US2072375A

US2072375A - Process and apparatus for oxidizing materials

Info

Publication number: US2072375A
Application number: US546952A
Authority: US
Inventors: Mccallum Jean
Original assignee: Nat Lead Co
Current assignee: NL Industries Inc
Priority date: 1931-06-26
Filing date: 1931-06-26
Publication date: 1937-03-02
Anticipated expiration: 1954-03-02

Description

J. MCCALLUM March 2, 1937.

PROCESS AND `APPJ'KATUS .FOR OXIDIZING MATERIALS` 2 Sheets-Sheet 1 Filed June 26, 1951 March 2, 1937. J. MocALLUM I PROCESS AND APPARATUS FOR OXIDIZNG MATERIALS Filed June 26, 1951 2 Sheets-'Sheet 2 mil/vll Patented Mar. 2, i937 Fries amaai .lean McCallum, St.

ALS

Louis, Mo., assignor to National Lead Company, St. Louis, Mo., a corporation of New .'slersey Application .Enne 26,

l2 Claims.

This invention relates generally to the atomization or sub-dividing materials and particularly to the oxidation of sub-divided molten leadf'or the formation of fumed litharge.

In the various processes which have heretofore been employed for atomizing molten metals,

- such as, lead, in the formation of fumed litharge, and in which it is desired to oxidize the atomized material, it has been recognized that in order to secure a high -fume production or in other words to oxidize a substantial proportion of the atomized material, the atomization must be extremely fine. Again it has been heretofore recognized that in order to secure fine atomization, it is desirable l5 that the stream to be atomized be of relatively small size. Various processes and apparatuses have heretofore been proposed for atomizing molten materials for various purposes, including oxidation, andv these prior processes have followed generally the principle of impinging a fluid blast, such as for instance, air upon a stream of molten metal or the material. In the processes of the prior art, however, it has been impossible to se` cure high fume production or in other words to oxidize substantially all of the atomized material. Perhaps the reason for this inability of the prior art process to accomplish thorough oxidation is principally the fact that it has been heretofore impossible to suiiiciently sub-divide the molten stream before the fluid blast has been implnged upon it. Although it has been possible to reduce the size of the stream of molten material by directing it through a relatively small orice, it has been found, and particularly in processes where the molten stream is to be oxidized, by the impinging blast, that when a small orifice is employed for projectinga small stream, continuous operation of the apparatuses or processes is impossible for the ,reason that such small oriiices readily clog or dross so that it becomes necessary for an attendant to stop the operation of the apparatus and open the clogged orifice, which necessitates in any event the discontinua .ce of operation, so that the attendant might place himself in a position which would permit working upon the nozzle.

The object of this invention, generally stated, is to provide a process and apparatus suitable for atomizing molten metal, particularly for oxidation.

Another object of this invention is to provide Ian atomizing nozzle which will be eiilcient in its operation.

A further object of this invention is to provide an atomizing nozzle which will mechanically di B931, Serial No. 5%,952

vide the stream of molten material into relatively small jets.

Another object of this invention is to provide an atomizing nozzle, which may be readily cleaned' without discontinuing the operation thereof.

A further object of this invention is to provide an apparatus for eiiiciently atomizing and oxidizing molten material.

A more specic object of this invention is to provide a process and apparatus for oxidizing molten lead to form fumed litharge.

Other objects will become apparent to those skilled in the art when the following description is read in connection with the accompanying drawings in which:

Figure 1 is a view somewhat diagrammatical in form, of-an apparatus for producing fumed litharge, provided with an atomizing nozzle constructed in accordance with this invention.

Figure 2 is a longitudinal, sectional view of an atomizing nozzle, constructed in accordance with one embodiment of this invention.

Figure 3 is a longitudinal, sectional view of an atomizing nozzle, constructed in accordance with another embodiment of this invention.

Figure 4 is a view in end elevation of the nozzle shown in Figure 2.

