US2591533A - Oil burner - Google Patents

Description

April 1, 1952 w. J.- J. FRITZ 2,591,533

OIL BURNER Filed Feb. 10, 1947 v 6 Sheets-Sheet 1 INVENTOR WJ-J. F'RITZ ATTORNEY W. J. J. FRITZ April 1, 195 2 OIL BURNER s Sheets-Sheet 2 Filed Feb. 10, 1947 INVENTOR ATTORNEY April 1, 1952 w. J. J. FRITZ OIL BURNER Filed Feb. 10, 1947 6 Sheets-Sheet 5 INVENTOR ATTORNEY.

W. J. J. FRITZ April 1, 1952 OIL BURNER 'G/Sheets-Sheeg 4 Filed Feb. 10, 1947 INVENTOR VV..J.J7 FRITZ ATTORNEY April 1952 w. J. J. FRITZ 2,591,533

OIL BURNER Filed Feb. 10, 1947 6 Sheets-Sheet 5 INVENTOR WJJ. F'RITZ ATTORNEY W. J. J. FRITZ April 1, 1952 OIL BURNER 6 Sheets-Sheet Filed Feb. 10, 1947 INVENTOR ATTORNEY Patented Apr. 1, 1 952 OIL BURNER Wilfred J. J. Fritz, Seattle, Wash., assignor to Iron Fireman Manufacturing Company, Portland, Oreg.

Application February 10, 1947, Serial No. 727,592

3 Claims.

This invention relates to oil burners generally but more particularly to that class of industrial oil burners using the horizontal rotary cup methd of atomization of the fuel oil.

This invention provides a system for supplying, and controlling the supply of, fuel oil to an oil burner which system, to the best of my knowledge, has never been used before but is economical to produce and has great utility.

The operation of this class of industrial oil burners is to surround a horizontally rotating metal cup with a conical stream of high pressure air and to drip oil into the metal cup from where it spins off into the air stream. This primary air stream usually amounts to less than 20% of the total air required for combustion and the remaining or secondary air is supplied near the floor of the combustion chamber by natural, forced, or induced draft.

One of the great problems of burning or #6 oil which is the so-called heavy industrial fuel oil, is due to the great variation in viscosity which the oil has over the temperature range in which it is stored and handled and is further complicated by the oil not being free of all small solid matter. This is the problem of control of the oil feeding rate in accordance with the demands of the heat load to which the oil burner is applied.

A common method which has been used in the attempt to gain uniformity in the oil feed of horizontal rotary cup type oil burners is to use a positive pressure gear type pump to force oil thru two parallel resistance paths and to vary the restrictions in these parallel paths to obtain the oil feed desired through one of the paths. This path leads to the rotary cup while the other path returns oil to the storage tank or to the inlet side of the pump. This scheme is sometimes effective in maintaining a fixed ratio of the oil rates in the two paths but does not provide sufiicient control of the oil rate to the rotary cup. And, of course, some sort of relief valve is required to prevent breakage in case the line to the rotary cup becomes plugged.

Since the location of the oil storage tank for each individual installation will vary with respect to the burner, it is common practice to provide a second pump to pump oil to a sump near the burner from which sump the oil flows by gravity to the first pump mentioned above.

It is seen that to maintain proper control of the oil flow to the nozzle of a rotary cup oil burner means must be provided for at least the following five functions: (1) To pump oil from the storage tank to a reservoir near the burner; (2) to hold a reserve supply of oil near the burner; (3) to pump oil from the reservoir to the rotary cup; (4) to control the oil rate from the reservoir to the rotary cup, and (5) to limit the pressure in the oil lines from the reservoir to the rotary cup in case the line becomes clogged.

It is the principal object of this invention to provide these means in one unitary structure enclosing a minimum number of interdependent parts. That this object has been attained is clearly shown in th attached specifications and drawings, wherein Fig. 1 is a vertical section thru the main axis of my oil burner.

Fig. 2 is a vertical section thru the transverse axis of my oil burner.

