US2357587A - Oil burner - Google Patents

Description

v Sept. 5, 1944. K. M. HAMMELL OIL BURNER Filed Feb; 25. 1942 2 Sheets-Sheet 1 K'EMPEH M HAMMEL Sept. 5, 1944. K. M. HAMMELL OIL BURNER Filed Feb. 25, 1942 2 Sheets-Sheet 2 gwvem bwu KEMPEP M HAMMELL q @k'w Patented Sept. 5, 1944 on. BURNER -Kemper-*M. Hamniell, Toledo, Ohio, assignor to The Swartzbaugh Manufacturing Company, Toledo, Ohio, a corporation of Ohio Application February 25, 1942, Serial No. 432,208

' ,-16 Claims.- (miss-91) I This invention relates to oil burners, and is more particularly directed to. a pot typeburner and the air and fuel feeds therefor.

The primary object ofathe present inventionis to provide a pot type oil-burner] in which the primary air inlet, secondary air inlet and fuel inlet are all controlled simultaneously to the end that fuel introduced into the burner is consumed properly, and at, relatively high eificiencies.

Another object of the invention is to provide to the constant fuel level inthe sump i4 and if the burner pot is lowered the fuel 'head'isincreased and more fuel will enter the pot in a given time than -if the burner pot is-raised to decrease theeifective head of fuel. Q'I'hus, for ahigh" fire the burner pot is moved down and for a low" fire the burner pot is moved upwardly to decrease the rate of'fuel supply. The-sump air distributing means within the burner defining zones of combustion and serving the additional function, of causing intimate admixture of the partially hydroxylated fuel with the" subsequently introducedair. v; Still another object of the invention is to providea burner which requires no forced draft, but which will burn ordinary furnace oil with an efficient, smokeless flame using adraft as, low as 104 inch and which will havean extended range of fuelnconsumptionrates,on such draft. Still another object of the invention is to provide-a burner in which the primary and secondary air are introducedat a rate which varies with the rate of fuel inputfa'nd in which the fuel feed means isso constructed as tomaintain a constant rate of supply at low fires.

Another, objectfis to provide a? burner which may readily be removed from the furnace, dis-' assembled, cleaned and replaced without disturb ing furnace, flue connections, etc.

Other objects and advantages of the invention will become apparent as thedescriptionproceeds, reference being had to the accompanying drawings, in whichf Fig. lis a fragmentary vertical sectional view of a furnace and burner pot embodying the present invention; Fig. 2 is a section on line 22"of Fig; 1; Fig. 3 isan enlarged fragmentary view ofthe upper section of the burner pot; Fig. 4 is a central vertical section of "a" modification of the invention and Fig. 51s a section on line 5-4 of Fig.4.

Referring to the drawings, in Figs. 1 and 2 the invention is shown in one embodiment incorporated in a heater having a Jacket lliheated by a burner pot l2 and supplied withfuel from a constant level sump l4 through a flexible pipe l8. zFuel is maintained at a constant level in the sump It by anyof several well-known devices, and the combustion rate is varied by varying the rate of introduction of the fuel through pipe Iii into the bottom of, the burner pot i2. It willbe seen; that the effective head of fuel depends on the vertical position of the, burner pot relative II is provided with a strainer ll which surrounds the upper end of a fuel conduit l8, which fuel conduit is provided with a metering orifice of relatively large dimensions, designated l8; It will be appreciated that by using a large orifice l5 andvarying the effective hea'd'of the fuel,

much moreaccurate control on low firesis obtainable than if the head of the fuel remained the same and the size of the orifice varied. Mod

ern fuel oils have a tendency to clog a small orifice over a period of time, and for this reason a furnace which adjusts its rate of combustion by adjusting the size of the port through which fuel flows to the furnace is unreliable on flow? fire because of the tendency of the fuel to clog the port and cut the fire 08- entirely. a

The burner pot I: has a generally circular cross-section, and is provided adjacent its upper end with an enlarged secondary air supply zone 18, the lower'part of the pot forming a hy-'- droxylating zone 20; Between the hydroxylating zone 20 and the-secondary air supply'zone IS the pot tapers as at l9,

The base of the pot I2 is providedwith a circular'opening which is closed at its upper end'by a primary air distributing member or super: charger 2 2 which is a flattened hollow lriodyand which is provided with openings 24 in its upper and lower surfaces through whichair passes both upwardly and downwardly to combine with the fuel vapor. In addition to the holes" 24; the supercharger is further provided with lanced openings 26 in its lower surface adjacent-the v inner edge, so-that air passing from suchopen ings passes rapidly outward across thelower surface of the supercharger body fi. As used herein, alanced opening maybe defined as one" which is substantially normal to-thepi'erced surface andresults from rupture of tneysurracealong a singleline and displacement ofa portion' of the surface material in the form'of a The supercharger serves to define'two bulge. precombustion zones, one above andone -below' itself in, each ofwhich the oxygen of theair com--v bines with the hydrocarbonvapor in a hydroxyl ating process.

