US2569887A - Combustion apparatus, including flame type ignition means - Google Patents

Description

1951 R. H. GODDARD 2,569,887

COMBUSTION APPARATUS, INCLUDING FLAME TYPE IGNITION MEANS Original Filed Nov.l8, 1941 2 Sheets-Sheet l a I; r- .2" I221 0 ,11 9 INVEHTOR I ROBERT H GODDARJLDEC'F J ESTHER GGonIARmExecuTmx BY mfimwa mw Oct. 2, 1951 R. H. GODDARD COMBUSTION APPARATUS, INCLUDING FLAME TYPE IGNITION MEANS Original Filed Nov. 18, 1941 2 Sheets-Sheet 2 m v5 H T R Roam-r H.GODIMRU,DEC'D ESTHER C. Gown/mu, Ex ecqm 1 x WILM/ EM Patented Oct. 2, 1951 COMBUSTION. APPARATUS, INCLUDING FLAME TYPE IGNITION MEANS Robert Goddard, deceased,zlate of Annapolis, Md.,.by Esther C. Goddariexecutrix, Paxton, Mass.,. assignor of one-half. to The Daniel and Florence Guggenheim Foundation, New York, N. Y.,. a corporation of New York fliiginal. application November 18,1941, Serial No. 419,617, now Patent No; 2,395,406, dated February 26,1946; Divided and this application: December. 19;; 1945, Serial No. 635,996-

4" Claims. 1?

This application isa division. of original application Serial No. 419,617,.filed November 18, 19.41:, now Patent Nos 2,395,406., issued. February 26,1946;

This invention relates to apparatus. particularlydesigned. for the. combustion of. a mixture oi liquid: fuel, as gasoline, and a liquid. oxidiz ing agent, as liquidrox-ygenl or liquid air. While certain features of: the invention are capable of general application, the invention is of exceptionaL value in connection with the propulsion of. rockets or rocket craft, in which gases are: continuously produced under. pressure in a oombustionchamber and are continuously ejected througha rearwardly open discharge nozzle.

An. important object of. the invention is to provide means to produce allarge ignition flame for a verybrief period, beginning: just prior to the admissionof gasoline and-liquid oxygen when starting the. apparatus To the attainmentofthis object, there is provided novel means for injecting measured'quantitles of liquid fuel and liquid oxidizer to the igniter chamber when the apparatus is about tcbe started, together with improved meansfor igniting. said intermingled. liquids. Provision is also'made for rendering the ignition means inoperative as-soon as. said: intermingled liquids are ignited.

The invention further relates to arrangements and.- combinations of. parts. which will. be hereinafter described. andmore. particularly pointed out. in the appended claims.

A preferred form of. the. invention isshown in: the. drawings, in which Fig. l is a side elevation, partly in section, of theimproved combustion. apparatus Fig. 2. isa sectional side elevationof a fuel feeding nozzle;

Fig. 3. is. a detail. sectional view,. taken along the line. 3-3 in. Fig. 2;

Fig. 4. isa. collective view, showing. structural .detailsofa deflector shown in. Fig. 2;

clbsing; device. to be described; and

Fig. I0 is a partial" side elevation of the inner wall of. the combustion chamber.

Referring to Fig. 1, the improved" combustion apparatus. preferably comprises a substantially spherical casing and a discharge nozzle H. A plurality of liquid fuel nozzles F and liquid oxygen nozzles H are mounted inspaced relation in the spherical side wall of the combustion chamber. Each nozzle F or H is also'located at the depressed apex of a rectangular pyramidal metal shield or guard structure I2.

