US2341704A - Method of disintegrating metal into abrasive material - Google Patents

Description

Feb. 15, 1944. ERvlNg 2,341,704

METHOD OF DISINTEGRA-TING METAL INTO ABRASIVE MATERIAL Filed Aug. 26. 1942 2 Sheets-Sheet 1 LIQUID Feb. 15, 1944. J. F. ERVIN 2,341,704

METHOD OF DISINTEGRATING METAL INTO ABRASIVE MATERIAL Filed Aug. 26, 1942 WSheets-Sheet 2' Patented Feb. 15, 1944 artists a rm'rnen or msmrscnac Mn'r nvro' RASWE MAT M J J Ann Arbor, lvhch.

John F.

Application August as, 1942, Serial No. man

s on. (ores-91) I ing certain technical difliculties, .one of same being to secure a uniform comminution of the metalso that the bulk is formed into globule orspheroids of the same desired size, while avoiding any substantial loss orwastage 'due to irregularly shaped fragments, and mere pulverulent or dust. Another main dimculty is to obtain a substantially perfect globular or spherical formation oi the shotted particles of metal when broken up into discrete term, so as to avoid loss due to imperfect formations.

In my prior Patent No. 2,159,433, a method is disclosed utilizing a combination of'separate liquid and separate vapor .iete or streams into which the molten metal is discharged.

In my copending application, SerialNo. 361,158, a method is disclosed consisting broadly in discharging a stream of molten metal into a closely spaced series of solid pencil-like jets of liquid, between, through and around which the molten stream passes, said liquid streams shattering and uniformly dividing the molten metal stream into drops which solidify. into substantially round shape due to surface tension; also the molten stream of metal may be discharged into the angle formed between convergently meeting streams oi liquid at or adjacent the line of intersection of the liquid streams, each liquid stream bein maintained under regulated variablepressure.

The object of my present invention is to provide an improved and more emcient method of shutting metal, utilizing, in place of the liquid streams disclosed in my aforesaid application, a closely spaced series of jets of air, gas, vapor or steam, under pressure,.into which is injected heavier-than-air, or non-expansible liquid, under pressure, to create acombined medium havins a controlled or regulated expansion, density, and velocity, thereby attaining a finer, more forceiul spray permitting definite controlled uniformity in size ofv the comminuted metal particles, and materially reducing the consequent loss due to irregulardislntegration. I

Heretofore, gaseous jets, such as compressed air, vapor or steam have been used for disintetlon or molten metal. The action or a Jet of.

such gaseous medium iunctions difierently from Y a jet of non-expanslble fluid. In a, gaseous medium the velocity of the medium in the direction of projection as well as the expanding velocity" of the gaseous medium must be taken into conslderation as soon as the medium is released into the atmosphere. The large amount of kinetic energy which is active when the gaseous medium is released from the nozzle has a harsh action on the molten metal, and thusuniform disintegration which is required in a production of the shotted metal cannot be obtained. Steam or air projected under pressure sufllcient for th operation has a much higher velocity than a liquid projected under the same pressure. he high velocity of a gaseous medium, in addition to the ,energy'of expansion, 'does not give the desired V approximately 110 pounds per square inch-pres cording to the square of the velocity.

sure will have a velocity when projected into the atmosphere of approximately 1000 feet per sec- 0nd. Due to the high velocity and to the kinetic activity of the compressed air, gas or steam an expansion takes place which creates a Wlndage condition which blows the stream of metal -and at the same time, when contacted at such high velocities, produces a. tearing efiect on the metal due to the absorption of the kinetic energy of the medium.

A liquid projected under the same pressure, 110 pounds per square inch, has a velocity approximating feet per second. Under this condition, to deliver the same amount of, energy to disintegrate the molten metal, a certain volume of liquid is required since the energy varies so- As a result, it is very difilcult to properly contact the molten metal with a projected stream of either a liquid or gaseous medium when the stream is projected at sumcient energy to subdivide the molten metal into particles without having quite aipercentage of the-product discharged. without proper disintegration.

I have found that a combination of a liquid and gaseous medium provides a range of velocities and weights which is much more eiiicient than obtained by using either liquid or gaseous gs medium projected alone, the combination medium having a velocity of approximately 150 feet per second while having sufficient volume of liquid to give the stream the proper density as well as velocity to uniformly disintegrate the stream of metal which is contacted with the multiple drops.

