US2302329A - Liquid fuel burning apparatus - Google Patents

Description

1942- J. R. KIRKPATRICK LIQUID FUEL BURNING APPARATUS Original Filed April 15, 1939 2 Sheets-Sheet l IN VENTOR.

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LIQUID FUEL BURNING APPARATUS Original Filed April 15, 1939 2 Sheets-Sheet 2 INVENTOR. JOSEPH l2. KIRKPATRICK.

M, ukunvflimrh ATTORNEYS.

Patented Nov. 17, 1942 UNlE SATES PATENT FFIE LIQUID FUEL BURNING APPARATUS Joseph it. Kirkpatrick, South Euclid,

Ohio, asa.

signor to Perfection Stove Company, Cleveland, Ohio, a corporation of Ohio Claims.

This application is a division of one filed by me on April 15, 1939, Serial No. 268,138.

The invention pertains to liquid fuel burning apparatus that is especially suitable for use in furnaces of heating systems for houses or other buildings, and whose operating range includes low and relatively higher fires, and in which, through suitable fuel feeding and governing means, the burner is supplied with fue1-at'no time, so' long as the apparatus is in operation, with less than enough to sustain operation at low fire, and at other times, with a sufficiently increased amount of fuel to produce higher fires.

customarily, in apparatus of the class to which the invention relates, liquid fuel of a rather heavy grade is used, such as that known as fuel oil; and at low fire, which practically amounts to pilot flame, very little fuel is required. For example; in the average size furnace burner, from onehalf to one gallon of fuel is fed every 24 hours for the purpose of sustaining operation at low fire, and this amounts to very considerably less than one drop per second. Consequently, uniform feeding of the fuel at so low a rate represents a problem rendered diflicult by several factors including variation in viscosity of different fuels; in the differences in viscosity of the same fuel at different temperatures, or the presence of sediment or foreign matter in the fuel. Under any circumstances, and especially those requiring accurate feeding of a very small quantity of fuel, the customary control of the fiow by means of orifices (as is the case in practically all types of valves) is quite unsatisfactory and unreliable.

It is the fundamental object of my invention to provide liquid fuel burning apparatus of the character referred to in which the fuel is volumetrically fedthat is to say, is fed in measured quantities. In the presently disclosed embodiment of the invention, the volumetric feeding means comprises a plurality of dippers.

The invention may be defined, broadly, as comprising, with a liquid fuel burner and a source of liquid fuel supply, a fuel feeding and governing system through which the source communicates with the burner, and a part of which system serves as a reservoir to which fuel is delivered from the source, and a delivery part that communicates with the burner and that is separated by a barrier from the reservoir part so as to prevent natural fiow of the fuel directly from the reservoir part to the delivery part. A substantially constant fuel level is maintained in the reservoir part, desirably by a suitable liquid level vention, being constantly actuated so long as the apparatus is in operation.

Another object of the invention is to provide an automatic control by means of which the apparatus is caused to operate under certain conditions at intermediate fire, so to speak, thereby to maintain a given temperature, within rather close limits, in a space to be heated-as in a room, apartment or other enclosure-and which, in case the temperature of said space drops below a predetermined value, will act to cause an increase in the fuel supply to the burner so as to produce a higher fire; and. in case the temperature of said space rises above a predetermined value, will function to suspend operation of all but the feeding means that supplies fuel for low or pilot fire, thereby to reduce the heat output of the apparatus.

A further object is to provide, in an automatically controlled fuel feeding apparatus of the character described, means for effecting delivery of fuel to the burner in sufiicient quantity to sustain operation thereof at approximately intermediate fire in case of failure of the automatic control system, as, for example, by the stoppage or suspension of the supply of current, in case the control system is electrical.

A still further and more limited object of the invention is to provide fuel feeding and governing means in the form of a compact unit that is convenient of incorporation in a liquid fuel buming apparatus and is so constructed as to facilitate assembly and installation and that is efficient and reliable in operation.

An additional object isto provide a simple and convenient adjustment for varying the feeding capacity of the volumetric fuel feeding or transfer means.

