US2839593A - Gas conversion assembly for a vaporizing oil burner - Google Patents

Description

June 17, 1958 c, c, YOUNG 2,839,593

GAS CONVERSiON ASSEMBLY FOR A VAPORIZING OIL BURNER Filed April 23. 1953 2 Sheets-Sheet 1 I7 FE TiZZUT" Cyril Char/e5 Ybzmy C. C. YOUNG June 17, 1958 GAS CONVERSION ASSEMBLY FOR A VAPORIZING OIL BURNER 2 Sheets-Sheet 2 Filed April 23. 1953 nfmT Cyril Char/e5 Ybzzzzy W MW United States Paten'tQ GAS CONVERSION ASSEMBLY FOR A I VAPORIZING OIL BURNER Cyril Charles Young, Kansas City, Mo.

Application April 23, 1953, Serial No. 350,666

2 Claims. (Cl. 1364) This invention relates generally to burner units and more particularly relates to a gas conversion assembly for quickly and conveniently converting a conventionalform of vaporizing oil burner into a combination gas-oil burner unit.

According to the general principles of the present invention, an oil vaporizing type burner unit including. a perforated inner drum surrounded by an air chamber supplying combustion supporting air through the inner drum is conditioned for conversion into a combination gas-oil type burner unit by forming an opening in the walls thereof and insertinga gas burner unit therethrough constructed in accordance with the principles of the present invention. The gas burning unit, more particularly, comprises an annular hollow ring forming a pilot burner and comprising axially extending concentrically spaced side walls joined by a curved radially inwardly extending front wall perforated by a row of circumferentially spaced pilot burner ports.

At the center of the annular ring is mounted a thermocouple generating unit consisting of a multiplicity of thermocouples in series assembled as a single generating unit and adapted to provide an electric potentialacros s a pair of terminals upon the application of heat thereto so that one end of the thermocouple unit, preferably the end adapted to have heat energy applied thereto, is located in a recessed area provided by the curved front wall of the pilot burner unit.

Gas fuel emanating from the pilot burner unit ports will burn in the recessed area, thereby providing a flame shield across the front of the thermocouple generating unit. By virtue of such provision,'the thermocouple unit is shielded from the excessive temperatures generated within the combustion chamber of the oil. vaporizing burner and also from contact with the injurious gases emanating from the burning oil.

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Patented June 17, 1958 close the control damper.

An independent passageway is provided by means of f combustion chamber of the inner drum through the perv forations communicating the air space surrounding the inner drum to the combustion chamber.

The burner unit provided preferably is of the type utilizing draft control means of thebarometric type wherein a rotatable barometric damper is pivotally hinged 7 in a rotatably adjustable frame member. weight is provided on the damper so that rotary adjustment of the frame member will change the relative position of the counterweight with respect to the pivot axis A counterthereby permitting the counterweight toexert more or less leverage against the pivotal hinges and adjusting the A control handle is provided which is operatively connected to the adjustable frame member, the control mem ber also being operatively connected to the oil supply valve in control of the supply of oil fuel to the combustion chamber of the oil vaporizing burner unit.

In'accordance with the principles of the present invention, an electrically operated gas valve controls the supply of gas to the conversion unit and circuit means are connected to the gas valve which circuit means are controlled by a switch including a switch contact member operatively connected to the control handle so that the gas-valve will be interlocked with the draft control, thereby insuring the combustion of gas fuel only under conditions of adjusted draft and the combustion of oil fuel under different adjusted conditions of draft.

It is an object of the present invention, therefore, to provide a control system for a gas-oil burner unit of the type including draft control means wherein the supply of gas or oil fuel to the burner unit will be controlledby an interlocking control means operable as a function of adjusted draft conditions.-

Another object of the present invention is top'rovide a control system for a combination gas-oil burner unit wherein interlocking means are provided to insure combustion of gas fuel only under adjusted conditions of draft.

