US2997101A - Control for oil and gas burners and the like - Google Patents

Description

J. L. BREESE CONTROL FOR OIL AND GAS BURNERS AND THE LIKE Filed April 4, 1958 Aug. 22, 1961 2 Sheets-Sheet 1 VAL v5 oooooiioooooooooooooomo Inverzfar J'amea .Lfireese y Purim?" 5 62122622" JZzto rnega Aug. 22, 1961 J. L. BREESE 2,997,101

CONTROL FOR OIL AND GAS BURNERS AND THE LIKE Filed April 4, 1958 2 Sheets-Sheet 2 IIIIII l I l\ H 3 60 GFQOOOOOOOOOO000006660095'56 0 0 O O 0 Q B Inventor James llfireese 2,997,101 CONTROL FOR OIL AND GAS BURNERS AND THE LIKE James L. Breese, Santa Fe, N. Mex., assignor, by mesne assignments, to Controls Company of America, Schiller Park, 111., a corporation of Delaware Filed Apr.-4, 1958, Ser. No. 726,549 3 Claims. (Cl. 158-43) The present invention is directed to a new and improved controlling system for hydroxylating pot type liquid fuel burners. It is particularly directed to a new and improved system for controlling the supply of fuel to the burner pot.

One object of the present invention is the provision of a controlling system for automatically supplying fuel to a burner pot in accordance with the demands of a room thermostat while at the same time insuring against an excessive buildup of fuel in the pot in the event that ignition of the fuel fails.

Another purpose of the present invention is the provision of a controlling circuit for a fuel supply valve for a pot type burner wherein the actuation of the valve is dependent upon the direct heat of the burner pot.

Another purpose of the present invention is the provision of a controlling system for the fuel supply valve of a burner pot assembly and which is quickly responsive to either a small or large flame in the pot for maintaining the flow of fuel through the valve and which in the absence of a flame in the pot shuts off the supply of fuel to the valve.

Another object of the present invention is the provision of a controlling system for a solenoid actuated valve for burner pots and which is responsive to either the absence of a flame in the burner pot or failure of a blower unit associated with the pot for terminating the flow of fuel through the valve.

Other objects and purposes will appear from time to time in the course of the ensuing specification and claims.

Referring generally now to the drawings:

FIGURE 1 is a diagrammatic view of one embodiment of the present invention; and

FIGURE 2 is a diagrammatic view of another embodiment of the present invention.

Referring specifically now to the drawings and in the first instance to FIGURE 1, 1 represents more or less diagrammatically a burner casing within which is supported a conventional burner pot 2 of the hydroxylating type. The pot 2 may include, for example, a plurality of vertically spaced rows of primary and secondary air inlet apertures 3 which are located at various levels within the pot. The burner pot may include a flame ring 4 at the upper portion thereof and may include a pilot baffle 5 located between the two lowermost rows of air inlet apertures. I wish it to be understood that the details of the pot, flame ring and pilot baflle may be varied without departing from the scope of the present invention. The particular burner pot assembly herein illustrated should be taken as typical or illustrative of a burner pot assembly which is associated with the present invention.

Shown generally at 6 is a fuel supply valve which is adapted to control the supply of hydrocarbon liquid fuel from any suitable fuel reservoir (not shown) through a conduit 7 and a conduit 8 leading to the bottom of the burner pot. Represented generally at 9 is a solenoid adapted, when energized, to open the valve and permit the flow of fuel from the conduit 7 and into the conduit 8 and thence into the burner pot.

The pot assembly may include an electrical ignition assembly 10 which has a heating element positioned adjacent the bottom of the pot and adjacent to the point of Zfifllllll Patented Aug. 22, 1961 admission of fuel so as to ignite the mixture of air and hydrocarbon vapor formed in the pot.

