US2204451A - Oil burner - Google Patents

Description

June 11, 1940- R. D. scHoENwET'n-:R 2,204,451

l OIL BURNER I Filed oct. 5. 193e 4 sheets-*sheet 2 duo: nu'

June 1l, l1 R. D. scHoENwE'rTER OIL BURNER Filed 0G13. 5, 1936 4 Sheets-Sheet 5 June 1'1, 1940. R115. scHQE-NWETTER I" 2,204,451

oIL BURNER Filedy oct. 5; 1956 4 sheets-shamA 4 Luz...

Perenled June 11, 1940l '9 yUNITED STATES PATENT' ori-lcs i OIL BURNER Reinhold D. sehoenweuer, Clarendon, ve., ee-

signor to Swirling Heat, Inc., a corporation of Delaware Application october s,

, e claims.

i This invention relates generally to oil burners, and more particularly to that type of burner adapted for use in furnaces of household heating systems. The specific type of burner contemplated by this invention involves means for imparting t'o the combustion supporting air streamV a violent swirling action which causes the air to commingle with the atomized fuel and thereby to quickly form a combustible mixture that will burn in complete suspension in such a manner that substantial carbon deposits are eliminated.

Additionally the invention contemplates means refractory bodies for their operation. Such construction retards heating efficiency, increases the cost of operation, and results in the formation of carbon which causes many of the diillculties experienced 'with such burners. Furthermore prior to initiating operation these refractory bodies are cold and a considerable quantity of oil is required to bring them up to normalloperating temperature. This obviously results in an appreciable amount of time being lost before the heat generated can become effective for heating the household.

Normally oil burners sold in industry today are assembled, tested and adjusted at a central plantwithout regard to conditions under which they are to operate. In practical installations, hardly any'two oil burners are installed tov operate under proper commingling of oil and air. The size and design of refractories differ according'to size and ,type of boilers.A The refractory is not a part of the burner and its design is leftto the questionable skill of the installation man with the result that many burners operate with a low ciliciency. b Deflectors for causing the with atomized fuel have come into wide use but the provision of an auxiliary defiector which will cooperate with the primary deector to causev ,overcome such difliculties as' have heretofore been encountered in the use of oil burners.

air to commingle 193s, serial no. 104,069

(Cl. 158-28) v VAdditionally this invention has for a primary object the provision of means' for so directing the lair supplied to the burner head that it will quickly form a combustible mixture with the atomized fuel without the aid of refractory bodies and which will be easy to ignite and will burn in complete suspension without the formation of objectionable carbon.

l -Another object of this invention is the provision of novel means whereby the volume and' Velocity of air supplied to the burner head may be controlled to form the best proportional combustible mixture with the atomizedfuel.

This invention further contemplates the` novel disposition of a group of secondary air passageways in such a manner that a portion of the supplied air will be directed tangentially against the fuel atomizing nozzle to effect a circling m'otion of air around the nozzle and thereby cool it. The air in its rising circling-motion, also serves to lift the stray oil spray into .the flame and will i, causeall of the oil to burn at a distance from the nozzle whereby carbonization of the nozzle is prevented.

Another object of this invention is to provide means for preventing the vformation'of a partial vacuum in the center of the inverted cone of air 4which :would normally cause the top of the flame to be drawn inwardly and downwardly with the result that the name would pulsate and Vbe excessively noisy. 1 f

This invention still further contemplates the provision of means for compensating for the unequal distribution of oilv by the atomizing nomle which when air is supplied all the way around'thev burner head uniformly, willcause thin spots in the flame.v W

Other objects and advantages will appear from the following detailed description when considered `in connection with the accompanying drawings wherein: y

`Figure 1 is a perspective view of a household type ,furnace with a portion of the wall thereof broken away to show the burner as contemplated by this invention installed therein; Figure 2 is a vertical elevation of the outer end of the burner showing the prime mover, ignitiontransformer, fuel pump and air pump or fan casingwith` a portion thereof broken away disclosing in detail the means wherebyethe amount of air supplied to the burner head may be adjustably controlled. i l

Figure 3` is a'plan view` of the entire burner;

4 is an enlarged detailed view of the lower air deeotor plate showing the tangentially disposed air passages;

Figure 5 is a vertical elevation of the lower air deector plate shown in Figure 4;

Figure 6 is an enlarged detailed plan view of a modified form of lower air deflector plate showing a plurality of symmetrically disposed vanes;

Figure 7 is a vertical section of the modified form of the lower air deflector plate taken along the line 1-1 of Figure 6;

Figure 8 is an elevation of the entire burner with the burner head and a portion of the air supply tube in vertical section;