The liquid fuel or liquid oxygen issuing from each nozzle is diverted by a deflector l4 and flows laterally therefrom and substantially parallel to the surfaces of its pyramidal shield f2. The sprays of fuel and oxygen intermingle at the edges a of" the substantially square areas defined by the shields l2',"as indicated'- in Fig. 10, and along these edges combustible mixtures are formed and-combustion largely takes place:

It will be noted in Fig. 1 that the combustion areas thus formed at theinterse'ctions a of the pyramidal guards or shields l2 are substantially spaced inward from the cylindrical casing Hi, as indicated at b. Overheating of the casing is thus prevented. Openings I 5 in the shields l2 equalize the pressures on the opposite faces thereof. l

The detailed construction of one of the fuel feeding nozzles F is shown in Figs, 2, 3 and 4. Each nozzle' consistsof' a tube 211' having arounded inner end welded orotherwise secured in an opening in the casing lll-and'having a feed outlet 2].

A" valve rod 22- is secured at the inner end of abellowsmember'fi, and the outer end of the bellows member is secured to the perforated outer end 20 of the tube 211': A compression spring S holds themember 23 normally distended.

The rod 22- is provided with vanes or guide members 25 (Fi'gi 3) by' which it'isloosely cent'ered in-t'hetub'e 20'but is freely slida'bletherein. Stops 2'6 are engaged by the vanes 25 to limit outward. movement of the rod 22. Al. ipe 211 provides liquid fuelifrom anysuitable source of supply; such: asza" pressure tank; through ashutoff; valve? V and reducing valveR', both of usual commercial construction.

. When thefuelpressureis sufficient to overcome the resistance of the bellows member Z3=andthe spring. St and the; atmospheric pressure. exerted on the bellows, the plunger or valve rod 2-2. will be. withdrawn. fromthe outlet 2 I r and. fuel willbe admitt'edto.thecombustionchamben H is exactly the same as that of the fuel feeding nozzles F, except that the oxygen nozzles and connections are preferably jacketed to prevent evaporation of the liquid oxygen, which might otherwise cause gas bind in the apparatus. One of the oxygen feeding nozzles H is shown in Fig. in which the jacket covering of the nozzle H and (5f its supply connection is indicated in broken lines. The liquid oxygen may be supplied from a second storage tank through a shut-61f valve V reducing valve R and pipe 28 all as previously described. y

The liquid feeding devices F and H are all constructed to open at the same pressure, and the reducing valves R and R maintain the liquid fuel and liquid oxygen always at equal pressures. Consequently, when the liquid pressure rises to a predetermined point, all of the feedin devices F and H will open simultaneously and will feed .their respective liquids into the combustion chamber.

v .The deflector I4 provided for each feeding nozzlepreferably comprises an inwardly pointed copper disc held in spaced relation to the opening 2| by supporting members 30 and 3|, which members are notched-and crossed as indicated in Fig.

4 and have their depending legs secured to the inner ends of the tubes 20. The members 3|] and 3t are seated in slotsin the deflecting disc and are preferably secured and protected by brazing material, such as copper, applied to the outer face of the disc.

The-fuel feeding devices F and the oxygen feeding devices H are alternately arranged in the inner surface of the casing l0, so that fuel and oxygen will interi'riingle along each dividing lin a between adjacent pyramidal depressions (Fig. r

The supporting members 30 and 3| are mounted' on the nozzletubes 20 in such angular positions that the depending legs thereof are aligned with the'corners of the pyramidal guards or shields l2, so that very little gasoline or oxygen .is sprayed along these corner surface intersections and consequently like liquids intermingle only slightly at the corners of the square deflecting areas shown in Fig. 10.

' The fuel and oxygen feeding devices adjacent ,the discharge nozzle I l and also adjacent the igniter K to be described are substantially the same as the nozzles previously described, except for the provision of special deflectors which divert the injected liquids in certain directions only, rather "than in all directions as with the form previously described.

One of these special deflectors is shown in Figs. 5 and 6 and comprises a deflecting element 33 mounted on a plate 34 which is secured to the inner end of the associated nozzle. The member 33 covers only a semi-circumference or less and is provided with a middle portion 35 and raised edge portions 36. With this construction, the liquid will be diverted toward the adjacent sprayed ?areas and away from the adjacent discharge outlet or ignition device. The raised edge portions 36 reduce the density of the spray at the edges reduce the amount of sidewise spray, where the nozzles F and H and the deflectors 33 are placed close together, as around the igniter K of Fig. 1.

