US2224081A - Melting pot - Google Patents

Description

A. H. JUNG Dec. 3, 1940.

MELTING POT Filed April 28. 1939 3 Sheets-Sheet l maar Afm@ A. H. JUNG Dec. 3, 1940.

MELTING POT I3 Sheets-Sheet 2 Filed April 28.' 1939.

' A. H. JUNG Dec. 3, 1940.

MELTING `POT Filed April 28, 1939 3 Sheets-Sheet 3 Patented Dec. 3, 1940 Albert n. Jung, Flushing, N. Y., assignor to United American Metals Corporation, Brooklyn, N. Y.,

a corporation of New York Application April 28, 1939, Serial No. 270,634

7 Claims.

Thisinvention relates to melting pots and more particularly to melting pots capable of supplying molten `metal rapidly and economicallyto facilitate `the casting of relatively large quantities 5 thereoi'.4

Priortto the instant invention, melting pots have hadtheirburnersmor heating elements so associated therewith as to maintain the temperature of the molten metal at a level generally corresponding to the casting temperature and when relatively large -quantities of molten metal are cast, a measurable` period of time must elapse before `additional solid metal may be `melted or fed to the pot and its state changed from a solid to u liquid, before additional metal may be used for casting. 'I'his necessarytime delay associated with prior `constructions has been found to be costly as the labor and overhead which must be charged to each casting is proportional to the 20 time involved in the fabrication of each casting.

Other prior constructions havelbeen designed to melt metal relatively rapidly" but such constructions have been relatively large and necessarily costly and further by reason `of their size Other objects and the nature and advantages 35 of the invention will be apparent from the iol-l lowing description taken in conjunction with the` accompanying drawings, wherein:

Fig. 1 is a vertical section of a melting pot/*in A p accordance with the invention;

Fig.2 is a top plan view of the embodiment of` [the invention illustrated in Fig. 1, depicting the metal ingot being fed to the melting bath in section; Y

Fig. 3 is a sectional view taken along line 3-3 45 of Figi;

Fig. 4"is a fragmentary sectional view illustrating the flue and its association with the furnace walls; and

Fig. 5 is a view similar to Fig. 1 but of a modi- 50 fied forni of the invention;

Referring to the drawings the furnace IU comprises a refractory lining II and a cap I2 of material `which may or `may not be of refractory lsubstance but should be capable of withstanding u high temperature. The Acombined melting pot I3 have been wasteful of fuel especially during those may be supported on this cap I2 by the integral flange vI4 associated with the recess I5 and the cap I2. I n

-The combined melting pot I3 may include ,the relatively small capacity, but deep, high tem- .5 perature cavity I6 and a relatively large capacity but shallow serving cavity Il. The two cavities may be connected by the relatively small diameter integrally formed passage I 8 which may be controlled-by the adjustable restrictior element I9 lo associated with its support in screw-threaded relation whereby it may be raised or lowered to effectincrease or decrease oftrestriction of the passage I8.` l5

A heating element 2| is associated with the exterior of the `relatively high temperature cavity I6 of the pot I3 and is depicted in Fig. 1 as being located directly therebelow. Depending from the under side of the top wall of the pot I3 there is located between the cavity I6 and the cavity Il 2 a baffle member 22 cooperating with the'remain-` I ing structure to prevent the direct passage of all the relativelyhot gases emanatingirom the burner 2l to the exterior of the cavity I1.

Though the bafnezz extends from the top wall t of the pot, I3 completely about the connecting passage I8 and depends therefrom, it does not contact` the `refractory lining Ilbut is spaced therefrom on three sides; namely, the.l bottom side 23, see Fig. 1, the side 24, and side 25, see

`Fig. 2, to permit a predetermined proportion of the gases to flow about vthe exterior of the cavity I1 andV convey heat tothe molten metal therewithin. 'I'hat portion of the refractory lining which is `adjacent to the cavity Il is built up to provide a predetermined hot gas passage size thereabout.

' The 'gasburner--H is supplied with fuel through thepipe 26 which is controlled by electro-magnetic valve 2l which in turn receives its energy 40 from the source of current 28 when the switch 29 is in a closed position. The switch 29 is in turn controlled by the thermo-couple 30 which through relay 3| affects the operation ofv the same. The meter 32 mounted on the `panel 33 45 may visibly register the vtemperature of the molten metal in the bath 34 within the cavity Il and about the thermo-couple 30.

As'the high temperature molten bath 35 communicates with the relatively low temperature molten bath 34 'through the passage I8, under static conditionsor substantially static condition, thev level within the cavity lI6 and Il will be substantially the same. As metal 'is removed from the serving cavity I1 the level therein willdrop 55 y'ns and the level within the cavity I6 will also drop. Associated with the high temperature bath and directly above the cavity I6 is an ingot feeding mechanism 36 comprising a float 31 secured to the mechanism by chain 38. When the level within the molten bath 35 is lowered, the float 31 drops, pulling chain 3,8 and releasing the feeding mechanism 36 to lower the feed hook h to which is attached the ingot 39 which may be of any suitable typebut is depicted as being an automatic slip-off ingot. Lowering of the ingot 39 within the molten bath 35 effects the melting thereof and the replenishment of the molten bath to raise its level and effect a corresponding raising of the float 31 which slacks the chain 38 to cause cessation of operation of the feeder mech` anism 36 until the level of molten metal is again owered, at which time the cycle above described s repeated.

