CA1216423A - Apparatus for submerging, entraining, melting and circulating metal charge in molten media - Google Patents

Abstract

METHOD AND APPARATUS FOR SUBMERGING, ENTRAINING, MELTING AND CIRCULATING METAL CHARGE IN MOLTEN MEDIA

Abstract of the Invention This invention relates to a method and a system including apparatus for submerging, entraining, melting and circulating aluminum scrap in a molten metal media, which scrap is comprised of pieces not capable of self-submergence. The apparatus of the system includes means to introduce a supply of scrap into an open bay that has heatred molten metal drawn from an entry point below the surface of the molten metal by the action of a molten metal scrap entrainment circulator submerged beneath the surface of the molten metal at a point beneath the entry point of the heated molten metal. The circulator continuously draws the heated molten metal including the scrap into the circulator wherein the scrap is completely entrained in the molten metal and delivered into a molten metal circulation path that delivers the scrap metal entrained in the molten metal for subsequent heating, further melting, and recirculation to the circulator.

Description

i2iG423 MET~OD AND APPARATUS POR SUBMERGING, ~NTRAINING I
MELTING AND CIRCULATING ~ETAI, C~ARGE I~ MOLTEN MF.DIA

Technical Field This inven~ion rela~es to an lmproved method and apparatus for submerging, entraining, fflelting and cir~ulating a metal charge in a molten media.

S Back~round ~rt The recycling of ~crap alwninum that has a high surEace to volume ratio causes the scrap to float on the ~urface of the molten alu~inum. The presence of ~crap that resists sinking has been ~che bane of aluminum recycling processors whether they b~ large or mall. The fact that l~rger ~anufacturers have unlimi~ced capital resources to invest ~n the improvement of the aluminum recycling processes has lead to increasingly sophi~tic:ated ~h~pes ~co the ~y. tems that pump ~he molten aluminum thr~ugh 'che heating ~nd allelting pha~es ~f the ,~ ii, ~Z~23 system. These systems ~ppear in drawings to be simple in a functional layout sense. Rarely mentioned is the great expense of forming from refrac~cory material the pumps which are precisely designed to cooperate with the specially contoured walls th~t surround the pump ,. impeller, or the walls ~ha~ provide a vPlute through wh ich the molten Jae~al along with ~crap is deli ver ed to the pump . The walls that ~urround and house the pump ar e made of refractory material. ~heir fabrication, formin~
and la~er maintenance represent a siynificant expense.
In respect of maintenance it ~hould be kept in mind that the shop environment in which recycling is performed is hostile, insofar as ~he rough handling of the materials charged into ~he furnaces is concerned. ~he loading and subsequent cleaning of the sys~em ~ubjeet the walls to damage. This damage may be costly to repair especially when a precisely formed wall surface in the regivn of the pump is involved. The expensive na~ure of the construction and repair just described renders these approaches unacceptable to a small recycling concern b~cause of the cost.

A pump jamming problem is not an uncommon occurrence when there is an inadvertent inclusion of non-aluminum scrap, such as ~teel, in the scrap charged into the system. The non-aluminum scrap can become lodged between a pump impeller and the cooperatin~ walls that surround the pump impeller thereby bringing the impeller ~o a stop. The walls and pump impeller are f requently damaged when ~his occurs .

