Title:
Liquid fuel feeding means
United States Patent 2416514


Abstract:
This invention relates, generally, to liquid fuel burning apparatus that is especially suitable for use in furnaces of heating systems of houses or other buildings, and whose operating range includes low and relatively higher fires, and in which, through suitable feeding and governing mechanism,...



Inventors:
Chadwick, Lee S.
Application Number:
US47904243A
Publication Date:
02/25/1947
Filing Date:
03/13/1943
Assignee:
PERFECTION STOVE CO
Primary Class:
Other Classes:
137/80, 137/153, 137/391, 137/425, 137/571, 251/11, 251/125, 431/64, 431/339
International Classes:
F24C5/18
View Patent Images:
US Patent References:
2295799Liquid fuel combustion apparatus1942-09-15
2293697Flame propagator for pilot burners1942-08-25
2286497Pot type vaporizing oil burner1942-06-16
2253056Liquid fuel burner1941-08-19
2213521Reagent siphon1940-09-03
2086884Apparatus for controlling liquid fuel burners1937-07-13
2082149Reagent feeder1937-06-01
2075242Liquid fuel burner1937-03-30
1970880Constant liquid feed apparatus1934-08-21
1734388Filling device for lighters1929-11-05
1488771Receptacle drain1924-04-01
1349703Disinfecting or deodorizing device1920-08-17
0897131N/A1908-08-25
0796129N/A1905-08-01
0710928N/A1902-10-07
0583582N/A1897-06-01
0353276N/A1886-11-23
0231730N/A1880-08-31



Description:

This invention relates, generally, to liquid fuel burning apparatus that is especially suitable for use in furnaces of heating systems of houses or other buildings, and whose operating range includes low and relatively higher fires, and in which, through suitable feeding and governing mechanism, the burner is constantly supplied with fuel-at no time, so long as the apparatus is in operation, with less than enough to sustain operation at low fire, and at certain times with sufficient additional fuel to produce higher fire.

More particularly, the invention has, to do with improved means for use in such apparatus for feeding fuel at the rate required for low fire.

When apparatus of the class referred to is operating at low fire, which amounts practically to pilot fire, very little fuel is required. For example: In a size furnace burner wherewith the invention is intended for use, little more than one-half gallon of fuel is fed every 24 hours for the purpose of sustaining operation at low fire, and this amounts to approximately one drop every two seconds. It will be apparent, therefore, that uniform and dependable feeding of the fuel at so low a rate presents a problem, and contrivances heretofore employed for the purpose have generally proven to be unsatisfactory and unreliable, especially those wherein the control of the flow of fuel is accomplished by means of orifices, as is the case with practically all types of valves.

It is the fundamental object of the present invention to provide a relatively simple and thoroughly reliable fuel feeding means involving a capillary siphon for feeding the liquid fuel to the burner in limited quantity, such as that re'quired for low fire; and a further object is to provide means whereby said capillary siphon may be adjusted to vary and control the amount of fuel feed, or to stop the feed entirely.

The capillary siphon consists of an inverted U-shaped wick, and in the present preferred construction, the wick is supported by a carrier -astride a partition or barrier located in the communicative connections between a constant level liquid fuel supply and the burner. The partition or barrier extends above the level of said supply and thus prevents the feeding of fuel from the supply to the burner solely by gravity. The wick is unsheathed' intermediate its ends (in contradistinction to siphon tubes containing wicks) to -that its siphonic action is cqnfined entirely to that dependent upon capillarity; and changes in the rate of flow through the wick are effected by raising and lowering the wick. Elevating the wick clear of the liquid supply obviously arrests the flow.

A further object of the invention is to provide a simple and convenient means of adjusting the wick; and a still further object is to provide a construction that is designed to facilitate and cheapen the manufacture and fabrication of its parts, the majority of which are die-stamped and formed from sheet metal, and are adapted for connection to one another by welding.

A further object is to provide, in apparatus of the aforesaid class, a liquid fuel burner involving two sumps to one of which the fuel Is fed by said capillary siphon and wherein it is concentrated for low fire, while valve controlled means is employed for delivering additional fuel to the burner in sufficient amount to supply the, other sump for the purpose of producing high fire.