A further object of the present invention is to provide a gas conversion unit for use with a well known form of oil vaporizing burner unit.

Yet another object of the present invention is to provide an improved pilot burner structure wherein a thermocouple generating unit may be provided for the pilot burner and associated therewith in a protected and shielded location.'v p 'Another object of the present invention is to providea pilot burner with a thermocouple generating unit; for use in an oil burner pot wherein the end of the thermocouple generating unit will be shielded by a flame shield from excessive temperatures generated within the pot and from contact with injurious gases emanating from the burning oil in the pot. 'Another object of the present invention is to provide a gas burning pilot which performs the dual function of protecting the exposed surface of a thermocouple generator unit while providing it with heat energy necessary to generate a control current.

Yet another object of the present invention is to provide an improved burner assembly utilizing as an integral unit a gas burner having a thermocouple generator unit and a pilot burner. 1 Many other advantages, additional features and further objects of the present invention will become manifest to invention is shown by way of illustrative example'only.

On the drawings: Figure 1 is a somewhat diagrammatic cross-sectional view of a burner unit provided in accordance with the principles of the present invention; 7

Figure 2 is an isometric view of a conversion burner unit provided in accordance with the principles of the present invention; Figure 3 is a fragmentary cross-sectional view with parts shown in elevation showing additional details of construction of the burner unit of Figure 2;

Figure 4 is a fragmentary cross-sectional view taken substantially on lineIVIV of Figure 3; V

Figure 5 is an enlarged fragmentary cross-sectional 89 view showing additional details of construction of the gas conversion unit as mounted in an oil vaporizer burner; and

Figure 6 is a somewhat schematic view of an oil heater converted into a gas-oil heater in accordance with the principles of the present invention and illustrating the principles of the control system provided in accordance with the principles of present invention.

As shown in the drawings:

Referring first of all to Figure 6, anoil heater is indicated generally by the reference numeral 10 and includes an oil vaporizing burner unit indicated generally by the reference numeral 11 adapted to burn either an oil fuel or a gas fuel by virtue of the association therewith ofa gas conversion assembly indicated generally 'by the reference numeral 12.

The burner unit 10 utilizes draft control means of the barometric type and indicated generally at 13.

Although the details of construct-ion of the gas conver sion assembly 12 form an important part of the present invention, the control system utilized in connection with the converted burner unit 10 is of general utility and an explanation thereof follows.

As shown in Figure 6, an oil valve 14 has an oil inlet conduit 16 connected to a suitable source of vaporizable oil fuel and controls the supply of oil fuel to the oil burner pot 11 through a conduit 17.

A gas valve 18 operated by a suitable electric means 19 receives a supply of gas fuel from an inlet conduit 20 connected to a suitable source of gas fuel and controls the supply of the gas fuel to the gas conversion assembly 12 throughconduits 21, 22 and 23, conduit 22 comprising a main supply line for the gas conversion assembly 12 and a conduit 23 comprising a pilot burner supply line for the gas conversion assembly 12.

The "burner unit 10 comprises an oil burner pot 11 mounted at the bottom of a larger combustion or fire chamber with an extended radiator section for the purpose of transferring thermal energy to the air flowing through the heater. It will be understood that a'fire box-radiator section surrounded by air chambers separated from one another by an inner baflie is enclosed by an outer casing for the burner unit 10, indicated at 24.

The flue pipe 26 and draft control assembly are connected to the unit and are supported by the outer casing 24. On one wall of the casing 24 is provided an opening in which is slidably mounted for rotatable adjustment a frame member 27 of generally annular configuration, suitable slide rollers for the frame member 27 being indicated at 28.

A barometric draft controldamper 29 is retained within the annular frame member 27 and is pivotally hinged in said frame memberas at as. A counter-weight 31 is connected to the control damper 29 and under the force of gravity will normally tend to exert a displacement force on the damper 29 tending to continuously bias the damper 29 into closed position.