Fig. 3 is a vertical section along line 3--3 of Fig. 2, modified to show the addition of an outlet pipe sleeve required when an external oil heater is used with the apparatus of my invention.

Fig. 4 is a vertical section along line i -4 of Fig. 2.

Fig. 5 Fig. 2.

Fig. .6 is a horizontal section along line 6-5 of Fig. 2.

Referring now to the drawings: Denoted by the number I is the main shaft of the oil burner driven through V-belt 2 and sheaves 3 and 4 by motor 5 supported on the main frame 6 supported by fan housing 1 which in turn is hinged to and supported by the stationary front plate, not shown, of the furnace or boiler, not shown, to which the burner is applied.

Fan 8 is fixed to fan hub 9 keyed to main shaft I. Rotary cup I0 is supported on shaft I by threads II. Transverse hole i2 in shaft I intercepts axial hole I3, shown dotted, drilled in the end of shaft I. Oil transfer fitting M has inlet opening I5, leading to cored chamber I6 communicating with oil inlet hole I2 in shaft I. Right and. left from chamber l6, fitting I4 is bored and spiral grooved for close clearance over shaft I. In operation spiral grooves I7 tend to prevent leakage of oil along surface of shaft I from chamber I6, I8 and I9 are bearings supporting shaft I in main frame 6. Worm 20 formed on shaft I mates with worm wheel 2I keyed to transverse shaft 22 journalled in main frame cover plates 23 and 24 of main frame 6.

Reservoir 25 is carried thru rear cover plate is a vertical section along line 5-5 of v26, supports 21 and frame cover plate 24 by frame 6. Pump plate 28 and pump body 29 are secured to rear cover 26 by cap screws 30. Coupled to transverse shaft 22 is pump haft 3| journalled in rear cover 26 and pump plate 28. In the pump cavity 3T of body 29 and closely confined by plate 28 and cover 23 is pump gear 32 keyed to shaft 3|. Mating with gear 32 in. the pump cavity 3'! of body 29 and also closely confined by plate 28 and cover 26 is pump idler gear 33 freely mounted on idler shaft 34 firmly supported by plate 28 and cover 28.

Oil inlet opening 35 in cover 26 communicates thru oil passage 36 in pump body 29 with pump cavity 31 at one side of mesh of pump gears 32 and 33. On the other side of mesh of pump gears 32 and 33 outlet passage 38 leads from pump cavity 31 to outlet opening 39 of pump body 29. Pump riser 4B is firmly supported in outlet opening 39.

Pump pistons 42 are freely carried in cylinders 46 and guides 41 of pump barrel i splined to shaft 3 l. Springs 43 located between snap rings 44 on pistons 42 and surface 45 of barrel ll yieldably urge plane surface 48 of barrel 4! against plane surface 49 of pump plate 28. The reactions of springs 33 also supply the power required for the suction stroke of pistons 42 as limited by the angularly adjustable rectangular piston reaction plate 50 pivotally carried near one edge on hinge pivots 5| supported by ears 52 of front cover plate 53 of reservoir 25.

Depression 54 below surface 49 of plate 28 al lows each cylinder 46 in rotation to communicate with the interior cavity 55 of reservoir 25 when the cylinder is below the axis of pump shaft 31 and to communicate with depression 55 in plate 28 when above the axis. Depression 56 in plate 28 communicates with oil outlet 75 in cover 25 thru passageway 5? in plate 28, hole 58 thru body 29 and hole 59 in cover 25.

Journalled in front cover plate 53 is cam shaft 60 to which is welded cam faced disc 61 which through pin 62 fixed to reaction plate 56 near the edge opposite pivots 51 determines the angular position of plate 59 and thereby determines the stroke of pistons 42 which in turn determines the rate at which oil is fed to the burner nozzle. The angular position of cam 65 is adjusted by lever 63 fixed at one end to shaft 83. At the other end lever 63 may be held in fixed position by clamping bolt 65 which is used to clamp lever 63 to indicating quadrant 65 fixed to front cover 53.

