molten metal (26) is at a lower temperature, and its effluent is directed into contact with metal chips (80) being charged into the second section, thereby assisting in the more rapid melting of the chips into the molten metal (26) mass in the second section. The inert gas (IG) employed to actuate the molten metal pump (PU) is captured beneath a heat-resistant and flame-resistant cover (30) located above the exit port of the pump (PU) and over a substantial portion of the molten (26) mass in the second section, thereby providing a non-oxidizing atmosphere at the surface of the molten metal (26) mass or pool beneath said cover (30). In this manner the inert gas (IG) is employed not only to actuate the inert gas bubble-actuated molten metal pump (PU), but also to assist in the rapid melting of metal chips (80) being charged, as well as to provide a non-oxidizing atmosphere at the surface of the molten metal (26).

Description

PUMP FOR FUSED METAL AND BEAR METHOD BACKGROUND OF THE INVENTION Field of the Invention The use of a pump for molten metal, driven inert gas bubbles to carry more hot molten metal and thereby assist the rapid melting of metal cleaved introduced into the molten metal colder in a melting furnace metal and, Combined with a heat and flame resistant coating, they simultaneously provide a non-oxidizing atmosphere to the surface of the molten metal mass, thereby also achieving maximum economic utilization of the inert gas.

Previous Technique The state of the art with respect to the introduction of pieces or metal fragments into the loading well of a metal smelting furnace, and the transportation of molten metal from one place to another inside or outside a smelting furnace REF .: 30236 metal, has been completely revised in prior USPatents, namely US patents Nos. 4,702,768, 4,710,126, 4,721,457, 4,872,907, 5,211,744, 5,203,910, 5,403,381, 5,468,280 and 5,407,462, the disclosures of which patents are incorporated by reference in the present. In particular, the use of a pump for molten metal, driven by bubbles of inert gas to move the molten metal from one place to another in a metal melting furnace or out of a metal melting furnace, has been described in FIG. the previous North American Application No. 5,203,910, as well as in US Patents Nos. 5,403,381 and 5,468,280. A flame and heat resistant cover for at least a substantial portion of a cargo well has been described in US Application No. 5,211,744. Various methods and means for loading to introduce sliced or metal fragments into the wellbore charging a melting furnace metal, have been described in previous US applications, in particular a briqueteador device or forming bricks, to form strips, and a method in the prior American Patent No. 4,702,768, a method of compacting extruder and a medium No. 4,872,907 US Patent, a method and gravity feed mass flow and an apparatus for loading metal cleaved into the well of load of a furnace, of metal melting, in the prior North American patent No. 5,407,462. Although the inventions of these prior patents have advanced much the state of the art including the efficiency of loading metal chips into the loading well of a metal smelting furnace and the transportation of molten metal from one place to another in an electric furnace. casting metal or outward. of the metal melting furnace, an improvement in efficiency is always a highly desirable objective and one that is admirably fulfilled by the provision of the present invention, whereby some of the salient features of the previous inventions and patents are combined from a . manner that minimizes unnecessary losses of inert gas used in the pump for molten metal driven by bubbles of inert gas, using the temperature gradient between the different sections of a melting furnace metal, with such a pump for molten metal, driven by inert gas bubbles to help -a faster casting metal cleaved loaded into the charge well of a metal melting furnace and the molten in- metal mass therein, while the inert gas used _pcopelente or actuator from the molten metal pump driven by inert gas bubbles, in combination, with * a heat resistant cover and. flame retardant, at least a substantial portion of the surface • of the mass of molten metal in a loading well, to capture the inert gas used as an actuator below such a cover on the surface of the molten metal mass in the loading well, the combination of the various aspects of the invention as described below greatly increases the efficiency of the operation by a clever combination of the thermal gradient between the poz.os, the pump, the inert gas bubbles that drive the pump, and the cover, contributing together, raise the efficiency and economy of the operation to new heights and previously not achievable. This applies without saying that it is not essential that the hotter molten metal be transported from an adjacent well to a loading well of a metal smelting furnace, provided that the hotter molten metal is transported from a section of the smelting furnace. from metal to a second section of the metal melting furnace that contains the coldest molten metal, in which a new load of chips or fragments is being introduced, and it should be clear that these two sections could involve two separate wells from the kiln or to be present in the same well the furnace for metal smelting. As used herein, the term "driven", with reference to the pump for molten metal "driven" by inert gas bubbles, means that the pump is put into action by the inert gas. Synonymously, one could say that the pump is driven, propelled or energized by inert gas bubbles.

