US1943632A

US1943632A - Liquid fuel burning apparatus

Info

Publication number: US1943632A
Authority: US
Publication date: 1934-01-16
Anticipated expiration: 1951-01-16

Description

Jan. 16, 1934;

-w. J. sMH'H LIQUID FUEL BURNING APPARATUS I Filed June 24, 1931" 5 Sheets-Sheet 1 r ATTORNEYS R o T N E V m Jan. 16, 1934. w J s n' LIQUID FUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 2 WI i/2 INVENTOR r/Wo ATTQRNEYi Jan. 16, 1934. w. J. SMITH LIQUID FUEL BURNING APPARATUS Filed June 24. 1931 5 Sheets-Sheet 3 7 ATTORNEYS 61 INVENT R 4/44 4. I BY Jan. 16, 1934. w. J. SMITH 1,943,532

LIQUID FUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 4 F 13. INVEN OR W f Mb ATTORNEY5 .Jan. 16, 1934. w, J, SWTH 1,943,632

LIQUID FUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 5 lent explosion occurred.

Patented Jan. '16, 1934 UNITED STA LIQUID FUEL BURNING APPARATUS William #1. Smith, Lakewood, 01110, assignor to Cleveland. Steel Products Corporation, Cleveland, Ohio, a corporation of Ohio Application June 24, 1931. No. 546,504

11 Claims. (Cl. 175-415) This invention relates to liquid fuel burning appa'ratus and more particularly to means for igniting the fuel. It is well known that the best and most eflicient means for igniting liquid fuel is an electric spark but, in spite of this fact, no safe and practical means for making use of the electric spark for igniting liquid fuel has been heretofore developed for use in connection with liquid fuelburnera-such as furnaces. In many types of liquid fuel burning devices, especially those making use of a fuel distributing fan or blower, a fine mist of liquid fuel is discharged against a refractory member and the fuel so collected on this member is ignited.

One'disadvantage heretofore encountered in the use of spark gapelectrodes is that the elec-, trodes were not properly arranged with respect to the hearth and would become shorted, due to carbon deposits, and when the demand was made for heat the liquid fuel gasified upon its contact with the refractory member if it was hot and as a result when the electrodes eventually did spark upon the breakage of the carbon deposits, a vio- One of the objects of the present invention is to provide spark ignition means for usein connection with liquid fuel burning apparatus which will function quickly and eflicientl y without danger of explosions resulting from theiroperation.

Another object is to provide a liquid fuel burn-- ing apparatus with a simple and efllcient spark ignition means which can be economically pro- .duced and easily assembled.

Another object is to provide liquid fuel buming apparatus of the rotary fuel discharge type with sparkignition means which will functionat all times during normal operation of the apparatus, and will produce an igniting spark at the proper location.

Another object is to provide liquid fuel burn? ing apparatus with a spark ignition means so arranged as to substantially eliminate the difllculties heretofore encountered by reason of the ing certain of its electrodes. mounted for substantial movement after the fuel. has been ignited. With the above and other objects in view, which will be apparent from the following deand shown in section to illustrate the application tailed description, the present invention consists in certain features of construction and combinations of parts which will be readily understood by those skilled in the art to which the invention appertains.

In the drawings, which illustrate suitable emm bodiments'of the invention,

Figure 1 is a perspective view of a furnace construction, portions of the same being broken away of the present invention thereto;

Fig.2 is an enlarged fragmentary inner elevation of the hearth segment showing the spark ignition device attached thereto; a

Fi 3 is a fragmentary plan; view of the ap- To paratus shown in Fig. 2;

Fi 4 is a section taken substantially on line H of Fig. 3, the normal position'of one of the ignition electrodes being shown in broken outline;

showing a modified mounting means for one of the electrodes, the operative po'sition'of the electrode being shown in broken outline;

Fig. 12 is a section taken substantially on the line 12-12 of Fig. 11; Fig. 13 is atop plan view of a further modified mounting for one of the electrodes;