Fine examples o how the art has been ~dvanced in respect of pump impeller and surrounding wall design of the type ~ust described can be found in the~patents to van Linden et al, ~o. 3,997,336 and ~o. 4,12~,415, as well as Claxton et al, No. 3,9~4,234. Each of ~hese patents recognizes and treat6 the problem of ~ubmerging ~crap that is inherently non-~elf~6ubmerging~
~dditionally these paten~s recognize and attempt ~o trea~c 'che problem of ~kim developing on the ~urface of the molten aluminum. q'he forma~ion of ~kim or dro~s, as it t ~ay be termed, in aluminum melting proces es i~ an - especially noa~iou~ problem due 'co the fact that the ~kim which i~ primarily aluminum oxide quizkly fc>rJns due to the highly reactive nature of aluminum and the atmosphere enhanced by the pre~ence of high temperatures of the ~olten metal. ~he pump impellers of each of the patents noted next above are posi~ioned in close proximity to the walls that cooperate with the pump impeller to either enhance ~he pumping ac~ion ~r quide ~he molten ~luminum carrying ~crap to ~he pump. The problems of impeller pump jamming and skim generation, though considered by the patentees noted above, has not been avoided. ~his is esp~cially true in respect of jamming when a pi ece of non-meltable material su~h as refr~ctory material having the same specific gravity as aluminum, and which therefore flows in the molten metal, is delivered to the pump portion of ~he ~ystem.
. , Disclosure of Invention More specifically this invention relates ts:~ a method and a ~ystem including apparatus for submerging, entraining, mel~ing and circulatin~ aluminum ~crap in a molten metal media, which sc:rap i~ compri~ed of pieces not s~apable of self~ubmergence. The apparatu~ of the 6ystem includes means to int~oduce a ~upply of scrap into an open bay that has heated molten me~al drawn from an entry point below the ~urface of the molten ~Detal by ~che action of a ~olten s~etal scrap entrainment circula~or ~216~3 submerqed beneath the ~ur~ace o~ the molten metal at a point beneath the entry point o~ the heated molten me~al. The circulator continuously draws the heated molten me~al including ~che scsap into the circulator wherein the ~crap i8 completely ~ntrained in the molten ,- metal and delivered in~co a molten ~etal circula~ion path that delivers the ~;crap ~etal entrained in the molten metal f or ~ub~equent heating further ~el'~ing the recirculation to the circulator.

The invention to be de~cr ibed more fully hereinafter completely eliminates the need for closely spaced walls adjacent an impeller typical of the prior art while simultaneously providing for ~crap entrainment in molten me~al ~long with a concurrent reduction of skim f ormat ion .

It is therefore a primary object of the invention to provide an inexpensive method and ~pparatus for submerging, entraining, ~elting and circulating aluminum scrap whi~h ~crap is character ized by not being c~pable of self -8 ubmer 9 enc e .

Another object of the invention i6 the provision of a molten rnetal circulator hat cooperates wi~h a molten metal media in such a fashion that ne~n-self-submerging ~crap is drawn into the molten metal media and is melted.

Yet another object of the $nvention is tc> provide a system in which there is a molten ~etal circulator that cooperates with a molten meta~ media and vertically disposed walls to thereby e~tabli~h a l~luid current path in the molten ~etal media whi~:h fluid curren~ path causes the molten metal to l:DoYe through the system, Still yet another object of 'che invelltic)n i~ to provide a furnace and mol~en metal holding bay that is simple in constructit)n and easy to clean and ~ervice.

O~her o~jec~cs and advantages of the pre~ent invention will become ~pparent from ~he ensuing 5- description and ~he illus~rative embodiment ~hereo~, in the course of whi~h, r@ference i~ made to the accompanying drawings~

Brief Description of Drawin~s Figure 1 is a block di~gram of a recirculating scrap melting ~ystem that embodies the invention, Figure 2 i~ a top plan view of the apparatus involved in the pre~erred erabodiment of the invention~

Figur~ 3 is an elevational æection ~aken along line 3-3 in Yigure 2, .. Figure 4 i8 a view along lines 4-4 in Figure 2, Figure 5 is a three dimensional view of a molten metal, ~crap entrainment circulator, ~igure 6 is a view along 1{ ne 6-6 in Figure 5, Figure 7 is a tc~p pl~n view of a furnace, holding 2û bay and molten media circulator ~ystem that embc:>dies the invention, Figure 8 i~ a vi~w ~long line 8 8 in Figu e 7, ~nd Figure 9 i5 a view along line 9-9 in ~igure 7~

