# US 8,784,727 B2 · Molten metal furnace > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,727 B2 - Document ID: US8784727B2 - Status: Granted - Kind: B2 - Application number: 13/402,590 - Filed: 2012-02-22 - Published: 2013-09-26 - Granted: 2014-07-22 - Earliest claimed: 2011-07-10 - Applicants: Jorge A Morando - Inventors: Jorge A Morando - Web page: https://patentgrep.com/patent/US8784727B2 ## CPC - F27B 3/26: Arrangements of heat-exchange apparatus - C22B 7/003: {only remelting, e.g. of chips, borings, turnings; apparatus used therefor} - F27B 3/045: {Multiple chambers, e.g. one of which is used for charging} - F27B 3/10: Details, accessories or equipment, e.g. dust-collectors, specially adapted for hearth-type furnaces - F27D 99/0073: {Seals} - Y02P 10/20: Recycling - F27B: FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - F27D: DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An improved molten metal furnace including an enlarged buffer plate of nickel-based superalloy material which seals and separates the furnace burners from the product to be heated. The seal from the buffer plate provides for the creation of a generally inert atmosphere for the bath of molten metal. Additionally, angling the interconnecting passageways between the furnace regions improve the thermal efficiency of the circulating molten metal. ## Claims ### Claim 1 An improved molten metal furnace comprising: a molten metal reservoir adapted to retain a bath of molten metal; at least one heater proximate to said reservoir, wherein said at least one heater is surrounded by an atmosphere comprising air and heater exhaust gases; and a buffer plate disposed between said bath of molten metal and said at least one heater, wherein said buffer plate seals and separates said molten metal bath from said heater atmosphere; wherein said at least one heater generates sufficient heat to melt a metal which makes up said molten metal bath, said heat passing through said buffer plate to said molten metal bath; and wherein said buffer plate is a superalloy having an emissivity of approximately 0.96-0.98. ### Claim 2 (depends on 1) The improved molten metal furnace as defined in claim 1, wherein said superalloy has an iron composition of at least 15%, producing a layer of iron oxide upon an exterior surface facing said at least one heater. ### Claim 3 An improved molten metal furnace comprising: a molten metal reservoir adapted to retain a bath of molten metal, said reservoir including a walls which cooperatively define a hearth, a pump well, and a charge well and a separate passageway interconnects each of said hearth, pump well and charge well; at least one heater proximate to said reservoir, wherein said at least one heater is surrounded by an atmosphere comprising air and heater exhaust gases; and a superalloy buffer plate having an emissivity of approximately 0.960.98 which is disposed between said bath of molten metal and said at least one heater, wherein said buffer plate seals and separates said molten metal bath from said heater atmosphere; wherein said at least one heater generates sufficient heat to melt a metal which makes up said molten metal bath, said heat passing through said buffer plate to said molten metal bath; wherein the passageway interconnecting the hearth to the pump well is angled downwardly from a region adjacent to a metal line of said molten metal bath toward a floor of said reservoir; wherein the passageway interconnecting the charge well to the hearth is angled upwardly from a region proximate to a floor of said charge well into said hearth. ### Claim 4 (depends on 3) The improved molten metal furnace as defined in claim 3, wherein said buffer plate seals said molten metal reservoir and cooperatively defines an enclosed cavity between said molten metal and said buffer plate, wherein an inert gas fills said enclosed cavity. ### Claim 5 (depends on 3) The improved molten metal furnace as defined in claim 3, wherein said superalloy has an iron composition of at least 15%, producing a layer of iron oxide upon an exterior surface facing said at least one heater. ### Claim 6 (depends on 3) The improved molten metal furnace as defined in claim 3, wherein said heater portion includes downwardly projecting furnace walls which cooperatively define a heater cavity; wherein said buffer plate has a generally flat cover portion which spans said reservoir portion, wherein at least two ends of said buffer plate form a channel which receive one of said downwardly projecting furnace walls. ### Claim 7 (depends on 6) The improved molten metal furnace as defined in claim 6, wherein each of said channels includes an outer channel wall which is adjacent to a surface of said downwardly projecting furnace wall, wherein said buffer plate is coupled to said heater portion through only a single fastener passing through each of said outer channel walls. ### Claim 8 (depends on 3) The improved molten metal furnace as defined in claim 3, wherein said buffer plate permits said at least one heater to be mounted less than two feet from an upper metal line of said molten metal bath. ### Claim 9 (depends on 3) The improved molten metal furnace as defined in claim 3, wherein said at least one heater is mounted between six to twelve inches from said buffer plate. ### Claim 10 (depends on 3) The improved molten metal furnace as defined in claim 3 comprising ceramic liners seated within both the passageway interconnecting the hearth to the pump well and the passageway interconnecting the charge well to the hearth.