Figure 5 is a detail view in side elevation, illustrating a suitable form of valve for sub-dividing the stream of molten metal.

Figure 6 is a detail, sectional view, in end elevation, of the valve, illustrated in Figure 5.

Figure '7 is a detail view in sideelevation of a modified form of valve.

Figure 8 is a detail, sectional view in end elevation of the valve shown in Figure '1.

Figure 9 is a longitudinal, sectional view of a slightly modified form of an atomizing nozzle.

In accordance with this invention as adapted particularly for the atomizing of lead for the production of fumed litharge, and with particular reference to which the invention will be de scribed herein, a stream of molten metal may be mechanically sub-divided into a plurality of thin jets, or into a continuous relatively thin sheet, and a iluid blast then implnged upon the thin sheet or jets. In accordance with the usual practice, the lead is introduced to the atomizlng nozzle in a molten condition and a blast of air or other fluid, pre-heated to a temperature' above the melting point of the lead prior to its introduction into thel nozzle, implnged thereagainst. In the nozzle of the present invention the stream of molten lead or other material is first mechanically sub-divided, as pointed out above, and

projected axially under pressure into the path of a fluid blast, which may be either pre-heated or cold air or any suitable lraw or inert gas. When the stream of molten material is first mechanically sub-divided and thence impinged by uid blast, it has been found that more efficient atomization is accomplished. In accordance with one embodiment of the present invention, the stream of molten material, after being subdivided, is projected in a conical form and the fluid blast impinged thereupon from the exterior of the cone. Under some circumstances, it has been discovered, however, even though complete atomization of the molten material takes place at the point of impingement, the stream tends to contract a short distance from the point of impingement so that the so-called vena contracta", Well known to those skilled in the art of hydraulics is formed. In accordance with the present invention a second fluid blast may be introduced axially of the conical stream of molten material, thus relieving the negative pressure on the interior of the cone and preventing the formation of the vena contracta, the effect of which it will be understood is to occulate the atomized particles of molten material and thus defeat the purpose of efcient and complete atomization.

Referring now to the drawings for an illustrative embodiment of this invention, the usual apparatus for the production of fumed litharge is illustrated diagrammatically in Figure 1. conventional apparatus for fuming lead comprises generally a revolving retort I, having a restricted mouth 2. Adjacent the mouth 2 of the retort, an

atomizing nozzle 3 is provided. In accordance with the usual practice, the atomizing nozzle 3 delivers a stream of molten lead or other suitable material to the retort and also delivers a stream of oxidizing fluid, which may be eitherpre-heated or cold air or any suitable gas. The lead may be introduced into the nozzle 3 by a suitable pipe or conduit 4, while the oxidizing gas may be introduced through a suitable pipe or conduit 5. In accordance with one embodiment of the present invention an additional supply of oxidizing gas or fluid may be introduced to the nozzle through a second conduit 8. In the operation of the apparatus just described, the lead is atomized at the nozzle 3, which will be more particularly described hereinafter with reference to the several embodiments thereof shown in the drawings. Oxidation of the lead then takes place while in its atomized condition within the retort I and the fumes thus produced are removed from the retort and conveyed through any suitable type of conduit 1 to the usual cooling flues. After the fumes thus produced have been suflici'ently cooled, they are collected in the form of an impalpable powder and may then be prepared for the market.

