US2381372A - Liquid fuel feed control - Google Patents

Description

Aug. 7,' 194s.

I1'. J. 'STEPHENS 2,381,372 LIQUID FUEL FEED CONTROL i 4 original FiledAug. s, 194e` i 7? I i l q *76 70 l l 65 \l y HIGH FULL .LQ/izh- LOWFUELv l Y. Li/ C A v al n v j \V MNNOILLINEI y v v OVEN a7 L- Y .INVENTOR i, TmmnsJSi'ephens, W

Patented Aug. 7, 1945 .facilem- Theipresent#invention AL`relates; broadly-Lto the y l'lb iii-nglof-lliquidtuel;fsuchrforiexample.as f-uel fland has reference speciiically I to-the confthe result-that. an; 'almost exact temperature can f be continuously maintained in the zoneoffheat -rrc onsum-ption- I `til/leans;i or-carrying theinvention intol eiTect; is

lustratively:5.exemplied :inthe. accompanying 4fdrawingfn which therlgure shows.J a control feed idevice:gappliedto-the baking chamber of an oven', whichchamber maylbe vconsideredas representae o f any zone wherein@heat'isr absorbed by a Aproduct lor, otherwise consumed or vrendered Referring tofthe drawing; Gland-163 denote ,two 'uprightiflengths of gstandard .twoinch pipe which .farenunited by "means of a 4cross-fitting t4. The '.fupperxend offethezlowerfpipe 63` isrreduced by a bronzefinishing;` *65% havingan inside diameter of inches. 4"Af-flen-gthnof light 1,1/2 inch diameter brass 'tube 16BI isrslidablyxdisposed through v*the bi-'shlirigwthin.thefpipesGZ and 63 and is of sufcient length to extend below the bushing 65 and above the level of an atomizing nozzle 61 under allV conditions of service. The upper pipe 62 is loosely closed at its top by a cap or other apl propriate fitting having a concentric opening 69 at vits upper end. A inch rod 10 passes slidably through the opening 68 in said cap and is concentrically xed. at its lower end to the upper end of said brass tube B6. The brass tube and rod assembly are slidably disposed relative to the pipe assembly 62-63 in a manner which allows the rod and tube to be actuated by gravity. A radial arm 1I is attached to the Vpipe 62 by being clamped thereto near its upper end. At the outer end of said arm an upwardly 'extending post 12 is xed, the upper end of which pivotally supports one end of a movable lever 13. Intermediately of the post andthe pipe and on the f arm a pressure operated bellows 14 is located,v the f lolledifeedvcfl sucnz fuel .un Aresponse to cheatwde- PATENT foss-laca- LIQUID-FUEL FEEDJCONTROL n I I l U i V.'lj-hoiriars QStephens, New York,

j oiginaiapplipation Auguste, `1940, serial No. l 350;927; Dvidedand this application April24,

1... .-1943,serialfzNopisasso i bellows used being preferably of the known ylphon typewhich -is* covered lby a protective "housing: 15having' a guiding tube V1f5'iitted cony''centrically'in"itstcp A"ro`d-11 is slidably iitted A5 inythe'tubewith its vlower 1 end resting on the "head-of theybellows and engages the said lever "1S-by means of afslidable connection 18. The 'other-end jof the `lever 13 yis Ipivotally andl slid- Y"aib'lyconnectedto^said rod 10 in such manner .10 `fthat-upward or downward-movement of the lever v{jwillfrespec'ztive'ly,elevate and lower the tube. 'O pe'rfrings 119 are-provided in the wallof the brassftbe (l'at-an elevation below thelevel of @the'bu'rner nozzle'-when Atheitube is' in its maxifffngfuel'foil@from-iailsourcel of supply is connected 'lto a-.pipe'l ywhich isconnectednto .one of the lateralfopenings ofsa'i'dr cross-ttingll. The. op- `VApositella'teral opening of -lsaid cross is connected i"ing-nozzle 61. ffAsthezpump istoperated, fuel :oil willflow into the cross-fitting 64 and ll 'f the annular .space l'f'above I the lzbushing. '65. between the .pipe 62 and I thebrasstube' 66' untiliits ylevel reacheszthe open- Sings -1llin` the litube.y The oil thenzilows through :,said .'openingsland Ydownwardly through; the brass vftube 62 and: pipe :6311t'o a' return .pipe connection Iilfthrough' whichitlreturnsio .the source of fuel l 30. .iSupply from which; it -.was drawn 'by the pump.

