US2680478A - Fuel and air feeding means for liquid fuel burning apparatus, and mounting for said means and associated elements - Google Patents

Description

June 8, 1954 A. scHuL'rz Erm. 6801478 FUEL AND AIR FEEDING MEANS FOR LIQUID FUEL BURNING APPARATUS, AND MOUNTING FOR sun MEANS AND ASSOCIATED ELEMENTS Filed March 21, 1951 3 Sheets-Sheet 2 V` Tg H 42 il .I 1|

1 OI I Ol IO O O O NN. a2 w 02'100 a? f0.5 x? J0 /c/ G. 2 /0/ 7 i 4 WZ /c7 G- 7 5 INVENToRs I/V/ 50p/l. 5cm/L rz Bxl/VM @MW/94mm( rrak/vsys June 8, 1954 W. A. S ULTZ FUEL AND AIR FEEDING MEANS FOR L UID FUEL BURNING APPARATUS, A

MEANS AND ASSOCIATED ELEMENTS Filed March 2l, 1951 3 Sheets-Sheet 3 ND MOUNTING FOR SAID INVENTOILJ` W/L aan ,4. 5mm rz BY u caMllrre/ck Patented June 8, 1954 Wilbur A. Schultz, Lakewood, and Malcom W.

Patrick, Hudson, Ohi Stove Company, Cly

of Ohio Application March 21, 1951, sufall No;

7 Claims.

ticularly to improved means for feeding' fuel and a limited amount of air to the combustion space of a type of such apparatus characterized by a natural draft pot type burner. The vinvention has to do, also, with a mounting for saidv fuel and air feeding means and associated elements.

The fuel and air bustion space of apparatus ofthe aforesaid class, originally disclosedin an application of Lee S. Chadwick et al., filed September 21,` 1948, Serial No. 50,312, which has matured into Patent No. 2,614,618 of October 2 1, 1952,

present application. In each ofthese former cases, the apparatus was of the forced drafttype in that the air supplied thereto wasv of' consider'- able quantity and for combustion purposes. p

The fundamental purpose o f this invention; like that of its predecessors, is to provide aliquid fuel combustion apparatus that is eiicient, economical and sat1 sfactory'-V in the 4 burning Iof so4called catalytic fuels; and thatwillfunction Without the formation or depositionY of carbonor other residue upon any part of theV apparatus Where the presence of suclwould adversely affect the operation.v H y It has been found that, in order tof successfully handle liquid fuels of necessary that the fuel be'maintained Vat arela` tively low temperature during its passage toi the point of its admission to the combustionsp'acje'.

However, upon being admitted tosaid'jspace; the fuel must be rapidly transformed.intona state,

suitable for burning, which generally means that' it must be convertedffroxr liquid toi gas ,ancljjinn mediately mixedwith ajsu'itable amount of airf. It is essential, on theotherhand, that the Yactual combustion take place rela'tivnelyfV reifiote vfrom the point where'the fuelenters s o'tliaft theffuel discharge means, or nozzle, paratiyelyv low temperatu the formation'ofcarbon'it er'leoii.

Another object ofl the` invention' isto soarrange the air Yconducting?"means with respectgto the region o fh combusticgr'i that the combustion airisj prelfieatedfa Ylimiteicfamount "before reach'L ing thei'po'int of itsfxnixturwit i hefuel, thereby't better' advance'vaprizatio of' the` latter.

the aforesaid type, it is" Willjbe kept at acqui;-` r'e in' order to prevent' o, assign'ors to Perfection and, Ohio, a corporation elements of the fuel and air feeding means and associated electrical devices, and a portion of which serves as a closure for an opening that leads into the combustion space of the apparatus, and Fig. 'l is a diagram of an electrical control system for the apparatus, certain elements of Our invention is to a liquid fuel burner of the bowl or pot type, and in Figs. 1, 2 and 3 a portion of the burner bowl is shown, the same being designated, generally, by the reference numeral l. A relatively large opening 2 occupies the front portion of the peripheral wall 3 of the bowl, and it is surrounded by an outwardly extending flange about which fits the inner end of a neck 4. The neck is secured to the wall 3, desirably by welding, as indicated at 5, and at its forward end the neck is flared outwardly to provide a ange l. The bottom wall 1 of the burner bowl is slightly dished and is shown as provided with a central sump B, and within the relatively large opening of the annular top wall I8 of the bowl is secured the reduced lower end of an upwardly divergent throat member ll, shown as terminating in a flat marginal portion l2 that may constitute the bottom wall of a combustion chamber. The throat member Il is provided with openings l and the peripheral wall 3 of the bowl l with openings l, for the admission of air to the combustion space of the apparatus, such space being consituted of the interior of the burner bowl and the combustion chamber above (not shown).