The foregoing objects, with other and more limited ones hereinafter appearing, are attained in the embodiment of the invention illustrated in the accompanying drawings wherein Fig. 1 is a more or less diagrammatic representation of a liquid fuel burning apparatus incorporating the invention; and Fig. 2-is a detail in perspective, with parts broken away, of the volumetric fuel volves means for automatically controlling the operation of the burner so as to maintain, in the space or apartment heated by the system, a sub stantially constant temperature within relatively close limits, notwithstanding variations in outside temperature or other exterior influences.

According to the present illustration, the burner is of the pot or bowl variety and is designated, generally, by the reference character A. It comprises a bowl I that is suitably supported with its top wall 2 in spaced relation to the bottom wall 3 of a combustion chamber 4. Said walls have aligned openings shown as surrounded by depending flanges 2 and 3, that are in concentric, spaced relation to each other and define a slot 5 for the admission of secondary air to the bumer bowl, as will hereinafter more fully appear. Primary air is admitted to the bowl through perforations 6 in the peripheral wall of the bowl. A relatively large lighting and cleanout opening is formed in said peripheral wall and the same is surrounded by a radially projecting neck 8 normally closed by a plug 9 shown as having a bayonet joint connection with the neck. The combustion apparatus comprising the bowl I and the chamber 4 may be that of a furnace of appropriate type for use in systems of the class above mentioned. For more detailed information on such apparatus, reference. may be had to. Letters Patent No. 1,944,593, dated January 23, 1934; No. 1,979,865, dated November 4 6, 1934; No. 1,987,179, dated January 8, 1935, and

No. 2,000,884, dated May 7, 1935.

Liquid fuel is supplied to the burner A from a source B (represented as a tank) through a fuel feeding and governing system C (Fig. l). A conduit l leads from said source to the system, and a conduit leads from the system to the burner, the latter conduit being shown as opening through the bottom wall of the bowl I. The system involves a. reservoir part, to which fuel is supplied through said conduit i0, and a delivery part that communicates with the burner through the aforesaid conduit Ii. A liquid level control tends to maintain a constant liquid level in the reservoir part, as will hereinafter more fully appear.

The fuel from the conduit l0 enters a float chamber l2 through a port l3. The passage of fuel through said port is controlled by a valve it that is depressed and closed by a float i through the intervention of a lever |6 fulcrumed on a pivot pin I! that is suitably supported in a fixed position within the float chamber, as by and between the opposed side walls thereof. A spring l8 tends to open the valve in opposition to the action of the float. By this control means, the level of liquid in the reservoir part of the system is maintained substantially at the elevation indicated by the dot-and-dash line a-a.

What has been referred to as the reservoir part of the system includes, also, the receiving compartment or reservoir 20 of a vessel 2|, said compartment being separated from an outlet compartment 22, or more generally, the delivery part of the system, by a barrier or partition ,23 that extends from the bottom of the vessel to a height a material distance above the maximum liquid level indicated by the dot-and-dash line a-q. Communication between the float chain ,ber l2 and the reservoir 20 is established through a conduit 25. The outlet compartment 22 of the vessel 2| is communicatively connected to the burner A through the before-mentioned conduit II; and a by-pass between the reservoir part of the system--specifically, conduit 25- and the delivery part of the systemin the present instance, the conduit H-is provided by a conduit 21 that contains valve means comprising a casing 28 and a valve member 29, the latter being in the form of a tube having a V-notch 30 at its lower end in the region of the diaphragm 3| of the valve casing. The casing in.- cludes a sleeve 32 wherein the stem portion of the valve member is housed and whose open top is a substantial distance above the maximum liquid level in the system. The valve is normally held in closed position by a solenoid 35. while a spring 36 tends to shift the valve to open position when the solenoid is deenergized, these actuating elements being shown as operatively' con nected to the valve member 29 through the medium of a bell crank lever 31. The full open position of the valveis determined by an adjustable stop 38.

