US3265313A

US3265313A - Device for mixing two fluid streams

Info

Publication number: US3265313A
Application number: US470280A
Authority: US
Inventors: Paris Jean Cambile Hyppolyte
Original assignee: SECRETARIAT DE M MARSOT
Current assignee: SECRETARIAT DE M MARSOT
Priority date: 1962-05-01
Filing date: 1965-05-12
Publication date: 1966-08-09
Anticipated expiration: 1983-08-09

Description

A Ug- 9, 1956 J. c. H. PARIS 3,265,313 I DEVICE FOR MIXING TWO FLUID STREAMS Original Filed May l. 1962 2 Sheets-Sheet l` a Flg.1 6

`JEAN CAMILLE HIPPOLYTE PARIS INVENTOR.

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Aug. 9, 1966 J. c. H. PARIS DEVICE FOR MIXING TWO FLUI-D STREAMS 2 Sheets-Sheet 2 Original Filed May l, `1962 111 111177111/ lll/[1mi INVENTOR:

/ IIIl/l/j/J/ lll l I7] I lll/1 S m. D.. w. O D| W. H E .L H. m C N A E J BY Wfl 9329 Attorney United States Patent O 605s 4 Claims. (el. Z39-427.5)

This is a division of application Serial No. 191,594, tiled May l, 1962.

My present invention relates to a device, such as an oil burner, in which streams of two fluids are to be intimately commingled within a mixing chamber.

An object o-f this invention is to provide an improved mixing device of this character adapted to insure a thorough intermingling of the particles, e.-g. as required in a burner designe-d to operate with a silent, substantially soot-free llame.

I have found, in accordance with the instant invention, that this obje-ct can be realized in a simple and effective manner by the provision of a set of annular baffles spacedly surrounding the outlet end of a nozzle Within a generally but not necessarily exactly cylindrical shell having an open end beyond the nozzle outlet, these .bailles forming one or more outwardly diver-ging channels for a fluid (such as combustion air) to be admixed with another iluid (eg. fuel oil) discharge-d in a substantially conical stream from the nozzle. The baflles serve to suppress turbulence at the nozzle by dividing the air flow into a primary branch hugging the nozzle and asecondary branch directed outwardly toward the inner shell wall by way of the aforementioned channel or channels, the latter air ilow being ultimately combined with the conical nozzle spray at a location closer to the open end of the shell so that substantially the entire air input is utilized without losses. If the nozzle and the shell are so dimensioned that the conical spray reaches the shell wall ahead of the open end, the outwardly diverted secondary air flow may have sutllcient force to penetrate the cone of rarelied fuel in the zone of intersection; other- Wise it will be desirable to provide special detlecting means, such as an inturned ledge at the open end of the shell, for directing this secondary air toward the cone axis. The number of bailles may vary Wi-th the dimensions of the burner, yet they preferably include an inner baille and at least two outer baffles with axially and radially staggered edges facing the oncoming air flolw.

The invention will be described hereafte-r with reference to the accompanying drawing in which:

FIG. 1 is a side-elevational view, partly in longitudinal section, of an oil burner embodying the invention;

FIG. 2 is a sectional view similar to that of FIG. l, illustrating a modification;

FIG. 2A is a similar view of a modification of the system of FIG. 2;

FIG. 3 is a view similar to FIG. 2 showing a further modification;

FIG. 4 is a view taken on line IV-IV of FIG. 3;

FIG. 5 is a fragmentary sectional view similar to that of FIG. 3 but showing still another embodiment; and

FIG. 6 is a view taken on line VI-VI of FIG. 5.

In FIG. 1 I have shown an oil burner comprising a conventional nozzle 1 forming the terminal part of a conduit which extends from a controllable source (not shown) of fuel oil under pressure. Nozzle 1 is coaxially surrounded by a cylindrical shell 6 and has an outlet 1a designed to emit a stream of atomized fuel oil A in a conical spray with apex angle a toward the open end of the shell. An air stream B directed toward that open end "ice is created within the shell 6 by suitable forced-circulation means such as a blower 7.

