US1985934A - Oil burner - Google Patents

Description

Ja -1,1935, 1,14. LOGAN 198 9 OIL BURNER Fild Feb. 10, 1955' IN ENTOR; v JossrH A. Loam IV B V. y @M 1 M ATTORNEYS; v

sp r- 9 1 1 ons Bonm f Joseph-Arum, Springfield, Mall, assig'norfto j 1 (lilliert Barker-v Mannheturin,.Cmpany,' west" sn nrfle I omm e! surmise Feb n, 0, 19:1. t J 1Clalm."(Cl. l58- 28)1f fl 'Ihia inv,ent10n improvements fin' oil side 0! the ia'n housing. On'the othersiiie o! burners'.e.'lhe, invention has ior its object an the tan housing is'fixed teasing 11 having open- 1 improvement, in that tweet 'burnerjlnhwhich 1n'8 th f k 'iv ph -fair is driimi'indunthe oil is iorced under heavypress'ure, such for ex tan. Within casingfll' is asuitable airregulat- I ample as 80Vpounils. tothe no azle or, the burner mg device 13'. Fixed to casing'li is anxoil pump by a pump which, heretoiore, hasrbeen' permaf 14 driven by motor10.f-0il is drawn into the nentlyfi -eoupled to the motor which drives the pump through-a pipe 1 5* and'rorced out throuzh iansupplyinz air to the burner. rjlheimprov ea; pipe 16 toa suitablepressure' regulating and ment'consistsin interposingin thedrive'between b'y -pass valve 17,w hic'hprevents oil irompassinl M the motor and the "pump aclutch which is reto the burnernozzleuntil it is placed under], 10 sponsiveto the speedo! the motor and is efiecpredetermined minimum pressure and Gallows tive to connect the pump tolthe motor some of thep mp 011 to be Y-Dwe m after the motor has acquired considerable speed. the pump, it and when the oil exceeds'apre- The improvement enables the im ,tohuild up determined maximum "pressure: The .byspw' ll speedvery rapidly because the motor is free irom outletis mar ied 18 andth'e outlet to the burner 16 the heavy load of the man pressure oilpump. is marked 19. Thejoutlet '19 is connected by Accordingly, normal air howls-established quickpipin's'zo to the oil-nozzle 21 ot'the burner." -'lhe' ly and it is insured thatair at the proper condifburner tube't' has-ahead in the-"outlet end tions or pressure and velocityhto atomise theoil thereof in" which head air nozzles areprovided. will be present at the nozzle beiore; any oil is "I'henozz'le 21, hereinshowmisoithepressure 20 emitted'thereirom. When theburner motor is 'or'mechariicalatomizink type The a'ir' noszles deenerzised; the pumpwill be quicklydisconnect; are or may' be oi the'type'shown'in the Kunitz ed therefrom; andjsinee itworks under aheavy patent. [The t bes through the wall 23 load, it "will :stop almost. instantaneouslm, gBut oi the iurnace'and the 'air and, oil noszlesde- 25 the motor, beinrreleasediromthe major-part liverfintofthe combustion ohamber2L 25 of its'load-when the clutch openssto disconnect The hurrier Just described is kitten merelyhy the pump, will continue in operation'by the moway ofan illustrative exampleot one typefot mentum of its rotor tor a much longer period burner with which my invention 'may 'be than it otherwise would and the fanthus coasts The invention."however, is capable of other ap- 1 for asuhstantial time and scav'enxes the burner. plication's and maybe used generally wherever it 30 Also, the oil iiowls stopped before the air supply, is desired to start thei'air flow in advance of the wherefore there is no chance, as heretofore, for oil flow and tostopfthe oil flow before stopping oll'to'beemitted at afl time when there is aninthe air flow. f "f A, f '1 1 I suilicient'supply of air toproperly atomize it. t Forgthe purpose ,iust mentioned; I provide a 5 Otherohiects will appear as the detailedvdellitflhletolutch. actuatedjhye'entriiueal force, in scription proceeds and will be pointed out in the the drivingconnection'hetweenthe'motor 9" appended claim." I and the drive shaitflfioipump 14'." per example,

