US1954293A - Oil burning apparatus - Google Patents

Description

April 10, 1934.

F. A. HEATH .OIL BURNING APPARATUS original lFiled Aug. vs. 1925 INVENTOR ATTORNEY Patented Apr. 10, 1934 UNITED STATES '1,954,293 on. .BURNING APPARATUS Forrest A.V Heath, Philadelphia, ra., mignr u himself, Karl B. Segall, and Walter F. Tant,

Detroit, Mich. l

original application August s, 192s, semi No.

Divided and this application April 19,

1.928, Serial N0. 271,129 y 7 ciaims. (c1. 15a-i7) My present invention relates to oil burners of the so-called automatic type adapted to burn liquid fuel, particularly the heavier yor so-called fuel oils, and the construction is peculiarly adapted for converting ordinary coal burning furnaces into oil furnaces although it will be evident that various features of the invention may be applied to other burners .which may also be adapted for other uses. This application is a division of my copending application Ser. No. 47,709, filed August 3, 1925. Y

The apparatus in connection with which the present invention is shown' includes means for initially forming a crude, over-rich carburetted mixture of oil spray suspended in and projected with a relatively small percentage of primary air in combination with special homogenizing and propelling means whereby the spray in this initial draft is atomized and-intimately mixed with said initial air and also with some additional primary air and the Whole projected as a homogeneous fuel draft in close relation to the main4 draft of air necessary for complete combustion. The'means for forming the initial spray in an air draft is shown as being ofthe centrifugal spray cup type and the cup is rotated at the speeds required for centrifugal operation by a small electric motor which preferably is also utilized for driving the homogenizing and propelling means.

An important feature of the present invention relates to means for supplying oil to the centrifugal cup and according to a preferred form of the invention the feeding of the oil to the centrifugal cup is effected by means ofA picker tubes arranged vertically and having at their lower ends narrow integral extensions formed\by cutting away theftube, bending it horizontally through somewhat less than a quadrant of a circle and cutting the end to V-shape, the side walls of the V being vertical, so that they tend to laterally deflect the oil in which they are normally submerged.- The forwardly presented upper surface of the pick acts to skim olf and deflect the oil upwardly. 'I'he rate at which the' oil is elevated varies approximately as the depth to which the deflecting surface is submerged in the oil. As the depth of submergence of the tip is increased, the more there is of the uniform width portion ofthe pick? which is submerged and the -greater' is the rate of oil elevation. Hence, for any given setting of the pick tubes, the amount or rate of oil supply can be gauged with greatest accuracy by raising orfl'owering the level cf the oil ,to increase or decrease the depth of sub.

'centrifugal cup and the pickers.

mergence of the tip of the pick. Air is also carried up through the pickers and ,the outward movement of the air and oil'at the top of the `spray producing devices together with the motor are suspended from the central part of the hearth by a three-point suspension arrangement. The motor is also connected with the spray cup and picker tube rotating structure by means of a flexible connection. One important feature of this form of support is that both the hearth and the oil atomizing parts can be adjusted both vertically and as to inclination. Furthermore, by suspendingthe oil atomizing structure and the motor from the hearth the' vibrations of the running parts are not transmitted directly `to the iioor and not only is the vibration cut down but the .apparatus is very much quieter in operation. This adjustment is also important to position the oil well' so that the pickers will enter the oil to the same extent in all points around their path.

The above and other features and novel details of. my invention will be more-fully understood from the following description in connection with the accompanying drawing, in which Fig. l is a vertical axial section through the burner and a portion of the hearth in one form of installation;

Fig. 2 is an axial sectional detail of one of th picker tubes 37 of Fig. 1; and

Fig. 3 is a section on a smaller scale and taken o n the staggeredline 3--3 of Fig. l.