In accordance with the principles of the invention the solenoid 9 which controls the flow of fuel through the valve body 6, is energized by a circuit including a heat responsive switch 11 and a thermostatically controlled switch 12. The heat responsive switch 11 is shown as affixed directly to the burner pot so that the switch is in heat transferring relation to the burner pot. The switch 11 is shown as including a bimetallic element 13, one end of which is fastened to the bottom of the pot as at 14. The other end of the bimetallic element is adapted upon being heated to a predetermined degree to move into contact with a switch element 15 and thus complete the circuit from the solenoid valve to the thermostat 12. The thermostat 12 is shown as including a bimetallic element 16 which is adapted for movement between two contacts 17 and 18 respectively. When the bimetallic element 16 moves against the contact 17 a circuit is completed between any suitable source of electrical energy such as' is represented by the transformer 49 and the switch contact 15. When the bimetallic element 13 contacts the switch element 15, the energizing circuit to the solenoid 9 is thus completed.

When the bimetallic element 16 contacts the other switch element 18 a circuit is completed through a resistance heating element 19 which is wrapped around the bimetallic element 13. When the element 16 completes the cir cuit through the element 19, the circuit to the solenoid valve is open. The heating element 19 is adapted during energization thereof to heat the bimetallic element 13 sufiiciently to close the switch designated generally at 11.

The thermostatic switch contact 17 is adapted to be closed whenever the thermostat 12 (which will be positioned in the building space being heated), is calling for heat. On the other hand, the contact 17 is open and the contact 18 is closed, when the burner has satisfied the heating demands of the building space. Thus the thermostat 12 controls two circuits, one circuit being the energizing circuit which includes the heating element 19 to maintain the switch 11 closed and the other circuit including the energizing circuit for the solenoid 9 which includes the switch 11.

As soon as the thermostat 12 calls for heat as by closure of the switch contact 17 the circuit to the heating element 19 is broken. The residual heat in resistance 19, however, is suflicient to maintain the switch 11 closed for a predetermined interval of time, say for example, 6 0 seconds' As long as the switch contacts 17 and 15 are closed, the solenoid valve 9 is energized, thus permitting fuel to flow into the pot. As the fuel flows into the pot it is ignited by the electrical ignition assembly 10. The presence of the relatively small flame with the small amount of fuel in the pot is sufficient to maintain the heat 'of the bimetallic element 13 and keep the switch 11 closed. If, however, ignition fails to take place within the time necessary to cool the bimetallic element 13, the bimetallic element 13 will move away from the switch contact 15 and open the circuit to the solenoid 9, thus shutting off the flow of fuel to the pot.

In FIGURE 2 I illustrate a modified form of the invention. In FIGURE 2, the burner casing 30, burner pot 31, and electrical ignition assembly 32, as Well as the valve 33 and solenoid 34 are the same as the corresponding elements in FIGURE 1. In this form of the invention, however, the burner is adapted for operation under a forced draft, as produced by a blower 35 positioned beneath the pot and adapted to direct a forced stream of air upwardly about the pot, whereas in FIGURE 1, the burner is adapted for operation under natural draft conditions. In this form of the invention, a thermostat 36 is adapted to selectively open and close switch contacts 37 and 38 which lead, respectively, through a heat responsive switch 39 and to a resistance heating element 40. As in FIGURE 1, the resistance heating element 40 is associated with a bimetallic switch member 41 which is adapted. upon being heated to move into contact with a switch element 42 and thus complete a circuit through the energizing solenoid 34 for the valve 33.

In this form of the invention, however, the heat responsive switch 39 is mounted in a tube 43 which is mounted on the casing 30 and is in communication with the space between the casing and the burner pot 31.