Fig. 14 is a section taken on the line 1km of Fi 131',

Fig. 15 is a section through a hearth segment showing another meansof mounting the electrodes;

Fig. 16 is a Plan View of the apparatus shown in Fig. 15; and

Fig. 1'! is a transverse section through a hearth ring showing the use of further modified electrodes;

Referring to the accompanying drawings, in which likenumerals refer to like parts throughout .the several views, the apparatus of the present invention is shown in connection with a-liquid fuel burning apparatus of the rotary fuel discharge type. It is to be understood, however, that *the present invention is adaptable to liquid fuel burning devices of types other than those shown in the drawings I In the type of liquid fuel burning apparatus showninl'lglmdtakenforthepurposeofib. lustration, the furnace 1 is provided with a continuous hearth segment 2 of suitable refractory I Figs. '5 to 10, inclusive, are wiring diagrams "f material whichis supported well above the base of the structure'on a bed 3 of refractory material that .is carried by a hearth pan l. The hearth pan '4 extends completely across the furnace l and is suitably supported at its periphery.

In the construction shown, the hearth segment 2 is preformed and is preferably provided with an endless channel or recess 5 of suitable shape which opens inwardly and upwardly to provide a suitable face against which the liquid fuel may be discharged.

The liquid fuel is fed from a source of supply through control valves 6 to a feeder line 'i that is in communication with suitable distributing mechanism 8. The distributing mechanism 8 includes a motor driven fan 9 that is horizontally mounted above the refractory bed 3 and which is arranged to distribute the liquid fuel in a suitable spray or mist against the wall of the continuous recess 5.

The present invention has to do with the means for igniting the liquid fuel as it is initially discharged against the face of the hearth segment when the distributing apparatus 8 is set in operation by the demand for operation by the control mechanism ii (not shown in detail).

The present invention provides a practical,

eillcient and safe means for spark igniting the fuel, in which precautions are taken to guard against explosions.

In heretofore known liquid fuel burning devices employing spark ignition there is a considerable tendency for the electrodes to become shorted-by the accumulation of carbon deposits, with the result that, in the case when the hearth .segments become warm or hot, the fuel, upon distribution against the hearth segment, may gasify. The carbon deposits may be broken away by the weight of the fuel which is impinged thereon, and this will allow a spark to pass between the electrodes, with the result that the vaporized fuel will suddenly explode with great force. It is thus obvious that precautions must be taken that the electrodes or igniters will always spark at the instant when the fuel distributing mechanism is set in operation by the demand for heat. I

In the drawings different types of ignition devices are shown, any one of which may be under control by various electric hook-ups. These different types, however, regardless of the type of electric hook-up used, are arranged to provide safe and unfailing operation whenever the demand for operation of the fuel burning apparatus is created.

In some cases, such as in small furnace installations, it may be desirable to use a single .spark ignition device, whereasin other cases it may be desirable to use two or more devices.

In Fig. 1, and as shown in Figs. 5 to 10, inclusive, two such ignition devices are shown mounted diametrically opposite each other.

Referring to Figs. 1 to a, inclusive, each ignition device includes a. pair of

electrodes

10 and 11 carried by the hearth segment 2 and spaced to obtain the best and most efficient spark.

The electrode 10 comprises a body of suitable heat resistant material, such as carborundum cement, mounted within a recess 12 formed in the segment at the inner side thereof, the body.

being preferably recessed out in the same manner as the recess 5 to provide continuous surfaces. The body 10 should, for the most efficient operation of the apparatus, terminate substantially at the face of the recess 5. It is to be understood, however, that'the body may terminate slightly inwardly or outwardly of the face of the recess 5 without departing from the spirit and scope of the appended claims.

An electrode rod 13 of steel or other suitable conducting material is embedded in the body 10 and extends downwardly through the hearth segment 2. The portion ofthe rod 13 extending beyond the segment 2 is enclosed within asuitable insulating tube 14 which preferably extends intothe hearth segment.