OBJECTIVES OF THE INVENTION An object of the present invention is to provide a new and improved method for the use of shreds or metal fragments including scratches, by loading them into a section of the furnace for melting metal containing colder molten metal, which involves the feeding of shreds or metal fragments in that section of the furnace, covering at least a substantial portion of the surface of the molten metal in that section of the furnace, with a heat-resistant and flame-resistant cover, carried on. molten metal from another section of the furnace to the section containing the colder, molten metal, and within which the metal chips are being introduced (usually into the well of a well adjacent to the loading well), and directing the metal Hotter cast to the chopped or metal fragments to help faster casting of the same in the molten metal mass in that section of the furnace, the transportation of the hottest molten metal from the hottest sections to the coldest ones, is effected by a pump for molten metal, driven by bubbles of inert gas, and the inert gas used for such actuation is captured on the surface of the molten metal below the cover provided above the outlet gate of said pump, to provide. a non-oxidizing atmosphere on the surface of the molten metal. Still another objective is to provide more efficient casting of a new chopping load in the mass of molten metal in the furnace. A further objective is to provide a non-oxidizing atmosphere on the surface of the molten metal in the furnace. A further object of the invention is to provide improved and more efficient utilization of inert gas used in the form of bubbles / for the actuation of the pump for molten metal, which is no longer wasted but is used to provide a non-oxidizing atmosphere in the surface of the molten metal. Still another object of the invention is to provide an efficient method for using the gradient between the highest temperature of the molten metal in one section of a metal melting furnace and the lower temperature of the molten metal in another section of the melting furnace. of metal in which a new batch of chips or fragments is being loaded. Other additional objects of the invention will become apparent later in the present, and further objects will be obvious to one of ordinary skill in the art to which this invention pertains. All of these objects of the invention are in fact achieved by the provision of the method and the specific combination of the apparatus of the present invention.

BRIEF DESCRIPTION OF THE INVENTION What is believed by the present invention, then, among other things, comprises the following, alone or in combination: A method comprising the following steps: the provision of a pump for molten metal, driven by inert gas bubbles, in a section of a metal melting furnace containing hotter molten metal, and the provision of a section of a metal melting furnace containing molten metal cooler, directing the molten metal warmer than that. emerges from the pump, in contact with a load of metal chips that are introduced into the colder molten metal, to aid faster melting of the chips, providing a heat-resistant and flame-resistant cover above the gate of the pump, and on at least a substantial portion of the molten metal within which the pieces are being charged, and capturing the inert gas used as a driving agent in the molten metal pump, below said shell / to provide a non-oxidizing atmosphere on the surface of the molten metal within which the cuttings are being loaded, and below the cover; such method comprises the following steps: the provision of a pump for molten metal driven by bubbles of inert gas, between a first section of a metal melting furnace containing hotter molten metal, and a second section of an oven of cast metal containing cooler molten metal, directing the hottest molten metal that arises, from the pump from the first section, in contact with a load of metal troc.e-two that are introduced into the second section, to help to the faster melting of the pieces, providing a heat resistant and resistant cover. to the flame above the outlet gate of the pump, and over at least a substantial portion of the molten metal in the second section, and capturing the inert gas used as the actuation agent in the molten metal pump below the cover , to provide a non-oxidizing atmosphere on the surface of the molten metal in the second section, and below the cover; such method, wherein the pump comprises an elongated conveying conduit, having a lower end and an upper end, at least a portion of the conduit is inclined - with upward direction from the horizontal; Such a method wherein the flow of molten metal in the transportation conduit is effected by means of the inert gas introduced into the transportation conduit at or adjacent to its lower end. and which rises by the inclination -in this one to come out at its upper end; a method such that the pump is adjusted in a wall between a loading station and an adjacent well in the metal melting furnace; • a method in which the pump is adjusted to an angle in an opening in the wall, with its lower end immersed in the molten metal in the adjacent well, and its upper end in the molten metal in the loading well; a method such that the elongated conveying conduit is angled with a substantially horizontal portion and a lower portion extending downwardly at an angle to the horizontal; a method such that the molten metal and the metal chips charged into the loading well comprise aluminum, magnesium, titanium, brass, iron or steel, or an alloy thereof, or a metal for alloying with one of the metals; a method such that the load of the metallic pieces is provided by a metal cutter for gravity feed of the flow of the dough. In addition, in a metal melting furnace, the following combination: a section, which contains hotter molten metal, a section containing colder molten metal, a pump for molten metal driven, by inert gas bubbles, having one end of entry into the hottest molten metal and an outlet end in the coldest molten metal, located between the two * sections of the metal melting furnace, a metal chopper loader to introduce metal chips into the section containing the molten metal colder, and a heat-resistant and flame-resistant cover above the pump outlet gate, and over at least a substantial portion of the colder, molten metal, the pump outlet for molten metal. driven by inert gas bubbles, it is directed towards an area of the molten metal. colder inside • from which the metal slices are introduced by the chopping loader. Also, in a metal melting furnace, the following combination: a well, an adjacent well, a pump for molten metal driven by Inert gas bubbles, having an inlet end in the adjacent well, and a Exit end in the loading well, located between, the adjacent wall in the well. loading, a metal chopper loader for introducing metal chips into the loading well, and a heat-resistant and flame-resistant cover above the pump outlet gate and over at least a substantial portion of the cargo well, the outlet of the pump for molten metal, driven by bubbles of inert gas, is directed towards a. area of the loading well inside, from which the metallic pieces are introduced by the loader.; a combination such that the pump comprises an elongated conveying conduit, having a lower end and an upper end, at least a portion of the product is inclined-in an upward direction from the horizontal; such a combination, wherein the conveying conduit has an inlet of inert gas and molten metal at or adjacent to its lower end, and an outlet of inert gas and molten metal at its upper end; such a combination wherein the pump is fitted in a wall between a loading well and an adjacent well of the metal smelting furnace; such a combination wherein the pump is adjusted to an angle in an opening in the wall, at its lower end in the adjacent well and its upper end in the loading well; such a combination wherein the elongated conveying conduit is angled with a substantially horizontal upper portion and a lower portion extending downwardly at an angle to the horizontal; such a combination wherein the conveying conduit is molded in or routed out of a block of refractory material resistant to molten metal and at high temperature; such a combination wherein the refractory material is a graphite, ceramic, silica or silicon carbide material; such combination in which the loader of metallic pieces is a metal chopper for gravity feeding of the mass flow; a method such that the cover is floated on the surface of the molten metal; such combination where the cover is a floating cover that floats on the surface of the molten metal.