4~3 Best ~ode or Carryin~ Out the Invention Reference is n~w made to ~igure 1 which depicts in block diagram form, a recirculatin~ scrap melting 6ystem . ~hat will embody the invention. ~he appara~us of the system includes a clo6ed hea~ing bay 11 ~nd an open bay 12. In the open bay 12 ~crap ~nd flux are introduced. A
scrap entrainment mol~en me~al circulator described more fully hereinaf ~er positioned in the open bay 12 causes molten metal to circulate from the closed hea~ing bay 11 into the open b~y 12 as indicated by flow arrow 13. The molten metal is then airculated into the closed heating bay 11 as indicated by flow arrow 14. Scrap and flux are introduced at one end of the open bay 12 as indicated by flow arrow 16 and ~kim or dross is removed frvm the }5 opposite end of 'che open bay 12 as indicated by flow arr~w 17. ~he final product of the systems apparatus is skim free molten aluminum delivered rom the closed heating bay 11 as indic:ated by flow ~rr~w 15.

Reference i~ now made to Figure 2 and Figu~e 3 which illustrate r~spectively a top plan view and a front elevation ~ectional view ~howing the details of the pref erred embodiment of the invention.

The descr iption ~hat follows will descr ibed the apparatus of both Figure 2 ~nd Fiyure 3 at the same time. In Figure 2 there is ~hown a closed heating bay 11 an~ an open bay 12. The closed heating bay ~nd its details of constru~ion are conventional in the ~ense tha~ a cover 18 is positioned over the clo~ed heating bay 11. The ~losed hea~ing bay 11 and open bay 12 ~re ~onstruc~d of refractory ~aterial. A~ best ~en in ~i~ure 3, the refra~tory ~aterial i. ~nclosed by a me~al ~hell 19. The me~al ~hell 19 i~ preferably s~eel.

pair of burners 21, 21a are shown directed downwardly into the heating bay 11. The nature and function of the burner~ 21, 21a is imilar to burners curren~ly used by industry. Only two burners are ~hown. It ~hould be underst~od that the arrangement Gf burners and their number are a ma~ter of design dependent on the type of burner available and the nature of the fuel employed in the combustion proces~. The open and closed bays 11, 1 are ~hown filled with a molten metal media 20~ in the preferred embodimen~ the molten me~al i~ aluminum.

The open bay 12 is provided with a wall segment 22 formed of refractory material and integrally connected to a ~eparating wall 23 that extends the length of both ~he closed heating bay 11 and the ~pen bay 12~ The open bay 1~ has end walls 24, 26 and front wall 27. The closed heating bay 11 has a back wall 28.

The separating wall 23 has two openin~s 29, 31.
The location of separating wall 23 openings 29, 31 are important to ~he operation of the ~ystem apparatus and the me'chod involving the invention. A molten metal scrap - entrainment circulator 32 is connected by a drive shaf~
33 to a motor 34. ~he motor 34 may be an electric or any suitable motor the speed of which can be ~el~cted~ I~
can be seen that the circulator 32 is positioned midway between the wall segment 22 and end wall 26~ The opening 31 iB al~o positioned midway between the wall segment 22 and end wall 26 at ~ point ~bove the circulator 32 but beneath the surfac~ 35 of the mol~en metal media 20. The relative locations, B~ 6hown, of the circulat~r 32 ~ the op~ning 31 ~nd wall ~egment ~2, provide op~imum performance for the ~ethod of the invention. The circulator 32 driven by mot~r 34 crea~es a ~luid current path of molten metal. This molten metal path indicated by ~rrows no~ referenced draw~ molten metal ~hrough the ~Z~23 opening 31 and e:irculates ~he molten metal through the opeil bay 12 and thence ~hrough s:~pening 29 and back into the closed heating bay 11. Though not ~hs:~wn in ~he drawings it ~hould be understood that there i5 little or S no skim on ~he ~urface of the ~olten m~ter ial in the ,- heating bay 18. There is of cour~e a very ~hin layer of o~ide skin that is present on the ~urface o the molten material of the heating bay. ~t ~hould be noted that all the walls of the heating and open bay are ~imple straight, vertically disposed walls which are easily and inexpensively formed of refractory material. The ~erm inexpensive i5 intended to be a relative term which takes ~nto account more sophisticated wall shapes of currently available scrap recycling systems noted earlier. The dynamic operation of the molten metal s~rap entrainment ~irculator 32 will be explained more fully h~reinafter.
The opening 29 in ~eparating wall 23 is located uch that its lower side (not referenced~ is flush with the floor 36 of the closed bay 11 ~nd open bay 12. The location of the opening 29 is important from the ~tandpoint that large and readily ~ubmersible ~crap 37 sinks to ~he bottom of the open bay, is caught up in molten metal fluid current path generated by the circula~or 32, and - can be deliver~d to the closed heating bay 11 where the large pieces are melted. Practically speaking the submersible ~crap 37 sinks to the bottom where much of it is melted in the position in which i~ comes to rest.