, The 'vention'will be disclosed for illustrative a eas @3126 having-the general iorm'of a brake purposes in connection with the accompanying drum. is mountedto turn Ireely on shaft 9,- being 40'-'drawing, in which:-'-" v v held against axial'niovement between s collar '2'! 40 a Fig. 1 isan' elevational view 01 an oil'burner ands plate -28,fboth"tlxed to shat t 9. "Platef28 "embodying'theinvention; 4 closes the otherwise openend e'oi dr um 28 and is a sectional view taken on the line 2-2 has iixedthereto a series, asthree; oi studs 29. of m 1; v h which,extendinto theinterlor of drumflo. Pig. 3 is asectional view taken on theline'3-8 Mounted in the with'i e d mi r redid i 01 p 25 m I 1 H a movementare three shoes 30'which arerecessed Fig. 4 is a'sectional view-taken on the as shown to receivestuds 29 and in ct Fig. 3, a I I, 1 bpthend iacestoreceiye'a coil spring alof cir-l. v "In Fig. 1 there is shown an oil burner 01 the cular i'orination Spring 31 tends to'hold the v general'type disclosed in U; B.P'atent N0.'-l,832,- hree shoes 29 in theirinnerrnost positions, shown 131, granted November 1?;1931 to Hannibal A. in F18. 3,1 in which the innerends oi the shoes Kunitz. It'includes a tubular air conduito'com. abut acentralihub 32 .on drumfzo. The nected to the outlet" ota ran housing 7'; which on itsputer lace, ispro videdswlth driving 33. contains a suitable ran a (Fig. 2) iixed to the which coop ate with similar ut r sht'ansularly 5F shalt 9 of an electric motor 10 iastenedttoone p sed drivi D1118 34 fi ed to shell 25. and I I which fills the burner tube 6, the combustion often results in the establishment flexible disc 35, in which the ends of all the pins are received to provide a flexible coupling between .the drum and shaft 25;

In operation, on energization of motor 10, the fan 8 will be immediately rotated but the rotor of the oil pump will not be turned untilthe motor shaft 9 has acquired considerable speed. Shaft 9 drives the shoes 30 through studs 29 and plate 28 and, when a predetermined speed has been attained, the shoes 30 will be moved radially outward by centrifugal force to press against the internal periphery of the drum and force it to rotate, and with it the driving shaft 25 of pump 14. When the motor 10 is deenergized, and the speed of its armature slackens sufliciently, the springs 31 will draw shoes 30 inwardly and release drum 26 and the pump. Actually, the pump will be dis-- connected from the motor very shortly after the latter is deenergized because there is a heavy load on the pump which'will cause the armature of the motor to rapidly slow down to the point where the clutch elements disengage. Actually the pump 14 stops almost instantaneously when. the current to motor 10 is broken. After the pump is disconnected, the fan will rotate for a considerable interval because of the lackof any substantialload (such as the pump) and because of the momene turn of the relatively heavy armature or rotor of the motor. 'Thus the air flow will be started through the tube 6 and air nozzles before the flow of oil through nozzle 21 is started. Also, after the oil flow stops, the air flow will be continued for an appreciable interval.

From the-arrangement above described, there are manyadvantages derived which result in material improvement in'the operation of the burner. Under normal conditions, in a burner of the type described operated according to prior practice, the oil begins to issue from the nozzle in atomized condition before the air has attained its maximum velocity. Although the pump and fan start simultaneously, according toprior practice,

the pump builds up the proper pressure for atomizing the oil much more rapidly than the fan builds up the properair pressure, probably" because the pump is positive in its actionand the fan is not. The fact, as above stated, that atomized oilissues from the nozzle before the air has attained its maximum velocity, results in producing a rich flre condition on starting, at which time a lean fire condition is wanted. Not enough air is supplied at thistime to completely burn the oil. This adverse condition is' further aggravated by the fact that the fan, as its first work,

chamber and stack. 'This delays the' flow of "air but not the flow of oil and increases the time lag between the initiation of the oil flow and the initiation of normal air flow atproper pressure and velocity. Arich mixture at the time of starting of undesired pulsations which create noise. The mixture starts to burn but is too rich to burn completely.