DESCRIPTION OF THE DRAWINGS Reference is now made to the drawings, in which: FIGURE 1 is a top plan view of a metal melting furnace, in this case a reverberation furnace, partially schematic and partially in section, taken along the line II of FIGURE 2, with the superstructure removed to show the apparatus required according to the invention and illustrating the method of the invention, including especially the various chambers or wells of the metal melting furnace, a cover over a substantial portion of the its loading well, and a pump for molten metal, driven by inert gas bubbles between a different furnace well from the loading well, here an adjacent well, and the same cargo well. FIGURE 2 is a front elevational view, partially schematic and partly in section, showing a device required according to the invention and illustrating the method of the invention in association with the reverberation furnace charging well, a charger of gravity feed metal cuttings of mass flow and a loading well that is not in this FIGURE, as well as an adjacent intermediate well and the pump for molten metal driven by gas bubbles -in between them. FIGURE 3 is an enlarged view of a portion of FIGURE 2, which shows in greater detail the pump for molten metal driven by inert gas bubbles, its placement in a wall between the adjacent well and the loading well, and a portion of the cover on the surface of the mass of molten metal in the well-load .. The -FIGURA 4 is a. extreme view of the apparatus of FIGURE 3, observed from the right-hand side of FIGURE 3.

DETAILED DESCRIPTION OF THE INVENTION The present invention, in its aspects of method and apparatus, will be more readily understood from the following detailed description, particularly when taken in conjunction with the drawings, in which all significant parts are numbered or with letters and where the same numbers and letters are used to identify the same parts throughout the description. A metal melting furnace, as shown, a reverberation furnace, of refractory material or having the usual refractory lining and ignited by combustion burners fueled by natural gas or petroleum which throw flames into the interior of the main chamber 18 thereof, through the usual flame introduction means, is shown in FIGURES at 10. The furnace well comprises the bottom wall 11 and the side or vertical walls 12 and 13, with a mass of molten metal. , pref.erente and usually aluminum or magnesium or an aluminum or magnesium alloy, in it, being shown in 26.

