US2685917A - Oil burner - Google Patents

Description

kk SSRN @WFL QR w. .MN

S, PERRY OIL BURNER Aug. 10, 1954 Filed Maron 1o, 195o Za which, when the warping bar is cold, is efective to flex the switch blade 2l to the inoperative position shown in Fig. l. The blade is mounted on an insulating structure 28 which also carries the leaves 29 and 3E with their respective contacts Eea and 35a. Thus, when the warping bar Ztl rises it will close circuits through 29a and Sdu which circuits are broken when the warping bar again returns to the position in which it is shown in Fig. l.

The type of burner herein shown is of the socalled pot or vaporizing type and includes the burner pot liti, with a plurality of primary air inlets il spaced circumferentially thereabout and located at various levels. Secondary air to complete the combustion of the mixture formed by the primary air and vaporized fuel may be supplied, for example, by the secondary air inlets ft2, it is any suitable iiame ring and 4t indicates the wall of any suitable combustion chamber or radiator located above the flame ring 43. 1lb indicates a pilot ring located above the lowest row of primary air inlets lil. It will be understood that liquid fuel for combustion is supplied along the duct il to the control and ignition unit il. di indicates any suitable opening to the interior of the burner pot 4t. In the normal use of the device, the liquid fuel supplied through the inlet tl iiows across the bottom of the pot di) and is vaporized by the heat of combustion taking place in or above the pot. The vaporized fuel rises and, at the high-nre stage, receives suincient primary air through the inlets 4l to produce a rich mixture. As this mixture rises upwardly to and past the level of the secondary air inlets 32, it receives adequate secondary air to produce a combustible mixture which burns at or above the top of the name ring 43. At low rire, as the rate of fuel delivery is reduced to a minimum, the level of combustion drops until combustion takes place at or just above the pilot ring 55. At that stage, the lowest row of primary air inlets lll provides adequate primary air and as the primary mixture iiows upwardly through and above the pilot ring d5, it receives its secondary air from the air delivered into the pot by the intermediate and upper apertures 4|.

It will be understood that in the structure herein shown air is supplied under pressure. 66 indicates a closed chamber which surrounds the pot ilo. ci is a fan housing with any suitable air inlet means not shown. t2 diagrammatically indicates a fan and S3 a fan motor. It will be understood that when themotor circuit is closed the motor 53 drives the fan 62 and delivers air under pressure to the interior of the housing 60 and thus to and through the apertures 4! and 42. At the same time, the increased air pressure within the housing Eil is communicated through an air duct til to the closed interior of the float chamber l. Since the lower edge of the standpipe or bell 9 is at all times below the liquid fuel level, the increase in air pressure within the chamber i tends to reduce the oil level and thus move the float il toward the valve opening position. There is a varied supply of liquid fuel along the duct The liquid fuel level within the bell 9 is at an adequate level to flow through the metering aperture l2 and thus to flow to the burner pipe.

'lil generally indicates a hot wire ignition coil which is shown as having any suitable wick ll whereby liquid fuel is picked up from the bottom or the iitting et for easy ignition by the coil 'lll when current is passing through it. 'l2 is a warping bar or heat motor which, when cold, takes the vertical position in which it is shown in Fig. l. When the pot Gil is hot, the warping bar 12 warps to the dotted line position or" Fig, l. It is connected by any suitabie connector '53 with the spring 'lll which carries a closure 'l5 to close an air inlet it in an upper part of the ignition unit Lid. The inlet it is effective to supply air for combustion of the liquid fuel on the wick. Il when it is vaporized and ignited by the hot wire ignition coil l. It will also be seen from Fig. l that when the heat motor l2 warps to the right, referring to the position of the parts in which they are shown in Fig. 1, it permits the spring contact 'il to snap from the full line or circuit closing position to the dotted line or circuit breaking position.

Referring to the wiring diagram, 8o, Si indicate any suitable connections to a source of electric current. 82 is a transformer for the ignition coil le. S3 is a resistance in a motor circuit ior low-speed motor operation. 84 is an electrical translating device in the form of a relay coil adapted to operate the below described switch structure generally indicated at S5. it is a transformer which powers the relay coil 84 and also powers an anticipator coil El associated with a room thermostat Sli. 89 is a normally xed contact opposed by any suitable movable contact of the room thermostat 88.

