Metal remelting with concentrated solar power

Abstract

One disclosed embodiment is a concentrated solar thermal system for re-melting recycled or scrap metal. The system includes a solar receiver configured to receive concentrated solar flux reflected from one or many reflecting surfaces to heat a quantity of the recycled metal and cause at least a portion of the recycled metal to melt. The molten metal is then passed to a solidification stage where the molten metal may be cast into any type of solid form useful for sale or the subsequent production of metal products. The solidified metal may be sold or otherwise removed from the system. In certain embodiments, heat exchange is made to occur between the molten metal and the working fluid of an electrical power generation cycle resulting in electrical power generation. Methods of remelting metal using solar thermal power and methods of generating power using a molten metal heat transfer material derived from recycled metal or scrap are also disclosed.

1 . A concentrated solar thermal system for remelting recycled metal comprising:
 a source of recycled metal;   a solar receiver configured to receive concentrated solar flux to heat a quantity of the recycled metal and cause at least a portion of the recycled metal to melt; and   a solidification stage receiving molten recycled metal from the solar receiver, the solidification stage providing for the molten recycled metal to be cast into a solid form.   
     
     
         2 . The concentrated solar thermal system for remelting recycled metal of  claim 1  further comprising a heat exchanger in fluid communication with the solar receiver, the heat exchanger receiving molten recycled metal, and providing for heat exchange between the molten recycled metal and a working fluid of an electric power generation cycle. 
     
     
         3 . The concentrated solar thermal system for remelting recycled metal of  claim 1  further comprising a fluid conduit system providing for transportation of a first portion of molten recycled metal from an outlet of the solar receiver to an inlet of the solar receiver, the fluid conduit system further providing for transportation of a second portion of the molten recycled metal to the solidification stage. 
     
     
         4 . The concentrated solar thermal system for remelting recycled metal of  claim 3  further comprising:
 a shredder receiving recycled metal at a shredder input and providing shredded recycled metal at a shredder output; and 
 a material transport system providing for the transportation of shredded recycled metal to the solar receiver input. 
 
     
     
         5 . (canceled) 
     
     
         6 . The concentrated solar thermal system for remelting recycled metal of  claim 1  further comprising a compressor providing for the forming of recycled metal into a compressed form for input into the solar receiver. 
     
     
         7 . (canceled) 
     
     
         8 . The concentrated solar thermal system for remelting recycled metal of  claim 1  further comprising:
 molten metal storage providing for the storage of molten recycled metal received from an output from the solar receiver; 
 a recuperative heat transfer conduit providing for the transfer of heat energy from at least one of the solidification stage; the solar receiver outlet or the molten metal storage; and 
 a recuperative pre-heater providing for the pre-heating of the recycled metal prior to input into the solar receiver. 
 
     
     
         9 . The concentrated solar thermal system for remelting recycled metal of  claim 1  further comprising molten metal storage providing for the storage of molten recycled metal received from an output from the solar receiver, wherein the molten metal storage provides for thermal energy storage using the molten recycled metal as a thermal energy storage medium. 
     
     
         10 . The concentrated solar thermal system for remelting recycled metal of  claim 9  further comprising a heat exchanger in fluid communication with at least one of the solar receiver or the molten metal storage, the heat exchanger receiving molten recycled metal from at least one of the solar receiver or the molten metal storage, and providing for heat exchange between the molten recycled metal and a working fluid of an electrical generation power generation cycle. 
     
     
         11 . The concentrated solar thermal system for remelting recycled metal of  claim 10  wherein the heat exchanger comprises a direct contact heat exchanger providing for physical contact between the molten recycled metal and the working fluid. 
     
     
         12 . The concentrated solar thermal system for remelting recycled metal of  claim 10  wherein the heat exchanger comprises a multiple stage heat exchanger comprising at least a primary stage where heat exchange occurs between molten recycled metal and the working fluid and a solidification stage where heat exchange between the heat transfer material and the working fluid causes solidification of the molten recycled metal. 
     
     
         13 . (canceled) 
     
     
         14 . A method of recycling metal comprising:
 providing a source of recycled metal;   heating a quantity of the recycled metal in a solar receiver configured to receive concentrated solar flux causing at least a portion of the recycled metal to melt; and   casting the molten metal into a solid form in a solidification stage receiving molten recycled metal from the solar receiver.   
     
     
         15 . (canceled) 
     
     
         16 . The method of  claim 14  further comprising:
 shredding the provided recycled metal at a shredder input; and 
 transporting shredded recycled metal to the solar receiver input. 
 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 14  further comprising compressing the received recycled metal into a form for input into the solar receiver. 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 14  further comprising:
 storing molten recycled metal received from an output from the solar receiver in a molten metal storage system; 
 transferring heat energy in a recuperative heat transfer conduit from at least one of the solidification stage; the solar receiver outlet or the molten metal storage; and 
 pre-heating the provided recycled metal prior to input into the solar receiver using the transferred heat energy. 
 
     
     
         21 . An electrical power generation method comprising:
 providing a source of recycled metal;   heating a quantity of the recycled metal in a solar receiver configured to receive concentrated solar flux causing at least a portion of the recycled metal to melt;   exchanging heat between the molten recycled metal and a working fluid of a power generation cycle;   generating electrical power with a turbine driven by energy provided by the working fluid; and   casting the molten metal into a solid form in a solidification stage.   
     
     
         22 - 24 . (canceled) 
     
     
         25 . The method of  claim 21  further comprising compressing the received recycled metal into a form for input into the solar receiver. 
     
     
         26 . (canceled) 
     
     
         27 . The method of  claim 21  further comprising:
 storing molten recycled metal received from an output from the solar receiver in a molten metal storage system; 
 transferring heat energy in a recuperative heat transfer conduit from at least one of the solidification stage; the solar receiver outlet or the molten metal storage to a recuperative pre-heater; and 
 pre-heating the provided recycled metal in the recuperative pre-heater prior to input into the solar receiver using the transferred heat energy. 
 
     
     
         28 . The method of  claim 27  further comprising exchanging heat between the molten recycled metal and a working fluid of an electrical power generation cycle in a heat exchanger in fluid communication with at least one of the solar receiver or the molten metal storage. 
     
     
         29 . The method of  claim 28  further comprising exchanging heat in a direct contact heat exchanger providing for physical contact between the molten recycled metal and the working fluid. 
     
     
         30 . The method of  claim 29  further comprising exchanging heat in a multiple stage heat exchanger comprising at least a primary stage where heat exchange occurs between molten recycled metal and the working fluid and a solidification stage where heat exchange between the heat transfer material and the working fluid causes solidification of the molten recycled metal.