Supported by the vessel 2| a material distance above the partition 23 is a channel bar 40, best shown in Fig. 2; and through square holes in the bottom flange of said channel bar are guided, for vertical adjustment, hangers 4|. The hangers, which are square in cross section and are of a size to slidably fit the aforesaid holes, are adjustably supported by screws 42 that are threaded in axial recesses in the upper ends of the hangers and extend freely through holes in the top flange of the channel bar 40. Pivotally conn'eetedto the lower ends of the hangers 4| are the trough-like buckets or clippers 45, 45 and 41, the size and capacity of the last mentioned dipper being considerably greater than the dipper 46, while the dipper 46 is of somewhat greater capacity than the dipper 45. The dipper 45 serves to supply fuel to the burner in sufficient quantity to sustain operation at low or pilot fire. As will more fully appear hereinafter, the dipper 46 supplies the additional fuel necessary to sustain operation of the burner at intermediate flre, while the dipper 41 further increases-the fuel supply to that necessary to cause the burner to operate at high fire.

Shown (in dotted lines) as supported by and exteriorly of an upwardly extended portion of one of the side walls of the vessel 2| is an electric motor 50 whose drive shaft 5| is extended through an aperture in the wall extension and has fastened to it inwardly beyond said extension a pinion 52 that meshes with a spur gear 53, journaled on a stud 54 that projects inwardly from said wall extension. A crank pin 55 on the gear 53 is operatively connected to the dipper 45, near the free end of the latter, by 9. connecting rod or link 56. Fastened to the outer end of the motor shaft 5!, beyond the pinion 52, is a double crank 51, the diametrically opposed pins whereof are designated 58v and 59. These -respective crank pins extend freely through slots in connecting rods or links 60 and 6|, the former being attached to the bucket 45 and the latter to the bucket 41.

Secured to and depending from an overhanging portion 64 of the upwardly extending end wall of the vessel 2| are thermostatic elements or bimetal strips 65 and 66, by the lower free ends of which are carried latch members 61 an'tl 68, respectively, for holding engagement with extensions and H on the respective dlppers t6 and 41. Electric heaters 13 and Id, in the nature of resistance coils, are suitably attached to the respective thermostatic elements or strips 65 and 66. When the thermostatic elements or strips are cold, so to speak, they occupy the positions indicated in the drawings, element 65 being in a position to cause the latch member 68 thereof to engage beneath the extension ll and sustain the dipper ll, in elevated position; while the element or strip 65 is normally in' a position winding 80 of the transformer 80, and the other, 7

represented by conductors 81 and 88 and leading to the aforesaid motor 50. One side of the secondary winding 80' of the transformer 80 is connected through a conductor 90, with the movable contact element St of the room thermostat 81, while the other side of said winding has connection, through a conductor 92, with the'heaters l3 and 14. The former heater is placed in circuit, through a conductor 93, with the contact 95 of theroom thermostat, while contact 95 thereof is connected, through the conductor 96, with the heater M.

The burner, under given conditions which may be regarded as normal; operates on fuel supplied by the two dippers 45 and 46, the heat produced by the'apparatus under these circumstances being sufilcient to maintain a room temperature of the desired range, under the influence of which the movable contact element 9! of the room thermostat remains in neutral position. Should the room temperature rise beyond the predetermined range the movable contact element 9! will swing to the left and engage contact 94, closing the circuit to the heater 13 and under the influence of the energized heater, the thermostatic element 65 will warp in the direction to bring the latch member 61 into the path of the extension 10 thereby to retain the dipper 66 in inactive, elevated position while the crank pins 58 slots in the connect- This leaves only the and 59 play idly Within the ing rods or links 60 and BI. dipper B5 in operation, and this will supply sufficient fuel to the burner to sustain operation thereof at a low fire. Under these circumstances and the influence of a relatively lower outside temperature, the room temperature will drop, causing the movable element 9| to withdraw from the contact 94, thereby to interrupt the supply of current to the heater 13, allowing the thermostatic element 65 to cool and withdraw the latch member 61 from the extension it, thus throwing the dipper back into operation.

In the eventthe outside temperature continues to fall, similarly affecting the room temperature sufficiently to cause the movable contact element 5| of the room thermostat ill to swing over into engagement with contact 95, a circuit will be established through heater I4, causing it to warp the thermostatic element a direction to withdraw the latch member 68 from holding engagement with the extension i I, freeing the dipper 41 so that it may be oscillated through the action of the crank 59, thereby to increase the fuel supply and cause the burner to operate at high fire, this condition continuing until the temperature affecting the room thermostat has risen to within the aforesaid predetermined range, under which circumstances the contact element 9! will withdraw from contact 95, opening the circuit to the heater I4 so that the thermostatic element or strip t6 may cool and resume its former position wherein the latch member 68 engages the extension H and retains the dipper 47 elevated and out of operation.