In accordance with the present invention, the atomizing nozzle 3 is made up of a, plurality of parts as is illustrated in Figures 2, 3 and 9, and between each of the respective parts a recess or passageway is left, thus defining a conduit for conducting either the stream of molten material or one of the fluid blasts. Referring now particularly to Figure 2, one embodiment of a nozzle The and is provided with a threaded opening adapted to receive the conduit 5 for transmitting a fluid blast to the nozzle. As is clearly illustrated in Figure 2, the core piece 8 is so machined as to provide a number of off-sets longitudinally thereof, thus forming a plurality of shoulders, such as I2. At one side of the core piece 8 an opening I3 connects the shoulder I2 with the threaded opening so that a passageway for conducting the fluid delivered by conduit 5 is thereby provided. The core piece 8 is preferably provided with a threaded part I4, adapted to engage a shell I5. The shell I5 is generally cylindrical in shape and is internally machined to provide a plurality of off-sets adapted to cooperate wth the off-sets on the core piece 8 so that a passageway between the shell I5 and the core piece 8 is thereby defined. In the particular embodiment illustrated, the shell I5 is provided at its outer end I6 with an internal opening Il of a diameter slightly in excess of the diameter of the outer end I8 of the core piece 8. It is thus apparent that when the shell I5 is assembled upon the core piece 8, a passageway is defined between its two parts which will conduct a fluid delivered by the conduit 5 therethrough and emit the same at the open end of the nozzle through the orifice which exists between the end I8 of the core piece 8 and the opening Il in the shell I5. In the embodiment illustrated in the drawings, the shell I5 is preferably so machined internally that the velocity of a blast issuing therefrom is relatively high and the direction thereof is substantially parallel to the axis of the core piece 8 for al purpose which will be more fully described hereinafter.

At the outer end |8 the tubular opening 9 which extends through the core piece 8 terminates in a valve seat I9, which in the embodiment illustrated is frusto-conical in shape, being continuous from the outer circumference at the end I8 to the inner opening 9 therethrough. Near the end I8 the tubular opening 9 which extends through the core piece 8 is constricted as illustrated at 2| so that the diameter of the opening between this point and the valve seat |9 is less than the diameter of the remainder of the tubular opening. A valve 22 ls provided for co-operating with the valve seat I9 and is adapted to be moved relative to the valve seat I9 to vary the opening between the seat I9 and the valve 22. The valve 22 is provided with a stem 23 extending through the tubular opening 9 and guided at the end thereof opposite, the valve 22 by a suitable packing gland 24, connecting to the core piece 8 or any other suitable connection. It will be understood that the stem 23 is slidable axially, relative to the packing gland 24 in order to axially adjust the valve 22 with reference to the valve seat I9. The diameter of the stem 23 is preferably substantially equal to the diameter of the constricted portion 2| of the tube 9 so that a substantially snug fit is obtained between the stem 23 and the constricted portion 2| of the tube 9 in the embodiment illustrated. In the region of the constricted portion 2|, however, the stem 23 is provided with a plurality of axially extending. grooves 25, clearly illustrated in Figures 5 to 8 inclusive for sub-dividing the stream of molten material in the opening 9 and conducting the same past the constricted portion 2| to the opening between the valve seat I9 and the valve 22. It will be understood that the grooves 25 may extend from the stem part 23 to the ared portion of the valve 22, as is illustrated in the aovaavs embodiment shown in Figures 5 and 6, and'in which instance the stream of molten material will be projectedin the form of a plurality of radial jets. In the embodiment illustrated in Figures 'Tand 8, however, it is apparent that the grooves 25 terminate adjacent the flared part of molten material in the form of radial streams,

the form of the valve in Figures 5 and 6 is preferably employed. I In the embodiment illustrated in Figure 2, the stem 23 of the valve 22 is provided with a central passageway for 'conducting an additional blast'of fluid for assisting in the atomization of the molten fluid as well as maintaining the dispersion of the material previously atomized by the blast issuing from opening I'I by preventing the so-called vena contracta" which would tend toeform in the event that the `negative pressure within the jet was not over' come. In .the embodiment illustrated in Figure 2, the stem 23 terminates at the outer end thereof, adjacent the valve 22, with a flared mouth 21, which may be of any suitable shape, preferably adapted to spread the blast owing through the passageway 26 in the stem 23, outwardly against the stream of atomized metal flowing from the opening between the valve seat I9. and the valve 22, so as to further disperse the atomized material, it being apparent that when. the blast is directed outwardly as illustrated by the direction of mouth 21 in Figure 2, that the stream issuing from the mouth 21 will impinge upon`the 'already atomized material and further disperse the particles thereof. Moreover this internal blast issuing from the mouth 21 relieves the negative pressure created within the jet and thus prevents the flame from contracting a short distance from the nozzle, so that the tendency for the vena contracta to form is thus eliminated and the dispersion of the particles is maintained.