By rotating the annular frame member 27 relative to the casing 24, the counterweight 31 is'selecn'vely given more or less leverage against the pivotal hinges thereby requiring more or less draft force against thecontrol damper 29 in order to open the damper 29 and in order to adjust the draft through the burner unit 10.

In other Words, the control damper 29 will resist movement toward an open position from the 'forceof. the chimney draft manifested through the smoke pipe 26 "by the counterweight 31. Asthe'chimney draft increases, the force operating on the greater part of the area'of the damper 29 will cause the damper 2910 tilt inwardly, thereby permitting air to bedrawn from the space in which the burner unit 19 is located into 'thefiuefpas'sage controlled by the damper 29 and, accordingly," the amount of air drawn through the burner unit" 10 will be reduced.

a'gssasaa A control assembly is provided for adjustably rotating the frame member 27. As is shown on the drawings, ad-

justment knob 32 connected: to the frame member 27 is received in an elongated slot 33 provided in a lever arm 7 34 connected to a control stem assembly 36.

The control stem assembly 36 is reciprocably carried on the casing 24 and isalso provided with a rotatable driving connection with the oil valve 14 to selectively actuate the oil valve. In other words, by lifting the stem assembly 36, the frame member 27 is angularly positioned to adjust the control damper 29 and by rotating the stem assembly 36 the oil valve 14 is adjusted.

Means areprovided'to correlate the lifting and rotary motions of the stem assembly 36 and include a radially extending manual control handle 37 on the upper end of the stem assembly 36 which cooperates with a stepped stop member 38 having a plurality of steps 39 thereon, therebyrequiring the stem assembly 36 to be lifted in steps inattempting to open the oil valve 14, the various steps 39 being arranged in obstructing alignment with respect to the manual operating handle 37.

As the manual operating handle 37 is turned 'andlifted, the damper 29 will be adjusted so thatthe draft and oil supply will beeoncurrently regulated,

In other words, as the oil control handle 37 is turned and lifted, the damper 29 is rotated clockwise, thereby givingthe counterweight 31 more leverage against the hinges 30 and requiring more draft force against the portion of the regulator damper 29 to open the damper for increasing chimney draft to the burner. In this manner, the draft will be increased or decreased depending upon the-quantity of fuel desired to be burned.

'Inaccorda'nce'with theprinciples of the present invention, circuit means are provided to control the energizetion of-the electric means 19 in control of the gas valve 18. As shown in Figure 6, the circuit means comprises a room thermostat 35 and a control switch 40 as wellas a thermocouple generating unit which will be described in more appropriate detail in connection with the explanation'of the gas conversion assembly 12.

The control switch 40 includes a stationary contact member 41 and a movable contact member 42 having a pivoted actuating arm 43 engaged by a projection 44 carried by thestem assembly 36.

By virtue of such arrangement, the gasvalve 18 is effectively interlocked with the barometric draft control 13 and with the oil valve 14 so that gas fuel'will be burned in the unit 10 only under conditions of reduced draft and oil fuel will be burned in the unit 10 only under conditions of increased draft.

Generally, it requires less draft to burn a gas fuel efficiently than is required for an oil fuel and in combination gas-oil heating units, one of the serious problems of design has resided in the control of the combustion air supply in a manner suitable for the safe and efiicient combustion of each type of fuel. Theinterlocked-control herein provided is a solution-for this problem since the control switch 40 willbe actuated to an open position when the oil control valve 14 is opened and will be closed to permit the combustion of gas fuel only when the oil control valve 14 is in the ofi or closed position, and when the control damper 29 is suitably adjusted so that the draft through the heater unit 10 will be reduced to the extent desired for the combustion of gas fuel.

As shown in Figure l, the oil burner pot 11 comprises an inner drum 46 of generally cylindrical configuration and having vertically spaced rows of circumferentially spaced apertures each indicated at 47.

