US1698624A - Casting method and apparatus - Google Patents

Description

Jan. 8, 1929.

' R. B. DALE CASTING METHOD AND APPARATUS Filed Nov. 12, 1924 l l l I l I l INVENTOR fi fiurdxtte IDs/Le Arm/Mrs Patented a... s, 1929.

Y 1,698,624; UNITED STATES P T N oFF-ICEZ.

ROBERT BURDETT E DALE, OF JAMAICA, NEW YORK, ASSIGNOR TO WILLIAM W. WEITLING,,TRUSTEE, OF COLLEGE POINT, LONG ISLAND, NEW YORK.

cnscrmo METHOD A m APPARATUS.

Application filed November 12, 1924. Serial No. 749,476.

This invention relates to the art of casting metals, especially ferrous metals, as iron and even steel; the invention being highly advantageous even in the art of casting by the rotary or so-called centrifugal method.

The present invention has also as an object, in the latter connection, to provide an improved method, and apparatus for facilitating said method and to render the latter particularly valuable for the making of cast iron pipe or "other elongated generally cylindrical articles in permanent/'01 rotary molds of metal,although of course the invention is seen to be of value in rotary casting whatever be the material or character of the moldand whatever the nature and shape of the cast article.

The prime object of the invention is to provide a method of supervising the ultimate qualities of the cast articles, and a method characterized by the employment of a vaporous medium in heat-transfer relation to the mold during the pouring of the charge and its cooling to form a casting,

the casting and during the period'starting with such extraction and ending with the pouring of a second charge. A vaporous mediumhas been heretofore proposed in this art, to wit, an aqueous vapor (steam).

But steam has a con'iparatively low vaporization temperature; and it has been ascertained that to employ steam at high enough temperatures to heat the mold to the minirapid congelation and cooling of the charge, and incidentally too great changes of temperature of the mold, the pressures at which the steam must be at times maintained are so high as not to permit an economical and practical structural design for the mold and particularly for the steam chamber associated therewith. It has been calculated that, where steam is used, the confining walls for holding the steam, .and' the joints between such walls, must be capable at times of withstandinga pressure of approximately 2,000 pounds per square incl.

According to the present invention, however, the object thereof beinghere con.-. sidered is perfectly attainedby the use of a non-aqueous vapor, and preferably, by the use of a metallic vapor, which may be maintained at a very high temperature but and also preferably, during extraction of mum temperature required to defeat too,

. at a comparatively low pressure, duetothe very much higher than that of Water. As the problem faced is now understood, the

metallic vapor to be employed is mercury vapor, diphenyl oxide or some other material capable of passing into 'the vaporous state at high temperatures as compared to steam.

Further, the invention is adapted to attain various. other" objects, which will be clearly understood from the hereinbelow disclosure of a preferred method'of carrying out .the invention. Some of such olo-- jects may be briefly mentioned, as follows:

Another object is to provide an exceedingly simple casting machine, and one particularly wherein the mold even if a rotary one, will be rugged and long lived; and a machine adapted to be easily subjected'to the vaporous medium proposed by the present invention. 4

Another object is to provide a casting maand low pressures chine wherein the congelation and cooling of the casting may be supervised by the use of a vaporous medium which may be increased or decreased in quantity by mow ments of portions of the vapor toward and away from the mold, that is, into and out. of the machine, by way of a single combined inlet and oulet; whereby in operation such inlet and outlet may be of small diameter compared with the mold.

Another object is to provide arotary casting machine with said inlet and outlet arranged concentric with the axis of rotation of the mold, thus in-turn to avoid swinging or gyrating connections and at the same time make perfectly practical the use of the wellknown labyrinth or other suitable packing to provide an absolutelyvapor-tight joint, be-

tween two relatively movable members for forming conduit means for the vapori Another object is to provide a method of operating a plurality'of casting machines while supervising the :ultimate qualities of the castings made in them, by the use of quantities of the vapor medium in such "a wayasto permit the heat-absorbed by portions of the medium bled at the proper instant from one machine, to be added at the,

proper instant to the heat contentofjpthe' portion of the medium in heat-transfer relation' to another of the casting maichinesg- Another-object is to provide a circulatory a sytem such system including vapor cham-,

bers in a plurality ofthe casting machines, and a vaporizationchamber exterior to. said machines for holding a collection'of vapor generating material, as liquid mercury, associatedwith various by-pass conduits and separately. operable Valves in various parts of the eystem; whereby the vapor may be, at

' taken in connection with the accompanying drawing, showing one apparatus adapted to constitute an embodiment, but an illustrative one only, of a casting machine, of a collection of such machines, and of the system aforesaid, all facilitative of a carrying out of the method of the invention.