A primary air control valve- 28- i'sfcarried opening being dependent upon the extent of movement of the pot. The number and location of the holes in the supercharger body are such that no substantial secondary combustion occurs at this point, that is, no flame is visible.

In addition to the primary air supplied through the supercharger, the sides of the pot II are further provided with primary air openings, preferably in three series, being designated 36 in Fig. 1. It has been found in practice that drilled holes will ordinarily sufllce for the openings, but in some installations it is desirable to lance alternate openings in the second series, thereby pro viding a tangential direction for the air passing through such openings and giving a slight swirl to the mixture at that point.

Secondary air enters the pot through a plurality of series of openings 38, individually designated as 38, 38*, 38, 38 and 38.". The upper end of' the .burner pot slides vertically in the lower wall 40 of a combustion chamber or furnace 42,

rows of the holes, for example 38- and 38, a burner is provided which burns very satisfactorily through a range in which the fuel consump tion varies as much as six or eight to one, and which will not growl" or pulsate when the bumer is rapidly turned from one extreme position to the other. The flame is stable under all conditions and the combustion is essentially complete, as practically no carbon is deposited in the flue of the furnace, even though the draft used is kept to a minimum.

In the form shown in Figs. 1 and 2 adjustment of the burner is, as previously indicated, made by moving the fire pot bodily in a vertical direction with reference to the combustion chamber 42 and the remaining parts of the furnace ii. For this purpose, the burner is carried on a cross member 48 and the cross member is vertically adjustthe upper end of which communicates with a suitable flue outlet, which is not shown. It will be appreciated that the form and disposition of the combustion chamber is conventionaland no claim for improvement is made in connection with this part. By raising or lowering the pot l2, one or more of the series of secondary air openings 38 is exposed and utilized for the introduction of secondary air to the previously partially hydroxylated fuel vapor. The supply of air to the entire burner is, of course, taken from the floor under the furnace and up through the interior thereof in the space around the burner pot l2.

A fire bailie 44 is provided within the burner pot and is carried preferably by the stem and is spaced vertically from the supercharger and laterally from the interior wall of the burner pot, so as'to force the fuel vapors passing upwardly into the combustion chamber into close and in-,

timate contact with air entering through the secondary air openings 38. The fire baille 44 thus assures a complete intermingling of the fuel vapor and secondary air and prevents any "starved zone in the center of the ascending body of vapor which might result in a smoky, incompletely burned mass of fuel. Further, the flre baflle cooperates with the tapered portion I9 of the burner pot to define an annular orifice for the passage of -fuel into the secondary zone It, which orifice is automatically increased in size as the burner pot is moved down for higher fire.

It has been found that in most installations more satisfactory burning of the fuel vapor can be had if the flame in the combustion chamber is kept relatively short in'its vertical dimensions and is given a directional movement such that the path of movement of the burning mass within the combustion chamber is lengthened by fol@ lowing a helical path. For this purpose certain series of secondary air openings 38, for example 38' and 38, may be lanced to, give the flame a rotary movement of any desired velocity, the velocity being dependent upon the number of lanced holes as compared to the number of drilled opening through which air enters radially into the secondary combustion zone I8. It has been found in use that by lanclng alternate ed at one end by a control lever 48 which operates on a connecting rod 50 attached at one end to the control lever and at its other end to one end of the cross member 48. For automatic operation, the connecting rod 50 may be left stationary and used as a fulcrum about which the cross member 46 is pivoted and operated by a thermostat motor 52 connected to the rear end of the lever through a connecting rod 54 and operated in response to a suitable thermostat T. For manual operation, the pivot between the connecting rod 54 and the cross member 48 remains stationary and the pot is moved by the connecting rod 50 and control lever 48.