Figure 9 is a plan view of the burner with the burner head removed showing the l air bafes which serve as a nozzle guide, and also showing the outer end of the burner in horizontal section thereby disclosing the fuel supply conduit and its assembled relationship to the casing;

Figure 10 is a bottom plan view of the burner head showing in detail the disposition Vof the upper air deilector vanes;

Figure 11 is a vertical elevation of the burner head showing the top cover which serves as an air director plate partially in section disclosing in detail the means whereby the upper air deilector plate is adjustably spaced from the cover plate;

Figure 12 is a vertical section taken along the line IZ-IZ of Figure 9 showing the fuel supply conduit in cross-section, and the vertical wall which divides the air passageway; and

Figure 13 is a vertical section similar to Figure 12 showing a modification of the air blast tube with the vertical wall omitted and the conductors as bus bars. i

Referring to the drawings in detail, particularly Figure l, a conventional boiler I of the household heating variety is shown with a portion of the side wall thereof broken away to disclose my improved oil burner, indicated generally as II, in operative position. In this instance the burner head I2 and air tube I3 are inserted through an opening in the bottom door Il of the furnace. The outer portion of the burner assembly is supported by adjustable legs I while the burner head is supported within the furnace by a third adjustable leg I5. 'Ihe burner head is preferably positioned centrally with respect to the diameter of the furnace and at an altitude approximating that of the ire grates in the conventional solid fuel burning furnace. This burner, unlike the gun type burners commonly known, is provided with a vertical stationary head adapted to supply the mixture of fuel and air in such a manner that the flame will burn substantially vertically, as indicated in Figure 1, rather than horizontally as with` gun type burners.

An air pump, blower, or air wheel I1, is mounted on the shaft of a motor I6 and is adapted to be driven by a source of power not shown. A fuel pump I8 having its shaft in substantially axial alignment with that of the motor I6 is connected to the motor shaft and is driven thereby by means of a flexible coupling. Blower I1 supplies combustion supporting air through the air blast tube I3 to the burner head assembly I2. Fuel is pumped from a supply not shown through conduit I9 fabricated of copper, brass or other suitable matcrial, into the strainer chamber 20 from which it is drawn by the rotary pump I8 into the pump chamber. Pump I8 discharges the fuel at a predetermined pressure through pressure controlling valves into conduit 2I which communicates with the conduit 22l leading to strainerY chamber 23 thence to an atomizing nozzle 2l. Superuous fuel delivered to the pressure controlling valves is discharged through an overflow conduit 25 that communicates with the tank or source of supply not shown. The strainer chamber 23 is disposed between the conduit 22 and the atomizing nozzle 24 and carries a fine mesh strainer 26 adapted to co-operate with the pump strainer to f-ree the oil which is fed to the atomizing nozzle 2l from extraneous matter that would tend to clog the orifice 21.

The fuel oil is discharged under pressure from the orifice in the form of a jet which if unmolested would be substantially conical in shape. This however is not the case for air supplied by the air pump or blower I1 through the air blast tube I3 is divided and deflected by my improved defiector means in such a manner that a, swirling motion will be imparted to it. This causes the combustion supporting air to be more intimately mixed with the atomized fuel to quickly form a combustible mixture.

'Ihe outer casing for my improved burner head is constructed in two parts, the bottom part 28 being in the form of an upturned elbow that is secured to the air blast tube I3 in a conventional manner. The upturned portion of the elbow is flared and provided with a vertical cylindrical wall 29 on which rests the upper portion 30 of the burner head casing. The upper portion of the burner head casing. is so formed as to have a depending cylindrical wall 3| which rests upon the vertical Wall 29 of the upturned elbow. The top face of the portion 30 is provided with an opening which cooperates with the deflector band 32 to form a bowl. The deiiector band 32 may be given any desired shape.

Supported in adjusted spaced relation to the top face of the burner casing 30 by suitable screws 35, is the air deflector assembly which is composed of an upper plate 38 provided with radial vanes 31 around the periphery ,thereof that cooperate with the cylindrical side wall of the casing to form a group of air passageways. These varies 31 which perform an important function in the operation of the burner are given a substantial pitch whereby the air forced through the passageways between them will have a swirling motion imparted to it. The air fed through these passageways will strike the inner surface of the top wall of the burner head casing at an acute angle of incidence and due to the continued supply of pressure will be forced inwardly and downwardly in the form of a swirling sheet tending to converge in the vicinity of the atomizing nozzle 24 Where it will then be forced upwardly in contact with the atomized fuel.