In the drawing,

Fig. 1 shows more or. less diagrammatically, the system just mentioned including a battery of three casting machines;.and Fig. 2 is ahorizontal axial sectional. view of one of such machines. I

Referring first to Fig.2, which is also somewhat diagrammatic in that the antifriction journalling means for the outer casing is merely indicated at 3, such machine includes a metal mold 4, an outer casin 5, an end plate 6 for the mold, a-spider a cone-casing 8 and a packing-cover 9, all of .which' rotate as one unit, relative to a fixed conduit 10 and the latters packing cover 11; Said covers 9 and 11 house a labyrinth or other suitable type of packing, thus making a vapor-tight joint between members 8 and 10 during rotation of the mold and its associated parts as thus described. Thus, since also cone-casing 8 and outer casing 5 arev welded as indicated at 12, outer casing 5 and mold 4 are welded as indicated at 13, and

mold 4 and plate 6 are welded as indicated at 14,there. are provided at'all times, and whether the mold is rotating or not, a vapor chamber 15 sleeving the mold, a vapor vesti- 55 bule 16 always in comunication with conduit 10, and means .for maintaining the vestibule always in o -in communication with chamber 15, to wit,- the ports 17 in spider 7.

This spider also has acentral opening which snugly accommodates a cylindrical projection 18 ofiset from the center of closingplatefi. Thus the spider isit'self held inplace by its illustrated engagements with casing 5 and plate 6, in turnsupports said plate. co-axial with the mold, and adapts the mol

Referring nowto Fig. 1, the three casting machines are seen at A,'B and C. The outer casings of these machines are shown ate, 5" and 5, the-cone-casi'n'gs' at 8, 8 'and 8 and-the fixed conduits joined to the conecasings, by 'the labrinth or similar packing, at 10 ,10 and 10 Each of these conduits leads from avapor conduit or manifold 19 one end of which opens into the upper portion of a liquid mercury boiler 20 and the other end of which opens into the condensing chamber of a condenser 21. The liquid levels in the devices 20 and 21 are indicated at 22 and 23. The boiler 20' may be heated in any suitable way, as by assing heated vapors, say from the'stack o the cupola delivering the molten metal, through a duct 24. Such vapor as is condensed in condenser 21 passes from the condenser to the boiler, by way of conduits 24, 25 and 26, a pump 27 being interposed in conduit 24 to maintain circulation. The condenser includes suitable cooling coilsvor other passages forming parts of an auxiliary circulatory system for water and steam, such s stem including a water inlet conduit 28 an a stem outlet conduit, 29.

Conduits 10, 10 and 10 have branch conduits 30, 30? and 30, all leading to a conduit or manifold 31 leading to a suitable condensing chamber in ;an auxilia condenser dplate to support the inner end of the 32 similar to condenser 21 especially in that This pump discharges into a conduit 37,.

leading, as does conduit 25 from pump 27, to the return conduit 26 boiler 20.

In each of conduits 10, 10 and 10, is a.

separately operable valve 38, and in each of the conduits 30, 30 and 30, is a separately operable valve 83.

Operation: Assuming the system cold, and assuming the liquid mercury level is as indicated by the lines 22 and 23, it is first ascertained that the valves 38 in the conduits 10, 10 and 10 are all open and that the valves 83 in the conduits 30"., 30" and 30. are all closed. Then the heated gases are passed through duct 24 until the mercury liquid in the boiler generates. vapor. Such generation is continued until the chambers 15 in all the machines are filled with vapor at the correct pressure to raise the temperature of each mold 4 to that predetermined. Until such a condition is attained, of course, the

the condenser. Al o, lf-c ur e, pump 36-is going back to the idle, and no Water is being passed through pipe 33 into condenser 32.