As will be readily understood, the combustion space communicates with a suitable flue or chimney, and in the present instance the apparatus operates on natural draft, in contra-distinction to the forced draft apparatus disclosed in each of the above-identified applications.

Turning now tc a detailed description of the present invention, 2B denotes, generally, a mounting, shown in perspective in Fig. 6. The major portion of the flat rear wall 2l of the mounting constitutes a closure for the opening 2 of the burner bowl, and it is adapted to be applied to the flange l, with a gasket 22 of suitable packing material interposed between the latter and the opposed area of said wall. Dowels 23, that project forwardly from the flange e, extend through aligned holes in the gasket 22 and wall 2l. Also projecting forwardly from the flange E are threaded studs 2li that are engaged through holes in the gasket and occupy notches 25 in the wall 2i. Wing nuts 28 are applied to the studs 25 for drawing the parts firmly together. By reason of this simple means of attachment, the assembly may be easily and quickly applied to and removed from the combustion apparatus. The forward end of an outer air tube or cuplike shell 3Q occupies an opening on the wall 2l and said end is secured to the surrounding portion of the wall, desirably by welding. An inner tube or shell 33, which is of less diameter but somewhat longer than the outer shell 3e, is arranged within the latter in substantially concentric relation thereto. The end wall 35 of the outer shell is imperorate, while the corresponding Wall 35 of the inner shell, which is spaced from the wall 35, is provided with a relatively large opening 31.

A9 denotes an annular member or nozzle guide which is shown as cylindrical and of reduced diameter at its lower end. The smaller end of the guide occupies an opening in the peripheral wall of the outer shell 3d, to which wall said end 4 is welded or otherwise secured; and the adjacent end of the portion of greater diameter fits within a hole in the peripheral wall of the inner shell 33 and is secured to said wall in similar fashion. It will be observed that the previously mentioned opening 31 is spaced nearer the top than the bottom of the inner shell, and disposed transversely of said shell, some distance forwardly of the nozzle guide 49, is a dam Ml, that 'rises to about the height of the lower side of said opening 3l, the dam being suitably sealed, as by welding, to the peripheral wall of the inner shell. Thus, an overflow basin is provided within the inner shell about the nozzle guide f'll; and any fuel overflowing into said basin will be conducted, by a drain tube 45, to the lower portion of the burner bowl l, or to some other suitable place of disposal. In the present instance, as in the construction disclosed in the Resek et al application above referred to, a trough surrounds the lower portion of the peripheral wall of the burner bowl. The trough herein is designated 3, and upon liquid fuel attaining an abnormally high level in the bowl, it will overflow through the openings i6 of the bottom row in the peripheral wall 3 and be carried away by a pipe 3l.

et designates a fuel supply pipe that is extended inwardly through a notch in the forward end of the shell 33 and thence rearwardly to where it has connection, through a union l and an elbow 48, with a fuel nozzle that is designated, generally, by the reference numeral 5G. The nozzle guide 40 has an axial passage enlarged at its upper end to provide an annular shoulder or seat 5l, and at a distance below said shoulder the passage is downwardly convergent. Removably nested within the upper end of the nozzle guide, so as to rest upon the shoulder 5l, is the relatively deep disc-like part or flange 52 of the nozzle 53, the tubular tip of the nozzle depending axially from said flange and terminating at its lower end in a frusto-oonical portion that is disposed in spaced concentric relation to the convergent wall portion of the passage of the nozzle guide QG. Opening into the upper end of said passage are a plurality of air holes 53 in the flange 52. The nozzle is provided with an axial port 55 that is counterbored and threaded at its upper end for the reception of the threaded lower end of the elbow 48. Above its frusto-conical portion, the nozzle 50 is bored transversely to provide lateral openings, and below said openings the nozzle is slotted in line with said openings, thus imparting a bill-like appearance to the lower or fuel discharge end of the nozzle. This particular nozzle forms a part of the subject matter of the above mentioned application, Serial No. 168,524, and, as pointed out in that case, it affords highly satisfactory fuel discharge, and so directs the fuel as to prevent contact thereof with the noazle guide. This is highly important as otherwise residue and carbon would collect and build up about the fuel inlet under the influence of the high temperatures prevailing within the combustion space during burner operation. n Rigidity is imparted to the outer end of the inner tube or shell 33 by a suitable number of spacers 58 that are interposed between the shells 3!! and 33 in the approximate plane of the wall 2| of the mounting 20, said spacers being suitably fastened to either or both of the shells. Telescoped over the forward end of the inner shell 33 is the peripheral flange of a reducing collar 53, said flange having a relatively wide s 'notch to accommodate mit limited Carried by the wall 2| of the mounting 20, is

an arcuate delector 69, located adjacent `the extending engaged through holes in a plate 1| to which said terminal portions are Secured to and projecting forwardly from the wall 2| of the mounting 2@ is a bracket 15 that supports a flow-control or shut-01T valve T6, with In the present instance a sor-called Micro-switch Sais supported-directly above'theffor-ward end: of the inner shell or tube by a brackety 8|. This 6 bracket has a base ange 86 that' is welded or otherwise secured to the Wall electrical control system, as are also the igniter T9, motor 68 and solenoid '19.