The foregoing objects, with others hereinafter appearing, are attained in the embodiment of the invention illustrated in the accompanying drawings wherein Fig. 1 is a diagrammatic representation of a liquid fuel -burning apparatus incorporating the invention; Fig. 2 is an elevational view of the fuel feeding means involving the capillary or wick siphon; Fig. 3 is a plan view thereof with a part of the cover broken away; Fig. 4 is a central veitical section through the fuel feeding means on the line 4-4 of Fig. 2; FM. 5 is a horizontal section on the lines 5-- of Figs. 4 and 6; Fig. 6 is a vertical section on the line --6 of Fig. 4; Fig. 7 is a perspective view of the wick carrier, with parts broken away in order to better show its construction, and Fig. 8 is a perspective view of the adjusting screw supporting bracket.

In the liquid fuel burning apparatus schematically illustrated in Fig. 1, a burner of the so-called pot or bowl type is employed, the burner bowl being designated generally by the reference numeral I, and the same is suitably supported with its top wall 2 in spaced relation to the bottom wall 3 of the combustion chamber 4. Said walls 2 and 3 have aligned openings, that of wall 2 being surrounded by a downwardly and inwardly turned flange 5, while the opening of the wall I is surrounded by a depending flange I. The flanges 5 and 8 are spaced apart to provide a slot 8 for the admission of secondary air to the burner bowl, as will hereinafter more fully appear. Primary air is admitted through perforations 9 and 0I in the peripheral wall of the bowl. A relatively large lighting and cleanout opening is made in said wall and the same is surroundedby a neck (2 that is normally closed by a plug II.

shown as having a bayonet Joint connection with the neck.

Liquid fuel is supplied to the above described combustion apparatus from a suitable source, such as that represented by a tank 15, through a fuel feeding and governing system which I shall now describe. A pipe 16, shown as including a valve 6- leads from the tank II to a receptacle 17. The pipe communicates with said receptacle through a port 18 controlled by a valve 20. A spring 21 tends to lift the valve from its seat, and the valve is closed by a float 22 that is carried by a lever 23, fulcrumed on a pivot pin 24 suitably supported in the receptacle 17, as by having its ends connected to the side walls of the receptacle.

The end of the lever 23 remote from the float bears against the head of the valve 20. This float mechanism, as will be readily understood, serves to maintain a constant liquid level in the receptacle, as indicated in Fig. 1, and shown as rising from the bottom wall of the receptacle is an overflow tube 25 that terminates a short distance below the said liquid level. This overflow tube communicates, through a pipe 26 and a tubular extension 27, with a sump 28 that is illustrated as being incorporated in and located centrally of the bottom wall of the burner bowl I, said sump being constituted of a relatively small cup-like element the perimeter of which is spaced above ,the bottom of a second and larger surrounding sump 29, formed by the depressed central portion of said bottom wall. The tubular extension 27 is closed at its outer end, desirably by a screw cap 30 which may be removed for the purpose of cleaning the extension and sump 28.

Operating with a sliding fit within the overflow tube 26 is a valve member 32 which is formed with a slot 33 at its lower end. The valve member extends freely through an opening in the cover 34 of the receptacle 17, and said member may be lifted to uncover a part of the slot 33 thereby to permit liquid fuel to flow from the receptacle through the overflow tube 25, pipe 26 and extension 27 to the sump 28 from which it overflows into the sump 28. In the absence of combustion, and with the valve 69 open and the valve member 32 lifted to uncover the slot 33, fuel will accumulate within the sumps 28 and 29 to the depth indicated by the dot-and-dash line which is, of course, the same level as that prevailing in the receptacle 17. It will be seen, therefore, that in case the fire is extinguished from any cause, the combustion apparatus will not overflow, it being understood that, when both branches of the wick siphon 62 are equally submerged, the wick will cease to function as a siphon.

According to the present illustration, the valve member 32 is automatically operated by a thermostatic element in the form of a bimetallic strip 35 that is rigidly connected at one end to a bracket 36, shown as mounted on the cover 34 of the receptacle 17. At its end opposite said bracket, the strip 35 has connection through a member 37 and a link 38 with the upper end of the valve member 32. Attached to one side of the bimetal strip 35 is an electrical resistance heater 40 to which is supplied current from the secondary winding 41 of a transformer 42 through a conductor 43. The other terminal of the heater is connected through a conductor 44 with a contact element 45 of a so-called room thermostat 46. From the other or movable contact element 47 of said thermostat leads . conductor 48 to the opposite end of the secondary winding 41 of the transformer. The primary winding 49 of the transformer may be in the house circuit represented by the conductors 50 and 1 , in the latter of which is shown a manually operated switch 52.