The electrode 11 which. as shown in the drawings, may be in the form of a bar of suitable heat resistant material, is mounted on asupporting head 15 that is carried at the end of an electrode rod 16. The electrode rod 16 is also mounted within an insulating tube 17 that extends through a flange 18 formed on the hearth segment 2 at the inner side thereof. The electrode 11 extends over the innermost portion of the segment 2, substantially into the recess 5, and is arranged at an angle to the radius of the segment in order that liquid fuel may be distributed without hindrance against the walls of the recess formed in the electrode body 10. The insulating

tubes

14 and 17 may be clamped against rotation by means of a suitable clamp 19 arranged at the lower side of the segment 2.

When a single ignition device is used, such as in small furnace installations, the

electrode rods

13 and 16 are connected through suitable 'lead wires to the secondary winding of a suitable transformer.

When two or more ignition devices are used, such as in large furnace installations, the ignition devices may be connected in parallel and connected with a suitable transformer, 20, as

shown in Figs. 5, 6 and '1, or they may be connected in series and connected with the transformer 20, as shown in Figs. 8, 9 and 10.

In the wiring diagrams Figs. 5'to 10, inclusive, the electrodes of one ignition device are designated as 10 and 11 and the corresponding electrodes of the other ignition device are designated as 10 and. 11, the other parts being corre= spondingly numbered.

Referring to Fig. 5, the electrode 10 is connected by a suitable lead wire 21 to a pole 22 of the secondary winding 23 of the transformer 20, and the electrode 11 is connected by a suitable lead wire 24 to the other pole 25 of the secondary winding 23. In a similar manner, the electrode 10, which corresponds to the electrode 10, is connected by a lead, wire 21 to the pole 22 of the secondary winding, and the electrode isl which corresponds to the electrode 11 by a lead wire 24 I to the pole 25 of the secondary winding. It will be noted in this hook-up that if the electrodes of either of the ignition devices are inoperative, the other electrodes will function as soon as a demand for ignition is created. This installation insures the passage of a spark between the electrodes of either one or both of the ignition devices.

Referring to Fig. 8, the electrode 10 of the on ignition device is connected by a lead wire 26 to the pole 22 of the secondary winding, and the electrode 10 which corresponds to the electrode 10, is connected by a lead wire 27 to the other pole 25 of the secondary winding 23. The

electrodes

11 and 11 are directly connected with each other by means of a lead wire 28. In this installation the two ignition devices are in series and it will be noted that if the electrodes of one of the devices is shorted, the current will flow 156 1,943,032 therethrough to the other device, with the result of the electrode 11 in order to obtain the proper is provided at the upper end of the electrode rod spark gap is provided for by loosening the nut 30 and rotating the rod 16. The stationary arrangement of the electrode 11 is not shown in the drawings, but it is obvious that this may be obtained by merely lengthening the insulating tube 1'7 to bring it into engagement with the head 15.

Modified arrangements oi the electrodes are shown in Figs. 15 to 1'7, inclusive. In Figs. 16

and 15 the

electrode rods

31 and 32 are arranged side by side at the inner side of the hearth segment 2. These electrode rods 31 and 32-are surrounded by suitable insulators 33 and 34 which extend through an oiiset portion 36 formed at the inner side of the hearth segment 2. One

electrode 37 inthe form of a suitable block is mounted inthe segment 2 in substantially the same manner as the electrode 10, and the electrode rod 31 is bent over and embedded in a portion of the electrode body 3'7; The electrode 38 32 in the proper sparking position with respect to the electrode 37.

In Fig. 1'? the electrode rods 39 and .0 are mounted in suitable insulating tubes 41 and 42, respectively, the tube 41 being extended into the body of the hearth segment 2. One electrode 43 in the form of a suitable rod or bar is joined with the rod 39 and is positioned'within an opening at formed in the segment 2 and opening at the face of the circumferential recess 5. The electrode 43 preferably extends to and terminates at the edge of the opening 44.