Substantially the same density of spray is thus refractory lining 4i and Welded or otherwise se-- cured to the casing Hl opposite the discharge nozzle ll. Spark terminals T and T are mountmember 60.

ed at opposite sides of the casing 40 but are suitably insulated therefrom and extend through the refractory lining 4|. Wires 42 and 43 (Figs. '7 and 1) connect the terminals T and T to the secondary Winding of a spark coil 44.

One side of the primary winding of the coil 44 is connected by a wire 45 to a battery B or other suitable source of current, and the other terminal of the primary is connected by a wire 46 through a solenoid 50, wire 5|, second solenoid 52, wire 53, normally open contacts 54 and 55, and a wire 56 to the opposite pole of the battery B. The operation of these electrical connections will be hereinafter described.

In starting this improved combustion apparatus, it is desirable to have a relatively large volume of burning gases injected into the combustion chamber just prior to the admission of liquid fuel and oxygen through the nozzles F and H, so that the mingled sprays of these liquids may be immediately ignited, thus avoiding any danger of explosion. It is not necessary, however, that the ignition flame should continue after combustion is well started in the combustion chamber. Consequently the igniter K is provided with special devices for feeding limited quantities of fuel and oxygen into the igniter chamber K just prior to admission of fuel and oxygen to the combustion chamber C.

One of these special devices is shown in detail in Fig. 7, in which a bellows member 60 is mount ed within an enclosing casing 6!, the perforated outer end 62 of which forms a guideway for a rod 63 which extends outward from the plate 64 which forms the movable end of the bellows member 60. Gasoline is fed through a restricted connection 35 to the inside of the bellows member 60, which is thus normally filled with gasoline. A spring 66 is provided to deflate the bellows member 6|] but this spring is normally prevented from operating by a latch or plunger 61 which is seated in a notch 68 in the side of the rod 63 when the rod 63 is pulled out manually prior to starting. The spring 66 is too strong to be compressed by the liquid pressure in the bellows The plunger 61 extends into the solenoid 52 previously described and is actuated thereby. V

The casing 6! is mounted on a connection 70 extending through the igniter casing 40 and through the refractory material 4| and closed at its inner end, except for a relatively small opening H. An opening 12 connects the interior of the bellows member 60 with the interior of the connection T0, and this opening 12 is normally closed by a valve 13 having a valve stem 14 slidable in perforated partitions 15 in the connection 10. A light spring Hi holds the valve 13 normally closed against the pressure of the liquid in the bellows member 60.

The construction of the fuel feeding device above described is duplicated for the liquid oxygen, as indicated at til (Fig. l), the construction being identical except for the addition of the usual jacket to the oxygen feeding device.

Means fortiming the release of the liquids for the igniter with respect to the admissionof a; rod 82" which: is. non-conductive; of electricity and which. is: fixed; to the; movable end plate 83 of. the bellowsamember BI and slidable-through an opening in the; outer end of thecasing. 80. The, space between: the casing. 8.0 and the bellows member. 8!. isiconnectedbyv a-tubaMto the pipe 21:- by which fuel. is supplied to, the. fuel nozzles F.

A-compression spring S. holdsthe bellowsmember- 81 normally. distended.

When. pressure. is exerted in the pipe .2], the

. bellow membertl will. be compressed, causing the rod. 82. to-move the. contact 55,.into engagement with itsassociatedcontact 54', .thus completinsacircuit through the, so1enoilds'50l and 52.

soon as. these solenoids are energized, the ,solenoid plunger 61 are withdrawn, releasing the rods 63' so that the springs 68 may immediately 'deflate the bellows members 60 in the devices 6| and 61 and" eject the liquids therein through the openings H to the ignitionv chamber'K'. At the same time the spark coil 44 is energized, producing sparks between the terminals -T andT. The 'mixedliquids are thus ignited and the combustion 'gases are-injected intothe combustion chambe (-3 as a large volume of flame-which, however, is of relatively short duration.