In this form of the invention, the thermostat 36 is adapted, by closure of the contact 38 to heat the bimetallic element 41 and thus close the switch 39 when the thermostat 36 ceases to call for heat. When the thermostat calls for heat, the bimetallic element of the thermostat closes the circuit, by movement against the contact 37, through the heat responsive switch and the solenoid 34. The residual heat in resistance 40 is sufiicient to maintain the switch 39 closed for a predetermined interval of time. When the flow of fuel to the pot has thus been initiated and the fuel is ignited by the ignition assembly 32, the blower 35 will direct hot air through the tube 43 and maintain the switch 39 in its closed position. If ignition fails to take place, the blower 35 will merely direct cool air over the bimetallic element 4-1, cool this element, and open the switch 39. If, for some reason, the blower is not operating, the natural draft exerted upon the burner pot and the space around the burner pot will cause an inflow of outside air through the tube 43 and thus cool the bimetallic element 41 suificiently to open the circuit to the solenoid valve.

Thus in the form of the invention illustrated in FI URE 2, the circuit to the solenoid valve is interrupted if ignition fails to take place in the pot or if the blower 35 fails to operate.

It should be understood that the blower 35 may, if desired, be operated in response to closure of the thermostatic switch element 37 or if desired, it may be controlled by another circuit as long as the motor driving the fan is energized whenever the thermostat 36 calls for heat.

Whereas I have shown and described an illustrative form of my invention, I wish it to be understood that there are modifications to the invention which will fall within the scope and spirit thereof and which will be apparent to those skilled in the art. The showing and description of the invention should be taken in an illustrative or diagrammatic sense only. The scope of the invention should be limited only by the scope of the hereinafter appended claims.

The use and operation of my invention are as follows:

I illustrate a controlling circuit for controlling the flow of fuel to an hydroxylating pot type liquid fuel burner. In each form of the invention, an energizing circuit for the solenoid is closed by a thermostatically controlled switch which is responsive to the temperature of the building space being heated. The energizing circuit for the solenoid is maintained for a predetermined period of time after the thermostat commences to call for heat. In each form of the invention, the energizing circuit for the solenoid controlled valve includes a heat responsive switch which is in direct heat transferring relation to the burner pot. As long as a flame is present in the pot this heat responsive switch remains closed and the solenoid remains energized, thus holding the valve in the open position. If, however, ignition has failed to take place in the pot, the heat responsive switch will gradually cool and will open, thus breaking the circuit to the solenoid valve. If ignition does fail, the circuit to the solenoid valve will be open and the valve closed with only a small amount of fuel remaining in the pot.

In each form of the invention, the room or building space thermostat terminates energization of the solenoid and thus terminates the flow of fuel to the pot when the temperature of the room or space has attained the desired temperature. When this happens, the thermostat automatically conditions the safety switch associated with the pot and valve for the next period when heat is required.

I claim:

1. A burner and control system therefor, comprising a pot type burner, a fuel flow valve for the burner and including a solenoid valve, a bimetallic switch positioned in heat receiving relation to the pot to close in respense to heat, a heater for said switch, a room thermostat switch having a hot contact closed in absence of heat demand and having a cold contact closed in response to heat demand, an energizing circuit including a source of power and said hot contact and the switch heater, and another energizing circuit including said source of power and said cold contact, the solenoid valve and the bimetallic switch.

2. The combination according to claim 1 in which the bimetallic switch is positioned adjacent the burner pot so that it is responsive to combustion therein.

3. The structure of claim 1 characterized by and including a fan adapted to direct a forced flow of air past said burner pot, and a conduit for conducting the air heated by contact with the pot wall to said heat responsive switch whereby said heat responsive switch remains closed while said fan is in operation and said burner pot wall is hot and opens when said forced supply of air is diminished.

References Cited in the file of this patent UNITED STATES PATENTS 1,681,421 McCabe Aug. 21, 1928 1,883,246 Koch Oct. 18, 1932 2,287,248 Holmes June 23, 1942 2,640,648 Judson June 2, 1953 2,710,056 Parrett June 7, 1955 2,710,181 Parrett June 7, 1955 2,729,282 Lennox Jan. 3, 1956

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