US1681647A - Oil burner - Google Patents

Description

Aug. 21, 1928.

w. R. RAY

OIL BURNER Filed May 1925 2 Sh eets -Sheet 1 M m g O 1km QM INVENTOR. BYWILLIAM- R. RAY

naw/ ATTORNEYS.

Aug. 21, 1928. 1,681,647

w. R. RAY

OIL BURNER Fil ed May 5, 1923 2 Shgets-Sheet 2 Q: I N V E N T O R WILLIAM R. RAY.

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Patented Aug 21, 1928.

WILLIAM R. BAY, OF SAN FRANCISCO, CALIFORNIA.

OIL BURNER.

Application filed May 5,

This invention relates to oil burners of the rotary atomizing type, such as are driven by electrlc motors, and especially to means for rendering such burners automatic in operation and safe against fire hazard.

The object of the present invention is to generally improve and simplify the construction and operation of burners of the character described; to provide means for automatic-ally igniting the oil when the burner is started; to provide a specially constructed furnace box which serves as a support for the burner and motor, and which may be readily removed with relation to the furnace proper for repair, inspection or otherwise; and further to provide means for collecting and burning unconsumed oil escaping from the burner and for automatically shutting off the oil supply to the burner if the fire should become extinguished or the escape ofunconsumed oil should be so great as tocause flooding or fire danger exterior of the furnace. Other objects will hereinafter appear.

One form which my invention may assume is exemplified in the following description and illustrated in the accompanying drawings. in which Fig. 1 is a front view of a hot water or steam boiler, showing the position of the burner with relation to the furnace, said view also showing the position of the electric wiring conduits,.the automatic gas valve and the oil feed line.

Fig. 2 is a central, vertical, longitudinal section through the burner and the furnace box, said view also showing the electric motor whereby the burner is operated.

Fig. 3 is a central. vertical section of the gas valve and the solenoid magnet whereby it is actuated.

Referring to the drawings in detail, and particularly to Figs. 1 and 2, A indicates a standard form ofsteam'or hot water boiler, and 2 the base thereof in which the furnace proper is located. B indicates the burner in general, C a fan or blower, and D an electric motor whereby the fan and the burner are operated.

The burner is of the rotary atomizing type and consists of a cup 3 secured on the outer end of a hollow or tubular shaft 4. This shaft is supported in anti-friction bearings as indicated at 5, and it forms a support for the atomizing cup 3, a blower 6 and the armature 7 of the motor D. The blower 6 is en- 1923. Serial No. 636,965.

closed by a housing 8 and this housing is sup ported by hinges 9 carried by a front plate 10 forming a part of the furnace box generally indicated at E. (See Figs. 2 and 4.) The fan housing also forms a support for an air nozzle 11 surrounding the atomizing cup, and it furthermore forms a support for the antl-friction bearings 5 and the motor housing D. This motor housing is provided with a acket in which is formed an annular passage12 and oil is circulated through this passage as will hereinafter .be described, first, to cool the motor, and secondly to heat the 011 beforeit is delivered to the atomizing cup 3.

The entire burning unit, to-wit, the fan housing, the bearing members 5 and the motor D, together with the air nozzle as previously stated, is supported by hinges 9 on the front plate 10 of the furnace box and as such may be readily swung to or from the furnace chamber for inspection. repair or otherwise. I

The furnace box proper consists of a base plate provided with side and end flanges as lndicated at 14. The front plate of the furnace indicated at 10 is secured to the forward end of the base plate 13, while the sides and ends of the base plate have sheet-iron plates secured thereto as at 15 to permit the box as a whole to be lined with firebrick or other refractory material, such as indicated at 16. The fire box is entirely independent of the furnace proper and as such may be readily removed or inserted whenever de- SUP-Cl. This is exceedingly important as it permits accessibility when it is desired to reline the fire box or re-arrange the bafiling bricks, etc., such as shown at 17, said accessibility being due to the fact that the fire box may be removed endwise with relation to the furnace, thus rendering the interior of the fire box accessible for any work desired.

