US1640730A - Oil burner - Google Patents

Description

Aug. 30, 1927.

0 IL BURNER Original Filed Feb. 25, 1922 2 Sheets-Sheet 1 all/2 A. mN N btl | L. scoTT OIL BURNER Original Filed Feb. 23. 1922 2 Sheets-Sheet 2 INVENTOR Lw/.s L. Jco 77? BY MJM ATTORNEY Patented Aug. 30, 1927.

UNITED STATES PATENT OFFICE.

LEWIS I1. SCOTT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO ELEGTROL, INC. OF MISSOURI, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

OIL BURNER.

. Original application filed February 23, 1922, Serial No. 538,559. Divided and this application filed February 3, 1926.

This invention relates to novel apparatus I for use in burning heavy oils which are practically non-volatile at normal temperature, and is a division of my prior application Serial No. 538,559, filed February 23rd, 1922.

The present invent-ion is directed more particularly to the control system illustrated and described in my said prior application, and while this invention can be used for many purposes, I have shown it as applied to a furnace, such as is used for domestic heating. a

One of the objects of this invention is to provide means for automatically igniting a mixture of oil and air by an electric spark and to provide means for cutting off the electric spark after ignition takes place. A further object is to provide a means of catching unburned fuel, in case of failure of ignition, and returningsaid fuel to the safety device, which is designed to act, under certain conditions, to shut off the flow of fuel.

The invention is illustrated in the accompanying drawings, in which Figure 1 is a vertical sectional view of the lower part of a domestic hot-air furnace showing my improved oil burner attached thereto; the air pipe and safety float are shown partly in section, said section being taken on the line 11 of Figure 2;

Figure 2 is a plan view of the air blower ang connected parts as shown in Figure 1; an

Figure 3 is a diagrammatic drawing showing the complete wiring diagram and control switches. F 7

Referring now to the drawings, the numeral 1 indicates the drum of a domestic furnace; 2 indicates the grate bars commonly used with a coal fired furnace; 3 is the fire door opening; 4 is the fire door of said furnace; 5 is the ash door; 6 is an electric motor which drives the fan 7 and oil pump 8. -The suction pipe 9 runs to an oil tank (not shown); oil is delivered under pressure through the pipe 10 to the fuel spray nozzle 11. The spray nozzle 11 can be any of the well known pressure spraying fuel nozzles. 12 is a blower housing which delivers low pressureair through the pipe 13 to the air receiver 14. The casting 15 is removably attached to the air receiver 14 and carries the spark plug 16 and fuel nozzle 11. The spark plug and nozzle are Serial No. 85,661.

located entirely outside of the furnace proper, and the electric wires connected to the former will thus not be subjected to the pipe, preferably curved downward, which is attached to the air receiver 14 and to the furnace 1 and is for the purpose of conducting and directing the burning fuel mixture into the furnace. 20 is a box-like casting having an open top; said castin rests on the fire bricks 21, which fire bric rs rest on the grate bars 2. The casting 20 serves the purpose of directing the burning fuel and air, and also serves the purpose of catching unburned fuel in the event said fuel fails to ignite, and returning said fuel to the safety chamber 22 through the pipe 23. It will be noted that the cast-ing 20 has a raised boss 24: where the pipe 23 connects to said casting. The object in using this raised boss 24 is to prevent fuel from running into the pipe 23 when the burner is started from cold and is operating in the normal way. I have found that when the burner is started there is a small amount of wet fuel that will drip out into the casting 20, which fuel is burned as soon as the burner is operating for a few minutes. If I did not provide this raised boss, the fuel would run into the pipe 23 and would operate the safety device when there was no occasion for operating it. 25 is a metal float which is attached to the arm 26, which arm is pivoted at 27. 28 is a rod which is moved upward by the operation of the float 25 and which acts to break thecircuit to the motorb, thereby stopping the pump 8 (see Figure 3). The operationof the electric circuit breaker to the motor. will coil 34 of which is connected to the main line circuit through the wires 33 and 34 35 indicates a spark coil Whichis connected to the winding 36 of the transformer 33 through the wires 35 and 36", the wire 35 being connected to a wire 47, later referred to. Said spark coil furnishes current to the spark plug 16. 37 indicates an electric contact which is mounted on the flat spring 38; 39 is a fiat spring, the end of which is engaged in the end of the flat spring 40. The 8 )ring 40 is secured to the post 41 and bears agaimt the rod 28. The springs 38 and 39 are secured to the post 42. The contact 37 bears against the contact 43 and forms a switch or circuit breaker in the main line wire 44 so that when said contacts 37 and 43 are separated, the main line circuits are broken. 45 indicates a thermostat which is usually placed in the living room of the house; said thermostat is adapted to move in one direction when the room is cold and in the opposite direction when the temperature in the room rises. The purpose of the thermostat 45 is to control the operation of the motor 6, which motor controls the flow of oil to the furnace, thereby controlling the temperature in the room in which the ther mostat is located. 46 is an electro-magnet which gets its current from the coil 36 of the transformer 33 through the wires 47 and 36 The switches 49 and 50 are located in the line 36*. The magnet 46 when energized will move the armature 51 to the i left, as shown in the drawing. The magnet 52 gets its current from the same source as magnet 46, but the current to said magnet 52 is controlled by the switches 53 and 54. When the magnet 52'is energized, it will move the armature to the right. The armature 51 is pivoted at 55 and the upper part of said armature contains the ball 56, which ball is pressed upward by the spring 57. 58 is a fixed piece of metal which is located between the arms 59 and 60. The arm 59 is pivoted at 61 and said arm carries the contact 62, which is the switch toithe motor 6,

