US2248395A - Fuel oil burner - Google Patents

Description

3 Sheets -Sheet 2 a 3 n R T m u E a O 1 O! O 8 m A R 8 .l x m Y 4 R E 8 v E w e N -l l I P l l I l l I .l l \i IN.- R r W M H I. um 0 Y Jul s, 1941.

July 8, 1941. o. c. TAPER ETAL.

FUEL OIL BURNER Filed Sept. 7, 1939 3 Sheets-Sheet 3 i k I i I "I \f LLJ INVENTORS OSCAR C. WIPE/P BY doH/v F/Poaf 5N ATTO EYS Patented July 8, 1941 FUEL 01L BURNER Oscar C. Taper and John G. Frost, Seattle, Wash, assignors to Ray Oil Burner 00., San Francisco, Calif., a corporation of Delaware Application September 7, 1939, Serial No. 293,830

7 Claims.

Our present invention relates to the general art of oil burning devices normally referred to as a pressure atomizing type such as is usually employed for domestic uses. More particularly our invention relates to a fuel oil burner.

Our oil burner, which may be applied to any acceptable type of furnace, is characterized by being provided with means for heating the heavier, and cheaper fuel oils, so that they can be properly atomized and burned in the smaller types of domestic furnaces. To accomplish this purpose we provide a water heating unit which, preferably, maintains the oil passing into the burner at suiiiciently high temperatures so that it will flow and atomize freely, yet by the use of this water heating means the temperature can be maintained within very close limits so that there is no danger of .forming gas or partially cracking the oil or carbonizing such as might be encountered if the oil came into contact with a high temperature electric heating element.

When the heavier oils are raised to a proper working temperature they function very similarly to the lighter fuel oils, normally referred to as Diesel oils, and the normal working parts of the ordinary Diesel oil burner are employed in our arrangement, such as the fuel pump, the

fan to produce a blast of air under pressure, and

the usual electrical ignition means which assures proper ignition and the maintenance of it.

One of the objects of our present invention is to provide, therefore, a water heating means for an oil burner that will properly condition the heavier fuel oils so that they will function satisfactorily in an oil burner of more or less conventional design of the type with which service men, generally, are familiar, and for which the trade has already produced the necessary functioning parts.

A further object of our invention is to provide a water heating means for the fuel oil that is disposed below the level of the burner jet, or tip, soas to provide a medium in which sensitive electrical controls'can be embodied so that the temperature of theoil can be properly maintained within the narrowsecondly, that one of these controls can be so positioned as to insure that'the oil pump will not start to supply oil to the nozzle until the oil itself has reached the proper satisfactory functioning;

Another important object of-our water heating means is to provide a thermal syphon flow of water to a point adjacent the burner tip, so

limits required, and,

temperature for that during operation, there is provided, in efiect, a water heated nozzle for starting and for normal operation, and further and very important. a water cooled nozzle when the fire shuts off leaving the nozzle exposed to the intense heat built up in the firebox.

Further object of our present construction is to provide an oil heater that is carried close to the nozzle and which also serves as a protection for the oil supply tube so that no hot tubes are exposed.

Still another object of our present invention is to provide means whereby when the burner is started the oil that will be first fed to the burner tip is well within the water heating unit so that the very first oil supplied is at a proper operating temperature.

An important object of our present invention is to provide means for withdrawing the oil from the supply line adjacent the burner tip to the end that there will be no drip from the nozzle when it shuts off and, secondly, that the oil will be withdrawn fully into the water heating chamber so that it will be maintained in proper condition for the next use of the burner or, if

the burner is to be shut off for some time, the oil will be in condition so that it will be properly reconditioned before it is again supplied to the burner tip.

A further object of our present invention is to provide a permanent air vent for the oil pump.

A further object is to provide means whereby if oil, of lower viscosity and flash point than is normally used with the burner, is supplied, the same will be by-pa'ssed back into tank without going through the heating coils, or it being possible for the same to be passed through the burner tip.

Another object of our invention is to provide means whereby the oil is shut off to the nozzle, when the burner shuts down, while still under full atomizing pressure.

A further object is to provide means for causing' a reverse circulation of oil through the small strainers that are employed to remove impurities from the oil before it is discharged to the bumer tip, this reversible flow tending to loosen up any materials that may have become lodged on the fine meshed screen.

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawings,

wherein Figure 1 is a side elevation of our burner with the furnace walls shown in dashed line.

Figure 2 is a top plan view of our burner with the furnace walls again shown in dashed line.