6 The fuel feeding means involving the capillary or wick siphon hereinbefore referred to, for supplying fuel in very limited amount to the burner, consists of a casing .designated generally by the reference numeral 55 and which is divided by a barrier or partition 56 into a receiving part 57 and a delivery part 58. Said barrier or partition extends from one side wall to the other of the casing 55, as will hereinafter more fully appear, and it rises from the bottom of the casing to a substantial distance above the level of liquid in the receptacle 17. The receiving part 57 is supplied with liquid fuel from the receptacle 17 through a pipe 59, all of which is below the liquid level maintained in said receptacle. Consequently fuel is constantly present in the receiving part 57 to the same level as that prevailing in said receptacle. The delivery part 58 communicates with the burner through a pipe 60, through part of the previously mentioned pipe 26, and the tubular extension 27. An inverted U-shaped wick 62 is sustained by a carrier 63 (later to be described in detail) astride the partition 56.

Through capillary and siphonic action of this wick, the liquid fuel is transported at a slow rate from the receiving part 57 to the delivery part 58 from which it flows through the previously described connections to the sump 28. While the burner is operating at low or pilot fire, the fuel is consumed at such a rate that the level of the fuel is well below the top of the sump 28, as illustrated in Fig. 1 of the drawings; and obviously this level is further dependent upon the rate of fuel supply, and such supply, in turn, is governed by the vertical adjustment of the wick '40 which is accomplished by means of a screw 65 that is rotatably supported within the casing 55 in a manner hereinafter to be described, said screw having threaded engagement with a part 68 of the wick carrier 83.

,45 I shall now describe in detail the structural features of the fuel feeding means involving the capillary or wick siphon, reference being had to Figs. 2 to 8. The casing 55 is made of two substantially identical members 70 and 71, desirably formed of sheet metal. These casing members are applied to the opposite sides of a structural .element, designated 72, which includes as integral parts the previously mentioned barrier or partition 56 and a supporting bracket 73 that may be attached to a convenient part of the apparatus for supporting the casing 55 in proper relation to the burner I and receptacle 17. The pipes 59 and 60, that communicate respectively with the receiving part 57 and the delivery part 00 58 of the casing 55, have their upper ends projected through apertures in the bottoms of the casing members and suitably attached thereto with a leakproof joint, as by welding. Above the plane of the upper edge of the partition 66, the edges of the corresponding side walls of the two casing members 70 and 71 are welded together in abutting relation, while below said plane, said edges, and those across the bottom, are flanged outwardly and bear against the opposite sides of the element 72 to which they. are welded.

The wick carrier hereinbefore referred to and designated generally by the reference numeral 63, consists of two identical plates 75 (Fig. 7) that are connected at their upper ends, as by welding, to the opposite sides of a spacer 76. This spacer Is turned laterally above said plates to provide the previously mentioned part 66 that is formed with a threaded hole 11. The plates 75 have transverse slots 78 that are located near their upper ends and register with a notch 79 of the same area in the spacer 76. At their lower ends the plates 75 are provided with lugs 80 that are turned outwardly and thence upwardly in spaced relation to the body portions of the plates. Engaged through the slots 78 and the notch 19 is a wick 82 of suitable material, such as asbestos webbing. The wick is drawn down along the outer sides of the plates 75 and has its ends clamped between the plates and the clinched in lugs 80. Thus, the wick 82 is given an inverted U-shape, and is disposed astride the barrier or partition 56 when the carrier is lowered thereover.

To adjust the wick vertically with respect to the liquid fuel level for the purpose of changing the rate at which the fuel is fed, or for stopping the feed altogether, I employ the previously mentioned screw 65 which is projected downwardly through a threadless aperture 85 formed in a lateral extension 86 of a bracket 87 (Fig. 8) that is fastened to a side wall of the casing B5 by screws 88. These screws pass freely through openings in the casing wall and are threaded into tapped holes 89 of the bracket. The adjusting screw 65 is threaded through the hole 71 in the part 66 of the wick carrier and its reduced lower end is piloted in a bearing aperture of a lug 90 that is attached to and extends inwardly from the casing wall. A flanged cover 92 is telescoped over the upper end of the casing 55 and is apertured for the passage of the screws 88. The cover 92 has a hole 93 through which the upper end of the screw 65 extends so that the screw may be conveniently turned by means of its knurled head for the purpose of adjusting the wick or raising it clear of the liquid fuel supply. To prevent accidental dislodgement of the lower end of the screw from the lug 90, an abutment 94, such as a cotter pin, may be applied to the screw below the extension 86. In considering the operation of the apparatus it will be assumed that the valve 6* is open and oil is present in the system and that the burner has been ignited, as by removing the plug 13, projecting a lighted match or taper through the opening of the neck 12, and replacing the plug.