and the contact 63, which is the switch for breaking the circuit to the magnet 46. The arm 60 is pivoted at 64, and said arm carries the contact 65, which is the switch to the spark coil 35, and the contact 54', which is the switch for breaking the. circuit to the magnet 52. The numeral 66 indicates a piece of thermostatic metal which is fixed at one end to the post 67, and carries the contact 68 at the opposite end. The contact 68 is connected in series with the switch 65 through the wire 69 and thereby controls the operation of the spark coil 35. The post 67 is grounded through the wire 67 as is the wire 68"-, which is connected to one side of the primary winding of the spark coil 35. The thermostatic metal 66 is adapted to move upward when heated so as to break the contact between 68 and 69. 70 is a coil of. wire which is wound around the insulating material 71, which insulating material fits loosely around the thermostatic metal 66. The coil 7 0 is connected in series with the motor 6 by the wires 7 2 and 73. When the motor 6 is started, the current flowing through the coil 70 will heat up the thermostatic metal 66 and cause same to move upward so as to open the switch 68 and thereby only allow the spark coil 35 to operate for a short period of time after the motor is started. When the motor is shut oif, the thermostatic metal will cool off and close the switch 68.

I will now describe the general operation of my oil burner. Let us assume that the lire has been burning and the room temperature has been brought up to the desired point and that the motor 6 has just been shut off. As the room temperature drops, the thermostat 45 will move to the right and close the switch 53, thereby sending current through the magnet 52, whereupon the armature 51 will move to the right, thereby allowing the arm 59 to drop downward and moving the arm 60 upward. As the arm 59 drops clownward, the switches 62 and 63 close and the motor 6 starts. ward, the switch 54 opens, breaking the circuit to the magnet 52, and the switch 65 closes, thereby sending current to the spark As the arm 60 moves up-- coil 35. The switch 68 will open in a short period of time, as before described. When the motor 6 starts, fuel is pumped by the pump 8 and is forced under pressure through the spray nozzle 11. The fan 7 forces air through the pipe 13 into the air receiver 14, which air receiver is so formed as to make the air take the path of an involute curve and to rapidly rotate said air. The funnel-like casting 15 forces the air toward the outlet pipe 19. The plate 17 acts to direct the air around the points of the spark plug 16 and fuel nozzle 11 so that the air velocity at these points is high enough to prevent flame propagation around the spark plug points and fuel nozzle. Themixture of air and fuel is ignited by the spark plug 16 and the flame of said mixture is directed into the furnace by the outlet pipe 19.

I am fully aware of the fact that it is not new to ignite a spray of oil by an electric spark and that it is not new to bring in air around said fuel spray tangential to an air receiver which is located around said fuel spray. These features are clearly shown in Patent Number 1,207 ,897, to John Good, dated December 12th, 1916. a

In the event that the fuel should fail to ignite, it will run into the casting 20 and out through the pipe 23 to the casting 22, whereupon the float 25 will move upward, thereby moving the rod 28 and spring 40 upward, (see Figure 3). As spring 40 moves upward, it will move out of engagement with the spring 39 and said spring 39 will move to the left, thereby moving spring 38 and contact 37 to the left so that the main line circuit to the motor Will be broken and the motor Will stop pumping oil.

I claim:

1. In an oil burning system, a spray nozzle for spraying oil, means for furnishing air to promote combustion, an electrically-controlled device for supplying fuel to the burner, an electrically-controlled device for igniting the fuel, an electricallyheated thermostat for controlling the time of operation of the ignition device.

2. In an oil burning system, a spray nozzle for spraying oil, an air blower for furnishing air to promote combustion, a motor for operating the blower, an electric device for igniting the fuel, an electricallyheated thermostat for controlling the time of operation of the electric ignition device, and means for turning on or turning ofi the current to the motor and electrically-heated thermostat in substantial unison.

3. In an oil burning system, a spray nozzle for spraying oil, means for furnishing air to promote combustion, an electricallycontrolled device for supplying fuel to the burner, an electric device for igniting the fuel, an electrically-heated thermostat for controlling the time of operation of the ignition device.

4. In an oil burning system, a spray nozzle for spraying oil, means for furnishing air to promote combustion, an electricallycontrolled device for supplying fuel to the burner, an electrically-controlled device for igniting the fuel, an electrically-heated thermostat for making or breaking the circuit to the electrically-controlled ignition device.

5. In an oil burning system. a spray nozzle for spraying oil, means for furnishing air to promote combustion, controlled device for supplying fuel to the burner, an electrically-controlled device for igniting the fuel, an electrically-heated thermostat for making or breaking the circuit to an electrically thermostat to control the circuit to the sec- 0nd transformer, and an electric heater for said thermostat connected to the feed circuit to cause the thermostat to cut out said igniting transformer.

7. In a liquid-fuel burner, the combination of electrically operated means to produce a spray of liquid fuel, a. main feed circuit therefor, an electric transformer to produce sparks to ignite the spray, a feed circuit for the transformer, an electric heater connected to the main feed circuit, and a thermostat adjacent said heater and affected thereby to open the circuit to said ignition transformer when heated.

8. In a liquid-fuel burner, the combination of electrically operated means to produce a spray of liquid fuel, a main feed circuit therefor, an electric transformer to produce sparks to ignite the spray, a feed circuit for the transformer, an electric heater connected to the main feed circuit, and a thermostat adjacent said heater and affected thereby to open the circuit to said ignition transformer when heated, a relay to control the main feed circuit, a second transformer connected into the main feed circuit, a secondary circuit connecting to the second transformer and to the relay, and a thermostat connected into the relay circuit and adapted to open and close the relay circuit and thereby the main circuit.

In testimony whereof, I have hereunto set my hand.

LEWIS L. SCOTT.

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