Should the electric circuit that supplies current to the automatic control cause, thereby to deenergize the motor and throw the fuel feeding and governing system out of commission; the solenoid 35 will likewise be deenergized, whereupon the spring 36 will open the emergency valve 29, permitting a practical amount of fuel to by-pass the multiple volumetric feed comprising the buckets or clippers 45,. 46 and 41 and sustain operation of the burner until the difficulty is rectified and the system returned to normal operation. Through the adjustable stop 38 the emergency valve 29 may be set to feed fuel in sufficient quantity to sustain operation of the burner at a stage equivalent to intermediate fire.

By reason of the fact that the top of the valve casing 32 is a substantial distance above the maximum liquid level in the system, a stuffing box or other seal is rendered unnecessary between the valve member 29 and the casing 32 and freedom of action of'the valve is assured.

While I have specifically described a practical embodiment of the invention, I wish it to be understood that I do not limit myself to the structural character thereof further than required by the scope of the appended claims.

Having thus described my invention, what I claim is:

or bimetal strip-66 in 1. In combination, a liquid fuel burner. a source of liquid fuel supply, a fuel feeding system, a barrier separating said system into a rcservoir part to which fuel is supplied from said source and a delivery part from which fuel flows to the burner, power operated means acting to periodically transfer fuel from the reservoir part past said barrier to the delivery part in sufficient amount to sustain operation of the burner at low fire,furtherpower operatedmeans for periodically transferring fuel from the reservoir part past said barrier to the delivery part in a sufficiently increased amount to produce higher fire, control means governing the action of the power operated means, communicative connections by-passing the aforesaid barrier and through which fuel may flow from the source to the burner, a valve in said connections biased toward open position, power operated meahs for retaining said valve closed, and a source of power common to all said power operated means.

2. In combination, a liquid fuel burner. a source of liquid fuel supply, a fuel feeding system, a barrier separating said system into a reservoir part to which fuel is supplied from said source and a delivery part from which fuel flows to the burner, means maintaining a substantially constant fuel level in said reservoir part, power operated means acting to periodically transfer measured amounts of fuel from the reservoir part past said barrier to the delivery part in sufficient quantity to sustain uninterrupted operasystem fail from any tion of the burner at low fire, further power operated means for periodically transferring measured amounts of fuel from the reservoir part past said barrier to the delivery part thereby to produce higher fire, and control means" for throwing said further power operated means into and out of operation.

3. In combinaito'n, a liquid fuel burner, a source of liquid fuel supply, a fuel feeding systern, a barrier separating said sy tem into a reservoir part to which fuel is supplied from said source and a delivery part from which fuel flows to the burner, means maintaining a substantially constant fuel level in said reservoir part, power operated means for periodically transferring measured amounts of fuel from the reservoir part past said barrier to the delivery part in sufficient quantity to sustain operation of the burner at low fire, further power operated means for periodically transferring measured amounts of fuel from the reservoir part past said barrier to the delivery part thereby to produce higher fire. a source of power from which all said power operated means receive their power, control means for throwing said further power operated means into and out of operation, communicative connections by-passing the aforesaid barrier and through which fuel may fiow from the source to the burner, a valve in said connections biased toward open position, and power means operatively connected to and capable of retaining said valve closed, said power means being subjected to the aforesaid source of power.

4. In combination, a liquid fuel burner whose operating range includes low and relatively higher fires, a source of liquid fuel supply, a fuel feeding system, a barrier separating said system into a reservoir part to which fuel is supplied from said source and a delivery part from which fuel flows to the burner, communicative connections by-passing said barrier, a plurality of mechanical means arranged to dip into said reservoir part and periodically transfer measured amounts of fuel therefrom past the barrier to the delivery part, power means for operating said mechanical means, control means for throwing different ones of said mechanical means into and out of operation according to the size fire required, a source of power for said power operated means, a valve in the aforesaid connections biased toward open position, and power means subjected to said source of power and serving when energized to hold said valve closed whereby, upon failure of the power, the valve is disposed in open position to permit fuel to fiow from the reservoir part of the system to the burner.

