US3814327A

US3814327A - Nozzle for chemical reaction processes

Info

Publication number: US3814327A
Application number: US00131684A
Authority: US
Inventors: A Dada
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1971-04-06
Filing date: 1971-04-06
Publication date: 1974-06-04
Anticipated expiration: 1991-06-04
Also published as: DE2215958A1; JPS5615944B1; IT950974B; DE2215958C2; BE781679A; NL7204629A; CH577339A5; FR2136221A5; SE394857B; GB1361533A; ES401291A1

Abstract

A nozzle for injecting fluid reactants into a reaction zone is presented in various embodiments. The nozzle is held by a supporting means and has a first inlet means for receiving and guiding a first fluid reactant into the reaction zone. The nozzle has a second inlet means for receiving and guiding a shielding fluid into the reaction zone for temporarily separating the fluid reactants entering the reaction zone. A third inlet means is disposed and slightly recessed within the second inlet means and has a chamber for receiving a second fluid reactant which chamber is connected preferably to a plurality of tubular members for guiding the second fluid reactant into the reaction zone. A directional control plate is secured transversely in the second inlet means and this plate is provided with openings through which the plurality of tubular members extend coaxially forming an annular opening around each tubular member enabling the shielding fluid in the second inlet means to flow unidirectionally through the annular openings and then into the reaction zone.

Description

[ June 4, 1974 NOZZLE FOR CHEMICAL REACTION PROCESSES Abdul G. Dada, San Jose, Calif.

[73] Assignee: General Electric Company, San

Jose, Calif.

22 Filed: Apr.6, 1971 211 App]. No.: 131,684

[75] lnventor:

[52] US. Cl 239/290, 239/422, 239/424 [51] Int. Cl B05b 7/00 [58] Field of Search 239/290, 291, 296, 400,

FOREIGN PATENTS OR APPLICATlONS 189,540 12/1922 Great Britain 239/4l9.3

Primary ExaminerM. Henson Wood, Jr. Assistant Examiner.lohn J. Love Attorney, Agent, .or Firm-Sam E. Laub; Samuel m nl sarl-Jsmssdr- [5 7] ABSTRACT A nozzle for injecting fluid reactants into a reaction zone is presented in various embodiments. The nozzle is held by a supporting means and has a first inlet means for receiving and guiding a first fluid reactant into the reaction zone. The nozzle has a second inlet means for receiving and guiding a shielding fluid into the reactionzone for temporarily separating the fluid reactants entering the reaction zone. A third inlet means is disposed and slightly recessed within the second inlet means and has a chamber for receiving a second fluid reactant which chamber is connected preferably to a plurality of tubular members for guiding the second fluid reactant into the reaction zone. A

directional control plate is secured transversely in the second inlet means and this plate is provided with openings through which the plurality of tubular members extend coaxially forming an annular opening around each tubular member enabling the shielding fluid in the second inlet means to flow unidirectionally through the annular openings and then into the reaction zone.

15 Claims, 8 Drawing Figures PATENTEDJUN 41914 SHEEI 1 0F 4 INVENTOR:

ABDUL G. DADA jmzfzi ATTORNEY sum 2 0r 4 Fig. 4

reactantstoihe reactionlone. a

-configurations of improved design whereby reaction of 1 NOZZLE FOR CHEMICAL REACTION PROCESSES BACKGROUND OF THE INVENTION It is known to conduct chemical reactions by feeding cent, generally unidirectional streams of fluid reactants introduced to a reaction zone initially separated by a shielding fluid. 7

Still another object of this invention is to provide a reactive fluids in nozzles having separate inlets to a renozzle with a directional control plate producing unidiaction zone at proper conditions for carrying out the desired reaction usually by producing a flame. In many cases the nozzles for feeding the reactive fluids to the reaction zones are designed for specific purposes and rectional flow of a shielding fluid around tubular members introducing a reactant into a reaction zone thus temporarily and efficiently shielding and separating the reactant from another reactant in the reaction zone aIC nOt Useful in a variety Of applications. In mOSt 10 until cross difi'hsion of the reactants ccurs instances the nozzles are such that the flame produced is rooted or attached at the opening of the inlets to the reaction zone and the result is that any solid product produced in the reaction is concentrated close to the inlets. In this manner a solid deposit of the reaction.

product can build up on the inlets and this build up of the solid reaction product can result in plugging of the inlets, thus impeding any further chemical reaction and necessitating disassembly of the apparatus for cleanup.