The burner installation shown in this instance is entirely automatic in operation. It is provided with means for maintaining a predetermined temperature in the rooms to be heated; the means employed being an adjustable thermostat, such as indicated at 18. This thermostat is centrally located in the room to be heated and it is connected with a thermostat relay 19, which automatically controls the circuit through the motor. For instance, if it is desired to maintain a temperature of 72, it is only necessary to set the thermostat 18 at this temperature. The moment this temperature is reached, the relay 19 is auto matically actuated and the circuit through the motor is opened. Again, if the temperature drops below 72, the relay 19 is again automatically actuated and the circuit through the motor is closed. Means are also employed for automatically igniting the oil when the burner is started, and means are also employed for automatically opening and closing the oil flow to the atomizingcup when the burner is started or stopped.

The gas fed pilot burner, generally indi cated at F, is employed for igniting the oil when the burner is started. The pilot burner is positioned directly below the atomizing cup 3' and as such is readily accessible. A small flame is kept burning all the time and expands momentarily when the burner is started. It never fails to ignite the oil as the oil is thoroughly atomized and as heat is not depended upon to gasify or atomize the oil. To momentarily expand or increase the size of the pilot flame an automatic valve is 'employed. This valve is generally indicated at G and is perhaps best illustrated in Fig. 3. It consists of a casing 20 provided with an inlet passage 21 and an outlet passage 22, the inlet passage being connected with a suitable Source of gas supply such as a pipe 23. Formed centrally of the casing 20 is a vertically disposed passage 24 and mounted in said passage is an armature 25, the upper end of which extends into a solenoid magnet 26. The lower end of the armature 25 serves as a valve and is pointed as at 27 to engage a valve seat 28. The valve end of the armature is provided with a small central passage 29 which permits a sufiicient amount of gas to pass through the casing 20 to maintain the pilot light, but the valve or armature 1s automatically lifted from the seat 28 when the burner is started to permit a momentary large flow of gas so as to insure ignition of the oil when the burner is started. The movement of the armature 25 is limited by an adjusting screw 30, and practically any size gas flamemay thus be momentarily maintained during the starting operation. i

The solenoid magnet 26 is connected in series with the motor D and as such is energized the instant the motor is started. The amount of current consumed when the motor is started is comparatively excessive and the windings of the magnet 26 are, therefore, so arranged that an excessive flow of current is required to energize the same; that is the excessive flow of current consumed by the motor during the first period of starting is sufiicient to energize the magnet and thereby elevate the armature 25, but it is not suflicient to retain the armature in an elevated position when the motor has attained full speed as the current flow has by that time decreased to such an extent that the magnet will not be sufliciently strong to retain the armature in an elevated position.

It will, therefore, drop when the motor hasv attained its full speed and the size of the pilot flame will thus be automatically reduced; that is, a large flame is produced the to an ordinary pilot flame as the gas valve will then automatically close, due to the drop in current consumption in the motor. The valve is, therefore, entirely automatic as it opens only momentarily when the motor is started, and again automatically closes itself when the motor has gained full speed. It is only during the starting of the motor that the as flame is required as the oil readily ignites tie moment the motor begins to attain full speed, and when the oil has once been ignited further assistance on the part of the pilot burner is not required.

The solenoid magnet as previously stated is connected in series with the motor. This is perhaps best illustrated in Fig. 1. The mam line wires indicated at 31 and 32 enter the thermostat relay 19. They then pass down through a conduit 33, the wire 31 being connected with one terminal of the motor. A second wire '35 connects the other terminal of the motor with one terminal of the solenoid magnet, and the other terminal of the solenoid magnet is connected to the wire 32, thus completing the circuit.