5. In combination, a liquid fuel burner whose operating range includes low and relatively higher fires, a source of fuel supply, a fuel feeding system through which said source communicates with the burner, a barrier separating said system into a reservoir part to which fuel flows from said source and a delivery part from which fuel flows to the burner, a liquid level control tending to maintain a constant fuel level in said reservoir part, a plurality of power driven fuel receiving means arranged to dip into said reservoir part and periodically transfer measured amounts of fuel therefrom to the delivery part of the system, one of said means acting continually and being of a capacity to supply sufiicient fuel to the burner to sustain operation thereof at low fire, and an instrumentality for effecting actuation of additional of said means thereby to deliver more fuel the second of which from the reservoir part to the burner so as to produce higher fire.

6. In combination, a liquid fuel combustion device whose operating range includes low, intermediate and high fires, a source of liquid fuel supply, a fuel feeding system through which said source communicates with the combustion device, a barrier separating said system into a reservoir part to which fuel fiows from said source and a delivery part from which fuel fiows to the burner, three power operated volumetric fuel feeding means incorporated in said system the first of which transfers fuel from the reservoir part to the delivery part in sufficient quantity to sustain operation of the combustion device at low fire, the second of which transfers enough additional fuel to produce intermediate fire, and the third of which transfers the further additional amount of fuel necessary to produce high fire, electrical means having operative connection with the volumetric fuel feeding means and serving to actuate the first of said means continually, holding means for restraining the second and third means from action, that associated with the second means being biased toward ineffective condition and that associated with said third means being biased toward effective condition, an electrical device associated with each holding means, a thermostatic switch subjected to the temperature of the space heated by the combustion device, an electrical circuit including said thermostatic switch, the said electrical energization of the device associated with the holding means of the second fuel feeding means and cause said holding means to assume effecmeans causing said effective.

said source communicates with the combustion source and a delivery part from which fuel fiows to the burner, three volumetric fuel feeding in said system the first of operation of the combustion device at low fire, transfers enough additional fuel to produce intermediate fire and the third of which transfers the further additional amount so restraining said second and third means, that and said electric heaters so organized and arranged that when said temperature rises above a predetermined range it will cause the energization of the heater associated with the latch of.

the second fuel feeding means, and when thesaid temperature falls below said predetermined range it will cause energization of the heater associated with the latch of the third fuel feed:

.ing means. 1

to the burner, fuel receiving means movably supv ported and arranged to intermittently dip into I said reservoir part for periodically transferring fuel therefrom pasts'aid barrier to the delivery part,=an instrumentality' for effecting operation I a 1 e I I F reservoir part-to whic .source and-.-at

of said means thereby to transfer fuel in sufflcient amount toi sustain operation of the burner at low fire, further fuel receiving means similarly supported and arranged for periodically transsupply', a fuel feeding systo the burner, fuel receiving means movably supported and arranged to intermittently dip into said reservoir part for periodically transferring fuel therefrompast said barrier to the delivery part, an instrumentality for eifecting operation thereby to transfer fuel in suflicie'nt; amount tosustain operation of th'e'vburner;

of said means transferring fuel from, the reservoir part past at low -flre, further fuel receiving means simi-- larly supported-and arranged for periodically 1 said barrier-tdzthe delivery part, an instrumen ta1ityfor1efiecting operation of said further fuel receiving'gineans thereby to transfer fuel in a ferring fuel 'from' the reservoir part past said barrier to the delivery part, and an instrumentality for effecting operation of said further fuel receiving means thereby to transfer fuel in a sufficiently increased amount to produce higher fire. f

9. In combination, a liquid fuel burner, a source of liquid fuel supply, a fuel feeding system, a barrier separating said system into a reservoir part to which fuel is supplied from said source and a delivery part from which fuel flows sufficiently increased amount to produce higher fine-and adjustment means for. varying. the

n cornliiruttion,2a; liquid fuel burner, a

source of gun fueI"supply,,-a fuel'feeding sysery part from which fuel flows m ne burner means arranged-to'intermittently dip into said reservoir part and periodically transfer .fuel

, amme amme. said system into a hfl-fuel'is supplied from said power operated fuel receiving

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