Figure 3 is a perspective view showing the water heating chamber and water jacketed supply line to the burner nozzle.

Figure 4 is a perspective view of one form of electric heating unit that has been found effective with our equipment.

Figure 5 is a fragmentary, elevational view, shown in section, illustrating the proximity to the nozzle of the water that is used for both heating the oil and cooling the nozzle.

Figure 6 is a side elevation taken in the same sense as Figure 1, but showing many of the essential parts making up our invention, in section, to better illustrate their construction.

Figure 7 is an enlarged sectional view, in elevation, of a portion of Figure 6.

Figure 8 is a cross-sectional view taken along the line 8-8 of Figure 7.

Figure 9 is a view partly in section taken along the line 9 9 of Figure 7.

Figure 10 is a cross-sectional view taken along the line Ill-Ill of Figure 7.

Figure 11 is an enlarged sectional view, in elevation, showing the oil heating coil and its position in the water heating chamber.

Figure 12 is a cross-sectional view taken along the line I 2l2 of Figure 11.

Figure 13 is a horizontal, sectional view through the water-heating chamber, taken along the line I3I3 of Figure 11.

Figure 14 is a diagrammatic circuit arrangement showing the electrical circuits employed in the controls used with our burner.

Referring to the drawings, throughout which like reference characters indicate like parts, l6 designates the fire or blast tube of our oil burner. This follows more or less conventional structure as does the air fan l8, and the oil pump 20. As is usual in many types of oil burners, we provide a common electric motor 22 which is directly connected to the rotor of fan l8, and is then connected by means of the speed reducing belt 23 and with fuel pump 20. Inasmuch as the fuel pump in this instance is to handle oil of greater viscosity than the usual Diesel oil burner, the pump is supplied in an increased size and oper-' ated at somewhat slower speed than is usual. The fire tube extends through the wall of furnace F as is common with burners of this type.

Our invention resides largely in the means disposed between the delivery side of the pump and the burner nozzle or tip 24. Disposed by preference below the level of the tip 24 is the water heating compartment 26. This we form in any approved manner, normally by casting the same in the form of a reservoir or chamber which after the showing of Figure 3 is adapted to fit around tube l6 and be secured thereto, The chamber is preferably provided with insulation as 21 and is equipped with the electric heating element 28 and further provides for the oil heating coil 30. This coil should have sufficient turns, or at least sumcient area so that the flow of oil required by the burner, usually around a gallon and a half or two gallons an hour, will be in the chamber long enough to pick up the full temperature of the water. Also immersed in the water of chamber 26 are .two heat control switches 32 and 33;

switch 32 is so connected as to close the energizing circuit for a relay 34 which in turn energizes the motor 22 and transformer 36 which supplies the current to the ignition electrodes 38. Switch 33 controls the heating element 28 and in this manner the Water temperature within chamber 26 is maintained within the limit found to produce most satisfactory operation. This temperature will vary somewhat with different types of oil. For a fuel oil of gravity 18 Baum this temperature can be satisfactorily maintained between the limits of 175 degrees and 190 degrees F. Formed as part of and communicating with chamber 26 is the neck or tube 40 which supports burner 24. This tube is preferably insulated as illustrated at 42 and supplies a water jacket for the oil supply pipe 44. Tube 40 with its insulation passes through an opening 46 out in the lower portion .of tube l6 after the showing particulariy of Figure 6.

For purposes of reference the fluid used in the heater reservoir is spoken of as water for the reason that that fluid is almost universally available for use where such a device may be installed. Where these designations appear in the specification and in the claims, it is to be understood that they are not considered as limitative for obviously a multitude of fluids, if available, could be used and the device per se would clearly come within the scope of the invention no matter what fluid be used.

Disposed in the oil circuit between chamber 26 and pump 20 is an oil control cylinder 50. This cylinder is provided with a reciprocable piston 52 which is normally drawn to the right as viewed in Figures 6 and '7 by the tension spring 54. This spring is anchored at one end by bolt 55 and is anchored to piston 52 by bolt 56. A small spring is inserted in the end of cylinder 50 as illustrated at 58. This spring, the pressure of which can be adjusted by the threaded nut 59, regulates the oil pressure Within cylinder 50, by determining the position of piston 52 with respect to post 1| thereby indirectly affecting the oil pressure at the nozzle. At one end cylinder 50 is provided with a port 60 through which the line 62 leading from pump 20 discharges the fuel and, at the same time, the same opening provides. a by-pass connection for tube 64 which is connected into a return 66 communicating directly with the supply tank.