The-inner drum- 46 is surrounded-by an outer drum -48 anddsconcentrically spaced'with respect thereto so as "to form' together-there'with an annular air chamber 4 9'havin'g an air inlet-passagewayindicated at 50 so that a supply of air furnished to the air chamber 49 will be to supply a vaporizable type oil to the bottom of the.

combustion chamber 51. Oil vapors arising from the pool of oil collected in the bottom of the combustion chamber 51 will be mixed with the air entering the combustion chamber through the apertures 47 and thereby burned.

The gas conversion assembly 12 is shown in greater detail in Figures 2-5.

As shown in Figure 5, in order to convert a conventional oil burner pot 11 for using a gas fuel in addition to an oil fuel an opening of approximately circular shape is cut through the side Walls of the inner and outer drums 46 and 48, the bottom of such opening being approximately level with, but not below, the lowest row of apertures 47 piercing the side walls of the inner drum 46.

In the openings so provided, a cylindrical guide tube 56 is introduced and is welded securely as at 57 to the inner drum 46, one end of the guide tube 56 protruding into the combustion chamber 51 and the other end extending through the outer drum 48. The guide tube 56 provides a passage 58 for receiving the gas conversion assembly 12.

Retained within the passageways 58 is an annular hollow ring 59 providing a pilot burner unit. The ring 59 comprises a pair of axially extending concentrically parallel walls 60 and 61 spaced to provide an annular chamber 62 for receiving a supply of gas fuel conducted thereto by the pilot gas conduit 23. A radial wall 63 closes one end of the annular space 62 and is intersected by the pilot gas conduit 23.

At the other end of the ring 59 is provided a front wall which is indicated at 64 and which extends from the outermost wall 60 of the ring 59 radially inwardly to the innermost Wall 61 of the ring 59, the front wall 64 being curved to provide a recessed areaway indicated generally by the reference numeral 66.

Centrally located within the gas conversion assembly 12 is thermocouple generating unit 67 which comprises a multiplicity of thermocouples in series assembled as a single generating unit and having an end portion 68 adapted to have thermal energy applied thereto for developing an electrical potential across a pair of terminals 69 and 70 in circuit connection with the circuit means shown in Figure 6.

In the heater of Figure 6, gas fuel is automatically burned in response to control conditions imposed upon the circuit by the room thermostat 35 and the oil valve 14 is controlled manually, however, it will be readily understood by those versed in the art that automatic control of the oil valve 14 could be readily effected and control means could also be provided to automatically select oil fuel or gas fuel in response to conditions sensed by an outdoor thermostat as is well known in the art.

One of the great difficulties in the utilization of thermocouples in the interior of oil vaporizing burning units has resided in the harmful burning oil vapors upon. the physical structure of the thermocouple assembly.

In accordance with the principles of the present invention, the thermocouple generating unit 67 is centrally disposed and concentrically spaced with respect to the wall 61 of the ring 59 thereby forming an annular passageway 71 for carrying combustion supporting air along the surface of the thermocouple unit 67 to the recessed areaway 66.

In this connection, it may be noted that a radially extending support ring 72 flanged as at 73 carries the back end of the conversion assembly 12"and may be.

locked to the guide tube 56 by means of a set screw 74. One or more apertures 76 are provided in the support ring 72 and admit combustion supporting air into thef interior of the guide tube 56 provided by the passagewayv 58 so that such air will pass along the surface of the thermocouple unit 67 through thepassageway 71 and into the recessed areaway 66.

The front wall 64 of the ring 59 is provided with a row of circumferentially spaced openings or slots indicated at 77 which are provided to form pilot burner ports for discharging gas fuel from the annular recess 62 into the recessed areaway 66. By virtue of such provision, the

gas fuel is. mixed with the air from the passageway 71 and is burned in the recessed areaway 66 so as to completely surround the end 68 of the thermocouple unit 67. There is thus provided a flame shield which protects the end 68 of the thermocouple unit 67 against exposure to the interior of the inner drum 46 and the combustion chamber 51. Accordingly, protection is afforded the thermocouple unit 67 against excessive temperatures generated within the combustion chamber 51 and from contact with the injurious gases emanating from the burning oil'in the'combustion chamber 51.