The refractory hearth 10 is supported at its center by a circular plate 11, which is supported in turn at its inner edge by a'platform member l2 having an integrali upstanding iiange 13 defining a drainage groove 14, for draining off any oil that may leak through the joint o f the refractory hearth with its metal support 12. At the upper edge of the platform member 12 there is a collar 15 throughsyhich projects shaft 1'6 carrying 4the homogenizing rotor .17 having pro-` peller blades 18 surrounding the outlet from the aov centrifugal spray cup 19, which is also mounted on said shaft 16. As shown in Fig. 1, there is an annular passage between the spray cup 19`and collar 15, not only for clearance to permit rotation of the former, but also to provide for the main air draft drawn into the furnace by chimney suction.

The platform member 12 is supported by leg sections 20 telescoped in leg sections 21 and adjustably held by screws 21a. Preferably, there are three legs to afford three-point support. Each legl section 21 has screwed into the lower end thereof an adjustable section 22 secured by a lock nut 23 whereby the legs may be readily adjusted to true vertical even though the floor of the ash pit be very uneven. The lower end of each member 22 is preferably headed as at 22a, and the head is cushioned by a rubber block 24 held by a metal clip 25 secured to the head 22a. The adjustable leg sections are held in fixed relation by a U-shaped casting 2lb. The three-point support afforded by the telescoping leg sections makes it easy to adjust them for proper support of the hearth 10 through its supporting .platform member 12. l

Projecting through and concentric with th collar 15 is the centrifugal or carburetting spray cup 19 formedat the bottom with inlets 26 for supplying the oil spray to be mixed with the air and projected from the top of the cup at 27. The cup is formed with a central tubular member 28 fitting the vertical'shaft at 29 and resting on an enlargement thereof as at 30. On top of thisy tubular projection is tted a disk 31 carrying radial fan blades 32. On disk 31 are clamped a cover member 33 which closes the whole top of the Icup and is dish shaped so that its peripheral wall 33a. is approximately parallel with the lip portion of the cup, and a second cover member 33y fitted on top of 33. Obviously, the cover members 33 and 33 may be considered as parts of the cup 19. Disk 31 and covers 33 and 33 are clamped down on the top of the tubular member 28 by an annular clamping collar 34 secured by a clamping nut 35. All of the parts may be sufliciently held against rotation on the shaft 16 by the clamping action of nut 35, but I prefer to provide a key 36 engaging clamping collar 34 and extending through 33', 33 and 31.

The bottom of the cup 19 is thickened down- Wardly to provide an adequate lateral bearing for the picker tubes 37 that extend downwardly therethrough and are secured therein in any desired position of vertical adjustment by means of screws 38. Also integral with the bottom of the cup and outside of the downward extending picker tubes is a circular depending lip 39 adapted to close the opening into a suitable oil Well casing 40. 'I'his casing is preferably provided with a plurality of horizontal diaphragms, such as 41 and 42, which clear the rotary closure or lip 39 and with it form a labyrinth facilitating down- Ward drainage of oil into the oil supply chamber or Well 43 and baffling escape of oil from said chamber to the outside. 'I'he depending annulus 44 serves similarly to baffle splash and to damp Wave motion that may be set up by the pickers when rapidly rotated to lift the oil. Rotation of the oil is damped by radial ribs 45 projecting from the bottom of the oil reservoir almost to the level of the normal surface of the oil.

The oil well 43 has a central cylindrical barrel 46 and the cup bearing shaft 16, 29 has a downward extension 47 which is journaled on suitable bearings, such as ball bearings, in said barrel.

For lubricating purposes the top and bottom of the barrel below the lower ball bearing and above the upper ball bearing are closed by suitable pack,- ings such as shown in said co-pending application of which this is a division. 'Ihe cavity is initially filled with bearing grease and additional grease may be forced in at any time through duct 48 in one of the ribs 45 by removing screw plug 49 and applying a grease gun.

Below the shaft and in alignment therewith is the electric motor 50, which may be of ordinary construction adapted to use alternating or direct current, and designed to rotate a spray cup, pickers and homogenizing propellers carried thereby at the required speed, which may be as low as 1700 to 1800 revolutions per minute, for a model built on a scale which will make the extreme overall diameter of the homogenizer 8 (Fig. 1) inches.

The armature shaft 51 of the motor 50 is detachably secured to the cup shaft by -a flexible coupling 52 which may comprise a block of elastic material 53 through which the drive is applied. This exible coupling may be the same as that disclosed in my said co-pending application.