A series of pressure waves are set up in'opposition to the fan and are transmittedthrough tube 6 to the fan and, impacting thereon, tend still further to delay the normal flow of air at the desired velocity, and pressure. These waves, once started, tend to continue and the wave motion is sustained for some time. The wave motion results in alternate lean and rich mixtures in the combustion chamber. By the present arrangement, the fan is placed in operation flrst and is given time to sweep out all the dead air and establish normal air flow before the atomized oil issues from the nozzle. The opposition to establishment of proper air flow does not have a chance to get started and the former difficulties are overcome by preventing their inception because enough air is provided under proper conditions at the time of initiation of oil flow to produce the desired lean fire condition rather than the too rich condition, which tends to set in motion the pulsations that continue long after the conditions which initiated them have disappeared.

By allowing the fan time to get started and build up the desired pressure, such pressure is available as a force to oppose any explosion wave that may be produced. The explosion wave is repelled and has no chance to impact on the fan and set up the undesirable wave motion referred to. The effects of puffs or explosion waves are thus minimized and reduced to a negligible degree by the arrangement described.

When the burner is shut down, it is very desirable to have the air flow continue for a while. Any oil dripping from the nozzle will'be carried forward by the air stream into the combustion chamber, whereas otherwise the oil would fall on'the nozzleor parts adjacent thereto, which derived from continuing the fan inaction for awhile after the cessation of oil flowp. Not only does the incoming cool air tend tocool the burner parts but more important still, such airgflow prevents the very hot gases from the combustion chamberfrom backing upinto the burner and delaying the cooling of the-parts thereof. In the normal operation of the burner, the flame is sustained with its inner end spaced from the nozzle 21' and the continuance of air flow after the pump stops prevents the flame from backing up to' the nozzle and heating the same. as itdid according to prior practice. The flame is sustained in spaced relation with. the nozzle by the continuance of air flow after the motor is ,de-

gases from these members, leaving them fresh V and clean and in better condition for the next operation thereof.

The described arrangement also helps materially in securing a quick, sharp starting and stopping of the oil'flowr The pressure regulating valve is intended to secure this result and does so to a certain extent but the action is improved materially by the centrifugal clutch arrangement. With the prior practice,'the motor was slow 'in building up speed against the substantial load of the pump. With the described arrangement, the motor startsup without any loadexcept the small load on the fan. It acquires speed very rapidly and, afterthe desired speed has been acquired, the clutch engages and starts the pump more quickly than heretofore. When the burner stops, the pump stops almost instantaneously with the opening of the motor circuit. "A practically instantaneous stopping of oil flow results. Also on starting, the oil flow is established very quickly.

The described arrangement also offers a certain amount of protection against an excessively large drop in the voltage supplied to motor 10 during the running cycle of the burner. The electrical controls for the burner usually include electro-magnetically .operated switches. These switches, if adapted for volt operation would not close if the voltage dropped excessively but,

once closed, they would be held closed by a voltage much less than that necessary to close them, wherefore it is possible to have during the running cycle of the burner, .a drop in voltage oi such as a degree as tomaterially reduce the speed of the fan without causing the stopping of the burner. The air supply would be reduced but the oil supply would not be correspondingly reduced owing to the fact thatthe pump 14 pumps much more oil than is needed and a considerable part of the pumped oilis by-passed by valve 17. Hence, a smoky fire results but as long as there is a ilrethe usual burner thermostat will not 7 loading the motor on starting. A smaller motor can be used than would otherwise be possible.

The invention, however, is more particularly characterized by the improved conditions aflecting the operation of the burner, as above set forth. 7

What I claimis: j In an oil burner, a pressure-atomi'zing nozzle, a pump for supplying oilthereto-under heavy pressure, a conduit connecting the pumpand nozzle, a pressure responsive valve interposed therein and opening to allow oil to flow to the nozzle only after the pump has built up the V 'requisite heavy pressure, a fan supplying air at low pressure, a conduit conducting such 'air to the nozzle to mix with the atomized oil, a motordriving the fan and pump, means connecting the fan to the motor to start and stop coincidentally therewith, and means responsive to the speed or the motor andian operable to couple the pump to the motor only after the latter and the tan have acquired a predetermined speed suiflcient to establish a flow oi airin said air conduit at proper velocity and pressure to mix with the oil and operable when the motor isdeenergized to disconnect the pump from the motor and fan and allow. thesame to continue in operation and scavenge said tube after ilow "oi oil at said nozzle has ceased.

V JOSEPH a. LOGAN.

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