A lower deflector plate 38 is secured to the bottom of the upper deflector plate 36 and functions to keep the atomizing nozzle cool and to cause combustion to take place at a distance sufficiently remote from the nozzle to prevent the formation of carbon. Slots 39 in the'upper surface of plate 38 cooperate with the baffle plate 4U clamped between the upper and lower deflcctor plates by screws 4I, to form passageways for a secondary supply of air which is directed tangentially against the atomizing nozzle 24. The size of these passageways is sufficiently large to supply the critical quantity of air required to keep the nozzle 24 cool while the burner is in operation, thereby preventing the formation of carbon, An other purpose or function of the air passing through the passageways in plate 38 is that'its circling or swirling motion lifts any stray oil spray into theflame 'I u 4 thereby preventingthe spray-from1iepositingon by the air that is discharged from the burner head after passing 4through the vanes 31.

The opening in baille plate 40 is just suiciently large to admit the passage of that amount of air .required to keep the nozzle cool and to aid in' Y the support of combustion-in the immediate vicinity` of the nozzle. This opening in baille plate 40 has still another important function in4 that it causes .the air passing through it to rise from the burner head in the shape of a hollow inverted cone. This hollow inverted cone thus formed, however.'is of smaller diameter thany the hollow cone'of the primary air mentioned above. Thus, in effect, there is produced a hollow air cone within a hollow air cone. This distribution of the air causes the oil to burn with" a hollow llame. y

Lower deector plate 33 being provided with a centrally disposed opening 4l slightly greater in diameter than the diameter of the atomizing nozzle 24, but having a smaller diameter than that of the strainer casing 23, will, when assembled, eontact the strainer casing thereby permitting the atomizing nozzle to project upwardly through the openings in the dflectbr plates, The upperiportion 30 of the burner casing with the deflecting means adjustably secured thereto in assembled spaced 'relationship is adapted to be detached as a unit from the bottom portion 28 of the burner casing and when' replaced is properly aligned by the atomizing nozzle 24 and the opening 4|' in the lower deilector plate 38.

Disposed immediately below the detachable burner head assembly are baille plates 42, clearly shown in Figures 8 and 9, that perform dual functions, namely, to serve as a fuel supply nozzle rguide and as means whereby the air blast is deflected vertically to insure a llame that will be symmetrical with respect to the burner head. Defiector vanes 42 are secured in the bottomof the lowerportion of the burner casing in` any conventional manner such as, for example, by a screw 43.

It will be seen that air passing through tube i3 will strike against the baille plates 42 and be deflected upwardly in separate strata where it is divided into two groups of paths, the first group being defined by the deflector vanes 31 and the second group of paths being those disposed tangentially with respect to the atomizing nozzle in thelower defleetor plate 38.

To obtain the maximum efficiency from a burner ofy this character,l it is necessary `to properly proportion the amountof supplied air toV the amount of fuel atomized, otherwise one does not obtain complete combustion. In view ofthe fact that variations in draft caused by stacks of different altitude will cause a greater or lesser suction force to be exerted on the burner head, it is necessary to provide means whereby the amount ofl air escaping 'from the burner head may be controlled. This invention therefore also contemplates means whereby the inlet air to the air pump or blower I1y may be regulated as well as the volume and velocity ol air that escapes from. the vhead ol the burner to support combustion. This is in vpart laccomplished by placing in the inlet duct 44 to the pump. a damper or valve 45 that is pivotally mounted at 46 and 41 casing of the inlet duct "u, is biased ,mwsatheemsea position. The setting ofY the `damper iseifected manually .by means of a thumbscrew I2 whichextends from without the casing -throughgthertapped lhole I3 into engagement vwith -the"'"damper. construction is clearly shown in 'Figures v2 'and 8.

In conjunction 'withwthefdamper' 45 the air passing through theiburner head is further regulated by positioning the deflector plate assembly toward or away fromthe casing Il! of the burner head. :If the burner is to be installed in a system where a stack of-excessive altitude is used, considerable natural draft is applied to the burner head and, as a result, a volume of air in excess of that which is normally supplied by ythe fan or air pumpwouldpass through the burner head and result in an: improper combustible mixture with the atomizedfuel. On the other hand'.v

'Further in orderltc produce a flame that will4 burn most efllciently, i. e., which will not have thi'nspots in it, compensation must be made for the unequal distribution ci oil by the atomizing nozzle. unequal distribution of?. fuel a zone which receives too much air will appearr thin, while the reniainder of the zene will receive insufllcient air to support complete combustion. I'I have found that such a phenomena will resultv in -a flame one side of which will deposit soot or carbon streaksfon the vinside of a furnace while the thin side will not give a flame offmaximum radiant heat.v