The other electrode 45 is attached to the electrode rod 40 in a manner similar to the electrode 11 first described.

The electrodes shown in Figs. 15 and 1'7 may be connected with a suitable transformer in any of the manners previously described or in any other desired manner.

The

electrodes

11, 38 and 45 shown in Figs. 4, 15 and 17, may be of any suitable material, and furthermore may be of any suitable shape, such as a rod, bar or strap.

This invention further contemplates, in cases where desired, the provision of means for moving one of the electrodes of each ignition device relative .to the other in order to doubly insure sparking across the gap between the electrodes at the time the demand for operation of the apparatus isv created.

One means of accomplishing this object is shown in Fig. 4. Asshown in this view, the electrode rod 16 is made of a material having a low ironcontent and is'of greater length than the surrounding insulator tube 1.7- in order that the rod 16 and consequently the electrode 11 may be moved-relative to the tube 1'7. Movement in this case is provided by means of a suitable solenoid 46 surrounding the insulator tube 17, which attracts a suitable soft iron core '16 secured to the end ofthe rod 16. In operation, the solenoid, at

the time the demand for operation of the apps ratus is created, moves the electrode 11 from its normal position to the sparking position shown in solid outline in Fig. 4. As'soon as the sparking period is terminated, the supply 01' electrical energy to the'solenoid is cut off and the electrode 11 then drops back by gravity to the normal position shown in broken outline in Fig. 4. The electrode rod 16 may be of sufiicient weight as to drop back to the inoperative position or, if desired, ad-- ditional weights may be attached to the rod 16 or in some cases a spring arrangement may be pro vided to cause the rod.16 and electrode 11 to assume the position shown in broken outline.

' A suitable cap 47 may be arranged over-the head 15 to telescope with the projecting portion of the insulator tube 17 in order to exclude dirt,

liquid fuel, and other foreign matter from the rod v16. Suitable guides are provided to prevent turning movement of the electrode rod 16 relative to the axis of the tube 17, and this maybe accomplished in any desired manner such as forming depressions as in the upper end of the tube 17 which may receive guide ribs 49 formed on the inner surface of the cap 4'7.

In Figs. 11 and 12 a modified arrangement is shown for moving the electrode 11 relative to the electrode 10. In-this arrangement the electrode rod 16 and insulating tube 1'7 are rigidly held together against relative movement, and the complete electrode assembly is mounted for bodily tilting movement transversely of the axis thereof.

One means for accomplishing this tilting move ment is to provide a sleeve 50 about the tube 17, which has oppositely disposed pivot pins 51 thereon arranged to seat in the depressions 52 formed in the hearth segment 2. A suitable protector 53 'is provided to protect ,the pivot pins 51 from dirt and the like. In the normal position, the electrode assembly is maintained in a vertical position by gravity, in which 1))Sltl0l'l the electrode 11 is .out of its sparking position as shown in solid outline in Fig. 11. A suitable weighti'v may be mounted on the tube 17 to insure a vertical position of the electrode assembly.

In order to pivotally move the electrode assembly to-the operative position where a spark may be passed between the

electrodes

16 and 11, a solehold 54 or other suitable means may be employed to attract a core 54 carried by a sleeve 55 that is clamped to the insulator tube 1'7, and thereby swing the assembly about the pins 51 as axes to the desired sparking position indicated in broken .outline in Fig, 11. Means other than the electro: magnets 54 may, However, be employed to provide the desired pivotal movement.