In an actual installation a pipe 63 connects inlet 35 with the fuel oil storage tank, not shown. A. pipe 67 connects pump outlet with nozzle inlet l5. A pipe 68 connects top outlet 69 of reservoir 25 to storage'tank, not shown.

With motor 5 operating, pump shaft 3| drives both gear pump 25, 29, 32, 33, 28 and piston pump 28, H, 42, 43, 4 58. Oil flows from storage tank, not shown, thru pipe 66, to inlet 35 of the gear pump and from the gear pump thru outlet 39, up riser 4B and spills over the top of riser 41'} thru clearance due to raised dome Hi and into the interior 55 of reservoir 25. From interior 55 oil enters depressing 54 in plate 28 and into the lower cylinders 43 of piston pump barrel 41. As pump barrel 41 rotates and pistons travel to upper position the oil trapped in cylinders 45 is forced out into depression 56 of plate 28 due to the squeezing action of reaction plate 59 on pistons 42. From depression 53 the oil is forced on to outlet 5?, thru pipe 61, thru fitting I4 and thru holes I2 and IS in shaft 1 to the interior of rotary cup if! from the lip of which the oil is spun off into the combustion chamber as a. fine oil mist. Since the gear pump is of considerably greater capacity than is the piston pump, the interior of the oil reservoir gradually fills with oil and in so doing forces any air in the reservoir out thru top outlet 69. When the reservoir becomes filled with oil both air and excess oil is forced out thru outlet 59 and pipe 68 to the storage tank, not shown.

In operation should the discharge line of the oil from the piston pump to the rotary cup be blocked, the pressure of the pistons on the oil in the cylinders will squeeze the oil from the cylinder out between the surface 48 of barrel ll and the surface 49 of pump plate 28 thereby compressing springs 43 and discharging the oil back to the interior 55 of reservoir.

It is therefore seen that I have provided in one unitary structure and with a minimum of parts, a gear pump oil supplying means, a means for returning excess oil to the main storage tank, a means of storing at the burner sufficient oil to absorb the variations of oil requirements of the burner and to maintain a head of oil on the metering pump, a piston pump means for supplying and metering at all times the exact amount of oil required to be burned and safety relief means to prevent damage to the equipment should the oil line to the rotary cup be blocked.

It should further be noted that in case it is found desirable to improve the operation of the burner by raising the temperature of the oil, my structure is admirably adapted to work in combination with an external oil heater as follows. Sleeve H is entered thru top outlet 69 and telescoped into riser i9. Nut 12 prevents sleeve H from getting unworkably out of position. Pipe 88 is now redirected to the oil heater, not shown, instead of to the main oil storage tank. It is seen that with sleeve H in place practically all of the oil from the gear pump will go to the oil heater and not overflow into reservoir interior 55. Oil from the heater returns thru pipe 73 and enters the reservoir thru top inlet 74. Because the gear pump sends to the heater more oil than the piston pump can use pipe 13 must be equipped with a relief valve, not shown, which opens at a pressure limit determined by the pressure desired on the oil in the reservoir. Excess oil released by the relief valve is piped back to the main storage tank. In this method of operation not only is warmed oil supplied to the reservoir ahead of the piston type metering pump but also warm oil is returned to the main storage tank which it enters near the cold oil outlet to the gear pump and has a tempering effect on this cold oil.

Having fully explained the operation of my oil burner with particular regard for the fuel supply and meteringsystem which has caused my burner to be unusually effective in operation, I further declare that certain unique features of my burner could be used in other analogous arts and therefore I intend that my invention shall not be considered to be less than the full scope of the attached claims.