To overcome this 'objectionable feature the upper air deilector plates with their radial'vanes are cast or moulded and used intheirrough condition. with the upper porton30' of the burner head and rotating the assembly about its vertical axis while the flame is burning the unevenness of the oil distribution from. the nozzle can be compensated for by the uneven air distribution thus produced by the rough upper air deilector plate. Obviously the upper defiector plate including its vanescould be formed in any conventional manner other than by moulding or casting,

.A modified' form of lower air deflector plate is shown in detail in Figures 6 and?. This plate differs from plate 38 shown in Figures lv and 5 in that it is provided with substantially radial vanes 54 very similar in construction and pitch to'those around the periphery of the upper deflector plate. The air `being forced through the passageways dened by these rvanes strikes the Then by assembling-the deflector plate Unless compensation is made for thisv bottom of thel baille plate 40 at an acute anglev Y of incidence, in a very similar manner tothat described'in connection with the upper deflector plate 3E, and converge'sinwardly through the passage formed between the baille plate .'40 and the annular portion 55 of the deflector plate in the form. of a swirling sheet to strike against the nozzle 24 to effect a cooling thereof and to cause 75' combustion to take place at a. distance sumciently remote from the nozzle to prevent the formation oi' carbon. The air at this point is defiected upwardly where it will lift any loose stray oil spray and commingle with the atomized fuel to aid in causing the flame to burn in complete suspension. The outside dimensions of this modified form. of lower defiector plate are the same as those of deiiector plate Il shown in Figures 4 and 5 and is adapted to be used interchangeably therewith with equal effectiveness.

As shown in Figure 12, the space within the air blast tube i3 is divided by a vertical wall 56 extending throughout the length thereof and forms a second air passageway 51 through which the conductors comprising insulated wires 58 which supply current to the ignition electrodes 59 may be passed. Such an arrangement obviously would prevent injury to the insulation on theconductors by the fuel nozzle when inserting it in the air blast tube or removing it therefrom.

In Figure 13 is shown a modification in which the vertical wall 56 has been omitted from the air blast tube and in which the flexible insulated conductors 53 have been replaced by substantially rigid bus bars 58' which carry suitable snap-connectors (not shown) to permit their easy insertion or removal.

A novel arrangement of means associated with the ignition electrodes whereby they may be adjustably positioned in the zone of ignition from a point outside the furnace is shown. This is being made the subject matter of a separate application and will be set out in detail therein.

Casting 60 which is secured to the outer end of the air blast tube in any conventional manner, is provided with openings 6| and 62. The opening GI is adapted to be closed by a side of the ignition transformer 63 when secured in operative relationship thereagainst. The other opening 62 in the casing is adapted to be closed by a plate il which has an elbow passageway 65 formed therein. Both openings 66 and 61 of the passageway are interiorly threaded to receive conduits 2| and 22,-respectively. Plate il is held in position by screws 68 and covers an opening which is so disposed that the fuel supply conduit 22, the strainer chamber 23 and the atomizing nozzle 24 can be withdrawn as a unit. This obviously is advantageous from a service point of view.

In operation when an electric current is supplied to the motor I6 it drives the blowervand fuel pump. The fuel pump supplies fuel oil through pressure controlling valves to the atomizing nozzle at a predetermined pressure. The atomized fuel commingles with the combustion supporting air that is supplied by the blower through the air blast tube I3 over baille plates 42 and finally through the adjustable upper and, lower air passageways. Thus a combustible mixture is quickly formed that may be readily ignited and will burn, due to the novel design of the deiiector plates, in complete suspension without the formation of objectionable carbon. Then to insure complete combustion and to obtain a flame that will give oil the greatest amount of radiant heat the amount of intake air to the blower is regulated by the valve or damper located in the inlet duct to the blower. It will be understood that the lower air* deflector plate could obviously be constructed and used without the baflie plate 40 by forming radial apertures therein instead of grooves 39.

The foregoing description conveys a clear understanding of the objects prefaced in the open- 'ing statements of my invention, and while said description is directed solely toward the construction illustrated, I desire it understoodthat the privilege is reversed of resorting to al1 the .mechanical changes to which the device issusceptible, the invention being defined and limited only by the terms of the appended claims.

I claim:

1. An oil burner vcomprising in combination a fuel atomizing nozzle. means for conducting air to and around the axis of said nozzle, air deflector plates disposed coaxially with respect to the axis of said nozzle, and means formed on each oi said plates for imparting a swirling motion to the air supplied to said nozzle. the upper surface of one of said plates being substantially in the same horizontal plane as the discharge end of said nozzle and another of said plates being substantially above said plane, whereby air is conducted to fuel sprayed from said nozzle both in the plane of the discharge end of the nozzle and thereabove.