With the parts in the condition illustrated in Fig. 1, the liquid fuel within the sump 28 will gradually vaporize and burn, air.to support combustion entering through the holes 9 and 10 in the perinheral wall of the bowl I. Under the low fire condition at present prevailing, the products, and, incidentally, air entering through the slot 8, rise into the combustion chamber 4 and are carried away through the usual flue connections (not shown). The capillary or wick siphon 62 is adjusted with respect to the liquid level in the receiving part 57 of the casing 55 (which, obviously, is the same as that maintained in the receptacle 17) so as to feed fuel at a rate that will produce a flame of the desired volume for low fire, a shallow pool of fuel being maintained in the sump 28 under these conditions.

The room thermostat 46, as the term implies, is situated in a room or other space that is to be heated by the apparatus, and when the temperature of said room or space is within the range for which the thermostat is set-for example, between 70* and 720 F.-the movable contact element 47 will be in spaced relation to the contact element 46 and maintain open the circuit that includes the secondary 41 of the transformer and the resistance heater 40 that is supported in heat exchanging relation to and preferably by the bimetal strip 35. A drop in temperature below said range will cause the contact element 41 to swing into engagement with the contact element 45 and close said circuit thereby to energize the heater 40. Under the influence of the higher temperature of said heater, the bimetal strip 35 will flex in the direction indicated in dotted lines in Fig. 1 and lift the valve member 32 thereby to uncover the slot 33 and allow liquid fuel to pass from the receptacle 17 through the previously described connections to the burner. This fuel, augmenting the quantity fed by the capillary or wick siphon 62, will flood the sump 28 and cause it to overflow into the sump 29 thereby greatly enlarging the fire within the burner bowl I. Under these conditions the enlarged volume of vapors generated within the lower portion of the bowl will be supplied with primary air through the openings 9 and 10 and, upon reaching the plane of the slot 8, will be rendered highly combustible by the addition of secondary air entering through said slot and will vigorously burn in the combustion chamber 4.

The high fire condition will continue until sufficient heat has been delivered to the room or space to which the thermostat 46 is exposed to cause the contact element 47 to swing away from the contact element 45 and open the circuit of the heater 40. As the heater cools the bimetal strip 35 will return to its former position and lower the valve member 32 sufficiently to close the slot 33 thereby to shut off the supply of fuel to the burner other than that continually fed by the capillary or wick siphon 62.

This invention is not to be confused with liquid fuel feeds involving siphon tubes that are filled with absorbent material which may be in the form of a continuous wick and serves to initiate flow through the tube. While in those cases the absorbent material or wick may, strictly speaking, function as a capillary siphon, the siphonic action thereof is so inferior to that of the tubular siphon that vertical adjustment of the unit has no appreciable effect in changing the rate of flow through the unit.

Having thus described my invention, what I claim is: 1. Liquid fuel feeding means comprising a casing, a partition disposed transversely of the casing and extending from the bottom thereof to a given height within the casing, inlet and outlet connections communicating with the casing adjacent the bottom thereof on opposite sides of said partition, a rigid wick carrier including branches depending on opposite sides of the partition, a wick supported in inverted U-shaped formation by said carrier with its end portions extended downwardly along the branches of 'the carrier and secured thereto, the carrier including a lateral extension adjacent its upper end, said extension being provided with a threaded hole, a bracket projectibfg from the wall of the casing in vertically spaced relation to said extension and having an aperture in alignment with the hole in said extension, and a screw engaged downwardly through said aperture with its head bearing upon said bracket and threadedly engaged through said hole.