As shown in the drawings, pilot gas is delivered to the annular pilot burner or ring 59 by the pilot gas conduit 23 and incorporated in the pilot gas conduit 23 is a mixer device indicated somewhat schematically in Figure 5 by the opening 78 but shown in more detail in Figurelas in the recessed areaway 66. Since the pilot gas is burn-- ing as the. narrower sections of the recessed areaway 66 expand to fill the increasing combustion space towards the interior of the inner drum 46, the cntirerecessed area 66 will be filled with burning pilot gas, clean air and the products of combustion from the chemical reaction inherent to the combustion, thereby forming a combustion area which completely surrounds the sides and the end of the thermocouple unit 67 and operating to develop the dual function of protecting the exposed surfaces of the thermocouple unit 67 while providing it with the thermal energy necessary to develop a control electrical current.

In order to supply the main gas fuel supply to the combustion chamber 51 for combustion in the inner drum 46, the main gas supply conduit 22 is provided with a tubular portion indicated at 80 which extends through the recess 62 and which registers with an outlet opening or gas port 81 provided in the front wall 64. The tubular portion 80 not only pierces the wall 63 and the front wall 64 but may be firmly connected thereto by means of welding. Since the port 81 is immediately adjacent the slotted pilot burner ports 77, any gas fuel passing through the main gas burner port 81 is instantly ignited by the pilot flame. Air for the combustion of the gas fuel is introduced into the combustion chamber 51 by the apertures 47 of the oil burner pot 11.

Although various minor structural modifications might be suggested by those versed in the art in connection with the preferred embodiment herein described by way of illustrative example only, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come Within the scope of my contribution to the art.

I claim as my invention:

1. A gas burner unit comprising, a generally cylindrical thermocouple generating unit providing a surface at one end adapted to have thermal energy applied thereto and having conductor wires connected thereto at the 7- other end exhibiting-an electric potential in response to the application of thermal energy to said one end, an annular double wall pilot burner member concentrically disposed to said unit and surrounding said one end of said unit to provide an annular air flow passage between said burner member and said thermocouple unit, the end of said pilot burner member outwardly adjacentsaid one end of said thermocouple unit having an inner wall curved radially-inwardly relative to an outer wall of the pilot burner member to provide a recessed areaway around said one end of said thermocouple unit and receiving combustion supporting air from said annular passage, said one end of said burner member having a plurality of circumferentiall-y spaced slots providing pilot gas ports discharging through said inner wall into said areaway forcombustion around the end of said thermocouple unit, means to supplygas to said pilot burner member, and a main gas supply tube extending through said annular pilot=burner member and through said wall for discharging gas fuel adjacent said areaway.

2. In a burner assembly having a combustion chamber, the improvement of-a closed annular hollow ring having appreciable longitudinal extent and extending into said combustion chamber, a thermocouple generating unit adapted to be exposed to thermal energy, means support ing one endof'said unit centrally disposed and concentrically spaced with respect to said annular hollow ring on the longitudinal axis thereof forming an air passage inwardly of said hollow ring, said hollow ring having a curved end wall with a row of circumferentially spaced openings formed therein extending inwardly and rearwardly to direct a gas fuelacross said one end of said thermocouple unit to provide a flame shieldtherefor, means carrying a supply of pilotxburner gas tosaid-ring for combustionat saidcircumferentially spaced openings in said end wall, and main burner gas means including meanstcarrying-asupp'ly of mainburner gas andfurther includin'gsmeans forming an'independent longitudinally extending passage through said ring having an outlet opening adjacent said row of circumferentially spaced openings in said endlwall for carrying a main supply of gas fuel tosaid outlet opening. for combustion in said combustion chamber.

References Cited in the file of thispatent UNITED STATES PATENTS

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