'-In ith-is; manner faicontinuousisupply of fuel oil @in excessllof that required bythe;operation is .fcirculate'd. .1-.rIhe1fuel' oil fin the lateral branch 1:18-2v`vhich suppliesuithe atomizer f61 will standat .35 the'zsame ylevelzasin ltheseannular space in the lspipegZ. I Thus, by elevatingor': lowering the slidable tube 66, the Aoil supply level, below the atomizer in the pipe 82 is respectively elevated or lowered. Theatomizer nozzle 61 is of the 40 vaspirating or Venturi type and is operated by a supply of steam or compressed air maintained at constant pressure, and delivered to the nozzle through a tube-84. Under constant conditions of aspiration the quantity of fuel projected from the nozzle will vary on an inverse ratio to the distance through which the liquid is raised by the aspirating influence.

The said Sylphon bellows 15 mounted on the carrying 'arm 1| is provided with a gasket to minute bleed opening 'in its base. The pressure tight tube 84 communicates between the interior of the bellows and the supply of steam or compressed air which comprises the aspirating or atomizing agent for the fuel. An electrically .establish a pressure tight seal except for a operated valve 86, normally open, is placed in said latter tube. An electric switch normally closed is operative by a heat sensitive instrument thereby allowing pressure to be exhausted `fromthe interior of the bellows 14 through said bleed opening 85. The lever arm 13 is provided with a weight 89 which, together with the weight of the rod and the tube 66 is sufficient to cause the tube 66 to descend as pressure is exhausted from the bellows 14, thus lowering the level of the liquid fuel in the supply pipe 82 to the atomizer, resulting in diminishing of fuel feed to the zone of combustion.

Inasmuch as the lifting power of the lever 13 is applied intermediately of its tWo ends and one end is pivotally fixed, it is obvious that the range of movement of the other end will be limited by the position of the lifting element 18. The housing 15 of the bellows 14 is slidably mounted onthe arm 1I in a manner such that it can be shifted along the arm 1I and fixed thereto in any position between a point near the fulcrum of the lever 13 and a point near its opposite end. The expansion of the bellows 14 is limited by its contactfwith the top of the housing v15, thus defining the maximumelevation of the rod 10. The descent of the rod 10 is limited to that position at which the lower end of the slidable connection 18 rests upon the upper end of the tube 16.l Accordingly, by adjusting` the position of the housing 15 together with its assembled parts 16, 11 and 18, the differential between the low level and the high level of the opening 1S can be varied from a very considerable differential to a very slight one to meet the requirements of a wide variety of operations. For example, in an operation in which heat consumption proceeds at a uniform rate a slight differential in the fuel levels resulting in a slight Variation between lowre and high fire is desirable; on the other hand, vin the case of an operation in which heat consumption `is considerable for a short period and inconsiderable during a succeeding period, a wider range between high re and low re is desirable in order to cover both conditions economically. In all cases the high fire should be such as to generate a quantity of heat slightly in excess of the rate of heat consumption and the low re should be such as to generate a quantity of heat slightly less than the rate of heat consumption. The high fire will correspond to the high level and the low fire to the low level of the fuel in the stand pipe 62.

It is to be noted that the present invention is useful only in combination with aspirating atomizers. The term aspirating atomizers designates that type of atomizing nozzle or device through Which gas, such for example as compressed air or steam under pressure, when released through the nozzle, vis capable of elevating liquid from a level beneath that of the nozzle -and projecting it, in finely divided form,

suspended in the jet issuing from the nozzle. A synonym for aspirating atomizer or nozzle is ,"Venturi-tube or Venturi nozzle or any combination employing the Venturi principle.

I claim: l. In a heat generating and consuming apparatus, the combinationfof a combustion chamber,

a stationary aspirating nozzle disposed to deliver atomizedliquid fuel into said chamber, means for passing through said `nozzle an aspirating agent maintained at uniform pressure, a rise pipe communicating between said nozzle and a source of fuel supply, means for supplying fuel under pressure to said pipe, and an overflow `mechanism arranged for cooperation with said pipe to maintain the fuellevel inthe latter below that of the nozzle and including means for automatically varying the vertical distance between the level of said nozzle and the overflow level and, thus, the level of the fuel in said pipe in response to the varying demand upon the combustion chamber for heat between a predetermined high level and a predetermined low level, both below the level of said nozzle.

2. In a heat -generating and consuming apparatus the combination of a combustion chamber, a stationary aspirating nozzle disposed to deliver atomized liquid fuel into said chamber,y means for passing through said nozzle an aspirating agent maintained at uniform pressure, a rise pipe disposed between said nozzle and a source of fuel supply and in communication therewith, means for supplying fuel under pressure to said pipe and an overflow mechanism arranged for cooperation with said pipe to maintain the fuel level in the latter below that of the nozzle and including means for automatically varying the overflow level and thus varying the level of the fuel in said pipe in response to the varying demand upon the combustion chamber for heat.

THOMAS J. STEPHENS.

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