Accordingly it has remained desirable to provide a nozing UTS. Pat. application Ser. No. 77,446, now US.

Pat. No. 3,796,672, entitled Process for Producing Uranium Dioxide Rich Compositions From Uranium Hexafluoride, filed Oct. 2, 1970 in the names of W. R. DeHollander and A. G. Dada, 3 presents a very satisfactory reaction for the conversion of uranium hexafluoride to uranium dioxide rich compositions. The foregoing patent is hereby incorporated by reference for convenience of presenting the present-invention. In the process presented in Ser. No.77,446, US. Pat. No. 3,796,672,

- the uranium hexafluoride is reacted with a reducing gas and an oxygen-containing carrier gas in a reduction-hydrolysis reaction in an active flame to yield a uranium dioxide rich composition. The

uranium dioxide rich composition is a particulate, solid product, and it is desirableto have the reaction removed from the inlets introducing the reactants to the reac tig zone to prevent plugging of have a nozzle for introducing to a reaction zone the reactants needed for producing uranium dioxide so that the resulting reaction flame is removedor lifted away from the nozzle used to introduce the OBJECTS OF THE INVENTION It is an object of this invention to provide nozzle configurations for introducing fluid reactants to a reaction zone separated by a shielding fluid to prevent temporarily substantial mixing and reaction of the fluid reactants until the reactants are removed from the nozzle. Another object of this invention is to provide nozzle fluid reactants issuing from the nozzle results in controlled location of solid reaction product away from the nozzle.

A further object of this invention is to control the point of formation of a reactive mixture between adja- An additional object of this invention is to provide apparatus in the in the form' of a nozzle mounted in a cover adapted to fit a reaction vessel defining an enclosed reaction zone for flame conversion of fluid reactants avoiding the buildup of solid reaction products at the outlet of the nozzle and the back diffusion of reaction products to the outlet of the nozzle since the reaction is removed from the nozzle.

Other objects and advantages of this invention will become apparent to a person skilled in the art from a reading of the following summary and description of the invention along with the appended claims and by reference to the accompanying drawings.

SUMMARY OF THE INVENTION This invention achieves the foregoing objects by presenting a nozzle for guiding fluid reactants into a re action zone in various embodiments. The nozzle is held by a supporting means and has a first inlet means for receiving and guiding a first fluid reactant into the reaction zone. The nozzle has a second inlet means for receiving and guidingashielding fluid into the reaction zone for temporarily separating the fluid reactants entering the reaction zone. A third inlet means is disposed within and recessed within the second inlet means and has a chamber for receiving a second fluid reactant which chamber is connected, to at least one tubular member for guiding the second fluid reactant into the reaction zone. A directional control plate is secured transversely in the second inlet means and this plate is provided with an opening for each tubular member to extend there through so that the plate coaxially forms an annular opening around each tubular member enabling the shielding fluid in the second inlet means to flow unidirectionally through the annular opening and then into the reaction zone.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 show respectively a top view partially cut away and a cut away side view of the upper portion of a reactor having a nozzle as presented in this invention.

FIGS. 3 and 4 show'respect ively a top view partially cut away and a cut away side view of the upper portion of a reactor having another embodiment of the nozzle presented in this invention.

FIGS. 5 andti show respectively a top view and a lsectionalside view of the lower portion of a nozzle FIG. 8 shows another topview of a p fefiarred embodiment of the lower portion of a nozzle which has four tubular members symmetrically arranged on an irrgtginary circle.

DETAILED DESCRIPTION OF THE INVENTION The foregoing objects have been accomplished in a new nozzle for thermal conversion of fluid reactants in the presence of an autogenous flame in a' reaction zone. Referring to FIGS. 1 and 2 there is presented an apparatus having a nozzle generally designated by the number mounted in a supporting means such as a cover 11 which forms an air tight seal (which can be disconnected) with reaction vessel 12 defining an enclosed reaction zone 9. First inlet means in the form of two tubes 13 are mounted and sealed in cover 11 on opposite sides of tube 18. Vessel 12 has an outwardly protruding space 14 which holds a pilot burner 15 which can receive gas and maintain a pilot flame 16 to initiate a flame reaction.