While the metal charge for the first casting is being poured and shaped in the mold of say machine A, thevalve 38 of conduit is wholly closed. "As soon as it is required to lower the temperature of .the mold of machine A, that is, as soon as the actual creation of the casting is to occur, said valve 38 is opened to the required amount and, if necessary, one of both of the valves 38 in conduits 10 and1() are wholly or partially opened. Possibly, if the next casting is to to be made say in machine B, the valve 38, in conduit 10 may be wholly opened and the valve 38 in conduit 10 may be wholly tive to the various machines; permitting a charge in one machine to set and cool at.

the predetermined rate, and to hold the casting in say still another machine at a temperature such that the casting may be rigid enough to be slid out of the machine and yet not cooled enough to commence to chill as the result of its contact with the metal mold during the process of extraction.

It will thus be understood that during each casting" operation in any of the machines, it is required at times, not only to .raise the temperature of the mold, but to reduce such temperature, and to make this reduction at a certain predetermined' rate. The temperature of a mold is always increased really-by increasing the pressure of the vapor blanket for that mold, and decreased by decreasing the pressure of such blanket. Thus it is that the single conduit 10*, 10 or 1O serves to modify the vapor blanket of the associated machine,

quantitatively as well as qualitatively. Also at times, obviously, the pressure and content of a particular vapor blanket, innst be reduced without affecting the similar characteristics of ,another blanket or the other blankets; and this is \vhy'the' auxiliary conduits 30*, 30 and 30, and their valves 83, are provided. Whenever the pressure or content of a vapor blanket of oneof the-machines is to be reduced, but withoutcausing a variation in the vapor pressure in conduit 19, the valve 83 interposed in the appropriate conduit 30, 30 or 30 is partially onwholly 9pened,; but first the valve38 in the associated conduit 10 ,10 or '10 is I fully closed. It will be understood thay the manipulations of the various valves 38 and 83 will in practice depend on many factors and particular exigencies, and a description of all possible operations of such valve settings would make the specification too extended.

'Water is of course passed through pipes 28 and 33 and into condensers 21 and 32 as the accumulations of vapor at too high temperatures occur in different parts ofthe system. It has been carefullycalculated that after the making of several castings in. one or more of the machines, the pressure of the vapor in the system will rise so high that uninterruptedly thereafter and during continuance of the run, heat unitswill have to be absorbed from the vapor by way of the condensers,thus serving the useful purpose of delivering steam in large quantities through the conduits. 29 and 34, for doing work about the foundry, in operating the machines and otherwise.

The system may obviously be operated as above'described, even when the boiler 20 is not used at all as a generator of the heat to be stored inthe taper blankets in the casting machines. Thus, such boiler may be used solely as a balancer element for the system, exactly as a fly wheel is used onan engine shaft receiving rotation-impulses intermittently. In such case', it has been calculated that only the first two or three pipes made will be chilled,.or at worst have to be scrapped and remelted; According to this method of operation,ionly enough heat will be initially given by Way of the boiler 20 to fill the system and particularly the vapor chambers of all or someof the machines with vapor, at a low enough temperature not sufficient materially to raise the temperature of the molds. Each vapor blanket, and also all the vapor in the system, would very shortly become charged with so much heat from the first two or three castings congealing that the main problem thereafter Wouldbe to cause, as above described, transferences of some of this he at from different parts of the system to other parts thereof, while-utilizing the surplus heat to generate steam in .the conduits 29 and34; the boiler '20, being run at a very low temperature, continuously or sporadically, in ordermerely to act as a balancer as aforesaid tocompensate for intermittent pressure drops in the conduit 19, and then only, in all probthe mold.

'2. In the art'of rotary easting the method ability, when castings are not made at the the variation of the ressure I of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves rotating the mold while maintaining the mold in heat-transfer relation to a collection "of vapor and varying the pressure of such vapor during the forming and cooling-in the mold of the casting being formed'in said mold from the molten metal.

3. The method as claimed in claim 1 characterized by the fact that the vapor is maintainable at a lower pressure than superheated steam at the same temperature.