In the embodiment illustrated in Figure 2, the mouth 21 is provided with a valve 28, adapted to seat thereon and movable to control the blast issuing from the mouth 21. In the embodiment illustrated the valve 28 is provided with a stem 29, extending axially through the opening 26 of the stem 23, and being guided at the end thereof and opposite the valve 2S, by a suitable packing gland 3l, mounted upon'the stem 23 and forming a fluid tight connection between the stem 29 and the passageway 26. The packing gland 3l permits relative movement of the stemV 29 and the stem 23, so that thestem 29 may be moved to adjust the position of valve 28, relative to the mouth 21, and thus control the fluid blast issuing from the mouth 21. In the embodiment illust/rated the mouth 21 is provided with a plurality of openings 82, Vextending outwardly from the region of the vertex thereof so that anoutlet In the operation of the nozzle Ajust described,

a supply of moltenmaterial, such as for instance,

lead, is admitted to the passage 9 through vthe conduit d and a supplyof fluid, such as for instance,"preheated,air, is admitted to the'passageway I3. through the conduit 5 and is emitted at the opening I1. .It will beunderstood thatthe molten material in the-opening 9, as well as the pre-heated air in the recess between the core piece8 and the shell I5, is underA suflicient pressure to cause the respective streams thereof to issue from the corresponding orices with substantial velocity. Similarly a supply of fluid Such as for instance pre-heated air, is admitted to the passage 26 from the conduit t. It will be understood, of course, that the various conduits e, 5 and 6 may be suitably controlled with valves for discontinuing or regulating the operation of either when lso desired. Assuming, however, that the valve controlling each of the conduits i, 5 and Ii is open, and that a stream of molten material is being forced through the recess 9, itwill be apparent that the stream is sub-.divided upon contact with the constricted portion 2l into a plurality of smaller streams, the number of which will be determined by the number of grooves 25 in the stem 23. The sub-divided streams of molten material will be conducted past the constrictedportion 2| and delivered to the opening between the valve seat I9 and the va1ve'22. Assuming that the valve 22 isformed as illustrated in Figures '1 .and 8, the sub-divided streams of molten material will be forced outwardlykand projected in the form of a conical sheet from the opening of the valve seat I9 andthe valve 22. Atthe same time a blast of `fluid, such as for instance, pre-heated air, is issuing at a relatively high velocity from the orifice I l, it being recalled that the direction of the blast issuing from the orifice I1 is substantially parallel to the axis of the nozzle, it is apparent that the blast issuing from the orifice I1 will impinge upon-the sheet of molten material being projected from the open ing `between valve seat I9 and the valve 22, so that the stream is completely nebulized. When the blast issuing from the orifice I1 strikes the sheet of molten material, it is apparent that the direction of travel of the metal particles will be changed, and they will be projected in a direction substantially axially to the nozzle. It is apparent, therefore, that the flame thus -producrd 's in its entirety substantially cylindrical and the tendency will be for such aflamevto contract a short distance from the nozzle. vIn accordance with the present invention, however. a second fluid blast is being supplied through the passage 26 and issues on the interior of the flame creaied by the blast from opening I1 and the stream rf molten material so that the internal pressure rf the conical flame is counteracted and contraction thereof thus prevented. Furthermore when the blast from passage 26 is spread outwardly, it is apparent that this second blast will also be effective to-further disperse the nebulized particles of molten metal. i

-As has beenhereinbefore pointed out, when a stream of molten material, such as for instance.

