US2190099A

US2190099A - Fluid fuel burner device

Info

Publication number: US2190099A
Authority: US
Publication date: 1940-02-13
Anticipated expiration: 1957-02-13

Description

Feb. 13, 1940. o. w. HAHN 2,190,099

FLUID FUEL BURNER DEVICE Filed Dec. 8, 1934 .2 Sheets-Sheet 1 INVENTOR. Orro W. HA HN ATTORNEYS. V

FBfis, 1940.

0. w. HAHN FLUID FUEL BURNERDEVICE Filed Dec. 8, 1934 2 Sheets-Sheet 2 v INVENTOR. Orv-o W. HAHN ATTORNEYS.

. Patented Feb- 1 1940 I w Fwmrunr. some. mrvrcn on w. Hahn, San Francisco, cane, assignor to Industrial Research laboratories, Ltd., a corporation of Nevada Application December 8, 1934, Serial No. 758,622

9 Claims.

This invention relates to 88s pilot burners generally and has for one of its objects the provision of means associated with the pilot burner tor rendering objectionable air currents'lneiiectiveburner. Other objects will appear in the iollow- 1 ing specification.

In the drawings, Fig. 1 represents a side view of one form of the invention partly in section and partly in diagrammatic form.

Fig. 2 is a sectional view of Fig. 1 taken along 15 the line 2--2 thereof.

Fig. 3 is a plan view oi the device associated with the pilot burner of Fig. 1.

Fig. 4 is a side elevation of a different iorm of device for use in association with a pilot burner. 20

of Fig. 4 as seen at right angles to Fig. 4.

Fig. 6 is a plan view of a device similar to that of Fig. 5, with slots in the top of the device.

Fig. '7 is a side view of a still diflerent form of 25 device from that of Figs; 1 to 6 inclusive, but closely resembling the previous showings in. many respects.

Figs. 8 and 9 are views of another form of the invention.

Referring first to Figs. 1 to 3 inclusive, the gas to the pilot device is conducted through a pipe I having an inlet 2 at one end'and a vertically disposed discharge nozzle or burner 3 at the opposite end, which nozzle is formed with a rein Fig. 1. The nozzle 3 discharges into the lower end of a vertically extending conduit 6 positioned parallel to and alongside a vertically "extending,

open ended tubular body I.

The body I is generally cylindrical incross section and has its two opposite sides formed with longitudinally extending outwardly extending portions 4 providing inwardly opening outwardly extending recesses 8 along opposite inner sides of the c lindrical body, which recesses extend from en to end of the body and are respectively adapted to receive one of the legs of a vertically disposed horseshoe-shaped heat responsive theramostatic element 9 of fiat metal as described and shown in my United States Patent No. 2,064,909,

dated December 22, 1936. The recesses B are sufliciently deep to permit movementoi the legs of the horseshoe-shaped element in a direction outwardly of each other when the inner arch of 55 the element is heated.

Fig. is a side view of the pilot burner device stricted neck and a flaring mouth as indicated (01. lib-117.1)

Conduit 6 is secured along the outside of one or the projections 4 and is open at its opposite ends, the upper open end of said conduit termi hating close to the upper end of body I, while the lower end may project below the lower end 5 of said body or may terminate at some point below the level of the inner arch of the horseshoeshaped element. Intermediate the open ends of conduit 6 is a laterally extending by-pass or duct l0, such as a short open ended pipe that 210 communicates between the interior of conduit 6 and the inside of body I at a point below the inner arch of the horseshoe-shaped element 9. This pipe ill extends at one and through the projection 4 on the body I and is slotted as at II to conform to the recess! to pass the. one leg of the horseshoe-shaped element.

Conduit 6 is interiorly provided with a baflie l2 projectinginwardly from one side to a point opposite the opening of duct III, which bame extends only about halt the distance across the passage through the conduit, so as to direct some of the gas passing through the conduit into duct l0 and to a point below the inner arch of the horseshoe-shaped element where combustion takes place, since air is free to pass into the body 1 through its lower open end and also some air is mixed with the gas at theburner nozzle 3 since the external diameter of the nozzle is smaller than the internal diameter 0! conduit 6. 30,

A portion of the gas also passes out 0! the upper open end of conduit i.