Thus according to my invention, for the disintegration of a, metal in a uniform way without creating disturbing influences which might make the molecular action impossible, a force is applied of such characteristic that the molten metal may enter therein and be acted upon thereby in semiuniform manner. In my method the'pressure of the compressed air, gas, vapor or steam introduced into the inlet of the nozzle may be varied from zero to 100 pounds per square inch, while the pressure of the heavier-than-air or non-expanding liquid supply to the inlet may be varied up to 60 pounds per square inch. By regulating these pressures using suitable valve mechanism I am able to project sprays with variable densities and velocities to effect the degree'of disintegration required, the samebeing much more efficient than any other method known. My ejection method permits the use of a medium ranging from a rarified vapor-projected in excess of 1000 feet per second for use in very fine disintegration, to and including a medium con- 1 sisting of a liquid projected at velocity which may approximate only 50 feet per second for use in disintegration into larger particles; and the use of a combined gaseous and liquid medium is new in the manufacture of shotted material.

The invention will be more particularly described by the following specification'with reference to the accompanying drawings, illustrating the same in exemplary working embodiments. In said drawings- Fig. 1 is a view diagrammatically illustrating the method utilizing my novel mixing nozzle.

Fig. 2 is an enlarged longitudinal section through the nozzle shown in Fig. 1.

Fig. 3 is an outlet end view of the nozzle showing th arrangement of the projected jets.

Fig. 4 is a vertical section on the line 44, Fig. 2.

Fig. 5 is a section through a modified nozzle.

Fig. 6 is an outlet end view of the nozzle shown in Fig. 5 showing one arrangement of outlet jets.

Fig. 7 is an end view of the nozzle shown in Fig. 5, but showing a different arrangement of outlet ,1 ets.

As shown in Fig. 1, the nozzle I receives, through pipe 2 having-a valve 3 therein, a supply of compressed air, gas, vapor or steam from a suitable supply diagrammatically indicated at 4. Nozzle I also is connected, by a pipe 5 having a valve 6, with a supply I of liquid, such as water, under pressure, the liquid and gaseous mediums being combined within the nozzle, and being projected through the orificed end thereof in the form of closely adjacent streams 8. The stream of molten metal M is discharged from a trough T or the like and falls into the liquidvapor streams 8, as indicated in Fig. 1.

Nozzle I may take the form shown in Fig. 2, the same consisting of a cylindrical body i having at one end a. chamber la provided with an inlet lb connected with pipe 2 which supplies the compressed air, gas or vapor or steam in quantities regulated by valve 3. Adjacent the opposite end of nozzle l is achamber lc having an inlet Id connected with the liquid supply pipe 5; whereby the liquids under pressure are admitted in regulated quantities, by valve 6, into the nozzle. Between the chambers Id and I0 are arranged a series of parallel bores le which may be disposed in one or more horizontal rows as shown in Figs. 6 and 7, or may bearranged in the form of the letter V, as shown in Fig. 4, said bores Ie being relatively small and admitting jets of the compressed air, gas, vapor or steam from the chamber Ia into the chamber Ic. In the outer end of nozzle l are a series of tapering bores If disposed in alignment with the bores le, said bores if, each approximately fifty times the area of the bores le, bores if having their inlet ends beveled as at lg, and bore if tapering towards their outer ends. In the form shown in Fig. 3 the bores if are arranged in V-formation and thereforethe smaller portion le between the chambers l alc would have a similar arrangetion of gas, air, steam or gas alone the medium would have comparatively small weight projected at high velocity. For example, air or steamat approximately 110 pounds per square inch pressure will have a velocity projecting into the atmosphere of approximately 1000 feet per second due to high velocity, and the kinetic activity of the compressed air, gas or steam, would create a windage condition which would blow the stream of metal, and at the same time when contacted at such high velocity, a tearing effect would be produced upon the molten metal due to the absorption of kinetic energy at the point of contact. When liquid alone is projected to deliver an equivalent amount of energy, since a liquid is many times heavier than air, steam or gas, the velocity is naturally much lower. Under an equivalent pressure of 110 pounds per square inch, the projecting velocity of a liquid would be approximately '70 feet per second, and hence to deliver the same amount of energy in order to disintegrate the bodies of molten metal, a certain volume of liquid is required since the energy varies with the square of the velocity. As a result, it is very difficult to properly contact the molten metal with a projected stream of either liquid or compressed gas when the stream is projected at suflicient energy to sub-divide the 'moltenmetal into particles without having quite a percentage of the product discharged without proper disintegration.

I have found that there is. a point between the above liquid and gaseous medium velocities and weights which is more eflicient, and I preferably use compressed air at approximately pounds gauge pressure projected through the bores le and into the chamber lc which is supplied with the liquid, Concentric with the line of projection of the gaseous 'streams'from bores Ie are the larger bores if which are slightly tapering.

density as well as velocity, in order to uniformly disintegrate all of the molten metal of the stream M which is contacted with the multiple streams 8, which. streams may be arranged in one or I more parallel rows, or may have a v-shaped' formation as shown in Fig. 3.