A cover 91 is shown as applied to the' mounting 29, and the same is preferably constructed of sheet metal. its ends it overlies the top and front edges of the walls 81 and 88, and is flanged downwardly and inwardly along said respective edges exteriorly of said walls, and is held in place by screws 98.

The combustion apparatus wherewith we have` of electrical energy (not shown) which source may be the usual house for example. |02 designates a the apparatus becomes overheated or a short circuit occurs. The conductor |0| leads to the master thermostat 06, the iinger of which is arranged to engage a contact |3 from which a conductor leads to the blade ofthe Micro-switchv 89, which has been previously describedv as carried 82, withthe.v free end ofthe bi Y other connection thereof a conductor |3| leads to the return conductor H2.

From the junction ||0, a'conductor |33 leads to the pivoted end of the blade ||1 of the relay 9|?, while the corresponding end of the other blade I8 is placed in electrical connection with one of the binding posts of the igniter 1G through a conductor |35, a conductor |36 leading from the other binding post of the igniter to the return conductor ||2. Current is also carried from the junction H0, by a conductor |31, to one end of the coil of the solenoid 'i9 that operates the fuel valve 16, the opposite end of said coil being electrically connected, through a conductor |38, with the return conduit ||2. It would be well to eX- plain that the fuel valve 1B is biased toward closed position, as by means of a spring, and that it is opened by the solenoid I9 when the latter is energized.

We have described the control system as operating on the line voltage of a house circuit. Obviously a transformer may be employed, the primary of which would be connected across the house circuit, while the two ends of its secondary coil would represent, respectively, the positive and negative sides of the source of electrical energy, and wherewith the respective conductors |3| and ||2 would be connected. In such a case, electrical devices would be selected that would operate on the reduced voltage.

We have also shown the motor 68 of the air impeller or blower as being connected to the positive side of the circuit ahead of the master thermostat |60. Accordingly, the impeller or blower will operate at all times that the system is in connection with a source of electrical energy. This constant running of the impeller or blower has the advantage of keeping the fuel and air feeding means relatively cool during burner operation. Also, through the above described circuit, including the blade ||3 of the relay 90, and the igniter l0, said igniter is maintained at fuel igniting temperature as long as the relay 90 is de-energized.

As previously pointed out, the Micro-switch 85 is closed when the bimetal strip 33 is relatively cool. This presupposes that there is no iire in the combustion apparatus. Accordingly, when the master thermostat |03, responsive to a drop in the medium to be kept heated, operates to close the circuit (in the present instance by the nger of the themostat swinging into engagement with the contact |03), current flows through conductor |05, Micro-switch 80, conductor |09, junction ||6 and conductor ||i to the winding of the relay 90, the current continuing on to the source through the return conductor ||2. Upon the relay thus being energized, blade ill into engagement with the contact I2@ and the blade H6 away from the contact 12|. Consequently current reaches junction ||3 not only through the path including the Micro-switch 80, but also through a holding circuit represented by conductor |25, blade ||1 and conductor |33; thereafter the relay 90 and the solenoid 'i9 are no longer dependent on the circuit through the Micro-switch 8|) for their current supply since suiiicient current reaches junction ||0 through the holding circuit to energize these elements.

Therefore, the conditions at the moment are as follows: the temperature to be controlled is below a predetermined value for which the master thermostat is set; said thermostat has functioned to close the circuit through the Micro-switch Si? that initially supplies current to the relay 9|) and the solenoid l5; the relay 30 operates, firstly, to establish the holding circuit that will continue to supply current to the relay 9G and to the solenod 19 after the Micro-switch 80 opens, and, secondly, to simultaneously interrupt the flow of currentto the igniter 10; the fuel valve 'i6 is held open by the solenoid so that fuel, with air from the continually operating lmpeller or blower 65, is discharged into the combustion space, and is vaporized and lighted by the igniter 16 that remains hot enough to perform these functions, notwithstanding the fact that flow of current thereto has been interrupted.