The base portions 11 of the furnace can be supported on the underlying floor by means of I-beam supports 15, as shown. The main chamber 18 is provided with the extensions 19 of the main chamber in the shape of the intermediate and adjacent well 20, which is usually referred to as the circulation well, and the loading well 22, connected with each other and with the main chamber 18"by means of the communication passageways 24. The molten metal 26 is brought into contact with the main chamber 18 and is circulated from the hottest part thereof, indicated at 38, through the intermediate well 20 to the loading well 22, by means of the communication passages 24. The necessary circulation is provided by means of the pump for molten metal PU, triggered by bubbles of inert gas, located in an opening in the wall 12 between the intermediate well and adjacent 20 and the loading well 22. The separate circulation medium in what is normally the circulation well 20, is not required. The transport duct CC is molded in or routed out of a block of refractory material B, which is resistant to the molten metal 26 and the high temperatures employed, the refractory material is usually a graphite, ceramic, silica or of silicon carbide. The elongated conveyance conduit CC is angled with a substantially horizontal upper portion and a lower portion extending downwardly at an angle to the horizontal, the lower end thereof being designated LE and the upper end thereof being designated UE. Also visible in the drawings are the oxide or slag 25 of molten metal, which is ordinarily collected on the surface of the well or bath or mass 26 of molten metal, this being shown as being present in all the wells of the furnace 10 for melting metal. According to the flow path or pattern 36 in a furnace 10 for metal melting, as created by the action of the PU molten metal pump driven by inert gas bubbles, and the CC conveying conduit thereof, the circulation of the molten metal 26 in the main chamber 18 of the furnace is constantly and continuously moved from the hottest point 38 in the main chamber 18, through the communication passageways 24 and especially by means of the PU pump, and the duct transportation CC thereof to the intermediate and adjacent well 20, and thence to the loading well 22. Due to its proximity to the hottest point to the main chamber 18, the molten metal 26 in the intermediate and adjacent well 20 it is hotter, for example at point 38A, than in the molten metal in the loading well 22 in which the coldest point 40 of the molten metal in the complete furnace for metal melting is located. As shown, this coldest point 40 is at a point or at a point closely adjacent to the normal point of introduction of a load of unmelted pieces 80, new or used, into the loading well 22, as by means 100 of loading of chopped or fragments of any suitable type, and the need to put the hot molten metal into this relatively cold loading well 22 by maintaining adequate circulation throughout the length of the metal melting furnace 10 and in all the chambers of the It is well understood by someone of ordinary skill in the art. As shown, the shredding loading means 100 comprises a vertically placed metal chopping loading duct 51, which is an integral part of the magazine 50 of metal shreds for gravity feed of the dough flow. Internally to the loading duct 51 of metal chips, vertically placed, a new load of metal chips 80 is placed, as fully described in the prior North American Application 5,407,462, whose gravity feed magazine 50 is positioned above an opening 33 in cover 30 flame resistant and temperature resistant, which comprised an upper metal surface 31 la. which is provided with a metal flange 34, angled iron supports 35, and flanges 36, and which advantageously has refractory materials 32 secured to the flat steel plate 31 or plated thereto, or otherwise constituted such as a cargo well cover as described in the previous North American Application 5,211,744. The cover 30 of the loading well. preferably covers the entire upper surface of the cavity 22C of the loading well and the mass of the molten metal 26 in it and in any case covers both the surface of the well cavity 22C. loading and the mass of the molten metal 26 thereon as possible and convenient, and in all cases is adapted to cover a substantial portion of the surface of the cavity 22-C of the loading well and the mass of the molten metal 26 therein . In a preferred embodiment, the cover 30 is a floating self-leveling cover, which floats on the surface of the mass 26 of molten metal and, in such case, the weight of the cover is simply reduced to a. point where the density of the cover 30 is sufficiently lower than that of the mass 26 of molten metal, to allow that. the cover 30 floats on top of the molten metal mass. Such an objective is easily achieved by employing more of the refractory material 32 and less of the heavy material such as the flat steel plate 31, to achieve the desired ratio of density of the cover 30 to the density of the mass of the molten metal. and, if desired, in at least some cases, the cover 30 may only comprise refractory material 32, since the refractory board of improved stability and increased strength, heat and flame, is now commercially available. If desired, the cover 30 can be lifted in and out of its position above the mass 26 of molten metal, by means of a chain and crane type mechanism, such as CH and HO to allow the cleaning phase of the lower part of the cover 30 and, in the event that the cover 30 is a "floating cover, it simply floats up and down on the upper part of the bath 26 of molten metal, notwithstanding the level of metal in the furnace chamber As a further preferred embodiment to facilitate achievement of the objectives of the present invention, the cover 30 may also be threaded, if desired, to straddle the exit gate UE of the PU pump and its transportation conduit. CC, to allow the most efficient capture of the inert gas IG that leaves the exit gate UE of the PU pump The cylindrical conduit 51 of the load of metal cutting is substantially vertical or in any case placed vertically of the mass flow gravity feed charger 50 is, as is usual, associated with and possibly connected to the cover 30, and the bottom of the interior thereof communicates with the central opening 33 of the cover 30, with which metal slices 80 are allowed to fall by gravity force through the central opening 33 in the cover 30 into the mass 26 of molten metal in the loading well 22. Any other means for loading chopped, for introducing metal chips into the loading pit of a metal melting furnace, can be used instead of the gravity feed charger 50 of the mass flow shown in the drawings, always in conjunction with a cover 30 and always involving a suitable opening or opening to the cover 30 but not necessarily involving a central opening such as the central opening 33 shown in the drawings in association with the gravity feed charger 50 mass flow,. such as the chopping loader means of the prior North American Patents Nos. 4,702,768, 4,872,907, or of course any variation of the gravity feed loader of the mass flow, of the prior US Patent No. 5,407,462, the exact cutting load means employed is not of the essence of the present invention, although a gravity feed loader 50 as shown in the drawings and as further described in detail in the prior North American Patent No. 5,407,462 is preferred. In any case, fresh metal chips, either new or used, are introduced into the mass 26 of molten metal in the loading well 22. Returning to the PU pump for molten metal driven by inert gas bubbles, as is usual, the flow of molten metal 26 in the PU pump is effected by means of inert gas bubbles IG introduced into the transportation conduit CC or adjacent to its lower end LE, and rising by the inclination therein to emerge at its upper end UE, at which point the hottest molten metal 26 and the inert gas IG, jointly referred to as the IG 26 effluent, is in effect "released" to the molten metal 26 in the loading well 22, the upper outlet end UE of the transport duct CC, and thus of the pump PU, is directed towards an area of the loading well 22 and the mass of molten metal 26 in it in which the metal chips 80 are introduced by the loader 100 of chopped, in est e) the gravity feed charger 50 of the mass flow. The entrance of the hotter molten metal 26 into the cooler molten metal mass 26 of the loading well 22, in that it is directed towards the area of the molten metal mass 26 in the loading well 22 in which it is being introduced the new chopping load 80, it raises the temperature in that area considerably and greatly aids with the melting of the new chopping load 80 within the mass 26 of molten metal. In addition to this, when the hotter, molten metal 26 coming from the intermediate well 20 collides on or makes contact with the new load of 80. metal chips, the melting process is greatly facilitated. Further, in accordance, the bubbles of the inert gas IG arise from the upper end UE of the transport conduit CC of the pump PU and within the mass of molten metal 26 in the loading well 22, the bubbles of inert gas IG. they are released and rise in an upward direction but, instead of escaping, at least a substantial portion of the inert gas IG is captured in the cargo well 22 below the cover 30 and there provides a non-oxidizing atmosphere in the form of bubbles and a layer of inert gas on the surface of the molten metal 26 in the loading well 22 and below the cover 30. In this way, the inert gas IG used for driving the PU pump for molten metal, is used to provide a non-oxidizing atmosphere below cover 30 in the loading well 22.