Theuse of air, steam, vapor, or gas, compressed to sufiicient pressure above atmospheric,

' of approximately 100 feet per second. By regulating these quantities and pressures, by means of the valves 3 and 6, I am able to project sprays with variable densities and velocities to efiect the degree of disintegration required.

My method is anentirely new development in the disintegration of molten metals, and is much more efilcient than any known method, and permits the use of high pressure air, steam or vapor which heretofore have not been used in such operation. The use of the high pressure air is not practical in any way unless it is used in the manner above described;

One of the primary advantages derived from situation such as above mentioned in the use of liquids. The velocity as created by the discharge at sufficient pressure to exert disintegratin force is so high that a considerable proportion of the material is broken down beyond commercial use for blasting operations,

Instead of using the form ofnozzle shown in Figs. 2 and 4, a modified nozzle may be utilized shown in Figs.'5, 6 and 7. In thismodiilcation,

the use of my method is due to the velocity and weight of the liquid, and to the expansion of the steam, compressed air or vaporbeing projected from the multiple bores if, thereby creating two actions, one of which is forward and one of which is angular to the axis of the stream due to the expansion forces of the released gas, air or vapors. The action immediately spreads and sub-divides the molten metal M into an umbrella shape and allows it to drop quietly "into the liquid. Thus the vital element of my method is itsadaptability for adjustment to a balanced position with respect to velocity and density in order to create the necessary conditions which are best adapted to the particular situation.

It is necessary to have .some force applied to the molten stream which is sumcient to sub-di-' vide to disintegrate same, and at the same time the force must be as equally'distributed as possible over a certain sectional area. Due to the force and the velocities of different sections of crease the pressure, the impact created by the density of the medium with the velocities at these pressures, distorts the particles and inter feres with their forming into" spherical shot. when a gas or vapor is discharged the velocities follow the sameformula, but the density of the mediums have to be considered; As a result, with an equivalent pressure the velocities vary asthe square root of the relative densities. You

then obtain a condition where you flnda similar the nozzle I0 is provided with a single inner chamber l I connected with the valved liquid supply pipe 5. At one end of the nozzle area plurality of bores l2 connected with the valved'gas pipe 2 through which jets of compressed air, gases or vapors are emitted in regulated amounts by manipulation of valve 3. In the opposite end of nozzle in, opposite each of the bores 12, are outlet bores I3 which are each preferably fifty times the area of the bores i2. Figs. 5 and 6 indicate various other arrangements of the bores I2 and it which may be utilized in the nozzles l'or Ill. The gas or vapor passing through the orifices i2 are mixed in chamber II with the liquid supplied through the pipe 5, and the mixture then discharged through the outlet orifices it. The facilities for regulating the pressure and supply of the liquid and of the compressed air, gases or vapor, make it possible to discharge through orifices 43 a medium with density and velocity varying from vapor density and velocities, to that of liquid density and velocities. By projecting a number of these stream from the multiple orifices 03 it is possible to create a, large cross-sectional area of almost uniformly applied force into which may be poured the stream M of molten metal, and thereby obtain a wide degree of sub-division and at the same time have a force applied which is such that it does not distort the metal particles but allow same to freeze into spherical bodies when dropped into a quenching or cooling medium.

I have found that there is practically no limit to the size of the molten stream M which can be disintegrated utilizing my method, this being possible because my method may be adjusted to deliver a force through multiple orifices, and second, that thisforce can be delivered at varying velocities and densities. A .vital feature of my method is due to the velocity of the liquid,

and to the expansion of the gaseous medium such as steam, air, gas or vapor after projection from the multiple ports if or ie of the nozzles, same creating two actions, one of which is forward,

and one of'which is angular to the streams due to the expansion of the gas, air or vapor when released. This expansion action immediately spreads and sub-divides the molten metal into umbrella shape, and allows same to drop quietly into the liquid; and the use of my method permits adjustment of the velocity and density of the steps of entraining a flowing liquid in a fiowing gas so as to increase the velocity of the liquid over that of pure liquid jets flowing under the same differential of pressure, discharging the resulting mixture at said velocity in the form of a closely spaced series of pencil-like jets of controlled expansion, density and velocity, and discharging a stream of molten metal into said series of Jets, the forward action of the liquid element of the jets between, through and around which the molten stream passes, thereby shattering and uniformly dividing said molten stream into drops which solidify into substantially round shape due to surface tension; and the expanding action of the gaseous element when re leased from the jets causing said element to spread the divided molten metal into umbrella shape allowing same to drop quietly into a quenching medium.

2. In a method as set forth in claim lflsaid liquid medium comprising water under pressure, 3. In a method as set forth in claim 1, said gaseous medium comprising compressed air.

10 gaseous medium comprising steam above atmospheric pressure.

JOHN F. ERVIN.

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