In the operation of the device, a primary electrie circuit is normally closed from the main power lines 8o and 8l, through the primary side of the transformer 86, the normally closed switch contacts lil@ and lb, and the contacts ll-'lla of a switch means associated with the burner di! which contacts are closed when the burner is cold. Assuming that the burner is initiating its operation, and that the room thermostat 88 is calling for heat, a secondary circuit is closed through the contact 3e and the secondary winding of the transformer Bt. Thus, the relay coil 8i; is energized and moves the switches i535, l0! and it into circuit closing relation with the contacts Nida, lla and m2o. It will be observed that the switches Hill, ll, and [22 are springbiased upwardly (spring not shown) so that when the relay coil 84 is not energized said switches occupy the positions shown in Fig. 2. The closure of the switch H32 energizes a i'lrst motor circuit including the motor 53, and the blower El 'then begins to supply air to the interior of the housing 60 and through the duct Gli to the interior of the housing i. The closing of the switch lill closes a circuit through the cold contacts l'l-l'la of the switch means at the burner and through the primary winding of the transformer 32, the secondary of which in turn energizes the circuit which includes the hot wire ignition coil l. The closure of the switch 58 closes a holding circuit which maintains energization of the transformer 86 so that it is continually energized. The relay Ztl is of the usual. slow-acting type and has a residual magnetism metallic portion on it, soy that sufiioient residual magnetism will remain in the metallic mass after the spring switch arm lilo has disengaged from the contact Hllb. The armature of the relay carries an inertia element 84 to insure the proper switchcver from contact Hill) to contact iota. Initially, the switch Tl maintains the position in which it is shown in Fig. 2, which is the position it keeps when the pot it is cold. The effect of the delivery of pressure to the pipe 5&5 to the interior of the housing l is to raise the nel" level of liquid fuel within :the standpipe oribell 9. As a result, fuel flows through the orifice I and the duet III to -the 'passage "4t and, past the ignitor coil it, to ythe bottom of the pot `4l). Meanwhile, air Ais free -to -iiow into the Ifitting 4&5 through-the open `inlet 16.

During the initial delivery of fuel, current is also supplied by the transformer 185 through Ithe econdary electric ycircuit tothe resistance 216 as long as the room thermostat 38 is -in`closed relation with the switch S9. The result is 'to heat the warping bar 24 and to store heat in ythe heat storage element 25. The result is a slow upwarping of the warping '-bar 2e which eventually reieases the switch spring -2'I to permit circuits to .be closed through the contacts 29a and Sec. However, since the hook 2:4u1i's not actual-ly secured to the spring .21, ythe 11p-warping of the bar 2t! continues for a time after the circuits through .29a and 36a are closed. The result is a lifting of the pin I3 by the spring Ie which permits the valve element I'3 to lbe lifted by the float I6. Meanwhile, the pot 4i? is heating `up and it eventually warps the heat motor 'I2 which releases the .switch Ti from the full line to the dotted line position of Fig. .1. VIn other words, it leaves a Contact 77d and moves into circuit closing relation with a contact 71h. One result is to close the air inlet 'I6 by means of the movable closure l5. Another result is that the Acircuit through the primary of the ignition transformer 82 is opened to 'de-energize the igniter .'I-il. Another result is to complete an auxiliary circuit through 30a which ,cuts in the resistance Snto complete a second motor circuit designed for .low-speed operation of .the motor v63 when the rst motor circuit is broken at IIiZ, I Za. However, .as long as current continues to flow uninterruptedly through switch .Ill2 to the motor 6.3 during the .so-.called high fire, resistance 81' will .have no effect as it is only .placed in the power line to the vmotor 63 when switch |52 has become disconnected Vby the .de-energization of coil -84 which is under control of the thermostat 8,8. As heat is delivered from the .pot Il and from the .burner unit lit to the space in which the V.thermostat 88 is located Vthe thermostat 88 warps back to the position in which it is show-n ,in Fig. 2.V This `de-energires the relay 84 returning :switches It, itl, Ir02 .to their .original position. It also de-energizes the resistance ,26. However, the Vmember' 25 constitutes a heat storage element which, if desired, may be insulated. The result is that -even though the heat is no longer called for, the downward movement of the warping bar 24 and thus the closure of the valve d3, is relatively gradual. When the thermostat circuit is broken, the Ametal mass or heat storage element 25 may retain-suicient heat so that .a considerable time, .say .5 to minutes, is re- .quired to `break the .circuits controlled by the warping bar 24 :through the hook Zta. As .long vas 'a circuit is made, the burner will continue to .Qllerate on -high llame when the thermostat is calling for heat and at low flame when the thermostat circuitis broken.