The lower end of the inert gas supply or feed line in the shape of the tube P can not be or can be bifurcated (as shown) to provide a plurality of outlet gates E for the inert gas, thereby providing a plurality of streams of inert gas bubbles IG within the transportation conduit CC for the best actuation of the pump P_U for molten metal, if desired, or this can achieve a similar result by the use of a plurality of tubes P, or by the use of a multiple gas pipeline, although the latter is usually employed only with a plurality of CC transportation conduits as shown in U.S. Patent 5,203,910. As shown in the drawings, the feeding means comprises the inlet gate I and the tube P having an outlet gate E at its lower end, which communicates with the lower end LE of the transport duct CC of the pump PU, the tube P being housed in a support column SC and the support block B of the refractory material also coupled to the support columns SC, the connections between the support columns SC and the block B are insubstantial, as long as These are durable, either by clamps or suitable welds resistant to molten metal and heat, by means of pressure adjustment, by means of. welding to metal inserts, or similar. Since the connection means are immaterial, these are not shown in the drawings. The supporting columns SC are supported from the hanging support H, which in turn is supported by the chain or cable connections CH to a ring or hook, in turn suitably connected to a HO crane, not shown, for the introduction Quick and convenient and removal of the PU pump and its auxiliary accessories, supports and the inert gas feed line, as a unit from its operating site between the wells of the metal melting furnace.