Extending over and spaced above the upper openings of body] and-conduit 6 isa plate of gable-like form comprising oppositely extending downwardly inclined plates l3, l4, the plate I! extending over the body I and plate l4 extending over conduit 8, and the two plates being joined at the apex or the gable at a point above the body 1. 7 Plate I4 is connectedat its portion adjacent its lower edge to the outer side of the conduit, and plate I! is connected to opposite sides of the body I by vertically extending plates l5 extending downwardly from the opposite inclined edges of plate IS. The side edges of plate H are free of any depending plates, thus permitting gas coming out of the open ends of conduit 6 and body I to pass out from under the gable at the opposite ends of the apex of the gable at the connection between plates l3, l4. Also the sides 60.

The construction comprising the conduit 8,

, body i, and its top plates i3, i4, comprises an 'iii integral structure that is supported in proper position relative to nozzle 3 on the outer end of pipe 2&3, which pipe is above and parallel to gas pipe i. The pipes 26 and i are supported at one end by a casting 2i which casting is formed with the inlet 2.

The outer end of pipe 26 is slotted on its upper and lower sides at 23 to receive the lower ends of the horseshoe-shaped element 8, one of the legs oi said element being secured to the outer end of the pipe by a pin 24, and the other leg being pivoted at 26 to the outer end of a shaft 1 or rod 26, which rod passes through pipe 26 and projects from the inner end thereof where it is connected to a spring arm 21 at a point intermediate the ends of the arm. One end of arm 2? is provided on opposite sides with electrical contact members 28, 28' respectively, and the opposite end of the arm is secured at 26 to a block 3i! of suitable electrical insulation material. Block so is suitably secured to the outer side of casting 2i, which casting in turn is sec ed against the outer mde of the furnace wall as indicated, the well being provided with an r pening E8 to pass the pipes I, 20 to the inside of the furnace. The connection between rod 26 and arm's? is suitably insulated at 32.

Eetween pipes i and 20 is a tube 33 of electrical insulation and refractory material, which tube-extends through casting 2! at one end to outside the furnace and the opposite end of the graatically shown at '46, together with an tube terminates adjacent the body 'i, said tube being secured'ln spaced relation to pipes l and as by suitable clamps 34', which clamps also serve. to, hold. said pip s rig d in properly spaced relatlon.

The tube 33 carries through it a relatively heavy electrical conductor 36 of non-corrosive;

heat-resistant material, the one end of the conductor being secured at to the'casting 2i outside the furnace, and the opposite end of the conductor extending upwardly alongside the body l and terminating at its 'upper end close to the upper open end of said body but with a gap between the body and the termination of the con-' ductor so that a spark across the gap will ignite the gas should'the burner be extinguished for any reason. .An insulating member 31 is provided alongside the body I through which the conductor passes, which member is secured to the body by any suitable clamping means such as clamp 68 and screws 69, as best seen in Fig. 2.

Block 30'on casting II is provided with a pair I of electrical contact members 40, 4| positioned respectively on opposite sides of contacts 26, 28', which contacts 40, are suitably secured to block 80 by suitable posts 40', 4| respectively. When the pilot burner is extinguished, or the flame is not in the zone below the inner arch of the horseshoe shaped element 6, the contacts.

as, M are in engagement. This condition also when the pilot and furnace generally are not being used, as insummer time, as willlater he described.

The :u 1 gas burner of the furnace is diaa line from the transformer, indicated at 6|, connects with one of the terminals oi the solenoid of valve 46 and also by a branch 6| with one oi .the terminals of a primary coil in box 62. The

opposite terminal of the primary coil connects by line It with terminal 4| through post 4!. One

' terminal of a secondary coil in box 52 connects with the inner end of the conductor 36 at a point outside the furnace by line 64, and the other terminal of the secondary coil is grounded at 66.

Casting 2| is grounded at 66. The conductor 36 is, of course, suitably insulated from the casting.