The burner is turned on and ignited when the thermostat .88 calls :for heat. Immediately lthe accelerator coil :81 starts to heat the thermostat which is possibly a ,3 =to:51minute operation. At the same time the warping bar .24 responds to heat from vthe resistance 26 and starts to close the contacts .2;9a1and ;3lla ,ipessib1y .a 1 minute .0D-

6 of switch iti, the ignition coil l0 is energized and the burner is ignited, with the result that the heat motor 'I2 Astarts to heat, possibly a two or three minute operation.

When the contacts .of the thermostat S8 break, the `relay 84 is de-energized and current for the combustion air fan motor 63 must then go through the second motor circuit including .the fan motor resistor 83, due to the opening of switch I2. Normally, the burner will continue to operate at reduced re until the thermostat 88 again calls for heat. Then the relay circuit including thermostat 88 is closed and high flame will again be produced.

Overrun is -provided for the low iire; the burner will 'always be lreduced from high fire to low fire and have several .minutes on the low stage before shutting down completely. After such a shut-down, it is necessary to wait until the heat motor 'I2 is cold again before the burner can be restarted.

The needle or metering valve I3 is supported on the adjusting screw I4, carried by the iloat I5 so that as the float rises or falls, the effective opening through aperture I2 controlled by the needle valve I3 varies. If heavy ol is the medium in which float E6 floats, IS will .oat high in the oil and needle valve I 3 will be raised. On the other hand, if lighter fuel, for instance gasoline, is in the oat chamber, float I6 will sink further and needle valve I3 will reduce the `size of the aperture but because the heavy oil is more viscous, the increased effective opening resultant from its weight will compensate for the increased viscosity of vthe oil. On the other hand, with gasoline for instance the decreased viscosity permits gasoline to enter through a smaller aperture so the arrangement of-oat with its supported needle valve automatically compensates for changes in fuel density and viscosity.

It will berealized that whereas I have described and shown a practical and operative device and. mode of operation, nevertheless, many changes may be made in size, shape, number and disposition of parts without departing from the spirit of my invention. I, therefore, wish my description and drawings to be-taken as in a broad sense illustrative or diagrammatic rather than as limiting me to my specific showing herein.

I claim:

Y l. In a device for generating heat, a liquid fuel burner of the vaporizing type., a housing in Vcommunication with the interior Vof the burner, a blower, a motor for driving theblower, agconnetion between the blower and the lhousing whereby the blower will increase the air lpressure -in `the housing and thelburner to above atmospheric pressure, a float chamber, an air duct extending from the housing to the float chamber so that the air pressure in the housing will be communicated to the oat chamber, a liquid fuel .supply line extending to the oat chamber, a fuel .-delivery line vextending from the float chamber to v.the burner, a valve mechanism adapted to :control the now of fuel from the supply line tothe float chamber and maintain therein a predetermined fuel level, valve means for controlling the flow of fuel from the float chamber -to lthe burner, lan igniter interposed .in the delivery line between the iioat chamber and Athe burner, a primary electric circuit, -a secondary electric circuit including switch means responsive `to changes in ambient temperature and which switch means closed vand opened at predetermined temperaeration. .And at thesame tima-.duetotheiclosure .-7.5 tures, mea-ns wnerebysaid secondary electriccircuit is operatively associated with said primary electric circuit to be energized thereby, electric translating means in said secondary electric circuit, a first motor circuit including switch means closed in response to the energization of the electric translating means in said secondary electric circuit, a circuit for said igniter including switch means closed in response to energization of said electric translating means in said secondary electric circuit so that the igniter is energized when said secondary electric circuit closes in response to predetermined changes in ambient temperature, a second motor circuit, a time delay device including a warping bar and switch means operated thereby controlling energization of the second motor circuit, means operatively connecting the warping bar with the valve means for controlling iiow or fuel to the burner, means responsive to energization oi the secondary electric circuit for operating the warping bar structure, said second motor circuit including means effective when said motor is being driven in response tc energization by said second motor circuit to operate the blower at a slower rate of speed then when the motor is being driven in response to energization by the first motor circuit, both of said motor circuits being closed concurrently after the switch means in the second motor circuit has been actuated by movement of the warping bar, the blower during the period in which both the rst and second moto-r circuits are closed being driven at a speed determined by the electrical characteristics of the rst motor circuit, said igniter circuit and said primary circuit including switch means responsive to temperature adjacent the burner and operatively associated therewith so as to close said circuits through said switch means when the burner is cold and to open said circuits through said switch means when the burner has reached a predetermined temperature, and a holding circuit for said primary electric circuit including switch means responsive to energization or" said electric translating means in said secondary electric circut for conne-cting said holding circuit around the switch means which is responsive to burner temperature, so that, when the burn reaches a predetermined temperature, the ignition circuit is opened while the primary energizing circuit remains intact.

