US1705263A - Liquid-fuel-feeding apparatus - Google Patents

Description

March 12, 1929. J. Mc'lLVAlNE 1,705 263 LIQUID FUEL FEEDING APPARATUS Original Filed Dec. 8, 1925 Patented Mar. 12, 1929.

UNITED STATES PATENT OFFICE;

JOHN H. MCILVAINE, OF LAKE FOREST, ILLINOIS.

LIQUID-FUEL-FEEDING APPARATUS.

Original application-filed December s, 1923, Serial No. 679,467. Divided and. this application niea November 23, 1925.

This application is a division of my copending application Serial No. 67 9,467, filed December 8, 1923, and relates to improve ments in apparatus for feeding liquid fuel. The present invention is particularly concerned with the provision in an apparatus of this kind of a centrifugal fuel pump supplied with fuelunder a constant gravity pressure head and arranged to supply the fuel in a predetermined and uniform quantity per hour to the burner, provision being made for varying or regulating the feeding of oil so as to burn a steady, low flame or to secure, by gradations up to a maximum feed, a correspondingly increased flame and heat production.

Among the features of novelty incorporated in the pump, may be mentioned the pro; vision of a driving shaft for the impeller which has no packing in order thereby to eliminate frictional losses and reduce to a minimum the operating cost, combined with a leakage drain pipe for conductin the oil seeping by the shaft to a suitab e point either to be burned in the furnace directly or to be conducted back to the gravity tank for future use.

Another important feature consists in the. provision of means in connection with the pump to insure a uniform feeding of oil by preventing the delivery with the oil feed of any air introduced in the oil by vthe churning of the impeller, the means I prefer to employ consisting of stand-pipes one of which conducts air bubbles from the center of the impeller disk to insure the production of uniform pressure in the operation of the disk and the other of which is disposed in the delivery line to avoid the feeding of oil in slugs or gulps to the burner.

. The invention is illustrated in the accompanying drawing, wherein- Figure 1 is a more orless diagrammatic view showing the application of my improved fuel feeding apparatus to an oil burner in an ordinaryfurnace, the burner and its attendant fuel pump and air blower being shown in elevation withthe furnace appearing in sect-ion; I

Fig. 2 s an enlarged fragmentary section through the centrifugal fuel pump taken substantially on the line 22 of Fig. 1 looking in the direction of the arrows;

Fig. 3 is a vertical section through the pump taken substantially on the line 3-3 applied.

Serial No. 70,754.

of Fig. 2 looking in the direction of'the arrows.

The same reference numerals are applied to corresponding parts in the three views.

In order more readily to understand and appreciate the features of the centrifugal pump, designated generally by the reference numeral 5, and the provisions made in connection therewith, a brief discussion of the apparatus shown in Fig. 1 will be given describing the conditions under which the pump operates in practice and showing its relation to the other devices going to make up a complete liquid fuel burning apparatus of the type to which the resent invention is In the following discussion, the liquid fuel will be referred to as oil, it bein contemplated that the present pump an apparatus shall operate with gas or fuel oil of approximately 30 Baum'. Oil is supplied from any'suitable source such, for example, as from a storage tank (not shown) to a service tank 6. From this tank, the oil flows by gravity through a shut-off valve and strainer (not shown) and pipe 7 to a float valve 8 mounted on a suitable frame support and serving to maintain the oil at a constant level in relation 'to the pump 5. The oil flows by gravity from the float valve to the pump 5 through a connection 9. A coiled torsion spring 10 connects the impeller shaft 11 of the pump 5 with the armature shaft 12 of an electric motor 13 which is preferablyof a constant speed type. Both the pump and motor are mounted on a suitable frame 14. The pump 5 has its inlet through the connection 9 and has an outlet 14 connected with a delivery line 15 leading to the furnace. The impeller 16 of the pump in revolving raises t e oil pressure to a comparatively low 'value in proportion to the square of the s eed of revolution. An adjusting valve 17 is inserted in the delivery line 15 which allows the passage only of a tially as described in myco-pending application, Serial No. 45,448, filed July 23, 1925. The feeding is continuous rather than intermittent or 1n gulps and is arranged to 'cease when the motor 13 stops. The pipe 23, as described in the co-pending application above referred to, leads from the base of the chamber 22 suitably to a trip bucket (not shown) for actuating a safety valve to shut, off the feeding of oil in the event of a failure of the flame. Concurrent with the feeding of the oil, air is fed through the delivery pipe 24 from the blower 25 which is driven by the motor'13 suitably by direct connection of the impeller with the armature shaft 12 of the motor.