Part way up toward the opposite end of cylinder 50 is an elongated discharge port 68; this port connects to a chamber housing screen 10 which in turn connects to the fuel pipe 44 in the center of which is formed the heating coil 30, Disposed further along cylinder 50 is a second port 1 I; this port connects by passageway 12 to the left-hand end of the cylinder and also back to the tank return line 66, there being a ball check valve disposed in the line.

Method of operation The general functioning of our fuel oil burner,

aside from the heating of the oil, is similar to to that required for the proper functioning of the device. been attained, the rise in temperature will cause switch 32 to complete its circuit. This will in As soon as this temperature has ever, a warm-up period is required after the Figure 7 must complete its cycle of operation.

As soon as motor 22 is cut in it starts the pumping of oil through pump 20 and this causes the functioning of the pressure control and the nozzle suck-back assembly, etc. Normally, when the unit is cold and at rest piston 52 is disposed at the right-hand end of cylinder 50 as viewed in Figures 6 and 7. The first action of the pump in starting is to build up pressure within cylinder 50 and drive piston 52 to the left as viewed until port 68 is opened: At this point oil is then forced under pressure through tube 44, caused to circulate through the heating coil 30 and is'then discharged from the burner tip or nozzle 24 into the electrical discharge from electrodes 38. This discharge ispreferably a continuous one so that there will be no pulsation in the flame due to any tendency for .it to fail to remain in motion.

When the desired flow of heat has been effected and thermostat 15 operates to shut the plant by gravity as well as suction subsequently, there is no tendency to draw bubbles through the oil as might occur if coil were on the level of or above tip 44.

By-pass 64 serves in addition to the purpose described three other functions; it provides a permanent air vent for the oil pump 20; it eliminates the possibility of any oil or lower viscosity and flash point from entering the heater due to accidental delivery, as when an oil delivery company may have delivered the wrong type; this, therefore, eliminates the possible danger due to such a mistake, as pump 20 will by-pass the oil if the cross-section of the by-pass is such that pump 20 can discharge its total capacity of a lower viscosity oil through it without building up sufiicient pressure on piston 52 to open the discharge port 68. A reversal of flow of the fuel oil when the plant shuts down has a self-cleaning efiect on both the nozzle screen 80 and the cylinder screen H! which has been found to be of real.

value in the successful operation of a plant of this order.

Chamber 26 may be supplied with water from any suitable source; a very convenient'arrangement is to supply water from the normal pressure source through pipe 82. In this manner the cylinder will at all times be filled with water.

- Provided at the time of the initial filling, plug as pump 20 ceases to supply fuel under pressure to cylinder 50 the pressure immediately begins to drop in cylinder 50 owing to the by-pass arrangement 64. A slight decrease in pressure allows spring 54 to immediately retract piston 52 so that port 68 is sealedwith, normally, full pressure on the oil in line 44. As piston 52 continues to move to the right as viewed in Figures 6 and '7, it creates a vacuum'in the left-hand end of the cylinder inasmuch as port II is also closed by the movement of piston 52 and ball check 13 is so seated as to prevent any suction through it. Assoon as piston 52 has moved suiiiciently far to the right as viewed, port 68 l is again uncovered and the vacuum drawn gives a very quick suction effect on pipe 44, thus withdrawing quickly the oil in the burner end of tube 44. It will be apparent it is believed from the portion illustrated, that as piston 52 moves to the right the oil will be withdrawn for quite I 'a degree in pipe 44 so that full assurance will be given that there will be none whatever left in the upwardly slanting portion of pipe 44. This prevents drip at the burner tip when the unit is shut down and by withdrawing the oil into the coil 30 the oil will be retained at its desirable 84 is removed until water appears at this point. This will dispel all of the air from chamber 26 after which time the normal water pressure will keep the tank filled, and any pressure due to expansion will back up in the water in the supply pipe. Where water pressure is not available the chamber may be filled from an expansion tank located above the unit.

The foregoing description and the accompanying drawings are believed to clearly disclose a preferred embodiment of our invention but it will be understood that this disclosure is merely illustrative and that such changes in the invention may be made as are fairly within the scope and spirit of the following claims.