' molten lead,.is oxidized at a relatively small opening, adross will usually form about the opening, building up in the form of a cylinder abcut the opening, and thus prevent properv operai-ion cf the nozzle. In accordance with the present invention, however, as illustrated in Figure 2, it

to build itself up around the orifice which delivers the molten material, in view of the fact that the fluid blast is being directed in such a direction as to continuously impinge the metal at the time it issues from the orifice, and in view of the fact that there is a continuous force in` the region of the orifice, it is impossible for any formation to build itself up around the orifice. In the use of the nozzle of this invention, however, it becomes necessary at times to clean the orifice for the molten material as well as a Dart of the grooves 25, since there is a slight tendency for oxidation or drossing along this area. In accordance with .the present invention, however, it will be observed that the valve 22 may be moved relative to the valve seat I9 by a manipulation of the stem 23, so that when it becomes necessary y for an attendant to remove the dross from the valve and the grooves 25, this may readily be accomplished without even interrupting the operation of the nozzle by moving the valve 22 away from the valve seat I9 for a short distance. With a nozzle constructed and arranged as illustrated in Figure 2, it is apparent that a workman may view the portions to be cleaned from the rear, after the valve has been moved outwardly for a short distance, so that any suitable cleaning device may be readily employed without dismantling the nozzle as has been necessary in the cleaning of nozzles constructed in accordance with the prior art. When the cleaning operation has been completed the stem 23 may then be moved back to its original position or moved to the desired position, so that the stream of molten material issuing from the orifice controlled by the valve 22 may be adjusted in order to accomplish complete and eilicient atomization.

It may be pointed out that the mouth of passage 26 may be formed to any desired shape depending upon the conditions of operation. The passage 26 may or may not be provided with a controlling valve such as 28, as is desired. If no controlling valve is provided the mouth 21 may be conically shaped as shown at 33 in Figure '7 `or cylindrical as indicated in Figure 3, or the passage 26 may be eliminated as shown in Figures 5 and 6.

Referring now particularly to Figure 3, an atornizing nozzle constructed in accordance with another embodiment of this invention is shown. The nozzle illustrated in Figure 3 is substantially the same as that illustrated in Figure 2 with the exception of the valve controlling the internal fluid passage. In the embodiment illustrated in Figure 3, the valve 22 and. stem 23 are provided with a continuous axial opening 35, extending therethrough for supplying a continuous fluid blast from a suitable conduit such as 6. In the embodiment illustrated in Figure 3, 'it-is apparent, therefore, that all the features of the embodiment illustrated in Fig. 2 are present with the exception of the valve for controlling the internal fluid blast, which as pointed out above, 1s, under some circumstances, unnecessary.

Referring now particularly to Figure 9, another r and further embodiment is illustrated in which the nozzle is provided with a plurality of external orifices for directing fluid blasts against the stream of molten metal. In the embodiment illustrated in Figure 9, the core piece 8 is substantially the same as the core piece provided in the embodiments hereinbefore described, and the core piece is provided with a shell i5 in threaded connection therewith, but spaced therefrom in order to define a passageway between the two pieces,