A set of

annular bailles

3, 4 and 5 are coaxially disposed in the path of the air flow B between the nozzle 1 and the shell 6. The innermost baille 3 is of V-shaped cross-section so as to form a converging inner surface 3a and a diverging louter surface 3b. The vertex of the V, pointing in the upstream direction of flo-w, forms a sharp annular ridge 3c substantially in the plane of the nozzle outlet 1a. The baille 3 is also advantageously provided with peripherally spaced per-forations 3d to help create some circulation in the forward space within the V (see also FIGS. 3 and 4). The

outer baffles

4 and 5 are of frustoconical shape and `lie parallel to the diverging surface 3b of inner baille 3. Thus there are defined between the

bailles

3, 4 and 5 a pair of diverging annular -channels 8 and 9, the apex angle of these channels and of the conically diverging sur-faces of

bailles

3, 4 and 5 having been designated b. The baffles are xedly supported from the shell 6 by sui-table stays 16 of small air resistance so as to be spaced from the nozzle 1 and the shell 6 to provide additional air passage. A pair of spark electrodes 2, energizable over an ignition circuit not further illustrated, are disposed in the space between nozzle la and baille surface 3a to light the llame of the burner.

The

outer baflles

4 and 5 have

upstream edges

4a and 5a which are relatively offset in axial and radial directions so that the air layers deviated into the channels 8 yand 9 are of substantially constant width; thus, the radial staggering of these edges relatively to each other and to ridge 3c may be substantially equal to the width d of each of these channels. It is not absolutely necessary that the downstream edges 3e, 3f, 4b, 5b of the three batlles terminate all in the same plane as shown in FIG. l; channels S and 9 should, however, be long enough to prevent the flow of any air therethrough in the axial direction.

`In operation, the oncoming air divides at ridge 3c substantially without turbulence into a primary flow B1 detllected inwardly by baille surface 3a and a secondary flow B2 vdirec-ted outwardly by

bailles

3b, 4 and 5. Whereas kthe primary flow B1 joins the fuel spray A in the vicinity of nozzle `outlet 1a, the secondary flow B2 passes along the inner wall 6a of shell .6 until it strikes an inturned ledge 6b of the shell at the yopen end thereof and is deected inwardly and slightly rearwardly toward the axis of Icone A. Ledge 6b forms with shell wall 6a a rounded corner whose angle c may .be close to as shown, though it could also be `an obtuse angle.

It will be apparent that the converging surface 3a of lbaille 3 promotes the .circulation of air in the vicinity of nozzle 3 in a sense counteracting the suction created by air tlow B2 so as to minimize or prevent carbonization of both the nozzle outlet 1a and the baille surface 3b. The airflow past the baffles 3 to 5 will be substantially laminar since the diversion of the secondary air through channels 8 and 9 reduces the possibility of turbulence within an axial plane. If desired, however, a certain rotary twist may be imparted to the air stream B2 by means of suitable vanes as described hereinafter with reference to lFIG. 3. Substantially all the ai-r delivered by blower 7 will be admixed 'with the fuel spray A, partly directly vi-a path B1 and partly over the circuitous path B2, so that the burner will operate at maximum efficiency. The tlame maintained forwardly of nozzle 1 =will be detached from its -outlet 1a by the flow-directing action of baille surface 3a.

The intensity and character of the llame will, of course, be controlled by the rates by which air and fuel are delivered to the interior of shell 6 and nozzle 1, respectively. YIn many instances it will also be advantageous to be 3 yable to control the size of the llame by changing the width of the discharge end of the shell, eg., with the aid of a manually controllable iris-type diaphragm 11.

=In FIG. 2 I have shown an otherwise identical bu-rner in which the baies 3', 4', 5 have

tubular extensions

23, 24, 25 with inturned ledges 23a, 23b, 23e terminating along the periphery of the cone A to discharge the secondary air substantially radially into the cone.

FIG. 3 illustrates the possibility of omitting the deflecting edge 6b of the previous embodiments, the nozzle outylet Ila being here so designed that the diameter of the cone A at the mouth of shell 6 equals substantially the shell diameter. Thus the axially owing secondary air B2 mingles with the fuel spray of cone A at a location `where this spray is substantially attenuated so as to be re-adily penetrated by the air. FIG. 3 also illustrates the provision of vanes 12 for setting the air flow B2 in rotation about the axis of the cone A.