The contact 40 is connected by line 58 with one of the terminals of a temperature responsive thermostat 51, positioned in one of the rooms of the building the furnace is intended to heat, and the opposite terminal of the thermostat connects by line 58 with the, other terminal of the solenoid valve. A suitable switch 66 may be provided on the incoming power lines 48.

controlling the flow of gas to the main valve is controlled by temperature variations in the ate mosphere in the rooms of the building, and closes by means of a spring, as is common in the art, when the electrical circuit is broken.

In operation, when the gas pressure in the lines is normal and safe, and the pilot is lighted, combustion takes place within the body I at a point below the inner arch of the horseshoe-shaped element 9 and also at the upper end of conduit 6, the flame being directed by the covering plates l3, M in opposite lateral directions from under the apex of the covering plates so as to direct the flame to burners on either side of the body.

Air for combustion of the gas passes into the conduit and body 1 through their lower ends respectively as already described.

- when the flame is burning normally below the inner arch ofthe horseshoe-shaped element, the inner edge of the element is always heated more than the opposite edge, and the legs of the element tend to move apart, thus the contact 28 is moved to engagement with contact 40 and the circuit is closed through thermostat 57 and the valve 46 and transformer 49, it being assumed that switch 60 is closed. Thus the valve 46 is free to open and close under control of the room thermostat.

Assume that the pilot flame is extinguished, by blowing of the gas under sudden excessive pressure or by failure of gas or for any other reason, the heat being removed from under the arch of the horseshoe-shaped element will result in' the legs thereof coming together upon cooling of the element and contacts 46, 28 will be broken, while contacts 26', 4| will be made. Thus the circuit through the coil in box 52 will be made and sparks will be produced at the upper end of body 1 to ignite the gas as soon as the flow is resumed. The relative movement of the legs of the horseshoe-shaped member is very rapid, and only from.

about 6 to 8 seconds elapse after extingulshment and while the lire box is intensely hot.

It is manifest from the foregoing that the main gas valve 46 cannot possibly be actuated, other than manually, when the pilot burner is extinguished, since the circuit thereto is broken until reestablished through actuation of the horseshoe-shaped element.

It may now be assumed that the gas pressure drops to say about 1 inch of water, which is unsafe for furnace burner operation. This. results or the open upper end orthe conduit. since the baine therein is not sufliclent to direct the gas into the body I. The flamethus beingremoved from below the innerarch of the horseshoe-shaped element, the circuit through the solenoid valve is broken, thevalve is automatically closed, and

allgas to the main burner is cut 01! .until the gas pressure is increased sufliciently to make ignition safe. I on the other hand, should there be an abnormal increase in gas pressure, the point of combustion of the gas in body 1 rises and'the combus tion takes place'at the upper ends of the body and conduit 6. Such increase sometimes results in ,the main burners being extinguished, with disastrous results. Immediately upon the cone of combustion rising above the inner arch oi the horseshoe-shaped element said inner arch is cooled relative to the'outer archand the leg oi 5 said element that is connected to rod 20 moves toward the opposite 'leg or the element and the circuit through the solenoid valve is broken at

contacts

28, 40 andfthevalvefis automatically closed as by the.heretofore-mentioned spring in solenoid valve it until asafe gas pressure is reestablished. However, the pilot will not ordijnarily be extinguishedupon such rise, since the as is deflected byIthe covering plate and there is adequate air to,.promote combustion at the upper open ends 01' the body 1 and conduit 8, and

the electric spark between the conductor 38 and the body wouldbe eflective in any eventto ignite gerous condition existing in the furnace and to automatically reestablish the desired normal operation of the main burner when the gasflowis rod connected to the leg of the thermostaticelw within safe limits. Inthe drawings, Fig. 1, it is thought clear thatthe gas line 41 leading to the main gasburner and inlet 2 to the pipe lleading to the pilot burner are connected with a commo'n source of gas supply as through pipe 41".:

In Figs.4 and 5, the same electrical'hook-up including conductor 36 is used as in Figs. 1 to 3,'a 3 showing of the circuit and various electrical con-" tacts and conductor 36' not being necessary, since such showing would be merely a duplication of elements already shown, the adaptability being obvious. a

In Figs. 4 and 5 a pilot burner}! extends into I the cylindrical bore of a body member 1. Recesses 8' are formed onopposite inner sides or said body within portions 4' thersame as in Figs.. 1 and 2. However, there is no separate conduit in thedevice of Figs. 4 and 5. 'The body 'I' is transverselyslotted along opposite,sides as at B2 and '63, slots 62 being below the discharge end of the gas pilot burner and slots 63 being above the discharge end of the burner, while the space between the slots is imperiorate. The covering plate in this form of device is aninverted V- shaped, roof-like hood 8! connected at the lower edges of the hoodto opposite sides of the body 1'.