2. The device for generating heat described in claim i wherein an auxiliary circuit is provided to maintain the second .motor circuit intact for a predetermined length of time after the first motor circuit has been de-energized following the opening of the switch means in the secondary electric circuit in response to a predetermined ambient temperature, said auxiliary circuit being operatively connected between the switch means of the time delay device and the switch means responsive to temperature at the burner and closed in response to a predetermined elevated temperature at the burner.

3. The device ior generating heat described in claim 2 wherein the switch means associated with the time delay device includes a switch device in the auxiliary circuit arranged so that the auxiliary circuit will be cle-energized in response to movement of the warping bar in cooling.

fi. The device for generating heat as described in claim l wherein said switch means in the primary circuit responsive to temperature at the burner includes a heat motor adjacent the burner for operating said switch means.

5. The device for generating heat described in claim 4 wherein an air inlet aperture is provided in the burner structure adjacent to the ignitcr.

closure means for said aperture, and means operatively connecting the heat motor and said closure to open the aperture when the igniter is energized and the burner is cold and to close said aperture when the igniter is (le-energized and the burner has reached a predetermined temperature.

6. The device for generating heat described in claim 1 wherein the warping bar of the time delay device is operatively associated with the valve means for controlling the now oi fuel from the float chamber to the burner and with the switch means of the time delay device so that, upon energization of the warping bar in response to a predetermined ambient temperature closing the secondary electric circuit, the warping bar will iirst initiate the admission of fuel from the float chamber to the fuel delivery line and will secondly energize the second motor circuit.

'7. In a device for generating heat, a liquid fuel burner of the vaporizing type, a housing in communication with the interior of the burner, a blower housing connected to the first-mentioned housing, a blower whereby the air pressure in the first-mentioned housing and burner may be increased above atmospheric, a 4iioat chamber having a normal fuel level, an air duct connecting the interior of the inst-mentioned housing with the interior oi the float chamber, a liquid fuel supply line extending to the float chamber, admission valve mechanism adapted to control the flow of fuel through the supply line to maintain a predetermined normal fuel level in the chamber, a fuel delivery duct extending from the float chamber to the burner, valve means for controlling the amount f fuel admitted to the fuel delivery duct including a member defining an oriiice in communication with the fuel delivery duct, valve `mechanism responsive to changes in ambient temperatures for varying the effective size of the orice, said oriice being positioned above the normal fuel level, means responsive to the air pressure in the inst-mentioned housing for elevating the level of the fuel above the normal fuel level immediately adjacent said orifice for flow through said orifice, and a fuel density compensator for increasing the eiective size of the orice in response to an increase in the density of the fuel.

8. In a fuel control system for oil burners, a burner, means for supplying air at a pressure greater than atmospheric to the burner, a housing including a float chamber, means for supplying fuel to the float chamber, an inlet valve mechanism adapted to control the flow of fuel into the float chamber, said iioat chamber having means to maintain therein a normal predetermined fuel level, a fuel outlet, an outlet valve mechanism therefor adapted to vary the amount of fuel delivered through the outlet in direct proportion to the pressure of the air supplied to the burner and in accordance with predetermined ambient temperatures, said outlet valve mechanism including an outlet orifice positioned slightly above the normal fuel level in said float chamber, a float in the chamber, and means controlled by said iloat to increase the effective size of the orifice in response to an increase in fuel density resulting from the diierence in densities involved in the use of more than one fuel, and means responsive to the pressure of the air supplied to the burner for elevating the level of the fuel above the normal fuel level immediately adjacent the orifice for ilow therethrough.