The timing device shown in Fig. 9 'is set to'be deflated at slightly less pressure than the bellows members n in: the fuel and oxygen nozzles F and H. Consequently, the flame will be injected into the combustion chamber C slightly before the fuel and oxygen are fed from the nozzlesF and H. As soon as. the, ejecting action of the springs 65 and movable plates 64 has been completed, the valves 13. again close the openings 12 and prevent further operation of the igniter K.

Itis important that the timeelapsing-between the beginning orthe ignition flame and the admission of thel-iqu-ids be a minimum, in order toavoid burning or melting of the thin metal .structures inthe-chamber before they can be 5 protected by the-sprays of liquids.

In Figs. 1 and 8 there i shown the special construction which is provided for cooling the discharge nozzle I I. For this purpose there is provided aseries or longitudinally extendingstrips 99, each having a thickened edge portion 9| welded or otherwise secured to the inner surface of the nozzle II and each having its upper end curved over and secured as indicated at 92 in Fig. 1 to provide smooth entrance to the discharge nozzle. The inside surfaces of the edge portions 9| are curved, as at 9 l (Fig. 8) in order to avoid abrupt changes in direction of the streams from the nozzles F.

Fuel nozzles F are provided in the frustroconical wall of the nozzle ll, said fuel nozzles being spaced lengthwise of the discharge nozzle and also spaced apart circumferentially and being located behind the strips 90 as shown in Fig. 8. The nozzles F may be the same in construction and method of operation as the nozzles F previously described, except that no deflector is required The liquid issuing through the end opening of each nozzle engages the inner side of the adjacent strip 90 at an acute angle and is deflected circumferentially of the discharge nozzle, as indicated by arrows in Fig. 8.

The inner surface of the discharge nozzle is thusfieffectively cooled, while at thesa-me time there are no: shoulders nor openings inthe surface engaged by the ejected combustion gases and. consequently free discharge of the gases is attained. The nozzles F are commonlynor-flreduced' size and have smaller discharge openings than the nozzlesiF, so that only sufiicient liquid fuel is discharged therethroughto cool the adjacent metal surfaces. Combustion in the discharge nozzle is not desired.

Having described the details of construction of this improved combustion apparatus, it is believedthat the method of operation and the advantages thereof will be readily apparent.

In order to start the apparatus in operation, it is merely necessary to simultaneously open the valves V and V (Fig. 1), which valves are preferably connected by a link 95 and may be manually operated. The liquid fuel and liquid oxygen under pressurein the storage tanksthen pass through the reducing valves R and R and into the distributing pipes 21 and 281. As the pressure rises in the pipes 21' and 28 and in'the feeding nozzles F and H, the fuel under pressure will overcome the bellows member BI and thespring S (Fig. 9) and will thus completethe ignition circuit through the spark terminals T and-T". At the same time the solenoids 5'0 and 5-2; will release the rods 1E3. (Fig. 7), so that the bellowsrmembers 60 may discharge fuel and oxygen into. ignition chamber K, where the mixed liquidsareimmediately ignited.

:Such. ignition: takes place just prior to. the opening; of the valves F and as: previously .explained,.-so that a considerable volume ofaflame is. present in the combustion chamber when, the

fuel and oxygen are admitted thereto. The igniter K then goes out of operation through exhaustion of liquids. in the bellows members 60 and. the; igniter and. solenoid circuits: are broken by. continued, outward movement of the ,non conducting rod. .82 -Fig. 9).. A stop- 82 limits such outward movement.

The combustion gases in the combustion chamber C are then elected. through the discharge nozzle H... The Walls of the casing I 0 and, of the nozzle U are effectively cooled. and proczrctedv durin combustion by the shields l2 and the strips respectively and by the liquid films associated'therewith.