2. Liquid fuel feeding means comprising a casing, a partition disposed transversefy of the casing and extending from the bottom thereof to a given height within the casing, inlet and outlet con-- I il~~ ii ยท nections communicating with the casing adjacent the bottom thereof on opposite sides of said partition, a rigid wick carrier including branches depending on opposite sides of the partition, the branches having lugs at their lower ends, a wick supported in inverted U-shaped formation by said carrier with the end portions thereof extended downwardly along the branches of the carrier and secured thereto by the aforesaid lugs, the carrier including a lateral extension adjacent its 1C upper end provided with a threaded hole, a bracket projecting from the wall of the casing in vertically spaced relation to said extension and having an aperture in alignment with the hole in said extension, a screw engaged downwardly I1 through said aperture with its head bearing upon said bracket and threadedly engaged through said. hole, means on the casing wherein the lower end of the screw has bearing, and a cover for said casing. 3. Liquid fuel feeding means comprising a casing, a partition extending across the lower portion of said casing, inlet and outlet connections communicating with the casing adjacent the bottom thereof on opposite sides of said partition, respectively, an adjusting screw, means supporting the screw for rotation on a vertical axis adjacent the top of the casing, a wick carrier including a spacer disposed above the partition and in the plane thereof, the spacer being provided with a lateral extension having threaded engagement with the screw, two plates incorporated in the wick carrier, one arranged on each side of said partition and having its upper end secured to said spacer, said plates having slots adjacent their upper ends, and a wick projected through said slots and having its end portions carried down alongside and secured to the plates.

4. Liquid fuel feeding means comprising a casing composed of two substantially identical members, a supporting element including a part comprising a partition on opposite sides of which the lower portions of said members are disposed and to which said edge portions are welded, the edges of said members above the plane of the upper edge of said partition being welded together, inlet and outlet connections communicating with the casing adjacent the bottom thereof on opposite sides of said partition, a bracket secured to a wall of the casing adjacent the top thereof, the same having a laterally extended lug provided with an aperture, a second lug extending from said wall and having a bearing aperture in axial alignment with the former aperture, a wick carrier having a lateral extension disposed between the aforesaid lugs and provided with a threaded hole in axial alignment with said apertures, a screw projected downwardly through the first mentioned aperture and threaded through said hole and having its lower end guided within the second mentioned aperture, an inverted U-shaped wick sustained by the carrier astride said partition, and a cover for the casing.

5. Liquid fuel feeding means comprising a casing, a partition separating said casing into a receiving part and a delivery part. inlet and outlet connections communicating, respectively, with said teceiving and delivery parts, means for supplying liquid fuel to the receiving compartment and for maintaining a substantially Sconstant liquid level therein, an inverted Ushaped wick, a rigid carrier supporting the same astride said partition, and means for adjusting the carrier bodily vertically of said partition to and between a position wherein the lower end of the branches of the wick are a material distance below said liquid level, and a position wherein the branch of the wick that is in the receiving part of the casing is above said level.

6. In a liquid fuel feeding means, the combination of a casing including a bottom and opposed side walls, a partition rising from said bottom and extending between said side walls thereby to separate the lower portion of the casing into a receiving part and a delivery part, inlet and outlet connections communicating, respectively, with said receiving and delivery parts, a rigid wick carrier comprising a top member located above and in the plane of said partition, and side plates depending from said member on both sides of the partition, the carrier having a horizontal slot in the region of said top member, a broad fiat wick extending through said slot and down alongside said plates and having Its ends secured to the plates adjacent the lower edges of the latter, and means accessible from above the casing for raising and lowering the wick carrier.

LEE S. CHADWICK.

REFERENCES CITED The following references are of record in the file of this patent: UNITED STATES PATENTS Number 1,734,388 796,129 897,131 1,488,771 2,082,149 2,213,521 1,970,880 710,928 1,349,703 2,075,242 353,276 2,295,799 2,293,697 231,730 2,086,884 2,253,056 2,286,497 583,582 Name Date Marsh Laughton Owen Ainsa Cheavons Haeberlin Bird --------- Aug. 21, 1934 Winton ----------- Oct. 7, 1902 Williams --------- Aug. 17, 1920 Todaro ---------- Mar. 30, 1937 Walton ---------_ Nov. 23, 1886 Focke et al. -------_ Sept. 15, 1942 Chadwick --------- Aug. 25, 1942 Rippingille .------- Aug. 31, 1880 Sherman -------- July 13, 1937 Ullstrand -------- Aug. 19, 1941 Micell et al. ------ June 16, 1942 Rhind ------------ June 1, 1897