The oil delivered to the burner may be supplied by a pump or gravity flow may be maintained from a tank 36, as shown in Fig. 1. The oil from this tank passes through a pipe 37 and a strainer 38. It then passes through a hollow pintle connecting the hin e members 9 and is finally directed to one si e of the annular passage 12 formed in the motor housing as indicated at 39. It then passes through the jacket and out through a pipe 40. This pipe is connected with one end of a pipe 41, extending through the hollow or tubular motor shaft 4, and the opposite end of pipe 41 terminates in a goose-neck 42 positioned within the atomizing cup 3. Mounted on the pipe 40 is an automatic valve 43. This valve is actuated by a solenoid magnet similar to that employed in connection with the gas valve. This magnet is also connected in series with the motor and as such is energized when the motor circuit is closed, the only difference between the two solenoid magnets being that the solenoid magnet controlling the valve 43 will retain the valve in an .open position as long as the circuit through the motor is closed and'will not permit closing of the valve 43 except when the motor circuit is open.

From the foregoing it can be seen that means are employed for automatically turning on the oil when the motor is started and that such means also automatically shuts off the oil flow when the motor is stopped. Simi- Inn larly, that means are employed for automatically igniting the oil when the motor is started.

In actual practice it has been discovered that a small amount of oil escapes from the atomizing cup during the'starting operation and that this oil leaks down into the furnace box. It has also been discovered that the gas pilot burner cannot always be depended upon as the flow of gas in the city mains might be temporarily shut off or the motor temporarily disconnected and so on. Therefore, if such conditions should prevail and the motor is started, it is obvious that the oil would not be i 'nited and that the furnace box would soon become flooded and oil might leak out of the box and flood the furnace room, thus producing fire hazard. Having these facts in mind it is obvious that means should be employed for automatically shutting off the oil if t e burner is not ignited, and furthermore that means should be provided for burning the leakage oil escaping from the burner during the first part of the starting operation. This is accomplished as follows:

Formed directly below the pilot burner F is a trap chamber 50. This chamber serves the function of .collecting leakage oil, and it also serves as a drain to prevent flooding of the furnace if the oil should not be ignited that is, it is provided with an overflow pipe 51 which drains into a bucket 52. This bucket is carried by a chain 53 and this chain is in turn connected to the handle of an automatic shut ofl valve 54. In other words, if the oil should not be ignited and continued .to enter and flood the furnace, it would first enter the trap and then discharge through the pipe 51 into the bucket 52, and when the bucket is filled to a predetermined extent, the automatic shut off valve is tripped and the oil flow to the burner is consequently stopped. The leakage of oil referred to as escaping from the burner or atomizer 3 only takes place during the first part of the starting operation; that is, the moment the circuit through the motor D is closed it starts rotating at a comparatively low speed. The oil is turned on simultaneously with the circuit through the motor and therefore commences entering the cup 3 simultaneously with the starting of the motor. The speed of the cup 3 is, therefore, not suflicient to project the oil centrifugally and the oil therefore enters the air nozzle 11 and collects in the same. A dam 60 is formed at the rear end of the nozzle and the nozzle is perforated so that the oil will drain into a secondary nozzle indicated at 61. This nozzle is also providedwith a dam at its rear end, as indicated at 62, and the leakage oil collecting behind the dam is conducted through a pipe 63 Into the trap chamber 50. The overflow pipe 51 is so elevated that this small amount of leakage oil will not overflow, but will merely collect in the trap chamber.

The trap chamber is, however, in open communication with the fire box as shown in Fig. 3 and the oil will be consumed or burnt whenthe fire is started. The trap chamber is in this manner kept clean and free of oil, and overflow from the trap chamber will only take place if the oil fails to ignite.

The operation will, briefly, be as follows If a thermostat such as shown at 18 is employed the operation will be entirely automatic as the burner will be automatically started if the temperature reaches a point below that to which the thermostat is set and will conversely open the circuit through the motor and stop the same when the predetermined temperature is reached. We will now suppose that the thermostat has closed a circuit through the relay 19. If this is the case, both solenoid magnets will be energized;