It will be seen that by pivoting each end of the cross member 46, a seasonal control can be had from this combination of elements. For example, if the control lever 48 is moved to lower the burner pot, which would result in a normal "high fire, the thermostat motor 52 can be used to cause a fluctuation of the burner from, for example high to "medium" fires. However, if the control lever 48 is turned to raise theburner pot to the "medium" position, the thermostat motor, operating through the same range, will cause a fluctuation in the fire from, for example, "low" to medium." This feature is of considerable advantage since it may be employed during mild weather to maintain a relatively constant low fire and during severe weather to maintain a relatively constant "high fire, but, of course, the device may be set to operate in any range between these extremes, depending on the severity of the climatic conditions.

An additional feature of construction is of considerable importance in connection with the present invention, in that the burner pot I2 is readily removable in its entirety from the furnace for cleaning or needed repairs. In order to remove the burner, it is only necessary to disconnect the coupling 56 where the fuel pipe ll enters the burner pot and to uncouple the connection between the cross member 48 and the thermostat motor connecting rod 54' at the rear end and the manual control rod 60 at the front end. The burner pot I! will then move downwardly in the furnace to such an extent that its upper end becomes completely free of the lower wall 40 of the combustion chamber 42, and by unseating the rod 30 from its adjustable stop 32 in the lower furnac member 34 'the entire burner and its supports 48 and rod 30 may be moved'outwardly through an access door 58 in established. It has been found in practice that" less than a minute :is required tocompletely dis-g,

connect and remove theburner from the furnace.

' A modified form of the invention is shown in Figs; 4 and 5.- In thisformthe burner pot is left stationary and adjustment oi the primary rain-secondary air," and fuel supplies made by an interrelated mechanism. Thus the various factors which influence the rate and character of burning withinthe pot are simultaneously controlled, as in the modification previously de scribed.

fully lowered by the thermostatKthepot can.

:The combustion control mechanism in this modification includes a fuel "valve 70 which may be any satisfactory, non-jclog'ging construction, operated by rotating a stem 12. g The stem 12 carries a cam 14 which drives a cam follower "and operator plate l8. The operator plate is connected to a belllcrank lever 8|! pivoted to I the furnace on a bracket 82. One arm ofthe bell crank lever, 8ll', operates, the primary air -valve by lifting its stem 30'. Theother. arm of the bell crank lever controls the secondary air H pot l2 causing an increase in the heat, and e' raising of the pot causingthe fuelconsumption to be reduced.

fseasonal' -control. For example lithe manual control ismoved to the "low fire" position, in

which. the potls raised about'to the dotted ine position indicated atL in Fig. 1 thethermostatic controlwill then operate between the: lower tire position anda medium fire position,. since, when travel. only i'ar enoughto expose about half of the secondaryairholes. -In-moresevere weather the manual. control is moved to the'medium fire position-which.;is shownqinfull lines :in Fig. 1 and. the ,thermostat then operates between the medium andzhigh fire positions becauseits mo.- tion is sufficient to-lowerthe pot enough to ex'-, pose all of the secondary air holes and give the.

' maximum efiective fuel ahead thus giving the supply by rotating a perforated, circular 'plate I highest possible fire. 1

While the invention has been described in con nectionwith two modificationsit will be'appre ciated that numerous other =modillcations willsuggest themselves to'those skilled in the art'and: that such modifications are included within'the scope of the appended'cl'aims.

What! claim-'asnew and desire to'secure United States Letters Patent is? '1. In'a'device for burning liquid hydrocarbon fuel, a pot having apertures in its side wall and pot and passes up around the .supercharger where it receives primary air' bothfrom the perforations in the side of the pot and from the regulated in quantity by the primary air con trol valve 28. j e Combining with the primary air in a hydroxyl"-' 'ated mixture the fuel passes "upwardly in the pot andis forced outwardly by the fire baflle 44 into intimate contact withthe secondary air.en

interior of the supercharger. This latter air is tering through the' periphery of-=-the top. The

secondary air is-controlle'd in quantity either by raising or lowering thepot to exposeone or more series of openings'a's in Fig.1 or by increasing or decreasing the registry of openings 86 and 88 to admit more or less air into the plenum chamber 90 in Fig, 4. The thoroughly. hydroxylated mixture is'then burned in the combustionjchamberv l2 thecontour and length of the flame being largely controlled by the directional characterise tics imparted to it by the secondary air stream.