In Figure 3 it can readily be ~een that ~crap is introduced ~o the open bay 12 at either end by ~onveyors 38, 39. The ~crap 37 on conveyor 38 as already noted is of the larger type that is ~elf-~ubmerging because o~ its weight and shape.

The conveyor 39, ~owever, carries ~crap 41 that has by it~ nature a high ~urface area ~o volume ratio and ~2~6~2;~

therefore tends no'c to be ~e~f-~ubmerRible. Shredded aluminum cans or entire cans, as well as ~mall chips collected from manufacturin~ operations are typical of non-self-~ubmersible ~crap.

Non-~elf-submersible ~rap in order to be drawn into the mol~en metal 20 must overoome the ~urface tension of ~he layer of ~kim 40 tha~ forms on molten metal 20. The non-~elf-submersible ~crap 41 is introduced as shown into a mild vor~ex 4~ created by the circulator 3~. A ~evere vortex is ~o be avoided because the severe vortex while drawin~ the non-self-~ubmersible scrap into the molten ~etal also draws the ~urrounding atmosphere into the vortex thereby greatly enhancing the formation of skim which i~ a very unde~irable lS by-product. The mild vortex 42 coopera~es with ~he mc>lten metal drawn through the opening 31 to thereby ~ubmerge the non-self-subm~rging ~crap 41 in~o the molten metal 20. The circulator by it dynamic action to be described completely entrains the ~crap 41 in ~che molten me'cal 20 where ~he scrap begins to be melted. The circulator 32 delivers mol~en metal with scrap entrained into a fluid current path. The scrap i~ then melted by heat drawn from 'che flowing molten metal media during ~he passage ~hrough the open bay 12 and thus becomes part of ~he circulating ~olten media.

The closed heating bay 11 has in its back wall 28 an opening 30 through which kim free molten aluminum is delivered. In Figure 3 it can be ~een that the opening 30 in back wall 28 i~ lo~ated at a point benea~h ~he ~urface of the ~olten metal 20 ~uch that any ~kim that is present in ~he ~losed he~ting bay 12 does n~t enter ~hP
inished ~ol~en metal 15r The fini~hed ~olten ~e~al 15 overflow~ the heating bay 11 through the ~pecially configured pa~sage 30 ~t a rate ~ub~t~ntially ~.Z~6~'~3 comsnensurate with the xate of introduction of solid ~crap to the open bay 12.

The removal of ~kim and ~he introduction of a fluxing agent to the ~ystem can be~t be ~een in and understood by a study of Figure 3. Flux cUpply 44 is ~hown delivering a fluxing ag*nt in~o ~he mild vortex 42 as shown, Skim removal is accomplished as ~hown in Fiqure 3 by the provision of a ramped ~haped top surface 25 at the top of end wall 24. As ~klm 40 forms and is moved by the action of the moving molten met~l 20, it tends to build up on the ramp 25 where it may be removed manually or by an automated meaDs not shown.

Reference is now made to Figure 4 wherein reference numeral~ e~ploy~d in respect of Figure 1 and Figure 3 ~re utilized to idencify the same componen~s. Th~ mol~en metal ~crap en~rainment circulator 32 is ~hown in ~ection in order to facilitate an explanation vf the dynamics of i~s operation insofar ~s the circulator 32 acts upvn the 20 ' ~olten me'cal 20 tc> draw molten metal from ~he closed heating bay 11 through the opening 31 and into a central region 50 of the circulator 32. The fluid current path of molten metal from the closed heating bay 11 is ~hown by broken line arrows 51, 52.