I.ln certain cases, particularly with a high-power blower, it will be desirable to replace the

baille

3 or 3 of the preceding embodiments by an annular disk 13 positioned forwardly of the

upstream edges

4a, 5a of the outer bales 4 and 5 (or their modifications 4 and 5'). This can be seen in FIG. 2A in which the baffle 3 of FIG. 2 has been replaced by the disk 13 and has been illustrated in FIGS. and 6 which also show two circular arrays of perforations l1i3a, 13b provided in the baffle plate .13 for the purpose mentioned in connection with perforations K3d. With bale plate 13 dispos-ed slightly downstream of the nozzle outlet 1a, the flame will again be detached from the nozzle to avoid the deposit of soot thereon. The system operates otherwise in substantially the manner previously described.

IFurther modifications of the arrangement described and illustrated, including substitutions and combinations of compatible features from different embodiments, are of course possible and are intended to be included in the spirit and scope of the invention as defined in the appended claims.

I Claim:

l. In an oil burner, in combination, a cylindrical shell having an open end, fuel-supply means including a tubular nozzle extending substant-ially axially within said shell and terminating therewithin ahead of said open end, said nozzle having an outlet spaced from said open end for ydischarging a substantially conical stream of atomized fuel toward said open end, means for Creating a generally ax-ial air ow in said shell toward said open end, and annular baffle means spacedly surrounding said nozzle with an annular clearance in the path of said air ow, said baffle means forming at least one `su-bstantially frustoconical channel diverging from the vicinity of said nozzle outwardly toward said shell in the direction of said open end for subdividing said lair ow into an inner branch through said clearance and along said nozzle allowed to mix with said atomized fuel in the vicinity of said outlet of sa-id nozzle and into an outer branch diverted through said channel toward said shell for mixture with said conical stream at a location forwardly of -said outlet toward said open end, said baille means comprising an inner baffle and ya plurality of outer baffles, at least said outer baffles having substantially frustoconical surfaces forming said channel therebetween, said -inner baffle being disklshaped and disposed in a plane transvere to the nozzle 'axis while being provided with vat least one circular array of perforations transverse to the axis of said shell and in the path of said air flow for passing individual axial streams thereof through said perforations in the direction of said open end.

2. The combination according to claim 1 wherein said outer baies each have a tubular forward extension directed toward said open end and are provided with an annular inturned deflecting ledge terminating substantially at the perpihery of said conical stream.

3. in an oil burner, in combination, a substantially cylindrical shell having an open end, a source of axial air flow opening into said shell at a location forwardly of said open end and trained toward the latter, fuel-supply means including a tubular nozzle extending axially within said shell at a location intermediate said source and said open end, said nozzle having an outlet disposed ahead of said open end for discharging a substantially conical stream of atomized fuel toward said open end, a set of coaxial centrally symmetrical annular bale-s separated by a first annular clearance from the inner annular wall of said shell and spacedly surrounding said nozzle in the region of said outlet for intercepting an intermediate part of said air flow and deilecting it outwardly toward the inner wall of said shell while giving passage to an outer part of said air fiow through said first clearance and to a nonrotating inner part of said air flow through a second annular -clearance separating said battles from said nozzle whereby said inner part mingles with said conical fuel stream just beyond said outlet, said baffles having parallel frustoconical surfaces dening a plurality of jutxaposed frustoconical channels for directing said intermediate part as a plurality of parallel laminar flows of outwardly diverging shape toward said inner wall, said baffles terminating at a plane perpendicular to the axis of said shell rearwardly of said outlet in the direction of flow of said air and fuel through the burner, and annular guide means within said shell close to Said end for deflecting 4said cylindrical flow radially inwardly and thence together with said outer part as a cylindrical flow coaxial with said inner wall toward said conical fuel stream for intermingl-ing therewith at a location substantially beyond its zone of merger with said inner part, said outer 'baffles each having a respective cylindrical tubular forward extension directed toward said open end and provided with a respective annular inturned deflecting ledge terminating substantiallyat the periphery of said conical stream and forming part of said guide means.