The gas is free to pass out from under the hood at opposite sides for directing the name to main burners at either or both sides of the body 'I'.

This hood can be disposed across the top of body I at right angles to the position shown, so as- 'to .direct the gas at a different angle such as in Fig. '7, or the hood may have slots therein as at 65 in Fig. 6. In Fig. '7 a slot 66 is shown along the apex of the walls of the covering plate andthe in the gas in theconduit t passing directly out .-locity 01 15 miles ,The end of pipe 26' on which;

apex is slanted. Many such variations may be tohow it indciired that the name be directed; T-Attention is alsocalled, to the fact that the-slots II in' liga tand Bmay be eliminated, as in Fig. 7, where slots 86' are at the bottom of the body 'I" and varyinwidth." These slots may be disposed in one position or another along the sides according to the character of the gas that is being used,'and,a diagonally extending slot 63' relative toslotsll greatly assists. in ignition or the gas. Q W

I have found that with the use of :thevarious devices-disclosed that enclose the pilot -burner, there is little ii any objections! eflect on the flame from external air currents, and a pilot suchas shown in 'Flg. 4 burning about 24 feet of gasper 24 hour day will continue todirect the pilot flame under the element 9 in 'a side wind having a vefeature, since a steady flame is desirable in order to properly restrict the flame to a fixed zoneand the .backfiring, or sudden ignition orextinguishment of the flame with abnormal ior'ce does not aiiect the pilot flame with my'devicec In the devices of Figs.' 4% m n isnianifest that the same control 0! the main gas valve is'obtained in the event of excessgas pressureas in the devices of Figs l and}; although :for low pressure it is notas accurate, except where there is insuflicientgas to maintain the pilot lighted,

per hour. This is an important since the'ilame is always-directly under the inner arch o1 element '9. a. a r

It might also be noted that-the pilot burner enclosing bodies 1 to I' are iormed'to coact with the element syfor positioningjsaid bodiesrespec- I tively and retainingthemdn proper-relation to the pilotburner and said "bodies are "easily re- "movablemerely by slipping them on the element 9 for adjusting crreplaci'ng-the' pilot; burner.

It is also apparent-that the movement oi' the actuate someother device.-

The deviceoi Fig. 8 shows a fox-moi theinvem tiongpartly in section and partly broken away and in section in which the gas supply line and operating rod 2! are enclosed withiira large pipe 20', which pipe extends to the outside .ofthe furnace wall at one endat .70; :This pipe 2|! may be a casting if desired, withs flange H thereon ior securing to the furnace walf'and fox-"supporting the block 3i! otinsulating material at the outer end thereof. on aplate ll secured-tothe outer end of pipe portion ll. This block"! supportsnelectrical contacts similar to thou shown in Fig. 1. the tubular body enclosing the element I is positioned is closed as at T0, by aplug or other closure.

.In this form ofthe invention the tubular body member 18 corresponding to the body I of Fig. 1 or the bodies I, l" ot Flgs. 4 to (is formed with holes It along the sides instead of slots, andthe lower end or the bodyis formed tom; the curva- ,ture of pipe 20' with an enlarged opening in the upper side of said pipe as defined by edge 15 indicated in Fig. 8 to pass the legs of the element l and a pilot burner. 11 that connects with the outerend oi thegas conduit. The burner 11 is tubular in shape as indicated, and extends"upwardly between the legs of element 9. Thusthe only admission ofkair inside the furnace to-the gas outlets of burner 11 for promoting combustion of the gas is through holes 16 and under the since the lower end of the body is pipe 20' onwhich the bodyis supplate 84', blocked by ported.