In Fig. 13, electromagnet means 56 is shown for causing a rotational movement of the electrode rod 16 in order to movethe electrode 11 relative to the electrode 10. As shown in Fig. 14, an arm 57. may be'attached to the lower end of the rod 16 which carries a core 5'7 that may be attracted by the magnet means 56. Means other than the magnet 54 may also be employed to impart the desired swinging movement to the and 13, the electrode 11 is movable with respect to the electrode 10 after the ignition period is over. Assuming for the purposes of illustration that the

electrodes

10 and 11 are sparking and that they may become shorted by reason of carbon deposits, then they will no longer spark. The

' current may, by the operation of the system, then be cut off by the control mechanism, and as soon as this occurs the electrode 11 bodily moves relative to the electrode 10 with the result that the carbon deposit is broken.

Now assuming that the electrode 11 is in its normal position and a carbon deposit has accumulated on the electrodes to such an extent as to close the gap, then in this case as soon as the demand for ignition is created, the electrode' 11 moves and breaks the carbon deposit, with the result that the electrodes will spark immediately and coincident with the starting of the liquid fuel distributing mechanism 8,'and will immediately ignite the fuel that is dispelled against the hearth segment 2, and incidentally against the electrode 10. i

In constructions heretofore known, the electrodes may become shorted by reason of the deposit of carbon across the spark gap when the system is normally inoperative, with the result quantity may collect on the carbon deposit tocause the deposit to break away from the electrodes. The result is obvious. since the electrodes 1 will then spark and as a result the gasified fuel will be ignited and produce a violent explosion, the consequences of which may be very disastrous.

It is thus seen that the device of the present invention will overcome the disadvantages heretofore known, and will provide a safe-and efficient ignition system'for liquid fuel burning apparatus.

Several different methods of connecting the solenoid 46 with a source of electrical energy may be employed.

Referring to Fig. 5 which is a wiring diagram for the apparatus when two ignition devices are employed. the solenoid coils 46 and 46' may be connected in series with the transformer 20. The solenoid coils 46 and 46': of the two ignition devices are connected in series by the wire 59, theremaining end of the one coil 46 being connected by a wire 60 into the hot line 61 of the electrical energy supply, and the'other solenoid coil 46 being connected by a wire 62 to, the primary coil 63 of the transformer. In this circuit it will be seen that if either of the solenoid coils becomes inoperative or burned out, the supply of energy to the other and to the electrodes is immediately cut off. If only the one ignition device is used the wire 59 may be connected into the circuit in the same manner as the wire62.

Referring to Fig. 6, the solenoid coils 46 and 46 are connected in parallel with the energy or temperature

responsive wires

65 and 66 directly with the

main supply lines

61 and 64, respectively, and the solenoid coil 46'- is connected by wires 65 and 66' directly with the

main supply lines

61 and 64, respectively. In this circuit the electrodes are all connected in parallel with the secondary winding of the transformer. It is obvious that if either of the solenoid coils burns out or is broken the other will properly function. Referring to Fig. '1, the solenoid coils 46 and 46" are connected in multiple series with the transformer 26. The coils 46 and 46'- are con-' nected together by the wires 6'? and 68, the-wire 68 being connected into the hot supply line 61 in advance of the transformer by the wire 69,

function independently of each other, and that each ignition device will function independently of the other.

In Figs. 8. 9 and 10, the circuits for the solenoids are the same as the circuits for the sole-- noids in Figs. 5, 6 and 7. respectively, the only difference in the circuits being that the electrodes in Figs. 8, 9 and 10 are in series instead of in parallel, as shown'in Figs. 5, '6 and '7.

It is obvious that other combinations of circuits for the ignition devices and the solenoids may be employed, if desired. v

Many advantageous features are present in this invention that are not present in liquid fuel burning devices heretofore known, and it is possible in the use of the various structuresand circuits therefore shown and described herein, to use a spark ignition apparatus for fuel burners which is eilicient in operation and which can be safely used without danger of explosions resulting from the deposit of carbon on the electrode.