' and in addition thereto is provided with an additional outer shell 36 in threaded connection with the core piece 8 and so machined as to define a passageway between the exterior of shell l5 and the interior of shell 36 when in the assembled position illustrated in Figure 9. In the use of the embodiment illustrated in Figure 9, it is intended to supply a blast of gas which may be either raw gas or any suitable fuel gas which may be controlled in order to secure either a reducing, neutrai or oxidizing flame. Such gas may be supplied from a suitable conduit 31 and conducted through the passageway 38 existing between the shell i5 and the core piece 8 to the annular orice 39 adjacent the orifice 4i from which the molten metal issues in the manner described with reference to the embodiments previously described. An additional annular orifice 42 is provided for delivering another fluid blast which may be a stream of air supplied from conduit 5 and transmitted through the recess defined between the shells I5 and 36. With the various orifices arranged as illustrated in Figure 9, it is apparent that the raw gas issuing from orifice 39 impinges upon the sheet or plurality of jets of metal issuing from the orifice 4| so that the stream of molten metal is first broken up by the impingement of the fluid blast issuing from orifice 39, which may be for instance a blast of raw or fuel gas. In the embodiment illustrated in Figure 9 the direction of the uid blast issuing from orifice 42 is preferable at an angle to the blast which issues from orifice 39 in order that further -atomization of the particles of molten metal may be accomplished by impingement of the blast issuing from orifice 42 upon the blast issuing from 39 containing the inital atomized particles. In the nozzlev illustrated in Figure 9 the central opening for supplying a .fluid blast on the interior of the ame which was present in the embodiments previously described has been dispensed with and it will be noted that the outer end of the valve 22 is formed into the shape of a hemisphere 43. With the end of the valve 22 so arranged and the blast issuing from orifice 42, directed at an angle to the flame, there is little tendency for the vena c'ontracta to form since a spherical formation of the valve 22 substantially fills that area within the blast wherein there is a tendency for a negative pressure 'to be set' up, and furthermore, the fact that the blast issuing from orifice 42 is directed at an angle, tends. to maintain tlfe dispersion initially created by impingement of the blast issuing from orifice 3S upon the jet or sheet of molten metal issuing from the orifice 4I.

In each of the embodiments which has been described, it is apparent, however, that the valve 22 may be moved away from its seat for a sufficient distance to permit the stream controlling surfaces thereof to be cleansed without dismantling the nozzle, and, under4 ordinary circumstances, without interfering with the operation thereof. When any one of the nozzles is provided with a valve, such as that illustrated in Figures 5 and 6, in which the grooves extend outwardly on to the flared portion of the valve and thus cause the stream of molten material to be projected in a plurality of radial jets, a suitable spring, such as 44,.may be provided for maintaining the valve 22 in such a position that the area 45 between the grooves 25 on the flared portion of the valve 22 is in contact with the valve seat i9 so that the various grooves 25 in the valve are separated and the flow of molten material, except through the grooves in the flared portion of the valve, is thus prevented. If, however, the stem 23 be manipulated to increase the distance between the valve 22 and the seat it, it is apparent that the valve illustrated in detail 5 in Figures 5 and 6 will then cause the'molten metal to be projected in the form of a sheet.

From the foregoing description, it is apparent that in accordance with the present invention an atomizing nozzle is provided which accomplishes, l rst, a mechanism sub-dividedyof a stream of molten material, such as for instance, lead, and so projects the sub-divided stream either in the formation of a plurality of jets or a thin conical sheet that they become impinged by an annular l fluid blast, which may, in a process of making fumed litharge, be air, oxidizing the lead so that a line state of atomization is accomplished, it

being understood that the degree of oxidation is dependent almost entirely upon the degree of 20 atomization, since the more nely divided the lead particles, the greater the surface thereof, which is exposed to the action of the oxygen. In accordance with the present invention, the lead stream is completely and emciently atomized into 25 fine particles so that oxidation thereof is complete. Moreover in accordance with the present invention, means is provided for preventing the flame from contracting, thus maintaining the dispersion and atomization which was created upon impingement of the blast against the thin jet of metal.

It is apparent that many modifications of the process and apparatus hereinbefore described and illustrated in the accompanying process will be- 35 come apparent to those skilled in the art, which will not depart from the spirit of this invention.

Furthermore, it is apparent that the arrangement of passages and orifices may be varied to any extent and without departing from the spirit of 40 stood, therefore, that the nozzle of this invention is not limited to the specific configuration of passages' and orifices and the arrangement thereof, nor is it limited to use in connection with the filming of metals to which the foregoing description has been confined. It is to be distinctly understood, therefore, that such modifications or the use of such individual parts or subcomblnations, of parts in other relations and for other purposes than the fuxning of lead, which do not depart from the spirit of this invention, are, although not speciilcally described herein, contemplated by and within the scope o the appended claims. l

Having thus described the invention, what is claimed is:

1.` In the art of oxidizing molten materials, the process comprising projecting a stream of material in the form of a hollow conical jet,'directing an annular blast of air against the jet, and surrounding the 'jet with an envelope of preheated 89.8.