As previously notedfit is frequently desirable to impart a whirling motion to the flaming gases t'o lreep theflames' short for complete com'bus tion in a furnace whose vertical dimension is smallL- To adjust the degree of heat output the user may turn the'manual control lever 48 in Fig. l

or the stem I2 in Fig. 4. This operation causes a simultaneous change inai'uel input, primary air input and secondary air input. In other words, the user does not make an adjustment of, any singleelement which enters into the combustion, but adjusts all elements at once.

' Should a thermostatic'control be used,'assuggested in Fig. 1, operation of the thermostat motor causes a movement of the parts to give an increase ordecrease in'the amount of heat by raising or lowering the pot 12, a loweringoi the having an open toppmeansto introducefuel-into said pot, primary air distributing nieansdisposed within said pot and comprising a flattened hollow body, controllable means to supply air to the" in terior of saidbodyfisaid body having perforations in its upper and lower surfaces todistribute air downwardly and outwardlyl into" a first" precombustion zone immediately over the body of fuel in the bottom of said pot and upwardly and outwardly into af-second precombu'stion zone; means to introduce secondary air adiace'nt'the top of said pot and means to vary thefquantit'y' of'secondaryflair slmultaneouslygwith the q es tity' of, primary air introduced into said" hollow body.

2:111 a device for burningfliquid hydrocarbon fuel, a pothaving apertures in its side wall and haying'an open top;said pot having a top portion e: enlarged diameter withjrelat'ion tdthelO'wer portion thereof," a tapered side portion 10m,-

ing said upper and lower portions of the, pot, means to introduce fuel'into the-bottom 'of's'aid pot, means to introduce primary air into the'jiower portion of said pot, means to introduce secondary air into the enlarged upper portion of said pot, a tire baflle disposedfwithin 'saidpotand forming with said" tapered portion an annular orifice Ebetween said upper and lower portions'of the pot, and meansto change the relative vertical disposition f said'ifire baffle, end said tapered wall portionwhereby the effectivearea of the oriflce between them may be increased or decreased.

" 3. Ina device for burning liquid hydrocarbon *fuel, a pot having openingsiin' its lower portion for the admission of primarylair to its'lowerinterior portion and having openings in its side wall for admitting secondary air to its upperinterior portion, mea'ns'fo'r supplying fuel to the iewer interior portion of the pot, separate valve means for respectively controlling the "admission of'primary air to'the pot through said first openings and secondary air to the pot, and means oper- As previously" 1eserjibci', the eeasses and. manual controls may'be combined" to give'a,

=taneously and in predetermined proportions the admission .ofprimary and secondary air to the pot An arrangement has called for in claim 3 wherein the .means which actuates the separate air admission valve means also connects to and is operable to control the fuel supply means to vary the supply offuel to the pot simultaneously with "and in predetermined proportion to the aadmissionlof primary and second air. n

l 5. In a device for burning liquid hydrocarbon fuel, Ja' pot having apertures in itswtop portion for the admission of secondary -;air ?and being mounted for vertical movements, means cooperating with said apertures to vary the amount of air admitted to-the pot when the latteris vertically moved, and means operable to move said potto eifect such movements.

6. In 1a device-for burning liquid hydrocarbon fuel, .a fuel pot mounted for vertical movement andhaving apertures in its top portion for the admission of secondary :air and having apertures in its lower portion for the admission ofprimary air to the interior of the pot, separate means for varying the quantity of air permitted toenter the pot through said upper and lower sets of apertures when the pot =isvertically moved, and means for admitting fuel to the pot below said apertures. 7; In a device for burning liquid hydrocarbon fuel, apot having an imperforate bottom portion for holdingfuel, means for supplyingfuel to said bottom'portion, means interiorly of the pot above its bottom andforming an airchamber with perfo'rated walls for discharging air upwardly and downwardly. into the interior of the pot and having an air admission port in its bottom, a valve controllingsaid port, and means operable to ere .able atO actuate said valve means to vary simulthroughsaid upper andlower sets of apertures when the pot is vertically "moved and including a valve element in association "with said'upper set of apertures and a valve element in association with said lower'sot of apertures. andmeans operable to supply fuel to the pot, the quantity of fuel supplied being "dependent on the elevation ofthe pot. I

. 11. In a device'jfor burning liquid hydrocarbon fuel, a fuel pot, means forming a chamber within the lower portion of the pot and having an air inlet opening and o nings'for discharging air from the chamber into the pot. said pot and means vbeing in fixed relation,a valve for said inlet opening, one of said valve and pot being vertically movable relative to the other to open and close said inlet opening, means for supplying fuel to the pot, means'for controlling the supply of fuel tofs'aidpot, and means connecting ate relative movement between said valve'and controlling the supply of fuel to'said pot and the supply of primary and secondary air thereto, and means connecting said several controlmeans and operable to impart simultaneous movements thereto to vary in predetermined proportions the admission of fuel and of primary and secondary air to the pot.