As the cavity I1 is much larger than the cavity 6, see Fig. 2, the lowering of the level of' the ormer requires the melting of a considerable amount of `metal to effect its replenishment. To melt the necessary amount of metal rapidly, the rnolten bath 35 is maintained at a higher temperature than the molten bath 34, which latter temperature may be generally corresponding to the casting temperature. For example, if the castingtemperatureis approximately 700 F., the temperature of the molten bath 34 may be maintained at that temperature whereas the temperature of the molten bath 35 may be permitted t0 reach 900 F. or even more. As the communi- :ating passage lv'connects the high temperature bath 35 with the bottom of the lower temperature bath 34, the relatively high temperature molten metal passing to the molten bath 34 must diffuse upwardly and therethrough and thereby prevent undue rising of temperature in any one portion of the molten bath 34.

Should the temperature of the molten bath tend to rise above a predetermined level of, for example, 2700 F., the thermo-couple 30 will cause the relay 3| tol close the switch 29 and permit electric currentA to flow from the source 28 to the electro-magnetic valve 21 to effect closing the fuel line 26 and cause cessation of operation of the burner 2| whereupon the temperature of.

the molten bath 35 will drop somewhat, whereby metal passing to the molten bath 34 through the communicating passage I8 will not transfer a maximum of heat to the bath 34 and further, there will be no ue gases about the exterior of the cavity I1 to transfer heat to the molten bath 34. When the bath 34 requires additional heat to maintain the ltemperature at the predetermined level which may be '700 F., the thermocouple 30 will be so actuated as to generate sufcient current to hold the switch 29 down against the action of the spring 3 I whereupon theV switch 29 will open and break the ilow of current from the Asource 28 to the electro-magnetic valve 21V permitting the latter to fall open whereupon the fuel will pass through the line 26 and will be ignited by pilot 40. Flue gases from the burner 2| pass in intimate contact with lthe exterior of the cavity I6` to maintain the temperature of the molten bath 36 substantially above that of the molten bath 34 and then passes about the baffle 22`along its sides 23, 24 and 25 to about the exterior of the cavity I1 and thence out the flue 4I. The flue 4| is arranged on the exterior of the furnace I0 but relatively` remote from the front 42 where the operator may stand and ladle molten metal from the cavity I1 as desired,

Not only is the construction of the melting pot I3 and the furnace I0 such as to effect a higher temperature within the molten bath 35 than within the molten bath 34, in order to permit rapid casting without depleting the available molten metal, by effecting the rapid melting of the ingot'by feeding it to the high temperature bath, but the adjusting element I9 is so aligned in association with the passage I8 as to slow down the lowering of the level within the molten bath 35 even though thevflevel within the molten bath 34 is iowered rapidly corresponding to rapid casting. This control of flow from the molten bath 35 to the molten bath 34 permits a relatively high level of hot metal within the bath 35 to be maintained effecting rapid melting of ingot 39 and the molten metal will be replenished before the level therein has opportunity to be considerably lowered.

It will be understood from the above description that applicant has provided a melting pot system which may be relatively small in size but high in capacity and simultaneously economical of fuel whereby casting, or utilization of the molten metal produced, may be effectedrapidly. without interruption of the rapid melting of the metal in proportions corresponding to the metal used to eflciently utilize the heat energy operating to the device.

While the heating element associated with the metal furnace I0 has been described as a gas burner, it isv to be undertsood that other heating elements may be incorporated'in the furnace construction such as for example an electric heater.` When an electric heater is utilized in place of the burner 2 I, the control thereof is somewhat simpler as the electro-magnetic valve 21 may be eliminated,`the source of current 28 directly associated with the electric heater, and the control of the source eifected by the switch 29 which is in turn controlled by the thermo-couple 30.

In certain casting processes in the field where an apparatus in accordance with the instant invention is utilized; it is essential that an additional burner be utilized in connection with the low temperature compartment of the two compartment melting pot. For example, where the casting operations take place intermittently with relatively long periods of time eiapsing between successive casting operations-the low temperature compartment may not receive enough heat" I compartment may not receive enough heat, `or

if it does by reason of the fact that the thermocouple will make the single burner operate as long as the low temperature compartment does not have enough heat, the system willloperate inefciently. Accordingly, see Fig. 5, an additional burner |00 is provided in association with the cavity I1 and located within a well IOI within the refractory material II and directly below the cavity I1.