9. In a fuel control system for oil burners, a

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burner, means for supplying air at a pressure greater than atmospheric to the burner, a housing including a float chamber, means for supplying fuel to the float chamber, an inlet valve mechanism adapted to control the flow of fuel into the float chamber and to maintain Within said iioat chamber a normal predetermined fuel level, a fuel outlet, an outlet valve mechanism therefor adapted to vary the amount of fuel delivered through the outlet in direct proportion to the pressure of the air supplied to the burner and in accordance with predetermined ambient temperatures, including means defining an orifice positioned slightly above the normal fuel level, means including a float in the chamber adapted to increase the effective size of the orifice in response to an increase in fuel Vdensity resulting from the difference in densities involved in the use of more than one fuel, and means responsiveto the pressure of the air supplied to the burner for elevating the level of the fuel above said normal fuel level immediately adjacent said orifice for flow therethrough, said last-mentioned means including a depending cylinder on the inside of the float chamber encompassing said orifice and extending below the surface of the fuel at normal fuel level.

10. In a fuel control system for oil burners, a burner, means for supplying air at a pressure greater than atmospheric to the burner, a housing including a float chamber, means for supplying fuel to the fioat chamber, an inlet valve mechanism adapted to control the flow of fuel into the float chamber and to maintain Within said float chamber a normal predetermined fuel level, a fuel outlet, an outlet valve mechanism therefor adapted to vary the amount of fuel delivered through the outlet in direct proportion to the pressure of the air supplied to the burner and in accordance with predetermined ambient temperatures, including means defining an orifice positioned slightly above the normal fuel level, a float in the chamber, means operable in response to movement of said float to increase the effective size of the orifice in response to an increase in fuel density resulting from the differences in densities involved in the use of more than one fuel, and means responsive to the pressure of the air supplied to the burner for elevating the level ofthe fuel above said normal fuel level immediately adjacent said orifice for flow therethrough,

said outlet valve mechanism including atapere'd element movable into and out of said orifice to vary the effective size thereof, said element being biased to move in a direction to increase the effective size of the orifice by the float in response to an increase in fuel density, and means for resisting movement of said tapered element under the influence of said float bias, said last-mentioned means including means for rendering said resistance means ineffective to resist the float bias in response to a predetermined ambient temperature.

11. In a fuel control system for oil burners, a burner, means for supplying air at a pressure greater than atmospheric to the burner, a housing including a float chamber, means for supplying fuel to the float chamber, an inlet valve mechanism adapted to control the flow of fuel into the float chamber and to maintain within said float chamber a normal predetermined fuel level, a fuel outlet, an outlet valve mechanism therefor adapted to vary the amount of fuel delivered through the outlet in direct proportion to the pressure of the air supplied to the burner and in accordance with predetermined ambient temperatures, said outlet valve mechanism including an orifice positioned slightly above the normal fuel level, a float in the chamber, means operable in response to movements of said float to increase the effective size of the orifice in response to an increase in fuel density resulting from the differences in densities involved in the use of more than one fuel, and means responsive to the pressure of the air supplied to the burner for elevating the level of the fuel above said normal fuel level immediately adjacent said orifice for flow therethrough, said outlet valve mechanism including a tapered element movable into and out of said orifice to vary the effective size thereof, said element being biased by the float to move in a direction to increase the eective size of said orifice in response to an increase in fuel density, means for resisting said movement of said element, said last-mentioned means including means for rendering said resisting means ineffective to resist said float bias in response to a predetermined ambient temperature, and yielding means biasing the tapered element in the same direction as said fioat.

12. In a fuel control system for oil burners, a burner, means for supplying air at a, pressure greater than atmospheric to the burner, a housing including a float chamber, means for supplying fuel to the float chamber, an inlet valve mechanisem adapted to control the flow of fuel into the float chamber and to maintain Within said float chamber a normal predetermined fuel level, a fuel outlet, an outlet valve mechanism therefor adapted to vary the amount of fuel 'delivered through the outlet in direct proportion to the pressure of the air supplied to the burner and in accordance with predetermined ambient temperatures, said outlet valve mechanism including an orifice positioned slightly above the normal fuel level, a float in the chamber, means operable in response to movement of said float to increase the effective size of the orifice in response to an increase in fuel density resulting from the differences in densities involved in the use of more than one fuel, means responsive to the pressure of the air supplied to the burner for elevating the level of the fuel above said normal fuel level immediately adjacent said orifice for flow therethrough, said outlet valve mechanism including a tapered element movable into and out of said orifice to vary the effective size thereof, said element being biased for movement in a direction to increase the effective size of said orifice by the float in response to an increase in fuel density, means resisting said movement of said element, said last-mentioned means including means for rendering said resisting means ineffective to resist said float bias in response to a predetermined ambient temperature, and manually operable means for adjusting the position of the tapered element with respect to the orifice for any predetermined position of the float.

yReferences Cited in the file of this patent UNITED STATES PATENTS

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