We claim:

1. The combination with an oil burner having a blast tube, of an oil heater comprising a receptacle located below the tube'and forming a liquid bath heating chamber, a heating unit in the receptacle, an oil-feed pipe having a coil in said chamber, said receptacle having an up wardly inclined tubular extension projecting into the blast tube and which communicates with said chamberto receive liquid therefrom, a discharge pipe extending from said coil through said extension, and a burner nozzle on the end of the discharge pipe adjacent the end of said extension.

2. The combination with a burner having a blast tube, of an oil-heater including a receptacle forming a liquid bath heating chamber, means on the receptacle for attachment to the exterior of the tube at the underside thereof, said receptacle having an upwardly and forwardly projecting tubular extensionrterminating in the tube, said tubular extension communicating with said chamber to receive liquid therefrom, an oilfeed pipe passing through said receptacle and terminating in a discharge pipe extending through said extension, and a nozzle on the discharge pipe closing said extension.'

3. In an oil burner the combination of a receptacle forming a liquid bath heating cham-' her, an oil feed pipe extending into said chamber and including a coil within said chamber,

an upwardly inclined oil discharge pipe connected to the coil, said receptacle having an upwardly inclined tubular extension about said oil discharge pipe and which commimicates with said chamber to receive liquid therefrom, a nozzle on the discharge pipe adjacent the end of said tubular extension, pressure operated means for feed of oil to the feed pipe, and control means including a suction device for withdrawing oil from said nozzle and said discharge pipe when pressure is released from the oil.

4. A pressure atomizlng type oil burner comprising a nozzle, means for pumping oil under pressure to said nozzle, piping between said pumping means and said .nozzle for conducting the oil, a liquid bath heater about said piping for heating said oil to adapt said burner for use with viscous oils, and means associated with said piping influenced by oil pressure created by said pumping means for automatically withdrawing oil from said nozzle when said pumping means is rendered inactive after operation thereof and the pressure on the oil is consequently released.

5. A pressure atomizing type oil burner adapted for burning of viscous oils comprising an air blast tube having an open air discharge end, a pressure atomizing nozzle adjacent said end, means for forcing oil under pressure to said nozzle, piping between said forcing means and said nozzle for conducting the oil, said piping including a coiled portion adjacent and underneath said air blast tube in which oil is adapted to be heated, and an upwardly inclined oil delivery portion extending into said air blast tube and which is connected between said coiled portion and said nozzle, a liquid bath heating chamber supported underneath said air blast tube and enclosing said coiled portion, and an upwardly inclined cooling jacket extending into said air blast tube and surrounding said oil delivery portion of said piping, said jacket being connected at one end to said chamber to receive'liquid therefrom and being closely adjacent said nozzle at the opposite end.

6. A pressure atomizing type oil burner adapted for burning of viscous oils comprising an air blast tube having an open air discharge end, a pressure atomizing nozzle adjacent said end, means for forcing oil under pressure to said nozzle, piping between said forcing means and said nozzle for conducting the oil, said piping including a coiled portion adjacent and underneath said air blast tube in which 011 is adapted to be heated, and an upwardly inclined oil delivery portion extending into said air blast tube and which is connected between said coiled portion and said nozzle, a main liquid bath heating chamber enclosing said coiled portion, said liquid bath heating chamber providing the sole heating means for the oil and being supported underneath and closely adjacent said air blast tube to provide a relatively compact and portable structure, and an upwardly inclined cooling jacket extending into said air blast tube and surrounding said oil delivery portion of said piping, said jacket being connected a one end to said chamber to receive liquid therefrom and being closely adjacent said nozzle at the opposite end. I 7. A pressure atomizing type oil burner adapted for burning of viscous'oils comprising an air blast tube having an open air discharge end, a pressure atomizing nozzle adjacent said end, means for forcing oil under pressure to said nozzle, piping between said forcing means and said nozzle for conducting the oil, said piping including a coiled portion adjacent and underneath said air blast tube in which oil is adapted to be heated, and an upwardly inclined oil delivery portion extending into said air blast tube and which is connected between said coiled portion and said nozzle, a main liquid bath heating chamber enclosing said coiled portion, said liquid bath heating chamber providing the sole heating means for the oil,and being supported underneath and closely adjacent said air blast tube to provide a relatively compact and portable structure, an upwardly inclined cooling jacket extending into said air blast tube and surrounding said oil delivery portion of said piping, said jacket being connected at one end to said chamber to receive liquid therefrom and being closely adjacent said nozzle at the opposite end, and means for automatically withdrawing oil from said nozzle and said upwardly inclined oil delivery portion of said piping when said burner is shut off.

OSCAR C. TAPER. JOHN G. FROST.

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