The burner 2| is located below the cavity I6 in the same manner as'that illustrated in Fig. l and serves to heat the molten metal within the said cavity. The pilot 40 cooperates with the burner 2| andthe pilot |02 cooperates with c temperature within thelmolten bath I4, in..this u embodimentcf theinventionfit is controlledby i i respectively. The masterV switch the source of current lC and thev individual ,v

ao` ma the thermo-,couple T loatedrwithin `the molten bath andthe temperature of the'molten bath `34 is controlled bygthe thermo-couple T'. The thermo-couples T and Tserve to control the switches S and S through the medium of electro-magnets E and E', respectively. A source of current C serves to supply energy necessary to operate `electro-magnetic valves 21 and` |03, IM controls switches 105 Vand |08 serve to operate the individual temperature control circuits ill'i and |08, respectively. `The remaining equipment and apparatus in this embodiment to the invention is similar to `that described in connection with Figs. 1, 2 and 3.

`In operation, the molten baths 34 and 35 are intained within the same temperature ranges as `described `in connection with the iirst ernbodiment o1' the invention, but the Vcontrol is s effected by a thermo-couple associated with` each cavity and in those instances in which such abnormal operationsr occur 'as to involve long f' periods of time between successive casting operations, satisfactory eillciency will nevertheless result, the individualvmolten baths in the multi-V ple compartment, melting pot being maintained inthe proper temperatures and the fuel consumption being relatively low,

Itwill be` obvious to those skilled in the art that various changes may bermade in this devvice without departing from thespirit of the invention `and therefore the invention is not limited to what is shown in the ,drawings and described in'the specification but,` only as Vindicated inthe appended claims.' i

What is` claimed is:

`1v. A melting and molten metal storage apparatus comprising: a furnace having a refractory lining, `a heating element in said furnace. a` shell adapted to hold molten metal supported by said furnace. said `shell including a pair of cavities. the first of lWhichiis located "directly above said heating element and the second of which is located in the path of ilowloffhot gases from said heating element whereby it may be heated in- ,directly by said heating element, and means for 60 controlling said heating element in response to the temperature ofnmolten` metal within said second cavity, said rst cavity being adapted to have solid metal fed thereto and melted therein, and restricted passage means i communicating 65 Vsaid cavities.

2. A melting pot comprising a `relatively high temperature bath adaptedto have solid metal fed thereto and melted therein.` and a relatively` low temperature bath adapted to have molten 70 metal withdrawn therefrom, means for heating the relatively high temperature bath, means for passing molten metal from said' high tempera ture bath into the bottom of the relatively low temperature bath whereby the hot molten metal 75 in said high temperature bath may serve to molten metal withdrawn 4ed within said lining,

transfer heat to said low-temperature bath, and control means for Vsaid heating means responsive Y to the temperature oi' said low temperature bath.

l compartment melting. pot includ- 'j ing `a relatively deep cavityaoi' small horizontal 1 section adaptedV to` have solid 3. A plural metal-lied thereto and melted therein, and a ity of great horizontal section'adapted to have therefrom; heating means `directly associated with said deep cavity relatively shallow cavand indirectly associated with said shallow cavity,` means for passing molten metal'from said deep cavity into the bottom of saidshallow cav- 4. The structure recited in claim l, and means for adjustably restricting said passage means communicating said cavities. .f

5. A combined furnace and melting pot comprising a refractory lining, said refractory lining including a relatively small well, a burner in said well, a pair of molten bath cavities suspendthe first of said cavities being relatively small in horizontal section and located directly above said burner, the second of said cavities being located in a vertical plane distinct from said ilrst cavity and said burner, means for passing molten material from said first cavltyinto the bottom of said second cavity, baille means located between said two cavities and extending about said molten material passing means toward said refractory lining but being spaced therefrom to provide a restricted hot gas passage whereby hot gases from said burner may not only serve to heat said ilrst cavity but they may also heat said second cavity, means responsive to the temperature within said second cavity for controlling said heating element, and means responsive to the level of molten liquid in said first cavity for feeding solid metal thereto.

6. A metal melting apparatus comprising a plural compartment melting pot, a rst of said compartments being relatively deep but small in horizontal section. a second oi' said compartments being relatively shallow and large in horizontal section, means for passing molten material from said first deep compartment into the bottom of said second shallow compartment,`

means for restricting said passing means, `a heat-` ing element located directly below said deep compartment for supplying a `relatively great amount of heat thereto, restricting baflie means between said two `compartments and in association with said heating element whereby most of the heat emanating from said heating element will be transmitted to said deep compartment, but some of said heat will be transmitted to said shallow compartment. said baille means and said heat element tending to maintain the temperature of said deep compartment higher than the temper-v of small horizontal section and a second of said compartments being-relatively shallow but of large horizontal section, said first compartment being located substantially directly above said heating element, said rst compartment being generally circular in horizontal section and said second -compartment being generally kidney shape in horizontal section, `means for passing molten material from an intermediate portion of said deep compartment into the bottom of said shallow compartment, baiile beans depending from the under side of the top of said melting pot extending-about said communicating means on all sides and generally between said two com- Y partments in spaced relation thereto and vfur-- vther extending toward said refractory lining `'but spaced from said lining whereby said deep cavity will be in direct heat exchange relation with said heating element and said shallow cavity will receive heat from said heating element indirectly from hot' gasespassing'rom the heating element perature range, and' means for feedingsolid metal to said deepcompartmentfin accordance with the level of, molten'liquid therein.

- ALBET H. JUNG.

Images