The burner I1 is of tubular form and is bent laterally at a point under the inner arch of elethe element 9 if the and also furnishing disposed within said tubular body aperture at a point spaced from the ends thereof,

ment 9 as at 19 and then is straightened vertically to extend alongside the arched portion of the element to terminate in an open upper end at a point slightly above the upper openend of the body. The upper side wall of the bent portion i9 is provided with a relatively small opening ,80 positioned directly below the inner arch obthe element 9. V

actual practice and under normal conditions a relatively large flame will be produced at the upper open end of the burner for igniting the gas of the main burners, such as 45 in Fig. 1 (not shown in Fig. 8) aperture to keep the inner arch of element 9 heated more than the outer arch and thereby maintain the legs apart in expanded position for actuating the contacts on block 30 the same as described for Fig. 1. V

With the structure as above described, in the event of a suddenback-flring or blowing of the main burners when coming on or when going out, there is an abnormal disturbance of currents within the furnace, such as the creation of a vacuum, which many times would extinguish the pilot burner and cause undesirable actuation of against such conditions. To overcome this, the portion Ill of the pipe supporting the body 15 is provided with air inlets 8| which will admit air from outside the furnace at all times, these inlets coacting with holes 16 to maintain a proper air mixture within body 15 under normal conditions,

ever the above indicated abnormal conditions exist. The body 15, of course, also acts as a shield to minimize the eflect of such abnormal conditions.

It is thought obvious that theformation of the pilot burner itself acts similar in certainrespects to the form of the invention shown in Fig. 1, in that the aperture 80 is so proportioned that adecrease in pressure in the gas line to say 1 inch of water, will result in the flame at aperture so being substantially extinguished, the main flow of gas going out of the open end of the burner. Thus the heat will be removed from under the inner arch and the element 9 will move to actuate the main gas valve through electrical connections and contacts as described in Fig. 1.

Having described my invention, I claim:

1. In combination, a vertically positioned tubular body, a pilot burner having a flame aperture in a gas pressure line, said pilot burner being with its flame the walls of said body being imperforate at the level of said flame aperture ior shielding flame developed at said aperture against side drafts, a

cover plate over the upper end of said body formed to provide a laterally directed flame outlet at the side of the body at its upper end and to dampen the effect of vertical drafts and an air inlet at the lower end of said body. below said flame aperture for admitting air to said body for mixing with gas from said aperture'to normally promote combustion within the upper end of the body below the flame outlet, means enclosed within said body below said flame outlet and extending over said flame aperture responsive and a small flame will burn from burner were not protected ample air to the pilot whento heat developed at said flame aperture for movement for doing work.

2. In a device 'of the character described. a shield for a pilot burner comprising 0. vertically disposed tubular hollow body having an air inlet at its lower end and open at its upper end and formed to admit the upper end of a vertically disposed tubular pilot burner through the lower end to within the body, a cover plate extending over the upper open end of the body of substantially inverted V-shape forming a gable-like hood over the body providing flame outlet under the ends of the hood, the side walls of said body being provided with laterally directed air inlets adjacent the upper end thereof below the aforesaid flame outlets, said side walls being imperforate for a substantial distance below said latorally directed air inlet for insuring a space within the body against the influence of side drafts.

3. In a device of disposed, open ended tubular member, an inverted U-shaped hood over the upper open end of the member, said member having openings formed in the walls thereof and the walls having vertically extending inwardly opening channels on opposed sides thereof, a thermo-responsive element slidably fitting within said channels and extending across between the inner opposed sides of said member, a pilot burner extending vertically within said member, said pilot burner having a flame outlet positioned below the portion of the element that extends between the sides of said member.

4. A device of the character described comprising a substantially horseshoe=shaped thermoresponsive element, a tubular body substantially enclosing said element with the arched portion of the element extending transversely across the bore of the body at one end thereof with the ends of the legs of said element at the opposite end of the body, one of the sides of said body being formed to provide spaced. guide means adapted to slidably receive the outer edge of one of the legs of the element therein for preventing relative rotation of the element and body about the axis of the bore of the body, the opposite ends of said body respectively being provided with an opening and gas supply means with the body adjacent the inner side of the arched portion of the element for supplying a gas flame to the arched portion for heating said arched portion.