The oil well structure and motor are supported in any suitable Way. As shown in Fig. 1, the oil well has three-point support from the platform member 12 by means of stud bolts 54, screwthreaded into 12 and passing through vertically apertured ears 55 which' are integral with and outside of a drainage. gutter 56 which is integral with the oil well. Any desired position of vertical adjustment for the oil well, drive shaft and spray cup carried thereby may be fixed for each stud bolt 54 by means of a lock nut 57, vertical displacement being prevented by thumb nut 58. In

the form shown the motor is secured by screws l 59 adjustably engaging a depending bracket 60 Wh'ch is secured to the bottom of the oil well casing by flanges 61 fitting against the same and secured thereto by screws not shown. 'I'he vertical bracket member is stayed by deep flanges 62 and 63.

Oil is supplied through the bottom of the oil Well by pipe 64 and waste oil in the collecting gutter 56 is drained voff through pipe 65. It should be understood that the supply of oil through the pipe 64 may be controlled in any. suitable manner, for example, by a float-controlled valve. The gutter 56 is in position to collect oil from the spray cup and also from the groove 14 which discharges throughA the duct 14a, but its main purpose is to collect oil that drains from the inclined hearth when the pilot light fails or for any other reason when oil is to be discharged at a rate greatly in excess of the rate at which it is being burned. In such cases the oll drains down the incline of the hearth and through the slots 15a in collar 15 and drips into the collecting gutter 56,- whence it goes through p ipe 65 to a suitable control mechanism forming no part of my present invention. It is sufficient to say that this mechanism, accurately controls the level of the oil in the oil well and completely shuts off the supply 0f oil whenever there is excess drainage through pipe 65.

The picker tubes 37 are preferably of the form shown in Fig. 2, the picker at the lower end consisting of a narrow integral extension 37a formed by cutting away the tube, bending it horizontally through something less than a quadrant of a lat proximately vertical, but this while desirable is not essential. 'Ihe thin film of oil is skimmed off by reason of the fact hat the loil is stationary while the picker tube is traveling circularly at high linear speed around a circle which may be, say, 6 or 8 inches in diameter, driven by a motor which is rotated, say, 175,0 revolutions per minute.

Although the oil is mobile, it is held by inertia against the thrust of the picker and is deflected upwardly through the tube at high velocity. Air is also carried up in the same way and the upward movement of both of them is facilitated by the fact that the tube is cut off at an angle on the rear side as shown at 37e. The effect is that by as much as the speed of rotationof the upper end of the tube is greater than the air within the spray cup, by so much is there a suction effect applied at the outlet. In this connection, it is to be remembered that an even greater suction effect is applied by reason of the fact that the cup itself is a centrifugal blower, see fan blades 32, and tends to draw in air through each picker tube 37, as well as througluthe regular air inlet 26. Obviously also the picker is itself an air scoop, as well as an oil scoop.

The amount of oil supply can be gauged with greatest accuracy by gauging the depth of oil in the oil well, and one advantage in having ,the picker cut away to a mere finger with its lower, ,oil skimming portion of approximately uniform width as shown in the drawing, is that the amount of o'1 lifted will be more nearly proportional to` `the depth of the oil. The amount of oil could also be varied by vertically adjusting the picker tubes, but this is an undesirable way, since the oil level in the well should be kept YVas near the top of the ribs 45 as is practicable, thereby making the ribs as effective as possible in preventing the pickersfrom imparting rotary motion tothe oil, it being obviously desirable to minimize all disturbances of the oil and hold it stationary as against the scoop action of the pickers.

The spray thrown from the upper end of the picker tubes is subjected to centrifugal fdrce tending to drive it through the air currents within tlie cup19 and in practiceimuch of it impinges on the side of the cup adjacent the outlet annulus.

Much of it, however, goes into suspension in the.

primary a'r,` which is discharged through the same outlet by centrifugal force which is assisted by the fan blades 32, although the latter may be omitted if desired. The richly'carburetted mix'- ture is discharged upwardly. against the horizontal baflie a-nnulus 66 of the cover plate 33, and the adjacent bases of the inner propeller blades 18a.