. '9. In a device for burning squis y-amass fuel, a pot for containing liquid fuel in its hottom portion, means operable to control the supply of fuel to the pot, means forming anair chamber interiorly of the pot andhaving openings for discharging primary air into the pot and an'air, inlet opening, said pot and'the chamber forming means being mountedfor vertical movemen s e h r. me ns foreifecting said move ments, and means for closing'said inlet opening when the pot is in one position of its movement and to progressively open it [when the .pot is moved from such position. p

.10. In a device for burning liquidhydrocarbon fuel, a fuel pot mountedfor verticalflmovements and having apertures in its top portion for the admission of secondary air thereto and having apertures in its lower portion for the admission ofprimary air thereto, means operable to vary the quantity of air permitted to enter the pot said last means 'and the movable one of said valve and pot t -cause the supply of fuel to the pot and the supply of'air to the chamber through said inlet opening, to be varied in unison and in predetermined relation when the fuel control means is operated,

12. In a device for burning liquid hydrocarbon fuel, a fuel pot having openings in its upper portion for admitting secondary air into the pot, a chamber disposed within the lowerportion of the pot in fixed relation thereto and having an inlet opening for admitting air thereto and, outlet openings for discharging primary air into'the pot, separate valve means for said first-mentioned openings and the inlet opening to said chamber, means for supplying fuel to the lower portion of said pot,'means for controlling the supply of fuel to the pot, and means operable by said fuel controlmeans to actuate said separate valve means to control the admission of air to the upper portion of the pot and to the interior of; said chamber in predetermined proportion to the fuel supplied to the pct.

13. In a device for burning liquid hydrocarbon fuel, a fuel pot having air admission openings in its upper side wall portion and air admission openings in its lower portion and also having an internal enlargement in its side wall, a bafiie 'in the upper portionof the pot between said upper and lower air-admission openings and spaced from the enlarged portion of the pot wall, one of said pot and baille being vertically movable relative to the other and when moved cooperating with the other to vary-the size of the space between the baflle and pot, means for'supplying fuel in variable quantity to the bottom portion of the pot, and means operable to effect relative movementsof said baflleto vary the size of the spacebetweenfthebafiie and pot enlargement in accordance with: the quantity of fuel supplytothe pot. a

14. In a device iorfburning liquid hydrocarbon fuel, a fuel pot having an upper set of openings for admitting secondary/air to the pot and a lower set of openings'for admitting primary air to the pot and'having-a tapered sidewall between said sets of openings, means forming a chamber in the lower portion ofthe, pot and having a porsaid tapered sidewall portion, and means for effecting relative movement of the stem and pot lengthwise of the stem whereby said inlet opening is varied by the valve and the space between the heme and pot wall is varied in predetermined relation with said variation in the inlet opening.

. having a portion at least of said lower set of openings, said means having an air inlet opening, a stem projecting up into the pot through said means and inlet opening, a valve on said stein for closing said inlet opening, a baflieon said stem within the pot adjacent and in spaced relation to said tapered side wall portion, and

means operable to raise and lower the pot relative to the stem to eflect opening or closing respectively or the valve and a respective simultaneous enlarging or restricting of the space between the baflle and pot wall. v

16. In a device ior burning liquid hydrocarbon fuel, a fuel pot having an upper set 01' openings for admitting secondary air to the pot and a lower set oi openings ior admitting primary air to the pot and having a tapered side wall portion between said sets of openings, means forming a chamber in the lower portion of the pot and having a portion at least of said lower set of openings, said means having an air inlet open ing, a stem projecting up into the pot through said means and inlet opening, a valve on said stem for closing said inlet opening, a battle on said stem within the pot adjacent and in spaced relation to saidtapered side wall portion, and

means to raise and lower said stem relative to the pot to simultaneously move the valve and bailie to increase or diminish the quantity of air permitted to pass through said inlet opening and to accordingly increase or diminish the size 01 the space between the baflle and pot wall.

KEMPER M. HAMMEIL

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