. valve43 will thus open and admit oil to the the size of the pilot flame will be material- 1 ly increased. By the time the motor has reached half speed, the oil will ignite. and by the time the motor reaches normal speed, the solenoid magnet G will let go of the armature. due to the drop in current flow and the pilot flame will thus be reduced to normal. The valve 43 will. however, remain open as the winding of the solenoid operating the same is such that it will retain the armature in an elevated position as long as the circuit is closed through the motor. The average speed of rotation of the atomizing cup is usually around 3000 revolutions per minute. This speed causes the oil to be centrifugally projected as a finely atomized mist. The speed of the blower is, of course, the same as the atomizing cup. Air is admitted through an opening 80 which is in communication With the suction side of the blower, the air is' thus passed through the blower and discharged through the nozzle 11. This nozzle is round and forms an annular passage about the atomizing cup and as through the mist-like atomized oil projected by the cup and as such thoroughly commingles with the same and projects it in a forward direction into the fire box where combustion takes place, the flame burning back practically to the mouth of the cup. The fire will continue until a predetermined temperature is reached and it will be automatically stopped by the thermostat and the relay the moment the temperature is exceeded. -The circuit will thus be broken through the motor and the blower and cup will come to rest. The oil flow to the cup will simultaneously be shut off as the armature in the solenoid will then drop and close the valve 43. The motor will then remain at rest until the circuit is again automatically established. The small amount of leakage oil escaping from the atomizing cup 3 when the burner is started drains back through the nozzles 11 and 61 and is finally collected in the trap 50, where it is burned by the intense heat produced by the flame when the burner has been properly started. If the burnershould fail to ignite, due to lack of gas in the mains, or due to plugging or stoppage of the pilot burner, flooding of the fire box will take place, but such oil will drain into the trap and overflow through the pipe 51. This in turn will direct the oil to the bucket 52 and this, as previously stated, exerts a pull on the chain 53 and thereby automatically: closes the shut off valve 54. Any danger of flooding the furnace or the floor of the furnace room is thus obviated and fire hazard is prevented.

The boiler and furnace here illustrated are also shown as equipped with a draft regulator actuated by steam pressure in the boiler. This feature is, however, covered by patents previously issued to me and as such forms no part of the present application. It is, nevertheless, important in an oil burning equipment of this character as it automatically regulates the air flow to the furnace.

While certain features of the present invention are more or less specifically illllS! trated, I Wish it understood that various changes in form and proportion may be resorted to within the scope of the appended claims; similarly, that the materials and finish of the several parts employed maybe such as the experience and judgment of the manufacturer may dictate or various used may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. The combination with an electric motor driven oil burner of the character described and a gas feed pilot burner cooperating therewith, of means for maintaining a continuous flow of gas to the pilot burner, a valve cooperating with the pilot burner adapted to increase or decrese the flow of gas to the pilot burner, and'an electro-magnet adapted to open and close the valve, said magnet being responsive to the starting current flowing to and a gas feed pilot burner cooperating therewith, of means for maintaining a continuous fiow of gas to the pilot burner,-a valve cooperating with the pilot burner adapted to increase or decrease the flow of gas to the pilot burner, a solenoid magnet, an armature vertically movable therein, a valve extension on the armature adapted to open or close the valve which regulates the flow of gas to the pilot burner, said solenoid magnet having a winding connected in series with the electric motor and being responsive to the starting 'current flowing to said motor whereby it will energize and lift the armature and the valve only when the circuit through the motor is closed and the motor is starting and will release the armature and valve when the motor attains full speed, due to the difference in energy between the starting current and running current flowing to the motor.

3. The combination with an electric motor driven oil burner of the character described, and a gas feed pilot burner cooperating therewith, of a valve cooperating with the pilot burner adapted to increase or decrease the flow of gas to the pilot burner, a solenoid ,magnet, an armature vertically movable therein, a valve extension on the armature and adapted to open or close a passage in the valve to regulate the flow of gas to the pilot burner, and a series connected electrical connection between the solenoid magnet and the motor whereby the magnet is responsive to the starting current flowing to the motor and whereby when a circuit is simultaneously closed through the motor and the magnet the armature and valve is momentarily elevated when the motor is started and automatically lowered when the motor reaches running .speed, said valve having a bypass formed therein permitting a predetermined flow of gas to the pilot burner to maintain a continuous pilot flame.

WILLIAM R. RAY.

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