Non-self -submersible ~crap 41 shown entering from above into the mild vortex 42 i~ caught in the curren~
flow and drawn down into 'che central opening 50 of the circulator 32 where 'che ~crap i~ completely en~rained in ~he moving ~ol ten metal . The ci rculator 32 has v~nes 53, 54 connected at an inner end to a frusto ~onic~l hub 56 shown in ~ tion. l'he scr~p 41 entrained in mol'cen me~al i~ propell~d outwardly along the vane~. The details of ~2~6~3 ~he s:irculator 32 and its ~pecific operation will be explained more fully in respect o the description of Figure 5 an~ Figure 6.

Reference is now made to Figure 5 which illustrates 5,- in three dim~nsional form 'che molten metal ~rap entrainment circulator 32. The circulator 32 i~ formed of refrac~ory material and con~ruc~ed by eonventisnal techniques. ~he circulator has what s~ay be termed a bottom plate 45 and a top plate 46~ The top and bottom plates 45, 46 are ~paced part ~s ~hown and have integrally secured thereto a plurality of radially extending vanes 53, $4~ 55, 56, 57 and 58. A frusto conical shaped hub 47 i8 integrally secured to the bottom plate 45 at the center ~hereof. The frusto conical hub 47 has a drive shaft 33 fitted into the hub 47 in a manner not ~hown. The height of the hub 47 is less than ~he distance between the top and bot~4m plates 46, 45.
The vanes 53, 54, 55~ 56, 57 and 58 ~t their inner radial ends are integrally secured to hub 47 at a point on the hub 47 outer surface between 'che top and bottom of the frusto conical hub as shown. The bottom radially extending edges of the vanes are æecured to the bottom . pla~e 45 and ~he outer ends of 'che vanes are secured to the ~op plate 46 as shown. ~he top plate 46 has a central circular opening 48, which circular s>penirlg 48 has a center axis coincident with ~he center axis of the drive ~haf ~ 33 . Tt i8 important to ~he operation of the circulator 32 that in~ide di~meter of the central circular opening 48 be greater than the outside diameter of lthe base of the fru~to conical hub 47~, The downwardly sloping sides 59, 60, 61" 62, 63 and 64 of the vanes S3, 54, 55, 56, 57 and SB in cooperation with the fru;to conical hub 47, the t:Qp ~nd bo'ctom plat~s 46, 45, ac~ to cr~ate broad region Qf suction (shown in do~ted ou~line) extending above and around the ~irculator 3~ trong ~L2~L6~3 fluid flow curren~ path a~ ~hown by arrow 6B draws molten metal delivered fr~m the heating bay 11 as described earlier along with non-~elf-~ubmer~ible scrap down into the circulator 32 where the scrap i~ completely entrained and then expelled outwardly tow~rds the ~urrounding walls ~- of the open bay 12 ~oted earlier.

Returning now to ~igure 2, it can be ~een that the outward radial flow as evidenced by ~rrows 65, 66, 67, 68, 69 and 70 because of the clockwise rotation of the circulator 32 cause a build-up of pressure against the side 71 of wall segment 22, the ~eparating wall 23, end wall 2~ and front wall 27. The only relief for this pressure i5 through the opening defined between ~he end 72 of wall ~egment 22 and front wall 27. It is the constant release of this pressure that establishes the strong fluid current flow path through the molten metal media that delivers entrained ~crap and molten metal through the open bay 12, and then delivers the mol~en metal product re~ulting from the combination of freshly melted scrap and the surrounding molten me~al through the openin~ 29, the closed heating bay 11 and ~hence to the ....... opening 31 where the circulator 32 draws the molten metal into the circulator to begin ~he cycle anew. It is important to note that the circulator 32 is spaced away ~S from the walls that ~urround it ~hereby preventing any large pieces of non-melt~ble scrap from becoming jammed between the circulator 32 and the walls. The possibility of damage to the circula~or ~nd walls from this type of jammin~ is therefore removed.