The nozzle 10 has a second inlet means in the form of tube 18 with two tubular inlets 19 for introduction of a fluid, particularly a shielding fluid. The tube 18 is positioned preferably in a centrally located opening in cover II and sealed in an air tight seal by seals 17. The tube 18 has a cover 20 with an opening for a tubular inlet 21 for introduction of a fluid, particularly a second fluid reactant. A third inlet means is disposed within tube 18 in the form of tubular chamber 23 defining a volume 22 for receiving fluid from inlet 21. Chamber 23 has eight openings in portion 24 of size equal to the outer diameter of eight tubes 25 which are connected to chamber 23 such as by welding or threading so that tubes 25 receive the gas mixture from chamber 23. Tube 18 extends farther into the reaction zone 9 than tubes 25 by the distance generally designated A directional control plate 26 is secured transversely in the lower portion of tube 18 at a distance 1 above the open ends of tubes 25 and this plate is provided with openings through which tubes 25 extend.

The plate 26 coaxially forms an annular opening In a preferred use of the nozzle of this invention for conversion of uranium hexafluoride to a uranium dioxide rich composition, a continuous flow of a reactant of a reducing gas selected from the group consisting of hydrogen, dissociated ammonia and mixtures thereof is maintained in tubes 13 in the direction of the arrows throughout the reaction so that there is a strong reducing atmosphere generally maintained in the .reaction zone 9. A shielding gas is fed through inlets 19 into tube 18 in the direction of the arrows into the reaction zone 9. The shielding gas can be a non-reactive gas selected from the group consisting of nitrogen, argon, helium, neon, krypton, xenon and mixtures thereof or the shielding gas can be a reactive gas selected from the group consisting of oxygen, air or a mixture thereof, or either air, oxygen or a mixture of air and oxygen with any of the foregoing non-reactive gases. A reactant comprising a mixture of uranium hexafluoride and an oxygen-containing carrier gas is fed through inlet 21,

chamber 23 and tubes 25 into reaction zone 9 in the direction of the arrow in inlet 21. The oxygen-containing carrier gas is selected from the group consisting of oxygen, air and mixtures thereof. The flow's of the gases in

tubes

18 and 25 occur so that the shielding gas in tube 18 surrounds the jets of gaseous reactant coming from tubes 25 as the gases enter the reaction zone 9. The shielding gas shields the mixture of uranium hexafluoride and the oxygen-containing carrier gas from the reducing gas for' sufficient time so that the boundary of initiation of the reaction flame 28 in the reaction zone 9 is removed from contact with tube 18 and this is referred to as a lifted flame. The reaction results in a bright orange flame.

Another configuration of the nozzle generally designated by the number 30 is presented in FIGS. 3 and 4 using two concentric

outer tubes

33 and 38. The nozzle 30 is mounted and sealed by seals 37 in a supporting means such as a cover 31 which forms an air tight seal (which can be disconnected) with reaction vessel 32 defining a reaction zone 29. Vessel 32 has an outwardly protruding space 34 which holds a pilot burner 35 which receives gas and maintains a pilot flame 36 to initiate a flame reaction.

The nozzle 30 has a first inlet means in the form of tube 33 with tubular inlets 47 for introduction of afluid reactant and a second inlet means in the form of tube 38 with two tubular inlets 39 for introduction of another fluid. Tube 38 has a cover 40 with an opening for a tubular inlet 41 for introduction of a fluid. A third inlet means is disposed in tube 38 inthe form'oftubular chamber 43 defining a volume 42 for receiving fluid from inlet 41. Chamber 43 has eight openings in the portion 44 of size equal to the external diameter of tubes 45 which are connected to chamber 43 such as by welding or threading so that tubes 45 receive the fluid from chamber 43.