5. A device of the character described comprising an elongated, substantially cylindrical tubular body formed on opposite inner sides thereof with elongated recesses extending longitudinally of the body, a horseshoe-shaped thermoresponsive element within said body with the legs thereof disposed within the recesses and across one end of the bore of said body between the recesses and the ends of the legs projecting outwardly of the opposite end of the body, a gas burner having a flame aperture, said aperture being positioned adjacent the inner side of the arched portion of the element between the legs of the arched portion for supplying a flame for heating the arched portion of the element.

6. In a device of the character described comprising a generally vertically extending tubular body, having a vertical bore therein extending from end to end and the ends of said bore opening outwardly of the body at the top and bottom the character described, a shield for a pilot-burner comprising a vertically the arched portion of the element extendingends thereof, a thermoresponsive element positioned within said bore and extending transversely ,thereacross adjacent the upper endof the bore, means for a conduit for conducting fuel gas into the bore, said conduit being provided with a pair of flame apertures respectively positioned above said element and below said element and the upper aperture being formed and positioned to directly produce a flame at said aperture at a point outwardly of the upper end of saidbore and. the lower flame aperture being adapted to produce a flame at a point within the bore of said body for heating said element.

7. In combination, a fire box having a generally vertical side wall, a generally horizontally extending air conduit extending from said wall inwardly into the fire box, said air conduit being provided with an air inlet at one-end opening outwardly of said wall and upwardly directed air outlet at the opposite end within the flre box, a generally vertical open-ended tubular housing supported on said opposite end of mean conduit with its lower open end over said air outlet, a

7 gas supply pipe within said air conduit extending outwardly thereof at one end outwardly of said wall and provided with a vertically extending tubular gas pilot burner at the opposite end disposed within said tubular housing, a thermoresponsive element within said housing positioned over said pilot burner to receive heat from the burner when the latter is ignited and responsive to changes in temperature for movement, a member connected to aid element for movement therebyupon movement ofthe element in response to changes in temperature, said member being disposed within said air conduit and extending outwardly thereof and outwardly of said wall, gas control means outwardly of said wall, and gas control operating means connecting between said member and said gas control means for actuating the control means upon movement of the member to control the flow of gas to said pilot burner" said pilot burner being formed with a flame aperture adjacent the upper end thereof and an opening in the wall of said housing at a point below said flame aperture for admitting air from the firebox to said burner in addition to the air entering said air conduit.

8. In combination, a gas supply pipe provided with a gas outlet, a generally vertically extending tubular pilot burner extending from said outlet provided with a pair of flame apertures at different heights, one being, lower than the other, said burner having a through passageway fromsaid outlet to the uppermost aperture with thelower aperture communicating with said passageway, a thermo-responsive element, positioned to receive heat developed from a flame at the lower aperture of the pair whenthe gas is ignited at said aperture, but out of direct influence of flame at theupper aperture, said element being responsive to heat developed at said lower aperture for movement for doing work, a cover plate extending over and spaced above said pair of apertures and generally vertical walls enclosing said apertures and depending from and supporting said cover, said walls and cover forming a housing and said housing having a laterally directed opening at substantially the level of said upper aperture and substantially at the juncture between the cover and said walls for emission of flame from said upper aperture.

9. A device of the character described, an elongated tubular gas pilot burner provided with a single, continuous through passageway and a flame aperture at one end and-a gas inlet at the opposite end, a second flame aperture communicating with said passageway and positioned between the inlet and the flame aperture at said one end, a thermo-responsive element disposed over said second flame aperture responsive to heat from a flame at said second aperture, the

walls of said passageway being formed adjacent the point of communication of said second aperture therewith to deflect a portion of the gas passing through said passageway toward said second flame aperture and the portion of the passageway'between said second flame aperture and the aperture at the end of the burner being offset to one side of the said element and extending past said element for conducting the gas therein past said element, means substantially enclosing said thermo-responsive element and said second flame aperture and a flame deflecting cover plate spaced above and extending over both of said flame apertures.

'1'1'0 7W. HAHN.