The centrifugal pump, shown in Figs. 2 and 3, comprises a casing 26 having an inlet 27 in a plate 28 secured as by means of screws 29 to the side of the casing 26 and having the-connection 9 leading therein through a nipple 30, as shown. The outlet .14 has the bore 31 thereof tangent to the eccentric portion 32 of the otherwise circular impeller chamber 33 in which the impeller 16 operates. 'The impeller is driven constantly in a clockwise direction viewing Fig. 3 with the shaft 11 and raises the pressure of the oil to a comparatively low pressure head in proportion to the square of its speed of revolution. The casing has an integral bearing 34 extending laterall therefrom which receives the impeller shaf t 11. The latter'is fitted inthe bearing with a small clearance for easy running and has no packing so that the frictional drag which would otherwise be imposed is eliminated, thereby reducing the electric current consumption required for operating the pump. The elimination of packing and the provision of an easy fit of the shaft in its bearg allows the passage of a few drops of oil per minute about the shaft. I provide a leakage drain pipe 35 for conveying the leaking oil to any suitable receptacle either to be burned directly in the furnace or conducted back to the main oil supply for future consumption. In my co-pending application first above referred to, this pipe leads to the combustion chamber directly while in the other co-pending applicationlast above referred to, this pipe leads to an intermediate point of the fuel delivery line. The pipe 35 is shown secured bya screw 36 on a pending tongue 37 provided on the bear- 11 order further to insure a uniform feeding of oil, I have provided means for preventing any air from being delivered by the pump. In experimenting, I have; found that the churmn of oil by the rapid revolution of the impe er causes the formation of small bubbles of air or gas some of which line and rise in the stand-pipe 18 and thus e exhaustpump outlet. The air accumulates in the\ cavity or chamber 38 provided in the inner face of the plate 28 adjacent the. impeller disk 16 and escapes through a hole 39,

drilled axially in .the shaft 11, to a point intermediate the ends of the bearing 34 at which a diametric hole 40 and the latter by an annular groove 41 turned in the periphery point the axial hole is intersected by of the shaft 11. A stand-pipe 42 communicating with the annular groove *41 allows the escape of the air to the atmosphere since the pipe is open to the atmosphere at its up-- per end.

- It is believed that the foregoing conveys a clear understanding of the ciples of my invention, and it should be understood that when putting these into practice,-various changes might be made in the objects and prmconstruction and arrangement of the necess sary parts and devices without departing from the spirit and $00 of the invention as expressed in the app nded claims, in which- I claim:

" 1. In a centrifugal pump, the combination of a casing, a driven shaft extending into said casing through a hearing in one side wall thereof, an impeller on said shaft arranged to turn in said casing, said casing having a low pressure inlet opening for liquid in the other side wall-communicating withv a low pressure chamber provided in said casing between said wall and the face of said impeller, and having a comparatively high pressure outlet opening for liquid communicating with the periphery of said imeller, and said shaft having an air drain iiole extending substantially axially thereof opening at its one end at the face of said impeller substantially centrally thereof for comnnmication with said low pressure chamber and having communication with the atmosphere at its other end;

2. In a pum' as set forth in claim 1 wherein the sha has a diametrical hole intersecting the axial hole at a point intermediate the ends of the shaft bearing, the said shaft and bearing providing therebetween an annular passage communicating with the ends of the diametrical hole, and a standpipe mounted on said bearing in comthe ends of the shaft bearing, a standpipe mounted on said bearing to have communication at its lower end with sald diametrical in the shaft has a- .the ends through a bearing said bearing and holie aiid open to the atmosphere at its upper en y 4. In a pump asset forth in claim 1 wherediametrical hole intersect ing'the axial hole at a pointintermediate I of the shaft bearing, a standpipe mounted on said bearing to have communication at its lower end with said diametrical hole-and open to the atmosphere at its upper end, said" shaft Operating without packing in said-bearing to minimize friction losses wherebyliquid is arranged. to leak from the end of the bearing, a jection on the end of said bearing beneath the shaft, and'means communicating with said projection for conducting the drippage away from said. bearing.

5. In a pump, the combination of a casing, a driven shaft extending into said casing in one side wall thereof for operating the pump, said shaft operating without packing in said bearing to minimize friction losses,

the construction being such that liquid may seep past the shaft through thereby further provide for self-lubrication of the pump, a drip conducting projection on the end of said bearing beneath the shaft, and means communicating with said projection for conducting the drippage away from said bearing.

6. A pump in the projection is in the form of a tongue having an inclined back face and wherein the last mentioned means comprises a tube having a flared end wherein the end of said tongue is received, the flared 'end of said tube being attached the tongue.

7. A centrifugal pump comprising a casto the inclined back face of 'ing,

drip conducting proas set forth in claim 5 wheretially circular,

the body portion of which is substansaid casing having an exten-' sion leading-from th i l body portion substantially on; a tangent a driven shaft extendin into said casing through-a bearing in one si e wall of the body portion, animpeller on said shaft arranged to turn in the body portion of said casing, said casinghav ingla low pressure inlet opening for liquid in the other side wall of the body portion communicatin with the .face of said'jim peller and having a comparatively high pressure outlet opening for liquid at the outer end of the aforesaid extens1on,.and a standpipe communicating with the top of said extension intermediate the body portion of said casing and said outlet opening.

8. In a punip as set forth in claim 7 wherein the im Her is formed integral with the driven sha 4 and wherein the body por-' tion of said casing has an opening in the one side wall thereof to permit the insertion therethrough of the shaft and impeller, a plate for closing said opening having the low pressure inlet opening provided therein.

9. In a pum the combination of a casing, a driven s aft extending into said cas- 2 JOHN H. 'McILVAINE.

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