Tubes

33 and 38 extend further into the reaction zone 29 than tubes 45 by the distance generally designated d. A directional control plate 46 is secured transversely in the lower portion of tube 38 at a distance 1 above the open ends of tubes 45 and this plate is provided with openings through which tubes 45 extend. The plate 46 coaxially forms an annular opening around each tube 45. Plate 46 forces the shielding fluid to pass through the annular openings and then into the reaction zone surrounding the jets of fluid reactant from tubes 45. The relation between the size of the holes in the plate and the thickness of the plate 46 is such that the shielding fluid passes between the plate 46 and the tubes 45 in approximately unidirectional flow toward the reaction zone 29. The symbol The preferred use of the foregoing nozzle of this invention is for conversion of uranium hexafluoride to a uranium dioxide rich composition similarly to that described for FIGS. 1 and 2.

FIGS. 5 and 6 present another embodiment of the directional control plate here assigned the number 50 showing only the lower portion of the nozzle and 6 tubes 45. The nozzle is similar to the nozzle presented in FIGS. 3 and 4. Plate 50 is fastened to the inside of tube 38 at points 51. Plate 50 has a multiplicity of openings 52 enabling the shield gas to flow through the openings 52 as well as through the annular openings 53 around each of the six tubes 45. This has the advantage that a double layer of shielding gas is formed, one layer immediately around. each jet issuing. from tube 45 and one layer generally surrounding all the tubes 45. This gives further protection against the build up of solid reaction products at the tip of

tubes

38 and 33. While this embodiment of the plate has been presented for the nozzle of FIGS. 3 and4, it can also be utilized. with all the otherembodiments as presented in this invention.

FIG. 7' presents another embodiment of this invention in which only atop view of the lower portion of the nozzle is shown andtten tubes 60 are arranged symmetrically on an" imaginary circle inside tube 63 with directional control plate 61 having annular openings 62. for passage of the shielding fluid. aroundtubes 60 through annular openings 62. toward the reaction zone. FIG. 8 presents still another embodiment of this invention in which only a top view of the lower portion of the nozzle is shown and four tubes 60 are arranged symmetrically on an imaginary circle inside tube 63 with directional control plate 61 havingopenings 62 for the passage of the shielding fluid arounditubes 60 toward thereaction zone.

The term tube used in the description of this invention is meant to include any cross sectional configuration for such members including, but not limited to circular, square, rectangular and triangular cross sections. It is also preferred to have. the. tubes for the second reactive fluid. positioned symmetrically so that if the points forming the centers of the tubes were connected they would form a circle, but it isalso meant to be within the scope of this invention to have nonsymmetrical arrangements of these tubes.

The dimensions of the directional control plate are controlled so that unidirectional flow of the shielding fluid occurs in the annular openings between the plate and the tubes (e.g., 25, 45, etc.) carrying the second fluid reactant. In particular the thickness of the directional control plate and the sizeof the. openings in the plate are correlated so that unidirectional flow of the shielding fluid occurs in theannular openings. ln practice, when the tube guiding the shielding fluid has an inside diameter in the range of about 2.0 to about 6.0 inches and the tubes guiding the second fluid reactant have an outside diameter of about 0.250 to about 0.840 inch, a directional control plate thickness of about 0.062 to' about 0.750 inch and'openings in the plate of about 0.375 inch to about 1.340 inches in diameter result in unidirectional flow of the shielding fluid through the annular openings in. the plate. It is preferred that the distance 1 (Le, the distance between the openings of the tubes guiding the second fluid reactant and. the directional control plate.) be in the range of 0.01 to about 2.0 inch. in this manner the plate is located close to the open ends of the tubes guiding the second fluid reactant so that the shielding fluid closely surrounds the jets 9 the s dfluiqt qtant eit er ea e e reaction zone.

The distance d, which specifies the distance the tubes guiding the second. fluid reactant are recessed within the tube guiding the shielding fluid, can vary depending upon the velocities of the shielding fluid and the second fluid reactant. Generally the smaller tubes guiding the second fluid reactant (i.e., 25', 45, etc.) terminate within the shielding fluid. tube (i.e., 18, 38, etc.) by a distance of at least about one-eighth inch and preferably in the range of about one-eighth of an inch to about one-half an inch. As a general. rule, the larger the diameter'of the shielding fluid tube (i.e., 18; 38, etc.), the greater is distance d. This recessingof the tubes guiding the second fluid reactant more easily enables maintaining. a lifted flamewith lower flow rates than required without the recessing of the tubes guiding the second fluid reactant.