2. In an oil burner, an oil atomizing nozzle, an air conduit delivering air about said nozzle and a detachable head at the delivery end of said conduit, said head comprising a. top portion forming an extension of the conduit, air deiiector means and means securing said deflector means below said top portion, and said air deffector means comprisingnn upper air deflector plate having a centrally-"disposed opening therein, substantially radialf'vanes on the periphery of the upper air defiector plate forming passageways for a portion of the air supplied to said head, a lower air deflectorplate secured to the bottom of the upper air deiiector plate and having a centrally disposed opening therein in alignment with the opening in the upper air deiiector plate, said lower air deflector plate having substantially V-shaped slots in the top surface thereof disposed in a horizontal plane and tangentially to the opening therein, and a baille plate secured between the upper and lower air deflector plates forming with the substantially V-shaped slots passageways f or directing another portion of the air supplied to said head tangentially against said nozzle to cool said nozzle. l

3. In an oil burner. an oil atomizing nozzle, an air conduit delivering air about said nozzle and a detachable head at the delivery end of said conduit, said head comprising a top portion forming an extension of the conduit, air defiector means and means securing said deflector means below said top portion, and said air deiiector means comprising an upper air deiiector plate having a central opening therein, a plurality of vanes associated with the periphery of said upper deflector plate forming passageways for a portion ofthe air supplied to said head, a lower air deflec-A tor plate secured to the bottom of the vupper air deector plate and having a central openingv therein in alignment with the opening in the upper air deflector plate, said lower air defiector plate having slots tangentially disposed with respect to the central opening, a plate overlying said slots and cooperating therewith to form a group of passageways for another portion of the air supplied to said head, said last mentioned portion of air aiding said first mentioned portion of air in supporting combustion and striking said atomizing nozzle tangentially, whereby said nozzle is maintained in a cool state while inoperation.

4. In an oil burner, an oil'atomizing nozzle, an

- 'air conduit delivering air about said nozzle and a detachable head at the delivery end of said con- `duit, said head comprising a top portion forming an extension or the conduit, air deilector .1 means and means securing said deetor means f1. below said top portion, and said air deector means comprising an upper air detlector plate :having a centrally disposed opening therein, a plurality oi vanes associated withtheperiphery 10 o! said upperdefiector vplate forming passageways for a portion of the air supplied to said head, a lower air deiiector plate secured to the bottom of the upper air deflector plate and hav- Lment with the opening in the upper air deilector f plate, said lower air deflector plate having slots disposed in the top surface thereot'in a horizontal plane tangentially to the opening therein, a plate overlying said slots and cooperating thereanother portion of the air supplied to said head tangentially against said nozzle to cool said nozzle.

` 5. In combination in an oil burner, an atomizing nozzle having a substantially vertical axis and an upwardly directed discharge end, means for supplying oil under pressure to said atomizing nozzle, means for conducting air to said nozzle, substantially circular upper air deector means 'i0 arranged substantially concentrically with respectto said nozzle axis and 'above the discharge end oi said nozzle and lower air deector means Aarranged substantially concentrically with respect to said nozzle axis and with the upper porcharge end of said nozzle; each of said air deing a centrally disposed opening 'therein in alignwith to form a group of passageways for directing tion thereof substantially in the plane of the disiiector means having means disposed therein to direct air passing therethrough toward the nozzle axis in a direction tangential to a circle` about said nozzle axis, whereby air is directed about the axis of said nozzle both in the plane of said dis- .charge end and thereabove.

6. In an oil burner, an oil atomizing nozzle, an air conduit delivering air about said nozzle and v a detachable head at the delivery end of said conduit, said head comprising a top portion forming an extension ot the conduit, air deflector means below said top lportion, and said air deflector means comprising an upper circular air deector plate having a central opening therein, f

said upper plate being disposed with the said opening about the axis of said nozzle, substantially radial varies extending from theyperiphery oi said upper deilector `plate forming passageways for a portion of the airv supplied to said head, a lower air deilector plate secured to the bottom of the upper air deilector plate and having a central opening therein in alignment with the opening in the upper air deector plate, a baffle plate secured between the upper and lower air deflector plates, said lower air deflector plate having substantially V-shaped slots tangentially disposed with respect to the central opening, said slots and said baille plate cooperating to form a group of passageways foranother portion of the air supplied to said head, said last mentioned portion of air aiding said rst mentioned portion of air in supporting combustion and striking said atomizing nozzle tangentially, whereby said nozzle is maintained in a cool' state while in operation.

REINHOLD D. SCHOENWE'I'I'ER.

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