2. A nozzle for. atomizing molten material, comprising, a tube for conducting a stream ot molten material, a spreader disposed in the tube and adapted to spread the stream in the form of a conical sheet, a conduit having an orifice adjacent the exterior vof said conical sheet, and a second conduit having its orifice lon the interior of said conical sheet.

3. A nozzle for atomizing molten material. comprising, a tube for conducting a stream of molten material, a spreader disposed in the tube and adapted to spread the stream in the form of 75 a conical sheet. a conduit having an orifice adaovaevs this invention, and it is to be distinctly underjacent the exterior of said conical sheet, and a second conduit having an oriiice adapted to de. hiver a conical blast on the interior of the conical s eet.

4. A nozzle for atomizing molten material, comprising, a tube for conducting a stream of molten material, a spreader disposed in the tube and adapted to spread the stream in the form of a conical sheet, and means forimpinging a iiuid blast against the conical sheet from the exterior and interior thereof.

5l A nozzle for atomizing molten material, comprising, a tube for conducting a stream of molten material, the mouth of said tube being formed to provide a valve seat, a valve for cooperating with said seat having a stem extending through said tube and movable relative thereto to adjust the valve, said stem having a passage therethrough adapted to conduct a uid blast, adjustable means for spreading the blast, and m'eans for directing a second blast centrally of said ilrst blast.

7. In the art of oxidizing-materials the process, comprising, projecting a stream of molten material in the form of a conical jet, directing a blast of air against the jet, and surrounding the jet with an envelope of reducing gas.

7. In the art of oxidizing materials the process comprising, projecting a stream of molten material in the form of a conical jet, directing a blast of air against the jet, and surrounding the jet with an envelope of neutral gas.

8. A nozzle for oxidizing liquids comprising. a tube for conducting the liquid, a spreader at the end of said tube for directing the liquid stream in directions diverging outwardly from said tube,

said spreader having a spheroidal surfaceexe-- tending outwardly substantially beyond the end of said tube to counteract the vena contracta tendency of said diverging stream, and a conduit for delivering an atomizing blast against the stream issuing oi said spreader.

9. A nozzle for oxidizing liquids comprising, a tube for conducting the liquid in the form of an annular stream, means in the tube for subdividing the annular stream, a spreader at the end of said tube for ,directing the subdivided liquid stream in directions diverging outwardly from said tube, said spreader having a spheroidal surface extending outwardly substantially beyond the end of said tube to counteract the vena contracta tendency of said diverging stream. and a conduit for delivering an atomizing blast against the stream issuing 0E said spreader.

10. A nozzle for oxidizing liquids comprising, a tube for conducting the liquid, a stem extending axially through said tube, said tube terminating in a aring mouth, a spreader on the end of said stem having a surface substantially complemental to the flaring mouth of saidtube, said spreader having a spheroidal part outwardly beyond the mouth of said tube -to counteract the vena contracte. tendency of a diverging stream issuing between said flaring mouth and spreader. and a conduit for delivering an atomizing blastv against the stream issuing oi said spreader.

11. A nozzle for oxidizing liquids comprising, a tube for conducting the liquid, a stem extending axially through said tube, said tube terminating in a flaring mouth, a spreader on the end of said stem having a surface substantially4 complemental to the ilaring mouth of said tube, said spreader having a rounded part outwardly beyond the mouth of said tube, a passage extending axially through said stem and opening into the surface 5 process comprising,

of said rounded part, and a conduit for delivering an atomizing blast against the stream issuing of! said spreader.

12. In the art of oxidizing liquid materials the mechanically subdividing and spreading a stream o! liquid into a diverging conical stream, impinging a fluid blast against the conical stream from the exterior thereof, and directing a second :fluid blast interiorly of and codirectionally with said conical stream.

JEAN MCCALLUM.