To stop operations, it is merely necessary to simultaneously close the valves V and V so that the feeding of fuel and oxygen to the combustion chamber will likewise be simultaneously stopped. This is desirable, as any residue of either liquid is objectionable and may cause damage to the apparatus, particularly if excess oxygen is present. Any residual fuel combining with any residual oxygen after the flow of cooling liquids has ceased may cause burning of the thin metal casings and shields and other light structures. It will be noted also that the perforations [5 in the shields l2 are all adjacent the oxygen nozzles H, so that no fuel will accumulate behind the shields and be present in the chamber after combustion has ceased.

The use of a relatively small number of feeding nozzles, spaced substantially apart, is an important improvement over the use of a large number of very small feeding orifices, which has been the previous practice. The larger outlets of the spaced nozzles substantially reduce friction losses. The terms combustion chamber and ignition chamber are used in the claims in their usual engineering sense to indicate both ,normally containing small and predetermined "chamber, means to ignite said intermingled liquids in said ignition chamber, thereby producthe enclosing structure and the area defined thereby and Within which combustion or ignition takes place.

' Having thus described the invention and the advantages thereof, I do not wish to be limited to the :details herein disclosed, otherwise than as set forth in the claims, but what is claimed is:

- 1. In a combustion apparatus having a combustion chamber, and valve means for admitting combustion liquids for continuous operation of saidchamber, in combination, an igniter chamher opening into said combustion chamber, means .to inject a predetermined amount of liquid fuel to said igniter chamber, means to simultaneously inject a predetermined amount of a liquid oxidant 1 into said igniter chamber, means to ignite said intermingled liquids in said igniter chamber, an electric circuit for said igniting means, and sequence-defining circuit-changing means effective to render said igniting means operative just prior! to the opening of said valve means to admit combustion liquids to said combustion chamber.

2. In a combustion apparatus having a combustion chamber and valve means for admittin combustion liquids for continuous operation of said chamber, in combination, an igniter chamher opening into said combustion chamber, means 3' to inject a predetermined amount of liquid fuel to said igniter chamber, means to simultaneously -inject a predetermined amount of a liquid oxidant into said igniter chamber, means to ignite said intermingled'liquids in said igniter chamber, sequence-defining means efiective to render said igniting means operative just prior to the opening of said valve means to admit combustion liquids to said combustion chamber, and a device to render said igniter means inoperative after a very limited time interval only.

- 3. In a combustion apparatus, in combination, a combustion chamber, means to feed liquid fuel and liquid oxygen to said chamber, an ignition chamber communicating directly and openly with said combustion chamber, storage devices adjacent and connected to said ignition chamber and amounts of liquid fuel and liquid oxygen, means to abruptly and simultaneously eject all of the .liquids stored in said devices to, said ignition ing an ignition flame of large volume but short duration which is directed into said combustion a combustion chamber, means to feed liquid fuel and liquid oxygen to said combustion chamber, an ignition chamber communicating with said combustion chamber, means to feed relatively small amounts of liquid fuel and liquid oxygen to said ignition chamber, valve means controlling the feed of combustion liquids to the combustion chamber, and feeding means controlling the feed of combustion liquids to the ignition chamber, means to supply said liquids to said valve means and to said feeding means under increasing pressure and each of said means becoming operative in response to the attainment of a predetermined liquid pressure thereon, and said feeding means responding to a lower liquid pressure than said valve means and thereby admitting combustion liquids to the ignition chamber before combustion liquids are admitted by said valve means to the combustion chamber.

ESTHER C. GODDARD, Emecutriac of the Last Will and Testament of Robert H. Goddard, Deceased.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,879,186 Goddard Sept. 27, 1932 2,016,921 Goddard Oct. 8, 1935 2,061,873 Hutton Nov. 24:, 1936 2,090,039 Goddard Aug. 17, 1937 2,117,108 Spencer May 10, 1938 2,279,546 Ziegler Apr. '14, 1942 FOREIGN PATENTS Number Country Date 735,757 France Sept. 6, 1932

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