OPERATION In operation, the molten metal from the main chamber 18 of the metal melting furnace 10 is circulated, with the help of the PU molten metal pump driven by inert gas bubbles, which is preferably located between what is usually the "circulation" well 20 of the metal smelting furnace and the loading well 22 of the metal smelting furnace, and in any case in any well or between any wells of the metal smelting furnace, including the well of the metal casting furnace. As shown, the PU pump is located in an opening in a wall 12 between an intermediate wall 20 adjacent to the loading well 22 where the molten metal 26, which comes directly from the main chamber 18, is hotter than it is. in the loading well 22, where a new load of metal chips 80 is periodically or continuously introduced. Inert gas bubbles IG that drive, propel or propel the PU pump enter the transportation conduit CC at the lower end LE thereof and exit at the upper end UE thereof, the inert gas IG provided by gas supply means including the inlet gate I, the pipe P, and the outlet gate E, entering the PU pump and the transportation conduit CC thereof at or near the lower end LE thereof. Exiting the upper end of the PU pump is a 26 IG combination of the molten metal and the inert gas bubbles that propel it. The upper end UE or output gate of the PU pump and the transport duct CC thereof is directed towards the area of the melt in the loading well into which a new load of metal cuttings 80 is introduced, and thus in contact with the metal slices. Since the molten metal 26 that enters from the well 20 different from the furnace loading well, in this case the well. adjacent intermediate 22, is at a higher temperature and warmer than the molten metal 26 of the loading well 22 itself, and certainly has a higher temperature than the new load of metal chips 80 that are introduced by the metal chip loading machine, as shown by the charger 50 of the mass flow gravity feed furnace, preferred, although the same principles are indeed achieved. same results, notwithstanding the type of loader used, the new load of metal chips that is fed into the loading well 22 of the metal melting furnace, after coming into contact with the hotter molten metal, melts more rapidly in the mass 26 of molten metal in the loading well 22 of the furnace. In addition, instead of being thrown out, the inert IG gas used to drive the PU pump for molten metal driven by inert gas bubbles is captured in the well. load 22 below the cover 30 of the loading well, which may conveniently be a floating cover, thereby providing a non-oxidizing atmosphere of the inert gas IG on the surface of the molten metal mass 26 in the well of load 22, and below deck 30. In this way,. according to the method and using the apparatus herein. invention, the necessary circulation of the molten metal in the metal melting furnace is efficiently effected, the molten metal is taken from a well or chamber of the metal melting furnace, where the molten metal is at a temperature higher than that of the metal melted in the same loading well, and considerably hotter than the new load of metal chips that are fed into the loading well of the metal melting furnace and, the output end of the PU pump and the DC transport pipe of They are the same. pointed in the area in which the new load of metal chips is introduced, and thus is directed in contact with the new load of metal chips, greatly helps the faster melting of the new load of metal chips in the Mass of molten metal in the loading well. In addition, the inert gas used is used not only as the actuator or propellant for the molten metal PU pump, driven by inert gas bubbles, but in combination with the heat-resistant and flame-resistant cover on at least one portion Substantial loading well, is captured below the deck and used to create the highly desirable non-oxidizing atmosphere on the surface of the molten metal in the cargo well, and below the cover, thereby presenting a full efficiency high and still a highly economical arrangement of the apparatus and method for circulating the molten metal throughout the various chambers of the metal melting furnace and particularly from a chamber where the latter is at a hotter temperature than in the well of cargo in. the loading well itself, for the faster melting of a new load of metal chips in the molten metal or in the combined in the loading well, and for the establishment of a non-oxidizing atmosphere in the surface of the mass of molten metal in the loading well, and below the heat-resistant and flame-resistant cover on the surface of the molten metal mass in it.