While preferred embodiments of the invention have been described, it is to beunderstood'that changes and variations may be made without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:.

l. A nozzle'for injecting fluid reactants into a.reaction zone comprising, in combination a. a supporting means supporting b. a first inlet for receiving and guiding afirst fluid reactant into the reaction zone,

0. a second inlet means for receiving and guiding a.

shielding fluid for temporarily separating the first fluid reactant anda second fluid reactant upon initial injection into the reaction zone,

d; a. third inlet means for receiving and guiding the second fluid reactant into the reaction zone. the third inlet means being disposed in the second inlet means and the third: inlet means having a chamber with at least one opening therein which is connected. with at least one. tubular member with the tip of said. tubular member being recessed within the second. inlet means, and

e. a directional control plate being securedv transversely in the second. inlet means, theplate having an opening for each of the at least one tubular member to extend therethrough coaxially forming an annular opening around the at least one tubular member so that the shielding fluid flows unidirectionally through theannular opening and then into the reaction zone.

2. The nozzle of claim 1 where the supporting means is a cover which removably fits with a vessel to define the reaction zone.

3. The nozzle of claim 1 in which the chamber of the third inlet means has four openings which are connected with four tubular members.

4. The nozzle of claim 1 in which the chamber of the third inlet means has six openings which are connected with six tubular members.

5. The nozzle of claim 1 in which the chamber of the third inlet means has eight openings which are connected with eight tubular members.

6. The nozzle of claim 1 in which the chamber of the third inlet means has ten openings which are connected with ten tubular members.

7. The nozzle of claim 1 in which the chamber of the third inlet means has a plurality of openings symmetrically located and the openings are each connected with a tubular member.

8. The nozzle. of claim l'in which the first fluid reactant is a reducing gas, the second fluid reactant is a mixture of uranium hexafluoride and an oxygen-containing carrier gas and the fluid is selected from the group consisting of nitrogen, argon, helium, neon, krypton, xenon, oxygen, air or'mixtures of any of the foregoing.

9. The nozzle of claim 1 in which the first inlet means and the second inlet means are concentric tubular members.

10. The nozzle of claim 1 in which the first inlet means is a plurality of tubular members located at a position on the supporting means removed from the second inlet means.

11. The nozzle of claim 1 in which the directional control plate has openings in the form of slits adjacent the second inlet means so that a second layer of shielding gas is formed around the at least one tubular member.

12. The nozzle of claim 1 in which the third inlet means is recessed within the second inlet means by a distance of at least about one-eighth of an inch.

13. The nozzle of claim 1 in which the first fluid reactant is selected from the reducing gases consisting of dissociated ammonia, hydrogen and mixtures thereof.

mixtures of any of the foregoing.

Claims

1. A nozzle for injecting fluid reactants into a reaction zone comprising, in combination a. a supporting means supporting b. a first inlet for receiving and guiding a first fluid reactant into the reaction zone, c. a second inlet means for receiving and guiding a shielding fluid for temporarily separating the first fluid reactant and a second fluid reactant upon initial injection into the reaction zone, d. a third inlet means for receiving and guiding the second fluid reactant into the reaction zone, the third inlet means being disposed in the second inlet means and the third inlet means having a chamber with at least one opening therein which is connected with at least one tubular member with the tip of said tubular member being recessed within the second inlet means, and e. a directional control plate being secured transversely in the second inlet means, the plate having an opening for each of the at least one tubular member to extend therethrough coaxially forming an annular opening around the at least one tubular member so that the shielding fluid flows unidirectionally through the annular opening and then into the reaction zone.

8. The nozzle of claim 1 in which the first fluid reactant is a reducing gas, the second fluid reactant is a mixture of uranium hexafluoride and an oxygen-containing carrier gas and the fluid is selected from the group consisting of nitrogen, argon, helium, neon, krypton, xeon, oxygen, air or mixtures of any of the foregoing. gas.

14. The nozzle of claim 1 in which the second fluid reactant is a mixture of uranium hexafluoride and an oxygen-containing carrier gas selected from the group of oxygen, air and mixtures thereof.

15. The nozzle of claim 1 in which the shielding fluid is a gas selected from the group consisting of nitrogen, argon, helium, neon, krypton, xenon, oxygen, air or mixtures of any of the foregoing.