Reference i~ now ~de to Figure 6 which illustr~tes the circulator 32 of Figure S ~n section~ As has been noted earlier, there i~ ~n ever present pos~ibili~y that non-melt~ble ~cr~p or even pieces of refractory material may enter the molten ~etal media ~na thereafter come i~

c:ontact with whatever means is provided tc> move the ~olten metal through the ~ys~em. In Figure 6 ~chere is shc~wn a foreign object 73 lodged in the central region or Gpening 50. It is a simple pr~cedure to remove the object 73 by merely lifting the circulator 32 momentarily from ~he molten metal, after stopping the ~otor, and with tongs removing the object 73. In the event that ~chis f oreign obj ect does not enter the cen~cer c~pening, but strike the top plate 46, the object would fall harmlessly between the circulator 32 and the ~paced away walls in the vicinity of the circulator 32. It should be further noted that the circulator 32 of ~igure 6 has formed in the bottom plate 45 thereof a grooved or notched portion 47a as shown. ThiS groove 47a prevents cracking due to curing rate differences in different sections of ~he refractory casting of the ~irculator 32.

The 6ection of Fisure 6 allows a clear showing of mol~en metal fl~id current paths 74a, 74b, 74c through the circulator 32.

Reference is now made to Figure 7 which illustrates - in a top plan view a furnace, holding bay and molten media circulator ~ystem that embodies thi~ invention.
The description up to thi~ point has treated primarily the cooperative relationship of the molten metal or media circulator and the manner in which the circulator advantageously func~ion6 to en~rain and mel~ scrap~
Figures 7~ 8 and 9 provide a detailed ~howing of additional features of the ~nvention as the invention ~inds utili~y in a complete ~ys~em.

More specifically here i6 shown a closed heating bay 75 and a ~108ed holding bay 85. The heating bay 75 and holding bay 85 are formed in a common 6:hamber defined by a front wall 76, a back wall 77, a cover 7~, a first end 79, a ~ecor~d end 80 and finally a floor 81. The cover 78 i~ not ~hown in Figure 7. A dividing wall 82 Geparate~ a heating region in the heating bay 75 from a holding regi~n in the holding bay 85~ The dividing wall 82 has a number sf pa~sages 83, 84, 86 ~nd 87 whi~h t~ prc>vide for eo3mnunication between ~he heat;ng bay 75 and the holding bay 85 .

As best ~een in Figure 7, passages ~3 and 84 allow molten media (not ~hown) to pass freely from the hea~ing bay 75 to the holding bay 85. As ~hown in Figures 7 and B, passages 86a, 86 and 87 allow combustion gases from the oil or gas treaters 88, 89 to move freely over the surface of the molten media from the heating bay 75 to the holding bay 85. The combustic~n or flue gases as ~hey are terme~ are vented through a ~ack 91 In the heating bay 75 there i5 provided a clean-out ramp 92 which terminates at its upper end with a clo~ure in the form of a guillotine door 93. The holding bay 85 also has a clean-out ramp 94 and guillotine door 95~

2û Fron~ wall 76 has openings 96, 97 ~hrough which molten media i~ circulated by molten media circulator 98 here shown ~ch~ma'cically. The ~:ircula~cor 9~ is shown positioned in an open bay lOn. The open bay 100 has skim ramp 101 and wall ~ction 102 as ~hown~

A tapping ~pout 105 for molten metal or media is provided a~ ~hown in Figure 7. The ~apping spout 105 is 6hown p~sitioned ~uch that ~ mold train 106 carried by rails 107, 108 can carry th~ molten metal or media away f or ~ubseguent proces~ing ,. ~ h~ating bay and c~pen bay dra~n spollt 109 i~ po~itioned a~ ~hownu Skim par:s 110, 111, 112 ~re ~hos~n c~rried by rai~s 113, 114.

The location o~ guillotine door 93 is important ~o the invention in ~hat when this door g3 i~ opened, ready access ~an be had to ~ervice opening 96, 97, as well as . passages 83, B4, 86 and 87.