4. In an oil burner, in combination, a substantially cylindrical shell having an open end, a source of axial air flow opening into said shell at a location forwardly of said open end and trained toward the latter, fuel-supply means including a tubular nozzle extending axially within said shell at a location intermediate said source and said open end, said nozzle having an outlet disposed ahead of said open end for discharging a substantially conical stream of atomized fuel toward said open end, a set of coaxial centrally symmetrical annular baffles separated by a first annular clearance from the inner annular wall of said shell and spacedly surrounding said nozzle in the region of said outlet for intercepting an intermediate part of said air flow and deecting it outwardly toward the inner wall of said shell while giving passage to an outer part of said air flow through said rst clearance and to a nonrotating inner part of said air flow through a second annular clearance separating said baffles from said nozzle whereby said inner part mingles with said conical fuel stream just beyond said outlets said baffles having parallel frustoconical surfaces dening a plurality of juxtaposed furstoconical channels for directing said intermediate part as a plurality of parallel laminar flows of outwardly diverging shape toward said inner wall, and annular guide means within said shell close to said end for deflecting said cylindrical flow radially inwardly and thence together with said outer part yas a cylindrical ow coaxial with said inner wall toward said conical fuel stream for intermingling therewith at a location substantially 'beyond its zone of merger with said inner part, said outer bales each having a tubular forward extension directed toward said open end and provided with an annular inturned deilecting ledge terminating substantially at the periphery of said conical stream and forming part of said guide means, said set of baflles including an inner vbaille and a plural-ity of outer bales, said inner baffle being disk-shaped and disposed in a plane transverse to the nozzle axis while being formed with at least 5 6 one `circular `array of perforations in the path of air ow FOREIGN PATENTS through 'Shld Shell- 16s,969 7/1934 switzerland.

3 References Cited by the Examiner 178351 9/19 5 Swltzerland UNITED STATES PATENTS 2,344,519 3/1944 Nagel 158 76 JAMES W. WESTHAVER, Examiner.

5 FERDERICK L. MATTESON, JR., Primary Examiner.

Claims

1. IN AN OIL BURNER, IN COMBINATION, A CYLINDRICAL SHELL HAVING AN OPEN END, FUEL-SUPPLY MEANS INCLUDING A TUBULAR NOZZLE EXTENDING SUBSTANTIALLY AXIALLY WITHIN SAID SHELL AND TERMINATING THEREWITHIN AHEAD OF SAID OPEN END, SAID NOZZLE HAVING AN OUTLET SPACED FROM SAID OPEN END FOR DISCHARGING A SUBSTANTIALLY CONICAL STREAM OF ATOMIZED FUEL TOWARD SAID OPEN END, MEANS FOR CREATING A GENERALLY AXIAL AIR FLOW IN SAID SHELL TOWARD SAID OPEN END, AND ANNULAR BAFFLE MEANS SPACEDLY SURROUNDING SAID NOZZLE WITH AN ANNULAR CLEARANCE IN THE PATH OF SAID AIR FLOW, SAID BAFFLE MEANS FORMING AT LEAST ONE SUBSTANTIALLY FRUSTOCONICAL CHANNEL DIVERGING FROM THE VICINITY OF SAID NOZZLE OUTWARDLY TOWARD SAID SHELL IN THE DIRECTION OF SAID OPEN END FOR SUBDIVIDING SAID AIR FLOW INTO AN INNER BRANCH THROUGH SAID CLEARANCE AND ALONG SAID NOZZLE ALLOWED TO MIX WITH SAID ATOMIZED FUEL IN THE VICINITY OF SAID OUTLET OF SAID NOZZLE AND INTO AN OUTER BRANCH DIVERTED THROUGH SAID CHANNEL TOWARD SAID SHELL FOR MIXTURE WITH SAID CONICAL STREAM AT A LOCATION FORWARDLY OF SAID OUTLET TOWARD SAID OPEN END, SAID BAFFLE MEANS COMPRISING AN INNER BAFFLE AND A PLURALITY OF OUTER BAFFLES, AT LEAST SAID OUTER BAFFLES HAVING SUBSTANTIALLY FRUSTOCONICAL SURFACES FORMING SAID CHANNEL THEREBETWEEN, SAID INNER BAFFLE BEING DISKSHAPED AND DISPOSED IN A PLANE TRANSVERSE TO THE NOZZLE AXIS WHILE BEING PROVIDED WITH AT LEAST ONE CIRCULAR ARRAY OF PERFORATIONS TRANSVERSE TO THE AXIS OF SAID SHELL AND IN THE PATH OF SAID AIR FLOW FOR PASSING INDIVIDUAL AXIAL STREAMS THEREOF THROUGH SAID PERFORATIONS IN THE DIRECTION OF SAID OPEN END.