I claim:

1. In an industrial oil burner for burning heavy fuel oil, an oil control unit comprising an oil reservoir having an opening in the rear wall thereof, a rear cover plate for said opening, a gear type positive displacement pump, a piston type positive displacement pump, a drive gear impeller for said gear pump, a cylinder barrel for said piston pump, a common shaft on which said impeller and said barrel are carried to rotate therewith, said cover comprising a rear plate for said gear pump, said cover plate having formed therein an inlet opening for oil to pass from the exterior of said reservoir through said opening to the oil pick up side of said gear impeller, a gear pump body, said body having formed therein an outlet opening for oil to pass from the discharge side of said gear impeller through said opening to the interior of said reservoir, a second plate comprising a front plate for said gear pump and'a port plate for said piston pump, said port plate having an oil inlet opening from said reservoir to the inlet of said piston pump formed therein, said second plate being secured to said rear cover and spaced therefrom by said pump body, said shaft being journalled in said cover plate and said second plate, driving means for said shaft outside said reservoir, said shaft extending rearwardly through said cover plate to said driving means and forwardly through said second plate to carry said barrel, said barrel having a hole therethrough parallel said shaft, a piston in said hole, a plane surfaced reaction plate laterally and hingedly supported on the interior of said reservoir forwardly of said barrel, means cooperating with said barrel and said piston yieldably to position one end of said barrel in operative position with respect to said port plate and the opposite end of said piston in operative position with respect to said reaction plate, cam means operable from outside said reservoir for angu larly positioning said reaction plate about its hinge support, and an outlet conduit for oil to be discharged from said piston pump to the exterior of said reservoir.

2. In an industrial oil burner a control unit comprising an oil reservoir having front and rear openings therethrough, a front cover, a rear cover, a fuel supply pump, a fuel metering pump, means for driving said pumps, a reaction plate for said metering pump, and cam means for positioning said reaction plate to control the rate of fuel supply, said fuel supply pump being carried interiorly of said reservoir on said rear cover, said pumps having a common shaft journalled in said rear cover and extending through said rear cover to said driving means, said fuel metering pump being carried on said shaft, said reaction plate being hingedly supported interiorly of said reservoir on said front cover, said cam means comprising a cam shaft journalled in said front cover and axially aligned with said pump shaft, a cam plate secured to the end of said cam shaft interiorly of said reservoir, the rear surface of said cam plate forming a plane surface set at a predetermined angle With respect to the axis of said shafts, a cam follower on said reaction plate, means exterior of said reservoir for angularly positioning said cam shaft, and oil conduit means whereby oil is conducted from the exterior of said reservoir through said fuel supply pump to the interior of said reservoir and from the interior of said reservoir through said metering pump to the exterior of said reservoir.

3. In an industrial oil burner the combination of a fuel supply pump, a fuel metering pump and a reservoir containing fuel oil, and oil conduit means for conducting oil from the exterior of said reservoir through said fuel supply pump to the interior of said reservoir and from the interior of said reservoir through said metering pump to the exterior of said reservoir, said fuel pumps being submerged in said oil and having a common shaft journalled in one side of said reservoir, said metering pump comprising a port plate, a reaction plate hingedly supported on an interior wall of said reservoir, a cylinder barrel between said port plate and said reaction plate, a piston, a cam shaft journalled in the side of said reservoir opposite said one side and in axial alignment with said pump shaft, a cam :plate secured to said cam shaft interiorly of said reservoir, a cam follower interposed between said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 617,135 Weeks Jan. 3, 1899 867,932 Weeks Oct. 8, 1907 1,577,622 Gaston Mar. 23, 1926 1,817,051 Williams Aug. 4, 1931 1,899,396 Ray Feb. 28,1933

1,971,601 Dilg Aug. 28, 1934 2,016,802 Fick Oct. 8, 1935 2,056,259 Cummins Oct. 6, 1936 2,209,856 Smith July 30, 1940 2,291,084 Klimpel July 28, 1942 2,308,864 1 Davis Jan. 19, 1943 2,362,411 Schreiter Nov. 7, 1944 2,375,884 Arvins May 15, 1945 2,455,330 Denison Nov. 30, 1948 FOREIGN PATENTS Number Country Date 220,417 Great Britain Aug. 24, 1924 289,701 Italy 1931 593,597 Germany 1934

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