4. The method as claimed in claim 1 characterized by the fact that the vapor is nonaqueous vapor.

5. The method as claimed in claim 1 characterized by the fact that the vapor is a metallic vapor. g y

6. The method as claimed in claim 1 characterized by \the fact that the vapor is mercury vapor,

of supervising the ultimate qualities of the articles cast, which involves providing a mold including metallic portions tormlng parts of the mold cavity, rotating said mold, 1

controlling the rate of heat-conduction from and while holding a molten charge in the mold maintaining said portions of the mold in heat-transfer relation to a collection of vapor and modifying the pressure of such vapor. I y

9. In the art of'rotary casting, the method of supervising the ultimate qualities of the articles cast, which involves providing a mold includ ng metallic portions forming parts of the mold cavity, rotating said mold,

and, between the introduction of a molten charge in the mold to make a first casting, and the introduction of another charge to make a second casting following extraction of'the first casting, maintaining saidportions of the mold in heat-transfer relation to a collection of vapor and modifying the pressure of such vapor,

10.1fm the art of rotary casting, the

method of supervising the ultimate qualities of the articles cast, which involves utilizing a mold including metallic portions forming partsof the mold cavity, and during the making of several successive castings,.maintaining said portions of the mold in heat transter relation to a collection of nonaqueous vapor and modifying the pressure of such vapor during each casting operation and between successive casting operations.

11. In the art ofrotary casting, the

m ethod of operating a plurality of molds to supervise the ultimate qualities of the articles cast by said molds,'which involves molds in said system.-

of such collections, providing a circulatory system for the vapor thus bled and the vapor thus added, and confining all the vaporemploye'd in' connection with said plurality of 12. The method defined in claim 11, wherein said vapor is non-aqueous.

13. The method defined in claim 11, wherein said vaporris non-aqueous, and wherein surplus heat units in the non-aqueous vapor in said system are used to generate aqueous vapor.

14. In the artof casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves confining a vapor for travel toward and away from heat-transferring relation to the mold, and predeterminedly atfecting said travel of the vapor to control the rate of cooling of the pour.

15. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through various molds, which involves confining a vapor for heat-transfer relation to a plurality of said molds simultaneously.

16. In the art of casting, the method of the molten metal pour through Various molds, which involves confining a vapor for heat-transfer relation to a plurality of said anolds simultaneously, and maintaining colwhich involves subjecting such mold to heattransfer relation to a collection of vapor, and modifying the pressure of said vapor by modifying the spatial characteristics of the collection. V 4

18. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves confining a vapor for, travel toward and away from heat-transfer relation to the mold, and controlling such vapor travel to ali'cct the rate of cooling "of the pour.

19. In the art oi casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves confining a vapor for travel toward and away from heat-transfer rela-,

20. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves subjecting such mold to heattransfer relation to a collection of vapor, and modif ,ing the pressure of said vapor by modifying the spatial characteristics of the collection, said vapor being a non-aqueous vapor.

21. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold,

. which involves confining a vapor for travel toward and away from heat-transfer relation to the mold, and controlling such vapor travel to afi'ect the rate of cooling of the pour, said vapor being a metallic vapor.

22. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves subjecting such mold to heattransfer relation to a collection of mercury vapor.

23. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves subjecting such mold to heattransfer relation to a non-oleaginous vapor generated from a liquid having a vaporization temperature considerably higher than water and considerably lower than zinc.

24. In the art of casting, the method of controlling the rate of heat conduction from the molten metal pour through the mold, which involves subjecting such mold to heattransfer relation toa collection of vapor,

and modifying the temperature of said vapor by modifying the natural ability ofthe same to vary its pressure.

25. In the art of casting, the method of the molten metal pour through the mold,

which involves subjecting such mold to heattransfer relation to a collection of vapor, and modifying its degree of confinement'in the vicinity of the mold as compared with its degree of confinement at a point comby modifylng the spatial characteristics of the collection, said vapor being maintainable at a bi h pressure and low temperature as compare to steam. 1 v

27. In the art of casting, the method of controlling the rate of heat-conduction from the molten metal pour through the mold, which involves maintaining the mold in heat-transfer relation to a collection of metallic vapor.

a. BURnETTE DALE.

40 controlling the rate of heat conduction from

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