It is to be understood that in some cases the electrodes may both be rigidly held against relative movement and that in other cases it may be desirable to mount one of the electrodes for movement relative to the other, as previously described. a

Aside from the specific embodiments of the herein shown and described invention, it will be understood that numerous details of the embodiments may be altered or omitted without departing from the spirit and scopev of this invention, and that I do not desire to limit the invention to-the exact constructions herein set forth, as I desire to claim the invention broadly as well as specifically as indicated in the appended claims.

What I claim is:

1. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap across which a spark may be passed to ignite the fuel, and means for moving one of said electrodes relative to the other and into an eflicient sparking position spaced from the other when the fuel is to be ignited. and for maintaining said last mentioned electrode in such position during the ignition period.

2. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap for maintaining said electrodes in such relation during substantially the entire ignition period. 1

3. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap across which a spark may be passed to ignite the fuel, electrical means for bodily moving one of said electrodes'relative-to the other at the time ignition of the fuel is desired to bring said electrodes into spaced sparking relation and for maintaining said electrodes in such relation during substantially the entire ignition period, and means for returning the said one electrode to its initial position after the ignition period is terminated.

4. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap across which a spark may be passed to ignite the fuel, means for bodily tilting one of said electrodes relative to the other at the time ignition of the fuel is desired to bring said electrodes into spaced sparking relation and for maintaining said electrodes in such relation during substantially the entire ignition period, and means for returning the said one' electrode to its initial position after the ignition period is terminated.

5. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap across which a spark may be passed to ignite the fuel, means for rotating one of said electrodes relative to the other at the time ignition of the fuel is desired to bring said electrodes into spaced sparking relation and for maintaining said electrodes in such relation during substantially the entire ignition period, and means for returning the said one electrode to its initial position after 6. In a liquid fuel burning apparatus, ignition means comprising a hearth member, an ignition electrode mounted on said hearth member and arranged to have liquid fuel discharged against the same, a second ignition electrode spaced from said first electrode, a movable support for said second. electrode, and electrical means for longitudinally moving said support to bring said electrade into proper sparking position spaced from the first electrode at the time ignition of the fuel is desired and for holding said second electrode in such position during the ignition period, said support being movable back to its initial position after the ignition period is terminated.

'7. In a liquid fuel burning apparatus, ignition means comprising a hearth member, an ignition electrode embedded in said hearth member substantially flush with the surface thereof and arranged to have liquid fuel discharged against by said tube for longitudinally-moving said support to bring said electrode into proper sparking position at the time ignition of the fuel is desired for holding the same in such position during substantially the entire ignition period, said support being movable back to its initial position after the ignition period is terminated.

8. In a rotary oil burning apparatus, including an endless hearth member having an upstanding portion for intercepting the path of a projected stream of oil, and ignition means for'igniting the oil intercepted by said upstanding portion, said ignition means including an electrode fixedly embedded in said hearth member and having a face substantially flush with the face of said upstanding portion, a second electrode spaced from the first electrode and electrical means to bodily move said second electrode into proper sparking position at the start of the ignition period and to maintain the same in such position during substantially the entire ignition period.

9. In a liquid fuel burning apparatus, a pair of spaced ignition electrodes providing an air gap across which a spark may be passed to ignite the fuel during an ignition period, means for moving'one of said electrodes relative to the other and into an eflicient sparking position spaced from the other and for maintaining the same in such position during substantially the entire ignition period, and means for moving the said one electrode to its original position afterithe'ig'nition period is terminated.

10. In a liquid fuel burning apparatus, a pair of ignition electrodes spaced from each other. at all times for ignitingfuellduring an ignition period, one of said electrodesibeing fixed, and means for moving the other of said electrodesrelative to the fixed electrode into spaced sparking relation at the beginning .of the ignition period.

11. In a liquid fuel .burning apparatus, a pair of ignition electrodes spaced from each other at all timesfor igniting the fuel during an ignition period by means of a spark passed between the same, one of said electrodes being fixed and means for moving the other of said electrodes relative to the fixed electrode after the ignition pe; riod is terminated to increase the space therebetween.

WILLIAM J. SMITH.