With the combustion apparatus thus set in operation, the temperature of the burner parts will rise and cause the bi-metal strip B3 to warp in the direction to open the Micro-switch 60, this action requiring a brief period of timeapproximately two minutes in practice. Operation of the apparatus will continue, however, by virtue of the holding circuit, until the temperature of the medium rises enough to cause the master ther mostat |33 to open the circuit at the contact |63, This opening of the circuit eiiects immediate deenergization of the relay 90, and of the solenoid 19, the former, incidentally, re-establishing the ignition circuit, and the latter allowing the valve 16 to close and shut olf the supply of fuel to the apparatus. As a consequence, the fire will go out and the burner parts excepting the igniter lf3 will cool off and permit the birnetal strip S3 (in the space of about two minutes, for example) to resume its former condition and close the Micro-switch 88, thus placing the system in readiness for the next operation.

We claim'.

l. Fuel and air feeding means for liquid fuel combustion apparatus, said means comprising a first cup-like shell in the form of a tubular member which is entirely closed at one end and isfully open at the other, said shell being arranged with its axis substantially horizontal, a second similar cup-like shell of substantially lesser cross sectional area than the first disposed within the first shell in spaced relation to the walls of the latter, the second shell having an opening in the end thereof that corresponds to the bottom of the cup and which end is contiguous to the closed end of the first shell, the opposite end of the second shell being its outer end, the interiors of the shells communicating through said opening so that the space enclosed by the second shell and the space between said shells provide a circulating air passageway, each shell having an aperture in its lower side that is aligned with the aperture of the other shell, an annular member connecting the shells aboutthe apertures thereof, fuel conducting means extending into the second shell and including a nozzle at its inner end that is disposed within said annular member in spaced relation to the portion of said annular member that surrounds the nozzle, the space within the annular member being in communication with through said passageway. l

2. Fuel and air feeding means for liquid fuel combustion apparatus, said means comprising a first cup-lik shell in the form of a tubular memof proceeds through said passageway.

3. Fuel and air feeding means for liquid fuel passageway, and an assembly comprising an air impeller and its driving motor attached to the a part of said output passes through said annular member and the remainder thereof Vproceeds vthrough said passageway.

4. Fuel and air feeding means for liquid fuel combustion apparatus, said means comprising a first cup-like shell in the form of a tubular mem- .proceeds through said passageway. e 5. Fuel and air feeding means for liquid fuel means extending into the second shell and including a nozzle at its inner end that is disposed within said annular member in spaced relation to the portion of said member that surrounds the nozzle, the space within the annular member bustion space and having a side opening leading into said space; a mounting including a wall portion adapted to serve as a closure for said opening, said wall portion having an aperture, aiirst cup-like shell in the form of a tubular member which is entirely closed at one end and is fully open at the other and that is adapted to extend into the combustion space and having its open end attached to the wall portion about said aperture, and a second similar cup-like shell of substantially lesser cross sectional area than the first projecting into the rst shell in spaced relation to the walls thereof, the second shell having an opening in the end thereof that corresponds to the bottom of the cup and which end is contiguous to the closed end of the iirst shell, the interiors of the shells communicating through said opening so that the space enclosed by the second shell and the space between the shells provide a circulating air passageway, each shell having a hole in the lower side thereof that is in alignment with the hole of the other shell, a nozzle guide secured to the shells about the holes thereof, a fuel nozzle positioned within the guide, the

nozzle and guide defining an air passage leading from the interior of the second shell so as to receive air from the aforesaid circulating air passageway and which passage continues about the discharge end of thenozzle, a fuel supply pipe extending into the second shell and connected to Y the nozzle, and an air impeller including a casing having an outlet so connected to the outer end of the second shell that said second shell provides the sole support for the air impeller and receives the output thereof.

7. Fuel and air feeding means for liquid fuel combustion apparatus, said means comprising a mounting adapted to be disposed in a substantially vertical plane across an opening leading into the combustion space of such apparatus, said mounting having an aperture, a rst cup-like shell in the form of a tubular member which is entirely closed at one end and is open at the other and which has its open end connected to the mounting about said aperture, a second similar cup-like shell of substantially lesser cross sectional area than the first projecting into the rst shell and arranged in spaced relation to the walls of the latter, the second shell having an opening in the end thereof that corresponds to the bottom of the cup and which end is contiguous to the closed end of the rst shell, the interiors of the shells communicating through said opening so that the space enclosed by the second shell and the space between said shells provide a circulating air passageway, each shell having an aperture in its lower side that is aligned with the aperture of the other shell, an annular member connecting the shells about the apertures thereof, means sustaining the end of the second shell that is adjacent the open end of the iirst shell in fixed relation to the mounting, fuel conducting means extending into the second shell and including a nozzle at its inner end that is disposed within said annular member in spaced relation to the portion of said member that surrounds thenozzle, the space within the annular member being in communication with said circulating air passageway, an air impeller including a casing having its outlet so connected to the end of the second shell adjacent the mounting that said second shell provides the sole support for the air impeller and receives the output thereof, and a cover applied to the mounting and overlying the air impeller.

References Cited in the file of this patent UNITED STATES PATENTS

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