In view of the above descripti~n it ~hould be abundantly clear that the ~ys~em and apparatus, as well as the method of the systems operation provides a distinct improvement over the ~tate of the art, in a manner that is simple and less expensive than heretofore available.

Although a single embcdiment of the present inventi~n has been illustrated and descri~ed, it will be apparent to those skilled in the art that various changes and modifications may be made to this embodimen~ without departing from the spirit and ~cope of ~he invention.

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A recirculating melting system for submerging and entraining a charge in a molten melting media wherein said charge comprises pieces not capable of self-submergence, said system including in combination, a closed heating bay, and an open charging bay, said molten melting media filling said bay to a predetermined level, wall means separating said closed heating bay from said open charging bay, said wall means having integral therewith a wall segment extending into said open charging bay, said wall means further having two openings through said wall means, such that said openings are always beneath the surface of said molten melting media, one of said openings on either side of said wall segment, a molten media circulator submerged in said molten melting media and positioned to one side of said wall segment and at a point beneath one of said openings in said wall means, means to introduce said charge into said open bay in the vicinity of said submerged molten media circula-tor to thereby initiate melting of said charge in said molten melting media,
1. Claim 1 continued...
   said molten media circulator acting upon said molten melting media to circulate said molten melting media from said closed heating bay into said open charging bay by drawing molten media from said closed heating bay through said opening in said wall in the immediate vicinity of said molten media circulator, said initial scrap melting and drawing of said molten melting media being induced directly by said molten media circulator, said molten media circulator having a spaced apart bottom plate and top plate, said top plate having a circular opening centrally disposed therein, said bottom plate having centrally disposed a frusto conical hub integrally secured thereto at its base, said frusto conical hub having a central axis coincident with the center axis of said top plate circular opening, said hub having a drive shaft secured thereto; radially extending vanes secured to said hub and along the entire radial length thereof to said bottom plate, said top plate central circular opening having an inside diameter greater than that of said frusto conical hub, said vanes secured at the ends thereof to said top plate; rotation of said drive shaft creating by the cooperation of said molten melting media with said circulator vanes, frusto conical hub top and bottom plate, a mild vortex in said molten melting media to thereby entrain said charge in said molten melting media and deliver entrained charge into and through said central opening in said top plate and thence through the space between said plates whereupon a fluid current path is created in said molten melting media which draws said molten melting media from said closed heating bay through said wall opening adjacent said circulator and into said open charging bay and thereafter from said open charging bay through said opening remote from said molten metal circulator to said closed heating bay.
2. 2. The recirculating scrap melting system of Claim 1 wherein said charge is scrap, which scrap is comprised of aluminous cans, can portions, saw chips or punchings.
3. 3. The recirculating scrap melting system of Claim 1 wherein the wall opening remote from said molten media circulator is located such that the bottom of said opening is at a point lower than said molten media circulator and the top of said opening is at a point beneath the surface of said molten melting media.
4. 4. The combination of Claim 1 which further includes means to introduce a fluxing agent into said open bay along with said charge in close proximity to said molten media circulator.
5. 5. The combination of Claim 1 which further includes means to continuously remove molten media from said current path at a rate approximating the rate of introduction of said scrap.
6. 6. The combination of Claim 1 which further includes means to facilitate the removal of skim from the surface of the molten melting media above the molten media current path prior to reheating in said closed bay.
7. 7. A furnace and holding device for a molten media including in combination, a common chamber, said common chamber separated into a heating region and a holding region by a dividing wall, said common chamber having a first and second end, a front wall and a back wall, said dividing wall extending between said front wall and said back wall and having passages therein to thereby simultaneously allow physical movement of molten media between said heating region and said holding region as well as movement of heated atmosphere above said molten media between said heating region and said holding region, molten media circulating means integral with said front wall and adjacent said heating region, said front wall having at least two openings in communication with said molten media circulating means, a closure means positioned in a vertical plane that intersects said first end and said back wall such that when said closure means is open, direct access to said passages and said openings is readily attainable to thereby facilitate the servicing of said passages and said openings, heating means disposed in said heating and holding regions, and means venting said common chamber at a point above the molten media, molten media tapping means in communication with said holding region.