Thev unsuspended oil creeps by the walls of the cup by centrifugal force and is projected in minute drops against the intermediate portions of said blades. This is on a level below the primarilyn carburetted air and in the path of the main air draft coming up through` the collar 15 -at a high angle to the horizontally projected liquid. This tends to drive upward the minute drops that have been shattered by impact with the inner faces of the blades 18a toward the baille plate 66 and those that have been caught by the outer surface of blades 18a upward towards the horizontal or baffle annulus 66a of the outer propeller.

vAs a result'of the baffling, eddying, mixing and shattering thus produced, a desired amount of additional primary 'air comes incorporated in homogenous mixturewith a'flnely atomized and partially vaporized liquid which is propelled outward. A large part of the upward maingdraft,

however, is deflected, part being driven upward by the propeller blades over the hearth as an air stratum, merging into a richly carburetted stratum, another part eddying back and being again projected upward by the injector -action of the upper part of the draft stream.

The radially projected stratum has its upward surface exposed to the products of combustion within the furnace chamber and, as pointed out, in said co-pending application of which this is a division, entraine and merges with both the upper and lower sheet as it accentuates by spreading along the divergent lines of the circle. Fur-` ther disclosure of the action of the homogenizing propeller may be found in said prior application Ser. No. 47,709 and inasmuch as the features of the homogenizing propeller are not claimeddn the present applibation, further discussion thereof is unnecessary.

It should be understood that my invention is not limited to the details of construction above described.

I claim: i 1. Fuel metering apparatus, including an oil well and a motor driven spray cup, in combination with means including a picker finger carried by the cup, extending downwardly, and curving forwardly to skim a film from the surface of the oil in the well and discharge it into the air inthe cup, said finger being formed with V- shaped tip, the forwardly presented surfaces thereof being disposed approximately vertically to have a lateral plowing effect onthe oil.

2. Fuel metering apparatus, including an oil Well and a motor driven spray cup, in combination with means including a picker finger .carried by the cup,. extending downwardly, and curving forwardly to skim a film from the surface of theoil in the well and discharge it into the air in the cup, the oil skimming portions of said finger near and above the point of engagement with the surface of the oil being of approximately uniform width.

3. Fuel metering apparatus, including an il skimming portions of said nger near and above the point of engagement with the surface of the oil being of approximately uniform width.

4. .Fuel metering apparatus, including an oil well and a motor driven spray cup, in combination with picker tubes extending through the bottom of the cup, eccentric to and approximately parallel with the axis thereof, each carrying at its lower end a downwardly extending finger, curved forwardly in the direction of rotation, in position to skim the surface of the oil in said well and deflect it upward into said tubes, said tubes beingentirely open at the upper end and cut diagonally so as to afford free rearward and upward exit to the Voil discharged therethrough.

K 5. Fuel metering'apparatus, including an' oil well and a motor driven spray cup, in combination with pickerv tubes extending through the bottom of the cup, eccentric to andapproximately4 the direction of rotation, in'

position to skim the surface of the oil in said well and deect it upward into said tubes, said tubes being entirely open at the upper'end, the oil skimming portion of said fingers near and above the point of engagement with the surface of the oil being of approximately uniform width.

6. Fuel metering apparatus, including an oil well and a motor driven spray cup, in combination with picker tubes extending through the bottom of the cup, eccentric to and approximately parallel with the axis thereof, each carrying at its lower end a downwardly extending nger, curved forwardly in the direction of rotation, in position to skim the surface of the oil in said well and deect it upward into said tubes said fingers being formed with V`shaped tips, the forwardly presented surfaces thereof being disposed approximately vertically to have a lateral plowing effect on the oil.

7. Fuel metering apparatus, including an oil :well and a motor driven rotor for centrifugally spraying oil, in combination with means including a picker finger carried by said rotor, extending downwardly and curving forwardly to skim a film of desired depth from the surface of the deflect the oil Without substantial lifting effectv thereon.

FORREST A. HEATH.

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