IN GENERAL The method and apparatus of the present invention is particularly adapted for use in connection with the casting and recycling of non-magnetic metal chips or grates such as brass, aluminum, aluminum alloys, and the like, and such non-magnetic metal chip or scratch can to be conveniently separated from a mass of the metal grated including also cut into pieces or ferrous, ferric and other magnetic chips, by the use of magnetic separation means, as is now well known and established in the art. The transport conduit of the invention, as well as the gas feeding means of the invention are generally constructed of ceramic, graphite, silica or silicon carbide material resistant to molten metal at high temperature, or similar materials, and the hanging supports and supporting columns supporting them within the metal mass are joined to it either by welding, clamping or bonding by ceramic or adhesive around the outside thereof or in some cases they can be molded into the material ceramic, graphite, silica or silicon carbide construction, or in some cases may even be made of stainless steel or mild steel or steel coated or plated with a refractory material. As illustrated here, the term "chopped or metal fragments" means metal chips or scraps of any type or description, as conventionally used in the art to be loaded into the loading well of a metal smelting furnace, and includes aluminum, magnesium, titanium, brass, iron or steel, or an alloy thereof, or a metal for alloying with one of said metals. In this specification and in the claims, where reference is made to molten metal, a mass or combination of molten metal, and "metal chips" the type of metal, comprises the molten metal combo as already described, and the term "chopped" metallic "is going to be understood as that which encompasses the metallic pieces of various proportions, almost unlimited configurations and dimensions, but particularly including small pieces and / or particles, likewise of extremely variable dimensions, and in general the term" metallic pieces "is employed herein as having the usual meaning for a person skilled in the art, including not only parts, parts, particles and. fragments of the usual type coming from the scratching, but also metal previously not used in standard or other configurations that remain of the oparations of the molding process, of extrusion, of casting, of rolling or. similar priors, and this without saying that the inconveniently large parts can be reduced in size in any convenient way, and used as metal slices and that, consequently, any suitable metal, either grated or otherwise, can be converted into chips and used in the method and apparatus of the invention, whether it be new metal or previously used metal, including even and especially new and used aluminum foil and can scratching, when it is determined that such additional processing into a new metal is required or desired by the operator.

Of what. previous it is observed that the. Objects of the present invention have been achieved and that a novel, efficient and economical method and apparatus has been provided, all in accordance with the objects of the invention and the present description of the invention, as described hereinabove. It should be understood that the present invention is not limited to the exact details of operation, or to the exact compounds, compositions, methods, procedures or modalities shown and described, since various modifications and equivalents will be apparent to a person skilled in the art, Therefore, the present invention has to be limited only by the full scope it can. be legally agreed for the appended claims.

It is stated that in relation to. • this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (20)

RE I INDICAC IONE S Having described the invention as above, the content of the following claims is claimed as property:

1. n method., characterized in that it comprises the following steps: the provision of a pump for molten metal, driven by inert gas bubbles, in a section of a metal melting furnace containing molten, hotter metal, and the provision of a section of a metal melting furnace that contains colder molten metal, directing the molten metal that rises from the pump in contact with a load of the metal chips that are introduced into the colder molten metal, to help the faster melting of the pieces, providing a heat-resistant and flame-resistant cover, above the pump outlet gate, and over at least a substantial portion of the molten metal in which the pieces are being loaded, and capturing the inert gas used as a driving agent in the molten metal pump below the cover, to provide a non-oxidizing atmosphere on the surface of the 'molten metal within which the cut pieces are being loaded and below said cover. 2. A method, characterized in that it comprises the following steps: the provision of a pump for molten metal, driven by inert gas bubbles, between a metal melting section containing hotter molten metal, and a second section of a furnace metal casting containing the coldest molten metal, directing the hottest molten metal leaving the pump from the first section in contact with a load of metal chips that are introduced into the second section, to aid the faster casting of chopped, providing a heat-resistant and flame-resistant cover above the pump outlet gate, and at least a substantial portion of the molten metal in the second section, and capturing the inert gas used as the actuation agent in the molten metal pump below the cover, to provide a non-oxidizing atmosphere on the surface of the molten metal in the second s ection, and below the cover. 3. A method according to claim 2, characterized in that the pump comprises an elongated conveying conduit having a lower end and an upper end, at least a portion of the conduit is inclined in an upward direction from the horizontal. 4. A method according to claim 3, characterized in that the flow of molten metal in the transportation conduit is effected by means of inert gas introduced into the transportation conduit at or adjacent to its lower end and which rises above the inclination. in this one to exit at its top end. 5. A method according to claim 2, characterized in that the pump is adjusted in a wall between a loading well and. the adjacent well in the metal smelting furnace. 6. A method according to claim 5, characterized in that the pump is adjusted to an angle in an opening in the wall with its lower end submerged in the molten metal in the adjacent well, and its upper end in the molten metal in the well of load. 7. A method according to claim 3., characterized in that the elongated transport conduit is angled with a substantially horizontal upper portion and a lower portion extending with. Direction down at an angle to the horizontal. 8. A method according to claim 2, characterized in that the molten metal and the metal chips. charged in the loading well include aluminum, magnesium, titanium, brass, iron, or steel, or an alloy thereof, or a metal for alloying with one of said metals. 9. A method according to claim 2, characterized in that the loading of metal slices is provided by a magazine of metal slices, by gravity feed of mass flow. 10. In a metal melting furnace, the following combination: a first section for containing hotter molten metal, a second section for containing molten metal. Cooler, a pump for molten metal driven by inert gas bubbles, which has one end. of entry into the - first section, and for placement in the hottest molten metal when contained in the. first section, and. one outlet end in the second section, and for placement in the coldest molten metal, when contained in the second section, located between the two. sections of the metal melting furnace, a metal chopping loader to introduce chopped, metal to the second section, when the coldest molten metal is contained therein, and a heat-resistant and flame-resistant cover above the gate of the pump, and on at least a substantial portion of the second section, and on a substantial portion of the. When the molten metal is cooler when it is contained in it, the outlet of the molten metal pump, driven by inert gas bubbles, is directed towards an area of the second section and the coldest molten metal, when contained in it, inside from which the metal slices are introduced by the chopping loader. 11. In a metal melting furnace, a combination that is characterized by: a loading well, an adjacent well,. a pump for molten metal driven by inert gas bubbles, which has an inlet end in the adjacent well, and an outlet end in the loading well, located between, the adjacent well and the loading well, a chopping loader metal to insert., metal chips into the loading well, a heat-resistant and flame-resistant cover above the pump outlet gate and over at least a substantial portion of the loading well, the pump outlet , for molten metal driven by inert gas bubbles, is directed towards an area of the loading well into which the metallic pieces are introduced by the chopping loader. 12. A combination-in accordance with claim 10, characterized in that the pump comprises an elongated conveying conduit having a lower end and an upper end, at least a portion of the conduit is inclined in an upward direction from the horizontal. ' 13. A combination according to claim 12, characterized in that the transport conduit has an inlet of inert gas and molten metal at or adjacent to its lower end / an outlet of inert gas and molten metal at its upper end. 14. A combination according to claim 10, characterized in that the pump is fitted in a wall between a loading well and an adjacent well of the metal casting surface. 15. A combination according to claim 14, characterized in that the pump is adjusted to an angle in an opening in the wall, with its lower end in the adjacent well and its upper end in the loading well. 16. A combination according to claim 12, characterized in that the elongated conveying conduit is angled in a substantially horizontal portion and a lower portion extending in a downward direction with an angle to the horizontal. 17. A combination according to claim 13, characterized in that the transport conduit is molded in or routed out of a block of refractory material resistant to molten metal and resistant to high temperature. 18. A combination according to claim 17, characterized in that the refractory material is a material of graphite, ceramic, silica or silicon carbide. 19. A combination according to claim 10, characterized in that the metal chopper loader is a metal chopper for gravity feed of mass flow. 20. A method according to claim 1, characterized in that the cover floats on the surface of the molten metal.

2. 1 . A combination according to claim 10, characterized in that the cover is a floating cover that floats above the molten metal surface when it is contained in the second section. SUMMARY OF THE INVENTION A pump for molten metal driven by inert gas (PU) bubbles is described which is located between a section of a metal melting furnace (10) and a second section for pumping the molten metal from a section, where the molten metal it is at a higher temperature, towards the second section, where the molten metal (26) is at a lower temperature, and its effluent is directed in contact with the metal chips. (80) which are loaded in the second section, which helps the faster melting of the troceadps in the molten metal mass (26) in the second section. The inert gas (IG) used to drive the molten metal pump (PU) is captured below a heat-resistant and flame-resistant cover (30), located above the pump outlet (PU) gate. and about a substantial portion of the melt (26) in the second section, whereby a non-oxidizing atmosphere is provided to the surface of the molten mass or combination of molten metal (26) below the cover (30). In this way, the inert gas (IG) is used not only to drive the pump (PU) for molten metal driven by inert gas bubbles, but also to aid the rapid melting of the metal chips (80) that are loaded, as well as to provide a non-oxidizing atmosphere on the surface of the molten metal (26).